WorldWideScience

Sample records for digital simulation

  1. Digital Simulation in the Geosciences

    Directory of Open Access Journals (Sweden)

    Alexandr A. Lobanov

    2014-09-01

    Full Text Available This article provides an analysis of methods for digital modeling in the area of Earth Sciences. The author illustrates the difference between digital modeling in radio communication and that in the area of Earth Sciences. The article examines the integration aspect of digital models, demonstrates the advantages of digital over analog models, and illustrates that digital models are discrete. The author outlines the characteristics of digital modeling and illustrates the logical structure of digital models.

  2. Digital simulation of power electronic systems

    International Nuclear Information System (INIS)

    Mehring, P.; Jentsch, W.; John, G.; Kraemer, D.

    1981-01-01

    The following paper contains the final report on the NETSIM-Project. The purpose of this project is to develop a special digital simulation system, which could serve as a base for routine application of simulation in planning and development of power electronic systems. The project is realized in two steps. First a basic network analysis system is established. With this system the basic models and methods in treating power electronic networks could be probed. The resulting system is then integrated into a general digital simulation system for continous systems (CSSL-System). This integrated simulation system allows for convenient modeling and simulation of power electronic systems. (orig.) [de

  3. Security Information System Digital Simulation

    OpenAIRE

    Tao Kuang; Shanhong Zhu

    2015-01-01

    The study built a simulation model for the study of food security information system relay protection. MATLAB-based simulation technology can support the analysis and design of food security information systems. As an example, the food security information system fault simulation, zero-sequence current protection simulation and transformer differential protection simulation are presented in this study. The case studies show that the simulation of food security information system relay protect...

  4. Digital Simulation Games for Social Studies Classrooms

    Science.gov (United States)

    Devlin-Scherer, Roberta; Sardone, Nancy B.

    2010-01-01

    Data from ten teacher candidates studying teaching methods were analyzed to determine perceptions toward digital simulation games in the area of social studies. This research can be used as a conceptual model of how current teacher candidates react to new methods of instruction and determine how education programs might change existing curricula…

  5. Ship maneuvering digital simulator; Simulador digital de manobras de navios

    Energy Technology Data Exchange (ETDEWEB)

    Souza Junior, Jesse Rebello; Tannuri, Eduardo Aoun; Oshiro, Anderson Takehiro [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Naval e Oceanica

    2008-07-01

    This paper reports on two case studies making use of a digital simulator to investigate the maneuvering motions of ships in canals with shallow and restricted waters. The first case study corresponds to a maneuvering analysis conducted for the Port of Rio Grande (RS - Brazil), whose aim was to assess the potential impact upon maneuvers of the presence of a large offshore platform (the PETROBRAS P-53) which is to remain docked for several months at the Port to complete its construction. The second study made use of the simulator to evaluate the maneuvering conditions along the approach route and maneuvering basin of the Port of Ponta do Felix (PR - Brazil). The simulator includes a complete mathematical model of the ship dynamics in the horizontal plane when subjected to wind and current forces. It also comprises detailed models for the action of thrusters and propellers, both fixed and azimuth, employed to control maneuvers and dynamically position ships, as well as rudders and tugboats. He models used by the simulator allow for the effects of shallow and restricted waters, including the increase in resistance and lateral forces, increase in additional mass and the appearance of lateral and vertical suction (squatting). The simulator is implemented via an interactive interface through which the user is able to apply control actions (rudder angle, main engine, thrusters and tugboats) in real time during maneuvers, thereby reproducing to some extent the action of a pilot. (author)

  6. Process simulation in digital camera system

    Science.gov (United States)

    Toadere, Florin

    2012-06-01

    The goal of this paper is to simulate the functionality of a digital camera system. The simulations cover the conversion from light to numerical signal and the color processing and rendering. We consider the image acquisition system to be linear shift invariant and axial. The light propagation is orthogonal to the system. We use a spectral image processing algorithm in order to simulate the radiometric properties of a digital camera. In the algorithm we take into consideration the transmittances of the: light source, lenses, filters and the quantum efficiency of a CMOS (complementary metal oxide semiconductor) sensor. The optical part is characterized by a multiple convolution between the different points spread functions of the optical components. We use a Cooke triplet, the aperture, the light fall off and the optical part of the CMOS sensor. The electrical part consists of the: Bayer sampling, interpolation, signal to noise ratio, dynamic range, analog to digital conversion and JPG compression. We reconstruct the noisy blurred image by blending different light exposed images in order to reduce the photon shot noise, also we filter the fixed pattern noise and we sharpen the image. Then we have the color processing blocks: white balancing, color correction, gamma correction, and conversion from XYZ color space to RGB color space. For the reproduction of color we use an OLED (organic light emitting diode) monitor. The analysis can be useful to assist students and engineers in image quality evaluation and imaging system design. Many other configurations of blocks can be used in our analysis.

  7. Simulation of Wireless Digital Communication Systems

    Directory of Open Access Journals (Sweden)

    A. Mohammed

    2004-12-01

    Full Text Available Due to the explosive demands for high speed wireless services, suchas wireless Internet, email and cellular video conferencing, digitalwireless communications has become one of the most exciting researchtopics in electrical and electronic engineering field. The never-endingdemand for such personal and multimedia services, however, demandstechnologies operating at higher data rates and broader bandwidths. Inaddition, the complexity of wireless communication and signalprocessing systems has grown considerably during the past decade.Therefore, powerful computer­aided techniques are required for theprocess of modeling, designing, analyzing and evaluating theperformance of digital wireless communication systems. In this paper wediscuss the basic propagation mechanisms affecting the performance ofwireless communication systems, and present a simple, powerful andefficient way to simulate digital wireless communication systems usingMatlab. The simulated results are compared with the theoreticalanalysis to validate the simulator. The simulator is useful inevaluating the performance of wireless multimedia services and theassociated signal processing structures and algorithms for current andnext generation wireless mobile communication systems.

  8. A generic digitization framework for the CDF simulation

    International Nuclear Information System (INIS)

    Kowalkowski, J.; Paterno, M.

    2001-01-01

    Digitization from GEANT tracking requires a predictable sequence of steps to produce raw simulated detector readout information. The authors have developed a software framework that simplifies the development and integration of digitizers by separating the coordination activities (sequencing and dispatching) from the actual digitization process. This separation allows the developers of digitizers to concentrate on digitization. The framework provides the sequencing infrastructure and a digitizer model, which means that all digitizers are required to follow the same sequencing rules and provide an interface that fits the model

  9. Atucha II nuclear power plant digital simulation

    International Nuclear Information System (INIS)

    Santome, D.; Rovere, L.A.T.

    1987-01-01

    This paper describes the start-up of a digital simulation code apt to be performed in real time of Atucha II nuclear power plant, foreseeing its subsequent usage in a Basic Principles Simulator. Adaptability and modification of existing routines and development of modules in order to incorporate the necessary variables dynamics to couple the different modes, were the main tasks. The mathematical model used allows the representation of the following sub-systems: a) a reactor's core point model, which comprehends the neutronic kinetics, fission and decaying powers, thermal transfer and Xe-poisoning calculation; b) pressurizer, which considers two sub-systems that may or may not be in thermodynamic equilibrium, both in two phases; c) coolants and moderators bonds considering separate moderator loops with the aim of introducing asymmetric perturbations; d) secondary sub-subsystem, which includes the feed water loop, pumps, steam generators and control valves; e) steam generators; f) control and safety systems, including power control, steam generators levels, moderator's temperature primary loop system, limitations and protection. (Author)

  10. Simulation study of pixel detector charge digitization

    Science.gov (United States)

    Wang, Fuyue; Nachman, Benjamin; Sciveres, Maurice; Lawrence Berkeley National Laboratory Team

    2017-01-01

    Reconstruction of tracks from nearly overlapping particles, called Tracking in Dense Environments (TIDE), is an increasingly important component of many physics analyses at the Large Hadron Collider as signatures involving highly boosted jets are investigated. TIDE makes use of the charge distribution inside a pixel cluster to resolve tracks that share one of more of their pixel detector hits. In practice, the pixel charge is discretized using the Time-over-Threshold (ToT) technique. More charge information is better for discrimination, but more challenging for designing and operating the detector. A model of the silicon pixels has been developed in order to study the impact of the precision of the digitized charge distribution on distinguishing multi-particle clusters. The output of the GEANT4-based simulation is used to train neutral networks that predict the multiplicity and location of particles depositing energy inside one cluster of pixels. By studying the multi-particle cluster identification efficiency and position resolution, we quantify the trade-off between the number of ToT bits and low-level tracking inputs. As both ATLAS and CMS are designing upgraded detectors, this work provides guidance for the pixel module designs to meet TIDE needs. Work funded by the China Scholarship Council and the Office of High Energy Physics of the U.S. Department of Energy under contract DE-AC02-05CH11231.

  11. MATLAB simulation for an experimental setup of digital feedback control

    International Nuclear Information System (INIS)

    Zheng Lifang; Liu Songqiang

    2005-01-01

    This paper describes the digital feedback simulation using MATLAB for an experimental accelerator control setup. By analyzing the plant characteristic in time-domain and frequency-domain, a guideline for design of digital filter and PID controller is derived. (authors)

  12. Digital Rock Simulation of Flow in Carbonate Samples

    Science.gov (United States)

    Klemin, D.; Andersen, M.

    2014-12-01

    Reservoir engineering has becomes more complex to deal with current challenges, so core analysts must understand and model pore geometries and fluid behaviors at pores scales more rapidly and realistically. We introduce an industry-unique direct hydrodynamic pore flow simulator that operates on pore geometries from digital rock models obtained using microCT or 3D scanning electron microscope (SEM) images. The PVT and rheological models used in the simulator represent real reservoir fluids. Fluid-solid interactions are introduced using distributed micro-scale wetting properties. The simulator uses density functional approach applied for hydrodynamics of complex systems. This talk covers selected applications of the simulator. We performed microCT scanning of six different carbonate rock samples from homogeneous limestones to vuggy carbonates. From these, we constructed digital rock models representing pore geometries for the simulator. We simulated nonreactive tracer flow in all six digital models using a digital fluid description that included a passive tracer solution. During the simulation, we evaluated the composition of the effluent. Results of tracer flow simulations corresponded well with experimental data of nonreactive tracer floods for the same carbonate rock types. This simulation data of the non-reactive tracer flow can be used to calculate the volume of the rock accessible by the fluid, which can be further used to predict response of a porous medium to a reactive fluid. The described digital core analysis workflow provides a basis for a wide variety of activities, including input to design acidizing jobs and evaluating treatment efficiency and EOR economics. Digital rock multiphase flow simulations of a scanned carbonate rock evaluated the effect of wettability on flow properties. Various wetting properties were tested: slightly oil wet, slightly water wet, and water wet. Steady-state relative permeability simulations yielded curves for all three

  13. Digitalization and networking of analog simulators and portal images

    Energy Technology Data Exchange (ETDEWEB)

    Pesznyak, C.; Zarand, P.; Mayer, A. [Uzsoki Hospital, Budapest (Hungary). Inst. of Oncoradiology

    2007-03-15

    Background: Many departments have analog simulators and irradiation facilities (especially cobalt units) without electronic portal imaging. Import of the images into the R and V (Record and Verify) system is required. Material and Methods: Simulator images are grabbed while portal films scanned by using a laser scanner and both converted into DICOM RT (Digital Imaging and Communications in Medicine Radiotherapy) images. Results: Image intensifier output of a simulator and portal films are converted to DICOM RT images and used in clinical practice. The simulator software was developed in cooperation at the authors' hospital. Conclusion: The digitalization of analog simulators is a valuable updating in clinical use replacing screen-film technique. Film scanning and digitalization permit the electronic archiving of films. Conversion into DICOM RT images is a precondition of importing to the R and V system. (orig.)

  14. Digitalization and networking of analog simulators and portal images.

    Science.gov (United States)

    Pesznyák, Csilla; Zaránd, Pál; Mayer, Arpád

    2007-03-01

    Many departments have analog simulators and irradiation facilities (especially cobalt units) without electronic portal imaging. Import of the images into the R&V (Record & Verify) system is required. Simulator images are grabbed while portal films scanned by using a laser scanner and both converted into DICOM RT (Digital Imaging and Communications in Medicine Radiotherapy) images. Image intensifier output of a simulator and portal films are converted to DICOM RT images and used in clinical practice. The simulator software was developed in cooperation at the authors' hospital. The digitalization of analog simulators is a valuable updating in clinical use replacing screen-film technique. Film scanning and digitalization permit the electronic archiving of films. Conversion into DICOM RT images is a precondition of importing to the R&V system.

  15. Computer Simulation and Digital Resources for Plastic Surgery Psychomotor Education.

    Science.gov (United States)

    Diaz-Siso, J Rodrigo; Plana, Natalie M; Stranix, John T; Cutting, Court B; McCarthy, Joseph G; Flores, Roberto L

    2016-10-01

    Contemporary plastic surgery residents are increasingly challenged to learn a greater number of complex surgical techniques within a limited period. Surgical simulation and digital education resources have the potential to address some limitations of the traditional training model, and have been shown to accelerate knowledge and skills acquisition. Although animal, cadaver, and bench models are widely used for skills and procedure-specific training, digital simulation has not been fully embraced within plastic surgery. Digital educational resources may play a future role in a multistage strategy for skills and procedures training. The authors present two virtual surgical simulators addressing procedural cognition for cleft repair and craniofacial surgery. Furthermore, the authors describe how partnerships among surgical educators, industry, and philanthropy can be a successful strategy for the development and maintenance of digital simulators and educational resources relevant to plastic surgery training. It is our responsibility as surgical educators not only to create these resources, but to demonstrate their utility for enhanced trainee knowledge and technical skills development. Currently available digital resources should be evaluated in partnership with plastic surgery educational societies to guide trainees and practitioners toward effective digital content.

  16. Digital Quantum Simulation of Spin Models with Circuit Quantum Electrodynamics

    Directory of Open Access Journals (Sweden)

    Y. Salathé

    2015-06-01

    Full Text Available Systems of interacting quantum spins show a rich spectrum of quantum phases and display interesting many-body dynamics. Computing characteristics of even small systems on conventional computers poses significant challenges. A quantum simulator has the potential to outperform standard computers in calculating the evolution of complex quantum systems. Here, we perform a digital quantum simulation of the paradigmatic Heisenberg and Ising interacting spin models using a two transmon-qubit circuit quantum electrodynamics setup. We make use of the exchange interaction naturally present in the simulator to construct a digital decomposition of the model-specific evolution and extract its full dynamics. This approach is universal and efficient, employing only resources that are polynomial in the number of spins, and indicates a path towards the controlled simulation of general spin dynamics in superconducting qubit platforms.

  17. Digital Quantum Simulation of Spin Models with Circuit Quantum Electrodynamics

    OpenAIRE

    Salathé, Y.; Mondal, M.; Oppliger, M.; Heinsoo, J.; Kurpiers, P.; Potočnik, A.; Mezzacapo, Antonio; Las Heras García, Urtzi; Lamata Manuel, Lucas; Solano Villanueva, Enrique Leónidas; Filipp, S.; Wallraff, A.

    2015-01-01

    Systems of interacting quantum spins show a rich spectrum of quantum phases and display interesting many-body dynamics. Computing characteristics of even small systems on conventional computers poses significant challenges. A quantum simulator has the potential to outperform standard computers in calculating the evolution of complex quantum systems. Here, we perform a digital quantum simulation of the paradigmatic Heisenberg and Ising interacting spin models using a two transmon-qubit circuit...

  18. Digital Simulation-Based Training: A Meta-Analysis

    Science.gov (United States)

    Gegenfurtner, Andreas; Quesada-Pallarès, Carla; Knogler, Maximilian

    2014-01-01

    This study examines how design characteristics in digital simulation-based learning environments moderate self-efficacy and transfer of learning. Drawing on social cognitive theory and the cognitive theory of multimedia learning, the meta-analysis psychometrically cumulated k?=?15 studies of 25 years of research with a total sample size of…

  19. Advanced distributed simulation technology: Digital Voice Gateway Reference Guide

    Science.gov (United States)

    Vanhook, Dan; Stadler, Ed

    1994-01-01

    The Digital Voice Gateway (referred to as the 'DVG' in this document) transmits and receives four full duplex encoded speech channels over the Ethernet. The information in this document applies only to DVG's running firmware of the version listed on the title page. This document, previously named Digital Voice Gateway Reference Guide, BBN Systems and Technologies Corporation, Cambridge, MA 02138, was revised for revision 2.00. This new revision changes the network protocol used by the DVG, to comply with the SINCGARS radio simulation (For SIMNET 6.6.1). Because of the extensive changes to revision 2.00 a separate document was created rather than supplying change pages.

  20. SIMULACIÓN DE CONTROLADORES DIGITALES SIMULATION OF DIGITAL CONTROLLERS

    Directory of Open Access Journals (Sweden)

    Carlos Álvarez G

    2009-12-01

    Full Text Available El presente trabajo tiene como objetivo la implementación de controladores digitales en un entorno de simulación controlado, para esto se desarrolla una plataforma de hardware que permite ejecutar los programas en lenguaje C generados en una estación de trabajo. Estos programas corresponden al controlador y a la planta que son generados por un software que genera dichos programas a partir de sus parámetros de modelación aplicando teoría de control digital sobre procesos reales.This paper describes an implementation of digital controllers in a simulation environment for including a hardware platform for running programs generated on a workstation. These programs for both the controller and the plant are generated by software based on parameters using digital control theory for real processes.

  1. Digital simulation of anodic stripping voltammetry from thin film electrodes

    International Nuclear Information System (INIS)

    Magallanes, J.F.

    1984-01-01

    The anodic stripping voltammetry (ASV) is routinely applied to control of Cu(II) in heavy water in the primary cooling loop of the Nuclear Power Reactor. The anodic stripping voltammetry (ASV) is a very well-known technique in electroanalytical chemistry. However, due to the complexity of the phenomena, it is practised with the fundamentals of empiric considerations. A geometric model for the anodic stripping voltammetry (ASV) from thin film electrodes which can be calculated by explicit digital simulation method is proposed as a possibility of solving the electrochemically reversible, cuasi-reversible and irreversible reactions under linear potential scan and multiple potential scans. (Until now the analytical mathematical method was applied to reversible reactions). All the results are compared with analytical solutions and experimental results and it permits to conclude that the anodic stripping voltammetry (ASV) can be studied with the simplicity and potentialities of explicit digital simulation methods. (M.E.L.) [es

  2. Comparison of piping models for digital power plant simulators

    International Nuclear Information System (INIS)

    Sowers, G.W.

    1979-08-01

    Two piping models intended for use in a digital power plant simulator are compared. One is a finite difference approximation to the partial differential equation called PIPE, and the other is a function subroutine that acts as a delay operator called PDELAY. The two models are compared with respect to accuracy and execution time. In addition, the stability of the PIPE model is determined. The PDELAY model is found to execute faster than the PIPE model with comparable accuracy

  3. DIGITAL SIMULATIONS FOR IMPROVING EDUCATION: Learning Through Artificial Teaching Environments

    OpenAIRE

    Reviewed by Özlem OZAN

    2009-01-01

    DIGITAL SIMULATIONS FOR IMPROVING EDUCATION:Learning Through Artificial Teaching EnvironmentsGibson, David, Ed.D.; Information Science Reference, Hershey, PA,SBN-10: 1605663239, ISBN-13: 9781605663234, p.514 Jan 2009Reviewed byÖzlem OZANFaculty of Education, Eskişehir Osmangazi University,Eskisehir-TURKEYSimulations in education, both for children and adults,become popular with the development of computer technology, because they are fun and engaging and allow learners to internalize knowledg...

  4. Digital control computer upgrade at the Cernavoda NPP simulator

    International Nuclear Information System (INIS)

    Ionescu, T.

    2006-01-01

    The Plant Process Computer equips some Nuclear Power Plants, like CANDU-600, with Centralized Control performed by an assembly of two computers known as Digital Control Computers (DCC) and working in parallel for safely driving of the plan at steady state and during normal maneuvers but also during abnormal transients when the plant is automatically steered to a safe state. The Centralized Control means both hardware and software with obligatory presence in the frame of the Full Scope Simulator and subject to changing its configuration with specific requirements during the plant and simulator life and covered by this subsection

  5. D Digital Simulation of Minnan Temple Architecture CAISSON'S Craft Techniques

    Science.gov (United States)

    Lin, Y. C.; Wu, T. C.; Hsu, M. F.

    2013-07-01

    Caisson is one of the important representations of the Minnan (southern Fujian) temple architecture craft techniques and decorative aesthetics. The special component design and group building method present the architectural thinking and personal characteristics of great carpenters of Minnan temple architecture. In late Qing Dynasty, the appearance and style of caissons of famous temples in Taiwan apparently presented the building techniques of the great carpenters. However, as the years went by, the caisson design and craft techniques were not fully inherited, which has been a great loss of cultural assets. Accordingly, with the caisson of Fulong temple, a work by the well-known great carpenter in Tainan as an example, this study obtained the thinking principles of the original design and the design method at initial period of construction through interview records and the step of redrawing the "Tng-Ko" (traditional design, stakeout and construction tool). We obtained the 3D point cloud model of the caisson of Fulong temple using 3D laser scanning technology, and established the 3D digital model of each component of the caisson. Based on the caisson component procedure obtained from interview records, this study conducted the digital simulation of the caisson component to completely recode and present the caisson design, construction and completion procedure. This model of preserving the craft techniques for Minnan temple caisson by using digital technology makes specific contribution to the heritage of the craft techniques while providing an important reference for the digital preservation of human cultural assets.

  6. Method of simulating dose reduction for digital radiographic systems

    International Nuclear Information System (INIS)

    Baath, M.; Haakansson, M.; Tingberg, A.; Maansson, L. G.

    2005-01-01

    The optimisation of image quality vs. radiation dose is an important task in medical imaging. To obtain maximum validity of the optimisation, it must be based on clinical images. Images at different dose levels can then either be obtained by collecting patient images at the different dose levels sought to investigate - including additional exposures and permission from an ethical committee - or by manipulating images to simulate different dose levels. The aim of the present work was to develop a method of simulating dose reduction for digital radiographic systems. The method uses information about the detective quantum efficiency and noise power spectrum at the original and simulated dose levels to create an image containing filtered noise. When added to the original image this results in an image with noise which, in terms of frequency content, agrees with the noise present in an image collected at the simulated dose level. To increase the validity, the method takes local dose variations in the original image into account. The method was tested on a computed radiography system and was shown to produce images with noise behaviour similar to that of images actually collected at the simulated dose levels. The method can, therefore, be used to modify an image collected at one dose level so that it simulates an image of the same object collected at any lower dose level. (authors)

  7. Application of the PRBS/FFT technique to digital simulations

    International Nuclear Information System (INIS)

    Hinds, H.W.

    1977-01-01

    This paper describes a method for obtaining a small-signal frequency response from a digital dynamic simulation. It employs a modified form of the PRBS/FFT technique, whereby a system is perturbed by a pseudo-random binary sequence and its response is analyzed using a fast Fourier transform-based program. Two applications of the technique are described; one involves a set of two coupled, second-order, ordinary differential equations; the other is a set of non-linear partial differential equations describing the thermohydraulic behaviour of water boiling in a fuel channel. (author)

  8. Research methods of simulate digital compensators and autonomous control systems

    Directory of Open Access Journals (Sweden)

    V. S. Kudryashov

    2016-01-01

    Full Text Available The peculiarity of the present stage of development of the production is the need to control and regulate a large number of process parameters, the mutual influence on each other that when using single-circuit systems significantly reduces the quality of the transition process, resulting in significant costs of raw materials and energy, reduce the quality of the products. Using a stand-alone digital control system eliminates the correlation of technological parameters, to give the system the desired dynamic and static properties, improve the quality of regulation. However, the complexity of the configuration and implementation of procedures (modeling compensators autonomous systems of this type, associated with the need to perform a significant amount of complex analytic transformation significantly limit the scope of their application. In this regard, the approach based on the decompo sition proposed methods of calculation and simulation (realization, consisting in submitting elements autonomous control part digital control system in a series parallel connection. The above theoretical study carried out in a general way for any dimension systems. The results of computational experiments, obtained during the simulation of the four autonomous control systems, comparative analysis and conclusions on the effectiveness of the use of each of the methods. The results obtained can be used in the development of multi-dimensional process control systems.

  9. U(1) Wilson lattice gauge theories in digital quantum simulators

    Science.gov (United States)

    Muschik, Christine; Heyl, Markus; Martinez, Esteban; Monz, Thomas; Schindler, Philipp; Vogell, Berit; Dalmonte, Marcello; Hauke, Philipp; Blatt, Rainer; Zoller, Peter

    2017-10-01

    Lattice gauge theories describe fundamental phenomena in nature, but calculating their real-time dynamics on classical computers is notoriously difficult. In a recent publication (Martinez et al 2016 Nature 534 516), we proposed and experimentally demonstrated a digital quantum simulation of the paradigmatic Schwinger model, a U(1)-Wilson lattice gauge theory describing the interplay between fermionic matter and gauge bosons. Here, we provide a detailed theoretical analysis of the performance and the potential of this protocol. Our strategy is based on analytically integrating out the gauge bosons, which preserves exact gauge invariance but results in complicated long-range interactions between the matter fields. Trapped-ion platforms are naturally suited to implementing these interactions, allowing for an efficient quantum simulation of the model, with a number of gate operations that scales polynomially with system size. Employing numerical simulations, we illustrate that relevant phenomena can be observed in larger experimental systems, using as an example the production of particle-antiparticle pairs after a quantum quench. We investigate theoretically the robustness of the scheme towards generic error sources, and show that near-future experiments can reach regimes where finite-size effects are insignificant. We also discuss the challenges in quantum simulating the continuum limit of the theory. Using our scheme, fundamental phenomena of lattice gauge theories can be probed using a broad set of experimentally accessible observables, including the entanglement entropy and the vacuum persistence amplitude.

  10. Dynamic simulation of hvdc transmission systems on digital computers

    Energy Technology Data Exchange (ETDEWEB)

    Hingorani, N G; Hay, J L; Crosbie, R E

    1966-05-01

    A digital computer technique is based on the fact that the operation of an hvdc converter consists of similar consecutive processes, each process having features which are common to all processes. Each bridge converter of an hvdc system is represented by a central process, and repetitive use of the latter simulates continuous converter operation. This technique may be employed to obtain the waveforms of transient or steady state voltages and currents anywhere in the dc system. To illustrate the method, an hvdc link is considered; the link which connects two independent ac systems conprises two converters with their control systems, and a dc transmission line. As an example, the transient behavior of the system is examined following changes in the current settings of the control system.

  11. Digital simulation of an enrichment process for solutions by means of an advection-diffusion chamber

    International Nuclear Information System (INIS)

    Artucio, G.; Suarez, R.; Uruguay Catholic University)

    1995-01-01

    An ab-initio digital simulation of the space-time dynamics of the concentration field of a solute in an advection-diffusion chamber is done. Some questions related to the digital simulation of the concentration field using the analytical solution obtained in a previous paper are discussed

  12. How processing digital elevation models can affect simulated water budgets

    Science.gov (United States)

    Kuniansky, E.L.; Lowery, M.A.; Campbell, B.G.

    2009-01-01

    For regional models, the shallow water table surface is often used as a source/sink boundary condition, as model grid scale precludes simulation of the water table aquifer. This approach is appropriate when the water table surface is relatively stationary. Since water table surface maps are not readily available, the elevation of the water table used in model cells is estimated via a two-step process. First, a regression equation is developed using existing land and water table elevations from wells in the area. This equation is then used to predict the water table surface for each model cell using land surface elevation available from digital elevation models (DEM). Two methods of processing DEM for estimating the land surface for each cell are commonly used (value nearest the cell centroid or mean value in the cell). This article demonstrates how these two methods of DEM processing can affect the simulated water budget. For the example presented, approximately 20% more total flow through the aquifer system is simulated if the centroid value rather than the mean value is used. This is due to the one-third greater average ground water gradients associated with the centroid value than the mean value. The results will vary depending on the particular model area topography and cell size. The use of the mean DEM value in each model cell will result in a more conservative water budget and is more appropriate because the model cell water table value should be representative of the entire cell area, not the centroid of the model cell.

  13. On the simulation of transients and accidents in PWRs with digital instrumentation and control using an LQR digital controller

    International Nuclear Information System (INIS)

    Alvarenga, M.A.B.; Melo, P.F. Frutuoso e; Medeiros, J.A.C.C.; Oliva, J.J. Rivero

    2015-01-01

    New nuclear power plant designs are including integrated I and C digital systems for protection, control, alarming and monitoring. Existing operating nuclear power plants, as is the case of Angra 1 nuclear power plant, have to consider the replacement of their I and C analog systems by digital systems for retrofitting their facilities. However, before replacing the analog control loops by digital ones it is necessary to design and evaluate their performance, which requires modeling of the plant and its control system with extensive simulations under several normal and abnormal operation conditions. This paper discusses the use of a linear quadratic regulator (LQR) digital controller for evaluating the plant stability behavior before the actuation of the reactor protection system. The objective is to evaluate the effect of digital controllers on plant behavior for several transients and accident conditions. For this purpose, a numerical model was developed and implemented as a MatlabTM tool. This paper discusses an adequate framework in order to simulate a set of transients and accidents that constitute the design basis in the final safety analysis report of PWR power plants to evaluate the performance of digital controllers such as LQR regulators.(author)

  14. A short introduction to digital simulations in electrochemistry: simulating the Cottrell experiment in NI LabVIEW

    Directory of Open Access Journals (Sweden)

    Soma Vesztergom

    2018-05-01

    Full Text Available A brief introduction to the use of digital simulations in electrochemistry is given by a detailed description of the simulation of Cottrell’s experiment in the LabVIEW programming language. A step-by-step approach is followed and different simulation techniques (explicit and implicit Euler, Runge–Kutta and Crank–Nicolson methods are applied. The applied techniques are introduced and discussed on the basis of Padé approximants. The paper might be found useful by undergraduate and graduate students familiarizing themselves with the digital simulation of electrochemical problems, as well as by university lecturers involved with the teaching of theoretical electrochemistry.

  15. Digital I and C system pre-tests using plant specific simulators

    International Nuclear Information System (INIS)

    Holl, B.; Probst, H.; Wischert, W.

    2006-01-01

    The paper focuses on strategic aspects of the implementation of modern digital instrumentation and control system (I and C) in nuclear power plant (NPP) training simulators and points out the way to identify the most appropriate implementation method of the digital I and C system in the simulator development environment which fulfils the requirement imposed by the nuclear power plants. This regards mainly training aspects, simulator as a test bed for design verification and validation (V and V), and software maintenance aspects with respect to future evolutions of the digital I and C system. (author)

  16. The establishment of Digital Image Capture System(DICS) using conventional simulator

    International Nuclear Information System (INIS)

    Oh, Tae Sung; Park, Jong Il; Byun, Young Sik; Shin, Hyun Kyoh

    2004-01-01

    The simulator is used to determine patient field and ensure the treatment field, which encompasses the required anatomy during patient normal movement such as during breathing. The latest simulator provide real time display of still, fluoroscopic and digitalized image, but conventional simulator is not yet. The purpose of this study is to introduce digital image capture system(DICS) using conventional simulator and clinical case using digital captured still and fluoroscopic image. We connect the video signal cable to the video terminal in the back up of simulator monitor, and connect the video jack to the A/D converter. After connection between the converter jack and computer, We can acquire still image and record fluoroscopic image with operating image capture program. The data created with this system can be used in patient treatment, and modified for verification by using image processing software. (j.e. photoshop, paintshop) DICS was able to establish easy and economical procedure. DCIS image was helpful for simulation. DICS imaging was powerful tool in the evaluation of the department specific patient positioning. Because the commercialized simulator based of digital capture is very expensive, it is not easily to establish DICS simulator in the most hospital. DICS using conventional simulator enable to utilize the practical use of image equal to high cost digitalized simulator and to research many clinical cases in case of using other software program.

  17. Development of the FIFI digital simulation language and an up-to-date users guide

    International Nuclear Information System (INIS)

    Hopkinson, A.

    1976-03-01

    The report describes some recent improvements to the FIFI digital simulation language following its conversion to FORTRAN IV for use on ICL 4-70 computers and including a stand alone guide for users. (author)

  18. [Precision of digital impressions with TRIOS under simulated intraoral impression taking conditions].

    Science.gov (United States)

    Yang, Xin; Sun, Yi-fei; Tian, Lei; Si, Wen-jie; Feng, Hai-lan; Liu, Yi-hong

    2015-02-18

    To evaluate the precision of digital impressions taken under simulated clinical impression taking conditions with TRIOS and to compare with the precision of extraoral digitalizations. Six #14-#17 epoxy resin dentitions with extracted #16 tooth preparations embedded were made. For each artificial dentition, (1)a silicone rubber impression was taken with individual tray, poured with type IV plaster,and digitalized with 3Shape D700 model scanner for 10 times; (2) fastened to a dental simulator, 10 digital impressions for each were taken with 3Shape TRIOS intraoral scanner. To assess the precision, best-fit algorithm and 3D comparison were conducted between repeated scan models pairwise by Geomagic Qualify 12.0, exported as averaged errors (AE) and color-coded diagrams. Non-parametric analysis was performed to compare the precisions of digital impressions and model images. The color-coded diagrams were used to show the deviations distributions. The mean of AE for digital impressions was 7.058 281 μm, which was greater than that of 4.092 363 μm for the model images (Pimpressions were no more than 10 μm, which meant that the consistency between the digital impressions was good. The deviations distribution was uniform in the model images,while nonuniform in the digital impressions with greater deviations lay mainly around the shoulders and interproximal surfaces. Digital impressions with TRIOS are of good precision and up to the clinical standard. Shoulders and interproximal surfaces scanning are more difficult.

  19. Signal-to-noise ratio estimation in digital computer simulation of lowpass and bandpass systems with applications to analog and digital communications, volume 3

    Science.gov (United States)

    Tranter, W. H.; Turner, M. D.

    1977-01-01

    Techniques are developed to estimate power gain, delay, signal-to-noise ratio, and mean square error in digital computer simulations of lowpass and bandpass systems. The techniques are applied to analog and digital communications. The signal-to-noise ratio estimates are shown to be maximum likelihood estimates in additive white Gaussian noise. The methods are seen to be especially useful for digital communication systems where the mapping from the signal-to-noise ratio to the error probability can be obtained. Simulation results show the techniques developed to be accurate and quite versatile in evaluating the performance of many systems through digital computer simulation.

  20. Simulation and Digitization of a Gas Electron Multiplier Detector Using Geant4 and an Object-Oriented Digitization Program

    Science.gov (United States)

    McMullen, Timothy; Liyanage, Nilanga; Xiong, Weizhi; Zhao, Zhiwen

    2017-01-01

    Our research has focused on simulating the response of a Gas Electron Multiplier (GEM) detector using computational methods. GEM detectors provide a cost effective solution for radiation detection in high rate environments. A detailed simulation of GEM detector response to radiation is essential for the successful adaption of these detectors to different applications. Using Geant4 Monte Carlo (GEMC), a wrapper around Geant4 which has been successfully used to simulate the Solenoidal Large Intensity Device (SoLID) at Jefferson Lab, we are developing a simulation of a GEM chamber similar to the detectors currently used in our lab. We are also refining an object-oriented digitization program, which translates energy deposition information from GEMC into electronic readout which resembles the readout from our physical detectors. We have run the simulation with beta particles produced by the simulated decay of a 90Sr source, as well as with a simulated bremsstrahlung spectrum. Comparing the simulation data with real GEM data taken under similar conditions is used to refine the simulation parameters. Comparisons between results from the simulations and results from detector tests will be presented.

  1. A methodology to simulate the cutting process for a nuclear dismantling simulation based on a digital manufacturing platform

    International Nuclear Information System (INIS)

    Hyun, Dongjun; Kim, Ikjune; Lee, Jonghwan; Kim, Geun-Ho; Jeong, Kwan-Seong; Choi, Byung Seon; Moon, Jeikwon

    2017-01-01

    Highlights: • Goal is to provide existing tech. with cutting function handling dismantling process. • Proposed tech. can handle various cutting situations in the dismantlement activities. • Proposed tech. can be implemented in existing graphical process simulation software. • Simulation results have demonstrated that the proposed technology achieves its goal. • Proposed tech. enlarges application of graphic simulation into dismantlement activity. - Abstract: This study proposes a methodology to simulate the cutting process in a digital manufacturing platform for the flexible planning of nuclear facility decommissioning. During the planning phase of decommissioning, visualization and verification using process simulation can be powerful tools for the flexible planning of the dismantling process of highly radioactive, large and complex nuclear facilities. However, existing research and commercial solutions are not sufficient for such a situation because complete segmented digital models for the dismantling objects such as the reactor vessel, internal assembly, and closure head must be prepared before the process simulation. The preparation work has significantly impeded the broad application of process simulation due to the complexity and workload. The methodology of process simulation proposed in this paper can flexibly handle various dismantling processes including repetitive object cuttings over heavy and complex structures using a digital manufacturing platform. The proposed methodology, which is applied to dismantling scenarios of a Korean nuclear power plant in this paper, is expected to reduce the complexity and workload of nuclear dismantling simulations.

  2. SIDAS - a block-diagram programming system for the interactive digital simulation of dynamic systems

    International Nuclear Information System (INIS)

    Moll, H.; Burkhardt, H.

    1978-01-01

    The paper describes a block-oriented digital simulation system. Some applications clarify the basic structure and operation. The main features of the system are: Easy handling and manipulation through interactive graphical input/output, operational flexibility through successive simulation runs and online modification of parameters, direct access to all facilities of a medium-sized computing system. (orig.) [de

  3. Methodology for digital radiography simulation using the Monte Carlo code MCNPX for industrial applications

    International Nuclear Information System (INIS)

    Souza, E.M.; Correa, S.C.A.; Silva, A.X.; Lopes, R.T.; Oliveira, D.F.

    2008-01-01

    This work presents a methodology for digital radiography simulation for industrial applications using the MCNPX radiography tally. In order to perform the simulation, the energy-dependent response of a BaFBr imaging plate detector was modeled and introduced in the MCNPX radiography tally input. In addition, a post-processing program was used to convert the MCNPX radiography tally output into 16-bit digital images. Simulated and experimental images of a steel pipe containing corrosion alveoli and stress corrosion cracking were compared, and the results showed good agreement between both images

  4. Digitization

    DEFF Research Database (Denmark)

    Finnemann, Niels Ole

    2014-01-01

    what a concept of digital media might add to the understanding of processes of mediatization and what the concept of mediatization might add to the understanding of digital media. It is argued that digital media open an array of new trajectories in human communication, trajectories which were...

  5. Digital Quantum Simulation of Z2 Lattice Gauge Theories with Dynamical Fermionic Matter

    Science.gov (United States)

    Zohar, Erez; Farace, Alessandro; Reznik, Benni; Cirac, J. Ignacio

    2017-02-01

    We propose a scheme for digital quantum simulation of lattice gauge theories with dynamical fermions. Using a layered optical lattice with ancilla atoms that can move and interact with the other atoms (simulating the physical degrees of freedom), we obtain a stroboscopic dynamics which yields the four-body plaquette interactions, arising in models with (2 +1 ) and higher dimensions, without the use of perturbation theory. As an example we show how to simulate a Z2 model in (2 +1 ) dimensions.

  6. Method for simulating dose reduction in digital mammography using the Anscombe transformation

    OpenAIRE

    Borges, Lucas R.; de Oliveira, Helder C. R.; Nunes, Polyana F.; Bakic, Predrag R.; Maidment, Andrew D. A.; Vieira, Marcelo A. C.

    2016-01-01

    Purpose: This work proposes an accurate method for simulating dose reduction in digital mammography starting from a clinical image acquired with a standard dose. Methods: The method developed in this work consists of scaling a mammogram acquired at the standard radiation dose and adding signal-dependent noise. The algorithm accounts for specific issues relevant in digital mammography images, such as anisotropic noise, spatial variations in pixel gain, and the effect of dose reduction on the d...

  7. Noise-shaping all-digital phase-locked loops modeling, simulation, analysis and design

    CERN Document Server

    Brandonisio, Francesco

    2014-01-01

    This book presents a novel approach to the analysis and design of all-digital phase-locked loops (ADPLLs), technology widely used in wireless communication devices. The authors provide an overview of ADPLL architectures, time-to-digital converters (TDCs) and noise shaping. Realistic examples illustrate how to analyze and simulate phase noise in the presence of sigma-delta modulation and time-to-digital conversion. Readers will gain a deep understanding of ADPLLs and the central role played by noise-shaping. A range of ADPLL and TDC architectures are presented in unified manner. Analytical and simulation tools are discussed in detail. Matlab code is included that can be reused to design, simulate and analyze the ADPLL architectures that are presented in the book.   • Discusses in detail a wide range of all-digital phase-locked loops architectures; • Presents a unified framework in which to model time-to-digital converters for ADPLLs; • Explains a procedure to predict and simulate phase noise in oscil...

  8. Quantitative evaluation of fault coverage for digitalized systems in NPPs using simulated fault injection method

    International Nuclear Information System (INIS)

    Kim, Suk Joon

    2004-02-01

    Even though digital systems have numerous advantages such as precise processing of data, enhanced calculation capability over the conventional analog systems, there is a strong restriction on the application of digital systems to the safety systems in nuclear power plants (NPPs). This is because we do not fully understand the reliability of digital systems, and therefore we cannot guarantee the safety of digital systems. But, as the need for introduction of digital systems to safety systems in NPPs increasing, the need for the quantitative analysis on the safety of digital systems is also increasing. NPPs, which are quite conservative in terms of safety, require proving the reliability of digital systems when applied them to the NPPs. Moreover, digital systems which are applied to the NPPs are required to increase the overall safety of NPPs. however, it is very difficult to evaluate the reliability of digital systems because they include the complex fault processing mechanisms at various levels of the systems. Software is another obstacle in reliability assessment of the systems that requires ultra-high reliability. In this work, the fault detection coverage for the digital system is evaluated using simulated fault injection method. The target system is the Local Coincidence Logic (LCL) processor in Digital Plant Protection System (DPPS). However, as the LCL processor is difficult to design equally for evaluating the fault detection coverage, the LCL system has to be simplified. The simulations for evaluating the fault detection coverage of components are performed by dividing into two cases and the failure rates of components are evaluated using MIL-HDBK-217F. Using these results, the fault detection coverage of simplified LCL system is evaluated. In the experiments, heartbeat signals were just emitted at regular interval after executing logic without self-checking algorithm. When faults are injected into the simplified system, fault occurrence can be detected by

  9. Digital filter algorithm study and simulation of SSRF feedback system

    International Nuclear Information System (INIS)

    Han Lifeng; Yuan Renxian; Ye Kairong

    2008-01-01

    Least Square Fitting was used to design a FIR filter of the transverse feedback system for the Shanghai Synchrotron Radiation Facility (SSRF). The algorithm helped us to set appropriate gain and phase at special frequency points. This reduced the power needed for damping the beam oscillations, which was proved by System View signal simulation. And with AT (Accelerator Tool) simulation, the Gain calculation and settings to the output signals from the FIR filter were deduced. The relationship between the Kicker power and the system damping time was also given. (authors)

  10. Sustainability Enhancement of a Turbine Vane Manufacturing Cell through Digital Simulation-Based Design

    Directory of Open Access Journals (Sweden)

    Alessandra Caggiano

    2016-09-01

    Full Text Available Modern manufacturing systems should satisfy emerging needs related to sustainable development. The design of sustainable manufacturing systems can be valuably supported by simulation, traditionally employed mainly for time and cost reduction. In this paper, a multi-purpose digital simulation approach is proposed to deal with sustainable manufacturing systems design through Discrete Event Simulation (DES and 3D digital human modelling. DES models integrated with data on power consumption of the manufacturing equipment are utilized to simulate different scenarios with the aim to improve productivity as well as energy efficiency, avoiding resource and energy waste. 3D simulation based on digital human modelling is employed to assess human factors issues related to ergonomics and safety of manufacturing systems. The approach is implemented for the sustainability enhancement of a real manufacturing cell of the aerospace industry, automated by robotic deburring. Alternative scenarios are proposed and simulated, obtaining a significant improvement in terms of energy efficiency (−87% for the new deburring cell, and a reduction of energy consumption around −69% for the coordinate measuring machine, with high potential annual energy cost savings and increased energy efficiency. Moreover, the simulation-based ergonomic assessment of human operator postures allows 25% improvement of the workcell ergonomic index.

  11. Simulation Exercises for an Undergraduate Digital Process Control Course.

    Science.gov (United States)

    Reeves, Deborah E.; Schork, F. Joseph

    1988-01-01

    Presents six problems from an alternative approach to homework traditionally given to follow-up lectures. Stresses the advantage of longer term exercises which allow for creativity and independence on the part of the student. Problems include: "System Model,""Open-Loop Simulation,""PID Control,""Dahlin…

  12. Conventional and digital radiographic methods in the detection of simulated external root resorptions: A comparative study

    Directory of Open Access Journals (Sweden)

    C J Sanjay

    2009-01-01

    Full Text Available Objective : To evaluate and compare the efficacy of conventional and digital radiographic methods in the detection of simulated external root resorption cavities and also to evaluate whether the detectability was influenced by resorption cavity sizes. Methods : Thirty-two selected teeth from human dentate mandibles were radiographed in orthoradial, mesioradial and distoradial aspect using conventional film (Insight Kodak F-speed; Eastman Kodak, Rochester, NY and a digital sensor (Trophy RVG advanced imaging system with 0.7mm and 1.0mm deep cavities prepared on their vestibular, mesial and distal surfaces at the cervical, middle and apical thirds. Three dental professionals, an endodontist, a radiologist and a general practitioner, evaluated the images twice with a one-week time interval. Results : No statistical significance was seen in the first observation for both conventional and digital radiographic methods in the detection of simulated external root resorptions and for small and medium cavities but statistical difference was noted in the second observation (P< 0.001 for both the methods. Conclusion : Considering the methodology and the overall results, conventional radiographic method (F-speed performed slightly better than the digital radiographic method in the detection of simulated radiographic method but better consistency was seen with the digital system. Overall size of the resorption cavity had no influence on the performance of both methods and suggests that initial external root resorption lesion is not well-appreciated with both the methods as compared to the advanced lesion.

  13. Simulating Optical Correlation on a Digital Image Processing

    Science.gov (United States)

    Denning, Bryan

    1998-04-01

    Optical Correlation is a useful tool for recognizing objects in video scenes. In this paper, we explore the characteristics of a composite filter known as the equal correlation peak synthetic discriminant function (ECP SDF). Although the ECP SDF is commonly used in coherent optical correlation systems, the authors simulated the operation of a correlator using an EPIX frame grabber/image processor board to complete this work. Issues pertaining to simulating correlation using an EPIX board will be discussed. Additionally, the ability of the ECP SDF to detect objects that have been subjected to inplane rotation and small scale changes will be addressed by correlating filters against true-class objects placed randomly within a scene. To test the robustness of the filters, the results of correlating the filter against false-class objects that closely resemble the true class will also be presented.

  14. The use of digital games and simulators in veterinary education: an overview with examples

    NARCIS (Netherlands)

    de Bie, M.; Lipman, L.J.A.

    2012-01-01

    In view of current technological possibilities and the popularity of games, the interest in games for educational purposes is remarkably on the rise. This article outlines the (future) use of (digital) games and simulators in several disciplines, especially in the veterinary curriculum. The

  15. Development and validation of a digital work simulation to predict workplace deviance

    NARCIS (Netherlands)

    Dubbelt, L.; Oostrom, J.K.; drs. Hiemstra, A.M.F.; Modderman, J.P.L.

    2015-01-01

    ”This paper describes a new and innovative measure that is developed to predict workplace deviance through the measurement of Machiavellianism and Compliant Behavior. Two field studies were conducted to study the validity of the digital work simulation. In Study 1, (N = 113) support was found for

  16. Validation of a digital work simulation to assess Macchiavellianism and compliant behavior

    NARCIS (Netherlands)

    Dubbelt, L.; Oostrom, J.K.; Hiemstra, A.M.; Modderman, J.P.L.

    ”This paper describes a new and innovative measure that is developed to predict workplace deviance through the measurement of Machiavellianism and Compliant Behavior. Two field studies were conducted to study the validity of the digital work simulation. In Study 1, (N = 113) support was found for

  17. Effects of Simulated Conductive Hearing Loss on Dichotic Listening Performance for Digits.

    Science.gov (United States)

    Niccum, Nancy; And Others

    1987-01-01

    Conductive hearing losses were simulated in 12 subjects aged 19-35 and performance was compared with normal hearing performance. Digit dichotic performance was affected when test intensities were within 8 dB of the "knees" (95 percent correct point) of monotic performance intensity functions, but not when test intensities were 12 dB…

  18. A behavioral simulator for switched-capacitor sigma-delta modulator analog-to-digital converter

    International Nuclear Information System (INIS)

    San, H. Y.; Rezaul Hasan, S. M.

    1998-01-01

    In this paper, a PC-based simulator for state of the art oversampled switched-capacitor sigma-delta analog-to-digital converters is presented. The proposed simulator employs behavioral model of switched-capacitor integrator and non-linear quantizer to stimulate the system. The behavioral simulation of the integrator is also verified with SPICE. The simulator is fully integrated and standalone. It integrates an input netlist file interpreter, a behavioral simulator, a generic part library and a powerful post-processor to evaluate the SNR, SDR And TSNR. Both passive and active sensitivities can be investigated by the proposed simulator. The simulator is coded in C++, and is very fast

  19. Digitization of simulated clinical dental impressions: virtual three-dimensional analysis of exactness.

    Science.gov (United States)

    Persson, Anna S K; Odén, Agneta; Andersson, Matts; Sandborgh-Englund, Gunilla

    2009-07-01

    To compare the exactness of simulated clinical impressions and stone replicas of crown preparations, using digitization and virtual three-dimensional analysis. Three master dies (mandibular incisor, canine and molar) were prepared for full crowns, mounted in full dental arches in a plane line articulator. Eight impressions were taken using an experimental monophase vinyl polysiloxane-based material. Stone replicas were poured in type IV stone (Vel-Mix Stone; Kerr). The master dies and the stone replicas were digitized in a touch-probe scanner (Procera) Forte; Nobel Biocare AB) and the impressions in a laser scanner (D250, 3Shape A/S), to create virtual models. The resulting point-clouds from the digitization of the master dies were used as CAD-Reference-Models (CRM). Discrepancies between the points in the pointclouds and the corresponding CRM were measured by a matching-software (CopyCAD 6.504 SP2; Delcam Plc). The distribution of the discrepancies was analyzed and depicted on color-difference maps. The discrepancies of the digitized impressions and the stone replicas compared to the CRM were of similar size with a mean+/-SD within 40microm, with the exception of two of the digitized molar impressions. The precision of the digitized impressions and stone replicas did not differ significantly (F=4.2; p=0.053). However, the shape affected the digitization (F=5.4; p=0.013) and the interaction effect of shape and digitization source (impression or stone replica) was pronounced (F=28; pimpressions varied with shape. Both impressions and stone replicas can be digitized repeatedly with a high reliability.

  20. Operational characteristic analysis of conduction cooling HTS SMES for Real Time Digital Simulator based power quality enhancement simulation

    International Nuclear Information System (INIS)

    Kim, A.R.; Kim, G.H.; Kim, K.M.; Kim, D.W.; Park, M.; Yu, I.K.; Kim, S.H.; Sim, K.; Sohn, M.H.; Seong, K.C.

    2010-01-01

    This paper analyzes the operational characteristics of conduction cooling Superconducting Magnetic Energy Storage (SMES) through a real hardware based simulation. To analyze the operational characteristics, the authors manufactured a small-scale toroidal-type SMES and implemented a Real Time Digital Simulator (RTDS) based power quality enhancement simulation. The method can consider not only electrical characteristics such as inductance and current but also temperature characteristic by using the real SMES system. In order to prove the effectiveness of the proposed method, a voltage sag compensation simulation has been implemented using the RTDS connected with the High Temperature Superconducting (HTS) model coil and DC/DC converter system, and the simulation results are discussed in detail.

  1. Digital system verification a combined formal methods and simulation framework

    CERN Document Server

    Li, Lun

    2010-01-01

    Integrated circuit capacity follows Moore's law, and chips are commonly produced at the time of this writing with over 70 million gates per device. Ensuring correct functional behavior of such large designs before fabrication poses an extremely challenging problem. Formal verification validates the correctness of the implementation of a design with respect to its specification through mathematical proof techniques. Formal techniques have been emerging as commercialized EDA tools in the past decade. Simulation remains a predominantly used tool to validate a design in industry. After more than 5

  2. DIGITAL

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — The Digital Flood Insurance Rate Map (DFIRM) Database depicts flood risk information and supporting data used to develop the risk data. The primary risk...

  3. Pyroprocess Deployment Analysis and Remote Accessibility Experiment using Digital Mockup and Simulation

    International Nuclear Information System (INIS)

    Kim, K. H.; Park, H. S.; Kim, S. H.; Choi, C. H.; Lee, H. J.; Park, B. S.; Yoon, G. S.; Kim, K. H.; Kim, H. D.

    2009-11-01

    Nuclear fuel cycle facility that treats with spent fuel must be designed and manufactured a Pyroprcess facility and process with considering a speciality as every process have to be processed remotely. To prevent an unexpected accident under a circumstance that must operate with a remote manipulator after done the Pyroprocess facility, an procedure related Pyroprocess operation and maintenance need to establish it in the early design stage. To develop the simulator that is mixed by 3D modelling and simulation, a system architecture was designed. A full-scale digital mockup with a real pyroprocess facility was designed and manufactured. An inverse kinematics algorithm of remote manipulator was created in order to simulate an accident and repair that could happen in pyroprocess operation and maintenance under a virtual digital mockup environment. Deployment analysis of process devices through a workspace analysis was carried out and Accessibility analysis by using haptic device was examined

  4. A 3D technique for simulation of irregular electron treatment fields using a digital camera

    International Nuclear Information System (INIS)

    Bassalow, Roustem; Sidhu, Narinder P.

    2003-01-01

    Cerrobend inserts, which define electron field apertures, are manufactured at our institution using perspex templates. Contours are reproduced manually on these templates at the simulator from the field outlines drawn on the skin or mask of a patient. A previously reported technique for simulation of electron treatment fields uses a digital camera to eliminate the need for such templates. However, avoidance of the image distortions introduced by non-flat surfaces on which the electron field outlines were drawn could only be achieved by limiting the application of this technique to surfaces which were flat or near flat. We present a technique that employs a digital camera and allows simulation of electron treatment fields contoured on an anatomical surface of an arbitrary three-dimensional (3D) shape, such as that of the neck, extremities, face, or breast. The procedure is fast, accurate, and easy to perform

  5. Six-degree-of-freedom missile simulation using the ADI AD 100 digital computer and ADSIM simulation language

    Science.gov (United States)

    Zwaanenburg, Koos

    1989-01-01

    The use of an AD 100 computer and the ADSIM language in the six-degree-of-freedom digital simulation of an air-to-ground missile is illustrated. The missile is launched from a moving platform, typically a helicopter, and is capable of striking a mobile target up to 10 kilometers away. The missile could be any tactical missile. The performance numbers of the AD 100 show that it is possible to implement a high performance missile model in a real-time simulation without the problems associated with an implementation on a general purpose computer using FORTRAN.

  6. Digital Quantum Simulation of Z_{2} Lattice Gauge Theories with Dynamical Fermionic Matter.

    Science.gov (United States)

    Zohar, Erez; Farace, Alessandro; Reznik, Benni; Cirac, J Ignacio

    2017-02-17

    We propose a scheme for digital quantum simulation of lattice gauge theories with dynamical fermions. Using a layered optical lattice with ancilla atoms that can move and interact with the other atoms (simulating the physical degrees of freedom), we obtain a stroboscopic dynamics which yields the four-body plaquette interactions, arising in models with (2+1) and higher dimensions, without the use of perturbation theory. As an example we show how to simulate a Z_{2} model in (2+1) dimensions.

  7. Method for Lumped Parameter simulation of Digital Displacement pumps/motors based on CFD

    DEFF Research Database (Denmark)

    Rømer, Daniel; Johansen, Per; Pedersen, Henrik C.

    2013-01-01

    Digital displacement fluid power pumps/motors offers improved efficiency and performance compared to traditional variable displacement pump/motors. These improvements are made possible by using efficient electronically controlled seat valves and careful design of the flow geometry. To optimize...... the design and control of digital displacement machines, there is a need for simulation models, preferably models with low computational cost. Therefore, a low computational cost generic lumped parameter model of digital displacement machine is presented, including a method for determining the needed model...... parameters based on steady CFD results, in order to take detailed geometry information into account. The response of the lumped parameter model is compared to a computational expensive transient CFD model for an example geometry....

  8. An Object-Oriented Simulator for 3D Digital Breast Tomosynthesis Imaging System

    Directory of Open Access Journals (Sweden)

    Saeed Seyyedi

    2013-01-01

    Full Text Available Digital breast tomosynthesis (DBT is an innovative imaging modality that provides 3D reconstructed images of breast to detect the breast cancer. Projections obtained with an X-ray source moving in a limited angle interval are used to reconstruct 3D image of breast. Several reconstruction algorithms are available for DBT imaging. Filtered back projection algorithm has traditionally been used to reconstruct images from projections. Iterative reconstruction algorithms such as algebraic reconstruction technique (ART were later developed. Recently, compressed sensing based methods have been proposed in tomosynthesis imaging problem. We have developed an object-oriented simulator for 3D digital breast tomosynthesis (DBT imaging system using C++ programming language. The simulator is capable of implementing different iterative and compressed sensing based reconstruction methods on 3D digital tomosynthesis data sets and phantom models. A user friendly graphical user interface (GUI helps users to select and run the desired methods on the designed phantom models or real data sets. The simulator has been tested on a phantom study that simulates breast tomosynthesis imaging problem. Results obtained with various methods including algebraic reconstruction technique (ART and total variation regularized reconstruction techniques (ART+TV are presented. Reconstruction results of the methods are compared both visually and quantitatively by evaluating performances of the methods using mean structural similarity (MSSIM values.

  9. An object-oriented simulator for 3D digital breast tomosynthesis imaging system.

    Science.gov (United States)

    Seyyedi, Saeed; Cengiz, Kubra; Kamasak, Mustafa; Yildirim, Isa

    2013-01-01

    Digital breast tomosynthesis (DBT) is an innovative imaging modality that provides 3D reconstructed images of breast to detect the breast cancer. Projections obtained with an X-ray source moving in a limited angle interval are used to reconstruct 3D image of breast. Several reconstruction algorithms are available for DBT imaging. Filtered back projection algorithm has traditionally been used to reconstruct images from projections. Iterative reconstruction algorithms such as algebraic reconstruction technique (ART) were later developed. Recently, compressed sensing based methods have been proposed in tomosynthesis imaging problem. We have developed an object-oriented simulator for 3D digital breast tomosynthesis (DBT) imaging system using C++ programming language. The simulator is capable of implementing different iterative and compressed sensing based reconstruction methods on 3D digital tomosynthesis data sets and phantom models. A user friendly graphical user interface (GUI) helps users to select and run the desired methods on the designed phantom models or real data sets. The simulator has been tested on a phantom study that simulates breast tomosynthesis imaging problem. Results obtained with various methods including algebraic reconstruction technique (ART) and total variation regularized reconstruction techniques (ART+TV) are presented. Reconstruction results of the methods are compared both visually and quantitatively by evaluating performances of the methods using mean structural similarity (MSSIM) values.

  10. SNOW: a digital computer program for the simulation of ion beam devices

    International Nuclear Information System (INIS)

    Boers, J.E.

    1980-08-01

    A digital computer program, SNOW, has been developed for the simulation of dense ion beams. The program simulates the plasma expansion cup (but not the plasma source itself), the acceleration region, and a drift space with neutralization if desired. The ion beam is simulated by computing representative trajectories through the device. The potentials are simulated on a large rectangular matrix array which is solved by iterative techniques. Poisson's equation is solved at each point within the configuration using space-charge densities computed from the ion trajectories combined with background electron and/or ion distributions. The simulation methods are described in some detail along with examples of both axially-symmetric and rectangular beams. A detailed description of the input data is presented

  11. Design and simulation of a totally digital image system for medical image applications

    International Nuclear Information System (INIS)

    Archwamety, C.

    1987-01-01

    The Totally Digital Imaging System (TDIS) is based on system requirements information from the Radiology Department, University of Arizona Health Science Center. This dissertation presents the design of this complex system, the TDIS specification, the system performance requirements, and the evaluation of the system using the computer-simulation programs. Discrete-event simulation models were developed for the TDIS subsystems, including an image network, imaging equipment, storage migration algorithm, data base archive system, and a control and management network. The simulation system uses empirical data generation and retrieval rates measured at the University Medical Center hospital. The entire TDIS system was simulated in Simscript II.5 using a VAX 8600 computer system. Simulation results show the fiber-optical-image network to be suitable; however, the optical-disk-storage system represents a performance bottleneck

  12. Improved importance sampling technique for efficient simulation of digital communication systems

    Science.gov (United States)

    Lu, Dingqing; Yao, Kung

    1988-01-01

    A new, improved importance sampling (IIS) approach to simulation is considered. Some basic concepts of IS are introduced, and detailed evolutions of simulation estimation variances for Monte Carlo (MC) and IS simulations are given. The general results obtained from these evolutions are applied to the specific previously known conventional importance sampling (CIS) technique and the new IIS technique. The derivation for a linear system with no signal random memory is considered in some detail. For the CIS technique, the optimum input scaling parameter is found, while for the IIS technique, the optimum translation parameter is found. The results are generalized to a linear system with memory and signals. Specific numerical and simulation results are given which show the advantages of CIS over MC and IIS over CIS for simulations of digital communications systems.

  13. A 4D digital phantom for patient-specific simulation of brain CT perfusion protocols.

    Science.gov (United States)

    van den Boom, Rieneke; Manniesing, Rashindra; Oei, Marcel T H; van der Woude, Willem-Jan; Smit, Ewoud J; Laue, Hendrik O A; van Ginneken, Bram; Prokop, Mathias

    2014-07-01

    Optimizing CT brain perfusion protocols is a challenge because of the complex interaction between image acquisition, calculation of perfusion data, and patient hemodynamics. Several digital phantoms have been developed to avoid unnecessary patient exposure or suboptimum choice of parameters. The authors expand this idea by using realistic noise patterns and measured tissue attenuation curves representing patient-specific hemodynamics. The purpose of this work is to validate that this approach can realistically simulate mean perfusion values and noise on perfusion data for individual patients. The proposed 4D digital phantom consists of three major components: (1) a definition of the spatial structure of various brain tissues within the phantom, (2) measured tissue attenuation curves, and (3) measured noise patterns. Tissue attenuation curves were measured in patient data using regions of interest in gray matter and white matter. By assigning the tissue attenuation curves to the corresponding tissue curves within the phantom, patient-specific CTP acquisitions were retrospectively simulated. Noise patterns were acquired by repeatedly scanning an anthropomorphic skull phantom at various exposure settings. The authors selected 20 consecutive patients that were scanned for suspected ischemic stroke and constructed patient-specific 4D digital phantoms using the individual patients' hemodynamics. The perfusion maps of the patient data were compared with the digital phantom data. Agreement between phantom- and patient-derived data was determined for mean perfusion values and for standard deviation in de perfusion data using intraclass correlation coefficients (ICCs) and a linear fit. ICCs ranged between 0.92 and 0.99 for mean perfusion values. ICCs for the standard deviation in perfusion maps were between 0.86 and 0.93. Linear fitting yielded slope values between 0.90 and 1.06. A patient-specific 4D digital phantom allows for realistic simulation of mean values and

  14. Design of DSP-based high-power digital solar array simulator

    Science.gov (United States)

    Zhang, Yang; Liu, Zhilong; Tong, Weichao; Feng, Jian; Ji, Yibo

    2013-12-01

    To satisfy rigid performance specifications, a feedback control was presented for zoom optical lens plants. With the increasing of global energy consumption, research of the photovoltaic(PV) systems get more and more attention. Research of the digital high-power solar array simulator provides technical support for high-power grid-connected PV systems research.This paper introduces a design scheme of the high-power digital solar array simulator based on TMS320F28335. A DC-DC full-bridge topology was used in the system's main circuit. The switching frequency of IGBT is 25kHz.Maximum output voltage is 900V. Maximum output current is 20A. Simulator can be pre-stored solar panel IV curves.The curve is composed of 128 discrete points .When the system was running, the main circuit voltage and current values was feedback to the DSP by the voltage and current sensors in real-time. Through incremental PI,DSP control the simulator in the closed-loop control system. Experimental data show that Simulator output voltage and current follow a preset solar panels IV curve. In connection with the formation of high-power inverter, the system becomes gridconnected PV system. The inverter can find the simulator's maximum power point and the output power can be stabilized at the maximum power point (MPP).

  15. A digital simulation of a pressurizer in a PWR nuclear power plant

    International Nuclear Information System (INIS)

    Sato, E.F.

    1980-11-01

    A model for pressurizer digital simulation of a PWR nuclear power plant during transients, considering all pressurizer control features, is presented. The pressurizer is divided into two regions separated by a water-vapor interface and non-equilibrium conditions are considered. The particular thermodynamic process followed during insurge and outsurges is determined at each instant of analysis without any previous assumption. The pressure behavior is defined by an explicit equation in any of four possible pressurizer thermodynamic conditions. Thermodynamic properties of steam and water are computed by ASME subroutines and the mathematical formulation presented in this study was programed in FORTRAN IV for a Burroughs-6700 digital computer system. This program was employed to simulate the Shippingport Atomic Power Station and Almirante Alvaro Alberto Nuclear Power Plant - Unit 1 pressurizers. The test results compared with experimental or vendor data show the validity of this analysis method. (Author) [pt

  16. Digital video timing analyzer for the evaluation of PC-based real-time simulation systems

    Science.gov (United States)

    Jones, Shawn R.; Crosby, Jay L.; Terry, John E., Jr.

    2009-05-01

    Due to the rapid acceleration in technology and the drop in costs, the use of commercial off-the-shelf (COTS) PC-based hardware and software components for digital and hardware-in-the-loop (HWIL) simulations has increased. However, the increase in PC-based components creates new challenges for HWIL test facilities such as cost-effective hardware and software selection, system configuration and integration, performance testing, and simulation verification/validation. This paper will discuss how the Digital Video Timing Analyzer (DiViTA) installed in the Aviation and Missile Research, Development and Engineering Center (AMRDEC) provides quantitative characterization data for PC-based real-time scene generation systems. An overview of the DiViTA is provided followed by details on measurement techniques, applications, and real-world examples of system benefits.

  17. Formulae for thermal feedback of group constants in digital reactor simulation

    International Nuclear Information System (INIS)

    Perneczky, L.; Toth, I.; Vigassy, J.

    1976-01-01

    The problem, how the feedback of the thermohydraulic field to the neutron density in a reactor can be calculated is analysed. After a brief survey of the digital models in reactor simulation the applied model based on the time-dependent two-group diffusion equations is described. Using the reactor physical code system THERESA numerical results for the VVER-440 reactor are presented. (Sz.Z.)

  18. Simulation of Digital Control Computer of Nuclear Power Plant Based on Virtual Machine Technology

    International Nuclear Information System (INIS)

    Hou, Xue Yan; Li, Shu; Li, Qing

    2011-01-01

    Based on analyzing DCC (Digital Control Computer) instruction sets, memory map, display controllers and I/O system, virtual machine of DCC (abbr. VM DCC) has been developed. The executive and control programs, same as running on NPP (Nuclear Power Plant) unit's DCC, can run on the VM DCC smoothly and get same control results. Dual VM DCC system has been successfully applied in NPP FSS(Full Scope Simulator) training. It not only improves FSS's fidelity but also makes maintaining easier

  19. Digitization and simulation realization of full range control system for steam generator water level

    International Nuclear Information System (INIS)

    Qian Hong; Ye Jianhua; Qian Fei; Li Chao

    2010-01-01

    In this paper, a full range digital control system for the steam generator water level is designed by a control scheme of single element control and three-element cascade feed-forward control, and the method to use the software module configuration is proposed to realize the water level control strategy. This control strategy is then applied in the operation of the nuclear power simulation machine. The simulation result curves indicate that the steam generator water level maintains constant at the stable operation condition, and when the load changes, the water level changes but finally maintains the constant. (authors)

  20. Practical algorithms for simulation and reconstruction of digital in-line holograms.

    Science.gov (United States)

    Latychevskaia, Tatiana; Fink, Hans-Werner

    2015-03-20

    Here we present practical methods for simulation and reconstruction of in-line digital holograms recorded with plane and spherical waves. The algorithms described here are applicable to holographic imaging of an object exhibiting absorption as well as phase-shifting properties. Optimal parameters, related to distances, sampling rate, and other factors for successful simulation and reconstruction of holograms are evaluated and criteria for the achievable resolution are worked out. Moreover, we show that the numerical procedures for the reconstruction of holograms recorded with plane and spherical waves are identical under certain conditions. Experimental examples of holograms and their reconstructions are also discussed.

  1. Digitalized design of extraforaminal lumbar interbody fusion: a computer-based simulation and cadaveric study.

    Directory of Open Access Journals (Sweden)

    Mingjie Yang

    Full Text Available PURPOSE: This study aims to investigate the feasibility of a novel lumbar approach named extraforaminal lumbar interbody fusion (ELIF, a newly emerging minimally invasive technique for treating degenerative lumbar disorders, using a digitalized simulation and a cadaveric study. METHODS: The ELIF surgical procedure was simulated using the Mimics surgical simulator and included dissection of the superior articular process, dilation of the vertebral foramen, and placement of pedicle screws and a cage. ELIF anatomical measures were documented using a digitalized technique and subsequently validated on fresh cadavers. RESULTS: The use of the Mimics allowed for the vivid simulation of ELIF surgical procedures, while the cadaveric study proved the feasibility of this novel approach. ELIF had a relatively lateral access approach that was located 8-9 cm lateral to the median line with an access depth of approximately 9 cm through the intermuscular space. Dissection of the superior articular processes could fully expose the target intervertebral discs and facilitate a more inclined placement of the pedicle screws and cage with robust enhancement. CONCLUSIONS: According to the computer-based simulation and cadaveric study, it is feasible to perform ELIF. Further research including biomechanical study is needed to prove ELIF has a superior ability to preserve the posterior tension bands of the spinal column, with similar effects on spinal decompression, fixation, and fusion, and if it can enhance post-fusion spinal stability and expedites postoperative recovery.

  2. Digitalized design of extraforaminal lumbar interbody fusion: a computer-based simulation and cadaveric study.

    Science.gov (United States)

    Yang, Mingjie; Zeng, Cheng; Guo, Song; Pan, Jie; Han, Yingchao; Li, Zeqing; Li, Lijun; Tan, Jun

    2014-01-01

    This study aims to investigate the feasibility of a novel lumbar approach named extraforaminal lumbar interbody fusion (ELIF), a newly emerging minimally invasive technique for treating degenerative lumbar disorders, using a digitalized simulation and a cadaveric study. The ELIF surgical procedure was simulated using the Mimics surgical simulator and included dissection of the superior articular process, dilation of the vertebral foramen, and placement of pedicle screws and a cage. ELIF anatomical measures were documented using a digitalized technique and subsequently validated on fresh cadavers. The use of the Mimics allowed for the vivid simulation of ELIF surgical procedures, while the cadaveric study proved the feasibility of this novel approach. ELIF had a relatively lateral access approach that was located 8-9 cm lateral to the median line with an access depth of approximately 9 cm through the intermuscular space. Dissection of the superior articular processes could fully expose the target intervertebral discs and facilitate a more inclined placement of the pedicle screws and cage with robust enhancement. According to the computer-based simulation and cadaveric study, it is feasible to perform ELIF. Further research including biomechanical study is needed to prove ELIF has a superior ability to preserve the posterior tension bands of the spinal column, with similar effects on spinal decompression, fixation, and fusion, and if it can enhance post-fusion spinal stability and expedites postoperative recovery.

  3. Power system analysis of Hanlim superconducting HVDC system using real time digital simulator

    International Nuclear Information System (INIS)

    Won, Y.J.; Kim, J.G.; Kim, A.R.; Kim, G.H.; Park, M.; Yu, I.K.; Sim, K.D.; Cho, J.; Lee, S.; Jeong, K.W.; Watanabe, K.

    2011-01-01

    KEPCO has planned to construct a test site for renewable energy in Jeju power system. One kilometer length of total 8 km was designed as superconducting DC cable. We have developed a simulation model of the 8 km HVDC system using real time digital simulator. The simulation result shows that the HVDC line was not affected by wind power variation. Jeju island is located approximately 100 km south from the mainland of Korea, and had a peak load of about 553 MW in 2008. The demand increases 7.2% a year over the last 5 years. Since the wind profiles of Jeju island are more favorable than mainland of Korea, many companies have shown interest in the wind power business at the Jeju island. Moreover KEPCO has a plan for renewable energy test too whose power will be delivered by HVDC system. One kilometer length of total 8 km was designed as superconducting DC cable. Rest 7 km will be the conventional overhead line. In this paper, the authors have developed a simulation model of the power network around 8 km HVDC system using real time digital simulator (RTDS).

  4. The simulation of 3D microcalcification clusters in 2D digital mammography and breast tomosynthesis

    International Nuclear Information System (INIS)

    Shaheen, Eman; Van Ongeval, Chantal; Zanca, Federica; Cockmartin, Lesley; Marshall, Nicholas; Jacobs, Jurgen; Young, Kenneth C.; Dance, David R.; Bosmans, Hilde

    2011-01-01

    Purpose: This work proposes a new method of building 3D models of microcalcification clusters and describes the validation of their realistic appearance when simulated into 2D digital mammograms and into breast tomosynthesis images. Methods: A micro-CT unit was used to scan 23 breast biopsy specimens of microcalcification clusters with malignant and benign characteristics and their 3D reconstructed datasets were segmented to obtain 3D models of microcalcification clusters. These models were then adjusted for the x-ray spectrum used and for the system resolution and simulated into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. Six radiologists were asked to distinguish between 40 real and 40 simulated clusters of microcalcifications in two separate studies on 2D mammography and tomosynthesis datasets. Receiver operating characteristic (ROC) analysis was used to test the ability of each observer to distinguish between simulated and real microcalcification clusters. The kappa statistic was applied to assess how often the individual simulated and real microcalcification clusters had received similar scores (''agreement'') on their realistic appearance in both modalities. This analysis was performed for all readers and for the real and the simulated group of microcalcification clusters separately. ''Poor'' agreement would reflect radiologists' confusion between simulated and real clusters, i.e., lesions not systematically evaluated in both modalities as either simulated or real, and would therefore be interpreted as a success of the present models. Results: The area under the ROC curve, averaged over the observers, was 0.55 (95% confidence interval [0.44, 0.66]) for the 2D study, and 0.46 (95% confidence interval [0.29, 0.64]) for the tomosynthesis study, indicating no statistically significant difference between real and simulated

  5. Digital simulation of staining in histopathology multispectral images: enhancement and linear transformation of spectral transmittance.

    Science.gov (United States)

    Bautista, Pinky A; Yagi, Yukako

    2012-05-01

    Hematoxylin and eosin (H&E) stain is currently the most popular for routine histopathology staining. Special and/or immuno-histochemical (IHC) staining is often requested to further corroborate the initial diagnosis on H&E stained tissue sections. Digital simulation of staining (or digital staining) can be a very valuable tool to produce the desired stained images from the H&E stained tissue sections instantaneously. We present an approach to digital staining of histopathology multispectral images by combining the effects of spectral enhancement and spectral transformation. Spectral enhancement is accomplished by shifting the N-band original spectrum of the multispectral pixel with the weighted difference between the pixel's original and estimated spectrum; the spectrum is estimated using M transformed to the spectral configuration associated to its reaction to a specific stain by utilizing an N × N transformation matrix, which is derived through application of least mean squares method to the enhanced and target spectral transmittance samples of the different tissue components found in the image. Results of our experiments on the digital conversion of an H&E stained multispectral image to its Masson's trichrome stained equivalent show the viability of the method.

  6. Simulation, elaboration and analysis of inter-digitated back contacts photovoltaic cells

    International Nuclear Information System (INIS)

    Nichiporuk, O.

    2005-05-01

    Solar energy is the most promising and powerful energy source among renewable energies. Photovoltaic electricity is obtained by direct transformation of the sunlight into electricity by means of photovoltaic cells. The objective of this work is to develop photovoltaic cells with back inter-digitated contacts. In the first chapter, we recall the principle of operation and the fundamental parameters of a photovoltaic cell. In a second part, we explain specificities of the inter-digitated back-contact solar cells, as well as the advantages and the disadvantages of such cells. In the second chapter we study the operation of inter-digitated back-contacts solar cells by two dimensional numerical simulation in order to optimize the geometry and doping profiles of the cell. The third chapter relates to the techniques and the methods of characterization of photovoltaic devices and components. In the fourth chapter, we describe the elaboration of inter-digitated back-contact cells. Three technological processes are presented in order to develop a simple technology for cells realization. In particular, we develop the auto-aligned technological process, which enables to elaborate the cells by using only one lithography step. In the last chapter we examine various approaches to reduce the surface recombination: SiO 2 , silicon nitride deposited by UVCVD, hydrogen annealing, etc.. (author)

  7. Simulation, elaboration and analysis of inter-digitated back-contacts photovoltaic cells

    International Nuclear Information System (INIS)

    Nichiporuk, O.

    2005-05-01

    Solar energy is the most promising and powerful energy source among renewable energies. Photovoltaic electricity is obtained by direct transformation of the sunlight into electricity by means of photovoltaic cells. The objective of this work is to develop photovoltaic cells with back inter-digitated contacts. In the first chapter, we recall the principle of operation and the fundamental parameters of a photovoltaic cell. In a second part, we explain specificities of the inter-digitated back-contact solar cells, as well as the advantages and the disadvantages of such cells. In the second chapter we study the operation of inter-digitated back-contacts solar cells by two dimensional numerical simulation in order to optimize the geometry and doping profiles of the cell. The third chapter relates to the techniques and the methods of characterization of photovoltaic devices and components. In the fourth chapter, we describe the elaboration of inter-digitated back-contact cells. Three technological processes are presented in order to develop a simple technology for cells realization. In particular, we develop the auto-aligned technological process, which enables to elaborate the cells by using only one lithography step. In the last chapter we examine various approaches to reduce the surface recombination: SiO 2 , silicon nitride deposited by UVCVD, hydrogen annealing, etc... (author)

  8. 3D DIGITAL SIMULATION OF MINNAN TEMPLE ARCHITECTURE CAISSON'S CRAFT TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Y. C. Lin

    2013-07-01

    Full Text Available Caisson is one of the important representations of the Minnan (southern Fujian temple architecture craft techniques and decorative aesthetics. The special component design and group building method present the architectural thinking and personal characteristics of great carpenters of Minnan temple architecture. In late Qing Dynasty, the appearance and style of caissons of famous temples in Taiwan apparently presented the building techniques of the great carpenters. However, as the years went by, the caisson design and craft techniques were not fully inherited, which has been a great loss of cultural assets. Accordingly, with the caisson of Fulong temple, a work by the well-known great carpenter in Tainan as an example, this study obtained the thinking principles of the original design and the design method at initial period of construction through interview records and the step of redrawing the "Tng-Ko" (traditional design, stakeout and construction tool. We obtained the 3D point cloud model of the caisson of Fulong temple using 3D laser scanning technology, and established the 3D digital model of each component of the caisson. Based on the caisson component procedure obtained from interview records, this study conducted the digital simulation of the caisson component to completely recode and present the caisson design, construction and completion procedure. This model of preserving the craft techniques for Minnan temple caisson by using digital technology makes specific contribution to the heritage of the craft techniques while providing an important reference for the digital preservation of human cultural assets.

  9. Method for simulating dose reduction in digital mammography using the Anscombe transformation.

    Science.gov (United States)

    Borges, Lucas R; Oliveira, Helder C R de; Nunes, Polyana F; Bakic, Predrag R; Maidment, Andrew D A; Vieira, Marcelo A C

    2016-06-01

    This work proposes an accurate method for simulating dose reduction in digital mammography starting from a clinical image acquired with a standard dose. The method developed in this work consists of scaling a mammogram acquired at the standard radiation dose and adding signal-dependent noise. The algorithm accounts for specific issues relevant in digital mammography images, such as anisotropic noise, spatial variations in pixel gain, and the effect of dose reduction on the detective quantum efficiency. The scaling process takes into account the linearity of the system and the offset of the detector elements. The inserted noise is obtained by acquiring images of a flat-field phantom at the standard radiation dose and at the simulated dose. Using the Anscombe transformation, a relationship is created between the calculated noise mask and the scaled image, resulting in a clinical mammogram with the same noise and gray level characteristics as an image acquired at the lower-radiation dose. The performance of the proposed algorithm was validated using real images acquired with an anthropomorphic breast phantom at four different doses, with five exposures for each dose and 256 nonoverlapping ROIs extracted from each image and with uniform images. The authors simulated lower-dose images and compared these with the real images. The authors evaluated the similarity between the normalized noise power spectrum (NNPS) and power spectrum (PS) of simulated images and real images acquired with the same dose. The maximum relative error was less than 2.5% for every ROI. The added noise was also evaluated by measuring the local variance in the real and simulated images. The relative average error for the local variance was smaller than 1%. A new method is proposed for simulating dose reduction in clinical mammograms. In this method, the dependency between image noise and image signal is addressed using a novel application of the Anscombe transformation. NNPS, PS, and local noise

  10. Simulation of the High Performance Time to Digital Converter for the ATLAS Muon Spectrometer trigger upgrade

    International Nuclear Information System (INIS)

    Meng, X.T.; Levin, D.S.; Chapman, J.W.; Zhou, B.

    2016-01-01

    The ATLAS Muon Spectrometer endcap thin-Resistive Plate Chamber trigger project compliments the New Small Wheel endcap Phase-1 upgrade for higher luminosity LHC operation. These new trigger chambers, located in a high rate region of ATLAS, will improve overall trigger acceptance and reduce the fake muon trigger incidence. These chambers must generate a low level muon trigger to be delivered to a remote high level processor within a stringent latency requirement of 43 bunch crossings (1075 ns). To help meet this requirement the High Performance Time to Digital Converter (HPTDC), a multi-channel ASIC designed by CERN Microelectronics group, has been proposed for the digitization of the fast front end detector signals. This paper investigates the HPTDC performance in the context of the overall muon trigger latency, employing detailed behavioral Verilog simulations in which the latency in triggerless mode is measured for a range of configurations and under realistic hit rate conditions. The simulation results show that various HPTDC operational configurations, including leading edge and pair measurement modes can provide high efficiency (>98%) to capture and digitize hits within a time interval satisfying the Phase-1 latency tolerance.

  11. A new parallel algorithm and its simulation on hypercube simulator for low pass digital image filtering using systolic array

    International Nuclear Information System (INIS)

    Al-Hallaq, A.; Amin, S.

    1998-01-01

    This paper introduces a new parallel algorithm and its simulation on a hypercube simulator for the low pass digital image filtering using a systolic array. This new algorithm is faster than the old one (Amin, 1988). This is due to the the fact that the old algorithm carries out the addition operations in a sequential mode. But in our new design these addition operations are divided into tow groups, which can be performed in parallel. One group will be performed on one half of the systolic array and the other on the second half, that is, by folding. This parallelism reduces the time required for the whole process by almost quarter the time of the old algorithm.(authors). 18 refs., 3 figs

  12. Evaluation of body simulator for chest and abdomen in digital X-ray equipment

    International Nuclear Information System (INIS)

    Soares, Sidney S.; Cardoso, Gabriela P.; Oliveira, Giovanni Antônio P.; Batista, Adriana S.M.; Pereira, Esther Lorrayne M.

    2017-01-01

    The use of body simulators to control the quality of X-ray images is a practice that guarantees the control of essential parameters for diagnosis by the technique. The evolution of the equipment, between the analogue, digital computerized radiology (CR) and direct radiography (DR), requires evaluation of the equivalence in grayscale, of simulators, for an adjustment according to the specific technology of obtaining the image. In this sense, the present work presents the evaluation of a body simulator with regard to the representation of mean values of signal, noise and contrast obtained in chest radiographs and panoramic of the abdomen. For the thorax the cardiac region was considered as simulation target and for the abdomen simulation of the liver and small intestine. We used a retrospective study of images obtained with X-ray equipment - CR system, in which the images were studied using the ImageJ program, generating a data catalog. These were subsequently compared with those obtained experimentally using gel filled polymer body simulator. For the validation of the simulator, it was observed the gel equivalence of filling of the polymer box required to reach the image parameters of the cataloged radiographs. The results are discussed as to the physical principles of radiation interaction with biological and equivalent tissues

  13. Matlab/Simulink-based simulation for digital-control system of marine three-shaft gas-turbine

    International Nuclear Information System (INIS)

    Yu Youhong; Chen Lingen; Sun Fengrui; Wu Chih

    2005-01-01

    A gas-turbine plant model is required in order to design and develop its control system. In this paper, a simulation model of a marine three-shaft gas-turbine's digital-control system is presented. Acceleration processes are simulated via a Matlab/Simulink program. The effects of some of the main variables on the system's performance are analyzed and the optimum values of parameters obtained. A simulation experiment upon a real gas-turbine plant is performed using the digital-control model. The results show that the simulation model is reliable

  14. RESEARCH ON THE DIGITAL SIMULATION FOR THE WHOLE PROCESS OF MARS EXPLORATION

    Directory of Open Access Journals (Sweden)

    L. Lyu

    2018-05-01

    Full Text Available China has paid considerable attention to space exploration and made great strides in the field. The first Chinese Mars Exploration Mission will be carried out in 2020. Digital simulation has been proved to be an effective and efficient means for planning and deduction in many fields. Thus, it was introduced for the Mars exploration in this paper and key technologies was researched above three aspects. First of all, complicated time-space benchmark was combed to support the interplanetary simulation. Secondly, the multi-resolution pyramid model and indexing strategy were adopted to preprocess the geographical environment data, which ensured the efficiency of data loading, browsing, and querying. Then, the activity objects were abstracted and modelled based on four aspects, including property, ephemeris, geometry, and behavior. Therefore, a digital simulation system, called Sino-Mars, was developed. The architecture of Sino- Mars consists of five layers, including data collection, data processing, scenario modelling, visualization and application layer. Using the Chinese Mars Exploration Mission slated for 2020 as an example, we demonstrated the capabilities of Sino-Mars for data integration, visualization, process deduction, and auxiliary analysis.

  15. The benefit of accounting for DQE variations in simulated dose reduction of digital radiographic systems

    International Nuclear Information System (INIS)

    Svalkvist, A.; Baath, M.

    2010-01-01

    Adding noise to clinical radiographs to simulate dose reduction can be used to investigate the relationship between dose level and clinical image quality without exposing patients to additional radiation. The purpose of the present paper was to examine the benefits of using a method that accounts for detective quantum efficiency (DQE) variations that may occur in different dose ranges in the simulated dose reduction process. A method initially intended for simulated dose reduction in tomo-synthesis was applied to extremely low-dose posterio-anterior radiographs of an anthropomorphic chest phantom, selected from a group of projection images included in a tomo-synthesis examination and compared with a previous method that do not account for DQE variations. A comparison of images simulated to be collected at a lower dose level (73% of the original dose level) and images actually collected at this lower dose level revealed that the error in the integrated normalised noise power spectrum was smaller than 4% for the method that accounts for DQE variations in the simulated dose reduction, whereas the error was larger than 20% for the previous method. This indicates that an increased validity in dose reduction simulation of digital radiographic systems is obtained with a method accounting for DQE variations. (authors)

  16. Simulation of Digital Control Computer of Nuclear Power Plant Based on Virtual Machine Technology

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xue Yan; Li, Shu; Li, Qing [China Nuclear Power Operation Technology Co., Wuhan (China)

    2011-08-15

    Based on analyzing DCC (Digital Control Computer) instruction sets, memory map, display controllers and I/O system, virtual machine of DCC (abbr. VM DCC) has been developed. The executive and control programs, same as running on NPP (Nuclear Power Plant) unit's DCC, can run on the VM DCC smoothly and get same control results. Dual VM DCC system has been successfully applied in NPP FSS(Full Scope Simulator) training. It not only improves FSS's fidelity but also makes maintaining easier.

  17. Developing Digital Simulations and its Impact on Physical Education of Pre-Service Teachers

    Directory of Open Access Journals (Sweden)

    Esther Zaretsky

    2006-08-01

    Full Text Available The creation of digital simulations through the use of computers improved physical education of pre-service teachers. The method which was based on up-to-date studies focuses on the visualization of the body's movements in space. The main program of the research concentrated on building curriculum for teaching physical education through computerized presentations. The pre-service teachers reported about their progress in a variety of physical skills and their motivation in both kinds of learning was enhanced.

  18. A digital simulation of message traffic for natural disaster warning communications satellite

    Science.gov (United States)

    Hein, G. F.; Stevenson, S. M.

    1972-01-01

    Various types of weather communications are required to alert industries and the general public about the impending occurrence of tornados, hurricanes, snowstorms, floods, etc. A natural disaster warning satellite system has been proposed for meeting the communications requirements of the National Oceanic and Atmospheric Administration. Message traffic for a communications satellite was simulated with a digital computer in order to determine the number of communications channels to meet system requirements. Poisson inputs are used for arrivals and an exponential distribution is used for service.

  19. A digital computer simulation and study of a direct-energy-transfer power-conditioning system

    Science.gov (United States)

    Burns, W. W., III; Owen, H. A., Jr.; Wilson, T. G.; Rodriguez, G. E.; Paulkovich, J.

    1975-01-01

    An investigation of the behavior of the power-conditioning system as a whole is a necessity to ensure the integrity of the aggregate system in the case of space applications. An approach for conducting such an investigation is considered. A description is given of the application of a general digital analog simulator program to the study of an aggregate power-conditioning system which is being developed for use on the International Ultraviolet Explorer spacecraft. The function of the direct energy transfer system studied involves a coupling of a solar array through a main distribution bus to the spacecraft electrical loads.

  20. Electrochemical Study of Esculetin Nitration by Digital Simulation of Cyclic Voltammograms

    Directory of Open Access Journals (Sweden)

    Lida Khalafi

    2013-01-01

    Full Text Available The reaction of electrochemically generated o-quinones from oxidation of esculetin as Michael acceptor with nitrite ion as nucleophile has been studied using cyclic voltammetry. The reaction mechanism is believed to be EC, including oxidation of catechol moiety of esculetin followed by Michael addition of nitrite ion. The observed homogeneous rate constants (obs for reactions were estimated by comparing the experimental voltammetric responses with the digitally simulated results based on the proposed mechanism. Also the effects of pH and nucleophile concentration on voltammetric behavior and the rate constants of chemical reactions were described.

  1. A Monte Carlo-based model for simulation of digital chest tomo-synthesis

    International Nuclear Information System (INIS)

    Ullman, G.; Dance, D. R.; Sandborg, M.; Carlsson, G. A.; Svalkvist, A.; Baath, M.

    2010-01-01

    The aim of this work was to calculate synthetic digital chest tomo-synthesis projections using a computer simulation model based on the Monte Carlo method. An anthropomorphic chest phantom was scanned in a computed tomography scanner, segmented and included in the computer model to allow for simulation of realistic high-resolution X-ray images. The input parameters to the model were adapted to correspond to the VolumeRAD chest tomo-synthesis system from GE Healthcare. Sixty tomo-synthesis projections were calculated with projection angles ranging from + 15 to -15 deg. The images from primary photons were calculated using an analytical model of the anti-scatter grid and a pre-calculated detector response function. The contributions from scattered photons were calculated using an in-house Monte Carlo-based model employing a number of variance reduction techniques such as the collision density estimator. Tomographic section images were reconstructed by transferring the simulated projections into the VolumeRAD system. The reconstruction was performed for three types of images using: (i) noise-free primary projections, (ii) primary projections including contributions from scattered photons and (iii) projections as in (ii) with added correlated noise. The simulated section images were compared with corresponding section images from projections taken with the real, anthropomorphic phantom from which the digital voxel phantom was originally created. The present article describes a work in progress aiming towards developing a model intended for optimisation of chest tomo-synthesis, allowing for simulation of both existing and future chest tomo-synthesis systems. (authors)

  2. TRANP - a computer code for digital simulation of steady - state and transient behavior of a pressurizer water reactor primary circuit

    International Nuclear Information System (INIS)

    Chalhoub, E.S.

    1980-09-01

    A digital computer code TRANP was developed to simulate the steady-state and transient behavior of a pressurizer water reactor primary circuit. The development of this code was based on the combining of three codes already developed for the simulation of a PWR core, a pressurizer, a steam generator and a main coolant pump, representing the primary circuit components. (Author) [pt

  3. Science Based Human Reliability Analysis: Using Digital Nuclear Power Plant Simulators for Human Reliability Research

    Science.gov (United States)

    Shirley, Rachel Elizabeth

    Nuclear power plant (NPP) simulators are proliferating in academic research institutions and national laboratories in response to the availability of affordable, digital simulator platforms. Accompanying the new research facilities is a renewed interest in using data collected in NPP simulators for Human Reliability Analysis (HRA) research. An experiment conducted in The Ohio State University (OSU) NPP Simulator Facility develops data collection methods and analytical tools to improve use of simulator data in HRA. In the pilot experiment, student operators respond to design basis accidents in the OSU NPP Simulator Facility. Thirty-three undergraduate and graduate engineering students participated in the research. Following each accident scenario, student operators completed a survey about perceived simulator biases and watched a video of the scenario. During the video, they periodically recorded their perceived strength of significant Performance Shaping Factors (PSFs) such as Stress. This dissertation reviews three aspects of simulator-based research using the data collected in the OSU NPP Simulator Facility: First, a qualitative comparison of student operator performance to computer simulations of expected operator performance generated by the Information Decision Action Crew (IDAC) HRA method. Areas of comparison include procedure steps, timing of operator actions, and PSFs. Second, development of a quantitative model of the simulator bias introduced by the simulator environment. Two types of bias are defined: Environmental Bias and Motivational Bias. This research examines Motivational Bias--that is, the effect of the simulator environment on an operator's motivations, goals, and priorities. A bias causal map is introduced to model motivational bias interactions in the OSU experiment. Data collected in the OSU NPP Simulator Facility are analyzed using Structural Equation Modeling (SEM). Data include crew characteristics, operator surveys, and time to recognize

  4. Good mixing length: Digital simulation of fluid mixing with and without obstacles

    International Nuclear Information System (INIS)

    Suarez Antola, R.; Burgos, D.

    2006-07-01

    The good mixing length of a tracer assures that the samples or measures taken are fair. A non homogeneous tracer mixing through the cross section of the fluid medium involved in the experiment (eg. a river or a pipe) may conduct to erroneous conclusions. For establishing that length, a digital simulation of a two dimensional fluid flow, using Navier-Stokes equations, was done. A continuous tracer injection was simulated.The good mixing length was studied in two cases, first with a free of obstacles situation and then the effect of a significant obstacle located after the tracer injection point. As usual in practice, the good mixing length was estimated using a suitable upper bound for the concentration deviations from the mean in a given cross section. An analytical discussion of the obtained results is done

  5. Power system analysis of Hanlim superconducting HVDC system using real time digital simulator

    Science.gov (United States)

    Won, Y. J.; Kim, J. G.; Kim, A. R.; Kim, G. H.; Park, M.; Yu, I. K.; Sim, K. D.; Cho, J.; Lee, S.; Jeong, K. W.; Watanabe, K.

    2011-11-01

    Jeju island is located approximately 100 km south from the mainland of Korea, and had a peak load of about 553 MW in 2008. The demand increases 7.2% a year over the last 5 years. Since the wind profiles of Jeju island are more favorable than mainland of Korea, many companies have shown interest in the wind power business at the Jeju island. Moreover KEPCO has a plan for renewable energy test too whose power will be delivered by HVDC system. One kilometer length of total 8 km was designed as superconducting DC cable. Rest 7 km will be the conventional overhead line. In this paper, the authors have developed a simulation model of the power network around 8 km HVDC system using real time digital simulator (RTDS).

  6. The use of digital games and simulators in veterinary education: an overview with examples.

    Science.gov (United States)

    de Bie, M H; Lipman, L J A

    2012-01-01

    In view of current technological possibilities and the popularity of games, the interest in games for educational purposes is remarkably on the rise. This article outlines the (future) use of (digital) games and simulators in several disciplines, especially in the veterinary curriculum. The different types of game-based learning (GBL)-varying from simple interactive computer board games to more complex virtual simulation strategies-will be discussed as well as the benefits, possibilities, and limitations of the educational use of games. The real breakthrough seems to be a few years away. Technological developments in the future might diminish the limitations and stumbling blocks that currently exist. Consequently, educational games will play a new and increasingly important role in the future veterinary curriculum, providing an attractive and useful way of learning.

  7. Development of a digital solar simulator based on full-bridge converter

    Science.gov (United States)

    Liu, Chen; Feng, Jian; Liu, Zhilong; Tong, Weichao; Ji, Yibo

    2014-02-01

    With the development of solar photovoltaic, distribution schemes utilized in power grid had been commonly application, and photovoltaic (PV) inverter is an essential equipment in grid. In this paper, a digital solar simulator based on full-bridge structure is presented. The output characteristic curve of system is electrically similar to silicon solar cells, which can greatly simplify research methods of PV inverter, improve the efficiency of research and development. The proposed simulator consists on a main control board based on TM320F28335, phase-shifted zero-voltage-switching (ZVS) DC-DC full-bridge converter and voltage and current sampling circuit, that allows emulating the voltage-current curve with the open-circuit voltage (Voc) of 900V and the short-circuit current (Isc) of 18A .When the system connected to a PV inverter, the inverter can quickly track from the open-circuit to the maximum power point and keep stability.

  8. Simulation of Controller Pilot Data Link Communications over VHF Digital Link Mode 3

    Science.gov (United States)

    Bretmersky, Steven C.; Murawski, Robert; Nguyen, Thanh C.; Raghavan, Rajesh S.

    2004-01-01

    The Federal Aviation Administration (FAA) has established an operational plan for the future Air Traffic Management (ATM) system, in which the Controller Pilot Data Link Communications (CPDLC) is envisioned to evolve into digital messaging that will take on an ever increasing role in controller to pilot communications, significantly changing the way the National Airspace System (NAS) is operating. According to FAA, CPDLC represents the first phase of the transition from the current analog voice system to an International Civil Aviation Organization (ICAO) compliant system in which digital communication becomes the alternate and perhaps primary method of routine communication. The CPDLC application is an Air Traffic Service (ATS) application in which pilots and controllers exchange messages via an addressed data link. CPDLC includes a set of clearance, information, and request message elements that correspond to existing phraseology employed by current Air Traffic Control (ATC) procedures. These message elements encompass altitude assignments, crossing constraints, lateral deviations, route changes and clearances, speed assignments, radio frequency assignments, and various requests for information. The pilot is provided with the capability to respond to messages, to request clearances and information, to report information, and to declare/rescind an emergency. A 'free text' capability is also provided to exchange information not conforming to defined formats. This paper presents simulated results of the aeronautical telecommunication application Controller Pilot Data Link Communications over VHF Digital Link Mode 3 (VDL Mode 3). The objective of this simulation study was to determine the impact of CPDLC traffic loads, in terms of timely message delivery and capacity of the VDL Mode 3 subnetwork. The traffic model is based on and is used for generating air/ground messages with different priorities. Communication is modeled for the en route domain of the Cleveland

  9. Online Synchrophasor-Based Dynamic State Estimation using Real-Time Digital Simulator

    DEFF Research Database (Denmark)

    Khazraj, Hesam; Adewole, Adeyemi Charles; Udaya, Annakkage

    2018-01-01

    Dynamic state estimation is a very important control center application used in the dynamic monitoring of state variables. This paper presents and validates a time-synchronized phasor measurement unit (PMU)-based for dynamic state estimation by unscented Kalman filter (UKF) method using the real-...... using the RTDS (real-time digital simulator). The dynamic state variables of multi-machine systems are monitored and measured for the study on the transient behavior of power systems.......Dynamic state estimation is a very important control center application used in the dynamic monitoring of state variables. This paper presents and validates a time-synchronized phasor measurement unit (PMU)-based for dynamic state estimation by unscented Kalman filter (UKF) method using the real......-time digital simulator (RTDS). The dynamic state variables of the system are the rotor angle and speed of the generators. The performance of the UKF method is tested with PMU measurements as inputs using the IEEE 14-bus test system. This test system was modeled in the RSCAD software and tested in real time...

  10. Simulation of the Direct Digital Synthesis module for Helium RFQ LLRF system

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae-Seong; Ahn, Tae-Sung; Kim, Seong-Gu; Kwon, Hyeok-Jung; Kim, Han-Sung; Song, Young-Gi; Seol, Kyung-Tae; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of)

    2015-10-15

    In this paper, the DDS module in the FPGA simulated and the analysis result will be introduced. Using Xilinx ISE design suite which is tool for developing the FPGA logic module, DDS module simulated. KOMAC (Korea Multi-purpose Accelerator Complex) has a plan to develop the helium irradiation system. This system includes the Ion source, LEBT, RFQ, MEBT systems to transport helium particles to the target. Especially, the RFQ (Radio Frequency Quadrupole) system should receive the 200 MHz RF within 1% amplitude error stability. For supplying stable 200 MHz RF to the RFQ, the LLRF (low-level radio frequency) should be controlled by control system. This helium RFQ LLRF control system have a concept to track the cavity resonance frequency. For tracking the cavity resonance frequency, the FPGA (Field Programmable Gate Array) in the digital board will tune the frequency of the output sinusoidal signal. In order to implement this frequency tracking concept, the DDS (Direct Digital Synthesis) module should be implemented in the FPGA. In the future, frequency tracking system will be tested using test cavity.

  11. Method for simulating dose reduction in digital mammography using the Anscombe transformation

    International Nuclear Information System (INIS)

    Borges, Lucas R.; Oliveira, Helder C. R. de; Nunes, Polyana F.; Vieira, Marcelo A. C.; Bakic, Predrag R.; Maidment, Andrew D. A.

    2016-01-01

    Purpose: This work proposes an accurate method for simulating dose reduction in digital mammography starting from a clinical image acquired with a standard dose. Methods: The method developed in this work consists of scaling a mammogram acquired at the standard radiation dose and adding signal-dependent noise. The algorithm accounts for specific issues relevant in digital mammography images, such as anisotropic noise, spatial variations in pixel gain, and the effect of dose reduction on the detective quantum efficiency. The scaling process takes into account the linearity of the system and the offset of the detector elements. The inserted noise is obtained by acquiring images of a flat-field phantom at the standard radiation dose and at the simulated dose. Using the Anscombe transformation, a relationship is created between the calculated noise mask and the scaled image, resulting in a clinical mammogram with the same noise and gray level characteristics as an image acquired at the lower-radiation dose. Results: The performance of the proposed algorithm was validated using real images acquired with an anthropomorphic breast phantom at four different doses, with five exposures for each dose and 256 nonoverlapping ROIs extracted from each image and with uniform images. The authors simulated lower-dose images and compared these with the real images. The authors evaluated the similarity between the normalized noise power spectrum (NNPS) and power spectrum (PS) of simulated images and real images acquired with the same dose. The maximum relative error was less than 2.5% for every ROI. The added noise was also evaluated by measuring the local variance in the real and simulated images. The relative average error for the local variance was smaller than 1%. Conclusions: A new method is proposed for simulating dose reduction in clinical mammograms. In this method, the dependency between image noise and image signal is addressed using a novel application of the Anscombe

  12. Method for simulating dose reduction in digital mammography using the Anscombe transformation

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Lucas R., E-mail: lucas.rodrigues.borges@usp.br; Oliveira, Helder C. R. de; Nunes, Polyana F.; Vieira, Marcelo A. C. [Department of Electrical and Computer Engineering, São Carlos School of Engineering, University of São Paulo, 400 Trabalhador São-Carlense Avenue, São Carlos 13566-590 (Brazil); Bakic, Predrag R.; Maidment, Andrew D. A. [Department of Radiology, Hospital of the University of Pennsylvania, University of Pennsylvania, 3400 Spruce Street, Philadelphia, Pennsylvania 19104 (United States)

    2016-06-15

    Purpose: This work proposes an accurate method for simulating dose reduction in digital mammography starting from a clinical image acquired with a standard dose. Methods: The method developed in this work consists of scaling a mammogram acquired at the standard radiation dose and adding signal-dependent noise. The algorithm accounts for specific issues relevant in digital mammography images, such as anisotropic noise, spatial variations in pixel gain, and the effect of dose reduction on the detective quantum efficiency. The scaling process takes into account the linearity of the system and the offset of the detector elements. The inserted noise is obtained by acquiring images of a flat-field phantom at the standard radiation dose and at the simulated dose. Using the Anscombe transformation, a relationship is created between the calculated noise mask and the scaled image, resulting in a clinical mammogram with the same noise and gray level characteristics as an image acquired at the lower-radiation dose. Results: The performance of the proposed algorithm was validated using real images acquired with an anthropomorphic breast phantom at four different doses, with five exposures for each dose and 256 nonoverlapping ROIs extracted from each image and with uniform images. The authors simulated lower-dose images and compared these with the real images. The authors evaluated the similarity between the normalized noise power spectrum (NNPS) and power spectrum (PS) of simulated images and real images acquired with the same dose. The maximum relative error was less than 2.5% for every ROI. The added noise was also evaluated by measuring the local variance in the real and simulated images. The relative average error for the local variance was smaller than 1%. Conclusions: A new method is proposed for simulating dose reduction in clinical mammograms. In this method, the dependency between image noise and image signal is addressed using a novel application of the Anscombe

  13. Application of digital image processing for the generation of voxels phantoms for Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Boia, L.S.; Menezes, A.F.; Cardoso, M.A.C. [Programa de Engenharia Nuclear/COPPE (Brazil); Rosa, L.A.R. da [Instituto de Radioprotecao e Dosimetria-IRD, Av. Salvador Allende, s/no Recreio dos Bandeirantes, CP 37760, CEP 22780-160 Rio de Janeiro, RJ (Brazil); Batista, D.V.S. [Instituto de Radioprotecao e Dosimetria-IRD, Av. Salvador Allende, s/no Recreio dos Bandeirantes, CP 37760, CEP 22780-160 Rio de Janeiro, RJ (Brazil); Instituto Nacional de Cancer-Secao de Fisica Medica, Praca Cruz Vermelha, 23-Centro, 20230-130 Rio de Janeiro, RJ (Brazil); Cardoso, S.C. [Departamento de Fisica Nuclear, Instituto de Fisica, Universidade Federal do Rio de Janeiro, Bloco A-Sala 307, CP 68528, CEP 21941-972 Rio de Janeiro, RJ (Brazil); Silva, A.X., E-mail: ademir@con.ufrj.br [Programa de Engenharia Nuclear/COPPE (Brazil); Departamento de Engenharia Nuclear/Escola Politecnica, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970 Rio de Janeiro, RJ (Brazil); Facure, A. [Comissao Nacional de Energia Nuclear, R. Gal. Severiano 90, sala 409, 22294-900 Rio de Janeiro, RJ (Brazil)

    2012-01-15

    This paper presents the application of a computational methodology for optimizing the conversion of medical tomographic images in voxel anthropomorphic models for simulation of radiation transport using the MCNP code. A computational system was developed for digital image processing that compresses the information from the DICOM medical image before it is converted to the Scan2MCNP software input file for optimization of the image data. In order to validate the computational methodology, a radiosurgery treatment simulation was performed using the Alderson Rando phantom and the acquisition of DICOM images was performed. The simulation results were compared with data obtained with the BrainLab planning system. The comparison showed good agreement for three orthogonal treatment beams of {sup 60}Co gamma radiation. The percentage differences were 3.07%, 0.77% and 6.15% for axial, coronal and sagital projections, respectively. - Highlights: Black-Right-Pointing-Pointer We use a method to optimize the CT image conversion in voxel model for MCNP simulation. Black-Right-Pointing-Pointer We present a methodology to compress a DICOM image before conversion to input file. Black-Right-Pointing-Pointer To validate this study an idealized radiosurgery applied to the Alderson phantom was used.

  14. Digital simulation of a communication link for Pioneer Saturn Uranus atmospheric entry probe, part 1

    Science.gov (United States)

    Hinrichs, C. A.

    1975-01-01

    A digital simulation study is presented for a candidate modulator/demodulator design in an atmospheric scintillation environment with Doppler, Doppler rate, and signal attenuation typical of the conditions of an outer planet atmospheric probe. The simulation results indicate that the mean channel error rate with and without scintillation are similar to theoretical characterizations of the link. The simulation gives information for calculating other channel statistics and generates a quantized symbol stream on magnetic tape from which error correction decoding is analyzed. Results from the magnetic tape data analyses are also included. The receiver and bit synchronizer are modeled in the simulation at the level of hardware component parameters rather than at the loop equation level and individual hardware parameters are identified. The atmospheric scintillation amplitude and phase are modeled independently. Normal and log normal amplitude processes are studied. In each case the scintillations are low pass filtered. The receiver performance is given for a range of signal to noise ratios with and without the effects of scintillation. The performance is reviewed for critical reciever parameter variations.

  15. Digital simulation of FM-ZCS-quasi resonant converter fed DD servo drive using Matlab Simulink

    Directory of Open Access Journals (Sweden)

    Kattamuri Narasimha Rao

    2009-01-01

    Full Text Available This paper deals with digital simulation of FM-ZCS-quasi resonant converter fed DC servo drive using Matlab Simulink. Quasi Resonant Converter (QRC is fast replacing conventional PWM converters in high frequency operation. The salient feature of QRC is that the switching devices can be either switched on at zero voltage or switched off at zero current, so that switching losses are zero ideally. Switching stresses are low, volumes are low and power density is high. This property imparts high efficiency and high power density to the converters. The output of QRC is regulated by varying the switching frequency of the converter. Hence it is called Frequency modulated Zero current/zero voltage switching quasi resonant converter. The present work deals with simulation of DC Servo motor fed from ZCS-QRC using Matlab. Simulation results show that the ZCS-QRC's have low total harmonic distortion. The ZCS-QRC operating in half wave and full wave modes are simulated successfully. .

  16. Estimation of reliability on digital plant protection system in nuclear power plants using fault simulation with self-checking

    International Nuclear Information System (INIS)

    Lee, Jun Seok; Kim, Suk Joon; Seong, Poong Hyun

    2004-01-01

    Safety-critical digital systems in nuclear power plants require high design reliability. Reliable software design and accurate prediction methods for the system reliability are important problems. In the reliability analysis, the error detection coverage of the system is one of the crucial factors, however, it is difficult to evaluate the error detection coverage of digital instrumentation and control system in nuclear power plants due to complexity of the system. To evaluate the error detection coverage for high efficiency and low cost, the simulation based fault injections with self checking are needed for digital instrumentation and control system in nuclear power plants. The target system is local coincidence logic in digital plant protection system and a simplified software modeling for this target system is used in this work. C++ based hardware description of micro computer simulator system is used to evaluate the error detection coverage of the system. From the simulation result, it is possible to estimate the error detection coverage of digital plant protection system in nuclear power plants using simulation based fault injection method with self checking. (author)

  17. Creating high-resolution digital elevation model using thin plate spline interpolation and Monte Carlo simulation

    International Nuclear Information System (INIS)

    Pohjola, J.; Turunen, J.; Lipping, T.

    2009-07-01

    In this report creation of the digital elevation model of Olkiluoto area incorporating a large area of seabed is described. The modeled area covers 960 square kilometers and the apparent resolution of the created elevation model was specified to be 2.5 x 2.5 meters. Various elevation data like contour lines and irregular elevation measurements were used as source data in the process. The precision and reliability of the available source data varied largely. Digital elevation model (DEM) comprises a representation of the elevation of the surface of the earth in particular area in digital format. DEM is an essential component of geographic information systems designed for the analysis and visualization of the location-related data. DEM is most often represented either in raster or Triangulated Irregular Network (TIN) format. After testing several methods the thin plate spline interpolation was found to be best suited for the creation of the elevation model. The thin plate spline method gave the smallest error in the test where certain amount of points was removed from the data and the resulting model looked most natural. In addition to the elevation data the confidence interval at each point of the new model was required. The Monte Carlo simulation method was selected for this purpose. The source data points were assigned probability distributions according to what was known about their measurement procedure and from these distributions 1 000 (20 000 in the first version) values were drawn for each data point. Each point of the newly created DEM had thus as many realizations. The resulting high resolution DEM will be used in modeling the effects of land uplift and evolution of the landscape in the time range of 10 000 years from the present. This time range comes from the requirements set for the spent nuclear fuel repository site. (orig.)

  18. An assessment of the realism of digital human manikins used for simulation in ergonomics.

    Science.gov (United States)

    Nérot, Agathe; Skalli, Wafa; Wang, Xuguang

    2015-01-01

    In this study, the accuracy of the joint centres of the manikins generated by RAMSIS and Human Builder (HB), two digital human modelling (DHM) systems widely used in industry for virtual ergonomics simulation, was investigated. Eighteen variously sized females and males were generated from external anthropometric dimensions and six joint centres (knee, hip and four spine joints) were compared with their anatomic locations obtained from the three-dimensional reconstructed bones from a low-dose X-ray system. Both RAMSIS and HB could correctly reproduce external anthropometric dimensions, while the estimation of internal joint centres location presented an average error of 27.6 mm for HB and 38.3 mm for RAMSIS. Differences between both manikins showed that a more realistic kinematic linkage led to better accuracy in joint location. This study opens the way to further research on the relationship between the external body geometry and internal skeleton in order to improve the realism of the internal skeleton of DHMs, especially for a biomechanical analysis requiring information of joint load and muscle force estimation. This study assessed two digital human modelling (DHM) systems widely used in industry for virtual ergonomics. Results support the need of a more realistic human modelling, especially for a biomechanical analysis and a standardisation of DHMs.

  19. Use of different simulators to quality evaluation of image quality in digital mammography; Utilizacao de diferentes simuladores na avaliacao da qualidade da imagem em mamografia digital

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Leslie S.; Coutinho, Celia M.C., E-mail: leslie@ird.gov.br, E-mail: celia@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Magalhaes, Luis A.G.; Almeida, Carlos Eduardo de, E-mail: luisalexandregm@hotmail.com, E-mail: cea71@yahoo.com.br [Universidade do Estado do Rio de Janeiro (LCR/UERJ), Rio de Janeiro, RJ (Brazil). Laboratorio de Ciencias Radiologicas

    2013-11-01

    In this study, the digital images were acquired with different exposure simulators to evaluate the quality of the image, noting the tumor mass detection, microcalcification fiber and representing regions of interest during mammography. The technical parameters of exposure depends on the thickness and composition of the breast, thus affecting the dose and image quality. The simulators were used: ACR, SBP 1054, BREAST PHANTOM CIRS and for evaluation of image quality, as well as measures kerma incident on the entrance surface (Ki) and calculating the mean glandular dose (MGD)

  20. Phasor Measurement Unit and Phasor Data Concentrator test with Real Time Digital Simulator

    DEFF Research Database (Denmark)

    Diakos, Konstantinos; Wu, Qiuwei; Nielsen, Arne Hejde

    2014-01-01

    that is able to derive and communicate synchrophasor measurements of different parts of the power network and the development of tests, according to IEEE standards, that evaluate the performance of PMUs and PDCs. The tests are created by using a Real Time Digital Simulation (RTDS) system. The results obtained......The main focus of the electrical engineers nowadays, is to develop a smart grid that is able to monitor, evaluate and control the power system operation. The integration of Intelligent Electronic Devices (IED s) to the power network, is a strong indication of the inclination to lead the power...... network to a more reliable, secure and economic operation. The implementation of these devices though, demands the warranty of a secure operation and high-accuracy performance. This paper describes the procedure of establishing a PMU (Phasor Measurement Unit)–PDC (Phasor Data Concentrator) platform...

  1. Dose-image quality study in digital chest radiography using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Correa, S.C.A.; Souza, E.M.; Silva, A.X.; Lopes, R.T.; Yoriyaz, H.

    2008-01-01

    One of the main preoccupations of diagnostic radiology is to guarantee a good image-sparing dose to the patient. In the present study, Monte Carlo simulations, with MCNPX code, coupled with an adult voxel female model (FAX) were performed to investigate how image quality and dose in digital chest radiography vary with tube voltage (80-150 kV) using air-gap technique and a computed radiography system. Calculated quantities were normalized to a fixed value of entrance skin exposure (ESE) of 0.0136 R. The results of the present analysis show that the image quality for chest radiography with imaging plate is improved and the dose reduced at lower tube voltage

  2. Digital simulation of a commercial scale high temperature gas-cooled reactor (HTGR) steam power plant

    International Nuclear Information System (INIS)

    Ray, A.; Bowman, H.F.

    1978-01-01

    A nonlinear dynamic model of a commercial scale high temperature gas-cooled reactor (HTGR) steam power plant was derived in state-space form from fundamental principles. The plant model is 40th order, time-invariant, deterministic and continuous-time. Numerical results were obtained by digital simulation. Steady-state performance of the nonlinear model was verified with plant heat balance data at 100, 75 and 50 percent load levels. Local stability, controllability and observability were examined in this range using standard linear algorithms. Transfer function matrices for the linearized models were also obtained. Transient response characteristics of 6 system variables for independent step distrubances in 2 different input variables are presented as typical results

  3. Real-time digital simulation of power electronics systems with Neutral Point Piloted multilevel inverter using FPGA

    Energy Technology Data Exchange (ETDEWEB)

    Rakotozafy, Mamianja [Groupe de Recherches en Electrotechnique et Electronique de Nancy (GREEN), Faculte des Sciences et Techniques, BP 70239, 54506 Vandoeuvre Cedex (France); CONVERTEAM SAS, Parc d' activites Techn' hom, 24 avenue du Marechal Juin, BP 40437, 90008 Belfort Cedex (France); Poure, Philippe [Laboratoire d' Instrumentation Electronique de Nancy (LIEN), Faculte des Sciences et Techniques, BP 70239, 54506 Vandoeuvre Cedex (France); Saadate, Shahrokh [Groupe de Recherches en Electrotechnique et Electronique de Nancy (GREEN), Faculte des Sciences et Techniques, BP 70239, 54506 Vandoeuvre Cedex (France); Bordas, Cedric; Leclere, Loic [CONVERTEAM SAS, Parc d' activites Techn' hom, 24 avenue du Marechal Juin, BP 40437, 90008 Belfort Cedex (France)

    2011-02-15

    Most of actual real time simulation platforms have practically about ten microseconds as minimum calculation time step, mainly due to computation limits such as processing speed, architecture adequacy and modeling complexities. Therefore, simulation of fast switching converters' instantaneous models requires smaller computing time step. The approach presented in this paper proposes an answer to such limited modeling accuracies and computational bandwidth of the currently available digital simulators.As an example, the authors present a low cost, flexible and high performance FPGA-based real-time digital simulator for a complete complex power system with Neutral Point Piloted (NPP) three-level inverter. The proposed real-time simulator can model accurately and efficiently the complete power system, reducing costs, physical space and avoiding any damage to the actual equipment in the case of any dysfunction of the digital controller prototype. The converter model is computed at a small fixed time step as low as 100 ns. Such a computation time step allows high precision account of the gating signals and thus avoids averaging methods and event compensations. Moreover, a novel high performance model of the NPP three-level inverter has also been proposed for FPGA implementation. The proposed FPGA-based simulator models the environment of the NPP converter: the dc link, the RLE load and the digital controller and gating signals. FPGA-based real time simulation results are presented and compared with offline results obtained using PLECS software. They validate the efficiency and accuracy of the modeling for the proposed high performance FPGA-based real-time simulation approach. This paper also introduces new potential FPGA-based applications such as low cost real time simulator for power systems by developing a library of flexible and portable models for power converters, electrical machines and drives. (author)

  4. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis

    International Nuclear Information System (INIS)

    Shaheen, Eman; De Keyzer, Frederik; Bosmans, Hilde; Ongeval, Chantal Van; Dance, David R.; Young, Kenneth C.

    2014-01-01

    Purpose: This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Methods: Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. Results: The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly

  5. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis.

    Science.gov (United States)

    Shaheen, Eman; De Keyzer, Frederik; Bosmans, Hilde; Dance, David R; Young, Kenneth C; Van Ongeval, Chantal

    2014-08-01

    This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly suggestive for malignancy (BIRADS 5

  6. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Shaheen, Eman, E-mail: eman.shaheen@uzleuven.be; De Keyzer, Frederik; Bosmans, Hilde; Ongeval, Chantal Van [Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium); Dance, David R.; Young, Kenneth C. [National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford GU2 7XX, United Kingdom and Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2014-08-15

    Purpose: This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Methods: Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. Results: The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly

  7. Patients setup verification tool for RT (PSVTs): DRR, simulation, portal and digital images

    International Nuclear Information System (INIS)

    Lee, Suk; Seong, Jin Sil; Chu, Sung Sil; Lee, Chang Geol; Suh, Chang Ok; Kwon, Soo Il

    2003-01-01

    To develop a patients' setup verification tool (PSVT) to verify the alignment of the machine and the target isocenters, and the reproducibility of patients' setup for three dimensional conformal radiotherapy (3DCRT) and intensity modulated radiotherapy (MRT). The utilization of this system is evaluated through phantom and patient case studies. We developed and clinically tested a new method for patients' setup verification, using digitally reconstructed radiography (DRR), simulation, portal and digital images. The PSVT system was networked to a Pentium PC for the transmission of the acquired images to the PC for analysis. To verify the alignment of the machine and target isocenters, orthogonal pairs of simulation images were used as verification images. Errors in the isocenter alignment were measured by comparing the verification images with DRR of CT images. Orthogonal films were taken of all the patients once a week. These verification films were compared with the DRR were used for the treatment setup. By performing this procedure every treatment, using humanoid phantom and patient cases, the errors of localization can be analyzed, with adjustments made from the translation. The reproducibility of the patients' setup was verified using portal and digital images. The PSVT system was developed to verify the alignment of the machine and the target isocenters, and the reproducibility of the patients' setup for 3DCRT and IMRT The results show that the localization errors are 0.8±0.2 mm (AP) and 1.0±0.3 mm (Lateral) in the cases relating to the brain and 1.1± 0.5 mm (AP) and 1.0±0.6 mm (Lateral) in the cases relating to the pelvis. The reproducibility of the patients' setup was verified by visualization, using real-time image acquisition, leading to the practical utilization of our software. A PSVT system was developed for the verification of the alignment between machine and the target isocenters, and the reproducibility of the patients' setup in 3DCRT and IMRT

  8. Research on real-time simulation test for upgrades of digital I and C system in nuclear power plant

    International Nuclear Information System (INIS)

    Shi Ji; Jiang Mingyu; Ma Yunqin

    2005-01-01

    The developing trend that digital instrument and control (I and C) system will supplant traditional analog I and C system in nuclear power plant is emphasized. This paper introduces mathematical model of steam generator of full scope simulator for nuclear power plant. The independent real-time simulation system, which forms the interactive closed loop together with the steam generator control system, can be applied to provide a simulation target for upgrades of instrument and control system and the research of control schemes. At the same time, a simulation method for this purpose is presented in this paper. In this method all of the hardware and software are composed of real distributed control system except the model of controlled object. This will not only create favorable conditions for commissioning on site in the future, but also give a theoretical analysis for upgrades of digital I and C system in nuclear power plant. (authors)

  9. Simulation and Measurement of the Transmission Distortions of the Digital Television DVB-T/H Part 2: Hierarchical Modulation Performance

    Directory of Open Access Journals (Sweden)

    R. Stukavec

    2010-09-01

    Full Text Available The paper deals with the second part of results of the Czech Science Foundation research project that was aimed into the simulation and measurement of the transmission distortions of the digital terrestrial television according to DVB-T/H standards. In this part the hierarchical modulation performance characteristics and its simulation and laboratory measurements are presented. The paper deals with the hierarchical oriented COFDM modulator for the digital terrestrial television transmission and DVB-T/H standards and possible utilization of this technique in real broadcasting scenarios – fixed, portable and mobile digital TV, all in one TV channel. Impact of the hierarchical modulation on Modulation Error Rate from I/Q constellations and Bit Error Rates before and after Viterbi decoding in DVB-T/H signal decoding are evaluated and discussed.

  10. Flexible Simulation E-Learning Environment for Studying Digital Circuits and Possibilities for It Deployment as Semantic Web Service

    Science.gov (United States)

    Radoyska, P.; Ivanova, T.; Spasova, N.

    2011-01-01

    In this article we present a partially realized project for building a distributed learning environment for studying digital circuits Test and Diagnostics at TU-Sofia. We describe the main requirements for this environment, substantiate the developer platform choice, and present our simulation and circuit parameter calculation tools.…

  11. Clinical Simulation and Workflow by use of two Clinical Information Systems, the Electronic Health Record and Digital Dictation

    DEFF Research Database (Denmark)

    Schou Jensen, Iben; Koldby, Sven

    2013-01-01

    digital dictation and the EHR (electronic health record) were simulated in realistic and controlled clinical environments. Useful information dealing with workflow and patient safety were obtained. The clinical simulation demonstrated that the EHR locks during use of the integration of digital dictation......Clinical information systems do not always support clinician workflows. An increasing number of unintended clinical inci-dents might be related to implementation of clinical infor-mation systems and to a new registration praxis of unin-tended clinical incidents. Evidence of performing clinical...... simulations before implementation of new clinical information systems provides the basis for use of this method. The intention has been to evaluate patient safety issues, functionality, workflow, and usefulness of a new solution before implementation in the hospitals. Use of a solution which integrates...

  12. Advanced Research and Education in Electrical Drives by Using Digital Real-Time Hardware-in-the-Loop Simulation

    DEFF Research Database (Denmark)

    Bojoi, R.; Profumo, F.; Griva, G.

    2002-01-01

    The authors present in this paper a digital real-time hardware-in-the-loop simulation of a three-phase induction motor drive. The main real-time simulation tool is the dSPACE DS1103 PPC Controller Board which simulates the power and signal conditioning parts. The control algorithm of the virtual...... drive has been implemented on the Evaluation Board of TMS320F240 DSP. The experimental results validate this solution as a powerful tool to be used in research and advanced education. Thus, the students can put in practic the theory without spending too much time with details concerning the hardware...

  13. Use of a graphical user interface approach for digital and physical simulation in power systems control education

    International Nuclear Information System (INIS)

    Shoults, R.R.; Barrera-Cardiel, E.

    1992-01-01

    This paper presents the design of a laboratory with software and hardware structures for digital and physical simulation in the area of Power Systems Control Education. The hardware structure includes a special man-machine interface designed with a graphical user interface approach. This interface allows the user full control over the simulation and provides facilities for the study of the response of the simulated system. This approach is illustrated with the design of a control system for a physically based HVDC transmission system model

  14. Comparison of conventional panoramic radiography and panoramic digital subtraction radiography in detection of simulated lesions of mandibular condyle

    Directory of Open Access Journals (Sweden)

    Panjnoush M.

    2008-12-01

    Full Text Available "n  "nBackground and Aim: Digital subtraction Radiography (DSR is a method of accurate assessing condylar head changes. several studies have been carried out in applying DSR in dentistry, however there is a few number of studies in efficacy of DSR method in assesment of condylar head changes, The aim of this study was to compare panoramic radiography and DSR detecting simulated lesions of the mandibular condyl. "nMaterials and Methods: this was a process reaserch study, in which two dry human skulls with no obvious temporomandibular joint pathology were used. Osteophytic lesions were simulated using three sizes of bone chips that were placed on the medial portion of anterior and superolateral aspects of the condyle. Osteolytic lesions were simulated making 1 and 2 mm holes using round burr in the central portion of anterior aspect and Lateral pole of the condyle. Panoramic radiographs were prepared with and without the lesions in place. These paired radiographs were digitized and digital- subtraction images of the original panoramic images were obtained. Eight observers evaluated 155 images of each modality for the presence or absence and the type of simulated lesions of the mandibular condyle. Sensitivity, specificity, reliability and measure of agreement were analyzed using kappa test and crossed tables and qualitative variables were assess by chi-square and fisher's Exact test. "nResults: Specificity of panoramic and DSR methods were 15.4% and 66.7% respectively. Sensitivity of panoramic and DSR methods were 61.1% and 80.6% for osteophytic lesions and 37.5% and 83.3% for Osteolytic lesions. The percentage of correct decisions made in DSR method was significantly more than conventional panoramic method (82.6% vs 41.9% (p<0.0001. "nConclusion: Based on the results of this study digital subtraction technique was significantly more accurate than the panoramic radiographs in detection of simulated lesions of the mandibular condyle.

  15. 3D pore-type digital rock modeling of natural gas hydrate for permafrost and numerical simulation of electrical properties

    Science.gov (United States)

    Dong, Huaimin; Sun, Jianmeng; Lin, Zhenzhou; Fang, Hui; Li, Yafen; Cui, Likai; Yan, Weichao

    2018-02-01

    Natural gas hydrate is being considered as an alternative energy source for sustainable development and has become a focus of research throughout the world. In this paper, based on CT scanning images of hydrate reservoir rocks, combined with the microscopic distribution of hydrate, a diffusion limited aggregation (DLA) model was used to construct 3D hydrate digital rocks of different distribution types, and the finite-element method was used to simulate their electrical characteristics in order to study the influence of different hydrate distribution types, hydrate saturation and formation of water salinity on electrical properties. The results show that the hydrate digital rocks constructed using the DLA model can be used to characterize the microscopic distribution of different types of hydrates. Under the same conditions, the resistivity of the adhesive hydrate digital rock is higher than the cemented and scattered type digital rocks, and the resistivity of the scattered hydrate digital rock is the smallest among the three types. Besides, the difference in the resistivity of the different types of hydrate digital rocks increases with an increase in hydrate saturation, especially when the saturation is larger than 55%, and the rate of increase of each of the hydrate types is quite different. Similarly, the resistivity of the three hydrate types decreases with an increase in the formation of water salinity. The single distribution hydrate digital rock constructed, combined with the law of microscopic distribution and influence of saturation on the electrical properties, can effectively improve the accuracy of logging identification of hydrate reservoirs and is of great significance for the estimation of hydrate reserves.

  16. Digital Simulation of a Hybrid Active Filter - An Active Filter in Series with a Shunt Passive Filter

    OpenAIRE

    Sitaram, Mahesh I; Padiyar, KR; Ramanarayanan, V

    1998-01-01

    Active filters have long been in use for the filtering of power system load harmonics. In this paper, the digital simulation results of a hybrid active power filter system for a rectifier load are presented. The active filter is used for filtering higher order harmonics as the dominant harmonics are filtered by the passive filter. This reduces the rating of the active filter significantly. The DC capacitor voltage of the active filter is controlled using a PI controller.

  17. Digital Simulation of Closed Loop Zvs-Zcs Bidirectional Dc-Dc Converter for Fuel Cell and Battery Application

    Directory of Open Access Journals (Sweden)

    V. V. Subrahmanya Kumar Bhajana

    2010-08-01

    Full Text Available A closed loop ZVS-ZCS bidirectional dc-dc converter is modeled and appropriate digital simulations are provided. With the ZVS-ZCS concept, the MATLAB simulation results of application to a fuel cell and battery application have been obtained whenever the input voltage exceeds the given 24V, at that time the load voltage will change from 180V to 230V. But due to this usage the load is disturbed and there is instability in the model. Using closed loop the output voltage is stabilized.

  18. Scatter correction using a primary modulator for dual energy digital radiography: A Monte Carlo simulation study

    Science.gov (United States)

    Jo, Byung-Du; Lee, Young-Jin; Kim, Dae-Hong; Kim, Hee-Joung

    2014-08-01

    In conventional digital radiography (DR) using a dual energy subtraction technique, a significant fraction of the detected photons are scattered within the body, making up the scatter component. Scattered radiation can significantly deteriorate image quality in diagnostic X-ray imaging systems. Various methods of scatter correction, including both measurement- and non-measurement-based methods, have been proposed in the past. Both methods can reduce scatter artifacts in images. However, non-measurement-based methods require a homogeneous object and have insufficient scatter component correction. Therefore, we employed a measurement-based method to correct for the scatter component of inhomogeneous objects from dual energy DR (DEDR) images. We performed a simulation study using a Monte Carlo simulation with a primary modulator, which is a measurement-based method for the DEDR system. The primary modulator, which has a checkerboard pattern, was used to modulate the primary radiation. Cylindrical phantoms of variable size were used to quantify the imaging performance. For scatter estimates, we used discrete Fourier transform filtering, e.g., a Gaussian low-high pass filter with a cut-off frequency. The primary modulation method was evaluated using a cylindrical phantom in the DEDR system. The scatter components were accurately removed using a primary modulator. When the results acquired with scatter correction and without scatter correction were compared, the average contrast-to-noise ratio (CNR) with the correction was 1.35 times higher than that obtained without the correction, and the average root mean square error (RMSE) with the correction was 38.00% better than that without the correction. In the subtraction study, the average CNR with the correction was 2.04 (aluminum subtraction) and 1.38 (polymethyl methacrylate (PMMA) subtraction) times higher than that obtained without the correction. The analysis demonstrated the accuracy of the scatter correction and the

  19. A Monte-Carlo simulation framework for joint optimisation of image quality and patient dose in digital paediatric radiography

    International Nuclear Information System (INIS)

    Menser, Bernd; Manke, Dirk; Mentrup, Detlef; Neitzel, Ulrich

    2016-01-01

    In paediatric radiography, according to the as low as reasonably achievable (ALARA) principle, the imaging task should be performed with the lowest possible radiation dose. This paper describes a Monte-Carlo simulation framework for dose optimisation of imaging parameters in digital paediatric radiography. Patient models with high spatial resolution and organ segmentation enable the simultaneous evaluation of image quality and patient dose on the same simulated radiographic examination. The accuracy of the image simulation is analysed by comparing simulated and acquired images of technical phantoms. As a first application example, the framework is applied to optimise tube voltage and pre-filtration in newborn chest radiography. At equal patient dose, the highest CNR is obtained with low-kV settings in combination with copper filtration. (authors)

  20. Digital techniques in simulation, communication and control. Proceedings of the IMACS European meeting held at University of Patras, Patras, Greece, July 9-12, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Tzafestas, S G

    1985-01-01

    The book contains 90 papers which are classified in the following five parts: Modelling and simulation; Digital signal processing and 2-D system design; Information and communication systems; Control systems; and Applications (robotics, industrial and miscellaneous applications). The volume reflects the state-of-art of the field of digital techniques. (Auth.).

  1. Quality comparison between DEF-10 digital image from simulation technique and Computed Tomography (CR) technique in industrial radiography

    International Nuclear Information System (INIS)

    Siti Nur Syatirah Ismail

    2012-01-01

    The study was conducted to make comparison of digital image quality of DEF-10 from the techniques of simulation and computed radiography (CR). The sample used is steel DEF-10 with thickness of 15.28 mm. In this study, the sample is exposed to radiation from X-ray machine (ISOVOLT Titan E) with certain parameters. The parameters used in this study such as current, volt, exposure time and distance are specified. The current and distance of 3 mA and 700 mm respectively are specified while the applied voltage varies at 140, 160, 180 and 200 kV. The exposure time is reduced at a rate of 0, 20, 40, 60 and 80 % for each sample exposure. Digital image of simulation produced from aRTist software whereas digital image of computed radiography produced from imaging plate. Therefore, both images were compared qualitatively (sensitivity) and quantitatively (Signal to-Noise Ratio; SNR, Basic Spatial Resolution; SRb and LOP size) using Isee software. Radiographic sensitivity is indicated by Image Quality Indicator (IQI) which is the ability of the CR system and aRTist software to identify IQI of wire type when the time exposure is reduced up to 80% according to exposure chart ( D7; ISOVOLT Titan E). The image of the thinnest wire diameter achieved by radiograph from simulation and CR are the wire numbered 7 rather than the wire numbered 8 required by the standard. In quantitative comparison, this study shows that the SNR values decreases with reducing exposure time. SRb values increases for simulation and decreases for CR when the exposure time decreases and the good image quality can be achieved at 80% reduced exposure time. The high SNR and SRb values produced good image quality in CR and simulation techniques respectively. (author)

  2. A 4D Digital Phantom for Patient-Specific Simulation of Brain CT Perfusion Protocols

    NARCIS (Netherlands)

    Boom, R. van den; Manniesing, R.; Oei, M.T.H.; Woude, W.J. van der; Smit, E.J.; Laue, H.O.A.; Ginneken, B. van; Prokop, M.

    2014-01-01

    Purpose Optimizing CT brain perfusion protocols is a challenge because of the complex interaction between image acquisition, calculation of perfusion data and patient hemodynamics. Several digital phantoms have been developed to avoid unnecessary patient exposure or suboptimum choice of parameters.

  3. Digital Full-Scope Simulation of a Conventional Nuclear Power Plant Control Room, Phase 2: Installation of a Reconfigurable Simulator to Support Nuclear Plant Sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Boring; Vivek Agarwal; Kirk Fitzgerald; Jacques Hugo; Bruce Hallbert

    2013-03-01

    The U.S. Department of Energy’s Light Water Reactor Sustainability program has developed a control room simulator in support of control room modernization at nuclear power plants in the U.S. This report highlights the recent completion of this reconfigurable, full-scale, full-scope control room simulator buildout at the Idaho National Laboratory. The simulator is fully reconfigurable, meaning it supports multiple plant models developed by different simulator vendors. The simulator is full-scale, using glasstop virtual panels to display the analog control boards found at current plants. The present installation features 15 glasstop panels, uniquely achieving a complete control room representation. The simulator is also full-scope, meaning it uses the same plant models used for training simulators at actual plants. Unlike in the plant training simulators, the deployment on glasstop panels allows a high degree of customization of the panels, allowing the simulator to be used for research on the design of new digital control systems for control room modernization. This report includes separate sections discussing the glasstop panels, their layout to mimic control rooms at actual plants, technical details on creating a multi-plant and multi-vendor reconfigurable simulator, and current efforts to support control room modernization at U.S. utilities. The glasstop simulator provides an ideal testbed for prototyping and validating new control room concepts. Equally importantly, it is helping create a standardized and vetted human factors engineering process that can be used across the nuclear industry to ensure control room upgrades maintain and even improve current reliability and safety.

  4. Application of digital human modeling and simulation for vision analysis of pilots in a jet aircraft: a case study.

    Science.gov (United States)

    Karmakar, Sougata; Pal, Madhu Sudan; Majumdar, Deepti; Majumdar, Dhurjati

    2012-01-01

    Ergonomic evaluation of visual demands becomes crucial for the operators/users when rapid decision making is needed under extreme time constraint like navigation task of jet aircraft. Research reported here comprises ergonomic evaluation of pilot's vision in a jet aircraft in virtual environment to demonstrate how vision analysis tools of digital human modeling software can be used effectively for such study. Three (03) dynamic digital pilot models, representative of smallest, average and largest Indian pilot population were generated from anthropometric database and interfaced with digital prototype of the cockpit in Jack software for analysis of vision within and outside the cockpit. Vision analysis tools like view cones, eye view windows, blind spot area, obscuration zone, reflection zone etc. were employed during evaluation of visual fields. Vision analysis tool was also used for studying kinematic changes of pilot's body joints during simulated gazing activity. From present study, it can be concluded that vision analysis tool of digital human modeling software was found very effective in evaluation of position and alignment of different displays and controls in the workstation based upon their priorities within the visual fields and anthropometry of the targeted users, long before the development of its physical prototype.

  5. References and benchmarks for pore-scale flow simulated using micro-CT images of porous media and digital rocks

    Science.gov (United States)

    Saxena, Nishank; Hofmann, Ronny; Alpak, Faruk O.; Berg, Steffen; Dietderich, Jesse; Agarwal, Umang; Tandon, Kunj; Hunter, Sander; Freeman, Justin; Wilson, Ove Bjorn

    2017-11-01

    We generate a novel reference dataset to quantify the impact of numerical solvers, boundary conditions, and simulation platforms. We consider a variety of microstructures ranging from idealized pipes to digital rocks. Pore throats of the digital rocks considered are large enough to be well resolved with state-of-the-art micro-computerized tomography technology. Permeability is computed using multiple numerical engines, 12 in total, including, Lattice-Boltzmann, computational fluid dynamics, voxel based, fast semi-analytical, and known empirical models. Thus, we provide a measure of uncertainty associated with flow computations of digital media. Moreover, the reference and standards dataset generated is the first of its kind and can be used to test and improve new fluid flow algorithms. We find that there is an overall good agreement between solvers for idealized cross-section shape pipes. As expected, the disagreement increases with increase in complexity of the pore space. Numerical solutions for pipes with sinusoidal variation of cross section show larger variability compared to pipes of constant cross-section shapes. We notice relatively larger variability in computed permeability of digital rocks with coefficient of variation (of up to 25%) in computed values between various solvers. Still, these differences are small given other subsurface uncertainties. The observed differences between solvers can be attributed to several causes including, differences in boundary conditions, numerical convergence criteria, and parameterization of fundamental physics equations. Solvers that perform additional meshing of irregular pore shapes require an additional step in practical workflows which involves skill and can introduce further uncertainty. Computation times for digital rocks vary from minutes to several days depending on the algorithm and available computational resources. We find that more stringent convergence criteria can improve solver accuracy but at the expense

  6. A computer simulation study comparing lesion detection accuracy with digital mammography, breast tomosynthesis, and cone-beam CT breast imaging

    International Nuclear Information System (INIS)

    Gong Xing; Glick, Stephen J.; Liu, Bob; Vedula, Aruna A.; Thacker, Samta

    2006-01-01

    Although conventional mammography is currently the best modality to detect early breast cancer, it is limited in that the recorded image represents the superposition of a three-dimensional (3D) object onto a 2D plane. Recently, two promising approaches for 3D volumetric breast imaging have been proposed, breast tomosynthesis (BT) and CT breast imaging (CTBI). To investigate possible improvements in lesion detection accuracy with either breast tomosynthesis or CT breast imaging as compared to digital mammography (DM), a computer simulation study was conducted using simulated lesions embedded into a structured 3D breast model. The computer simulation realistically modeled x-ray transport through a breast model, as well as the signal and noise propagation through a CsI based flat-panel imager. Polyenergetic x-ray spectra of Mo/Mo 28 kVp for digital mammography, Mo/Rh 28 kVp for BT, and W/Ce 50 kVp for CTBI were modeled. For the CTBI simulation, the intensity of the x-ray spectra for each projection view was determined so as to provide a total average glandular dose of 4 mGy, which is approximately equivalent to that given in conventional two-view screening mammography. The same total dose was modeled for both the DM and BT simulations. Irregular lesions were simulated by using a stochastic growth algorithm providing lesions with an effective diameter of 5 mm. Breast tissue was simulated by generating an ensemble of backgrounds with a power law spectrum, with the composition of 50% fibroglandular and 50% adipose tissue. To evaluate lesion detection accuracy, a receiver operating characteristic (ROC) study was performed with five observers reading an ensemble of images for each case. The average area under the ROC curves (A z ) was 0.76 for DM, 0.93 for BT, and 0.94 for CTBI. Results indicated that for the same dose, a 5 mm lesion embedded in a structured breast phantom was detected by the two volumetric breast imaging systems, BT and CTBI, with statistically

  7. Internet-Based Digital Simulation for Cleft Surgery Education: A 5-Year Assessment of Demographics, Usage, and Global Effect.

    Science.gov (United States)

    Kantar, Rami S; Plana, Natalie M; Cutting, Court B; Diaz-Siso, Jesus Rodrigo; Flores, Roberto L

    2018-01-29

    In October 2012, a freely available, internet-based cleft simulator was created in partnership between academic, nonprofit, and industry sectors. The purpose of this educational resource was to address global disparities in cleft surgery education. This report assesses demographics, usage, and global effect of our simulator, in its fifth year since inception. Evaluate the global effect, usage, and demographics of an internet-based educational digital simulation cleft surgery software. Simulator modules, available in five languages demonstrate surgical anatomy, markings, detailed procedures, and intraoperative footage to supplement digital animation. Available data regarding number of users, sessions, countries reached, and content access were recorded. Surveys evaluating the demographic characteristics of registered users and simulator use were collected by direct e-mail. The total number of simulator new and active users reached 2865 and 4086 in June 2017, respectively. By June 2017, users from 136 countries had accessed the simulator. From 2015 to 2017, the number of sessions was 11,176 with a monthly average of 399.0 ± 190.0. Developing countries accounted for 35% of sessions and the average session duration was 9.0 ± 7.3 minutes. This yields a total simulator screen time of 100,584 minutes (1676 hours). Most survey respondents were surgeons or trainees (87%) specializing in plastic, maxillofacial, or general surgery (89%). Most users found the simulator to be useful (88%), at least equivalent or more useful than other resources (83%), and used it for teaching (58%). Our internet-based interactive cleft surgery platform reaches its intended target audience, is not restricted by socioeconomic barriers to access, and is judged to be useful by surgeons. More than 4000 active users have been reached since inception. The total screen time over approximately 2 years exceeded 1600 hours. This suggests that future surgical simulators of this kind may be sustainable by

  8. Steering the conversation: A linguistic exploration of natural language interactions with a digital assistant during simulated driving.

    Science.gov (United States)

    Large, David R; Clark, Leigh; Quandt, Annie; Burnett, Gary; Skrypchuk, Lee

    2017-09-01

    Given the proliferation of 'intelligent' and 'socially-aware' digital assistants embodying everyday mobile technology - and the undeniable logic that utilising voice-activated controls and interfaces in cars reduces the visual and manual distraction of interacting with in-vehicle devices - it appears inevitable that next generation vehicles will be embodied by digital assistants and utilise spoken language as a method of interaction. From a design perspective, defining the language and interaction style that a digital driving assistant should adopt is contingent on the role that they play within the social fabric and context in which they are situated. We therefore conducted a qualitative, Wizard-of-Oz study to explore how drivers might interact linguistically with a natural language digital driving assistant. Twenty-five participants drove for 10 min in a medium-fidelity driving simulator while interacting with a state-of-the-art, high-functioning, conversational digital driving assistant. All exchanges were transcribed and analysed using recognised linguistic techniques, such as discourse and conversation analysis, normally reserved for interpersonal investigation. Language usage patterns demonstrate that interactions with the digital assistant were fundamentally social in nature, with participants affording the assistant equal social status and high-level cognitive processing capability. For example, participants were polite, actively controlled turn-taking during the conversation, and used back-channelling, fillers and hesitation, as they might in human communication. Furthermore, participants expected the digital assistant to understand and process complex requests mitigated with hedging words and expressions, and peppered with vague language and deictic references requiring shared contextual information and mutual understanding. Findings are presented in six themes which emerged during the analysis - formulating responses; turn-taking; back

  9. Magnification mammography: a comparison of full-field digital mammography and screen-film mammography for the detection of simulated small masses and microcalcifications

    International Nuclear Information System (INIS)

    Hermann, K.P.; Obenauer, S.; Funke, M.; Grabbe, E.H.

    2002-01-01

    The objective of this study was a comparison of a full-field digital mammography (FFDM) system and a conventional screen-film mammography (SFM) system with respect to the detectability of simulated small masses and microcalcifications in the magnification mode. All images were obtained using 1.8 times magnification. The FFDM images were obtained at radiation dose levels of 1.39, 1.0, 0.7, 0.49 and 0.24 times that of the SFM images. A contrast-detail phantom was used to compare the detection of simulated lesions using a four alternative forced-choice reader study with three readers. The correct observation ratio (COR) was calculated as the fraction of correctly identified lesions to the total number of simulated lesions. Soft-copy reading was performed for all digital images. Direct magnification images acquired with the digital system showed a lower object contrast threshold than those acquired with the conventional system. For equal radiation dose, the digital system provided a significantly increased COR (0.95) compared with the screen-film system (0.82). For simulated microcalcifications, the corresponding difference was 0.90 to 0.72. The digital system allowed equal detection to screen-film at 40% of the radiation dose used for screen film. Digital magnification images are superior to screen-film magnification images for the detection of simulated small masses and microcalcifications even at a lower radiation dose. (orig.)

  10. Digital libraries applications CBIR, education, social networks, eScience/simulation, and GIS

    CERN Document Server

    Fox, Edward A

    2014-01-01

    Digital libraries (DLs) have evolved since their launch in 1991 into an important type of information system, with widespread application. This volume advances that trend further by describing new research and development in the DL field that builds upon the 5S (Societies, Scenarios, Spaces, Structures, Streams) framework, which is discussed in three other DL volumes in this series.While the 5S framework may be used to describe many types of information systems, and is likely to have even broader utility and appeal, we focus here on digital libraries.Drawing upon six (Akbar, Kozievitch, Leidig

  11. Digital linear control theory applied to automatic stepsize control in electrical circuit simulation

    NARCIS (Netherlands)

    Verhoeven, A.; Beelen, T.G.J.; Hautus, M.L.J.; Maten, ter E.J.W.; Di Bucchianico, A.; Mattheij, R.M.M.; Peletier, M.A.

    2006-01-01

    Adaptive stepsize control is used to control the local errors of the numerical solution. For optimization purposes smoother stepsize controllers are wanted, such that the errors and stepsizes also behave smoothly. We consider approaches from digital linear control theory applied to multistep

  12. Digital linear control theory applied to automatic stepsize control in electrical circuit simulation

    NARCIS (Netherlands)

    Verhoeven, A.; Beelen, T.G.J.; Hautus, M.L.J.; Maten, ter E.J.W.

    2005-01-01

    Adaptive stepsize control is used to control the local errors of the numerical solution. For optimization purposes smoother stepsize controllers are wanted, such that the errors and stepsizes also behave smoothly. We consider approaches from digital linear control theory applied to multistep

  13. Technical study of real-time simulation system for digital I and C system of steam generator in nuclear power plant

    International Nuclear Information System (INIS)

    Shi Ji; Jiang Mingyu; Ma Yunqin

    2004-01-01

    The real-time simulation system, which forms a interactive closed circle together with the steam generator control system, has been developed using a dynamic mathematical model of steam generator in this paper. It can provide a simulation target for upgrades of digital Instrument and Control system in Nuclear Power Plant (NPP) and is applicable for further research of control schemes. With this program, the authors have studied and analyzed the response of transient parameters to some different disturbance, the calculated results are in good agreement with those calculated by NPP simulator program. This will give a theoretical analysis for upgrades of digital I and C system in nuclear power plant

  14. Modelling, simulation and experimental verification for renewable agents connected to a distorted utility grid using a Real-Time Digital Simulation Platform

    International Nuclear Information System (INIS)

    Guerrero-Rodríguez, N.F.; Rey-Boué, Alexis B.

    2014-01-01

    Highlights: • A MSOGI-FLL is used to detect the frequency. • A PR harmonic-compensator is used. • Grid-connected PV system insensitive to harmonic pollution. • RTDS reinforced the final validation of the control algorithms. • Several algorithms are combined in this paper. - Abstract: The large number of Photovoltaic plants and its utilization as agents of a Distributed Generation Systems justified the increasing efforts towards the optimal design of the overall grid-connected System. In a Distributed Generation environment the low voltage 3-phase utility grid could be affected by some disturbances such as voltage unbalanced, variations of frequency and harmonics distortion and it is mandatory that the control algorithms used in the inverter can be able to maintain the power flow between the renewable agent and the low voltage 3-phase utility grid; in addition a unitary power factor must be attained. A Proportional-Resonant regulator is used to performance a current control with the output current of the inverter and a Multiple Second Order Generalized Integrator Frequency-Locked Loop (MSOGI-FLL) is used to detect the frequency of the low voltage 3-phase utility grid. Some low order harmonics are introduced in the low voltage 3-phase utility grid in order to see the effect of the harmonic compensator. In order to validate the model of the Photovoltaic Renewable agent, the synchronization algorithm and the inverter control algorithm, some simulations using MATLAB/SIMULINK from The MathWorks, Inc. are shown firstly, and secondly, some Real-Time Digital Simulation tests using a Real-Time Digital Simulation (RTDS) Platform are carried out

  15. Ideas in Practice (3): A Simulated Laboratory Experience in Digital Design.

    Science.gov (United States)

    Cleaver, Thomas G.

    1988-01-01

    Gives an example of the use of a simplified logic simulator in a logic design course. Discusses some problems in logic design classes, commercially available software, and software problems. Describes computer-aided engineering (CAE) software. Lists 14 experiments in the simulated laboratory and presents students' evaluation of the course. (YP)

  16. Integument pattern formation involves genetic and epigenetic controls: feather arrays simulated by digital hormone models.

    Science.gov (United States)

    Jiang, Ting-Xin; Widelitz, Randall B; Shen, Wei-Min; Will, Peter; Wu, Da-Yu; Lin, Chih-Min; Jung, Han-Sung; Chuong, Cheng-Ming

    2004-01-01

    Pattern formation is a fundamental morphogenetic process. Models based on genetic and epigenetic control have been proposed but remain controversial. Here we use feather morphogenesis for further evaluation. Adhesion molecules and/or signaling molecules were first expressed homogenously in feather tracts (restrictive mode, appear earlier) or directly in bud or inter-bud regions ( de novo mode, appear later). They either activate or inhibit bud formation, but paradoxically colocalize in the bud. Using feather bud reconstitution, we showed that completely dissociated cells can reform periodic patterns without reference to previous positional codes. The patterning process has the characteristics of being self-organizing, dynamic and plastic. The final pattern is an equilibrium state reached by competition, and the number and size of buds can be altered based on cell number and activator/inhibitor ratio, respectively. We developed a Digital Hormone Model which consists of (1) competent cells without identity that move randomly in a space, (2) extracellular signaling hormones which diffuse by a reaction-diffusion mechanism and activate or inhibit cell adhesion, and (3) cells which respond with topological stochastic actions manifested as changes in cell adhesion. Based on probability, the results are cell clusters arranged in dots or stripes. Thus genetic control provides combinational molecular information which defines the properties of the cells but not the final pattern. Epigenetic control governs interactions among cells and their environment based on physical-chemical rules (such as those described in the Digital Hormone Model). Complex integument patterning is the sum of these two components of control and that is why integument patterns are usually similar but non-identical. These principles may be shared by other pattern formation processes such as barb ridge formation, fingerprints, pigmentation patterning, etc. The Digital Hormone Model can also be applied to

  17. Modeling and numerical techniques for high-speed digital simulation of nuclear power plants

    International Nuclear Information System (INIS)

    Wulff, W.; Cheng, H.S.; Mallen, A.N.

    1987-01-01

    Conventional computing methods are contrasted with newly developed high-speed and low-cost computing techniques for simulating normal and accidental transients in nuclear power plants. Six principles are formulated for cost-effective high-fidelity simulation with emphasis on modeling of transient two-phase flow coolant dynamics in nuclear reactors. Available computing architectures are characterized. It is shown that the combination of the newly developed modeling and computing principles with the use of existing special-purpose peripheral processors is capable of achieving low-cost and high-speed simulation with high-fidelity and outstanding user convenience, suitable for detailed reactor plant response analyses

  18. Simulation of 3D-treatment plans in head and neck tumors aided by matching of digitally reconstructed radiographs (DRR) and on-line distortion corrected simulator images

    International Nuclear Information System (INIS)

    Lohr, Frank; Schramm, Oliver; Schraube, Peter; Sroka-Perez, Gabriele; Seeber, Steffen; Schlepple, Gerd; Schlegel, Wolfgang; Wannenmacher, Michael

    1997-01-01

    Background and purpose: Simulation of 3D-treatment plans for head and neck malignancy is difficult due to complex anatomy. Therefore, CT-simulation and stereotactic techniques are becoming more common in the treatment preparation, overcoming the need for simulation. However, if simulation is still performed, it is an important step in the treatment preparation/execution chain, since simulation errors, if not detected immediately, can compromise the success of treatment. A recently developed PC-based system for on-line image matching and comparison of digitally reconstructed radiographs (DRR) and distortion corrected simulator monitor images that enables instant correction of field placement errors during the simulation process was evaluated. The range of field placement errors with noncomputer aided simulation is reported. Materials and methods: For 14 patients either a primary 3D-treatment plan or a 3D-boost plan after initial treatment with opposing laterals for head and neck malignancy with a coplanar or non-coplanar two- or three-field technique was simulated. After determining the robustness of the matching process and the accuracy of field placement error detection with phantom measurements, DRRs were generated from the treatment planning CT-dataset of each patient and were interactively matched with on-line simulator images that had undergone correction for geometrical distortion, using a landmark algorithm. Translational field placement errors in all three planes as well as in-plane rotational errors were studied and were corrected immediately. Results: The interactive matching process is very robust with a tolerance of <2 mm when suitable anatomical landmarks are chosen. The accuracy for detection of translational errors in phantom measurements was <1 mm and for in-plane rotational errors the accuracy had a maximum of only 1.5 deg.. For patient simulation, the mean absolute distance of the planned versus simulated isocenter was 6.4 ± 3.9 mm. The in

  19. Ergonomic aspects simulation digital online: an educational game proposal to promote environmental education.

    Science.gov (United States)

    Arbex, D F; Jappur, R; Selig, P; Varvakis, G

    2012-01-01

    This article addresses the ergonomic criteria that guide the construction of an educational game called Environmental Simulator. The focus is on environment navigation considering aspects of content architecture and its esthetics functionality.

  20. Digitized Onondaga Lake Dissolved Oxygen Concentrations and Model Simulated Values using Bayesian Monte Carlo Methods

    Data.gov (United States)

    U.S. Environmental Protection Agency — The dataset is lake dissolved oxygen concentrations obtained form plots published by Gelda et al. (1996) and lake reaeration model simulated values using Bayesian...

  1. Real-time simulation of MHD/steam power plants by digital parallel processors

    International Nuclear Information System (INIS)

    Johnson, R.M.; Rudberg, D.A.

    1981-01-01

    Attention is given to a large FORTRAN coded program which simulates the dynamic response of the MHD/steam plant on either a SEL 32/55 or VAX 11/780 computer. The code realizes a detailed first-principle model of the plant. Quite recently, in addition to the VAX 11/780, an AD-10 has been installed for usage as a real-time simulation facility. The parallel processor AD-10 is capable of simulating the MHD/steam plant at several times real-time rates. This is desirable in order to develop rapidly a large data base of varied plant operating conditions. The combined-cycle MHD/steam plant model is discussed, taking into account a number of disadvantages. The disadvantages can be overcome with the aid of an array processor used as an adjunct to the unit processor. The conversion of some computations for real-time simulation is considered

  2. Estimation variance bounds of importance sampling simulations in digital communication systems

    Science.gov (United States)

    Lu, D.; Yao, K.

    1991-01-01

    In practical applications of importance sampling (IS) simulation, two basic problems are encountered, that of determining the estimation variance and that of evaluating the proper IS parameters needed in the simulations. The authors derive new upper and lower bounds on the estimation variance which are applicable to IS techniques. The upper bound is simple to evaluate and may be minimized by the proper selection of the IS parameter. Thus, lower and upper bounds on the improvement ratio of various IS techniques relative to the direct Monte Carlo simulation are also available. These bounds are shown to be useful and computationally simple to obtain. Based on the proposed technique, one can readily find practical suboptimum IS parameters. Numerical results indicate that these bounding techniques are useful for IS simulations of linear and nonlinear communication systems with intersymbol interference in which bit error rate and IS estimation variances cannot be obtained readily using prior techniques.

  3. Simulation of continuously logical base cells (CL BC) with advanced functions for analog-to-digital converters and image processors

    Science.gov (United States)

    Krasilenko, Vladimir G.; Lazarev, Alexander A.; Nikitovich, Diana V.

    2017-10-01

    The paper considers results of design and modeling of continuously logical base cells (CL BC) based on current mirrors (CM) with functions of preliminary analogue and subsequent analogue-digital processing for creating sensor multichannel analog-to-digital converters (SMC ADCs) and image processors (IP). For such with vector or matrix parallel inputs-outputs IP and SMC ADCs it is needed active basic photosensitive cells with an extended electronic circuit, which are considered in paper. Such basic cells and ADCs based on them have a number of advantages: high speed and reliability, simplicity, small power consumption, high integration level for linear and matrix structures. We show design of the CL BC and ADC of photocurrents and their various possible implementations and its simulations. We consider CL BC for methods of selection and rank preprocessing and linear array of ADCs with conversion to binary codes and Gray codes. In contrast to our previous works here we will dwell more on analogue preprocessing schemes for signals of neighboring cells. Let us show how the introduction of simple nodes based on current mirrors extends the range of functions performed by the image processor. Each channel of the structure consists of several digital-analog cells (DC) on 15-35 CMOS. The amount of DC does not exceed the number of digits of the formed code, and for an iteration type, only one cell of DC, complemented by the device of selection and holding (SHD), is required. One channel of ADC with iteration is based on one DC-(G) and SHD, and it has only 35 CMOS transistors. In such ADCs easily parallel code can be realized and also serial-parallel output code. The circuits and simulation results of their design with OrCAD are shown. The supply voltage of the DC is 1.8÷3.3V, the range of an input photocurrent is 0.1÷24μA, the transformation time is 20÷30nS at 6-8 bit binary or Gray codes. The general power consumption of the ADC with iteration is only 50÷100μW, if the

  4. Real-time simulation of a Doubly-Fed Induction Generator based wind power system on eMEGASimRTM Real-Time Digital Simulator

    Science.gov (United States)

    Boakye-Boateng, Nasir Abdulai

    The growing demand for wind power integration into the generation mix prompts the need to subject these systems to stringent performance requirements. This study sought to identify the required tools and procedures needed to perform real-time simulation studies of Doubly-Fed Induction Generator (DFIG) based wind generation systems as basis for performing more practical tests of reliability and performance for both grid-connected and islanded wind generation systems. The author focused on developing a platform for wind generation studies and in addition, the author tested the performance of two DFIG models on the platform real-time simulation model; an average SimpowerSystemsRTM DFIG wind turbine, and a detailed DFIG based wind turbine using ARTEMiSRTM components. The platform model implemented here consists of a high voltage transmission system with four integrated wind farm models consisting in total of 65 DFIG based wind turbines and it was developed and tested on OPAL-RT's eMEGASimRTM Real-Time Digital Simulator.

  5. Integrated Design Validation: Combining Simulation and Formal Verification for Digital Integrated Circuits

    Directory of Open Access Journals (Sweden)

    Lun Li

    2006-04-01

    Full Text Available The correct design of complex hardware continues to challenge engineers. Bugs in a design that are not uncovered in early design stages can be extremely expensive. Simulation is a predominantly used tool to validate a design in industry. Formal verification overcomes the weakness of exhaustive simulation by applying mathematical methodologies to validate a design. The work described here focuses upon a technique that integrates the best characteristics of both simulation and formal verification methods to provide an effective design validation tool, referred as Integrated Design Validation (IDV. The novelty in this approach consists of three components, circuit complexity analysis, partitioning based on design hierarchy, and coverage analysis. The circuit complexity analyzer and partitioning decompose a large design into sub-components and feed sub-components to different verification and/or simulation tools based upon known existing strengths of modern verification and simulation tools. The coverage analysis unit computes the coverage of design validation and improves the coverage by further partitioning. Various simulation and verification tools comprising IDV are evaluated and an example is used to illustrate the overall validation process. The overall process successfully validates the example to a high coverage rate within a short time. The experimental result shows that our approach is a very promising design validation method.

  6. Analysis of lightning fault detection, location and protection on short and long transmission lines using Real Time Digital Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Andre Luiz Pereira de [Siemens Ltda., Sao Paulo, SP (Brazil)], E-mail: andreluiz.oliveira@siemens.com

    2007-07-01

    The purpose of this paper is to present an analysis of lightning fault detection, location and protection using numeric distance relays applied in high voltage transmission lines, more specifically in the 500 kV transmission lines of CEMIG (Brazilian Energy Utility) between the Vespasiano 2 - Neves 1 (short line - 23.9 km) and Vespasiano 2 - Mesquita (long line - 148.6 km) substations. The analysis was based on the simulations results of numeric distance protective relays on power transmission lines, realized in September 02 to 06, 2002, at Siemens AG's facilities (Erlangen - Germany), using Real Time Digital Simulator (RTDS{sup TM}). Several lightning faults simulations were accomplished, in several conditions of the electrical power system where the protective relays would be installed. The results are presented not only with the times of lightning faults elimination, but also all the functionality of a protection system, including the correct detection, location and other advantages that these modern protection devices make possible to the power system. (author)

  7. Visibility Analysis of the Oriental Pearl Based on Digital Landscape Simulation – View from East Daming Road of Shanghai

    Directory of Open Access Journals (Sweden)

    S. Liu

    2015-08-01

    Full Text Available As the demand for visual quality of environment increases, visual analysis therefore plays progressively important role in current urban landscape construction and management. Guided by the City Image theory, this paper presents a covered scene index “X” to describe the visibility of the target scene, and formulates a digital analysis model based on ArcGIS and 3D simulation. This method is applied to the viewpoint analysis from the East Daming Road of the North Bund to the Oriental Pearl in Shanghai and optimized solutions are proposed according to the results. It turns out that this simple and objective technique can serve as a good tool for the reference of urban landscape planning and management.

  8. Main control system verification and validation of NPP digital I and C system based on engineering simulator

    International Nuclear Information System (INIS)

    Lin Meng; Hou Dong; Liu Pengfei; Yang Zongwei; Yang Yanhua

    2010-01-01

    Full-scope digital instrumentation and controls system (I and C) technique is being introduced in Chinese new constructed Nuclear Power Plant (NPP), which mainly includes three parts: control system, reactor protection system and engineered safety feature actuation system. For example, SIEMENS TELEPERM XP and XS distributed control system (DCS) have been used in Ling Ao Phase II NPP, which is located in Guangdong province, China. This is the first NPP project in China that Chinese engineers are fully responsible for all the configuration of actual analog and logic diagram, although experience in NPP full-scope digital I and C is very limited. For the safety, it has to be made sure that configuration is right and control functions can be accomplished before the phase of real plant testing on reactor. Therefore, primary verification and validation (V and V) of I and C needs to be carried out. Except the common and basic way, i.e. checking the diagram configuration one by one according to original design, NPP engineering simulator is applied as another effective approach of V and V. For this purpose, a virtual NPP thermal-hydraulic model is established as a basis according to Ling Ao Phase II NPP design, and the NPP simulation tools can provide plant operation parameters to DCS, accept control signal from I and C and give response. During the test, one set of data acquisition equipments are used to build a connection between the engineering simulator (software) and SIEMENS DCS I/O cabinet (hardware). In this emulation, original diagram configuration in DCS and field hardware structures are kept unchanged. In this way, firstly judging whether there are some problems by observing the input and output of DCS without knowing the internal configuration. Then secondly, problems can be found and corrected by understanding and checking the exact and complex configuration in detail. At last, the correctness and functionality of the control system are verified. This method is

  9. Simulation of proportional control of hydraulic actuator using digital hydraulic valves

    Science.gov (United States)

    Raghuraman, D. R. S.; Senthil Kumar, S.; Kalaiarasan, G.

    2017-11-01

    Fluid power systems using oil hydraulics in earth moving and construction equipment have been using proportional and servo control valves for a long time to achieve precise and accurate position control backed by system performance. Such valves are having feedback control in them and exhibit good response, sensitivity and fine control of the actuators. Servo valves and proportional valves are possessing less hysteresis when compared to on-off type valves, but when the servo valve spools get stuck in one position, a high frequency called as jitter is employed to bring the spool back, whereas in on-off type valves it requires lesser technology to retract the spool. Hence on-off type valves are used in a technology known as digital valve technology, which caters to precise control on slow moving loads with fast switching times and with good flow and pressure control mimicking the performance of an equivalent “proportional valve” or “servo valve”.

  10. Upgrading of the KSU simulators with new digital I and C systems

    International Nuclear Information System (INIS)

    Randen, K.

    1997-01-01

    Nearly all Swedish nuclear power plants, 9 ABB Atom BWRs and 3 Westinghouse PWRs in total, are presently in various stages of modernizing their I and C systems. This includes also major changes to the main control room with the introduction of large numbers of workstations for soft process control and supervision. These modernization programs also have implications on the seven plant specific full-scope simulators used at the KSU Nuclear Training and Safety Center for operator training. The utilities are considering this training to be an integral part of their programs and have requested KSU to provide training of operators before commissioning of the new equipment in the plants. There is also a request to validate modified operating procedures with the new I and C systems integrated into the simulators. Since the utilities are using different vendors, KSU is now Working with equipment from three vendors in the upgrading of the simulators. (author)

  11. Understanding the concept of resolving power in the Fabry-Perot interferometer using a digital simulation

    International Nuclear Information System (INIS)

    Juvells, I; Carnicer, A; Ferre-Borrull, J; MartIn-Badosa, E; Montes-Usategui, M

    2006-01-01

    The resolution concept in connection with the Fabry-Perot interferometer is difficult to understand for undergraduate students enrolled in physical optics courses. The resolution criterion proposed in textbooks for distinguishing equal intensity maxima and the deduction of the resolving power equation is formal and non-intuitive. In this paper, we study the practical meaning of the resolution criterion and resolution power using a computer simulation of a Fabry-Perot interferometer. The light source in the program has two monochromatic components, the wavelength difference being tunable by the user. The student can also adjust other physical parameters so as to obtain different simulation results. By analysing the images and graphics of the simulation, the resolving power concept becomes intuitive and understandable

  12. Optimization of x-ray spectra in digital mammography through Monte Carlo simulations.

    Science.gov (United States)

    Cunha, D M; Tomal, A; Poletti, M E

    2012-04-07

    In this work, a Monte Carlo code was used to investigate the performance of different x-ray spectra in digital mammography, through a figure of merit (FOM), defined as FOM = CNR²/(¯)D(g), with CNR being the contrast-to-noise ratio in image and [Formula: see text] being the average glandular dose. The FOM was studied for breasts with different thicknesses t (2 cm ≤ t ≤ 8 cm) and glandular contents (25%, 50% and 75% glandularity). The anode/filter combinations evaluated were those traditionally employed in mammography (Mo/Mo, Mo/Rh, Rh/Rh), and a W anode combined with Al or K-edge filters (Zr, Mo, Rh, Pd, Ag, Cd, Sn), for tube potentials between 22 and 34 kVp. Results show that the W anode combined with K-edge filters provides higher values of FOM for all breast thicknesses investigated. Nevertheless, the most suitable filter and tube potential depend on the breast thickness, and for t ≥ 6 cm, they also depend on breast glandularity. Particularly for thick and dense breasts, a W anode combined with K-edge filters can greatly improve the digital technique, with the values of FOM up to 200% greater than that obtained with the anode/filter combinations and tube potentials traditionally employed in mammography. For breasts with t < 4 cm, a general good performance was obtained with the W anode combined with 60 μm of the Mo filter at 24-25 kVp, while 60 μm of the Pd filter provided a general good performance at 24-26 kVp for t = 4 cm, and at 28-30 and 29-31 kVp for t = 6 and 8 cm, respectively.

  13. Digital simulation of chronoamperometry at a disk electrode under a flat polymer film containing an enzyme

    DEFF Research Database (Denmark)

    Britz, Dieter; Strutwolf, Jörg

    2015-01-01

    Current-time and steady state current behaviour were simulated for an ultramicrodisk electrode (UMDE) inlaid flush with an insulating plane and overlaid by a flat film of polymer containing an enzyme, of various film thicknesses and essentially infinite extent. Steady state currents go through a maxim...

  14. Digital design and fabrication of simulation model for measuring orthodontic force.

    Science.gov (United States)

    Liu, Yun-Feng; Zhang, Peng-Yuan; Zhang, Qiao-Fang; Zhang, Jian-Xing; Chen, Jie

    2014-01-01

    Three dimensional (3D) forces are the key factors for determining movement of teeth during orthodontic treatment. Designing precise forces and torques on tooth before treatment can result accurate tooth movements, but it is too difficult to realize. In orthodontic biomechanical systems, the periodontal tissues, including bones, teeth, and periodontal ligaments (PDL), are affected by braces, and measuring the forces applied on the teeth by braces should be based on a simulated model composed of these three types of tissues. This study explores the design and fabrication of a simulated oral model for 3D orthodontic force measurements. Based on medical image processing, tissue reconstruction, 3D printing, and PDL simulation and testing, a model for measuring force was designed and fabricated, which can potentially be used for force prediction, design of treatment plans, and precise clinical operation. The experiment illustrated that bi-component silicones with 2:8 ratios had similar mechanical properties to PDL, and with a positioning guide, the teeth were assembled in the mandible sockets accurately, and so a customized oral model for 3D orthodontic force measurement was created.

  15. Digital quantum simulation, Schrödinger cat state spectroscopy and setting up a linear ion trap

    International Nuclear Information System (INIS)

    Hempel, C.

    2014-01-01

    This PhD thesis reports on two experiments in the field of quantum information processing using trapped calcium ions. In addition, the text covers the setup and characterization of a new linear Paul trap accompanied by a novel implementation of single-ion addressing using an acousto-optic deflector. The first of the two experiments is concerned with the proof-of-principle implementation of digital quantum simulations using up to 6 ions and 100 gate operations. It investigates the scaling behavior of simulations of elementary models of magnetism in terms of the number of involved spins and the complexity of their mutual interactions. The second experiment introduces the application of a Schroedinger cat state in the indirect detection of photon scattering events on a broad electronic transition. The method is shown to have a sensitivity down to the single photon level in a proof-of-principle demonstration using a mixed-isotope crystal of 40Ca+ and 44Ca+. A brief outlook towards future experiments and extensions of the experimental setup concludes the manuscript.(author) [de

  16. Digital simulation of an arbitrary stationary stochastic process by spectral representation.

    Science.gov (United States)

    Yura, Harold T; Hanson, Steen G

    2011-04-01

    In this paper we present a straightforward, efficient, and computationally fast method for creating a large number of discrete samples with an arbitrary given probability density function and a specified spectral content. The method relies on initially transforming a white noise sample set of random Gaussian distributed numbers into a corresponding set with the desired spectral distribution, after which this colored Gaussian probability distribution is transformed via an inverse transform into the desired probability distribution. In contrast to previous work, where the analyses were limited to auto regressive and or iterative techniques to obtain satisfactory results, we find that a single application of the inverse transform method yields satisfactory results for a wide class of arbitrary probability distributions. Although a single application of the inverse transform technique does not conserve the power spectra exactly, it yields highly accurate numerical results for a wide range of probability distributions and target power spectra that are sufficient for system simulation purposes and can thus be regarded as an accurate engineering approximation, which can be used for wide range of practical applications. A sufficiency condition is presented regarding the range of parameter values where a single application of the inverse transform method yields satisfactory agreement between the simulated and target power spectra, and a series of examples relevant for the optics community are presented and discussed. Outside this parameter range the agreement gracefully degrades but does not distort in shape. Although we demonstrate the method here focusing on stationary random processes, we see no reason why the method could not be extended to simulate non-stationary random processes. © 2011 Optical Society of America

  17. Merging LIDAR digital terrain model with direct observed elevation points for urban flood numerical simulation

    Science.gov (United States)

    Arrighi, Chiara; Campo, Lorenzo

    2017-04-01

    In last years, the concern about the economical and lives loss due to urban floods has grown hand in hand with the numerical skills in simulating such events. The large amount of computational power needed in order to address the problem (simulating a flood in a complex terrain such as a medium-large city) is only one of the issues. Among them it is possible to consider the general lack of exhaustive observations during the event (exact extension, dynamic, water level reached in different parts of the involved area), needed for calibration and validation of the model, the need of considering the sewers effects, and the availability of a correct and precise description of the geometry of the problem. In large cities the topographic surveys are in general available with a number of points, but a complete hydraulic simulation needs a detailed description of the terrain on the whole computational domain. LIDAR surveys can achieve this goal, providing a comprehensive description of the terrain, although they often lack precision. In this work an optimal merging of these two sources of geometrical information, measured elevation points and LIDAR survey, is proposed, by taking into account the error variance of both. The procedure is applied to a flood-prone city over an area of 35 square km approximately starting with a DTM from LIDAR with a spatial resolution of 1 m, and 13000 measured points. The spatial pattern of the error (LIDAR vs points) is analysed, and the merging method is tested with a series of Jackknife procedures that take into account different densities of the available points. A discussion of the results is provided.

  18. The problem of a digital simulation of Xe oscillations in power reactors

    International Nuclear Information System (INIS)

    Elzmann, H.J.

    1974-04-01

    Xe-induced power oscillations are simulated in a pressurized water reactor. The coupled balance equation for the neutrons and the decay products iodine/xenon are decoupled via a quasi-stationary approach. The stationary multigroup diffusion equation is solved with a difference method. The whole model is realized with the aid of already existing modules of the reactor program system RSYST. Its basic usefulness is established. A further expansion of the method is discussed with the aim to develop rod drive programs for real reactors. (orig./LN) [de

  19. Comparing the Performance of Commonly Available Digital Elevation Models in GIS-based Flood Simulation

    Science.gov (United States)

    Ybanez, R. L.; Lagmay, A. M. A.; David, C. P.

    2016-12-01

    With climatological hazards increasing globally, the Philippines is listed as one of the most vulnerable countries in the world due to its location in the Western Pacific. Flood hazards mapping and modelling is one of the responses by local government and research institutions to help prepare for and mitigate the effects of flood hazards that constantly threaten towns and cities in floodplains during the 6-month rainy season. Available digital elevation maps, which serve as the most important dataset used in 2D flood modelling, are limited in the Philippines and testing is needed to determine which of the few would work best for flood hazards mapping and modelling. Two-dimensional GIS-based flood modelling with the flood-routing software FLO-2D was conducted using three different available DEMs from the ASTER GDEM, the SRTM GDEM, and the locally available IfSAR DTM. All other parameters kept uniform, such as resolution, soil parameters, rainfall amount, and surface roughness, the three models were run over a 129-sq. kilometer watershed with only the basemap varying. The output flood hazard maps were compared on the basis of their flood distribution, extent, and depth. The ASTER and SRTM GDEMs contained too much error and noise which manifested as dissipated and dissolved hazard areas in the lower watershed where clearly delineated flood hazards should be present. Noise on the two datasets are clearly visible as erratic mounds in the floodplain. The dataset which produced the only feasible flood hazard map is the IfSAR DTM which delineates flood hazard areas clearly and properly. Despite the use of ASTER and SRTM with their published resolution and accuracy, their use in GIS-based flood modelling would be unreliable. Although not as accessible, only IfSAR or better datasets should be used for creating secondary products from these base DEM datasets. For developing countries which are most prone to hazards, but with limited choices for basemaps used in hazards

  20. A Software Prototype For Accessing Large Climate Simulation Data Through Digital Globe Interface

    Science.gov (United States)

    Chaudhuri, A.; Sorokine, A.

    2010-12-01

    The IPCC suite of global Earth system models produced terabytes of data for the CMIP3/AR4 archive and is expected to reach the petabyte scale by CMIP5/AR5. Dynamic downscaling of global models based on regional climate models can potentially lead to even larger data volumes. The model simulations for global or regional climate models like CCSM3 or WRF are typically run on supercomputers like the ORNL/DOE Jaguar and the results are stored on high performance storage systems. Access to these results from a user workstation is impeded by a number of factors such as enormous data size, limited bandwidth of standard office networks, data formats which are not fully supported by applications. So, a user-friendly interface for accessing and visualizing these results over standard Internet connection is required to facilitate collaborative work among geographically dispersed groups of scientists. To address this problem, we have developed a virtual globe based application which enables the scientists to query, visualize and analyze the results without the need of large data transfers to desktops and department-level servers. We have used open-source NASA WorldWind as a virtual globe platform and extended it with modules capable of visualizing model outputs stored in NetCDF format, while the data resides on the high-performance system. Based on the query placed by the scientist, our system initiates data processing routines on the high performance storage system to subset the data and reduce its size and then transfer it back to scientist's workstation through secure shell tunnel. The whole operation is kept totally transparent to the scientist and for the most part is controlled from a point-and-click GUI. The virtual globe also serves as a common platform for geospatial data, allowing smooth integration of the model simulation results with geographic data from other sources such as various web services or user-specific data in local files, if required. Also the system has

  1. Monte Carlo simulation for the estimation of the glandular breast dose for a digital breast tomosynthesis system

    International Nuclear Information System (INIS)

    Rodrigues, Leonardo; Braz, Delson; Goncalves Magalhaes, Luis Alexandre

    2015-01-01

    Digital breast tomosynthesis (DBT) is a screening and diagnostic modality that acquires images of the breast at multiple angles during a short scan. The Selenia Dimensions (Hologic, Bedford, Mass) DBT system can perform both full-field digital mammography and DBT. The system acquires 15 projections over a 15 deg. angular range (from -7.5 deg. to +7.5 deg.). An important factor in determining the optimal imaging technique for breast tomosynthesis is the radiation dose. In breast imaging, the radiation dose of concern is that deposited in the glandular tissue of the breast because this is the tissue that has a risk of developing cancer. The concept of the normalised mean glandular dose (DgN) has been introduced as the metric for the dose in breast imaging. The DgN is difficult to measure. The Monte Carlo techniques offer an alternative method for a realistic estimation of the radiation dose. The purpose of this work was to use the Monte Carlo code MCNPX technique to generate monoenergetic glandular dose data for estimating the breast tissue dose in tomosynthesis for arbitrary spectra as well as to observe the deposited radiation dose by projection on the glandular portion of the breast in a Selenia Dimensions DBT system. A Monte Carlo simulation of the system was developed to compute the DgN in a craniocaudal view. Monoenergetic X-ray beams from 10 to 49 keV in 1-keV increments were used. The simulation utilised the assumption of a homogeneous breast composition and three compositions (0 % glandular, 50 % glandular and 100 % glandular). The glandular and adipose tissue compositions were specified according ICRU Report 44. A skin layer of 4 mm was assumed to encapsulate the breast on all surfaces. The breast size was varied using the chest wall-to-nipple distance (CND) and compressed breast thickness (t). In this work, the authors assumed a CND of 5 cm and the thicknesses ranged from 2 to 8 cm, in steps of 2 cm. The fractional energy absorption increases (up to 44

  2. Patient dose simulations for scanning-beam digital x-ray tomosynthesis of the lungs

    International Nuclear Information System (INIS)

    Nelson, Geoff; Fahrig, Rebecca; Yoon, Sungwon; Krishna, Ganesh; Wilfley, Brian

    2013-01-01

    Purpose: An improved method of image guidance for lung tumor biopsies could help reduce the high rate of false negatives. The aim of this work is to optimize the geometry of the scanning-beam digital tomography system (SBDX) for providing real-time 3D tomographic reconstructions for target verification. The unique geometry of the system requires trade-offs between patient dose, imaging field of view (FOV), and tomographic angle.Methods: Tomosynthetic angle as a function of tumor-to-detector distance was calculated. Monte Carlo Software (PCXMC) was used to calculate organ doses and effective dose for source-to-detector distances (SDDs) from 90 to 150 cm, patient locations with the tumor at 20 cm from the source to 20 cm from the detector, and FOVs centered on left lung and right lung as well as medial and distal peripheries of the lungs. These calculations were done for two systems, a SBDX system and a GE OEC-9800 C-arm fluoroscopic unit. To evaluate the dose effect of the system geometry, results from PCXMC were calculated using a scan of 300 mAs for both SBDX and fluoroscopy. The Rose Criterion was used to find the fluence required for a tumor SNR of 5, factoring in scatter, air-gap, system geometry, and patient position for all models generated with PCXMC. Using the calculated fluence for constant tumor SNR, the results from PCXMC were used to compare the patient dose for a given SNR between SBDX and fluoroscopy.Results: Tomographic angle changes with SDD only in the region near the detector. Due to their geometry, the source array and detector have a peak tomographic angle for any given SDD at a source to tumor distance that is 69.7% of the SDD assuming constant source and detector size. Changing the patient location in order to increase tomographic angle has a significant effect on organ dose distribution due to geometrical considerations. With SBDX and fluoroscopy geometries, the dose to organs typically changes in an opposing manner with changing patient

  3. Patient dose simulations for scanning-beam digital x-ray tomosynthesis of the lungs

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Geoff; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Yoon, Sungwon [Varian Medical Systems, Palo Alto, California 94304 (United States); Krishna, Ganesh [Palo Alto Medical Foundation, Mountain View, California 94040 (United States); Wilfley, Brian [Triple Ring Technologies, Inc., Newark, California 94560 (United States)

    2013-11-15

    Purpose: An improved method of image guidance for lung tumor biopsies could help reduce the high rate of false negatives. The aim of this work is to optimize the geometry of the scanning-beam digital tomography system (SBDX) for providing real-time 3D tomographic reconstructions for target verification. The unique geometry of the system requires trade-offs between patient dose, imaging field of view (FOV), and tomographic angle.Methods: Tomosynthetic angle as a function of tumor-to-detector distance was calculated. Monte Carlo Software (PCXMC) was used to calculate organ doses and effective dose for source-to-detector distances (SDDs) from 90 to 150 cm, patient locations with the tumor at 20 cm from the source to 20 cm from the detector, and FOVs centered on left lung and right lung as well as medial and distal peripheries of the lungs. These calculations were done for two systems, a SBDX system and a GE OEC-9800 C-arm fluoroscopic unit. To evaluate the dose effect of the system geometry, results from PCXMC were calculated using a scan of 300 mAs for both SBDX and fluoroscopy. The Rose Criterion was used to find the fluence required for a tumor SNR of 5, factoring in scatter, air-gap, system geometry, and patient position for all models generated with PCXMC. Using the calculated fluence for constant tumor SNR, the results from PCXMC were used to compare the patient dose for a given SNR between SBDX and fluoroscopy.Results: Tomographic angle changes with SDD only in the region near the detector. Due to their geometry, the source array and detector have a peak tomographic angle for any given SDD at a source to tumor distance that is 69.7% of the SDD assuming constant source and detector size. Changing the patient location in order to increase tomographic angle has a significant effect on organ dose distribution due to geometrical considerations. With SBDX and fluoroscopy geometries, the dose to organs typically changes in an opposing manner with changing patient

  4. Virtual patient simulation in psychiatric care - A pilot study of digital support for collaborate learning.

    Science.gov (United States)

    Sunnqvist, Charlotta; Karlsson, Karin; Lindell, Lisbeth; Fors, Uno

    2016-03-01

    Psychiatric and mental health nursing is built on a trusted nurse and patient relationship. Therefore communication and clinical reasoning are two important issues. Our experiences as teachers in psychiatric educational programmes are that the students feel anxiety and fear before they start their clinical practices in psychiatry. Therefore there is a need for bridging over the fear. Technology enhanced learning might support such activities so we used Virtual patients (VPs), an interactive computer simulations of real-life clinical scenarios. The aim of this study was to investigate 4th term nursing students' opinions on the use of Virtual Patients for assessment in a Mental Health and Ill-health course module. We asked 24 volunteering students to practise with five different VP cases during almost 10 weeks before the exam. The participants were gathered together for participating in a written and an oral evaluation. The students were positive to the use of VPs in psychiatry and were very positive to use VPs in their continued nursing education. It seems that Virtual Patients can be an activity producing pedagogic model promoting students' independent knowledge development, critical thinking, reflection and problem solving ability for nurse students in psychiatric care. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Digital Controller Development Methodology Based on Real-Time Simulations with LabVIEW FPGA Hardware-Software Toolset

    Directory of Open Access Journals (Sweden)

    Tommaso Caldognetto

    2013-12-01

    Full Text Available In this paper, we exemplify the use of NI Lab-VIEW FPGA as a rapid prototyping environment for digital controllers. In our power electronics laboratory, it has been successfully employed in the development, debugging, and test of different power converter controllers for microgrid applications.The paper shows how this high level programming language,together with its target hardware platforms, including CompactRIO and Single Board RIO systems, allows researchers and students to develop even complex applications in reasonable times. The availability of efficient drivers for the considered hardware platforms frees the users from the burden of low level programming. At the same time, the high level programming approach facilitates software re-utilization, allowing the laboratory know-how to steadily grow along time. Furthermore, it allows hardware-in-the-loop real-time simulation, that proved to be effective, and safe, in debugging even complex hardware and software co-designed controllers. To illustrate the effectiveness of these hardware-software toolsets and of the methodology based upon them, two case studies are

  6. Design and Simulation of Seido Buffer for Analog to Digital Converter (ADC) on Multichannel Analyzer (MCA) Application

    International Nuclear Information System (INIS)

    Harzawadi Hasim; Maslina Ibrahim; Nolida Yusop; Mohd Ashhar Khalid

    2011-01-01

    Most of our electronic equipment has buffer, thus this make buffer as one of importance in electronic gadget. This paper introduced Single Ended Input Differential Output (SEIDO) buffer to predict the bias at approximately 2.5 V. For this purpose, the input range between -1 mV to 4 V was implemented. The software used to cascade SEIDO buffer is called LTspice IV; an open source software developed by Linear Technology Incorporation. The component involve in this development was Operational Amplifier (OP AMP) AD826 from Analog Devices Incorporation, capacitor and resistor. Kirchhoffs Current Law and Kirchhoffs Voltage Law was applied to calculated voltage gain and biasing voltage. All design has been verified by LTspice IV. The result produced from simulation was between -0.3 V to 6.3 V with bias roughly at 2.5 V. These results prove that it was capable to drive Analog Digital Converter (ADC) that can subsequently apply for Multichannel Analyzer (MCA). (author)

  7. Using LabVIEW for the design and control of digital signal processing systems. Simulation of the ultra slow extraction at COSY

    International Nuclear Information System (INIS)

    Heinrichs, G.; Rongen, H.; Jamal, R.

    1994-01-01

    For the ultraslow extraction system of the COler SYnchrotron COSY a direct digital synthesis system is being developed. LabVIEW from National Instruments has been chosen as a tool for the simulation of the digital signal processing algorithms as well as the generation of test sequences. In order to generate adjustable band-limited noise centered at a carrier frequency, alternative algorithms have been studied. LabVIEW permits the interactive variation of relevant system parameters by means of a graphical language in order to study the quality of the frequency band limitation as a function of noise parameters, digital accuracy and frequency range and to generate test sequences by means of a real-time function generator. Advantages and limitations of LabVIEW for such applications are discussed. ((orig.))

  8. Power quality improvement by using multi-pulse AC-DC converters for DC drives: Modeling, simulation and its digital implementation

    Directory of Open Access Journals (Sweden)

    Mohd Tariq

    2014-12-01

    Full Text Available The paper presents the modeling, simulation and digital implementation of power quality improvement of DC drives by using multi pulse AC–DC converter. As it is a well-known fact that power quality determines the fitness of electrical power to consumer devices, hence an effort has been made to improve power quality in this work. Simulation and digital implementation with the help of MATLAB/Simulink has been done and results obtained are discussed in detail to verify the theoretical results. The multipulse converter was connected with DC drives and was run at no load condition to find out the transient and steady state performances. FFT analysis has been performed and Total Harmonic Distortion (THD results obtained at different pulses are shown here.

  9. Design of a digital beam attenuation system for computed tomography: Part I. System design and simulation framework

    International Nuclear Information System (INIS)

    Szczykutowicz, Timothy P.; Mistretta, Charles A.

    2013-01-01

    Purpose: The purpose of this work is to introduce a new device that allows for patient-specific imaging-dose modulation in conventional and cone-beam CT. The device is called a digital beam attenuator (DBA). The DBA modulates an x-ray beam by varying the attenuation of a set of attenuating wedge filters across the fan angle. The ability to modulate the imaging dose across the fan beam represents another stride in the direction of personalized medicine. With the DBA, imaging dose can be tailored for a given patient anatomy, or even tailored to provide signal-to-noise ratio enhancement within a region of interest. This modulation enables decreases in: dose, scatter, detector dynamic range requirements, and noise nonuniformities. In addition to introducing the DBA, the simulation framework used to study the DBA under different configurations is presented. Finally, a detailed study on the choice of the material used to build the DBA is presented. Methods: To change the attenuator thickness, the authors propose to use an overlapping wedge design. In this design, for each wedge pair, one wedge is held stationary and another wedge is moved over the stationary wedge. The composite thickness of the two wedges changes as a function of the amount of overlap between the wedges. To validate the DBA concept and study design changes, a simulation environment was constructed. The environment allows for changes to system geometry, different source spectra, DBA wedge design modifications, and supports both voxelized and analytic phantom models. A study of all the elements from atomic number 1 to 92 were evaluated for use as DBA filter material. The amount of dynamic range and tube loading for each element were calculated for various DBA designs. Tube loading was calculated by comparing the attenuation of the DBA at its minimum attenuation position to a filtered non-DBA acquisition. Results: The design and parametrization of DBA implemented FFMCT has been introduced. A simulation

  10. Development of a system based in a digital signal processor (DSP) for a simulator of power regulation in a reactor: first stage

    International Nuclear Information System (INIS)

    Benitez R, J.S.; Perez C, B.

    2002-01-01

    The first stage of the development of a digital system based on a DSP is presented which forms part of an hybrid simulator for the power regulation in am model of the punctual kinetics of a TRIGA reactor type. The DSP performs the regulation, using a Mandami type algorithm of diffuse control. In the algorithm, the universe of the output variable is discretized for performing in an unique stage the aggregation functions and dis-diffusization. (Author)

  11. Test of the little Higgs model in Atlas at LHC: simulation of the digitization of the electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Lechowski, M.

    2005-04-01

    LHC is a proton-proton collider with an energy of 14 TeV in the center of mass, which will start operating in 2007 at CERN. Two of its experiments, ATLAS, and CMS, will search and study in particular the Higgs boson, Supersymmetry and other new physics. This thesis was about two aspects of the ATLAS experiment. On one hand the simulation of the liquid Argon electromagnetic calorimeter, with the emulation of the electronic chain in charge of the digitization of the signal and also the evaluation of the electronic noise and the pile-up noise (coming from minimum bias events of inelastic collisions at LHC). These two points have been validated by the analysis of the data taken during beam tests in 2002 and 2004. On the other hand, a physics study concerning the Little Higgs model. This recent model solves the hierarchy problem of the Standard Model, in introducing new heavy particles to cancel quadratic divergences arising in the calculation of the Higgs boson mass. These new particles, with a mass about the TeV/c 2 , are a heavy quark top, heavy gauge bosons Z H , W H and A H , and a heavy Higgs boson triplet. The physics study dealt with the characteristic decays of the model, Z H in Z + H and W H in W + H, with a Higgs mass either at 120 GeV/c 2 decaying in two photons or at 200 GeV/c 2 decaying in ZZ or WW. Results show that in both cases, for 300 fb -1 (3 years at high luminosity), an observation of the signal at 5 σ for Z H et W H masses less than 2 TeV/c 2 is possible, covering a large part of the parameter space. (author)

  12. COUNTS-IN-CYLINDERS IN THE SLOAN DIGITAL SKY SURVEY WITH COMPARISONS TO N-BODY SIMULATIONS

    International Nuclear Information System (INIS)

    Berrier, Heather D.; Barton, Elizabeth J.; Bullock, James S.; Berrier, Joel C.; Zentner, Andrew R.; Wechsler, Risa H.

    2011-01-01

    Environmental statistics provide a necessary means of comparing the properties of galaxies in different environments, and a vital test of models of galaxy formation within the prevailing hierarchical cosmological model. We explore counts-in-cylinders, a common statistic defined as the number of companions of a particular galaxy found within a given projected radius and redshift interval. Galaxy distributions with the same two-point correlation functions do not necessarily have the same companion count distributions. We use this statistic to examine the environments of galaxies in the Sloan Digital Sky Survey Data Release 4 (SDSS DR4). We also make preliminary comparisons to four models for the spatial distributions of galaxies, based on N-body simulations and data from SDSS DR4, to study the utility of the counts-in-cylinders statistic. There is a very large scatter between the number of companions a galaxy has and the mass of its parent dark matter halo and the halo occupation, limiting the utility of this statistic for certain kinds of environmental studies. We also show that prevalent empirical models of galaxy clustering, that match observed two- and three-point clustering statistics well, fail to reproduce some aspects of the observed distribution of counts-in-cylinders on 1, 3, and 6 h -1 Mpc scales. All models that we explore underpredict the fraction of galaxies with few or no companions in 3 and 6 h -1 Mpc cylinders. Roughly 7% of galaxies in the real universe are significantly more isolated within a 6 h -1 Mpc cylinder than the galaxies in any of the models we use. Simple phenomenological models that map galaxies to dark matter halos fail to reproduce high-order clustering statistics in low-density environments.

  13. Simulación digital de procesos de construcción de estructura en concreto: casos de estudio práctico en Bogotá Digital simulation of concrete structure construction: practical case-study in Bogota

    Directory of Open Access Journals (Sweden)

    Diego Echeverry

    2008-08-01

    Full Text Available Se están desarrollando actividades de simulación digital de procesos encaminadas a modelar la construcción de la estructura de muros y losas en concreto en proyectos inmobiliarios de una firma constructora colombiana. En un primer proyecto se generaron modelos que permitieron emitir recomendaciones prácticas para reducir el tiempo total de construcción. Actualmente se está concluyendo otro proceso de modelación aplicado en un proyecto nuevo de la misma firma constructora. Con estas herramientas de simulación se logra poner en manos de los planeadores de proyectos un instrumento que permite evaluar diferentes escenarios de manera probabilística, permitiendo así una mejor toma de decisiones ante condiciones de incertidumbre.Activities are in progress to develop digital simulation of the construction of structural walls and slabs made of concrete, in building projects of a Colombian construction firm. In an initial project, the models that were generated allowed to produce recommendations to reduce the total construction time. At present another simulation process is concluding, applied to two new construction projects of the same firm. With these simulation tools the planning staff can evaluate different scenarios with a probabilistic approach, enabling an improved decision making in uncertain conditions.

  14. A feasibility study of projection-based energy weighting based on a photon-counting detector in contrast-enhanced digital subtraction mammography: a simulation study

    International Nuclear Information System (INIS)

    Choi, Sunghoon; Lee, Seungwan; Choi, Yuna; Kim, Heejoung

    2014-01-01

    Contrast media, such as iodine and gadolinium, are generally used in digital subtraction mammography to enhance the contrast between target and background materials. In digital subtraction mammography, where one image (with contrast medium) is subtracted from another (anatomical background) to facilitate visualization of the tumor structure, tumors can be more easily distinguished after the injection of a contrast medium. In order to have more an effective method to increase the contrast-to-noise ratio (CNR), we applied a projection-based energy-weighting method. The purpose of this study is to demonstrate the feasibility of using the projection-based energy-weighting method in digital subtraction mammography. Unlike some other previous studies, we applied the projection-based energy-weighting method to more practical mammography conditions by using the Monte Carlo method to simulate four different iodine solutions embedded in a breast phantom comprised of 50% adipose and 50% glandular tissues. We also considered an optimal tube voltage and anode/filter combination in digital iodine contrast media mammography in order to maximize the figure-of-merit (FOM). The simulated source energy was from 20 to 45 keV to prevent electronic noise and include the k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy-weighting improved the CNR by factors of 1.05 - 1.86 compared to the conventionally integrated images. Consequently, the CNR of digital subtraction mammography images can be improved by using projection-based energy-weighting with photon-counting detectors.

  15. A feasibility study of projection-based energy weighting based on a photon-counting detector in contrast-enhanced digital subtraction mammography: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sunghoon; Lee, Seungwan; Choi, Yuna; Kim, Heejoung [Yonsei University, Wonju (Korea, Republic of)

    2014-06-15

    Contrast media, such as iodine and gadolinium, are generally used in digital subtraction mammography to enhance the contrast between target and background materials. In digital subtraction mammography, where one image (with contrast medium) is subtracted from another (anatomical background) to facilitate visualization of the tumor structure, tumors can be more easily distinguished after the injection of a contrast medium. In order to have more an effective method to increase the contrast-to-noise ratio (CNR), we applied a projection-based energy-weighting method. The purpose of this study is to demonstrate the feasibility of using the projection-based energy-weighting method in digital subtraction mammography. Unlike some other previous studies, we applied the projection-based energy-weighting method to more practical mammography conditions by using the Monte Carlo method to simulate four different iodine solutions embedded in a breast phantom comprised of 50% adipose and 50% glandular tissues. We also considered an optimal tube voltage and anode/filter combination in digital iodine contrast media mammography in order to maximize the figure-of-merit (FOM). The simulated source energy was from 20 to 45 keV to prevent electronic noise and include the k-edge energy of iodine (33.2 keV). The results showed that the projection-based energy-weighting improved the CNR by factors of 1.05 - 1.86 compared to the conventionally integrated images. Consequently, the CNR of digital subtraction mammography images can be improved by using projection-based energy-weighting with photon-counting detectors.

  16. Integration of airborne Thematic Mapper Simulator (TMS) data and digitized aerial photography via an ISH transformation. [Intensity Saturation Hue

    Science.gov (United States)

    Ambrosia, Vincent G.; Myers, Jeffrey S.; Ekstrand, Robert E.; Fitzgerald, Michael T.

    1991-01-01

    A simple method for enhancing the spatial and spectral resolution of disparate data sets is presented. Two data sets, digitized aerial photography at a nominal spatial resolution 3,7 meters and TMS digital data at 24.6 meters, were coregistered through a bilinear interpolation to solve the problem of blocky pixel groups resulting from rectification expansion. The two data sets were then subjected to intensity-saturation-hue (ISH) transformations in order to 'blend' the high-spatial-resolution (3.7 m) digitized RC-10 photography with the high spectral (12-bands) and lower spatial (24.6 m) resolution TMS digital data. The resultant merged products make it possible to perform large-scale mapping, ease photointerpretation, and can be derived for any of the 12 available TMS spectral bands.

  17. Digital broadcasting

    International Nuclear Information System (INIS)

    Park, Ji Hyeong

    1999-06-01

    This book contains twelve chapters, which deals with digitization of broadcast signal such as digital open, digitization of video signal and sound signal digitization of broadcasting equipment like DTPP and digital VTR, digitization of equipment to transmit such as digital STL, digital FPU and digital SNG, digitization of transmit about digital TV transmit and radio transmit, digital broadcasting system on necessity and advantage, digital broadcasting system abroad and Korea, digital broadcasting of outline, advantage of digital TV, ripple effect of digital broadcasting and consideration of digital broadcasting, ground wave digital broadcasting of DVB-T in Europe DTV in U.S.A and ISDB-T in Japan, HDTV broadcasting, satellite broadcasting, digital TV broadcasting in Korea, digital radio broadcasting and new broadcasting service.

  18. Dosimetric characterization and organ dose assessment in digital breast tomosynthesis: Measurements and Monte Carlo simulations using voxel phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Mariana, E-mail: marianabaptista@ctn.ist.utl.pt; Di Maria, Salvatore; Barros, Sílvia; Vaz, Pedro [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139,7, Bobadela LRS 2695-066 (Portugal); Figueira, Catarina [Centre for Plasma Physics, School of Mathematics and Physics, Queen’s University, Belfast BT7 1NN (United Kingdom); Sarmento, Marta; Orvalho, Lurdes [Serviço de Imagiologia, Hospital da Luz, Avenida Lusíada, 100, Lisboa 1500-650 (Portugal)

    2015-07-15

    Purpose: Due to its capability to more accurately detect deep lesions inside the breast by removing the effect of overlying anatomy, digital breast tomosynthesis (DBT) has the potential to replace the standard mammography technique in clinical screening exams. However, the European Guidelines for DBT dosimetry are still a work in progress and there are little data available on organ doses other than to the breast. It is, therefore, of great importance to assess the dosimetric performance of DBT with respect to the one obtained with standard digital mammography (DM) systems. The aim of this work is twofold: (i) to study the dosimetric properties of a combined DBT/DM system (MAMMOMAT Inspiration Siemens{sup ®}) for a tungsten/rhodium (W/Rh) anode/filter combination and (ii) to evaluate organs doses during a DBT examination. Methods: For the first task, measurements were performed in manual and automatic exposure control (AEC) modes, using two homogeneous breast phantoms: a PMMA slab phantom and a 4 cm thick breast-shaped rigid phantom, with 50% of glandular tissue in its composition. Monte Carlo (MC) simulations were performed using Monte Carlo N-Particle eXtended v.2.7.0. A MC model was implemented to mimic DM and DBT acquisitions for a wide range of x-ray spectra (24 –34 kV). This was used to calculate mean glandular dose (MGD) and to compute series of backscatter factors (BSFs) that could be inserted into the DBT dosimetric formalism proposed by Dance et al. Regarding the second aim of the study, the implemented MC model of the clinical equipment, together with a female voxel phantom (“Laura”), was used to calculate organ doses considering a typical DBT acquisition. Results were compared with a standard two-view mammography craniocaudal (CC) acquisition. Results: Considering the AEC mode, the acquisition of a single CC view results in a MGD ranging from 0.53 ± 0.07 mGy to 2.41 ± 0.31 mGy in DM mode and from 0.77 ± 0.11 mGy to 2.28 ± 0.32 mGy in DBT mode

  19. Budget Impact Analysis of Switching to Digital Mammography in a Population-Based Breast Cancer Screening Program: A Discrete Event Simulation Model

    Science.gov (United States)

    Comas, Mercè; Arrospide, Arantzazu; Mar, Javier; Sala, Maria; Vilaprinyó, Ester; Hernández, Cristina; Cots, Francesc; Martínez, Juan; Castells, Xavier

    2014-01-01

    Objective To assess the budgetary impact of switching from screen-film mammography to full-field digital mammography in a population-based breast cancer screening program. Methods A discrete-event simulation model was built to reproduce the breast cancer screening process (biennial mammographic screening of women aged 50 to 69 years) combined with the natural history of breast cancer. The simulation started with 100,000 women and, during a 20-year simulation horizon, new women were dynamically entered according to the aging of the Spanish population. Data on screening were obtained from Spanish breast cancer screening programs. Data on the natural history of breast cancer were based on US data adapted to our population. A budget impact analysis comparing digital with screen-film screening mammography was performed in a sample of 2,000 simulation runs. A sensitivity analysis was performed for crucial screening-related parameters. Distinct scenarios for recall and detection rates were compared. Results Statistically significant savings were found for overall costs, treatment costs and the costs of additional tests in the long term. The overall cost saving was 1,115,857€ (95%CI from 932,147 to 1,299,567) in the 10th year and 2,866,124€ (95%CI from 2,492,610 to 3,239,638) in the 20th year, representing 4.5% and 8.1% of the overall cost associated with screen-film mammography. The sensitivity analysis showed net savings in the long term. Conclusions Switching to digital mammography in a population-based breast cancer screening program saves long-term budget expense, in addition to providing technical advantages. Our results were consistent across distinct scenarios representing the different results obtained in European breast cancer screening programs. PMID:24832200

  20. Fully iterative scatter corrected digital breast tomosynthesis using GPU-based fast Monte Carlo simulation and composition ratio update

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyungsang; Ye, Jong Chul, E-mail: jong.ye@kaist.ac.kr [Bio Imaging and Signal Processing Laboratory, Department of Bio and Brain Engineering, KAIST 291, Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Lee, Taewon; Cho, Seungryong [Medical Imaging and Radiotherapeutics Laboratory, Department of Nuclear and Quantum Engineering, KAIST 291, Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Seong, Younghun; Lee, Jongha; Jang, Kwang Eun [Samsung Advanced Institute of Technology, Samsung Electronics, 130, Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 443-803 (Korea, Republic of); Choi, Jaegu; Choi, Young Wook [Korea Electrotechnology Research Institute (KERI), 111, Hanggaul-ro, Sangnok-gu, Ansan-si, Gyeonggi-do, 426-170 (Korea, Republic of); Kim, Hak Hee; Shin, Hee Jung; Cha, Joo Hee [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro, 43-gil, Songpa-gu, Seoul, 138-736 (Korea, Republic of)

    2015-09-15

    Purpose: In digital breast tomosynthesis (DBT), scatter correction is highly desirable, as it improves image quality at low doses. Because the DBT detector panel is typically stationary during the source rotation, antiscatter grids are not generally compatible with DBT; thus, a software-based scatter correction is required. This work proposes a fully iterative scatter correction method that uses a novel fast Monte Carlo simulation (MCS) with a tissue-composition ratio estimation technique for DBT imaging. Methods: To apply MCS to scatter estimation, the material composition in each voxel should be known. To overcome the lack of prior accurate knowledge of tissue composition for DBT, a tissue-composition ratio is estimated based on the observation that the breast tissues are principally composed of adipose and glandular tissues. Using this approximation, the composition ratio can be estimated from the reconstructed attenuation coefficients, and the scatter distribution can then be estimated by MCS using the composition ratio. The scatter estimation and image reconstruction procedures can be performed iteratively until an acceptable accuracy is achieved. For practical use, (i) the authors have implemented a fast MCS using a graphics processing unit (GPU), (ii) the MCS is simplified to transport only x-rays in the energy range of 10–50 keV, modeling Rayleigh and Compton scattering and the photoelectric effect using the tissue-composition ratio of adipose and glandular tissues, and (iii) downsampling is used because the scatter distribution varies rather smoothly. Results: The authors have demonstrated that the proposed method can accurately estimate the scatter distribution, and that the contrast-to-noise ratio of the final reconstructed image is significantly improved. The authors validated the performance of the MCS by changing the tissue thickness, composition ratio, and x-ray energy. The authors confirmed that the tissue-composition ratio estimation was quite

  1. Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study

    International Nuclear Information System (INIS)

    Molon, Rafael Scaf; Morais Camillo, Juliana Aparecida Najarro Dearo; Ferreira, Mauricio Goncalves; Loffredo, Leonor Castro Monteiro; Scaf, Gulnara; Sakakura, Celso Eduardo

    2012-01-01

    This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC 95% :6.04-6.54) and 6.79 mm (IC 95% :6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64 mm(IC 95% :6.40-6.89) and 6.79 mm(IC 95% :6.45-7.11), respectively. The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

  2. Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Molon, Rafael Scaf; Morais Camillo, Juliana Aparecida Najarro Dearo; Ferreira, Mauricio Goncalves; Loffredo, Leonor Castro Monteiro; Scaf, Gulnara [Araraquara Dental School, Universidade Estadual Paulista, Sao Paulo (Brazil); Sakakura, Celso Eduardo [Barretos Dental School, Barretos Educational Fundation, Sao Paulo (Brazil)

    2012-09-15

    This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC{sub 95%}:6.04-6.54) and 6.79 mm (IC{sub 95%}:6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64 mm(IC{sub 95%}:6.40-6.89) and 6.79 mm(IC{sub 95%}:6.45-7.11), respectively. The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

  3. Simulation of dynamic behaviour of a digital displacement motor using transient 3d computational fluid dynamics analysis

    DEFF Research Database (Denmark)

    Rømer, Daniel; Johansen, Per; Pedersen, Henrik C.

    2013-01-01

    . Movement of the low and high pressure valves is coupled to fluid forces and valve actuation is included to control the valve movement according to the pressure cycle of the digital displacement motor. The fluid domain is meshed using a structured/unstructured non-conformal mesh, which is updated throughout...

  4. Development of digital phantoms based on a finite element model to simulate low-attenuation areas in CT imaging for pulmonary emphysema quantification.

    Science.gov (United States)

    Diciotti, Stefano; Nobis, Alessandro; Ciulli, Stefano; Landini, Nicholas; Mascalchi, Mario; Sverzellati, Nicola; Innocenti, Bernardo

    2017-09-01

    To develop an innovative finite element (FE) model of lung parenchyma which simulates pulmonary emphysema on CT imaging. The model is aimed to generate a set of digital phantoms of low-attenuation areas (LAA) images with different grades of emphysema severity. Four individual parameter configurations simulating different grades of emphysema severity were utilized to generate 40 FE models using ten randomizations for each setting. We compared two measures of emphysema severity (relative area (RA) and the exponent D of the cumulative distribution function of LAA clusters size) between the simulated LAA images and those computed directly on the models output (considered as reference). The LAA images obtained from our model output can simulate CT-LAA images in subjects with different grades of emphysema severity. Both RA and D computed on simulated LAA images were underestimated as compared to those calculated on the models output, suggesting that measurements in CT imaging may not be accurate in the assessment of real emphysema extent. Our model is able to mimic the cluster size distribution of LAA on CT imaging of subjects with pulmonary emphysema. The model could be useful to generate standard test images and to design physical phantoms of LAA images for the assessment of the accuracy of indexes for the radiologic quantitation of emphysema.

  5. Simulating single-phase and two-phase non-Newtonian fluid flow of a digital rock scanned at high resolution

    Science.gov (United States)

    Tembely, Moussa; Alsumaiti, Ali M.; Jouini, Mohamed S.; Rahimov, Khurshed; Dolatabadi, Ali

    2017-11-01

    Most of the digital rock physics (DRP) simulations focus on Newtonian fluids and overlook the detailed description of rock-fluid interaction. A better understanding of multiphase non-Newtonian fluid flow at pore-scale is crucial for optimizing enhanced oil recovery (EOR). The Darcy scale properties of reservoir rocks such as the capillary pressure curves and the relative permeability are controlled by the pore-scale behavior of the multiphase flow. In the present work, a volume of fluid (VOF) method coupled with an adaptive meshing technique is used to perform the pore-scale simulation on a 3D X-ray micro-tomography (CT) images of rock samples. The numerical model is based on the resolution of the Navier-Stokes equations along with a phase fraction equation incorporating the dynamics contact model. The simulations of a single phase flow for the absolute permeability showed a good agreement with the literature benchmark. Subsequently, the code is used to simulate a two-phase flow consisting of a polymer solution, displaying a shear-thinning power law viscosity. The simulations enable to access the impact of the consistency factor (K), the behavior index (n), along with the two contact angles (advancing and receding) on the relative permeability.

  6. Simulation of digital pixel readout chip architectures with the RD53 SystemVerilog-UVM verification environment using Monte Carlo physics data

    International Nuclear Information System (INIS)

    Conti, E.; Marconi, S.; Christiansen, J.; Placidi, P.; Hemperek, T.

    2016-01-01

    The simulation and verification framework developed by the RD53 collaboration is a powerful tool for global architecture optimization and design verification of next generation hybrid pixel readout chips. In this paper the framework is used for studying digital pixel chip architectures at behavioral level. This is carried out by simulating a dedicated, highly parameterized pixel chip description, which makes it possible to investigate different grouping strategies between pixels and different latency buffering and arbitration schemes. The pixel hit information used as simulation input can be either generated internally in the framework or imported from external Monte Carlo detector simulation data. The latter have been provided by both the CMS and ATLAS experiments, featuring HL-LHC operating conditions and the specifications related to the Phase 2 upgrade. Pixel regions and double columns were simulated using such Monte Carlo data as inputs: the performance of different latency buffering architectures was compared and the compliance of different link speeds with the expected column data rate was verified

  7. Digital positron annihilation spectrometer

    International Nuclear Information System (INIS)

    Cheng Bin; Weng Huimin; Han Rongdian; Ye Bangjiao

    2010-01-01

    With the high speed development of digital signal process, the technique of the digitization and processing of signals was applied in the domain of a broad class of nuclear technique. The development of digital positron lifetime spectrometer (DPLS) is more promising than the conventional positron lifetime spectrometer equipped with nuclear instrument modules. And digital lifetime spectrometer has many advantages, such as low noise, long term stability, flexible online or offline digital processing, simple setup, low expense, easy to setting, and more physical information. Digital constant fraction discrimination is for timing. And a new method of optimizing energy windows setting for digital positron lifetime spectrometer is also developed employing the simulated annealing for the convenient use. The time resolution is 220ps and the count rate is 200cps. (authors)

  8. Developing Digital Dashboard Management for Learning System Dynamic Cooperative Simulation Behavior of Indonesia. (Study on Cooperative Information Organization in the Ministry of Cooperatives and SME)

    Science.gov (United States)

    Eni, Yuli; Aryanto, Rudy

    2014-03-01

    There are problems being experienced by the Ministry of cooperatives and SME (Small and Medium Enterprise) including the length of time in the decision by the Government to establish a policy that should be taken for local cooperatives across the province of Indonesia. The decision-making process is still analyzed manually, so that sometimes the decisions taken are also less appropriate, effective and efficient. The second problem is the lack of monitoring data cooperative process province that is too much, making it difficult for the analysis of dynamic information to be useful. Therefore the authors want to fix the system that runs by using digital dashboard management system supported by the modeling of system dynamics. In addition, the author also did the design of a system that can support the system. Design of this system is aimed to ease the experts, head, and the government to decide (DSS - Decision Support System) accurately effectively and efficiently, because in the system are raised alternative simulation in a description of the decision to be taken and the result from the decision. The system is expected to be designed dan simulated can ease and expedite the decision making. The design of dynamic digital dashboard management conducted by method of OOAD (Objects Oriented Analysis and Design) complete with UML notation.

  9. DESIGN OF AN EDUCATIONAL SIMULATION PROGRAM USING DIGITAL VIDEO PROCESSING TO DETERMINE THE THERMAL EXPANSION OF MATERIALS

    Directory of Open Access Journals (Sweden)

    V. Gökhan BÖCEKÇİ

    2013-01-01

    Full Text Available The present report describes the realization of an educational simulation program to determine the amount of linear thermal expansion in experimental materials. An interferogram signal derived from an interferometric measurement system was modeled as a video signal in a computer environment. A simulation program was designed from the model signal in order to detect the amount of expansion in materials. The simulation program determined the amount of to heat by detecting the number of fringes in interferogram video signals of the material. This simulation program facilitated experimental studies n academic institutions which are deprived of interferometric measurement systems.

  10. Contribution to the aid to computer-aided design. Simulation of digital and logical sets. The CHAMBOR software

    International Nuclear Information System (INIS)

    Mansuy, Guy

    1973-01-01

    This report presents a simulation software which belongs to a set of software aimed at the design, analysis, test and tracing of electronic and logical assemblies. This software simulates the operation in time, and considers the propagation of signals through the network elements, with taking the delay created by each of them into account. The author presents some generalities (modules, description, library, simulation of a network in function of time), proposes a general and then a detailed description of the software: data interpretation, processing of dynamic data and network simulation, display of results on a graphical workstation

  11. Simulations

    CERN Document Server

    Ngada, Narcisse

    2015-06-15

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  12. Effects of exposure equalization on image signal-to-noise ratios in digital mammography: A simulation study with an anthropomorphic breast phantom

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xinming; Lai Chaojen; Whitman, Gary J.; Geiser, William R.; Shen Youtao; Yi Ying; Shaw, Chris C. [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4009 (United States); Department of Diagnostic Radiology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4009 (United States); Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030-4009 (United States)

    2011-12-15

    Purpose: The scan equalization digital mammography (SEDM) technique combines slot scanning and exposure equalization to improve low-contrast performance of digital mammography in dense tissue areas. In this study, full-field digital mammography (FFDM) images of an anthropomorphic breast phantom acquired with an anti-scatter grid at various exposure levels were superimposed to simulate SEDM images and investigate the improvement of low-contrast performance as quantified by primary signal-to-noise ratios (PSNRs). Methods: We imaged an anthropomorphic breast phantom (Gammex 169 ''Rachel,'' Gammex RMI, Middleton, WI) at various exposure levels using a FFDM system (Senographe 2000D, GE Medical Systems, Milwaukee, WI). The exposure equalization factors were computed based on a standard FFDM image acquired in the automatic exposure control (AEC) mode. The equalized image was simulated and constructed by superimposing a selected set of FFDM images acquired at 2, 1, 1/2, 1/4, 1/8, 1/16, and 1/32 times of exposure levels to the standard AEC timed technique (125 mAs) using the equalization factors computed for each region. Finally, the equalized image was renormalized regionally with the exposure equalization factors to result in an appearance similar to that with standard digital mammography. Two sets of FFDM images were acquired to allow for two identically, but independently, formed equalized images to be subtracted from each other to estimate the noise levels. Similarly, two identically but independently acquired standard FFDM images were subtracted to estimate the noise levels. Corrections were applied to remove the excess system noise accumulated during image superimposition in forming the equalized image. PSNRs over the compressed area of breast phantom were computed and used to quantitatively study the effects of exposure equalization on low-contrast performance in digital mammography. Results: We found that the highest achievable PSNR improvement

  13. Effects of exposure equalization on image signal-to-noise ratios in digital mammography: A simulation study with an anthropomorphic breast phantom

    International Nuclear Information System (INIS)

    Liu Xinming; Lai Chaojen; Whitman, Gary J.; Geiser, William R.; Shen Youtao; Yi Ying; Shaw, Chris C.

    2011-01-01

    Purpose: The scan equalization digital mammography (SEDM) technique combines slot scanning and exposure equalization to improve low-contrast performance of digital mammography in dense tissue areas. In this study, full-field digital mammography (FFDM) images of an anthropomorphic breast phantom acquired with an anti-scatter grid at various exposure levels were superimposed to simulate SEDM images and investigate the improvement of low-contrast performance as quantified by primary signal-to-noise ratios (PSNRs). Methods: We imaged an anthropomorphic breast phantom (Gammex 169 ''Rachel,'' Gammex RMI, Middleton, WI) at various exposure levels using a FFDM system (Senographe 2000D, GE Medical Systems, Milwaukee, WI). The exposure equalization factors were computed based on a standard FFDM image acquired in the automatic exposure control (AEC) mode. The equalized image was simulated and constructed by superimposing a selected set of FFDM images acquired at 2, 1, 1/2, 1/4, 1/8, 1/16, and 1/32 times of exposure levels to the standard AEC timed technique (125 mAs) using the equalization factors computed for each region. Finally, the equalized image was renormalized regionally with the exposure equalization factors to result in an appearance similar to that with standard digital mammography. Two sets of FFDM images were acquired to allow for two identically, but independently, formed equalized images to be subtracted from each other to estimate the noise levels. Similarly, two identically but independently acquired standard FFDM images were subtracted to estimate the noise levels. Corrections were applied to remove the excess system noise accumulated during image superimposition in forming the equalized image. PSNRs over the compressed area of breast phantom were computed and used to quantitatively study the effects of exposure equalization on low-contrast performance in digital mammography. Results: We found that the highest achievable PSNR improvement factor was 1.89 for

  14. Blending technology in teaching advanced health assessment in a family nurse practitioner program: using personal digital assistants in a simulation laboratory.

    Science.gov (United States)

    Elliott, Lydia; DeCristofaro, Claire; Carpenter, Alesia

    2012-09-01

    This article describes the development and implementation of integrated use of personal handheld devices (personal digital assistants, PDAs) and high-fidelity simulation in an advanced health assessment course in a graduate family nurse practitioner (NP) program. A teaching tool was developed that can be utilized as a template for clinical case scenarios blending these separate technologies. Review of the evidence-based literature, including peer-reviewed articles and reviews. Blending the technologies of high-fidelity simulation and handheld devices (PDAs) provided a positive learning experience for graduate NP students in a teaching laboratory setting. Combining both technologies in clinical case scenarios offered a more real-world learning experience, with a focus on point-of-care service and integration of interview and physical assessment skills with existing standards of care and external clinical resources. Faculty modeling and advance training with PDA technology was crucial to success. Faculty developed a general template tool and systems-based clinical scenarios integrating PDA and high-fidelity simulation. Faculty observations, the general template tool, and one scenario example are included in this article. ©2012 The Author(s) Journal compilation ©2012 American Academy of Nurse Practitioners.

  15. Dosimetric quality control of treatment planning systems in external radiation therapy using Digital Test Objects calculated by PENELOPE Monte-Carlo simulations

    International Nuclear Information System (INIS)

    Ben Hdech, Yassine

    2011-01-01

    To ensure the required accuracy and prevent from mis-administration, cancer treatments, by external radiation therapy are simulated on Treatment Planning System or TPS before radiation delivery in order to ensure that the prescription is achieved both in terms of target volumes coverage and healthy tissues protection. The TPS calculates the patient dose distribution and the treatment time per beam required to deliver the prescribed dose. TPS is a key system in the decision process of treatment by radiation therapy. It is therefore essential that the TPS be subject to a thorough check of its performance (quality control or QC) and in particular its ability to accurately compute dose distributions for patients in all clinical situations that be met. The 'traditional' methods recommended to carry out dosimetric CQ of algorithms implemented in the TPS are based on comparisons between dose distributions calculated with the TPS and dose measured in physical test objects (PTO) using the treatment machine. In this thesis we propose to substitute the reference dosimetric measurements performed in OTP by benchmark dose calculations in Digital Test Objects using PENELOPE Monte-Carlo code. This method has three advantages: (i) it allows simulation in situations close to the clinic and often too complex to be experimentally feasible; (ii) due to the digital form of reference data the QC process may be automated; (iii) it allows a comprehensive TPS CQ without hindering the use of an equipment devoted primarily to patients treatments. This new method of CQ has been tested successfully on the Eclipse TPS from Varian Medical Systems Company. (author) [fr

  16. SU-F-J-204: Carbon Digitally Reconstructed Radiography (CDRR): A GPU Based Tool for Fast and Versatile Carbonimaging Simulation

    International Nuclear Information System (INIS)

    Dias, M F; Seco, J; Baroni, G; Riboldi, M

    2016-01-01

    Purpose: Research in carbon imaging has been growing over the past years, as a way to increase treatment accuracy and patient positioning in carbon therapy. The purpose of this tool is to allow a fast and flexible way to generate CDRR data without the need to use Monte Carlo (MC) simulations. It can also be used to predict future clinically measured data. Methods: A python interface has been developed, which uses information from CT or 4DCT and thetreatment calibration curve to compute the Water Equivalent Path Length (WEPL) of carbon ions. A GPU based ray tracing algorithm computes the WEPL of each individual carbon traveling through the CT voxels. A multiple peak detection method to estimate high contrast margin positioning has been implemented (described elsewhere). MC simulations have been used to simulate carbons depth dose curves in order to simulate the response of a range detector. Results: The tool allows the upload of CT or 4DCT images. The user has the possibility to selectphase/slice of interested as well as position, angle…). The WEPL is represented as a range detector which can be used to assess range dilution and multiple peak detection effects. The tool also provides knowledge of the minimum energy that should be considered for imaging purposes. The multiple peak detection method has been used in a lung tumor case, showing an accuracy of 1mm in determine the exact interface position. Conclusion: The tool offers an easy and fast way to simulate carbon imaging data. It can be used for educational and for clinical purposes, allowing the user to test beam energies and angles before real acquisition. An analysis add-on is being developed, where the used will have the opportunity to select different reconstruction methods and detector types (range or energy). Fundacao para a Ciencia e a Tecnologia (FCT), PhD Grant number SFRH/BD/85749/2012

  17. SU-F-J-204: Carbon Digitally Reconstructed Radiography (CDRR): A GPU Based Tool for Fast and Versatile Carbonimaging Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Dias, M F [Dipartamento di Elettronica, Informazione e Bioingegneria - DEIB, Politecnico di Milano (Italy); Department of Radiation Oncology, Francis H. Burr Proton Therapy Center Massachusetts General Hospital (MGH), Boston, Massachusetts (United States); Seco, J [Department of Radiation Oncology, Francis H. Burr Proton Therapy Center Massachusetts General Hospital (MGH), Boston, Massachusetts (United States); Baroni, G; Riboldi, M [Dipartamento di Elettronica, Informazione e Bioingegneria - DEIB, Politecnico di Milano (Italy); Bioengineering Unit, Centro Nazionale di Adroterapia Oncologica, Pavia (Italy)

    2016-06-15

    Purpose: Research in carbon imaging has been growing over the past years, as a way to increase treatment accuracy and patient positioning in carbon therapy. The purpose of this tool is to allow a fast and flexible way to generate CDRR data without the need to use Monte Carlo (MC) simulations. It can also be used to predict future clinically measured data. Methods: A python interface has been developed, which uses information from CT or 4DCT and thetreatment calibration curve to compute the Water Equivalent Path Length (WEPL) of carbon ions. A GPU based ray tracing algorithm computes the WEPL of each individual carbon traveling through the CT voxels. A multiple peak detection method to estimate high contrast margin positioning has been implemented (described elsewhere). MC simulations have been used to simulate carbons depth dose curves in order to simulate the response of a range detector. Results: The tool allows the upload of CT or 4DCT images. The user has the possibility to selectphase/slice of interested as well as position, angle…). The WEPL is represented as a range detector which can be used to assess range dilution and multiple peak detection effects. The tool also provides knowledge of the minimum energy that should be considered for imaging purposes. The multiple peak detection method has been used in a lung tumor case, showing an accuracy of 1mm in determine the exact interface position. Conclusion: The tool offers an easy and fast way to simulate carbon imaging data. It can be used for educational and for clinical purposes, allowing the user to test beam energies and angles before real acquisition. An analysis add-on is being developed, where the used will have the opportunity to select different reconstruction methods and detector types (range or energy). Fundacao para a Ciencia e a Tecnologia (FCT), PhD Grant number SFRH/BD/85749/2012.

  18. Design of a digital system for operational parameters simulation of IPR-R1 TRIGA nuclear research reactor

    International Nuclear Information System (INIS)

    Lage, Aldo M.F.; Mesquita, Amir Z.; Felippe, Adriano de A.M.

    2017-01-01

    The instrumentation of nuclear reactors is designed based on the reliability, redundancy and diversification of control systems. The monitoring of the parameters is of crucial importance with regard to the operational efficiency and safety of the installation. Since the first criticality of a nuclear reactor, achieved by Fermi et al. in 1942, there has been concern about the reliable monitoring of the parameters involved in the chain reaction. This paper presents the current stage of the system of simulation, which is under development at the CDTN, which intends to simulate the operation of the TRIGA IPR-R1 nuclear reactor, involving the evolution of neutron flux and reactor power related events. The system will be developed using LabVIEW® software, using the modern concept of virtual instruments (VIs) that are visualized in a video monitor. For the implementation of this model, computational tools and systems analysis are necessary, which help and facilitate the implementation of the simulator. In this article we will show some of these techniques and the initial design of the model to be implemented. The design of a computational system is of great importance, since it guides in the implementation stages and generates the documentation for later maintenance and updating of the computational system. It is noteworthy that the innovations developed in research reactors are normally used in power reactors. The relatively low costs enable research reactors to be an excellent laboratory for developing techniques for future reactors. (author)

  19. Design of a digital system for operational parameters simulation of IPR-R1 TRIGA nuclear research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lage, Aldo M.F.; Mesquita, Amir Z.; Felippe, Adriano de A.M., E-mail: aldo@cdtn.br, E-mail: amir@cdtn.br, E-mail: adrianoamfelippe@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN /CNEN-MG), Belo Horizonte, MG (Brazil); Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2017-11-01

    The instrumentation of nuclear reactors is designed based on the reliability, redundancy and diversification of control systems. The monitoring of the parameters is of crucial importance with regard to the operational efficiency and safety of the installation. Since the first criticality of a nuclear reactor, achieved by Fermi et al. in 1942, there has been concern about the reliable monitoring of the parameters involved in the chain reaction. This paper presents the current stage of the system of simulation, which is under development at the CDTN, which intends to simulate the operation of the TRIGA IPR-R1 nuclear reactor, involving the evolution of neutron flux and reactor power related events. The system will be developed using LabVIEW® software, using the modern concept of virtual instruments (VIs) that are visualized in a video monitor. For the implementation of this model, computational tools and systems analysis are necessary, which help and facilitate the implementation of the simulator. In this article we will show some of these techniques and the initial design of the model to be implemented. The design of a computational system is of great importance, since it guides in the implementation stages and generates the documentation for later maintenance and updating of the computational system. It is noteworthy that the innovations developed in research reactors are normally used in power reactors. The relatively low costs enable research reactors to be an excellent laboratory for developing techniques for future reactors. (author)

  20. Wind turbine rotor blade monitoring using digital image correlation: a comparison to aeroelastic simulations of a multi-megawatt wind turbine

    International Nuclear Information System (INIS)

    Winstroth, J; Ernst, B; Seume, J R; Schoen, L

    2014-01-01

    Optical full-field measurement methods such as Digital Image Correlation (DIC) provide a new opportunity for measuring deformations and vibrations with high spatial and temporal resolution. However, application to full-scale wind turbines is not trivial. Elaborate preparation of the experiment is vital and sophisticated post processing of the DIC results essential. In the present study, a rotor blade of a 3.2 MW wind turbine is equipped with a random black-and-white dot pattern at four different radial positions. Two cameras are located in front of the wind turbine and the response of the rotor blade is monitored using DIC for different turbine operations. In addition, a Light Detection and Ranging (LiDAR) system is used in order to measure the wind conditions. Wind fields are created based on the LiDAR measurements and used to perform aeroelastic simulations of the wind turbine by means of advanced multibody codes. The results from the optical DIC system appear plausible when checked against common and expected results. In addition, the comparison of relative out-ofplane blade deflections shows good agreement between DIC results and aeroelastic simulations

  1. Wind turbine rotor blade monitoring using digital image correlation: a comparison to aeroelastic simulations of a multi-megawatt wind turbine

    Science.gov (United States)

    Winstroth, J.; Schoen, L.; Ernst, B.; Seume, J. R.

    2014-06-01

    Optical full-field measurement methods such as Digital Image Correlation (DIC) provide a new opportunity for measuring deformations and vibrations with high spatial and temporal resolution. However, application to full-scale wind turbines is not trivial. Elaborate preparation of the experiment is vital and sophisticated post processing of the DIC results essential. In the present study, a rotor blade of a 3.2 MW wind turbine is equipped with a random black-and-white dot pattern at four different radial positions. Two cameras are located in front of the wind turbine and the response of the rotor blade is monitored using DIC for different turbine operations. In addition, a Light Detection and Ranging (LiDAR) system is used in order to measure the wind conditions. Wind fields are created based on the LiDAR measurements and used to perform aeroelastic simulations of the wind turbine by means of advanced multibody codes. The results from the optical DIC system appear plausible when checked against common and expected results. In addition, the comparison of relative out-ofplane blade deflections shows good agreement between DIC results and aeroelastic simulations.

  2. Digital simulation of two-dimensional random fields with arbitrary power spectra and non-Gaussian probability distribution functions.

    Science.gov (United States)

    Yura, Harold T; Hanson, Steen G

    2012-04-01

    Methods for simulation of two-dimensional signals with arbitrary power spectral densities and signal amplitude probability density functions are disclosed. The method relies on initially transforming a white noise sample set of random Gaussian distributed numbers into a corresponding set with the desired spectral distribution, after which this colored Gaussian probability distribution is transformed via an inverse transform into the desired probability distribution. In most cases the method provides satisfactory results and can thus be considered an engineering approach. Several illustrative examples with relevance for optics are given.

  3. The use of digital simulation to improve the cyclic voltammetric determination of rate constants for homogeneous chemical reactions following charge transfers

    International Nuclear Information System (INIS)

    Mozo, J.D.; Carbajo, J.; Sturm, J.C.; Nunez-Vergara, L.J.; Moscoso, R.; Squella, J.A.

    2011-01-01

    Cyclic voltammetry (CV) is a very useful electrochemical tool used to study reaction systems that include chemical steps that are coupled to electron transfers. This type of system generally involves the chemical reaction of an electrochemically generated free radical. Published methods exist that are used to determine the kinetics of electrochemically initiated chemical reactions from the measurements of the peak current ratio (i pa /i pc ) of a cyclic voltammogram. The published method requires working curves to relate a kinetic parameter to the peak current ratio. In the presented work, a digital simulation package was used to obtain improved working curves for specific working conditions. The curves were compared with the published results for the first- and second-order chemical reactions following the charge transfer step mechanisms. According to the presented results, the previously published working curve is reliable for a mechanism with a first-order chemical reaction; however, a change in the switching potential requires a recalculation of the curve. In the case of mechanisms with a second-order step (dimerisation and disproportionation), several different views exist on how the second-order chemical term should be expressed so that different values of the constant are obtained. Parameters such as electrode type, electrode area, electroactive species concentration, switching potential, scan rate and method for peak current ratio calculation modify the working curves and must always be specified. We propose a standardised method to obtain the most reliable kinetic constant values. The results of this work will permit researchers who handle simulation software to construct their own working curves. Additionally, those who do not have the simulation software could use the working curves described here. The revelations of the presented experiments may be useful to a broad chemistry audience because this study presents a simple and low-cost procedure for the

  4. Student-directed investigation of natural phenomena: Using digital simulations to achieve NGSS-aligned 3D learning in middle school

    Science.gov (United States)

    Selvans, M. M.; Spafford, C. D.

    2016-12-01

    Many Earth Science phenomena cannot be observed directly because they happen slowly (e.g., Plate Motion) or at large spatial scales (e.g., Weather Patterns). Such topics are investigated by scientists through analysis of large data sets, numerical modeling, and laboratory studies that isolate aspects of the overall phenomena. Middle school students have limited time and lab equipment in comparison, but can employ authentic science practices through investigations using interactive digital simulations (sims). Designing a sim aligned to the Next Generation Science Standards (NGSS) allows students to explore and connect to science ideas in a seamless and supportive way that also deepens their understanding of the phenomena. We helped develop seven units, including the two above, that cover the middle school Earth Science Disciplinary Core Ideas and give students exposure to the other two dimensions of the NGSS (science practices and cross-cutting concepts). These units are developed by the Learning Design Group and Amplify Science. Sims are key to how students engage in 3D learning in these units. For example, in the Rock Transformations Sim students can investigate the ideas that energy from the sun and from Earth's interior can transform rock, and that the transformation processes change the Earth's surface at varying time and spatial scales (ESS2.A). Students can choose and selectively apply transformation processes (melting, weathering, etc.) or energy sources to rock in a cross-section landscape to explore their effects. Students are able to plan steps for making a particular rock transformation happen and carry out their own investigations. A benefit of using a digital platform for student learning is the ability to embed formative assessment. When students plan and carry out missions to achieve specific objectives, the digital platform can capture a record of their actions to measure how they apply science ideas from instruction. Data of these actions, combined

  5. Optimization of the resolution of remotely sensed digital elevation model to facilitate the simulation and spatial propagation of flood events in flat areas

    Science.gov (United States)

    Karapetsas, Nikolaos; Skoulikaris, Charalampos; Katsogiannos, Fotis; Zalidis, George; Alexandridis, Thomas

    2013-04-01

    The use of satellite remote sensing products, such as Digital Elevation Models (DEMs), under specific computational interfaces of Geographic Information Systems (GIS) has fostered and facilitated the acquisition of data on specific hydrologic features, such as slope, flow direction and flow accumulation, which are crucial inputs to hydrology or hydraulic models at the river basin scale. However, even though DEMs of different resolution varying from a few km up to 20m are freely available for the European continent, these remotely sensed elevation data are rather coarse in cases where large flat areas are dominant inside a watershed, resulting in an unsatisfactory representation of the terrain characteristics. This scientific work aims at implementing a combing interpolation technique for the amelioration of the analysis of a DEM in order to be used as the input ground model to a hydraulic model for the assessment of potential flood events propagation in plains. More specifically, the second version of the ASTER Global Digital Elevation Model (GDEM2), which has an overall accuracy of around 20 meters, was interpolated with a vast number of aerial control points available from the Hellenic Mapping and Cadastral Organization (HMCO). The uncertainty that was inherent in both the available datasets (ASTER & HMCO) and the appearance of uncorrelated errors and artifacts was minimized by incorporating geostatistical filtering. The resolution of the produced DEM was approximately 10 meters and its validation was conducted with the use of an external dataset of 220 geodetic survey points. The derived DEM was then used as an input to the hydraulic model InfoWorks RS, whose operation is based on the relief characteristics contained in the ground model, for defining, in an automated way, the cross section parameters and simulating the flood spatial distribution. The plain of Serres, which is located in the downstream part of the Struma/Strymon transboundary river basin shared

  6. Digital radiography

    International Nuclear Information System (INIS)

    Brody, W.R.

    1984-01-01

    Digital Radiography begins with an orderly introduction to the fundamental concepts of digital imaging. The entire X-ray digital imagining system is described, from an overall characterization of image quality to specific components required for a digital radiographic system. Because subtraction is central to digital radiographic systems, the author details the use of various subtraction methods for image enhancement. Complex concepts are illustrated with numerous examples and presented in terms that can readily be understood by physicians without an advanced mathematics background. The second part of the book discusses implementations and applications of digital imagining systems based on area and scanned detector technologies. This section includes thorough coverage of digital fluoroscopy, scanned projection radiography, and film-based digital imaging systems, and features a state-of-the-art synopsis of the applications of digital subtraction angiography. The book concludes with a timely assessment of anticipated technological advances

  7. La simulación digital como herramienta para el reacondicionamiento bioclimático de edificios = Digital simulation as a tool for bioclimatic re-conditioning of buildings

    Directory of Open Access Journals (Sweden)

    Andrea Sancho Salas

    2017-04-01

    Full Text Available El presente estudio propone e implementa una metodología para analizar el comportamiento de edificios existentes en respuesta a variables climáticas y geográficas específicas, mediante el uso de simulaciones termodinámicas digitales que permitan modificaciones para mejorar el confort interno. El análisis se realizó por medio de seis casos de estudio ubicados en tres zonas de vida de Costa Rica: Bosque Seco Tropical (Bs-T, Bosque Húmedo Premontano (Bh-p y Bosque Muy Húmedo Premontano (Bmh-p. Las edificaciones estudiadas son iglesias vernaculares de la época de 1901-1950. La metodología permite identificar los factores principales que influyen dentro del comportamiento térmico interior y establecer cuáles modificaciones se pueden implementar para lograr mayor bienestar, tanto en los casos de estudio, como en futuros diseños con condiciones similares. Abstract The present study proposes and implements a methodology to analyze the behavior of existing buildings in response to specific climatic and geographic variables, through the use of digital thermodynamic simulations that allow modifications to improve internal comfort. The analysis was carried out by means of six case studies located in three zones of life of Costa Rica: Tropical Dry Forest (Bs-T, Premontane Wet Forest (Bh-p and Premontane Very Humid Forest (Bmh-p. The buildings studied are vernacular churches dating from 1901-1950. The methodology allows to identify the main factors that influence the internal thermal behavior and to establish which modifications can be implemented to achieve greater welfare, both in the case studies and in future designs with similar conditions.

  8. Real-Time Digital Simulation of Inertial Response with Hardware-in-the-Loop Implementation on the CART3 Wind Turbine at the National Wind Technology Center

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Wenzhong; Wang, Xiao; Muljadi, Eduard; Gevorgian, Vahan; Scholbrock, Andrew

    2017-09-01

    With increasing penetrations of wind power on electric grids, the stability and reliability of interconnected power systems may be impacted. In some countries that have developed renewable energy sources and systems, grid codes have been revised to require wind power plants (WPPs) to provide ancillary services to support the power system frequency in case of severe grid events. To do this, wind turbine generators (WTGs) should be deloaded to reserve a certain amount of active power for primary frequency response; however, deloading curtails annual energy production, and the market for this type of service needs to be further developed. In this report, we focus on the temporary frequency support provided by WTGs through inertial response. WTGs have potential to provide inertial response, but appropriate control methods should be implemented. With the implemented inertial control methods, wind turbines are capable of increasing their active power output by releasing some of their stored kinetic energy when a frequency excursion occurs. Active power can be temporarily boosted above the maximum power points, after which the rotor speed decelerates, and subsequently an active power output reduction restores the kinetic energy. In this report, we develop two types of models for wind power systems: the first is common, based on the wind power aerodynamic equation, and the power coefficient can be regressed using nonlinear functions; the second is much more complicated, wherein the wind turbine system is modeled using the Fatigue, Aerodynamics, Structures, and Turbulence Modeling (FAST) tool with several degrees of freedoms. A nine-bus test power system is built in Simulink and the Real-Time Digital Simulator, respectively, which are used to evaluate the frequency support performance of the WPPs. We implement two distinct types of inertial control methods in the modeled wind turbines: frequency-based inertial control (FBIC) and stepwise inertial control (SIC). We compare

  9. Digital Culture and Digital Library

    Directory of Open Access Journals (Sweden)

    Yalçın Yalçınkaya

    2016-12-01

    Full Text Available In this study; digital culture and digital library which have a vital connection with each other are examined together. The content of the research consists of the interaction of culture, information, digital culture, intellectual technologies, and digital library concepts. The study is an entry work to integrity of digital culture and digital library theories and aims to expand the symmetry. The purpose of the study is to emphasize the relation between the digital culture and digital library theories acting intersection of the subjects that are examined. Also the perspective of the study is based on examining the literature and analytical evaluation in both studies (digital culture and digital library. Within this context, the methodology of the study is essentially descriptive and has an attribute for the transmission and synthesis of distributed findings produced in the field of the research. According to the findings of the study results, digital culture is an inclusive term that describes the effects of intellectual technologies in the field of information and communication. Information becomes energy and the spectrum of the information is expanding in the vertical rise through the digital culture. In this context, the digital library appears as a new living space of a new environment. In essence, the digital library is information-oriented; has intellectual technology support and digital platform; is in a digital format; combines information resources and tools in relationship/communication/cooperation by connectedness, and also it is the dynamic face of the digital culture in time and space independence. Resolved with the study is that the digital libraries are active and effective in the formation of global knowing and/or mass wisdom in the process of digital culture.

  10. Dose optimization for dual-energy contrast-enhanced digital mammography based on an energy-resolved photon-counting detector: A Monte Carlo simulation study

    International Nuclear Information System (INIS)

    Lee, Youngjin; Lee, Seungwan; Kang, Sooncheol; Eom, Jisoo

    2017-01-01

    Dual-energy contrast-enhanced digital mammography (CEDM) has been used to decompose breast images and improve diagnostic accuracy for tumor detection. However, this technique causes an increase of radiation dose and an inaccuracy in material decomposition due to the limitations of conventional X-ray detectors. In this study, we simulated the dual-energy CEDM with an energy-resolved photon-counting detector (ERPCD) for reducing radiation dose and improving the quantitative accuracy of material decomposition images. The ERPCD-based dual-energy CEDM was compared to the conventional dual-energy CEDM in terms of radiation dose and quantitative accuracy. The correlation between radiation dose and image quality was also evaluated for optimizing the ERPCD-based dual-energy CEDM technique. The results showed that the material decomposition errors of the ERPCD-based dual-energy CEDM were 0.56–0.67 times lower than those of the conventional dual-energy CEDM. The imaging performance of the proposed technique was optimized at the radiation dose of 1.09 mGy, which is a half of the MGD for a single view mammogram. It can be concluded that the ERPCD-based dual-energy CEDM with an optimal exposure level is able to improve the quality of material decomposition images as well as reduce radiation dose. - Highlights: • Dual-energy mammography based on a photon-counting detector was simulated. • Radiation dose and image quality were evaluated for optimizing the proposed technique. • The proposed technique reduced radiation dose as well as improved image quality. • The proposed technique was optimized at the radiation dose of 1.09 mGy.

  11. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable p...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used....

  12. The Influence of E-learning Use to Student Cognitive Performance and Motivation in Digital Simulation Course

    Directory of Open Access Journals (Sweden)

    Tigowati Tigowati

    2017-12-01

    Full Text Available Currently the technology is growing and sophisticated. Technological advances have also entered the world of education. One of them their is  online learning. Examples of learning that utilizes technology that is using Schoology and Edmodo. By using Schoology and Edmodo is expected to increase student motivation and learning outcomes. This study investigates whether the use of different learning management would affect (1 the student’s cognitive achievement (2 student’s motivation (3 the level motivation. This research method using mixed methods. The data collection technique using the test method to determine the cognitive performance. Questionnaires and interviews to find the motivation. The analysis of quantitative data using normality test, homogeneity test, tests of balance and hypothesis testing using independent t test, while the analysis of qualitative data using interactive models. Based on the results of the study (1 there are differences in the cognitive performance between classes that use e-learning based Schoology and e-learning based Edmodo. The cognitive performance classes that use Schoology better than the class that uses Edmodo, because schoology easiness to acces, the students has a target value, better understand the lesson and more active in study this may have an effect on cognitive performance.(2 there is a difference in motivation between classes that use e-learning based Schoology and e-learning based Edmodo. Motivation class with Schoology based e-learning is better than classes with e-learning based Edmodo, because schoology can interested in simulation course, more passion, make happy, easier to learn anywhere and more motivated to learn. (3 the level of motivation of students using e-learning based Schoology and Edmodo included in the medium category

  13. Dose optimization for dual-energy contrast-enhanced digital mammography based on an energy-resolved photon-counting detector: A Monte Carlo simulation study

    Science.gov (United States)

    Lee, Youngjin; Lee, Seungwan; Kang, Sooncheol; Eom, Jisoo

    2017-03-01

    Dual-energy contrast-enhanced digital mammography (CEDM) has been used to decompose breast images and improve diagnostic accuracy for tumor detection. However, this technique causes an increase of radiation dose and an inaccuracy in material decomposition due to the limitations of conventional X-ray detectors. In this study, we simulated the dual-energy CEDM with an energy-resolved photon-counting detector (ERPCD) for reducing radiation dose and improving the quantitative accuracy of material decomposition images. The ERPCD-based dual-energy CEDM was compared to the conventional dual-energy CEDM in terms of radiation dose and quantitative accuracy. The correlation between radiation dose and image quality was also evaluated for optimizing the ERPCD-based dual-energy CEDM technique. The results showed that the material decomposition errors of the ERPCD-based dual-energy CEDM were 0.56-0.67 times lower than those of the conventional dual-energy CEDM. The imaging performance of the proposed technique was optimized at the radiation dose of 1.09 mGy, which is a half of the MGD for a single view mammogram. It can be concluded that the ERPCD-based dual-energy CEDM with an optimal exposure level is able to improve the quality of material decomposition images as well as reduce radiation dose.

  14. Digital mammography; Mamografia digital

    Energy Technology Data Exchange (ETDEWEB)

    Chevalier, M.; Torres, R.

    2010-07-01

    Mammography represents one of the most demanding radiographic applications, simultaneously requiring excellent contrast sensitivity, high spatial resolution, and wide dynamic range. Film/screen is the most widely extended image receptor in mammography due to both its high spatial resolution and contrast. The film/screen limitations are related with its narrow latitude, structural noise and that is at the same time the medium for the image acquisition, storage and presentation. Several digital detector made with different technologies can overcome these difficulties. Here, these technologies as well as their main advantages and disadvantages are analyzed. Also it is discussed its impact on the mammography examinations, mainly on the breast screening programs. (Author).

  15. Digital Tectonics

    DEFF Research Database (Denmark)

    Christiansen, Karl; Borup, Ruben; Søndergaard, Asbjørn

    2014-01-01

    Digital Tectonics treats the architectonical possibilities in digital generation of form and production. The publication is the first volume of a series, in which aspects of the strategic focus areas of the Aarhus School of Architecture will be disseminated.......Digital Tectonics treats the architectonical possibilities in digital generation of form and production. The publication is the first volume of a series, in which aspects of the strategic focus areas of the Aarhus School of Architecture will be disseminated....

  16. Digital squares

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Kim, Chul E

    1988-01-01

    Digital squares are defined and their geometric properties characterized. A linear time algorithm is presented that considers a convex digital region and determines whether or not it is a digital square. The algorithm also determines the range of the values of the parameter set of its preimages....... The analysis involves transforming the boundary of a digital region into parameter space of slope and y-intercept...

  17. Digital skrivedidaktik

    DEFF Research Database (Denmark)

    Digital skrivedidaktik består af to dele. Første del præsenterer teori om skrivekompetence og digital skrivning. Digital skrivning er karakteriseret ved at tekster skrives på computer og med digitale værktøjer, hvilket ændrer skrivningens traditionelle praksis, produkt og processer. Hvad er digital...... om elevens skriveproces) og Blogskrivning (der styrker eleverne i at bruge blogs i undervisningen)....

  18. Digital Citizenship

    Science.gov (United States)

    Isman, Aytekin; Canan Gungoren, Ozlem

    2014-01-01

    Era in which we live is known and referred as digital age.In this age technology is rapidly changed and developed. In light of these technological advances in 21st century, schools have the responsibility of training "digital citizen" as well as a good citizen. Digital citizens must have extensive skills, knowledge, Internet and …

  19. Simulation

    CERN Document Server

    Ross, Sheldon

    2006-01-01

    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  20. Digital subtraktion

    DEFF Research Database (Denmark)

    Mussmann, Bo Redder

    2004-01-01

    Digital subtraktion er en metode til at fjerne uønskede oplysninger i et røntgenbillede. Subtraktionsteknikken bruges primært i forbindelse med angiografi hvor man kun er interesseret i at se selve karret. Derfor er digital subtraktion i daglig tale synonymt med DSA eller DVI – hhv. Digital...... Subtraction Angiography eller Digital Vascular Imaging. Benævnelserne er to røntgenfirmaers navn for den samme teknik. Digital subtraktion kræver speciel software, samt at apparaturet kan eksponere i serier....

  1. Digital preservation

    CERN Document Server

    Deegan, Marilyn

    2013-01-01

    Digital preservation is an issue of huge importance to the library and information profession right now. With the widescale adoption of the internet and the rise of the world wide web, the world has been overwhelmed by digital information. Digital data is being produced on a massive scale by individuals and institutions: some of it is born, lives and dies only in digital form, and it is the potential death of this data, with its impact on the preservation of culture, that is the concern of this book. So how can information professionals try to remedy this? Digital preservation is a complex iss

  2. Digital Natives or Digital Tribes?

    Science.gov (United States)

    Watson, Ian Robert

    2013-01-01

    This research builds upon the discourse surrounding digital natives. A literature review into the digital native phenomena was undertaken and found that researchers are beginning to identify the digital native as not one cohesive group but of individuals influenced by other factors. Primary research by means of questionnaire survey of technologies…

  3. Digital Communication and Modulation

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2011-01-01

    system. Having passed the course, the student will be able to accomplish the following, within the areas shown below: Model for Communication System. Prepare and explain the functional block in a digital communication system, corresponding to the specific course contents. Model for Communication Channel...... system.   Sessions in class with active participation by the students. The time will be divided between lectures and the students solving problems, including simulating digital communication building blocks in Matlab. Combines lectures and hands-on work. Semester: E2011 Extent: 7.5 ects......, the fundamental principles for modulation and detection in Gaussian noise is treated. This includes the principles for the determination of the bit-error rate for a digital communication system. During the course, a selection of small Matlab exercises are prepared, for simulation of parts of a communication...

  4. Digital Communication and Modulation

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2011-01-01

    system. Having passed the course, the student will be able to accomplish the following, within the areas shown below: Model for Communication System. Prepare and explain the functional block in a digital communication system, corresponding to the specific course contents. Model for Communication Channel...... system. Sessions in class with active participation by the students. The time will be divided between lectures and the students solving problems, including simulating digital communication building blocks in Matlab. Combines lectures and hands-on work. Semester: F2011 Extent: 7.5 ects......, the fundamental principles for modulation and detection in Gaussian noise is treated. This includes the principles for the determination of the bit-error rate for a digital communication system. During the course, a selection of small Matlab exercises are prepared, for simulation of parts of a communication...

  5. Digital mammography

    International Nuclear Information System (INIS)

    Bick, Ulrich; Diekmann, Felix

    2010-01-01

    This state-of-the-art reference book provides in-depth coverage of all aspects of digital mammography, including detector technology, image processing, computer-aided diagnosis, soft-copy reading, digital workflow, and PACS. Specific advantages and disadvantages of digital mammography in comparison to screen-film mammography are thoroughly discussed. By including authors from both North America and Europe, the book is able to outline variations in the use, acceptance, and quality assurance of digital mammography between the different countries and screening programs. Advanced imaging techniques and future developments such as contrast mammography and digital breast tomosynthesis are also covered in detail. All of the chapters are written by internationally recognized experts and contain numerous high-quality illustrations. This book will be of great interest both to clinicians who already use or are transitioning to digital mammography and to basic scientists working in the field. (orig.)

  6. Digital Insights

    DEFF Research Database (Denmark)

    Knudsen, Gry Høngsmark

    , by incorporating media as both channel, frame, and apparatus for advertising response, the dissertation brings into attention that more aspects than the text-reader relationship influence ad response. Finally, the dissertation proposes the assemblage approach for exploring big data in consumer culture research...... and practices with digital media, when they meet and interpret advertising. Through studies of advertising response on YouTube and experiments with consumers’ response to digitally manipulated images, the dissertation shows how digital media practices facilitate polysemic and socially embedded advertising......This dissertation forwards the theory of digital consumer-response as a perspective to examine how digital media practices influence consumers’ response to advertising. Digital consumer-response is a development of advertising theory that encompasses how consumers employ their knowledge...

  7. Digital Signage

    OpenAIRE

    Fischer, Karl Peter

    2011-01-01

    Digital Signage for in-store advertising at gas stations/retail stores in Germany: A field study Digital Signage networks provide a novel means of advertising with the advantage of easily changeable and highly customizable animated content. Despite the potential and increasing use of these media empirical research is scarce. In a field study at 8 gas stations (with integrated convenience stores) we studied the effect of digital signage advertising on sales for different products and servi...

  8. Sports Digitalization

    DEFF Research Database (Denmark)

    Xiao, Xiao; Hedman, Jonas; Tan, Felix Ter Chian

    2017-01-01

    evolution, as digital technologies are increasingly entrenched in a wide range of sporting activities and for applications beyond mere performance enhancement. Despite such trends, research on sports digitalization in the IS discipline is surprisingly still nascent. This paper aims at establishing...... a discourse on sports digitalization within the discipline. Toward this, we first provide an understanding of the institutional characteristics of the sports industry, establishing its theoretical importance and relevance in our discipline; second, we reveal the latest trends of digitalization in the sports...

  9. Digital printing

    Science.gov (United States)

    Sobotka, Werner K.

    1997-02-01

    Digital printing is described as a tool to replace conventional printing machines completely. Still this goal was not reached until now with any of the digital printing technologies to be described in the paper. Productivity and costs are still the main parameters and are not really solved until now. Quality in digital printing is no problem anymore. Definition of digital printing is to transfer digital datas directly on the paper surface. This step can be carried out directly or with the use of an intermediate image carrier. Keywords in digital printing are: computer- to-press; erasable image carrier; image carrier with memory. Digital printing is also the logical development of the new digital area as it is pointed out in Nicholas Negropotes book 'Being Digital' and also the answer to networking and Internet technologies. Creating images text and color in one country and publishing the datas in another country or continent is the main advantage. Printing on demand another big advantage and last but not least personalization the last big advantage. Costs and being able to coop with this new world of prepress technology is the biggest disadvantage. Therefore the very optimistic growth rates for the next few years are really nonexistent. The development of complete new markets is too slow and the replacing of old markets is too small.

  10. Digitization errors using digital charge division positionsensitive detectors

    International Nuclear Information System (INIS)

    Berliner, R.; Mildner, D.F.R.; Pringle, O.A.

    1981-01-01

    The data acquisition speed and electronic stability of a charge division position-sensitive detector may be improved by using digital signal processing with a table look-up high speed multiply to form the charge division quotient. This digitization process introduces a positional quantization difficulty which reduces the detector position sensitivity. The degree of the digitization error is dependent on the pulse height spectrum of the detector and on the resolution or dynamic range of the system analog-to-digital converters. The effects have been investigated analytically and by computer simulation. The optimum algorithm for position sensing determination using 8-bit digitization and arithmetic has a digitization error of less than 1%. (orig.)

  11. Digital Audiobooks

    DEFF Research Database (Denmark)

    Have, Iben; Pedersen, Birgitte Stougaard

    Audiobooks are rapidly gaining popularity with widely accessible digital downloading and streaming services. The paper is framing how the digital audiobook expands and changes the target groups for book publications and how it as an everyday activity is creating new reading experiences, places...

  12. Digital TMI

    Science.gov (United States)

    Rios, Joseph

    2012-01-01

    Presenting the current status of the Digital TMI project to visiting members of the FAA Command Center. Digital TMI is an effort to store national-level traffic management initiatives in a standards-compliant manner. Work is funded by the FAA.

  13. Test of the little Higgs model in Atlas at LHC: simulation of the digitization of the electromagnetic calorimeter; Test du modele du petit Higgs dans ATLAS au LHC: simulation de la numerisation du calorimetre electromagnetique

    Energy Technology Data Exchange (ETDEWEB)

    Lechowski, M

    2005-04-15

    LHC is a proton-proton collider with an energy of 14 TeV in the center of mass, which will start operating in 2007 at CERN. Two of its experiments, ATLAS, and CMS, will search and study in particular the Higgs boson, Supersymmetry and other new physics. This thesis was about two aspects of the ATLAS experiment. On one hand the simulation of the liquid Argon electromagnetic calorimeter, with the emulation of the electronic chain in charge of the digitization of the signal and also the evaluation of the electronic noise and the pile-up noise (coming from minimum bias events of inelastic collisions at LHC). These two points have been validated by the analysis of the data taken during beam tests in 2002 and 2004. On the other hand, a physics study concerning the Little Higgs model. This recent model solves the hierarchy problem of the Standard Model, in introducing new heavy particles to cancel quadratic divergences arising in the calculation of the Higgs boson mass. These new particles, with a mass about the TeV/c{sup 2}, are a heavy quark top, heavy gauge bosons Z{sub H}, W{sub H} and A{sub H}, and a heavy Higgs boson triplet. The physics study dealt with the characteristic decays of the model, Z{sub H} in Z + H and W{sub H} in W + H, with a Higgs mass either at 120 GeV/c{sup 2} decaying in two photons or at 200 GeV/c{sup 2} decaying in ZZ or WW. Results show that in both cases, for 300 fb{sup -1} (3 years at high luminosity), an observation of the signal at 5 {sigma} for Z{sub H} et W{sub H} masses less than 2 TeV/c{sup 2} is possible, covering a large part of the parameter space. (author)

  14. Digital displacements

    DEFF Research Database (Denmark)

    Pors, Anja Svejgaard

    2014-01-01

    In recent years digital reforms are being introduced in the municipal landscape of Denmark. The reforms address the interaction between citizen and local authority. The aim is, that by 2015 at least 80 per cent of all correspondence between citizens and public authority will be transmitted through...... digital interface. However, the transformation of citizen services from traditional face-to-face interaction to digital self-service gives rise to new practices; some citizens need support to be able to manage self-service through digital tools. A mixture of support and teaching, named co......-service, is a new task in public administration, where street level bureaucrats assist citizens in using the new digital solutions. The paper is based on a case study conducted primarily in a citizen service centre in Copenhagen, Denmark. Based on ethnography the paper gives an empirical account of the ongoing...

  15. Digitized mammograms

    International Nuclear Information System (INIS)

    Bruneton, J.N.; Balu-Maestro, C.; Rogopoulos, A.; Chauvel, C.; Geoffray, A.

    1988-01-01

    Two observers conducted a blind evaluation of 100 mammography files, including 47 malignant cases. Films were read both before and after image digitization at 50 μm and 100 μm with the FilmDRSII. Digitization permitted better analysis of the normal anatomic structures and moderately improved diagnostic sensitivity. Searches for microcalcifications before and after digitization at 100 μm and 50 μm showed better analysis of anatomic structures after digitization (especially for solitary microcalcifications). The diagnostic benefit, with discovery of clustered microcalcifications, was more limited (one case at 100 μm, nine cases at 50 μm). Recognition of microcalcifications was clearly improved in dense breasts, which can benefit from reinterpretation after digitization at 50 μm rather 100μm

  16. Evaluation of body simulator for chest and abdomen in digital X-ray equipment; Avaliação de simulador de corpo para regiões do tórax e abdômen em equipamento de raios-X digital

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Sidney S.; Cardoso, Gabriela P.; Oliveira, Giovanni Antônio P.; Batista, Adriana S.M., E-mail: sidneyss70soares@gmail.com, E-mail: gabrielapontesc@gmail.com, E-mail: giovanni.paiva@pbh.gov.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem; Pereira, Esther Lorrayne M., E-mail: esther_machado@outlook.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-07-01

    The use of body simulators to control the quality of X-ray images is a practice that guarantees the control of essential parameters for diagnosis by the technique. The evolution of the equipment, between the analogue, digital computerized radiology (CR) and direct radiography (DR), requires evaluation of the equivalence in grayscale, of simulators, for an adjustment according to the specific technology of obtaining the image. In this sense, the present work presents the evaluation of a body simulator with regard to the representation of mean values of signal, noise and contrast obtained in chest radiographs and panoramic of the abdomen. For the thorax the cardiac region was considered as simulation target and for the abdomen simulation of the liver and small intestine. We used a retrospective study of images obtained with X-ray equipment - CR system, in which the images were studied using the ImageJ program, generating a data catalog. These were subsequently compared with those obtained experimentally using gel filled polymer body simulator. For the validation of the simulator, it was observed the gel equivalence of filling of the polymer box required to reach the image parameters of the cataloged radiographs. The results are discussed as to the physical principles of radiation interaction with biological and equivalent tissues.

  17. Digital Ethics/Going Digital.

    Science.gov (United States)

    Wilson, Bradley

    1996-01-01

    Finds that the recent National Press Photographers Association code of ethics can serve as a model for any photography staff. Discusses how digital imaging is becoming commonplace in classrooms, due to decreasing costs and easier software. Explains digital terminology. Concludes that time saved in the darkroom and at the printer is now spent on…

  18. Digital radiography

    International Nuclear Information System (INIS)

    Coulomb, M.; Dal Soglio, S.; Pittet-Barbier, L.; Ranchoup, Y.; Thony, F.; Ferretti, G.; Robert, F.

    1992-01-01

    Digital projection radiography may replace conventional radiography some day, provided it can meet several requirements: equal or better diagnostic effectiveness of the screen-film systems; reasonable image cost; real improvement in the productivity of the Departments of Imaging. All digital radiographic systems include an X-ray source, an image acquisition and formatting sub-system, a display and manipulation sub-system, and archiving subsystem and a laser editing system, preferably shared by other sources of digital images. Three digitization processes are available: digitization of the radiographic film, digital fluorography and phospholuminescent detectors with memory. The advantages of digital fluoroscopy are appealing: real-time image acquisition, suppression of cassettes; but its disadvantages are far from negligible: it cannot be applied to bedside radiography, the field of examination is limited, and the wide-field spatial resolution is poor. Phospholuminescent detectors with memory have great advantages: they can be used for bedside radiographs and on all the common radiographic systems; spatial resolution is satisfactory; its current disadvantages are considerable. These two systems, have common properties making up the entire philosophy of digital radiology and specific features that must guide our choice according to the application. Digital fluorography is best applied in pediatric radiology. However, evaluation works have showed that it was applicable with sufficient quality to many indications of general radiology in which a fluoroscopic control and fast acquisition of the images are essential; the time gained on the examination may be considerable, as well as the savings on film. Detectors with memory are required for bedside radiographs, in osteoarticular and thoracic radiology, in all cases of traumatic emergency and in the resuscitation and intensive care departments

  19. Becoming digital

    DEFF Research Database (Denmark)

    Pors, Anja Svejgaard

    2015-01-01

    . An ethnographic account of how digital reforms are implemented in practice shows how street-level bureaucrat’s classic tasks such as specialized casework are being reconfigured into educational tasks that promote the idea of “becoming digital”. In the paper, the author argues that the work of “becoming digital....... Originality/value: The study contributes to ethnographic research in public administration by combining two separate subfields, e-government and street-level bureaucracy, to discern recent transformations in public service delivery. In the digital era, tasks, control and equality are distributed in ways...

  20. Digital Humanities

    DEFF Research Database (Denmark)

    Brügger, Niels

    2016-01-01

    , and preserving material to study, as an object of study in its own right, as an analytical tool, or for collaborating, and for disseminating results. The term "digital humanities" was coined around 2001, and gained currency within academia in the following years. However, computers had been used within......Digital humanities is an umbrella term for theories, methodologies, and practices related to humanities scholarship that use the digital computer as an integrated and essential part of its research and teaching activities. The computer can be used for establishing, finding, collecting...

  1. Digital Snaps

    DEFF Research Database (Denmark)

    Sandbye, Mette; Larsen, Jonas

    . Distance as the New Punctum / Mikko Villi -- pt. II. FAMILY ALBUMS IN TRANSITION -- ch. 4. How Digital Technologies Do Family Snaps, Only Better / Gillian Rose -- ch. 5. Friendship Photography: Memory, Mobility and Social Networking / Joanne Garde-Hansen -- ch. 6. Play, Process and Materiality in Japanese...... -- ch. 9. Retouch Yourself: The Pleasures and Politics of Digital Cosmetic Surgery / Tanya Sheehan -- ch. 10. Virtual Selves: Art and Digital Autobiography / Louise Wolthers -- ch. 11. Mobile-Media Photography: New Modes of Engagement / Michael Shanks and Connie Svabo....

  2. Digital electronics

    CERN Document Server

    Morris, John

    2013-01-01

    An essential companion to John C Morris's 'Analogue Electronics', this clear and accessible text is designed for electronics students, teachers and enthusiasts who already have a basic understanding of electronics, and who wish to develop their knowledge of digital techniques and applications. Employing a discovery-based approach, the author covers fundamental theory before going on to develop an appreciation of logic networks, integrated circuit applications and analogue-digital conversion. A section on digital fault finding and useful ic data sheets completes th

  3. Digital Leadership

    DEFF Research Database (Denmark)

    Zupancic, Tadeja; Verbeke, Johan; Achten, Henri

    2016-01-01

    Leadership is an important quality in organisations. Leadership is needed to introduce change and innovation. In our opinion, in architectural and design practices, the role of leadership has not yet been sufficiently studied, especially when it comes to the role of digital tools and media....... With this paper we intend to initiate a discussion in the eCAADe community to reflect and develop ideas in order to develop digital leadership skills amongst the membership. This paper introduces some important aspects, which may be valuable to look into when developing digital leadership skills....

  4. Digital radiography

    International Nuclear Information System (INIS)

    Zani, M.L.

    2002-01-01

    X-ray radiography is a very common technique used to check the homogeneity of a material or the inside of a mechanical part. Generally the radiation that goes through the material to check, produced an image on a sensitized film. This method requires time because the film needs to be developed, digital radiography has no longer this inconvenient. In digital radiography the film is replaced by digital data and can be processed as any computer file. This new technique is promising but its main inconvenient is that today its resolution is not so good as that of film radiography. (A.C.)

  5. Digital radiography

    International Nuclear Information System (INIS)

    Kusano, Shoichi

    1993-01-01

    Firstly, from an historic point of view, fundamental concepts on digital imaging were reviewed to provide a foundation for discussion of digital radiography. Secondly, this review summarized the results of ongoing research in computed radiography that replaces the conventional film-screen system with a photo-stimulable phosphor plate; and thirdly, image quality, radiation protection, and image processing techniques were discussed with emphasis on picture archiving and communication system environment as our final goal. Finally, future expansion of digital radiography was described based on the present utilization of computed tomography at the National Defense Medical College Hospital. (author) 60 refs

  6. Digital Hadron Calorimetry

    Science.gov (United States)

    Bilki, Burak

    2018-03-01

    The Particle Flow Algorithms attempt to measure each particle in a hadronic jet individually, using the detector providing the best energy/momentum resolution. Therefore, the spatial segmentation of the calorimeter plays a crucial role. In this context, the CALICE Collaboration developed the Digital Hadron Calorimeter. The Digital Hadron Calorimeter uses Resistive Plate Chambers as active media and has a 1-bit resolution (digital) readout of 1 × 1 cm2 pads. The calorimeter was tested with steel and tungsten absorber structures, as well as with no absorber structure, at the Fermilab and CERN test beam facilities over several years. In addition to conventional calorimetric measurements, the Digital Hadron Calorimeter offers detailed measurements of event shapes, rigorous tests of simulation models and various tools for improved performance due to its very high spatial granularity. Here we report on the results from the analysis of pion and positron events. Results of comparisons with the Monte Carlo simulations are also discussed. The analysis demonstrates the unique utilization of detailed event topologies.

  7. Digital fabrication

    CERN Document Server

    2012-01-01

    The Winter 2012 (vol. 14 no. 3) issue of the Nexus Network Journal features seven original papers dedicated to the theme “Digital Fabrication”. Digital fabrication is changing architecture in fundamental ways in every phase, from concept to artifact. Projects growing out of research in digital fabrication are dependent on software that is entirely surface-oriented in its underlying mathematics. Decisions made during design, prototyping, fabrication and assembly rely on codes, scripts, parameters, operating systems and software, creating the need for teams with multidisciplinary expertise and different skills, from IT to architecture, design, material engineering, and mathematics, among others The papers grew out of a Lisbon symposium hosted by the ISCTE-Instituto Universitario de Lisboa entitled “Digital Fabrication – A State of the Art”. The issue is completed with four other research papers which address different mathematical instruments applied to architecture, including geometric tracing system...

  8. Digital Relationships

    DEFF Research Database (Denmark)

    Ledborg Hansen, Richard

    -­rich information and highly interesting communication are sky-­high and rising. With a continuous increase in digitized communication follows a decrease in face-­to-­face encounters and our ability to engage in inter-­personal relationships are suffering for it (Davis, 2013). The behavior described in this paper......-­‐Jones, 2011) for increases in effectiveness and efficiency we indiscriminately embrace digital communication and digitized information dissemination with enthusiasm – at the risk of ignoring the potentially dark side of technology. However, technology also holds a promise for better understanding precisely...... for the same reasons – that the growing amount of digitized communication “out there” represents data waiting to be sifted, analyzed and decoded. In this paper “Facebook behavior” refers to a particular behavior characterized by presenting your self and representations of selected self in the hope of getting...

  9. Digital Discretion

    DEFF Research Database (Denmark)

    Busch, Peter Andre; Zinner Henriksen, Helle

    2018-01-01

    discretion is suggested to reduce this footprint by influencing or replacing their discretionary practices using ICT. What is less researched is whether digital discretion can cause changes in public policy outcomes, and under what conditions such changes can occur. Using the concept of public service values......This study reviews 44 peer-reviewed articles on digital discretion published in the period from 1998 to January 2017. Street-level bureaucrats have traditionally had a wide ability to exercise discretion stirring debate since they can add their personal footprint on public policies. Digital......, we suggest that digital discretion can strengthen ethical and democratic values but weaken professional and relational values. Furthermore, we conclude that contextual factors such as considerations made by policy makers on the macro-level and the degree of professionalization of street...

  10. Research on digital multi-channel pulse height analysis techniques

    International Nuclear Information System (INIS)

    Xiao Wuyun; Wei Yixiang; Ai Xianyun; Ao Qi

    2005-01-01

    Multi-channel pulse height analysis techniques are developing in the direction of digitalization. Based on digital signal processing techniques, digital multi-channel analyzers are characterized by powerful pulse processing ability, high throughput, improved stability and flexibility. This paper analyzes key techniques of digital nuclear pulse processing. With MATLAB software, main algorithms are simulated, such as trapezoidal shaping, digital baseline estimation, digital pole-zero/zero-pole compensation, poles and zeros identification. The preliminary general scheme of digital MCA is discussed, as well as some other important techniques about its engineering design. All these lay the foundation of developing homemade digital nuclear spectrometers. (authors)

  11. Impact of compressed breast thickness and dose on lesion detectability in digital mammography: FROC study with simulated lesions in real mammograms

    Energy Technology Data Exchange (ETDEWEB)

    Salvagnini, Elena, E-mail: elena.salvagnini@gmail.com [Department of Imaging and Pathology, Radiology, KUL, Herestraat 49, Leuven B-3000 (Belgium); SCK-CEN, Boeretang 200, Mol 2400 (Belgium); Bosmans, Hilde; Marshall, Nicholas W. [Department of Imaging and Pathology, Radiology, KUL, Herestraat 49, Leuven B-3000 (Belgium); Department of Radiology, Radiology, UZ Gasthuisberg, Herestraat 49, Leuven B-3000 (Belgium); Van Ongeval, Chantal; Van Steen, Andreas; Cockmartin, Lesley [Department of Radiology, Radiology, UZ Gasthuisberg, Herestraat 49, Leuven B-3000 (Belgium); Michielsen, Koen [Department of Imaging and Pathology, Nuclear Medicine and Molecular Imaging, KUL, Herestraat 49, Leuven B-3000 (Belgium); Struelens, Lara [SCK-CEN, Boeretang 200, Mol 2400 (Belgium)

    2016-09-15

    Purpose: The aim of this work was twofold: (1) to examine whether, with standard automatic exposure control (AEC) settings that maintain pixel values in the detector constant, lesion detectability in clinical images decreases as a function of breast thickness and (2) to verify whether a new AEC setup can increase lesion detectability at larger breast thicknesses. Methods: Screening patient images, acquired on two identical digital mammography systems, were collected over a period of 2 yr. Mammograms were acquired under standard AEC conditions (part 1) and subsequently with a new AEC setup (part 2), programmed to use the standard AEC settings for compressed breast thicknesses ≤49 mm, while a relative dose increase was applied above this thickness. The images were divided into four thickness groups: T1 ≤ 29 mm, T2 = 30–49 mm, T3 = 50–69 mm, and T4 ≥ 70 mm, with each thickness group containing 130 randomly selected craniocaudal lesion-free images. Two measures of density were obtained for every image: a BI-RADS score and a map of volumetric breast density created with a software application (VolparaDensity, Matakina, NZ). This information was used to select subsets of four images, containing one image from each thickness group, matched to a (global) BI-RADS score and containing a region with the same (local) VOLPARA volumetric density value. One selected lesion (a microcalcification cluster or a mass) was simulated into each of the four images. This process was repeated so that, for a given thickness group, half the images contained a single lesion and half were lesion-free. The lesion templates created and inserted in groups T3 and T4 for the first part of the study were then inserted into the images of thickness groups T3 and T4 acquired with higher dose settings. Finally, all images were visualized using the ViewDEX software and scored by four radiologists performing a free search study. A statistical jackknife-alternative free-response receiver operating

  12. Digital Collections, Digital Libraries & the Digitization of Cultural Heritage Information.

    Science.gov (United States)

    Lynch, Clifford

    2002-01-01

    Discusses digital collections and digital libraries. Topics include broadband availability; digital rights protection; content, both non-profit and commercial; digitization of cultural content; sustainability; metadata harvesting protocol; infrastructure; authorship; linking multiple resources; data mining; digitization of reference works;…

  13. digital natives and digital immigrants

    OpenAIRE

    Cardina, Bruno; Francisco, Jerónimo; Reis, Pedro; trad. Silva, Fátima

    2011-01-01

    This article focuses on the generational gaps in school learning. Initially, we have tried to provide the framework in relation to the term digital native in order to understand the key aspects of the generation born after the advent and the global use of the Internet. They were found to be “multitasking” people, linked to technology and connectivity, as opposed to digital immigrants, born in an earlier period and seeking to adapt to the technological world. We also present some r...

  14. Digital evidence

    Directory of Open Access Journals (Sweden)

    Lukić Tatjana

    2012-01-01

    Full Text Available Although computer makes human activities faster and easier, innovating and creating new forms of work and other kinds of activities, it also influenced the criminal activity. The development of information technology directly affects the development of computer forensics without which, it can not even imagine the discovering and proving the computer offences and apprehending the perpetrator. Information technology and computer forensic allows us to detect and prove the crimes committed by computer and capture the perpetrators. Computer forensics is a type of forensics which can be defined as a process of collecting, preserving, analyzing and presenting digital evidence in court proceedings. Bearing in mind, that combat against crime, in which computers appear as an asset or object of the offense, requires knowledge of digital evidence as well as specific rules and procedures, the author in this article specifically addresses the issues of digital evidence, forensic (computer investigation, specific rules and procedures for detecting, fixing and collecting digital evidence and use of this type of evidence in criminal proceedings. The author also delas with international standards regarding digital evidence and cyber-space investigation.

  15. Digital watermark

    Directory of Open Access Journals (Sweden)

    Jasna Maver

    2000-01-01

    Full Text Available The huge amount of multimedia contents available on the World-Wide-Web is beginning to raise the question of their protection. Digital watermarking is a technique which can serve various purposes, including intellectual property protection, authentication and integrity verification, as well as visible or invisible content labelling of multimedia content. Due to the diversity of digital watermarking applicability, there are many different techniques, which can be categorised according to different criteria. A digital watermark can be categorised as visible or invisible and as robust or fragile. In contrast to the visible watermark where a visible pattern or image is embedded into the original image, the invisible watermark does not change the visual appearance of the image. The existence of such a watermark can be determined only through a watermark ex¬traction or detection algorithm. The robust watermark is used for copyright protection, while the fragile watermark is designed for authentication and integrity verification of multimedia content. A watermark must be detectable or extractable to be useful. In some watermarking schemes, a watermark can be extracted in its exact form, in other cases, we can detect only whether a specific given watermarking signal is present in an image. Digital libraries, through which cultural institutions will make multimedia contents available, should support a wide range of service models for intellectual property protection, where digital watermarking may play an important role.

  16. Digital Creativity

    DEFF Research Database (Denmark)

    Petersson Brooks, Eva; Brooks, Anthony Lewis

    2014-01-01

    This paper reports on a study exploring the outcomes from children’s play with technology in early childhood learning practices. The paper addresses questions related to how digital technology can foster creativity in early childhood learning environments. It consists of an analysis of children......’s interaction with the KidSmart furniture focusing on digital creativity potentials and play values suggested by the technology. The study applied a qualitative approach and included125 children (aged three to five), 10 pedagogues, and two librarians. The results suggests that educators should sensitively...... consider intervening when children are interacting with technology, and rather put emphasize into the integration of the technology into the environment and to the curriculum in order to shape playful structures for children’s digital creativity....

  17. Digital radiography

    International Nuclear Information System (INIS)

    Rath, M.; Lissner, J.; Rienmueller, R.; Haendle, J.; Siemens A.G., Erlangen

    1984-01-01

    Using a prototype of an electronic, universal examination unit equipped with a special X-ray TV installation, spotfilm exposures and digital angiographies with high spatial resolution and wide-range contrast could be made in the clinic for the first time. With transvenous contrast medium injection, the clinical results of digital angiography show excellent image quality in the region of the carotids and renal arteries as well as the arteries of the extremities. The electronic series exposures have an image quality almost comparable to the quality obtained with cutfilm changers in conventional angiography. There are certain limitations due to the input field of 25 cm X-ray image intensified used. In respect of the digital angiography imaging technique, the electronic universal unit is fully suitable for clinical application. (orig.) [de

  18. Digital photogrammetry

    CERN Document Server

    Egels, Yves

    2003-01-01

    Photogrammetry is the use of photography for surveying primarily and is used for the production of maps from aerial photographs. Along with remote sensing, it represents the primary means of generating data for Geographic Information Systems (GIS). As technology develops, it is becoming easier to gain access to it. The cost of digital photogrammetric workstations are falling quickly and these new tools are therefore becoming accessible to more and more users. Digital Photogrammetry is particularly useful as a text for graduate students in geomantic and is also suitable for people with a good basic scientific knowledge who need to understand photogrammetry, and who wish to use the book as a reference.

  19. Digital Marketing

    OpenAIRE

    Jerry Wind; Vijay Mahajan

    2002-01-01

    The digital revolution has shaken marketing to its core with consumers being offered greater price transparency and often even the chance to dictate the price. What does pricing mean in a world in which customers propose their own prices (as at priceline.com) or buyers and sellers haggle independently in auctions (as at e-Bay)? The most significant changes in the digital marketing show the emergence of 'cyber consumers', the cyber business-to-business world and the changing reality of an incr...

  20. Digital "X"

    DEFF Research Database (Denmark)

    Baiyere, Abayomi; Grover, Varun; Gupta, Alok

    2017-01-01

    Interest in using digital before existing research concepts seem to be on the rise in the IS field. This panel is positioned to explore what value lies in labelling our research as digital “x” as opposed to the well established IT “x” (where “x” can be strategy, infrastructure, innovation, artifa...... between this stream of research and existing research. Central among the expected output of the panel is the advancement of suggestions for future research and the critical pitfalls to avoid in doing so....

  1. Digital Radiography

    Science.gov (United States)

    1986-01-01

    System One, a digital radiography system, incorporates a reusable image medium (RIM) which retains an image. No film is needed; the RIM is read with a laser scanner, and the information is used to produce a digital image on an image processor. The image is stored on an optical disc. System allows the radiologist to "dial away" unwanted images to compare views on three screens. It is compatible with existing equipment and cost efficient. It was commercialized by a Stanford researcher from energy selective technology developed under a NASA grant.

  2. Digital filters

    CERN Document Server

    Hamming, Richard W

    1997-01-01

    Digital signals occur in an increasing number of applications: in telephone communications; in radio, television, and stereo sound systems; and in spacecraft transmissions, to name just a few. This introductory text examines digital filtering, the processes of smoothing, predicting, differentiating, integrating, and separating signals, as well as the removal of noise from a signal. The processes bear particular relevance to computer applications, one of the focuses of this book.Readers will find Hamming's analysis accessible and engaging, in recognition of the fact that many people with the s

  3. Digital voltmeter

    International Nuclear Information System (INIS)

    Yohannes Kamadi; Soekarno.

    1976-01-01

    The electrical voltage measuring equipment with digital display has been made. This equipment uses four digits display with single polarity measurement and integrating system. Pulses from the oscillator will be counted and converted to the staircase voltages, and compared to the voltage measured. When the balance is already achieved, the pulse will appear at the comparator circuit. This pulse will be used to trigger univibrator circuit. The univibrator output is used as signal for stopping the counting, and when reading time T already stops, the counting system will be reset. (authors)

  4. Digital communication

    CERN Document Server

    Das, Apurba

    2010-01-01

    ""Digital Communications"" presents the theory and application of the philosophy of Digital Communication systems in a unique but lucid form. This book inserts equal importance to the theory and application aspect of the subject whereby the authors selected a wide class of problems. The Salient features of the book are: the foundation of Fourier series, Transform and wavelets are introduces in a unique way but in lucid language; the application area is rich and resemblance to the present trend of research, as we are attached with those areas professionally; a CD is included which contains code

  5. Digital literacies

    CERN Document Server

    Hockly, Nicky; Pegrum, Mark

    2014-01-01

    Dramatic shifts in our communication landscape have made it crucial for language teaching to go beyond print literacy and encompass the digital literacies which are increasingly central to learners' personal, social, educational and professional lives. By situating these digital literacies within a clear theoretical framework, this book provides educators and students alike with not just the background for a deeper understanding of these key 21st-century skills, but also the rationale for integrating these skills into classroom practice. This is the first methodology book to address not jus

  6. Procedures for high precision setup verification and correction of lung cancer patients using CT-simulation and digitally reconstructed radiographs (DRR).

    NARCIS (Netherlands)

    Sornsen de Koste, van J.R.; Boer, de HC; Schuchhard-Schipper, RH; Senan, S.; Heijmen, BJ

    2003-01-01

    PURPOSE: In a recent study, large systematic setup errors were detected in patients with lung cancer when a conventional simulation procedure was used to define and mark the treatment isocenter. In the present study, we describe a procedure to omit the session at a conventional simulator to remove

  7. Digital delicacies

    OpenAIRE

    Holley, Rose

    2001-01-01

    This presentation outlines the purpose and work of the newly appointed Digital Projects Librarian at the University of Auckland. It gives a brief overview of what digitisation is, the benefits, the stages of a digitisation project and also samples of interesting international digitisation projects and new University of Auckland Library Digitisation projects.

  8. Digital Forensics

    Science.gov (United States)

    Harron, Jason; Langdon, John; Gonzalez, Jennifer; Cater, Scott

    2017-01-01

    The term forensic science may evoke thoughts of blood-spatter analysis, DNA testing, and identifying molds, spores, and larvae. A growing part of this field, however, is that of digital forensics, involving techniques with clear connections to math and physics. This article describes a five-part project involving smartphones and the investigation…

  9. Digital Disruption

    DEFF Research Database (Denmark)

    Rosenstand, Claus Andreas Foss

    det digitale domæne ud over det niveau, der kendetegner den nuværende debat, så præsenteres der ny viden om digital disruption. Som noget nyt udlægges Clayton Christens teori om disruptiv innovation med et særligt fokus på små organisationers mulighed for eksponentiel vækst. Specielt udfoldes...... forholdet mellem disruption og den stadig accelererende digitale udvikling i konturerne til ny teoridannelse om digital disruption. Bogens undertitel ”faretruende og fascinerende forandringer” peger på, at der er behov for en nuanceret debat om digital disruption i modsætning til den tone, der er slået an i...... videre kalder et ”disruption-råd”. Faktisk er rådet skrevet ind i 2016 regeringsgrundlaget for VLK-regeringen. Disruption af organisationer er ikke et nyt fænomen; men hastigheden, hvormed det sker, er stadig accelererende. Årsagen er den globale mega-trend: Digitalisering. Og derfor er specielt digital...

  10. Digital books.

    Science.gov (United States)

    Wink, Diane M

    2011-01-01

    In this bimonthly series, the author examines how nurse educators can use the Internet and Web-based computer technologies such as search, communication, and collaborative writing tools; social networking and social bookmarking sites; virtual worlds; and Web-based teaching and learning programs. This article describes digital books.

  11. Digital forvaltning

    DEFF Research Database (Denmark)

    Remmen, Arne; Larsen, Torben; Mosgaard, Mette

    2004-01-01

    Større effektivitet, bedre service og mere demokrai er blot nogle af forventningerne til indførelse af digital forveltning i kommunerne. Kapitlet giver bland andet svar på spørgsmålene : Hvordan lever kommunerne op hertil i dagligdagen? hvilke virkemidler anvender de? Hvilke barrierer har der været...

  12. Digital Methods

    NARCIS (Netherlands)

    Rogers, R.

    2013-01-01

    In Digital Methods, Richard Rogers proposes a methodological outlook for social and cultural scholarly research on the Web that seeks to move Internet research beyond the study of online culture. It is not a toolkit for Internet research, or operating instructions for a software package; it deals

  13. Efficacy of conventional and digital radiographic imaging methods for diagnosis of simulated external root resorption Eficácia dos métodos radiográficos convencional e digital no diagnóstico de reabsorções radiculares simuladas

    Directory of Open Access Journals (Sweden)

    Vânia Portela Ditzel Westphalen

    2004-06-01

    Full Text Available This in vitro study evaluated and compared the efficacy of conventional (Kodak F-speed (Insight, Kodak and a digital (DRS Gnatus System, Gnatus radiographic imaging for diagnosis of simulated external root resorption cavities. Human mandibles containing teeth were covered with bovine muscle slices in order to simulate the soft tissues. Nine teeth out of each group of teeth were investigated. Initially, three periapical radiographs of each tooth were taken using a tube shift technique with mesial and distal angulations in both methods. All teeth were subsequently extracted and had 0.7 and 1.0-mm deep cavities prepared on their buccal, mesial and distal surfaces at the cervical, middle and apical thirds. Steel cylinder burs (DORMER® - HSS with 0.7 and 1.0-mm diameter were used. Each tooth was replaced on its socket and new radiographs were taken. Three examiners, an endodontist (1, a radiologist (2 and a general dentist (3, evaluated the images. Results were compared by z-test and showed a higher number of cavities detected by the digital method compared to the conventional, regardless of the deepness of the cavity. In decreasing order, examiners 2, 3 and 1 exhibited different potentials of detection of cavities with the conventional method. Examiners 1 and 3 exhibited superior potential than examiner 2 for detection of cavities of different sizes with the digital method.O presente estudo visou avaliar e comparar, in vitro, a eficácia dos métodos radiográficos convencional (filmes de grupos de sensibilidade E/F Kodak Insight e digital (Sistema Gnatus DRS, no diagnóstico de cavidades simulando reabsorções radiculares externas, em dentes contidos em mandíbulas humanas secas com músculo bovino simulando o tecido mole. As variáveis consideradas foram: tamanhos das cavidades e examinadores envolvidos. Foram utilizadas nove unidades de cada grupo dentário, incisivos (central e lateral, caninos, pré-molares e molares, sem lesões periapicais

  14. Digital data monitoring display and logging

    International Nuclear Information System (INIS)

    Ficaro, E.P.; Wehe, D.K.

    1987-01-01

    A digital data acquisition system for monitoring plant variables has been designed and implemented at the University of Michigan's Ford Nuclear Reactor (FNR), a 2 Megawatt, open-pool, research reactor. The digital data provided by this system is useful for: closed loop control, real time experimental calculations, advanced simulation-as-knowledge techniques, improved operator training, and expert system applications. The purpose of this paper is to discuss the transition to the digital data world and the anticipated applications and benefits

  15. Digital Humanities and networked digital media

    DEFF Research Database (Denmark)

    Finnemann, Niels Ole

    2014-01-01

    This article discusses digital humanities and the growing diversity of digital media, digital materials and digital methods. The first section describes the humanities computing tradition formed around the interpretation of computation as a rule-based process connected to a concept of digital...... materials centred on the digitisation of non-digital, finite works, corpora and oeuvres. The second section discusses “the big tent” of contemporary digital humanities. It is argued that there can be no unifying interpretation of digital humanities above the level of studying digital materials with the help...... of software-supported methods. This is so, in part, because of the complexity of the world and, in part, because digital media remain open to the projection of new epistemologies onto the functional architecture of these media. The third section discusses the heterogeneous character of digital materials...

  16. Digital Materia

    OpenAIRE

    Lindgren, Marcus; Richey, Emma

    2014-01-01

    Med tankar från pedagogen Montessori och filosoferna Platon och Baudrillard har detta arbete behandlat frågor om datorn och dess betydelse för en grafiker. Frågeställningen formulerades efter hand och lydde tillslut: ”Hur kan materia te sig i digital form?” Forskningen resulterade i en hypotes för hur digital materia skulle födas i datorn: genom att blanda två uppsättningar av data, såsom två genuppsättningar tillsammans skapar en ny organism. Under produktionen utvecklades därmed en metod fö...

  17. Becoming digital

    DEFF Research Database (Denmark)

    Pors, Anja Svejgaard

    2015-01-01

    government, and draws on empirical material generated through observations, field notes, interviews and policy documents. The material is documenting how service is performed by frontline agents in the ‘bureaucratic encounter’ with citizens, who needs assistance to use digital self-service in order to apply...... online for a public benefit. Findings: The paper shows that e-government technology changes the mode of professionalism in citizen service from service to support. The paper gives an empirical account of recent Danish digital reforms and shows how the reforms both enable and constrain the work...... of ‘becoming digital’ by frontline agents. Overall the street-level bureaucrat’s classical tasks such as specialized casework are being displaced into promoting and educational tasks. An implication of this is blurred distinctions between professional skills and personal competences of the frontline agent...

  18. Digital resources

    Directory of Open Access Journals (Sweden)

    Redazione Reti Medievali (a cura di

    2005-12-01

    Full Text Available Bibliotheca Latinitatis Mediaevalis (circa VII sec. - XIV sec. IntraText Digital Library [01/06] Corpus Scriptorum Latinorum. A digital library of Latin literature by David Camden [01/06] Fonti disponibili online concernenti la vita religiosa medievale Rete Vitae Religiosae Mediaevalis Studia Conectens [01/06] Fuentes del Medievo Hispanico Instituto de Historia, Consejo Superior de Investigaciones Científicas [01/06] Latin Literature Forum Romanum [01/06] Ludovico Antonio Muratori, Dissertazioni sopra le antichità italiane, 1751 Biblioteca dei Classici Italiani di Giuseppe Bonghi [01/06] Medieval Latin The Latin Library [01/06] Médiévales Presses Universitaires de Vincennes - Revues.org [01/06] Regesta imperii Deutsche Kommission für die Bearbeitung der Regesta Imperii e.V. [01/06] Suda On Line Byzantine Lexicography [01/06

  19. Digital teenagers

    Directory of Open Access Journals (Sweden)

    Rafael Conde Melguizo

    2011-12-01

    Full Text Available Espín, Manuel (Coord.(2011 Adolescentes Digitales.  Revista Estudios de Juventud, Nº 92. Marzo 2011. INJUVE, Madrid."Adolescentes digitales" se nos muestra como una obra que pretende explorar desde distintos puntos de vista la realidad de la generación conocida como “nativos digitales” (Prensky, la generación actual de adolescentes que ha crecido con internet y el mundo digital como su entorno normal de socialización.

  20. Digital Flora

    OpenAIRE

    Bunnell, Katie

    2007-01-01

    This research is concerned with developing a new business model for flexible small scale ceramic production that exploits the customisation capabilities of digital manufacturing technologies and the market potential and global connectivity of the world wide web. It is arguably of particular relevance to regional economic development in remote areas (Amin, Tomaney, Sabel) such as Cornwall where there is a culture of high quality small scale production, limited market and manufacturing opportun...

  1. Simulação humana digital na concepção de postos de trabalho: estudo comparativo de casos Digital human simulation for ergonomic workplace design: comparative study of cases

    Directory of Open Access Journals (Sweden)

    Daniel Braatz

    2012-01-01

    Full Text Available Este artigo apresenta como a ferramenta computacional de Modelagem e Simulação Humana contextualizada pela Análise Ergonômica do Trabalho (AET e pela análise da Atividade Futura Possível pode auxiliar nos processos de projeto de postos de trabalho. São analisados dois estudos de caso nos quais a Simulação Humana foi empregada com auxílio do software Jack. O primeiro estudo aborda a concepção de um balcão de atendimento em uma empresa pública de serviços postais. O segundo apresenta o desenvolvimento de uma estação de trabalho de abastecimento de agulhas cirúrgicas em uma empresa de manufatura de produtos relacionados às áreas de saúde e higiene. A partir dos resultados dos estudos de caso, são explicitadas as contribuições e desafios da utilização dessa tecnologia em projetos visando equacionar as questões de saúde e produtividade. O uso da simulação integrada ao processo de intervenção da AET permitiu melhorar a antecipação das futuras atividades prováveis das novas situações de trabalho e auxiliou a integração e comunicação dos atores envolvidos nesses processos sociais.This paper investigates a computational tool for Human Modeling and Simulation contextualized by Ergonomic Analysis of Work (EAW and future work activity forecasting that can assist in the design processes of workplaces. Two case studies using Human Simulation was employed and the software Jack were analyzed. The first study presents the design of a counter in a public post office. The second shows the development of a workstation for the supply of surgical needles in a company that manufactures hygiene and healthcare products. The results of the case studies show the contributions and challenges of using this design technology aiming to solve problems related to health and productivity. The use of simulation combined with EAW helped to improve future work activity forecasting of new work situations and helped the integration and

  2. Speckle reduction techniques in digital holography

    Energy Technology Data Exchange (ETDEWEB)

    Monaghan, David; Kelly, Damien; Hennelly, Bryan [Department of Computer Science, National University of Ireland, Maynooth, Co. Kildare (Ireland); Javidi, Bahram, E-mail: bryanh@cs.nuim.i [University of Connecticut Electrical and Computer Engineering Department 371 Fairfield Road, Unit 2157 Storrs, CT 06269-2157 (United States)

    2010-02-01

    We have studied several speckle reduction techniques, applicable to digital holography. These include the use of optical diffusers, wavelet filtering, simulating temporal incoherence and filtering in the Fourier domain. The Digital Holograms (DHs) used in this study are captured using a Phase Shift Interferometric (PSI) in-line setup and subsequently reconstructed numerically.

  3. Digital citizens Digital nations: the next agenda

    NARCIS (Netherlands)

    A.W. (Bert) Mulder; M.W. (Martijn) Hartog

    2015-01-01

    DIGITAL CITIZENS CREATE A DIGITAL NATION Citizens will play the lead role as they – in the next phase of the information society – collectively create a digital nation. Personal adoption of information and communication technology will create a digital infrastructure that supports individual and

  4. Current status and progress of digital orthopaedics in China

    Directory of Open Access Journals (Sweden)

    Guo-Xian Pei

    2014-07-01

    Full Text Available Based on the development of digital medicine and digital anatomy, the concept of “digital orthopaedics” was raised by Pei Guo-Xian in China in 2006. The most striking feature of digital orthopaedics is the combination of basic and clinical orthopaedic knowledge with digital technology. In this review, we summarised the development of digital orthopaedics in China in recent years with respect to: the foundation of the Chinese Association of Digital Orthopedics, virtual human project (VHP, three-dimensional (3D reconstruction, finite element simulation, navigation in orthopaedic operations, and robot-assisted orthopaedic operations. In addition, we briefly reviewed digital orthopaedics in world leading institutes. We also looked into the future of digital orthopaedics in China and proposed the major challenges in digital technology and application in orthopaedics.

  5. Digital fluorimeter

    International Nuclear Information System (INIS)

    Mello, H.A. de.

    1980-11-01

    The specifications of a digital fluorimeter. That with adequated analytical techniques permits to determine trace amounts of fluorescents materials in samples, are described. The fluorimeter is of the reflection type, and uses fluorescents lamps for the excitation and an optical system which is connected to a photomultiplyer machine and permits the measurement of the light intensity. In the case of IEN (Instituto de Engenharia Nuclear) the equipment is used for to determine the uranium content in sample materials to be exported. The precision of the instrument is about + - 1% in the scale of 0.1 which is the normally one used in the current researchs. (E.G.) [pt

  6. Digital entrepreneurship

    DEFF Research Database (Denmark)

    Brem, Alexander; Richter, Chris; Kraus, Sascha

    2017-01-01

    comprising guided interviews with 14 companies from Germany, Austria and Switzerland provides detailed insights into different aspects of the sharing economy phenomenon. Our results make a direct contribution to sharing economy research, especially regarding the new business models of start-ups. Here, we...... find a clear difference between the relevance of economic and social orientation. The latter appears to be in higher demand among customers than entrepreneurs. The increasingly digitalized environment has led to a changed living situation characterized by urbanity, openness to new solutions, changed...

  7. Focus: Digital

    DEFF Research Database (Denmark)

    Technology has been an all-important and defining element within the arts throughout the 20th century, and it has fundamentally changed the ways in which we produce and consume music. With this Focus we investigate the latest developments in the digital domain – and their pervasiveness and rapid...... production and reception of contemporary music and sound art. With ‘Digital’ we present four composers' very different answers to how technology impact their work. To Juliana Hodkinson it has become an integral part of her sonic writing. Rudiger Meyer analyses the relationships between art and design and how...

  8. [Constructing 3-dimensional colorized digital dental model assisted by digital photography].

    Science.gov (United States)

    Ye, Hong-qiang; Liu, Yu-shu; Liu, Yun-song; Ning, Jing; Zhao, Yi-jiao; Zhou, Yong-sheng

    2016-02-18

    To explore a method of constructing universal 3-dimensional (3D) colorized digital dental model which can be displayed and edited in common 3D software (such as Geomagic series), in order to improve the visual effect of digital dental model in 3D software. The morphological data of teeth and gingivae were obtained by intra-oral scanning system (3Shape TRIOS), constructing 3D digital dental models. The 3D digital dental models were exported as STL files. Meanwhile, referring to the accredited photography guide of American Academy of Cosmetic Dentistry (AACD), five selected digital photographs of patients'teeth and gingivae were taken by digital single lens reflex camera (DSLR) with the same exposure parameters (except occlusal views) to capture the color data. In Geomagic Studio 2013, after STL file of 3D digital dental model being imported, digital photographs were projected on 3D digital dental model with corresponding position and angle. The junctions of different photos were carefully trimmed to get continuous and natural color transitions. Then the 3D colorized digital dental model was constructed, which was exported as OBJ file or WRP file which was a special file for software of Geomagic series. For the purpose of evaluating the visual effect of the 3D colorized digital model, a rating scale on color simulation effect in views of patients'evaluation was used. Sixteen patients were recruited and their scores on colored and non-colored digital dental models were recorded. The data were analyzed using McNemar-Bowker test in SPSS 20. Universal 3D colorized digital dental model with better color simulation was constructed based on intra-oral scanning and digital photography. For clinical application, the 3D colorized digital dental models, combined with 3D face images, were introduced into 3D smile design of aesthetic rehabilitation, which could improve the patients' cognition for the esthetic digital design and virtual prosthetic effect. Universal 3D colorized

  9. Development of the user Interface of digital simulation system of the operational parameters of the TRIGA IPR-R1 Nuclear Research Reactor

    International Nuclear Information System (INIS)

    Felippe, Adriano de A.M.; Lage, Aldo M.F.; Mesquita, Amir Z.

    2017-01-01

    The development of simulation systems has been increasingly improved to ensure security and reliability to the systems being associated. Computational tools, simulation systems and programming languages increasingly allow the diversification of control systems. With increasing concern about monitoring the key parameters involved in chain reactions inside a nuclear reactor, new technologies are being developed to ensure operations safety. This paper deals with a practical application of a work that is being developed in the Center for the Development of Nuclear Technology - CDTN, which intends to simulate the operation of the TRIGA-IPR-R1 nuclear research reactor using the LabVIEW® software, evaluating the evolution of the neutron flux and other related events. In this paper, the visual interface of the reactor control table, developed through virtual instruments that allow, in a vast repertoire of tools, replicating the panels of the control table in modern screens that can be operated by a user of an analogous form, but still more practical and complete. Since the innovations developed for research reactors can be replicated in power reactors, and because of their lower operating and maintenance costs, projects in this area allow the development of several technologies

  10. Digital Humanities

    DEFF Research Database (Denmark)

    Nielsen, Hans Jørn

    2015-01-01

    overgangen fra trykkekultur til digital kultur. For det første problemstillingen omkring digitalisering af litterær kulturarv med fokus på kodning og tagging af teksten samt organisering i hypertekststrukturer. For det andet reorganiseringen af det digitale dokument i dataelementer og database. For det......Artiklen præsenterer først nogle generelle problemstillinger omkring Digital Humanities (DH) med det formål at undersøge dem nærmere i relation til konkrete eksempler på forskellige digitaliseringsmåder og ændringer i dokumentproduktion. I en nærmere afgrænsning vælger artiklen den tendens i DH......, der betragter DH som forbundet med "making" og "building" af digitale objekter og former. Dette kan også karakteriseres som DH som praktisk-produktiv vending. Artiklen har valgt tre typer af digitalisering. De er valgt ud fra, at de skal repræsentere forskellige måder at håndtere digitaliseringen på...

  11. Mejoramiento de procesos constructivos a partir de un módulo programable para captura de imágenes y simulación digital Improvement of constructive processes based on a programmable unit for images capture and digital simulation

    Directory of Open Access Journals (Sweden)

    Adriana Gómez Cabrera

    2012-08-01

    modelo de simulación digital del proceso constructivo. Los resultados obtenidos, permiten reducir tiempos de ciclo y dar un mejor uso a los recursos, representando ahorro de recursos para el proyecto.Civil projects executors are constantly dealing with the challenge of increasing productivity through resources optimization and their interaction; this has been addressed from different points of view using computational tools and manual tools. This challenge demands also, the implementation of new information technologies and digital tools as an effective strategy to capture reliable data that could contribute to improve the productivity quality and security indicators. This work presents a value generation in construction projects, through the use of new technologies to capture digital information that allows a construction process re-engineering using Lean Construction philosophy and digital simulation. At first, the design and development of an autonomous and programmable module is presented, powered with solar energy, used to capture digital images of construction processes. This system includes hardware and electronic components such as cameras, video cameras, electronic cards, computers, solar panels, web platform and communication systems; all controlled by a specially designed software which simplifies the control of the equipment and its components. This system simplifies the decision-making process regarding the construction methods and the resources involved, in order to minimize the costs and to increase the performance. The results obtained in the implementation of the module in a construction project in Bogota, Colombia, are presented in the second part of this paper. The analysis of the results, the constructive process characterization using Time-Lapse videos and a digital simulation model of the construction process are presented. These results allow reducing cycle times and using better the resources, which is translated into resources savings for the

  12. Research challenges in digital education.

    Science.gov (United States)

    Norman, Geoff

    2014-09-01

    Simulation and other forms of digital learning will occupy a place of increasing prominence in medical education in the future. However, to maximally use the potential of these media, we must go beyond a research agenda dictated by a 'Does it work?' question to one driven by careful analysis of the nature of the task to be learned and its relation to the characteristics of the technology. Secondly, we must change the focus from the characteristics of individual devices to a broader approach to design of a digital curriculum based on current understanding of the nature of human learning.

  13. Total filmless digital radiology service

    International Nuclear Information System (INIS)

    Mun, S.K.; Goeringer, F.; Benson, H.; Horii, S.C.

    1989-01-01

    The completion of a comprehensive picture archiving and communication system (PACS) at Georgetown University Hospital has allowed us to identify a number of technical, administrative, personnel, and operational issues that will affect a total digital radiology service. With a hospital-wide digital imaging network system, computer simulation of communications and storage options, and economic modeling, we have developed a feasibility study and implementation strategy for the smooth transition to a nearly filmless radiology service over the next several years. This paper describes the technical and operational requirements for various database operations, workstations (used in diagnosis, review, and education), and communications. Site and installation planning, personnel training, and transition operations are discussed

  14. Digital radiography

    DEFF Research Database (Denmark)

    Precht, H; Gerke, O; Rosendahl, K

    2012-01-01

    BACKGROUND: New developments in processing of digital radiographs (DR), including multi-frequency processing (MFP), allow optimization of image quality and radiation dose. This is particularly promising in children as they are believed to be more sensitive to ionizing radiation than adults....... OBJECTIVE: To examine whether the use of MFP software reduces the radiation dose without compromising quality at DR of the femur in 5-year-old-equivalent anthropomorphic and technical phantoms. MATERIALS AND METHODS: A total of 110 images of an anthropomorphic phantom were imaged on a DR system (Canon DR...... with CXDI-50 C detector and MLT[S] software) and analyzed by three pediatric radiologists using Visual Grading Analysis. In addition, 3,500 images taken of a technical contrast-detail phantom (CDRAD 2.0) provide an objective image-quality assessment. RESULTS: Optimal image-quality was maintained at a dose...

  15. Fokus: Digital

    DEFF Research Database (Denmark)

    2014-01-01

    i det digitale domæne – udviklinger, der foregår hastigt og er gennemgribende, og som derfor kræver et nærmere blik på forholdet mellem kunsten og teknologien. Komponistens forståelse af sin metier udfordres – samtidig med at befæstede ideer om kunstværket møder modstand fra nye mediemæssige...... sammenhænge og fra forandrede distributionsformer. Dette betyder ændrede betingelser for både produktion og reception af kunstmusik og lydkunst. Med Digital tager vi udgangspunkt i fire komponisters meget forskellige bud på hvordan teknologien spiller en rolle i arbejdet. Juliana Hodkinson beskriver hvordan...

  16. CORTAP: a coupled neutron kinetics-heat transfer digital computer program for the dynamic simulation of the high temperature gas cooled reactor core

    International Nuclear Information System (INIS)

    Cleveland, J.C.

    1977-01-01

    CORTAP (Core Transient Analysis Program) was developed to predict the dynamic behavior of the High Temperature Gas Cooled Reactor (HTGR) core under normal operational transients and postulated accident conditions. CORTAP is used both as a stand-alone component simulation and as part of the HTGR nuclear steam supply (NSS) system simulation code ORTAP. The core thermal neutronic response is determined by solving the heat transfer equations for the fuel, moderator and coolant in an average powered region of the reactor core. The space independent neutron kinetics equations are coupled to the heat transfer equations through a rapidly converging iterative technique. The code has the capability to determine conservative fuel, moderator, and coolant temperatures in the ''hot'' fuel region. For transients involving a reactor trip, the core heat generation rate is determined from an expression for decay heat following a scram. Nonlinear effects introduced by temperature dependent fuel, moderator, and coolant properties are included in the model. CORTAP predictions will be compared with dynamic test results obtained from the Fort St. Vrain reactor owned by Public Service of Colorado, and, based on these comparisons, appropriate improvements will be made in CORTAP

  17. Average glandular dose in digital mammography and digital breast tomosynthesis: comparison of phantom and patient data

    NARCIS (Netherlands)

    Bouwman, R. W.; van Engen, R. E.; Young, K. C.; den Heeten, G. J.; Broeders, M. J. M.; Schopphoven, S.; Jeukens, C. R. L. P. N.; Veldkamp, W. J. H.; Dance, D. R.

    2015-01-01

    For the evaluation of the average glandular dose (AGD) in digital mammography (DM) and digital breast tomosynthesis (DBT) phantoms simulating standard model breasts are used. These phantoms consist of slabs of polymethyl methacrylate (PMMA) or a combination of PMMA and polyethylene (PE). In the last

  18. Digital work in a digitally challenged organization

    NARCIS (Netherlands)

    Davison, R.M.; Ou, Carol

    Digitally literate employees are accustomed to having free access to digital media technologies. However, some organizations enact information technology (IT) governance structures that explicitly proscribe access to these technologies, resulting in considerable tension between employees and the

  19. Digital implementation, simulation and tests in MATLAB of the models of Steam line, the turbines, the pressure regulator of a BWR type nucleo electric power plant

    International Nuclear Information System (INIS)

    Lopez R, A.

    2004-01-01

    In this phase of the project they were carried out exhaustive tests to the models of the steam lines, turbines and pressure regulator of a BWR type nucleo electric central for to verify that their tendencies and behaviors are it more real possible. For it, it was necessary to also analyze the transfer functions of the different components along the steam line until the power generator. Such models define alone the dominant poles of the system, what is not limitation to reproduce a wide range of anticipated transitoriness of a power station operation. In the same manner, it was integrated and proved the integrated model form with the models of feeding water of the SUN-RAH, simulating the nuclear reactor starting from predetermined entrances of the prospective values of the vessel. Also it was coupled with the graphic interface developed with the libraries DirectX implementing a specific monitoring panel for this system. (Author)

  20. USNA DIGITAL FORENSICS LAB

    Data.gov (United States)

    Federal Laboratory Consortium — To enable Digital Forensics and Computer Security research and educational opportunities across majors and departments. Lab MissionEstablish and maintain a Digital...

  1. Can We Teach Digital Natives Digital Literacy?

    Science.gov (United States)

    Ng, Wan

    2012-01-01

    In recent years, there has been much debate about the concept of digital natives, in particular the differences between the digital natives' knowledge and adoption of digital technologies in informal versus formal educational contexts. This paper investigates the knowledge about educational technologies of a group of undergraduate students…

  2. Math for the digital factory

    CERN Document Server

    Hömberg, Dietmar; Landry, Chantal

    2017-01-01

    This volume provides a unique collection of mathematical tools and industrial case studies in digital manufacturing. It addresses various topics, ranging from models of single production technologies, production lines, logistics and workflows to models and optimization strategies for energy consumption in production. The digital factory represents a network of digital models and simulation and 3D visualization methods for the holistic planning, realization, control and ongoing improvement of all factory processes related to a specific product. In the past ten years, all industrialized countries have launched initiatives to realize this vision, sometimes also referred to as Industry 4.0 (in Europe) or Smart Manufacturing (in the United States). Its main goals are • reconfigurable, adaptive and evolving factories capable of small-scale production • high-performance production, combining flexibility, productivity, precision and zero defects • energy and resource efficiency in manufacturing None of these...

  3. INCORRECT PRESERVATION OF AMPUTATED DIGITS

    Directory of Open Access Journals (Sweden)

    Uroš Ahčan

    2004-09-01

    Full Text Available Background. A decision to replant is critically dependent on the condition of the amputated digit and the way it was preserved during transport. The most common error is exposing the amputated digit to very low temperatures. Preservation directly on ice, on cooling devices in portable refrigerators, or on top of packets of frozen meat often result in a frozen and therefore unusable body digit.Methods. An inquiry questionnaire on correct methods of preservation of amputated digits was conducted on a sample of 30 lay persons, 30 medical students, and 15 physicians.Three simulations of most frequently used methods of preservation of amputated digit were conducted (the correct method; directly on ice; on cooling devices of portable refrigerators. Environment temperature of the (simulated amputated digits stored was measured.In a retrospective study, hospital records of patients treated at the Clinical department of plastic surgery and burns in Ljubljana between 1998 and 2002 were examined. We determined the number of replantations performed, gender of the patients, their age, the mechanism of the injury, the success rate of the replantation, and the duration of hospitalisation. In five case described in detail, we present an inadequate treatment of the amputated digits.Results. The results of the questionnaire survey show that no less than 86.7% of lay person respondents would have treated the injuries in an incorrect way; same holds for 43.4% students of medicine, and 33.3% of practicing physicians.The temperature of the simulated amputated digit remained above 5°C throughout the simulated correct treatment. When preserved directly on ice on or coolant bodies, the temperature dropped below the freezing point and never climbed above 0°C throughout the duration of the simulation (150 minutes.Between years 1998 and 2002, Clinical department of plastic surgery and burns at the University clinical centre Ljubljana admitted 124 injured persons with

  4. Digital produktion

    DEFF Research Database (Denmark)

    Bogen sætter fokus på digital produktion, som er en stærk læringsform, der faciliterer elevernes læreprocesser og kvalificerer elevernes faglige læringsresultater. Det sker når lærerne udarbejder didaktiske rammedesign, hvor eleverne arbejder selvstændigt inden for dette rammedesign, og hvor mål og...... procesevaluering stilladserer elevernes faglige proces. I digitale produktionsprocesser arbejder eleverne iterativt, de udvikler ejerskab til produktionen og fastholder selv deres læreprocesser. It’s multimodalitet, elevernes kollaborative tilgange, videndeling mellem eleverne og elevernes uformelle lege- og...... elevernes digitale produktion er lærernes didaktiske rammesætning og stilladserende tilgange. Her lægger lærerne op til, at eleverne som didaktiske designere i relation til rammesætningen skal organisere og planlægge deres læreprocesser, inddrages i målsætning, evaluering og valg af digitale ressourcer...

  5. Digital dannelse

    DEFF Research Database (Denmark)

    Bundsgaard, Jeppe

    2012-01-01

    I al vores iver efter at få presset nogle flere digitale dimser ind i skolen, er vi i fare for at glemme hvad det er vi skal med disse dimser. Der er store forventninger til at de kan gøre det lettere at være lærer (og dermed billigere), og det kan det måske. Men der er jo også et dannelsesspørgs......I al vores iver efter at få presset nogle flere digitale dimser ind i skolen, er vi i fare for at glemme hvad det er vi skal med disse dimser. Der er store forventninger til at de kan gøre det lettere at være lærer (og dermed billigere), og det kan det måske. Men der er jo også et...... dannelsesspørgsmål knyttet til it. Hvad er egentlig digital dannelse? Og hvad betyder det for danskfaget?...

  6. Digital forensics digital evidence in criminal investigations

    CERN Document Server

    Marshall, Angus McKenzie

    2009-01-01

    The vast majority of modern criminal investigations involve some element of digital evidence, from mobile phones, computers, CCTV and other devices. Digital Forensics: Digital Evidence in Criminal Investigations provides the reader with a better understanding of how digital evidence complements "traditional" scientific evidence and examines how it can be used more effectively and efficiently in a range of investigations. Taking a new approach to the topic, this book presents digital evidence as an adjunct to other types of evidence and discusses how it can be deployed effectively in s

  7. Reduction of digital errors of digital charge division type position-sensitive detectors

    International Nuclear Information System (INIS)

    Uritani, A.; Yoshimura, K.; Takenaka, Y.; Mori, C.

    1994-01-01

    It is well known that ''digital errors'', i.e. differential non-linearity, appear in a position profile of radiation interactions when the profile is obtained with a digital charge-division-type position-sensitive detector. Two methods are presented to reduce the digital errors. They are the methods using logarithmic amplifiers and a weighting function. The validities of these two methods have been evaluated mainly by computer simulation. These methods can considerably reduce the digital errors. The best results are obtained when both methods are applied. ((orig.))

  8. Digital platforms as enablers for digital transformation

    DEFF Research Database (Denmark)

    Hossain, Mokter; Lassen, Astrid Heidemann

    transformation is crucial. This study aims at exploring how organizations are driven towards transformation in various ways to embrace digital platforms for ideas, technologies, and knowledge. It shows the opportunities and challenges digital platforms bring in organizations. It also highlights underlying......Digital platforms offer new ways for organizations to collaborate with the external environment for ideas, technologies, and knowledge. They provide new possibilities and competence but they also bring new challenges for organizations. Understanding the role of these platforms in digital...... mechanisms and potential outcomes of various digital platforms. The contribution of the submission is valuable for scholars to understand and further explore this area. It provides insight for practitioners to capture value through digital platforms and accelerate the pace of organizations’ digital...

  9. H. Sapiens Digital: From Digital Immigrants and Digital Natives to Digital Wisdom

    Science.gov (United States)

    Prensky, Marc

    2009-01-01

    As we move further into the 21st century, the digital native/digital immigrant paradigm created by Marc Prensky in 2001 is becoming less relevant. In this article, Prensky suggests that we should focus instead on the development of what he calls "digital wisdom." Arguing that digital technology can make us not just smarter but truly wiser, Prensky…

  10. Dual beam vidicon digitizer

    International Nuclear Information System (INIS)

    Evans, T.L.

    1976-01-01

    A vidicon waveform digitizer which can simultaneously digitize two independent signals has been developed. Either transient or repetitive waveforms can be digitized with this system. A dual beam oscilloscope is used as the signal input device. The light from the oscilloscope traces is optically coupled to a television camera, where the signals are temporarily stored prior to digitizing

  11. Digital lattice gauge theories

    Science.gov (United States)

    Zohar, Erez; Farace, Alessandro; Reznik, Benni; Cirac, J. Ignacio

    2017-02-01

    We propose a general scheme for a digital construction of lattice gauge theories with dynamical fermions. In this method, the four-body interactions arising in models with 2 +1 dimensions and higher are obtained stroboscopically, through a sequence of two-body interactions with ancillary degrees of freedom. This yields stronger interactions than the ones obtained through perturbative methods, as typically done in previous proposals, and removes an important bottleneck in the road towards experimental realizations. The scheme applies to generic gauge theories with Lie or finite symmetry groups, both Abelian and non-Abelian. As a concrete example, we present the construction of a digital quantum simulator for a Z3 lattice gauge theory with dynamical fermionic matter in 2 +1 dimensions, using ultracold atoms in optical lattices, involving three atomic species, representing the matter, gauge, and auxiliary degrees of freedom, that are separated in three different layers. By moving the ancilla atoms with a proper sequence of steps, we show how we can obtain the desired evolution in a clean, controlled way.

  12. Enabling Digital Literacy

    DEFF Research Database (Denmark)

    Ryberg, Thomas; Georgsen, Marianne

    2010-01-01

    There are some tensions between high-level policy definitions of “digital literacy” and actual teaching practice. We need to find workable definitions of digital literacy; obtain a better understanding of what digital literacy might look like in practice; and identify pedagogical approaches, which...... support teachers in designing digital literacy learning. We suggest that frameworks such as Problem Based Learning (PBL) are approaches that enable digital literacy learning because they provide good settings for engaging with digital literacy. We illustrate this through analysis of a case. Furthermore......, these operate on a meso-level mediating between high-level concepts of digital literacy and classroom practice....

  13. Progress in digital radiography

    International Nuclear Information System (INIS)

    Cappelle, A.

    2016-01-01

    Because of its practical aspect digital radiography is more and more used in the industrial sector. There are 2 kinds of digital radiography. First, the 'computed radiography' that uses a photon-stimulated screen, and after radiation exposure this screen must be read by an analyser to get a digit image. The second type is the 'direct radiography' that allows one to get a digit radiograph of the object directly. Digital radiography uses the same radioactive nuclides as radiography with silver films: cobalt, iridium or selenium. The spatial resolution of digital radiography is less good than with classical silver film radiography but digital radiography offers a better visual contrast. (A.C.)

  14. High-Fidelity Simulation in Biomedical and Aerospace Engineering

    Science.gov (United States)

    Kwak, Dochan

    2005-01-01

    Contents include the following: Introduction / Background. Modeling and Simulation Challenges in Aerospace Engineering. Modeling and Simulation Challenges in Biomedical Engineering. Digital Astronaut. Project Columbia. Summary and Discussion.

  15. Digital Sensor Technology

    Energy Technology Data Exchange (ETDEWEB)

    Ted Quinn; Jerry Mauck; Richard Bockhorst; Ken Thomas

    2013-07-01

    The nuclear industry has been slow to incorporate digital sensor technology into nuclear plant designs due to concerns with digital qualification issues. However, the benefits of digital sensor technology for nuclear plant instrumentation are substantial in terms of accuracy, reliability, availability, and maintainability. This report demonstrates these benefits in direct comparisons of digital and analog sensor applications. It also addresses the qualification issues that must be addressed in the application of digital sensor technology.

  16. Digital preservation for heritages

    CERN Document Server

    Lu, Dongming

    2011-01-01

    ""Digital Preservation for Heritages: Technologies and Applications"" provides a comprehensive and up-to-date coverage of digital technologies in the area of cultural heritage preservation, including digitalization, research aiding, conservation aiding, digital exhibition, and digital utilization. Processes, technical frameworks, key technologies, as well as typical systems and applications are discussed in the book. It is intended for researchers and students in the fields of computer science and technology, museology, and archaeology. Dr. Dongming Lu is a professor at College of Computer Sci

  17. Tree-Structured Digital Organisms Model

    Science.gov (United States)

    Suzuki, Teruhiko; Nobesawa, Shiho; Tahara, Ikuo

    Tierra and Avida are well-known models of digital organisms. They describe a life process as a sequence of computation codes. A linear sequence model may not be the only way to describe a digital organism, though it is very simple for a computer-based model. Thus we propose a new digital organism model based on a tree structure, which is rather similar to the generic programming. With our model, a life process is a combination of various functions, as if life in the real world is. This implies that our model can easily describe the hierarchical structure of life, and it can simulate evolutionary computation through mutual interaction of functions. We verified our model by simulations that our model can be regarded as a digital organism model according to its definitions. Our model even succeeded in creating species such as viruses and parasites.

  18. Standardisation of digital human models.

    Science.gov (United States)

    Paul, Gunther; Wischniewski, Sascha

    2012-01-01

    Digital human models (DHM) have evolved as useful tools for ergonomic workplace design and product development, and found in various industries and education. DHM systems which dominate the market were developed for specific purposes and differ significantly, which is not only reflected in non-compatible results of DHM simulations, but also provoking misunderstanding of how DHM simulations relate to real world problems. While DHM developers are restricted by uncertainty about the user need and lack of model data related standards, users are confined to one specific product and cannot exchange results, or upgrade to another DHM system, as their previous results would be rendered worthless. Furthermore, origin and validity of anthropometric and biomechanical data is not transparent to the user. The lack of standardisation in DHM systems has become a major roadblock in further system development, affecting all stakeholders in the DHM industry. Evidently, a framework for standardising digital human models is necessary to overcome current obstructions. Practitioner Summary: This short communication addresses a standardisation issue for digital human models, which has been addressed at the International Ergonomics Association Technical Committee for Human Simulation and Virtual Environments. It is the outcome of a workshop at the DHM 2011 symposium in Lyon, which concluded steps towards DHM standardisation that need to be taken.

  19. Single Bit Radar Systems for Digital Integration

    OpenAIRE

    Bjørndal, Øystein

    2017-01-01

    Small, low cost, radar systems have exciting applications in monitoring and imaging for the industrial, healthcare and Internet of Things (IoT) sectors. We here explore, and show the feasibility of, several single bit square wave radar architectures; that benefits from the continuous improvement in digital technologies for system-on-chip digital integration. By analysis, simulation and measurements we explore novel and harmonic-rich continuous wave (CW), stepped-frequency CW (SFCW) and freque...

  20. Cognitive Hacking and Digital Government: Digital Identity

    OpenAIRE

    Paul Thompson

    2004-01-01

    Recently the National Center for Digital Government held a workshop on "The Virtual Citizen: Identity, Autonomy, and Accountability: A Civic Scenario Exploration of the Role of Identity in On-Line. Discussions at the workshop focused on five scenarios for future authentication policies with respect to digital identity. The underlying technologies considered for authentication were: biometrics: cryptography, with a focus on digital signatures; secure processing/computation; and reputation syst...

  1. Digital Materialisms: Frameworks for Digital Media Studies

    OpenAIRE

    Casemajor, Nathalie

    2015-01-01

    Since the 1980s, digital materialism has received increasing interest in the field of media studies. Materialism as a theoretical paradigm assumes that all things in the world are tied to physical processes and matter. Yet within digital media studies, the understanding of what should be the core object of a materialist analysis is debated. This paper proposes to untangle some of the principal theoretical propositions that compose the field of digital materialism. It outlines six frameworks t...

  2. Development of a system based in a digital signal processor (DSP) for a simulator of power regulation in a reactor: first stage; Desarrollo de un sistema basado en un DSP para un simulador de regulacion de potencia en un reactor: 1. etapa

    Energy Technology Data Exchange (ETDEWEB)

    Benitez R, J.S.; Perez C, B. [Instituto Nacional de Investigaciones Nucleares, Km. 36.5 Carretera Mexico-Toluca, Municipio de Ocoyoacac, 52045 Estado de Mexico (Mexico)

    2002-07-01

    The first stage of the development of a digital system based on a DSP is presented which forms part of an hybrid simulator for the power regulation in am model of the punctual kinetics of a TRIGA reactor type. The DSP performs the regulation, using a Mandami type algorithm of diffuse control. In the algorithm, the universe of the output variable is discretized for performing in an unique stage the aggregation functions and dis-diffusization. (Author)

  3. Digital multilayer tomography

    International Nuclear Information System (INIS)

    Dueber, C.; Klose, K.J.; Thelen, M.

    1991-01-01

    With digital multilayer tomography a sequence of projection images is recorded by an image intensifier television system and stored as digital data during a linear run of a layer sequence. Using this data record, tomograms of the examined body region can be computed for any layer thickness by shifts and superimposition of the single projections later at a digital workstation. The qualities of digital and conventional tomograms are basically comparable. A drawback of digital tomography is its lower local resolution (512 x 512 image matrix), advantages are a lower radiation exposure, a shorter patient examination time, and the facilities of digital image processing (later processing, archive setup, transmission). (orig.) [de

  4. Experience with digital mammography

    Directory of Open Access Journals (Sweden)

    G. P. Korzhenkova

    2011-01-01

    Full Text Available The use of digital techniques in mammography has become a last step for completing the process of digitization in diagnostic imaging. It is assumed that such a spatial decision will be required for digital mammography, as well as for high-resolution intensifying screen-film systems used in conventional mammography and that the digital techniques will be limited by the digitizer pixel size on detecting minor structures, such as microcalcifications. The introduction of digital technologies in mammography involves a tight control over an image and assures its high quality.

  5. Logic of the digital

    CERN Document Server

    Evens, Aden

    2015-01-01

    Building a foundational understanding of the digital, Logic of the Digital reveals a unique digital ontology. Beginning from formal and technical characteristics, especially the binary code at the core of all digital technologies, Aden Evens traces the pathways along which the digital domain of abstract logic encounters the material, human world. How does a code using only 0s and 1s give rise to the vast range of applications and information that constitutes a great and growing portion of our world? Evens' analysis shows how any encounter between the actual and the digital must cross an ontolo

  6. Digital time-interpolator

    International Nuclear Information System (INIS)

    Schuller, S.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica

    1990-01-01

    This report presents a description of the design of a digital time meter. This time meter should be able to measure, by means of interpolation, times of 100 ns with an accuracy of 50 ps. In order to determine the best principle for interpolation, three methods were simulated at the computer with a Pascal code. On the basis of this the best method was chosen and used in the design. In order to test the principal operation of the circuit a part of the circuit was constructed with which the interpolation could be tested. The remainder of the circuit was simulated with a computer. So there are no data available about the operation of the complete circuit in practice. The interpolation part however is the most critical part, the remainder of the circuit is more or less simple logic. Besides this report also gives a description of the principle of interpolation and the design of the circuit. The measurement results at the prototype are presented finally. (author). 3 refs.; 37 figs.; 2 tabs

  7. Direct digital conversion detector technology

    Science.gov (United States)

    Mandl, William J.; Fedors, Richard

    1995-06-01

    Future imaging sensors for the aerospace and commercial video markets will depend on low cost, high speed analog-to-digital (A/D) conversion to efficiently process optical detector signals. Current A/D methods place a heavy burden on system resources, increase noise, and limit the throughput. This paper describes a unique method for incorporating A/D conversion right on the focal plane array. This concept is based on Sigma-Delta sampling, and makes optimum use of the active detector real estate. Combined with modern digital signal processors, such devices will significantly increase data rates off the focal plane. Early conversion to digital format will also decrease the signal susceptibility to noise, lowering the communications bit error rate. Computer modeling of this concept is described, along with results from several simulation runs. A potential application for direct digital conversion is also reviewed. Future uses for this technology could range from scientific instruments to remote sensors, telecommunications gear, medical diagnostic tools, and consumer products.

  8. Product Maturation Guide - A Digital Simulation Outcome

    DEFF Research Database (Denmark)

    Boorla, Srinivasa Murthy; Howard, Thomas J.

    2016-01-01

    . Tolerance analysis tools, those optimizing the individual part tolerances at the time of design can generate a product maturation guide that eliminates many problem solving procedures and saves time on root cause analysis. Assume a first product built on a new assembly line was found to need improvements....... To conclude the actions we need information about all the dimensions of child parts and processes involved and their influence. At the time of product design, the tolerance analysis system works with the same variables with a given range of variations virtually. For a practical build, instead of variation...... range, it has to consider one fixed value measured from initial parts. By adding information about process characteristics, like speed, cost, etc. to all the dimensions, the system can directly guide the manufacturing team, on which parameter to modify, which direction and how much. At the same time...

  9. Coastal California Digital Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This digital ortho-imagery dataset is a survey of coastal California. The project area consists of approximately 3774 square miles. The project design of the digital...

  10. Digital rectal exam

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007069.htm Digital rectal exam To use the sharing features on this page, please enable JavaScript. A digital rectal exam is an examination of the lower ...

  11. Digital dannelse til gymnasieeleverne

    DEFF Research Database (Denmark)

    Kaarsted, Thomas; Holch Andersen, Knud

    2012-01-01

    Søsætningen af en ny tænketank skal udstikke nye digital retningslinjer for gymnasiekolerne. Baggrunden er en erkendelse af, at it-infrastruktur og digital teknologi ikke gør de alene.......Søsætningen af en ny tænketank skal udstikke nye digital retningslinjer for gymnasiekolerne. Baggrunden er en erkendelse af, at it-infrastruktur og digital teknologi ikke gør de alene....

  12. Basic digital signal processing

    CERN Document Server

    Lockhart, Gordon B

    1985-01-01

    Basic Digital Signal Processing describes the principles of digital signal processing and experiments with BASIC programs involving the fast Fourier theorem (FFT). The book reviews the fundamentals of the BASIC program, continuous and discrete time signals including analog signals, Fourier analysis, discrete Fourier transform, signal energy, power. The text also explains digital signal processing involving digital filters, linear time-variant systems, discrete time unit impulse, discrete-time convolution, and the alternative structure for second order infinite impulse response (IIR) sections.

  13. Digital asset management.

    Science.gov (United States)

    Humphrey, Clinton D; Tollefson, Travis T; Kriet, J David

    2010-05-01

    Facial plastic surgeons are accumulating massive digital image databases with the evolution of photodocumentation and widespread adoption of digital photography. Managing and maximizing the utility of these vast data repositories, or digital asset management (DAM), is a persistent challenge. Developing a DAM workflow that incorporates a file naming algorithm and metadata assignment will increase the utility of a surgeon's digital images. Copyright 2010 Elsevier Inc. All rights reserved.

  14. Digital Inkjet Textile Printing

    OpenAIRE

    Wang, Meichun

    2017-01-01

    Digital inkjet textile printing is an emerging technology developed with the rise of the digital world. It offers a possibility to print high-resolution images with unlimited color selection on fabrics. Digital inkjet printing brings a revolutionary chance for the textile printing industry. The history of textile printing shows the law how new technology replaces the traditional way of printing. This indicates the future of digital inkjet textile printing is relatively positive. Differen...

  15. Digital Language Death

    Science.gov (United States)

    Kornai, András

    2013-01-01

    Of the approximately 7,000 languages spoken today, some 2,500 are generally considered endangered. Here we argue that this consensus figure vastly underestimates the danger of digital language death, in that less than 5% of all languages can still ascend to the digital realm. We present evidence of a massive die-off caused by the digital divide. PMID:24167559

  16. Digital language death.

    Directory of Open Access Journals (Sweden)

    András Kornai

    Full Text Available Of the approximately 7,000 languages spoken today, some 2,500 are generally considered endangered. Here we argue that this consensus figure vastly underestimates the danger of digital language death, in that less than 5% of all languages can still ascend to the digital realm. We present evidence of a massive die-off caused by the digital divide.

  17. Digital Imaging. Chapter 16

    Energy Technology Data Exchange (ETDEWEB)

    Clunie, D. [CoreLab Partners, Princeton (United States)

    2014-09-15

    The original means of recording X ray images was a photographic plate. Nowadays, all medical imaging modalities provide for digital acquisition, though globally, the use of radiographic film is still widespread. Many modalities are fundamentally digital in that they require image reconstruction from quantified digital signals, such as computed tomography (CT) and magnetic resonance imaging (MRI)

  18. Preparing collections for digitization

    CERN Document Server

    Bulow, Anna E

    2010-01-01

    Most libraries, archives and museums are confronting the challenges of providing digital access to their collections. This guide offers guidance covering the end-to-end process of digitizing collections, from selecting records for digitization to choosing suppliers and equipment and dealing with documents that present individual problems.

  19. Digital voltage discriminator

    International Nuclear Information System (INIS)

    Zhou Zhicheng

    1992-01-01

    A digital voltage discriminator is described, which is synthesized by digital comparator and ADC. The threshold is program controllable with high stability. Digital region of confusion is approximately equal to 1.5 LSB. This discriminator has a single channel analyzer function model with channel width of 1.5 LSB

  20. Playtesting the Digital Playground

    DEFF Research Database (Denmark)

    Majgaard, G.; Jessen, Carsten

    2009-01-01

    Being able to be absorbed in play in the digital playground is motivating for children who are used digital computer games. The children can play and exercise outdoors while using the same literacy as in indoor digital games. This paper presents a new playground product where an outdoor playgroun...

  1. A digital silicon photomultiplier with multiple time-to-digital converters

    Energy Technology Data Exchange (ETDEWEB)

    Garutti, Erika [University Hamburg (Germany); Silenzi, Alessandro [DESY, Hamburg (Germany); Xu, Chen [DESY, Hamburg (Germany); University Hamburg (Germany)

    2013-07-01

    A silicon photomultiplier (SiPM) with pixel level signal digitization and column-wise connected time-to-digital converters (TDCs) has been developed for an endoscopic Positron Emission Tomography (PET) detector. A digital SiPM has pixels consist of a single photon avalanche diode (SPAD) and circuit elements to optimize overall dark counts and temporal response. Compared with conventional analog SiPM, digital SiPM's direct signal route from SPAD to TDC improves single photon time resolution. In addition, using multiple TDCs can perform the statistical estimation of the time-of-arrival in multiple photon detection case such as readout of scintillation crystals. Characterization measurements of the prototype digital SiPM and a Monte-Carlo simulation to predict the timing performance of the PET detector are shown.

  2. Digital disruption ?syndromes.

    Science.gov (United States)

    Sullivan, Clair; Staib, Andrew

    2017-05-18

    The digital transformation of hospitals in Australia is occurring rapidly in order to facilitate innovation and improve efficiency. Rapid transformation can cause temporary disruption of hospital workflows and staff as processes are adapted to the new digital workflows. The aim of this paper is to outline various types of digital disruption and some strategies for effective management. A large tertiary university hospital recently underwent a rapid, successful roll-out of an integrated electronic medical record (EMR). We observed this transformation and propose several digital disruption "syndromes" to assist with understanding and management during digital transformation: digital deceleration, digital transparency, digital hypervigilance, data discordance, digital churn and post-digital 'depression'. These 'syndromes' are defined and discussed in detail. Successful management of this temporary digital disruption is important to ensure a successful transition to a digital platform. What is known about this topic? Digital disruption is defined as the changes facilitated by digital technologies that occur at a pace and magnitude that disrupt established ways of value creation, social interactions, doing business and more generally our thinking. Increasing numbers of Australian hospitals are implementing digital solutions to replace traditional paper-based systems for patient care in order to create opportunities for improved care and efficiencies. Such large scale change has the potential to create transient disruption to workflows and staff. Managing this temporary disruption effectively is an important factor in the successful implementation of an EMR. What does this paper add? A large tertiary university hospital recently underwent a successful rapid roll-out of an integrated electronic medical record (EMR) to become Australia's largest digital hospital over a 3-week period. We observed and assisted with the management of several cultural, behavioural and

  3. Ageing and digital games

    DEFF Research Database (Denmark)

    Iversen, Sara Mosberg

    Digital games are still to a great degree considered a medium mainly for young boys. However, available statistics on Western media use show that this is far from the case. Increasingly, people of all ages and genders play digital games, also older adults in their early 60s and beyond. The aim...... of the book is to examine, analyse and discuss: 1) What older adults do with digital games and what meanings the use of digital games take on in the everyday life of older adults; 2) How older adults are perceived by society in relation to digital games; 3) How play and games can be used both...

  4. Digital Living at Home

    DEFF Research Database (Denmark)

    Andersen, Pernille Viktoria Kathja; Christiansen, Ellen Tove

    2013-01-01

    of these user voices has directed us towards a ‘home-keeping’ design discourse, which opens new horizons for design of digital home control systems by allowing users to perform as self-determined controllers and groomers of their habitat. The paper concludes by outlining the implications of a ‘home......Does living with digital technology inevitably lead to digital living? Users talking about a digital home control system, they have had in their homes for eight years, indicate that there is more to living with digital technology than a functional-operational grip on regulation. Our analysis......-keeping’ design discourse....

  5. Digital Human Modeling

    Science.gov (United States)

    Dischinger, H. Charles, Jr.

    2017-01-01

    The development of models to represent human characteristics and behaviors in human factors is broad and general. The term "model" can refer to any metaphor to represent any aspect of the human; it is generally used in research to mean a mathematical tool for the simulation (often in software, which makes the simulation digital) of some aspect of human performance and for the prediction of future outcomes. This section is restricted to the application of human models in physical design, e.g., in human factors engineering. This design effort is typically human interface design, and the digital models used are anthropometric. That is, they are visual models that are the physical shape of humans and that have the capabilities and constraints of humans of a selected population. They are distinct from the avatars used in the entertainment industry (movies, video games, and the like) in precisely that regard: as models, they are created through the application of data on humans, and they are used to predict human response; body stresses workspaces. DHM enable iterative evaluation of a large number of concepts and support rapid analysis, as compared with use of physical mockups. They can be used to evaluate feasibility of escape of a suited astronaut from a damaged vehicle, before launch or after an abort (England, et al., 2012). Throughout most of human spaceflight, little attention has been paid to worksite design for ground workers. As a result of repeated damage to the Space Shuttle which adversely affected flight safety, DHM analyses of ground assembly and maintenance have been developed over the last five years for the design of new flight systems (Stambolian, 2012, Dischinger and Dunn Jackson, 2014). The intent of these analyses is to assure the design supports the work of the ground crew personnel and thereby protect the launch vehicle. They help the analyst address basic human factors engineering questions: can a worker reach the task site from the work platform

  6. New method for electric equivalents synthesis expressed in digital filters form for transitory simulations in real time for great power nets; Novo metodo para sintese de equivalentes eletricos a filtros digitais para simulacao de transitorios em tempo real em redes eletricas de grande porte

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Clever [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Nucleo de Desenvolvimento Cientifico e Tecnologico em Descargas Atmosfericas]. E-mail: clever@cpdee.ufmg.br; Carneiro Junior, Sandoval [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Szczupak, Jacques [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil)

    2001-07-01

    This article presents a new method to obtain subtransmission nets equivalents, expressed in form of digital filters of finite answer to the impulse, for transitory simulations in great power nets. Initially, it has been made considerations in the way of obtaining these filters, showing that they basically have been synthesized from the impedance and admittance functions of the secondary electric net to be processed in terms of equivalents in the domain of the w analogical frequency. It also is shown the transference technique to the time domain, in which it is used the z plane of the digital frequencies as an intermediate plane, being obtained from this way a set of equations susceptible of being implemented in program of transitory simulation in the time domain. The evaluation of this new method and evaluation of the reduction effect in the order of representative filters of the equivalents, are executed through the comparison of simulations which use the new technique together with other ones coming from EMTP. The obtained replies have demonstrated the effectiveness of the proposed method, opening new possibilities for transitory simulations in great power nets.

  7. Design Principles of Next-Generation Digital Gaming for Education.

    Science.gov (United States)

    Squire, Kurt; Jenkins, Henry; Holland, Walter; Miller, Heather; O'Driscoll, Alice; Tan, Katie Philip; Todd, Katie.

    2003-01-01

    Discusses the rapid growth of digital games, describes research at MIT that is exploring the potential of digital games for supporting learning, and offers hypotheses about the design of next-generation educational video and computer games. Highlights include simulations and games; and design principles, including context and using information to…

  8. Digital Banking: Risks of Financial Digitalization

    Directory of Open Access Journals (Sweden)

    Kornіvska Valerіa O.

    2017-09-01

    Full Text Available The paper demonstrates the results of the research into development of the digital economy in the global financial space, shows the contradictions of these processes in the context of the growth of financial inclusion of households, identifies the risks of active introduction of digital banking in poor countries of the world. The characteristics of the processes of growth of the influence of banking institutions on the operational activity and daily life of households are given, and it is proved that under conditions of digital banking, without having any other alternative ways of economic activity in terms of money circulation than non-cash turnover, clients are forced to agree to unlimited presence of financial operators in social systems. It is substantiated that in Ukraine the global risk of digitalization of the society is gradually developing as a result of the creation of unified information systems for the control of global financial flows.

  9. Digital rights management for digital cinema

    Science.gov (United States)

    Kirovski, Darko; Peinado, Marcus; Petitcolas, Fabien A. P.

    2001-12-01

    There is a wide consensus among the feature film production studios that the Internet era brings a new paradigm for film distribution to cinemas worldwide. The benefits of digital cinema to both producers and cinemas are numerous: significantly lower distribution and maintenance costs, immediate access to film libraries, higher presentation quality, and strong potential for developing new business models. Despite these advantages, the studios are still reluctant to jump into the digital age. The main showstopper for digital cinema is the danger of widespread piracy. Piracy already costs Hollywood an estimated two billion dollars annually and digital cinema without proper copyright enforcement could increase this number. In this paper, we present a copyright management system that aims at providing the set of necessary security tools: standard cryptographic primitives and copyright protection mechanisms that enable a reliable and secure feature film delivery system.

  10. Robotic Vehicle Proxy Simulation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Energid Technologies proposes the development of a digital simulation that can replace robotic vehicles in field studies. This proxy simulation will model the...

  11. Digital control system of advanced reactor

    International Nuclear Information System (INIS)

    Peng Huaqing; Zhang Rui; Liu Lixin

    2001-01-01

    This article produced the Digital Control System For Advanced Reactor made by NPIC. This system uses Siemens SIMATIC PCS 7 process control system and includes five control system: reactor power control system, pressurizer level control system, pressurizer pressure control system, steam generator water level control system and dump control system. This system uses three automatic station to realize the function of five control system. Because the safety requisition of reactor is very strict, the system is redundant. The system configuration uses CFC and SCL. the human-machine interface is configured by Wincc. Finally the system passed the test of simulation by using RETRAN 02 to simulate the control object. The research solved the key technology of digital control system of reactor and will be very helpful for the nationalization of digital reactor control system

  12. Digital Collections, Digital Libraries and the Digitization of Cultural Heritage Information.

    Science.gov (United States)

    Lynch, Clifford

    2002-01-01

    Discusses the development of digital collections and digital libraries. Topics include digitization of cultural heritage information; broadband issues; lack of compelling content; training issues; types of materials being digitized; sustainability; digital preservation; infrastructure; digital images; data mining; and future possibilities for…

  13. Digitalizing the Circular Economy

    Science.gov (United States)

    Reuter, Markus A.

    2016-12-01

    Metallurgy is a key enabler of a circular economy (CE), its digitalization is the metallurgical Internet of Things (m-IoT). In short: Metallurgy is at the heart of a CE, as metals all have strong intrinsic recycling potentials. Process metallurgy, as a key enabler for a CE, will help much to deliver its goals. The first-principles models of process engineering help quantify the resource efficiency (RE) of the CE system, connecting all stakeholders via digitalization. This provides well-argued and first-principles environmental information to empower a tax paying consumer society, policy, legislators, and environmentalists. It provides the details of capital expenditure and operational expenditure estimates. Through this path, the opportunities and limits of a CE, recycling, and its technology can be estimated. The true boundaries of sustainability can be determined in addition to the techno-economic evaluation of RE. The integration of metallurgical reactor technology and systems digitally, not only on one site but linking different sites globally via hardware, is the basis for describing CE systems as dynamic feedback control loops, i.e., the m-IoT. It is the linkage of the global carrier metallurgical processing system infrastructure that maximizes the recovery of all minor and technology elements in its associated refining metallurgical infrastructure. This will be illustrated through the following: (1) System optimization models for multimetal metallurgical processing. These map large-scale m-IoT systems linked to computer-aided design tools of the original equipment manufacturers and then establish a recycling index through the quantification of RE. (2) Reactor optimization and industrial system solutions to realize the "CE (within a) Corporation—CEC," realizing the CE of society. (3) Real-time measurement of ore and scrap properties in intelligent plant structures, linked to the modeling, simulation, and optimization of industrial extractive process

  14. Electronic Concepts Simulation Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The laboratory utilizes state-of-the-art digital models and simulations of both friendly and enemy airborne and ground-based weapon and command and control systems....

  15. Flight Trainer Digital Computer Study

    Science.gov (United States)

    1951-03-21

    b’e "ä"dö|rtedr rfoS^ hfe "digital airplane simulator is .dependent on the accTuracy demanded for representing airp2ane^mo±i6h---as4 on the method...analogue- quantity such as- a vQ.lt:äfa.:e’ .süit;*.v £jr- äc\\t„ü’at.ing an, inst’riMen’t’.i. Since in gene /paiL " ~ instruments, v^𔃻

  16. Digital calculations of engine cycles

    CERN Document Server

    Starkman, E S; Taylor, C Fayette

    1964-01-01

    Digital Calculations of Engine Cycles is a collection of seven papers which were presented before technical meetings of the Society of Automotive Engineers during 1962 and 1963. The papers cover the spectrum of the subject of engine cycle events, ranging from an examination of composition and properties of the working fluid to simulation of the pressure-time events in the combustion chamber. The volume has been organized to present the material in a logical sequence. The first two chapters are concerned with the equilibrium states of the working fluid. These include the concentrations of var

  17. Digital radiology and ultrasound

    International Nuclear Information System (INIS)

    Todd-Pokropek, A.

    1991-01-01

    With the access to digital methods for handling and processing images in general, many medical imaging methods are becoming more effectively handled digitally. This applies in particular to basically digital techniques such as CT and MR but also now includes Nuclear Medicine (NM), Ultrasound (US) and a variety of radiological procedures such as Digital Subtraction Angiography (DSA) and Fluoroscopy (DF). The access to conventional projection images by stimulatable plates (CR) or by digitization of film makes all of radiology potentially accessible, and the management of such images by a network is the basic aim of Picture Archiving and Communication Systems (PACS). However, it is suggested that in order for such systems to be of greater value, that way in which such images are treated needs to change, that is, digital images can be used to derive additional clinical value by appropriate processing

  18. Digital cine-imaging

    International Nuclear Information System (INIS)

    Masuda, Kazuhiro

    1992-01-01

    Digitization of fluoroscopic images has been developed for the digital cine imaging system as a result of the computer technology, television technology, and popularization of interventional radiology. Present digital cine imaging system is able to offer images similar to cine film because of the higher operatability and better image quality with the development of interventional radiology. As a result, its higher usefulness for catheter diagnosis examination except for interventional radiology was reported, and the possibility of having filmless cine is close to becoming a reality. However several problems have been pointed out, such as spatial resolution, time resolution, storage and exchangeability of data, disconsolidated viewing functions, etc. Anyhow, digital cine imaging system has some unresolved points and lots the needs to be discussed. The tendency of digitization is the passage of the time and we have to promote a study for more useful digital cine imaging system in team medical treatment which centers on the patients. (author)

  19. Theory of Digital Automata

    CERN Document Server

    Borowik, Bohdan; Lahno, Valery; Petrov, Oleksandr

    2013-01-01

    This book serves a dual purpose: firstly to combine the treatment of circuits and digital electronics, and secondly, to establish a strong connection with the contemporary world of digital systems. The need for this approach arises from the observation that introducing digital electronics through a course in traditional circuit analysis is fast becoming obsolete. Our world has gone digital. Automata theory helps with the design of digital circuits such as parts of computers, telephone systems and control systems. A complete perspective is emphasized, because even the most elegant computer architecture will not function without adequate supporting circuits. The focus is on explaining the real-world implementation of complete digital systems. In doing so, the reader is prepared to immediately begin design and implementation work. This work serves as a bridge to take readers from the theoretical world to the everyday design world where solutions must be complete to be successful.

  20. Digital twins of human robot collaboration in a production setting

    DEFF Research Database (Denmark)

    Malik, Ali Ahmad; Bilberg, Arne

    2018-01-01

    This paper aims to present a digital twin framework to support the design, build and control of human-machine cooperation. In this study, computer simulations are used to develop a digital counterpart of a human-robot collaborative work environment for assembly work. The digital counterpart remains...... updated during the life cycle of the production system by continuously mirroring the physical system for quick and safe embed for continuous improvements. The case of a manufacturing company with human-robot work teams is presented for developing and validating the digital twin framework....

  1. Digital collections and exhibits

    CERN Document Server

    Denzer, Juan

    2015-01-01

    Today's libraries are taking advantage of cutting-edge technologies such as flat panel displays using touch, sound, and hands-free motions to design amazing exhibits using everything from simple computer hardware to advanced technologies such as the Microsoft Kinect. Libraries of all types are striving to add new interactive experiences for their patrons through exciting digital exhibits, both online and off. Digital Collections and Exhibits takes away the mystery of designing stunning digital exhibits to spotlight library trea

  2. The digital computer

    CERN Document Server

    Parton, K C

    2014-01-01

    The Digital Computer focuses on the principles, methodologies, and applications of the digital computer. The publication takes a look at the basic concepts involved in using a digital computer, simple autocode examples, and examples of working advanced design programs. Discussions focus on transformer design synthesis program, machine design analysis program, solution of standard quadratic equations, harmonic analysis, elementary wage calculation, and scientific calculations. The manuscript then examines commercial and automatic programming, how computers work, and the components of a computer

  3. Digital Textile Printing

    OpenAIRE

    Moltchanova, Julia

    2011-01-01

    Rapidly evolving technology of digital printing opens new opportunities on many markets. One of them is the printed fabric market where printing companies as well as clients benefit from new printing methods. This thesis focuses on the digital textile printing technology and its implementation for fabric-on-demand printing service in Finland. The purpose of this project was to study the technology behind digital textile printing, areas of application of this technology, the requirements ...

  4. Digital Sensor Technology

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Ken D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Quinn, Edward L. [Technology Resources, Dana Point, CA (United States); Mauck, Jerry L. [Technology Resources, Dana Point, CA (United States); Bockhorst, Richard M. [Technology Resources, Dana Point, CA (United States)

    2015-02-01

    The nuclear industry has been slow to incorporate digital sensor technology into nuclear plant designs due to concerns with digital qualification issues. However, the benefits of digital sensor technology for nuclear plant instrumentation are substantial in terms of accuracy and reliability. This paper, which refers to a final report issued in 2013, demonstrates these benefits in direct comparisons of digital and analog sensor applications. Improved accuracy results from the superior operating characteristics of digital sensors. These include improvements in sensor accuracy and drift and other related parameters which reduce total loop uncertainty and thereby increase safety and operating margins. An example instrument loop uncertainty calculation for a pressure sensor application is presented to illustrate these improvements. This is a side-by-side comparison of the instrument loop uncertainty for both an analog and a digital sensor in the same pressure measurement application. Similarly, improved sensor reliability is illustrated with a sample calculation for determining the probability of failure on demand, an industry standard reliability measure. This looks at equivalent analog and digital temperature sensors to draw the comparison. The results confirm substantial reliability improvement with the digital sensor, due in large part to ability to continuously monitor the health of a digital sensor such that problems can be immediately identified and corrected. This greatly reduces the likelihood of a latent failure condition of the sensor at the time of a design basis event. Notwithstanding the benefits of digital sensors, there are certain qualification issues that are inherent with digital technology and these are described in the report. One major qualification impediment for digital sensor implementation is software common cause failure (SCCF).

  5. Preserving Digital Materials

    CERN Document Server

    Harvey, Ross

    2011-01-01

    This book provides a single-volume introduction to the principles, strategies and practices currently applied by librarians and recordkeeping professionals to the critical issue of preservation of digital information. It incorporates practice from both the recordkeeping and the library communities, taking stock of current knowledge about digital preservation and describing recent and current research, to provide a framework for reflecting on the issues that digital preservation raises in professional practice.

  6. Dakwah di Era Digital

    OpenAIRE

    Budiantoro, Wahyu

    2018-01-01

    These days dakwah is not only interpreted as transformation of a pure religious value, but also transformation of a more relevant value including many aspects in digital era. Digital era is when society succumbed into the flow of information causing cultural shock and difficulties on synthesizing meaning from those scattered information. Dakwah on Digital age must accommodate societal needs which tend to move into a mass society. It results in strategy and more humane and innovative dakwah me...

  7. The Digital Imperative

    OpenAIRE

    Veling, Louise; Murnane, Sinéad; Carcary, Marian; Zlydareva, Olga

    2014-01-01

    The pervasiveness of digital technologies and their potential for reshaping the industry landscape dictates that organizations operating today have little choice but to incorporate digital technologies into their business strategies. Failure to do so will impede the business’s viability, and may ultimately lead to business failure. However, for those organizations that successfully transition to digital business, unprecedented business opportunities exist for value creation and reali...

  8. Digital piracy : theory

    OpenAIRE

    BELLEFLAMME, Paul; PEITZ, Martin

    2010-01-01

    This article reviews recent theoretical contributions on digital piracy. It starts by elaborating on the reasons for intellectual property protection, by reporting a few facts about copyright protection, and by examining reasons to become a digital pirate. Next, it provides an exploration of the consequences of digital piracy, using a base model and several extensions (with consumer sampling, network effects, and indirect appropriation). A closer look at market-structure implications of end-u...

  9. La radio digital

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Cortés S.

    2015-01-01

    Full Text Available La radio digital es un producto de la llamada convergencia digital. Las nuevas tecnologías interconectadas permiten la aparición de nuevos modos de audiencia y la implementación de herramientas versátiles. Habla del problema de los estándares, de la radio satelital, la radio digital terrestre, las radios internacionales, la interactividad.

  10. Easy digital engineering

    International Nuclear Information System (INIS)

    Jin, Dal Bok

    2002-02-01

    This book lists basic of digital engineering, number system and digital code, Boolean algebra and basic logic circuit, simplify of logical expression, combinational circuit, arithmetic circuit, multivibrator circuit, sequential circuit, memory unit of semiconductor and logical element for program, D/A converter and A/D converter, logic element and integrated circuit and logic circuit and micro controller. It has exercises and answers about digital engineering and summary in the end of each chapter.

  11. Debunking the "Digital Native": Beyond Digital Apartheid, towards Digital Democracy

    Science.gov (United States)

    Brown, C.; Czerniewicz, L.

    2010-01-01

    This paper interrogates the currently pervasive discourse of the "net generation" finding the concept of the "digital native" especially problematic, both empirically and conceptually. We draw on a research project of South African higher education students' access to and use of Information and Communication Technologies (ICTs)…

  12. Digital Natives and Digital Divide: Analysing Perspective for Emerging Pedagogy

    Science.gov (United States)

    Onye, Uriel U.; Du, Yunfei

    2016-01-01

    This paper addresses the concepts of digital natives and digital divide from the perspective of the digital outsiders (part of digital natives). It takes a critical look at the implications of available ICT in both developed and underdeveloped countries in the fight against digital divide. The major contribution to literature is by drawing…

  13. The digital media handbook

    CERN Document Server

    Dewdney, Andrew

    2013-01-01

    The new edition of The Digital Media Handbook presents an essential guide to the historical and theoretical development of digital media, emphasising cultural continuity alongside technological change, and highlighting the emergence of new forms of communication in contemporary networked culture.Andrew Dewdney and Peter Ride present detailed critical commentary and descriptive historical accounts, as well as a series of interviews from a range of digital media practitioners, including producers, developers, curators and artists.The Digital Media Handbook highlights key concerns of today's prac

  14. Digitization of conventional radiographs

    International Nuclear Information System (INIS)

    Wenz, W.; Buitrago-Tellez, C.; Blum, U.; Hauenstein, K.H.; Gufler, H.; Meyer, E.; Ruediger, K.

    1992-01-01

    The diagnostic value of a digitization system for analogue films based on a charge-coupled-device (CCD) scanner with adjustable resolution of 2.5 or 5 lp/mm was assessed. Some 110 skeletal radiographs, 50 contrast studies, including 25 of patients with Crohn's disease, and 70 abdominal plain films before and after successful lithotripsy for renal stones were digitized. Receiver operating characteristic (ROC) studies showed improved detection of cortical and trabecular defects with contrast-optimized digitized films. Edge enhancement algorithms yielded no additional information. Inflammatory lesions of Crohn's disease were detected equally well by conventional films and digitized images. A statistically significant improvement (p [de

  15. Digital security technology simplified.

    Science.gov (United States)

    Scaglione, Bernard J

    2007-01-01

    Digital security technology is making great strides in replacing analog and other traditional security systems including CCTV card access, personal identification and alarm monitoring applications. Like any new technology, the author says, it is important to understand its benefits and limitations before purchasing and installing, to ensure its proper operation and effectiveness. This article is a primer for security directors on how digital technology works. It provides an understanding of the key components which make up the foundation for digital security systems, focusing on three key aspects of the digital security world: the security network, IP cameras and IP recorders.

  16. Digitally-Driven Architecture

    Directory of Open Access Journals (Sweden)

    Henriette Bier

    2014-07-01

    Full Text Available The shift from mechanical to digital forces architects to reposition themselves: Architects generate digital information, which can be used not only in designing and fabricating building components but also in embedding behaviours into buildings. This implies that, similar to the way that industrial design and fabrication with its concepts of standardisation and serial production influenced modernist architecture, digital design and fabrication influences contemporary architecture. While standardisation focused on processes of rationalisation of form, mass-customisation as a new paradigm that replaces mass-production, addresses non-standard, complex, and flexible designs. Furthermore, knowledge about the designed object can be encoded in digital data pertaining not just to the geometry of a design but also to its physical or other behaviours within an environment. Digitally-driven architecture implies, therefore, not only digitally-designed and fabricated architecture, it also implies architecture – built form – that can be controlled, actuated, and animated by digital means.In this context, this sixth Footprint issue examines the influence of digital means as pragmatic and conceptual instruments for actuating architecture. The focus is not so much on computer-based systems for the development of architectural designs, but on architecture incorporating digital control, sens­ing, actuating, or other mechanisms that enable buildings to inter­act with their users and surroundings in real time in the real world through physical or sensory change and variation.

  17. Digitally-Driven Architecture

    Directory of Open Access Journals (Sweden)

    Henriette Bier

    2010-06-01

    Full Text Available The shift from mechanical to digital forces architects to reposition themselves: Architects generate digital information, which can be used not only in designing and fabricating building components but also in embedding behaviours into buildings. This implies that, similar to the way that industrial design and fabrication with its concepts of standardisation and serial production influenced modernist architecture, digital design and fabrication influences contemporary architecture. While standardisa­tion focused on processes of rationalisation of form, mass-customisation as a new paradigm that replaces mass-production, addresses non-standard, complex, and flexible designs. Furthermore, knowledge about the designed object can be encoded in digital data pertaining not just to the geometry of a design but also to its physical or other behaviours within an environment. Digitally-driven architecture implies, therefore, not only digitally-designed and fabricated architecture, it also implies architecture – built form – that can be controlled, actuated, and animated by digital means. In this context, this sixth Footprint issue examines the influence of digital means as prag­matic and conceptual instruments for actuating architecture. The focus is not so much on computer-based systems for the development of architectural designs, but on architecture incorporating digital control, sens­ing, actuating, or other mechanisms that enable buildings to inter­act with their users and surroundings in real time in the real world through physical or sensory change and variation.

  18. Exploring digital professionalism.

    Science.gov (United States)

    Ellaway, Rachel H; Coral, Janet; Topps, David; Topps, Maureen

    2015-01-01

    The widespread use of digital media (both computing devices and the services they access) has blurred the boundaries between our personal and professional lives. Contemporary students are the last to remember a time before the widespread use of the Internet and they will be the first to practice in a largely e-health environment. This article explores concepts of digital professionalism and their place in contemporary medical education, and proposes a series of principles of digital professionalism to guide teaching, learning and practice in the healthcare professions. Despite the many risks and fears surrounding their use, digital media are not an intrinsic threat to medical professionalism. Professionals should maintain the capacity for deliberate, ethical, and accountable practice when using digital media. The authors describe a digital professionalism framework structured around concepts of proficiency, reputation, and responsibility. Digital professionalism can be integrated into medical education using strategies based on awareness, alignment, assessment, and accountability. These principles of digital professionalism provide a way for medical students and medical practitioners to embrace the positive aspects of digital media use while being mindful and deliberate in its use to avoid or minimize any negative consequences.

  19. Radiographic film digitizing devices

    International Nuclear Information System (INIS)

    McFee, W.H.

    1988-01-01

    Until recently, all film digitizing devices for use with teleradiology or picture archiving and communication systems used a video camera to capture an image of the radiograph for subsequent digitization. The development of film digitizers that use a laser beam to scan the film represents a significant advancement in digital technology, resulting in improved image quality compared with video scanners. This paper discusses differences in resolution, efficiency, reliability, and the cost between these two types of devices. The results of a modified receiver operating characteristic comparison study of a video scanner and a laser scanner manufactured by the same company are also discussed

  20. Cognitive Hacking and Digital Government: Digital Identity

    Directory of Open Access Journals (Sweden)

    Paul Thompson

    2004-04-01

    Full Text Available Recently the National Center for Digital Government held a workshop on "The Virtual Citizen: Identity, Autonomy, and Accountability: A Civic Scenario Exploration of the Role of Identity in On-Line. Discussions at the workshop focused on five scenarios for future authentication policies with respect to digital identity. The underlying technologies considered for authentication were: biometrics: cryptography, with a focus on digital signatures; secure processing/computation; and reputation systems. Most discussion at the workshop focused on issues related to authentication of users of digital government, but, as implied by the inclusion of a scenario related to ubiquitous identity theft, there was also discussion of problems related to misinformation, including cognitive hacking. Cognitive hacking refers to a computer or information system attack that relies on changing human users' perceptions and corresponding behaviors in order to succeed. This paper describes cognitive hacking, suggests countermeasures, and discusses the implications of cognitive hacking for identity in digital government. In particular, spoofing of government websites and insider misuse are considered.

  1. New techniques in digital holography

    CERN Document Server

    Picart, Pascal

    2015-01-01

    A state of the art presentation of important advances in the field of digital holography, detailing advances related to fundamentals of digital holography, in-line holography applied to fluid mechanics, digital color holography, digital holographic microscopy, infrared holography, special techniques in full field vibrometry and inverse problems in digital holography

  2. Experience of digital control systems in Scandinavian BWRs

    International Nuclear Information System (INIS)

    Rydahl, I.

    1989-01-01

    Since 1984 digital control systems have been in operation in various Scandinavian BWRs. Examples of such digital control systems are: dual microprocessor based system for complete control of radwaste plant, three channel recirculation control system, and three channel feedwater control system. This paper describes Swedish development from one channel through three channel analog control systems to digital systems. The author describes experience of digital control systems during design, testing, commissioning and operation. The main benefits of digital compared with analog technology are discussed. Especially the outstanding facility of using a built-in process simulator for commissioning and tuning. The use of digital technology in nuclear safety system and future plans are dealt with

  3. Performance Analysis of Digital loudspeaker Arrays

    DEFF Research Database (Denmark)

    Pedersen, Bo Rohde; Kontomichos, Fotios; Mourjopoulos, John

    2008-01-01

    An analysis of digital loudspeaker arrays shows that the ways in which bits are mapped to the drivers influence the quality of the audio result. Specifically, a "bit-summed" rather than the traditional "bit-mapped" strategy greatly reduces the number of times drivers make binary transitions per...... period of the input frequency. Detailed simulations compare the results for a 32-loudspeaker array with a similar configuration with analog excitation of the drivers. Ideally, drivers in digital arrays should be very small and span a small area, but that sets limits on the low-frequency response...

  4. Digital temperature meter

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, S

    1982-01-01

    Digital temperature meter for precise temperature measurements is presented. Its parts such as thermostat, voltage-frequency converter and digital frequency meter are described. Its technical parameters such as temperature range 50degC-700degC, measurement precision 1degC, measurement error +-1degC are given. (A.S.).

  5. Changing State Digital Libraries

    Science.gov (United States)

    Pappas, Marjorie L.

    2006-01-01

    Research has shown that state virtual or digital libraries are evolving into websites that are loaded with free resources, subscription databases, and instructional tools. In this article, the author explores these evolving libraries based on the following questions: (1) How user-friendly are the state digital libraries?; (2) How do state digital…

  6. Digital signage sobre IP

    OpenAIRE

    Casademont Filella, Albert

    2012-01-01

    Projecte que versa sobre el disseny i la implementació d'un sistema de Digital Signage (Cartelleria Digital) sobre IP, creant un gestor que permeti controlar de forma remota tot un conjunt de petits dispositius connectats a pantalles que emeten continguts multimèdia com vídeos, imatges, feeds rss...

  7. Digital gaming expertise

    DEFF Research Database (Denmark)

    Toft-Nielsen, Claus

    In a digitally saturated environment digital media users of all kinds, engaged in different areas of activity, are increasingly categorized in terms of their ability to appropriate and use digital media – they are regarded as non-users, experts, natives, or literates for instance. Within communic......In a digitally saturated environment digital media users of all kinds, engaged in different areas of activity, are increasingly categorized in terms of their ability to appropriate and use digital media – they are regarded as non-users, experts, natives, or literates for instance. Within...... communication and game studies there are multiple understandings of how digital expertise is expressed and performed, and subsequently how these expressions and performances can be valued, understood and theorized within the research community. Among other things expertise with and within digital games has......-of-game (Schrøder, 2003) in a three-year-long study of men and women (couples and singles) playing the largest Massively Multiplayer Online Role-Playing Game to date, World of Warcraft. In focusing on how different aspects of gaming expertise are articulated, negotiated, and performed, I aim to illustrate how...

  8. The First Digit 1

    Indian Academy of Sciences (India)

    IAS Admin

    1075. RESONANCE | December 2013. GENERAL | ARTICLE. Table 2. The first digits distri- bution according to Benford's law. First Frequency. Digit. 1. 30.1 %. 2. 17.6 %. 3. 12.4 %. 4. 9.7 %. 5. 7.9 %. 6. 6.7 %. 7. 5.8 %. 8. 5.1 %. 9. 4.5 % ...

  9. Digital Cultural Heritage

    NARCIS (Netherlands)

    Navarrete, T.; Rizzo, I.; Mignosa, A.

    2013-01-01

    What is the impact of media technology on the supply and demand of heritage with what is usually described as digitization? This chapter presents the concept of digitization as concerning far more than just the introduction of computers, the development of databases and websites, and the conversion

  10. Digital formidling af kulturarv

    DEFF Research Database (Denmark)

    En af tidens store kulturelle dagsordner drejer sig om digital tilgængeliggørelse af kulturarv. Fortidens spor dukker op i nye former på nettet - næsten alle kulturinstitutioner arbejder med, og befolkningen har fået helt nye muligheder for at se med og deltage. Digital formidling af kulturarv...

  11. Digitizing migration heritage

    DEFF Research Database (Denmark)

    Marselis, Randi

    2011-01-01

    Museums are increasingly digitizing their collections and making them available to the public on-line. Creating such digital resources may become means for social inclusion. For museums that acknowledge migration history and cultures of ethnic minority groups as important subjects in multiethnic...

  12. Beyond Digital Citizenship

    Science.gov (United States)

    Mitchell, Lynn

    2016-01-01

    Conversations in middle school about digital citizenship tend to focus on the responsibilities of citizenship and the issues of surveillance, safety, cyberbullying, and internet etiquette. While these are important and essential conversations, digital citizenship education needs to consider youth political identity and democratic participation in…

  13. Navigate the Digital Rapids

    Science.gov (United States)

    Lindsay, Julie; Davis, Vicki

    2010-01-01

    How can teachers teach digital citizenship when the digital landscape is changing so rapidly? How can teachers teach proper online social interactions when the students are outside their classroom and thus outside their control? Will encouraging students to engage in global collaborative environments land teachers in hot water? These are the…

  14. Monetizing Digital Assets

    Directory of Open Access Journals (Sweden)

    Felician ALECU

    2013-04-01

    Full Text Available This article covers the options the digital content creators have to monetize their creations. The simplest solution seems to be the winning one, so by enabling the ads, the digital content may be quickly transformed into money with no cost.

  15. Digital chest radiography

    DEFF Research Database (Denmark)

    Debess, Jeanne Elisabeth; Johnsen, Karen Kirstine; Thomsen, Henrik

    on collimation and dose reduction in digital chest radiography Methods and Materials A retrospective study of digital chest radiography is performed to evaluate the primary x-ray tube collimation of the PA and lateral radiographs. Data from one hundred fifty self-reliant female patients between 15 and 55 years...

  16. Recurrent infantile digital fibromatosis

    African Journals Online (AJOL)

    We present a case of an 8-year-old-boy with recurrent infantile digital fibromatosis (IDF) who presented with new ... Keywords: fibrous tumors, inclusion body fibromatosis, infantile digital fibromatosis, spindle cells, Reye tumor .... watch-and-wait strategy for patients with histologically confirmed IDF nodules that do not cause ...

  17. Practical digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Beverly E. [Washington Univ., Seattle, WA (United States)]|[Virginia Mason Medical Center, VA (United States)

    2008-07-01

    This book is meant for the radiologist who is facing the challenge of organizing a digital mammographic imaging center. This text is meant to be a practical book that provides information about digital mammographic physics and equipment which will allow one to intelligently compare technologies and systems. Some of the major challenges include: large expense; rapidly changing technology, and inconsistent connectivity; and finally, need for strong information technology support. The initial conversion cost to digital mammographic imaging is relatively expensive due to the cost of digital mammography hardware, software, and storage. Virtually all other imaging modalities are being converted to purely digital storage and transfer, and the digital trend in mammography is inevitable. Technical advantages of digital mammography are described. However, the improved flexibility in image display and transfer are some of its strongest features. In conclusion, although there are increasing imaging modalities that may be used to evaluate breast disease, mammography will continue to play a key role in detecting breast cancer. To be an effective imager, the radiologist should become familiar with digital mammography and understand its role within the increasing complex structure of breast imaging techniques.

  18. Practical digital mammography

    International Nuclear Information System (INIS)

    Hashimoto, Beverly E.

    2008-01-01

    This book is meant for the radiologist who is facing the challenge of organizing a digital mammographic imaging center. This text is meant to be a practical book that provides information about digital mammographic physics and equipment which will allow one to intelligently compare technologies and systems. Some of the major challenges include: large expense; rapidly changing technology, and inconsistent connectivity; and finally, need for strong information technology support. The initial conversion cost to digital mammographic imaging is relatively expensive due to the cost of digital mammography hardware, software, and storage. Virtually all other imaging modalities are being converted to purely digital storage and transfer, and the digital trend in mammography is inevitable. Technical advantages of digital mammography are described. However, the improved flexibility in image display and transfer are some of its strongest features. In conclusion, although there are increasing imaging modalities that may be used to evaluate breast disease, mammography will continue to play a key role in detecting breast cancer. To be an effective imager, the radiologist should become familiar with digital mammography and understand its role within the increasing complex structure of breast imaging techniques

  19. Educating Digital Citizens

    Science.gov (United States)

    Tan, Thomas

    2011-01-01

    Digital citizenship is how educators, citizens, and parents can teach where the lines of cyber safety and ethics are in the interconnected online world their students will inhabit. Aside from keeping technology users safe, digital citizenship also prepares students to survive and thrive in an environment embedded with information, communication,…

  20. Digital Rights Management

    NARCIS (Netherlands)

    Koster, P.; Jonker, Willem; Blanken, Henk; de Vries, A.P.; Blok, H.E.; Feng, L.

    2007-01-01

    Digital Rights Management, or DRM for short, is a much-discussed topic nowadays. The main reason for this is that DRM technology is often mentioned in the context of protection of digital audio and video content, for example to avoid large scale copying of CDs and DVDs via peer-to-peer networks in

  1. Digitalization of daycare institutions

    DEFF Research Database (Denmark)

    Chimirri, Niklas Alexander

    in the intergenerational interaction with as well as the intragenerational interaction among daycare children. To some extent, digital media usage, foremost of tablet computers, has seen a discursive and material normalization across a number Danish daycare institutions before at all clarifying how it could be rendered...... as on situated sociomaterial approaches to critical psychological practice research in order to inquire into possible specificities of digital media device usage: How is this usage similar to and different from interacting via other material-communicative devices in a pedagogical practice? How do digital media......The digitalization of Danish daycare institutions is not only affecting the ways staff is documenting and reporting on its pedagogical work. It also appears to be redefining what pedagogical work itself is about, given the drastic increase in deployment of digital (mobile) media devices...

  2. Creative Digital Media Practices

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth

    , 2006, 2009), machinima (machine + cinema + anime, real-time animation captured in games etc.), and the digital storytelling movement. A dialogic perspective on the diversity of digital media practices opens up for understanding the complex evolution of language on socio-historical, cultural......The presentation reviews the interplay of dialogic (Bakhtin, 1981) and multimodal theories on media production practices, with attention to visual communication (Kress and van Leeuwen, 2001, 2006). This theoretical approach aids in reflecting on digital media practices as novel (new) sign systems...... develop a collaborative digital storytelling showcase for their own digital stories about Roskilde University. This course is intended to bring up reflections on the wider phenomenon of contemporary media practices, such as: YouTube, DIY (do-it-yourself) filmmaking or homemade, garage cinema (Jenkins...

  3. Digital Technology Entrepreneurship

    DEFF Research Database (Denmark)

    Giones, Ferran; Brem, Alexander

    2017-01-01

    Technology entrepreneurship is an established concept in academia. However, recent developments in the context of digital entrepreneurship call for revision and advance- ment. The multiple possible combinations of technology and entrepreneurship have res- ulted in a diversity of phenomena...... with significantly different characteristics and socio-economic impact. This article is focused on the identification and description of technology entrepreneurship in times of digitization. Based on current examples, we identify and describe characterizations of technology entrepreneurship, digital techno- logy...... entrepreneurship, and digital entrepreneurship. With this new delineation of terms, we would like to foster discussion between researchers, entrepreneurs, and policy makers on the impact of digitization on entrepreneurship, and set a future research agenda....

  4. Transformation of Digital Ecosystems

    DEFF Research Database (Denmark)

    Henningsson, Stefan; Hedman, Jonas

    2014-01-01

    the Digital Ecosystem Technology Transformation (DETT) framework for explaining technology-based transformation of digital ecosystems by integrating theories of business and technology ecosystems. The framework depicts ecosystem transformation as distributed and emergent from micro-, meso-, and macro- level......In digital ecosystems, the fusion relation between business and technology means that the decision of technical compatibility of the offering is also the decision of how to position the firm relative to the coopetive relations that characterize business ecosystems. In this article we develop...... coopetition. The DETT framework consists an alternative to the existing explanations of digital ecosystem transformation as the rational management of one central actor balancing ecosystem tensions. We illustrate the use of the framework by a case study of transformation in the digital payment ecosystem...

  5. The digital spine

    DEFF Research Database (Denmark)

    Ebbesen, Toke Riis

    2019-01-01

    In the words of the Oxford English Dictionary, a book is 'a portable volume consisting of a series of written, printed, or illustrated pages bound together for ease of reading' (‘book, n.’nd). Yet, the world of books isn’t what it used to be. If differences between media are material differences...... analyze books as digital or even 'post-digital' artifacts (Cramer 2014), while preserving the material dimension of the book artifact. In other words: is there is such a thing as a (post-)digital spine, and how can it be described? This article outlines an answer to this question within an inferential...... (Seiter 2015), and books are produced, distributed and read on various digital media and devices, it is no longer possible to understand digital books on the basis of the material and syntactical features of the codex artifact. It then becomes important to discuss how to conceptualize and subsequently...

  6. Digital Tectonic Tools

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due

    2005-01-01

    Tectonics has been an inherent part of the architectural field since the Greek temples while the digital media is new to the field. This paper is built on the assumption that in the intermediate zone between the two there is a lot to be learned about architecture in general and the digital media...... in particular. A model of the aspects in the term tectonics – epresentation, ontology and culture – will be presented and used to discuss the current digital tools’ ability in tectonics. Furthermore it will be discussed what a digital tectonic tool is and could be and how a connection between the digital...... and tectonic could become a part of the architectural education....

  7. Digital forensic standards: international progress

    CSIR Research Space (South Africa)

    Grobler, MM

    2010-05-01

    Full Text Available With the explosion of digital crime, digital forensics is more often applied. The digital forensic discipline developed rather rapidly, but up to date very little international standardization with regard to processes, procedures or management has...

  8. Computing Logarithms Digit-by-Digit

    Science.gov (United States)

    Goldberg, Mayer

    2005-01-01

    In this work, we present an algorithm for computing logarithms of positive real numbers, that bears structural resemblance to the elementary school algorithm of long division. Using this algorithm, we can compute successive digits of a logarithm using a 4-operation pocket calculator. The algorithm makes no use of Taylor series or calculus, but…

  9. Principles of synchronous digital hierarchy

    CERN Document Server

    Jain, Rajesh Kumar

    2012-01-01

    The book presents the current standards of digital multiplexing, called synchronous digital hierarchy, including analog multiplexing technologies. It is aimed at telecommunication professionals who want to develop an understanding of digital multiplexing and synchronous digital hierarchy in particular and the functioning of practical telecommunication systems in general. The text includes all relevant fundamentals and provides a handy reference for problem solving or defining operations and maintenance strategies. The author covers digital conversion and TDM principles, line coding and digital

  10. Research on Digital Product Modeling Key Technologies of Digital Manufacturing

    Institute of Scientific and Technical Information of China (English)

    DING Guoping; ZHOU Zude; HU Yefa; ZHAO Liang

    2006-01-01

    With the globalization and diversification of the market and the rapid development of Information Technology (IT) and Artificial Intelligence (AI), the digital revolution of manufacturing is coming. One of the key technologies in digital manufacturing is product digital modeling. This paper firstly analyzes the information and features of the product digital model during each stage in the product whole lifecycle, then researches on the three critical technologies of digital modeling in digital manufacturing-product modeling, standard for the exchange of product model data and digital product data management. And the potential signification of the product digital model during the process of digital manufacturing is concluded-product digital model integrates primary features of each stage during the product whole lifecycle based on graphic features, applies STEP as data exchange mechanism, and establishes PDM system to manage the large amount, complicated and dynamic product data to implement the product digital model data exchange, sharing and integration.

  11. DSA in digital replantations

    International Nuclear Information System (INIS)

    Wang Liuhong; Chao Ming; Jiang Dingyao; Zhang Guangqiang; Wu Jianjun; Chen Xianyi; Li Bin; Sun Jihong

    2008-01-01

    Objective: To assess revascularization and vessel anastomosis in digital replantations with DSA. Methods: Twelve cases of digital replantations underwent digital subtract angiography during 2 to 4 days after fingers reattachment. The vessel anastomosis, hemodynamics, stenosis and discontinuation were investigated. The unobstructed and smooth anastomosis was suggested as early stage survival of the reattached fingers, the spasm and stenosis of the reattached vessels were considered as mild vascular crisis, and the discontinuation of hemodynamics were indicated as severe vascular crisis. Results: The total 27 vessels were clearly displayed on DSA. Of these vessels, 23 vessels were unobstructed and smooth, all digits were survived. Diagnosis coincidence of early stage survival was 100% (23/23). Two vessels were obstructed, which were testified having thrombus by operation research. The other 2 vessels were spasm, the digits were also survived ultimately by expectant treatment. All 4 abnormal vessel anatomosis were found by DSA. Conclusion: DSA is important modality in assessing revascularization and blood circulation for digital replantations, guiding in dealing with the vascular crisis, and in predicting early stage survival of the reattached digits. (authors)

  12. Digital mineral logging system

    International Nuclear Information System (INIS)

    West, J.B.

    1980-01-01

    A digital mineral logging system acquires data from a mineral logging tool passing through a borehole and transmits the data uphole to an electronic digital signal processor. A predetermined combination of sensors, including a deviometer, is located in a logging tool for the acquisition of the desired data as the logging tool is raised from the borehole. Sensor data in analog format is converted in the logging tool to a digital format and periodically batch transmitted to the surface at a predetermined sampling rate. An identification code is provided for each mineral logging tool, and the code is transmitted to the surface along with the sensor data. The self-identifying tool code is transmitted to the digital signal processor to identify the code against a stored list of the range of numbers assigned to that type of tool. The data is transmitted up the d-c power lines of the tool by a frequency shift key transmission technique. At the surface, a frequency shift key demodulation unit transmits the decoupled data to an asynchronous receiver interfaced to the electronic digital signal processor. During a recording phase, the signals from the logging tool are read by the electronic digital signal processor and stored for later processing. During a calculating phase, the stored data is processed by the digital signal processor and the results are outputted to a printer or plotter, or both

  13. Digital cardiovascular imaging

    International Nuclear Information System (INIS)

    Myerowitz, P.D.; Mistretta, C.A.; Shaw, C.-G.; Van Lysel, M.S.; Swanson, D.K.; Lasser, T.A.; Dhanani, S.P.; Zarnstorff, W.C.; Vander Ark, C.R.; Dobbins, J.T.; Peppler, W.W.; Crummy, A.B.

    1982-01-01

    The authors have previously reported on real time digital fluoroscopic subtraction techniques developed in the laboratory during the past 10 years. This paper outlines basic apparatus configuration and imaging modes used for preliminary studies involving visualization of the canine and human heart. All of the techniques involve the use of real time digital subtraction processing of data from an image intensified television fluoroscopy system. Based on the configuration of the digital processing equipment a number of different imaging modalities are possible. A brief description of the apparatus and these imaging modes is given. (Auth.)

  14. Digital Enlightenment Yearbook 2012

    CERN Document Server

    Bus, J; Hildebrandt, M

    2012-01-01

    There have been many inevitable transformations in society due to digitization - the introduction of digital technology, including communication technology, through the Internet and its use via the Web.This book is the first Yearbook of the Digital Enlightenment Forum. Whilst it cannot cover all the many aspects which the forum encompasses, the book gives an impression of the broad spectrum of the forum and a clear picture of the multi-disciplinary nature of the issues at stake.The first paper in the book is a contribution from the father of the Web, Sir Tim Berners-Lee, and Harry Halpin. They

  15. Fast transient digitizer

    International Nuclear Information System (INIS)

    Villa, F.

    1982-01-01

    Method and apparatus for sequentially scanning a plurality of target elements with an electron scanning beam modulated in accordance with variations in a high-frequency analog signal to provide discrete analog signal samples representative of successive portions of the analog signal; coupling the discrete analog signal samples from each of the target elements to a different one of a plurality of high speed storage devices; converting the discrete analog signal samples to equivalent digital signals; and storing the digital signals in a digital memory unit for subsequent measurement or display

  16. Digital Marketing Communication

    OpenAIRE

    Margherita Corniani

    2006-01-01

    Digital marketing communication is directed to profiled targets, which are active in the communication process. Every communication flow can ask for an information answer from the market. This opportunity grants immediate feed-backs and feed-forwards, so that digital communication can be easily and cheaply measured; digital communication flows are diffused at costs that are getting lower and lower, but it asks specialized and deep competences to communication managers. The ease in the flowing...

  17. plano de Marketing Digital

    OpenAIRE

    Bento, Daniel Jorge Cunha Correia

    2015-01-01

    O projeto aqui apresentado consiste no desenvolvimento de um plano estratégico de marketing digital para o projeto Laboratório de Criação Digital (LCDPorto). O LCDPorto tem sete anos de existência, sem nunca ter definido uma estratégia de comunicação. O principal objetivo passa por aprofundar os vários temas que integram Marketing Digital, e desenvolver um plano que permita ao LCDPorto ganhar mais notoriedade pelas atividades que desenvolve e, também, obter mais público para...

  18. Transitioning to digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, F., E-mail: Francisco.Miranda@pwc.ca [Pratt & Whitney Canada, Longueuil, Quebec (Canada)

    2015-09-15

    This article provides insight on the technical and business considerations necessary to implement or to transition to digital radiography Continued refinements in digital radiography technology have resulted in significant improvements in image quality and detectability of indications. These improvements have resulted in the acceptance of the technology by users and aerospace primes for final product inspection and disposition. Digital radiography has also been identified as an interesting cost reduction initiative with the potential of providing gains in productivity through increased throughput and decreased inspection lead-times and resulting costs. (author)

  19. The Digital Marmor Parium

    OpenAIRE

    Berti, Monica

    2017-01-01

    The Digital Marmor Parium is a project of the Alexander von Humboldt Chair of Digital Humanities at the University of Leipzig (http://www.dh.uni-leipzig.de/wo/dmp). The aim of this work is to produce a new digital edition of the so called Marmor Parium (Parian Marble), which is a Hellenistic chronicle on a marble slab coming from the Greek island of Paros. The importance of the document is due to the fact that it preserves a Greek chronology (1581/80-299/98 BC) with a list of kings and archon...

  20. SHDAS Production Digitizer Evaluation.

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Bion J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    The Seismo-Hydroacoustic Data Acquisition System (SHDAS) is undergoing evaluation in preparation for its engineering, development, and deployment by the U.S Navy as an ocean bottom seismic monitoring system. At the current stage of development, the production digitizers are being evaluated to confirm their performance prior to packaging and assembly for deployment. The testing of the digitizers is being conducted at Delta Group Electronics, the digitizer fabricator, in San Diego, California, performed by Sandia National Laboratories with the assistance of Leidos and Delta Group Electronics.

  1. Advanced Digital Preservation

    CERN Document Server

    Giaretta, David

    2011-01-01

    There is growing recognition of the need to address the fragility of digital information, on which our society heavily depends for smooth operation in all aspects of daily life. This has been discussed in many books and articles on digital preservation, so why is there a need for yet one more? Because, for the most part, those other publications focus on documents, images and webpages -- objects that are normally rendered to be simply displayed by software to a human viewer. Yet there are clearly many more types of digital objects that may need to be preserved, such as databases, scientific da

  2. Digitization in Maritime Industry

    DEFF Research Database (Denmark)

    Constantiou, Ioanna; Shollo, Arisa; Kreiner, Kristian

    2017-01-01

    Digitization in the maritime industry is expected to transform businesses. The recently introduced mobile technologies in inter-organizational processes is an example of digitization in an industry which moves very slowly towards digital transformation. We focus on the influence of mobile...... technologies on control practices in inter-organizational processes related to coping with an engine failure. We collected qualitative data from in depth interviews with representatives of the involved parties. We identify organizational and behavioural challenges hindering information sharing during problem...... technologies increase information sharing and thus the efficiency of inter-organizational processes when coping with an engine failure....

  3. Digital archives. Alcune note

    Directory of Open Access Journals (Sweden)

    Francesca Zanella

    2014-12-01

    Full Text Available MoRE is a digital native museum where projects of artworks are exposed, and also a digital archive where documents about art projectsare collected. MoRE is a multi-layered platform where artists, curators, art historians confront each other collecting art projects, organizing their documentation and defining tools for the communication and surveys on the public. In this paper some critical referencesare identified, that constitute a model for the project as they reflect on the impact of the digital dimension on the transformation of the museum and archive.

  4. Effects of optimization and image processing in digital chest radiography

    International Nuclear Information System (INIS)

    Kheddache, S.; Maansson, L.G.; Angelhed, J.E.; Denbratt, L.; Gottfridsson, B.; Schlossman, D.

    1991-01-01

    A digital system for chest radiography based on a large image intensifier was compared to a conventional film-screen system. The digital system was optimized with regard to spatial and contrast resolution and dose. The images were digitally processed for contrast and edge enhancement. A simulated pneumothorax and two and two simulated nodules were positioned over the lungs and the mediastinum of an anthro-pomorphic phantom. Observer performance was evaluated with Receiver Operating Characteristic (ROC) analysis. Five observers assessed the processed digital images and the conventional full-size radiographs. The time spent viewing the full-size radiographs and the digital images was recorded. For the simulated pneumothorax, the results showed perfect performance for the full-size radiographs and detectability was high also for the processed digital images. No significant differences in the detectability of the simulated nodules was seen between the two imaging systems. The results for the digital images showed a significantly improved detectability for the nodules in the mediastinum as compared to a previous ROC study where no optimization and image processing was available. No significant difference in detectability was seen between the former and the present ROC study for small nodules in the lung. No difference was seen in the time spent assessing the conventional full-size radiographs and the digital images. The study indicates that processed digital images produced by a large image intensifier are equal in image quality to conventional full-size radiographs for low-contrast objects such as nodules. (author). 38 refs.; 4 figs.; 1 tab

  5. Parity simulation for nuclear plant analysis

    International Nuclear Information System (INIS)

    Hansen, K.F.; Depiente, E.

    1986-01-01

    The analysis of the transient performance of nuclear plants is sufficiently complex that simulation tools are needed for design and safety studies. The simulation tools are needed for design and safety studies. The simulation tools are normally digital because of the speed, flexibility, generality, and repeatability of digital computers. However, communication with digital computers is an awkward matter, requiring special skill or training. The designer wishing to gain insight into system behavior must expend considerable effort in learning to use computer codes, or else have an intermediary communicate with the machine. There has been a recent development in analog simulation that simplifies the user interface with the simulator, while at the same time improving the performance of analog computers. This development is termed parity simulation and is now in routine use in analyzing power electronic network transients. The authors describe the concept of parity simulation and present some results of using the approach to simulate neutron kinetics problems

  6. Digital Library and Digital Reference Service: Integration and Mutual Complementarity

    Science.gov (United States)

    Liu, Jia

    2008-01-01

    Both the digital library and the digital reference service were invented and have been developed under the networked environment. Among their intersections, the fundamental thing is their symbiotic interest--serving the user in a more efficient way. The article starts by discussing the digital library and its service and the digital reference…

  7. Digital Literacy Learning in Higher Education through Digital Storytelling Approach

    Science.gov (United States)

    Chan, Banny S. K.; Churchill, Daniel; Chiu, Thomas K. F.

    2017-01-01

    It is necessary to develop digital literacy skills with which students can communicate and express their ideas effectively using digital media. The educational sectors around the world are beginning to incorporate digital literacy into the curriculum. Digital storytelling, one of the possible classroom activities, is an approach which may help…

  8. Digitization and digital archiving a practical guide for librarians

    CERN Document Server

    Leggett, Elizabeth R

    2014-01-01

    Modern library patrons are embracing the ease with which information can be accessed digitally, and so many librarians are currently working toward making information available electronically. Digitization and Digital Archiving: A Practical Guide for Librarians is a comprehensive guide with step-by-step instructions for forming digital archives.

  9. Digital Citizenship Means Character Education for the Digital Age

    Science.gov (United States)

    Ohler, Jason

    2012-01-01

    The reality of students' cyber lives has thrust upon educators a new approach: creating character education programs tuned to digital youth that are proactive and aggressive. This will help integrate students' digital activities within the context of the communities in which they live, both local and digital. The digital age beckons a new era of…

  10. Digital luminescence radiography of the chest

    International Nuclear Information System (INIS)

    Kehler, M.

    1991-10-01

    The aim of the present study was to evaluate the efficacy of a digital system in chest radiology compared to the conventional film-screen system. The first studies (1-3) were purely clinical, had two parts, one clinical and one using phantoms, and the 5:th used solely phantoms. Except for the first - pilot - study, the studies were performed as receiver operating characteristic (ROC) analysis. From one exposure, two digital radiographs were obtained, one simulating the film-screen radiograph and one enhanced, using an unsharp mask. The conventional radiograph was compared to this double-image, but in addition to this, even to the simulated normal and enhanced separately (1-3). To evaluate the value of inverted (positive) radiographs, the original digital (negative) radiographs were inverted, and then compared to the originals (4). As digitzation means easy storing and transfer of data and possibility of electronic display, the diagnostic performance of an interactive workstation was assessed (5). In the clinical studies, a variety of chest affections were used: atelectasis, tumor, pneumothorax, fibrosis, mediastinal and bony changes, tuberculosis, incompensations and enlargement of the heart (1), pneumothorax (2), fibrosis (3), and tumor (4). In the phantom studies, test objects simulating tumors (4) and pneumothorax (5) were used. In no study was statistical significant difference seen between the digital and conventional system (p>0.05). Neither in the clinical nor the phantom study did inversion of the radiographs improve diagnostic performance. The workstation performed almost equally well as the radiographs even with a resolution of 1.25 1p/mm compared to the digital radiographs 2.5 and film-screen radiographs 5 1p/mm. (au) (50 refs.)

  11. Fast digitization and digital receiver technology

    International Nuclear Information System (INIS)

    Kimball, Ralph C.

    2002-01-01

    The potentially lucrative wireless market has led to technological advances in mixed signal devices such as high speed, high resolution A/D and D/A converters. This same market has also driven the development of high performance multi-channel digital receiver and digital transmitter ICs. Similarly, advances in semiconductor processes, coupled with the need for reduced time-to-market, has led to the development of large, enhanced performance, in-circuit programmable logic devices. A review of the key characteristics of these mixed-signal, signal processing and programmable logic devices is presented. The application of these devices and technologies to the instrumentation of Accelerators and Storage Rings is discussed and presented by way of examples. Issues relating to the requirements associated with real-time processing, I/O throughput, reconfigurability, reliability, maintainability and packaging requirements are also addressed

  12. Digital literacies at school. Students' digital profiles

    Directory of Open Access Journals (Sweden)

    Valentina Pennazio

    2013-04-01

    Full Text Available L’articolo presenta una ricerca volta a focalizzare le modalità in cui la Digital Literacy si traduce a scuola. Lo studio ha inteso sottolineare le molteplici dimensioni della Digital Literacy: Information Technology Literacy; Information Literacy; Visual Literacy e Media Literacy ed è stato effettuato nelle scuole primarie e secondarie di primo grado in Liguria. Sono state organizzate settimane di attività di ricerca, analisi e rielaborazione di informazioni, in classe e in rete, individualmente e in gruppo. Dalle autovalutazione degli studenti, svolte al termine di ogni attività, sono emersi i profili digitali che gli studenti tendono ad assumere quando utilizzano le tecnologie digitali. Tali profili possono essere utilizzati dagli insegnanti per progettare in maniera più mirata e significativa le attività con le tecnologie a scuola.

  13. When Forgetting Becomes Digital

    DEFF Research Database (Denmark)

    Marton, Attila; Kallinikos, Jannis

    The structure of social memory is in a process of significant change as social operations of forgetting and remembering are increasingly written in IT and mediated in digital media. Based on an in-depth case study about the digitalization of memory institutions (libraries, archives, museums......), the paper demonstrates the emergence of a digital social memory structure that stores data as a means of forgetting. Building on such a concept, we explain the shifting structure of social memory from pre-defined, taxonomic order to algorithmic computation of artefacts and ordering. Finally, we draw...... implications from our study with regards to core organizational concepts of institutions and platforms as well as broader categories of information infrastructures and a sociology of digital knowledge....

  14. TV Digital Station Transmitters

    Data.gov (United States)

    Department of Homeland Security — This file is an extract from the Consolidated Database System (CDBS) licensed by the Media Bureau. It consists of Digital Television broadcasters (see Rule Part47...

  15. Digital pulse shape discrimination

    International Nuclear Information System (INIS)

    Miller, L. F.; Preston, J.; Pozzi, S.; Flaska, M.; Neal, J.

    2007-01-01

    Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rather than the traditional, and well-established, analogous techniques. One issue that complicates PSD for neutrons in mixed fields is that the light output characteristics of typical scintillators available for PSD, such as BC501A, vary as a function of energy deposited in the detector. This behaviour is more easily accommodated with digital processing of signals than with analogous signal processing. Results illustrate the effectiveness of digital PSD. (authors)

  16. Comprehension of digital media

    International Nuclear Information System (INIS)

    Kim, Ju Hwan

    2008-11-01

    This book is divided four parts. The first part describes media and mark on sign and media, what is the sign?, interpretation of sign and semiotics. The second part is for production sign theory and origin of digital revolution such as the problem of origin of digital revolution, homogeneity of producing goods and sign : triple triangle model for production sign theory, triple triangle model for producing goods, triple triangle model of producing sign and triple triangle model of art works. The third parts deals with development of the media and meaning of digital revolution with four changes : invention of letter, appearance of printed media and establishment modernity, appearance electronic media and mess media and appearance of digital media. The last part mentions ontology of world wide web.

  17. Students’ digital learning environments

    DEFF Research Database (Denmark)

    Caviglia, Francesco; Dalsgaard, Christian; Davidsen, Jacob

    2018-01-01

    The objective of the paper is to examine the nature of students’ digital learning environments to understand the interplay of institutional systems and tools that are managed by the students themselves. The paper is based on a study of 128 students’ digital learning environments. The objectives...... used tools in the students’ digital learning environments are Facebook, Google Drive, tools for taking notes, and institutional systems. Additionally, the study shows that the tools meet some very basic demands of the students in relation to collaboration, communication, and feedback. Finally...... of the study are 1) to provide an overview of tools for students’ study activities, 2) to identify the most used and most important tools for students and 3) to discover which activities the tools are used for. The empirical study reveals that the students have a varied use of digital media. Some of the most...

  18. Digital Mammography Tomosynthesis

    International Nuclear Information System (INIS)

    Gergov, I.; Alexov, G.; Rusonov, K.

    2017-01-01

    Siemens MAMMOMAT Inspiration with Tomosynthesis enhances the diagnostic precision in mammographic screening. The apparatus has a wide-angle tomosynthesis up to 50 degrees. The Siemens breast augmentation algorithm reconstructs multiple two-dimensional breast images into three-dimensional images at the lowest doses to help detect tumors hidden from the overlapping chest tissue, allowing for a more accurate diagnosis than standard 2-dimensional digital mammography, and reducing the number of false positive results. 3D digital tomosynthesis improves the precision of detecting and diagnosing a larger number of expansive lesions, ensures better morphological mass analysis and architectural distortion, and detecting calcifications by adding digital breast tomosynthesis to the traditional two-dimensional digital mammogram of the patient. In this way, it solves the problem of overlapping parenchyma, reduces the number of unnecessary biopsies from questionable sonomammographic findings, and the need for stressful repeating procedures, which usually contributes to both better patient outcomes and cost saving. [bg

  19. Digital image processing

    National Research Council Canada - National Science Library

    Gonzalez, Rafael C; Woods, Richard E

    2008-01-01

    Completely self-contained-and heavily illustrated-this introduction to basic concepts and methodologies for digital image processing is written at a level that truly is suitable for seniors and first...

  20. Developing digital forensic governance

    CSIR Research Space (South Africa)

    Grobler, M

    2010-03-01

    Full Text Available This paper presents a Digital Forensic (DF) governance framework and its mapping on the SANS ISO/IEC 38500:2009 Corporate governance of information technology structure. DF governance assists organisations in guiding the management team...

  1. Academia Leads Digital Revolution

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ As the Chinese book publishing industry sits nervously on the edqe of possible market economy led reforms, one key area to address will be its ability to come to terms with the onset of digital publishing.

  2. Students’ digital learning environments

    DEFF Research Database (Denmark)

    Caviglia, Francesco; Dalsgaard, Christian; Davidsen, Jacob

    2018-01-01

    of the study are 1) to provide an overview of tools for students’ study activities, 2) to identify the most used and most important tools for students and 3) to discover which activities the tools are used for. The empirical study reveals that the students have a varied use of digital media. Some of the most......, the study shows that most of the important tools are not related to the systems provided by the educational institutions. Based on the study, the paper concludes with a discussion of how institutional systems connect to the other tools in the students’ practices, and how we can qualify students’ digital......The objective of the paper is to examine the nature of students’ digital learning environments to understand the interplay of institutional systems and tools that are managed by the students themselves. The paper is based on a study of 128 students’ digital learning environments. The objectives...

  3. Digital radiology. Clinical experience

    Energy Technology Data Exchange (ETDEWEB)

    Stacul, F; Smathers, R L

    1985-01-01

    The authors report the experience achieved ad the Stanford University (USA) with a digital radiography system which allows the digitization of the film and of the images collected with photostimulable phophors. The phophor is essentially an intensifying screen where a latent image is stored after exposure to X-rays and is extracted by a laser scanning. The images collected with the digitized film and with the phophor (chest, breast, bone) have been analyzed. The digitized film offers potential diagnostic advantages over the conventional film, because of the contrast manipulation and many other processing options. The possibility to recover the information of overexposed films appears very attractive. The photostimulable phophors allow to get good quality images, with a consistent reduction of dose and costs. These plates offer the possibility, in the next future, to replace the conventional screen-film systems.

  4. Digital signature feasibility study

    Science.gov (United States)

    2008-06-01

    The purpose of this study was to assess the advantages and disadvantages of using digital signatures to assist the Arizona Department of Transportation in conducting business. The Department is evaluating the potential of performing more electronic t...

  5. Performing Digital Literature

    Directory of Open Access Journals (Sweden)

    Jerome Fletcher

    2015-11-01

    Full Text Available Digital literature is a complex assemblage of related elements –material, spatial, linguistic, performative, textual, cultural, social– each of which is at one time interdependent and detached. This article discusses the literary creation within the cyberculture from the performativity point of view in relation to the textual apparatus. This is done through the analysis of a selection of performances where physical corporeality has a collaborative function with the body to a greater or lesser degree. Therefore, this physical feature can not only change, but stand at three possible and hybridizable axes: 1 the digital text as protagonist, 2 the digital text as counterpart, and 3 the digital text as site.

  6. Comprehension of digital media

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ju Hwan

    2008-11-15

    This book is divided four parts. The first part describes media and mark on sign and media, what is the sign?, interpretation of sign and semiotics. The second part is for production sign theory and origin of digital revolution such as the problem of origin of digital revolution, homogeneity of producing goods and sign : triple triangle model for production sign theory, triple triangle model for producing goods, triple triangle model of producing sign and triple triangle model of art works. The third parts deals with development of the media and meaning of digital revolution with four changes : invention of letter, appearance of printed media and establishment modernity, appearance electronic media and mess media and appearance of digital media. The last part mentions ontology of world wide web.

  7. NLM Digital Collections

    Data.gov (United States)

    U.S. Department of Health & Human Services — The National Library of Medicine's (NLM) Digital Collections offers a search-based Web service that provides access to the Dublin Core metadata and full-text OCR of...

  8. Digital subtraction angiography

    International Nuclear Information System (INIS)

    Neuwirth, J. Jr.; Bohutova, J.

    1987-01-01

    The quality of radiodiagnostic methods to a great extent depends on the quality of the resulting image. The basic technical principles are summed up of the different parts of digital subtraction angiography apparatus and of methods of improving the image. The instrument is based on a videochain consisting of an X-ray tube, an intensifier of the radiographic image, optical parts, a video camera, an analog-to-digital converter and a computer. The main advantage of the digitally processed image is the possibility of optimizing the image into a form which will contain the biggest amount of diagnostically valuable information. Described are the mathematical operations for improving the digital image: spatial filtration, pixel shift, time filtration, image integration, time interval differentation and matched filtering. (M.D.). 8 refs., 3 figs

  9. Digital imaging primer

    CERN Document Server

    Parkin, Alan

    2016-01-01

    Digital Imaging targets everyyone with an interest in digital imaging, be they professional or private, who uses even quite modest equipment such as a PC, digital camera and scanner, a graphics editor such as Paint, and an inkjet printer. Uniquely, it is intended to fill the gap between highly technical texts for academics (with access to expensive equipment) and superficial introductions for amateurs. The four-part treatment spans theory, technology, programs and practice. Theory covers integer arithmetic, additive and subtractive color, greyscales, computational geometry, and a new presentation of discrete Fourier analysis; Technology considers bitmap file structures, scanners, digital cameras, graphic editors, and inkjet printers; Programs develops several processing tools for use in conjunction with a standard Paint graphics editor and supplementary processing tools; Practice discusses 1-bit, greyscale, 4-bit, 8-bit, and 24-bit images for the practice section. Relevant QBASIC code is supplied an accompa...

  10. Advanced digital optical communications

    CERN Document Server

    Binh, Le Nguyen

    2015-01-01

    This book provides a fundamental understanding of digital communication applications in optical communication technologies. Emphasizing operation principles versus mathematical analysis, the Second Edition includes new coverage of superchannel optical transmission systems, metropolitan and long-haul optical systems and networks, and Nyquist pulse shaping and high spectral efficiency of optical transmission systems, as well as new homework problems and examples. Featuring theoretical foundations as well as practical case studies, the text focuses on enhancements to digital technologies that are

  11. Digital Communication and Modulation

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2010-01-01

    Fundamental principles in modern digital communication system like modems and wire- and wireless transmission over physical channels. Class room sessions and projects. Semester: Spring 2010 Extent: 7.5 ects Class size: 9......Fundamental principles in modern digital communication system like modems and wire- and wireless transmission over physical channels. Class room sessions and projects. Semester: Spring 2010 Extent: 7.5 ects Class size: 9...

  12. Digital Communication and Modulation

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2010-01-01

    Fundamental principles in modern digital communication system like modems and wire- and wireless transmission over physical channels. Class room sessions and projects. Semester: Autumn 2010 Extent: 7.5 ects Class size: 18......Fundamental principles in modern digital communication system like modems and wire- and wireless transmission over physical channels. Class room sessions and projects. Semester: Autumn 2010 Extent: 7.5 ects Class size: 18...

  13. Strategies in digital marketing

    OpenAIRE

    Robert DRAGOMIR; Mihai ANDRONIE

    2017-01-01

    The present paper deals with digital marketing. The approach into discussion is the strategies met with the concept mentioned above. Within the actual socio-economic context, the electronic equipments offer on one hand new and innovative methods for products promoting and, on the other hand new challenges for the consumers. Thus, we analysed different and major types of strategies, which have a great impact on the digital marketing.

  14. Science & Technology Digital Library

    OpenAIRE

    Solodovnik, Iryna

    2014-01-01

    This document contains information on the activities carried out within the project Science & Technology Digital Library and in particular, it describes the Metadata Core Reference Model. Metadata are strategic for semantic interoperability to and, from the repository. Metadata are essential for available and safe management of digital objects, and for their sustainability and preservation. For these reasons, the project needs to define a specific metadata model. The purpose of this document ...

  15. Introduction of digital control

    International Nuclear Information System (INIS)

    Kim, Sang Jin

    1988-01-01

    This book is one of mechatronics series. It deals with digital control, which includes what is digital control?, display way of control system, output of primary system, secondary system like example of system and display way of the system, stabilizing of control system such as method to decide stability and system out of control, displaying equation of state into vector, good control such as the right characteristic, transient behavior and design of position control system using DC servo motor.

  16. Digital academia: How higher education is affected by digital technology

    OpenAIRE

    Eriksmo, Anton; Sundberg, Johan

    2016-01-01

    Digital technology in higher education is constantly evolving. Understanding the effects of digital technology is important for higher education institutions in order to make good investments of digital technology. Previous research has focused on learning, teaching or the organization and the relation between one of these aspects and digital technology, thereby missing a broader understanding of how materiality in digital technology affects higher education. In this study themed interviews w...

  17. Design and construction of a digital Dermatoscope

    International Nuclear Information System (INIS)

    Rojas, E.; Stolik, S.; De la Rosa, J.; Espina, J.; Perez, M.

    2012-01-01

    This paper presents the design and construction of a digital dermatoscope. The system consists of a digital camera for image acquisition, a light source that uniformly illuminates the area of interest, a 10x magnification lens and a base to carry out the immersion technique. The operating principle consists on obtaining two magnified images of the pigmented lesion, the first illuminating with a white light source and the second with a near-infrared source. With the developed software, both images are overlap in order to get more features that help the dermatologist to diagnose malignant melanoma with more reliably and accurately. It was simulated for the used geometry the surface pattern of irradiation and it was developed a simulation software for any distribution of light emitting diodes irradiance. (Author)

  18. Digital Inheritance in the Netherlands

    NARCIS (Netherlands)

    Berlee, A.

    2017-01-01

    Our accumulation of assets is increasingly digital. What happens to these digital assets upon our death? In this Country Report, the topic of a digital inheritance is discussed in the context of Dutch law. It includes general rules on succession and their application to digital assets, which

  19. The Coevolution of Digital Ecosystems

    Science.gov (United States)

    SungYong, Um

    2016-01-01

    Digital ecosystems are one of the most important strategic issues in the current digital economy. Digital ecosystems are dynamic and generative. They evolve as new firms join and as heterogeneous systems are integrated into other systems. These features digital ecosystems determine economic and technological success in the competition among…

  20. Digital tomosynthesis of the breast

    International Nuclear Information System (INIS)

    Barkhausen, Joerg; Rody, Achim; Schaefer, Fritz K.W.

    2015-01-01

    The digital tomosynthesis applies the digital image analysis and 3D technology for improves diagnostic uses. The text book on the digital tomosynthesis of the breast covers the following issues: technique of tomosynthesis, clinical significance of digital breast tomosynthesis, innovations and future developments, case studies.

  1. Digital and analog communication systems

    Science.gov (United States)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  2. Digital imaging in health care

    International Nuclear Information System (INIS)

    1987-01-01

    This volume describes equipment for the generation and processing of digital images in medicine. Separate chapters deal with international trade i this equipment, with economic and social considerations of digital imaging, with experiences in the use and production of digital imaging equipment and with the current status and likely trends in applications of digital imaging. 84 refs, figs and tabs

  3. Flight code validation simulator

    Science.gov (United States)

    Sims, Brent A.

    1996-05-01

    An End-To-End Simulation capability for software development and validation of missile flight software on the actual embedded computer has been developed utilizing a 486 PC, i860 DSP coprocessor, embedded flight computer and custom dual port memory interface hardware. This system allows real-time interrupt driven embedded flight software development and checkout. The flight software runs in a Sandia Digital Airborne Computer and reads and writes actual hardware sensor locations in which Inertial Measurement Unit data resides. The simulator provides six degree of freedom real-time dynamic simulation, accurate real-time discrete sensor data and acts on commands and discretes from the flight computer. This system was utilized in the development and validation of the successful premier flight of the Digital Miniature Attitude Reference System in January of 1995 at the White Sands Missile Range on a two stage attitude controlled sounding rocket.

  4. Digital X-ray imager

    CERN Document Server

    LLNL &MedOptics Corporation

    1998-01-01

    The global objective of this cooperation was to lower the cost and improve the quality of breast health care in the United States. We planned to achieve it by designing a very high performance digital radiography unit for breast surgical specimen radiography in the operating room. These technical goals needed to be achieved at reasonable manufacturing costs to enable MedOptics to achieve high market penetration at a profit. Responsibility for overall project execution rested with MedOptics. MedOptics fabricated and demonstrated hardware, and selected components and handled the overall integration. After completion of this CRADA, MedOptics worked with collaborators to demonstrate clinical performance and utility. Finally, the company marketed the device. LLNL convened a multi-directorate expert panel for an intensive review of MedOptics point design. A written brief of panel conclusions and recommendations was prepared. In addition, LLNL was responsible for: computationally simulating the effects of varying so...

  5. Digital models for architectonical representation

    Directory of Open Access Journals (Sweden)

    Stefano Brusaporci

    2011-12-01

    Full Text Available Digital instruments and technologies enrich architectonical representation and communication opportunities. Computer graphics is organized according the two phases of visualization and construction, that is modeling and rendering, structuring dichotomy of software technologies. Visualization modalities give different kinds of representations of the same 3D model and instruments produce a separation between drawing and image’s creation. Reverse modeling can be related to a synthesis process, ‘direct modeling’ follows an analytic procedure. The difference between interactive and not interactive applications is connected to the possibilities offered by informatics instruments, and relates to modeling and rendering. At the same time the word ‘model’ describes different phenomenon (i.e. files: mathematical model of the building and of the scene; raster representation and post-processing model. All these correlated different models constitute the architectonical interpretative model, that is a simulation of reality made by the model for improving the knowledge.

  6. Future approaches to digital systems

    International Nuclear Information System (INIS)

    Woodrough, R.E.; Beckmann, E.; Jenkins, D.; Belcher, D.

    1984-01-01

    The introduction of the first digital imaging systems has led to the concept of a totally digital imaging department - the 'filmless department'. This concept and its associated network system for digital departments are briefly considered. A transducer system of scanned projection radiography with solid state detectors used in digital chest imaging is described. The principles of this transducer system are applicable to other forms of digital radiography. (U.K.)

  7. Film-screen digital radiography

    International Nuclear Information System (INIS)

    Schwenker, R.P.; Eger, H.

    1985-01-01

    The excellent performance of the digital film-screen system as a receptor for projection radiographic data is discussed. An experimental system for obtaining high quality digital radiographic data by laser scanning radiographic films is described. This system is being used to evaluate the clinical utility of various digital image processing algorithms. Future plans include an investigation of quantitative analysis of projection radiographic data. Digital data obtained by film scanning can be used with digital image archiving and communications systems. (author)

  8. FPGA-based digital convolution for wireless applications

    CERN Document Server

    Guan, Lei

    2017-01-01

    This book presents essential perspectives on digital convolutions in wireless communications systems and illustrates their corresponding efficient real-time field-programmable gate array (FPGA) implementations. Covering these digital convolutions from basic concept to vivid simulation/illustration, the book is also supplemented with MS PowerPoint presentations to aid in comprehension. FPGAs or generic all programmable devices will soon become widespread, serving as the “brains” of all types of real-time smart signal processing systems, like smart networks, smart homes and smart cities. The book examines digital convolution by bringing together the following main elements: the fundamental theory behind the mathematical formulae together with corresponding physical phenomena; virtualized algorithm simulation together with benchmark real-time FPGA implementations; and detailed, state-of-the-art case studies on wireless applications, including popular linear convolution in digital front ends (DFEs); nonlinear...

  9. Nonlinear machine learning and design of reconfigurable digital colloids.

    Science.gov (United States)

    Long, Andrew W; Phillips, Carolyn L; Jankowksi, Eric; Ferguson, Andrew L

    2016-09-14

    Digital colloids, a cluster of freely rotating "halo" particles tethered to the surface of a central particle, were recently proposed as ultra-high density memory elements for information storage. Rational design of these digital colloids for memory storage applications requires a quantitative understanding of the thermodynamic and kinetic stability of the configurational states within which information is stored. We apply nonlinear machine learning to Brownian dynamics simulations of these digital colloids to extract the low-dimensional intrinsic manifold governing digital colloid morphology, thermodynamics, and kinetics. By modulating the relative size ratio between halo particles and central particles, we investigate the size-dependent configurational stability and transition kinetics for the 2-state tetrahedral (N = 4) and 30-state octahedral (N = 6) digital colloids. We demonstrate the use of this framework to guide the rational design of a memory storage element to hold a block of text that trades off the competing design criteria of memory addressability and volatility.

  10. Improving image quality of parallel phase-shifting digital holography

    International Nuclear Information System (INIS)

    Awatsuji, Yasuhiro; Tahara, Tatsuki; Kaneko, Atsushi; Koyama, Takamasa; Nishio, Kenzo; Ura, Shogo; Kubota, Toshihiro; Matoba, Osamu

    2008-01-01

    The authors propose parallel two-step phase-shifting digital holography to improve the image quality of parallel phase-shifting digital holography. The proposed technique can increase the effective number of pixels of hologram twice in comparison to the conventional parallel four-step technique. The increase of the number of pixels makes it possible to improve the image quality of the reconstructed image of the parallel phase-shifting digital holography. Numerical simulation and preliminary experiment of the proposed technique were conducted and the effectiveness of the technique was confirmed. The proposed technique is more practical than the conventional parallel phase-shifting digital holography, because the composition of the digital holographic system based on the proposed technique is simpler.

  11. The Three-dimensional Digital Factory for Shipbuilding Technology Research

    Directory of Open Access Journals (Sweden)

    Xu Wei

    2016-01-01

    Full Text Available The three-dimensional digital factory technology research is the hotspot in shipbuilding recently. The three-dimensional digital factory technology not only focus on design the components of the product, but also discuss on the simulation and analyses of the production process.Based on the three-dimensional model, the basic data layer, application control layer and the presentation layer of hierarchical structure are established in the three-dimensional digital factory of shipbuilding in this paper. And the key technologies of three-dimensional digital factory of shipbuilding are analysed. Finally, a case study is applied and the results show that the three-dimensional digital factory will play an important role in the future.

  12. Digital citizenship and neoliberalization: governing digital citizens in Denmark

    DEFF Research Database (Denmark)

    Schou, Jannick; Hjelholt, Morten

    2018-01-01

    Digital citizenship is becoming increasingly normalized within advanced democratic states. As society and governmental institutions become reliant on digital technologies, citizens are expected to be and act digitally. This article examines the governance of digital citizens through a case study...... this case study, the article contributes to current critical perspectives on the digital citizen as a new political figure. It adds new insights into digital citizenship by connecting this figure to wider processes of neoliberalization and state restructuring, pushing for a more pronounced focus...... of digitalization efforts in Denmark. Drawing on multiple forms of data, the article showcases how digital citizens are governed through a combination of discursive, legal and institutional means. The article highlights the political, but also institutional work that goes into making citizens digital. Providing...

  13. Direct digital temperature control of the A-1 nuclear reactor

    International Nuclear Information System (INIS)

    Karpeta, C.

    1975-01-01

    The application is described of one of the modern control methods for designing an experimental digital temperature control system for heavy water moderated gas cooled reactors. The synthesis of the optimal stochastic regulator for reactor control in the area of the rated steady state was carried out using the method of dynamic programming and the Kalman filter technique. The analysis of the feedback circuit was conducted using control simulation on a universal digital computer. Results and experience are summed up. (author)

  14. Digital Actuator Technology

    Energy Technology Data Exchange (ETDEWEB)

    Ken Thomas; Ted Quinn; Jerry Mauck; Richard Bockhorst

    2014-09-01

    There are significant developments underway in new types of actuators for power plant active components. Many of these make use of digital technology to provide a wide array of benefits in performance of the actuators and in reduced burden to maintain them. These new product offerings have gained considerable acceptance in use in process plants. In addition, they have been used in conventional power generation very successfully. This technology has been proven to deliver the benefits promised and substantiate the claims of improved performance. The nuclear industry has been reluctant to incorporate digital actuator technology into nuclear plant designs due to concerns due to a number of concerns. These could be summarized as cost, regulatory uncertainty, and a certain comfort factor with legacy analog technology. The replacement opportunity for these types of components represents a decision point for whether to invest in more modern technology that would provide superior operational and maintenance benefits. Yet, the application of digital technology has been problematic for the nuclear industry, due to qualification and regulatory issues. With some notable exceptions, the result has been a continuing reluctance to undertake the risks and uncertainties of implementing digital actuator technology when replacement opportunities present themselves. Rather, utilities would typically prefer to accept the performance limitations of the legacy analog actuator technologies to avoid impacts to project costs and schedules. The purpose of this report is to demonstrate that the benefits of digital actuator technology can be significant in terms of plant performance and that it is worthwhile to address the barriers currently holding back the widespread development and use of this technology. It addresses two important objectives in pursuit of the beneficial use of digital actuator technology for nuclear power plants: 1. To demonstrate the benefits of digital actuator

  15. Research on digital PID control algorithm for HPCT

    International Nuclear Information System (INIS)

    Zeng Yi; Li Rui; Shen Tianjian; Ke Xinhua

    2009-01-01

    Digital PID applied in high-precision HPCT (High-precision current transducer) based on Digital Signal Processor (DSP) TMS320F2812 and special D/A converter was researched. By using increment style PID Control algorithm, the stability and precision of high-precision HPCT output voltage is improved. On basis of deeply analysing incremental digital PID, the scheme model of HPCT is proposed, the feasibility simulation using Matlab is given. Practical hardware circuit verified the incremental PID has closed-loop control process in tracking HPCT output voltage. (authors)

  16. Coaxial waveguide mode reconstruction and analysis with THz digital holography.

    Science.gov (United States)

    Wang, Xinke; Xiong, Wei; Sun, Wenfeng; Zhang, Yan

    2012-03-26

    Terahertz (THz) digital holography is employed to investigate the properties of waveguides. By using a THz digital holographic imaging system, the propagation modes of a metallic coaxial waveguide are measured and the mode patterns are restored with the inverse Fresnel diffraction algorithm. The experimental results show that the THz propagation mode inside the waveguide is a combination of four modes TE₁₁, TE₁₂, TM₁₁, and TM₁₂, which are in good agreement with the simulation results. In this work, THz digital holography presents its strong potential as a platform for waveguide mode charactering. The experimental findings provide a valuable reference for the design of THz waveguides.

  17. Digital imaging in dentistry.

    Science.gov (United States)

    Essen, S Donovan

    2011-01-01

    Information technology is vital to operations, marketing, accounting, finance and administration. One of the most exciting and quickly evolving technologies in the modern dental office is digital applications. The dentist is often the business manager, information technology officer and strategic planning chief for his small business. The information systems triangle applies directly to this critical manager supported by properly trained ancillary staff and good equipment. With emerging technology driving all medical disciplines and the rapid pace at which it emerges, it is vital for the contemporary practitioner to keep abreast of the newest information technology developments. This article compares the strategic and operational advantages of digital applications, specifically imaging. The focus of this paper will be on digital radiography (DR), 3D computerized tomography, digital photography and digitally-driven CAD/CAM to what are now considered obsolescing modalities and contemplates what may arrive in the future. It is the purpose of this essay to succinctly evaluate the decisions involved in the role, application and implications of employing this tool in the dental environment

  18. Digital Information and Value

    Directory of Open Access Journals (Sweden)

    Paul Walton

    2015-11-01

    Full Text Available Digital information changes the ways in which people and organisations interact. This paper examines the nature of this change in the context of the author’s Model for Information (MfI. It investigates the relationship between outcomes and value, selection processes and some attributes of information and explores how this relationship changes in the move from analogue to digital information. Selection processes shape the evolution of information ecosystems in which conventions are established for the ways in which information is used. The conventions determine norms for information friction and information quality as well as the sources of information and channels used. Digital information reduces information friction, often dramatically, and changes information quality. The increasing use of analytics in business increasingly delivers predictive or prescriptive digital information. These changes are happening faster than information ecosystem conventions can change. The relationships established in the paper enable an analysis of, and guide changes to, these conventions enabling a more effective use of digital information.

  19. Dakwah di Era Digital

    Directory of Open Access Journals (Sweden)

    Wahyu Budiantoro

    2018-04-01

    Full Text Available These days dakwah is not only interpreted as transformation of a pure religious value, but also transformation of a more relevant value including many aspects in digital era. Digital era is when society succumbed into the flow of information causing cultural shock and difficulties on synthesizing meaning from those scattered information. Dakwah on Digital age must accommodate societal needs which tend to move into a mass society. It results in strategy and more humane and innovative dakwah methods. One of innovative dakwah methods is conducted dakwah activities through digital media,with the consequences of this is that da’i must developed soft skill and technological capabilities. Another beneficial comes from this is that dakwah could become more modern and practical in terms of methods and material. On the other hand, citizen Journalism as a mass cultural product and the results of technological development, gives an opportunity for da’i to able to record the entire activities, including the dynamics of islamic life. In terms of learning curriculum, dakwah in digital format must be included, so then the intellectual and cultural spirit which flourished in pesantren could be adapted and competed in a global world.

  20. Digital Signal Processing and Control for the Study of Gene Networks

    Science.gov (United States)

    Shin, Yong-Jun

    2016-04-01

    Thanks to the digital revolution, digital signal processing and control has been widely used in many areas of science and engineering today. It provides practical and powerful tools to model, simulate, analyze, design, measure, and control complex and dynamic systems such as robots and aircrafts. Gene networks are also complex dynamic systems which can be studied via digital signal processing and control. Unlike conventional computational methods, this approach is capable of not only modeling but also controlling gene networks since the experimental environment is mostly digital today. The overall aim of this article is to introduce digital signal processing and control as a useful tool for the study of gene networks.