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Sample records for computer vision point

  1. Computational vision

    CERN Document Server

    Wechsler, Harry

    1990-01-01

    The book is suitable for advanced courses in computer vision and image processing. In addition to providing an overall view of computational vision, it contains extensive material on topics that are not usually covered in computer vision texts (including parallel distributed processing and neural networks) and considers many real applications.

  2. Computer vision for sports

    DEFF Research Database (Denmark)

    Thomas, Graham; Gade, Rikke; Moeslund, Thomas B.

    2017-01-01

    fixed to players or equipment is generally not possible. This provides a rich set of opportunities for the application of computer vision techniques to help the competitors, coaches and audience. This paper discusses a selection of current commercial applications that use computer vision for sports...

  3. Computer Vision Syndrome.

    Science.gov (United States)

    Randolph, Susan A

    2017-07-01

    With the increased use of electronic devices with visual displays, computer vision syndrome is becoming a major public health issue. Improving the visual status of workers using computers results in greater productivity in the workplace and improved visual comfort.

  4. Progress in computer vision.

    Science.gov (United States)

    Jain, A. K.; Dorai, C.

    Computer vision has emerged as a challenging and important area of research, both as an engineering and a scientific discipline. The growing importance of computer vision is evident from the fact that it was identified as one of the "Grand Challenges" and also from its prominent role in the National Information Infrastructure. While the design of a general-purpose vision system continues to be elusive machine vision systems are being used successfully in specific application elusive, machine vision systems are being used successfully in specific application domains. Building a practical vision system requires a careful selection of appropriate sensors, extraction and integration of information from available cues in the sensed data, and evaluation of system robustness and performance. The authors discuss and demonstrate advantages of (1) multi-sensor fusion, (2) combination of features and classifiers, (3) integration of visual modules, and (IV) admissibility and goal-directed evaluation of vision algorithms. The requirements of several prominent real world applications such as biometry, document image analysis, image and video database retrieval, and automatic object model construction offer exciting problems and new opportunities to design and evaluate vision algorithms.

  5. Riemannian computing in computer vision

    CERN Document Server

    Srivastava, Anuj

    2016-01-01

    This book presents a comprehensive treatise on Riemannian geometric computations and related statistical inferences in several computer vision problems. This edited volume includes chapter contributions from leading figures in the field of computer vision who are applying Riemannian geometric approaches in problems such as face recognition, activity recognition, object detection, biomedical image analysis, and structure-from-motion. Some of the mathematical entities that necessitate a geometric analysis include rotation matrices (e.g. in modeling camera motion), stick figures (e.g. for activity recognition), subspace comparisons (e.g. in face recognition), symmetric positive-definite matrices (e.g. in diffusion tensor imaging), and function-spaces (e.g. in studying shapes of closed contours).   ·         Illustrates Riemannian computing theory on applications in computer vision, machine learning, and robotics ·         Emphasis on algorithmic advances that will allow re-application in other...

  6. Python and computer vision

    Energy Technology Data Exchange (ETDEWEB)

    Doak, J. E. (Justin E.); Prasad, Lakshman

    2002-01-01

    This paper discusses the use of Python in a computer vision (CV) project. We begin by providing background information on the specific approach to CV employed by the project. This includes a brief discussion of Constrained Delaunay Triangulation (CDT), the Chordal Axis Transform (CAT), shape feature extraction and syntactic characterization, and normalization of strings representing objects. (The terms 'object' and 'blob' are used interchangeably, both referring to an entity extracted from an image.) The rest of the paper focuses on the use of Python in three critical areas: (1) interactions with a MySQL database, (2) rapid prototyping of algorithms, and (3) gluing together all components of the project including existing C and C++ modules. For (l), we provide a schema definition and discuss how the various tables interact to represent objects in the database as tree structures. (2) focuses on an algorithm to create a hierarchical representation of an object, given its string representation, and an algorithm to match unknown objects against objects in a database. And finally, (3) discusses the use of Boost Python to interact with the pre-existing C and C++ code that creates the CDTs and CATS, performs shape feature extraction and syntactic characterization, and normalizes object strings. The paper concludes with a vision of the future use of Python for the CV project.

  7. Functional programming for computer vision

    Science.gov (United States)

    Breuel, Thomas M.

    1992-04-01

    Functional programming is a style of programming that avoids the use of side effects (like assignment) and uses functions as first class data objects. Compared with imperative programs, functional programs can be parallelized better, and provide better encapsulation, type checking, and abstractions. This is important for building and integrating large vision software systems. In the past, efficiency has been an obstacle to the application of functional programming techniques in computationally intensive areas such as computer vision. We discuss and evaluate several 'functional' data structures for representing efficiently data structures and objects common in computer vision. In particular, we will address: automatic storage allocation and reclamation issues; abstraction of control structures; efficient sequential update of large data structures; representing images as functions; and object-oriented programming. Our experience suggests that functional techniques are feasible for high- performance vision systems, and that a functional approach simplifies the implementation and integration of vision systems greatly. Examples in C++ and SML are given.

  8. Computer Vision for Timber Harvesting

    DEFF Research Database (Denmark)

    Dahl, Anders Lindbjerg

    The goal of this thesis is to investigate computer vision methods for timber harvesting operations. The background for developing computer vision for timber harvesting is to document origin of timber and to collect qualitative and quantitative parameters concerning the timber for efficient harvest...... segments. The purpose of image segmentation is to make the basis for more advanced computer vision methods like object recognition and classification. Our second method concerns image classification and we present a method where we classify small timber samples to tree species based on Active Appearance...... to the development of the logTracker system the described methods have a general applicability making them useful for many other computer vision problems....

  9. Artificial intelligence and computer vision

    CERN Document Server

    Li, Yujie

    2017-01-01

    This edited book presents essential findings in the research fields of artificial intelligence and computer vision, with a primary focus on new research ideas and results for mathematical problems involved in computer vision systems. The book provides an international forum for researchers to summarize the most recent developments and ideas in the field, with a special emphasis on the technical and observational results obtained in the past few years.

  10. Computer vision for an autonomous mobile robot

    CSIR Research Space (South Africa)

    Withey, Daniel J

    2015-10-01

    Full Text Available Computer vision systems are essential for practical, autonomous, mobile robots – machines that employ artificial intelligence and control their own motion within an environment. As with biological systems, computer vision systems include the vision...

  11. Reinforcement learning in computer vision

    Science.gov (United States)

    Bernstein, A. V.; Burnaev, E. V.

    2018-04-01

    Nowadays, machine learning has become one of the basic technologies used in solving various computer vision tasks such as feature detection, image segmentation, object recognition and tracking. In many applications, various complex systems such as robots are equipped with visual sensors from which they learn state of surrounding environment by solving corresponding computer vision tasks. Solutions of these tasks are used for making decisions about possible future actions. It is not surprising that when solving computer vision tasks we should take into account special aspects of their subsequent application in model-based predictive control. Reinforcement learning is one of modern machine learning technologies in which learning is carried out through interaction with the environment. In recent years, Reinforcement learning has been used both for solving such applied tasks as processing and analysis of visual information, and for solving specific computer vision problems such as filtering, extracting image features, localizing objects in scenes, and many others. The paper describes shortly the Reinforcement learning technology and its use for solving computer vision problems.

  12. [Ophthalmologist and "computer vision syndrome"].

    Science.gov (United States)

    Barar, A; Apatachioaie, Ioana Daniela; Apatachioaie, C; Marceanu-Brasov, L

    2007-01-01

    The authors had tried to collect the data available on the Internet about a subject that we consider as being totally ignored in the Romanian scientific literature and unexpectedly insufficiently treated in the specialized ophthalmologic literature. Known in the specialty literature under the generic name of "Computer vision syndrome", it is defined by the American Optometric Association as a complex of eye and vision problems related to the activities which stress the near vision and which are experienced in relation, or during, the use of the computer. During the consultations we hear frequent complaints of eye-strain - asthenopia, headaches, blurred distance and/or near vision, dry and irritated eyes, slow refocusing, neck and backache, photophobia, sensation of diplopia, light sensitivity, and double vision, but because of the lack of information, we overlooked them too easily, without going thoroughly into the real motives. In most of the developed countries, there are recommendations issued by renowned medical associations with regard to the definition, the diagnosis, and the methods for the prevention, treatment and periodical control of the symptoms found in computer users, in conjunction with an extremely detailed ergonomic legislation. We found out that these problems incite a much too low interest in our country. We would like to rouse the interest of our ophthalmologist colleagues in the understanding and the recognition of these symptoms and in their treatment, or at least their improvement, through specialized measures or through the cooperation with our specialist occupational medicine colleagues.

  13. Advances in embedded computer vision

    CERN Document Server

    Kisacanin, Branislav

    2014-01-01

    This illuminating collection offers a fresh look at the very latest advances in the field of embedded computer vision. Emerging areas covered by this comprehensive text/reference include the embedded realization of 3D vision technologies for a variety of applications, such as stereo cameras on mobile devices. Recent trends towards the development of small unmanned aerial vehicles (UAVs) with embedded image and video processing algorithms are also examined. The authoritative insights range from historical perspectives to future developments, reviewing embedded implementation, tools, technolog

  14. Computer vision and machine learning for archaeology

    NARCIS (Netherlands)

    van der Maaten, L.J.P.; Boon, P.; Lange, G.; Paijmans, J.J.; Postma, E.

    2006-01-01

    Until now, computer vision and machine learning techniques barely contributed to the archaeological domain. The use of these techniques can support archaeologists in their assessment and classification of archaeological finds. The paper illustrates the use of computer vision techniques for

  15. UNDERSTANDING AND PREVENTING COMPUTER VISION SYNDROME

    OpenAIRE

    REDDY SC; LOH KY

    2008-01-01

    The invention of computer and advancement in information technology has revolutionized and benefited the society but at the same time has caused symptoms related to its usage such as ocular sprain, irritation, redness, dryness, blurred vision and double vision. This cluster of symptoms is known as computer vision syndrome which is characterized by the visual symptoms which result from interaction with computer display or its environment. Three major mechanisms that lead to computer vision syn...

  16. Computer vision in control systems

    CERN Document Server

    Jain, Lakhmi

    2015-01-01

    Volume 1 : This book is focused on the recent advances in computer vision methodologies and technical solutions using conventional and intelligent paradigms. The Contributions include: ·         Morphological Image Analysis for Computer Vision Applications. ·         Methods for Detecting of Structural Changes in Computer Vision Systems. ·         Hierarchical Adaptive KL-based Transform: Algorithms and Applications. ·         Automatic Estimation for Parameters of Image Projective Transforms Based on Object-invariant Cores. ·         A Way of Energy Analysis for Image and Video Sequence Processing. ·         Optimal Measurement of Visual Motion Across Spatial and Temporal Scales. ·         Scene Analysis Using Morphological Mathematics and Fuzzy Logic. ·         Digital Video Stabilization in Static and Dynamic Scenes. ·         Implementation of Hadamard Matrices for Image Processing. ·         A Generalized Criterion ...

  17. Understanding and preventing computer vision syndrome.

    Science.gov (United States)

    Loh, Ky; Redd, Sc

    2008-01-01

    The invention of computer and advancement in information technology has revolutionized and benefited the society but at the same time has caused symptoms related to its usage such as ocular sprain, irritation, redness, dryness, blurred vision and double vision. This cluster of symptoms is known as computer vision syndrome which is characterized by the visual symptoms which result from interaction with computer display or its environment. Three major mechanisms that lead to computer vision syndrome are extraocular mechanism, accommodative mechanism and ocular surface mechanism. The visual effects of the computer such as brightness, resolution, glare and quality all are known factors that contribute to computer vision syndrome. Prevention is the most important strategy in managing computer vision syndrome. Modification in the ergonomics of the working environment, patient education and proper eye care are crucial in managing computer vision syndrome.

  18. UNDERSTANDING AND PREVENTING COMPUTER VISION SYNDROME

    Directory of Open Access Journals (Sweden)

    REDDY SC

    2008-01-01

    Full Text Available The invention of computer and advancement in information technology has revolutionized and benefited the society but at the same time has caused symptoms related to its usage such as ocular sprain, irritation, redness, dryness, blurred vision and double vision. This cluster of symptoms is known as computer vision syndrome which is characterized by the visual symptoms which result from interaction with computer display or its environment. Three major mechanisms that lead to computer vision syndrome are extraocular mechanism, accommodative mechanism and ocular surface mechanism. The visual effects of the computer such as brightness, resolution, glare and quality all are known factors that contribute to computer vision syndrome. Prevention is the most important strategy in managing computer vision syndrome. Modification in the ergonomics of the working environment, patient education and proper eye care are crucial in managing computer vision syndrome.

  19. Computer vision syndrome: A review.

    Science.gov (United States)

    Gowrisankaran, Sowjanya; Sheedy, James E

    2015-01-01

    Computer vision syndrome (CVS) is a collection of symptoms related to prolonged work at a computer display. This article reviews the current knowledge about the symptoms, related factors and treatment modalities for CVS. Relevant literature on CVS published during the past 65 years was analyzed. Symptoms reported by computer users are classified into internal ocular symptoms (strain and ache), external ocular symptoms (dryness, irritation, burning), visual symptoms (blur, double vision) and musculoskeletal symptoms (neck and shoulder pain). The major factors associated with CVS are either environmental (improper lighting, display position and viewing distance) and/or dependent on the user's visual abilities (uncorrected refractive error, oculomotor disorders and tear film abnormalities). Although the factors associated with CVS have been identified the physiological mechanisms that underlie CVS are not completely understood. Additionally, advances in technology have led to the increased use of hand-held devices, which might impose somewhat different visual challenges compared to desktop displays. Further research is required to better understand the physiological mechanisms underlying CVS and symptoms associated with the use of hand-held and stereoscopic displays.

  20. Color in Computer Vision Fundamentals and Applications

    CERN Document Server

    Gevers, Theo; van de Weijer, Joost; Geusebroek, Jan-Mark

    2012-01-01

    While the field of computer vision drives many of today’s digital technologies and communication networks, the topic of color has emerged only recently in most computer vision applications. One of the most extensive works to date on color in computer vision, this book provides a complete set of tools for working with color in the field of image understanding. Based on the authors’ intense collaboration for more than a decade and drawing on the latest thinking in the field of computer science, the book integrates topics from color science and computer vision, clearly linking theor

  1. From Deposit to Point Cloud – a Study of Low-Cost Computer Vision Approaches for the Straightforward Documentation of Archaeological Excavations

    Directory of Open Access Journals (Sweden)

    M. Doneus

    2011-12-01

    Full Text Available Stratigraphic archaeological excavations demand high-resolution documentation techniques for 3D recording. Today, this is typically accomplished using total stations or terrestrial laser scanners. This paper demonstrates the potential of another technique that is low-cost and easy to execute. It takes advantage of software using Structure from Motion (SfM algorithms, which are known for their ability to reconstruct camera pose and threedimensional scene geometry (rendered as a sparse point cloud from a series of overlapping photographs captured by a camera moving around the scene. When complemented by stereo matching algorithms, detailed 3D surface models can be built from such relatively oriented photo collections in a fully automated way. The absolute orientation of the model can be derived by the manual measurement of control points. The approach is extremely flexible and appropriate to deal with a wide variety of imagery, because this computer vision approach can also work with imagery resulting from a randomly moving camera (i.e. uncontrolled conditions and calibrated optics are not a prerequisite. For a few years, these algorithms are embedded in several free and low-cost software packages. This paper will outline how such a program can be applied to map archaeological excavations in a very fast and uncomplicated way, using imagery shot with a standard compact digital camera (even if the ima ges were not taken for this purpose. Archived data from previous excavations of VIAS-University of Vienna has been chosen and the derived digital surface models and orthophotos have been examined for their usefulness for archaeological applications. The a bsolute georeferencing of the resulting surface models was performed with the manual identification of fourteen control points. In order to express the positional accuracy of the generated 3D surface models, the NSSDA guidelines were applied.  Simultaneously acquired terrestrial laser scanning data

  2. Computer and machine vision theory, algorithms, practicalities

    CERN Document Server

    Davies, E R

    2012-01-01

    Computer and Machine Vision: Theory, Algorithms, Practicalities (previously entitled Machine Vision) clearly and systematically presents the basic methodology of computer and machine vision, covering the essential elements of the theory while emphasizing algorithmic and practical design constraints. This fully revised fourth edition has brought in more of the concepts and applications of computer vision, making it a very comprehensive and up-to-date tutorial text suitable for graduate students, researchers and R&D engineers working in this vibrant subject. Key features include: Practical examples and case studies give the 'ins and outs' of developing real-world vision systems, giving engineers the realities of implementing the principles in practice New chapters containing case studies on surveillance and driver assistance systems give practical methods on these cutting-edge applications in computer vision Necessary mathematics and essential theory are made approachable by careful explanations and well-il...

  3. Tensors in image processing and computer vision

    CERN Document Server

    De Luis García, Rodrigo; Tao, Dacheng; Li, Xuelong

    2009-01-01

    Tensor signal processing is an emerging field with important applications to computer vision and image processing. This book presents the developments in this branch of signal processing, offering research and discussions by experts in the area. It is suitable for advanced students working in the area of computer vision and image processing.

  4. Specifying colours for colour vision testing using computer graphics.

    Science.gov (United States)

    Toufeeq, A

    2004-10-01

    This paper describes a novel test of colour vision using a standard personal computer, which is simple and reliable to perform. Twenty healthy individuals with normal colour vision and 10 healthy individuals with a red/green colour defect were tested binocularly at 13 selected points in the CIE (Commission International d'Eclairage, 1931) chromaticity triangle, representing the gamut of a computer monitor, where the x, y coordinates of the primary colour phosphors were known. The mean results from individuals with normal colour vision were compared to those with defective colour vision. Of the 13 points tested, five demonstrated consistently high sensitivity in detecting colour defects. The test may provide a convenient method for classifying colour vision abnormalities.

  5. Dense image correspondences for computer vision

    CERN Document Server

    Liu, Ce

    2016-01-01

    This book describes the fundamental building-block of many new computer vision systems: dense and robust correspondence estimation. Dense correspondence estimation techniques are now successfully being used to solve a wide range of computer vision problems, very different from the traditional applications such techniques were originally developed to solve. This book introduces the techniques used for establishing correspondences between challenging image pairs, the novel features used to make these techniques robust, and the many problems dense correspondences are now being used to solve. The book provides information to anyone attempting to utilize dense correspondences in order to solve new or existing computer vision problems. The editors describe how to solve many computer vision problems by using dense correspondence estimation. Finally, it surveys resources, code, and data necessary for expediting the development of effective correspondence-based computer vision systems.   ·         Provides i...

  6. FPGA Implementation of Computer Vision Algorithm

    OpenAIRE

    Zhou, Zhonghua

    2014-01-01

    Computer vision algorithms, which play an significant role in vision processing, is widely applied in many aspects such as geology survey, traffic management and medical care, etc.. Most of the situations require the process to be real-timed, in other words, as fast as possible. Field Programmable Gate Arrays (FPGAs) have a advantage of parallelism fabric in programming, comparing to the serial communications of CPUs, which makes FPGA a perfect platform for implementing vision algorithms. The...

  7. Prevalence of computer vision syndrome in Erbil

    OpenAIRE

    Dler Jalal Ahmed; Eman Hussein Alwan

    2018-01-01

    Background and objective: Nearly all colleges, universities and homes today are regularly using video display terminals, such as computer, iPad, mobile, and TV. Very little research has been carried out on Kurdish users to reveal the effect of video display terminals on the eye and vision. This study aimed to evaluate the prevalence of computer vision syndrome among computer users. Methods: A hospital based cross-sectional study was conducted in the Ophthalmology Department of Rizgary...

  8. COMPUTER VISION SYNDROME: A SHORT REVIEW.

    OpenAIRE

    Sameena; Mohd Inayatullah

    2012-01-01

    Computers are probably one of the biggest scientific inventions of the modern era, and since then they have become an integral part of our life. The increased usage of computers have lead to variety of ocular symptoms which includ es eye strain, tired eyes, irritation, redness, blurred vision, and diplopia, collectively referred to as Computer Vision Syndrome (CVS). CVS may have a significant impact not only on visual com fort but also occupational productivit...

  9. Prevalence of computer vision syndrome in Erbil

    Directory of Open Access Journals (Sweden)

    Dler Jalal Ahmed

    2018-04-01

    Full Text Available Background and objective: Nearly all colleges, universities and homes today are regularly using video display terminals, such as computer, iPad, mobile, and TV. Very little research has been carried out on Kurdish users to reveal the effect of video display terminals on the eye and vision. This study aimed to evaluate the prevalence of computer vision syndrome among computer users. Methods: A hospital based cross-sectional study was conducted in the Ophthalmology Department of Rizgary and Erbil teaching hospitals in Erbil city. Those used computers in the months preceding the date of this study were included in the study. Results: Among 173 participants aged between 8 to 48 years (mean age of 23.28±6.6 years, the prevalence of computer vision syndrome found to be 89.65%. The most disturbing symptom was eye irritation (79.8%, followed by blurred vision(75.7%. Participants who were using visual display terminals for more than six hours per day were at higher risk of developing nearly all symptoms of computer vision syndrome. Significant correlation was found between time-consuming on computer and symptoms such as headache (P <0.001, redness (P <0.001, eye irritation (P <0.001, blurred vision (P <0.001 and neck pain (P <0.001. Conclusion: The present study demonstrates that more than three-fourths of the participants had one of the symptoms of computer vision syndrome while working on visual display terminals. Keywords: Computer vision syndrome; Headache; Neck pain; Blurred vision.

  10. Soft Computing Techniques in Vision Science

    CERN Document Server

    Yang, Yeon-Mo

    2012-01-01

    This Special Edited Volume is a unique approach towards Computational solution for the upcoming field of study called Vision Science. From a scientific firmament Optics, Ophthalmology, and Optical Science has surpassed an Odyssey of optimizing configurations of Optical systems, Surveillance Cameras and other Nano optical devices with the metaphor of Nano Science and Technology. Still these systems are falling short of its computational aspect to achieve the pinnacle of human vision system. In this edited volume much attention has been given to address the coupling issues Computational Science and Vision Studies.  It is a comprehensive collection of research works addressing various related areas of Vision Science like Visual Perception and Visual system, Cognitive Psychology, Neuroscience, Psychophysics and Ophthalmology, linguistic relativity, color vision etc. This issue carries some latest developments in the form of research articles and presentations. The volume is rich of contents with technical tools ...

  11. Computer vision based room interior design

    Science.gov (United States)

    Ahmad, Nasir; Hussain, Saddam; Ahmad, Kashif; Conci, Nicola

    2015-12-01

    This paper introduces a new application of computer vision. To the best of the author's knowledge, it is the first attempt to incorporate computer vision techniques into room interior designing. The computer vision based interior designing is achieved in two steps: object identification and color assignment. The image segmentation approach is used for the identification of the objects in the room and different color schemes are used for color assignment to these objects. The proposed approach is applied to simple as well as complex images from online sources. The proposed approach not only accelerated the process of interior designing but also made it very efficient by giving multiple alternatives.

  12. Object recognition in images by human vision and computer vision

    NARCIS (Netherlands)

    Chen, Q.; Dijkstra, J.; Vries, de B.

    2010-01-01

    Object recognition plays a major role in human behaviour research in the built environment. Computer based object recognition techniques using images as input are challenging, but not an adequate representation of human vision. This paper reports on the differences in object shape recognition

  13. [Meibomian gland disfunction in computer vision syndrome].

    Science.gov (United States)

    Pimenidi, M K; Polunin, G S; Safonova, T N

    2010-01-01

    This article reviews ethiology and pathogenesis of dry eye syndrome due to meibomian gland disfunction (MDG). It is showed that blink rate influences meibomian gland functioning and computer vision syndrome development. Current diagnosis and treatment options of MDG are presented.

  14. Object categorization: computer and human vision perspectives

    National Research Council Canada - National Science Library

    Dickinson, Sven J

    2009-01-01

    .... The result of a series of four highly successful workshops on the topic, the book gathers many of the most distinguished researchers from both computer and human vision to reflect on their experience...

  15. Computer vision for biomedical image applications. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanxi [Carnegie Mellon Univ., Pittsburgh, PA (United States). School of Computer Science, The Robotics Institute; Jiang, Tianzi [Chinese Academy of Sciences, Beijing (China). National Lab. of Pattern Recognition, Inst. of Automation; Zhang, Changshui (eds.) [Tsinghua Univ., Beijing, BJ (China). Dept. of Automation

    2005-07-01

    This book constitutes the refereed proceedings of the First International Workshop on Computer Vision for Biomedical Image Applications: Current Techniques and Future Trends, CVBIA 2005, held in Beijing, China, in October 2005 within the scope of ICCV 20. (orig.)

  16. Object extraction in photogrammetric computer vision

    Science.gov (United States)

    Mayer, Helmut

    This paper discusses state and promising directions of automated object extraction in photogrammetric computer vision considering also practical aspects arising for digital photogrammetric workstations (DPW). A review of the state of the art shows that there are only few practically successful systems on the market. Therefore, important issues for a practical success of automated object extraction are identified. A sound and most important powerful theoretical background is the basis. Here, we particularly point to statistical modeling. Testing makes clear which of the approaches are suited best and how useful they are for praxis. A key for commercial success of a practical system is efficient user interaction. As the means for data acquisition are changing, new promising application areas such as extremely detailed three-dimensional (3D) urban models for virtual television or mission rehearsal evolve.

  17. International Conference on Computational Vision and Robotics

    CERN Document Server

    2015-01-01

    Computer Vision and Robotic is one of the most challenging areas of 21st century. Its application ranges from Agriculture to Medicine, Household applications to Humanoid, Deep-sea-application to Space application, and Industry applications to Man-less-plant. Today’s technologies demand to produce intelligent machine, which are enabling applications in various domains and services. Robotics is one such area which encompasses number of technology in it and its application is widespread. Computational vision or Machine vision is one of the most challenging tools for the robot to make it intelligent.   This volume covers chapters from various areas of Computational Vision such as Image and Video Coding and Analysis, Image Watermarking, Noise Reduction and Cancellation, Block Matching and Motion Estimation, Tracking of Deformable Object using Steerable Pyramid Wavelet Transformation, Medical Image Fusion, CT and MRI Image Fusion based on Stationary Wavelet Transform. The book also covers articles from applicati...

  18. Ocular problems of computer vision syndrome: Review

    Directory of Open Access Journals (Sweden)

    Ayakutty Muni Raja

    2015-01-01

    Full Text Available Nowadays, ophthalmologists are facing a new group of patients having eye problems related to prolonged and excessive computer use. When the demand for near work exceeds the normal ability of the eye to perform the job comfortably, one develops discomfort and prolonged exposure, which leads to a cascade of reactions that can be put together as computer vision syndrome (CVS. In India, the computer-using population is more than 40 million, and 80% have discomfort due to CVS. Eye strain, headache, blurring of vision and dryness are the most common symptoms. Workstation modification, voluntary blinking, adjustment of the brightness of screen and breaks in between can reduce CVS.

  19. Computer vision camera with embedded FPGA processing

    Science.gov (United States)

    Lecerf, Antoine; Ouellet, Denis; Arias-Estrada, Miguel

    2000-03-01

    Traditional computer vision is based on a camera-computer system in which the image understanding algorithms are embedded in the computer. To circumvent the computational load of vision algorithms, low-level processing and imaging hardware can be integrated in a single compact module where a dedicated architecture is implemented. This paper presents a Computer Vision Camera based on an open architecture implemented in an FPGA. The system is targeted to real-time computer vision tasks where low level processing and feature extraction tasks can be implemented in the FPGA device. The camera integrates a CMOS image sensor, an FPGA device, two memory banks, and an embedded PC for communication and control tasks. The FPGA device is a medium size one equivalent to 25,000 logic gates. The device is connected to two high speed memory banks, an IS interface, and an imager interface. The camera can be accessed for architecture programming, data transfer, and control through an Ethernet link from a remote computer. A hardware architecture can be defined in a Hardware Description Language (like VHDL), simulated and synthesized into digital structures that can be programmed into the FPGA and tested on the camera. The architecture of a classical multi-scale edge detection algorithm based on a Laplacian of Gaussian convolution has been developed to show the capabilities of the system.

  20. An Enduring Dialogue between Computational and Empirical Vision.

    Science.gov (United States)

    Martinez-Conde, Susana; Macknik, Stephen L; Heeger, David J

    2018-04-01

    In the late 1970s, key discoveries in neurophysiology, psychophysics, computer vision, and image processing had reached a tipping point that would shape visual science for decades to come. David Marr and Ellen Hildreth's 'Theory of edge detection', published in 1980, set out to integrate the newly available wealth of data from behavioral, physiological, and computational approaches in a unifying theory. Although their work had wide and enduring ramifications, their most important contribution may have been to consolidate the foundations of the ongoing dialogue between theoretical and empirical vision science. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Empirical evaluation methods in computer vision

    CERN Document Server

    Christensen, Henrik I

    2002-01-01

    This book provides comprehensive coverage of methods for the empirical evaluation of computer vision techniques. The practical use of computer vision requires empirical evaluation to ensure that the overall system has a guaranteed performance. The book contains articles that cover the design of experiments for evaluation, range image segmentation, the evaluation of face recognition and diffusion methods, image matching using correlation methods, and the performance of medical image processing algorithms. Sample Chapter(s). Foreword (228 KB). Chapter 1: Introduction (505 KB). Contents: Automate

  2. Vision-Based Interest Point Extraction Evaluation in Multiple Environments

    National Research Council Canada - National Science Library

    McKeehan, Zachary D

    2008-01-01

    Computer-based vision is becoming a primary sensor mechanism in many facets of real world 2-D and 3-D applications, including autonomous robotics, augmented reality, object recognition, motion tracking, and biometrics...

  3. Impact of computer use on children's vision.

    Science.gov (United States)

    Kozeis, N

    2009-10-01

    Today, millions of children use computers on a daily basis. Extensive viewing of the computer screen can lead to eye discomfort, fatigue, blurred vision and headaches, dry eyes and other symptoms of eyestrain. These symptoms may be caused by poor lighting, glare, an improper work station set-up, vision problems of which the person was not previously aware, or a combination of these factors. Children can experience many of the same symptoms related to computer use as adults. However, some unique aspects of how children use computers may make them more susceptible than adults to the development of these problems. In this study, the most common eye symptoms related to computer use in childhood, the possible causes and ways to avoid them are reviewed.

  4. Computer vision syndrome (CVS) - Thermographic Analysis

    Science.gov (United States)

    Llamosa-Rincón, L. E.; Jaime-Díaz, J. M.; Ruiz-Cardona, D. F.

    2017-01-01

    The use of computers has reported an exponential growth in the last decades, the possibility of carrying out several tasks for both professional and leisure purposes has contributed to the great acceptance by the users. The consequences and impact of uninterrupted tasks with computers screens or displays on the visual health, have grabbed researcher’s attention. When spending long periods of time in front of a computer screen, human eyes are subjected to great efforts, which in turn triggers a set of symptoms known as Computer Vision Syndrome (CVS). Most common of them are: blurred vision, visual fatigue and Dry Eye Syndrome (DES) due to unappropriate lubrication of ocular surface when blinking decreases. An experimental protocol was de-signed and implemented to perform thermographic studies on healthy human eyes during exposure to dis-plays of computers, with the main purpose of comparing the existing differences in temperature variations of healthy ocular surfaces.

  5. Fulfilling the vision of automatic computing

    OpenAIRE

    Dobson, Simon; Sterritt, Roy; Nixon, Paddy; Hinchey, Mike

    2010-01-01

    Efforts since 2001 to design self-managing systems have yielded many impressive achievements, yet the original vision of autonomic computing remains unfulfilled. Researchers must develop a comprehensive systems engineering approach to create effective solutions for next-generation enterprise and sensor systems. Publisher PDF Peer reviewed

  6. AstroCV: Astronomy computer vision library

    Science.gov (United States)

    González, Roberto E.; Muñoz, Roberto P.; Hernández, Cristian A.

    2018-04-01

    AstroCV processes and analyzes big astronomical datasets, and is intended to provide a community repository of high performance Python and C++ algorithms used for image processing and computer vision. The library offers methods for object recognition, segmentation and classification, with emphasis in the automatic detection and classification of galaxies.

  7. Computational and cognitive neuroscience of vision

    CERN Document Server

    2017-01-01

    Despite a plethora of scientific literature devoted to vision research and the trend toward integrative research, the borders between disciplines remain a practical difficulty. To address this problem, this book provides a systematic and comprehensive overview of vision from various perspectives, ranging from neuroscience to cognition, and from computational principles to engineering developments. It is written by leading international researchers in the field, with an emphasis on linking multiple disciplines and the impact such synergy can lead to in terms of both scientific breakthroughs and technology innovations. It is aimed at active researchers and interested scientists and engineers in related fields.

  8. Computation and parallel implementation for early vision

    Science.gov (United States)

    Gualtieri, J. Anthony

    1990-01-01

    The problem of early vision is to transform one or more retinal illuminance images-pixel arrays-to image representations built out of such primitive visual features such as edges, regions, disparities, and clusters. These transformed representations form the input to later vision stages that perform higher level vision tasks including matching and recognition. Researchers developed algorithms for: (1) edge finding in the scale space formulation; (2) correlation methods for computing matches between pairs of images; and (3) clustering of data by neural networks. These algorithms are formulated for parallel implementation of SIMD machines, such as the Massively Parallel Processor, a 128 x 128 array processor with 1024 bits of local memory per processor. For some cases, researchers can show speedups of three orders of magnitude over serial implementations.

  9. Perceptual organization in computer vision - A review and a proposal for a classificatory structure

    Science.gov (United States)

    Sarkar, Sudeep; Boyer, Kim L.

    1993-01-01

    The evolution of perceptual organization in biological vision, and its necessity in advanced computer vision systems, arises from the characteristic that perception, the extraction of meaning from sensory input, is an intelligent process. This is particularly so for high order organisms and, analogically, for more sophisticated computational models. The role of perceptual organization in computer vision systems is explored. This is done from four vantage points. First, a brief history of perceptual organization research in both humans and computer vision is offered. Next, a classificatory structure in which to cast perceptual organization research to clarify both the nomenclature and the relationships among the many contributions is proposed. Thirdly, the perceptual organization work in computer vision in the context of this classificatory structure is reviewed. Finally, the array of computational techniques applied to perceptual organization problems in computer vision is surveyed.

  10. Eyesight quality and Computer Vision Syndrome.

    Science.gov (United States)

    Bogdănici, Camelia Margareta; Săndulache, Diana Elena; Nechita, Corina Andreea

    2017-01-01

    The aim of the study was to analyze the effects that gadgets have on eyesight quality. A prospective observational study was conducted from January to July 2016, on 60 people who were divided into two groups: Group 1 - 30 middle school pupils with a mean age of 11.9 ± 1.86 and Group 2 - 30 patients evaluated in the Ophthalmology Clinic, "Sf. Spiridon" Hospital, Iași, with a mean age of 21.36 ± 7.16 years. The clinical parameters observed were the following: visual acuity (VA), objective refraction, binocular vision (BV), fusional amplitude (FA), Schirmer's test. A questionnaire was also distributed, which contained 8 questions that highlighted the gadget's impact on the eyesight. The use of different gadgets, such as computer, laptops, mobile phones or other displays become part of our everyday life and people experience a variety of ocular symptoms or vision problems related to these. Computer Vision Syndrome (CVS) represents a group of visual and extraocular symptoms associated with sustained use of visual display terminals. Headache, blurred vision, and ocular congestion are the most frequent manifestations determined by the long time use of gadgets. Mobile phones and laptops are the most frequently used gadgets. People who use gadgets for a long time have a sustained effort for accommodation. A small amount of refractive errors (especially myopic shift) was objectively recorded by various studies on near work. Dry eye syndrome could also be identified, and an improvement of visual comfort could be observed after the instillation of artificial tears drops. Computer Vision Syndrome is still under-diagnosed, and people should be made aware of the bad effects the prolonged use of gadgets has on eyesight.

  11. Computer vision as an alternative for collision detection

    OpenAIRE

    Drangsholt, Marius Aarvik

    2015-01-01

    The goal of this thesis was to implement a computer vision system on a low power platform, to see if that could be an alternative for a collision detection system. To achieve this, research into fundamentals in computer vision were performed, and both hardware and software implementation were carried out. To create the computer vision system, a stereo rig were constructed using low cost Logitech webcameras, and connected to a Raspberry Pi 2 development board. The computer vision library Op...

  12. Application of Computer Vision in Agriculture

    OpenAIRE

    Archana B. Patankar; Priya A. Tayade

    2015-01-01

    Grading and sorting of fruits, leaf is one of the most important process in fruits production, while this process is typically performed manually in most countries. Computer vision techniques have applied for evaluating food quality as well as fruit grading. In this project different technique used that is image preprocessing, image segmentation k-means clustering algorithm to find out the infection present in image also calculate percentage of infection, from that percentage did the...

  13. Mahotas: Open source software for scriptable computer vision

    Directory of Open Access Journals (Sweden)

    Luis Pedro Coelho

    2013-07-01

    Full Text Available Mahotas is a computer vision library for Python. It contains traditional image processing functionality such as filtering and morphological operations as well as more modern computer vision functions for feature computation, including interest point detection and local descriptors. The interface is in Python, a dynamic programming language, which is appropriate for fast development, but the algorithms are implemented in C++ and are tuned for speed. The library is designed to fit in with the scientific software ecosystem in this language and can leverage the existing infrastructure developed in that language. Mahotas is released under a liberal open source license (MIT License and is available from http://github.com/luispedro/mahotas and from the Python Package Index (http://pypi.python.org/pypi/mahotas. Tutorials and full API documentation are available online at http://mahotas.readthedocs.org/.

  14. Algorithms for image processing and computer vision

    CERN Document Server

    Parker, J R

    2010-01-01

    A cookbook of algorithms for common image processing applications Thanks to advances in computer hardware and software, algorithms have been developed that support sophisticated image processing without requiring an extensive background in mathematics. This bestselling book has been fully updated with the newest of these, including 2D vision methods in content-based searches and the use of graphics cards as image processing computational aids. It's an ideal reference for software engineers and developers, advanced programmers, graphics programmers, scientists, and other specialists wh

  15. Digital image processing and analysis human and computer vision applications with CVIPtools

    CERN Document Server

    Umbaugh, Scott E

    2010-01-01

    Section I Introduction to Digital Image Processing and AnalysisDigital Image Processing and AnalysisOverviewImage Analysis and Computer VisionImage Processing and Human VisionKey PointsExercisesReferencesFurther ReadingComputer Imaging SystemsImaging Systems OverviewImage Formation and SensingCVIPtools SoftwareImage RepresentationKey PointsExercisesSupplementary ExercisesReferencesFurther ReadingSection II Digital Image Analysis and Computer VisionIntroduction to Digital Image AnalysisIntroductionPreprocessingBinary Image AnalysisKey PointsExercisesSupplementary ExercisesReferencesFurther Read

  16. Magic Pointing for Eyewear Computers

    DEFF Research Database (Denmark)

    Jalaliniya, Shahram; Mardanbegi, Diako; Pederson, Thomas

    2015-01-01

    In this paper, we propose a combination of head and eye movements for touchlessly controlling the "mouse pointer" on eyewear devices, exploiting the speed of eye pointing and accuracy of head pointing. The method is a wearable computer-targeted variation of the original MAGIC pointing approach...... which combined gaze tracking with a classical mouse device. The result of our experiment shows that the combination of eye and head movements is faster than head pointing for far targets and more accurate than eye pointing....

  17. Feature extraction & image processing for computer vision

    CERN Document Server

    Nixon, Mark

    2012-01-01

    This book is an essential guide to the implementation of image processing and computer vision techniques, with tutorial introductions and sample code in Matlab. Algorithms are presented and fully explained to enable complete understanding of the methods and techniques demonstrated. As one reviewer noted, ""The main strength of the proposed book is the exemplar code of the algorithms."" Fully updated with the latest developments in feature extraction, including expanded tutorials and new techniques, this new edition contains extensive new material on Haar wavelets, Viola-Jones, bilateral filt

  18. Colour vision and computer-generated images

    International Nuclear Information System (INIS)

    Ramek, Michael

    2010-01-01

    Colour vision deficiencies affect approximately 8% of the male and approximately 0.4% of the female population. In this work, it is demonstrated that computer generated images oftentimes pose unnecessary problems for colour deficient viewers. Three examples, the visualization of molecular structures, graphs of mathematical functions, and colour coded images from numerical data are used to identify problematic colour combinations: red/black, green/black, red/yellow, yellow/white, fuchsia/white, and aqua/white. Alternatives for these combinations are discussed.

  19. Computer Vision Using Local Binary Patterns

    CERN Document Server

    Pietikainen, Matti; Zhao, Guoying; Ahonen, Timo

    2011-01-01

    The recent emergence of Local Binary Patterns (LBP) has led to significant progress in applying texture methods to various computer vision problems and applications. The focus of this research has broadened from 2D textures to 3D textures and spatiotemporal (dynamic) textures. Also, where texture was once utilized for applications such as remote sensing, industrial inspection and biomedical image analysis, the introduction of LBP-based approaches have provided outstanding results in problems relating to face and activity analysis, with future scope for face and facial expression recognition, b

  20. A practical introduction to computer vision with OpenCV

    CERN Document Server

    Dawson-Howe, Kenneth

    2014-01-01

    Explains the theory behind basic computer vision and provides a bridge from the theory to practical implementation using the industry standard OpenCV libraries Computer Vision is a rapidly expanding area and it is becoming progressively easier for developers to make use of this field due to the ready availability of high quality libraries (such as OpenCV 2).  This text is intended to facilitate the practical use of computer vision with the goal being to bridge the gap between the theory and the practical implementation of computer vision. The book will explain how to use the relevant OpenCV

  1. Heterogeneous compute in computer vision: OpenCL in OpenCV

    Science.gov (United States)

    Gasparakis, Harris

    2014-02-01

    We explore the relevance of Heterogeneous System Architecture (HSA) in Computer Vision, both as a long term vision, and as a near term emerging reality via the recently ratified OpenCL 2.0 Khronos standard. After a brief review of OpenCL 1.2 and 2.0, including HSA features such as Shared Virtual Memory (SVM) and platform atomics, we identify what genres of Computer Vision workloads stand to benefit by leveraging those features, and we suggest a new mental framework that replaces GPU compute with hybrid HSA APU compute. As a case in point, we discuss, in some detail, popular object recognition algorithms (part-based models), emphasizing the interplay and concurrent collaboration between the GPU and CPU. We conclude by describing how OpenCL has been incorporated in OpenCV, a popular open source computer vision library, emphasizing recent work on the Transparent API, to appear in OpenCV 3.0, which unifies the native CPU and OpenCL execution paths under a single API, allowing the same code to execute either on CPU or on a OpenCL enabled device, without even recompiling.

  2. Gesture Recognition by Computer Vision : An Integral Approach

    NARCIS (Netherlands)

    Lichtenauer, J.F.

    2009-01-01

    The fundamental objective of this Ph.D. thesis is to gain more insight into what is involved in the practical application of a computer vision system, when the conditions of use cannot be controlled completely. The basic assumption is that research on isolated aspects of computer vision often leads

  3. Intelligent Computer Vision System for Automated Classification

    International Nuclear Information System (INIS)

    Jordanov, Ivan; Georgieva, Antoniya

    2010-01-01

    In this paper we investigate an Intelligent Computer Vision System applied for recognition and classification of commercially available cork tiles. The system is capable of acquiring and processing gray images using several feature generation and analysis techniques. Its functionality includes image acquisition, feature extraction and preprocessing, and feature classification with neural networks (NN). We also discuss system test and validation results from the recognition and classification tasks. The system investigation also includes statistical feature processing (features number and dimensionality reduction techniques) and classifier design (NN architecture, target coding, learning complexity and performance, and training with our own metaheuristic optimization method). The NNs trained with our genetic low-discrepancy search method (GLPτS) for global optimisation demonstrated very good generalisation abilities. In our view, the reported testing success rate of up to 95% is due to several factors: combination of feature generation techniques; application of Analysis of Variance (ANOVA) and Principal Component Analysis (PCA), which appeared to be very efficient for preprocessing the data; and use of suitable NN design and learning method.

  4. Template matching techniques in computer vision theory and practice

    CERN Document Server

    Brunelli, Roberto

    2009-01-01

    The detection and recognition of objects in images is a key research topic in the computer vision community.  Within this area, face recognition and interpretation has attracted increasing attention owing to the possibility of unveiling human perception mechanisms, and for the development of practical biometric systems. This book and the accompanying website, focus on template matching, a subset of object recognition techniques of wide applicability, which has proved to be particularly effective for face recognition applications. Using examples from face processing tasks throughout the book to illustrate more general object recognition approaches, Roberto Brunelli: examines the basics of digital image formation, highlighting points critical to the task of template matching;presents basic and  advanced template matching techniques, targeting grey-level images, shapes and point sets;discusses recent pattern classification paradigms from a template matching perspective;illustrates the development of a real fac...

  5. Null point of discrimination in crustacean polarisation vision.

    Science.gov (United States)

    How, Martin J; Christy, John; Roberts, Nicholas W; Marshall, N Justin

    2014-07-15

    The polarisation of light is used by many species of cephalopods and crustaceans to discriminate objects or to communicate. Most visual systems with this ability, such as that of the fiddler crab, include receptors with photopigments that are oriented horizontally and vertically relative to the outside world. Photoreceptors in such an orthogonal array are maximally sensitive to polarised light with the same fixed e-vector orientation. Using opponent neural connections, this two-channel system may produce a single value of polarisation contrast and, consequently, it may suffer from null points of discrimination. Stomatopod crustaceans use a different system for polarisation vision, comprising at least four types of polarisation-sensitive photoreceptor arranged at 0, 45, 90 and 135 deg relative to each other, in conjunction with extensive rotational eye movements. This anatomical arrangement should not suffer from equivalent null points of discrimination. To test whether these two systems were vulnerable to null points, we presented the fiddler crab Uca heteropleura and the stomatopod Haptosquilla trispinosa with polarised looming stimuli on a modified LCD monitor. The fiddler crab was less sensitive to differences in the degree of polarised light when the e-vector was at -45 deg than when the e-vector was horizontal. In comparison, stomatopods showed no difference in sensitivity between the two stimulus types. The results suggest that fiddler crabs suffer from a null point of sensitivity, while stomatopods do not. © 2014. Published by The Company of Biologists Ltd.

  6. Deep Learning for Computer Vision: A Brief Review

    Science.gov (United States)

    Doulamis, Nikolaos; Doulamis, Anastasios; Protopapadakis, Eftychios

    2018-01-01

    Over the last years deep learning methods have been shown to outperform previous state-of-the-art machine learning techniques in several fields, with computer vision being one of the most prominent cases. This review paper provides a brief overview of some of the most significant deep learning schemes used in computer vision problems, that is, Convolutional Neural Networks, Deep Boltzmann Machines and Deep Belief Networks, and Stacked Denoising Autoencoders. A brief account of their history, structure, advantages, and limitations is given, followed by a description of their applications in various computer vision tasks, such as object detection, face recognition, action and activity recognition, and human pose estimation. Finally, a brief overview is given of future directions in designing deep learning schemes for computer vision problems and the challenges involved therein. PMID:29487619

  7. Deep Learning for Computer Vision: A Brief Review

    Directory of Open Access Journals (Sweden)

    Athanasios Voulodimos

    2018-01-01

    Full Text Available Over the last years deep learning methods have been shown to outperform previous state-of-the-art machine learning techniques in several fields, with computer vision being one of the most prominent cases. This review paper provides a brief overview of some of the most significant deep learning schemes used in computer vision problems, that is, Convolutional Neural Networks, Deep Boltzmann Machines and Deep Belief Networks, and Stacked Denoising Autoencoders. A brief account of their history, structure, advantages, and limitations is given, followed by a description of their applications in various computer vision tasks, such as object detection, face recognition, action and activity recognition, and human pose estimation. Finally, a brief overview is given of future directions in designing deep learning schemes for computer vision problems and the challenges involved therein.

  8. Deep Learning for Computer Vision: A Brief Review.

    Science.gov (United States)

    Voulodimos, Athanasios; Doulamis, Nikolaos; Doulamis, Anastasios; Protopapadakis, Eftychios

    2018-01-01

    Over the last years deep learning methods have been shown to outperform previous state-of-the-art machine learning techniques in several fields, with computer vision being one of the most prominent cases. This review paper provides a brief overview of some of the most significant deep learning schemes used in computer vision problems, that is, Convolutional Neural Networks, Deep Boltzmann Machines and Deep Belief Networks, and Stacked Denoising Autoencoders. A brief account of their history, structure, advantages, and limitations is given, followed by a description of their applications in various computer vision tasks, such as object detection, face recognition, action and activity recognition, and human pose estimation. Finally, a brief overview is given of future directions in designing deep learning schemes for computer vision problems and the challenges involved therein.

  9. A memory-array architecture for computer vision

    Energy Technology Data Exchange (ETDEWEB)

    Balsara, P.T.

    1989-01-01

    With the fast advances in the area of computer vision and robotics there is a growing need for machines that can understand images at a very high speed. A conventional von Neumann computer is not suited for this purpose because it takes a tremendous amount of time to solve most typical image processing problems. Exploiting the inherent parallelism present in various vision tasks can significantly reduce the processing time. Fortunately, parallelism is increasingly affordable as hardware gets cheaper. Thus it is now imperative to study computer vision in a parallel processing framework. The author should first design a computational structure which is well suited for a wide range of vision tasks and then develop parallel algorithms which can run efficiently on this structure. Recent advances in VLSI technology have led to several proposals for parallel architectures for computer vision. In this thesis he demonstrates that a memory array architecture with efficient local and global communication capabilities can be used for high speed execution of a wide range of computer vision tasks. This architecture, called the Access Constrained Memory Array Architecture (ACMAA), is efficient for VLSI implementation because of its modular structure, simple interconnect and limited global control. Several parallel vision algorithms have been designed for this architecture. The choice of vision problems demonstrates the versatility of ACMAA for a wide range of vision tasks. These algorithms were simulated on a high level ACMAA simulator running on the Intel iPSC/2 hypercube, a parallel architecture. The results of this simulation are compared with those of sequential algorithms running on a single hypercube node. Details of the ACMAA processor architecture are also presented.

  10. Computer graphics visions and challenges: a European perspective.

    Science.gov (United States)

    Encarnação, José L

    2006-01-01

    I have briefly described important visions and challenges in computer graphics. They are a personal and therefore subjective selection. But most of these issues have to be addressed and solved--no matter if we call them visions or challenges or something else--if we want to make and further develop computer graphics into a key enabling technology for our IT-based society.

  11. Computer Vision Syndrome and Associated Factors Among Medical ...

    African Journals Online (AJOL)

    among college students the effects of computer use on the eye and vision related problems. ... which included the basic demographic profile, hours of computer use per ..... Male was reported by Costa et al., among call center workers in. Brazil.[17]. Headache .... the use of computer had become universal in higher education.

  12. Developments in medical image processing and computational vision

    CERN Document Server

    Jorge, Renato

    2015-01-01

    This book presents novel and advanced topics in Medical Image Processing and Computational Vision in order to solidify knowledge in the related fields and define their key stakeholders. It contains extended versions of selected papers presented in VipIMAGE 2013 – IV International ECCOMAS Thematic Conference on Computational Vision and Medical Image, which took place in Funchal, Madeira, Portugal, 14-16 October 2013.  The twenty-two chapters were written by invited experts of international recognition and address important issues in medical image processing and computational vision, including: 3D vision, 3D visualization, colour quantisation, continuum mechanics, data fusion, data mining, face recognition, GPU parallelisation, image acquisition and reconstruction, image and video analysis, image clustering, image registration, image restoring, image segmentation, machine learning, modelling and simulation, object detection, object recognition, object tracking, optical flow, pattern recognition, pose estimat...

  13. Stereo Vision for Unrestricted Human-Computer Interaction

    OpenAIRE

    Eldridge, Ross; Rudolph, Heiko

    2008-01-01

    Human computer interfaces have come long way in recent years, but the goal of a computer interpreting unrestricted human movement remains elusive. The use of stereo vision in this field has enabled the development of systems that begin to approach this goal. As computer technology advances we come ever closer to a system that can react to the ambiguities of human movement in real-time. In the foreseeable future stereo computer vision is not likely to replace the keyboard or mouse. There is at...

  14. Computer Vision and Image Processing: A Paper Review

    Directory of Open Access Journals (Sweden)

    victor - wiley

    2018-02-01

    Full Text Available Computer vision has been studied from many persective. It expands from raw data recording into techniques and ideas combining digital image processing, pattern recognition, machine learning and computer graphics. The wide usage has attracted many scholars to integrate with many disciplines and fields. This paper provide a survey of the recent technologies and theoretical concept explaining the development of computer vision especially related to image processing using different areas of their field application. Computer vision helps scholars to analyze images and video to obtain necessary information,    understand information on events or descriptions, and scenic pattern. It used method of multi-range application domain with massive data analysis. This paper provides contribution of recent development on reviews related to computer vision, image processing, and their related studies. We categorized the computer vision mainstream into four group e.g., image processing, object recognition, and machine learning. We also provide brief explanation on the up-to-date information about the techniques and their performance.

  15. Application of chaos and fractals to computer vision

    CERN Document Server

    Farmer, Michael E

    2014-01-01

    This book provides a thorough investigation of the application of chaos theory and fractal analysis to computer vision. The field of chaos theory has been studied in dynamical physical systems, and has been very successful in providing computational models for very complex problems ranging from weather systems to neural pathway signal propagation. Computer vision researchers have derived motivation for their algorithms from biology and physics for many years as witnessed by the optical flow algorithm, the oscillator model underlying graphical cuts and of course neural networks. These algorithm

  16. Machine learning and computer vision approaches for phenotypic profiling.

    Science.gov (United States)

    Grys, Ben T; Lo, Dara S; Sahin, Nil; Kraus, Oren Z; Morris, Quaid; Boone, Charles; Andrews, Brenda J

    2017-01-02

    With recent advances in high-throughput, automated microscopy, there has been an increased demand for effective computational strategies to analyze large-scale, image-based data. To this end, computer vision approaches have been applied to cell segmentation and feature extraction, whereas machine-learning approaches have been developed to aid in phenotypic classification and clustering of data acquired from biological images. Here, we provide an overview of the commonly used computer vision and machine-learning methods for generating and categorizing phenotypic profiles, highlighting the general biological utility of each approach. © 2017 Grys et al.

  17. Low computation vision-based navigation for a Martian rover

    Science.gov (United States)

    Gavin, Andrew S.; Brooks, Rodney A.

    1994-01-01

    Construction and design details of the Mobot Vision System, a small, self-contained, mobile vision system, are presented. This system uses the view from the top of a small, roving, robotic vehicle to supply data that is processed in real-time to safely navigate the surface of Mars. A simple, low-computation algorithm for constructing a 3-D navigational map of the Martian environment to be used by the rover is discussed.

  18. Computer Vision Syndrome: Implications for the Occupational Health Nurse.

    Science.gov (United States)

    Lurati, Ann Regina

    2018-02-01

    Computers and other digital devices are commonly used both in the workplace and during leisure time. Computer vision syndrome (CVS) is a new health-related condition that negatively affects workers. This article reviews the pathology of and interventions for CVS with implications for the occupational health nurse.

  19. DIKU-LASMEA Workshop on Computer Vision, Copenhagen, March, 2009

    DEFF Research Database (Denmark)

    Fihl, Preben

    This report will cover the participation in the DIKU-LASMEA Workshop on Computer Vision held at the department of computer science, University of Copenhagen, in March 2009. The report will give a concise description of the topics presented at the workshop, and briefly discuss how the work relates...... to the HERMES project and human motion and action recognition....

  20. Computing bubble-points of CO

    NARCIS (Netherlands)

    Ramdin, M.; Balaji, S.P.; Vicent Luna, J.M.; Torres-Knoop, A; Chen, Q.; Dubbeldam, D.; Calero, S; de Loos, T.W.; Vlugt, T.J.H.

    2016-01-01

    Computing bubble-points of multicomponent mixtures using Monte Carlo simulations is a non-trivial task. A new method is used to compute gas compositions from a known temperature, bubble-point pressure, and liquid composition. Monte Carlo simulations are used to calculate the bubble-points of

  1. Market-Oriented Cloud Computing: Vision, Hype, and Reality for Delivering IT Services as Computing Utilities

    OpenAIRE

    Buyya, Rajkumar; Yeo, Chee Shin; Venugopal, Srikumar

    2008-01-01

    This keynote paper: presents a 21st century vision of computing; identifies various computing paradigms promising to deliver the vision of computing utilities; defines Cloud computing and provides the architecture for creating market-oriented Clouds by leveraging technologies such as VMs; provides thoughts on market-based resource management strategies that encompass both customer-driven service management and computational risk management to sustain SLA-oriented resource allocation; presents...

  2. Foundations of computer vision computational geometry, visual image structures and object shape detection

    CERN Document Server

    Peters, James F

    2017-01-01

    This book introduces the fundamentals of computer vision (CV), with a focus on extracting useful information from digital images and videos. Including a wealth of methods used in detecting and classifying image objects and their shapes, it is the first book to apply a trio of tools (computational geometry, topology and algorithms) in solving CV problems, shape tracking in image object recognition and detecting the repetition of shapes in single images and video frames. Computational geometry provides a visualization of topological structures such as neighborhoods of points embedded in images, while image topology supplies us with structures useful in the analysis and classification of image regions. Algorithms provide a practical, step-by-step means of viewing image structures. The implementations of CV methods in Matlab and Mathematica, classification of chapter problems with the symbols (easily solved) and (challenging) and its extensive glossary of key words, examples and connections with the fabric of C...

  3. Artificial intelligence, expert systems, computer vision, and natural language processing

    Science.gov (United States)

    Gevarter, W. B.

    1984-01-01

    An overview of artificial intelligence (AI), its core ingredients, and its applications is presented. The knowledge representation, logic, problem solving approaches, languages, and computers pertaining to AI are examined, and the state of the art in AI is reviewed. The use of AI in expert systems, computer vision, natural language processing, speech recognition and understanding, speech synthesis, problem solving, and planning is examined. Basic AI topics, including automation, search-oriented problem solving, knowledge representation, and computational logic, are discussed.

  4. Computer vision and machine learning with RGB-D sensors

    CERN Document Server

    Shao, Ling; Kohli, Pushmeet

    2014-01-01

    This book presents an interdisciplinary selection of cutting-edge research on RGB-D based computer vision. Features: discusses the calibration of color and depth cameras, the reduction of noise on depth maps and methods for capturing human performance in 3D; reviews a selection of applications which use RGB-D information to reconstruct human figures, evaluate energy consumption and obtain accurate action classification; presents an approach for 3D object retrieval and for the reconstruction of gas flow from multiple Kinect cameras; describes an RGB-D computer vision system designed to assist t

  5. OpenCV 3.0 computer vision with Java

    CERN Document Server

    Baggio, Daniel Lélis

    2015-01-01

    If you are a Java developer, student, researcher, or hobbyist wanting to create computer vision applications in Java then this book is for you. If you are an experienced C/C++ developer who is used to working with OpenCV, you will also find this book very useful for migrating your applications to Java. All you need is basic knowledge of Java, with no prior understanding of computer vision required, as this book will give you clear explanations and examples of the basics.

  6. Computer vision and imaging in intelligent transportation systems

    CERN Document Server

    Bala, Raja; Trivedi, Mohan

    2017-01-01

    Acts as a single source reference providing readers with an overview of how computer vision can contribute to the different applications in the field of road transportation. This book presents a survey of computer vision techniques related to three key broad problems in the roadway transportation domain: safety, efficiency, and law enforcement. The individual chapters present significant applications within these problem domains, each presented in a tutorial manner, describing the motivation for and benefits of the application, and a description of the state of the art.

  7. Centaure: an heterogeneous parallel architecture for computer vision

    International Nuclear Information System (INIS)

    Peythieux, Marc

    1997-01-01

    This dissertation deals with the architecture of parallel computers dedicated to computer vision. In the first chapter, the problem to be solved is presented, as well as the architecture of the Sympati and Symphonie computers, on which this work is based. The second chapter is about the state of the art of computers and integrated processors that can execute computer vision and image processing codes. The third chapter contains a description of the architecture of Centaure. It has an heterogeneous structure: it is composed of a multiprocessor system based on Analog Devices ADSP21060 Sharc digital signal processor, and of a set of Symphonie computers working in a multi-SIMD fashion. Centaure also has a modular structure. Its basic node is composed of one Symphonie computer, tightly coupled to a Sharc thanks to a dual ported memory. The nodes of Centaure are linked together by the Sharc communication links. The last chapter deals with a performance validation of Centaure. The execution times on Symphonie and on Centaure of a benchmark which is typical of industrial vision, are presented and compared. In the first place, these results show that the basic node of Centaure allows a faster execution than Symphonie, and that increasing the size of the tested computer leads to a better speed-up with Centaure than with Symphonie. In the second place, these results validate the choice of running the low level structure of Centaure in a multi- SIMD fashion. (author) [fr

  8. Computer Vision for the Solar Dynamics Observatory (SDO)

    Science.gov (United States)

    Martens, P. C. H.; Attrill, G. D. R.; Davey, A. R.; Engell, A.; Farid, S.; Grigis, P. C.; Kasper, J.; Korreck, K.; Saar, S. H.; Savcheva, A.; Su, Y.; Testa, P.; Wills-Davey, M.; Bernasconi, P. N.; Raouafi, N.-E.; Delouille, V. A.; Hochedez, J. F.; Cirtain, J. W.; Deforest, C. E.; Angryk, R. A.; de Moortel, I.; Wiegelmann, T.; Georgoulis, M. K.; McAteer, R. T. J.; Timmons, R. P.

    2012-01-01

    In Fall 2008 NASA selected a large international consortium to produce a comprehensive automated feature-recognition system for the Solar Dynamics Observatory (SDO). The SDO data that we consider are all of the Atmospheric Imaging Assembly (AIA) images plus surface magnetic-field images from the Helioseismic and Magnetic Imager (HMI). We produce robust, very efficient, professionally coded software modules that can keep up with the SDO data stream and detect, trace, and analyze numerous phenomena, including flares, sigmoids, filaments, coronal dimmings, polarity inversion lines, sunspots, X-ray bright points, active regions, coronal holes, EIT waves, coronal mass ejections (CMEs), coronal oscillations, and jets. We also track the emergence and evolution of magnetic elements down to the smallest detectable features and will provide at least four full-disk, nonlinear, force-free magnetic field extrapolations per day. The detection of CMEs and filaments is accomplished with Solar and Heliospheric Observatory (SOHO)/ Large Angle and Spectrometric Coronagraph (LASCO) and ground-based Hα data, respectively. A completely new software element is a trainable feature-detection module based on a generalized image-classification algorithm. Such a trainable module can be used to find features that have not yet been discovered (as, for example, sigmoids were in the pre- Yohkoh era). Our codes will produce entries in the Heliophysics Events Knowledgebase (HEK) as well as produce complete catalogs for results that are too numerous for inclusion in the HEK, such as the X-ray bright-point metadata. This will permit users to locate data on individual events as well as carry out statistical studies on large numbers of events, using the interface provided by the Virtual Solar Observatory. The operations concept for our computer vision system is that the data will be analyzed in near real time as soon as they arrive at the SDO Joint Science Operations Center and have undergone basic

  9. Hubungan Antara Lama Penggunaan Komputer dengan Terjadinya Computer Vision Syndrome

    OpenAIRE

    Sahitra

    2016-01-01

    Computer Vision Syndrome is a list of symptoms to eyes which is caused by usage of computers for a long period of time. It is expected that 88% of computer users will come across this symptoms at least once in their lifetime. Period of usage of computer is one of the factor that causes this syndrome. This study is the type of analytic research with case control approach. The sample for this research are the students in the Computer Science department of University of Sumatera Utara 2012 ba...

  10. 1st International Conference on Computer Vision and Image Processing

    CERN Document Server

    Kumar, Sanjeev; Roy, Partha; Sen, Debashis

    2017-01-01

    This edited volume contains technical contributions in the field of computer vision and image processing presented at the First International Conference on Computer Vision and Image Processing (CVIP 2016). The contributions are thematically divided based on their relation to operations at the lower, middle and higher levels of vision systems, and their applications. The technical contributions in the areas of sensors, acquisition, visualization and enhancement are classified as related to low-level operations. They discuss various modern topics – reconfigurable image system architecture, Scheimpflug camera calibration, real-time autofocusing, climate visualization, tone mapping, super-resolution and image resizing. The technical contributions in the areas of segmentation and retrieval are classified as related to mid-level operations. They discuss some state-of-the-art techniques – non-rigid image registration, iterative image partitioning, egocentric object detection and video shot boundary detection. Th...

  11. X-ray machine vision and computed tomography

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This survey examines how 2-D x-ray machine vision and 3-D computed tomography will be used in industry in the 1988-1995 timeframe. Specific applications are described and rank-ordered in importance. The types of companies selling and using 2-D and 3-D systems are profiled, and markets are forecast for 1988 to 1995. It is known that many machine vision and automation companies are now considering entering this field. This report looks at the potential pitfalls and whether recent market problems similar to those recently experienced by the machine vision industry will likely occur in this field. FTS will publish approximately 100 other surveys in 1988 on emerging technology in the fields of AI, manufacturing, computers, sensors, photonics, energy, bioengineering, and materials

  12. Photogrammetric computer vision statistics, geometry, orientation and reconstruction

    CERN Document Server

    Förstner, Wolfgang

    2016-01-01

    This textbook offers a statistical view on the geometry of multiple view analysis, required for camera calibration and orientation and for geometric scene reconstruction based on geometric image features. The authors have backgrounds in geodesy and also long experience with development and research in computer vision, and this is the first book to present a joint approach from the converging fields of photogrammetry and computer vision. Part I of the book provides an introduction to estimation theory, covering aspects such as Bayesian estimation, variance components, and sequential estimation, with a focus on the statistically sound diagnostics of estimation results essential in vision metrology. Part II provides tools for 2D and 3D geometric reasoning using projective geometry. This includes oriented projective geometry and tools for statistically optimal estimation and test of geometric entities and transformations and their rela­tions, tools that are useful also in the context of uncertain reasoning in po...

  13. Computer Vision Systems for Hardwood Logs and Lumber

    Science.gov (United States)

    Philip A. Araman; Tai-Hoon Cho; D. Zhu; R. Conners

    1991-01-01

    Computer vision systems being developed at Virginia Tech University with the support and cooperation from the U.S. Forest Service are presented. Researchers at Michigan State University, West Virginia University, and Mississippi State University are also members of the research team working on various parts of this research. Our goals are to help U.S. hardwood...

  14. PIONEERING WORK IN COMPUTER VISION FOR HISTOLOGY

    OpenAIRE

    Andrei Daniel Timofte; Irina-Draga Căruntu

    2017-01-01

    The concept of computer-assisted training was firstly implemented in UMF Iasi in 1997, through the development of two pioneering digital instruments, namely the Histology Album and the Oral Histology Album. Both were built for learning purposes and became available, at that time, as Internet resources worldwide visible. The application of this particular e-learning method was dictated by the importance of well-defined visual images in acquiring basic histologic principles. Thus, t...

  15. Safety Computer Vision Rules for Improved Sensor Certification

    DEFF Research Database (Denmark)

    Mogensen, Johann Thor Ingibergsson; Kraft, Dirk; Schultz, Ulrik Pagh

    2017-01-01

    Mobile robots are used across many domains from personal care to agriculture. Working in dynamic open-ended environments puts high constraints on the robot perception system, which is critical for the safety of the system as a whole. To achieve the required safety levels the perception system needs...... to be certified, but no specific standards exist for computer vision systems, and the concept of safe vision systems remains largely unexplored. In this paper we present a novel domain-specific language that allows the programmer to express image quality detection rules for enforcing safety constraints...

  16. Grid computing : enabling a vision for collaborative research

    International Nuclear Information System (INIS)

    von Laszewski, G.

    2002-01-01

    In this paper the authors provide a motivation for Grid computing based on a vision to enable a collaborative research environment. The authors vision goes beyond the connection of hardware resources. They argue that with an infrastructure such as the Grid, new modalities for collaborative research are enabled. They provide an overview showing why Grid research is difficult, and they present a number of management-related issues that must be addressed to make Grids a reality. They list projects that provide solutions to subsets of these issues

  17. When Dijkstra Meets Vanishing Point: A Stereo Vision Approach for Road Detection.

    Science.gov (United States)

    Zhang, Yigong; Su, Yingna; Yang, Jian; Ponce, Jean; Kong, Hui

    2018-05-01

    In this paper, we propose a vanishing-point constrained Dijkstra road model for road detection in a stereo-vision paradigm. First, the stereo-camera is used to generate the u- and v-disparity maps of road image, from which the horizon can be extracted. With the horizon and ground region constraints, we can robustly locate the vanishing point of road region. Second, a weighted graph is constructed using all pixels of the image, and the detected vanishing point is treated as the source node of the graph. By computing a vanishing-point constrained Dijkstra minimum-cost map, where both disparity and gradient of gray image are used to calculate cost between two neighbor pixels, the problem of detecting road borders in image is transformed into that of finding two shortest paths that originate from the vanishing point to two pixels in the last row of image. The proposed approach has been implemented and tested over 2600 grayscale images of different road scenes in the KITTI data set. The experimental results demonstrate that this training-free approach can detect horizon, vanishing point, and road regions very accurately and robustly. It can achieve promising performance.

  18. Parallel algorithm for dominant points correspondences in robot binocular stereo vision

    Science.gov (United States)

    Al-Tammami, A.; Singh, B.

    1993-01-01

    This paper presents an algorithm to find the correspondences of points representing dominant feature in robot stereo vision. The algorithm consists of two main steps: dominant point extraction and dominant point matching. In the feature extraction phase, the algorithm utilizes the widely used Moravec Interest Operator and two other operators: the Prewitt Operator and a new operator called Gradient Angle Variance Operator. The Interest Operator in the Moravec algorithm was used to exclude featureless areas and simple edges which are oriented in the vertical, horizontal, and two diagonals. It was incorrectly detecting points on edges which are not on the four main directions (vertical, horizontal, and two diagonals). The new algorithm uses the Prewitt operator to exclude featureless areas, so that the Interest Operator is applied only on the edges to exclude simple edges and to leave interesting points. This modification speeds-up the extraction process by approximately 5 times. The Gradient Angle Variance (GAV), an operator which calculates the variance of the gradient angle in a window around the point under concern, is then applied on the interesting points to exclude the redundant ones and leave the actual dominant ones. The matching phase is performed after the extraction of the dominant points in both stereo images. The matching starts with dominant points in the left image and does a local search, looking for corresponding dominant points in the right image. The search is geometrically constrained the epipolar line of the parallel-axes stereo geometry and the maximum disparity of the application environment. If one dominant point in the right image lies in the search areas, then it is the corresponding point of the reference dominant point in the left image. A parameter provided by the GAV is thresholded and used as a rough similarity measure to select the corresponding dominant point if there is more than one point the search area. The correlation is used as

  19. Computer radiography-X-ray with vision

    International Nuclear Information System (INIS)

    Waitiki, C.

    2006-01-01

    Computer radiography describes an entire process of creating a digital image including acquiring, processing, presenting and managing the image data. the cassettes are special in that they use an imaging plate instead of films. the imaging plate is coated with storage phosphors which captures x-ray as they pass through the patient. the imaging plate is read with a bar code reader and the imaging plate number recorded in the computer. The cassette is then loaded in the reader unit where it is read using infra-red light which excites the particles on the plate which in turn illuminates and picked by photo-sensors which converts the signal into digital pulses. the pulses then run through a board which converts it into an image which is then displayed on the control console. The plate then runs through the erasure section where it is exposed to yellow light, which erases the plate. The IP is then put back in the cassette and locked and can be reused for the next episode

  20. Multiscale Methods, Parallel Computation, and Neural Networks for Real-Time Computer Vision.

    Science.gov (United States)

    Battiti, Roberto

    1990-01-01

    This thesis presents new algorithms for low and intermediate level computer vision. The guiding ideas in the presented approach are those of hierarchical and adaptive processing, concurrent computation, and supervised learning. Processing of the visual data at different resolutions is used not only to reduce the amount of computation necessary to reach the fixed point, but also to produce a more accurate estimation of the desired parameters. The presented adaptive multiple scale technique is applied to the problem of motion field estimation. Different parts of the image are analyzed at a resolution that is chosen in order to minimize the error in the coefficients of the differential equations to be solved. Tests with video-acquired images show that velocity estimation is more accurate over a wide range of motion with respect to the homogeneous scheme. In some cases introduction of explicit discontinuities coupled to the continuous variables can be used to avoid propagation of visual information from areas corresponding to objects with different physical and/or kinematic properties. The human visual system uses concurrent computation in order to process the vast amount of visual data in "real -time." Although with different technological constraints, parallel computation can be used efficiently for computer vision. All the presented algorithms have been implemented on medium grain distributed memory multicomputers with a speed-up approximately proportional to the number of processors used. A simple two-dimensional domain decomposition assigns regions of the multiresolution pyramid to the different processors. The inter-processor communication needed during the solution process is proportional to the linear dimension of the assigned domain, so that efficiency is close to 100% if a large region is assigned to each processor. Finally, learning algorithms are shown to be a viable technique to engineer computer vision systems for different applications starting from

  1. Review On Applications Of Neural Network To Computer Vision

    Science.gov (United States)

    Li, Wei; Nasrabadi, Nasser M.

    1989-03-01

    Neural network models have many potential applications to computer vision due to their parallel structures, learnability, implicit representation of domain knowledge, fault tolerance, and ability of handling statistical data. This paper demonstrates the basic principles, typical models and their applications in this field. Variety of neural models, such as associative memory, multilayer back-propagation perceptron, self-stabilized adaptive resonance network, hierarchical structured neocognitron, high order correlator, network with gating control and other models, can be applied to visual signal recognition, reinforcement, recall, stereo vision, motion, object tracking and other vision processes. Most of the algorithms have been simulated on com-puters. Some have been implemented with special hardware. Some systems use features, such as edges and profiles, of images as the data form for input. Other systems use raw data as input signals to the networks. We will present some novel ideas contained in these approaches and provide a comparison of these methods. Some unsolved problems are mentioned, such as extracting the intrinsic properties of the input information, integrating those low level functions to a high-level cognitive system, achieving invariances and other problems. Perspectives of applications of some human vision models and neural network models are analyzed.

  2. Computer vision in roadway transportation systems: a survey

    Science.gov (United States)

    Loce, Robert P.; Bernal, Edgar A.; Wu, Wencheng; Bala, Raja

    2013-10-01

    There is a worldwide effort to apply 21st century intelligence to evolving our transportation networks. The goals of smart transportation networks are quite noble and manifold, including safety, efficiency, law enforcement, energy conservation, and emission reduction. Computer vision is playing a key role in this transportation evolution. Video imaging scientists are providing intelligent sensing and processing technologies for a wide variety of applications and services. There are many interesting technical challenges including imaging under a variety of environmental and illumination conditions, data overload, recognition and tracking of objects at high speed, distributed network sensing and processing, energy sources, as well as legal concerns. This paper presents a survey of computer vision techniques related to three key problems in the transportation domain: safety, efficiency, and security and law enforcement. A broad review of the literature is complemented by detailed treatment of a few selected algorithms and systems that the authors believe represent the state-of-the-art.

  3. Monitoring system of multiple fire fighting based on computer vision

    Science.gov (United States)

    Li, Jinlong; Wang, Li; Gao, Xiaorong; Wang, Zeyong; Zhao, Quanke

    2010-10-01

    With the high demand of fire control in spacious buildings, computer vision is playing a more and more important role. This paper presents a new monitoring system of multiple fire fighting based on computer vision and color detection. This system can adjust to the fire position and then extinguish the fire by itself. In this paper, the system structure, working principle, fire orientation, hydrant's angle adjusting and system calibration are described in detail; also the design of relevant hardware and software is introduced. At the same time, the principle and process of color detection and image processing are given as well. The system runs well in the test, and it has high reliability, low cost, and easy nodeexpanding, which has a bright prospect of application and popularization.

  4. Computer vision syndrome: a study of the knowledge, attitudes and practices in Indian ophthalmologists.

    Science.gov (United States)

    Bali, Jatinder; Navin, Neeraj; Thakur, Bali Renu

    2007-01-01

    To study the knowledge, attitude and practices (KAP) towards computer vision syndrome prevalent in Indian ophthalmologists and to assess whether 'computer use by practitioners' had any bearing on the knowledge and practices in computer vision syndrome (CVS). A random KAP survey was carried out on 300 Indian ophthalmologists using a 34-point spot-questionnaire in January 2005. All the doctors who responded were aware of CVS. The chief presenting symptoms were eyestrain (97.8%), headache (82.1%), tiredness and burning sensation (79.1%), watering (66.4%) and redness (61.2%). Ophthalmologists using computers reported that focusing from distance to near and vice versa (P =0.006, chi2 test), blurred vision at a distance (P =0.016, chi2 test) and blepharospasm (P =0.026, chi2 test) formed part of the syndrome. The main mode of treatment used was tear substitutes. Half of ophthalmologists (50.7%) were not prescribing any spectacles. They did not have any preference for any special type of glasses (68.7%) or spectral filters. Computer-users were more likely to prescribe sedatives/anxiolytics (P = 0.04, chi2 test), spectacles (P = 0.02, chi2 test) and conscious frequent blinking (P = 0.003, chi2 test) than the non-computer-users. All respondents were aware of CVS. Confusion regarding treatment guidelines was observed in both groups. Computer-using ophthalmologists were more informed of symptoms and diagnostic signs but were misinformed about treatment modalities.

  5. Possible Computer Vision Systems and Automated or Computer-Aided Edging and Trimming

    Science.gov (United States)

    Philip A. Araman

    1990-01-01

    This paper discusses research which is underway to help our industry reduce costs, increase product volume and value recovery, and market more accurately graded and described products. The research is part of a team effort to help the hardwood sawmill industry automate with computer vision systems, and computer-aided or computer controlled processing. This paper...

  6. Quality Parameters of Six Cultivars of Blueberry Using Computer Vision

    Directory of Open Access Journals (Sweden)

    Silvia Matiacevich

    2013-01-01

    Full Text Available Background. Blueberries are considered an important source of health benefits. This work studied six blueberry cultivars: “Duke,” “Brigitta”, “Elliott”, “Centurion”, “Star,” and “Jewel”, measuring quality parameters such as °Brix, pH, moisture content using standard techniques and shape, color, and fungal presence obtained by computer vision. The storage conditions were time (0–21 days, temperature (4 and 15°C, and relative humidity (75 and 90%. Results. Significant differences (P<0.05 were detected between fresh cultivars in pH, °Brix, shape, and color. However, the main parameters which changed depending on storage conditions, increasing at higher temperature, were color (from blue to red and fungal presence (from 0 to 15%, both detected using computer vision, which is important to determine a shelf life of 14 days for all cultivars. Similar behavior during storage was obtained for all cultivars. Conclusion. Computer vision proved to be a reliable and simple method to objectively determine blueberry decay during storage that can be used as an alternative approach to currently used subjective measurements.

  7. Machine learning, computer vision, and probabilistic models in jet physics

    CERN Multimedia

    CERN. Geneva; NACHMAN, Ben

    2015-01-01

    In this talk we present recent developments in the application of machine learning, computer vision, and probabilistic models to the analysis and interpretation of LHC events. First, we will introduce the concept of jet-images and computer vision techniques for jet tagging. Jet images enabled the connection between jet substructure and tagging with the fields of computer vision and image processing for the first time, improving the performance to identify highly boosted W bosons with respect to state-of-the-art methods, and providing a new way to visualize the discriminant features of different classes of jets, adding a new capability to understand the physics within jets and to design more powerful jet tagging methods. Second, we will present Fuzzy jets: a new paradigm for jet clustering using machine learning methods. Fuzzy jets view jet clustering as an unsupervised learning task and incorporate a probabilistic assignment of particles to jets to learn new features of the jet structure. In particular, we wi...

  8. Computer vision based nacre thickness measurement of Tahitian pearls

    Science.gov (United States)

    Loesdau, Martin; Chabrier, Sébastien; Gabillon, Alban

    2017-03-01

    The Tahitian Pearl is the most valuable export product of French Polynesia contributing with over 61 million Euros to more than 50% of the total export income. To maintain its excellent reputation on the international market, an obligatory quality control for every pearl deemed for exportation has been established by the local government. One of the controlled quality parameters is the pearls nacre thickness. The evaluation is currently done manually by experts that are visually analyzing X-ray images of the pearls. In this article, a computer vision based approach to automate this procedure is presented. Even though computer vision based approaches for pearl nacre thickness measurement exist in the literature, the very specific features of the Tahitian pearl, namely the large shape variety and the occurrence of cavities, have so far not been considered. The presented work closes the. Our method consists of segmenting the pearl from X-ray images with a model-based approach, segmenting the pearls nucleus with an own developed heuristic circle detection and segmenting possible cavities with region growing. Out of the obtained boundaries, the 2-dimensional nacre thickness profile can be calculated. A certainty measurement to consider imaging and segmentation imprecisions is included in the procedure. The proposed algorithms are tested on 298 manually evaluated Tahitian pearls, showing that it is generally possible to automatically evaluate the nacre thickness of Tahitian pearls with computer vision. Furthermore the results show that the automatic measurement is more precise and faster than the manual one.

  9. Effect of contact lens use on Computer Vision Syndrome.

    Science.gov (United States)

    Tauste, Ana; Ronda, Elena; Molina, María-José; Seguí, Mar

    2016-03-01

    To analyse the relationship between Computer Vision Syndrome (CVS) in computer workers and contact lens use, according to lens materials. Cross-sectional study. The study included 426 civil-service office workers, of whom 22% were contact lens wearers. Workers completed the Computer Vision Syndrome Questionnaire (CVS-Q) and provided information on their contact lenses and exposure to video display terminals (VDT) at work. CVS was defined as a CVS-Q score of 6 or more. The covariates were age and sex. Logistic regression was used to calculate the association (crude and adjusted for age and sex) between CVS and individual and work-related factors, and between CVS and contact lens type. Contact lens wearers are more likely to suffer CVS than non-lens wearers, with a prevalence of 65% vs 50%. Workers who wear contact lenses and are exposed to the computer for more than 6 h day(-1) are more likely to suffer CVS than non-lens wearers working at the computer for the same amount of time (aOR = 4.85; 95% CI, 1.25-18.80; p = 0.02). Regular contact lens use increases CVS after 6 h of computer work. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

  10. Remote media vision-based computer input device

    Science.gov (United States)

    Arabnia, Hamid R.; Chen, Ching-Yi

    1991-11-01

    In this paper, we introduce a vision-based computer input device which has been built at the University of Georgia. The user of this system gives commands to the computer without touching any physical device. The system receives input through a CCD camera; it is PC- based and is built on top of the DOS operating system. The major components of the input device are: a monitor, an image capturing board, a CCD camera, and some software (developed by use). These are interfaced with a standard PC running under the DOS operating system.

  11. A study of computer-related upper limb discomfort and computer vision syndrome.

    Science.gov (United States)

    Sen, A; Richardson, Stanley

    2007-12-01

    Personal computers are one of the commonest office tools in Malaysia today. Their usage, even for three hours per day, leads to a health risk of developing Occupational Overuse Syndrome (OOS), Computer Vision Syndrome (CVS), low back pain, tension headaches and psychosocial stress. The study was conducted to investigate how a multiethnic society in Malaysia is coping with these problems that are increasing at a phenomenal rate in the west. This study investigated computer usage, awareness of ergonomic modifications of computer furniture and peripherals, symptoms of CVS and risk of developing OOS. A cross-sectional questionnaire study of 136 computer users was conducted on a sample population of university students and office staff. A 'Modified Rapid Upper Limb Assessment (RULA) for office work' technique was used for evaluation of OOS. The prevalence of CVS was surveyed incorporating a 10-point scoring system for each of its various symptoms. It was found that many were using standard keyboard and mouse without any ergonomic modifications. Around 50% of those with some low back pain did not have an adjustable backrest. Many users had higher RULA scores of the wrist and neck suggesting increased risk of developing OOS, which needed further intervention. Many (64%) were using refractive corrections and still had high scores of CVS commonly including eye fatigue, headache and burning sensation. The increase of CVS scores (suggesting more subjective symptoms) correlated with increase in computer usage spells. It was concluded that further onsite studies are needed, to follow up this survey to decrease the risks of developing CVS and OOS amongst young computer users.

  12. Computer vision syndrome and ergonomic practices among undergraduate university students.

    Science.gov (United States)

    Mowatt, Lizette; Gordon, Carron; Santosh, Arvind Babu Rajendra; Jones, Thaon

    2018-01-01

    To determine the prevalence of computer vision syndrome (CVS) and ergonomic practices among students in the Faculty of Medical Sciences at The University of the West Indies (UWI), Jamaica. A cross-sectional study was done with a self-administered questionnaire. Four hundred and nine students participated; 78% were females. The mean age was 21.6 years. Neck pain (75.1%), eye strain (67%), shoulder pain (65.5%) and eye burn (61.9%) were the most common CVS symptoms. Dry eyes (26.2%), double vision (28.9%) and blurred vision (51.6%) were the least commonly experienced symptoms. Eye burning (P = .001), eye strain (P = .041) and neck pain (P = .023) were significantly related to level of viewing. Moderate eye burning (55.1%) and double vision (56%) occurred in those who used handheld devices (P = .001 and .007, respectively). Moderate blurred vision was reported in 52% who looked down at the device compared with 14.8% who held it at an angle. Severe eye strain occurred in 63% of those who looked down at a device compared with 21% who kept the device at eye level. Shoulder pain was not related to pattern of use. Ocular symptoms and neck pain were less likely if the device was held just below eye level. There is a high prevalence of Symptoms of CVS amongst university students which could be reduced, in particular neck pain and eye strain and burning, with improved ergonomic practices. © 2017 John Wiley & Sons Ltd.

  13. Furnance grate monitoring by computer vision; Rosteroevervakning med bildanalys

    Energy Technology Data Exchange (ETDEWEB)

    Blom, Elisabet; Gustafsson, Bengt; Olsson, Magnus

    2005-01-01

    During the last couple of year's computer vision has developed a lot beside computers and video technic. This makes it technical and economical possible to use cameras as a monitoring instrument. The first experiments with this type of equipment were made in the early 1990s. Most of the experiments were made to measure the bed length from the back of the grate. In this experiment the cameras were mounted in the front instead. The highest priority was to detect the topography of the fuel bed. An uneven fuel bed means combustion with local temperature variations that do the combustion more difficult to control. The goal was to show possibilities to measure fuel bed highs, particle size and combustion intensity or the combustion spreading with pictures from one or two cameras. The test was done in a bark-fuelled boiler in Karlsborg because that boiler has doors from the fuel feeding side suitable for looking down on the grate. The results shows that the cameras mounting that were done in Karlsborg were not good enough to do a 3D calculation of the fuel bed. It was however possible to se the drying and it was possible to see the flames in the pictures. To see the flames and steam without over exposure because of different light in different points, it is possible to use a filter or an on linear sensibility camera. To test if a parallel mounting of the two cameras would work a cold test were done in the grate test facility at KMW in Norrtaelje. With the pictures from this test we were able to do 3D measurements of the bed topography. The conclusions are that it is possible to measure bed height and bed topography with other camera positions than we were able to use in this experiment. The particle size is easier to measure before entering the boiler for examples over a rim were the particles falling down. It is also possible to estimate a temperature zone were the steam goes off.

  14. CFD Vision 2030 Study: A Path to Revolutionary Computational Aerosciences

    Science.gov (United States)

    Slotnick, Jeffrey; Khodadoust, Abdollah; Alonso, Juan; Darmofal, David; Gropp, William; Lurie, Elizabeth; Mavriplis, Dimitri

    2014-01-01

    This report documents the results of a study to address the long range, strategic planning required by NASA's Revolutionary Computational Aerosciences (RCA) program in the area of computational fluid dynamics (CFD), including future software and hardware requirements for High Performance Computing (HPC). Specifically, the "Vision 2030" CFD study is to provide a knowledge-based forecast of the future computational capabilities required for turbulent, transitional, and reacting flow simulations across a broad Mach number regime, and to lay the foundation for the development of a future framework and/or environment where physics-based, accurate predictions of complex turbulent flows, including flow separation, can be accomplished routinely and efficiently in cooperation with other physics-based simulations to enable multi-physics analysis and design. Specific technical requirements from the aerospace industrial and scientific communities were obtained to determine critical capability gaps, anticipated technical challenges, and impediments to achieving the target CFD capability in 2030. A preliminary development plan and roadmap were created to help focus investments in technology development to help achieve the CFD vision in 2030.

  15. REDUCED DATA FOR CURVE MODELING – APPLICATIONS IN GRAPHICS, COMPUTER VISION AND PHYSICS

    Directory of Open Access Journals (Sweden)

    Małgorzata Janik

    2013-06-01

    Full Text Available In this paper we consider the problem of modeling curves in Rn via interpolation without a priori specified interpolation knots. We discuss two approaches to estimate the missing knots for non-parametric data (i.e. collection of points. The first approach (uniform evaluation is based on blind guess in which knots are chosen uniformly. The second approach (cumulative chord parameterization incorporates the geometry of the distribution of data points. More precisely, the difference is equal to the Euclidean distance between data points qi+1 and qi. The second method partially compensates for the loss of the information carried by the reduced data. We also present the application of the above schemes for fitting non-parametric data in computer graphics (light-source motion rendering, in computer vision (image segmentation and in physics (high velocity particles trajectory modeling. Though experiments are conducted for points in R2 and R3 the entire method is equally applicable in Rn.

  16. THE USE OF COMPUTER VISION ALGORITHMS FOR AUTOMATIC ORIENTATION OF TERRESTRIAL LASER SCANNING DATA

    Directory of Open Access Journals (Sweden)

    J. S. Markiewicz

    2016-06-01

    Full Text Available The paper presents analysis of the orientation of terrestrial laser scanning (TLS data. In the proposed data processing methodology, point clouds are considered as panoramic images enriched by the depth map. Computer vision (CV algorithms are used for orientation, which are applied for testing the correctness of the detection of tie points and time of computations, and for assessing difficulties in their implementation. The BRISK, FASRT, MSER, SIFT, SURF, ASIFT and CenSurE algorithms are used to search for key-points. The source data are point clouds acquired using a Z+F 5006h terrestrial laser scanner on the ruins of Iłża Castle, Poland. Algorithms allowing combination of the photogrammetric and CV approaches are also presented.

  17. The Use of Computer Vision Algorithms for Automatic Orientation of Terrestrial Laser Scanning Data

    Science.gov (United States)

    Markiewicz, Jakub Stefan

    2016-06-01

    The paper presents analysis of the orientation of terrestrial laser scanning (TLS) data. In the proposed data processing methodology, point clouds are considered as panoramic images enriched by the depth map. Computer vision (CV) algorithms are used for orientation, which are applied for testing the correctness of the detection of tie points and time of computations, and for assessing difficulties in their implementation. The BRISK, FASRT, MSER, SIFT, SURF, ASIFT and CenSurE algorithms are used to search for key-points. The source data are point clouds acquired using a Z+F 5006h terrestrial laser scanner on the ruins of Iłża Castle, Poland. Algorithms allowing combination of the photogrammetric and CV approaches are also presented.

  18. Dataflow-Based Mapping of Computer Vision Algorithms onto FPGAs

    Directory of Open Access Journals (Sweden)

    Ivan Corretjer

    2007-01-01

    Full Text Available We develop a design methodology for mapping computer vision algorithms onto an FPGA through the use of coarse-grain reconfigurable dataflow graphs as a representation to guide the designer. We first describe a new dataflow modeling technique called homogeneous parameterized dataflow (HPDF, which effectively captures the structure of an important class of computer vision applications. This form of dynamic dataflow takes advantage of the property that in a large number of image processing applications, data production and consumption rates can vary, but are equal across dataflow graph edges for any particular application iteration. After motivating and defining the HPDF model of computation, we develop an HPDF-based design methodology that offers useful properties in terms of verifying correctness and exposing performance-enhancing transformations; we discuss and address various challenges in efficiently mapping an HPDF-based application representation into target-specific HDL code; and we present experimental results pertaining to the mapping of a gesture recognition application onto the Xilinx Virtex II FPGA.

  19. Ergophthalmology in accounting offices: the computer vision syndrome (CVS

    Directory of Open Access Journals (Sweden)

    Arjuna Nudi Perin

    Full Text Available Abstract Purpose: This study aimed to determine the presence of the symptoms of computer vision syndrome (CVS accounting office employees. Methods: The research tools used were a questionnaire based on the set of symptoms of CVS rated by Likert scale (1-5 and workplace observations based on Ergonomic Workplace Analysis (EWA. Results: The participants who worked with a viewing angle of less than 10º relative to the screen had more symptoms, particularly of pain in the back of the neck and back (p = 0.0460. The participants who used lighting other than 450 and 699 lux reported significant headache (p = 0.0045 and dry eye (p = 0.0329 symptoms. Younger workers had more headaches (p = 0.0182, and workers with fewer years of employment had more headaches and dry eyes symptoms (p = 0.0164 and p = 0.0479, respectively. A total of 37% of the participants reported a lack of guidance regarding prevention and painful symptoms in the back of the neck and back (p = 0.0936. Conclusion: Younger participants with fewer years of employment, who had not received information regarding proper computer use, who did not use lighting between 450 and 699 lux or who worked with viewing angles of less than 10º had more computer vision syndrome symptoms.

  20. Fusion in computer vision understanding complex visual content

    CERN Document Server

    Ionescu, Bogdan; Piatrik, Tomas

    2014-01-01

    This book presents a thorough overview of fusion in computer vision, from an interdisciplinary and multi-application viewpoint, describing successful approaches, evaluated in the context of international benchmarks that model realistic use cases. Features: examines late fusion approaches for concept recognition in images and videos; describes the interpretation of visual content by incorporating models of the human visual system with content understanding methods; investigates the fusion of multi-modal features of different semantic levels, as well as results of semantic concept detections, fo

  1. Computer vision applications for coronagraphic optical alignment and image processing.

    Science.gov (United States)

    Savransky, Dmitry; Thomas, Sandrine J; Poyneer, Lisa A; Macintosh, Bruce A

    2013-05-10

    Modern coronagraphic systems require very precise alignment between optical components and can benefit greatly from automated image processing. We discuss three techniques commonly employed in the fields of computer vision and image analysis as applied to the Gemini Planet Imager, a new facility instrument for the Gemini South Observatory. We describe how feature extraction and clustering methods can be used to aid in automated system alignment tasks, and also present a search algorithm for finding regular features in science images used for calibration and data processing. Along with discussions of each technique, we present our specific implementation and show results of each one in operation.

  2. Shape perception in human and computer vision an interdisciplinary perspective

    CERN Document Server

    Dickinson, Sven J

    2013-01-01

    This comprehensive and authoritative text/reference presents a unique, multidisciplinary perspective on Shape Perception in Human and Computer Vision. Rather than focusing purely on the state of the art, the book provides viewpoints from world-class researchers reflecting broadly on the issues that have shaped the field. Drawing upon many years of experience, each contributor discusses the trends followed and the progress made, in addition to identifying the major challenges that still lie ahead. Topics and features: examines each topic from a range of viewpoints, rather than promoting a speci

  3. Comparison of progressive addition lenses for general purpose and for computer vision: an office field study.

    Science.gov (United States)

    Jaschinski, Wolfgang; König, Mirjam; Mekontso, Tiofil M; Ohlendorf, Arne; Welscher, Monique

    2015-05-01

    Two types of progressive addition lenses (PALs) were compared in an office field study: 1. General purpose PALs with continuous clear vision between infinity and near reading distances and 2. Computer vision PALs with a wider zone of clear vision at the monitor and in near vision but no clear distance vision. Twenty-three presbyopic participants wore each type of lens for two weeks in a double-masked four-week quasi-experimental procedure that included an adaptation phase (Weeks 1 and 2) and a test phase (Weeks 3 and 4). Questionnaires on visual and musculoskeletal conditions as well as preferences regarding the type of lenses were administered. After eight more weeks of free use of the spectacles, the preferences were assessed again. The ergonomic conditions were analysed from photographs. Head inclination when looking at the monitor was significantly lower by 2.3 degrees with the computer vision PALs than with the general purpose PALs. Vision at the monitor was judged significantly better with computer PALs, while distance vision was judged better with general purpose PALs; however, the reported advantage of computer vision PALs differed in extent between participants. Accordingly, 61 per cent of the participants preferred the computer vision PALs, when asked without information about lens design. After full information about lens characteristics and additional eight weeks of free spectacle use, 44 per cent preferred the computer vision PALs. On average, computer vision PALs were rated significantly better with respect to vision at the monitor during the experimental part of the study. In the final forced-choice ratings, approximately half of the participants preferred either the computer vision PAL or the general purpose PAL. Individual factors seem to play a role in this preference and in the rated advantage of computer vision PALs. © 2015 The Authors. Clinical and Experimental Optometry © 2015 Optometry Australia.

  4. Picture processing computer to control movement by computer provided vision

    Energy Technology Data Exchange (ETDEWEB)

    Graefe, V

    1983-01-01

    The author introduces a multiprocessor system which has been specially developed to enable mechanical devices to interpret pictures presented in real time. The separate processors within this system operate simultaneously and independently. By means of freely moveable windows the processors can concentrate on those parts of the picture that are relevant to the control problem. If a machine is to make a correct response to its observation of a picture of moving objects, it must be able to follow the picture sequence, step by step, in real time. As the usual serially operating processors are too slow for such a task, the author describes three models of a special picture processing computer which it has been necessary to develop. 3 references.

  5. Foreword to the theme issue on geospatial computer vision

    Science.gov (United States)

    Wegner, Jan Dirk; Tuia, Devis; Yang, Michael; Mallet, Clement

    2018-06-01

    Geospatial Computer Vision has become one of the most prevalent emerging fields of investigation in Earth Observation in the last few years. In this theme issue, we aim at showcasing a number of works at the interface between remote sensing, photogrammetry, image processing, computer vision and machine learning. In light of recent sensor developments - both from the ground as from above - an unprecedented (and ever growing) quantity of geospatial data is available for tackling challenging and urgent tasks such as environmental monitoring (deforestation, carbon sequestration, climate change mitigation), disaster management, autonomous driving or the monitoring of conflicts. The new bottleneck for serving these applications is the extraction of relevant information from such large amounts of multimodal data. This includes sources, stemming from multiple sensors, that exhibit distinct physical nature of heterogeneous quality, spatial, spectral and temporal resolutions. They are as diverse as multi-/hyperspectral satellite sensors, color cameras on drones, laser scanning devices, existing open land-cover geodatabases and social media. Such core data processing is mandatory so as to generate semantic land-cover maps, accurate detection and trajectories of objects of interest, as well as by-products of superior added-value: georeferenced data, images with enhanced geometric and radiometric qualities, or Digital Surface and Elevation Models.

  6. Computer Vision Based Measurement of Wildfire Smoke Dynamics

    Directory of Open Access Journals (Sweden)

    BUGARIC, M.

    2015-02-01

    Full Text Available This article presents a novel method for measurement of wildfire smoke dynamics based on computer vision and augmented reality techniques. The aspect of smoke dynamics is an important feature in video smoke detection that could distinguish smoke from visually similar phenomena. However, most of the existing smoke detection systems are not capable of measuring the real-world size of the detected smoke regions. Using computer vision and GIS-based augmented reality, we measure the real dimensions of smoke plumes, and observe the change in size over time. The measurements are performed on offline video data with known camera parameters and location. The observed data is analyzed in order to create a classifier that could be used to eliminate certain categories of false alarms induced by phenomena with different dynamics than smoke. We carried out an offline evaluation where we measured the improvement in the detection process achieved using the proposed smoke dynamics characteristics. The results show a significant increase in algorithm performance, especially in terms of reducing false alarms rate. From this it follows that the proposed method for measurement of smoke dynamics could be used to improve existing smoke detection algorithms, or taken into account when designing new ones.

  7. Computer vision uncovers predictors of physical urban change.

    Science.gov (United States)

    Naik, Nikhil; Kominers, Scott Duke; Raskar, Ramesh; Glaeser, Edward L; Hidalgo, César A

    2017-07-18

    Which neighborhoods experience physical improvements? In this paper, we introduce a computer vision method to measure changes in the physical appearances of neighborhoods from time-series street-level imagery. We connect changes in the physical appearance of five US cities with economic and demographic data and find three factors that predict neighborhood improvement. First, neighborhoods that are densely populated by college-educated adults are more likely to experience physical improvements-an observation that is compatible with the economic literature linking human capital and local success. Second, neighborhoods with better initial appearances experience, on average, larger positive improvements-an observation that is consistent with "tipping" theories of urban change. Third, neighborhood improvement correlates positively with physical proximity to the central business district and to other physically attractive neighborhoods-an observation that is consistent with the "invasion" theories of urban sociology. Together, our results provide support for three classical theories of urban change and illustrate the value of using computer vision methods and street-level imagery to understand the physical dynamics of cities.

  8. THE PIXHAWK OPEN-SOURCE COMPUTER VISION FRAMEWORK FOR MAVS

    Directory of Open Access Journals (Sweden)

    L. Meier

    2012-09-01

    Full Text Available Unmanned aerial vehicles (UAV and micro air vehicles (MAV are already intensively used in geodetic applications. State of the art autonomous systems are however geared towards the application area in safe and obstacle-free altitudes greater than 30 meters. Applications at lower altitudes still require a human pilot. A new application field will be the reconstruction of structures and buildings, including the facades and roofs, with semi-autonomous MAVs. Ongoing research in the MAV robotics field is focusing on enabling this system class to operate at lower altitudes in proximity to nearby obstacles and humans. PIXHAWK is an open source and open hardware toolkit for this purpose. The quadrotor design is optimized for onboard computer vision and can connect up to four cameras to its onboard computer. The validity of the system design is shown with a fully autonomous capture flight along a building.

  9. Effects of rearranged vision on event-related lateralizations of the EEG during pointing.

    Science.gov (United States)

    Berndt, Isabelle; Franz, Volker H; Bülthoff, Heinrich H; Gotz, Karl G; Wascher, Edmund

    2005-01-01

    We used event-related lateralizations of the EEG (ERLs) and reversed vision to study visuomotor processing with conflicting proprioceptive and visual information during pointing. Reversed vision decreased arm-related lateralization, probably reflecting the simultaneous activity of left and right arm specific neurons: neurons in the hemisphere contralateral to the observed action were probably activated by visual feedback, neurons in the hemisphere contralateral to the response side by the somatomotor feedback. Lateralization related to the target in parietal cortex increased, indicating that visual to motor transformation in parietal cortex required additional time and resources with reversed vision. A short period of adaptation to an additional lateral displacement of the visual field increased arm-contralateral activity in parietal cortex during the movement. This is in agreement with the, which showed that adaptation to a lateral displacement of the visual field is reflected in increased parietal involvement during pointing.

  10. COMPUTER VISION AND FACE RECOGNITION : Tietokonenäkö ja kasvojentunnistus

    OpenAIRE

    Ballester, Felipe

    2010-01-01

    Computer vision is a rapidly growing field, partly because of the affordable hardware (cameras, processing power) and partly because vision algorithms are starting to mature. This field started with the motivation to study how computers process images and how to apply this knowledge to develop useful programs. The purposes of this study were to give valuable knowledge for those who are interested in computer vision, and to implement a facial recognition application using the OpenCV librar...

  11. Computer vision syndrome: A study of the knowledge, attitudes and practices in Indian Ophthalmologists

    Directory of Open Access Journals (Sweden)

    Bali Jatinder

    2007-01-01

    Full Text Available Purpose: To study the knowledge, attitude and practices (KAP towards computer vision syndrome prevalent in Indian ophthalmologists and to assess whether ′computer use by practitioners′ had any bearing on the knowledge and practices in computer vision syndrome (CVS. Materials and Methods: A random KAP survey was carried out on 300 Indian ophthalmologists using a 34-point spot-questionnaire in January 2005. Results: All the doctors who responded were aware of CVS. The chief presenting symptoms were eyestrain (97.8%, headache (82.1%, tiredness and burning sensation (79.1%, watering (66.4% and redness (61.2%. Ophthalmologists using computers reported that focusing from distance to near and vice versa ( P =0.006, χ2 test, blurred vision at a distance ( P =0.016, χ2 test and blepharospasm ( P =0.026, χ2 test formed part of the syndrome. The main mode of treatment used was tear substitutes. Half of ophthalmologists (50.7% were not prescribing any spectacles. They did not have any preference for any special type of glasses (68.7% or spectral filters. Computer-users were more likely to prescribe sedatives/ anxiolytics ( P = 0.04, χ2 test, spectacles ( P = 0.02, χ2 test and conscious frequent blinking ( P = 0.003, χ2 test than the non-computer-users. Conclusions: All respondents were aware of CVS. Confusion regarding treatment guidelines was observed in both groups. Computer-using ophthalmologists were more informed of symptoms and diagnostic signs but were misinformed about treatment modalities.

  12. Online Graph Completion: Multivariate Signal Recovery in Computer Vision.

    Science.gov (United States)

    Kim, Won Hwa; Jalal, Mona; Hwang, Seongjae; Johnson, Sterling C; Singh, Vikas

    2017-07-01

    The adoption of "human-in-the-loop" paradigms in computer vision and machine learning is leading to various applications where the actual data acquisition (e.g., human supervision) and the underlying inference algorithms are closely interwined. While classical work in active learning provides effective solutions when the learning module involves classification and regression tasks, many practical issues such as partially observed measurements, financial constraints and even additional distributional or structural aspects of the data typically fall outside the scope of this treatment. For instance, with sequential acquisition of partial measurements of data that manifest as a matrix (or tensor), novel strategies for completion (or collaborative filtering) of the remaining entries have only been studied recently. Motivated by vision problems where we seek to annotate a large dataset of images via a crowdsourced platform or alternatively, complement results from a state-of-the-art object detector using human feedback, we study the "completion" problem defined on graphs, where requests for additional measurements must be made sequentially. We design the optimization model in the Fourier domain of the graph describing how ideas based on adaptive submodularity provide algorithms that work well in practice. On a large set of images collected from Imgur, we see promising results on images that are otherwise difficult to categorize. We also show applications to an experimental design problem in neuroimaging.

  13. Automated cutting in the food industry using computer vision

    KAUST Repository

    Daley, Wayne D R

    2012-01-01

    The processing of natural products has posed a significant problem to researchers and developers involved in the development of automation. The challenges have come from areas such as sensing, grasping and manipulation, as well as product-specific areas such as cutting and handling of meat products. Meat products are naturally variable and fixed automation is at its limit as far as its ability to accommodate these products. Intelligent automation systems (such as robots) are also challenged, mostly because of a lack of knowledge of the physical characteristic of the individual products. Machine vision has helped to address some of these shortcomings but underperforms in many situations. Developments in sensors, software and processing power are now offering capabilities that will help to make more of these problems tractable. In this chapter we will describe some of the developments that are underway in terms of computer vision for meat product applications, the problems they are addressing and potential future trends. © 2012 Woodhead Publishing Limited All rights reserved.

  14. Convolutional Deep Belief Networks for Single-Cell/Object Tracking in Computational Biology and Computer Vision

    OpenAIRE

    Zhong, Bineng; Pan, Shengnan; Zhang, Hongbo; Wang, Tian; Du, Jixiang; Chen, Duansheng; Cao, Liujuan

    2016-01-01

    In this paper, we propose deep architecture to dynamically learn the most discriminative features from data for both single-cell and object tracking in computational biology and computer vision. Firstly, the discriminative features are automatically learned via a convolutional deep belief network (CDBN). Secondly, we design a simple yet effective method to transfer features learned from CDBNs on the source tasks for generic purpose to the object tracking tasks using only limited amount of tra...

  15. Computer vision techniques for the diagnosis of skin cancer

    CERN Document Server

    Celebi, M

    2014-01-01

    The goal of this volume is to summarize the state-of-the-art in the utilization of computer vision techniques in the diagnosis of skin cancer. Malignant melanoma is one of the most rapidly increasing cancers in the world. Early diagnosis is particularly important since melanoma can be cured with a simple excision if detected early. In recent years, dermoscopy has proved valuable in visualizing the morphological structures in pigmented lesions. However, it has also been shown that dermoscopy is difficult to learn and subjective. Newer technologies such as infrared imaging, multispectral imaging, and confocal microscopy, have recently come to the forefront in providing greater diagnostic accuracy. These imaging technologies presented in this book can serve as an adjunct to physicians and  provide automated skin cancer screening. Although computerized techniques cannot as yet provide a definitive diagnosis, they can be used to improve biopsy decision-making as well as early melanoma detection, especially for pa...

  16. Computer vision techniques for rotorcraft low-altitude flight

    Science.gov (United States)

    Sridhar, Banavar; Cheng, Victor H. L.

    1988-01-01

    A description is given of research that applies techniques from computer vision to automation of rotorcraft navigation. The effort emphasizes the development of a methodology for detecting the ranges to obstacles in the region of interest based on the maximum utilization of passive sensors. The range map derived from the obstacle detection approach can be used as obstacle data for the obstacle avoidance in an automataic guidance system and as advisory display to the pilot. The lack of suitable flight imagery data, however, presents a problem in the verification of concepts for obstacle detection. This problem is being addressed by the development of an adequate flight database and by preprocessing of currently available flight imagery. Some comments are made on future work and how research in this area relates to the guidance of other autonomous vehicles.

  17. Jet-images: computer vision inspired techniques for jet tagging

    Energy Technology Data Exchange (ETDEWEB)

    Cogan, Josh; Kagan, Michael; Strauss, Emanuel; Schwarztman, Ariel [SLAC National Accelerator Laboratory,Menlo Park, CA 94028 (United States)

    2015-02-18

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon-initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  18. Jet-images: computer vision inspired techniques for jet tagging

    International Nuclear Information System (INIS)

    Cogan, Josh; Kagan, Michael; Strauss, Emanuel; Schwarztman, Ariel

    2015-01-01

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon-initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  19. Topics in medical image processing and computational vision

    CERN Document Server

    Jorge, Renato

    2013-01-01

      The sixteen chapters included in this book were written by invited experts of international recognition and address important issues in Medical Image Processing and Computational Vision, including: Object Recognition, Object Detection, Object Tracking, Pose Estimation, Facial Expression Recognition, Image Retrieval, Data Mining, Automatic Video Understanding and Management, Edges Detection, Image Segmentation, Modelling and Simulation, Medical thermography, Database Systems, Synthetic Aperture Radar and Satellite Imagery.   Different applications are addressed and described throughout the book, comprising: Object Recognition and Tracking, Facial Expression Recognition, Image Database, Plant Disease Classification, Video Understanding and Management, Image Processing, Image Segmentation, Bio-structure Modelling and Simulation, Medical Imaging, Image Classification, Medical Diagnosis, Urban Areas Classification, Land Map Generation.   The book brings together the current state-of-the-art in the various mul...

  20. Iris features-based heart disease diagnosis by computer vision

    Science.gov (United States)

    Nguchu, Benedictor A.; Li, Li

    2017-07-01

    The study takes advantage of several new breakthroughs in computer vision technology to develop a new mid-irisbiomedical platform that processes iris image for early detection of heart-disease. Guaranteeing early detection of heart disease provides a possibility of having non-surgical treatment as suggested by biomedical researchers and associated institutions. However, our observation discovered that, a clinical practicable solution which could be both sensible and specific for early detection is still lacking. Due to this, the rate of majority vulnerable to death is highly increasing. The delayed diagnostic procedures, inefficiency, and complications of available methods are the other reasons for this catastrophe. Therefore, this research proposes the novel IFB (Iris Features Based) method for diagnosis of premature, and early stage heart disease. The method incorporates computer vision and iridology to obtain a robust, non-contact, nonradioactive, and cost-effective diagnostic tool. The method analyzes abnormal inherent weakness in tissues, change in color and patterns, of a specific region of iris that responds to impulses of heart organ as per Bernard Jensen-iris Chart. The changes in iris infer the presence of degenerative abnormalities in heart organ. These changes are precisely detected and analyzed by IFB method that includes, tensor-based-gradient(TBG), multi orientations gabor filters(GF), textural oriented features(TOF), and speed-up robust features(SURF). Kernel and Multi class oriented support vector machines classifiers are used for classifying normal and pathological iris features. Experimental results demonstrated that the proposed method, not only has better diagnostic performance, but also provides an insight for early detection of other diseases.

  1. Computer and visual display terminals (VDT) vision syndrome (CVDTS).

    Science.gov (United States)

    Parihar, J K S; Jain, Vaibhav Kumar; Chaturvedi, Piyush; Kaushik, Jaya; Jain, Gunjan; Parihar, Ashwini K S

    2016-07-01

    Computer and visual display terminals have become an essential part of modern lifestyle. The use of these devices has made our life simple in household work as well as in offices. However the prolonged use of these devices is not without any complication. Computer and visual display terminals syndrome is a constellation of symptoms ocular as well as extraocular associated with prolonged use of visual display terminals. This syndrome is gaining importance in this modern era because of the widespread use of technologies in day-to-day life. It is associated with asthenopic symptoms, visual blurring, dry eyes, musculoskeletal symptoms such as neck pain, back pain, shoulder pain, carpal tunnel syndrome, psychosocial factors, venous thromboembolism, shoulder tendonitis, and elbow epicondylitis. Proper identification of symptoms and causative factors are necessary for the accurate diagnosis and management. This article focuses on the various aspects of the computer vision display terminals syndrome described in the previous literature. Further research is needed for the better understanding of the complex pathophysiology and management.

  2. Computer-Vision-Assisted Palm Rehabilitation With Supervised Learning.

    Science.gov (United States)

    Vamsikrishna, K M; Dogra, Debi Prosad; Desarkar, Maunendra Sankar

    2016-05-01

    Physical rehabilitation supported by the computer-assisted-interface is gaining popularity among health-care fraternity. In this paper, we have proposed a computer-vision-assisted contactless methodology to facilitate palm and finger rehabilitation. Leap motion controller has been interfaced with a computing device to record parameters describing 3-D movements of the palm of a user undergoing rehabilitation. We have proposed an interface using Unity3D development platform. Our interface is capable of analyzing intermediate steps of rehabilitation without the help of an expert, and it can provide online feedback to the user. Isolated gestures are classified using linear discriminant analysis (DA) and support vector machines (SVM). Finally, a set of discrete hidden Markov models (HMM) have been used to classify gesture sequence performed during rehabilitation. Experimental validation using a large number of samples collected from healthy volunteers reveals that DA and SVM perform similarly while applied on isolated gesture recognition. We have compared the results of HMM-based sequence classification with CRF-based techniques. Our results confirm that both HMM and CRF perform quite similarly when tested on gesture sequences. The proposed system can be used for home-based palm or finger rehabilitation in the absence of experts.

  3. An Application of Computer Vision Systems to Solve the Problem of Unmanned Aerial Vehicle Control

    Directory of Open Access Journals (Sweden)

    Aksenov Alexey Y.

    2014-09-01

    Full Text Available The paper considers an approach for application of computer vision systems to solve the problem of unmanned aerial vehicle control. The processing of images obtained through onboard camera is required for absolute positioning of aerial platform (automatic landing and take-off, hovering etc. used image processing on-board camera. The proposed method combines the advantages of existing systems and gives the ability to perform hovering over a given point, the exact take-off and landing. The limitations of implemented methods are determined and the algorithm is proposed to combine them in order to improve the efficiency.

  4. Hubungan Antara Faktor Risiko Individual Dan Komputer Terhadap Kejadian Computer Vision Syndrome

    OpenAIRE

    Azkadina, Amira; Julianti, Hari Peni; Pramono, Dodik

    2012-01-01

    Background : Computer USAge could cause health complaints called Computer Vision Syndrome (CVS). This syndrome was influenced by individual and computer risk factors. The objective of the study is to identify and to analyze individual and computer factors of Computer Vision Syndrome (CVS).Method : The study was an observational study by using case control method, which was held on May-June 2012 in RSI Sultan Agung, RSUP dr.Kariadi, and Bank Jateng. The samples were 60 people who were chosen b...

  5. The computer vision in the service of safety and reliability in steam generators inspection services

    International Nuclear Information System (INIS)

    Pineiro Fernandez, P.; Garcia Bueno, A.; Cabrera Jordan, E.

    2012-01-01

    The actual computational vision has matured very quickly in the last ten years by facilitating new developments in various areas of nuclear application allowing to automate and simplify processes and tasks, instead or in collaboration with the people and equipment efficiently. The current computer vision (more appropriate than the artificial vision concept) provides great possibilities of also improving in terms of the reliability and safety of NPPS inspection systems.

  6. Blink rate, incomplete blinks and computer vision syndrome.

    Science.gov (United States)

    Portello, Joan K; Rosenfield, Mark; Chu, Christina A

    2013-05-01

    Computer vision syndrome (CVS), a highly prevalent condition, is frequently associated with dry eye disorders. Furthermore, a reduced blink rate has been observed during computer use. The present study examined whether post task ocular and visual symptoms are associated with either a decreased blink rate or a higher prevalence of incomplete blinks. An additional trial tested whether increasing the blink rate would reduce CVS symptoms. Subjects (N = 21) were required to perform a continuous 15-minute reading task on a desktop computer at a viewing distance of 50 cm. Subjects were videotaped during the task to determine their blink rate and amplitude. Immediately after the task, subjects completed a questionnaire regarding ocular symptoms experienced during the trial. In a second session, the blink rate was increased by means of an audible tone that sounded every 4 seconds, with subjects being instructed to blink on hearing the tone. The mean blink rate during the task without the audible tone was 11.6 blinks per minute (SD, 7.84). The percentage of blinks deemed incomplete for each subject ranged from 0.9 to 56.5%, with a mean of 16.1% (SD, 15.7). A significant positive correlation was observed between the total symptom score and the percentage of incomplete blinks during the task (p = 0.002). Furthermore, a significant negative correlation was noted between the blink score and symptoms (p = 0.035). Increasing the mean blink rate to 23.5 blinks per minute by means of the audible tone did not produce a significant change in the symptom score. Whereas CVS symptoms are associated with a reduced blink rate, the completeness of the blink may be equally significant. Because instructing a patient to increase his or her blink rate may be ineffective or impractical, actions to achieve complete corneal coverage during blinking may be more helpful in alleviating symptoms during computer operation.

  7. Experiences Using an Open Source Software Library to Teach Computer Vision Subjects

    Science.gov (United States)

    Cazorla, Miguel; Viejo, Diego

    2015-01-01

    Machine vision is an important subject in computer science and engineering degrees. For laboratory experimentation, it is desirable to have a complete and easy-to-use tool. In this work we present a Java library, oriented to teaching computer vision. We have designed and built the library from the scratch with emphasis on readability and…

  8. Particular application of methods of AdaBoost and LBP to the problems of computer vision

    OpenAIRE

    Волошин, Микола Володимирович

    2012-01-01

    The application of AdaBoost method and local binary pattern (LBP) method for different spheres of computer vision implementation, such as personality identification and computer iridology, is considered in the article. The goal of the research is to develop error-correcting methods and systems for implements of computer vision and computer iridology, in particular. This article considers the problem of colour spaces, which are used as a filter and as a pre-processing of images. Method of AdaB...

  9. Deep hierarchies in the primate visual cortex: what can we learn for computer vision?

    Science.gov (United States)

    Krüger, Norbert; Janssen, Peter; Kalkan, Sinan; Lappe, Markus; Leonardis, Ales; Piater, Justus; Rodríguez-Sánchez, Antonio J; Wiskott, Laurenz

    2013-08-01

    Computational modeling of the primate visual system yields insights of potential relevance to some of the challenges that computer vision is facing, such as object recognition and categorization, motion detection and activity recognition, or vision-based navigation and manipulation. This paper reviews some functional principles and structures that are generally thought to underlie the primate visual cortex, and attempts to extract biological principles that could further advance computer vision research. Organized for a computer vision audience, we present functional principles of the processing hierarchies present in the primate visual system considering recent discoveries in neurophysiology. The hierarchical processing in the primate visual system is characterized by a sequence of different levels of processing (on the order of 10) that constitute a deep hierarchy in contrast to the flat vision architectures predominantly used in today's mainstream computer vision. We hope that the functional description of the deep hierarchies realized in the primate visual system provides valuable insights for the design of computer vision algorithms, fostering increasingly productive interaction between biological and computer vision research.

  10. Architecture and VHDL behavioural validation of a parallel processor dedicated to computer vision

    International Nuclear Information System (INIS)

    Collette, Thierry

    1992-01-01

    Speeding up image processing is mainly obtained using parallel computers; SIMD processors (single instruction stream, multiple data stream) have been developed, and have proven highly efficient regarding low-level image processing operations. Nevertheless, their performances drop for most intermediate of high level operations, mainly when random data reorganisations in processor memories are involved. The aim of this thesis was to extend the SIMD computer capabilities to allow it to perform more efficiently at the image processing intermediate level. The study of some representative algorithms of this class, points out the limits of this computer. Nevertheless, these limits can be erased by architectural modifications. This leads us to propose SYMPATIX, a new SIMD parallel computer. To valid its new concept, a behavioural model written in VHDL - Hardware Description Language - has been elaborated. With this model, the new computer performances have been estimated running image processing algorithm simulations. VHDL modeling approach allows to perform the system top down electronic design giving an easy coupling between system architectural modifications and their electronic cost. The obtained results show SYMPATIX to be an efficient computer for low and intermediate level image processing. It can be connected to a high level computer, opening up the development of new computer vision applications. This thesis also presents, a top down design method, based on the VHDL, intended for electronic system architects. (author) [fr

  11. Computer Vision Research and Its Applications to Automated Cartography

    Science.gov (United States)

    1984-09-01

    Imaging Geometry from a Camera Transformation Matrix. Many scene analysis algorithms require knowledge of the geometry of the image formation process as a...to compute the imaging geometry directly from the constraints provided by the known data points. Partial information such as the camera’s focal length...Artificial Infelli- 1 fence 4, 1973, 121-137. 8. Kanade, T., A theory of origami world, Artificial Intelligence 13, 1080, 270-311. 0. Barnard, S. T

  12. Selection of Norway spruce somatic embryos by computer vision

    Science.gov (United States)

    Hamalainen, Jari J.; Jokinen, Kari J.

    1993-05-01

    A computer vision system was developed for the classification of plant somatic embryos. The embryos are in a Petri dish that is transferred with constant speed and they are recognized as they pass a line scan camera. A classification algorithm needs to be installed for every plant species. This paper describes an algorithm for the recognition of Norway spruce (Picea abies) embryos. A short review of conifer micropropagation by somatic embryogenesis is also given. The recognition algorithm is based on features calculated from the boundary of the object. Only part of the boundary corresponding to the developing cotyledons (2 - 15) and the straight sides of the embryo are used for recognition. An index of the length of the cotyledons describes the developmental stage of the embryo. The testing set for classifier performance consisted of 118 embryos and 478 nonembryos. With the classification tolerances chosen 69% of the objects classified as embryos by a human classifier were selected and 31$% rejected. Less than 1% of the nonembryos were classified as embryos. The basic features developed can probably be easily adapted for the recognition of other conifer somatic embryos.

  13. A computer vision based candidate for functional balance test.

    Science.gov (United States)

    Nalci, Alican; Khodamoradi, Alireza; Balkan, Ozgur; Nahab, Fatta; Garudadri, Harinath

    2015-08-01

    Balance in humans is a motor skill based on complex multimodal sensing, processing and control. Ability to maintain balance in activities of daily living (ADL) is compromised due to aging, diseases, injuries and environmental factors. Center for Disease Control and Prevention (CDC) estimate of the costs of falls among older adults was $34 billion in 2013 and is expected to reach $54.9 billion in 2020. In this paper, we present a brief review of balance impairments followed by subjective and objective tools currently used in clinical settings for human balance assessment. We propose a novel computer vision (CV) based approach as a candidate for functional balance test. The test will take less than a minute to administer and expected to be objective, repeatable and highly discriminative in quantifying ability to maintain posture and balance. We present an informal study with preliminary data from 10 healthy volunteers, and compare performance with a balance assessment system called BTrackS Balance Assessment Board. Our results show high degree of correlation with BTrackS. The proposed system promises to be a good candidate for objective functional balance tests and warrants further investigations to assess validity in clinical settings, including acute care, long term care and assisted living care facilities. Our long term goals include non-intrusive approaches to assess balance competence during ADL in independent living environments.

  14. Computer Vision Malaria Diagnostic Systems—Progress and Prospects

    Directory of Open Access Journals (Sweden)

    Joseph Joel Pollak

    2017-08-01

    Full Text Available Accurate malaria diagnosis is critical to prevent malaria fatalities, curb overuse of antimalarial drugs, and promote appropriate management of other causes of fever. While several diagnostic tests exist, the need for a rapid and highly accurate malaria assay remains. Microscopy and rapid diagnostic tests are the main diagnostic modalities available, yet they can demonstrate poor performance and accuracy. Automated microscopy platforms have the potential to significantly improve and standardize malaria diagnosis. Based on image recognition and machine learning algorithms, these systems maintain the benefits of light microscopy and provide improvements such as quicker scanning time, greater scanning area, and increased consistency brought by automation. While these applications have been in development for over a decade, recently several commercial platforms have emerged. In this review, we discuss the most advanced computer vision malaria diagnostic technologies and investigate several of their features which are central to field use. Additionally, we discuss the technological and policy barriers to implementing these technologies in low-resource settings world-wide.

  15. A Computer Vision Approach to Identify Einstein Rings and Arcs

    Science.gov (United States)

    Lee, Chien-Hsiu

    2017-03-01

    Einstein rings are rare gems of strong lensing phenomena; the ring images can be used to probe the underlying lens gravitational potential at every position angles, tightly constraining the lens mass profile. In addition, the magnified images also enable us to probe high-z galaxies with enhanced resolution and signal-to-noise ratios. However, only a handful of Einstein rings have been reported, either from serendipitous discoveries or or visual inspections of hundred thousands of massive galaxies or galaxy clusters. In the era of large sky surveys, an automated approach to identify ring pattern in the big data to come is in high demand. Here, we present an Einstein ring recognition approach based on computer vision techniques. The workhorse is the circle Hough transform that recognise circular patterns or arcs in the images. We propose a two-tier approach by first pre-selecting massive galaxies associated with multiple blue objects as possible lens, than use Hough transform to identify circular pattern. As a proof-of-concept, we apply our approach to SDSS, with a high completeness, albeit with low purity. We also apply our approach to other lenses in DES, HSC-SSP, and UltraVISTA survey, illustrating the versatility of our approach.

  16. Identification of double-yolked duck egg using computer vision.

    Directory of Open Access Journals (Sweden)

    Long Ma

    Full Text Available The double-yolked (DY egg is quite popular in some Asian countries because it is considered as a sign of good luck, however, the double yolk is one of the reasons why these eggs fail to hatch. The usage of automatic methods for identifying DY eggs can increase the efficiency in the poultry industry by decreasing egg loss during incubation or improving sale proceeds. In this study, two methods for DY duck egg identification were developed by using computer vision technology. Transmittance images of DY and single-yolked (SY duck eggs were acquired by a CCD camera to identify them according to their shape features. The Fisher's linear discriminant (FLD model equipped with a set of normalized Fourier descriptors (NFDs extracted from the acquired images and the convolutional neural network (CNN model using primary preprocessed images were built to recognize duck egg yolk types. The classification accuracies of the FLD model for SY and DY eggs were 100% and 93.2% respectively, while the classification accuracies of the CNN model for SY and DY eggs were 98% and 98.8% respectively. The CNN-based algorithm took about 0.12 s to recognize one sample image, which was slightly faster than the FLD-based (about 0.20 s. Finally, this work compared two classification methods and provided the better method for DY egg identification.

  17. Uranus: a rapid prototyping tool for FPGA embedded computer vision

    Science.gov (United States)

    Rosales-Hernández, Victor; Castillo-Jimenez, Liz; Viveros-Velez, Gilberto; Zuñiga-Grajeda, Virgilio; Treviño Torres, Abel; Arias-Estrada, M.

    2007-01-01

    The starting point for all successful system development is the simulation. Performing high level simulation of a system can help to identify, insolate and fix design problems. This work presents Uranus, a software tool for simulation and evaluation of image processing algorithms with support to migrate them to an FPGA environment for algorithm acceleration and embedded processes purposes. The tool includes an integrated library of previous coded operators in software and provides the necessary support to read and display image sequences as well as video files. The user can use the previous compiled soft-operators in a high level process chain, and code his own operators. Additional to the prototyping tool, Uranus offers FPGA-based hardware architecture with the same organization as the software prototyping part. The hardware architecture contains a library of FPGA IP cores for image processing that are connected with a PowerPC based system. The Uranus environment is intended for rapid prototyping of machine vision and the migration to FPGA accelerator platform, and it is distributed for academic purposes.

  18. Convolutional Deep Belief Networks for Single-Cell/Object Tracking in Computational Biology and Computer Vision.

    Science.gov (United States)

    Zhong, Bineng; Pan, Shengnan; Zhang, Hongbo; Wang, Tian; Du, Jixiang; Chen, Duansheng; Cao, Liujuan

    2016-01-01

    In this paper, we propose deep architecture to dynamically learn the most discriminative features from data for both single-cell and object tracking in computational biology and computer vision. Firstly, the discriminative features are automatically learned via a convolutional deep belief network (CDBN). Secondly, we design a simple yet effective method to transfer features learned from CDBNs on the source tasks for generic purpose to the object tracking tasks using only limited amount of training data. Finally, to alleviate the tracker drifting problem caused by model updating, we jointly consider three different types of positive samples. Extensive experiments validate the robustness and effectiveness of the proposed method.

  19. Application of Computer Vision Methods and Algorithms in Documentation of Cultural Heritage

    Directory of Open Access Journals (Sweden)

    David Káňa

    2012-12-01

    Full Text Available The main task of this paper is to describe methods and algorithms used in computer vision for fully automatic reconstruction of exterior orientation in ordered and unordered sets of images captured by digital calibrated cameras without prior informations about camera positions or scene structure. Attention will be paid to the SIFT interest operator for finding key points clearly describing the image areas with respect to scale and rotation, so that these areas could be compared to the regions in other images. There will also be discussed methods of matching key points, calculation of the relative orientation and strategy of linking sub-models to estimate the parameters entering complex bundle adjustment. The paper also compares the results achieved with above system with the results obtained by standard photogrammetric methods in processing of project documentation for reconstruction of the Žinkovy castle.

  20. Computer Vision Syndrome and Associated Factors Among Medical and Engineering Students in Chennai

    OpenAIRE

    Logaraj, M; Madhupriya, V; Hegde, SK

    2014-01-01

    Background: Almost all institutions, colleges, universities and homes today were using computer regularly. Very little research has been carried out on Indian users especially among college students the effects of computer use on the eye and vision related problems. Aim: The aim of this study was to assess the prevalence of computer vision syndrome (CVS) among medical and engineering students and the factors associated with the same. Subjects and Methods: A cross-sectional study was conducted...

  1. Deep Hierarchies in the Primate Visual Cortex: What Can We Learn for Computer Vision?

    OpenAIRE

    Kruger, Norbert; Janssen, Peter; Kalkan, Sinan; Lappe, Markus; Leonardis, Ales; Piater, Justus; Rodriguez-Sanchez, Antonio J.; Wiskott, Laurenz

    2013-01-01

    Computational modeling of the primate visual system yields insights of potential relevance to some of the challenges that computer vision is facing, such as object recognition and categorization, motion detection and activity recognition or vision-based navigation and manipulation. This article reviews some functional principles and structures that are generally thought to underlie the primate visual cortex, and attempts to extract biological principles that could further advance computer ...

  2. Dynamic Programming and Graph Algorithms in Computer Vision*

    Science.gov (United States)

    Felzenszwalb, Pedro F.; Zabih, Ramin

    2013-01-01

    Optimization is a powerful paradigm for expressing and solving problems in a wide range of areas, and has been successfully applied to many vision problems. Discrete optimization techniques are especially interesting, since by carefully exploiting problem structure they often provide non-trivial guarantees concerning solution quality. In this paper we briefly review dynamic programming and graph algorithms, and discuss representative examples of how these discrete optimization techniques have been applied to some classical vision problems. We focus on the low-level vision problem of stereo; the mid-level problem of interactive object segmentation; and the high-level problem of model-based recognition. PMID:20660950

  3. Application of the SP theory of intelligence to the understanding of natural vision and the development of computer vision.

    Science.gov (United States)

    Wolff, J Gerard

    2014-01-01

    The SP theory of intelligence aims to simplify and integrate concepts in computing and cognition, with information compression as a unifying theme. This article is about how the SP theory may, with advantage, be applied to the understanding of natural vision and the development of computer vision. Potential benefits include an overall simplification of concepts in a universal framework for knowledge and seamless integration of vision with other sensory modalities and other aspects of intelligence. Low level perceptual features such as edges or corners may be identified by the extraction of redundancy in uniform areas in the manner of the run-length encoding technique for information compression. The concept of multiple alignment in the SP theory may be applied to the recognition of objects, and to scene analysis, with a hierarchy of parts and sub-parts, at multiple levels of abstraction, and with family-resemblance or polythetic categories. The theory has potential for the unsupervised learning of visual objects and classes of objects, and suggests how coherent concepts may be derived from fragments. As in natural vision, both recognition and learning in the SP system are robust in the face of errors of omission, commission and substitution. The theory suggests how, via vision, we may piece together a knowledge of the three-dimensional structure of objects and of our environment, it provides an account of how we may see things that are not objectively present in an image, how we may recognise something despite variations in the size of its retinal image, and how raster graphics and vector graphics may be unified. And it has things to say about the phenomena of lightness constancy and colour constancy, the role of context in recognition, ambiguities in visual perception, and the integration of vision with other senses and other aspects of intelligence.

  4. Learning openCV computer vision with the openCV library

    CERN Document Server

    Bradski, Gary

    2008-01-01

    Learning OpenCV puts you right in the middle of the rapidly expanding field of computer vision. Written by the creators of OpenCV, the widely used free open-source library, this book introduces you to computer vision and demonstrates how you can quickly build applications that enable computers to see" and make decisions based on the data. With this book, any developer or hobbyist can get up and running with the framework quickly, whether it's to build simple or sophisticated vision applications

  5. Computational Biology and the Limits of Shared Vision

    DEFF Research Database (Denmark)

    Carusi, Annamaria

    2011-01-01

    of cases is necessary in order to gain a better perspective on social sharing of practices, and on what other factors this sharing is dependent upon. The article presents the case of currently emerging inter-disciplinary visual practices in the domain of computational biology, where the sharing of visual...... practices would be beneficial to the collaborations necessary for the research. Computational biology includes sub-domains where visual practices are coming to be shared across disciplines, and those where this is not occurring, and where the practices of others are resisted. A significant point......, its domain of study. Social practices alone are not sufficient to account for the shaping of evidence. The philosophy of Merleau-Ponty is introduced as providing an alternative framework for thinking of the complex inter-relations between all of these factors. This [End Page 300] philosophy enables us...

  6. Computer Use and Vision.Related Problems Among University ...

    African Journals Online (AJOL)

    Related Problems Among University Students In Ajman, United Arab Emirate. ... of 500 Students studying in Gulf Medical University, Ajman and Ajman University of ... prevalence of vision related problems was noted among university students.

  7. Automated cutting in the food industry using computer vision

    KAUST Repository

    Daley, Wayne D R; Arif, Omar

    2012-01-01

    , mostly because of a lack of knowledge of the physical characteristic of the individual products. Machine vision has helped to address some of these shortcomings but underperforms in many situations. Developments in sensors, software and processing power

  8. Measurement of meat color using a computer vision system.

    Science.gov (United States)

    Girolami, Antonio; Napolitano, Fabio; Faraone, Daniela; Braghieri, Ada

    2013-01-01

    The limits of the colorimeter and a technique of image analysis in evaluating the color of beef, pork, and chicken were investigated. The Minolta CR-400 colorimeter and a computer vision system (CVS) were employed to measure colorimetric characteristics. To evaluate the chromatic fidelity of the image of the sample displayed on the monitor, a similarity test was carried out using a trained panel. The panelists found the digital images of the samples visualized on the monitor very similar to the actual ones (Pmeat sample and the sample image on the monitor in order to evaluate the similarity between them (test A). Moreover, the panelists were asked to evaluate the similarity between two colors, both generated by the software Adobe Photoshop CS3 one using the L, a and b values read by the colorimeter and the other obtained using the CVS (test B); which of the two colors was more similar to the sample visualized on the monitor was also assessed (test C). The panelists found the digital images very similar to the actual samples (Pcolors the panelists found significant differences between them (Pcolor of the sample on the monitor was more similar to the CVS generated color than to the colorimeter generated color. The differences between the values of the L, a, b, hue angle and chroma obtained with the CVS and the colorimeter were statistically significant (Pcolor of meat. Instead, the CVS method seemed to give valid measurements that reproduced a color very similar to the real one. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Computer vision techniques for rotorcraft low altitude flight

    Science.gov (United States)

    Sridhar, Banavar

    1990-01-01

    Rotorcraft operating in high-threat environments fly close to the earth's surface to utilize surrounding terrain, vegetation, or manmade objects to minimize the risk of being detected by an enemy. Increasing levels of concealment are achieved by adopting different tactics during low-altitude flight. Rotorcraft employ three tactics during low-altitude flight: low-level, contour, and nap-of-the-earth (NOE). The key feature distinguishing the NOE mode from the other two modes is that the whole rotorcraft, including the main rotor, is below tree-top whenever possible. This leads to the use of lateral maneuvers for avoiding obstacles, which in fact constitutes the means for concealment. The piloting of the rotorcraft is at best a very demanding task and the pilot will need help from onboard automation tools in order to devote more time to mission-related activities. The development of an automation tool which has the potential to detect obstacles in the rotorcraft flight path, warn the crew, and interact with the guidance system to avoid detected obstacles, presents challenging problems. Research is described which applies techniques from computer vision to automation of rotorcraft navigtion. The effort emphasizes the development of a methodology for detecting the ranges to obstacles in the region of interest based on the maximum utilization of passive sensors. The range map derived from the obstacle-detection approach can be used as obstacle data for the obstacle avoidance in an automatic guidance system and as advisory display to the pilot. The lack of suitable flight imagery data presents a problem in the verification of concepts for obstacle detection. This problem is being addressed by the development of an adequate flight database and by preprocessing of currently available flight imagery. The presentation concludes with some comments on future work and how research in this area relates to the guidance of other autonomous vehicles.

  10. PENGEMBANGAN COMPUTER VISION SYSTEM SEDERHANA UNTUK MENENTUKAN KUALITAS TOMAT Development of a simple Computer Vision System to determine tomato quality

    Directory of Open Access Journals (Sweden)

    Rudiati Evi Masithoh

    2012-05-01

    Full Text Available The purpose of this research was to develop a simple computer vision system (CVS to non-destructively measure tomato quality based on its Red Gren Blue (RGB color parameter. Tomato quality parameters measured were Brix, citric acid, vitamin C, and total sugar. This system consisted of a box to place object, a webcam to capture images, a computer to process images, illumination system, and an image analysis software which was equipped with artificial neural networks technique for determining tomato quality. Network architecture was formed with 3 layers consisting of1 input layer with 3 input neurons, 1 hidden layer with 14 neurons using logsig activation function, and 5 output layers using purelin activation function by using backpropagation training algorithm. CVS developed was able to predict the quality parameters of a Brix value, vitamin C, citric acid, and total sugar. To obtain the predicted values which were equal or close to the actual values, a calibration model was required. For Brix value, the actual value obtained from the equation y = 12,16x – 26,46, with x was Brix predicted. The actual values of vitamin C, citric acid, and total sugar were obtained from y = 1,09x - 3.13, y = 7,35x – 19,44,  and  y = 1.58x – 0,18,, with x was the value of vitamin C, citric acid, and total sugar, respectively. ABSTRAK Tujuan penelitian adalah mengembangkan computer vision system (CVS sederhana untuk menentukan kualitas tomat secara non­destruktif berdasarkan parameter warna Red Green Blue (RGB. Parameter kualitas tomat yang diukur ada­ lah Brix, asam sitrat, vitamin C, dan gula total. Sistem ini terdiri peralatan utama yaitu kotak untuk meletakkan obyek, webcam untuk menangkap citra, komputer untuk mengolah data, sistem penerangan, dan perangkat lunak analisis citra yang dilengkapi dengan jaringan syaraf tiruan untuk menentukan kualitas tomat. Arsitektur jaringan dibentuk dengan3 lapisan yang terdiri dari 1 lapisan masukan dengan 3 sel

  11. Crossing the divide between computer vision and data bases in search of image data bases

    NARCIS (Netherlands)

    Worring, M.; Smeulders, A.W.M.; Ioannidis, Y.; Klas, W.

    1998-01-01

    Image databases call upon the combined effort of computing vision and database technology to advance beyond exemplary systems. In this paper we charter several areas for mutually beneficial research activities and provide an architectural design to accommodate it.

  12. Reconfigurable FPGA architecture for computer vision applications in Smart Camera Networks

    OpenAIRE

    Maggiani , Luca; Salvadori , Claudio; Petracca , Matteo; Pagano , Paolo; Saletti , Roberto

    2013-01-01

    International audience; Smart Camera Networks (SCNs) is nowadays an emerging research field which represents the natural evolution of centralized computer vision applications towards full distributed and pervasive systems. In such a scenario, one of the biggest effort is in the definition of a flexible and reconfigurable SCN node architecture able to remotely support the possibility of updating the application parameters and changing the running computer vision applications at run-time. In th...

  13. On quaternion based parameterization of orientation in computer vision and robotics

    Directory of Open Access Journals (Sweden)

    G. Terzakis

    2014-04-01

    Full Text Available The problem of orientation parameterization for applications in computer vision and robotics is examined in detail herein. The necessary intuition and formulas are provided for direct practical use in any existing algorithm that seeks to minimize a cost function in an iterative fashion. Two distinct schemes of parameterization are analyzed: The first scheme concerns the traditional axis-angle approach, while the second employs stereographic projection from unit quaternion sphere to the 3D real projective space. Performance measurements are taken and a comparison is made between the two approaches. Results suggests that there exist several benefits in the use of stereographic projection that include rational expressions in the rotation matrix derivatives, improved accuracy, robustness to random starting points and accelerated convergence.

  14. Distance estimation by computer vision and shortest path planning ...

    African Journals Online (AJOL)

    Journal Home > Vol 10, No 6S (2018) > ... The proposed way also detects and avoids obstacles in an environment using a single ... This paper has a great importance because of its fast execution speed also vision is a smart sensor as it helps ...

  15. Advantages of computer cameras over video cameras/frame grabbers for high-speed vision applications

    Science.gov (United States)

    Olson, Gaylord G.; Walker, Jo N.

    1997-09-01

    Cameras designed to work specifically with computers can have certain advantages in comparison to the use of cameras loosely defined as 'video' cameras. In recent years the camera type distinctions have become somewhat blurred, with a great presence of 'digital cameras' aimed more at the home markets. This latter category is not considered here. The term 'computer camera' herein is intended to mean one which has low level computer (and software) control of the CCD clocking. These can often be used to satisfy some of the more demanding machine vision tasks, and in some cases with a higher rate of measurements than video cameras. Several of these specific applications are described here, including some which use recently designed CCDs which offer good combinations of parameters such as noise, speed, and resolution. Among the considerations for the choice of camera type in any given application would be such effects as 'pixel jitter,' and 'anti-aliasing.' Some of these effects may only be relevant if there is a mismatch between the number of pixels per line in the camera CCD and the number of analog to digital (A/D) sampling points along a video scan line. For the computer camera case these numbers are guaranteed to match, which alleviates some measurement inaccuracies and leads to higher effective resolution.

  16. Smartphone, tablet computer and e-reader use by people with vision impairment.

    Science.gov (United States)

    Crossland, Michael D; Silva, Rui S; Macedo, Antonio F

    2014-09-01

    Consumer electronic devices such as smartphones, tablet computers, and e-book readers have become far more widely used in recent years. Many of these devices contain accessibility features such as large print and speech. Anecdotal experience suggests people with vision impairment frequently make use of these systems. Here we survey people with self-identified vision impairment to determine their use of this equipment. An internet-based survey was advertised to people with vision impairment by word of mouth, social media, and online. Respondents were asked demographic information, what devices they owned, what they used these devices for, and what accessibility features they used. One hundred and thirty-two complete responses were received. Twenty-six percent of the sample reported that they had no vision and the remainder reported they had low vision. One hundred and seven people (81%) reported using a smartphone. Those with no vision were as likely to use a smartphone or tablet as those with low vision. Speech was found useful by 59% of smartphone users. Fifty-one percent of smartphone owners used the camera and screen as a magnifier. Forty-eight percent of the sample used a tablet computer, and 17% used an e-book reader. The most frequently cited reason for not using these devices included cost and lack of interest. Smartphones, tablet computers, and e-book readers can be used by people with vision impairment. Speech is used by people with low vision as well as those with no vision. Many of our (self-selected) group used their smartphone camera and screen as a magnifier, and others used the camera flash as a spotlight. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

  17. Automatic calibration system of the temperature instrument display based on computer vision measuring

    Science.gov (United States)

    Li, Zhihong; Li, Jinze; Bao, Changchun; Hou, Guifeng; Liu, Chunxia; Cheng, Fang; Xiao, Nianxin

    2010-07-01

    With the development of computers and the techniques of dealing with pictures and computer optical measurement, various measuring techniques are maturing gradually on the basis of optical picture processing technique and using in practice. On the bases, we make use of the many years' experience and social needs in temperature measurement and computer vision measurement to come up with the completely automatic way of the temperature measurement meter with integration of the computer vision measuring technique. It realizes synchronization collection with theory temperature value, improves calibration efficiency. based on least square fitting principle, integrate data procession and the best optimize theory, rapidly and accurately realizes automation acquisition and calibration of temperature.

  18. The computation of fixed points and applications

    CERN Document Server

    Todd, Michael J

    1976-01-01

    Fixed-point algorithms have diverse applications in economics, optimization, game theory and the numerical solution of boundary-value problems. Since Scarf's pioneering work [56,57] on obtaining approximate fixed points of continuous mappings, a great deal of research has been done in extending the applicability and improving the efficiency of fixed-point methods. Much of this work is available only in research papers, although Scarf's book [58] gives a remarkably clear exposition of the power of fixed-point methods. However, the algorithms described by Scarf have been super~eded by the more sophisticated restart and homotopy techniques of Merrill [~8,~9] and Eaves and Saigal [1~,16]. To understand the more efficient algorithms one must become familiar with the notions of triangulation and simplicial approxi- tion, whereas Scarf stresses the concept of primitive set. These notes are intended to introduce to a wider audience the most recent fixed-point methods and their applications. Our approach is therefore ...

  19. Precision of Points Computed from Intersections of Lines or Planes

    DEFF Research Database (Denmark)

    Cederholm, Jens Peter

    2004-01-01

    estimates the precision of the points. When using laser scanning a similar problem appears. A laser scanner captures a 3-D point cloud, not the points of real interest. The suggested method can be used to compute three-dimensional coordinates of the intersection of three planes estimated from the point...

  20. A CLINICAL STUDY TO EVALUATE THE ROLE OF AKSHITARPANA, SHIRODHARA AND AN AYURVEDIC COMPOUND IN CHILDHOOD COMPUTER VISION SYNDROME

    OpenAIRE

    Singh Omendra Pal; Singh Laxmi; Kumar Abhimanyu

    2011-01-01

    Computer vision syndrome is one among the lifestyle disorders in children. About 88% of people who use computers everyday suffer from this problem and children are no exception. Computer Vision Syndrome (CVS) is the complex of eye and vision problems related to near works which are experienced during the use of Video Display Terminals (TV and computers). Therefore, considering these prospects a randomized double blind placebo control study was conducted among 40 clinically diagnosed children ...

  1. Automatic Plant Annotation Using 3D Computer Vision

    DEFF Research Database (Denmark)

    Nielsen, Michael

    In this thesis 3D reconstruction was investigated for application in precision agriculture where previous work focused on low resolution index maps where each pixel represents an area in the field and the index represents an overall crop status in that area. 3D reconstructions of plants would allow...... reconstruction in occluded areas. The trinocular setup was used for both window correlation based and energy minimization based algorithms. A novel adaption of symmetric multiple windows algorithm with trinocular vision was developed. The results were promising and allowed for better disparity estimations...... on steep sloped surfaces. Also, a novel adaption of a well known graph cut based disparity estimation algorithm with trinocular vision was developed and tested. The results were successful and allowed for better disparity estimations on steep sloped surfaces. After finding the disparity maps each...

  2. Signal- and Symbol-based Representations in Computer Vision

    DEFF Research Database (Denmark)

    Krüger, Norbert; Felsberg, Michael

    We discuss problems of signal-- and symbol based representations in terms of three dilemmas which are faced in the design of each vision system. Signal- and symbol-based representations are opposite ends of a spectrum of conceivable design decisions caught at opposite sides of the dilemmas. We make...... inherent problems explicit and describe potential design decisions for artificial visual systems to deal with the dilemmas....

  3. A reliable and valid questionnaire was developed to measure computer vision syndrome at the workplace.

    Science.gov (United States)

    Seguí, María del Mar; Cabrero-García, Julio; Crespo, Ana; Verdú, José; Ronda, Elena

    2015-06-01

    To design and validate a questionnaire to measure visual symptoms related to exposure to computers in the workplace. Our computer vision syndrome questionnaire (CVS-Q) was based on a literature review and validated through discussion with experts and performance of a pretest, pilot test, and retest. Content validity was evaluated by occupational health, optometry, and ophthalmology experts. Rasch analysis was used in the psychometric evaluation of the questionnaire. Criterion validity was determined by calculating the sensitivity and specificity, receiver operator characteristic curve, and cutoff point. Test-retest repeatability was tested using the intraclass correlation coefficient (ICC) and concordance by Cohen's kappa (κ). The CVS-Q was developed with wide consensus among experts and was well accepted by the target group. It assesses the frequency and intensity of 16 symptoms using a single rating scale (symptom severity) that fits the Rasch rating scale model well. The questionnaire has sensitivity and specificity over 70% and achieved good test-retest repeatability both for the scores obtained [ICC = 0.802; 95% confidence interval (CI): 0.673, 0.884] and CVS classification (κ = 0.612; 95% CI: 0.384, 0.839). The CVS-Q has acceptable psychometric properties, making it a valid and reliable tool to control the visual health of computer workers, and can potentially be used in clinical trials and outcome research. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Rehabilitation of patients with motor disabilities using computer vision based techniques

    Directory of Open Access Journals (Sweden)

    Alejandro Reyes-Amaro

    2012-05-01

    Full Text Available In this paper we present details about the implementation of computer vision based applications for the rehabilitation of patients with motor disabilities. The applications are conceived as serious games, where the computer-patient interaction during playing contributes to the development of different motor skills. The use of computer vision methods allows the automatic guidance of the patient’s movements making constant specialized supervision unnecessary. The hardware requirements are limited to low-cost devices like usual webcams and Netbooks.

  5. Embedded Platforms for Computer Vision-based Advanced Driver Assistance Systems: a Survey

    OpenAIRE

    Velez, Gorka; Otaegui, Oihana

    2015-01-01

    Computer Vision, either alone or combined with other technologies such as radar or Lidar, is one of the key technologies used in Advanced Driver Assistance Systems (ADAS). Its role understanding and analysing the driving scene is of great importance as it can be noted by the number of ADAS applications that use this technology. However, porting a vision algorithm to an embedded automotive system is still very challenging, as there must be a trade-off between several design requisites. Further...

  6. How to Make Low Vision "Sexy": A Starting Point for Interdisciplinary Student Recruitment

    Science.gov (United States)

    Wittich, Walter; Strong, Graham; Renaud, Judith; Southall, Kenneth

    2007-01-01

    Professionals in the field of low vision are increasingly concerned about the paucity of optometry students who are expressing any interest in low vision as a clinical subspecialty. Concurrent with this apparent disinterest is an increased demand for these services as the baby boomer population becomes more predisposed to age-related vision loss.…

  7. Former food products safety: microbiological quality and computer vision evaluation of packaging remnants contamination.

    Science.gov (United States)

    Tretola, M; Di Rosa, A R; Tirloni, E; Ottoboni, M; Giromini, C; Leone, F; Bernardi, C E M; Dell'Orto, V; Chiofalo, V; Pinotti, L

    2017-08-01

    The use of alternative feed ingredients in farm animal's diets can be an interesting choice from several standpoints, including safety. In this respect, this study investigated the safety features of selected former food products (FFPs) intended for animal nutrition produced in the framework of the IZS PLV 06/14 RC project by an FFP processing plant. Six FFP samples, both mash and pelleted, were analysed for the enumeration of total viable count (TVC) (ISO 4833), Enterobacteriaceae (ISO 21528-1), Escherichia coli (ISO 16649-1), coagulase-positive Staphylococci (CPS) (ISO 6888), presumptive Bacillus cereus and its spores (ISO 7932), sulphite-reducing Clostridia (ISO 7937), yeasts and moulds (ISO 21527-1), and the presence in 25 g of Salmonella spp. (ISO 6579). On the same samples, the presence of undesired ingredients, which can be identified as remnants of packaging materials, was evaluated by two different methods: stereomicroscopy according to published methods; and stereomicroscopy coupled with a computer vision system (IRIS Visual Analyzer VA400). All FFPs analysed were safe from a microbiological point of view. TVC was limited and Salmonella was always absent. When remnants of packaging materials were considered, the contamination level was below 0.08% (w/w). Of note, packaging remnants were found mainly from the 1-mm sieve mesh fractions. Finally, the innovative computer vision system demonstrated the possibility of rapid detection for the presence of packaging remnants in FFPs when combined with a stereomicroscope. In conclusion, the FFPs analysed in the present study can be considered safe, even though some improvements in FFP processing in the feeding plant can be useful in further reducing their microbial loads and impurity.

  8. Head and eye movement as pointing modalities for eyewear computers

    DEFF Research Database (Denmark)

    Jalaliniya, Shahram; Mardanbeigi, Diako; Pederson, Thomas

    2014-01-01

    examined using head and eye movements to point on a graphical user interface of a wearable computer. The performance of users in head and eye pointing has been compared with mouse pointing as a baseline method. The result of our experiment showed that the eye pointing is significantly faster than head......While the new generation of eyewear computers have increased expectations of a wearable computer, providing input to these devices is still challenging. Hand-held devices, voice commands, and hand gestures have already been explored to provide input to the wearable devices. In this paper, we...

  9. Computer vision for automatic inspection of agricultural produce

    Science.gov (United States)

    Molto, Enrique; Blasco, Jose; Benlloch, Jose V.

    1999-01-01

    Fruit and vegetables suffer different manipulations from the field to the final consumer. These are basically oriented towards the cleaning and selection of the product in homogeneous categories. For this reason, several research projects, aimed at fast, adequate produce sorting and quality control are currently under development around the world. Moreover, it is possible to find manual and semi- automatic commercial system capable of reasonably performing these tasks.However, in many cases, their accuracy is incompatible with current European market demands, which are constantly increasing. IVIA, the Valencian Research Institute of Agriculture, located in Spain, has been involved in several European projects related with machine vision for real-time inspection of various agricultural produces. This paper will focus on the work related with two products that have different requirements: fruit and olives. In the case of fruit, the Institute has developed a vision system capable of providing assessment of the external quality of single fruit to a robot that also receives information from other senors. The system use four different views of each fruit and has been tested on peaches, apples and citrus. Processing time of each image is under 500 ms using a conventional PC. The system provides information about primary and secondary color, blemishes and their extension, and stem presence and position, which allows further automatic orientation of the fruit in the final box using a robotic manipulator. Work carried out in olives was devoted to fast sorting of olives for consumption at table. A prototype has been developed to demonstrate the feasibility of a machine vision system capable of automatically sorting 2500 kg/h olives using low-cost conventional hardware.

  10. Tightly-Coupled GNSS/Vision Using a Sky-Pointing Camera for Vehicle Navigation in Urban Areas.

    Science.gov (United States)

    Gakne, Paul Verlaine; O'Keefe, Kyle

    2018-04-17

    This paper presents a method of fusing the ego-motion of a robot or a land vehicle estimated from an upward-facing camera with Global Navigation Satellite System (GNSS) signals for navigation purposes in urban environments. A sky-pointing camera is mounted on the top of a car and synchronized with a GNSS receiver. The advantages of this configuration are two-fold: firstly, for the GNSS signals, the upward-facing camera will be used to classify the acquired images into sky and non-sky (also known as segmentation). A satellite falling into the non-sky areas (e.g., buildings, trees) will be rejected and not considered for the final position solution computation. Secondly, the sky-pointing camera (with a field of view of about 90 degrees) is helpful for urban area ego-motion estimation in the sense that it does not see most of the moving objects (e.g., pedestrians, cars) and thus is able to estimate the ego-motion with fewer outliers than is typical with a forward-facing camera. The GNSS and visual information systems are tightly-coupled in a Kalman filter for the final position solution. Experimental results demonstrate the ability of the system to provide satisfactory navigation solutions and better accuracy than the GNSS-only and the loosely-coupled GNSS/vision, 20 percent and 82 percent (in the worst case) respectively, in a deep urban canyon, even in conditions with fewer than four GNSS satellites.

  11. Comparative randomised active drug controlled clinical trial of a herbal eye drop in computer vision syndrome.

    Science.gov (United States)

    Chatterjee, Pranab Kr; Bairagi, Debasis; Roy, Sudipta; Majumder, Nilay Kr; Paul, Ratish Ch; Bagchi, Sunil Ch

    2005-07-01

    A comparative double-blind placebo-controlled clinical trial of a herbal eye drop (itone) was conducted to find out its efficacy and safety in 120 patients with computer vision syndrome. Patients using computers for more than 3 hours continuously per day having symptoms of watering, redness, asthenia, irritation, foreign body sensation and signs of conjunctival hyperaemia, corneal filaments and mucus were studied. One hundred and twenty patients were randomly given either placebo, tears substitute (tears plus) or itone in identical vials with specific code number and were instructed to put one drop four times daily for 6 weeks. Subjective and objective assessments were done at bi-weekly intervals. In computer vision syndrome both subjective and objective improvements were noticed with itone drops. Itone drop was found significantly better than placebo (pcomputer vision syndrome.

  12. Review: computer vision applied to the inspection and quality control of fruits and vegetables

    Directory of Open Access Journals (Sweden)

    Erick Saldaña

    2013-12-01

    Full Text Available This is a review of the current existing literature concerning the inspection of fruits and vegetables with the application of computer vision, where the techniques most used to estimate various properties related to quality are analyzed. The objectives of the typical applications of such systems include the classification, quality estimation according to the internal and external characteristics, supervision of fruit processes during storage or the evaluation of experimental treatments. In general, computer vision systems do not only replace manual inspection, but can also improve their skills. In conclusion, computer vision systems are powerful tools for the automatic inspection of fruits and vegetables. In addition, the development of such systems adapted to the food industry is fundamental to achieve competitive advantages.

  13. Inclusive vision for high performance computing at the CSIR

    CSIR Research Space (South Africa)

    Gazendam, A

    2006-02-01

    Full Text Available and computationally intensive applications. A number of different technologies and standards were identified as core to the open and distributed high-performance infrastructure envisaged...

  14. An innovative road marking quality assessment mechanism using computer vision

    Directory of Open Access Journals (Sweden)

    Kuo-Liang Lin

    2016-06-01

    Full Text Available Aesthetic quality acceptance for road marking works has been relied on subjective visual examination. Due to a lack of quantitative operation procedures, acceptance outcome can be biased and results in great quality variation. To improve aesthetic quality acceptance procedure of road marking, we develop an innovative road marking quality assessment mechanism, utilizing machine vision technologies. Using edge smoothness as a quantitative aesthetic indicator, the proposed prototype system first receives digital images of finished road marking surface and has the images processed and analyzed to capture the geometric characteristics of the marking. The geometric characteristics are then evaluated to determine the quality level of the finished work. System is demonstrated through two real cases to show how it works. In the end, a test comparing the assessment results between the proposed system and expert inspection is conducted to enhance the accountability of the proposed mechanism.

  15. A Novel Solar Tracker Based on Omnidirectional Computer Vision

    Directory of Open Access Journals (Sweden)

    Zakaria El Kadmiri

    2015-01-01

    Full Text Available This paper presents a novel solar tracker system based on omnidirectional vision technology. The analysis of acquired images with a catadioptric camera allows extracting accurate information about the sun position toward both elevation and azimuth. The main advantages of this system are its wide field of tracking of 360° horizontally and 200° vertically. The system has the ability to track the sun in real time independently of the spatiotemporal coordinates of the site. The extracted information is used to control the two DC motors of the dual-axis mechanism to achieve the optimal orientation of the photovoltaic panels with the aim of increasing the power generation. Several experimental studies have been conducted and the obtained results confirm the power generation efficiency of the proposed solar tracker.

  16. Big data computing: Building a vision for ARS information management

    Science.gov (United States)

    Improvements are needed within the ARS to increase scientific capacity and keep pace with new developments in computer technologies that support data acquisition and analysis. Enhancements in computing power and IT infrastructure are needed to provide scientists better access to high performance com...

  17. Front-end vision and multi-scale image analysis multi-scale computer vision theory and applications, written in Mathematica

    CERN Document Server

    Romeny, Bart M Haar

    2008-01-01

    Front-End Vision and Multi-Scale Image Analysis is a tutorial in multi-scale methods for computer vision and image processing. It builds on the cross fertilization between human visual perception and multi-scale computer vision (`scale-space') theory and applications. The multi-scale strategies recognized in the first stages of the human visual system are carefully examined, and taken as inspiration for the many geometric methods discussed. All chapters are written in Mathematica, a spectacular high-level language for symbolic and numerical manipulations. The book presents a new and effective

  18. Towards OpenVL: Improving Real-Time Performance of Computer Vision Applications

    Science.gov (United States)

    Shen, Changsong; Little, James J.; Fels, Sidney

    Meeting constraints for real-time performance is a main issue for computer vision, especially for embedded computer vision systems. This chapter presents our progress on our open vision library (OpenVL), a novel software architecture to address efficiency through facilitating hardware acceleration, reusability, and scalability for computer vision systems. A logical image understanding pipeline is introduced to allow parallel processing. We also discuss progress on our middleware—vision library utility toolkit (VLUT)—that enables applications to operate transparently over a heterogeneous collection of hardware implementations. OpenVL works as a state machine,with an event-driven mechanismto provide users with application-level interaction. Various explicit or implicit synchronization and communication methods are supported among distributed processes in the logical pipelines. The intent of OpenVL is to allow users to quickly and easily recover useful information from multiple scenes, in a cross-platform, cross-language manner across various software environments and hardware platforms. To validate the critical underlying concepts of OpenVL, a human tracking system and a local positioning system are implemented and described. The novel architecture separates the specification of algorithmic details from the underlying implementation, allowing for different components to be implemented on an embedded system without recompiling code.

  19. Computer vision and soft computing for automatic skull-face overlay in craniofacial superimposition.

    Science.gov (United States)

    Campomanes-Álvarez, B Rosario; Ibáñez, O; Navarro, F; Alemán, I; Botella, M; Damas, S; Cordón, O

    2014-12-01

    Craniofacial superimposition can provide evidence to support that some human skeletal remains belong or not to a missing person. It involves the process of overlaying a skull with a number of ante mortem images of an individual and the analysis of their morphological correspondence. Within the craniofacial superimposition process, the skull-face overlay stage just focuses on achieving the best possible overlay of the skull and a single ante mortem image of the suspect. Although craniofacial superimposition has been in use for over a century, skull-face overlay is still applied by means of a trial-and-error approach without an automatic method. Practitioners finish the process once they consider that a good enough overlay has been attained. Hence, skull-face overlay is a very challenging, subjective, error prone, and time consuming part of the whole process. Though the numerical assessment of the method quality has not been achieved yet, computer vision and soft computing arise as powerful tools to automate it, dramatically reducing the time taken by the expert and obtaining an unbiased overlay result. In this manuscript, we justify and analyze the use of these techniques to properly model the skull-face overlay problem. We also present the automatic technical procedure we have developed using these computational methods and show the four overlays obtained in two craniofacial superimposition cases. This automatic procedure can be thus considered as a tool to aid forensic anthropologists to develop the skull-face overlay, automating and avoiding subjectivity of the most tedious task within craniofacial superimposition. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Development of a Wireless Computer Vision Instrument to Detect Biotic Stress in Wheat

    Directory of Open Access Journals (Sweden)

    Joaquin J. Casanova

    2014-09-01

    Full Text Available Knowledge of crop abiotic and biotic stress is important for optimal irrigation management. While spectral reflectance and infrared thermometry provide a means to quantify crop stress remotely, these measurements can be cumbersome. Computer vision offers an inexpensive way to remotely detect crop stress independent of vegetation cover. This paper presents a technique using computer vision to detect disease stress in wheat. Digital images of differentially stressed wheat were segmented into soil and vegetation pixels using expectation maximization (EM. In the first season, the algorithm to segment vegetation from soil and distinguish between healthy and stressed wheat was developed and tested using digital images taken in the field and later processed on a desktop computer. In the second season, a wireless camera with near real-time computer vision capabilities was tested in conjunction with the conventional camera and desktop computer. For wheat irrigated at different levels and inoculated with wheat streak mosaic virus (WSMV, vegetation hue determined by the EM algorithm showed significant effects from irrigation level and infection. Unstressed wheat had a higher hue (118.32 than stressed wheat (111.34. In the second season, the hue and cover measured by the wireless computer vision sensor showed significant effects from infection (p = 0.0014, as did the conventional camera (p < 0.0001. Vegetation hue obtained through a wireless computer vision system in this study is a viable option for determining biotic crop stress in irrigation scheduling. Such a low-cost system could be suitable for use in the field in automated irrigation scheduling applications.

  1. Computing for magnetic fusion energy research: An updated vision

    International Nuclear Information System (INIS)

    Henline, P.; Giarrusso, J.; Davis, S.; Casper, T.

    1993-01-01

    This Fusion Computing Council perspective is written to present the primary of the fusion computing community at the time of publication of the report necessarily as a summary of the information contained in the individual sections. These concerns reflect FCC discussions during final review of contributions from the various working groups and portray our latest information. This report itself should be considered as dynamic, requiring periodic updating in an attempt to track rapid evolution of the computer industry relevant to requirements for magnetic fusion research. The most significant common concern among the Fusion Computing Council working groups is networking capability. All groups see an increasing need for network services due to the use of workstations, distributed computing environments, increased use of graphic services, X-window usage, remote experimental collaborations, remote data access for specific projects and other collaborations. Other areas of concern include support for workstations, enhanced infrastructure to support collaborations, the User Service Centers, NERSC and future massively parallel computers, and FCC sponsored workshops

  2. FAKTOR YANG BERHUBUNGAN DENGAN KELUHAN COMPUTER VISION SYNDROME (CVS PADA PEKERJA RENTAL KOMPUTER DI WILAYAH UNNES

    Directory of Open Access Journals (Sweden)

    Melati Aisyah Permana

    2015-07-01

    Full Text Available Computer as a tool that is widely used human beings, it also raises occupational diseases as well as the use of machine in industry. Vision problems caused bye the use of computers, the American Optometric Association (AOA called Computer Vision Syndrome (CVS as a compound eye problems related to employment experienced by a person at close range as or related to computer use. The purpose of this study was to analyze the relationship between the working length, the distance eye with the monitor, lighting intensity, work attitude, and identifity the incidence of complaints of CVS workers experienced computer rentals. This study used Cross Sectional approach. Number of population and sample of 36 peoples working computer rental in the area Unnes campus. The instruments used in the form of quetionnatires, meter, and Lux meter. Chi square test result : (1the working length (p=0,005; (2 the distance eye with the monitor (p=0,012; (3 lighting intensity (p=0,001; (4 work attitude (p=0,014 with complaints of CVS in workers computer rental at the campus Unnes. Suggestion for worker is to check their eyes regulary to the doctor if the complaints of CVS in order to minimize the occurrence of more severe diseases. While other researchers needed for further studies with different variables to better determine other factors associated with symptoms of Computer Vision Syndrome (CVS.

  3. Computer vision system in real-time for color determination on flat surface food

    Directory of Open Access Journals (Sweden)

    Erick Saldaña

    2013-03-01

    Full Text Available Artificial vision systems also known as computer vision are potent quality inspection tools, which can be applied in pattern recognition for fruits and vegetables analysis. The aim of this research was to design, implement and calibrate a new computer vision system (CVS in real-time for the color measurement on flat surface food. For this purpose was designed and implemented a device capable of performing this task (software and hardware, which consisted of two phases: a image acquisition and b image processing and analysis. Both the algorithm and the graphical interface (GUI were developed in Matlab. The CVS calibration was performed using a conventional colorimeter (Model CIEL* a* b*, where were estimated the errors of the color parameters: eL* = 5.001%, and ea* = 2.287%, and eb* = 4.314 % which ensure adequate and efficient automation application in industrial processes in the quality control in the food industry sector.

  4. Computer vision system in real-time for color determination on flat surface food

    Directory of Open Access Journals (Sweden)

    Erick Saldaña

    2013-01-01

    Full Text Available Artificial vision systems also known as computer vision are potent quality inspection tools, which can be applied in pattern recognition for fruits and vegetables analysis. The aim of this research was to design, implement and calibrate a new computer vision system (CVS in real - time f or the color measurement on flat surface food. For this purpose was designed and implemented a device capable of performing this task (software and hardware, which consisted of two phases: a image acquisition and b image processing and analysis. Both th e algorithm and the graphical interface (GUI were developed in Matlab. The CVS calibration was performed using a conventional colorimeter (Model CIEL* a* b*, where were estimated the errors of the color parameters: e L* = 5.001%, and e a* = 2.287%, and e b* = 4.314 % which ensure adequate and efficient automation application in industrial processes in the quality control in the food industry sector.

  5. Computer vision and augmented reality in gastrointestinal endoscopy

    Science.gov (United States)

    Mahmud, Nadim; Cohen, Jonah; Tsourides, Kleovoulos; Berzin, Tyler M.

    2015-01-01

    Augmented reality (AR) is an environment-enhancing technology, widely applied in the computer sciences, which has only recently begun to permeate the medical field. Gastrointestinal endoscopy—which relies on the integration of high-definition video data with pathologic correlates—requires endoscopists to assimilate and process a tremendous amount of data in real time. We believe that AR is well positioned to provide computer-guided assistance with a wide variety of endoscopic applications, beginning with polyp detection. In this article, we review the principles of AR, describe its potential integration into an endoscopy set-up, and envisage a series of novel uses. With close collaboration between physicians and computer scientists, AR promises to contribute significant improvements to the field of endoscopy. PMID:26133175

  6. Error Mitigation of Point-to-Point Communication for Fault-Tolerant Computing

    Science.gov (United States)

    Akamine, Robert L.; Hodson, Robert F.; LaMeres, Brock J.; Ray, Robert E.

    2011-01-01

    Fault tolerant systems require the ability to detect and recover from physical damage caused by the hardware s environment, faulty connectors, and system degradation over time. This ability applies to military, space, and industrial computing applications. The integrity of Point-to-Point (P2P) communication, between two microcontrollers for example, is an essential part of fault tolerant computing systems. In this paper, different methods of fault detection and recovery are presented and analyzed.

  7. Program computes single-point failures in critical system designs

    Science.gov (United States)

    Brown, W. R.

    1967-01-01

    Computer program analyzes the designs of critical systems that will either prove the design is free of single-point failures or detect each member of the population of single-point failures inherent in a system design. This program should find application in the checkout of redundant circuits and digital systems.

  8. Computer vision syndrome: a review of ocular causes and potential treatments.

    Science.gov (United States)

    Rosenfield, Mark

    2011-09-01

    Computer vision syndrome (CVS) is the combination of eye and vision problems associated with the use of computers. In modern western society the use of computers for both vocational and avocational activities is almost universal. However, CVS may have a significant impact not only on visual comfort but also occupational productivity since between 64% and 90% of computer users experience visual symptoms which may include eyestrain, headaches, ocular discomfort, dry eye, diplopia and blurred vision either at near or when looking into the distance after prolonged computer use. This paper reviews the principal ocular causes for this condition, namely oculomotor anomalies and dry eye. Accommodation and vergence responses to electronic screens appear to be similar to those found when viewing printed materials, whereas the prevalence of dry eye symptoms is greater during computer operation. The latter is probably due to a decrease in blink rate and blink amplitude, as well as increased corneal exposure resulting from the monitor frequently being positioned in primary gaze. However, the efficacy of proposed treatments to reduce symptoms of CVS is unproven. A better understanding of the physiology underlying CVS is critical to allow more accurate diagnosis and treatment. This will enable practitioners to optimize visual comfort and efficiency during computer operation. Ophthalmic & Physiological Optics © 2011 The College of Optometrists.

  9. Implementation of Automatic Focusing Algorithms for a Computer Vision System with Camera Control.

    Science.gov (United States)

    1983-08-15

    obtainable from real data, rather than relying on a stock database. Often, computer vision and image processing algorithms become subconsciously tuned to...two coils on the same mount structure. Since it was not possible to reprogram the binary system, we turned to the POPEYE system for both its grey

  10. Computer Vision Photogrammetry for Underwater Archaeological Site Recording in a Low-Visibility Environment

    Science.gov (United States)

    Van Damme, T.

    2015-04-01

    Computer Vision Photogrammetry allows archaeologists to accurately record underwater sites in three dimensions using simple twodimensional picture or video sequences, automatically processed in dedicated software. In this article, I share my experience in working with one such software package, namely PhotoScan, to record a Dutch shipwreck site. In order to demonstrate the method's reliability and flexibility, the site in question is reconstructed from simple GoPro footage, captured in low-visibility conditions. Based on the results of this case study, Computer Vision Photogrammetry compares very favourably to manual recording methods both in recording efficiency, and in the quality of the final results. In a final section, the significance of Computer Vision Photogrammetry is then assessed from a historical perspective, by placing the current research in the wider context of about half a century of successful use of Analytical and later Digital photogrammetry in the field of underwater archaeology. I conclude that while photogrammetry has been used in our discipline for several decades now, for various reasons the method was only ever used by a relatively small percentage of projects. This is likely to change in the near future since, compared to the `traditional' photogrammetry approaches employed in the past, today Computer Vision Photogrammetry is easier to use, more reliable and more affordable than ever before, while at the same time producing more accurate and more detailed three-dimensional results.

  11. Ontwikkeling en validatie van computer vision technologie ten behoeve van een broccoli oogstrobot

    NARCIS (Netherlands)

    Blok, Pieter M.; Tielen, Antonius P.M.

    2018-01-01

    De selectieve en handmatige oogst van broccoli is arbeidsintensief en omvat ongeveer 35% van de totale productiekosten. Dit onderzoek is uitgevoerd om te bepalen of computer vision kan worden gebruikt om broccoli kronen te detecteren, als eerste stap in de ontwikkeling van een autonome selectieve

  12. A Cellular Automata Approach to Computer Vision and Image Processing.

    Science.gov (United States)

    1980-09-01

    the ACM, vol. 15, no. 9, pp. 827-837. [ Duda and Hart] R. 0. Duda and P. E. Hart, Pattern Classification and Scene Analysis, Wiley, New York, 1973...Center TR-738, 1979. [Farley] Arthur M. Farley and Andrzej Proskurowski, "Gossiping in Grid Graphs", University of Oregon Computer Science Department CS-TR

  13. Computer Vision Syndrome in Eleven to Eighteen-Year-Old Students in Qazvin

    Directory of Open Access Journals (Sweden)

    Khalaj

    2015-08-01

    Full Text Available Background Prolonged use of computers can lead to complications such as eye strain, eye and head aches, double and blurred vision, tired eyes, irritation, burning and itching eyes, eye redness, light sensitivity, dry eyes, muscle strains, and other problems. Objectives The aim of the present study was to evaluate visual problems and major symptoms, and their associations among computer users, aged between 11 and 18 years old, residing in the Qazvin city of Iran, during year 2010. Patients and Methods This cross-sectional study was done on 642 secondary to pre university students who had referred to the eye clinic of Buali hospital of Qazvin during year 2013. A questionnaire consisting of demographic information and 26 questions on visual effects of the computer was used to gather information. Participants answered all questions and then underwent complete eye examinations and in some cases cycloplegic refraction. Visual acuity (VA was measured with a logMAR in six meters. Refraction errors were determined using an auto refractometer (Potece and Heine retinoscope. The collected data was then analyzed using the SPSS statistical software. Results The results of this study indicated that 63.86% of the subjects had refractive errors. Refractive errors were significantly different in children of different genders (P < 0.05. The most common complaints associated with the continuous use of computers were eyestrain, eye pain, eye redness, headache, and blurred vision. The most prevalent (81.8% eye-related problem in computer users was eyestrain and the least prevalent was dry eyes (7.84%. In order to reduce computer related problems 54.2% of the participants suggested taking enough rest, 37.9% recommended use of computers only for necessary tasks, while 24.4% and 19.1% suggested the use of monitor shields and proper working distance, respectively. Conclusions Our findings revealed that using computers for prolonged periods of time can lead to eye

  14. Survey of computer vision technology for UVA navigation

    Science.gov (United States)

    Xie, Bo; Fan, Xiang; Li, Sijian

    2017-11-01

    Navigation based on computer version technology, which has the characteristics of strong independence, high precision and is not susceptible to electrical interference, has attracted more and more attention in the filed of UAV navigation research. Early navigation project based on computer version technology mainly applied to autonomous ground robot. In recent years, the visual navigation system is widely applied to unmanned machine, deep space detector and underwater robot. That further stimulate the research of integrated navigation algorithm based on computer version technology. In China, with many types of UAV development and two lunar exploration, the three phase of the project started, there has been significant progress in the study of visual navigation. The paper expounds the development of navigation based on computer version technology in the filed of UAV navigation research and draw a conclusion that visual navigation is mainly applied to three aspects as follows.(1) Acquisition of UAV navigation parameters. The parameters, including UAV attitude, position and velocity information could be got according to the relationship between the images from sensors and carrier's attitude, the relationship between instant matching images and the reference images and the relationship between carrier's velocity and characteristics of sequential images.(2) Autonomous obstacle avoidance. There are many ways to achieve obstacle avoidance in UAV navigation. The methods based on computer version technology ,including feature matching, template matching, image frames and so on, are mainly introduced. (3) The target tracking, positioning. Using the obtained images, UAV position is calculated by using optical flow method, MeanShift algorithm, CamShift algorithm, Kalman filtering and particle filter algotithm. The paper expounds three kinds of mainstream visual system. (1) High speed visual system. It uses parallel structure, with which image detection and processing are

  15. Toward a Computational Neuropsychology of High-Level Vision.

    Science.gov (United States)

    1984-08-20

    known as visual agnosia ’ (also called "mindblindness’)l this patient failed to *recognize her nurses, got lost frequently when travelling familiar routes...visual agnosia are not blind: these patients can compare two shapes reliably when Computational neuropsychology 16 both are visible, but they cannot...visually recognize what an object is (although many can recognize objects by touch). This sort of agnosia has been well-documented in the literature (see

  16. Computer vision syndrome in presbyopia and beginning presbyopia: effects of spectacle lens type.

    Science.gov (United States)

    Jaschinski, Wolfgang; König, Mirjam; Mekontso, Tiofil M; Ohlendorf, Arne; Welscher, Monique

    2015-05-01

    This office field study investigated the effects of different types of spectacle lenses habitually worn by computer users with presbyopia and in the beginning stages of presbyopia. Computer vision syndrome was assessed through reported complaints and ergonomic conditions. A questionnaire regarding the type of habitually worn near-vision lenses at the workplace, visual conditions and the levels of different types of complaints was administered to 175 participants aged 35 years and older (mean ± SD: 52.0 ± 6.7 years). Statistical factor analysis identified five specific aspects of the complaints. Workplace conditions were analysed based on photographs taken in typical working conditions. In the subgroup of 25 users between the ages of 36 and 57 years (mean 44 ± 5 years), who wore distance-vision lenses and performed more demanding occupational tasks, the reported extents of 'ocular strain', 'musculoskeletal strain' and 'headache' increased with the daily duration of computer work and explained up to 44 per cent of the variance (rs = 0.66). In the other subgroups, this effect was smaller, while in the complete sample (n = 175), this correlation was approximately rs = 0.2. The subgroup of 85 general-purpose progressive lens users (mean age 54 years) adopted head inclinations that were approximately seven degrees more elevated than those of the subgroups with single vision lenses. The present questionnaire was able to assess the complaints of computer users depending on the type of spectacle lenses worn. A missing near-vision addition among participants in the early stages of presbyopia was identified as a risk factor for complaints among those with longer daily durations of demanding computer work. © 2015 The Authors. Clinical and Experimental Optometry © 2015 Optometry Australia.

  17. When Ultrasonic Sensors and Computer Vision Join Forces for Efficient Obstacle Detection and Recognition.

    Science.gov (United States)

    Mocanu, Bogdan; Tapu, Ruxandra; Zaharia, Titus

    2016-10-28

    In the most recent report published by the World Health Organization concerning people with visual disabilities it is highlighted that by the year 2020, worldwide, the number of completely blind people will reach 75 million, while the number of visually impaired (VI) people will rise to 250 million. Within this context, the development of dedicated electronic travel aid (ETA) systems, able to increase the safe displacement of VI people in indoor/outdoor spaces, while providing additional cognition of the environment becomes of outmost importance. This paper introduces a novel wearable assistive device designed to facilitate the autonomous navigation of blind and VI people in highly dynamic urban scenes. The system exploits two independent sources of information: ultrasonic sensors and the video camera embedded in a regular smartphone. The underlying methodology exploits computer vision and machine learning techniques and makes it possible to identify accurately both static and highly dynamic objects existent in a scene, regardless on their location, size or shape. In addition, the proposed system is able to acquire information about the environment, semantically interpret it and alert users about possible dangerous situations through acoustic feedback. To determine the performance of the proposed methodology we have performed an extensive objective and subjective experimental evaluation with the help of 21 VI subjects from two blind associations. The users pointed out that our prototype is highly helpful in increasing the mobility, while being friendly and easy to learn.

  18. When Ultrasonic Sensors and Computer Vision Join Forces for Efficient Obstacle Detection and Recognition

    Directory of Open Access Journals (Sweden)

    Bogdan Mocanu

    2016-10-01

    Full Text Available In the most recent report published by the World Health Organization concerning people with visual disabilities it is highlighted that by the year 2020, worldwide, the number of completely blind people will reach 75 million, while the number of visually impaired (VI people will rise to 250 million. Within this context, the development of dedicated electronic travel aid (ETA systems, able to increase the safe displacement of VI people in indoor/outdoor spaces, while providing additional cognition of the environment becomes of outmost importance. This paper introduces a novel wearable assistive device designed to facilitate the autonomous navigation of blind and VI people in highly dynamic urban scenes. The system exploits two independent sources of information: ultrasonic sensors and the video camera embedded in a regular smartphone. The underlying methodology exploits computer vision and machine learning techniques and makes it possible to identify accurately both static and highly dynamic objects existent in a scene, regardless on their location, size or shape. In addition, the proposed system is able to acquire information about the environment, semantically interpret it and alert users about possible dangerous situations through acoustic feedback. To determine the performance of the proposed methodology we have performed an extensive objective and subjective experimental evaluation with the help of 21 VI subjects from two blind associations. The users pointed out that our prototype is highly helpful in increasing the mobility, while being friendly and easy to learn.

  19. Computer vision for shoe upper profile measurement via upper and sole conformal matching

    Science.gov (United States)

    Hu, Zhongxu; Bicker, Robert; Taylor, Paul; Marshall, Chris

    2007-01-01

    This paper describes a structured light computer vision system applied to the measurement of the 3D profile of shoe uppers. The trajectory obtained is used to guide an industrial robot for automatic edge roughing around the contour of the shoe upper so that the bonding strength can be improved. Due to the specific contour and unevenness of the shoe upper, even if the 3D profile is obtained using computer vision, it is still difficult to reliably define the roughing path around the shape. However, the shape of the corresponding shoe sole is better defined, and it is much easier to measure the edge using computer vision. Therefore, a feasible strategy is to measure both the upper and sole profiles, and then align and fit the sole contour to the upper, in order to obtain the best fit. The trajectory of the edge of the desired roughing path is calculated and is then smoothed and interpolated using NURBS curves to guide an industrial robot for shoe upper surface removal; experiments show robust and consistent results. An outline description of the structured light vision system is given here, along with the calibration techniques used.

  20. TO STUDY THE ROLE OF ERGONOMICS IN THE MANAGEMENT OF COMPUTER VISION SYNDROME

    Directory of Open Access Journals (Sweden)

    Anshu

    2016-03-01

    Full Text Available INTRODUCTION Ergonomics is the science of designing the job equipment and workplace to fit the worker by obtaining a correct match between the human body, work related tasks and work tools. By applying the science of ergonomics we can reduce the difficulties faced by computer users. OBJECTIVES To evaluate the efficacy of tear substitutes and the role of ergonomics in the management of Computer Vision Syndrome. Development of counseling plan, initial treatment plan, prevent complications and educate the subjects about the disease process and to enhance public awareness. MATERIALS AND METHODS A minimum of 100 subjects were selected randomly irrespective of gender, place and nature of computer work & ethnic differences. The subjects were between age group of 10-60 years who had been using the computer for a minimum of 2 hours/day for atleast 5-6 days a week. The subjects underwent tests like Schirmer's, Test film breakup time (TBUT, Inter Blink Interval and Ocular surface staining. A Computer Vision score was taken out based on 5 symptoms each of which was given a score of 2. The symptoms included foreign body sensation, redness, eyestrain, blurring of vision and frequent change in refraction. The score of more than 6 was treated as Computer Vision syndrome and the subjects underwent synoptophore tests and refraction. RESULT In the present study where we had divided 100 subjects into 2 groups of 50 each and given tear substitutes only in one group and ergonomics was considered with tear substitutes in the other. We saw that there was more improvement after 4 weeks and 8 weeks in the group taking lubricants and ergonomics into consideration than lubricants alone. More improvement was seen in eyestrain and blurring (P0.05. CONCLUSION Advanced training in proper computer usage can decrease discomfort.

  1. A conceptual framework of computations in mid-level vision.

    Science.gov (United States)

    Kubilius, Jonas; Wagemans, Johan; Op de Beeck, Hans P

    2014-01-01

    If a picture is worth a thousand words, as an English idiom goes, what should those words-or, rather, descriptors-capture? What format of image representation would be sufficiently rich if we were to reconstruct the essence of images from their descriptors? In this paper, we set out to develop a conceptual framework that would be: (i) biologically plausible in order to provide a better mechanistic understanding of our visual system; (ii) sufficiently robust to apply in practice on realistic images; and (iii) able to tap into underlying structure of our visual world. We bring forward three key ideas. First, we argue that surface-based representations are constructed based on feature inference from the input in the intermediate processing layers of the visual system. Such representations are computed in a largely pre-semantic (prior to categorization) and pre-attentive manner using multiple cues (orientation, color, polarity, variation in orientation, and so on), and explicitly retain configural relations between features. The constructed surfaces may be partially overlapping to compensate for occlusions and are ordered in depth (figure-ground organization). Second, we propose that such intermediate representations could be formed by a hierarchical computation of similarity between features in local image patches and pooling of highly-similar units, and reestimated via recurrent loops according to the task demands. Finally, we suggest to use datasets composed of realistically rendered artificial objects and surfaces in order to better understand a model's behavior and its limitations.

  2. A conceptual framework of computations in mid-level vision

    Directory of Open Access Journals (Sweden)

    Jonas eKubilius

    2014-12-01

    Full Text Available If a picture is worth a thousand words, as an English idiom goes, what should those words – or, rather, descriptors – capture? What format of image representation would be sufficiently rich if we were to reconstruct the essence of images from their descriptors? In this paper, we set out to develop a conceptual framework that would be: (i biologically plausible in order to provide a better mechanistic understanding of our visual system; (ii sufficiently robust to apply in practice on realistic images; and (iii able to tap into underlying structure of our visual world. We bring forward three key ideas. First, we argue that surface-based representations are constructed based on feature inference from the input in the intermediate processing layers of the visual system. Such representations are computed in a largely pre-semantic (prior to categorization and pre-attentive manner using multiple cues (orientation, color, polarity, variation in orientation and so on, and explicitly retain configural relations between features. The constructed surfaces may be partially overlapping to compensate for occlusions and are ordered in depth (figure-ground organization. Second, we propose that such intermediate representations could be formed by a hierarchical computation of similarity between features in local image patches and pooling of highly-similar units, and reestimated via recurrent loops according to the task demands. Finally, we suggest to use datasets composed of realistically rendered artificial objects and surfaces in order to better understand a model’s behavior and its limitations.

  3. A conceptual framework of computations in mid-level vision

    Science.gov (United States)

    Kubilius, Jonas; Wagemans, Johan; Op de Beeck, Hans P.

    2014-01-01

    If a picture is worth a thousand words, as an English idiom goes, what should those words—or, rather, descriptors—capture? What format of image representation would be sufficiently rich if we were to reconstruct the essence of images from their descriptors? In this paper, we set out to develop a conceptual framework that would be: (i) biologically plausible in order to provide a better mechanistic understanding of our visual system; (ii) sufficiently robust to apply in practice on realistic images; and (iii) able to tap into underlying structure of our visual world. We bring forward three key ideas. First, we argue that surface-based representations are constructed based on feature inference from the input in the intermediate processing layers of the visual system. Such representations are computed in a largely pre-semantic (prior to categorization) and pre-attentive manner using multiple cues (orientation, color, polarity, variation in orientation, and so on), and explicitly retain configural relations between features. The constructed surfaces may be partially overlapping to compensate for occlusions and are ordered in depth (figure-ground organization). Second, we propose that such intermediate representations could be formed by a hierarchical computation of similarity between features in local image patches and pooling of highly-similar units, and reestimated via recurrent loops according to the task demands. Finally, we suggest to use datasets composed of realistically rendered artificial objects and surfaces in order to better understand a model's behavior and its limitations. PMID:25566044

  4. Near Point of Convergence Break for Different Age Groups in Turkish Population with Normal Binocular Vision: Normative Data

    Directory of Open Access Journals (Sweden)

    Nihat Sayın

    2013-12-01

    Full Text Available Purpose: The purpose of this study was to evaluate the near point of convergence break in Turkish population with normal binocular vision and to obtain the normative data for the near point of convergence break in different age groups. Such database has not been previously reported. Material and Method: In this prospective study, 329 subjects with normal binocular vision (age range, 3-72 years were evaluated. The near point of convergence break was measured 4 times repeatedly with an accommodative target. Mean values of near point of convergence break were provided for these age groups (≤10, 11-20, 21-30, 31-40, 41-50, 51-60, and >60 years old. A statistical comparison (one-way ANOVA and post-hoc test of these values between age groups was performed. A correlation between the near point of convergence break and age was evaluated by Pearson’s correlation test. Results: The mean value for near point of convergence break was 2.46±1.88 (0.5-14 cm. Specifically, 95% of measurements in all subjects were 60 year-old age groups in the near point of convergence break values (p=0.0001, p=0.0001, p=0.006, p=0.001, p= 0.004. A mild positive correlation was observed between the increase in near point of convergence break and increase of age (r=0.355 (p<0.001. Discussion: The values derived from a relatively large study population to establish a normative database for the near point of convergence break in the Turkish population with normal binocular vision are in relevance with age. This database has not been previously reported. (Turk J Ophthalmol 2013; 43: 402-6

  5. VISION development

    International Nuclear Information System (INIS)

    Hernandez, J.E.; Sherwood, R.J.; Whitman, S.R.

    1994-01-01

    VISION is a flexible and extensible object-oriented programming environment for prototyping computer-vision and pattern-recognition algorithms. This year's effort focused on three major areas: documentation, graphics, and support for new applications

  6. Factors leading to the computer vision syndrome: an issue at the contemporary workplace.

    Science.gov (United States)

    Izquierdo, Juan C; García, Maribel; Buxó, Carmen; Izquierdo, Natalio J

    2007-01-01

    Vision and eye related problems are common among computer users, and have been collectively called the Computer Vision Syndrome (CVS). An observational study in order to identify the risk factors leading to the CVS was done. Twenty-eight participants answered a validated questionnaire, and had their workstations examined. The questionnaire evaluated personal, environmental, ergonomic factors, and physiologic response of computer users. The distance from the eye to the computers' monitor (A), the computers' monitor height (B), and visual axis height (C) were measured. The difference between B and C was calculated and labeled as D. Angles of gaze to the computer monitor were calculated using the formula: angle=tan-1(D/A). Angles were divided into two groups: participants with angles of gaze ranging from 0 degree to 13.9 degrees were included in Group 1; and participants gazing at angles larger than 14 degrees were included in Group 2. Statistical analysis of the evaluated variables was made. Computer users in both groups used more tear supplements (as part of the syndrome) than expected. This association was statistically significant (p syndrome is the angle of gaze at the computer monitor. Pain in computer users is diminished when gazing downwards at angles of 14 degrees or more. The CVS remains an under estimated and poorly understood issue at the workplace. The general public, health professionals, the government, and private industries need to be educated about the CVS.

  7. Sigma: computer vision in the service of safety and reliability in the inspection services

    International Nuclear Information System (INIS)

    Pineiro, P. J.; Mendez, M.; Garcia, A.; Cabrera, E.; Regidor, J. J.

    2012-01-01

    Vision Computing is growing very fast in the last decade with very efficient tools and algorithms. This allows new development of applications in the nuclear field providing more efficient equipment and tasks: redundant systems, vision-guided mobile robots, automated visual defects recognition, measurement, etc., In this paper Tecnatom describes a detailed example of visual computing application developed to provide secure redundant identification of the thousands of tubes existing in a power plant steam generator. some other on-going or planned visual computing projects by Tecnatom are also introduced. New possibilities of application in the inspection systems for nuclear components appear where the main objective is to maximize their reliability. (Author) 6 refs.

  8. Computer vision syndrome and associated factors among medical and engineering students in chennai.

    Science.gov (United States)

    Logaraj, M; Madhupriya, V; Hegde, Sk

    2014-03-01

    Almost all institutions, colleges, universities and homes today were using computer regularly. Very little research has been carried out on Indian users especially among college students the effects of computer use on the eye and vision related problems. The aim of this study was to assess the prevalence of computer vision syndrome (CVS) among medical and engineering students and the factors associated with the same. A cross-sectional study was conducted among medical and engineering college students of a University situated in the suburban area of Chennai. Students who used computer in the month preceding the date of study were included in the study. The participants were surveyed using pre-tested structured questionnaire. Among engineering students, the prevalence of CVS was found to be 81.9% (176/215) while among medical students; it was found to be 78.6% (158/201). A significantly higher proportion of engineering students 40.9% (88/215) used computers for 4-6 h/day as compared to medical students 10% (20/201) (P medical students. Students who used computer for 4-6 h were at significantly higher risk of developing redness (OR = 1.2, 95% CI = 1.0-3.1,P = 0.04), burning sensation (OR = 2.1,95% CI = 1.3-3.1, P computer for less than 4 h. Significant correlation was found between increased hours of computer use and the symptoms redness, burning sensation, blurred vision and dry eyes. The present study revealed that more than three-fourth of the students complained of any one of the symptoms of CVS while working on the computer.

  9. Data Point Averaging for Computational Fluid Dynamics Data

    Science.gov (United States)

    Norman, Jr., David (Inventor)

    2016-01-01

    A system and method for generating fluid flow parameter data for use in aerodynamic heating analysis. Computational fluid dynamics data is generated for a number of points in an area on a surface to be analyzed. Sub-areas corresponding to areas of the surface for which an aerodynamic heating analysis is to be performed are identified. A computer system automatically determines a sub-set of the number of points corresponding to each of the number of sub-areas and determines a value for each of the number of sub-areas using the data for the sub-set of points corresponding to each of the number of sub-areas. The value is determined as an average of the data for the sub-set of points corresponding to each of the number of sub-areas. The resulting parameter values then may be used to perform an aerodynamic heating analysis.

  10. Computing three-point functions for short operators

    International Nuclear Information System (INIS)

    Bargheer, Till; Institute for Advanced Study, Princeton, NJ; Minahan, Joseph A.; Pereira, Raul

    2013-11-01

    We compute the three-point structure constants for short primary operators of N=4 super Yang.Mills theory to leading order in 1/√(λ) by mapping the problem to a flat-space string theory calculation. We check the validity of our procedure by comparing to known results for three chiral primaries. We then compute the three-point functions for any combination of chiral and non-chiral primaries, with the non-chiral primaries all dual to string states at the first massive level. Along the way we find many cancellations that leave us with simple expressions, suggesting that integrability is playing an important role.

  11. Computing three-point functions for short operators

    Energy Technology Data Exchange (ETDEWEB)

    Bargheer, Till [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Institute for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Minahan, Joseph A.; Pereira, Raul [Uppsala Univ. (Sweden). Dept. of Physics and Astronomy

    2013-11-15

    We compute the three-point structure constants for short primary operators of N=4 super Yang.Mills theory to leading order in 1/√(λ) by mapping the problem to a flat-space string theory calculation. We check the validity of our procedure by comparing to known results for three chiral primaries. We then compute the three-point functions for any combination of chiral and non-chiral primaries, with the non-chiral primaries all dual to string states at the first massive level. Along the way we find many cancellations that leave us with simple expressions, suggesting that integrability is playing an important role.

  12. COMPUTER GRAPHICAL REPRESENTATION, IN TREBLE ORTHOGONAL PROJECTION, OF A POINT

    Directory of Open Access Journals (Sweden)

    SLONOVSCHI Andrei

    2017-05-01

    Full Text Available In the stages of understanding and study, by students, of descriptive geometry, the treble orthogonal projection of a point, creates problems in the situations in that one or more descriptive coordinates are zero. Starting from these considerations the authors have created an original computer program which offers to the students the possibility to easily understanding of the way in which a point is represented, in draught, in the treble orthogonal projection whatever which are its values of the descriptive coordinates.

  13. Integrating computation into the undergraduate curriculum: A vision and guidelines for future developments

    Science.gov (United States)

    Chonacky, Norman; Winch, David

    2008-04-01

    There is substantial evidence of a need to make computation an integral part of the undergraduate physics curriculum. This need is consistent with data from surveys in both the academy and the workplace, and has been reinforced by two years of exploratory efforts by a group of physics faculty for whom computation is a special interest. We have examined past and current efforts at reform and a variety of strategic, organizational, and institutional issues involved in any attempt to broadly transform existing practice. We propose a set of guidelines for development based on this past work and discuss our vision of computationally integrated physics.

  14. Computational Analysis of Distance Operators for the Iterative Closest Point Algorithm.

    Directory of Open Access Journals (Sweden)

    Higinio Mora

    Full Text Available The Iterative Closest Point (ICP algorithm is currently one of the most popular methods for rigid registration so that it has become the standard in the Robotics and Computer Vision communities. Many applications take advantage of it to align 2D/3D surfaces due to its popularity and simplicity. Nevertheless, some of its phases present a high computational cost thus rendering impossible some of its applications. In this work, it is proposed an efficient approach for the matching phase of the Iterative Closest Point algorithm. This stage is the main bottleneck of that method so that any efficiency improvement has a great positive impact on the performance of the algorithm. The proposal consists in using low computational cost point-to-point distance metrics instead of classic Euclidean one. The candidates analysed are the Chebyshev and Manhattan distance metrics due to their simpler formulation. The experiments carried out have validated the performance, robustness and quality of the proposal. Different experimental cases and configurations have been set up including a heterogeneous set of 3D figures, several scenarios with partial data and random noise. The results prove that an average speed up of 14% can be obtained while preserving the convergence properties of the algorithm and the quality of the final results.

  15. Computer vision syndrome-A common cause of unexplained visual symptoms in the modern era.

    Science.gov (United States)

    Munshi, Sunil; Varghese, Ashley; Dhar-Munshi, Sushma

    2017-07-01

    The aim of this study was to assess the evidence and available literature on the clinical, pathogenetic, prognostic and therapeutic aspects of Computer vision syndrome. Information was collected from Medline, Embase & National Library of Medicine over the last 30 years up to March 2016. The bibliographies of relevant articles were searched for additional references. Patients with Computer vision syndrome present to a variety of different specialists, including General Practitioners, Neurologists, Stroke physicians and Ophthalmologists. While the condition is common, there is a poor awareness in the public and among health professionals. Recognising this condition in the clinic or in emergency situations like the TIA clinic is crucial. The implications are potentially huge in view of the extensive and widespread use of computers and visual display units. Greater public awareness of Computer vision syndrome and education of health professionals is vital. Preventive strategies should form part of work place ergonomics routinely. Prompt and correct recognition is important to allow management and avoid unnecessary treatments. © 2017 John Wiley & Sons Ltd.

  16. Analysis of the Indented Cylinder by the use of Computer Vision

    DEFF Research Database (Denmark)

    Buus, Ole Thomsen

    -groups: (1) “long” seeds and (2) “short” seeds (known as length-separation). The motion of seeds being physically manipulated inside an active indented cylinder was analysed using various computer vision methods. The data from such analyses were used to create an overview of the machine’s ability to separate...... as a cite-aware imagery data set. The work summarised in this thesis is very much related to the task of constructing models from observed data. This field is known as empirical model development or more specifically as “system identification”. System v identification deals specifically with estimating...... mathematical models from observed dynamic states (time series) of inputs and outputs to and from some physical system under investigation. The contribution of the work is to be found primarily within the problem domain of experimentation for system identification. Computer vision techniques were used...

  17. Computer Vision and Machine Learning for Autonomous Characterization of AM Powder Feedstocks

    Science.gov (United States)

    DeCost, Brian L.; Jain, Harshvardhan; Rollett, Anthony D.; Holm, Elizabeth A.

    2017-03-01

    By applying computer vision and machine learning methods, we develop a system to characterize powder feedstock materials for metal additive manufacturing (AM). Feature detection and description algorithms are applied to create a microstructural scale image representation that can be used to cluster, compare, and analyze powder micrographs. When applied to eight commercial feedstock powders, the system classifies powder images into the correct material systems with greater than 95% accuracy. The system also identifies both representative and atypical powder images. These results suggest the possibility of measuring variations in powders as a function of processing history, relating microstructural features of powders to properties relevant to their performance in AM processes, and defining objective material standards based on visual images. A significant advantage of the computer vision approach is that it is autonomous, objective, and repeatable.

  18. Recent advances in transient imaging: A computer graphics and vision perspective

    Directory of Open Access Journals (Sweden)

    Adrian Jarabo

    2017-03-01

    Full Text Available Transient imaging has recently made a huge impact in the computer graphics and computer vision fields. By capturing, reconstructing, or simulating light transport at extreme temporal resolutions, researchers have proposed novel techniques to show movies of light in motion, see around corners, detect objects in highly-scattering media, or infer material properties from a distance, to name a few. The key idea is to leverage the wealth of information in the temporal domain at the pico or nanosecond resolution, information usually lost during the capture-time temporal integration. This paper presents recent advances in this field of transient imaging from a graphics and vision perspective, including capture techniques, analysis, applications and simulation. Keywords: Transient imaging, Ultrafast imaging, Time-of-flight

  19. Development of a body motion interactive system with a weight voting mechanism and computer vision technology

    Science.gov (United States)

    Lin, Chern-Sheng; Chen, Chia-Tse; Shei, Hung-Jung; Lay, Yun-Long; Chiu, Chuang-Chien

    2012-09-01

    This study develops a body motion interactive system with computer vision technology. This application combines interactive games, art performing, and exercise training system. Multiple image processing and computer vision technologies are used in this study. The system can calculate the characteristics of an object color, and then perform color segmentation. When there is a wrong action judgment, the system will avoid the error with a weight voting mechanism, which can set the condition score and weight value for the action judgment, and choose the best action judgment from the weight voting mechanism. Finally, this study estimated the reliability of the system in order to make improvements. The results showed that, this method has good effect on accuracy and stability during operations of the human-machine interface of the sports training system.

  20. Computer Vision System For Locating And Identifying Defects In Hardwood Lumber

    Science.gov (United States)

    Conners, Richard W.; Ng, Chong T.; Cho, Tai-Hoon; McMillin, Charles W.

    1989-03-01

    This paper describes research aimed at developing an automatic cutup system for use in the rough mills of the hardwood furniture and fixture industry. In particular, this paper describes attempts to create the vision system that will power this automatic cutup system. There are a number of factors that make the development of such a vision system a challenge. First there is the innate variability of the wood material itself. No two species look exactly the same, in fact, they can have a significant visual difference in appearance among species. Yet a truly robust vision system must be able to handle a variety of such species, preferably with no operator intervention required when changing from one species to another. Secondly, there is a good deal of variability in the definition of what constitutes a removable defect. The hardwood furniture and fixture industry is diverse in the nature of the products that it makes. The products range from hardwood flooring to fancy hardwood furniture, from simple mill work to kitchen cabinets. Thus depending on the manufacturer, the product, and the quality of the product the nature of what constitutes a removable defect can and does vary. The vision system must be such that it can be tailored to meet each of these unique needs, preferably without any additional program modifications. This paper will describe the vision system that has been developed. It will assess the current system capabilities, and it will discuss the directions for future research. It will be argued that artificial intelligence methods provide a natural mechanism for attacking this computer vision application.

  1. Computer vision techniques applied to the quality control of ceramic plates

    OpenAIRE

    Silveira, Joaquim; Ferreira, Manuel João Oliveira; Santos, Cristina; Martins, Teresa

    2009-01-01

    This paper presents a system, based on computer vision techniques, that detects and quantifies different types of defects in ceramic plates. It was developed in collaboration with the industrial ceramic sector and consequently it was focused on the defects that are considered more quality depreciating by the Portuguese industry. They are of three main types: cracks; granules and relief surface. For each type the development was specific as far as image processing techn...

  2. Computer vision system R&D for EAST Articulated Maintenance Arm robot

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Linglong, E-mail: linglonglin@ipp.ac.cn; Song, Yuntao, E-mail: songyt@ipp.ac.cn; Yang, Yang, E-mail: yangy@ipp.ac.cn; Feng, Hansheng, E-mail: hsfeng@ipp.ac.cn; Cheng, Yong, E-mail: chengyong@ipp.ac.cn; Pan, Hongtao, E-mail: panht@ipp.ac.cn

    2015-11-15

    Highlights: • We discussed the image preprocessing, object detection and pose estimation algorithms under poor light condition of inner vessel of EAST tokamak. • The main pipeline, including contours detection, contours filter, MER extracted, object location and pose estimation, was carried out in detail. • The technical issues encountered during the research were discussed. - Abstract: Experimental Advanced Superconducting Tokamak (EAST) is the first full superconducting tokamak device which was constructed at Institute of Plasma Physics Chinese Academy of Sciences (ASIPP). The EAST Articulated Maintenance Arm (EAMA) robot provides the means of the in-vessel maintenance such as inspection and picking up the fragments of first wall. This paper presents a method to identify and locate the fragments semi-automatically by using the computer vision. The use of computer vision in identification and location faces some difficult challenges such as shadows, poor contrast, low illumination level, less texture and so on. The method developed in this paper enables credible identification of objects with shadows through invariant image and edge detection. The proposed algorithms are validated through our ASIPP robotics and computer vision platform (ARVP). The results show that the method can provide a 3D pose with reference to robot base so that objects with different shapes and size can be picked up successfully.

  3. Integral Images: Efficient Algorithms for Their Computation and Storage in Resource-Constrained Embedded Vision Systems.

    Science.gov (United States)

    Ehsan, Shoaib; Clark, Adrian F; Naveed ur Rehman; McDonald-Maier, Klaus D

    2015-07-10

    The integral image, an intermediate image representation, has found extensive use in multi-scale local feature detection algorithms, such as Speeded-Up Robust Features (SURF), allowing fast computation of rectangular features at constant speed, independent of filter size. For resource-constrained real-time embedded vision systems, computation and storage of integral image presents several design challenges due to strict timing and hardware limitations. Although calculation of the integral image only consists of simple addition operations, the total number of operations is large owing to the generally large size of image data. Recursive equations allow substantial decrease in the number of operations but require calculation in a serial fashion. This paper presents two new hardware algorithms that are based on the decomposition of these recursive equations, allowing calculation of up to four integral image values in a row-parallel way without significantly increasing the number of operations. An efficient design strategy is also proposed for a parallel integral image computation unit to reduce the size of the required internal memory (nearly 35% for common HD video). Addressing the storage problem of integral image in embedded vision systems, the paper presents two algorithms which allow substantial decrease (at least 44.44%) in the memory requirements. Finally, the paper provides a case study that highlights the utility of the proposed architectures in embedded vision systems.

  4. Integral Images: Efficient Algorithms for Their Computation and Storage in Resource-Constrained Embedded Vision Systems

    Directory of Open Access Journals (Sweden)

    Shoaib Ehsan

    2015-07-01

    Full Text Available The integral image, an intermediate image representation, has found extensive use in multi-scale local feature detection algorithms, such as Speeded-Up Robust Features (SURF, allowing fast computation of rectangular features at constant speed, independent of filter size. For resource-constrained real-time embedded vision systems, computation and storage of integral image presents several design challenges due to strict timing and hardware limitations. Although calculation of the integral image only consists of simple addition operations, the total number of operations is large owing to the generally large size of image data. Recursive equations allow substantial decrease in the number of operations but require calculation in a serial fashion. This paper presents two new hardware algorithms that are based on the decomposition of these recursive equations, allowing calculation of up to four integral image values in a row-parallel way without significantly increasing the number of operations. An efficient design strategy is also proposed for a parallel integral image computation unit to reduce the size of the required internal memory (nearly 35% for common HD video. Addressing the storage problem of integral image in embedded vision systems, the paper presents two algorithms which allow substantial decrease (at least 44.44% in the memory requirements. Finally, the paper provides a case study that highlights the utility of the proposed architectures in embedded vision systems.

  5. Computer vision system approach in colour measurements of foods: Part II. validation of methodology with real foods

    Directory of Open Access Journals (Sweden)

    Fatih TARLAK

    2016-01-01

    Full Text Available Abstract The colour of food is one of the most important factors affecting consumers’ purchasing decision. Although there are many colour spaces, the most widely used colour space in the food industry is L*a*b* colour space. Conventionally, the colour of foods is analysed with a colorimeter that measures small and non-representative areas of the food and the measurements usually vary depending on the point where the measurement is taken. This leads to the development of alternative colour analysis techniques. In this work, a simple and alternative method to measure the colour of foods known as “computer vision system” is presented and justified. With the aid of the computer vision system, foods that are homogenous and uniform in colour and shape could be classified with regard to their colours in a fast, inexpensive and simple way. This system could also be used to distinguish the defectives from the non-defectives. Quality parameters of meat and dairy products could be monitored without any physical contact, which causes contamination during sampling.

  6. Method of mobile robot indoor navigation by artificial landmarks with use of computer vision

    Science.gov (United States)

    Glibin, E. S.; Shevtsov, A. A.; Enik, O. A.

    2018-05-01

    The article describes an algorithm of the mobile robot indoor navigation based on the use of visual odometry. The results of the experiment identifying calculation errors in the distance traveled on a slip are presented. It is shown that the use of computer vision allows one to correct erroneous coordinates of the robot with the help of artificial landmarks. The control system utilizing the proposed method has been realized on the basis of Arduino Mego 2560 controller and a single-board computer Raspberry Pi 3. The results of the experiment on the mobile robot navigation with the use of this control system are presented.

  7. Vision 20/20: Automation and advanced computing in clinical radiation oncology

    International Nuclear Information System (INIS)

    Moore, Kevin L.; Moiseenko, Vitali; Kagadis, George C.; McNutt, Todd R.; Mutic, Sasa

    2014-01-01

    This Vision 20/20 paper considers what computational advances are likely to be implemented in clinical radiation oncology in the coming years and how the adoption of these changes might alter the practice of radiotherapy. Four main areas of likely advancement are explored: cloud computing, aggregate data analyses, parallel computation, and automation. As these developments promise both new opportunities and new risks to clinicians and patients alike, the potential benefits are weighed against the hazards associated with each advance, with special considerations regarding patient safety under new computational platforms and methodologies. While the concerns of patient safety are legitimate, the authors contend that progress toward next-generation clinical informatics systems will bring about extremely valuable developments in quality improvement initiatives, clinical efficiency, outcomes analyses, data sharing, and adaptive radiotherapy

  8. Vision 20/20: Automation and advanced computing in clinical radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Kevin L., E-mail: kevinmoore@ucsd.edu; Moiseenko, Vitali [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California 92093 (United States); Kagadis, George C. [Department of Medical Physics, School of Medicine, University of Patras, Rion, GR 26504 (Greece); McNutt, Todd R. [Department of Radiation Oncology and Molecular Radiation Science, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21231 (United States); Mutic, Sasa [Department of Radiation Oncology, Washington University in St. Louis, St. Louis, Missouri 63110 (United States)

    2014-01-15

    This Vision 20/20 paper considers what computational advances are likely to be implemented in clinical radiation oncology in the coming years and how the adoption of these changes might alter the practice of radiotherapy. Four main areas of likely advancement are explored: cloud computing, aggregate data analyses, parallel computation, and automation. As these developments promise both new opportunities and new risks to clinicians and patients alike, the potential benefits are weighed against the hazards associated with each advance, with special considerations regarding patient safety under new computational platforms and methodologies. While the concerns of patient safety are legitimate, the authors contend that progress toward next-generation clinical informatics systems will bring about extremely valuable developments in quality improvement initiatives, clinical efficiency, outcomes analyses, data sharing, and adaptive radiotherapy.

  9. Vision 20/20: Automation and advanced computing in clinical radiation oncology.

    Science.gov (United States)

    Moore, Kevin L; Kagadis, George C; McNutt, Todd R; Moiseenko, Vitali; Mutic, Sasa

    2014-01-01

    This Vision 20/20 paper considers what computational advances are likely to be implemented in clinical radiation oncology in the coming years and how the adoption of these changes might alter the practice of radiotherapy. Four main areas of likely advancement are explored: cloud computing, aggregate data analyses, parallel computation, and automation. As these developments promise both new opportunities and new risks to clinicians and patients alike, the potential benefits are weighed against the hazards associated with each advance, with special considerations regarding patient safety under new computational platforms and methodologies. While the concerns of patient safety are legitimate, the authors contend that progress toward next-generation clinical informatics systems will bring about extremely valuable developments in quality improvement initiatives, clinical efficiency, outcomes analyses, data sharing, and adaptive radiotherapy.

  10. A Novel adaptative Discrete Cuckoo Search Algorithm for parameter optimization in computer vision

    Directory of Open Access Journals (Sweden)

    loubna benchikhi

    2017-10-01

    Full Text Available Computer vision applications require choosing operators and their parameters, in order to provide the best outcomes. Often, the users quarry on expert knowledge and must experiment many combinations to find manually the best one. As performance, time and accuracy are important, it is necessary to automate parameter optimization at least for crucial operators. In this paper, a novel approach based on an adaptive discrete cuckoo search algorithm (ADCS is proposed. It automates the process of algorithms’ setting and provides optimal parameters for vision applications. This work reconsiders a discretization problem to adapt the cuckoo search algorithm and presents the procedure of parameter optimization. Some experiments on real examples and comparisons to other metaheuristic-based approaches: particle swarm optimization (PSO, reinforcement learning (RL and ant colony optimization (ACO show the efficiency of this novel method.

  11. Computer-enhanced stereoscopic vision in a head-mounted operating binocular

    International Nuclear Information System (INIS)

    Birkfellner, Wolfgang; Figl, Michael; Matula, Christian; Hummel, Johann; Hanel, Rudolf; Imhof, Herwig; Wanschitz, Felix; Wagner, Arne; Watzinger, Franz; Bergmann, Helmar

    2003-01-01

    Based on the Varioscope, a commercially available head-mounted operating binocular, we have developed the Varioscope AR, a see through head-mounted display (HMD) for augmented reality visualization that seamlessly fits into the infrastructure of a surgical navigation system. We have assessed the extent to which stereoscopic visualization improves target localization in computer-aided surgery in a phantom study. In order to quantify the depth perception of a user aiming at a given target, we have designed a phantom simulating typical clinical situations in skull base surgery. Sixteen steel spheres were fixed at the base of a bony skull, and several typical craniotomies were applied. After having taken CT scans, the skull was filled with opaque jelly in order to simulate brain tissue. The positions of the spheres were registered using VISIT, a system for computer-aided surgical navigation. Then attempts were made to locate the steel spheres with a bayonet probe through the craniotomies using VISIT and the Varioscope AR as a stereoscopic display device. Localization of targets 4 mm in diameter using stereoscopic vision and additional visual cues indicating target proximity had a success rate (defined as a first-trial hit rate) of 87.5%. Using monoscopic vision and target proximity indication, the success rate was found to be 66.6%. Omission of visual hints on reaching a target yielded a success rate of 79.2% in the stereo case and 56.25% with monoscopic vision. Time requirements for localizing all 16 targets ranged from 7.5 min (stereo, with proximity cues) to 10 min (mono, without proximity cues). Navigation error is primarily governed by the accuracy of registration in the navigation system, whereas the HMD does not appear to influence localization significantly. We conclude that stereo vision is a valuable tool in augmented reality guided interventions. (note)

  12. Genomic cloud computing: legal and ethical points to consider.

    Science.gov (United States)

    Dove, Edward S; Joly, Yann; Tassé, Anne-Marie; Knoppers, Bartha M

    2015-10-01

    The biggest challenge in twenty-first century data-intensive genomic science, is developing vast computer infrastructure and advanced software tools to perform comprehensive analyses of genomic data sets for biomedical research and clinical practice. Researchers are increasingly turning to cloud computing both as a solution to integrate data from genomics, systems biology and biomedical data mining and as an approach to analyze data to solve biomedical problems. Although cloud computing provides several benefits such as lower costs and greater efficiency, it also raises legal and ethical issues. In this article, we discuss three key 'points to consider' (data control; data security, confidentiality and transfer; and accountability) based on a preliminary review of several publicly available cloud service providers' Terms of Service. These 'points to consider' should be borne in mind by genomic research organizations when negotiating legal arrangements to store genomic data on a large commercial cloud service provider's servers. Diligent genomic cloud computing means leveraging security standards and evaluation processes as a means to protect data and entails many of the same good practices that researchers should always consider in securing their local infrastructure.

  13. Clinical efficacy of Ayurvedic management in computer vision syndrome: A pilot study.

    Science.gov (United States)

    Dhiman, Kartar Singh; Ahuja, Deepak Kumar; Sharma, Sanjeev Kumar

    2012-07-01

    Improper use of sense organs, violating the moral code of conduct, and the effect of the time are the three basic causative factors behind all the health problems. Computer, the knowledge bank of modern life, has emerged as a profession causing vision-related discomfort, ocular fatigue, and systemic effects. Computer Vision Syndrome (CVS) is the new nomenclature to the visual, ocular, and systemic symptoms arising due to the long time and improper working on the computer and is emerging as a pandemic in the 21(st) century. On critical analysis of the symptoms of CVS on Tridoshika theory of Ayurveda, as per the road map given by Acharya Charaka, it seems to be a Vata-Pittaja ocular cum systemic disease which needs systemic as well as topical treatment approach. Shatavaryaadi Churna (orally), Go-Ghrita Netra Tarpana (topically), and counseling regarding proper working conditions on computer were tried in 30 patients of CVS. In group I, where oral and local treatment was given, significant improvement in all the symptoms of CVS was observed, whereas in groups II and III, local treatment and counseling regarding proper working conditions, respectively, were given and showed insignificant results. The study verified the hypothesis that CVS in Ayurvedic perspective is a Vata-Pittaja disease affecting mainly eyes and body as a whole and needs a systemic intervention rather than topical ocular medication only.

  14. Computer use and vision-related problems among university students in ajman, United arab emirate.

    Science.gov (United States)

    Shantakumari, N; Eldeeb, R; Sreedharan, J; Gopal, K

    2014-03-01

    The extensive use of computers as medium of teaching and learning in universities necessitates introspection into the extent of computer related health disorders among student population. This study was undertaken to assess the pattern of computer usage and related visual problems, among University students in Ajman, United Arab Emirates. A total of 500 Students studying in Gulf Medical University, Ajman and Ajman University of Science and Technology were recruited into this study. Demographic characteristics, pattern of usage of computers and associated visual symptoms were recorded in a validated self-administered questionnaire. Chi-square test was used to determine the significance of the observed differences between the variables. The level of statistical significance was at P computer users were headache - 53.3% (251/471), burning sensation in the eyes - 54.8% (258/471) and tired eyes - 48% (226/471). Female students were found to be at a higher risk. Nearly 72% of students reported frequent interruption of computer work. Headache caused interruption of work in 43.85% (110/168) of the students while tired eyes caused interruption of work in 43.5% (98/168) of the students. When the screen was viewed at distance more than 50 cm, the prevalence of headaches decreased by 38% (50-100 cm - OR: 0.62, 95% of the confidence interval [CI]: 0.42-0.92). Prevalence of tired eyes increased by 89% when screen filters were not used (OR: 1.894, 95% CI: 1.065-3.368). High prevalence of vision related problems was noted among university students. Sustained periods of close screen work without screen filters were found to be associated with occurrence of the symptoms and increased interruptions of work of the students. There is a need to increase the ergonomic awareness among students and corrective measures need to be implemented to reduce the impact of computer related vision problems.

  15. Fixed-point image orthorectification algorithms for reduced computational cost

    Science.gov (United States)

    French, Joseph Clinton

    Imaging systems have been applied to many new applications in recent years. With the advent of low-cost, low-power focal planes and more powerful, lower cost computers, remote sensing applications have become more wide spread. Many of these applications require some form of geolocation, especially when relative distances are desired. However, when greater global positional accuracy is needed, orthorectification becomes necessary. Orthorectification is the process of projecting an image onto a Digital Elevation Map (DEM), which removes terrain distortions and corrects the perspective distortion by changing the viewing angle to be perpendicular to the projection plane. Orthorectification is used in disaster tracking, landscape management, wildlife monitoring and many other applications. However, orthorectification is a computationally expensive process due to floating point operations and divisions in the algorithm. To reduce the computational cost of on-board processing, two novel algorithm modifications are proposed. One modification is projection utilizing fixed-point arithmetic. Fixed point arithmetic removes the floating point operations and reduces the processing time by operating only on integers. The second modification is replacement of the division inherent in projection with a multiplication of the inverse. The inverse must operate iteratively. Therefore, the inverse is replaced with a linear approximation. As a result of these modifications, the processing time of projection is reduced by a factor of 1.3x with an average pixel position error of 0.2% of a pixel size for 128-bit integer processing and over 4x with an average pixel position error of less than 13% of a pixel size for a 64-bit integer processing. A secondary inverse function approximation is also developed that replaces the linear approximation with a quadratic. The quadratic approximation produces a more accurate approximation of the inverse, allowing for an integer multiplication calculation

  16. TU-FG-201-04: Computer Vision in Autonomous Quality Assurance of Linear Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Yu, H; Jenkins, C; Yu, S; Yang, Y; Xing, L [Stanford University, Stanford, CA (United States)

    2016-06-15

    Purpose: Routine quality assurance (QA) of linear accelerators represents a critical and costly element of a radiation oncology center. Recently, a system was developed to autonomously perform routine quality assurance on linear accelerators. The purpose of this work is to extend this system and contribute computer vision techniques for obtaining quantitative measurements for a monthly multi-leaf collimator (MLC) QA test specified by TG-142, namely leaf position accuracy, and demonstrate extensibility for additional routines. Methods: Grayscale images of a picket fence delivery on a radioluminescent phosphor coated phantom are captured using a CMOS camera. Collected images are processed to correct for camera distortions, rotation and alignment, reduce noise, and enhance contrast. The location of each MLC leaf is determined through logistic fitting and a priori modeling based on knowledge of the delivered beams. Using the data collected and the criteria from TG-142, a decision is made on whether or not the leaf position accuracy of the MLC passes or fails. Results: The locations of all MLC leaf edges are found for three different picket fence images in a picket fence routine to 0.1mm/1pixel precision. The program to correct for image alignment and determination of leaf positions requires a runtime of 21– 25 seconds for a single picket, and 44 – 46 seconds for a group of three pickets on a standard workstation CPU, 2.2 GHz Intel Core i7. Conclusion: MLC leaf edges were successfully found using techniques in computer vision. With the addition of computer vision techniques to the previously described autonomous QA system, the system is able to quickly perform complete QA routines with minimal human contribution.

  17. Fuzzy classification for strawberry diseases-infection using machine vision and soft-computing techniques

    Science.gov (United States)

    Altıparmak, Hamit; Al Shahadat, Mohamad; Kiani, Ehsan; Dimililer, Kamil

    2018-04-01

    Robotic agriculture requires smart and doable techniques to substitute the human intelligence with machine intelligence. Strawberry is one of the important Mediterranean product and its productivity enhancement requires modern and machine-based methods. Whereas a human identifies the disease infected leaves by his eye, the machine should also be capable of vision-based disease identification. The objective of this paper is to practically verify the applicability of a new computer-vision method for discrimination between the healthy and disease infected strawberry leaves which does not require neural network or time consuming trainings. The proposed method was tested under outdoor lighting condition using a regular DLSR camera without any particular lens. Since the type and infection degree of disease is approximated a human brain a fuzzy decision maker classifies the leaves over the images captured on-site having the same properties of human vision. Optimizing the fuzzy parameters for a typical strawberry production area at a summer mid-day in Cyprus produced 96% accuracy for segmented iron deficiency and 93% accuracy for segmented using a typical human instant classification approximation as the benchmark holding higher accuracy than a human eye identifier. The fuzzy-base classifier provides approximate result for decision making on the leaf status as if it is healthy or not.

  18. Gesture recognition based on computer vision and glove sensor for remote working environments

    Energy Technology Data Exchange (ETDEWEB)

    Chien, Sung Il; Kim, In Chul; Baek, Yung Mok; Kim, Dong Su; Jeong, Jee Won; Shin, Kug [Kyungpook National University, Taegu (Korea)

    1998-04-01

    In this research, we defined a gesture set needed for remote monitoring and control of a manless system in atomic power station environments. Here, we define a command as the loci of a gesture. We aim at the development of an algorithm using a vision sensor and glove sensors in order to implement the gesture recognition system. The gesture recognition system based on computer vision tracks a hand by using cross correlation of PDOE image. To recognize the gesture word, the 8 direction code is employed as the input symbol for discrete HMM. Another gesture recognition based on sensor has introduced Pinch glove and Polhemus sensor as an input device. The extracted feature through preprocessing now acts as an input signal of the recognizer. For recognition 3D loci of Polhemus sensor, discrete HMM is also adopted. The alternative approach of two foregoing recognition systems uses the vision and and glove sensors together. The extracted mesh feature and 8 direction code from the locus tracking are introduced for further enhancing recognition performance. MLP trained by backpropagation is introduced here and its performance is compared to that of discrete HMM. (author). 32 refs., 44 figs., 21 tabs.

  19. Objective definition of rosette shape variation using a combined computer vision and data mining approach.

    Directory of Open Access Journals (Sweden)

    Anyela Camargo

    Full Text Available Computer-vision based measurements of phenotypic variation have implications for crop improvement and food security because they are intrinsically objective. It should be possible therefore to use such approaches to select robust genotypes. However, plants are morphologically complex and identification of meaningful traits from automatically acquired image data is not straightforward. Bespoke algorithms can be designed to capture and/or quantitate specific features but this approach is inflexible and is not generally applicable to a wide range of traits. In this paper, we have used industry-standard computer vision techniques to extract a wide range of features from images of genetically diverse Arabidopsis rosettes growing under non-stimulated conditions, and then used statistical analysis to identify those features that provide good discrimination between ecotypes. This analysis indicates that almost all the observed shape variation can be described by 5 principal components. We describe an easily implemented pipeline including image segmentation, feature extraction and statistical analysis. This pipeline provides a cost-effective and inherently scalable method to parameterise and analyse variation in rosette shape. The acquisition of images does not require any specialised equipment and the computer routines for image processing and data analysis have been implemented using open source software. Source code for data analysis is written using the R package. The equations to calculate image descriptors have been also provided.

  20. Tensor Voting A Perceptual Organization Approach to Computer Vision and Machine Learning

    CERN Document Server

    Mordohai, Philippos

    2006-01-01

    This lecture presents research on a general framework for perceptual organization that was conducted mainly at the Institute for Robotics and Intelligent Systems of the University of Southern California. It is not written as a historical recount of the work, since the sequence of the presentation is not in chronological order. It aims at presenting an approach to a wide range of problems in computer vision and machine learning that is data-driven, local and requires a minimal number of assumptions. The tensor voting framework combines these properties and provides a unified perceptual organiza

  1. Simple computation of reaction–diffusion processes on point clouds

    KAUST Repository

    Macdonald, Colin B.; Merriman, Barry; Ruuth, Steven J.

    2013-01-01

    The study of reaction-diffusion processes is much more complicated on general curved surfaces than on standard Cartesian coordinate spaces. Here we show how to formulate and solve systems of reaction-diffusion equations on surfaces in an extremely simple way, using only the standard Cartesian form of differential operators, and a discrete unorganized point set to represent the surface. Our method decouples surface geometry from the underlying differential operators. As a consequence, it becomes possible to formulate and solve rather general reaction-diffusion equations on general surfaces without having to consider the complexities of differential geometry or sophisticated numerical analysis. To illustrate the generality of the method, computations for surface diffusion, pattern formation, excitable media, and bulk-surface coupling are provided for a variety of complex point cloud surfaces.

  2. Simple computation of reaction–diffusion processes on point clouds

    KAUST Repository

    Macdonald, Colin B.

    2013-05-20

    The study of reaction-diffusion processes is much more complicated on general curved surfaces than on standard Cartesian coordinate spaces. Here we show how to formulate and solve systems of reaction-diffusion equations on surfaces in an extremely simple way, using only the standard Cartesian form of differential operators, and a discrete unorganized point set to represent the surface. Our method decouples surface geometry from the underlying differential operators. As a consequence, it becomes possible to formulate and solve rather general reaction-diffusion equations on general surfaces without having to consider the complexities of differential geometry or sophisticated numerical analysis. To illustrate the generality of the method, computations for surface diffusion, pattern formation, excitable media, and bulk-surface coupling are provided for a variety of complex point cloud surfaces.

  3. A computational framework for automation of point defect calculations

    International Nuclear Information System (INIS)

    Goyal, Anuj; Gorai, Prashun; Peng, Haowei

    2017-01-01

    We have developed a complete and rigorously validated open-source Python framework to automate point defect calculations using density functional theory. Furthermore, the framework provides an effective and efficient method for defect structure generation, and creation of simple yet customizable workflows to analyze defect calculations. This package provides the capability to compute widely-accepted correction schemes to overcome finite-size effects, including (1) potential alignment, (2) image-charge correction, and (3) band filling correction to shallow defects. Using Si, ZnO and In2O3 as test examples, we demonstrate the package capabilities and validate the methodology.

  4. Tracking the Creation of Tropical Forest Canopy Gaps with UAV Computer Vision Remote Sensing

    Science.gov (United States)

    Dandois, J. P.

    2015-12-01

    The formation of canopy gaps is fundamental for shaping forest structure and is an important component of ecosystem function. Recent time-series of airborne LIDAR have shown great promise for improving understanding of the spatial distribution and size of forest gaps. However, such work typically looks at gap formation across multiple years and important intra-annual variation in gap dynamics remains unknown. Here we present findings on the intra-annual dynamics of canopy gap formation within the 50 ha forest dynamics plot of Barro Colorado Island (BCI), Panama based on unmanned aerial vehicle (UAV) remote sensing. High-resolution imagery (7 cm GSD) over the 50 ha plot was obtained regularly (≈ every 10 days) beginning October 2014 using a UAV equipped with a point and shoot camera. Imagery was processed into three-dimensional (3D) digital surface models (DSMs) using automated computer vision structure from motion / photogrammetric methods. New gaps that formed between each UAV flight were identified by subtracting DSMs between each interval and identifying areas of large deviation. A total of 48 new gaps were detected from 2014-10-02 to 2015-07-23, with sizes ranging from less than 20 m2 to greater than 350 m2. The creation of new gaps was also evaluated across wet and dry seasons with 4.5 new gaps detected per month in the dry season (Jan. - May) and 5.2 per month outside the dry season (Oct. - Jan. & May - July). The incidence of gap formation was positively correlated with ground-surveyed liana stem density (R2 = 0.77, p < 0.001) at the 1 hectare scale. Further research will consider the role of climate in predicting gap formation frequency as well as site history and other edaphic factors. Future satellite missions capable of observing vegetation structure at greater extents and frequencies than airborne observations will be greatly enhanced by the high spatial and temporal resolution bridging scale made possible by UAV remote sensing.

  5. The computer vision in the service of safety and reliability in steam generators inspection services; La vision computacional al servicio de la seguridad y fiabilidad en los servicios de inspeccion en generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Pineiro Fernandez, P.; Garcia Bueno, A.; Cabrera Jordan, E.

    2012-07-01

    The actual computational vision has matured very quickly in the last ten years by facilitating new developments in various areas of nuclear application allowing to automate and simplify processes and tasks, instead or in collaboration with the people and equipment efficiently. The current computer vision (more appropriate than the artificial vision concept) provides great possibilities of also improving in terms of the reliability and safety of NPPS inspection systems.

  6. Principle for the Validation of a Driving Support using a Computer Vision-Based Driver Modelization on a Simulator

    Directory of Open Access Journals (Sweden)

    Baptiste Rouzier

    2015-07-01

    Full Text Available This paper presents a new structure for a driving support designed to compensate for the problems caused by the behaviour of the driver without causing a feeling of unease. This assistance is based on a shared control between the human and an automatic support that computes and applies an assisting torque on the steering wheel. This torque is computed from a representation of the hazards encountered on the road by virtual potentials. However, the equilibrium between the relative influences of the human and the support on the steering wheel are difficult to find and depend upon the situation. This is why this driving support includes a modelization of the driver based on an analysis of several face features using a computer vision algorithm. The goal is to determine whether the driver is drowsy or whether he is paying attention to some specific points in order to adapt the strength of the support. The accuracy of the measurements made on the face features is estimated, and the interest of the proposal as well as the concepts raised by such assistance are studied through simulations.

  7. Comparative randomised controlled clinical trial of a herbal eye drop with artificial tear and placebo in computer vision syndrome.

    Science.gov (United States)

    Biswas, N R; Nainiwal, S K; Das, G K; Langan, U; Dadeya, S C; Mongre, P K; Ravi, A K; Baidya, P

    2003-03-01

    A comparative randomised double masked multicentric clinical trial has been conducted to find out the efficacy and safety of a herbal eye drop preparation, itone eye drops with artificial tear and placebo in 120 patients with computer vision syndrome. Patients using computer for at least 2 hours continuosly per day having symptoms of irritation, foreign body sensation, watering, redness, headache, eyeache and signs of conjunctival congestion, mucous/debris, corneal filaments, corneal staining or lacrimal lake were included in this study. Every patient was instructed to put two drops of either herbal drugs or placebo or artificial tear in the eyes regularly four times for 6 weeks. Objective and subjective findings were recorded at bi-weekly intervals up to six weeks. Side-effects, if any, were also noted. In computer vision syndrome the herbal eye drop preparation was found significantly better than artificial tear (p computer vision syndrome.

  8. EAST-AIA deployment under vacuum: Calibration of laser diagnostic system using computer vision

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang, E-mail: yangyang@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, 350 Shushanhu Rd, Hefei, Anhui (China); Song, Yuntao; Cheng, Yong; Feng, Hansheng; Wu, Zhenwei; Li, Yingying; Sun, Yongjun; Zheng, Lei [Institute of Plasma Physics, Chinese Academy of Sciences, 350 Shushanhu Rd, Hefei, Anhui (China); Bruno, Vincent; Eric, Villedieu [CEA-IRFM, F-13108 Saint-Paul-Lez-Durance (France)

    2016-11-15

    Highlights: • The first deployment of the EAST articulated inspection arm robot under vacuum is presented. • A computer vision based approach to measure the laser spot displacement is proposed. • An experiment on the real EAST tokamak is performed to validate the proposed measure approach, and the results shows that the measurement accuracy satisfies the requirement. - Abstract: For the operation of EAST tokamak, it is crucial to ensure that all the diagnostic systems are in the good condition in order to reflect the plasma status properly. However, most of the diagnostic systems are mounted inside the tokamak vacuum vessel, which makes them extremely difficult to maintain under high vacuum condition during the tokamak operation. Thanks to a system called EAST articulated inspection arm robot (EAST-AIA), the examination of these in-vessel diagnostic systems can be performed by an embedded camera carried by the robot. In this paper, a computer vision algorithm has been developed to calibrate a laser diagnostic system with the help of a monocular camera at the robot end. In order to estimate the displacement of the laser diagnostic system with respect to the vacuum vessel, several visual markers were attached to the inner wall. This experiment was conducted both on the EAST vacuum vessel mock-up and the real EAST tokamak under vacuum condition. As a result, the accuracy of the displacement measurement was within 3 mm under the current camera resolution, which satisfied the laser diagnostic system calibration.

  9. Container-code recognition system based on computer vision and deep neural networks

    Science.gov (United States)

    Liu, Yi; Li, Tianjian; Jiang, Li; Liang, Xiaoyao

    2018-04-01

    Automatic container-code recognition system becomes a crucial requirement for ship transportation industry in recent years. In this paper, an automatic container-code recognition system based on computer vision and deep neural networks is proposed. The system consists of two modules, detection module and recognition module. The detection module applies both algorithms based on computer vision and neural networks, and generates a better detection result through combination to avoid the drawbacks of the two methods. The combined detection results are also collected for online training of the neural networks. The recognition module exploits both character segmentation and end-to-end recognition, and outputs the recognition result which passes the verification. When the recognition module generates false recognition, the result will be corrected and collected for online training of the end-to-end recognition sub-module. By combining several algorithms, the system is able to deal with more situations, and the online training mechanism can improve the performance of the neural networks at runtime. The proposed system is able to achieve 93% of overall recognition accuracy.

  10. Computer vision-based method for classification of wheat grains using artificial neural network.

    Science.gov (United States)

    Sabanci, Kadir; Kayabasi, Ahmet; Toktas, Abdurrahim

    2017-06-01

    A simplified computer vision-based application using artificial neural network (ANN) depending on multilayer perceptron (MLP) for accurately classifying wheat grains into bread or durum is presented. The images of 100 bread and 100 durum wheat grains are taken via a high-resolution camera and subjected to pre-processing. The main visual features of four dimensions, three colors and five textures are acquired using image-processing techniques (IPTs). A total of 21 visual features are reproduced from the 12 main features to diversify the input population for training and testing the ANN model. The data sets of visual features are considered as input parameters of the ANN model. The ANN with four different input data subsets is modelled to classify the wheat grains into bread or durum. The ANN model is trained with 180 grains and its accuracy tested with 20 grains from a total of 200 wheat grains. Seven input parameters that are most effective on the classifying results are determined using the correlation-based CfsSubsetEval algorithm to simplify the ANN model. The results of the ANN model are compared in terms of accuracy rate. The best result is achieved with a mean absolute error (MAE) of 9.8 × 10 -6 by the simplified ANN model. This shows that the proposed classifier based on computer vision can be successfully exploited to automatically classify a variety of grains. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  11. Computer Vision Utilization for Detection of Green House Tomato under Natural Illumination

    Directory of Open Access Journals (Sweden)

    H Mohamadi Monavar

    2013-02-01

    Full Text Available Agricultural sector experiences the application of automated systems since two decades ago. These systems are applied to harvest fruits in agriculture. Computer vision is one of the technologies that are most widely used in food industries and agriculture. In this paper, an automated system based on computer vision for harvesting greenhouse tomatoes is presented. A CCD camera takes images from workspace and tomatoes with over 50 percent ripeness are detected through an image processing algorithm. In this research three color spaces including RGB, HSI and YCbCr and three algorithms including threshold recognition, curvature of the image and red/green ratio were used in order to identify the ripe tomatoes from background under natural illumination. The average error of threshold recognition, red/green ratio and curvature of the image algorithms were 11.82%, 10.03% and 7.95% in HSI, RGB and YCbCr color spaces, respectively. Therefore, the YCbCr color space and curvature of the image algorithm were identified as the most suitable for recognizing fruits under natural illumination condition.

  12. Design of an optimum computer vision-based automatic abalone (Haliotis discus hannai) grading algorithm.

    Science.gov (United States)

    Lee, Donggil; Lee, Kyounghoon; Kim, Seonghun; Yang, Yongsu

    2015-04-01

    An automatic abalone grading algorithm that estimates abalone weights on the basis of computer vision using 2D images is developed and tested. The algorithm overcomes the problems experienced by conventional abalone grading methods that utilize manual sorting and mechanical automatic grading. To design an optimal algorithm, a regression formula and R(2) value were investigated by performing a regression analysis for each of total length, body width, thickness, view area, and actual volume against abalone weights. The R(2) value between the actual volume and abalone weight was 0.999, showing a relatively high correlation. As a result, to easily estimate the actual volumes of abalones based on computer vision, the volumes were calculated under the assumption that abalone shapes are half-oblate ellipsoids, and a regression formula was derived to estimate the volumes of abalones through linear regression analysis between the calculated and actual volumes. The final automatic abalone grading algorithm is designed using the abalone volume estimation regression formula derived from test results, and the actual volumes and abalone weights regression formula. In the range of abalones weighting from 16.51 to 128.01 g, the results of evaluation of the performance of algorithm via cross-validation indicate root mean square and worst-case prediction errors of are 2.8 and ±8 g, respectively. © 2015 Institute of Food Technologists®

  13. Rapid, computer vision-enabled murine screening system identifies neuropharmacological potential of two new mechanisms

    Directory of Open Access Journals (Sweden)

    Steven L Roberds

    2011-09-01

    Full Text Available The lack of predictive in vitro models for behavioral phenotypes impedes rapid advancement in neuropharmacology and psychopharmacology. In vivo behavioral assays are more predictive of activity in human disorders, but such assays are often highly resource-intensive. Here we describe the successful application of a computer vision-enabled system to identify potential neuropharmacological activity of two new mechanisms. The analytical system was trained using multiple drugs that are used clinically to treat depression, schizophrenia, anxiety, and other psychiatric or behavioral disorders. During blinded testing the PDE10 inhibitor TP-10 produced a signature of activity suggesting potential antipsychotic activity. This finding is consistent with TP-10’s activity in multiple rodent models that is similar to that of clinically used antipsychotic drugs. The CK1ε inhibitor PF-670462 produced a signature consistent with anxiolytic activity and, at the highest dose tested, behavioral effects similar to that of opiate analgesics. Neither TP-10 nor PF-670462 was included in the training set. Thus, computer vision-based behavioral analysis can facilitate drug discovery by identifying neuropharmacological effects of compounds acting through new mechanisms.

  14. Aquatic Toxic Analysis by Monitoring Fish Behavior Using Computer Vision: A Recent Progress

    Directory of Open Access Journals (Sweden)

    Chunlei Xia

    2018-01-01

    Full Text Available Video tracking based biological early warning system achieved a great progress with advanced computer vision and machine learning methods. Ability of video tracking of multiple biological organisms has been largely improved in recent years. Video based behavioral monitoring has become a common tool for acquiring quantified behavioral data for aquatic risk assessment. Investigation of behavioral responses under chemical and environmental stress has been boosted by rapidly developed machine learning and artificial intelligence. In this paper, we introduce the fundamental of video tracking and present the pioneer works in precise tracking of a group of individuals in 2D and 3D space. Technical and practical issues suffered in video tracking are explained. Subsequently, the toxic analysis based on fish behavioral data is summarized. Frequently used computational methods and machine learning are explained with their applications in aquatic toxicity detection and abnormal pattern analysis. Finally, advantages of recent developed deep learning approach in toxic prediction are presented.

  15. Modeling molecular boiling points using computed interaction energies.

    Science.gov (United States)

    Peterangelo, Stephen C; Seybold, Paul G

    2017-12-20

    The noncovalent van der Waals interactions between molecules in liquids are typically described in textbooks as occurring between the total molecular dipoles (permanent, induced, or transient) of the molecules. This notion was tested by examining the boiling points of 67 halogenated hydrocarbon liquids using quantum chemically calculated molecular dipole moments, ionization potentials, and polarizabilities obtained from semi-empirical (AM1 and PM3) and ab initio Hartree-Fock [HF 6-31G(d), HF 6-311G(d,p)], and density functional theory [B3LYP/6-311G(d,p)] methods. The calculated interaction energies and an empirical measure of hydrogen bonding were employed to model the boiling points of the halocarbons. It was found that only terms related to London dispersion energies and hydrogen bonding proved significant in the regression analyses, and the performances of the models generally improved at higher levels of quantum chemical computation. An empirical estimate for the molecular polarizabilities was also tested, and the best models for the boiling points were obtained using either this empirical polarizability itself or the polarizabilities calculated at the B3LYP/6-311G(d,p) level, along with the hydrogen-bonding parameter. The results suggest that the cohesive forces are more appropriately described as resulting from highly localized interactions rather than interactions between the global molecular dipoles.

  16. A method of non-contact reading code based on computer vision

    Science.gov (United States)

    Zhang, Chunsen; Zong, Xiaoyu; Guo, Bingxuan

    2018-03-01

    With the purpose of guarantee the computer information exchange security between internal and external network (trusted network and un-trusted network), A non-contact Reading code method based on machine vision has been proposed. Which is different from the existing network physical isolation method. By using the computer monitors, camera and other equipment. Deal with the information which will be on exchanged, Include image coding ,Generate the standard image , Display and get the actual image , Calculate homography matrix, Image distort correction and decoding in calibration, To achieve the computer information security, Non-contact, One-way transmission between the internal and external network , The effectiveness of the proposed method is verified by experiments on real computer text data, The speed of data transfer can be achieved 24kb/s. The experiment shows that this algorithm has the characteristics of high security, fast velocity and less loss of information. Which can meet the daily needs of the confidentiality department to update the data effectively and reliably, Solved the difficulty of computer information exchange between Secret network and non-secret network, With distinctive originality, practicability, and practical research value.

  17. Computer vision syndrome: a study of knowledge and practices in university students.

    Science.gov (United States)

    Reddy, S C; Low, C K; Lim, Y P; Low, L L; Mardina, F; Nursaleha, M P

    2013-01-01

    Computer vision syndrome (CVS) is a condition in which a person experiences one or more of eye symptoms as a result of prolonged working on a computer. To determine the prevalence of CVS symptoms, knowledge and practices of computer use in students studying in different universities in Malaysia, and to evaluate the association of various factors in computer use with the occurrence of symptoms. In a cross sectional, questionnaire survey study, data was collected in college students regarding the demography, use of spectacles, duration of daily continuous use of computer, symptoms of CVS, preventive measures taken to reduce the symptoms, use of radiation filter on the computer screen, and lighting in the room. A total of 795 students, aged between 18 and 25 years, from five universities in Malaysia were surveyed. The prevalence of symptoms of CVS (one or more) was found to be 89.9%; the most disturbing symptom was headache (19.7%) followed by eye strain (16.4%). Students who used computer for more than 2 hours per day experienced significantly more symptoms of CVS (p=0.0001). Looking at far objects in-between the work was significantly (p=0.0008) associated with less frequency of CVS symptoms. The use of radiation filter on the screen (p=0.6777) did not help in reducing the CVS symptoms. Ninety percent of university students in Malaysia experienced symptoms related to CVS, which was seen more often in those who used computer for more than 2 hours continuously per day. © NEPjOPH.

  18. Medical and legal point of view for low-vision patients.

    Science.gov (United States)

    Bogdănici, Camelia-Margareta; Bogdănici, Ştefan Tudor; Săndulache, Diana Elena; Diaconu, Carmen-Mariana

    2018-01-01

    The aim of the study was to highlight the medical and legal difficulties in framing low-vision patients for certification. We performed a retrospective observational study conducted from January 2013 to January 2016, on 63 patients with the mean age of 16.37±3.34 years, evaluated at the Ophthalmology Clinic from "Sf. Spiridon" Hospital, Iași, in order to release a medical certificate required at the Expertise Board. The clinical parameters observed were visual acuity (VA) with correction, objective refraction (in Spherical Equivalent - SEq), intraocular pressure, slit lamp examination of the anterior pole, fundus examination, orthoptic eye exam, and ocular ultrasonography (in selected cases). The main causes for the decreased visual acuity found are refractive or strabic amblyopia determined by: high myopia (28.57%), esotropia (19.04%), astigmatism (17.46); congenital diseases - congenital nystagmus (12.69%), congenital cataract (7.93%), microphthalmia (7.93%); acquired diseases - retinopathy of prematurity (9.52%), optic nerve atrophy (7.93%), bandelette keratopathy (6.34); ocular trauma (7.93%). In 52.38% of the cases for the RE and 53.96% of the cases for the LE, decreased visual acuity was caused by an irreversible condition and could not be improved. Patients come every year for reevaluation in order to receive the medical certificate required at the Expertise Board. Evaluating the patient for a certificate for visual impairment is a time consuming process due to the high number of investigations necessary and, sometimes, difficult collaboration with the patient with associated general pathology. It also requires knowledge of frequently changing legislation to complete legal forms for patients with visual impairment. A medical certificate may now be issued with a validity of up to four years, given that certain diseases are irreversible and visual functional status does not change over time.

  19. Fast and accurate computation of projected two-point functions

    Science.gov (United States)

    Grasshorn Gebhardt, Henry S.; Jeong, Donghui

    2018-01-01

    We present the two-point function from the fast and accurate spherical Bessel transformation (2-FAST) algorithm1Our code is available at https://github.com/hsgg/twoFAST. for a fast and accurate computation of integrals involving one or two spherical Bessel functions. These types of integrals occur when projecting the galaxy power spectrum P (k ) onto the configuration space, ξℓν(r ), or spherical harmonic space, Cℓ(χ ,χ'). First, we employ the FFTLog transformation of the power spectrum to divide the calculation into P (k )-dependent coefficients and P (k )-independent integrations of basis functions multiplied by spherical Bessel functions. We find analytical expressions for the latter integrals in terms of special functions, for which recursion provides a fast and accurate evaluation. The algorithm, therefore, circumvents direct integration of highly oscillating spherical Bessel functions.

  20. Development of the method of aggregation to determine the current storage area using computer vision and radiofrequency identification

    Science.gov (United States)

    Astafiev, A.; Orlov, A.; Privezencev, D.

    2018-01-01

    The article is devoted to the development of technology and software for the construction of positioning and control systems in industrial plants based on aggregation to determine the current storage area using computer vision and radiofrequency identification. It describes the developed of the project of hardware for industrial products positioning system in the territory of a plant on the basis of radio-frequency grid. It describes the development of the project of hardware for industrial products positioning system in the plant on the basis of computer vision methods. It describes the development of the method of aggregation to determine the current storage area using computer vision and radiofrequency identification. Experimental studies in laboratory and production conditions have been conducted and described in the article.

  1. Dirt detection on brown eggs by means of color computer vision.

    Science.gov (United States)

    Mertens, K; De Ketelaere, B; Kamers, B; Bamelis, F R; Kemps, B J; Verhoelst, E M; De Baerdemaeker, J G; Decuypere, E M

    2005-10-01

    In the last 20 yr, different methods for detecting defects in eggs were developed. Until now, no satisfying technique existed to sort and quantify dirt on eggshells. The work presented here focuses on the design of an off-line computer vision system to differentiate and quantify the presence of different dirt stains on brown eggs: dark (feces), white (uric acid), blood, and yolk stains. A system that provides uniform light exposure around the egg was designed. In this uniform light, pictures of dirty and clean eggs were taken, stored, and analyzed. The classification was based on a few standard logical operators, allowing for a quick implementation in an online set-up. In an experiment, 100 clean and 100 dirty eggs were used to validate the classification algorithm. The designed vision system showed an accuracy of 99% for the detection of dirt stains. Two percent of the clean eggs had a light-colored eggshell and were subsequently mistaken for showing large white stains. The accuracy of differentiation of the different kinds of dirt stains was 91%. Of the eggs with dark stains, 10.81% were mistaken for having bloodstains, and 33.33% of eggs with bloodstains were mistaken for having dark stains. The developed system is possibly a first step toward an on line dirt evaluation technique for brown eggs.

  2. Monitoring and Optimization of the Process of Drying Fruits and Vegetables Using Computer Vision: A Review

    Directory of Open Access Journals (Sweden)

    Flavio Raponi

    2017-11-01

    Full Text Available An overview is given regarding the most recent use of non-destructive techniques during drying used to monitor quality changes in fruits and vegetables. Quality changes were commonly investigated in order to improve the sensory properties (i.e., appearance, texture, flavor and aroma, nutritive values, chemical constituents and mechanical properties of drying products. The application of single-point spectroscopy coupled with drying was discussed by virtue of its potentiality to improve the overall efficiency of the process. With a similar purpose, the implementation of a machine vision (MV system used to inspect foods during drying was investigated; MV, indeed, can easily monitor physical changes (e.g., color, size, texture and shape in fruits and vegetables during the drying process. Hyperspectral imaging spectroscopy is a sophisticated technology since it is able to combine the advantages of spectroscopy and machine vision. As a consequence, its application to drying of fruits and vegetables was reviewed. Finally, attention was focused on the implementation of sensors in an on-line process based on the technologies mentioned above. This is a necessary step in order to turn the conventional dryer into a smart dryer, which is a more sustainable way to produce high quality dried fruits and vegetables.

  3. A method of detection to the grinding wheel layer thickness based on computer vision

    Science.gov (United States)

    Ji, Yuchen; Fu, Luhua; Yang, Dujuan; Wang, Lei; Liu, Changjie; Wang, Zhong

    2018-01-01

    This paper proposed a method of detection to the grinding wheel layer thickness based on computer vision. A camera is used to capture images of grinding wheel layer on the whole circle. Forward lighting and back lighting are used to enables a clear image to be acquired. Image processing is then executed on the images captured, which consists of image preprocessing, binarization and subpixel subdivision. The aim of binarization is to help the location of a chord and the corresponding ring width. After subpixel subdivision, the thickness of the grinding layer can be calculated finally. Compared with methods usually used to detect grinding wheel wear, method in this paper can directly and quickly get the information of thickness. Also, the eccentric error and the error of pixel equivalent are discussed in this paper.

  4. The Event Detection and the Apparent Velocity Estimation Based on Computer Vision

    Science.gov (United States)

    Shimojo, M.

    2012-08-01

    The high spatial and time resolution data obtained by the telescopes aboard Hinode revealed the new interesting dynamics in solar atmosphere. In order to detect such events and estimate the velocity of dynamics automatically, we examined the estimation methods of the optical flow based on the OpenCV that is the computer vision library. We applied the methods to the prominence eruption observed by NoRH, and the polar X-ray jet observed by XRT. As a result, it is clear that the methods work well for solar images if the images are optimized for the methods. It indicates that the optical flow estimation methods in the OpenCV library are very useful to analyze the solar phenomena.

  5. Gait Analysis Using Computer Vision Based on Cloud Platform and Mobile Device

    Directory of Open Access Journals (Sweden)

    Mario Nieto-Hidalgo

    2018-01-01

    Full Text Available Frailty and senility are syndromes that affect elderly people. The ageing process involves a decay of cognitive and motor functions which often produce an impact on the quality of life of elderly people. Some studies have linked this deterioration of cognitive and motor function to gait patterns. Thus, gait analysis can be a powerful tool to assess frailty and senility syndromes. In this paper, we propose a vision-based gait analysis approach performed on a smartphone with cloud computing assistance. Gait sequences recorded by a smartphone camera are processed by the smartphone itself to obtain spatiotemporal features. These features are uploaded onto the cloud in order to analyse and compare them to a stored database to render a diagnostic. The feature extraction method presented can work with both frontal and sagittal gait sequences although the sagittal view provides a better classification since an accuracy of 95% can be obtained.

  6. UE4Sim: A Photo-Realistic Simulator for Computer Vision Applications

    KAUST Repository

    Mueller, Matthias; Casser, Vincent; Lahoud, Jean; Smith, Neil; Ghanem, Bernard

    2017-01-01

    We present a photo-realistic training and evaluation simulator (UE4Sim) with extensive applications across various fields of computer vision. Built on top of the Unreal Engine, the simulator integrates full featured physics based cars, unmanned aerial vehicles (UAVs), and animated human actors in diverse urban and suburban 3D environments. We demonstrate the versatility of the simulator with two case studies: autonomous UAV-based tracking of moving objects and autonomous driving using supervised learning. The simulator fully integrates both several state-of-the-art tracking algorithms with a benchmark evaluation tool and a deep neural network (DNN) architecture for training vehicles to drive autonomously. It generates synthetic photo-realistic datasets with automatic ground truth annotations to easily extend existing real-world datasets and provides extensive synthetic data variety through its ability to reconfigure synthetic worlds on the fly using an automatic world generation tool.

  7. Simulation of Specular Surface Imaging Based on Computer Graphics: Application on a Vision Inspection System

    Directory of Open Access Journals (Sweden)

    Seulin Ralph

    2002-01-01

    Full Text Available This work aims at detecting surface defects on reflecting industrial parts. A machine vision system, performing the detection of geometric aspect surface defects, is completely described. The revealing of defects is realized by a particular lighting device. It has been carefully designed to ensure the imaging of defects. The lighting system simplifies a lot the image processing for defect segmentation and so a real-time inspection of reflective products is possible. To bring help in the conception of imaging conditions, a complete simulation is proposed. The simulation, based on computer graphics, enables the rendering of realistic images. Simulation provides here a very efficient way to perform tests compared to the numerous attempts of manual experiments.

  8. Beyond the computer-based patient record: re-engineering with a vision.

    Science.gov (United States)

    Genn, B; Geukers, L

    1995-01-01

    In order to achieve real benefit from the potential offered by a Computer-Based Patient Record, the capabilities of the technology must be applied along with true re-engineering of healthcare delivery processes. University Hospital recognizes this and is using systems implementation projects, such as the catalyst, for transforming the way we care for our patients. Integration is fundamental to the success of these initiatives and this must be explicitly planned against an organized systems architecture whose standards are market-driven. University Hospital also recognizes that Community Health Information Networks will offer improved quality of patient care at a reduced overall cost to the system. All of these implementation factors are considered up front as the hospital makes its initial decisions on to how to computerize its patient records. This improves our chances for success and will provide a consistent vision to guide the hospital's development of new and better patient care.

  9. [Vision test program for ophthalmologists on Apple II, IIe and IIc computers].

    Science.gov (United States)

    Huber, C

    1985-03-01

    A microcomputer program for the Apple II family of computers on a monochrome and a color screen is described. The program draws most of the tests used by ophthalmologists, and is offered as an alternative to a projector system. One advantage of the electronic generation of drawings is that true random orientation of Pflueger's E is possible. Tests are included for visual acuity (Pflueger's E, Landolt rings, numbers and children's drawings). Colored tests include a duochrome test, simple color vision tests, a fixation help with a musical background, a cobalt blue test and a Worth figure. In the astigmatic dial a mobile pointer helps to determine the axis. New tests can be programmed by the user and exchanged on disks among collageues.

  10. UE4Sim: A Photo-Realistic Simulator for Computer Vision Applications

    KAUST Repository

    Mueller, Matthias

    2017-08-19

    We present a photo-realistic training and evaluation simulator (UE4Sim) with extensive applications across various fields of computer vision. Built on top of the Unreal Engine, the simulator integrates full featured physics based cars, unmanned aerial vehicles (UAVs), and animated human actors in diverse urban and suburban 3D environments. We demonstrate the versatility of the simulator with two case studies: autonomous UAV-based tracking of moving objects and autonomous driving using supervised learning. The simulator fully integrates both several state-of-the-art tracking algorithms with a benchmark evaluation tool and a deep neural network (DNN) architecture for training vehicles to drive autonomously. It generates synthetic photo-realistic datasets with automatic ground truth annotations to easily extend existing real-world datasets and provides extensive synthetic data variety through its ability to reconfigure synthetic worlds on the fly using an automatic world generation tool.

  11. Sim4CV: A Photo-Realistic Simulator for Computer Vision Applications

    KAUST Repository

    Müller, Matthias

    2018-03-24

    We present a photo-realistic training and evaluation simulator (Sim4CV) (http://www.sim4cv.org) with extensive applications across various fields of computer vision. Built on top of the Unreal Engine, the simulator integrates full featured physics based cars, unmanned aerial vehicles (UAVs), and animated human actors in diverse urban and suburban 3D environments. We demonstrate the versatility of the simulator with two case studies: autonomous UAV-based tracking of moving objects and autonomous driving using supervised learning. The simulator fully integrates both several state-of-the-art tracking algorithms with a benchmark evaluation tool and a deep neural network architecture for training vehicles to drive autonomously. It generates synthetic photo-realistic datasets with automatic ground truth annotations to easily extend existing real-world datasets and provides extensive synthetic data variety through its ability to reconfigure synthetic worlds on the fly using an automatic world generation tool.

  12. Lipid vesicle shape analysis from populations using light video microscopy and computer vision.

    Directory of Open Access Journals (Sweden)

    Jernej Zupanc

    Full Text Available We present a method for giant lipid vesicle shape analysis that combines manually guided large-scale video microscopy and computer vision algorithms to enable analyzing vesicle populations. The method retains the benefits of light microscopy and enables non-destructive analysis of vesicles from suspensions containing up to several thousands of lipid vesicles (1-50 µm in diameter. For each sample, image analysis was employed to extract data on vesicle quantity and size distributions of their projected diameters and isoperimetric quotients (measure of contour roundness. This process enables a comparison of samples from the same population over time, or the comparison of a treated population to a control. Although vesicles in suspensions are heterogeneous in sizes and shapes and have distinctively non-homogeneous distribution throughout the suspension, this method allows for the capture and analysis of repeatable vesicle samples that are representative of the population inspected.

  13. Micro Vision

    OpenAIRE

    Ohba, Kohtaro; Ohara, Kenichi

    2007-01-01

    In the field of the micro vision, there are few researches compared with macro environment. However, applying to the study result for macro computer vision technique, you can measure and observe the micro environment. Moreover, based on the effects of micro environment, it is possible to discovery the new theories and new techniques.

  14. Application of Computer Vision for quality control in frozen mixed berries production: colour calibration issues

    Directory of Open Access Journals (Sweden)

    D. Ricauda Aimonino

    2013-09-01

    Full Text Available Computer vision is becoming increasingly important in quality control of many food processes. The appearance properties of food products (colour, texture, shape and size are, in fact, correlated with organoleptic characteristics and/or the presence of defects. Quality control based on image processing eliminates the subjectivity of human visual inspection, allowing rapid and non-destructive analysis. However, most food matrices show a wide variability in appearance features, therefore robust and customized image elaboration algorithms have to be implemented for each specific product. For this reason, quality control by visual inspection is still rather diffused in several food processes. The case study inspiring this paper concerns the production of frozen mixed berries. Once frozen, different kinds of berries are mixed together, in different amounts, according to a recipe. The correct quantity of each kind of fruit, within a certain tolerance, has to be ensured by producers. Quality control relies on bringing few samples for each production lot (samples of the same weight and, manually, counting the amount of each species. This operation is tedious, subject to errors, and time consuming, while a computer vision system (CVS could determine the amount of each kind of berries in a few seconds. This paper discusses the problem of colour calibration of the CVS used for frozen berries mixture evaluation. Images are acquired by a digital camera coupled with a dome lighting system, which gives a homogeneous illumination on the entire visible surface of the berries, and a flat bed scanner. RBG device dependent data are then mapped onto CIELab colorimetric colour space using different transformation operators. The obtained results show that the proposed calibration procedure leads to colour discrepancies comparable or even below the human eyes sensibility.

  15. Automated egg grading system using computer vision: Investigation on weight measure versus shape parameters

    Science.gov (United States)

    Nasir, Ahmad Fakhri Ab; Suhaila Sabarudin, Siti; Majeed, Anwar P. P. Abdul; Ghani, Ahmad Shahrizan Abdul

    2018-04-01

    Chicken egg is a source of food of high demand by humans. Human operators cannot work perfectly and continuously when conducting egg grading. Instead of an egg grading system using weight measure, an automatic system for egg grading using computer vision (using egg shape parameter) can be used to improve the productivity of egg grading. However, early hypothesis has indicated that more number of egg classes will change when using egg shape parameter compared with using weight measure. This paper presents the comparison of egg classification by the two above-mentioned methods. Firstly, 120 images of chicken eggs of various grades (A–D) produced in Malaysia are captured. Then, the egg images are processed using image pre-processing techniques, such as image cropping, smoothing and segmentation. Thereafter, eight egg shape features, including area, major axis length, minor axis length, volume, diameter and perimeter, are extracted. Lastly, feature selection (information gain ratio) and feature extraction (principal component analysis) are performed using k-nearest neighbour classifier in the classification process. Two methods, namely, supervised learning (using weight measure as graded by egg supplier) and unsupervised learning (using egg shape parameters as graded by ourselves), are conducted to execute the experiment. Clustering results reveal many changes in egg classes after performing shape-based grading. On average, the best recognition results using shape-based grading label is 94.16% while using weight-based label is 44.17%. As conclusion, automated egg grading system using computer vision is better by implementing shape-based features since it uses image meanwhile the weight parameter is more suitable by using weight grading system.

  16. Visualizing stressful aspects of repetitive motion tasks and opportunities for ergonomic improvements using computer vision.

    Science.gov (United States)

    Greene, Runyu L; Azari, David P; Hu, Yu Hen; Radwin, Robert G

    2017-11-01

    Patterns of physical stress exposure are often difficult to measure, and the metrics of variation and techniques for identifying them is underdeveloped in the practice of occupational ergonomics. Computer vision has previously been used for evaluating repetitive motion tasks for hand activity level (HAL) utilizing conventional 2D videos. The approach was made practical by relaxing the need for high precision, and by adopting a semi-automatic approach for measuring spatiotemporal characteristics of the repetitive task. In this paper, a new method for visualizing task factors, using this computer vision approach, is demonstrated. After videos are made, the analyst selects a region of interest on the hand to track and the hand location and its associated kinematics are measured for every frame. The visualization method spatially deconstructs and displays the frequency, speed and duty cycle components of tasks that are part of the threshold limit value for hand activity for the purpose of identifying patterns of exposure associated with the specific job factors, as well as for suggesting task improvements. The localized variables are plotted as a heat map superimposed over the video, and displayed in the context of the task being performed. Based on the intensity of the specific variables used to calculate HAL, we can determine which task factors most contribute to HAL, and readily identify those work elements in the task that contribute more to increased risk for an injury. Work simulations and actual industrial examples are described. This method should help practitioners more readily measure and interpret temporal exposure patterns and identify potential task improvements. Copyright © 2017. Published by Elsevier Ltd.

  17. Vision of God from Islamic Gnosticism Point of View as Well as it’s Comparison with Some of the Famous Theological and Exegetic Views

    Directory of Open Access Journals (Sweden)

    Parvin Nabian

    2011-09-01

    Full Text Available   The possibility or impossibility of vision of God is exciting and complicated question which has allocated itself various views along Islamic thought. What become obvious from Islamic Gnostics sayings and shia imam ’s demonstration and statements is that they know the sensible vision and intellectual vision of God impossible.   They just know allowable the heartfelt vision which is the result of purity and safeness of inner faculties and therefore the verses of Quran about the vision of God or prophet ’s requesting about sighting of God have interpreted to heartfelt intuition.   This paper briefly reviews some Islamic theologies ideas with respect to their Quranic demonstrations and commentators views on this issue and comparing their understandings from Quranic verses whit each other specially verse 143 of sura Araf, in addition to speak about the meaning of intuition vision and its truth, its order, how human can be achieved that position with respect to three principles: "unity of being, velayat, love" and whit the centrality of holy Quran, hadiths and imam ’s statements. Therefore in this paper it will become obvious what is the meaning of intuition vision from Gnostics point of view and it’s the result of manifestation of God ’s attributes which man can achieve to intuition position .

  18. Computer vision syndrome among computer office workers in a developing country: an evaluation of prevalence and risk factors.

    Science.gov (United States)

    Ranasinghe, P; Wathurapatha, W S; Perera, Y S; Lamabadusuriya, D A; Kulatunga, S; Jayawardana, N; Katulanda, P

    2016-03-09

    Computer vision syndrome (CVS) is a group of visual symptoms experienced in relation to the use of computers. Nearly 60 million people suffer from CVS globally, resulting in reduced productivity at work and reduced quality of life of the computer worker. The present study aims to describe the prevalence of CVS and its associated factors among a nationally-representative sample of Sri Lankan computer workers. Two thousand five hundred computer office workers were invited for the study from all nine provinces of Sri Lanka between May and December 2009. A self-administered questionnaire was used to collect socio-demographic data, symptoms of CVS and its associated factors. A binary logistic regression analysis was performed in all patients with 'presence of CVS' as the dichotomous dependent variable and age, gender, duration of occupation, daily computer usage, pre-existing eye disease, not using a visual display terminal (VDT) filter, adjusting brightness of screen, use of contact lenses, angle of gaze and ergonomic practices knowledge as the continuous/dichotomous independent variables. A similar binary logistic regression analysis was performed in all patients with 'severity of CVS' as the dichotomous dependent variable and other continuous/dichotomous independent variables. Sample size was 2210 (response rate-88.4%). Mean age was 30.8 ± 8.1 years and 50.8% of the sample were males. The 1-year prevalence of CVS in the study population was 67.4%. Female gender (OR: 1.28), duration of occupation (OR: 1.07), daily computer usage (1.10), pre-existing eye disease (OR: 4.49), not using a VDT filter (OR: 1.02), use of contact lenses (OR: 3.21) and ergonomics practices knowledge (OR: 1.24) all were associated with significantly presence of CVS. The duration of occupation (OR: 1.04) and presence of pre-existing eye disease (OR: 1.54) were significantly associated with the presence of 'severe CVS'. Sri Lankan computer workers had a high prevalence of CVS. Female gender

  19. Enhancing informatics competency under uncertainty at the point of decision: a knowing about knowing vision

    DEFF Research Database (Denmark)

    Kaltoft, Mette Kjer; Nielsen, Jesper Bo; Salkeld, Glenn

    2014-01-01

    , and ‘big data’, when rigorously analysed, as inputs into the probability judgements that need to be made in decision making under uncertainty. But these judgements are needed irrespective of the state of ‘the evidence’ and personalised evidence on person/patient-important criteria is very often poor...... that an appropriate balance of intuition and analysis is required, as in Hammond's Cognitive Continuum, and are made aware of the cognitive and motivated biases that can prevent us knowing ‘how much we know about how much we know’, with its deleterious effect on decision quality. Probability exercises......Most informatics activity is aimed at reducing unnecessary errors, mistakes and misjudgements at the point of decision, insofar as these arise from inappropriate accessing and processing of data and information. Healthcare professionals use the results of scientific research, when available...

  20. Providing full point-to-point communications among compute nodes of an operational group in a global combining network of a parallel computer

    Energy Technology Data Exchange (ETDEWEB)

    Archer, Charles J.; Faraj, Daniel A.; Inglett, Todd A.; Ratterman, Joseph D.

    2018-01-30

    Methods, apparatus, and products are disclosed for providing full point-to-point communications among compute nodes of an operational group in a global combining network of a parallel computer, each compute node connected to each adjacent compute node in the global combining network through a link, that include: receiving a network packet in a compute node, the network packet specifying a destination compute node; selecting, in dependence upon the destination compute node, at least one of the links for the compute node along which to forward the network packet toward the destination compute node; and forwarding the network packet along the selected link to the adjacent compute node connected to the compute node through the selected link.

  1. Computer Vision for High-Throughput Quantitative Phenotyping: A Case Study of Grapevine Downy Mildew Sporulation and Leaf Trichomes.

    Science.gov (United States)

    Divilov, Konstantin; Wiesner-Hanks, Tyr; Barba, Paola; Cadle-Davidson, Lance; Reisch, Bruce I

    2017-12-01

    Quantitative phenotyping of downy mildew sporulation is frequently used in plant breeding and genetic studies, as well as in studies focused on pathogen biology such as chemical efficacy trials. In these scenarios, phenotyping a large number of genotypes or treatments can be advantageous but is often limited by time and cost. We present a novel computational pipeline dedicated to estimating the percent area of downy mildew sporulation from images of inoculated grapevine leaf discs in a manner that is time and cost efficient. The pipeline was tested on images from leaf disc assay experiments involving two F 1 grapevine families, one that had glabrous leaves (Vitis rupestris B38 × 'Horizon' [RH]) and another that had leaf trichomes (Horizon × V. cinerea B9 [HC]). Correlations between computer vision and manual visual ratings reached 0.89 in the RH family and 0.43 in the HC family. Additionally, we were able to use the computer vision system prior to sporulation to measure the percent leaf trichome area. We estimate that an experienced rater scoring sporulation would spend at least 90% less time using the computer vision system compared with the manual visual method. This will allow more treatments to be phenotyped in order to better understand the genetic architecture of downy mildew resistance and of leaf trichome density. We anticipate that this computer vision system will find applications in other pathosystems or traits where responses can be imaged with sufficient contrast from the background.

  2. Tundish Cover Flux Thickness Measurement Method and Instrumentation Based on Computer Vision in Continuous Casting Tundish

    Directory of Open Access Journals (Sweden)

    Meng Lu

    2013-01-01

    Full Text Available Thickness of tundish cover flux (TCF plays an important role in continuous casting (CC steelmaking process. Traditional measurement method of TCF thickness is single/double wire methods, which have several problems such as personal security, easily affected by operators, and poor repeatability. To solve all these problems, in this paper, we specifically designed and built an instrumentation and presented a novel method to measure the TCF thickness. The instrumentation was composed of a measurement bar, a mechanical device, a high-definition industrial camera, a Siemens S7-200 programmable logic controller (PLC, and a computer. Our measurement method was based on the computer vision algorithms, including image denoising method, monocular range measurement method, scale invariant feature transform (SIFT, and image gray gradient detection method. Using the present instrumentation and method, images in the CC tundish can be collected by camera and transferred to computer to do imaging processing. Experiments showed that our instrumentation and method worked well at scene of steel plants, can accurately measure the thickness of TCF, and overcome the disadvantages of traditional measurement methods, or even replace the traditional ones.

  3. Fire effects on the Point Reyes Mountain Beaver (Aplodontia rufa phaea) at Point Reyes National Seashore, 10 years after the Vision Fire

    Science.gov (United States)

    Fellers, Gary M.; Osbourn, Michael

    2009-01-01

    The 1995 Vision Fire burned 5000 ha and destroyed 40% of the habitat of the Point Reyes Mountain Beaver (Aplodontia rufa phaea). Surveys immediately post-fire and in 2000 showed that only 0.4 to 1.7% of Mountain Beavers within the burn area survived. In 2000, dense, ground-hugging Blue-blossom Ceanothus (Ceanothus thrysiflorus) appeared to make coastal scrub thickets much less suitable for Mountain Beavers even though the number of burrows at our 11 study sites had returned to 88% of pre-fire numbers. In 2005 (10 y post-fire), the habitat appeared to be better for Mountain Beavers; Blue-blossom Ceanothus had diminished and vegetation more typical of northern coastal scrub, such as Coyote Brush (Baccharis pilularis) overstory with a lower layer of herbaceous vegetation, had greatly increased; but the number of Mountain Beaver burrows had declined to 52% of pre-fire numbers and there was little change in the number of sites occupied between our 2000 and 2005 surveys. With the expected successional changes in thicket structure, Mountain Beaver populations are likely to recover further, but there will probably be considerable variation in how each population stabilizes.

  4. Oral omega-3 fatty acids treatment in computer vision syndrome related dry eye.

    Science.gov (United States)

    Bhargava, Rahul; Kumar, Prachi; Phogat, Hemant; Kaur, Avinash; Kumar, Manjushri

    2015-06-01

    To assess the efficacy of dietary consumption of omega-3 fatty acids (O3FAs) on dry eye symptoms, Schirmer test, tear film break up time (TBUT) and conjunctival impression cytology (CIC) in patients with computer vision syndrome. Interventional, randomized, double blind, multi-centric study. Four hundred and seventy eight symptomatic patients using computers for more than 3h per day for minimum 1 year were randomized into two groups: 220 patients received two capsules of omega-3 fatty acids each containing 180mg eicosapentaenoic acid (EPA) and 120mg docosahexaenoic acid (DHA) daily (O3FA group) and 236 patients received two capsules of a placebo containing olive oil daily for 3 months (placebo group). The primary outcome measure was improvement in dry eye symptoms and secondary outcome measures were improvement in Nelson grade and an increase in Schirmer and TBUT scores at 3 months. In the placebo group, before dietary intervention, the mean symptom score, Schirmer, TBUT and CIC scores were 7.5±2, 19.9±4.7mm, 11.5±2s and 1±0.9 respectively, and 3 months later were 6.8±2.2, 20.5±4.7mm, 12±2.2s and 0.9±0.9 respectively. In the O3FA group, these values were 8.0±2.6, 20.1±4.2mm, 11.7±1.6s and 1.2±0.8 before dietary intervention and 3.9±2.2, 21.4±4mm, 15±1.7s, 0.5±0.6 after 3 months of intervention, respectively. This study demonstrates the beneficial effect of orally administered O3FAs in alleviating dry eye symptoms, decreasing tear evaporation rate and improving Nelson grade in patients suffering from computer vision syndrome related dry eye. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  5. Computer Vision Syndrome among Call Center Employees at Telecommunication Company in Bandung

    Directory of Open Access Journals (Sweden)

    Ghea Nursyifa

    2016-06-01

    Full Text Available Background: The occurrence of Computer Vision Syndrome (CVS at the workplace has increased within decades due to theprolonged use of computers. Knowledge of CVS is necessary in order to develop an awareness of how to prevent and alleviate itsprevalence . The objective of this study was to assess the knowledge of CVS among call center employees and to explore the most frequent CVS symptom experienced by the workers. Methods: A descriptive cross sectional study was conducted during the period of September to November 2014 at Telecommunication Company in Bandung using a questionnaire consisting of 30 questions. Out of the 30 questions/statements, 15 statements were about knowledge of CVS and other 15 questions were about the occurrence of CVS and its symptoms. In this study 125 call center employees participated as respondents using consecutive sampling. The level of knowledge was divided into 3 categories: good (76–100%, fair (75–56% and poor (<56%. The collected data was presented in frequency tabulation. Results: There was 74.4% of the respondents had poor knowledge of CVS. The most symptom experienced by the respondents was asthenopia. Conclusions: The CVS occurs in call center employees with various symptoms and signs. This situation is not supported by good knowledge of the syndrome which can hamper prevention programs.

  6. Tactile and bone-conduction auditory brain computer interface for vision and hearing impaired users.

    Science.gov (United States)

    Rutkowski, Tomasz M; Mori, Hiromu

    2015-04-15

    The paper presents a report on the recently developed BCI alternative for users suffering from impaired vision (lack of focus or eye-movements) or from the so-called "ear-blocking-syndrome" (limited hearing). We report on our recent studies of the extents to which vibrotactile stimuli delivered to the head of a user can serve as a platform for a brain computer interface (BCI) paradigm. In the proposed tactile and bone-conduction auditory BCI novel multiple head positions are used to evoke combined somatosensory and auditory (via the bone conduction effect) P300 brain responses, in order to define a multimodal tactile and bone-conduction auditory brain computer interface (tbcaBCI). In order to further remove EEG interferences and to improve P300 response classification synchrosqueezing transform (SST) is applied. SST outperforms the classical time-frequency analysis methods of the non-linear and non-stationary signals such as EEG. The proposed method is also computationally more effective comparing to the empirical mode decomposition. The SST filtering allows for online EEG preprocessing application which is essential in the case of BCI. Experimental results with healthy BCI-naive users performing online tbcaBCI, validate the paradigm, while the feasibility of the concept is illuminated through information transfer rate case studies. We present a comparison of the proposed SST-based preprocessing method, combined with a logistic regression (LR) classifier, together with classical preprocessing and LDA-based classification BCI techniques. The proposed tbcaBCI paradigm together with data-driven preprocessing methods are a step forward in robust BCI applications research. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Computation of the locus crossing point location of MC circuit

    International Nuclear Information System (INIS)

    Liu Hai-Jun; Li Zhi-Wei; Bu Kai; Sun Zhao-Lin; Nie Hong-Shan

    2014-01-01

    In this paper, the crossing point property of the i–v hysteresis curve in a memristor–capacitor (MC) circuit is analyzed. First, the ideal passive memristor on the crossing point property of i–v hysteresis curve is studied. Based on the analysis, the analytical derivation with respect to the crossing point location of MC circuit is given. Then the example of MC with linear memristance-versus-charge state map is demonstrated to discuss the drift property of cross-point location, caused by the frequency and capacitance value. (interdisciplinary physics and related areas of science and technology)

  8. High spatial resolution three-dimensional mapping of vegetation spectral dynamics using computer vision and hobbyist unmanned aerial vehicles

    Science.gov (United States)

    Dandois, J. P.; Ellis, E. C.

    2013-12-01

    High spatial resolution three-dimensional (3D) measurements of vegetation by remote sensing are advancing ecological research and environmental management. However, substantial economic and logistical costs limit this application, especially for observing phenological dynamics in ecosystem structure and spectral traits. Here we demonstrate a new aerial remote sensing system enabling routine and inexpensive aerial 3D measurements of canopy structure and spectral attributes, with properties similar to those of LIDAR, but with RGB (red-green-blue) spectral attributes for each point, enabling high frequency observations within a single growing season. This 'Ecosynth' methodology applies photogrammetric ''Structure from Motion'' computer vision algorithms to large sets of highly overlapping low altitude (USA. Ecosynth canopy height maps (CHMs) were strong predictors of field-measured tree heights (R2 0.63 to 0.84) and were highly correlated with a LIDAR CHM (R 0.87) acquired 4 days earlier, though Ecosynth-based estimates of aboveground biomass densities included significant errors (31 - 36% of field-based estimates). Repeated scanning of a 0.25 ha forested area at six different times across a 16 month period revealed ecologically significant dynamics in canopy color at different heights and a structural shift upward in canopy density, as demonstrated by changes in vertical height profiles of point density and relative RGB brightness. Changes in canopy relative greenness were highly correlated (R2 = 0.88) with MODIS NDVI time series for the same area and vertical differences in canopy color revealed the early green up of the dominant canopy species, Liriodendron tulipifera, strong evidence that Ecosynth time series measurements capture vegetation structural and spectral dynamics at the spatial scale of individual trees. Observing canopy phenology in 3D at high temporal resolutions represents a breakthrough in forest ecology. Inexpensive user-deployed technologies for

  9. A computer vision-based automated Figure-8 maze for working memory test in rodents.

    Science.gov (United States)

    Pedigo, Samuel F; Song, Eun Young; Jung, Min Whan; Kim, Jeansok J

    2006-09-30

    The benchmark test for prefrontal cortex (PFC)-mediated working memory in rodents is a delayed alternation task utilizing variations of T-maze or Figure-8 maze, which requires the animals to make specific arm entry responses for reward. In this task, however, manual procedures involved in shaping target behavior, imposing delays between trials and delivering rewards can potentially influence the animal's performance on the maze. Here, we report an automated Figure-8 maze which does not necessitate experimenter-subject interaction during shaping, training or testing. This system incorporates a computer vision system for tracking, motorized gates to impose delays, and automated reward delivery. The maze is controlled by custom software that records the animal's location and activates the gates according to the animal's behavior and a control algorithm. The program performs calculations of task accuracy, tracks movement sequence through the maze, and provides other dependent variables (such as running speed, time spent in different maze locations, activity level during delay). Testing in rats indicates that the performance accuracy is inversely proportional to the delay interval, decreases with PFC lesions, and that animals anticipate timing during long delays. Thus, our automated Figure-8 maze is effective at assessing working memory and provides novel behavioral measures in rodents.

  10. Toward a Computer Vision-based Wayfinding Aid for Blind Persons to Access Unfamiliar Indoor Environments.

    Science.gov (United States)

    Tian, Yingli; Yang, Xiaodong; Yi, Chucai; Arditi, Aries

    2013-04-01

    Independent travel is a well known challenge for blind and visually impaired persons. In this paper, we propose a proof-of-concept computer vision-based wayfinding aid for blind people to independently access unfamiliar indoor environments. In order to find different rooms (e.g. an office, a lab, or a bathroom) and other building amenities (e.g. an exit or an elevator), we incorporate object detection with text recognition. First we develop a robust and efficient algorithm to detect doors, elevators, and cabinets based on their general geometric shape, by combining edges and corners. The algorithm is general enough to handle large intra-class variations of objects with different appearances among different indoor environments, as well as small inter-class differences between different objects such as doors and door-like cabinets. Next, in order to distinguish intra-class objects (e.g. an office door from a bathroom door), we extract and recognize text information associated with the detected objects. For text recognition, we first extract text regions from signs with multiple colors and possibly complex backgrounds, and then apply character localization and topological analysis to filter out background interference. The extracted text is recognized using off-the-shelf optical character recognition (OCR) software products. The object type, orientation, location, and text information are presented to the blind traveler as speech.

  11. m-BIRCH: an online clustering approach for computer vision applications

    Science.gov (United States)

    Madan, Siddharth K.; Dana, Kristin J.

    2015-03-01

    We adapt a classic online clustering algorithm called Balanced Iterative Reducing and Clustering using Hierarchies (BIRCH), to incrementally cluster large datasets of features commonly used in multimedia and computer vision. We call the adapted version modified-BIRCH (m-BIRCH). The algorithm uses only a fraction of the dataset memory to perform clustering, and updates the clustering decisions when new data comes in. Modifications made in m-BIRCH enable data driven parameter selection and effectively handle varying density regions in the feature space. Data driven parameter selection automatically controls the level of coarseness of the data summarization. Effective handling of varying density regions is necessary to well represent the different density regions in data summarization. We use m-BIRCH to cluster 840K color SIFT descriptors, and 60K outlier corrupted grayscale patches. We use the algorithm to cluster datasets consisting of challenging non-convex clustering patterns. Our implementation of the algorithm provides an useful clustering tool and is made publicly available.

  12. Differentiation of Ecuadorian National and CCN-51 cocoa beans and their mixtures by computer vision.

    Science.gov (United States)

    Jimenez, Juan C; Amores, Freddy M; Solórzano, Eddyn G; Rodríguez, Gladys A; La Mantia, Alessandro; Blasi, Paolo; Loor, Rey G

    2018-05-01

    Ecuador exports two major types of cocoa beans, the highly regarded and lucrative National, known for its fine aroma, and the CCN-51 clone type, used in bulk for mass chocolate products. In order to discourage exportation of National cocoa adulterated with CCN-51, a fast and objective methodology for distinguishing between the two types of cocoa beans is needed. This study reports a methodology based on computer vision, which makes it possible to recognize these beans and determine the percentage of their mixture. The methodology was challenged with 336 samples of National cocoa and 127 of CCN-51. By excluding the samples with a low fermentation level and white beans, the model discriminated with a precision higher than 98%. The model was also able to identify and quantify adulterations in 75 export batches of National cocoa and separate out poorly fermented beans. A scientifically reliable methodology able to discriminate between Ecuadorian National and CCN-51 cocoa beans and their mixtures was successfully developed. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  13. Real-Time Evaluation of Breast Self-Examination Using Computer Vision

    Directory of Open Access Journals (Sweden)

    Eman Mohammadi

    2014-01-01

    Full Text Available Breast cancer is the most common cancer among women worldwide and breast self-examination (BSE is considered as the most cost-effective approach for early breast cancer detection. The general objective of this paper is to design and develop a computer vision algorithm to evaluate the BSE performance in real-time. The first stage of the algorithm presents a method for detecting and tracking the nipples in frames while a woman performs BSE; the second stage presents a method for localizing the breast region and blocks of pixels related to palpation of the breast, and the third stage focuses on detecting the palpated blocks in the breast region. The palpated blocks are highlighted at the time of BSE performance. In a correct BSE performance, all blocks must be palpated, checked, and highlighted, respectively. If any abnormality, such as masses, is detected, then this must be reported to a doctor to confirm the presence of this abnormality and proceed to perform other confirmatory tests. The experimental results have shown that the BSE evaluation algorithm presented in this paper provides robust performance.

  14. Real-time evaluation of breast self-examination using computer vision.

    Science.gov (United States)

    Mohammadi, Eman; Dadios, Elmer P; Gan Lim, Laurence A; Cabatuan, Melvin K; Naguib, Raouf N G; Avila, Jose Maria C; Oikonomou, Andreas

    2014-01-01

    Breast cancer is the most common cancer among women worldwide and breast self-examination (BSE) is considered as the most cost-effective approach for early breast cancer detection. The general objective of this paper is to design and develop a computer vision algorithm to evaluate the BSE performance in real-time. The first stage of the algorithm presents a method for detecting and tracking the nipples in frames while a woman performs BSE; the second stage presents a method for localizing the breast region and blocks of pixels related to palpation of the breast, and the third stage focuses on detecting the palpated blocks in the breast region. The palpated blocks are highlighted at the time of BSE performance. In a correct BSE performance, all blocks must be palpated, checked, and highlighted, respectively. If any abnormality, such as masses, is detected, then this must be reported to a doctor to confirm the presence of this abnormality and proceed to perform other confirmatory tests. The experimental results have shown that the BSE evaluation algorithm presented in this paper provides robust performance.

  15. Measuring vigilance decrement using computer vision assisted eye tracking in dynamic naturalistic environments.

    Science.gov (United States)

    Bodala, Indu P; Abbasi, Nida I; Yu Sun; Bezerianos, Anastasios; Al-Nashash, Hasan; Thakor, Nitish V

    2017-07-01

    Eye tracking offers a practical solution for monitoring cognitive performance in real world tasks. However, eye tracking in dynamic environments is difficult due to high spatial and temporal variation of stimuli, needing further and thorough investigation. In this paper, we study the possibility of developing a novel computer vision assisted eye tracking analysis by using fixations. Eye movement data is obtained from a long duration naturalistic driving experiment. Source invariant feature transform (SIFT) algorithm was implemented using VLFeat toolbox to identify multiple areas of interest (AOIs). A new measure called `fixation score' was defined to understand the dynamics of fixation position between the target AOI and the non target AOIs. Fixation score is maximum when the subjects focus on the target AOI and diminishes when they gaze at the non-target AOIs. Statistically significant negative correlation was found between fixation score and reaction time data (r =-0.2253 and pdecrement, the fixation score decreases due to visual attention shifting away from the target objects resulting in an increase in the reaction time.

  16. Integrating Symbolic and Statistical Methods for Testing Intelligent Systems Applications to Machine Learning and Computer Vision

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Sumit Kumar [University of Central Florida, Orlando; Pullum, Laura L [ORNL; Ramanathan, Arvind [ORNL

    2016-01-01

    Embedded intelligent systems ranging from tiny im- plantable biomedical devices to large swarms of autonomous un- manned aerial systems are becoming pervasive in our daily lives. While we depend on the flawless functioning of such intelligent systems, and often take their behavioral correctness and safety for granted, it is notoriously difficult to generate test cases that expose subtle errors in the implementations of machine learning algorithms. Hence, the validation of intelligent systems is usually achieved by studying their behavior on representative data sets, using methods such as cross-validation and bootstrapping.In this paper, we present a new testing methodology for studying the correctness of intelligent systems. Our approach uses symbolic decision procedures coupled with statistical hypothesis testing to. We also use our algorithm to analyze the robustness of a human detection algorithm built using the OpenCV open-source computer vision library. We show that the human detection implementation can fail to detect humans in perturbed video frames even when the perturbations are so small that the corresponding frames look identical to the naked eye.

  17. Optimisation and assessment of three modern touch screen tablet computers for clinical vision testing.

    Directory of Open Access Journals (Sweden)

    Humza J Tahir

    Full Text Available Technological advances have led to the development of powerful yet portable tablet computers whose touch-screen resolutions now permit the presentation of targets small enough to test the limits of normal visual acuity. Such devices have become ubiquitous in daily life and are moving into the clinical space. However, in order to produce clinically valid tests, it is important to identify the limits imposed by the screen characteristics, such as resolution, brightness uniformity, contrast linearity and the effect of viewing angle. Previously we have conducted such tests on the iPad 3. Here we extend our investigations to 2 other devices and outline a protocol for calibrating such screens, using standardised methods to measure the gamma function, warm up time, screen uniformity and the effects of viewing angle and screen reflections. We demonstrate that all three devices manifest typical gamma functions for voltage and luminance with warm up times of approximately 15 minutes. However, there were differences in homogeneity and reflectance among the displays. We suggest practical means to optimise quality of display for vision testing including screen calibration.

  18. Optimisation and assessment of three modern touch screen tablet computers for clinical vision testing.

    Science.gov (United States)

    Tahir, Humza J; Murray, Ian J; Parry, Neil R A; Aslam, Tariq M

    2014-01-01

    Technological advances have led to the development of powerful yet portable tablet computers whose touch-screen resolutions now permit the presentation of targets small enough to test the limits of normal visual acuity. Such devices have become ubiquitous in daily life and are moving into the clinical space. However, in order to produce clinically valid tests, it is important to identify the limits imposed by the screen characteristics, such as resolution, brightness uniformity, contrast linearity and the effect of viewing angle. Previously we have conducted such tests on the iPad 3. Here we extend our investigations to 2 other devices and outline a protocol for calibrating such screens, using standardised methods to measure the gamma function, warm up time, screen uniformity and the effects of viewing angle and screen reflections. We demonstrate that all three devices manifest typical gamma functions for voltage and luminance with warm up times of approximately 15 minutes. However, there were differences in homogeneity and reflectance among the displays. We suggest practical means to optimise quality of display for vision testing including screen calibration.

  19. A Collaborative Approach for Surface Inspection Using Aerial Robots and Computer Vision

    Directory of Open Access Journals (Sweden)

    Martin Molina

    2018-03-01

    Full Text Available Aerial robots with cameras on board can be used in surface inspection to observe areas that are difficult to reach by other means. In this type of problem, it is desirable for aerial robots to have a high degree of autonomy. A way to provide more autonomy would be to use computer vision techniques to automatically detect anomalies on the surface. However, the performance of automated visual recognition methods is limited in uncontrolled environments, so that in practice it is not possible to perform a fully automatic inspection. This paper presents a solution for visual inspection that increases the degree of autonomy of aerial robots following a semi-automatic approach. The solution is based on human-robot collaboration in which the operator delegates tasks to the drone for exploration and visual recognition and the drone requests assistance in the presence of uncertainty. We validate this proposal with the development of an experimental robotic system using the software framework Aerostack. The paper describes technical challenges that we had to solve to develop such a system and the impact on this solution on the degree of autonomy to detect anomalies on the surface.

  20. Recent developments in computer vision-based analytical chemistry: A tutorial review.

    Science.gov (United States)

    Capitán-Vallvey, Luis Fermín; López-Ruiz, Nuria; Martínez-Olmos, Antonio; Erenas, Miguel M; Palma, Alberto J

    2015-10-29

    Chemical analysis based on colour changes recorded with imaging devices is gaining increasing interest. This is due to its several significant advantages, such as simplicity of use, and the fact that it is easily combinable with portable and widely distributed imaging devices, resulting in friendly analytical procedures in many areas that demand out-of-lab applications for in situ and real-time monitoring. This tutorial review covers computer vision-based analytical (CVAC) procedures and systems from 2005 to 2015, a period of time when 87.5% of the papers on this topic were published. The background regarding colour spaces and recent analytical system architectures of interest in analytical chemistry is presented in the form of a tutorial. Moreover, issues regarding images, such as the influence of illuminants, and the most relevant techniques for processing and analysing digital images are addressed. Some of the most relevant applications are then detailed, highlighting their main characteristics. Finally, our opinion about future perspectives is discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. a Holistic Approach for Inspection of Civil Infrastructures Based on Computer Vision Techniques

    Science.gov (United States)

    Stentoumis, C.; Protopapadakis, E.; Doulamis, A.; Doulamis, N.

    2016-06-01

    In this work, it is examined the 2D recognition and 3D modelling of concrete tunnel cracks, through visual cues. At the time being, the structural integrity inspection of large-scale infrastructures is mainly performed through visual observations by human inspectors, who identify structural defects, rate them and, then, categorize their severity. The described approach targets at minimum human intervention, for autonomous inspection of civil infrastructures. The shortfalls of existing approaches in crack assessment are being addressed by proposing a novel detection scheme. Although efforts have been made in the field, synergies among proposed techniques are still missing. The holistic approach of this paper exploits the state of the art techniques of pattern recognition and stereo-matching, in order to build accurate 3D crack models. The innovation lies in the hybrid approach for the CNN detector initialization, and the use of the modified census transformation for stereo matching along with a binary fusion of two state-of-the-art optimization schemes. The described approach manages to deal with images of harsh radiometry, along with severe radiometric differences in the stereo pair. The effectiveness of this workflow is evaluated on a real dataset gathered in highway and railway tunnels. What is promising is that the computer vision workflow described in this work can be transferred, with adaptations of course, to other infrastructure such as pipelines, bridges and large industrial facilities that are in the need of continuous state assessment during their operational life cycle.

  2. UAV and Computer Vision in 3D Modeling of Cultural Heritage in Southern Italy

    Science.gov (United States)

    Barrile, Vincenzo; Gelsomino, Vincenzo; Bilotta, Giuliana

    2017-08-01

    On the Waterfront Italo Falcomatà of Reggio Calabria you can admire the most extensive tract of the walls of the Hellenistic period of ancient city of Rhegion. The so-called Greek Walls are one of the most significant and visible traces of the past linked to the culture of Ancient Greece in the site of Reggio Calabria territory. Over the years this stretch of wall has always been a part, to the reconstruction of Reggio after the earthquake of 1783, the outer walls at all times, restored countless times, to cope with the degradation of the time and the adjustments to the technical increasingly innovative and sophisticated siege. They were the subject of several studies on history, for the study of the construction techniques and the maintenance and restoration of the same. This note describes the methodology for the implementation of a three-dimensional model of the Greek Walls conducted by the Geomatics Laboratory, belonging to DICEAM Department of University “Mediterranea” of Reggio Calabria. 3D modeling we made is based on imaging techniques, such as Digital Photogrammetry and Computer Vision, by using a drone. The acquired digital images were then processed using commercial software Agisoft PhotoScan. The results denote the goodness of the technique used in the field of cultural heritage, attractive alternative to more expensive and demanding techniques such as laser scanning.

  3. Prediction of pork loin quality using online computer vision system and artificial intelligence model.

    Science.gov (United States)

    Sun, Xin; Young, Jennifer; Liu, Jeng-Hung; Newman, David

    2018-06-01

    The objective of this project was to develop a computer vision system (CVS) for objective measurement of pork loin under industry speed requirement. Color images of pork loin samples were acquired using a CVS. Subjective color and marbling scores were determined according to the National Pork Board standards by a trained evaluator. Instrument color measurement and crude fat percentage were used as control measurements. Image features (18 color features; 1 marbling feature; 88 texture features) were extracted from whole pork loin color images. Artificial intelligence prediction model (support vector machine) was established for pork color and marbling quality grades. The results showed that CVS with support vector machine modeling reached the highest prediction accuracy of 92.5% for measured pork color score and 75.0% for measured pork marbling score. This research shows that the proposed artificial intelligence prediction model with CVS can provide an effective tool for predicting color and marbling in the pork industry at online speeds. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. A HOLISTIC APPROACH FOR INSPECTION OF CIVIL INFRASTRUCTURES BASED ON COMPUTER VISION TECHNIQUES

    Directory of Open Access Journals (Sweden)

    C. Stentoumis

    2016-06-01

    Full Text Available In this work, it is examined the 2D recognition and 3D modelling of concrete tunnel cracks, through visual cues. At the time being, the structural integrity inspection of large-scale infrastructures is mainly performed through visual observations by human inspectors, who identify structural defects, rate them and, then, categorize their severity. The described approach targets at minimum human intervention, for autonomous inspection of civil infrastructures. The shortfalls of existing approaches in crack assessment are being addressed by proposing a novel detection scheme. Although efforts have been made in the field, synergies among proposed techniques are still missing. The holistic approach of this paper exploits the state of the art techniques of pattern recognition and stereo-matching, in order to build accurate 3D crack models. The innovation lies in the hybrid approach for the CNN detector initialization, and the use of the modified census transformation for stereo matching along with a binary fusion of two state-of-the-art optimization schemes. The described approach manages to deal with images of harsh radiometry, along with severe radiometric differences in the stereo pair. The effectiveness of this workflow is evaluated on a real dataset gathered in highway and railway tunnels. What is promising is that the computer vision workflow described in this work can be transferred, with adaptations of course, to other infrastructure such as pipelines, bridges and large industrial facilities that are in the need of continuous state assessment during their operational life cycle.

  5. Computer Vision Tool and Technician as First Reader of Lung Cancer Screening CT Scans.

    Science.gov (United States)

    Ritchie, Alexander J; Sanghera, Calvin; Jacobs, Colin; Zhang, Wei; Mayo, John; Schmidt, Heidi; Gingras, Michel; Pasian, Sergio; Stewart, Lori; Tsai, Scott; Manos, Daria; Seely, Jean M; Burrowes, Paul; Bhatia, Rick; Atkar-Khattra, Sukhinder; van Ginneken, Bram; Tammemagi, Martin; Tsao, Ming Sound; Lam, Stephen

    2016-05-01

    To implement a cost-effective low-dose computed tomography (LDCT) lung cancer screening program at the population level, accurate and efficient interpretation of a large volume of LDCT scans is needed. The objective of this study was to evaluate a workflow strategy to identify abnormal LDCT scans in which a technician assisted by computer vision (CV) software acts as a first reader with the aim to improve speed, consistency, and quality of scan interpretation. Without knowledge of the diagnosis, a technician reviewed 828 randomly batched scans (136 with lung cancers, 556 with benign nodules, and 136 without nodules) from the baseline Pan-Canadian Early Detection of Lung Cancer Study that had been annotated by the CV software CIRRUS Lung Screening (Diagnostic Image Analysis Group, Nijmegen, The Netherlands). The scans were classified as either normal (no nodules ≥1 mm or benign nodules) or abnormal (nodules or other abnormality). The results were compared with the diagnostic interpretation by Pan-Canadian Early Detection of Lung Cancer Study radiologists. The overall sensitivity and specificity of the technician in identifying an abnormal scan were 97.8% (95% confidence interval: 96.4-98.8) and 98.0% (95% confidence interval: 89.5-99.7), respectively. Of the 112 prevalent nodules that were found to be malignant in follow-up, 92.9% were correctly identified by the technician plus CV compared with 84.8% by the study radiologists. The average time taken by the technician to review a scan after CV processing was 208 ± 120 seconds. Prescreening CV software and a technician as first reader is a promising strategy for improving the consistency and quality of screening interpretation of LDCT scans. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  6. Quick, Accurate, Smart: 3D Computer Vision Technology Helps Assessing Confined Animals' Behaviour.

    Directory of Open Access Journals (Sweden)

    Shanis Barnard

    Full Text Available Mankind directly controls the environment and lifestyles of several domestic species for purposes ranging from production and research to conservation and companionship. These environments and lifestyles may not offer these animals the best quality of life. Behaviour is a direct reflection of how the animal is coping with its environment. Behavioural indicators are thus among the preferred parameters to assess welfare. However, behavioural recording (usually from video can be very time consuming and the accuracy and reliability of the output rely on the experience and background of the observers. The outburst of new video technology and computer image processing gives the basis for promising solutions. In this pilot study, we present a new prototype software able to automatically infer the behaviour of dogs housed in kennels from 3D visual data and through structured machine learning frameworks. Depth information acquired through 3D features, body part detection and training are the key elements that allow the machine to recognise postures, trajectories inside the kennel and patterns of movement that can be later labelled at convenience. The main innovation of the software is its ability to automatically cluster frequently observed temporal patterns of movement without any pre-set ethogram. Conversely, when common patterns are defined through training, a deviation from normal behaviour in time or between individuals could be assessed. The software accuracy in correctly detecting the dogs' behaviour was checked through a validation process. An automatic behaviour recognition system, independent from human subjectivity, could add scientific knowledge on animals' quality of life in confinement as well as saving time and resources. This 3D framework was designed to be invariant to the dog's shape and size and could be extended to farm, laboratory and zoo quadrupeds in artificial housing. The computer vision technique applied to this software is

  7. Quick, Accurate, Smart: 3D Computer Vision Technology Helps Assessing Confined Animals’ Behaviour

    Science.gov (United States)

    Calderara, Simone; Pistocchi, Simone; Cucchiara, Rita; Podaliri-Vulpiani, Michele; Messori, Stefano; Ferri, Nicola

    2016-01-01

    Mankind directly controls the environment and lifestyles of several domestic species for purposes ranging from production and research to conservation and companionship. These environments and lifestyles may not offer these animals the best quality of life. Behaviour is a direct reflection of how the animal is coping with its environment. Behavioural indicators are thus among the preferred parameters to assess welfare. However, behavioural recording (usually from video) can be very time consuming and the accuracy and reliability of the output rely on the experience and background of the observers. The outburst of new video technology and computer image processing gives the basis for promising solutions. In this pilot study, we present a new prototype software able to automatically infer the behaviour of dogs housed in kennels from 3D visual data and through structured machine learning frameworks. Depth information acquired through 3D features, body part detection and training are the key elements that allow the machine to recognise postures, trajectories inside the kennel and patterns of movement that can be later labelled at convenience. The main innovation of the software is its ability to automatically cluster frequently observed temporal patterns of movement without any pre-set ethogram. Conversely, when common patterns are defined through training, a deviation from normal behaviour in time or between individuals could be assessed. The software accuracy in correctly detecting the dogs’ behaviour was checked through a validation process. An automatic behaviour recognition system, independent from human subjectivity, could add scientific knowledge on animals’ quality of life in confinement as well as saving time and resources. This 3D framework was designed to be invariant to the dog’s shape and size and could be extended to farm, laboratory and zoo quadrupeds in artificial housing. The computer vision technique applied to this software is innovative in non

  8. Quick, Accurate, Smart: 3D Computer Vision Technology Helps Assessing Confined Animals' Behaviour.

    Science.gov (United States)

    Barnard, Shanis; Calderara, Simone; Pistocchi, Simone; Cucchiara, Rita; Podaliri-Vulpiani, Michele; Messori, Stefano; Ferri, Nicola

    2016-01-01

    Mankind directly controls the environment and lifestyles of several domestic species for purposes ranging from production and research to conservation and companionship. These environments and lifestyles may not offer these animals the best quality of life. Behaviour is a direct reflection of how the animal is coping with its environment. Behavioural indicators are thus among the preferred parameters to assess welfare. However, behavioural recording (usually from video) can be very time consuming and the accuracy and reliability of the output rely on the experience and background of the observers. The outburst of new video technology and computer image processing gives the basis for promising solutions. In this pilot study, we present a new prototype software able to automatically infer the behaviour of dogs housed in kennels from 3D visual data and through structured machine learning frameworks. Depth information acquired through 3D features, body part detection and training are the key elements that allow the machine to recognise postures, trajectories inside the kennel and patterns of movement that can be later labelled at convenience. The main innovation of the software is its ability to automatically cluster frequently observed temporal patterns of movement without any pre-set ethogram. Conversely, when common patterns are defined through training, a deviation from normal behaviour in time or between individuals could be assessed. The software accuracy in correctly detecting the dogs' behaviour was checked through a validation process. An automatic behaviour recognition system, independent from human subjectivity, could add scientific knowledge on animals' quality of life in confinement as well as saving time and resources. This 3D framework was designed to be invariant to the dog's shape and size and could be extended to farm, laboratory and zoo quadrupeds in artificial housing. The computer vision technique applied to this software is innovative in non

  9. Prevalence and associated factors of computer vision syndrome among bank workers in Gondar City, northwest Ethiopia, 2015

    Directory of Open Access Journals (Sweden)

    Assefa NL

    2017-04-01

    Full Text Available Natnael Lakachew Assefa, Dawit Zenebe Weldemichael, Haile Woretaw Alemu, Dereje Hayilu Anbesse Department of Optometry, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia Introduction: Use of computers is generally encouraged; this is to keep up with the fast-moving world of technology, research and science. Extensive use of computers will result in computer vision syndrome (CVS, and the prevalence is increased dramatically. The main objective of the study was to assess the prevalence and associated factors of CVS among bank workers in Gondar city, northwest Ethiopia.Methods: A cross-sectional institution-based study was conducted among computer-using bank workers in Gondar city from April to June, 2015. Data were collected through structured questionnaires and observations with checklists, entered with Epi Info™ 7 and analyzed by Statistical Package for the Social Sciences (SPSS version 20. Descriptive statistics and logistic regression were carried out to compute the different rates, proportion and relevant associations.Results: Among the total 304 computer-using bank workers, the prevalence of CVS was 73% (95% confidence interval [CI]=68.04, 78.02. Blurred vision (42.4%, headache (23.0% and redness (23.0% were the most experienced symptoms. Inappropriate sitting position was 2.3 times (adjusted odds ratio [AOR]=2.33; 95% CI=1.27, 4.28 more likely to be associated with CVS when compared with appropriate sitting position. Those working on the computer for more than 20 minutes without break were nearly 2 times (AOR=1.93; 95% CI=1.11, 3.35 more likely to have suffered from CVS when compared with those taking break within 20 minutes, and those wearing eye glasses were 3 times (AOR=3.19; 95% CI=1.07, 9.51 more likely to suffer from CVS when compared with those not wearing glasses.Conclusion: About three-fourths of computer-using bank workers suffered from CVS with the most experienced symptoms being blurred vision

  10. A clinical study on "Computer vision syndrome" and its management with Triphala eye drops and Saptamrita Lauha.

    Science.gov (United States)

    Gangamma, M P; Poonam; Rajagopala, Manjusha

    2010-04-01

    American Optometric Association (AOA) defines computer vision syndrome (CVS) as "Complex of eye and vision problems related to near work, which are experienced during or related to computer use". Most studies indicate that Video Display Terminal (VDT) operators report more eye related problems than non-VDT office workers. The causes for the inefficiencies and the visual symptoms are a combination of individual visual problems and poor office ergonomics. In this clinical study on "CVS", 151 patients were registered, out of whom 141 completed the treatment. In Group A, 45 patients had been prescribed Triphala eye drops; in Group B, 53 patients had been prescribed the Triphala eye drops and SaptamritaLauha tablets internally, and in Group C, 43 patients had been prescribed the placebo eye drops and placebo tablets. In total, marked improvement was observed in 48.89, 54.71 and 06.98% patients in groups A, B and C, respectively.

  11. A computer vision system for rapid search inspired by surface-based attention mechanisms from human perception.

    Science.gov (United States)

    Mohr, Johannes; Park, Jong-Han; Obermayer, Klaus

    2014-12-01

    Humans are highly efficient at visual search tasks by focusing selective attention on a small but relevant region of a visual scene. Recent results from biological vision suggest that surfaces of distinct physical objects form the basic units of this attentional process. The aim of this paper is to demonstrate how such surface-based attention mechanisms can speed up a computer vision system for visual search. The system uses fast perceptual grouping of depth cues to represent the visual world at the level of surfaces. This representation is stored in short-term memory and updated over time. A top-down guided attention mechanism sequentially selects one of the surfaces for detailed inspection by a recognition module. We show that the proposed attention framework requires little computational overhead (about 11 ms), but enables the system to operate in real-time and leads to a substantial increase in search efficiency. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Volume Measurement Algorithm for Food Product with Irregular Shape using Computer Vision based on Monte Carlo Method

    Directory of Open Access Journals (Sweden)

    Joko Siswantoro

    2014-11-01

    Full Text Available Volume is one of important issues in the production and processing of food product. Traditionally, volume measurement can be performed using water displacement method based on Archimedes’ principle. Water displacement method is inaccurate and considered as destructive method. Computer vision offers an accurate and nondestructive method in measuring volume of food product. This paper proposes algorithm for volume measurement of irregular shape food product using computer vision based on Monte Carlo method. Five images of object were acquired from five different views and then processed to obtain the silhouettes of object. From the silhouettes of object, Monte Carlo method was performed to approximate the volume of object. The simulation result shows that the algorithm produced high accuracy and precision for volume measurement.

  13. Solution of the reactor point kinetics equations by MATLAB computing

    Directory of Open Access Journals (Sweden)

    Singh Sudhansu S.

    2015-01-01

    Full Text Available The numerical solution of the point kinetics equations in the presence of Newtonian temperature feedback has been a challenging issue for analyzing the reactor transients. Reactor point kinetics equations are a system of stiff ordinary differential equations which need special numerical treatments. Although a plethora of numerical intricacies have been introduced to solve the point kinetics equations over the years, some of the simple and straightforward methods still work very efficiently with extraordinary accuracy. As an example, it has been shown recently that the fundamental backward Euler finite difference algorithm with its simplicity has proven to be one of the most effective legacy methods. Complementing the back-ward Euler finite difference scheme, the present work demonstrates the application of ordinary differential equation suite available in the MATLAB software package to solve the stiff reactor point kinetics equations with Newtonian temperature feedback effects very effectively by analyzing various classic benchmark cases. Fair accuracy of the results implies the efficient application of MATLAB ordinary differential equation suite for solving the reactor point kinetics equations as an alternate method for future applications.

  14. Non-rigid Point Matching using Topology Preserving Constraints for Medical Computer Vision

    Directory of Open Access Journals (Sweden)

    Jong-Ha Lee

    2017-01-01

    Full Text Available This work presents a novel algorithm of finding correspondence using a relaxation labeling. For the variance experiments, the variance of all algorithms except the proposed algorithm is large. The largest variance of the proposed algorithm is +0.01 in the 0.08 deformation test of a character. Overall, the proposed algorithm outperforms compared to the rest of algorithms. Except the proposed algorithm, matching with neighborhood algorithm shows the best performance except an outlier to data ratio in a character test. The proposed algorithm shows the best performance as well as an outlier to data ratio in a character test.

  15. Computer vision-based apple grading for golden delicious apples based on surface features

    Directory of Open Access Journals (Sweden)

    Payman Moallem

    2017-03-01

    Full Text Available In this paper, a computer vision-based algorithm for golden delicious apple grading is proposed which works in six steps. Non-apple pixels as background are firstly removed from input images. Then, stem end is detected by combination of morphological methods and Mahalanobis distant classifier. Calyx region is also detected by applying K-means clustering on the Cb component in YCbCr color space. After that, defects segmentation is achieved using Multi-Layer Perceptron (MLP neural network. In the next step, stem end and calyx regions are removed from defected regions to refine and improve apple grading process. Then, statistical, textural and geometric features from refined defected regions are extracted. Finally, for apple grading, a comparison between performance of Support Vector Machine (SVM, MLP and K-Nearest Neighbor (KNN classifiers is done. Classification is done in two manners which in the first one, an input apple is classified into two categories of healthy and defected. In the second manner, the input apple is classified into three categories of first rank, second rank and rejected ones. In both grading steps, SVM classifier works as the best one with recognition rate of 92.5% and 89.2% for two categories (healthy and defected and three quality categories (first rank, second rank and rejected ones, among 120 different golden delicious apple images, respectively, considering K-folding with K = 5. Moreover, the accuracy of the proposed segmentation algorithms including stem end detection and calyx detection are evaluated for two different apple image databases.

  16. Ubiquitous Computing--Are We Crazy? Point/Counterpoint

    Science.gov (United States)

    DeWitt, Scott W.; Horn, Patricia S.

    2005-01-01

    The push for ubiquitous computing (UC) relies on an understandable and well-intentioned belief that teaching and schooling need to be transformed. This view appears credible based on large-scale criteria, such as test scores relative to other countries, drop-out rates, and economic changes. And the use of technology to achieve this goal is…

  17. OpenVX-based Python Framework for real-time cross platform acceleration of embedded computer vision applications

    Directory of Open Access Journals (Sweden)

    Ori Heimlich

    2016-11-01

    Full Text Available Embedded real-time vision applications are being rapidly deployed in a large realm of consumer electronics, ranging from automotive safety to surveillance systems. However, the relatively limited computational power of embedded platforms is considered as a bottleneck for many vision applications, necessitating optimization. OpenVX is a standardized interface, released in late 2014, in an attempt to provide both system and kernel level optimization to vision applications. With OpenVX, Vision processing are modeled with coarse-grained data flow graphs, which can be optimized and accelerated by the platform implementer. Current full implementations of OpenVX are given in the programming language C, which does not support advanced programming paradigms such as object-oriented, imperative and functional programming, nor does it have runtime or type-checking. Here we present a python-based full Implementation of OpenVX, which eliminates much of the discrepancies between the object-oriented paradigm used by many modern applications and the native C implementations. Our open-source implementation can be used for rapid development of OpenVX applications in embedded platforms. Demonstration includes static and real-time image acquisition and processing using a Raspberry Pi and a GoPro camera. Code is given as supplementary information. Code project and linked deployable virtual machine are located on GitHub: https://github.com/NBEL-lab/PythonOpenVX.

  18. A computer vision framework for finger-tapping evaluation in Parkinson's disease.

    Science.gov (United States)

    Khan, Taha; Nyholm, Dag; Westin, Jerker; Dougherty, Mark

    2014-01-01

    The rapid finger-tapping test (RFT) is an important method for clinical evaluation of movement disorders, including Parkinson's disease (PD). In clinical practice, the naked-eye evaluation of RFT results in a coarse judgment of symptom scores. We introduce a novel computer-vision (CV) method for quantification of tapping symptoms through motion analysis of index-fingers. The method is unique as it utilizes facial features to calibrate tapping amplitude for normalization of distance variation between the camera and subject. The study involved 387 video footages of RFT recorded from 13 patients diagnosed with advanced PD. Tapping performance in these videos was rated by two clinicians between the symptom severity levels ('0: normal' to '3: severe') using the unified Parkinson's disease rating scale motor examination of finger-tapping (UPDRS-FT). Another set of recordings in this study consisted of 84 videos of RFT recorded from 6 healthy controls. These videos were processed by a CV algorithm that tracks the index-finger motion between the video-frames to produce a tapping time-series. Different features were computed from this time series to estimate speed, amplitude, rhythm and fatigue in tapping. The features were trained in a support vector machine (1) to categorize the patient group between UPDRS-FT symptom severity levels, and (2) to discriminate between PD patients and healthy controls. A new representative feature of tapping rhythm, 'cross-correlation between the normalized peaks' showed strong Guttman correlation (μ2=-0.80) with the clinical ratings. The classification of tapping features using the support vector machine classifier and 10-fold cross validation categorized the patient samples between UPDRS-FT levels with an accuracy of 88%. The same classification scheme discriminated between RFT samples of healthy controls and PD patients with an accuracy of 95%. The work supports the feasibility of the approach, which is presumed suitable for PD monitoring

  19. Improved fixed point iterative method for blade element momentum computations

    DEFF Research Database (Denmark)

    Sun, Zhenye; Shen, Wen Zhong; Chen, Jin

    2017-01-01

    The blade element momentum (BEM) theory is widely used in aerodynamic performance calculations and optimization applications for wind turbines. The fixed point iterative method is the most commonly utilized technique to solve the BEM equations. However, this method sometimes does not converge...... are addressed through both theoretical analysis and numerical tests. A term from the BEM equations equals to zero at a critical inflow angle is the source of the convergence problems. When the initial inflow angle is set larger than the critical inflow angle and the relaxation methodology is adopted...

  20. - From point, line to plane - . New energy vision at Osafune Town area; 2001 nendo Osafune cho chiiki shin energy vision (Ten sen soshite men he)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-01

    With an objective of accelerating introduction of and uplifting consciousness on new energies at Osafune Town in Okayama Prefecture, investigations and discussions were given on the energy consumption structure, status of new energies available, and the new energy introduction projects for the town, thus a new energy vision was established. The estimated amount of energy consumed in Osafune Town is 1,443,467 GJ/year. By departments, the industrial department accounts for 41%, the transportation department for 40%, the civil household department for 13% and the civil business department for 6%. Energy types are accounted for by petroleum at 81%, and electric power at 19%. The important new energy introduction projects discussed as the first step include 'Cooperative projects by residents and the administration', and 'Wide area introduction of new energies' into public facilities, as the second step, 'New energy networking' targeted at mutual coordination, 'Information network' for new energies and energy saving, and as the third step, 'Acceleration of proliferation at general levels' beginning with housing, and 'Creation of green energy experiencing park' at the Osafune Beautiful Forest. (NEDO)

  1. Steering the Information Society Development as a Vision-based, Multi-stakeholder Process: a Point of View

    Directory of Open Access Journals (Sweden)

    Horatiu Dragomirescu

    2013-11-01

    Full Text Available The steering of the information society development at country level is a desideratum for the smooth unfolding of the respective societal change -- nowadays a key issue worldwide for scientific research and public governance. Some possible guidelines are presented on how to come up with a vision shared by stakeholders and how to ensure concertation among them along the way.

  2. From geospatial observations of ocean currents to causal predictors of spatio-economic activity using computer vision and machine learning

    Science.gov (United States)

    Popescu, Florin; Ayache, Stephane; Escalera, Sergio; Baró Solé, Xavier; Capponi, Cecile; Panciatici, Patrick; Guyon, Isabelle

    2016-04-01

    The big data transformation currently revolutionizing science and industry forges novel possibilities in multi-modal analysis scarcely imaginable only a decade ago. One of the important economic and industrial problems that stand to benefit from the recent expansion of data availability and computational prowess is the prediction of electricity demand and renewable energy generation. Both are correlates of human activity: spatiotemporal energy consumption patterns in society are a factor of both demand (weather dependent) and supply, which determine cost - a relation expected to strengthen along with increasing renewable energy dependence. One of the main drivers of European weather patterns is the activity of the Atlantic Ocean and in particular its dominant Northern Hemisphere current: the Gulf Stream. We choose this particular current as a test case in part due to larger amount of relevant data and scientific literature available for refinement of analysis techniques. This data richness is due not only to its economic importance but also to its size being clearly visible in radar and infrared satellite imagery, which makes it easier to detect using Computer Vision (CV). The power of CV techniques makes basic analysis thus developed scalable to other smaller and less known, but still influential, currents, which are not just curves on a map, but complex, evolving, moving branching trees in 3D projected onto a 2D image. We investigate means of extracting, from several image modalities (including recently available Copernicus radar and earlier Infrared satellites), a parameterized representation of the state of the Gulf Stream and its environment that is useful as feature space representation in a machine learning context, in this case with the EC's H2020-sponsored 'See.4C' project, in the context of which data scientists may find novel predictors of spatiotemporal energy flow. Although automated extractors of Gulf Stream position exist, they differ in methodology

  3. Retrospective study of effect of therapy on computer vision syndrome patients having convergence insufficiency

    Directory of Open Access Journals (Sweden)

    Nidhi Tiwari

    2017-01-01

    Full Text Available Aim: To study effect of therapy among computer users having convergence insufficiency. Materials and Methods: Hundred people between age group of 20-35 and who worked in IT companies were enrolled in the study. They were subjected to orthoptic evaluation to establish diagnosis of convergence insufficiency. They were then called for in-office therapy for 12 days daily. They underwent brock string exercises and at the end of therapy re-evaluation was done. Results: All the patients who underwent the therapy showed improvement in Near point of convergence at the end of therapy. They were also symptomatically better. Conclusions: Convergence insufficiency is a common occupation hazard among IT professionals. But it can be treated with appropriate therapy.

  4. Operating point resolved loss computation in electrical machines

    Directory of Open Access Journals (Sweden)

    Pfingsten Georg Von

    2016-03-01

    Full Text Available Magnetic circuits of electromagnetic energy converters, such as electrical machines, are nowadays highly utilized. This proposition is intrinsic for the magnetic as well as the electric circuit and depicts that significant enhancements of electrical machines are difficult to achieve in the absence of a detailed understanding of underlying effects. In order to improve the properties of electrical machines the accurate determination of the locally distributed iron losses based on idealized model assumptions solely is not sufficient. Other loss generating effects have to be considered and the possibility being able to distinguish between the causes of particular loss components is indispensable. Parasitic loss mechanisms additionally contributing to the total losses originating from field harmonics, non-linear material behaviour, rotational magnetizations, and detrimental effects caused by the manufacturing process or temperature, are not explicitly considered in the common iron-loss models, probably even not specifically contained in commonly used calibration factors. This paper presents a methodology being able to distinguish between different loss mechanisms and enables to individually consider particular loss mechanisms in the model of the electric machine. A sensitivity analysis of the model parameters can be performed to obtain information about which decisive loss origin for which working point has to be manipulated by the electromagnetic design or the control of the machine.

  5. In-line 3D print failure detection using computer vision

    DEFF Research Database (Denmark)

    Lyngby, Rasmus Ahrenkiel; Wilm, Jakob; Eiríksson, Eyþór Rúnar

    2017-01-01

    Here we present our findings on a novel real-time vision system that allows for automatic detection of failure conditions that are considered outside of nominal operation. These failure modes include warping, build plate delamination and extrusion failure. Our system consists of a calibrated came...

  6. Development of a Computer Vision Technology for the Forest Products Manufacturing Industry

    Science.gov (United States)

    D. Earl Kline; Richard Conners; Philip A. Araman

    1992-01-01

    The goal of this research is to create an automated processing/grading system for hardwood lumber that will be of use to the forest products industry. The objective of creating a full scale machine vision prototype for inspecting hardwood lumber will become a reality in calendar year 1992. Space for the full scale prototype has been created at the Brooks Forest...

  7. An artificial-vision responsive to patient motions during computer controlled radiation therapy

    International Nuclear Information System (INIS)

    Kalend, A.M.; Shimoga, K.; Kanade, T.; Greenberger, J.S.

    1997-01-01

    Purpose/Objectives: Automated precision radiotherapy using multiple conformal and modulated beams, requires monitoring of patient movements during irradiation. Immobilizers relying on patient cooperating in cradles have somewhat reduced positional uncertainties, but others including breathing are largely unknown. We built an artificial vision (AV) device for real-time vision of patient movements, their tracking and quantification. Method and Materials: The Artificial Vision System's 'acuity' and 'reflex' were evaluated in terms of imaged skin spatial resolutions and temporal dispersions measured using a mannequin and a fiduciated harmonic oscillator placed at 100cm isocenter. The device traced skin motion even in poorly lighted rooms without use of explicit skin fiduciation, or using standard radiotherapy skin tattoos. Results: The AV system tracked human skin at vision rates approaching 30Hz and sensitivity of 2mm. It successfully identified and tracked independent skin marks, either natural tattoos or artificial fiducials. Three alert levels triggered when patient movement exceeded preset displacements (2mm/30Hz), motion velocities (5m/sec) or acceleration (2m/sec 2 ). Conclusion: The AV system trigger should suit for patient ventilatory gating and safety interlocking of treatment accelerators, in order to modulate, interrupt, or abort radiation during dynamic therapy

  8. Identifying the computational requirements of an integrated top-down-bottom-up model for overt visual attention within an active vision system.

    Directory of Open Access Journals (Sweden)

    Sebastian McBride

    Full Text Available Computational visual attention systems have been constructed in order for robots and other devices to detect and locate regions of interest in their visual world. Such systems often attempt to take account of what is known of the human visual system and employ concepts, such as 'active vision', to gain various perceived advantages. However, despite the potential for gaining insights from such experiments, the computational requirements for visual attention processing are often not clearly presented from a biological perspective. This was the primary objective of this study, attained through two specific phases of investigation: 1 conceptual modeling of a top-down-bottom-up framework through critical analysis of the psychophysical and neurophysiological literature, 2 implementation and validation of the model into robotic hardware (as a representative of an active vision system. Seven computational requirements were identified: 1 transformation of retinotopic to egocentric mappings, 2 spatial memory for the purposes of medium-term inhibition of return, 3 synchronization of 'where' and 'what' information from the two visual streams, 4 convergence of top-down and bottom-up information to a centralized point of information processing, 5 a threshold function to elicit saccade action, 6 a function to represent task relevance as a ratio of excitation and inhibition, and 7 derivation of excitation and inhibition values from object-associated feature classes. The model provides further insight into the nature of data representation and transfer between brain regions associated with the vertebrate 'active' visual attention system. In particular, the model lends strong support to the functional role of the lateral intraparietal region of the brain as a primary area of information consolidation that directs putative action through the use of a 'priority map'.

  9. Identifying the computational requirements of an integrated top-down-bottom-up model for overt visual attention within an active vision system.

    Science.gov (United States)

    McBride, Sebastian; Huelse, Martin; Lee, Mark

    2013-01-01

    Computational visual attention systems have been constructed in order for robots and other devices to detect and locate regions of interest in their visual world. Such systems often attempt to take account of what is known of the human visual system and employ concepts, such as 'active vision', to gain various perceived advantages. However, despite the potential for gaining insights from such experiments, the computational requirements for visual attention processing are often not clearly presented from a biological perspective. This was the primary objective of this study, attained through two specific phases of investigation: 1) conceptual modeling of a top-down-bottom-up framework through critical analysis of the psychophysical and neurophysiological literature, 2) implementation and validation of the model into robotic hardware (as a representative of an active vision system). Seven computational requirements were identified: 1) transformation of retinotopic to egocentric mappings, 2) spatial memory for the purposes of medium-term inhibition of return, 3) synchronization of 'where' and 'what' information from the two visual streams, 4) convergence of top-down and bottom-up information to a centralized point of information processing, 5) a threshold function to elicit saccade action, 6) a function to represent task relevance as a ratio of excitation and inhibition, and 7) derivation of excitation and inhibition values from object-associated feature classes. The model provides further insight into the nature of data representation and transfer between brain regions associated with the vertebrate 'active' visual attention system. In particular, the model lends strong support to the functional role of the lateral intraparietal region of the brain as a primary area of information consolidation that directs putative action through the use of a 'priority map'.

  10. Computer vision syndrome prevalence, knowledge and associated factors among Saudi Arabia University Students: Is it a serious problem?

    Science.gov (United States)

    Al Rashidi, Sultan H; Alhumaidan, H

    2017-01-01

    Computers and other visual display devices are now an essential part of our daily life. With the increased use, a very large population is experiencing sundry ocular symptoms globally such as dry eyes, eye strain, irritation, and redness of the eyes to name a few. Collectively, all such computer related symptoms are usually referred to as computer vision syndrome (CVS). The current study aims to define the prevalence, knowledge in community, pathophysiology, factors associated, and prevention of CVS. This is a cross-sectional study conducted in Qassim University College of Medicine during a period of 1 year from January 2015 to January 2016 using a questionnaire to collect relevant data including demographics and various variables to be studied. 634 students were inducted from a public sector University of Qassim, Saudi Arabia, regardless of their age and gender. The data were then statistically analyzed on SPSS version 22, and the descriptive data were expressed as percentages, mode, and median using graphs where needed. A total of 634 students with a mean age of 21. 40, Std 1.997 and Range 7 (18-25) were included as study subjects with a male predominance (77.28%). Of the total patients, majority (459, 72%) presented with acute symptoms while remaining had chronic problems. A clear-cut majority was carrying the symptoms for 1 month. The statistical analysis revealed serious symptoms in the majority of study subjects especially those who are permanent users of a computer for long hours. Continuous use of computers for long hours is found to have severe problems of vision especially in those who are using computers and similar devices for a long duration.

  11. Distributed FPGA-based smart camera architecture for computer vision applications

    OpenAIRE

    Bourrasset, Cédric; Maggiani, Luca; Sérot, Jocelyn; Berry, François; Pagano, Paolo

    2013-01-01

    International audience; Smart camera networks (SCN) raise challenging issues in many fields of research, including vision processing, communication protocols, distributed algorithms or power management. Furthermore, application logic in SCN is not centralized but spread among network nodes meaning that each node must have to process images to extract significant features, and aggregate data to understand the surrounding environment. In this context, smart camera have first embedded general pu...

  12. Challenges of pin-point landing for planetary landing: the LION absolute vision-based navigation approach and experimental results

    OpenAIRE

    Voirin, Thomas; Delaune, Jeff; Le Besnerais, Guy; Farges, Jean Loup; Bourdarias, Clément; Krüger, Hans

    2013-01-01

    After ExoMars in 2016 and 2018, future ESA missions to Mars, the Moon, or asteroids will require safe and pinpoint precision landing capabilities, with for example a specified accuracy of typically 100 m at touchdown for a Moon landing. The safe landing requirement can be met thanks to state-of-the-art Terrain-Relative Navigation (TRN) sensors such as Wide-Field-of-View vision-based navigation cameras (VBNC), with appropriate hazard detection and avoidance algorithms. To reach the pinpoint pr...

  13. Vision-based interaction

    CERN Document Server

    Turk, Matthew

    2013-01-01

    In its early years, the field of computer vision was largely motivated by researchers seeking computational models of biological vision and solutions to practical problems in manufacturing, defense, and medicine. For the past two decades or so, there has been an increasing interest in computer vision as an input modality in the context of human-computer interaction. Such vision-based interaction can endow interactive systems with visual capabilities similar to those important to human-human interaction, in order to perceive non-verbal cues and incorporate this information in applications such

  14. Robotic Arm Control Algorithm Based on Stereo Vision Using RoboRealm Vision

    Directory of Open Access Journals (Sweden)

    SZABO, R.

    2015-05-01

    Full Text Available The goal of this paper is to present a stereo computer vision algorithm intended to control a robotic arm. Specific points on the robot joints are marked and recognized in the software. Using a dedicated set of mathematic equations, the movement of the robot is continuously computed and monitored with webcams. Positioning error is finally analyzed.

  15. The Effect of the Usage of Computer-Based Assistive Devices on the Functioning and Quality of Life of Individuals Who Are Blind or Have Low Vision

    Science.gov (United States)

    Rosner, Yotam; Perlman, Amotz

    2018-01-01

    Introduction: The Israel Ministry of Social Affairs and Social Services subsidizes computer-based assistive devices for individuals with visual impairments (that is, those who are blind or have low vision) to assist these individuals in their interactions with computers and thus to enhance their independence and quality of life. The aim of this…

  16. Fast calculation method of computer-generated hologram using a depth camera with point cloud gridding

    Science.gov (United States)

    Zhao, Yu; Shi, Chen-Xiao; Kwon, Ki-Chul; Piao, Yan-Ling; Piao, Mei-Lan; Kim, Nam

    2018-03-01

    We propose a fast calculation method for a computer-generated hologram (CGH) of real objects that uses a point cloud gridding method. The depth information of the scene is acquired using a depth camera and the point cloud model is reconstructed virtually. Because each point of the point cloud is distributed precisely to the exact coordinates of each layer, each point of the point cloud can be classified into grids according to its depth. A diffraction calculation is performed on the grids using a fast Fourier transform (FFT) to obtain a CGH. The computational complexity is reduced dramatically in comparison with conventional methods. The feasibility of the proposed method was confirmed by numerical and optical experiments.

  17. Computer-related vision problems in Osogbo, south-western Nigeria ...

    African Journals Online (AJOL)

    Widespread use of computers for office work and e-learning has resulted in increased visual demands among computer users. The increased visual demands have led to development of ocular complaints and discomfort among users. The objective of this study is to determine the prevalence of computer related eye ...

  18. Lambda Vision

    Science.gov (United States)

    Czajkowski, Michael

    2014-06-01

    There is an explosion in the quantity and quality of IMINT data being captured in Intelligence Surveillance and Reconnaissance (ISR) today. While automated exploitation techniques involving computer vision are arriving, only a few architectures can manage both the storage and bandwidth of large volumes of IMINT data and also present results to analysts quickly. Lockheed Martin Advanced Technology Laboratories (ATL) has been actively researching in the area of applying Big Data cloud computing techniques to computer vision applications. This paper presents the results of this work in adopting a Lambda Architecture to process and disseminate IMINT data using computer vision algorithms. The approach embodies an end-to-end solution by processing IMINT data from sensors to serving information products quickly to analysts, independent of the size of the data. The solution lies in dividing up the architecture into a speed layer for low-latent processing and a batch layer for higher quality answers at the expense of time, but in a robust and fault-tolerant way. This approach was evaluated using a large corpus of IMINT data collected by a C-130 Shadow Harvest sensor over Afghanistan from 2010 through 2012. The evaluation data corpus included full motion video from both narrow and wide area field-of-views. The evaluation was done on a scaled-out cloud infrastructure that is similar in composition to those found in the Intelligence Community. The paper shows experimental results to prove the scalability of the architecture and precision of its results using a computer vision algorithm designed to identify man-made objects in sparse data terrain.

  19. A malaria diagnostic tool based on computer vision screening and visualization of Plasmodium falciparum candidate areas in digitized blood smears.

    Directory of Open Access Journals (Sweden)

    Nina Linder

    Full Text Available INTRODUCTION: Microscopy is the gold standard for diagnosis of malaria, however, manual evaluation of blood films is highly dependent on skilled personnel in a time-consuming, error-prone and repetitive process. In this study we propose a method using computer vision detection and visualization of only the diagnostically most relevant sample regions in digitized blood smears. METHODS: Giemsa-stained thin blood films with P. falciparum ring-stage trophozoites (n = 27 and uninfected controls (n = 20 were digitally scanned with an oil immersion objective (0.1 µm/pixel to capture approximately 50,000 erythrocytes per sample. Parasite candidate regions were identified based on color and object size, followed by extraction of image features (local binary patterns, local contrast and Scale-invariant feature transform descriptors used as input to a support vector machine classifier. The classifier was trained on digital slides from ten patients and validated on six samples. RESULTS: The diagnostic accuracy was tested on 31 samples (19 infected and 12 controls. From each digitized area of a blood smear, a panel with the 128 most probable parasite candidate regions was generated. Two expert microscopists were asked to visually inspect the panel on a tablet computer and to judge whether the patient was infected with P. falciparum. The method achieved a diagnostic sensitivity and specificity of 95% and 100% as well as 90% and 100% for the two readers respectively using the diagnostic tool. Parasitemia was separately calculated by the automated system and the correlation coefficient between manual and automated parasitemia counts was 0.97. CONCLUSION: We developed a decision support system for detecting malaria parasites using a computer vision algorithm combined with visualization of sample areas with the highest probability of malaria infection. The system provides a novel method for blood smear screening with a significantly reduced need for

  20. Sigma: computer vision in the service of safety and reliability in the inspection services; Sigma: la vision computacional al servicio de la seguridad y fiabilidad en los servicios de inspeccion

    Energy Technology Data Exchange (ETDEWEB)

    Pineiro, P. J.; Mendez, M.; Garcia, A.; Cabrera, E.; Regidor, J. J.

    2012-11-01

    Vision Computing is growing very fast in the last decade with very efficient tools and algorithms. This allows new development of applications in the nuclear field providing more efficient equipment and tasks: redundant systems, vision-guided mobile robots, automated visual defects recognition, measurement, etc., In this paper Tecnatom describes a detailed example of visual computing application developed to provide secure redundant identification of the thousands of tubes existing in a power plant steam generator. some other on-going or planned visual computing projects by Tecnatom are also introduced. New possibilities of application in the inspection systems for nuclear components appear where the main objective is to maximize their reliability. (Author) 6 refs.

  1. Computer Use and Vision-Related Problems Among University Students In Ajman, United Arab Emirate

    OpenAIRE

    Shantakumari, N; Eldeeb, R; Sreedharan, J; Gopal, K

    2014-01-01

    Background: The extensive use of computers as medium of teaching and learning in universities necessitates introspection into the extent of computer related health disorders among student population. Aim: This study was undertaken to assess the pattern of computer usage and related visual problems, among University students in Ajman, United Arab Emirates. Materials and Methods: A total of 500 Students studying in Gulf Medical University, Ajman and Ajman University of Science and Technology we...

  2. Interesting Interest Points

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Dahl, Anders Lindbjerg; Pedersen, Kim Steenstrup

    2012-01-01

    on spatial invariance of interest points under changing acquisition parameters by measuring the spatial recall rate. The scope of this paper is to investigate the performance of a number of existing well-established interest point detection methods. Automatic performance evaluation of interest points is hard......Not all interest points are equally interesting. The most valuable interest points lead to optimal performance of the computer vision method in which they are employed. But a measure of this kind will be dependent on the chosen vision application. We propose a more general performance measure based...... position. The LED illumination provides the option for artificially relighting the scene from a range of light directions. This data set has given us the ability to systematically evaluate the performance of a number of interest point detectors. The highlights of the conclusions are that the fixed scale...

  3. Computationally determining the salience of decision points for real-time wayfinding support

    Directory of Open Access Journals (Sweden)

    Makoto Takemiya

    2012-06-01

    Full Text Available This study introduces the concept of computational salience to explain the discriminatory efficacy of decision points, which in turn may have applications to providing real-time assistance to users of navigational aids. This research compared algorithms for calculating the computational salience of decision points and validated the results via three methods: high-salience decision points were used to classify wayfinders; salience scores were used to weight a conditional probabilistic scoring function for real-time wayfinder performance classification; and salience scores were correlated with wayfinding-performance metrics. As an exploratory step to linking computational and cognitive salience, a photograph-recognition experiment was conducted. Results reveal a distinction between algorithms useful for determining computational and cognitive saliences. For computational salience, information about the structural integration of decision points is effective, while information about the probability of decision-point traversal shows promise for determining cognitive salience. Limitations from only using structural information and motivations for future work that include non-structural information are elicited.

  4. VibroCV: a computer vision-based vibroarthrography platform with possible application to Juvenile Idiopathic Arthritis.

    Science.gov (United States)

    Wiens, Andrew D; Prahalad, Sampath; Inan, Omer T

    2016-08-01

    Vibroarthrography, a method for interpreting the sounds emitted by a knee during movement, has been studied for several joint disorders since 1902. However, to our knowledge, the usefulness of this method for management of Juvenile Idiopathic Arthritis (JIA) has not been investigated. To study joint sounds as a possible new biomarker for pediatric cases of JIA we designed and built VibroCV, a platform to capture vibroarthrograms from four accelerometers; electromyograms (EMG) and inertial measurements from four wireless EMG modules; and joint angles from two Sony Eye cameras and six light-emitting diodes with commercially-available off-the-shelf parts and computer vision via OpenCV. This article explains the design of this turn-key platform in detail, and provides a sample recording captured from a pediatric subject.

  5. Virtual Vision

    Science.gov (United States)

    Terzopoulos, Demetri; Qureshi, Faisal Z.

    Computer vision and sensor networks researchers are increasingly motivated to investigate complex multi-camera sensing and control issues that arise in the automatic visual surveillance of extensive, highly populated public spaces such as airports and train stations. However, they often encounter serious impediments to deploying and experimenting with large-scale physical camera networks in such real-world environments. We propose an alternative approach called "Virtual Vision", which facilitates this type of research through the virtual reality simulation of populated urban spaces, camera sensor networks, and computer vision on commodity computers. We demonstrate the usefulness of our approach by developing two highly automated surveillance systems comprising passive and active pan/tilt/zoom cameras that are deployed in a virtual train station environment populated by autonomous, lifelike virtual pedestrians. The easily reconfigurable virtual cameras distributed in this environment generate synthetic video feeds that emulate those acquired by real surveillance cameras monitoring public spaces. The novel multi-camera control strategies that we describe enable the cameras to collaborate in persistently observing pedestrians of interest and in acquiring close-up videos of pedestrians in designated areas.

  6. SU-C-209-06: Improving X-Ray Imaging with Computer Vision and Augmented Reality

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, R.D.; Scherrer, B [Boston Children’s Hospital, Boston, MA (United States); Don, S [Washington University, St. Louis, MO (United States)

    2016-06-15

    Purpose: To determine the feasibility of using a computer vision algorithm and augmented reality interface to reduce repeat rates and improve consistency of image quality and patient exposure in general radiography. Methods: A prototype device, designed for use with commercially available hardware (Microsoft Kinect 2.0) capable of depth sensing and high resolution/frame rate video, was mounted to the x-ray tube housing as part of a Philips DigitalDiagnost digital radiography room. Depth data and video was streamed to a Windows 10 PC. Proprietary software created an augmented reality interface where overlays displayed selectable information projected over real-time video of the patient. The information displayed prior to and during x-ray acquisition included: recognition and position of ordered body part, position of image receptor, thickness of anatomy, location of AEC cells, collimated x-ray field, degree of patient motion and suggested x-ray technique. Pre-clinical data was collected in a volunteer study to validate patient thickness measurements and x-ray images were not acquired. Results: Proprietary software correctly identified ordered body part, measured patient motion, and calculated thickness of anatomy. Pre-clinical data demonstrated accuracy and precision of body part thickness measurement when compared with other methods (e.g. laser measurement tool). Thickness measurements provided the basis for developing a database of thickness-based technique charts that can be automatically displayed to the technologist. Conclusion: The utilization of computer vision and commercial hardware to create an augmented reality view of the patient and imaging equipment has the potential to drastically improve the quality and safety of x-ray imaging by reducing repeats and optimizing technique based on patient thickness. Society of Pediatric Radiology Pilot Grant; Washington University Bear Cub Fund.

  7. SU-C-209-06: Improving X-Ray Imaging with Computer Vision and Augmented Reality

    International Nuclear Information System (INIS)

    MacDougall, R.D.; Scherrer, B; Don, S

    2016-01-01

    Purpose: To determine the feasibility of using a computer vision algorithm and augmented reality interface to reduce repeat rates and improve consistency of image quality and patient exposure in general radiography. Methods: A prototype device, designed for use with commercially available hardware (Microsoft Kinect 2.0) capable of depth sensing and high resolution/frame rate video, was mounted to the x-ray tube housing as part of a Philips DigitalDiagnost digital radiography room. Depth data and video was streamed to a Windows 10 PC. Proprietary software created an augmented reality interface where overlays displayed selectable information projected over real-time video of the patient. The information displayed prior to and during x-ray acquisition included: recognition and position of ordered body part, position of image receptor, thickness of anatomy, location of AEC cells, collimated x-ray field, degree of patient motion and suggested x-ray technique. Pre-clinical data was collected in a volunteer study to validate patient thickness measurements and x-ray images were not acquired. Results: Proprietary software correctly identified ordered body part, measured patient motion, and calculated thickness of anatomy. Pre-clinical data demonstrated accuracy and precision of body part thickness measurement when compared with other methods (e.g. laser measurement tool). Thickness measurements provided the basis for developing a database of thickness-based technique charts that can be automatically displayed to the technologist. Conclusion: The utilization of computer vision and commercial hardware to create an augmented reality view of the patient and imaging equipment has the potential to drastically improve the quality and safety of x-ray imaging by reducing repeats and optimizing technique based on patient thickness. Society of Pediatric Radiology Pilot Grant; Washington University Bear Cub Fund

  8. Shape measurement system for single point incremental forming (SPIF) manufacts by using trinocular vision and random pattern

    International Nuclear Information System (INIS)

    Setti, Francesco; Bini, Ruggero; Lunardelli, Massimo; Bosetti, Paolo; Bruschi, Stefania; De Cecco, Mariolino

    2012-01-01

    Many contemporary works show the interest of the scientific community in measuring the shape of artefacts made by single point incremental forming. In this paper, we will present an algorithm able to detect feature points with a random pattern, check the compatibility of associations exploiting multi-stereo constraints and reject outliers and perform a 3D reconstruction by dense random patterns. The algorithm is suitable for a real-time application, in fact it needs just three images and a synchronous relatively fast processing. The proposed method has been tested on a simple geometry and results have been compared with a coordinate measurement machine acquisition. (paper)

  9. Selected Publications in Image Understanding and Computer Vision from 1974 to 1983

    Science.gov (United States)

    1985-04-18

    Germany, September 26-28, 1978), Plenum, New York, 1979. 9. Reconnaissance des Formes et Intelligence Artificielle (2’me Congres AFCET-IRIA, Toulouse...the last decade. .To L..... ABBREVIATIONS - AI Artificial Intelligence BC Biological Cybernetics CACM Communications of the ACM CG Computer Graphics... Intelligence PACM Proceedings of the ACM "P-IEEE Proceedings of the IEEE P-NCC Proceedings of the National Computer Conference PR Pattern Recognition PRL

  10. The peak efficiency calibration of volume source using 152Eu point source in computer

    International Nuclear Information System (INIS)

    Shen Tingyun; Qian Jianfu; Nan Qinliang; Zhou Yanguo

    1997-01-01

    The author describes the method of the peak efficiency calibration of volume source by means of 152 Eu point source for HPGe γ spectrometer. The peak efficiency can be computed by Monte Carlo simulation, after inputting parameter of detector. The computation results are in agreement with the experimental results with an error of +-3.8%, with an exception one is about +-7.4%

  11. The SmartBioPhone (TM), a point of care vision under development through two European projects: OPTOLABCARD and LABONFOIL

    DEFF Research Database (Denmark)

    Ruano-Lopez, J.M.; Agirregabiria, M.; Olabarria, G.

    2009-01-01

    LOCs are big enough to include all the sample preparation subcomponents at a low price. These LOCs will be used in four point of care applications: environment, food, cancer and drug monitoring. The user will obtain the results of the tests by connecting the Labcard/Skinpatch reader to a very popular...... equipment where LOCs will be fabricated at a low cost....

  12. Evaluation of body weight of sea cucumber Apostichopus japonicus by computer vision

    Science.gov (United States)

    Liu, Hui; Xu, Qiang; Liu, Shilin; Zhang, Libin; Yang, Hongsheng

    2015-01-01

    A postichopus japonicus (Holothuroidea, Echinodermata) is an ecological and economic species in East Asia. Conventional biometric monitoring method includes diving for samples and weighing above water, with highly variable in weight measurement due to variation in the quantity of water in the respiratory tree and intestinal content of this species. Recently, video survey method has been applied widely in biometric detection on underwater benthos. However, because of the high flexibility of A. japonicus body, video survey method of monitoring is less used in sea cucumber. In this study, we designed a model to evaluate the wet weight of A. japonicus, using machine vision technology combined with a support vector machine (SVM) that can be used in field surveys on the A. japonicus population. Continuous dorsal images of free-moving A. japonicus individuals in seawater were captured, which also allows for the development of images of the core body edge as well as thorn segmentation. Parameters that include body length, body breadth, perimeter and area, were extracted from the core body edge images and used in SVM regression, to predict the weight of A. japonicus and for comparison with a power model. Results indicate that the use of SVM for predicting the weight of 33 A. japonicus individuals is accurate ( R 2=0.99) and compatible with the power model ( R 2 =0.96). The image-based analysis and size-weight regression models in this study may be useful in body weight evaluation of A. japonicus in lab and field study.

  13. Computer Vision Based Smart Lane Departure Warning System for Vehicle Dynamics Control

    Directory of Open Access Journals (Sweden)

    Ambarish G. Mohapatra

    2011-09-01

    Full Text Available Collision Avoidance System solves many problems caused by traffic congestion worldwide and a synergy of new information technologies for simulation, real-time control and communications networks. The above system is characterized as an intelligent vehicle system. Traffic congestion has been increasing world-wide as a result of increased motorization, urbanization, population growth and changes in population density. Congestion reduces utilization of the transportation infrastructure and increases travel time, air pollution, fuel consumption and most importantly traffic accidents. The main objective of this work is to develop a machine vision system for lane departure detection and warning to measure the lane related parameters such as heading angle, lateral deviation, yaw rate and sideslip angle from the road scene image using standard image processing technique that can be used for automation of steering a motor vehicle. The exact position of the steering wheel can be monitored using a steering wheel sensor. This core part of this work is based on Hough transformation based edge detection technique for the detection of lane departure parameters. The prototype designed for this work has been tested in a running vehicle for the monitoring of real-time lane related parameters.

  14. Fractographic classification in metallic materials by using 3D processing and computer vision techniques

    Directory of Open Access Journals (Sweden)

    Maria Ximena Bastidas-Rodríguez

    2016-09-01

    Full Text Available Failure analysis aims at collecting information about how and why a failure is produced. The first step in this process is a visual inspection on the flaw surface that will reveal the features, marks, and texture, which characterize each type of fracture. This is generally carried out by personnel with no experience that usually lack the knowledge to do it. This paper proposes a classification method for three kinds of fractures in crystalline materials: brittle, fatigue, and ductile. The method uses 3D vision, and it is expected to support failure analysis. The features used in this work were: i Haralick’s features and ii the fractal dimension. These features were applied to 3D images obtained from a confocal laser scanning microscopy Zeiss LSM 700. For the classification, we evaluated two classifiers: Artificial Neural Networks and Support Vector Machine. The performance evaluation was made by extracting four marginal relations from the confusion matrix: accuracy, sensitivity, specificity, and precision, plus three evaluation methods: Receiver Operating Characteristic space, the Individual Classification Success Index, and the Jaccard’s coefficient. Despite the classification percentage obtained by an expert is better than the one obtained with the algorithm, the algorithm achieves a classification percentage near or exceeding the 60 % accuracy for the analyzed failure modes. The results presented here provide a good approach to address future research on texture analysis using 3D data.

  15. An automatic colour-based computer vision algorithm for tracking the position of piglets

    Energy Technology Data Exchange (ETDEWEB)

    Navarro-Jover, J. M.; Alcaniz-Raya, M.; Gomez, V.; Balasch, S.; Moreno, J. R.; Grau-Colomer, V.; Torres, A.

    2009-07-01

    Artificial vision is a powerful observation tool for research in the field of livestock production. So, based on the search and recognition of colour spots in images, a digital image processing system which permits the detection of the position of piglets in a farrowing pen, was developed. To this end, 24,000 images were captured over five takes (days), with a five-second interval between every other image. The nine piglets in a litter were marked on their backs and sides with different coloured spray paints each one, placed at a considerable distance on the RGB space. The programme requires the user to introduce the colour patterns to be found, and the output is an ASCII file with the positions (column X, lineY) for each of these marks within the image analysed. This information may be extremely useful for further applications in the study of animal behaviour and welfare parameters (huddling, activity, suckling, etc.). The software programme initially segments the image in the RGB colour space to separate the colour marks from the rest of the image, and then recognises the colour patterns, using another colour space [B/(R+G+B), (G-R), (B-G)] more suitable for this purpose. This additional colour space was obtained testing different colour combinations derived from R, G and B. The statistical evaluation of the programmes performance revealed an overall 72.5% in piglet detection, 89.1% of this total being correctly detected. (Author) 33 refs.

  16. Colour computer-generated holography for point clouds utilizing the Phong illumination model.

    Science.gov (United States)

    Symeonidou, Athanasia; Blinder, David; Schelkens, Peter

    2018-04-16

    A technique integrating the bidirectional reflectance distribution function (BRDF) is proposed to generate realistic high-quality colour computer-generated holograms (CGHs). We build on prior work, namely a fast computer-generated holography method for point clouds that handles occlusions. We extend the method by integrating the Phong illumination model so that the properties of the objects' surfaces are taken into account to achieve natural light phenomena such as reflections and shadows. Our experiments show that rendering holograms with the proposed algorithm provides realistic looking objects without any noteworthy increase to the computational cost.

  17. METHODS OF ASSESSING THE DEGREE OF DESTRUCTION OF RUBBER PRODUCTS USING COMPUTER VISION ALGORITHMS

    Directory of Open Access Journals (Sweden)

    A. A. Khvostov

    2015-01-01

    Full Text Available For technical inspection of rubber products are essential methods of improving video scopes analyzing the degree of destruction and aging of rubber in an aggressive environment. The main factor determining the degree of destruction of the rubber product, the degree of coverage is cracked, which can be described as the amount of the total area, perimeter cracks, geometric shapes and other parameters. In the process of creating a methodology for assessing the degree of destruction of rubber products arises the problem of the development of machine vision algorithm for estimating the degree of coverage of the sample fractures and fracture characterization. For the development of image processing algorithm performed experimental studies on the artificial aging of several samples of products that are made from different rubbers. In the course of the experiments it was obtained several samples of shots vulcanizates in real time. To achieve the goals initially made light stabilization of array images using Gaussian filter. Thereafter, for each image binarization operation is applied. To highlight the contours of the surface damage of the sample is used Canny algorithm. The detected contours are converted into an array of pixels. However, a crack may be allocated to several contours. Therefore, an algorithm was developed by combining contours criterion of minimum distance between them. At the end of the calculation is made of the morphological features of each contour (area, perimeter, length, width, angle of inclination, the At the end of the calculation is made of the morphological features of each contour (area, perimeter, length, width, angle of inclination, the Minkowski dimension. Show schedule obtained by the method parameters destruction of samples of rubber products. The developed method allows you to automate assessment of the degree of aging of rubber products in telemetry systems, to study the dynamics of the aging process of polymers to

  18. Performance of human observers and an automatic 3-dimensional computer-vision-based locomotion scoring method to detect lameness and hoof lesions in dairy cows

    NARCIS (Netherlands)

    Schlageter-Tello, Andrés; Hertem, Van Tom; Bokkers, Eddie A.M.; Viazzi, Stefano; Bahr, Claudia; Lokhorst, Kees

    2018-01-01

    The objective of this study was to determine if a 3-dimensional computer vision automatic locomotion scoring (3D-ALS) method was able to outperform human observers for classifying cows as lame or nonlame and for detecting cows affected and nonaffected by specific type(s) of hoof lesion. Data

  19. BUILD-IT : a computer vision-based interaction technique for a planning tool

    NARCIS (Netherlands)

    Rauterberg, G.W.M.; Fjeld, M.; Krueger, H.; Bichsel, M.; Leonhardt, U.; Meier, M.; Thimbleby, H.; O'Conaill, B.; Thomas, P.J.

    1997-01-01

    Shows a method that goes beyond the established approaches of human-computer interaction. We first bring a serious critique of traditional interface types, showing their major drawbacks and limitations. Promising alternatives are offered by virtual (or immersive) reality (VR) and by augmented

  20. More power : Accelerating sequential Computer Vision algorithms using commodity parallel hardware

    NARCIS (Netherlands)

    Jaap van de Loosdrecht; K. Dijkstra

    2014-01-01

    The last decade has seen an increasing demand from the industrial field of computerized visual inspection. Applications rapidly become more complex and often with more demanding real time constraints. However, from 2004 onwards the clock frequency of CPUs has not increased significantly. Computer

  1. Computer Vision Tool and Technician as First Reader of Lung Cancer Screening CT Scans

    NARCIS (Netherlands)

    Ritchie, A.J.; Sanghera, C.; Jacobs, C.; Zhang, W.; Mayo, J.; Schmidt, H.; Gingras, M.; Pasian, S.; Stewart, L.; Tsai, S.; Manos, D.; Seely, J.M.; Burrowes, P.; Bhatia, R.; Atkar-Khattra, S.; Ginneken, B. van; Tammemagi, M.; Tsao, M.S.; Lam, S.; et al.,

    2016-01-01

    To implement a cost-effective low-dose computed tomography (LDCT) lung cancer screening program at the population level, accurate and efficient interpretation of a large volume of LDCT scans is needed. The objective of this study was to evaluate a workflow strategy to identify abnormal LDCT scans in

  2. Computer Vision Syndrome for Non-Native Speaking Students: What Are the Problems with Online Reading?

    Science.gov (United States)

    Tseng, Min-chen

    2014-01-01

    This study investigated the online reading performances and the level of visual fatigue from the perspectives of non-native speaking students (NNSs). Reading on a computer screen is more visually more demanding than reading printed text. Online reading requires frequent saccadic eye movements and imposes continuous focusing and alignment demand.…

  3. An efficient algorithm to compute subsets of points in ℤ n

    OpenAIRE

    Pacheco Martínez, Ana María; Real Jurado, Pedro

    2012-01-01

    In this paper we show a more efficient algorithm than that in [8] to compute subsets of points non-congruent by isometries. This algorithm can be used to reconstruct the object from the digital image. Both algorithms are compared, highlighting the improvements obtained in terms of CPU time.

  4. Fast covariance estimation for innovations computed from a spatial Gibbs point process

    DEFF Research Database (Denmark)

    Coeurjolly, Jean-Francois; Rubak, Ege

    In this paper, we derive an exact formula for the covariance of two innovations computed from a spatial Gibbs point process and suggest a fast method for estimating this covariance. We show how this methodology can be used to estimate the asymptotic covariance matrix of the maximum pseudo...

  5. Sensor fusion and computer vision for context-aware control of a multi degree-of-freedom prosthesis.

    Science.gov (United States)

    Markovic, Marko; Dosen, Strahinja; Popovic, Dejan; Graimann, Bernhard; Farina, Dario

    2015-12-01

    Myoelectric activity volitionally generated by the user is often used for controlling hand prostheses in order to replicate the synergistic actions of muscles in healthy humans during grasping. Muscle synergies in healthy humans are based on the integration of visual perception, heuristics and proprioception. Here, we demonstrate how sensor fusion that combines artificial vision and proprioceptive information with the high-level processing characteristics of biological systems can be effectively used in transradial prosthesis control. We developed a novel context- and user-aware prosthesis (CASP) controller integrating computer vision and inertial sensing with myoelectric activity in order to achieve semi-autonomous and reactive control of a prosthetic hand. The presented method semi-automatically provides simultaneous and proportional control of multiple degrees-of-freedom (DOFs), thus decreasing overall physical effort while retaining full user control. The system was compared against the major commercial state-of-the art myoelectric control system in ten able-bodied and one amputee subject. All subjects used transradial prosthesis with an active wrist to grasp objects typically associated with activities of daily living. The CASP significantly outperformed the myoelectric interface when controlling all of the prosthesis DOF. However, when tested with less complex prosthetic system (smaller number of DOF), the CASP was slower but resulted with reaching motions that contained less compensatory movements. Another important finding is that the CASP system required minimal user adaptation and training. The CASP constitutes a substantial improvement for the control of multi-DOF prostheses. The application of the CASP will have a significant impact when translated to real-life scenarious, particularly with respect to improving the usability and acceptance of highly complex systems (e.g., full prosthetic arms) by amputees.

  6. Development of a Configurable Growth Chamber with a Computer Vision System to Study Circadian Rhythm in Plants

    Directory of Open Access Journals (Sweden)

    Marcos Egea-Cortines

    2012-11-01

    Full Text Available Plant development is the result of an endogenous morphogenetic program that integrates environmental signals. The so-called circadian clock is a set of genes that integrates environmental inputs into an internal pacing system that gates growth and other outputs. Study of circadian growth responses requires high sampling rates to detect changes in growth and avoid aliasing. We have developed a flexible configurable growth chamber comprising a computer vision system that allows sampling rates ranging between one image per 30 s to hours/days. The vision system has a controlled illumination system, which allows the user to set up different configurations. The illumination system used emits a combination of wavelengths ensuring the optimal growth of species under analysis. In order to obtain high contrast of captured images, the capture system is composed of two CCD cameras, for day and night periods. Depending on the sample type, a flexible image processing software calculates different parameters based on geometric calculations. As a proof of concept we tested the system in three different plant tissues, growth of petunia- and snapdragon (Antirrhinum majus flowers and of cladodes from the cactus Opuntia ficus-indica. We found that petunia flowers grow at a steady pace and display a strong growth increase in the early morning, whereas Opuntia cladode growth turned out not to follow a circadian growth pattern under the growth conditions imposed. Furthermore we were able to identify a decoupling of increase in area and length indicating that two independent growth processes are responsible for the final size and shape of the cladode.

  7. Sensor fusion and computer vision for context-aware control of a multi degree-of-freedom prosthesis

    Science.gov (United States)

    Markovic, Marko; Dosen, Strahinja; Popovic, Dejan; Graimann, Bernhard; Farina, Dario

    2015-12-01

    Objective. Myoelectric activity volitionally generated by the user is often used for controlling hand prostheses in order to replicate the synergistic actions of muscles in healthy humans during grasping. Muscle synergies in healthy humans are based on the integration of visual perception, heuristics and proprioception. Here, we demonstrate how sensor fusion that combines artificial vision and proprioceptive information with the high-level processing characteristics of biological systems can be effectively used in transradial prosthesis control. Approach. We developed a novel context- and user-aware prosthesis (CASP) controller integrating computer vision and inertial sensing with myoelectric activity in order to achieve semi-autonomous and reactive control of a prosthetic hand. The presented method semi-automatically provides simultaneous and proportional control of multiple degrees-of-freedom (DOFs), thus decreasing overall physical effort while retaining full user control. The system was compared against the major commercial state-of-the art myoelectric control system in ten able-bodied and one amputee subject. All subjects used transradial prosthesis with an active wrist to grasp objects typically associated with activities of daily living. Main results. The CASP significantly outperformed the myoelectric interface when controlling all of the prosthesis DOF. However, when tested with less complex prosthetic system (smaller number of DOF), the CASP was slower but resulted with reaching motions that contained less compensatory movements. Another important finding is that the CASP system required minimal user adaptation and training. Significance. The CASP constitutes a substantial improvement for the control of multi-DOF prostheses. The application of the CASP will have a significant impact when translated to real-life scenarious, particularly with respect to improving the usability and acceptance of highly complex systems (e.g., full prosthetic arms) by amputees.

  8. Floating-point geometry: toward guaranteed geometric computations with approximate arithmetics

    Science.gov (United States)

    Bajard, Jean-Claude; Langlois, Philippe; Michelucci, Dominique; Morin, Géraldine; Revol, Nathalie

    2008-08-01

    Geometric computations can fail because of inconsistencies due to floating-point inaccuracy. For instance, the computed intersection point between two curves does not lie on the curves: it is unavoidable when the intersection point coordinates are non rational, and thus not representable using floating-point arithmetic. A popular heuristic approach tests equalities and nullities up to a tolerance ɛ. But transitivity of equality is lost: we can have A approx B and B approx C, but A not approx C (where A approx B means ||A - B|| < ɛ for A,B two floating-point values). Interval arithmetic is another, self-validated, alternative; the difficulty is to limit the swell of the width of intervals with computations. Unfortunately interval arithmetic cannot decide equality nor nullity, even in cases where it is decidable by other means. A new approach, developed in this paper, consists in modifying the geometric problems and algorithms, to account for the undecidability of the equality test and unavoidable inaccuracy. In particular, all curves come with a non-zero thickness, so two curves (generically) cut in a region with non-zero area, an inner and outer representation of which is computable. This last approach no more assumes that an equality or nullity test is available. The question which arises is: which geometric problems can still be solved with this last approach, and which cannot? This paper begins with the description of some cases where every known arithmetic fails in practice. Then, for each arithmetic, some properties of the problems they can solve are given. We end this work by proposing the bases of a new approach which aims to fulfill the geometric computations requirements.

  9. Research on three-dimensional reconstruction method based on binocular vision

    Science.gov (United States)

    Li, Jinlin; Wang, Zhihui; Wang, Minjun

    2018-03-01

    As the hot and difficult issue in computer vision, binocular stereo vision is an important form of computer vision,which has a broad application prospects in many computer vision fields,such as aerial mapping,vision navigation,motion analysis and industrial inspection etc.In this paper, a research is done into binocular stereo camera calibration, image feature extraction and stereo matching. In the binocular stereo camera calibration module, the internal parameters of a single camera are obtained by using the checkerboard lattice of zhang zhengyou the field of image feature extraction and stereo matching, adopted the SURF operator in the local feature operator and the SGBM algorithm in the global matching algorithm are used respectively, and the performance are compared. After completed the feature points matching, we can build the corresponding between matching points and the 3D object points using the camera parameters which are calibrated, which means the 3D information.

  10. Mental vision: a computer graphics platform for virtual reality, science and education

    OpenAIRE

    Peternier, Achille

    2009-01-01

    Despite the wide amount of computer graphics frameworks and solutions available for virtual reality, it is still difficult to find a perfect one fitting at the same time the many constraints of research and educational contexts. Advanced functionalities and user-friendliness, rendering speed and portability, or scalability and image quality are opposite characteristics rarely found into a same approach. Furthermore, fruition of virtual reality specific devices like CAVEs or wearable systems i...

  11. Computer graphics testbed to simulate and test vision systems for space applications

    Science.gov (United States)

    Cheatham, John B.

    1991-01-01

    Artificial intelligence concepts are applied to robotics. Artificial neural networks, expert systems and laser imaging techniques for autonomous space robots are being studied. A computer graphics laser range finder simulator developed by Wu has been used by Weiland and Norwood to study use of artificial neural networks for path planning and obstacle avoidance. Interest is expressed in applications of CLIPS, NETS, and Fuzzy Control. These applications are applied to robot navigation.

  12. Low Vision

    Science.gov (United States)

    ... USAJobs Home » Statistics and Data » Low Vision Listen Low Vision Low Vision Defined: Low Vision is defined as the best- ... Ethnicity 2010 U.S. Age-Specific Prevalence Rates for Low Vision by Age, and Race/Ethnicity Table for 2010 ...

  13. White paper: A vision for a computing initiative for MFE. Revised version

    International Nuclear Information System (INIS)

    Cohen, R.H.; Crotinger, J.A.; Baldwin, D.E.

    1996-01-01

    The scientific base of magnetic fusion research comprises three capabilities: experimental research, theoretical understanding and computational modeling, with modeling providing the necessary link between the other two. The US now faces a budget climate that will preclude the construction of major new MFE facilities and limit MFE experimental operations. The situation is rather analogous to the one experienced by the DOE Defense Programs (DP), in which continued viability of the nuclear stockpile must be ensured despite the prohibition of underground experimental tests. DP is meeting this challenge, in part, by launching the Accelerated Strategic Computing Initiative (ASCI) to bring advanced algorithms and new hardware to bear on the problems of science-based stockpile stewardship (SBSS). ASCI has as its goal the establishment of a ''virtual testing'' capability, and it is expected to drive scientific software and hardware development through the next decade. The authors argue that a similar effort is warranted for the MFE program, that is, an initiative aimed at developing a comprehensive simulation capability for MFE, with the goal of enabling ''virtual experiments.'' It would play a role for MFE analogous to that played by present-day and future (ASCI) codes for nuclear weapons design and by LASNEX for ICF, and provide a powerful augmentation to constrained experimental programs. Developing a comprehensive simulation capability could provide an organizing theme for a restructured science-based MFE program. The code would become a central vehicle for integrating the accumulating science base. In the context the authors propose, the relationship would ultimately be reversed: computer simulation would become a primary vehicle for exploration, with experiments providing the necessary confirmatory evidence (or guidance for code improvements)

  14. Comparison of computed tomography scout based reference point localization to conventional film and axial computed tomography.

    Science.gov (United States)

    Jiang, Lan; Templeton, Alistair; Turian, Julius; Kirk, Michael; Zusag, Thomas; Chu, James C H

    2011-01-01

    Identification of source positions after implantation is an important step in brachytherapy planning. Reconstruction is traditionally performed from films taken by conventional simulators, but these are gradually being replaced in the clinic by computed tomography (CT) simulators. The present study explored the use of a scout image-based reconstruction algorithm that replaces the use of traditional film, while exhibiting low sensitivity to metal-induced artifacts that can appear in 3D CT methods. In addition, the accuracy of an in-house graphical software implementation of scout-based reconstruction was compared with seed location reconstructions for 2 phantoms by conventional simulator and CT measurements. One phantom was constructed using a planar fixed grid of 1.5-mm diameter ball bearings (BBs) with 40-mm spacing. The second was a Fletcher-Suit applicator embedded in Styrofoam (Dow Chemical Co., Midland, MI) with one 3.2-mm-diameter BB inserted into each of 6 surrounding holes. Conventional simulator, kilovoltage CT (kVCT), megavoltage CT, and scout-based methods were evaluated by their ability to calculate the distance between seeds (40 mm for the fixed grid, 30-120 mm in Fletcher-Suit). All methods were able to reconstruct the fixed grid distances with an average deviation of <1%. The worst single deviations (approximately 6%) were exhibited in the 2 volumetric CT methods. In the Fletcher-Suit phantom, the intermodality agreement was within approximately 3%, with the conventional sim measuring marginally larger distances, with kVCT the smallest. All of the established reconstruction methods exhibited similar abilities to detect the distances between BBs. The 3D CT-based methods, with lower axial resolution, showed more variation, particularly with the smaller BBs. With a software implementation, scout-based reconstruction is an appealing approach because it simplifies data acquisition over film-based reconstruction without requiring any specialized equipment

  15. Trends, visions and reality. Cloud computing in the energy industry; Trends, Visionen und Wirklichkeit. Cloud Computing in der Energiewirtschaft

    Energy Technology Data Exchange (ETDEWEB)

    Reuther, Achim [Energy Solution Center (Ensoc) e.V., Karlsruhe (Germany); Maurer, Marion; Pohling, Matthias [Bridging IT GmbH, Mannheim (Germany)

    2011-08-22

    The topic of cloud computing is not only just a temporary hype in the market of information technology, but also a true paradigm shift in the supply and use of information technology services. A sustainable change in the information technology in the energy sector is expected. The authors of the contribution under consideration present current cloud research projects with energy-economic relevance. Some important criteria are presented that should be considered in the selection and use of cloud services. The selective use of cloud services up to the outsourcing of entire business processes of an electric utility in the cloud may provide an added value. Both, current approaches as well as research projects are suitable for the optimization of processes and resources. The numerous possibilities have to be adjusted to the own general conditions.

  16. Development of a tool to aid the radiologic technologist using augmented reality and computer vision

    International Nuclear Information System (INIS)

    MacDougall, Robert D.; Scherrer, Benoit; Don, Steven

    2018-01-01

    This technical innovation describes the development of a novel device to aid technologists in reducing exposure variation and repeat imaging in computed and digital radiography. The device consists of a color video and depth camera in combination with proprietary software and user interface. A monitor in the x-ray control room displays the position of the patient in real time with respect to automatic exposure control chambers and image receptor area. The thickness of the body part of interest is automatically displayed along with a motion indicator for the examined body part. The aim is to provide an automatic measurement of patient thickness to set the x-ray technique and to assist the technologist in detecting errors in positioning and motion before the patient is exposed. The device has the potential to reduce the incidence of repeat imaging by addressing problems technologists encounter daily during the acquisition of radiographs. (orig.)

  17. Development of a tool to aid the radiologic technologist using augmented reality and computer vision

    Energy Technology Data Exchange (ETDEWEB)

    MacDougall, Robert D.; Scherrer, Benoit [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Don, Steven [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States)

    2018-01-15

    This technical innovation describes the development of a novel device to aid technologists in reducing exposure variation and repeat imaging in computed and digital radiography. The device consists of a color video and depth camera in combination with proprietary software and user interface. A monitor in the x-ray control room displays the position of the patient in real time with respect to automatic exposure control chambers and image receptor area. The thickness of the body part of interest is automatically displayed along with a motion indicator for the examined body part. The aim is to provide an automatic measurement of patient thickness to set the x-ray technique and to assist the technologist in detecting errors in positioning and motion before the patient is exposed. The device has the potential to reduce the incidence of repeat imaging by addressing problems technologists encounter daily during the acquisition of radiographs. (orig.)

  18. Utilizing the Double-Precision Floating-Point Computing Power of GPUs for RSA Acceleration

    Directory of Open Access Journals (Sweden)

    Jiankuo Dong

    2017-01-01

    Full Text Available Asymmetric cryptographic algorithm (e.g., RSA and Elliptic Curve Cryptography implementations on Graphics Processing Units (GPUs have been researched for over a decade. The basic idea of most previous contributions is exploiting the highly parallel GPU architecture and porting the integer-based algorithms from general-purpose CPUs to GPUs, to offer high performance. However, the great potential cryptographic computing power of GPUs, especially by the more powerful floating-point instructions, has not been comprehensively investigated in fact. In this paper, we fully exploit the floating-point computing power of GPUs, by various designs, including the floating-point-based Montgomery multiplication/exponentiation algorithm and Chinese Remainder Theorem (CRT implementation in GPU. And for practical usage of the proposed algorithm, a new method is performed to convert the input/output between octet strings and floating-point numbers, fully utilizing GPUs and further promoting the overall performance by about 5%. The performance of RSA-2048/3072/4096 decryption on NVIDIA GeForce GTX TITAN reaches 42,211/12,151/5,790 operations per second, respectively, which achieves 13 times the performance of the previous fastest floating-point-based implementation (published in Eurocrypt 2009. The RSA-4096 decryption precedes the existing fastest integer-based result by 23%.

  19. Vision Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Vision Lab personnel perform research, development, testing and evaluation of eye protection and vision performance. The lab maintains and continues to develop...

  20. Technical Note: A respiratory monitoring and processing system based on computer vision: prototype and proof of principle.

    Science.gov (United States)

    Leduc, Nicolas; Atallah, Vincent; Escarmant, Patrick; Vinh-Hung, Vincent

    2016-09-08

    Monitoring and controlling respiratory motion is a challenge for the accuracy and safety of therapeutic irradiation of thoracic tumors. Various commercial systems based on the monitoring of internal or external surrogates have been developed but remain costly. In this article we describe and validate Madibreast, an in-house-made respiratory monitoring and processing device based on optical tracking of external markers. We designed an optical apparatus to ensure real-time submillimetric image resolution at 4 m. Using OpenCv libraries, we optically tracked high-contrast markers set on patients' breasts. Validation of spatial and time accuracy was performed on a mechanical phantom and on human breast. Madibreast was able to track motion of markers up to a 5 cm/s speed, at a frame rate of 30 fps, with submillimetric accuracy on mechanical phantom and human breasts. Latency was below 100 ms. Concomitant monitoring of three different locations on the breast showed discrepancies in axial motion up to 4 mm for deep-breathing patterns. This low-cost, computer-vision system for real-time motion monitoring of the irradiation of breast cancer patients showed submillimetric accuracy and acceptable latency. It allowed the authors to highlight differences in surface motion that may be correlated to tumor motion.v. © 2016 The Authors.

  1. Detection of white spot lesions by segmenting laser speckle images using computer vision methods.

    Science.gov (United States)

    Gavinho, Luciano G; Araujo, Sidnei A; Bussadori, Sandra K; Silva, João V P; Deana, Alessandro M

    2018-05-05

    This paper aims to develop a method for laser speckle image segmentation of tooth surfaces for diagnosis of early stages caries. The method, applied directly to a raw image obtained by digital photography, is based on the difference between the speckle pattern of a carious lesion tooth surface area and that of a sound area. Each image is divided into blocks which are identified in a working matrix by their χ 2 distance between block histograms of the analyzed image and the reference histograms previously obtained by K-means from healthy (h_Sound) and lesioned (h_Decay) areas, separately. If the χ 2 distance between a block histogram and h_Sound is greater than the distance to h_Decay, this block is marked as decayed. The experiments showed that the method can provide effective segmentation for initial lesions. We used 64 images to test the algorithm and we achieved 100% accuracy in segmentation. Differences between the speckle pattern of a sound tooth surface region and a carious region, even in the early stage, can be evidenced by the χ 2 distance between histograms. This method proves to be more effective for segmenting the laser speckle image, which enhances the contrast between sound and lesioned tissues. The results were obtained with low computational cost. The method has the potential for early diagnosis in a clinical environment, through the development of low-cost portable equipment.

  2. Customized Computer Vision and Sensor System for Colony Recognition and Live Bacteria Counting in Agriculture

    Directory of Open Access Journals (Sweden)

    Gabriel M. ALVES

    2016-06-01

    Full Text Available This paper presents an arrangement based on a dedicated computer and charge-coupled device (CCD sensor system to intelligently allow the counting and recognition of colony formation. Microbes in agricultural environments are important catalysts of global carbon and nitrogen cycles, including the production and consumption of greenhouse gases in soil. Some microbes produce greenhouse gases such as carbon dioxide and nitrous oxide while decomposing organic matter in soil. Others consume methane from the atmosphere, helping to mitigate climate change. The magnitude of each of these processes is influenced by human activities and impacts the warming potential of Earth’s atmosphere. In this context, bacterial colony counting is important and requires sophisticated analysis methods. The method implemented in this study uses digital image processing techniques, including the Hough Transform for circular objects. The visual environment Borland Builder C++ was used for development, and a model for decision making was incorporated to aggregate intelligence. For calibration of the method a prepared illuminated chamber was used to enable analyses of the bacteria Escherichia coli, and Acidithiobacillus ferrooxidans. For validation, a set of comparisons were established between this smart method and the expert analyses. The results show the potential of this method for laboratory applications that involve the quantification and pattern recognition of bacterial colonies in solid culture environments.

  3. Image formation simulation for computer-aided inspection planning of machine vision systems

    Science.gov (United States)

    Irgenfried, Stephan; Bergmann, Stephan; Mohammadikaji, Mahsa; Beyerer, Jürgen; Dachsbacher, Carsten; Wörn, Heinz

    2017-06-01

    In this work, a simulation toolset for Computer Aided Inspection Planning (CAIP) of systems for automated optical inspection (AOI) is presented along with a versatile two-robot-setup for verification of simulation and system planning results. The toolset helps to narrow down the large design space of optical inspection systems in interaction with a system expert. The image formation taking place in optical inspection systems is simulated using GPU-based real time graphics and high quality off-line-rendering. The simulation pipeline allows a stepwise optimization of the system, from fast evaluation of surface patch visibility based on real time graphics up to evaluation of image processing results based on off-line global illumination calculation. A focus of this work is on the dependency of simulation quality on measuring, modeling and parameterizing the optical surface properties of the object to be inspected. The applicability to real world problems is demonstrated by taking the example of planning a 3D laser scanner application. Qualitative and quantitative comparison results of synthetic and real images are presented.

  4. PREMOR: a point reactor exposure model computer code for survey analysis of power plant performance

    International Nuclear Information System (INIS)

    Vondy, D.R.

    1979-10-01

    The PREMOR computer code was written to exploit a simple, two-group point nuclear reactor power plant model for survey analysis. Up to thirteen actinides, fourteen fission products, and one lumped absorber nuclide density are followed over a reactor history. Successive feed batches are accounted for with provision for from one to twenty batches resident. The effect of exposure of each of the batches to the same neutron flux is determined

  5. PREMOR: a point reactor exposure model computer code for survey analysis of power plant performance

    Energy Technology Data Exchange (ETDEWEB)

    Vondy, D.R.

    1979-10-01

    The PREMOR computer code was written to exploit a simple, two-group point nuclear reactor power plant model for survey analysis. Up to thirteen actinides, fourteen fission products, and one lumped absorber nuclide density are followed over a reactor history. Successive feed batches are accounted for with provision for from one to twenty batches resident. The effect of exposure of each of the batches to the same neutron flux is determined.

  6. Computer experiments on the imaging of point defects with the conventional transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Krakow, W [Xerox Corp., Rochester, N.Y. (USA)

    1978-02-01

    To aid in the interpretation of high resolution electron micrographs of defect structures in crystals, computer-simulated dark-field electron micrographs have been obtained for a variety of point defects in metals. Interpretation of these images in terms of atomic positions and atom correlations becomes straightforward, and it is a simple matter to distinguish between real structural information and image artifacts produced by the phase contrast mechanism in the electron optical imaging process.

  7. Implementation of the Two-Point Angular Correlation Function on a High-Performance Reconfigurable Computer

    Directory of Open Access Journals (Sweden)

    Volodymyr V. Kindratenko

    2009-01-01

    Full Text Available We present a parallel implementation of an algorithm for calculating the two-point angular correlation function as applied in the field of computational cosmology. The algorithm has been specifically developed for a reconfigurable computer. Our implementation utilizes a microprocessor and two reconfigurable processors on a dual-MAP SRC-6 system. The two reconfigurable processors are used as two application-specific co-processors. Two independent computational kernels are simultaneously executed on the reconfigurable processors while data pre-fetching from disk and initial data pre-processing are executed on the microprocessor. The overall end-to-end algorithm execution speedup achieved by this implementation is over 90× as compared to a sequential implementation of the algorithm executed on a single 2.8 GHz Intel Xeon microprocessor.

  8. Surrogate runner model for draft tube losses computation within a wide range of operating points

    International Nuclear Information System (INIS)

    Susan-Resiga, R; Ciocan, T; Muntean, S; De Colombel, T; Leroy, P

    2014-01-01

    We introduce a quasi two-dimensional (Q2D) methodology for assessing the swirling flow exiting the runner of hydraulic turbines at arbitrary operating points, within a wide operating range. The Q2D model does not need actual runner computations, and as a result it represents a surrogate runner model for a-priori assessment of the swirling flow ingested by the draft tube. The axial, radial and circumferential velocity components are computed on a conical section located immediately downstream the runner blades trailing edge, then used as inlet conditions for regular draft tube computations. The main advantage of our model is that it allows the determination of the draft tube losses within the intended turbine operating range in the early design stages of a new or refurbished runner, thus providing a robust and systematic methodology to meet the optimal requirements for the flow at the runner outlet

  9. Fast Computation of the Two-Point Correlation Function in the Age of Big Data

    Science.gov (United States)

    Pellegrino, Andrew; Timlin, John

    2018-01-01

    We present a new code which quickly computes the two-point correlation function for large sets of astronomical data. This code combines the ease of use of Python with the speed of parallel shared libraries written in C. We include the capability to compute the auto- and cross-correlation statistics, and allow the user to calculate the three-dimensional and angular correlation functions. Additionally, the code automatically divides the user-provided sky masks into contiguous subsamples of similar size, using the HEALPix pixelization scheme, for the purpose of resampling. Errors are computed using jackknife and bootstrap resampling in a way that adds negligible extra runtime, even with many subsamples. We demonstrate comparable speed with other clustering codes, and code accuracy compared to known and analytic results.

  10. FireProt: Energy- and Evolution-Based Computational Design of Thermostable Multiple-Point Mutants.

    Science.gov (United States)

    Bednar, David; Beerens, Koen; Sebestova, Eva; Bendl, Jaroslav; Khare, Sagar; Chaloupkova, Radka; Prokop, Zbynek; Brezovsky, Jan; Baker, David; Damborsky, Jiri

    2015-11-01

    There is great interest in increasing proteins' stability to enhance their utility as biocatalysts, therapeutics, diagnostics and nanomaterials. Directed evolution is a powerful, but experimentally strenuous approach. Computational methods offer attractive alternatives. However, due to the limited reliability of predictions and potentially antagonistic effects of substitutions, only single-point mutations are usually predicted in silico, experimentally verified and then recombined in multiple-point mutants. Thus, substantial screening is still required. Here we present FireProt, a robust computational strategy for predicting highly stable multiple-point mutants that combines energy- and evolution-based approaches with smart filtering to identify additive stabilizing mutations. FireProt's reliability and applicability was demonstrated by validating its predictions against 656 mutations from the ProTherm database. We demonstrate that thermostability of the model enzymes haloalkane dehalogenase DhaA and γ-hexachlorocyclohexane dehydrochlorinase LinA can be substantially increased (ΔTm = 24°C and 21°C) by constructing and characterizing only a handful of multiple-point mutants. FireProt can be applied to any protein for which a tertiary structure and homologous sequences are available, and will facilitate the rapid development of robust proteins for biomedical and biotechnological applications.

  11. FireProt: Energy- and Evolution-Based Computational Design of Thermostable Multiple-Point Mutants.

    Directory of Open Access Journals (Sweden)

    David Bednar

    2015-11-01

    Full Text Available There is great interest in increasing proteins' stability to enhance their utility as biocatalysts, therapeutics, diagnostics and nanomaterials. Directed evolution is a powerful, but experimentally strenuous approach. Computational methods offer attractive alternatives. However, due to the limited reliability of predictions and potentially antagonistic effects of substitutions, only single-point mutations are usually predicted in silico, experimentally verified and then recombined in multiple-point mutants. Thus, substantial screening is still required. Here we present FireProt, a robust computational strategy for predicting highly stable multiple-point mutants that combines energy- and evolution-based approaches with smart filtering to identify additive stabilizing mutations. FireProt's reliability and applicability was demonstrated by validating its predictions against 656 mutations from the ProTherm database. We demonstrate that thermostability of the model enzymes haloalkane dehalogenase DhaA and γ-hexachlorocyclohexane dehydrochlorinase LinA can be substantially increased (ΔTm = 24°C and 21°C by constructing and characterizing only a handful of multiple-point mutants. FireProt can be applied to any protein for which a tertiary structure and homologous sequences are available, and will facilitate the rapid development of robust proteins for biomedical and biotechnological applications.

  12. Local annealing of shape memory alloys using laser scanning and computer vision

    Science.gov (United States)

    Hafez, Moustapha; Bellouard, Yves; Sidler, Thomas C.; Clavel, Reymond; Salathe, Rene-Paul

    2000-11-01

    A complete set-up for local annealing of Shape Memory Alloys (SMA) is proposed. Such alloys, when plastically deformed at a given low temperature, have the ability to recover a previously memorized shape simply by heating up to a higher temperature. They find more and more applications in the fields of robotics and micro engineering. There is a tremendous advantage in using local annealing because this process can produce monolithic parts, which have different mechanical behavior at different location of the same body. Using this approach, it is possible to integrate all the functionality of a device within one piece of material. The set-up is based on a 2W-laser diode emitting at 805nm and a scanner head. The laser beam is coupled into an optical fiber of 60(mu) in diameter. The fiber output is focused on the SMA work-piece using a relay lens system with a 1:1 magnification, resulting in a spot diameter of 60(mu) . An imaging system is used to control the position of the laser spot on the sample. In order to displace the spot on the surface a tip/tilt laser scanner is used. The scanner is positioned in a pre-objective configuration and allows a scan field size of more than 10 x 10 mm2. A graphical user interface of the scan field allows the user to quickly set up marks and alter their placement and power density. This is achieved by computer controlling X and Y positions of the scanner as well as the laser diode power. A SMA micro-gripper with a surface area less than 1 mm2 and an opening of the jaws of 200(mu) has been realized using this set-up. It is electrically actuated and a controlled force of 16mN can be applied to hold and release small objects such as graded index micro-lenses at a cycle time of typically 1s.

  13. Autonomous Segmentation of Outcrop Images Using Computer Vision and Machine Learning

    Science.gov (United States)

    Francis, R.; McIsaac, K.; Osinski, G. R.; Thompson, D. R.

    2013-12-01

    As planetary exploration missions become increasingly complex and capable, the motivation grows for improved autonomous science. New capabilities for onboard science data analysis may relieve radio-link data limits and provide greater throughput of scientific information. Adaptive data acquisition, storage and downlink may ultimately hold implications for mission design and operations. For surface missions, geology remains an essential focus, and the investigation of in place, exposed geological materials provides the greatest scientific insight and context for the formation and history of planetary materials and processes. The goal of this research program is to develop techniques for autonomous segmentation of images of rock outcrops. Recognition of the relationships between different geological units is the first step in mapping and interpreting a geological setting. Applications of automatic segmentation include instrument placement and targeting and data triage for downlink. Here, we report on the development of a new technique in which a photograph of a rock outcrop is processed by several elementary image processing techniques, generating a feature space which can be interrogated and classified. A distance metric learning technique (Multiclass Discriminant Analysis, or MDA) is tested as a means of finding the best numerical representation of the feature space. MDA produces a linear transformation that maximizes the separation between data points from different geological units. This ';training step' is completed on one or more images from a given locality. Then we apply the same transformation to improve the segmentation of new scenes containing similar materials to those used for training. The technique was tested using imagery from Mars analogue settings at the Cima volcanic flows in the Mojave Desert, California; impact breccias from the Sudbury impact structure in Ontario, Canada; and an outcrop showing embedded mineral veins in Gale Crater on Mars

  14. Utilizing Commercial Hardware and Open Source Computer Vision Software to Perform Motion Capture for Reduced Gravity Flight

    Science.gov (United States)

    Humphreys, Brad; Bellisario, Brian; Gallo, Christopher; Thompson, William K.; Lewandowski, Beth

    2016-01-01

    Long duration space travel to Mars or to an asteroid will expose astronauts to extended periods of reduced gravity. Since gravity is not present to aid loading, astronauts will use resistive and aerobic exercise regimes for the duration of the space flight to minimize the loss of bone density, muscle mass and aerobic capacity that occurs during exposure to a reduced gravity environment. Unlike the International Space Station (ISS), the area available for an exercise device in the next generation of spacecraft is limited. Therefore, compact resistance exercise device prototypes are being developed. The NASA Digital Astronaut Project (DAP) is supporting the Advanced Exercise Concepts (AEC) Project, Exercise Physiology and Countermeasures (ExPC) project and the National Space Biomedical Research Institute (NSBRI) funded researchers by developing computational models of exercising with these new advanced exercise device concepts. To perform validation of these models and to support the Advanced Exercise Concepts Project, several candidate devices have been flown onboard NASAs Reduced Gravity Aircraft. In terrestrial laboratories, researchers typically have available to them motion capture systems for the measurement of subject kinematics. Onboard the parabolic flight aircraft it is not practical to utilize the traditional motion capture systems due to the large working volume they require and their relatively high replacement cost if damaged. To support measuring kinematics on board parabolic aircraft, a motion capture system is being developed utilizing open source computer vision code with commercial off the shelf (COTS) video camera hardware. While the systems accuracy is lower than lab setups, it provides a means to produce quantitative comparison motion capture kinematic data. Additionally, data such as required exercise volume for small spaces such as the Orion capsule can be determined. METHODS: OpenCV is an open source computer vision library that provides the

  15. A sampler of useful computational tools for applied geometry, computer graphics, and image processing foundations for computer graphics, vision, and image processing

    CERN Document Server

    Cohen-Or, Daniel; Ju, Tao; Mitra, Niloy J; Shamir, Ariel; Sorkine-Hornung, Olga; Zhang, Hao (Richard)

    2015-01-01

    A Sampler of Useful Computational Tools for Applied Geometry, Computer Graphics, and Image Processing shows how to use a collection of mathematical techniques to solve important problems in applied mathematics and computer science areas. The book discusses fundamental tools in analytical geometry and linear algebra. It covers a wide range of topics, from matrix decomposition to curvature analysis and principal component analysis to dimensionality reduction.Written by a team of highly respected professors, the book can be used in a one-semester, intermediate-level course in computer science. It

  16. Does vision work well enough for industry?

    DEFF Research Database (Denmark)

    Hagelskjær, Frederik; Krüger, Norbert; Buch, Anders Glent

    2018-01-01

    A multitude of pose estimation algorithms has been developed in the last decades and many proprietary computer vision packages exist which can simplify the setup process. Despite this, pose estimation still lacks the ease of use that robots have attained in the industry. The statement ”vision does...... not work” is still not uncommon in the industry, even from integrators. This points to difficulties in setting up solutions in industrial applications. In this paper, we analyze and investigate the current usage of pose estimation algorithms. A questionnaire was sent out to both university and industry...

  17. Dual-time-point Imaging and Delayed-time-point Fluorodeoxyglucose-PET/Computed Tomography Imaging in Various Clinical Settings

    DEFF Research Database (Denmark)

    Houshmand, Sina; Salavati, Ali; Antonsen Segtnan, Eivind

    2016-01-01

    The techniques of dual-time-point imaging (DTPI) and delayed-time-point imaging, which are mostly being used for distinction between inflammatory and malignant diseases, has increased the specificity of fluorodeoxyglucose (FDG)-PET for diagnosis and prognosis of certain diseases. A gradually incr...

  18. A fast point-cloud computing method based on spatial symmetry of Fresnel field

    Science.gov (United States)

    Wang, Xiangxiang; Zhang, Kai; Shen, Chuan; Zhu, Wenliang; Wei, Sui

    2017-10-01

    Aiming at the great challenge for Computer Generated Hologram (CGH) duo to the production of high spatial-bandwidth product (SBP) is required in the real-time holographic video display systems. The paper is based on point-cloud method and it takes advantage of the propagating reversibility of Fresnel diffraction in the propagating direction and the fringe pattern of a point source, known as Gabor zone plate has spatial symmetry, so it can be used as a basis for fast calculation of diffraction field in CGH. A fast Fresnel CGH method based on the novel look-up table (N-LUT) method is proposed, the principle fringe patterns (PFPs) at the virtual plane is pre-calculated by the acceleration algorithm and be stored. Secondly, the Fresnel diffraction fringe pattern at dummy plane can be obtained. Finally, the Fresnel propagation from dummy plan to hologram plane. The simulation experiments and optical experiments based on Liquid Crystal On Silicon (LCOS) is setup to demonstrate the validity of the proposed method under the premise of ensuring the quality of 3D reconstruction the method proposed in the paper can be applied to shorten the computational time and improve computational efficiency.

  19. UCH 3 and 4 plant computer system I/O point summary

    International Nuclear Information System (INIS)

    Sohn, Kwang Young; Lee, Tae Hoon; Lee, Soon Sung; Lee, Byung Chae; Yoon, Jong Keon; Park, Jeong Suk; Baek, Seung Min; Shin, Hyun Kook

    1996-05-01

    This technical report summarizes the UCN 3 and 4 I/O database points and is expected to be an important for many disciplines. There are several kind of plant tests before the commercial operation such as Preoperational Test, Cold Hydro Test (CHT), Hot Functional Test (HFT), and Power Ascension Test (PAT). Those are performed in a manner that the validity of the sensor inputs got to the Plant Computer System (PCS) and operational integrity of plant are determined by monitoring the addressable I/O point identification (PID) on the Plant Computer System operator console. For better performance of activities like Emergency Operating Procedure (EOP) computerization, Safety Parameter Display System (SPDS) development, and organizing integrated database for NSSS, referencing the past plant information about I/O database is highly expected. What's more, it is inevitable material for plant system research and general design document work to be done in future. So we present this report based on UCN database for better understanding of plant computer system. 5 refs. (Author) .new

  20. UCH 3 and 4 plant computer system I/O point summary

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Kwang Young; Lee, Tae Hoon; Lee, Soon Sung; Lee, Byung Chae; Yoon, Jong Keon; Park, Jeong Suk; Baek, Seung Min; Shin, Hyun Kook [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-05-01

    This technical report summarizes the UCN 3 and 4 I/O database points and is expected to be an important for many disciplines. There are several kind of plant tests before the commercial operation such as Preoperational Test, Cold Hydro Test (CHT), Hot Functional Test (HFT), and Power Ascension Test (PAT). Those are performed in a manner that the validity of the sensor inputs got to the Plant Computer System (PCS) and operational integrity of plant are determined by monitoring the addressable I/O point identification (PID) on the Plant Computer System operator console. For better performance of activities like Emergency Operating Procedure (EOP) computerization, Safety Parameter Display System (SPDS) development, and organizing integrated database for NSSS, referencing the past plant information about I/O database is highly expected. What`s more, it is inevitable material for plant system research and general design document work to be done in future. So we present this report based on UCN database for better understanding of plant computer system. 5 refs. (Author) .new.

  1. Curvature computation in volume-of-fluid method based on point-cloud sampling

    Science.gov (United States)

    Kassar, Bruno B. M.; Carneiro, João N. E.; Nieckele, Angela O.

    2018-01-01

    This work proposes a novel approach to compute interface curvature in multiphase flow simulation based on Volume of Fluid (VOF) method. It is well documented in the literature that curvature and normal vector computation in VOF may lack accuracy mainly due to abrupt changes in the volume fraction field across the interfaces. This may cause deterioration on the interface tension forces estimates, often resulting in inaccurate results for interface tension dominated flows. Many techniques have been presented over the last years in order to enhance accuracy in normal vectors and curvature estimates including height functions, parabolic fitting of the volume fraction, reconstructing distance functions, coupling Level Set method with VOF, convolving the volume fraction field with smoothing kernels among others. We propose a novel technique based on a representation of the interface by a cloud of points. The curvatures and the interface normal vectors are computed geometrically at each point of the cloud and projected onto the Eulerian grid in a Front-Tracking manner. Results are compared to benchmark data and significant reduction on spurious currents as well as improvement in the pressure jump are observed. The method was developed in the open source suite OpenFOAM® extending its standard VOF implementation, the interFoam solver.

  2. Rapid identification of pearl powder from Hyriopsis cumingii by Tri-step infrared spectroscopy combined with computer vision technology

    Science.gov (United States)

    Liu, Siqi; Wei, Wei; Bai, Zhiyi; Wang, Xichang; Li, Xiaohong; Wang, Chuanxian; Liu, Xia; Liu, Yuan; Xu, Changhua

    2018-01-01

    Pearl powder, an important raw material in cosmetics and Chinese patent medicines, is commonly uneven in quality and frequently adulterated with low-cost shell powder in the market. The aim of this study is to establish an adequate approach based on Tri-step infrared spectroscopy with enhancing resolution combined with chemometrics for qualitative identification of pearl powder originated from three different quality grades of pearls and quantitative prediction of the proportions of shell powder adulterated in pearl powder. Additionally, computer vision technology (E-eyes) can investigate the color difference among different pearl powders and make it traceable to the pearl quality trait-visual color categories. Though the different grades of pearl powder or adulterated pearl powder have almost identical IR spectra, SD-IR peak intensity at about 861 cm- 1 (v2 band) exhibited regular enhancement with the increasing quality grade of pearls, while the 1082 cm- 1 (v1 band), 712 cm- 1 and 699 cm- 1 (v4 band) were just the reverse. Contrastly, only the peak intensity at 862 cm- 1 was enhanced regularly with the increasing concentration of shell powder. Thus, the bands in the ranges of (1550-1350 cm- 1, 730-680 cm- 1) and (830-880 cm- 1, 690-725 cm- 1) could be exclusive ranges to discriminate three distinct pearl powders and identify adulteration, respectively. For massive sample analysis, a qualitative classification model and a quantitative prediction model based on IR spectra was established successfully by principal component analysis (PCA) and partial least squares (PLS), respectively. The developed method demonstrated great potential for pearl powder quality control and authenticity identification in a direct, holistic manner.

  3. Imaging and Computer Vision

    NARCIS (Netherlands)

    Regtien, Paulus P.L.; van der Heijden, Ferdinand

    2005-01-01

    The project COMET provides a multimedia training package for metrology and measurement. The package is developed by a consortium of 10 institutes from 7 European countries. It consists of 31 modules, each dealing with a particular aspect of metrology, and is available in English, German, French and

  4. Iterative method to compute the Fermat points and Fermat distances of multiquarks

    International Nuclear Information System (INIS)

    Bicudo, P.; Cardoso, M.

    2009-01-01

    The multiquark confining potential is proportional to the total distance of the fundamental strings linking the quarks and antiquarks. We address the computation of the total string distance and of the Fermat points where the different strings meet. For a meson the distance is trivially the quark-antiquark distance. For a baryon the problem was solved geometrically from the onset by Fermat and by Torricelli, it can be determined just with a rule and a compass, and we briefly review it. However we also show that for tetraquarks, pentaquarks, hexaquarks, etc., the geometrical solution is much more complicated. Here we provide an iterative method, converging fast to the correct Fermat points and the total distances, relevant for the multiquark potentials.

  5. Iterative method to compute the Fermat points and Fermat distances of multiquarks

    Energy Technology Data Exchange (ETDEWEB)

    Bicudo, P. [CFTP, Departamento de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)], E-mail: bicudo@ist.utl.pt; Cardoso, M. [CFTP, Departamento de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2009-04-13

    The multiquark confining potential is proportional to the total distance of the fundamental strings linking the quarks and antiquarks. We address the computation of the total string distance and of the Fermat points where the different strings meet. For a meson the distance is trivially the quark-antiquark distance. For a baryon the problem was solved geometrically from the onset by Fermat and by Torricelli, it can be determined just with a rule and a compass, and we briefly review it. However we also show that for tetraquarks, pentaquarks, hexaquarks, etc., the geometrical solution is much more complicated. Here we provide an iterative method, converging fast to the correct Fermat points and the total distances, relevant for the multiquark potentials.

  6. Iterative algorithms for computing the feedback Nash equilibrium point for positive systems

    Science.gov (United States)

    Ivanov, I.; Imsland, Lars; Bogdanova, B.

    2017-03-01

    The paper studies N-player linear quadratic differential games on an infinite time horizon with deterministic feedback information structure. It introduces two iterative methods (the Newton method as well as its accelerated modification) in order to compute the stabilising solution of a set of generalised algebraic Riccati equations. The latter is related to the Nash equilibrium point of the considered game model. Moreover, we derive the sufficient conditions for convergence of the proposed methods. Finally, we discuss two numerical examples so as to illustrate the performance of both of the algorithms.

  7. Analysis of random point images with the use of symbolic computation codes and generalized Catalan numbers

    Science.gov (United States)

    Reznik, A. L.; Tuzikov, A. V.; Solov'ev, A. A.; Torgov, A. V.

    2016-11-01

    Original codes and combinatorial-geometrical computational schemes are presented, which are developed and applied for finding exact analytical formulas that describe the probability of errorless readout of random point images recorded by a scanning aperture with a limited number of threshold levels. Combinatorial problems encountered in the course of the study and associated with the new generalization of Catalan numbers are formulated and solved. An attempt is made to find the explicit analytical form of these numbers, which is, on the one hand, a necessary stage of solving the basic research problem and, on the other hand, an independent self-consistent problem.

  8. An Improved Computational Method for the Calculation of Mixture Liquid-Vapor Critical Points

    Science.gov (United States)

    Dimitrakopoulos, Panagiotis; Jia, Wenlong; Li, Changjun

    2014-05-01

    Knowledge of critical points is important to determine the phase behavior of a mixture. This work proposes a reliable and accurate method in order to locate the liquid-vapor critical point of a given mixture. The theoretical model is developed from the rigorous definition of critical points, based on the SRK equation of state (SRK EoS) or alternatively, on the PR EoS. In order to solve the resulting system of nonlinear equations, an improved method is introduced into an existing Newton-Raphson algorithm, which can calculate all the variables simultaneously in each iteration step. The improvements mainly focus on the derivatives of the Jacobian matrix, on the convergence criteria, and on the damping coefficient. As a result, all equations and related conditions required for the computation of the scheme are illustrated in this paper. Finally, experimental data for the critical points of 44 mixtures are adopted in order to validate the method. For the SRK EoS, average absolute errors of the predicted critical-pressure and critical-temperature values are 123.82 kPa and 3.11 K, respectively, whereas the commercial software package Calsep PVTSIM's prediction errors are 131.02 kPa and 3.24 K. For the PR EoS, the two above mentioned average absolute errors are 129.32 kPa and 2.45 K, while the PVTSIM's errors are 137.24 kPa and 2.55 K, respectively.

  9. Decreasing Computational Time for VBBinaryLensing by Point Source Approximation

    Science.gov (United States)

    Tirrell, Bethany M.; Visgaitis, Tiffany A.; Bozza, Valerio

    2018-01-01

    The gravitational lens of a binary system produces a magnification map that is more intricate than a single object lens. This map cannot be calculated analytically and one must rely on computational methods to resolve. There are generally two methods of computing the microlensed flux of a source. One is based on ray-shooting maps (Kayser, Refsdal, & Stabell 1986), while the other method is based on an application of Green’s theorem. This second method finds the area of an image by calculating a Riemann integral along the image contour. VBBinaryLensing is a C++ contour integration code developed by Valerio Bozza, which utilizes this method. The parameters at which the source object could be treated as a point source, or in other words, when the source is far enough from the caustic, was of interest to substantially decrease the computational time. The maximum and minimum values of the caustic curves produced, were examined to determine the boundaries for which this simplification could be made. The code was then run for a number of different maps, with separation values and accuracies ranging from 10-1 to 10-3, to test the theoretical model and determine a safe buffer for which minimal error could be made for the approximation. The determined buffer was 1.5+5q, with q being the mass ratio. The theoretical model and the calculated points worked for all combinations of the separation values and different accuracies except the map with accuracy and separation equal to 10-3 for y1 max. An alternative approach has to be found in order to accommodate a wider range of parameters.

  10. A Practical Computational Method for the Anisotropic Redshift-Space 3-Point Correlation Function

    Science.gov (United States)

    Slepian, Zachary; Eisenstein, Daniel J.

    2018-04-01

    We present an algorithm enabling computation of the anisotropic redshift-space galaxy 3-point correlation function (3PCF) scaling as N2, with N the number of galaxies. Our previous work showed how to compute the isotropic 3PCF with this scaling by expanding the radially-binned density field around each galaxy in the survey into spherical harmonics and combining these coefficients to form multipole moments. The N2 scaling occurred because this approach never explicitly required the relative angle between a galaxy pair about the primary galaxy. Here we generalize this work, demonstrating that in the presence of azimuthally-symmetric anisotropy produced by redshift-space distortions (RSD) the 3PCF can be described by two triangle side lengths, two independent total angular momenta, and a spin. This basis for the anisotropic 3PCF allows its computation with negligible additional work over the isotropic 3PCF. We also present the covariance matrix of the anisotropic 3PCF measured in this basis. Our algorithm tracks the full 5-D redshift-space 3PCF, uses an accurate line of sight to each triplet, is exact in angle, and easily handles edge correction. It will enable use of the anisotropic large-scale 3PCF as a probe of RSD in current and upcoming large-scale redshift surveys.

  11. UABUC - Single energy point model burnup computer code for water reactors

    International Nuclear Information System (INIS)

    El-Meshad, Y.; Morsy, S.; El-Osery, I.A.

    1981-01-01

    UABUC is a single energy point reactor burnup computer program in FORTRAN language. The program calculates the change in the isotopic composition of the uranium fuel as a function of irradiation time with all its associated quantities such as the average point flux, the conversion ratio, macroscopic fuel cross sections, and the point reactivity profile. A step-wise time analytical solution was developed for the nonlinear first order burnup differential equations. The ''Westcott'' convention of the effective cross sections was used except for plutonium-240 and uranium-238. For plutonium-240, an effective microscopic cross section was derived from the direct physical arguments taking into account the selfshielding effect of plutonium-240 as well as the 1 ev. resonance absorption. For uranium-238, an effective cross section, reflecting the effect of fast fission and resonance absorption was used. The fission products were treated in the three groups with 50, 300, and 800 barns. The yields in the groups were treated as functions of the type of fissionable nuclides, the effective neutron temperature, and the epithermal index. Xenon-135 and Samarium-149 were treated separately as functions of irradiation time. (author)

  12. Estimation Methods of the Point Spread Function Axial Position: A Comparative Computational Study

    Directory of Open Access Journals (Sweden)

    Javier Eduardo Diaz Zamboni

    2017-01-01

    Full Text Available The precise knowledge of the point spread function is central for any imaging system characterization. In fluorescence microscopy, point spread function (PSF determination has become a common and obligatory task for each new experimental device, mainly due to its strong dependence on acquisition conditions. During the last decade, algorithms have been developed for the precise calculation of the PSF, which fit model parameters that describe image formation on the microscope to experimental data. In order to contribute to this subject, a comparative study of three parameter estimation methods is reported, namely: I-divergence minimization (MIDIV, maximum likelihood (ML and non-linear least square (LSQR. They were applied to the estimation of the point source position on the optical axis, using a physical model. Methods’ performance was evaluated under different conditions and noise levels using synthetic images and considering success percentage, iteration number, computation time, accuracy and precision. The main results showed that the axial position estimation requires a high SNR to achieve an acceptable success level and higher still to be close to the estimation error lower bound. ML achieved a higher success percentage at lower SNR compared to MIDIV and LSQR with an intrinsic noise source. Only the ML and MIDIV methods achieved the error lower bound, but only with data belonging to the optical axis and high SNR. Extrinsic noise sources worsened the success percentage, but no difference was found between noise sources for the same method for all methods studied.

  13. Image analysis with the computer vision system and the consumer test in evaluating the appearance of Lucanian dry sausage.

    Science.gov (United States)

    Girolami, Antonio; Napolitano, Fabio; Faraone, Daniela; Di Bello, Gerardo; Braghieri, Ada

    2014-01-01

    The object of the investigation was the Lucanian dry sausage appearance, meant as color and visible fat ratio. The study was carried out on dry sausages produced in 10 different salami factories and seasoned for 18 days on average. We studied the effect of the raw material origin (5 producers used meat bought from the market and other 5 producers used meat from pigs bred in their farms) and of the salami factories or brands on meat color, fat color and visible fat ratio in dry sausages. The sausages slices were photographed and the images were analysed with the computer vision system to measure the changes in the colorimetric characteristics L*, a*, b*, hue and chroma and in the visible fat area ratio. The last parameter was assessed on the slice surface using image binarization. A consumer test was conducted to determine the relationship between the perception of visible fat on the sausage slice surface and acceptability and preference of this product. The consumers were asked to look carefully at the 6 sausages slices in a photo, minding the presence of fat, and to identify (a) the slices they considered unacceptable for consumption and (b) the slice they preferred. The results show that the color of the sausage lean part varies in relation to the raw material employed and to the producer or brand (P<0.001). Besides, the sausage meat color is not uniform in some salami factories (P<0.05-0.001). In all salami factories the sausages show a high uniformity in fat color. The visible fat ratio of the sausages slices is higher (P<0.001) in the product from salami factories without pig-breeding farm. The fat percentage is highly variable (P<0.001) among the sausages of each salami factory. On the whole, the product the consumers consider acceptable and is inclined to eat has a low fat percentage (P<0.001). Our consumers (about 70%) prefer slices which are leaner (P<0.001). Women, in particular, show a higher preference for the leanest (P<0.001). © 2013.

  14. Detecting Faults in Southern California using Computer-Vision Techniques and Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) Interferometry

    Science.gov (United States)

    Barba, M.; Rains, C.; von Dassow, W.; Parker, J. W.; Glasscoe, M. T.

    2013-12-01

    Knowing the location and behavior of active faults is essential for earthquake hazard assessment and disaster response. In Interferometric Synthetic Aperture Radar (InSAR) images, faults are revealed as linear discontinuities. Currently, interferograms are manually inspected to locate faults. During the summer of 2013, the NASA-JPL DEVELOP California Disasters team contributed to the development of a method to expedite fault detection in California using remote-sensing technology. The team utilized InSAR images created from polarimetric L-band data from NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) project. A computer-vision technique known as 'edge-detection' was used to automate the fault-identification process. We tested and refined an edge-detection algorithm under development through NASA's Earthquake Data Enhanced Cyber-Infrastructure for Disaster Evaluation and Response (E-DECIDER) project. To optimize the algorithm we used both UAVSAR interferograms and synthetic interferograms generated through Disloc, a web-based modeling program available through NASA's QuakeSim project. The edge-detection algorithm detected seismic, aseismic, and co-seismic slip along faults that were identified and compared with databases of known fault systems. Our optimization process was the first step toward integration of the edge-detection code into E-DECIDER to provide decision support for earthquake preparation and disaster management. E-DECIDER partners that will use the edge-detection code include the California Earthquake Clearinghouse and the US Department of Homeland Security through delivery of products using the Unified Incident Command and Decision Support (UICDS) service. Through these partnerships, researchers, earthquake disaster response teams, and policy-makers will be able to use this new methodology to examine the details of ground and fault motions for moderate to large earthquakes. Following an earthquake, the newly discovered faults can

  15. Usability and Acceptability of ASSESS MS: Assessment of Motor Dysfunction in Multiple Sclerosis Using Depth-Sensing Computer Vision.

    Science.gov (United States)

    Morrison, Cecily; D'Souza, Marcus; Huckvale, Kit; Dorn, Jonas F; Burggraaff, Jessica; Kamm, Christian Philipp; Steinheimer, Saskia Marie; Kontschieder, Peter; Criminisi, Antonio; Uitdehaag, Bernard; Dahlke, Frank; Kappos, Ludwig; Sellen, Abigail

    2015-06-24

    Sensor-based recordings of human movements are becoming increasingly important for the assessment of motor symptoms in neurological disorders beyond rehabilitative purposes. ASSESS MS is a movement recording and analysis system being developed to automate the classification of motor dysfunction in patients with multiple sclerosis (MS) using depth-sensing computer vision. It aims to provide a more consistent and finer-grained measurement of motor dysfunction than currently possible. To test the usability and acceptability of ASSESS MS with health professionals and patients with MS. A prospective, mixed-methods study was carried out at 3 centers. After a 1-hour training session, a convenience sample of 12 health professionals (6 neurologists and 6 nurses) used ASSESS MS to capture recordings of standardized movements performed by 51 volunteer patients. Metrics for effectiveness, efficiency, and acceptability were defined and used to analyze data captured by ASSESS MS, video recordings of each examination, feedback questionnaires, and follow-up interviews. All health professionals were able to complete recordings using ASSESS MS, achieving high levels of standardization on 3 of 4 metrics (movement performance, lateral positioning, and clear camera view but not distance positioning). Results were unaffected by patients' level of physical or cognitive disability. ASSESS MS was perceived as easy to use by both patients and health professionals with high scores on the Likert-scale questions and positive interview commentary. ASSESS MS was highly acceptable to patients on all dimensions considered, including attitudes to future use, interaction (with health professionals), and overall perceptions of ASSESS MS. Health professionals also accepted ASSESS MS, but with greater ambivalence arising from the need to alter patient interaction styles. There was little variation in results across participating centers, and no differences between neurologists and nurses. In typical

  16. Computer Vision Evidence Supporting Craniometric Alignment of Rat Brain Atlases to Streamline Expert-Guided, First-Order Migration of Hypothalamic Spatial Datasets Related to Behavioral Control

    Science.gov (United States)

    Khan, Arshad M.; Perez, Jose G.; Wells, Claire E.; Fuentes, Olac

    2018-01-01

    The rat has arguably the most widely studied brain among all animals, with numerous reference atlases for rat brain having been published since 1946. For example, many neuroscientists have used the atlases of Paxinos and Watson (PW, first published in 1982) or Swanson (S, first published in 1992) as guides to probe or map specific rat brain structures and their connections. Despite nearly three decades of contemporaneous publication, no independent attempt has been made to establish a basic framework that allows data mapped in PW to be placed in register with S, or vice versa. Such data migration would allow scientists to accurately contextualize neuroanatomical data mapped exclusively in only one atlas with data mapped in the other. Here, we provide a tool that allows levels from any of the seven published editions of atlases comprising three distinct PW reference spaces to be aligned to atlas levels from any of the four published editions representing S reference space. This alignment is based on registration of the anteroposterior stereotaxic coordinate (z) measured from the skull landmark, Bregma (β). Atlas level alignments performed along the z axis using one-dimensional Cleveland dot plots were in general agreement with alignments obtained independently using a custom-made computer vision application that utilized the scale-invariant feature transform (SIFT) and Random Sample Consensus (RANSAC) operation to compare regions of interest in photomicrographs of Nissl-stained tissue sections from the PW and S reference spaces. We show that z-aligned point source data (unpublished hypothalamic microinjection sites) can be migrated from PW to S space to a first-order approximation in the mediolateral and dorsoventral dimensions using anisotropic scaling of the vector-formatted atlas templates, together with expert-guided relocation of obvious outliers in the migrated datasets. The migrated data can be contextualized with other datasets mapped in S space, including

  17. Computer Vision Evidence Supporting Craniometric Alignment of Rat Brain Atlases to Streamline Expert-Guided, First-Order Migration of Hypothalamic Spatial Datasets Related to Behavioral Control

    Directory of Open Access Journals (Sweden)

    Arshad M. Khan

    2018-05-01

    Full Text Available The rat has arguably the most widely studied brain among all animals, with numerous reference atlases for rat brain having been published since 1946. For example, many neuroscientists have used the atlases of Paxinos and Watson (PW, first published in 1982 or Swanson (S, first published in 1992 as guides to probe or map specific rat brain structures and their connections. Despite nearly three decades of contemporaneous publication, no independent attempt has been made to establish a basic framework that allows data mapped in PW to be placed in register with S, or vice versa. Such data migration would allow scientists to accurately contextualize neuroanatomical data mapped exclusively in only one atlas with data mapped in the other. Here, we provide a tool that allows levels from any of the seven published editions of atlases comprising three distinct PW reference spaces to be aligned to atlas levels from any of the four published editions representing S reference space. This alignment is based on registration of the anteroposterior stereotaxic coordinate (z measured from the skull landmark, Bregma (β. Atlas level alignments performed along the z axis using one-dimensional Cleveland dot plots were in general agreement with alignments obtained independently using a custom-made computer vision application that utilized the scale-invariant feature transform (SIFT and Random Sample Consensus (RANSAC operation to compare regions of interest in photomicrographs of Nissl-stained tissue sections from the PW and S reference spaces. We show that z-aligned point source data (unpublished hypothalamic microinjection sites can be migrated from PW to S space to a first-order approximation in the mediolateral and dorsoventral dimensions using anisotropic scaling of the vector-formatted atlas templates, together with expert-guided relocation of obvious outliers in the migrated datasets. The migrated data can be contextualized with other datasets mapped in S

  18. Fast and accurate three-dimensional point spread function computation for fluorescence microscopy.

    Science.gov (United States)

    Li, Jizhou; Xue, Feng; Blu, Thierry

    2017-06-01

    The point spread function (PSF) plays a fundamental role in fluorescence microscopy. A realistic and accurately calculated PSF model can significantly improve the performance in 3D deconvolution microscopy and also the localization accuracy in single-molecule microscopy. In this work, we propose a fast and accurate approximation of the Gibson-Lanni model, which has been shown to represent the PSF suitably under a variety of imaging conditions. We express the Kirchhoff's integral in this model as a linear combination of rescaled Bessel functions, thus providing an integral-free way for the calculation. The explicit approximation error in terms of parameters is given numerically. Experiments demonstrate that the proposed approach results in a significantly smaller computational time compared with current state-of-the-art techniques to achieve the same accuracy. This approach can also be extended to other microscopy PSF models.

  19. Development of Point Kernel Shielding Analysis Computer Program Implementing Recent Nuclear Data and Graphic User Interfaces

    International Nuclear Information System (INIS)

    Kang, Sang Ho; Lee, Seung Gi; Chung, Chan Young; Lee, Choon Sik; Lee, Jai Ki

    2001-01-01

    In order to comply with revised national regulationson radiological protection and to implement recent nuclear data and dose conversion factors, KOPEC developed a new point kernel gamma and beta ray shielding analysis computer program. This new code, named VisualShield, adopted mass attenuation coefficient and buildup factors from recent ANSI/ANS standards and flux-to-dose conversion factors from the International Commission on Radiological Protection (ICRP) Publication 74 for estimation of effective/equivalent dose recommended in ICRP 60. VisualShield utilizes graphical user interfaces and 3-D visualization of the geometric configuration for preparing input data sets and analyzing results, which leads users to error free processing with visual effects. Code validation and data analysis were performed by comparing the results of various calculations to the data outputs of previous programs such as MCNP 4B, ISOSHLD-II, QAD-CGGP, etc

  20. High-performance floating-point image computing workstation for medical applications

    Science.gov (United States)

    Mills, Karl S.; Wong, Gilman K.; Kim, Yongmin

    1990-07-01

    The medical imaging field relies increasingly on imaging and graphics techniques in diverse applications with needs similar to (or more stringent than) those of the military, industrial and scientific communities. However, most image processing and graphics systems available for use in medical imaging today are either expensive, specialized, or in most cases both. High performance imaging and graphics workstations which can provide real-time results for a number of applications, while maintaining affordability and flexibility, can facilitate the application of digital image computing techniques in many different areas. This paper describes the hardware and software architecture of a medium-cost floating-point image processing and display subsystem for the NeXT computer, and its applications as a medical imaging workstation. Medical imaging applications of the workstation include use in a Picture Archiving and Communications System (PACS), in multimodal image processing and 3-D graphics workstation for a broad range of imaging modalities, and as an electronic alternator utilizing its multiple monitor display capability and large and fast frame buffer. The subsystem provides a 2048 x 2048 x 32-bit frame buffer (16 Mbytes of image storage) and supports both 8-bit gray scale and 32-bit true color images. When used to display 8-bit gray scale images, up to four different 256-color palettes may be used for each of four 2K x 2K x 8-bit image frames. Three of these image frames can be used simultaneously to provide pixel selectable region of interest display. A 1280 x 1024 pixel screen with 1: 1 aspect ratio can be windowed into the frame buffer for display of any portion of the processed image or images. In addition, the system provides hardware support for integer zoom and an 82-color cursor. This subsystem is implemented on an add-in board occupying a single slot in the NeXT computer. Up to three boards may be added to the NeXT for multiple display capability (e

  1. Computationally derived points of fragility of a human cascade are consistent with current therapeutic strategies.

    Directory of Open Access Journals (Sweden)

    Deyan Luan

    2007-07-01

    Full Text Available The role that mechanistic mathematical modeling and systems biology will play in molecular medicine and clinical development remains uncertain. In this study, mathematical modeling and sensitivity analysis were used to explore the working hypothesis that mechanistic models of human cascades, despite model uncertainty, can be computationally screened for points of fragility, and that these sensitive mechanisms could serve as therapeutic targets. We tested our working hypothesis by screening a model of the well-studied coagulation cascade, developed and validated from literature. The predicted sensitive mechanisms were then compared with the treatment literature. The model, composed of 92 proteins and 148 protein-protein interactions, was validated using 21 published datasets generated from two different quiescent in vitro coagulation models. Simulated platelet activation and thrombin generation profiles in the presence and absence of natural anticoagulants were consistent with measured values, with a mean correlation of 0.87 across all trials. Overall state sensitivity coefficients, which measure the robustness or fragility of a given mechanism, were calculated using a Monte Carlo strategy. In the absence of anticoagulants, fluid and surface phase factor X/activated factor X (fX/FXa activity and thrombin-mediated platelet activation were found to be fragile, while fIX/FIXa and fVIII/FVIIIa activation and activity were robust. Both anti-fX/FXa and direct thrombin inhibitors are important classes of anticoagulants; for example, anti-fX/FXa inhibitors have FDA approval for the prevention of venous thromboembolism following surgical intervention and as an initial treatment for deep venous thrombosis and pulmonary embolism. Both in vitro and in vivo experimental evidence is reviewed supporting the prediction that fIX/FIXa activity is robust. When taken together, these results support our working hypothesis that computationally derived points of

  2. Computation of point reactor dynamics equations with thermal feedback via weighted residue method

    International Nuclear Information System (INIS)

    Suo Changan; Liu Xiaoming

    1986-01-01

    Point reactor dynamics equations with six groups of delayed neutrons have been computed via weighted-residual method in which the delta function was taken as a weighting function, and the parabolic with or without exponential factor as a trial function respectively for an insertion of large or smaller reactivity. The reactivity inserted into core can be varied with time, including insertion in forms of step function, polynomials up to second power and sine function. A thermal feedback of single flow channel model was added in. The thermal equations concerned were treated by use of a backward difference technique. A WRK code has been worked out, including implementation of an automatic selection of time span based on an input of error requirement and of an automatic change between computation with large reactivity and that with smaller one. On the condition of power varied slowly and without feedback, the results are not sensitive to the selection of values of time span. At last, the comparison of relevant results has shown that the agreement is quite well

  3. On the tip of the tongue: learning typing and pointing with an intra-oral computer interface.

    Science.gov (United States)

    Caltenco, Héctor A; Breidegard, Björn; Struijk, Lotte N S Andreasen

    2014-07-01

    To evaluate typing and pointing performance and improvement over time of four able-bodied participants using an intra-oral tongue-computer interface for computer control. A physically disabled individual may lack the ability to efficiently control standard computer input devices. There have been several efforts to produce and evaluate interfaces that provide individuals with physical disabilities the possibility to control personal computers. Training with the intra-oral tongue-computer interface was performed by playing games over 18 sessions. Skill improvement was measured through typing and pointing exercises at the end of each training session. Typing throughput improved from averages of 2.36 to 5.43 correct words per minute. Pointing throughput improved from averages of 0.47 to 0.85 bits/s. Target tracking performance, measured as relative time on target, improved from averages of 36% to 47%. Path following throughput improved from averages of 0.31 to 0.83 bits/s and decreased to 0.53 bits/s with more difficult tasks. Learning curves support the notion that the tongue can rapidly learn novel motor tasks. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, which makes the tongue a feasible input organ for computer control. Intra-oral computer interfaces could provide individuals with severe upper-limb mobility impairments the opportunity to control computers and automatic equipment. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, but does not cause fatigue easily and might be invisible to other people, which is highly prioritized by assistive device users. Combination of visual and auditory feedback is vital for a good performance of an intra-oral computer interface and helps to reduce involuntary or erroneous activations.

  4. Computer vision applied to herbarium specimens of German trees: testing the future utility of the millions of herbarium specimen images for automated identification.

    Science.gov (United States)

    Unger, Jakob; Merhof, Dorit; Renner, Susanne

    2016-11-16

    Global Plants, a collaborative between JSTOR and some 300 herbaria, now contains about 2.48 million high-resolution images of plant specimens, a number that continues to grow, and collections that are digitizing their specimens at high resolution are allocating considerable recourses to the maintenance of computer hardware (e.g., servers) and to acquiring digital storage space. We here apply machine learning, specifically the training of a Support-Vector-Machine, to classify specimen images into categories, ideally at the species level, using the 26 most common tree species in Germany as a test case. We designed an analysis pipeline and classification system consisting of segmentation, normalization, feature extraction, and classification steps and evaluated the system in two test sets, one with 26 species, the other with 17, in each case using 10 images per species of plants collected between 1820 and 1995, which simulates the empirical situation that most named species are represented in herbaria and databases, such as JSTOR, by few specimens. We achieved 73.21% accuracy of species assignments in the larger test set, and 84.88% in the smaller test set. The results of this first application of a computer vision algorithm trained on images of herbarium specimens shows that despite the problem of overlapping leaves, leaf-architectural features can be used to categorize specimens to species with good accuracy. Computer vision is poised to play a significant role in future rapid identification at least for frequently collected genera or species in the European flora.

  5. Edward Rhodes Stitt Award Lecture. Will a computer (with artificial vision) replace the surgical pathologist (or other health professionals)?

    Science.gov (United States)

    Heffner, D K

    1994-04-01

    Many jobs require vision for most of the tasks performed and the discussion focuses on the nature of human visual perception. Arguments are given to support the claim that visual perception is a very complicated function of the brain. To attempt to answer whether or not artificial intelligence (AI) will ever be able to essentially do what the brain does, the history and current state of AI research is examined, with special attention to neural net research.

  6. INTRA- AND INTER-OBSERVER RELIABILITY IN SELECTION OF THE HEART RATE DEFLECTION POINT DURING INCREMENTAL EXERCISE: COMPARISON TO A COMPUTER-GENERATED DEFLECTION POINT

    Directory of Open Access Journals (Sweden)

    Bridget A. Duoos

    2002-12-01

    Full Text Available This study was designed to 1 determine the relative frequency of occurrence of a heart rate deflection point (HRDP, when compared to a linear relationship, during progressive exercise, 2 measure the reproducibility of a visual assessment of a heart rate deflection point (HRDP, both within and between observers 3 compare visual and computer-assessed deflection points. Subjects consisted of 73 competitive male cyclists with mean age of 31.4 ± 6.3 years, mean height 178.3 ± 4.8 cm. and weight 74.0 ± 4.4 kg. Tests were conducted on an electrically-braked cycle ergometer beginning at 25 watts and progressing 25 watts per minute to fatigue. Heart Rates were recorded the last 10 seconds of each stage and at fatigue. Scatter plots of heart rate versus watts were computer-generated and given to 3 observers on two different occasions. A computer program was developed to assess if data points were best represented by a single line or two lines. The HRDP represented the intersection of the two lines. Results of this study showed that 1 computer-assessed HRDP showed that 44 of 73 subjects (60.3% had scatter plots best represented by a straight line with no HRDP 2in those subjects having HRDP, all 3 observers showed significant differences(p = 0.048, p = 0.007, p = 0.001 in reproducibility of their HRDP selection. Differences in HRDP selection were significant for two of the three comparisons between observers (p = 0.002, p = 0.305, p = 0.0003 Computer-generated HRDP was significantly different than visual HRDP for 2 of 3 observers (p = 0.0016, p = 0.513, p = 0.0001. It is concluded that 1 HRDP occurs in a minority of subjects 2 significant differences exist, both within and between observers, in selection of HRDP and 3 differences in agreement between visual and computer-generated HRDP would indicate that, when HRDP exists, it should be computer-assessed

  7. Finite element and node point generation computer programs used for the design of toroidal field coils in tokamak fusion devices

    International Nuclear Information System (INIS)

    Smith, R.A.

    1975-06-01

    The structural analysis of toroidal field coils in Tokamak fusion machines can be performed with the finite element method. This technique has been employed for design evaluations of toroidal field coils on the Princeton Large Torus (PLT), the Poloidal Diverter Experiment (PDX), and the Tokamak Fusion Test Reactor (TFTR). The application of the finite element method can be simplified with computer programs that are used to generate the input data for the finite element code. There are three areas of data input where significant automation can be provided by supplementary computer codes. These concern the definition of geometry by a node point mesh, the definition of the finite elements from the geometric node points, and the definition of the node point force/displacement boundary conditions. The node point forces in a model of a toroidal field coil are computed from the vector cross product of the coil current and the magnetic field. The computer programs named PDXNODE and ELEMENT are described. The program PDXNODE generates the geometric node points of a finite element model for a toroidal field coil. The program ELEMENT defines the finite elements of the model from the node points and from material property considerations. The program descriptions include input requirements, the output, the program logic, the methods of generating complex geometries with multiple runs, computational time and computer compatibility. The output format of PDXNODE and ELEMENT make them compatible with PDXFORC and two general purpose finite element computer codes: (ANSYS) the Engineering Analysis System written by the Swanson Analysis Systems, Inc., and (WECAN) the Westinghouse Electric Computer Analysis general purpose finite element program. The Fortran listings of PDXNODE and ELEMENT are provided

  8. The potential of computer vision, optical backscattering parameters and artificial neural network modelling in monitoring the shrinkage of sweet potato (Ipomoea batatas L.) during drying.

    Science.gov (United States)

    Onwude, Daniel I; Hashim, Norhashila; Abdan, Khalina; Janius, Rimfiel; Chen, Guangnan

    2018-03-01

    Drying is a method used to preserve agricultural crops. During the drying of products with high moisture content, structural changes in shape, volume, area, density and porosity occur. These changes could affect the final quality of dried product and also the effective design of drying equipment. Therefore, this study investigated a novel approach in monitoring and predicting the shrinkage of sweet potato during drying. Drying experiments were conducted at temperatures of 50-70 °C and samples thicknesses of 2-6 mm. The volume and surface area obtained from camera vision, and the perimeter and illuminated area from backscattered optical images were analysed and used to evaluate the shrinkage of sweet potato during drying. The relationship between dimensionless moisture content and shrinkage of sweet potato in terms of volume, surface area, perimeter and illuminated area was found to be linearly correlated. The results also demonstrated that the shrinkage of sweet potato based on computer vision and backscattered optical parameters is affected by the product thickness, drying temperature and drying time. A multilayer perceptron (MLP) artificial neural network with input layer containing three cells, two hidden layers (18 neurons), and five cells for output layer, was used to develop a model that can monitor, control and predict the shrinkage parameters and moisture content of sweet potato slices under different drying conditions. The developed ANN model satisfactorily predicted the shrinkage and dimensionless moisture content of sweet potato with correlation coefficient greater than 0.95. Combined computer vision, laser light backscattering imaging and artificial neural network can be used as a non-destructive, rapid and easily adaptable technique for in-line monitoring, predicting and controlling the shrinkage and moisture changes of food and agricultural crops during drying. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. The software for automatic creation of the formal grammars used by speech recognition, computer vision, editable text conversion systems, and some new functions

    Science.gov (United States)

    Kardava, Irakli; Tadyszak, Krzysztof; Gulua, Nana; Jurga, Stefan

    2017-02-01

    For more flexibility of environmental perception by artificial intelligence it is needed to exist the supporting software modules, which will be able to automate the creation of specific language syntax and to make a further analysis for relevant decisions based on semantic functions. According of our proposed approach, of which implementation it is possible to create the couples of formal rules of given sentences (in case of natural languages) or statements (in case of special languages) by helping of computer vision, speech recognition or editable text conversion system for further automatic improvement. In other words, we have developed an approach, by which it can be achieved to significantly improve the training process automation of artificial intelligence, which as a result will give us a higher level of self-developing skills independently from us (from users). At the base of our approach we have developed a software demo version, which includes the algorithm and software code for the entire above mentioned component's implementation (computer vision, speech recognition and editable text conversion system). The program has the ability to work in a multi - stream mode and simultaneously create a syntax based on receiving information from several sources.

  10. Measurement of liver and spleen volume by computed tomography using point counting technique

    International Nuclear Information System (INIS)

    Matsuda, Yoshiro; Sato, Hiroyuki; Nei, Jinichi; Takada, Akira

    1982-01-01

    We devised a new method for measurement of liver and spleen volume by computed tomography using point counting technique. This method is very simple and applicable to any kind of CT scanner. The volumes of the livers and spleens estimated by this method were significantly correlated with the weights of the corresponding organs measured on autopsy or surgical operation, indicating clinical usefulness of this method. Hepatic and splenic volumes were estimated by this method in 43 patients with chronic liver disease and 9 subjects with non-hepatobiliary disease. The mean hepatic volume in non-alcoholic liver cirrhosis was significantly smaller than those in non-hepatobiliary disease and other chronic liver diseases. The mean hepatic volume in alcoholic cirrhosis and alcoholic fibrosis tended to be slightly larger than that in non-hepatobiliary disease. The mean splenic volume in liver cirrhosis was significantly larger than those in non-hepatobiliary disease and other chronic liver diseases. However, there was no significant difference of the mean splenic volume between alcoholic and non-alcoholic cirrhosis. Significantly positive correlation between hepatic and splenic volumes was found in alcoholic cirrhosis, but not in non-alcoholic cirrhosis. These results indicate that estimation of hepatic and splenic volumes by this method is useful for the analysis of the pathophysiological condition of chronic liver diseases. (author)

  11. Image segmentation for enhancing symbol recognition in prosthetic vision.

    Science.gov (United States)

    Horne, Lachlan; Barnes, Nick; McCarthy, Chris; He, Xuming

    2012-01-01

    Current and near-term implantable prosthetic vision systems offer the potential to restore some visual function, but suffer from poor resolution and dynamic range of induced phosphenes. This can make it difficult for users of prosthetic vision systems to identify symbolic information (such as signs) except in controlled conditions. Using image segmentation techniques from computer vision, we show it is possible to improve the clarity of such symbolic information for users of prosthetic vision implants in uncontrolled conditions. We use image segmentation to automatically divide a natural image into regions, and using a fixation point controlled by the user, select a region to phosphenize. This technique improves the apparent contrast and clarity of symbolic information over traditional phosphenization approaches.

  12. Living with vision loss

    Science.gov (United States)

    Diabetes - vision loss; Retinopathy - vision loss; Low vision; Blindness - vision loss ... of visual aids. Some options include: Magnifiers High power reading glasses Devices that make it easier to ...

  13. Point Based Emotion Classification Using SVM

    OpenAIRE

    Swinkels, Wout

    2016-01-01

    The detection of emotions is a hot topic in the area of computer vision. Emotions are based on subtle changes in the face that are intuitively detected and interpreted by humans. Detecting these subtle changes, based on mathematical models, is a great challenge in the area of computer vision. In this thesis a new method is proposed to achieve state-of-the-art emotion detection performance. This method is based on facial feature points to monitor subtle changes in the face. Therefore the c...

  14. Computer simulation of vortex pinning in type II superconductors. II. Random point pins

    International Nuclear Information System (INIS)

    Brandt, E.H.

    1983-01-01

    Pinning of vortices in a type II superconductor by randomly positioned identical point pins is simulated using the two-dimensional method described in a previous paper (Part I). The system is characterized by the vortex and pin numbers (N/sub v/, N/sub p/), the vortex and pin interaction ranges (R/sub v/, R/sub p/), and the amplitude of the pin potential A/sub p/. The computation is performed for many cases: dilute or dense, sharp or soft, attractive or repulsive, weak or strong pins, and ideal or amorphous vortex lattice. The total pinning force F as a function of the mean vortex displacment X increases first linearly (over a distance usually much smaller than the vortex spacing and than R/sub p/) and then saturates, fluctuating about its averaging F-bar. We interpret F-bar as the maximum pinning force j/sub c/B of a large specimen. For weak pins the prediction of Larkin and Ovchinnikov for two-dimensional collective pinning is confirmed: F-bar = const. iW/R/sub p/c 66 , where W-bar is the mean square pinning force and c 66 is the shear modulus of the vortex lattice. If the initial vortex lattice is chosen highly defective (''amorphous'') the constant is 1.3--3 times larger than for the ideal triangular lattice. This finding may explain the often observed ''history effect.'' The function F-bar(A/sub p/) exhibits a jump, which for dilute, sharp, attractive pins occurs close to the ''threshold value'' predicted for isolated pins by Labusch. This jump reflects the onset of plastic deformation of the vortex lattice, and in some cases of vortex trapping, but is not a genuine threshold

  15. Efficient 2-D DCT Computation from an Image Representation Point of View

    OpenAIRE

    Papakostas, G.A.; Koulouriotis, D.E.; Karakasis, E.G.

    2009-01-01

    A novel methodology that ensures the computation of 2-D DCT coefficients in gray-scale images as well as in binary ones, with high computation rates, was presented in the previous sections. Through a new image representation scheme, called ISR (Image Slice Representation) the 2-D DCT coefficients can be computed in significantly reduced time, with the same accuracy.

  16. Accuracy of measurement of pulmonary emphysema with computed tomography: relevant points

    International Nuclear Information System (INIS)

    Hochhegger, Bruno; Marchiori, Edson; Oliveira, Hugo

    2010-01-01

    Some technical aspects should be taken into consideration in order to guarantee the reliability of the assessment of pulmonary emphysema with lung computed tomography densitometry. Changes in lung density associated with variations in lungs inspiratory and expiratory levels, computed tomography slice thickness, reconstruction algorithm and type of computed tomography apparatus make tomographic comparisons more difficult in follow-up studies of pulmonary emphysema. Nevertheless, quantitative computed tomography has replaced the visual assessment competing with pulmonary function tests as a sensitive method to measure pulmonary emphysema. The present review discusses technical variables of lung computed tomography and their influence on measurements of pulmonary emphysema. (author)

  17. Accuracy of measurement of pulmonary emphysema with computed tomography: relevant points

    Energy Technology Data Exchange (ETDEWEB)

    Hochhegger, Bruno, E-mail: brunohochhegger@googlemail.co [Hospital Moinhos de Vento, Porto Alegre, RS (Brazil); Marchiori, Edson [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Radiologia; Irion, Klaus L. [Liverpool Heart and Chest Hospital, Liverpool (United Kingdom); Oliveira, Hugo [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2010-07-15

    Some technical aspects should be taken into consideration in order to guarantee the reliability of the assessment of pulmonary emphysema with lung computed tomography densitometry. Changes in lung density associated with variations in lungs inspiratory and expiratory levels, computed tomography slice thickness, reconstruction algorithm and type of computed tomography apparatus make tomographic comparisons more difficult in follow-up studies of pulmonary emphysema. Nevertheless, quantitative computed tomography has replaced the visual assessment competing with pulmonary function tests as a sensitive method to measure pulmonary emphysema. The present review discusses technical variables of lung computed tomography and their influence on measurements of pulmonary emphysema. (author)

  18. Motion Control with Vision

    NARCIS (Netherlands)

    Ir. Dick van Schenk Brill; Ir Peter Boots

    2001-01-01

    This paper describes the work that is done by a group of I3 students at Philips CFT in Eindhoven, Netherlands. I3 is an initiative of Fontys University of Professional Education also located in Eindhoven. The work focuses on the use of computer vision in motion control. Experiments are done with

  19. [Key points for esthetic rehabilitation of anterior teeth using chair-side computer aided design and computer aided manufacture technique].

    Science.gov (United States)

    Yang, J; Feng, H L

    2018-04-09

    With the rapid development of the chair-side computer aided design and computer aided manufacture (CAD/CAM) technology, its accuracy and operability of have been greatly improved in recent years. Chair-side CAD/CAM system may produce all kinds of indirect restorations, and has the advantages of rapid, accurate and stable production. It has become the future development direction of Stomatology. This paper describes the clinical application of the chair-side CAD/CAM technology for anterior aesthetic restorations from the aspects of shade and shape.

  20. SOCIAL INSTITUTION OF EDUCATION AND COMPUTER VIRTUAL REALITY: POINTS OF INFLUENCE

    OpenAIRE

    Tarakanov Sergey Anatolevich

    2012-01-01

    This article discusses the impact of computer virtual reality to education as a social institution. Author gives a description of education as a social institution. Outlines the main changes of the institute of education under the influence of a virtual online-environment. Author makes the following conclusions: 1. Computer virtual reality expands sphere of activity of social institution of education. 2. Computer virtual reality deletes status and role differences. It influences on the system...

  1. Experiences of registered nurses with regard to accessing health information at the point-of-care via mobile computing devices.

    Science.gov (United States)

    Ricks, Esmeralda; Benjamin, Valencia; Williams, Margaret

    2015-11-19

    The volume of health information necessary to provide competent health care today has become overwhelming. Mobile computing devices are fast becoming an essential clinical tool for accessing health information at the point-of-care of patients. This study explored and described how registered nurses experienced accessing information at the point-of-care via mobile computing devices (MCDs). A qualitative, exploratory, descriptive and contextual design was used. Ten in-depth interviews were conducted with purposively sampled registered nurses employed by a state hospital in the Nelson Mandela Bay Municipality (NMBM). Interviews were recorded, transcribed verbatim and analysed using Tesch's data analysis technique. Ethical principles were adhered to throughout the study. Guba's model of trustworthiness was used to confirm integrity of the study. Four themes emerged which revealed that the registered nurses benefited from the training they received by enabling them to develop, and improve, their computer literacy levels. Emphasis was placed on the benefits that the accessed information had for educational purposes for patients and the public, for colleagues and students. Furthermore the ability to access information at the point-of-care was considered by registered nurses as valuable to improve patient care because of the wide range of accurate and readily accessible information available via the mobile computing device. The registered nurses in this study felt that being able to access information at the point-of-care increased their confidence and facilitated the provision of quality care because it assisted them in being accurate and sure of what they were doing.

  2. Numerical computation of inventory policies, based on the EOQ/sigma-x value for order-point systems

    DEFF Research Database (Denmark)

    Alstrøm, Poul

    2001-01-01

    This paper examines the numerical computation of two control parameters, order size and order point in the well-known inventory control model, an (s,Q)system with a beta safety strategy. The aim of the paper is to show that the EOQ/sigma-x value is both sufficient for controlling the system and e...

  3. Numerical computation of inventory policies, based on the EOQ/sigma-x value for order-point systems

    DEFF Research Database (Denmark)

    Alstrøm, Poul

    2000-01-01

    This paper examines the numerical computation of two control parameters, order size and order point in the well-known inventory control model, an (s,Q)system with a beta safety strategy. The aim of the paper is to show that the EOQ/sigma-x value is both sufficient for controlling the system and e...

  4. Generation of point isotropic source dose buildup factor data for the PFBR special concretes in a form compatible for usage in point kernel computer code QAD-CGGP

    International Nuclear Information System (INIS)

    Radhakrishnan, G.

    2003-01-01

    Full text: Around the PFBR (Prototype Fast Breeder Reactor) reactor assembly, in the peripheral shields special concretes of density 2.4 g/cm 3 and 3.6 g/cm 3 are to be used in complex geometrical shapes. Point-kernel computer code like QAD-CGGP, written for complex shield geometry comes in handy for the shield design optimization of peripheral shields. QAD-CGGP requires data base for the buildup factor data and it contains only ordinary concrete of density 2.3 g/cm 3 . In order to extend the data base for the PFBR special concretes, point isotropic source dose buildup factors have been generated by Monte Carlo method using the computer code MCNP-4A. For the above mentioned special concretes, buildup factor data have been generated in the energy range 0.5 MeV to 10.0 MeV with the thickness ranging from 1 mean free paths (mfp) to 40 mfp. Capo's formula fit of the buildup factor data compatible with QAD-CGGP has been attempted

  5. Energy-Efficient Management of Data Center Resources for Cloud Computing: A Vision, Architectural Elements, and Open Challenges

    OpenAIRE

    Buyya, Rajkumar; Beloglazov, Anton; Abawajy, Jemal

    2010-01-01

    Cloud computing is offering utility-oriented IT services to users worldwide. Based on a pay-as-you-go model, it enables hosting of pervasive applications from consumer, scientific, and business domains. However, data centers hosting Cloud applications consume huge amounts of energy, contributing to high operational costs and carbon footprints to the environment. Therefore, we need Green Cloud computing solutions that can not only save energy for the environment but also reduce operational cos...

  6. Computing half-plane and strip discrepancy of planar point sets

    NARCIS (Netherlands)

    Berg, de M.

    1996-01-01

    We present efficient algorithms for two problems concerning the discrepancy of a set S of n points in the unit square in the plane. First, we describe an algorithm for maintaining the half-plane discrepancy of S under insertions and deletions of points. The algorithm runs in O(nlogn) worst-case time

  7. Algorithmic strategies for FPGA-based vision

    OpenAIRE

    Lim, Yoong Kang

    2016-01-01

    As demands for real-time computer vision applications increase, implementations on alternative architectures have been explored. These architectures include Field-Programmable Gate Arrays (FPGAs), which offer a high degree of flexibility and parallelism. A problem with this is that many computer vision algorithms have been optimized for serial processing, and this often does not map well to FPGA implementation. This thesis introduces the concept of FPGA-tailored computer vision algorithms...

  8. Long-Term Deflection Prediction from Computer Vision-Measured Data History for High-Speed Railway Bridges

    Directory of Open Access Journals (Sweden)

    Jaebeom Lee

    2018-05-01

    Full Text Available Management of the vertical long-term deflection of a high-speed railway bridge is a crucial factor to guarantee traffic safety and passenger comfort. Therefore, there have been efforts to predict the vertical deflection of a railway bridge based on physics-based models representing various influential factors to vertical deflection such as concrete creep and shrinkage. However, it is not an easy task because the vertical deflection of a railway bridge generally involves several sources of uncertainty. This paper proposes a probabilistic method that employs a Gaussian process to construct a model to predict the vertical deflection of a railway bridge based on actual vision-based measurement and temperature. To deal with the sources of uncertainty which may cause prediction errors, a Gaussian process is modeled with multiple kernels and hyperparameters. Once the hyperparameters are identified through the Gaussian process regression using training data, the proposed method provides a 95% prediction interval as well as a predictive mean about the vertical deflection of the bridge. The proposed method is applied to an arch bridge under operation for high-speed trains in South Korea. The analysis results obtained from the proposed method show good agreement with the actual measurement data on the vertical deflection of the example bridge, and the prediction results can be utilized for decision-making on railway bridge maintenance.

  9. Long-Term Deflection Prediction from Computer Vision-Measured Data History for High-Speed Railway Bridges.

    Science.gov (United States)

    Lee, Jaebeom; Lee, Kyoung-Chan; Lee, Young-Joo

    2018-05-09

    Management of the vertical long-term deflection of a high-speed railway bridge is a crucial factor to guarantee traffic safety and passenger comfort. Therefore, there have been efforts to predict the vertical deflection of a railway bridge based on physics-based models representing various influential factors to vertical deflection such as concrete creep and shrinkage. However, it is not an easy task because the vertical deflection of a railway bridge generally involves several sources of uncertainty. This paper proposes a probabilistic method that employs a Gaussian process to construct a model to predict the vertical deflection of a railway bridge based on actual vision-based measurement and temperature. To deal with the sources of uncertainty which may cause prediction errors, a Gaussian process is modeled with multiple kernels and hyperparameters. Once the hyperparameters are identified through the Gaussian process regression using training data, the proposed method provides a 95% prediction interval as well as a predictive mean about the vertical deflection of the bridge. The proposed method is applied to an arch bridge under operation for high-speed trains in South Korea. The analysis results obtained from the proposed method show good agreement with the actual measurement data on the vertical deflection of the example bridge, and the prediction results can be utilized for decision-making on railway bridge maintenance.

  10. Critical Vulnerability: Defending the Decisive Point of United States Computer Networked Information Systems

    National Research Council Canada - National Science Library

    Virden, Roy

    2003-01-01

    .... The military's use of computer networked information systems is thus a critical strength. These systems are then critical vulnerabilities because they may lack adequate protection and are open to enemy attack...

  11. Technical Data Management Center: a focal point for meteorological and other environmental transport computing technology

    International Nuclear Information System (INIS)

    McGill, B.; Maskewitz, B.F.; Trubey, D.K.

    1981-01-01

    The Technical Data Management Center, collecting, packaging, analyzing, and distributing information, computer technology and data which includes meteorological and other environmental transport work is located at the Oak Ridge National Laboratory, within the Engineering Physics Division. Major activities include maintaining a collection of computing technology and associated literature citations to provide capabilities for meteorological and environmental work. Details of the activities on behalf of TDMC's sponsoring agency, the US Nuclear Regulatory Commission, are described

  12. A method for computing the stationary points of a function subject to linear equality constraints

    International Nuclear Information System (INIS)

    Uko, U.L.

    1989-09-01

    We give a new method for the numerical calculation of stationary points of a function when it is subject to equality constraints. An application to the solution of linear equations is given, together with a numerical example. (author). 5 refs

  13. Three Boundary Conditions for Computing the Fixed-Point Property in Binary Mixture Data.

    Directory of Open Access Journals (Sweden)

    Leendert van Maanen

    Full Text Available The notion of "mixtures" has become pervasive in behavioral and cognitive sciences, due to the success of dual-process theories of cognition. However, providing support for such dual-process theories is not trivial, as it crucially requires properties in the data that are specific to mixture of cognitive processes. In theory, one such property could be the fixed-point property of binary mixture data, applied-for instance- to response times. In that case, the fixed-point property entails that response time distributions obtained in an experiment in which the mixture proportion is manipulated would have a common density point. In the current article, we discuss the application of the fixed-point property and identify three boundary conditions under which the fixed-point property will not be interpretable. In Boundary condition 1, a finding in support of the fixed-point will be mute because of a lack of difference between conditions. Boundary condition 2 refers to the case in which the extreme conditions are so different that a mixture may display bimodality. In this case, a mixture hypothesis is clearly supported, yet the fixed-point may not be found. In Boundary condition 3 the fixed-point may also not be present, yet a mixture might still exist but is occluded due to additional changes in behavior. Finding the fixed-property provides strong support for a dual-process account, yet the boundary conditions that we identify should be considered before making inferences about underlying psychological processes.

  14. Embedded active vision system based on an FPGA architecture

    OpenAIRE

    Chalimbaud , Pierre; Berry , François

    2006-01-01

    International audience; In computer vision and more particularly in vision processing, the impressive evolution of algorithms and the emergence of new techniques dramatically increase algorithm complexity. In this paper, a novel FPGA-based architecture dedicated to active vision (and more precisely early vision) is proposed. Active vision appears as an alternative approach to deal with artificial vision problems. The central idea is to take into account the perceptual aspects of visual tasks,...

  15. Exsanguination of turbot and the effect on fillet quality measured mechanically by sensory evaluation, and with computer vision

    NARCIS (Netherlands)

    Roth, B.; Schelvis-Smit, A.A.M.; Stien, L.H.; Foss, A.; Nortvedt, R.; Imsland, A.

    2007-01-01

    In order to investigate the impact of blood residues on the end quality of exsanguinated and unbled farmed turbot (Scophthalmus maximus), meat quality was evaluated using mechanical, sensory, and computer imaging techniques. The results show that exsanguination is important for improving the visual

  16. Bio-inspired vision

    International Nuclear Information System (INIS)

    Posch, C

    2012-01-01

    Nature still outperforms the most powerful computers in routine functions involving perception, sensing and actuation like vision, audition, and motion control, and is, most strikingly, orders of magnitude more energy-efficient than its artificial competitors. The reasons for the superior performance of biological systems are subject to diverse investigations, but it is clear that the form of hardware and the style of computation in nervous systems are fundamentally different from what is used in artificial synchronous information processing systems. Very generally speaking, biological neural systems rely on a large number of relatively simple, slow and unreliable processing elements and obtain performance and robustness from a massively parallel principle of operation and a high level of redundancy where the failure of single elements usually does not induce any observable system performance degradation. In the late 1980's, Carver Mead demonstrated that silicon VLSI technology can be employed in implementing ''neuromorphic'' circuits that mimic neural functions and fabricating building blocks that work like their biological role models. Neuromorphic systems, as the biological systems they model, are adaptive, fault-tolerant and scalable, and process information using energy-efficient, asynchronous, event-driven methods. In this paper, some basics of neuromorphic electronic engineering and its impact on recent developments in optical sensing and artificial vision are presented. It is demonstrated that bio-inspired vision systems have the potential to outperform conventional, frame-based vision acquisition and processing systems in many application fields and to establish new benchmarks in terms of redundancy suppression/data compression, dynamic range, temporal resolution and power efficiency to realize advanced functionality like 3D vision, object tracking, motor control, visual feedback loops, etc. in real-time. It is argued that future artificial vision systems

  17. Computer program to fit a hyperellipse to a set of phase-space points in as many as six dimensions

    International Nuclear Information System (INIS)

    Wadlinger, E.A.

    1980-03-01

    A computer program that will fit a hyperellipse to a set of phase-space points in as many as 6 dimensions was written and tested. The weight assigned to the phase-space points can be varied as a function of their distance from the centroid of the distribution. Varying the weight enables determination of whether there is a difference in ellipse orientation between inner and outer particles. This program should be useful in studying the effects of longitudinal and transverse phase-space couplings

  18. [Quality system Vision 2000].

    Science.gov (United States)

    Pasini, Evasio; Pitocchi, Oreste; de Luca, Italo; Ferrari, Roberto

    2002-12-01

    A recent document of the Italian Ministry of Health points out that all structures which provide services to the National Health System should implement a Quality System according to the ISO 9000 standards. Vision 2000 is the new version of the ISO standard. Vision 2000 is less bureaucratic than the old version. The specific requests of the Vision 2000 are: a) to identify, to monitor and to analyze the processes of the structure, b) to measure the results of the processes so as to ensure that they are effective, d) to implement actions necessary to achieve the planned results and the continual improvement of these processes, e) to identify customer requests and to measure customer satisfaction. Specific attention should be also dedicated to the competence and training of the personnel involved in the processes. The principles of the Vision 2000 agree with the principles of total quality management. The present article illustrates the Vision 2000 standard and provides practical examples of the implementation of this standard in cardiological departments.

  19. Neuropathies of the optic nerve and visual evoked potentials with special reference to color vision and differential light threshold measured with the computer perimeter OCTOPUS.

    Science.gov (United States)

    Wildberger, H

    1984-10-31

    The contrast evoked potentials (VEPs) to different check sizes were recorded in about 200 cases of discrete optic neuropathies (ON) of different origin. Differential light threshold (DLT) was tested with the computer perimeter OCTOPUS. Saturated and desaturated tests were applied to evaluate the degree of acquired color vision deficiency. Delayed VEP responses are not confined to optic neuritis (RBN) alone and the different latency times obtained from other ON are confluent. The delay may be due to demyelination, to an increasing dominance of paramacular VEP subcomponents or to an increasing dominance of the upper half-field responses. Recording with smaller check sizes has the advantage that discrete dysfunctions in the visual field (VF) center are more easily detected: a correlation between amplitudes and visual acuity is best in strabismic amblyopias, is less expressed in maculopathies of the retina and weak in ON. The absence or reduction of amplitudes to smaller check sizes, however, is an important indication of a disorder in the VF center of ON in an early or recovered stage. Acquired color vision defects of the tritan-like type are more confined to discrete ON, whereas the red/green type is reserved to more severe ON. The DLT of the VF center is reduced in a different, significant and non significant extent in discrete optic neuropathies and the correlation between DLT and visual acuity is weak. A careful numerical analysis is needed in types of discrete ON where the central DLT lies within normal statistical limits: a side difference of the DLT between the affected and the normal fellow eye is always present. Evaluation of visual fatigue effects and of the relative sensitivity loss of VF center and VF periphery may provide further diagnostic information.

  20. Non-destructive analysis of sensory traits of dry-cured loins by MRI-computer vision techniques and data mining.

    Science.gov (United States)

    Caballero, Daniel; Antequera, Teresa; Caro, Andrés; Ávila, María Del Mar; G Rodríguez, Pablo; Perez-Palacios, Trinidad

    2017-07-01

    Magnetic resonance imaging (MRI) combined with computer vision techniques have been proposed as an alternative or complementary technique to determine the quality parameters of food in a non-destructive way. The aim of this work was to analyze the sensory attributes of dry-cured loins using this technique. For that, different MRI acquisition sequences (spin echo, gradient echo and turbo 3D), algorithms for MRI analysis (GLCM, NGLDM, GLRLM and GLCM-NGLDM-GLRLM) and predictive data mining techniques (multiple linear regression and isotonic regression) were tested. The correlation coefficient (R) and mean absolute error (MAE) were used to validate the prediction results. The combination of spin echo, GLCM and isotonic regression produced the most accurate results. In addition, the MRI data from dry-cured loins seems to be more suitable than the data from fresh loins. The application of predictive data mining techniques on computational texture features from the MRI data of loins enables the determination of the sensory traits of dry-cured loins in a non-destructive way. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  1. Industrial vision

    DEFF Research Database (Denmark)

    Knudsen, Ole

    1998-01-01

    This dissertation is concerned with the introduction of vision-based application s in the ship building industry. The industrial research project is divided into a natural seq uence of developments, from basic theoretical projective image generation via CAD and subpixel analysis to a description...... is present ed, and the variability of the parameters is examined and described. The concept of using CAD together with vision information is based on the fact that all items processed at OSS have an associated complete 3D CAD model that is accessible at all production states. This concept gives numerous...... possibilities for using vision in applications which otherwise would be very difficult to automate. The requirement for low tolerances in production is, despite the huge dimensions of the items involved, extreme. This fact makes great demands on the ability to do robust sub pixel estimation. A new method based...

  2. A technical report on YGN-3 and 4 plant computer system I/O point summary

    International Nuclear Information System (INIS)

    Zee, Sung Kyun; Lee, Ki Bog; Song, Jae Woong; Lee, Chang Ho; Kim, Jae Hak

    1994-02-01

    This report contains the results of the operational data analysis for nuclear key parameters in Yonggwang 2 cycle 5. It is verified that that the predicted values not only coincide well with the measured values except the end point boron concentration but also satisfy the safety limits. A quantitative evaluation to understand the discrepancy in the measured and predicted end point boron compared with the values of similar plants. Through this review and comparison, it is verified that the nuclear design and the related safety evaluation are properly executed. This analysis provides a means of validating the current nuclear design methodology. (Author) 12 refs., 54 figs., 6 tabs

  3. A technical report on YGN-3 and 4 plant computer system I/O point summary

    Energy Technology Data Exchange (ETDEWEB)

    Zee, Sung Kyun; Lee, Ki Bog; Song, Jae Woong; Lee, Chang Ho; Kim, Jae Hak [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-02-01

    This report contains the results of the operational data analysis for nuclear key parameters in Yonggwang 2 cycle 5. It is verified that that the predicted values not only coincide well with the measured values except the end point boron concentration but also satisfy the safety limits. A quantitative evaluation to understand the discrepancy in the measured and predicted end point boron compared with the values of similar plants. Through this review and comparison, it is verified that the nuclear design and the related safety evaluation are properly executed. This analysis provides a means of validating the current nuclear design methodology. (Author) 12 refs., 54 figs., 6 tabs.

  4. On computation of C-stationary points for equilibrium problems with linear complementarity constraints via homotopy method

    Czech Academy of Sciences Publication Activity Database

    Červinka, Michal

    2010-01-01

    Roč. 2010, č. 4 (2010), s. 730-753 ISSN 0023-5954 Institutional research plan: CEZ:AV0Z10750506 Keywords : equilibrium problems with complementarity constraints * homotopy * C-stationarity Subject RIV: BC - Control Systems Theory Impact factor: 0.461, year: 2010 http://library.utia.cas.cz/separaty/2010/MTR/cervinka-on computation of c-stationary points for equilibrium problems with linear complementarity constraints via homotopy method.pdf

  5. Experiences of registered nurses with regard to accessing health information at the point-of-care via mobile computing devices

    Directory of Open Access Journals (Sweden)

    Esmeralda Ricks

    2015-11-01

    Full Text Available Background: The volume of health information necessary to provide competent health care today has become overwhelming. Mobile computing devices are fast becoming an essential clinical tool for accessing health information at the point-of-care of patients. Objectives: This study explored and described how registered nurses experienced accessing information at the point-of-care via mobile computing devices (MCDs. Method: A qualitative, exploratory, descriptive and contextual design was used. Ten in–depth interviews were conducted with purposively sampled registered nurses employed by a state hospital in the Nelson Mandela Bay Municipality (NMBM. Interviews were recorded, transcribed verbatim and analysed using Tesch’s data analysis technique. Ethical principles were adhered to throughout the study. Guba’s model of trustworthiness was used to confirm integrity of the study. Results: Four themes emerged which revealed that the registered nurses benefited from the training they received by enabling them to develop, and improve, their computer literacy levels. Emphasis was placed on the benefits that the accessed information had for educational purposes for patients and the public, for colleagues and students. Furthermore the ability to access information at the point-of-care was considered by registered nurses as valuable to improve patient care because of the wide range of accurate and readily accessible information available via the mobile computing device. Conclusion: The registered nurses in this study felt that being able to access information at the point-of-care increased their confidence and facilitated the provision of quality care because it assisted them in being accurate and sure of what they were doing.

  6. Assessment of methods for computing the closest point projection, penetration, and gap functions in contact searching problems

    Czech Academy of Sciences Publication Activity Database

    Kopačka, Ján; Gabriel, Dušan; Plešek, Jiří; Ulbin, M.

    2016-01-01

    Roč. 105, č. 11 (2016), s. 803-833 ISSN 0029-5981 R&D Projects: GA ČR(CZ) GAP101/12/2315; GA MŠk(CZ) ME10114 Institutional support: RVO:61388998 Keywords : closest point projection * local contact search * quadratic elements * Newtons methods * geometric iteration methods * simplex method Subject RIV: JC - Computer Hardware ; Software Impact factor: 2.162, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/nme.4994/abstract

  7. Point Cloud-Based Automatic Assessment of 3D Computer Animation Courseworks

    Science.gov (United States)

    Paravati, Gianluca; Lamberti, Fabrizio; Gatteschi, Valentina; Demartini, Claudio; Montuschi, Paolo

    2017-01-01

    Computer-supported assessment tools can bring significant benefits to both students and teachers. When integrated in traditional education workflows, they may help to reduce the time required to perform the evaluation and consolidate the perception of fairness of the overall process. When integrated within on-line intelligent tutoring systems,…

  8. Robust Seismic Normal Modes Computation in Radial Earth Models and A Novel Classification Based on Intersection Points of Waveguides

    Science.gov (United States)

    Ye, J.; Shi, J.; De Hoop, M. V.

    2017-12-01

    We develop a robust algorithm to compute seismic normal modes in a spherically symmetric, non-rotating Earth. A well-known problem is the cross-contamination of modes near "intersections" of dispersion curves for separate waveguides. Our novel computational approach completely avoids artificial degeneracies by guaranteeing orthonormality among the eigenfunctions. We extend Wiggins' and Buland's work, and reformulate the Sturm-Liouville problem as a generalized eigenvalue problem with the Rayleigh-Ritz Galerkin method. A special projection operator incorporating the gravity terms proposed by de Hoop and a displacement/pressure formulation are utilized in the fluid outer core to project out the essential spectrum. Moreover, the weak variational form enables us to achieve high accuracy across the solid-fluid boundary, especially for Stoneley modes, which have exponentially decaying behavior. We also employ the mixed finite element technique to avoid spurious pressure modes arising from discretization schemes and a numerical inf-sup test is performed following Bathe's work. In addition, the self-gravitation terms are reformulated to avoid computations outside the Earth, thanks to the domain decomposition technique. Our package enables us to study the physical properties of intersection points of waveguides. According to Okal's classification theory, the group velocities should be continuous within a branch of the same mode family. However, we have found that there will be a small "bump" near intersection points, which is consistent with Miropol'sky's observation. In fact, we can loosely regard Earth's surface and the CMB as independent waveguides. For those modes that are far from the intersection points, their eigenfunctions are localized in the corresponding waveguides. However, those that are close to intersection points will have physical features of both waveguides, which means they cannot be classified in either family. Our results improve on Okal

  9. Implementation of a direct procedure for critical point computations using preconditioned iterative solvers

    Czech Academy of Sciences Publication Activity Database

    Kouhia, R.; Tůma, Miroslav; Mäkinen, J.; Fedoroff, A.; Marjamäki, H.

    108-109, October (2012), s. 110-117 ISSN 0045-7949 R&D Projects: GA ČR(CZ) GAP108/11/0853 Institutional research plan: CEZ:AV0Z10300504 Keywords : non-linear eigenvalue problem * equilibrium equations * critical points * preconditioned iterations Subject RIV: BA - General Mathematics Impact factor: 1.509, year: 2012

  10. A simplified computer code based on point Kernel theory for calculating radiation dose in packages of radioactive material

    International Nuclear Information System (INIS)

    1986-03-01

    A study on radiation dose control in packages of radioactive waste from nuclear facilities, hospitals and industries, such as sources of Ra-226, Co-60, Ir-192 and Cs-137, is presented. The MAPA and MAPAM computer codes, based on point Kernel theory for calculating doses of several source-shielding type configurations, aiming to assure the safe transport conditions for these sources, was developed. The validation of the code for point sources, using the values provided by NCRP, for the thickness of lead and concrete shieldings, limiting the dose at 100 Mrem/hr for several distances from the source to the detector, was carried out. The validation for non point sources was carried out, measuring experimentally radiation dose from packages developed by Brazilian CNEN/S.P. for removing the sources. (M.C.K.) [pt

  11. Green Grape Detection and Picking-Point Calculation in a Night-Time Natural Environment Using a Charge-Coupled Device (CCD Vision Sensor with Artificial Illumination

    Directory of Open Access Journals (Sweden)

    Juntao Xiong

    2018-03-01

    Full Text Available Night-time fruit-picking technology is important to picking robots. This paper proposes a method of night-time detection and picking-point positioning for green grape-picking robots to solve the difficult problem of green grape detection and picking in night-time conditions with artificial lighting systems. Taking a representative green grape named Centennial Seedless as the research object, daytime and night-time grape images were captured by a custom-designed visual system. Detection was conducted employing the following steps: (1 The RGB (red, green and blue. Color model was determined for night-time green grape detection through analysis of color features of grape images under daytime natural light and night-time artificial lighting. The R component of the RGB color model was rotated and the image resolution was compressed; (2 The improved Chan–Vese (C–V level set model and morphological processing method were used to remove the background of the image, leaving out the grape fruit; (3 Based on the character of grape vertical suspension, combining the principle of the minimum circumscribed rectangle of fruit and the Hough straight line detection method, straight-line fitting for the fruit stem was conducted and the picking point was calculated using the stem with an angle of fitting line and vertical line less than 15°. The visual detection experiment results showed that the accuracy of grape fruit detection was 91.67% and the average running time of the proposed algorithm was 0.46 s. The picking-point calculation experiment results showed that the highest accuracy for the picking-point calculation was 92.5%, while the lowest was 80%. The results demonstrate that the proposed method of night-time green grape detection and picking-point calculation can provide technical support to the grape-picking robots.

  12. Agrarian Visions.

    Science.gov (United States)

    Theobald, Paul

    A new feature in "Country Teacher,""Agrarian Visions" reminds rural teachers that they can do something about rural decline. Like to populism of the 1890s, the "new populism" advocates rural living. Current attempts to address rural decline are contrary to agrarianism because: (1) telecommunications experts seek to…

  13. Fractured Visions

    DEFF Research Database (Denmark)

    Bonde, Inger Ellekilde

    2016-01-01

    In the post-war period a heterogeneous group of photographers articulate a new photographic approach to the city as motive in a photographic language that combines intense formalism with subjective vision. This paper analyses the photobook Fragments of a City published in 1960 by Danish photograp...

  14. Embodied Visions

    DEFF Research Database (Denmark)

    Grodal, Torben Kragh

    Embodied Visions presents a groundbreaking analysis of film through the lens of bioculturalism, revealing how human biology as well as human culture determine how films are made and experienced. Throughout the book the author uses the breakthroughs of modern brain science to explain general featu...

  15. Vision Screening

    Science.gov (United States)

    ... an efficient and cost-effective method to identify children with visual impairment or eye conditions that are likely to lead ... main goal of vision screening is to identify children who have or are at ... visual impairment unless treated in early childhood. Other problems that ...

  16. Concentrator optical characterization using computer mathematical modelling and point source testing

    Science.gov (United States)

    Dennison, E. W.; John, S. L.; Trentelman, G. F.

    1984-01-01

    The optical characteristics of a paraboloidal solar concentrator are analyzed using the intercept factor curve (a format for image data) to describe the results of a mathematical model and to represent reduced data from experimental testing. This procedure makes it possible not only to test an assembled concentrator, but also to evaluate single optical panels or to conduct non-solar tests of an assembled concentrator. The use of three-dimensional ray tracing computer programs to calculate the mathematical model is described. These ray tracing programs can include any type of optical configuration from simple paraboloids to array of spherical facets and can be adapted to microcomputers or larger computers, which can graphically display real-time comparison of calculated and measured data.

  17. A code to compute borehole fluid conductivity profiles with multiple feed points

    International Nuclear Information System (INIS)

    Hale, F.V.; Tsang, C.F.

    1988-03-01

    It is of much current interest to determine the flow characteristics of fractures intersecting a wellbore in order to understand the hydrologic behavior of fractured rocks. Often inflow from these fractures into the wellbore is at very low rates. A new procedure has been proposed and a corresponding method of analysis developed to obtain fracture inflow parameters from a time sequence of electric conductivity logs of the borehole fluid. The present report is a companion document to NTB--88-13 giving the details of equations and computer code used to compute borehole fluid conductivity distributions. Verification of the code used and a listing of the code are also given. (author) 9 refs., 5 figs., 7 tabs

  18. On the Computational Content of the Krasnoselski and Ishikawa Fixed Point Theorems

    DEFF Research Database (Denmark)

    Kohlenbach, Ulrich

    2001-01-01

    This paper is part of a case study in proof mining applied to non-effective proofs in nonlinear functional analysis. More specifically, we are concerned with the fixed point theory of nonexpansive selfmappings f of convex sets C in normed spaces. We study Krasnoselski and more general so-called K......This paper is part of a case study in proof mining applied to non-effective proofs in nonlinear functional analysis. More specifically, we are concerned with the fixed point theory of nonexpansive selfmappings f of convex sets C in normed spaces. We study Krasnoselski and more general so...... and Shafrir (1992) to unbounded sets C. Our explicit bounds also imply new qualitative results concerning the independence of the rate of asymptotic regularity from various data....

  19. Computing fixed points of nonexpansive mappings by $\\alpha$-dense curves

    Directory of Open Access Journals (Sweden)

    G. García

    2017-08-01

    Full Text Available Given a multivalued nonexpansive mapping defined on a convex and compact set of a Banach space, with values in the class of convex and compact subsets of its domain, we present an iteration scheme which (under suitable conditions converges to a fixed point of such mapping. This new iteration provides us another method to approximate the fixed points of a singlevalued nonexpansive mapping, defined on a compact and convex set into itself. Moreover, the conditions for the singlevalued case are less restrictive than for the multivalued case. Our main tool will be the so called $\\alpha$-dense curves, which will allow us to construct such iterations. Some numerical examples are provided to illustrate our results.

  20. Comparing the Floating Point Systems, Inc. AP-190L to representative scientific computers: some benchmark results

    International Nuclear Information System (INIS)

    Brengle, T.A.; Maron, N.

    1980-01-01

    Results are presented of comparative timing tests made by running a typical FORTRAN physics simulation code on the following machines: DEC PDP-10 with KI processor; DEC PDP-10, KI processor, and FPS AP-190L; CDC 7600; and CRAY-1. Factors such as DMA overhead, code size for the AP-190L, and the relative utilization of floating point functional units for the different machines are discussed. 1 table