WorldWideScience

Sample records for model spacecraft construction

  1. Service Oriented Spacecraft Modeling Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The I-Logix team proposes development of the Service Oriented Spacecraft Modeling Environment (SOSME) to allow faster and more effective spacecraft system design...

  2. Modelling Constructs

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    2009-01-01

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

  3. Computational Model for Spacecraft/Habitat Volume

    Data.gov (United States)

    National Aeronautics and Space Administration — Please note that funding to Dr. Simon Hsiang, a critical co-investigator for the development of the Spacecraft Optimization Layout and Volume (SOLV) model, was...

  4. Advanced Spacecraft Thermal Modeling, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — For spacecraft developers who spend millions to billions of dollars per unit and require 3 to 7 years to deploy, the LoadPath reduced-order (RO) modeling thermal...

  5. Spacecraft Internal Acoustic Environment Modeling

    Science.gov (United States)

    Chu, SShao-sheng R.; Allen, Christopher S.

    2009-01-01

    Acoustic modeling can be used to identify key noise sources, determine/analyze sub-allocated requirements, keep track of the accumulation of minor noise sources, and to predict vehicle noise levels at various stages in vehicle development, first with estimates of noise sources, later with experimental data. In FY09, the physical mockup developed in FY08, with interior geometric shape similar to Orion CM (Crew Module) IML (Interior Mode Line), was used to validate SEA (Statistical Energy Analysis) acoustic model development with realistic ventilation fan sources. The sound power levels of these sources were unknown a priori, as opposed to previous studies that RSS (Reference Sound Source) with known sound power level was used. The modeling results were evaluated based on comparisons to measurements of sound pressure levels over a wide frequency range, including the frequency range where SEA gives good results. Sound intensity measurement was performed over a rectangular-shaped grid system enclosing the ventilation fan source. Sound intensities were measured at the top, front, back, right, and left surfaces of the and system. Sound intensity at the bottom surface was not measured, but sound blocking material was placed tinder the bottom surface to reflect most of the incident sound energy back to the remaining measured surfaces. Integrating measured sound intensities over measured surfaces renders estimated sound power of the source. The reverberation time T6o of the mockup interior had been modified to match reverberation levels of ISS US Lab interior for speech frequency bands, i.e., 0.5k, 1k, 2k, 4 kHz, by attaching appropriately sized Thinsulate sound absorption material to the interior wall of the mockup. Sound absorption of Thinsulate was modeled in three methods: Sabine equation with measured mockup interior reverberation time T60, layup model based on past impedance tube testing, and layup model plus air absorption correction. The evaluation/validation was

  6. Streamlined Modeling for Characterizing Spacecraft Anomalous Behavior

    Science.gov (United States)

    Klem, B.; Swann, D.

    2011-09-01

    Anomalous behavior of on-orbit spacecraft can often be detected using passive, remote sensors which measure electro-optical signatures that vary in time and spectral content. Analysts responsible for assessing spacecraft operational status and detecting detrimental anomalies using non-resolved imaging sensors are often presented with various sensing and identification issues. Modeling and measuring spacecraft self emission and reflected radiant intensity when the radiation patterns exhibit a time varying reflective glint superimposed on an underlying diffuse signal contribute to assessment of spacecraft behavior in two ways: (1) providing information on body component orientation and attitude; and, (2) detecting changes in surface material properties due to the space environment. Simple convex and cube-shaped spacecraft, designed to operate without protruding solar panel appendages, may require an enhanced level of preflight characterization to support interpretation of the various physical effects observed during on-orbit monitoring. This paper describes selected portions of the signature database generated using streamlined signature modeling and simulations of basic geometry shapes apparent to non-imaging sensors. With this database, summarization of key observable features for such shapes as spheres, cylinders, flat plates, cones, and cubes in specific spectral bands that include the visible, mid wave, and long wave infrared provide the analyst with input to the decision process algorithms contained in the overall sensing and identification architectures. The models typically utilize baseline materials such as Kapton, paints, aluminum surface end plates, and radiators, along with solar cell representations covering the cylindrical and side portions of the spacecraft. Multiple space and ground-based sensors are assumed to be located at key locations to describe the comprehensive multi-viewing aspect scenarios that can result in significant specular reflection

  7. Modeling Meteor Flares for Spacecraft Safety

    Science.gov (United States)

    Ehlert, Steven

    2017-01-01

    NASA's Meteoroid Environment Office (MEO) is tasked with assisting spacecraft operators and engineers in quantifying the threat the meteoroid environment poses to their individual missions. A more complete understanding of the meteoroid environment for this application requires extensive observations. One manner by which the MEO observes meteors is with dedicated video camera systems that operate nightly. Connecting the observational data from these video cameras to the relevant physical properties of the ablating meteoroids, however, is subject to sizable observational and theoretical uncertainties. Arguably the most troublesome theoretical uncertainty in ablation is a model for the structure of meteoroids, as observations clearly show behaviors wholly inconsistent with meteoroids being homogeneous spheres. Further complicating the interpretation of the observations in the context of spacecraft risk is the ubiquitous process of fragmentation and the flares it can produce, which greatly muddles any attempts to estimating initial meteoroid masses. In this talk a method of estimating the mass distribution of fragments in flaring meteors using high resolution video observations will be dis- cussed. Such measurements provide an important step in better understanding of the structure and fragmentation process of the parent meteoroids producing these flares, which in turn may lead to better constraints on meteoroid masses and reduced uncertainties in spacecraft risk.

  8. In-Orbit Additive Construction Using Modular Swarms of Spacecraft

    Data.gov (United States)

    National Aeronautics and Space Administration — Design and construction of large space systems is often constrained by factors that have more to do with surviving launch than the intended mission. Satellites...

  9. Modeling Cable-Harness Effects on Spacecraft Structures

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed research involves modeling the effects of cable-harnesses and wiring on the dynamics of spacecraft structures. As space structure mass decreases due to...

  10. Interactive modeling, design and analysis of large spacecraft

    Science.gov (United States)

    Garrett, L. B.

    1982-01-01

    An efficient computer aided design and analysis capability applicable to large space structures was developed to relieve the engineer of much of the effort required in the past. The automated capabilities can be used to rapidly synthesize, evaluate, and determine performance characteristics and costs for future large spacecraft concepts. The interactive design and evaluation of advanced spacecraft program (IDEAS) is used to illustrate the power, efficiency, and versatility of the approach. The coupling of space environment modeling algorithms with simplified analysis and design modules in the IDEAS program permits rapid evaluation of completing spacecraft and mission designs. The approach is particularly useful in the conceptual design phase of advanced space missions when a multiplicity of concepts must be considered before a limited set can be selected or more detailed analysis. Integrated spacecraft systems level data and data files are generated or subsystems and mission reexamination and/or refinement and for more rigorous analyses.

  11. Model of spacecraft atomic oxygen and solar exposure microenvironments

    Science.gov (United States)

    Bourassa, R. J.; Pippin, H. G.

    1993-01-01

    Computer models of environmental conditions in Earth orbit are needed for the following reasons: (1) derivation of material performance parameters from orbital test data, (2) evaluation of spacecraft hardware designs, (3) prediction of material service life, and (4) scheduling spacecraft maintenance. To meet these needs, Boeing has developed programs for modeling atomic oxygen (AO) and solar radiation exposures. The model allows determination of AO and solar ultraviolet (UV) radiation exposures for spacecraft surfaces (1) in arbitrary orientations with respect to the direction of spacecraft motion, (2) overall ranges of solar conditions, and (3) for any mission duration. The models have been successfully applied to prediction of experiment environments on the Long Duration Exposure Facility (LDEF) and for analysis of selected hardware designs for deployment on other spacecraft. The work on these models has been reported at previous LDEF conferences. Since publication of these reports, a revision has been made to the AO calculation for LDEF, and further work has been done on the microenvironments model for solar exposure.

  12. QMU in Integrated Spacecraft System Models Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ACTA and Sandia National Laboratories propose to quantify and propagate substructure modeling uncertainty for reduced-order substructure models to higher levels of...

  13. Using Empirical Models for Communication Prediction of Spacecraft

    Science.gov (United States)

    Quasny, Todd

    2015-01-01

    A viable communication path to a spacecraft is vital for its successful operation. For human spaceflight, a reliable and predictable communication link between the spacecraft and the ground is essential not only for the safety of the vehicle and the success of the mission, but for the safety of the humans on board as well. However, analytical models of these communication links are challenged by unique characteristics of space and the vehicle itself. For example, effects of radio frequency during high energy solar events while traveling through a solar array of a spacecraft can be difficult to model, and thus to predict. This presentation covers the use of empirical methods of communication link predictions, using the International Space Station (ISS) and its associated historical data as the verification platform and test bed. These empirical methods can then be incorporated into communication prediction and automation tools for the ISS in order to better understand the quality of the communication path given a myriad of variables, including solar array positions, line of site to satellites, position of the sun, and other dynamic structures on the outside of the ISS. The image on the left below show the current analytical model of one of the communication systems on the ISS. The image on the right shows a rudimentary empirical model of the same system based on historical archived data from the ISS.

  14. Lifetime of a spacecraft around a synchronous system of asteroids using a dipole model

    Science.gov (United States)

    dos Santos, Leonardo Barbosa Torres; de Almeida Prado, Antonio F. Bertachini; Sanchez, Diogo Merguizo

    2017-11-01

    Space missions allow us to expand our knowledge about the origin of the solar system. It is believed that asteroids and comets preserve the physical characteristics from the time that the solar system was created. For this reason, there was an increase of missions to asteroids in the past few years. To send spacecraft to asteroids or comets is challenging, since these objects have their own characteristics in several aspects, such as size, shape, physical properties, etc., which are often only discovered after the approach and even after the landing of the spacecraft. These missions must be developed with sufficient flexibility to adjust to these parameters, which are better determined only when the spacecraft reaches the system. Therefore, conducting a dynamic investigation of a spacecraft around a multiple asteroid system offers an extremely rich environment. Extracting accurate information through analytical approaches is quite challenging and requires a significant number of restrictive assumptions. For this reason, a numerical approach to the dynamics of a spacecraft in the vicinity of a binary asteroid system is offered in this paper. In the present work, the equations of the Restricted Synchronous Four-Body Problem (RSFBP) are used to model a binary asteroid system. The main objective of this work is to construct grids of initial conditions, which relates semi-major axis and eccentricity, in order to quantify the lifetime of a spacecraft when released close to the less massive body of the binary system (modeled as a rotating mass dipole). We performed an analysis of the lifetime of the spacecraft considering several mass ratios of a binary system of asteroids and investigating the behavior of a spacecraft in the vicinity of this system. We analyze direct and retrograde orbits. This study investigated orbits that survive for at least 500 orbital periods of the system (which is approximately one year), then not colliding or escaping from the system during this

  15. Jovian Proton and Heavy Ion Models for Spacecraft Design

    Science.gov (United States)

    Garrett, H. B.; Evans, R. W.; Jun, I.; Kim, W.

    2015-12-01

    This presentation will review the results of the latest modeling at the Jet Propulsion Laboratory of the high energy proton and ion environments at Jupiter. The existing models of the proton and ion environments at Jupiter have been revised and extended from the original 12 jovian radii out to 50 jovian radii using the latest Galileo data. In addition to the physical significance of these particle populations, the new models will be important in the evaluation and design of solar arrays at Jupiter as they can affect the radiation damage to the solar array cells and cover glass. The new models represent an important update to the tools currently being used to study the effects of the jovian environment on spacecraft. These models (part of the GIRE family of electron and proton models) are currently used worldwide to describe that jovian environment and are the main tools used by NASA to determine the effects of this environment on spacecraft systems and instruments. The update to be presented is the first significant revision (extending the proton and ion models from 12 Rj to 50 Rj) to the GIRE proton environment since 1983 and fills an important gap in our understanding.

  16. Mechanical Slosh Models for Rocket-Propelled Spacecraft

    Science.gov (United States)

    Jang, Jiann-Woei; Alaniz, Abram; Yang, Lee; Powers. Joseph; Hall, Charles

    2013-01-01

    Several analytical mechanical slosh models for a cylindrical tank with flat bottom are reviewed. Even though spacecrafts use cylinder shaped tanks, most of those tanks usually have elliptical domes. To extend the application of the analytical models for a cylindrical tank with elliptical domes, the modified slosh parameter models are proposed in this report by mapping an elliptical dome cylindrical tank to a flat top/bottom cylindrical tank while maintaining the equivalent liquid volume. For the low Bond number case, the low-g slosh models were also studied. Those low-g models can be used for Bond number > 10. The current low-g slosh models were also modified to extend their applications for the case that liquid height is smaller than the tank radius. All modified slosh models are implemented in MATLAB m-functions and are collected in the developed MST (Mechanical Slosh Toolbox).

  17. Modeling Laser Effects on Imaging Spacecraft using the SSM

    National Research Council Canada - National Science Library

    Buehler, Patrick; Smith, Joshua

    2006-01-01

    ...) engagement of spacecraft components. For laser engagements, the user creates a spacecraft, its optical system, any protection techniques used by the optical system, a laser threat, and an atmosphere through which the laser will pass...

  18. Development and evaluation of thermal model reduction algorithms for spacecraft

    Science.gov (United States)

    Deiml, Michael; Suderland, Martin; Reiss, Philipp; Czupalla, Markus

    2015-05-01

    This paper is concerned with the topic of the reduction of thermal models of spacecraft. The work presented here has been conducted in cooperation with the company OHB AG, formerly Kayser-Threde GmbH, and the Institute of Astronautics at Technische Universität München with the goal to shorten and automatize the time-consuming and manual process of thermal model reduction. The reduction of thermal models can be divided into the simplification of the geometry model for calculation of external heat flows and radiative couplings and into the reduction of the underlying mathematical model. For simplification a method has been developed which approximates the reduced geometry model with the help of an optimization algorithm. Different linear and nonlinear model reduction techniques have been evaluated for their applicability in reduction of the mathematical model. Thereby the compatibility with the thermal analysis tool ESATAN-TMS is of major concern, which restricts the useful application of these methods. Additional model reduction methods have been developed, which account to these constraints. The Matrix Reduction method allows the approximation of the differential equation to reference values exactly expect for numerical errors. The summation method enables a useful, applicable reduction of thermal models that can be used in industry. In this work a framework for model reduction of thermal models has been created, which can be used together with a newly developed graphical user interface for the reduction of thermal models in industry.

  19. Global Evolution of Plasmaspheric Plasma: Spacecraft-Model Reconstructions

    Science.gov (United States)

    Walsh, B.; Welling, D. T.; Morley, S.

    2017-12-01

    During times of geomagnetic disturbance, material from the plasmasphere will move radially outward into the magnetosphere. Once introduced to the outer magnetosphere, this material has been shown to impact a variety of plasma populations as well as the coupling of energy from the solar wind into the magnetosphere and ionosphere. The magnitude of any of these effects is inherently linked to the density and evolution of the plasmaspheric plasma. Much of our idea of how this population behaves in the outer-magnetosphere is however based on statistical pictures and model results. Here, in-situ measurements from 10 spacecraft are used to constrain a coupled, global numerical modeling in order to identify true spatial extents, time histories, and densities of the plasmasphere and plumes in the outer magnetosphere.

  20. Correlation of spacecraft thermal mathematical models to reference data

    Science.gov (United States)

    Torralbo, Ignacio; Perez-Grande, Isabel; Sanz-Andres, Angel; Piqueras, Javier

    2018-03-01

    Model-to-test correlation is a frequent problem in spacecraft-thermal control design. The idea is to determine the values of the parameters of the thermal mathematical model (TMM) that allows reaching a good fit between the TMM results and test data, in order to reduce the uncertainty of the mathematical model. Quite often, this task is performed manually, mainly because a good engineering knowledge and experience is needed to reach a successful compromise, but the use of a mathematical tool could facilitate this work. The correlation process can be considered as the minimization of the error of the model results with regard to the reference data. In this paper, a simple method is presented suitable to solve the TMM-to-test correlation problem, using Jacobian matrix formulation and Moore-Penrose pseudo-inverse, generalized to include several load cases. Aside, in simple cases, this method also allows for analytical solutions to be obtained, which helps to analyze some problems that appear when the Jacobian matrix is singular. To show the implementation of the method, two problems have been considered, one more academic, and the other one the TMM of an electronic box of PHI instrument of ESA Solar Orbiter mission, to be flown in 2019. The use of singular value decomposition of the Jacobian matrix to analyze and reduce these models is also shown. The error in parameter space is used to assess the quality of the correlation results in both models.

  1. Design, construction and testing of the Communications Technology Satellite protection against spacecraft charging

    Science.gov (United States)

    Gore, J. V.

    1977-01-01

    Detailed discussions are presented of the measures taken on the Communications Technology Satellite (CTS or Hermes) which provide protection against the effects of spacecraft charging. These measures include: a comprehensive grounding philosophy and implementation; provision of command and data line transmitters and receivers for transient noise immunity; and a fairly restrictive EMI specification. Ground tests were made on materials and the impact of these tests on the CTS spacecraft is described. Hermes, launched on 17 January 1976 on a 2914 Delta vehicle, has successfully completed 10 months of operations. Anomalies observed are being assessed in relation to spacecraft charging, but no definite correlations have yet been established. A list of conclusions with regard to the CTS experience is given and recommendations for future spacecraft are also listed.

  2. A geometric model of a V-slit Sun sensor correcting for spacecraft wobble

    Science.gov (United States)

    Mcmartin, W. P.; Gambhir, S. S.

    1994-01-01

    A V-Slit sun sensor is body-mounted on a spin-stabilized spacecraft. During injection from a parking or transfer orbit to some final orbit, the spacecraft may not be dynamically balanced. This may result in wobble about the spacecraft spin axis as the spin axis may not be aligned with the spacecraft's axis of symmetry. While the widely used models in Spacecraft Attitude Determination and Control, edited by Wertz, correct for separation, elevation, and azimuthal mounting biases, spacecraft wobble is not taken into consideration. A geometric approach is used to develop a method for measurement of the sun angle which corrects for the magnitude and phase of spacecraft wobble. The algorithm was implemented using a set of standard mathematical routines for spherical geometry on a unit sphere.

  3. Modeling spacecraft oscillations in HRSC images of Mars Express

    Directory of Open Access Journals (Sweden)

    J. Bostelmann

    2012-09-01

    Full Text Available Since January 2004 the High Resolution Stereo Camera (HRSC is mapping planet Mars. The multi-line sensor on board the ESA Mission Mars Express images the Martian surface with a resolution of up to 12m per pixel in three dimensions and in color. As part of the Photogrammetric/Cartographic Working Group of the HRSC Science Team the Institute of Photogrammetry and GeoInformation (IPI of the Leibniz Universit¨at Hannover is involved in photogrammetrically processing the HRSC image data. To derive high quality 3D surface models, color orthoimages or other products, the accuracy of the observed position and attitude information in many cases should be improved. This is carried out via a bundle adjustment. In a considerable number of orbits the results of the bundle adjustment are disturbed by high frequency oscillations. This paper describes the impact of the high frequency angular spacecraft movement to the processing results of the last seven years of image acquisition and how the quality of the HRSC data products is significantly improved by modeling these oscillations.

  4. Modeling Vacuum Arcs On Spacecraft Solar Panel Arrays, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Spacecraft charging and subsequent vacuum arcing poses a significant threat to satellites in LEO and GEO plasma conditions. Localized arc discharges can cause a...

  5. Economic analysis of open space box model utilization in spacecraft

    Science.gov (United States)

    Mohammad, Atif F.; Straub, Jeremy

    2015-05-01

    It is a known fact that the amount of data about space that is stored is getting larger on an everyday basis. However, the utilization of Big Data and related tools to perform ETL (Extract, Transform and Load) applications will soon be pervasive in the space sciences. We have entered in a crucial time where using Big Data can be the difference (for terrestrial applications) between organizations underperforming and outperforming their peers. The same is true for NASA and other space agencies, as well as for individual missions and the highly-competitive process of mission data analysis and publication. In most industries, conventional opponents and new candidates alike will influence data-driven approaches to revolutionize and capture the value of Big Data archives. The Open Space Box Model is poised to take the proverbial "giant leap", as it provides autonomic data processing and communications for spacecraft. We can find economic value generated from such use of data processing in our earthly organizations in every sector, such as healthcare, retail. We also can easily find retailers, performing research on Big Data, by utilizing sensors driven embedded data in products within their stores and warehouses to determine how these products are actually used in the real world.

  6. Modeling and analysis of spacecraft battery charger systems

    Science.gov (United States)

    Kim, Seong Joong

    Large signal analysis of various spacecraft power systems is performed to predict the bus dynamics in various modes of operation. The large-signal trajectories of the system's operating point are analyzed employing qualitative graphical representation. The analyses are verified through simulation using EASY5 software. Small-signal dynamic characteristics of spacecraft battery charge converter systems are analyzed to facilitate the design of a control loop for optimum performance and stability. Control-loop designs for the charge converters in bus voltage regulation mode, charge current regulation mode, and peak power tracking mode are discussed.

  7. Application of partial differential equation modeling of the control/structural dynamics of flexible spacecraft

    Science.gov (United States)

    Taylor, Lawrence W., Jr.; Rajiyah, H.

    1991-01-01

    Partial differential equations for modeling the structural dynamics and control systems of flexible spacecraft are applied here in order to facilitate systems analysis and optimization of these spacecraft. Example applications are given, including the structural dynamics of SCOLE, the Solar Array Flight Experiment, the Mini-MAST truss, and the LACE satellite. The development of related software is briefly addressed.

  8. Modeling and spacecraft data constraints on the global 3D structure of the heliosphere

    Science.gov (United States)

    Pogorelov, N.; Izmodenov, V.

    2017-12-01

    Modeling of the global heliosphere is essentially required for our understanding of the nature of the heliospheric boundaries. The models are also needed for correct analyses and interpretation of relevant spacecraft data both inside the heliosphere and at the boundary of the solar wind (SW) interaction with the local interstellar medium (LISM). Modern models of the SW/LISM interaction should essentially take into account multi-component nature of both the solar wind and local interstellar medium, the heliospheric and interstellar magnetic fields, the latitudinal and time variations of the solar wind parameters. Recent spacecraft data provide significant constraints on the model parameters. In this presentation, we will critically review current status in the modeling of the SW/LISM interactions and compare the model predictions with recent spacecraft data obtained on boards of Voyager, IBEX, SOHO and HST spacecraft. Problems and perspectives of the model development will be discussed as well.

  9. Constructing a Business Model Taxonomy

    DEFF Research Database (Denmark)

    Groth, Pernille; Nielsen, Christian

    2015-01-01

    Abstract Purpose: The paper proposes a research design recipe capable of leading to future business model taxonomies and discusses the potential benefits and implications of achieving this goal. Design/Methodology/Approach: The paper provides a review of relevant scholarly literature about business...... the quality of business model taxonomy studies in the future are identified. Originality/Value: The paper highlights the benefits and potential implications of designing business model taxonomy studies and makes the case for ensuring the quality of future studies relating to e.g. performance. Reviewing...... models to clarify the subject as well as highlighting the importance of past studies of business model classifications. In addition it reviews the scholarly literature on relevant methodological approaches, such as cluster analysis and latent class analysis, for constructing a business model taxonomy...

  10. Spacecraft Charging Technology, 1980

    Science.gov (United States)

    1981-01-01

    The third Spacecraft Charging Technology Conference proceedings contain 66 papers on the geosynchronous plasma environment, spacecraft modeling, charged particle environment interactions with spacecraft, spacecraft materials characterization, and satellite design and testing. The proceedings is a compilation of the state of the art of spacecraft charging and environmental interaction phenomena.

  11. Model-Based Real Time Assessment of Capability Left for Spacecraft Under Failure Mode, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project is aimed at developing a model based diagnostics system for spacecraft that will allow real time assessment of its state, while it is impacted...

  12. An empirical spectral bandwidth model for superior conjunction. [spacecraft communication

    Science.gov (United States)

    Rockwell, R. S.

    1978-01-01

    The downlink signal from spacecraft in superior solar conjunction phases suffers a great reduction in signal-to-noise ratio. Responsible in large part for this effect is the line broadening of the signal spectrum. An analytic empirical expression was developed for spectral bandwidth as a function of heliocentric distance from 1 to 20 solar radii. The study is based on spectral broadening data obtained from the superior conjunctions of Helios 1 (1975), Helios 2 (1976), and Pioneer 6 (1968). The empirical fit is based in part on a function describing the electron content in the solar corona.

  13. Adaptive relative pose control of spacecraft with model couplings and uncertainties

    Science.gov (United States)

    Sun, Liang; Zheng, Zewei

    2018-02-01

    The spacecraft pose tracking control problem for an uncertain pursuer approaching to a space target is researched in this paper. After modeling the nonlinearly coupled dynamics for relative translational and rotational motions between two spacecraft, position tracking and attitude synchronization controllers are developed independently by using a robust adaptive control approach. The unknown kinematic couplings, parametric uncertainties, and bounded external disturbances are handled with adaptive updating laws. It is proved via Lyapunov method that the pose tracking errors converge to zero asymptotically. Spacecraft close-range rendezvous and proximity operations are introduced as an example to validate the effectiveness of the proposed control approach.

  14. Modeling the angular motion dynamics of spacecraft with a magnetic attitude control system based on experimental studies and dynamic similarity

    Science.gov (United States)

    Kulkov, V. M.; Medvedskii, A. L.; Terentyev, V. V.; Firsyuk, S. O.; Shemyakov, A. O.

    2017-12-01

    The problem of spacecraft attitude control using electromagnetic systems interacting with the Earth's magnetic field is considered. A set of dimensionless parameters has been formed to investigate the spacecraft orientation regimes based on dynamically similar models. The results of experimental studies of small spacecraft with a magnetic attitude control system can be extrapolated to the in-orbit spacecraft motion control regimes by using the methods of the dimensional and similarity theory.

  15. Gravity and Macro-Model Tuning for the Geosat Follow-on Spacecraft

    Science.gov (United States)

    Lemoine, Frank G.; Rowlands, David D.; Marr, Gregory C.; Zelensky, Nikita P.; Luthcke, Scott B.; Cox, Christopher M.

    1999-01-01

    The US Navy's GEOSAT Follow-On (GFO) spacecraft was launched on February 10, 1998 and the primary objective of the mission was to map the oceans using a radar altimeter. The spacecraft tracking complement consisted of GPS receivers, a laser retroreflector and Doppler beacons. Since the GPS receivers have not yet returned reliable data, the only means of providing high-quality precise orbits has been though satellite laser ranging (SLR). The spacecraft has been tracked by the international satellite laser ranging network since April 22, 1998, and an average of 7.4 passes per day have been obtained from US and participating foreign stations. Since the predicted radial orbit error due to the gravity field is two to three cm, the largest contributor to the high SLR residuals (7-10 cm RMS for five day arcs) is the mismodelling of the non-conservative forces, not withstanding the development of a three-dimensional eight-panel model and an analytical attitude model for the GFO spacecraft. The SLR residuals show a clear correlation with beta-prime (solar elevation) angle, peaking in mid-August 1998 when the beta-prime angle reached -80 to -90 degrees. In this paper we discuss the tuning of the non-conservative force model, for GFO and report the subsequent addition of the GFO tracking data to the Earth gravity model solutions.

  16. Partnering models in Nordic construction

    DEFF Research Database (Denmark)

    Larsen, Jacob Norvig

    Traditionally, procurement and contractual policies adopted by building and construction clients produce a system in which clients procure design services separately from construction services, while operation and maintenance have been subject to further, separate procurement actions....... These fragmented structures have in recent years been criticised for leading to lack of co-ordination and conflict and ensuing litigation among parties to the construction project, and overall inefficiency in delivery. As a consequence there have been moves to promote more integrated collaborative forms of project...... delivery, often in combination with the introduction of private finance in hitherto publicly funded buildings and infrastructure works (PPP, PFI). Some construction clients have taken this a step further and adopted a much more collaborative approach towards project delivery, often known as partnering...

  17. Monte Carlo Technique Used to Model the Degradation of Internal Spacecraft Surfaces by Atomic Oxygen

    Science.gov (United States)

    Banks, Bruce A.; Miller, Sharon K.

    2004-01-01

    Atomic oxygen is one of the predominant constituents of Earth's upper atmosphere. It is created by the photodissociation of molecular oxygen (O2) into single O atoms by ultraviolet radiation. It is chemically very reactive because a single O atom readily combines with another O atom or with other atoms or molecules that can form a stable oxide. The effects of atomic oxygen on the external surfaces of spacecraft in low Earth orbit can have dire consequences for spacecraft life, and this is a well-known and much studied problem. Much less information is known about the effects of atomic oxygen on the internal surfaces of spacecraft. This degradation can occur when openings in components of the spacecraft exterior exist that allow the entry of atomic oxygen into regions that may not have direct atomic oxygen attack but rather scattered attack. Openings can exist because of spacecraft venting, microwave cavities, and apertures for Earth viewing, Sun sensors, or star trackers. The effects of atomic oxygen erosion of polymers interior to an aperture on a spacecraft were simulated at the NASA Glenn Research Center by using Monte Carlo computational techniques. A two-dimensional model was used to provide quantitative indications of the attenuation of atomic oxygen flux as a function of the distance into a parallel-walled cavity. The model allows the atomic oxygen arrival direction, the Maxwell Boltzman temperature, and the ram energy to be varied along with the interaction parameters of the degree of recombination upon impact with polymer or nonreactive surfaces, the initial reaction probability, the reaction probability dependence upon energy and angle of attack, degree of specularity of scattering of reactive and nonreactive surfaces, and the degree of thermal accommodation upon impact with reactive and non-reactive surfaces to be varied to allow the model to produce atomic oxygen erosion geometries that replicate actual experimental results from space. The degree of

  18. Planar rigid-flexible coupling spacecraft modeling and control considering solar array deployment and joint clearance

    Science.gov (United States)

    Li, Yuanyuan; Wang, Zilu; Wang, Cong; Huang, Wenhu

    2018-01-01

    Based on Nodal Coordinate Formulation (NCF) and Absolute Nodal Coordinate Formulation (ANCF), this paper establishes rigid-flexible coupling dynamic model of the spacecraft with large deployable solar arrays and multiple clearance joints to analyze and control the satellite attitude under deployment disturbance. Considering torque spring, close cable loop (CCL) configuration and latch mechanisms, a typical spacecraft composed of a rigid main-body described by NCF and two flexible panels described by ANCF is used as a demonstration case. Nonlinear contact force model and modified Coulomb friction model are selected to establish normal contact force and tangential friction model, respectively. Generalized elastic force are derived and all generalized forces are defined in the NCF-ANCF frame. The Newmark-β method is used to solve system equations of motion. The availability and superiority of the proposed model is verified through comparing with numerical co-simulations of Patran and ADAMS software. The numerical results reveal the effects of panel flexibility, joint clearance and their coupling on satellite attitude. The effects of clearance number, clearance size and clearance stiffness on satellite attitude are investigated. Furthermore, a proportional-differential (PD) attitude controller of spacecraft is designed to discuss the effect of attitude control on the dynamic responses of the whole system.

  19. Maneuver Performance Assessment of the Cassini Spacecraft Through Execution-Error Modeling and Analysis

    Science.gov (United States)

    Wagner, Sean

    2014-01-01

    The Cassini spacecraft has executed nearly 300 maneuvers since 1997, providing ample data for execution-error model updates. With maneuvers through 2017, opportunities remain to improve on the models and remove biases identified in maneuver executions. This manuscript focuses on how execution-error models can be used to judge maneuver performance, while providing a means for detecting performance degradation. Additionally, this paper describes Cassini's execution-error model updates in August 2012. An assessment of Cassini's maneuver performance through OTM-368 on January 5, 2014 is also presented.

  20. Modeling of the Lightning Plasma Channel Stroke to a Spacecraft during Ascent

    Science.gov (United States)

    Tarditi, Alfonso; Norgard, John

    2009-11-01

    Lightning protection is an important aspect of modern aerospace design: the increased use of composite materials (vs. metals) reduces the shielding and robustness of the conducting path that the outer shell of a vehicle can present to a lightning discharge. A spacecraft during ascent becomes vulnerable to lightning strokes immediately after leaving the launch pad: in addition to natural lightning conditions, there is the possibility of triggered lightning events, caused by a perturbation of the atmospheric electric field [1]. The purpose of this study, in support of the NASA Constellation program, is to determine the evolution of the plasma current and its distribution on the spacecraft surface. Following earlier ``gas dynamic'' approaches [2], the model considers a plasma channel attached to the ascending spacecraft after a return stroke is established. The conductive exhaust plume [3] is an integral part of the model. The NIMROD 3D plasma fluid code [4] is used to model the plasma channel, reproducing the full transient due to the self-consistent magnetic field and the possibility of sweeping of the attachment point along the moving structure [5]. References: [1] M.A. Uman, Proc. IEEE, 76, 1548 (1988). [2] V. A. Rakov, M. A. Uman, IEEE Trans. EMC, EMC-2940, 403 (1998). [3] J. D. Norgard, G.S. Smith, IEEE Trans. EMC, EMC-29, 157 (1987) [4] C. R. Sovinec et al., J. Comput. Phys. 195, 355 (2004). [5] Larsson et al., J. Phys. D, 33, 1876 (2000)

  1. Modeling and Analysis of Micro-Spacecraft Attitude Sensing with Gyrowheel

    Directory of Open Access Journals (Sweden)

    Xiaokun Liu

    2016-08-01

    Full Text Available This paper proposes two kinds of approaches of angular rate sensing for micro-spacecraft with a gyrowheel (GW, which can combine attitude sensing with attitude control into one single device to achieve a compact micro-spacecraft design. In this implementation, during the three-dimensional attitude control torques being produced, two-dimensional spacecraft angular rates can be sensed from the signals of the GW sensors, such as the currents of the torque coils, the tilt angles of the rotor, the motor rotation, etc. This paper focuses on the problems of the angular rate sensing with the GW at large tilt angles of the rotor. For this purpose, a novel real-time linearization approach based on Lyapunov’s linearization theory is proposed, and a GW linearized measurement model at arbitrary tilt angles of the rotor is derived. Furthermore, by representing the two-dimensional rotor tilt angles and tilt control torques as complex quantities and separating the twice periodic terms about the motor spin speed, the linearized measurement model at smaller tilt angles of the rotor is given and simplified. According to the respective characteristics, the application schemes of the two measurement models are analyzed from the engineering perspective. Finally, the simulation results are presented to demonstrate the effectiveness of the proposed strategy.

  2. X-Ray Detection and Processing Models for Spacecraft Navigation and Timing

    Science.gov (United States)

    Sheikh, Suneel; Hanson, John

    2013-01-01

    The current primary method of deepspace navigation is the NASA Deep Space Network (DSN). High-performance navigation is achieved using Delta Differential One-Way Range techniques that utilize simultaneous observations from multiple DSN sites, and incorporate observations of quasars near the line-of-sight to a spacecraft in order to improve the range and angle measurement accuracies. Over the past four decades, x-ray astronomers have identified a number of xray pulsars with pulsed emissions having stabilities comparable to atomic clocks. The x-ray pulsar-based navigation and time determination (XNAV) system uses phase measurements from these sources to establish autonomously the position of the detector, and thus the spacecraft, relative to a known reference frame, much as the Global Positioning System (GPS) uses phase measurements from radio signals from several satellites to establish the position of the user relative to an Earth-centered fixed frame of reference. While a GPS receiver uses an antenna to detect the radio signals, XNAV uses a detector array to capture the individual xray photons from the x-ray pulsars. The navigation solution relies on detailed xray source models, signal processing, navigation and timing algorithms, and analytical tools that form the basis of an autonomous XNAV system. Through previous XNAV development efforts, some techniques have been established to utilize a pulsar pulse time-of-arrival (TOA) measurement to correct a position estimate. One well-studied approach, based upon Kalman filter methods, optimally adjusts a dynamic orbit propagation solution based upon the offset in measured and predicted pulse TOA. In this delta position estimator scheme, previously estimated values of spacecraft position and velocity are utilized from an onboard orbit propagator. Using these estimated values, the detected arrival times at the spacecraft of pulses from a pulsar are compared to the predicted arrival times defined by the pulsar s pulse

  3. Execution-Error Modeling and Analysis of the GRAIL Spacecraft Pair

    Science.gov (United States)

    Goodson, Troy D.

    2013-01-01

    The GRAIL spacecraft, Ebb and Flow (aka GRAIL-A and GRAIL-B), completed their prime mission in June and extended mission in December 2012. The excellent performance of the propulsion and attitude control subsystems contributed significantly to the mission's success. In order to better understand this performance, the Navigation Team has analyzed and refined the execution-error models for delta-v maneuvers. There were enough maneuvers in the prime mission to form the basis of a model update that was used in the extended mission. This paper documents the evolution of the execution-error models along with the analysis and software used.

  4. Suprathermal ions in the solar wind from the Voyager spacecraft: Instrument modeling and background analysis

    International Nuclear Information System (INIS)

    Randol, B M; Christian, E R

    2015-01-01

    Using publicly available data from the Voyager Low Energy Charged Particle (LECP) instruments, we investigate the form of the solar wind ion suprathermal tail in the outer heliosphere inside the termination shock. This tail has a commonly observed form in the inner heliosphere, that is, a power law with a particular spectral index. The Voyager spacecraft have taken data beyond 100 AU, farther than any other spacecraft. However, during extended periods of time, the data appears to be mostly background. We have developed a technique to self-consistently estimate the background seen by LECP due to cosmic rays using data from the Voyager cosmic ray instruments and a simple, semi-analytical model of the LECP instruments

  5. Model-Based Autonomy for the Next Generation of Robotic Spacecraft

    Science.gov (United States)

    Fesq, L. M.; Ingham, M. D.; Pekala, M.; van Eepoel, J.; Williams, B. C.

    2002-01-01

    NASA' vision of an end-to-end autonomously operated space flight system is inspiring the development of enabling technologies for highly robust spacecraft. Over the past few years, a new approach to the design of reactive embedded software systems, called model-based autonomy, has generated significant interest in the space systems community. The goal of the model-based approach is to automate onboard sequence execution, by tightly integrating goal- driven commanding with fault detection, diagnosis, and recovery capabilities. Model-based autonomy has been deployed in various aerospace applications, including the Deep Space 1 (DS- 1) mission, and ground testbeds for the Space Interferometry Mission, the X-34 and X-37 rocket planes, and an in-situ propellant production system. This paper describes a system-level autonomy framework that significantly expands upon previous model-based approaches to configuration management, such as the Remote Agent mode identification and reconfiguration system (Livingstone), which was flown onboard the DS-1 spacecraft. This autonomy framework, named Titan, is a model-based executive that is capable of estimating current spacecraft modes, detecting and repairing failures, and executing commands, all within a fast sense-decide-act loop. Titan is composed of a model-based control sequencer and a deductive controller. The sequencer takes in system-level goals from theSystem-level ground or an onboard planner. Each system goal invokes a control program, which prescribesControl Sequencer complex spacecraft behaviors and issuesConfiguration appropriate configuration goals to the deductiveestimatesgoals controller, based on the system' estimated state trajectory. The deductive controller uses a common-sense plant model of the hardware and software components in the system to trackObservationsCommands state, diagnose faults and generate controlRT Control Layer actions that achieve the configuration goals. This paper first provides a

  6. A Quantitative Human Spacecraft Design Evaluation Model for Assessing Crew Accommodation and Utilization

    Science.gov (United States)

    Fanchiang, Christine

    Crew performance, including both accommodation and utilization factors, is an integral part of every human spaceflight mission from commercial space tourism, to the demanding journey to Mars and beyond. Spacecraft were historically built by engineers and technologists trying to adapt the vehicle into cutting edge rocketry with the assumption that the astronauts could be trained and will adapt to the design. By and large, that is still the current state of the art. It is recognized, however, that poor human-machine design integration can lead to catastrophic and deadly mishaps. The premise of this work relies on the idea that if an accurate predictive model exists to forecast crew performance issues as a result of spacecraft design and operations, it can help designers and managers make better decisions throughout the design process, and ensure that the crewmembers are well-integrated with the system from the very start. The result should be a high-quality, user-friendly spacecraft that optimizes the utilization of the crew while keeping them alive, healthy, and happy during the course of the mission. Therefore, the goal of this work was to develop an integrative framework to quantitatively evaluate a spacecraft design from the crew performance perspective. The approach presented here is done at a very fundamental level starting with identifying and defining basic terminology, and then builds up important axioms of human spaceflight that lay the foundation for how such a framework can be developed. With the framework established, a methodology for characterizing the outcome using a mathematical model was developed by pulling from existing metrics and data collected on human performance in space. Representative test scenarios were run to show what information could be garnered and how it could be applied as a useful, understandable metric for future spacecraft design. While the model is the primary tangible product from this research, the more interesting outcome of

  7. Proceedings of the Spacecraft Charging Technology Conference

    Science.gov (United States)

    Pike, C. P. (Editor); Lovell, R. R. (Editor)

    1977-01-01

    Over 50 papers from the spacecraft charging conference are included on subjects such as: (1) geosynchronous plasma environment, (2) spacecraft modeling, (3) spacecraft materials characterization, (4) spacecraft materials development, and (5) satellite design and test.

  8. MODELING THE SOLAR WIND AT THE ULYSSES , VOYAGER , AND NEW HORIZONS SPACECRAFT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T. K.; Pogorelov, N. V.; Zank, G. P. [Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, Huntsville, AL 35805 (United States); Elliott, H. A.; McComas, D. J. [Southwest Research Institute, San Antonio, TX 78238 (United States)

    2016-11-20

    The outer heliosphere is a dynamic region shaped largely by the interaction between the solar wind and the interstellar medium. While interplanetary magnetic field and plasma observations by the Voyager spacecraft have significantly improved our understanding of this vast region, modeling the outer heliosphere still remains a challenge. We simulate the three-dimensional, time-dependent solar wind flow from 1 to 80 astronomical units (au), where the solar wind is assumed to be supersonic, using a two-fluid model in which protons and interstellar neutral hydrogen atoms are treated as separate fluids. We use 1 day averages of the solar wind parameters from the OMNI data set as inner boundary conditions to reproduce time-dependent effects in a simplified manner which involves interpolation in both space and time. Our model generally agrees with Ulysses data in the inner heliosphere and Voyager data in the outer heliosphere. Ultimately, we present the model solar wind parameters extracted along the trajectory of the New Horizons spacecraft. We compare our results with in situ plasma data taken between 11 and 33 au and at the closest approach to Pluto on 2015 July 14.

  9. Modeling the Solar Wind at the Ulysses, Voyager, and New Horizons Spacecraft

    Science.gov (United States)

    Kim, T. K.; Pogorelov, N. V.; Zank, G. P.; Elliott, H. A.; McComas, D. J.

    2016-11-01

    The outer heliosphere is a dynamic region shaped largely by the interaction between the solar wind and the interstellar medium. While interplanetary magnetic field and plasma observations by the Voyager spacecraft have significantly improved our understanding of this vast region, modeling the outer heliosphere still remains a challenge. We simulate the three-dimensional, time-dependent solar wind flow from 1 to 80 astronomical units (au), where the solar wind is assumed to be supersonic, using a two-fluid model in which protons and interstellar neutral hydrogen atoms are treated as separate fluids. We use 1 day averages of the solar wind parameters from the OMNI data set as inner boundary conditions to reproduce time-dependent effects in a simplified manner which involves interpolation in both space and time. Our model generally agrees with Ulysses data in the inner heliosphere and Voyager data in the outer heliosphere. Ultimately, we present the model solar wind parameters extracted along the trajectory of the New Horizons spacecraft. We compare our results with in situ plasma data taken between 11 and 33 au and at the closest approach to Pluto on 2015 July 14.

  10. MODELING THE SOLAR WIND AT THE ULYSSES , VOYAGER , AND NEW HORIZONS SPACECRAFT

    International Nuclear Information System (INIS)

    Kim, T. K.; Pogorelov, N. V.; Zank, G. P.; Elliott, H. A.; McComas, D. J.

    2016-01-01

    The outer heliosphere is a dynamic region shaped largely by the interaction between the solar wind and the interstellar medium. While interplanetary magnetic field and plasma observations by the Voyager spacecraft have significantly improved our understanding of this vast region, modeling the outer heliosphere still remains a challenge. We simulate the three-dimensional, time-dependent solar wind flow from 1 to 80 astronomical units (au), where the solar wind is assumed to be supersonic, using a two-fluid model in which protons and interstellar neutral hydrogen atoms are treated as separate fluids. We use 1 day averages of the solar wind parameters from the OMNI data set as inner boundary conditions to reproduce time-dependent effects in a simplified manner which involves interpolation in both space and time. Our model generally agrees with Ulysses data in the inner heliosphere and Voyager data in the outer heliosphere. Ultimately, we present the model solar wind parameters extracted along the trajectory of the New Horizons spacecraft. We compare our results with in situ plasma data taken between 11 and 33 au and at the closest approach to Pluto on 2015 July 14.

  11. 874 CONSTRUCTION COST MODELS FOR HIGHRISE OFFICE ...

    African Journals Online (AJOL)

    USER

    2015-10-28

    Oct 28, 2015 ... Abstract. Existing cost estimating models offer frameworks for forecasting the probable cost of proposed construction pro ects. Nevertheless, they have been criticised to be either low in accuracy or slow in application. This paper describes the development of alternative cost- predicting models which will be ...

  12. Molecular Models: Construction of Models with Magnets

    Directory of Open Access Journals (Sweden)

    Kalinovčić P.

    2015-07-01

    Full Text Available Molecular models are indispensable tools in teaching chemistry. Beside their high price, commercially available models are generally too small for classroom demonstration. This paper suggests how to make space-filling (callote models from Styrofoam with magnetic balls as connectors and disc magnets for showing molecular polarity

  13. Gravity and Nonconservative Force Model Tuning for the GEOSAT Follow-On Spacecraft

    Science.gov (United States)

    Lemoine, Frank G.; Zelensky, Nikita P.; Rowlands, David D.; Luthcke, Scott B.; Chinn, Douglas S.; Marr, Gregory C.; Smith, David E. (Technical Monitor)

    2000-01-01

    The US Navy's GEOSAT Follow-On spacecraft was launched on February 10, 1998 and the primary objective of the mission was to map the oceans using a radar altimeter. Three radar altimeter calibration campaigns have been conducted in 1999 and 2000. The spacecraft is tracked by satellite laser ranging (SLR) and Doppler beacons and a limited amount of data have been obtained from the Global Positioning Receiver (GPS) on board the satellite. Even with EGM96, the predicted radial orbit error due to gravity field mismodelling (to 70x70) remains high at 2.61 cm (compared to 0.88 cm for TOPEX). We report on the preliminary gravity model tuning for GFO using SLR, and altimeter crossover data. Preliminary solutions using SLR and GFO/GFO crossover data from CalVal campaigns I and II in June-August 1999, and January-February 2000 have reduced the predicted radial orbit error to 1.9 cm and further reduction will be possible when additional data are added to the solutions. The gravity model tuning has improved principally the low order m-daily terms and has reduced significantly the geographically correlated error present in this satellite orbit. In addition to gravity field mismodelling, the largest contributor to the orbit error is the non-conservative force mismodelling. We report on further nonconservative force model tuning results using available data from over one cycle in beta prime.

  14. A neurolinguistic model of grammatical construction processing.

    Science.gov (United States)

    Dominey, Peter Ford; Hoen, Michel; Inui, Toshio

    2006-12-01

    One of the functions of everyday human language is to communicate meaning. Thus, when one hears or reads the sentence, "John gave a book to Mary," some aspect of an event concerning the transfer of possession of a book from John to Mary is (hopefully) transmitted. One theoretical approach to language referred to as construction grammar emphasizes this link between sentence structure and meaning in the form of grammatical constructions. The objective of the current research is to (1) outline a functional description of grammatical construction processing based on principles of psycholinguistics, (2) develop a model of how these functions can be implemented in human neurophysiology, and then (3) demonstrate the feasibility of the resulting model in processing languages of typologically diverse natures, that is, English, French, and Japanese. In this context, particular interest will be directed toward the processing of novel compositional structure of relative phrases. The simulation results are discussed in the context of recent neurophysiological studies of language processing.

  15. A proposed model for construction project management ...

    African Journals Online (AJOL)

    Keywords: Communication skills and leadership model, construction project management, leadership, South African .... If the recipients do not read it, it will not affect the project. These methods include intranet sites, ..... emotional intelligence or interpersonal skills and an understanding of crosscultural differences needed to ...

  16. Modeling and analysis of a flywheel microvibration isolation system for spacecrafts

    Science.gov (United States)

    Wei, Zhanji; Li, Dongxu; Luo, Qing; Jiang, Jianping

    2015-01-01

    The microvibrations generated by flywheels running at full speed onboard high precision spacecrafts will affect stability of the spacecraft bus and further degrade pointing accuracy of the payload. A passive vibration isolation platform comprised of multi-segment zig-zag beams is proposed to isolate disturbances of the flywheel. By considering the flywheel and the platform as an integral system with gyroscopic effects, an equivalent dynamic model is developed and verified through eigenvalue and frequency response analysis. The critical speeds of the system are deduced and expressed as functions of system parameters. The vibration isolation performance of the platform under synchronal and high-order harmonic disturbances caused by the flywheel is investigated. It is found that the speed range within which the passive platform is effective and the disturbance decay rate of the system are greatly influenced by the locations of the critical speeds. Structure optimization of the platform is carried out to enhance its performance. Simulation results show that a properly designed vibration isolation platform can effectively reduce disturbances emitted by the flywheel operating above the critical speeds of the system.

  17. Modeling and Parameter Estimation of Spacecraft Fuel Slosh with Diaphragms Using Pendulum Analogs

    Science.gov (United States)

    Chatman, Yadira; Gangadharan, Sathya; Schlee, Keith; Ristow, James; Suderman, James; Walker, Charles; Hubert, Carl

    2007-01-01

    Prediction and control of liquid slosh in moving containers is an important consideration in the design of spacecraft and launch vehicle control systems. Even with modern computing systems, CFD type simulations are not fast enough to allow for large scale Monte Carlo analyses of spacecraft and launch vehicle dynamic behavior with slosh included. It is still desirable to use some type of simplified mechanical analog for the slosh to shorten computation time. Analytic determination of the slosh analog parameters has met with mixed success and is made even more difficult by the introduction of propellant management devices such as elastomeric diaphragms. By subjecting full-sized fuel tanks with actual flight fuel loads to motion similar to that experienced in flight and measuring the forces experienced by the tanks, these parameters can be determined experimentally. Currently, the identification of the model parameters is a laborious trial-and-error process in which the hand-derived equations of motion for the mechanical analog are evaluated and their results compared with the experimental results. This paper will describe efforts by the university component of a team comprised of NASA's Launch Services Program, Embry Riddle Aeronautical University, Southwest Research Institute and Hubert Astronautics to improve the accuracy and efficiency of modeling techniques used to predict these types of motions. Of particular interest is the effect of diaphragms and bladders on the slosh dynamics and how best to model these devices. The previous research was an effort to automate the process of slosh model parameter identification using a MATLAB/SimMechanics-based computer simulation. These results are the first step in applying the same computer estimation to a full-size tank and vehicle propulsion system. The introduction of diaphragms to this experimental set-up will aid in a better and more complete prediction of fuel slosh characteristics and behavior. Automating the

  18. Implementing model-based system engineering for the whole lifecycle of a spacecraft

    Science.gov (United States)

    Fischer, P. M.; Lüdtke, D.; Lange, C.; Roshani, F.-C.; Dannemann, F.; Gerndt, A.

    2017-09-01

    Design information of a spacecraft is collected over all phases in the lifecycle of a project. A lot of this information is exchanged between different engineering tasks and business processes. In some lifecycle phases, model-based system engineering (MBSE) has introduced system models and databases that help to organize such information and to keep it consistent for everyone. Nevertheless, none of the existing databases approached the whole lifecycle yet. Virtual Satellite is the MBSE database developed at DLR. It has been used for quite some time in Phase A studies and is currently extended for implementing it in the whole lifecycle of spacecraft projects. Since it is unforeseeable which future use cases such a database needs to support in all these different projects, the underlying data model has to provide tailoring and extension mechanisms to its conceptual data model (CDM). This paper explains the mechanisms as they are implemented in Virtual Satellite, which enables extending the CDM along the project without corrupting already stored information. As an upcoming major use case, Virtual Satellite will be implemented as MBSE tool in the S2TEP project. This project provides a new satellite bus for internal research and several different payload missions in the future. This paper explains how Virtual Satellite will be used to manage configuration control problems associated with such a multi-mission platform. It discusses how the S2TEP project starts using the software for collecting the first design information from concurrent engineering studies, then making use of the extension mechanisms of the CDM to introduce further information artefacts such as functional electrical architecture, thus linking more and more processes into an integrated MBSE approach.

  19. Understanding sexual harassment using aggregate construct models.

    Science.gov (United States)

    Nye, Christopher D; Brummel, Bradley J; Drasgow, Fritz

    2014-11-01

    Sexual harassment has received a substantial amount of empirical attention over the past few decades, and this research has consistently shown that experiencing these behaviors has a detrimental effect on employees' well-being, job attitudes, and behaviors at work. However, these findings, and the conclusions that are drawn from them, make the implicit assumption that the empirical models used to examine sexual harassment are properly specified. This article presents evidence that properly specified aggregate construct models are more consistent with theoretical structures and definitions of sexual harassment and can result in different conclusions about the nomological network of harassment. Results from 3 large samples, 2 military and 1 from a civilian population, are used to illustrate the differences between aggregate construct and reflective indicator models of sexual harassment. These analyses suggested that the factor structure and the nomological network of sexual harassment differ when modeling harassment as an aggregate construct. The implications of these results for the continued study of sexual harassment are discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  20. Importance of Accurate Computation of Secondary Electron Emission for ModelingSpacecraft Charging

    OpenAIRE

    Clerc, Sebastien; Dennison, JR

    2005-01-01

    The secondary electron yield is a critical process in establishing the charge balance in spacecraft charging and the subsequent determination of the equilibrium potential. Spacecraft charging codes use a parameterized expression for the secondary electron yield δ(Eo) as a function of incident electron energy, Eo. A critical step in accurately characterizing a particular spacecraft material is establishing the most efficient and accurate way to determine the fitting parameters in terms of the ...

  1. Experimental evaluation of model predictive control and inverse dynamics control for spacecraft proximity and docking maneuvers

    Science.gov (United States)

    Virgili-Llop, Josep; Zagaris, Costantinos; Park, Hyeongjun; Zappulla, Richard; Romano, Marcello

    2018-03-01

    An experimental campaign has been conducted to evaluate the performance of two different guidance and control algorithms on a multi-constrained docking maneuver. The evaluated algorithms are model predictive control (MPC) and inverse dynamics in the virtual domain (IDVD). A linear-quadratic approach with a quadratic programming solver is used for the MPC approach. A nonconvex optimization problem results from the IDVD approach, and a nonlinear programming solver is used. The docking scenario is constrained by the presence of a keep-out zone, an entry cone, and by the chaser's maximum actuation level. The performance metrics for the experiments and numerical simulations include the required control effort and time to dock. The experiments have been conducted in a ground-based air-bearing test bed, using spacecraft simulators that float over a granite table.

  2. Modeling Temporal Processes in Early Spacecraft Design: Application of Discrete-Event Simulations for Darpa's F6 Program

    Science.gov (United States)

    Dubos, Gregory F.; Cornford, Steven

    2012-01-01

    While the ability to model the state of a space system over time is essential during spacecraft operations, the use of time-based simulations remains rare in preliminary design. The absence of the time dimension in most traditional early design tools can however become a hurdle when designing complex systems whose development and operations can be disrupted by various events, such as delays or failures. As the value delivered by a space system is highly affected by such events, exploring the trade space for designs that yield the maximum value calls for the explicit modeling of time.This paper discusses the use of discrete-event models to simulate spacecraft development schedule as well as operational scenarios and on-orbit resources in the presence of uncertainty. It illustrates how such simulations can be utilized to support trade studies, through the example of a tool developed for DARPA's F6 program to assist the design of "fractionated spacecraft".

  3. Software for Automated Generation of Reduced Thermal Models for Spacecraft Thermal Control, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal analysis is increasingly used in thermal engineering of spacecrafts in every stage, including design, test, and ground-operation simulation. Current...

  4. The Culture Based Model: Constructing a Model of Culture

    Science.gov (United States)

    Young, Patricia A.

    2008-01-01

    Recent trends reveal that models of culture aid in mapping the design and analysis of information and communication technologies. Therefore, models of culture are powerful tools to guide the building of instructional products and services. This research examines the construction of the culture based model (CBM), a model of culture that evolved…

  5. Item Construction and Psychometric Models Appropriate for Constructed Responses

    Science.gov (United States)

    1991-08-01

    which involve only one attribute per item. This is especially true when we are dealing with constructed-response items, we have to measure much more...Service University of Ilinois Educacional Testing Service Rosedal Road Capign. IL 61801 Princeton. K3 08541 Princeton. N3 08541 Dr. Charles LeiS Dr

  6. Spacecraft Multiple Array Communication System Performance Analysis

    Science.gov (United States)

    Hwu, Shian U.; Desilva, Kanishka; Sham, Catherine C.

    2010-01-01

    The Communication Systems Simulation Laboratory (CSSL) at the NASA Johnson Space Center is tasked to perform spacecraft and ground network communication system simulations, design validation, and performance verification. The CSSL has developed simulation tools that model spacecraft communication systems and the space and ground environment in which the tools operate. In this paper, a spacecraft communication system with multiple arrays is simulated. Multiple array combined technique is used to increase the radio frequency coverage and data rate performance. The technique is to achieve phase coherence among the phased arrays to combine the signals at the targeting receiver constructively. There are many technical challenges in spacecraft integration with a high transmit power communication system. The array combining technique can improve the communication system data rate and coverage performances without increasing the system transmit power requirements. Example simulation results indicate significant performance improvement can be achieved with phase coherence implementation.

  7. Materials and techniques for model construction

    Science.gov (United States)

    Wigley, D. A.

    1985-01-01

    The problems confronting the designer of models for cryogenic wind tunnel models are discussed with particular reference to the difficulties in obtaining appropriate data on the mechanical and physical properties of candidate materials and their fabrication technologies. The relationship between strength and toughness of alloys is discussed in the context of maximizing both and avoiding the problem of dimensional and microstructural instability. All major classes of materials used in model construction are considered in some detail and in the Appendix selected numerical data is given for the most relevant materials. The stepped-specimen program to investigate stress-induced dimensional changes in alloys is discussed in detail together with interpretation of the initial results. The methods used to bond model components are considered with particular reference to the selection of filler alloys and temperature cycles to avoid microstructural degradation and loss of mechanical properties.

  8. Conceptual Model for Systematic Construction Waste Management

    OpenAIRE

    Abd Rahim Mohd Hilmi Izwan; Kasim Narimah

    2017-01-01

    Development of the construction industry generated construction waste which can contribute towards environmental issues. Weaknesses of compliance in construction waste management especially in construction site have also contributed to the big issues of waste generated in landfills and illegal dumping area. This gives sign that construction projects are needed a systematic construction waste management. To date, a comprehensive criteria of construction waste management, particularly for const...

  9. Process-Based Modeling of Constructed Wetlands

    Science.gov (United States)

    Baechler, S.; Brovelli, A.; Rossi, L.; Barry, D. A.

    2007-12-01

    Constructed wetlands (CWs) are widespread facilities for wastewater treatment. In subsurface flow wetlands, contaminated wastewater flows through a porous matrix, where oxidation and detoxification phenomena occur. Despite the large number of working CWs, system design and optimization are still mainly based upon empirical equations or simplified first-order kinetics. This results from an incomplete understanding of the system functioning, and may in turn hinder the performance and effectiveness of the treatment process. As a result, CWs are often considered not suitable to meet high water quality-standards, or to treat water contaminated with recalcitrant anthropogenic contaminants. To date, only a limited number of detailed numerical models have been developed and successfully applied to simulate constructed wetland behavior. Among these, one of the most complete and powerful is CW2D, which is based on Hydrus2D. The aim of this work is to develop a comprehensive simulator tailored to model the functioning of horizontal flow constructed wetlands and in turn provide a reliable design and optimization tool. The model is based upon PHWAT, a general reactive transport code for saturated flow. PHWAT couples MODFLOW, MT3DMS and PHREEQC-2 using an operator-splitting approach. The use of PHREEQC to simulate reactions allows great flexibility in simulating biogeochemical processes. The biogeochemical reaction network is similar to that of CW2D, and is based on the Activated Sludge Model (ASM). Kinetic oxidation of carbon sources and nutrient transformations (nitrogen and phosphorous primarily) are modeled via Monod-type kinetic equations. Oxygen dissolution is accounted for via a first-order mass-transfer equation. While the ASM model only includes a limited number of kinetic equations, the new simulator permits incorporation of an unlimited number of both kinetic and equilibrium reactions. Changes in pH, redox potential and surface reactions can be easily incorporated

  10. Constructing a systems psychodynamic wellness model

    Directory of Open Access Journals (Sweden)

    Sanchen Henning

    2012-03-01

    Research purpose: The purpose of the research was to construct and refine the SPWM in order to understand psychological wellness at the individual, group and organisational levels. Motivation for the study: There is no psychological wellness model that integrates the principles of systems psychodynamics and positive psychology. Systems psychodynamics traditionally focuses on so-called negative behaviour whilst positive psychology tends to idealise positive behaviour. This research tried to merge these views in order to apply them to individual, group and organisational behaviour. Research design, approach and method: The researchers used qualitative, descriptive and conceptual research. They conducted an in-depth literature study to construct the model. They then refined it using the LP. Main findings: The researchers identified 39 themes. They categorised them into three different levels. Three first-level themes emerged as the highest level of integration: identity, hope and love. The nine second-level themes each consisted of three more themes. They were less complex and abstract than the first-level themes. The least complex 27 third-level themes followed. Practical/managerial implications: One can apply the SPWM as a qualitative diagnostic tool for understanding individual, group and organisational wellness and for consulting on systemic wellness. Contribution/value-add: The SPWM offers a model for understanding individual, group and organisational wellness and for consulting on systemic wellness.

  11. Software for Automated Generation of Reduced Thermal Models for Spacecraft Thermal Control, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal analysis is increasingly used in the engineering of spacecrafts at every stage, including design, test, and ground-operation simulation. Currently used...

  12. Reduced Order Electrostatic Force Field Modeling of 3D Spacecraft Shapes

    Data.gov (United States)

    National Aeronautics and Space Administration — The Autonomous Vehicles Systems (AVS) Lab at CU Boulder has been pursuing research in Coulomb charge control of spacecraft for several years. The electrostatic...

  13. Knowledge-based geometric modeling in construction

    DEFF Research Database (Denmark)

    Bonev, Martin; Hvam, Lars

    2012-01-01

    A wider application of IT-based solutions, such as configuration systems and the implementation of modeling standards, has facilitated the trend to produce mass customized products to support inter alia the specification process of the increasing product variety. However, not all industries have...... realized the full potential of using product and process modelling tools as well as the implementation of configuration systems to support their business processes. Especially in the building industry, where Engineer-to-Order (ETO) manufacturers provide complex custom tailored products, up to now, often...... a considerably high amount of their recourses is required for designing and specifying the majority of their product assortment. As design decisions are hereby based on knowledge and experience about behaviour and applicability of construction techniques and materials for a predefined design situation, smart...

  14. Model-based software engineering for an optical navigation system for spacecraft

    Science.gov (United States)

    Franz, T.; Lüdtke, D.; Maibaum, O.; Gerndt, A.

    2017-09-01

    The project Autonomous Terrain-based Optical Navigation (ATON) at the German Aerospace Center (DLR) is developing an optical navigation system for future landing missions on celestial bodies such as the moon or asteroids. Image data obtained by optical sensors can be used for autonomous determination of the spacecraft's position and attitude. Camera-in-the-loop experiments in the Testbed for Robotic Optical Navigation (TRON) laboratory and flight campaigns with unmanned aerial vehicle (UAV) are performed to gather flight data for further development and to test the system in a closed-loop scenario. The software modules are executed in the C++ Tasking Framework that provides the means to concurrently run the modules in separated tasks, send messages between tasks, and schedule task execution based on events. Since the project is developed in collaboration with several institutes in different domains at DLR, clearly defined and well-documented interfaces are necessary. Preventing misconceptions caused by differences between various development philosophies and standards turned out to be challenging. After the first development cycles with manual Interface Control Documents (ICD) and manual implementation of the complex interactions between modules, we switched to a model-based approach. The ATON model covers a graphical description of the modules, their parameters and communication patterns. Type and consistency checks on this formal level help to reduce errors in the system. The model enables the generation of interfaces and unified data types as well as their documentation. Furthermore, the C++ code for the exchange of data between the modules and the scheduling of the software tasks is created automatically. With this approach, changing the data flow in the system or adding additional components (e.g., a second camera) have become trivial.

  15. Maturity and maturity models in lean construction

    Directory of Open Access Journals (Sweden)

    Claus Nesensohn

    2014-03-01

    Full Text Available In recent years there has been an increasing interest in maturity models in management-related disciplines; which reflects a growing recognition that becoming more mature and having a model to guide the route to maturity can help organisations in managing major transformational change. Lean Construction (LC is an increasingly important improvement approach that organisations seek to embed. This study explores how to apply the maturity models to LC. Hence the attitudes, opinions and experiences of key industry informants with high levels of knowledge of LC were investigated. To achieve this, a review of maturity models was conducted, and data for the analysis was collected through a sequential process involving three methods. First a group interview with seven key informants. Second a follow up discussion with the same individuals to investigate some of the issues raised in more depth. Third an online discussion held via LinkedIn in which members shared their views on some of the results. Overall, we found that there is a lack of common understanding as to what maturity means in LC, though there is general agreement that the concept of maturity is a suitable one to reflect the path of evolution for LC within organisations.

  16. Constructing Dynamic Event Trees from Markov Models

    International Nuclear Information System (INIS)

    Paolo Bucci; Jason Kirschenbaum; Tunc Aldemir; Curtis Smith; Ted Wood

    2006-01-01

    In the probabilistic risk assessment (PRA) of process plants, Markov models can be used to model accurately the complex dynamic interactions between plant physical process variables (e.g., temperature, pressure, etc.) and the instrumentation and control system that monitors and manages the process. One limitation of this approach that has prevented its use in nuclear power plant PRAs is the difficulty of integrating the results of a Markov analysis into an existing PRA. In this paper, we explore a new approach to the generation of failure scenarios and their compilation into dynamic event trees from a Markov model of the system. These event trees can be integrated into an existing PRA using software tools such as SAPHIRE. To implement our approach, we first construct a discrete-time Markov chain modeling the system of interest by: (a) partitioning the process variable state space into magnitude intervals (cells), (b) using analytical equations or a system simulator to determine the transition probabilities between the cells through the cell-to-cell mapping technique, and, (c) using given failure/repair data for all the components of interest. The Markov transition matrix thus generated can be thought of as a process model describing the stochastic dynamic behavior of the finite-state system. We can therefore search the state space starting from a set of initial states to explore all possible paths to failure (scenarios) with associated probabilities. We can also construct event trees of arbitrary depth by tracing paths from a chosen initiating event and recording the following events while keeping track of the probabilities associated with each branch in the tree. As an example of our approach, we use the simple level control system often used as benchmark in the literature with one process variable (liquid level in a tank), and three control units: a drain unit and two supply units. Each unit includes a separate level sensor to observe the liquid level in the tank

  17. Constructive Empiricism and Model Nominalism. | Udokang | Sophia ...

    African Journals Online (AJOL)

    James Ladyman has argued that constructive empiricism entails modal realism, and that this renders constructive empiricism untenable. We maintain that constructive empiricism is compatible with modal nominalism. Although the central term “observable” has been analyzed in terms of counterfactuals, and in general ...

  18. Assessment of the Forward Contamination Risk of Mars by Clean Room Isolates from Space-Craft Assembly Facilities through Aeolian Transport - a Model Study

    Science.gov (United States)

    van Heereveld, Luc; Merrison, Jonathan; Nørnberg, Per; Finster, Kai

    2017-06-01

    The increasing number of missions to Mars also increases the risk of forward contamination. Consequently there is a need for effective protocols to ensure efficient protection of the Martian environment against terrestrial microbiota. Despite the fact of constructing sophisticated clean rooms for spacecraft assembly a 100 % avoidance of contamination appears to be impossible. Recent surveys of these facilities have identified a significant number of microbes belonging to a variety of taxonomic groups that survive the harsh conditions of clean rooms. These microbes may have a strong contamination potential, which needs to be investigate to apply efficient decontamination treatments. In this study we propose a series of tests to evaluate the potential of clean room contaminants to survive the different steps involved in forward contamination. We used Staphylococcus xylosus as model organism to illustrate the different types of stress that potential contaminants will be subjected to on their way from the spacecraft onto the surface of Mars. Staphylococcus xylosus is associated with human skin and commonly found in clean rooms and could therefore contaminate the spacecraft as a result of human activity during the assembling process. The path the cell will take from the surface of the spacecraft onto the surface of Mars was split into steps representing different stresses that include desiccation, freezing, aeolian transport in a Martian-like atmosphere at Martian atmospheric pressure, and UV radiation climate. We assessed the surviving fraction of the cellular population after each step by determining the integrated metabolic activity of the survivor population by measuring their oxygen consumption rate. The largest fraction of the starting culture (around 70 %) was killed during desiccation, while freezing, Martian vacuum and short-term UV radiation only had a minor additional effect on the survivability of Staphylococcus xylosus. The study also included a simulation

  19. Potential and Benefits of Building Information Modeling (BIM During Pre-Construction, Construction and Post Construction Stage

    Directory of Open Access Journals (Sweden)

    Aw Nien Wei

    2017-11-01

    Full Text Available The construction industry is the main economic support for all countries around the world in which continually adapting to meet competitive challenges around the global market. Nevertheless, the construction project is becoming much more complex and difficult to manage. This is because the construction project involves a large number of stakeholder, for example, the consultant companies, architects, engineers, building surveyors and quantity surveyors. The technology currently used in the construction industry is the AutoCAD (Automatic computeraided design. AutoCAD is a commercial software application for 2D and 3D computer-aided design (CAD and drafting develop by Autodesk. Generally, all the drawing design from Autocad will be exchanged among the stakeholder in the form of paper. Information exchanged among them mostly involves a lot of documents and drawings. This practice creates errors because of documents and drawings are mostly in a paper-based format that is not properly managed which results in miscommunication among them. Having wrong information in the construction process could hinder the productivity of projects because in a construction project information is one of the important construction materials. Building Information Modeling (BIM is one of the newly software in the architecture, engineering, and construction (AEC industries to ensure all parties receive the right information. BIM technology is also an intelligent model of a building constructed digitally in the way of 3D. The software will generate model containing the information needed to support the construction, fabrication, and procurement activities that needed to realize the building. This paper will discuss on potential and benefits of BIM during pre-construction stage, construction stage and during post construction stage

  20. Modelling of 67P cometary grains dynamic in the vicinity of the Rosetta spacecraft

    Science.gov (United States)

    Cipriani, F.; Altobelli, N.; Taylor, M.; Fulle, M.; Della Corte, V.; Rotundi, A.

    2017-09-01

    The interpretation of a number of Rosetta datasets (e.g. GIADA, COSIMA, MIDAS...), relies on the description of cometary grains dynamic in the close vicinity of the spacecraft. In particular the charged grains behaviour in the 3D spacecraft sheath open to the instrument entrances is complex and has not been described at such scales. The existence of a warm electrons population (a few 10eVs energy) in the cometary plasma as revealed during the Rendez-vous phase has been driving the spacecraft potential to negative values typically in the range -1 to -20V as inferred from RPC measurements [1]. Observation of cometary grains in the 10μm to mm range by GIADA and COSIMA[2] allowed to distinguish so called 'compact' grains of processed materials from the solar nebula from 'fluffy' aggregates of more primitive origin. When detected such grains have been observed to reach the instruments at m/s or less velocities. On particular it was inferred that fluffy aggregates are disrupted by electrostatic forces in the vicinity of the spacecraft due to the effects of local plasma hence resulting in particle showers observed by the instruments.

  1. The Engineering Model for the multi spectral imager of the EarthCARE spacecraft

    NARCIS (Netherlands)

    Albiñana, A.P.; Gelsthorpe, R.; Lefebvre, A.; Sauer, M.; Kruse, K.-W.; Münzenmayer, R.; Baister, G.; Chang, M.; Everett, J.; Barnes, A.; Bates, N.; Price, M.; Skipper, M.; Goeij, B.T.G. de; Meijer, E.A.; Knaap, F.G.P. van der; Hof, C.A. van 't

    2012-01-01

    The Multi-Spectral Imager (MSI) will be flown on board the EarthCARE spacecraft, under development by the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA). The fundamental objective of the EarthCARE mission is improving the understanding of the processes involving

  2. Spacecraft sterilization.

    Science.gov (United States)

    Kalfayan, S. H.

    1972-01-01

    Spacecraft sterilization is a vital factor in projects for the successful biological exploration of other planets. The microorganisms of major concern are the fungi and bacteria. Sterilization procedures are oriented toward the destruction of bacterial spores. Gaseous sterilants are examined, giving attention to formaldehyde, beta-propiolactone, ethylene oxide, and the chemistry of the bactericidal action of sterilants. Radiation has been seriously considered as another method for spacecraft sterilization. Dry heat sterilization is discussed together with the effects of ethylene oxide decontamination and dry heat sterilization on materials.

  3. A diagrammatic construction of formal E-independent model hamiltonian

    International Nuclear Information System (INIS)

    Kvasnicka, V.

    1977-01-01

    A diagrammatic construction of formal E-independent model interaction (i.e., without second-quantization formalism) is suggested. The construction starts from the quasi-degenerate Brillouin-Wigner perturbation theory, in the framework of which an E-dependent model Hamiltonian is simply constructed. Applying the ''E-removing'' procedure to this E-dependent model Hamiltonian, the E-independent formal model Hamiltonian either Hermitian or non-Hermitian can diagrammatically be easily derived. For the formal E-independent model Hamiltonian the separability theorem is proved, which can be profitably used for a rather ''formalistic ''construction of a many-body E-independent model Hamiltonian

  4. Side-effects of a bad attitude: How GNSS spacecraft orientation errors affect solar radiation pressure modelling

    Science.gov (United States)

    Dilssner, Florian; Springer, Tim; Schönemann, Erik; Zandbergen, Rene; Enderle, Werner

    2015-04-01

    Solar radiation pressure (SRP) is the largest non-gravitational perturbation for Global Navigation Satellite System (GNSS) satellites, and can therefore have substantial impact on their orbital dynamics. Various SRP force models have been developed over the past 30 years for the purpose of precise orbit determination. They all rely upon the assumption that the satellites continuously maintain a Sun-Nadir pointing attitude with the navigation antenna boresight (body-fixed z-axis) pointing towards Earth center, and the solar panel rotation axis (body-fixed y-axis) being normal to the Sun direction. However, in reality, this is not perfectly the case. Reasons for a non-nominal spacecraft attitude may be eclipse maneuvers, commanded attitude biases and Sun/horizon sensor measurement errors, for example due to mounting misalignment or incorrectly calibrated sensor electronics. In this work the effect of GNSS spacecraft orientation errors on SRP modelling is investigated. Simplified mathematical functions describing the SRP force acting on the solar arrays in the presence of yaw-, pitch- and roll-biases are derived. Special attention is paid to the yaw-bias and its relationship to the SRP dynamics, particular in direction of the spacecraft y-axis ("y-bias force"). Analytical and experimental results gathered from orbit and attitude analyses of GPS Block II/IIA/IIF satellites demonstrate how sensitive the SRP coefficients are to changes in yaw.

  5. Elaboration of technology organizational models of constructing high-rise buildings in plans of construction organization

    Science.gov (United States)

    Osipenkova, Irina; Simankina, Tatyana; Syrygina, Taisiia; Lukinov, Vitaliy

    2018-03-01

    This article represents features of the elaboration of technology organizational models of high-rise building construction in technology organizational documentation on the example of the plan of construction organization. Some examples of enhancing the effectiveness of high-rise building construction based on developments of several options of the organizational and technological plan are examined. Qualitative technology organizational documentation allows to increase the competitiveness of construction companies and provides prime cost of construction and assembly works reductions. Emphasis is placed on the necessity to comply with the principle of comprehensiveness of engineering, scientific and research works, development activities and scientific and technical support.

  6. Construction Worker Fatigue Prediction Model Based on System Dynamic

    Directory of Open Access Journals (Sweden)

    Wahyu Adi Tri Joko

    2017-01-01

    Full Text Available Construction accident can be caused by internal and external factors such as worker fatigue and unsafe project environment. Tight schedule of construction project forcing construction worker to work overtime in long period. This situation leads to worker fatigue. This paper proposes a model to predict construction worker fatigue based on system dynamic (SD. System dynamic is used to represent correlation among internal and external factors and to simulate level of worker fatigue. To validate the model, 93 construction workers whom worked in a high rise building construction projects, were used as case study. The result shows that excessive workload, working elevation and age, are the main factors lead to construction worker fatigue. Simulation result also shows that these factors can increase worker fatigue level to 21.2% times compared to normal condition. Beside predicting worker fatigue level this model can also be used as early warning system to prevent construction worker accident

  7. Construction of Fuzzy Ontologies from Fuzzy UML Models

    Directory of Open Access Journals (Sweden)

    Fu Zhang

    2013-05-01

    Full Text Available The success and proliferation of the Semantic Web depends heavily on construction of Web ontologies. However, classical ontology construction approaches are not sufficient for handling imprecise and uncertain information that is commonly found in many application domains. Therefore, great efforts on construction of fuzzy ontologies have been made in recent years. In this paper, we propose a formal approach and develop an automated tool for constructing fuzzy ontologies from fuzzy UML models. , we propose formalization methods of fuzzy UML models and fuzzy ontologies, where fuzzy UML models and fuzzy ontologies can be represented and interpreted by their respective formal definitions and semantic interpretation methods. , we propose an approach for constructing fuzzy ontologies from fuzzy UML models, i.e., transforming fuzzy UML models (including the structure and instance information of fuzzy UML models into fuzzy ontologies. , following the proposed approach, we implement a prototype transformation tool called that can construct fuzzy ontologies from fuzzy UML models. Constructing fuzzy ontologies from fuzzy UML models will facilitate the development of Web ontologies. , in order to show that the constructed fuzzy ontologies may be useful for reasoning on fuzzy UML models, we investigate how to reason on fuzzy UML models based on the constructed fuzzy ontologies, and it turns out that the reasoning tasks of fuzzy UML models can be checked by means of the reasoning mechanism of fuzzy ontologies.

  8. Error modeling and analysis of star cameras for a class of 1U spacecraft

    Science.gov (United States)

    Fowler, David M.

    As spacecraft today become increasingly smaller, the demand for smaller components and sensors rises as well. The smartphone, a cutting edge consumer technology, has impressive collections of both sensors and processing capabilities and may have the potential to fill this demand in the spacecraft market. If the technologies of a smartphone can be used in space, the cost of building miniature satellites would drop significantly and give a boost to the aerospace and scientific communities. Concentrating on the problem of spacecraft orientation, this study sets ground to determine the capabilities of a smartphone camera when acting as a star camera. Orientations determined from star images taken from a smartphone camera are compared to those of higher quality cameras in order to determine the associated accuracies. The results of the study reveal the abilities of low-cost off-the-shelf imagers in space and give a starting point for future research in the field. The study began with a complete geometric calibration of each analyzed imager such that all comparisons start from the same base. After the cameras were calibrated, image processing techniques were introduced to correct for atmospheric, lens, and image sensor effects. Orientations for each test image are calculated through methods of identifying the stars exposed on each image. Analyses of these orientations allow the overall errors of each camera to be defined and provide insight into the abilities of low-cost imagers.

  9. Multibody dynamical modeling for spacecraft docking process with spring-damper buffering device: A new validation approach

    Science.gov (United States)

    Daneshjou, Kamran; Alibakhshi, Reza

    2018-01-01

    In the current manuscript, the process of spacecraft docking, as one of the main risky operations in an on-orbit servicing mission, is modeled based on unconstrained multibody dynamics. The spring-damper buffering device is utilized here in the docking probe-cone system for micro-satellites. Owing to the impact occurs inevitably during docking process and the motion characteristics of multibody systems are remarkably affected by this phenomenon, a continuous contact force model needs to be considered. Spring-damper buffering device, keeping the spacecraft stable in an orbit when impact occurs, connects a base (cylinder) inserted in the chaser satellite and the end of docking probe. Furthermore, by considering a revolute joint equipped with torsional shock absorber, between base and chaser satellite, the docking probe can experience both translational and rotational motions simultaneously. Although spacecraft docking process accompanied by the buffering mechanisms may be modeled by constrained multibody dynamics, this paper deals with a simple and efficient formulation to eliminate the surplus generalized coordinates and solve the impact docking problem based on unconstrained Lagrangian mechanics. By an example problem, first, model verification is accomplished by comparing the computed results with those recently reported in the literature. Second, according to a new alternative validation approach, which is based on constrained multibody problem, the accuracy of presented model can be also evaluated. This proposed verification approach can be applied to indirectly solve the constrained multibody problems by minimum required effort. The time history of impact force, the influence of system flexibility and physical interaction between shock absorber and penetration depth caused by impact are the issues followed in this paper. Third, the MATLAB/SIMULINK multibody dynamic analysis software will be applied to build impact docking model to validate computed results and

  10. Modeling Attitude Dynamics in Simulink: A Study of the Rotational and Translational Motion of a Spacecraft Given Torques and Impulses Generated by RMS Hand Controllers

    Science.gov (United States)

    Mauldin, Rebecca H.

    2010-01-01

    In order to study and control the attitude of a spacecraft, it is necessary to understand the natural motion of a body in orbit. Assuming a spacecraft to be a rigid body, dynamics describes the complete motion of the vehicle by the translational and rotational motion of the body. The Simulink Attitude Analysis Model applies the equations of rigid body motion to the study of a spacecraft?s attitude in orbit. Using a TCP/IP connection, Matlab reads the values of the Remote Manipulator System (RMS) hand controllers and passes them to Simulink as specified torque and impulse profiles. Simulink then uses the governing kinematic and dynamic equations of a rigid body in low earth orbit (LE0) to plot the attitude response of a spacecraft for five seconds given known applied torques and impulses, and constant principal moments of inertia.

  11. Modeling-challenge paradigm using design of experiments for spacecraft immersed in nonstationary, between-regimes, flowing plasma

    Science.gov (United States)

    Koepke, Me; Marchand, R.

    2017-10-01

    A conducting sphere and cylinder under the conditions of nonstationary, between-regimes, flowing plasma is adopted as a test case for a modeling-challenge paradigm based on design of experiments (DOE) methodology that merges numerical simulation and testing. This model/simulation development platform facilitates a red-team/blue-team style challenge aimed at a tailored set of standard experimental conditions and measurements addressing specific questions in spacecraft-environment interactions and assessing the capability of models to describe those conditions. The goal is streamlining the Model/Simulation development process. A byproduct is an enhancement of the interrelationship between experiments in the laboratory and in space. Here, we conceptualize the advantage of the model-challenge over conventional validation in advancing whole-device modeling objectives in basic and applied plasma science.

  12. Modelling verb selection within argument structure constructions

    NARCIS (Netherlands)

    Matusevych, Yevgen; Alishahi, Afra; Backus, Albert

    2017-01-01

    This article looks into the nature of cognitive associations between verbs and argument structure constructions (ASCs). Existing research has shown that distributional and semantic factors affect speakers' choice of verbs in ASCs. A formal account of this theory has been proposed by Ellis,

  13. Polyether sulfone membrane modeling and construction for the ...

    African Journals Online (AJOL)

    Polyether sulfone membrane modeling and construction for the removal of nitrate from water using ion interference sulfate and iron nano-particle. ... The aim of this study was constructed the polyether sulfone membrane and modelling it, and for checking impact pressure, the amount of iron nanoparticles and sulfate iron ...

  14. DEVELOPMENT OF SMALL-SCALE CONSTRUCTION ENTERPRISE PROCESS MANAGEMENT MODEL

    OpenAIRE

    E. V. Folomeev

    2012-01-01

    Process approach is one of most effective ways of managing construction companies. Resulting from using models based on this approach, the company’s structure becomes flexible enough to quickly acquire the ability to get functionally and structurally tuned for specific projects. It is demonstrated in this article how to develop a process management model mechanism for a small-scale construction company.

  15. Constructing Realistic Szekeres Models from Initial and Final Data

    OpenAIRE

    Walters, Anthony; Hellaby, Charles

    2012-01-01

    The Szekeres family of inhomogeneous solutions, which are defined by six arbitrary metric functions, offers a wide range of possibilities for modelling cosmic structure. Here we present a model construction procedure for the quasispherical case using given data at initial and final times. Of the six arbitrary metric functions, the three which are common to both Szekeres and Lema\\^itre-Tolman models are determined by the model construction procedure of Krasinski & Hellaby. For the remaining th...

  16. Spacecraft operations

    CERN Document Server

    Sellmaier, Florian; Schmidhuber, Michael

    2015-01-01

    The book describes the basic concepts of spaceflight operations, for both, human and unmanned missions. The basic subsystems of a space vehicle are explained in dedicated chapters, the relationship of spacecraft design and the very unique space environment are laid out. Flight dynamics are taught as well as ground segment requirements. Mission operations are divided into preparation including management aspects, execution and planning. Deep space missions and space robotic operations are included as special cases. The book is based on a course held at the German Space Operation Center (GSOC).

  17. Constructing many atomic models in $\\aleph_1$

    OpenAIRE

    Baldwin, John T.; Laskowski, Michael C.; Shelah, Saharon

    2015-01-01

    We introduce the notion of pseudo-algebraicity to study atomic models of first order theories (equivalently models of a complete sentence of $L_{\\omega_1,\\omega}$. Theorem: Let $T$ be any complete first-order theory in a countable language with an atomic model. If the pseudo-minimal types are not dense, then there are $2^{\\aleph_1}$ pairwise non-isomorphic atomic models of $T$, each of size $\\aleph_1$.

  18. Masonry constructions mechanical models and numerical applications

    CERN Document Server

    Lucchesi, Massimiliano; Padovani, Cristina

    2008-01-01

    Numerical methods for the structural analysis of masonry constructions can be of great value in assessing the safety of artistically important masonry buildings and optimizing potential operations of maintenance and strengthening in terms of their cost-effectiveness, architectural impact and static effectiveness. This monograph firstly provides a detailed description of the constitutive equation of masonry-like materials, clearly setting out its most important features. It then goes on to provide a numerical procedure to solve the equilibrium problem of masonry solids. A large portion of the w

  19. 4D modeling in high-rise construction

    Directory of Open Access Journals (Sweden)

    Balakina Anastasiya

    2018-01-01

    Full Text Available High-rise construction is a complex construction process, requiring the use of more perfected and sophisticated tools for design, planning and construction management. The use of BIM-technologies allows minimizing the risks associated with design errors and errors that occur during construction. This article discusses a visual planning method using the 4D model, which allows the project team to create an accurate and complete construction plan, which is much more difficult to achieve with the help of traditional planning methods. The use of the 4D model in the construction of a 70-story building allowed to detect spatial and temporal errors before the start of construction work. In addition to identifying design errors, 4D modeling has allowed to optimize the construction, as follows: to optimize the operation of cranes, the placement of building structures and materials at various stages of construction, to optimize the organization of work performance, as well as to monitor the activities related to the preparation of the construction site for compliance with labor protection and safety requirements, which resulted in saving money and time.

  20. 4D modeling in high-rise construction

    Science.gov (United States)

    Balakina, Anastasiya; Simankina, Tatyana; Lukinov, Vitaly

    2018-03-01

    High-rise construction is a complex construction process, requiring the use of more perfected and sophisticated tools for design, planning and construction management. The use of BIM-technologies allows minimizing the risks associated with design errors and errors that occur during construction. This article discusses a visual planning method using the 4D model, which allows the project team to create an accurate and complete construction plan, which is much more difficult to achieve with the help of traditional planning methods. The use of the 4D model in the construction of a 70-story building allowed to detect spatial and temporal errors before the start of construction work. In addition to identifying design errors, 4D modeling has allowed to optimize the construction, as follows: to optimize the operation of cranes, the placement of building structures and materials at various stages of construction, to optimize the organization of work performance, as well as to monitor the activities related to the preparation of the construction site for compliance with labor protection and safety requirements, which resulted in saving money and time.

  1. Virtual Models Linked with Physical Components in Construction

    DEFF Research Database (Denmark)

    Sørensen, Kristian Birch

    components in the construction process and thereby improving the information handling. The present PhD project has examined the potential of establishing such a digital link between virtual models and physical components in construction. This is done by integrating knowledge of civil engineering, software......) project progress management, and 3) in operation and maintenance. Experiments and implementations in real life projects showed that mobile technology and passive RFID technology delineate an efficient and practically implementable ways to establish the digital links in construction and are ready for use...... virtual models that thoroughly mirror the performance of the final facility and its construction process. However, the potential of the virtual models in construction has not yet been fully utilised. One way to take more advantage of the virtual models is by digitally linking them with the physical...

  2. Spacecraft Attitude Determination

    DEFF Research Database (Denmark)

    Bak, Thomas

    This thesis describes the development of an attitude determination system for spacecraft based only on magnetic field measurements. The need for such system is motivated by the increased demands for inexpensive, lightweight solutions for small spacecraft. These spacecraft demands full attitude...... determination based on simple, reliable sensors. Meeting these objectives with a single vector magnetometer is difficult and requires temporal fusion of data in order to avoid local observability problems. In order to guaranteed globally nonsingular solutions, quaternions are generally the preferred attitude...... is a detailed study of the influence of approximations in the modeling of the system. The quantitative effects of errors in the process and noise statistics are discussed in detail. The third contribution is the introduction of these methods to the attitude determination on-board the Ørsted satellite...

  3. Competency-Based Model for Predicting Construction Project Managers Performance

    OpenAIRE

    Dainty, A. R. J.; Cheng, M.; Moore, D. R.

    2005-01-01

    Using behavioral competencies to influence human resource management decisions is gaining popularity in business organizations. This study identifies the core competencies associated with the construction management role and further, develops a predictive model to inform human resource selection and development decisions within large construction organizations. A range of construction managers took part in behavioral event interviews where staffs were asked to recount critical management inci...

  4. Construction cost forecast model : model documentation and technical notes.

    Science.gov (United States)

    2013-05-01

    Construction cost indices are generally estimated with Laspeyres, Paasche, or Fisher indices that allow changes : in the quantities of construction bid items, as well as changes in price to change the cost indices of those items. : These cost indices...

  5. Modelling, Construction, and Testing of a Simple HTS Machine Demonstrator

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Abrahamsen, Asger Bech

    2011-01-01

    This paper describes the construction, modeling and experimental testing of a high temperature superconducting (HTS) machine prototype employing second generation (2G) coated conductors in the field winding. The prototype is constructed in a simple way, with the purpose of having an inexpensive way...

  6. Shifting Constructions of Role Models for English Learners in China

    Science.gov (United States)

    Gao, Xuesong

    2014-01-01

    This essay draws attention to the shifting constructions of nationally famous role models for English learners. It examines how three individuals rose to national prominence because of their association with the craze for learning English in China in the last three decades. This essay compares the constructed images of these individuals and…

  7. A proposed model for construction project management ...

    African Journals Online (AJOL)

    The lack of a proper communication skills model for project management may contribute to ineffective project communication. This article reports the results of a study done to identify the most important project management communication skills and applications of communication that effective project managers should ...

  8. Review of constructive models for concrete

    International Nuclear Information System (INIS)

    Xiaoping, Y.; Ottosen, N.S.; Thelandersson, S.; Nielsen, M.P.

    1989-11-01

    This report has been prepared for the Commission of the European Communities, Joint Research Centre, ISPRA. The report reviews the constitutive models for concrete and is a part of a survey of the status of the analytical capabilities for predicting the structural response of NPP concrete containment buildings to severe loading conditions

  9. A Production Model for Construction: A Theoretical Framework

    Directory of Open Access Journals (Sweden)

    Ricardo Antunes

    2015-03-01

    Full Text Available The building construction industry faces challenges, such as increasing project complexity and scope requirements, but shorter deadlines. Additionally, economic uncertainty and rising business competition with a subsequent decrease in profit margins for the industry demands the development of new approaches to construction management. However, the building construction sector relies on practices based on intuition and experience, overlooking the dynamics of its production system. Furthermore, researchers maintain that the construction industry has no history of the application of mathematical approaches to model and manage production. Much work has been carried out on how manufacturing practices apply to construction projects, mostly lean principles. Nevertheless, there has been little research to understand the fundamental mechanisms of production in construction. This study develops an in-depth literature review to examine the existing knowledge about production models and their characteristics in order to establish a foundation for dynamic production systems management in construction. As a result, a theoretical framework is proposed, which will be instrumental in the future development of mathematical production models aimed at predicting the performance and behaviour of dynamic project-based systems in construction.

  10. Model Tests on the Retaining Walls Constructed from Geobags Filled with Construction Waste

    Directory of Open Access Journals (Sweden)

    Hua Wen

    2016-01-01

    Full Text Available Geobag retaining wall using construction waste is a new flexible supporting structure, and the usage of construction waste to fill geobags can facilitate the construction recycling. In this paper, model tests were performed on geobag retaining wall using construction waste. The investigation was concentrated on the slope top settlement, the distribution characteristics of the earth pressures on retaining walls and horizontal wall displacements, and slope failure modes. The results indicated that the ultimate loads that the slope tops with retaining walls could bear were 87.5%~125% higher than that of the slope top without retaining walls. The ultimate loading of strengthened slopes with different slope ratios from 1 : 0.75 to 1 : 0.25 could be reduced by 11.8% to 29.4%. The horizontal displacements of the retaining walls constructed from geobags were distributed in a drum shape, with the greatest horizontal displacements occurring about 1/3~1/2 of the wall height away from the bottom of the wall. As the slope ratio increased, the failure of the slope soil supported by geobag retaining wall using construction waste changed from sliding to sliding-toppling (dominated by sliding and then to toppling-sliding (dominated by toppling. The range of 1/3~1/2 of wall height is the weak part of the retaining walls, which should be strengthened with certain measures during the process of design and construction.

  11. Anthropomimetic Robots: Concept, Construction and Modelling

    Directory of Open Access Journals (Sweden)

    Alan Diamond

    2012-11-01

    Full Text Available An anthropomimetic robot is one that closely copies the mechanics of the human body by having a human-like jointed skeleton moved by compliant muscle-like actuators. This paper describes the progress achieved in building anthropomimetic torsos in two projects, CRONOS and ECCEROBOT. In each, the bones were hand-moulded in a thermoplastic and the muscles were implemented by DC motors shortening and extending elastic tendons. Anthropomimetic robots differ from conventionally engineered robots by having complex joints and compliant tendon driven actuation that can cross more than one joint. Taken together, these characteristics make the robots unsuitable for control by standard methods, and so the ability to model them is important for developing heuristic methods of control and also for providing forward models. The robots were modelled using physics-based techniques which enable the study of the generation of movements and also of interactions with arbitrary objects. The lightweight and compliant structure of the robots was found to be safe for human proximity and contact.

  12. Modeling protein structures: construction and their applications.

    Science.gov (United States)

    Ring, C S; Cohen, F E

    1993-06-01

    Although no general solution to the protein folding problem exists, the three-dimensional structures of proteins are being successfully predicted when experimentally derived constraints are used in conjunction with heuristic methods. In the case of interleukin-4, mutagenesis data and CD spectroscopy were instrumental in the accurate assignment of secondary structure. In addition, the tertiary structure was highly constrained by six cysteines separated by many residues that formed three disulfide bridges. Although the correct structure was a member of a short list of plausible structures, the "best" structure was the topological enantiomer of the experimentally determined conformation. For many proteases, other experimentally derived structures can be used as templates to identify the secondary structure elements. In a procedure called modeling by homology, the structure of a known protein is used as a scaffold to predict the structure of another related protein. This method has been used to model a serine and a cysteine protease that are important in the schistosome and malarial life cycles, respectively. The model structures were then used to identify putative small molecule enzyme inhibitors computationally. Experiments confirm that some of these nonpeptidic compounds are active at concentrations of less than 10 microM.

  13. Mathematical model of innovative sustainability “green” construction object

    Directory of Open Access Journals (Sweden)

    Slesarev Michail

    2016-01-01

    Full Text Available The paper addresses the issue of finding sustainability of “green” innovative processes in interaction between construction activities and the environment. The problem of today’s construction science is stated as comprehensive integration and automation of natural and artificial intellects within systems that ensure environmental safety of construction based on innovative sustainability of “green” technologies in the life environment, and “green” innovative products. The suggested solution to the problem should formalize sustainability models and methods for interpretation of optimization mathematical modeling problems respective to problems of environmental-based innovative process management, adapted to construction of “green” objects, “green” construction technologies, “green” innovative materials and structures.

  14. Lean construction as an effective organization model in Arctic

    Directory of Open Access Journals (Sweden)

    Balashova Elena S.

    2017-01-01

    Full Text Available In recent time, due to the sharp climatic changes, the Arctic attracts an increased interest of the world powers as a strategically important object. In 2013, the development strategy of the Arctic zone of the Russian Federation and national security for the period up to 2020 was approved by the President. In this strategy, the socio-economic development of the region in terms of improving the quality of life, expressed in the implementation of housing and civil engineering is very important. The goal of the study is to identify effective organization model of construction in the Arctic zone of the Russian Federation. Lean construction as a dynamically developing methodology abroad is analyzed. Characteristics of this organization model of construction meet the necessary requirements for the construction of various infrastructure objects in the Arctic. Therefore, the concept of lean construction can be an effective strategy of development of the Arctic regions of Russia as well as other Arctic countries.

  15. CFD modelling of moisture interactions between air and constructions

    DEFF Research Database (Denmark)

    Mortensen, Lone Hedegaard; Woloszyn, Monika; Hohota, Raluca

    2005-01-01

    There is a strong demand for accurate moisture modelling since moisture poses a risk for both the constructions and the indoor climate. Thus, in this investigation there is special focus on moisture modelling. The paper describes a new model based on a CFD tool that is enhanced to include both...

  16. Constructing realistic Szekeres models from initial and final data

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Anthony; Hellaby, Charles, E-mail: tony.walters@uct.ac.za, E-mail: charles.hellaby@uct.ac.za [Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch, 7701 (South Africa)

    2012-12-01

    The Szekeres family of inhomogeneous solutions, which are defined by six arbitrary metric functions, offers a wide range of possibilities for modelling cosmic structure. Here we present a model construction procedure for the quasispherical case using given data at initial and final times. Of the six arbitrary metric functions, the three which are common to both Szekeres and Lemaître-Tolman models are determined by the model construction procedure of Krasinski and Hellaby. For the remaining three functions, which are unique to Szekeres models, we derive exact analytic expressions in terms of more physically intuitive quantities — density profiles and dipole orientation angles. Using MATLAB, we implement the model construction procedure and simulate the time evolution.

  17. Performance of Gradient-Based Solutions versus Genetic Algorithms in the Correlation of Thermal Mathematical Models of Spacecrafts

    Directory of Open Access Journals (Sweden)

    Eva Anglada

    2017-01-01

    Full Text Available The correlation of the thermal mathematical models (TMMs of spacecrafts with the results of the thermal test is a demanding task in terms of time and effort. Theoretically, it can be automatized by means of optimization techniques, although this is a challenging task. Previous studies have shown the ability of genetic algorithms to perform this task in several cases, although some limitations have been detected. In addition, gradient-based methods, although also presenting some limitations, have provided good solutions in other technical fields. For this reason, the performance of genetic algorithms and gradient-based methods in the correlation of TMMs is discussed in this paper to compare the pros and cons of them. The case of study used in the comparison is a real space instrument flown aboard the International Space Station.

  18. Effective stimuli for constructing reliable neuron models.

    Directory of Open Access Journals (Sweden)

    Shaul Druckmann

    2011-08-01

    Full Text Available The rich dynamical nature of neurons poses major conceptual and technical challenges for unraveling their nonlinear membrane properties. Traditionally, various current waveforms have been injected at the soma to probe neuron dynamics, but the rationale for selecting specific stimuli has never been rigorously justified. The present experimental and theoretical study proposes a novel framework, inspired by learning theory, for objectively selecting the stimuli that best unravel the neuron's dynamics. The efficacy of stimuli is assessed in terms of their ability to constrain the parameter space of biophysically detailed conductance-based models that faithfully replicate the neuron's dynamics as attested by their ability to generalize well to the neuron's response to novel experimental stimuli. We used this framework to evaluate a variety of stimuli in different types of cortical neurons, ages and animals. Despite their simplicity, a set of stimuli consisting of step and ramp current pulses outperforms synaptic-like noisy stimuli in revealing the dynamics of these neurons. The general framework that we propose paves a new way for defining, evaluating and standardizing effective electrical probing of neurons and will thus lay the foundation for a much deeper understanding of the electrical nature of these highly sophisticated and non-linear devices and of the neuronal networks that they compose.

  19. Farmer's Friend Biodigester Model Construction Manual

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-11-15

    The success or failure of any biodigester depends mainly upon the suitability of the design, site for construction and quality of construction works, as well as quality of construction materials and workmanship involved during construction. This booklet provides the extensive information on various methods for selecting the appropriate size and site for construction, as well as construction work steps related to the Farmer's Friend model (2005) of biodigester. First, mason's responsibilities are explained. Second, the report continues with the sizes of available biodigesters and the quantity of feeding required. Then, the components of the biogas plant and instructions as to how to select the appropriate size are described. It continues with construction materials and appliances, and the selection of the construction site. Finally, the plant construction is explained from lay-out work to the construction of compost pits, finishing work and instructions to users. If the concerned mason/plumber strictly follows the instruction as described in this construction manual, the biodigester will function properly with the anticipated efficiency and the owner will get the return of his/her investment. This will encourage his/her relatives and neighbours to install biodigesters. However, if the biodigester functions poorly, nobody will be motivated to install it. Poor quality plants will harm the reputation of biogas technology and will have serious negative effects on promotion and extension activities. The masons should, therefore, be well aware that good quality plants will certainly increase the rate of installation with the demonstration effect that ultimately benefits itself, the farmer, and the country as a whole.

  20. Transformation of Malaysian Construction Industry with Building Information Modelling (BIM

    Directory of Open Access Journals (Sweden)

    Latiffi Aryani Ahmad

    2016-01-01

    Full Text Available Building Information Modelling (BIM is a revolution of technology and a process that transformed the way building is planned, designed, analysed, constructed and managed. The revolution of technology and process could increase the quality of construction projects. The knowledge of BIM has been expanding in many countries including Malaysia. Since its inception, the use of BIM has broadened up widely with different purposes. The aims of this paper is to investigate the BIM implementation and uses in Malaysian construction projects. The methodologies adopted for structuring this paper are by using literature review and semi-structured interview with construction players that have experienced and being involved in projects using BIM. The purpose of literature review is to illustrate on the pervious research on the subject matter. Meanwhile, the purpose of interviews is to explore the involvement of construction players, years of experience in projects using BIM and BIM uses in construction projects. The findings revealed that BIM has been implemented in Malaysia since 2007 by various construction players, which are client, architect, C&S engineer, M&E engineer, QS, contractor, facilities manager and BIM consultant. The findings also revealed that BIM is used for project’ visualisation, improving project design, detecting design clashes, quantity take off and operation and maintenance. Further work will be focused on the current practices of construction players in projects using BIM.

  1. Constructing Multidatabase Collections Using Extended ODMG Object Model

    Directory of Open Access Journals (Sweden)

    Adrian Skehill Mark Roantree

    1999-11-01

    Full Text Available Collections are an important feature in database systems. They provide us with the ability to group objects of interest together, and then to manipulate them in the required fashion. The OASIS project is focused on the construction a multidatabase prototype which uses the ODMG model and a canonical model. As part of this work we have extended the base model to provide a more powerful collection mechanism, and to permit the construction of a federated collection, a collection of heterogenous objects taken from distributed data sources

  2. A construction of observables for AKSZ sigma models

    OpenAIRE

    Mnev, Pavel

    2012-01-01

    A construction of gauge-invariant observables is suggested for a class of topological field theories, the AKSZ sigma-models. The observables are associated to extensions of the target Q-manifold of the sigma model to a Q-bundle over it with additional Hamiltonian structure in fibers.

  3. Simulation-based modeling of building complexes construction management

    Science.gov (United States)

    Shepelev, Aleksandr; Severova, Galina; Potashova, Irina

    2018-03-01

    The study reported here examines the experience in the development and implementation of business simulation games based on network planning and management of high-rise construction. Appropriate network models of different types and levels of detail have been developed; a simulation model including 51 blocks (11 stages combined in 4 units) is proposed.

  4. Cloud model construct for transaction-based cooperative systems ...

    African Journals Online (AJOL)

    Plethora of cooperative enterprise models exist in practice. Inherent complex and tasking operations and lack of financial strength to procure cutting edge Information Technology infrastructure are some of the problems faced by these cooperative enterprises. In this paper, a cloud model is constructed for transaction-based ...

  5. Social Perception and Social Reality: A Reflection-Construction Model.

    Science.gov (United States)

    Jussim, Lee

    1991-01-01

    A reflection-construction model of relations between social perception and social reality is presented that explicitly specifies several ways in which social perception may relate to social reality. Evidence supporting this model also supports a weaker version of the social-constructivist view. (SLD)

  6. An Environmentally Oriented Constructive Cost Model In Information ...

    African Journals Online (AJOL)

    A model was designed to assist software developers in Nigeria to estimate software effort, duration and cost as a result of the difficulties in understanding the parameters of the traditional Constructive Cost Model II (COCOMO II) , which was designed for a specif ic environment, using Source Lines of Code (SLOC) . Results ...

  7. The Solar Energetic Particle Event of 2010 August 14: Connectivity with the Solar Source Inferred from Multiple Spacecraft Observations and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Lario, D.; Kwon, R.-Y.; Raouafi, N. E. [The Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Richardson, I. G.; Thompson, B. J.; Rosenvinge, T. T. von; Mays, M. L.; Mäkelä, P. A.; Xie, H.; Thakur, N. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Bain, H. M. [Space Sciences Laboratory, UC Berkeley, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); Zhang, M.; Zhao, L. [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL (United States); Cane, H. V. [Department of Mathematics and Physics, University of Tasmania, Hobart (Australia); Papaioannou, A. [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, GR-15 236 Penteli (Greece); Riley, P., E-mail: david.lario@jhuapl.edu [Predictive Science, 9990 Mesa Rim Road, Suite 170, San Diego, CA 92121 (United States)

    2017-03-20

    We analyze one of the first solar energetic particle (SEP) events of solar cycle 24 observed at widely separated spacecraft in order to assess the reliability of models currently used to determine the connectivity between the sources of SEPs at the Sun and spacecraft in the inner heliosphere. This SEP event was observed on 2010 August 14 by near-Earth spacecraft, STEREO-A (∼80° west of Earth) and STEREO-B (∼72° east of Earth). In contrast to near-Earth spacecraft, the footpoints of the nominal magnetic field lines connecting STEREO-A and STEREO-B with the Sun were separated from the region where the parent fast halo coronal mass ejection (CME) originated by ∼88° and ∼47° in longitude, respectively. We discuss the properties of the phenomena associated with this solar eruption. Extreme ultraviolet and white-light images are used to specify the extent of the associated CME-driven coronal shock. We then assess whether the SEPs observed at the three heliospheric locations were accelerated by this shock or whether transport mechanisms in the corona and/or interplanetary space provide an alternative explanation for the arrival of particles at the poorly connected spacecraft. A possible scenario consistent with the observations indicates that the observation of SEPs at STEREO-B and near Earth resulted from particle injection by the CME shock onto the field lines connecting to these spacecraft, whereas SEPs reached STEREO-A mostly via cross-field diffusive transport processes. The successes, limitations, and uncertainties of the methods used to resolve the connection between the acceleration sites of SEPs and the spacecraft are evaluated.

  8. Celestial X-ray Source Modeling and Catalogues for Spacecraft Navigation and Timing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Microcosm X-ray pulsar-based navigation and timing (XNAV) team will provide the software and modeling infrastructure for NASA to support XNAV operations,...

  9. Nascap-2k Spacecraft-Plasma Environment Interactions Modeling: New Capabilities and Verification

    National Research Council Canada - National Science Library

    Davis, V. A; Mandell, M. J; Cooke, D. L; Ferguson, D. C

    2007-01-01

    .... Here we examine the accuracy and limitations of two new capabilities of Nascap-2k: modeling of plasma plumes such as generated by electric thrusters and enhanced PIC computational capabilities...

  10. Surface Modeling to Support Small-Body Spacecraft Exploration and Proximity Operations

    Science.gov (United States)

    Riedel, Joseph E.; Mastrodemos, Nickolaos; Gaskell, Robert W.

    2011-01-01

    In order to simulate physically plausible surfaces that represent geologically evolved surfaces, demonstrating demanding surface-relative guidance navigation and control (GN&C) actions, such surfaces must be made to mimic the geological processes themselves. A report describes how, using software and algorithms to model body surfaces as a series of digital terrain maps, a series of processes was put in place that evolve the surface from some assumed nominal starting condition. The physical processes modeled in this algorithmic technique include fractal regolith substrate texturing, fractally textured rocks (of empirically derived size and distribution power laws), cratering, and regolith migration under potential energy gradient. Starting with a global model that may be determined observationally or created ad hoc, the surface evolution is begun. First, material of some assumed strength is layered on the global model in a fractally random pattern. Then, rocks are distributed according to power laws measured on the Moon. Cratering then takes place in a temporal fashion, including modeling of ejecta blankets and taking into account the gravity of the object (which determines how much of the ejecta blanket falls back to the surface), and causing the observed phenomena of older craters being progressively buried by the ejecta of earlier impacts. Finally, regolith migration occurs which stratifies finer materials from coarser, as the fine material progressively migrates to regions of lower potential energy.

  11. Modelling the Hydraulic Processes on Constructed Stormwater Wetland

    Directory of Open Access Journals (Sweden)

    Isri Ronald Mangangka

    2017-03-01

    Full Text Available Constructed stormwater wetlands are manmade, shallow, and extensively vegetated water bodies which promote runoff volume and peak flow reduction, and also treat stormwater runoff quality. Researchers have noted that treatment processes of runoff in a constructed wetland are influenced by a range of hydraulic factors, which can vary during a rainfall event, and their influence on treatment can also vary as the event progresses. Variation in hydraulic factors during an event can only be generated using a detailed modelling approach, which was adopted in this research by developing a hydraulic conceptual model. The developed model was calibrated using trial and error procedures by comparing the model outflow with the measured field outflow data. The accuracy of the developed model was analyzed using a well-known statistical analysis method developed based on the regression analysis technique. The analysis results show that the developed model is satisfactory.

  12. Modeling of the ecological balance of construction and demolition facilities

    Directory of Open Access Journals (Sweden)

    Tskhovrebov Eduard Stanislavovich

    2017-09-01

    Full Text Available Anthropogenic impact of construction is diverse in nature and occurs at all stages of construction activities: beginning with the extraction of building materials and ending with the commissioning of completed construction projects, demolition of buildings, installations, and facilities with no life cycles. Stage-by-stage restoration of the natural environment in the territories disturbed by construction along with the rational use of Russia’s natural resources — land, water, forests and subsoil — is a priority in respect of both ecological safety and sustainable development of Russian society and the state. In the current multifaceted problem selected as the focus of the study that deals with the resource-saving and waste management in a building complex, the economic, civil, environmental, industrial, social relations defining the subject of the present study are closely interrelated. The research subject of this paper is represented by the processes of negative impact of construction on the components of the natural environment; the management of construction wastes and demolition of buildings, installations, facilities. This also includes issues of accounting and assessment of the potential economic damage to the environment and human health as a result of construction and demolition in justifying the costs of investment projects in this area. The purpose of the study is to create and justify the methodology for the formation of the organizational and structural as well as the economic model of the ecological balance of construction and demolition facilities. The background materials for this scientific research are guidelines, standards, methodologies, methodological recommendations, project and regulatory documentation in the field of construction, environmental protection and waste management, published data and materials of national and foreign scientific research on this subject. The methods of scientific research are based on the

  13. System dynamic modeling on construction waste management in Shenzhen, China.

    Science.gov (United States)

    Tam, Vivian W Y; Li, Jingru; Cai, Hong

    2014-05-01

    This article examines the complexity of construction waste management in Shenzhen, Mainland China. In-depth analysis of waste generation, transportation, recycling, landfill and illegal dumping of various inherent management phases is explored. A system dynamics modeling using Stella model is developed. Effects of landfill charges and also penalties from illegal dumping are also simulated. The results show that the implementation of comprehensive policy on both landfill charges and illegal dumping can effectively control the illegal dumping behavior, and achieve comprehensive construction waste minimization. This article provides important recommendations for effective policy implementation and explores new perspectives for Shenzhen policy makers.

  14. 150 kW Class Solar Electric Propulsion Spacecraft Power Architecture Model

    Science.gov (United States)

    Csank, Jeffrey T.; Aulisio, Michael V.; Loop, Benjamin

    2017-01-01

    The National Aeronautics and Space Administration (NASA) Solar Electric Propulsion Technology Demonstration Mission in conjunction with PC Krause and Associates has created a Simulink-based power architecture model for a 50 kilo-Watt (kW) solar electric propulsion system. NASA has extended this model to investigate 150 kW solar electric propulsion systems. Increasing the power system capability from 50 kW to 150 kW better aligns with the anticipated power requirements for Mars and other deep space explorations. The high-power solar electric propulsion capability has been identified as a critical part of NASAs future beyond-low-Earth-orbit for human-crewed exploration missions. This paper presents multiple 150 kW architectures, simulation results, and a discussion of their merits.

  15. Radiation Environment Inside Spacecraft

    Science.gov (United States)

    O'Neill, Patrick

    2015-01-01

    Dr. Patrick O'Neill, NASA Johnson Space Center, will present a detailed description of the radiation environment inside spacecraft. The free space (outside) solar and galactic cosmic ray and trapped Van Allen belt proton spectra are significantly modified as these ions propagate through various thicknesses of spacecraft structure and shielding material. In addition to energy loss, secondary ions are created as the ions interact with the structure materials. Nuclear interaction codes (FLUKA, GEANT4, HZTRAN, MCNPX, CEM03, and PHITS) transport free space spectra through different thicknesses of various materials. These "inside" energy spectra are then converted to Linear Energy Transfer (LET) spectra and dose rate - that's what's needed by electronics systems designers. Model predictions are compared to radiation measurements made by instruments such as the Intra-Vehicular Charged Particle Directional Spectrometer (IV-CPDS) used inside the Space Station, Orion, and Space Shuttle.

  16. Incentive Model Based on Cooperative Relationship in Sustainable Construction Projects

    Directory of Open Access Journals (Sweden)

    Guangdong Wu

    2017-07-01

    Full Text Available Considering the cooperative relationship between owners and contractors in sustainable construction projects, as well as the synergistic effects created by cooperative behaviors, a cooperative incentive model was developed using game theory. The model was formulated and analyzed under both non-moral hazard and moral hazard situations. Then, a numerical simulation and example were proposed to verify the conclusions derived from the model. The results showed that the synergistic effect increases the input intensity of one party’s resource transfer into the increase of marginal utility of the other party, thus the owner and contractor are willing to enhance their levels of effort. One party’s optimal benefit allocation coefficient is positively affected by its own output efficiency, and negatively affected by the other party’s output efficiency. The effort level and expected benefits of the owner and contractor can be improved by enhancing the cooperative relationship between the two parties, as well as enhancing the net benefits of a sustainable construction project. The synergistic effect cannot lower the negative effect of moral hazard behaviors during the implementation of sustainable construction projects. Conversely, the higher levels of the cooperative relationship, the wider the gaps amongst the optimal values under both non-moral hazard and moral hazard situations for the levels of effort, expected benefits and net project benefits. Since few studies to date have emphasized the effects of cooperative relationship on sustainable construction projects, this study constructed a game-based incentive model to bridge the gaps. This study contributes significant theoretical and practical insights into the management of cooperation amongst stakeholders, and into the enhancement of the overall benefits of sustainable construction projects.

  17. Understanding Piloted Ignition of Solid Combustibles in Spacecraft Environments through Numerical Modeling

    Science.gov (United States)

    Fereres, S.; Fernandez-Pello, C.; Ruff, G.; Urban, D.

    2012-01-01

    Space exploration vehicles can present internal atmospheres different from sea level standard atmospheric conditions (100 kPa, 21%O2). In NASA's most recent human space exploration crew vehicles the cabin environments were designed to have reduced ambient pressure and increased oxygen concentration (around 55 kPa, 32%O2,). These distinct ambient conditions, in addition to the absence of gravity, may increase the fire risk of combustible materials on board. Enhancing the oxygen concentration will lead to higher flame temperatures. Reducing the ambient pressure will decrease convective heat losses from heated surfaces but also will reduce the amount of pyrolyzate required to reach a flammable mixture near the pilot. This study explores the effect of ambient variables such as reduced pressure, oxygen concentration or microgravity on the physical mechanisms that lead to the piloted ignition of solid combustibles through numerical analysis. Two-dimensional simulations of piloted ignition of thermally irradiated samples of PMMA (polymethyl- methacrylate) were performed with the Fire Dynamics Simulator (FDS5) code. Finite-rate single-step combustion kinetics is used in the gas-phase and a single step Arrhenius type reaction rate describes the solid pyrolysis. Oxidative pyrolysis is not considered and the in-depth formed pyrolyzate is assumed to flow unrestricted through the PMMA. The model correctly describes the thermo-physical mechanisms leading to the piloted ignition of solid fuels. It is shown that as the ambient pressure is reduced or the oxygen concentration enhanced, both the time to ignition and the fuel mass loss rate at ignition are reduced, increasing the fire hazard of the material when externally heated. The calculated ignition times and mass loss rates at ignition are compared to those measured experimentally in a laboratory-scale combustion wind tunnel. It is also shown that with appropriate kinetic parameters the model agrees qualitatively well with the

  18. The role of business models in Finnish construction companies

    Directory of Open Access Journals (Sweden)

    Aki Pekuri

    2013-09-01

    Full Text Available Business models are seen as an essential part of successful businesses as they define the way companies create value for their customers and subsequently make profit from their operations. A good business model has a potential to separate a company from its competitors by creating a competitive advantage. The purpose of this research is to explore how managers understand and deploy the business model concept in construction. For this, eight experienced managers have been interviewed and their answers have been analysed using the theoretical aspects of business models as a reference. In the interviews, managers deployed business model concept very differently than what is accustomed in practice and in academia; they relate these models to different project delivery and contract structures or to companies’ business segments rather than to analysing how their companies provide value for customers in the selected markets. The results of the interviews indicate that the managers in construction do neither understand the concept properly nor exploit any similar value creation analysis in their business. The interviewees had significant problems describing their companies’ business models and value creation logic, pointing out the lack of analysis and understanding of customer values and needs in the project delivery process. This may be one of the overtones of the persistent client dissatisfaction in the construction industry.

  19. The role of business models in Finnish construction companies

    Directory of Open Access Journals (Sweden)

    Aki Pekuri

    2013-09-01

    Full Text Available Business models are seen as an essential part of successful businesses as they define the way companies create value for their customers and subsequently make profit from their operations. A good business model has a potential to separate a company from its competitors by creating a competitive advantage. The purpose of this research is to explore how managers understand and deploy the business model concept in construction. For this, eight experienced managers have been interviewed and their answers have been analysed using the theoretical aspects of business models as a reference. In the interviews, managers deployed business model concept very differently than what is accustomed in practice and in academia; they relate these models to different project delivery and contract structures or to companies’ business segments rather than to analysing how their companies provide value for customers in the selected markets. The results of the interviews indicate that the managers in construction do neither understand the concept properly nor exploit any similar value creation analysis in their business. The interviewees had significant problems describing their companies’ business models and value creation logic, pointing out the lack of analysis and understanding of customer values and needs in the project delivery process. This may be one of the overtones of the persistent client dissatisfaction in the construction industry. 

  20. Peculiarities of constructing the models of mass religious communication

    OpenAIRE

    Petrushkevych Maria Stefanivna

    2017-01-01

    Religious communication is a full-fledged, effective part of the mass information field. It uses new media to fulfil its needs. And it also functions in the field of mass culture and the information society. To describe the features of mass religious communication in the article, the author constructs a graphic model of its functioning.

  1. Models of cultural niche construction with selection and assortative mating.

    Science.gov (United States)

    Creanza, Nicole; Fogarty, Laurel; Feldman, Marcus W

    2012-01-01

    Niche construction is a process through which organisms modify their environment and, as a result, alter the selection pressures on themselves and other species. In cultural niche construction, one or more cultural traits can influence the evolution of other cultural or biological traits by affecting the social environment in which the latter traits may evolve. Cultural niche construction may include either gene-culture or culture-culture interactions. Here we develop a model of this process and suggest some applications of this model. We examine the interactions between cultural transmission, selection, and assorting, paying particular attention to the complexities that arise when selection and assorting are both present, in which case stable polymorphisms of all cultural phenotypes are possible. We compare our model to a recent model for the joint evolution of religion and fertility and discuss other potential applications of cultural niche construction theory, including the evolution and maintenance of large-scale human conflict and the relationship between sex ratio bias and marriage customs. The evolutionary framework we introduce begins to address complexities that arise in the quantitative analysis of multiple interacting cultural traits.

  2. A Constructive Neural-Network Approach to Modeling Psychological Development

    Science.gov (United States)

    Shultz, Thomas R.

    2012-01-01

    This article reviews a particular computational modeling approach to the study of psychological development--that of constructive neural networks. This approach is applied to a variety of developmental domains and issues, including Piagetian tasks, shift learning, language acquisition, number comparison, habituation of visual attention, concept…

  3. Construction of classical and quantum integrable field models ...

    Indian Academy of Sciences (India)

    85, No. 5. — journal of. November 2015 physics pp. 899–913. Construction of classical and quantum integrable field models unravelling hidden possibilities .... It is interesting to note that the infinite set of conserved quantities associated with an inte- ..... that taking c2 as the Hamiltonian would lead to a NLS-type equation.

  4. Models of cultural niche construction with selection and assortative mating.

    Directory of Open Access Journals (Sweden)

    Nicole Creanza

    Full Text Available Niche construction is a process through which organisms modify their environment and, as a result, alter the selection pressures on themselves and other species. In cultural niche construction, one or more cultural traits can influence the evolution of other cultural or biological traits by affecting the social environment in which the latter traits may evolve. Cultural niche construction may include either gene-culture or culture-culture interactions. Here we develop a model of this process and suggest some applications of this model. We examine the interactions between cultural transmission, selection, and assorting, paying particular attention to the complexities that arise when selection and assorting are both present, in which case stable polymorphisms of all cultural phenotypes are possible. We compare our model to a recent model for the joint evolution of religion and fertility and discuss other potential applications of cultural niche construction theory, including the evolution and maintenance of large-scale human conflict and the relationship between sex ratio bias and marriage customs. The evolutionary framework we introduce begins to address complexities that arise in the quantitative analysis of multiple interacting cultural traits.

  5. Peculiarities of constructing the models of mass religious communication

    Directory of Open Access Journals (Sweden)

    Petrushkevych Maria Stefanivna

    2017-07-01

    Full Text Available Religious communication is a full-fledged, effective part of the mass information field. It uses new media to fulfil its needs. And it also functions in the field of mass culture and the information society. To describe the features of mass religious communication in the article, the author constructs a graphic model of its functioning.

  6. Construction of a reliable model pyranometer for irradiance ...

    African Journals Online (AJOL)

    There is a problem of availability of sufficient and functional instruments for measuring solar radiation in Nigeria due to the high importation costs and maintenance. In order to alleviate this problem, the design, construction and testing of a reliable model pyranometer (RMP001) was done in Mubi, Adamawa State of Nigeria.

  7. Homology modelling and bivalent single-chain Fv construction of ...

    Indian Academy of Sciences (India)

    Homology modelling and bivalent single-chain Fv construction of anti-HepG2 single-chain immunoglobulin Fv fragments from a phage display library ... Department of Infectious Diseases, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; Department of ...

  8. Queering Constructs: Proposing a Dynamic Gender and Sexuality Model

    Science.gov (United States)

    Jourian, T. J.

    2015-01-01

    Higher education educators commonly understand social identities, including gender, to be fluid and dynamic. Lev's (2004) model of four components of sexual identity is commonly used to demonstrate the fluidity of sex, gender, and sexuality for individuals, but it does little to address the fixedness of those constructs. Through a multipronged…

  9. Financial and organizational models of NPP construction projects

    International Nuclear Information System (INIS)

    Ivanov, Timur

    2010-01-01

    The recent evolution of financial and organizational models of NPP projects can be truly reputed to open a new page of the world market of NPP construction. The definition of the concrete model is based mostly on specific cooperation backgrounds and current terms and conditions under which the particular NPP project is being evolved. In this article the most commonly known strategies and schemes of financing structuring for export NPP construction projects are scrutinized. Special attention is paid to the analysis of BOO/BOT models which are based on the public-private partnership. Most BOO/BOT projects in the power sector has Power Purchase Agreements (PPA) as an integral part of them. The PPA key principles are studied here as well. The flexibility and adaptability of the public-private partnership models for financing and organization of the NPP projects contributes substantially to the competitiveness of the NPP projects especially under current economic conditions. (orig.)

  10. Narrative Construction, Social Perceptions, and the Situation Model.

    Science.gov (United States)

    Costabile, Kristi A

    2016-05-01

    The present investigation examined how three salient features of narrative thinking (situation model construction, linguistic concreteness, and perspective-taking) influenced the social inference process. Results of four experiments indicated that compared with those given other objectives, perceivers given narrative objectives were: (a) more likely to make situation rather than trait attributions for observed behaviors (Experiment 1), (b) less likely to make implicit trait inferences (Experiment 2), and (c) less likely to rely on behavior valence when making evaluative judgments (Experiment 4). Linguistic analyses indicated that narrative construction consistently entailed the creation of situation models of events and linguistic concreteness, but only situation model creation mediated the relationship between narrative and inferences. Experiment 3 confirmed the mediating role of situation models: Perceivers with narrative objectives made trait inferences only when behaviors were inconsistent with contextual information. The role of these core narrative features on social perceptions is discussed. © 2016 by the Society for Personality and Social Psychology, Inc.

  11. Phenomenological Hints from a Class of String Motivated Model Constructions

    Directory of Open Access Journals (Sweden)

    Hans Peter Nilles

    2015-01-01

    Full Text Available We use string theory constructions towards the generalisation of the supersymmetric standard model of strong and electroweak interactions. Properties of the models depend crucially on the location of fields in extradimensional compact space. This allows us to extract some generic lessons for the phenomenological properties of the low energy effective action. Within this scheme we present a compelling model based on local grand unification and mirage mediation of supersymmetry breakdown. We analyse the properties of the specific model towards its possible tests at the LHC and the complementarity to direct dark matter searches.

  12. CFD modelling of moisture interactions between air and constructions

    DEFF Research Database (Denmark)

    Mortensen, Lone Hedegaard; Woloszyn, Monika; Hohota, Raluca

    2005-01-01

    There is a strong demand for accurate moisture modelling since moisture poses a risk for both the constructions and the indoor climate. Thus, in this investigation there is special focus on moisture modelling. The paper describes a new model based on a CFD tool that is enhanced to include both...... detailed modelling of airflows in rooms and heat and moisture transfer in walls by applying them as fluid walls. In a 3D configuration the impact of different boundary conditions are investigated and the results are discussed. The changes of boundary conditions that are studied are velocity, moisture...

  13. Construction

    Science.gov (United States)

    2002-01-01

    Harbor Deepening Project, Jacksonville, FL Palm Valley Bridge Project, Jacksonville, FL Rotary Club of San Juan, San Juan, PR Tren Urbano Subway...David. What is nanotechnology? What are its implications for construction?, Foresight/CRISP Workshop on Nanotechnology, Royal Society of Arts

  14. Autonomous mathematical models: constructing theories of metabolic control.

    Science.gov (United States)

    Donaghy, Josephine

    2013-01-01

    This paper considers how the relationship between mathematical models and theories in biology may change over time, on the basis of a historical analysis of the development of a mathematical model of metabolism, metabolic control analysis, and its relationship to theories of metabolic control. I argue that one can distinguish two ways of characterising the relationship between models and theories, depending on the stage of model and/or theory development that one is considering: partial independence and autonomy. Partial independence describes a model's relationship with existing theory, thus referring to relationships that have already been established between model and theory during model construction. By contrast, autonomy is a feature of relationships which may become established between model and theory in the future, and is expressed by a model's open ended role in constructing emerging theory. These characteristics have often been conflated by existing philosophical accounts, partly because they can only be identified and analysed when adopting a historical perspective on scientific research. Adopting a clear distinction between partial independence and autonomy improves philosophical insight into the changing relationship between models and theories.

  15. Spacecraft Electrostatic Radiation Shielding

    Science.gov (United States)

    2008-01-01

    This project analyzed the feasibility of placing an electrostatic field around a spacecraft to provide a shield against radiation. The concept was originally proposed in the 1960s and tested on a spacecraft by the Soviet Union in the 1970s. Such tests and analyses showed that this concept is not only feasible but operational. The problem though is that most of this work was aimed at protection from 10- to 100-MeV radiation. We now appreciate that the real problem is 1- to 2-GeV radiation. So, the question is one of scaling, in both energy and size. Can electrostatic shielding be made to work at these high energy levels and can it protect an entire vehicle? After significant analysis and consideration, an electrostatic shield configuration was proposed. The selected architecture was a torus, charged to a high negative voltage, surrounding the vehicle, and a set of positively charged spheres. Van de Graaff generators were proposed as the mechanism to move charge from the vehicle to the torus to generate the fields necessary to protect the spacecraft. This design minimized complexity, residual charge, and structural forces and resolved several concerns raised during the internal critical review. But, it still is not clear if such a system is costeffective or feasible, even though several studies have indicated usefulness for radiation protection at energies lower than that of the galactic cosmic rays. Constructing such a system will require power supplies that can generate voltages 10 times that of the state of the art. Of more concern is the difficulty of maintaining the proper net charge on the entire structure and ensuring that its interaction with solar wind will not cause rapid discharge. Yet, if these concerns can be resolved, such a scheme may provide significant radiation shielding to future vehicles, without the excessive weight or complexity of other active shielding techniques.

  16. Modelling in Primary School: Constructing Conceptual Models and Making Sense of Fractions

    Science.gov (United States)

    Shahbari, Juhaina Awawdeh; Peled, Irit

    2017-01-01

    This article describes sixth-grade students' engagement in two model-eliciting activities offering students the opportunity to construct mathematical models. The findings show that students utilized their knowledge of fractions including conceptual and procedural knowledge in constructing mathematical models for the given situations. Some students…

  17. Causality in Psychiatry: A Hybrid Symptom Network Construct Model

    Science.gov (United States)

    Young, Gerald

    2015-01-01

    Causality or etiology in psychiatry is marked by standard biomedical, reductionistic models (symptoms reflect the construct involved) that inform approaches to nosology, or classification, such as in the DSM-5 [Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; (1)]. However, network approaches to symptom interaction [i.e., symptoms are formative of the construct; e.g., (2), for posttraumatic stress disorder (PTSD)] are being developed that speak to bottom-up processes in mental disorder, in contrast to the typical top-down psychological construct approach. The present article presents a hybrid top-down, bottom-up model of the relationship between symptoms and mental disorder, viewing symptom expression and their causal complex as a reciprocally dynamic system with multiple levels, from lower-order symptoms in interaction to higher-order constructs affecting them. The hybrid model hinges on good understanding of systems theory in which it is embedded, so that the article reviews in depth non-linear dynamical systems theory (NLDST). The article applies the concept of emergent circular causality (3) to symptom development, as well. Conclusions consider that symptoms vary over several dimensions, including: subjectivity; objectivity; conscious motivation effort; and unconscious influences, and the degree to which individual (e.g., meaning) and universal (e.g., causal) processes are involved. The opposition between science and skepticism is a complex one that the article addresses in final comments. PMID:26635639

  18. Causality in Psychiatry: A Hybrid Symptom Network Construct Model

    Directory of Open Access Journals (Sweden)

    Gerald eYoung

    2015-11-01

    Full Text Available Causality or etiology in psychiatry is marked by standard biomedical, reductionistic models (symptoms reflect the construct involved that inform approaches to nosology, or classification, such as in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition; American Psychiatric Association, 2013. However, network approaches to symptom interaction (i.e., symptoms are formative of the construct; e.g., McNally, Robinaugh, Wu, Wang, Deserno, & Borsboom, 2014, for PTSD (posttraumatic stress disorder are being developed that speak to bottom-up processes in mental disorder, in contrast to the typical top-down psychological construct approach. The present article presents a hybrid top-down, bottom-up model of the relationship between symptoms and mental disorder, viewing symptom expression and their causal complex as a reciprocally dynamic system with multiple levels, from lower-order symptoms in interaction to higher-order constructs affecting them. The hybrid model hinges on good understanding of systems theory in which it is embedded, so that the article reviews in depth nonlinear dynamical systems theory (NLDST. The article applies the concept of emergent circular causality (Young, 2011 to symptom development, as well. Conclusions consider that symptoms vary over several dimensions, including: subjectivity; objectivity; conscious motivation effort; and unconscious influences, and the degree to which individual (e.g., meaning and universal (e.g., causal processes are involved. The opposition between science and skepticism is a complex one that the article addresses in final comments.

  19. Constructive Alignment for Teaching Model-Based Design for Concurrency

    DEFF Research Database (Denmark)

    Brabrand, Claus

    2007-01-01

    "How can we make sure our students learn what we want them to?" is the number one question in teaching. This paper is intended to provide the reader with: i) a general answer to this question based on the theory of constructive alignment by John Biggs; ii) relevant insights for bringing this answ...... from theory to practice; and iii) specific insights and experiences from using constructive alignment in teaching model-based design for concurrency (as a case study in implementing alignment)......."How can we make sure our students learn what we want them to?" is the number one question in teaching. This paper is intended to provide the reader with: i) a general answer to this question based on the theory of constructive alignment by John Biggs; ii) relevant insights for bringing this answer...

  20. A Spanish model for quantification and management of construction waste.

    Science.gov (United States)

    Solís-Guzmán, Jaime; Marrero, Madelyn; Montes-Delgado, Maria Victoria; Ramírez-de-Arellano, Antonio

    2009-09-01

    Currently, construction and demolition waste (C&D waste) is a worldwide issue that concerns not only governments but also the building actors involved in construction activity. In Spain, a new national decree has been regulating the production and management of C&D waste since February 2008. The present work describes the waste management model that has inspired this decree: the Alcores model implemented with good results in Los Alcores Community (Seville, Spain). A detailed model is also provided to estimate the volume of waste that is expected to be generated on the building site. The quantification of C&D waste volume, from the project stage, is essential for the building actors to properly plan and control its disposal. This quantification model has been developed by studying 100 dwelling projects, especially their bill of quantities, and defining three coefficients to estimate the demolished volume (CT), the wreckage volume (CR) and the packaging volume (CE). Finally, two case studies are included to illustrate the usefulness of the model to estimate C&D waste volume in both new construction and demolition projects.

  1. A Spanish model for quantification and management of construction waste

    International Nuclear Information System (INIS)

    Solis-Guzman, Jaime; Marrero, Madelyn; Montes-Delgado, Maria Victoria; Ramirez-de-Arellano, Antonio

    2009-01-01

    Currently, construction and demolition waste (C and D waste) is a worldwide issue that concerns not only governments but also the building actors involved in construction activity. In Spain, a new national decree has been regulating the production and management of C and D waste since February 2008. The present work describes the waste management model that has inspired this decree: the Alcores model implemented with good results in Los Alcores Community (Seville, Spain). A detailed model is also provided to estimate the volume of waste that is expected to be generated on the building site. The quantification of C and D waste volume, from the project stage, is essential for the building actors to properly plan and control its disposal. This quantification model has been developed by studying 100 dwelling projects, especially their bill of quantities, and defining three coefficients to estimate the demolished volume (CT), the wreckage volume (CR) and the packaging volume (CE). Finally, two case studies are included to illustrate the usefulness of the model to estimate C and D waste volume in both new construction and demolition projects.

  2. Intelligent spacecraft module

    Science.gov (United States)

    Oungrinis, Konstantinos-Alketas; Liapi, Marianthi; Kelesidi, Anna; Gargalis, Leonidas; Telo, Marinela; Ntzoufras, Sotiris; Paschidi, Mariana

    2014-12-01

    The paper presents the development of an on-going research project that focuses on a human-centered design approach to habitable spacecraft modules. It focuses on the technical requirements and proposes approaches on how to achieve a spatial arrangement of the interior that addresses sufficiently the functional, physiological and psychosocial needs of the people living and working in such confined spaces that entail long-term environmental threats to human health and performance. Since the research perspective examines the issue from a qualitative point of view, it is based on establishing specific relationships between the built environment and its users, targeting people's bodily and psychological comfort as a measure toward a successful mission. This research has two basic branches, one examining the context of the system's operation and behavior and the other in the direction of identifying, experimenting and formulating the environment that successfully performs according to the desired context. The latter aspect is researched upon the construction of a scaled-model on which we run series of tests to identify the materiality, the geometry and the electronic infrastructure required. Guided by the principles of sensponsive architecture, the ISM research project explores the application of the necessary spatial arrangement and behavior for a user-centered, functional interior where the appropriate intelligent systems are based upon the existing mechanical and chemical support ones featured on space today, and especially on the ISS. The problem is set according to the characteristics presented at the Mars500 project, regarding the living quarters of six crew-members, along with their hygiene, leisure and eating areas. Transformable design techniques introduce spatial economy, adjustable zoning and increased efficiency within the interior, securing at the same time precise spatial orientation and character at any given time. The sensponsive configuration is

  3. Modeling system for the rapid construction in Syria

    Directory of Open Access Journals (Sweden)

    Ahmed, Sonia

    2016-06-01

    Full Text Available Prefabrication is a manufacturing process conducted at a specialized facility, in which various materials are joined to form a component part of the final installation. Prefabrication techniques have been progressively adopted in the construction industry in various countries. The demand was at its peak in the early 1970s in Eastern and Western Europe for the construction of new towns. Worldwide, the highest precast levels in 1996 were located in Denmark (43%, the Netherlands (40%, Sweden and Germany (31%. In Asia, the precast levels in Japan and Singapore were about 15% and 8%, respectively, recently, the use of prefabrication is further encouraged to increase productivity and build ability. In Syria too, the first residential project in Damascus: the establishment of 2400 housing units in the year (77-80. Except that the rate of construction pre-cast in Syria is still not exceed 2% of Building of reinforced concrete. In order to participate in the reconstruction of Syria, after the destruction and devastation caused by the war over four years, this search evaluates successful international experiences in rapid construction technique, and modeled system that could serve the current Syrian reality. Introduction of this technology as a new method in the world of construction in Syria requires a good base, relying on the availability of the necessary raw materials and nearness of work site, as well as the need to replace old technology into modern technology, and analyzing the economic, social, environmental criteria, to make the decision about the best solution. Cost and time will form the most important indicators that will be analyzed and calculated, before the final model mode, in order to be able to use this system later in Syrian construction companies.

  4. A probabilistic graphical model based stochastic input model construction

    International Nuclear Information System (INIS)

    Wan, Jiang; Zabaras, Nicholas

    2014-01-01

    Model reduction techniques have been widely used in modeling of high-dimensional stochastic input in uncertainty quantification tasks. However, the probabilistic modeling of random variables projected into reduced-order spaces presents a number of computational challenges. Due to the curse of dimensionality, the underlying dependence relationships between these random variables are difficult to capture. In this work, a probabilistic graphical model based approach is employed to learn the dependence by running a number of conditional independence tests using observation data. Thus a probabilistic model of the joint PDF is obtained and the PDF is factorized into a set of conditional distributions based on the dependence structure of the variables. The estimation of the joint PDF from data is then transformed to estimating conditional distributions under reduced dimensions. To improve the computational efficiency, a polynomial chaos expansion is further applied to represent the random field in terms of a set of standard random variables. This technique is combined with both linear and nonlinear model reduction methods. Numerical examples are presented to demonstrate the accuracy and efficiency of the probabilistic graphical model based stochastic input models. - Highlights: • Data-driven stochastic input models without the assumption of independence of the reduced random variables. • The problem is transformed to a Bayesian network structure learning problem. • Examples are given in flows in random media

  5. Modeling, Specification and Construction of PLC-programs

    Directory of Open Access Journals (Sweden)

    E. V. Kuzmin

    2013-01-01

    Full Text Available A new approach to construction of reliable discrete PLC-programs with timers — programming based on specification and verification — is proposed. Timers are modelled in a discrete way. For the specification of a program behavior we use the linear-time temporal logic LTL. Programming is carried out in the ST-language according to a LTLspecification. A new approach to programming of PLC is shown by an example. The proposed programming approach provides an ability of a correctness analysis of PLC-programs using the model checking method. The programming requires fulfillment of the following two conditions: 1 a value of each variable should be changed not more than once per one full PLC-program implementation (per one full working cycle of PLC; 2 a value of each variable should only be changed in one place of a PLC-program. Under the proposed approach the change of the value of each program variable is described by a pair of LTL-formulas. The first LTL-formula describes situations that increase the value of the corresponding variable, the second LTL-formula specifies conditions leading to a decrease of the variable value. The LTL-formulas (used for specification of the corresponding variable behavior are constructive in the sense that they construct the PLC-program, which satisfies temporal properties expressed by these formulas. Thus, the programming of PLC is reduced to the construction of LTL-specification of the behavior of each program variable.

  6. A Systematic Approach to Modelling Change Processes in Construction Projects

    Directory of Open Access Journals (Sweden)

    Ibrahim Motawa

    2012-11-01

    Full Text Available Modelling change processes within construction projects isessential to implement changes efficiently. Incomplete informationon the project variables at the early stages of projects leads toinadequate knowledge of future states and imprecision arisingfrom ambiguity in project parameters. This lack of knowledge isconsidered among the main source of changes in construction.Change identification and evaluation, in addition to predictingits impacts on project parameters, can help in minimising thedisruptive effects of changes. This paper presents a systematicapproach to modelling change process within construction projectsthat helps improve change identification and evaluation. Theapproach represents the key decisions required to implementchanges. The requirements of an effective change processare presented first. The variables defined for efficient changeassessment and diagnosis are then presented. Assessmentof construction changes requires an analysis for the projectcharacteristics that lead to change and also analysis of therelationship between the change causes and effects. The paperconcludes that, at the early stages of a project, projects with a highlikelihood of change occurrence should have a control mechanismover the project characteristics that have high influence on theproject. It also concludes, for the relationship between changecauses and effects, the multiple causes of change should bemodelled in a way to enable evaluating the change effects moreaccurately. The proposed approach is the framework for tacklingsuch conclusions and can be used for evaluating change casesdepending on the available information at the early stages ofconstruction projects.

  7. A Model Suggestion to Predict Leverage Ratio for Construction Projects

    Directory of Open Access Journals (Sweden)

    Özlem Tüz

    2013-12-01

    Full Text Available Due to the nature, construction is an industry with high uncertainty and risk. Construction industry carries high leverage ratios. Firms with low equities work in big projects through progress payment system, but in this case, even a small negative in the planned cash flows constitute a major risk for the company.The use of leverage, with a small investment to achieve profit targets large-scale, high-profit, but also brings a high risk with it. Investors may lose all or the portion of the money. In this study, monitoring and measuring of the leverage ratio because of the displacement in cash inflows of construction projects which uses high leverage and low cash to do business in the sector is targeted. Cash need because of drifting the cash inflows may be seen due to the model. Work should be done in the early stages of the project with little capital but in the later stages, rapidly growing capital need arises.The values obtained from the model may be used to supply the capital held in the right time by anticipating the risks because of the delay in cashflow of construction projects which uses high leverage ratio.

  8. Using Health Belief Model Constructs to Examine Differences

    Science.gov (United States)

    Karimy, Mahmood; Azarpira, Hossein; Araban, Marzieh

    2017-05-01

    Despite documented successful Pap tests in routine care of women, screening levels are unfortunately often lower than recommended. This study aimed to assess differences in adherence to Pap test guidelines among a sample of Iranian women using the Health Belief Model (HBM). In this descriptive and analytical study, information was collected from a total of 305 women, (age range of 15-49) from Zarandieh health centers in Iran using a random multistage sampling method. The questionnaire covered demographic characteristics; health belief model constructs were gathered by a self-report method. The results were analyzed using the independent samples t test and logistic regression in SPSS-20. A total 32% of the subjects had a history of a Pap test and the score mean of the whole constructs model (knowledge, susceptibility, severity, benefits, barriers and self-efficacy) in these individuals was higher than those without a positive history. Among the predictive variables of HBM constructs, the highest weights were observed for perceived benefits ß)=0.36), perceived susceptibility =ß) 0.35) and self-efficacy ß)=0.29). Based on our finding of positive relationships for health belief model structures with performance of a pap smear test, designing educational interventions for changing the knowledge levels and beliefs of women is recommended. Creative Commons Attribution License

  9. Computer simulation of spacecraft/environment interaction

    CERN Document Server

    Krupnikov, K K; Mileev, V N; Novikov, L S; Sinolits, V V

    1999-01-01

    This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language.

  10. Computer simulation of spacecraft/environment interaction

    International Nuclear Information System (INIS)

    Krupnikov, K.K.; Makletsov, A.A.; Mileev, V.N.; Novikov, L.S.; Sinolits, V.V.

    1999-01-01

    This report presents some examples of a computer simulation of spacecraft interaction with space environment. We analysed a set data on electron and ion fluxes measured in 1991-1994 on geostationary satellite GORIZONT-35. The influence of spacecraft eclipse and device eclipse by solar-cell panel on spacecraft charging was investigated. A simple method was developed for an estimation of spacecraft potentials in LEO. Effects of various particle flux impact and spacecraft orientation are discussed. A computer engineering model for a calculation of space radiation is presented. This model is used as a client/server model with WWW interface, including spacecraft model description and results representation based on the virtual reality markup language

  11. Constructing topic models of Internet of Things for information processing.

    Science.gov (United States)

    Xin, Jie; Cui, Zhiming; Zhang, Shukui; He, Tianxu; Li, Chunhua; Huang, Haojing

    2014-01-01

    Internet of Things (IoT) is regarded as a remarkable development of the modern information technology. There is abundant digital products data on the IoT, linking with multiple types of objects/entities. Those associated entities carry rich information and usually in the form of query records. Therefore, constructing high quality topic hierarchies that can capture the term distribution of each product record enables us to better understand users' search intent and benefits tasks such as taxonomy construction, recommendation systems, and other communications solutions for the future IoT. In this paper, we propose a novel record entity topic model (RETM) for IoT environment that is associated with a set of entities and records and a Gibbs sampling-based algorithm is proposed to learn the model. We conduct extensive experiments on real-world datasets and compare our approach with existing methods to demonstrate the advantage of our approach.

  12. Constructing Topic Models of Internet of Things for Information Processing

    Directory of Open Access Journals (Sweden)

    Jie Xin

    2014-01-01

    Full Text Available Internet of Things (IoT is regarded as a remarkable development of the modern information technology. There is abundant digital products data on the IoT, linking with multiple types of objects/entities. Those associated entities carry rich information and usually in the form of query records. Therefore, constructing high quality topic hierarchies that can capture the term distribution of each product record enables us to better understand users’ search intent and benefits tasks such as taxonomy construction, recommendation systems, and other communications solutions for the future IoT. In this paper, we propose a novel record entity topic model (RETM for IoT environment that is associated with a set of entities and records and a Gibbs sampling-based algorithm is proposed to learn the model. We conduct extensive experiments on real-world datasets and compare our approach with existing methods to demonstrate the advantage of our approach.

  13. Artificial Intelligence for Constructing Accurate, Low-Cost Models and

    Science.gov (United States)

    2005-01-01

    models are a virtual representation of a robotic car constructed from the Lego ™ MindStorms ® Robotics Invention System. The baseline vehicle is shown in...sampled using a Lego ® RCX computer coupled with a high accuracy voltage measuring interface from Lego Dacta®. Data were captured using LabVIEW® Software... Lego ® RCX computer coupled with a high accuracy voltage measuring interface from Lego Dacta®. Data were captured using LabVIEW® Software from

  14. SSC superconducting dipole magnet cryostat model style B construction experience

    International Nuclear Information System (INIS)

    Engler, N.H.; Bossert, R.C.; Carson, J.A.; Gonczy, J.D.; Larson, E.T.; Nicol, T.H.; Niemann, R.C.; Sorensen, D.; Zink, R.

    1989-03-01

    A program to upgrade the full scale SSC dipole magnet cryostat model function and assembly methods has resulted in a series of dipole magnets designated as style B construction. New design features and assembly techniques have produced a magnet and cryostat assembly that is the basis for Phase 1 of the SSC dipole magnet industrialization program. Details of the assembly program, assembly experience, and comparison to previous assembly experiences are presented. Improvements in magnet assembly techniques are also evaluated. 6 refs., 5 figs

  15. Constructing unified models based on E8 in ten dimensions

    International Nuclear Information System (INIS)

    Kapetanakis, D.

    1992-01-01

    We examine the virtues and difficulties of the attempts to construct realistic four-dimensional models from a gauge theory based on E 8 and defined in ten dimensions. The four-dimensional theories are obtained using the coset space dimensional reduction scheme. Some of our points and in particular the proposed mechanism for supersymmetry breaking might be useful in other dimensional reduction schemes. (orig.)

  16. MEGACELL: A nanocrystal model construction software for HRTEM multislice simulation

    International Nuclear Information System (INIS)

    Stroppa, Daniel G.; Righetto, Ricardo D.; Montoro, Luciano A.; Ramirez, Antonio J.

    2011-01-01

    Image simulation has an invaluable importance for the accurate analysis of High Resolution Transmission Electron Microscope (HRTEM) results, especially due to its non-linear image formation mechanism. Because the as-obtained images cannot be interpreted in a straightforward fashion, the retrieval of both qualitative and quantitative information from HRTEM micrographs requires an iterative process including the simulation of a nanocrystal model and its comparison with experimental images. However most of the available image simulation software requires atom-by-atom coordinates as input for the calculations, which can be prohibitive for large finite crystals and/or low-symmetry systems and zone axis orientations. This paper presents an open source citation-ware tool named MEGACELL, which was developed to assist on the construction of nanocrystals models. It allows the user to build nanocrystals with virtually any convex polyhedral geometry and to retrieve its atomic positions either as a plain text file or as an output compatible with EMS (Electron Microscopy Software) input protocol. In addition to the description of this tool features, some construction examples and its application for scientific studies are presented. These studies show MEGACELL as a handy tool, which allows an easier construction of complex nanocrystal models and improves the quantitative information extraction from HRTEM images. -- Highlights: → A software to support the HRTEM image simulation of nanocrystals in actual size. → MEGACELL allows the construction of complex nanocrystals models for multislice image simulation. → Some examples of improved nanocrystalline system characterization are presented, including the analysis of 3D morphology and growth behavior.

  17. Model construction of nursing service satisfaction in hospitalized tumor patients.

    Science.gov (United States)

    Chen, Yongyi; Liu, Jingshi; Xiao, Shuiyuan; Liu, Xiangyu; Tang, Xinhui; Zhou, Yujuan

    2014-01-01

    This study aims to construct a satisfaction model on nursing service in hospitalized tumor patients. Using questionnaires, data about hospitalized tumor patients' expectation, quality perception and satisfaction of hospital nursing service were obtained. A satisfaction model of nursing service in hospitalized tumor patients was established through empirical study and by structural equation method. This model was suitable for tumor specialized hospital, with reliability and validity. Patient satisfaction was significantly affected by quality perception and patient expectation. Patient satisfaction and patient loyalty was also affected by disease pressure. Hospital brand was positively correlated with patient satisfaction and patient loyalty, negatively correlated with patient complaint. Patient satisfaction was positively correlated with patient loyalty, patient complaints, and quality perception, and negatively correlated with disease pressure and patient expectation. The satisfaction model on nursing service in hospitalized tumor patients fits well. By this model, the quality of hospital nursing care may be improved.

  18. Constructing Scientific Arguments Using Evidence from Dynamic Computational Climate Models

    Science.gov (United States)

    Pallant, Amy; Lee, Hee-Sun

    2015-04-01

    Modeling and argumentation are two important scientific practices students need to develop throughout school years. In this paper, we investigated how middle and high school students ( N = 512) construct a scientific argument based on evidence from computational models with which they simulated climate change. We designed scientific argumentation tasks with three increasingly complex dynamic climate models. Each scientific argumentation task consisted of four parts: multiple-choice claim, openended explanation, five-point Likert scale uncertainty rating, and open-ended uncertainty rationale. We coded 1,294 scientific arguments in terms of a claim's consistency with current scientific consensus, whether explanations were model based or knowledge based and categorized the sources of uncertainty (personal vs. scientific). We used chi-square and ANOVA tests to identify significant patterns. Results indicate that (1) a majority of students incorporated models as evidence to support their claims, (2) most students used model output results shown on graphs to confirm their claim rather than to explain simulated molecular processes, (3) students' dependence on model results and their uncertainty rating diminished as the dynamic climate models became more and more complex, (4) some students' misconceptions interfered with observing and interpreting model results or simulated processes, and (5) students' uncertainty sources reflected more frequently on their assessment of personal knowledge or abilities related to the tasks than on their critical examination of scientific evidence resulting from models. These findings have implications for teaching and research related to the integration of scientific argumentation and modeling practices to address complex Earth systems.

  19. Signalling network construction for modelling plant defence response.

    Directory of Open Access Journals (Sweden)

    Dragana Miljkovic

    Full Text Available Plant defence signalling response against various pathogens, including viruses, is a complex phenomenon. In resistant interaction a plant cell perceives the pathogen signal, transduces it within the cell and performs a reprogramming of the cell metabolism leading to the pathogen replication arrest. This work focuses on signalling pathways crucial for the plant defence response, i.e., the salicylic acid, jasmonic acid and ethylene signal transduction pathways, in the Arabidopsis thaliana model plant. The initial signalling network topology was constructed manually by defining the representation formalism, encoding the information from public databases and literature, and composing a pathway diagram. The manually constructed network structure consists of 175 components and 387 reactions. In order to complement the network topology with possibly missing relations, a new approach to automated information extraction from biological literature was developed. This approach, named Bio3graph, allows for automated extraction of biological relations from the literature, resulting in a set of (component1, reaction, component2 triplets and composing a graph structure which can be visualised, compared to the manually constructed topology and examined by the experts. Using a plant defence response vocabulary of components and reaction types, Bio3graph was applied to a set of 9,586 relevant full text articles, resulting in 137 newly detected reactions between the components. Finally, the manually constructed topology and the new reactions were merged to form a network structure consisting of 175 components and 524 reactions. The resulting pathway diagram of plant defence signalling represents a valuable source for further computational modelling and interpretation of omics data. The developed Bio3graph approach, implemented as an executable language processing and graph visualisation workflow, is publically available at http://ropot.ijs.si/bio3graph/and can be

  20. PopPlanner: Visually constructing demographic models for simulation

    Directory of Open Access Journals (Sweden)

    Gregory Bruce Ewing

    2015-04-01

    Full Text Available Currently there are a number of coalescent simulation programs that support a wide range of features, such as arbitrary demographic models, migration, and sub structure. Defining the model is done typically with either text files or command line switches. Although this has proven to be a powerful method of defining models of high complexity, it is often error prone and difficult to read without familiarity both with command lines and the program in question. A intuitive GUI based population structure program that can both read and write applicable command lines would dramatically simplify the construction, modification, and error checking of such models by a wider user base.Results: PopPlanner is a tool to both construct and inspect complicated demographic models visually with a GUI where the user’s primary interaction is through mouse gestures. Because of their popularity, we focus on ms and by extension msms, command line coalescent simulation programs. Our program can be used to find errors with existing command lines, or to build original command lines. Furthermore the graphical output supports a number of editing and output features including export of publication quality figures.

  1. Construction of UML class diagram with Model-Driven Development

    Directory of Open Access Journals (Sweden)

    Tomasz Górski

    2016-03-01

    Full Text Available Model transformations play a key role in software development projects based on Model--Driven Development (MDD principles. Transformations allow for automation of repetitive and well-defined steps, thus shortening design time and reducing a number of errors. In the object-oriented approach, the key elements are use cases. They are described, modelled and later designed until executable application code is obtained. The aim of the paper is to present transformation of a model-to-model type, Communication-2-Class, which automates construction of Unified Modelling Language (UML class diagram in the context of the analysis/design model. An UML class diagram is created based on UML communication diagram within use case realization. As a result, a class diagram shows all of the classes involved in the use case realization and the relationships among them. The plug-in which implements Communication-2-Class transformation was implemented in the IBM Rational Software Architect. The article presents the tests results of developed plug-in, which realizes Communication-2-Class transformation, showing capabilities of shortening use case realization’s design time.[b]Keywords[/b]: Model-Driven Development, transformations, Unified Modelling Language, analysis/design model, UML class diagram, UML communication diagram

  2. Modeling of Construction Cost of Villas in Oman

    Directory of Open Access Journals (Sweden)

    MA Al-Mohsin

    2014-06-01

    Full Text Available In this research, a model for estimating construction cost of villas is presented. The model takes into account four major factors affecting villa's cost, namely: built up area, number of toilets, number of bedrooms and the number of stories. A field survey was conducted to collect information required for such model using data collection form designed by the researchers. Information about 150 villas was collected from six well experienced consultants in the field of villa design and supervision in Oman. Collected data was analyzed to develop suggested model which consists of two main levels of estimate. The first level is at the conceptual design stage where the client presents his/her need of space and basic information about the available plot for construction. The second level of cost estimation is carried out after the preliminary design stage where the client has to decide on the finishes and type of structure. At the second level of estimation, the client should be able to decide whether to precede for construction or not, according to his/her budget. The model is general and can be used anywhere and was validated for accepted degree of confidence using the actual cost of the 112 executed villa projects in Oman. The villas included in this study were owned by clients from both high and low income brackets and had different types of finishing material. The developed equations showed good correlation between the selected variables and the actual cost with R2  = 0.79 in the case of conceptual estimate and R2  = 0.601 for preliminary estimate.

  3. Spacecraft Charging Technology, 1978

    Science.gov (United States)

    1979-01-01

    The interaction of the aerospace environment with spacecraft surfaces and onboard, high voltage spacecraft systems operating over a wide range of altitudes from low Earth orbit to geosynchronous orbit is considered. Emphasis is placed on control of spacecraft electric potential. Electron and ion beams, plasma neutralizers material selection, and magnetic shielding are among the topics discussed.

  4. Computer-Aided Construction of Chemical Kinetic Models

    Energy Technology Data Exchange (ETDEWEB)

    Green, William H. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2014-12-31

    The combustion chemistry of even simple fuels can be extremely complex, involving hundreds or thousands of kinetically significant species. The most reasonable way to deal with this complexity is to use a computer not only to numerically solve the kinetic model, but also to construct the kinetic model in the first place. Because these large models contain so many numerical parameters (e.g. rate coefficients, thermochemistry) one never has sufficient data to uniquely determine them all experimentally. Instead one must work in “predictive” mode, using theoretical rather than experimental values for many of the numbers in the model, and as appropriate refining the most sensitive numbers through experiments. Predictive chemical kinetics is exactly what is needed for computer-aided design of combustion systems based on proposed alternative fuels, particularly for early assessment of the value and viability of proposed new fuels before those fuels are commercially available. This project was aimed at making accurate predictive chemical kinetics practical; this is a challenging goal which requires a range of science advances. The project spanned a wide range from quantum chemical calculations on individual molecules and elementary-step reactions, through the development of improved rate/thermo calculation procedures, the creation of algorithms and software for constructing and solving kinetic simulations, the invention of methods for model-reduction while maintaining error control, and finally comparisons with experiment. Many of the parameters in the models were derived from quantum chemistry calculations, and the models were compared with experimental data measured in our lab or in collaboration with others.

  5. Multi-model-based Access Control in Construction Projects

    Directory of Open Access Journals (Sweden)

    Frank Hilbert

    2012-04-01

    Full Text Available During the execution of large scale construction projects performed by Virtual Organizations (VO, relatively complex technical models have to be exchanged between the VO members. For linking the trade and transfer of these models, a so-called multi-model container format was developed. Considering the different skills and tasks of the involved partners, it is not necessary for them to know all the models in every technical detailing. Furthermore, the model size can lead to a delay in communication. In this paper an approach is presented for defining model cut-outs according to the current project context. Dynamic dependencies to the project context as well as static dependencies on the organizational structure are mapped in a context-sensitive rule. As a result, an approach for dynamic filtering of multi-models is obtained which ensures, together with a filtering service, that the involved VO members get a simplified view of complex multi-models as well as sufficient permissions depending on their tasks.

  6. Modeling Escherichia coli removal in constructed wetlands under pulse loading.

    Science.gov (United States)

    Hamaamin, Yaseen A; Adhikari, Umesh; Nejadhashemi, A Pouyan; Harrigan, Timothy; Reinhold, Dawn M

    2014-03-01

    Manure-borne pathogens are a threat to water quality and have resulted in disease outbreaks globally. Land application of livestock manure to croplands may result in pathogen transport through surface runoff and tile drains, eventually entering water bodies such as rivers and wetlands. The goal of this study was to develop a robust model for estimating the pathogen removal in surface flow wetlands under pulse loading conditions. A new modeling approach was used to describe Escherichia coli removal in pulse-loaded constructed wetlands using adaptive neuro-fuzzy inference systems (ANFIS). Several ANFIS models were developed and validated using experimental data under pulse loading over two seasons (winter and summer). In addition to ANFIS, a mechanistic fecal coliform removal model was validated using the same sets of experimental data. The results showed that the ANFIS model significantly improved the ability to describe the dynamics of E. coli removal under pulse loading. The mechanistic model performed poorly as demonstrated by lower coefficient of determination and higher root mean squared error compared to the ANFIS models. The E. coli concentrations corresponding to the inflection points on the tracer study were keys to improving the predictability of the E. coli removal model. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Radiometric Performance of the Clouds and The Earth's Radiant Energy System (CERES) Proto-Flight Model on the Tropical Rainfall Measuring Mission (TRMM) Spacecraft for 1998

    Science.gov (United States)

    Priestley, Kory J.; Lee, Robert B., III; Green, Richard N.; Thomas, Susan; Wilson, Robert S.

    1999-01-01

    On November 27, 1997 the CERES Proto-Flight Model (PFM) instrument package was launched on the NASA Tropical Rainfall Measuring Mission (TRMM) spacecraft National Space Development Agency) NASA /Japan launch vehicle placed the TRMM spacecraft into a low-inclination 35-deg, 350-km altitude orbit. Analysis of the first thirteen months of on-orbit internal calibration and calibration validation studies indicate that the ground-based radiometric calibrations, which were tied to ITS'90 have been successfully carried into orbit to within 0.12, 0.08, and 0.29 percent for the Total, Window and Shortwave channels respectively. Additionally, these analyses have indicated that on-orbit radiometric stability has remained at levels of better than 0.13. 0.2 and 0.2-percent for the Total Window and Shortwave channels. In TOA these levels correspond to magnitudes of less than 0.3, 0.2 and 0.15 v /sq m.

  8. Formulation, construction and analysis of kinetic models of metabolism: A review of modelling frameworks

    DEFF Research Database (Denmark)

    Saa, Pedro A.; Nielsen, Lars K.

    2017-01-01

    Kinetic models are critical to predict the dynamic behaviour of metabolic networks. Mechanistic kinetic models for large networks remain uncommon due to the difficulty of fitting their parameters. Recent modelling frameworks promise new ways to overcome this obstacle while retaining predictive...... capabilities. In this review, we present an overview of the relevant mathematical frameworks for kinetic formulation, construction and analysis. Starting with kinetic formalisms, we next review statistical methods for parameter inference, as well as recent computational frameworks applied to the construction...

  9. Geometric Modeling of Construction Communications with Specified Dynamic Properties

    Science.gov (United States)

    Korotkiy, V. A.; Usmanova, E. A.; Khmarova, L. I.

    2017-11-01

    Among many construction communications the pipelines designed for the organized supply or removal of liquid or loose working bodies are distinguished for their functional purpose. Such communications should have dynamic properties which allow one to reduce losses on friction and vortex formation. From the point of view of geometric modeling, the given dynamic properties of the projected communication mean the required degree of smoothness of its center line. To model the axial line (flat or spatial), it is proposed to use composite curve lines consisting of the curve arcs of the second order or from their quadratic images. The advantage of the proposed method is that the designer gets the model of a given curve not as a set of coordinates of its points but in the form of a matrix of coefficients of the canonical equations for each arc.

  10. Architectural Large Constructed Environment. Modeling and Interaction Using Dynamic Simulations

    Science.gov (United States)

    Fiamma, P.

    2011-09-01

    How to use for the architectural design, the simulation coming from a large size data model? The topic is related to the phase coming usually after the acquisition of the data, during the construction of the model and especially after, when designers must have an interaction with the simulation, in order to develop and verify their idea. In the case of study, the concept of interaction includes the concept of real time "flows". The work develops contents and results that can be part of the large debate about the current connection between "architecture" and "movement". The focus of the work, is to realize a collaborative and participative virtual environment on which different specialist actors, client and final users can share knowledge, targets and constraints to better gain the aimed result. The goal is to have used a dynamic micro simulation digital resource that allows all the actors to explore the model in powerful and realistic way and to have a new type of interaction in a complex architectural scenario. On the one hand, the work represents a base of knowledge that can be implemented more and more; on the other hand the work represents a dealt to understand the large constructed architecture simulation as a way of life, a way of being in time and space. The architectural design before, and the architectural fact after, both happen in a sort of "Spatial Analysis System". The way is open to offer to this "system", knowledge and theories, that can support architectural design work for every application and scale. We think that the presented work represents a dealt to understand the large constructed architecture simulation as a way of life, a way of being in time and space. Architecture like a spatial configuration, that can be reconfigurable too through designing.

  11. ARCHITECTURAL LARGE CONSTRUCTED ENVIRONMENT. MODELING AND INTERACTION USING DYNAMIC SIMULATIONS

    Directory of Open Access Journals (Sweden)

    P. Fiamma

    2012-09-01

    Full Text Available How to use for the architectural design, the simulation coming from a large size data model? The topic is related to the phase coming usually after the acquisition of the data, during the construction of the model and especially after, when designers must have an interaction with the simulation, in order to develop and verify their idea. In the case of study, the concept of interaction includes the concept of real time "flows". The work develops contents and results that can be part of the large debate about the current connection between "architecture" and "movement". The focus of the work, is to realize a collaborative and participative virtual environment on which different specialist actors, client and final users can share knowledge, targets and constraints to better gain the aimed result. The goal is to have used a dynamic micro simulation digital resource that allows all the actors to explore the model in powerful and realistic way and to have a new type of interaction in a complex architectural scenario. On the one hand, the work represents a base of knowledge that can be implemented more and more; on the other hand the work represents a dealt to understand the large constructed architecture simulation as a way of life, a way of being in time and space. The architectural design before, and the architectural fact after, both happen in a sort of "Spatial Analysis System". The way is open to offer to this "system", knowledge and theories, that can support architectural design work for every application and scale. We think that the presented work represents a dealt to understand the large constructed architecture simulation as a way of life, a way of being in time and space. Architecture like a spatial configuration, that can be reconfigurable too through designing.

  12. Modeling Manpower and Equipment Productivity in Tall Building Construction Projects

    Science.gov (United States)

    Mudumbai Krishnaswamy, Parthasarathy; Rajiah, Murugasan; Vasan, Ramya

    2017-12-01

    Tall building construction projects involve two critical resources of manpower and equipment. Their usage, however, widely varies due to several factors affecting their productivity. Currently, no systematic study for estimating and increasing their productivity is available. What is prevalent is the use of empirical data, experience of similar projects and assumptions. As tall building projects are here to stay and increase, to meet the emerging demands in ever shrinking urban spaces, it is imperative to explore ways and means of scientific productivity models for basic construction activities: concrete, reinforcement, formwork, block work and plastering for the input of specific resources in a mixed environment of manpower and equipment usage. Data pertaining to 72 tall building projects in India were collected and analyzed. Then, suitable productivity estimation models were developed using multiple linear regression analysis and validated using independent field data. It is hoped that the models developed in the study will be useful for quantity surveyors, cost engineers and project managers to estimate productivity of resources in tall building projects.

  13. The study of the risk management model of construction project

    International Nuclear Information System (INIS)

    Jiang Bo; Feng Yanping; Liu Changbin

    2010-01-01

    The paper first analyzed the development of the risk management of construction project and the risk management processes, and then briefly introduced the risk management experience of foreign project management. From the project management by objectives point of view, the greatest risk came from the lack of clarity of the objectives in the project management, which led to the project's risk emergence. In the analysis of the principles of the project objectives identification and risk allocation, the paper set up a project management model which insurance companies involved in the whole process of the project management, and simply analyzed the roles of insurance company at last. (authors)

  14. Fuzzy pricing for urban water resources: model construction and application.

    Science.gov (United States)

    Zhao, Ranhang; Chen, Shouyu

    2008-08-01

    A rational water price system plays a crucial role in the optimal allocation of water resources. In this paper, a fuzzy pricing model for urban water resources is presented, which consists of a multi-criteria fuzzy evaluation model and a water resources price (WRP) computation model. Various factors affecting WRP are comprehensively evaluated with multiple levels and objectives in the multi-criteria fuzzy evaluation model, while the price vectors of water resources are constructed in the WRP computation model according to the definition of the bearing water price index, and then WRP is calculated. With the incorporation of an operator's knowledge, it considers iterative weights and subjective preference of operators for weight-assessment. The weights determined are more rational and the evaluation results are more realistic. Particularly, dual water supply is considered in the study. Different prices being fixed for water resources with different qualities conforms to the law of water resources value (WRV) itself. A high-quality groundwater price computation model is also proposed to provide optimal water allocation and to meet higher living standards. The developed model is applied in Jinan for evaluating its validity. The method presented in this paper offers some new directions in the research of WRP.

  15. Construction of Gait Adaptation Model in Human Splitbelt Treadmill Walking

    Directory of Open Access Journals (Sweden)

    Yuji Otoda

    2009-01-01

    Full Text Available There are a huge number of studies that measure kinematics, dynamics, the oxygen uptake and so on in human walking on the treadmill. Especially in walking on the splitbelt treadmill where the speed of the right and left belt is different, remarkable differences in kinematics are seen between normal and cerebellar disease subjects. In order to construct the gait adaptation model of such human splitbelt treadmill walking, we proposed a simple control model and made a newly developed 2D biped robot walk on the splitbelt treadmill. We combined the conventional limit-cycle based control consisting of joint PD-control, cyclic motion trajectory planning and a stepping reflex with a newly proposed adjustment of P-gain at the hip joint of the stance leg. We showed that the data of robot (normal subject model and cerebellum disease subject model experiments had high similarities with the data of normal subjects and cerebellum disease subjects experiments carried out by Reisman et al. (2005 and Morton and Bastian (2006 in ratios and patterns. We also showed that P-gain at the hip joint of the stance leg was the control parameter of adaptation for symmetric gaits in splitbelt walking and P-gain adjustment corresponded to muscle stiffness adjustment by the cerebellum. Consequently, we successfully proposed the gait adaptation model in human splitbelt treadmill walking and confirmed the validity of our hypotheses and the proposed model using the biped robot.

  16. Constructing Poverty Lines in Croatia Using Kakwani’s Model

    Directory of Open Access Journals (Sweden)

    Marinko Škare

    2017-06-01

    Full Text Available This paper presents a new model for defining the poverty line as a possible candidate for the construction of a new official poverty line in Croatia. The model, based on Kakwani’s (2010 approach (nutrition-based anchor, uses consumer theory as the basis for defining food and non-food poverty lines. In Croatia, various alternative poverty indicators have been developed to define the official poverty line. To ensure international comparability and consistency, the poverty threshold expressed in local currency by applying the exchange rate of currencies’ purchasing power (PPP is expressed in international dollars. It is important to ensure implementation of redistributive policies, maximization of market efficiency, and increased social justice. All this policy goals and instruments heavily depend on efficient and precise poverty measurement methods.

  17. Training for spacecraft technical analysts

    Science.gov (United States)

    Ayres, Thomas J.; Bryant, Larry

    1989-01-01

    Deep space missions such as Voyager rely upon a large team of expert analysts who monitor activity in the various engineering subsystems of the spacecraft and plan operations. Senior teammembers generally come from the spacecraft designers, and new analysts receive on-the-job training. Neither of these methods will suffice for the creation of a new team in the middle of a mission, which may be the situation during the Magellan mission. New approaches are recommended, including electronic documentation, explicit cognitive modeling, and coached practice with archived data.

  18. Recurrent Neural Network Model for Constructive Peptide Design.

    Science.gov (United States)

    Müller, Alex T; Hiss, Jan A; Schneider, Gisbert

    2018-02-26

    We present a generative long short-term memory (LSTM) recurrent neural network (RNN) for combinatorial de novo peptide design. RNN models capture patterns in sequential data and generate new data instances from the learned context. Amino acid sequences represent a suitable input for these machine-learning models. Generative models trained on peptide sequences could therefore facilitate the design of bespoke peptide libraries. We trained RNNs with LSTM units on pattern recognition of helical antimicrobial peptides and used the resulting model for de novo sequence generation. Of these sequences, 82% were predicted to be active antimicrobial peptides compared to 65% of randomly sampled sequences with the same amino acid distribution as the training set. The generated sequences also lie closer to the training data than manually designed amphipathic helices. The results of this study showcase the ability of LSTM RNNs to construct new amino acid sequences within the applicability domain of the model and motivate their prospective application to peptide and protein design without the need for the exhaustive enumeration of sequence libraries.

  19. Construction Of A Performance Assessment Model For Zakat Management Institutions

    Directory of Open Access Journals (Sweden)

    Sri Fadilah

    2016-12-01

    Full Text Available The objective of the research is to examine the performance evaluation using Balanced Scorecard model. The research is conducted due to a big gap existing between zakat (alms and religious tax in Islam with its potential earn of as much as 217 trillion rupiahs and the realization of the collected zakat fund that is only reached for three trillion. This indicates that the performance of zakat management organizations in collecting the zakat is still very low. On the other hand, the quantity and the quality of zakat management organizations have to be improved. This means the performance evaluation model as a tool to evaluate performance is needed. The model construct is making a performance evaluation model that can be implemented to zakat management organizations. The organizational performance with Balanced Scorecard evaluation model will be effective if it is supported by three aspects, namely:  PI, BO and TQM. This research uses explanatory method and data analysis tool of SEM/PLS. Data collecting technique are questionnaires, interviews and documentation. The result of this research shows that PI, BO and TQM simultaneously and partially gives a significant effect on organizational performance.

  20. Short Wavelength Electromagnetic Perturbations Excited Near the Solar Probe Plus Spacecraft in the Inner Heliosphere: 2.5D Hybrid Modeling

    Science.gov (United States)

    Lipatov, Alexander S.; Sittler, Edward C.; Hartle, Richard E.; Cooper, John F.

    2011-01-01

    A 2.5D numerical plasma model of the interaction of the solar wind (SW) with the Solar Probe Plus spacecraft (SPPSC) is presented. These results should be interpreted as a basic plasma model derived from the SW-interaction with the spacecraft (SC), which could have consequences for both plasma wave and electron plasma measurements on board the SC in the inner heliosphere. Compression waves and electric field jumps with amplitudes of about 1.5 V/m and (12-18) V/m were also observed. A strong polarization electric field was also observed in the wing of the plasma wake. However, 2.5D hybrid modeling did not show excitation of whistler/Alfven waves in the upstream connected with the bidirectional current closure that was observed in short-time 3D modeling SPPSC and near a tether in the ionosphere. The observed strong electromagnetic perturbations may be a crucial point in the electromagnetic measurements planned for the future Solar Probe Plus (SPP) mission. The results of modeling electromagnetic field perturbations in the SW due to shot noise in absence of SPPSC are also discussed.

  1. Short wavelength electromagnetic perturbations excited near the Solar Probe Plus spacecraft in the inner heliosphere: 2.5D hybrid modeling

    Science.gov (United States)

    Lipatov, Alexander S.; Sittler, Edward C., Jr.; Hartle, Richard E.; Cooper, John F.

    2012-03-01

    A 2.5D numerical plasma model of the interaction of the solar wind (SW) with the Solar Probe Plus spacecraft (SPPSC) is presented. These results should be interpreted as a basic plasma model derived from the SW interaction with the spacecraft (SC), which could have consequences for both plasma wave and electron plasma measurements on board the SC in the inner heliosphere. Compression waves and electric field jumps with amplitudes of about 1.5 V/m and (12-18) V/m were also observed. A strong polarization electric field was also observed in the wing of the plasma wake. However, 2.5D hybrid modeling did not show excitation of whistler/Alfvén waves in the upstream connected with the bi-directional current closure that was observed in short-time 3D modeling SPPSC and near a tether in the ionosphere. The observed strong electromagnetic perturbations may be a crucial point in the electromagnetic measurements planned for the future Solar Probe Plus (SPP) mission. The results of modeling electromagnetic field perturbations in the SW due to ;shot; noise in absence of SPPSC are also discussed.

  2. Spacecraft Spin Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides the capability to correct unbalances of spacecraft by using dynamic measurement techniques and static/coupled measurements to provide products of...

  3. THE INVESTMENT MODEL OF THE CONSTRUCTION OF PUBLIC OBJECTS

    Directory of Open Access Journals (Sweden)

    Reperger Šandor

    2009-11-01

    Full Text Available One of the possible models of the construction and use of sports objects, especi- ally indoor facilities (sports centres, halls, swimming pools, shooting alleys and others is the cooperation of the public and private sector, by the investment model of PPP (Pu- blic-Private Partnership. PPP (Public-Private Partnership construction is the new form of securing civil works, already known in the developed countries, in which the job of planning, construc- tion, functioning and financing is done by the private sector – in the scope of a precisely elaborated cooperation with the state. The state engages the private sector for the administering of the civil works. By public adverstisements and contests they will find the investors who accept the administe- ring of certain public works by themselves or with the help of project partners with their own resources (with 60-85% of bank loans, secure the conditions for conducting certain services (by using the objects, halls, etc until the expiration of the agreed deadline. The essence of PPP construction is the fact that an investor from the private sec- tor, chosen through a contest, realizes the project using its own means. The object beco- mes the property of the investor and it secures the regular functioning of the object with exclusive rights. The income from the functioning belongs to the investor, in return the costs of the functioning of the object, the upkeep, as well as the costs of the personnel and public utilities are the responsibility of the investor. The public use of the object is realised by the means that the authorised ministry and the partner from the contest in an agreement of the realization and functioning of the object accurately define the time of maintenance and the duration of the services on the behalf of social interest. From the time specified in the agreement the investor doesn’t charge precisely defined users for general and specific services. As Sebia, with all its

  4. A new approach for modelling variability in residential construction projects

    Directory of Open Access Journals (Sweden)

    Mehrdad Arashpour

    2013-06-01

    Full Text Available The construction industry is plagued by long cycle times caused by variability in the supply chain. Variations or undesirable situations are the result of factors such as non-standard practices, work site accidents, inclement weather conditions and faults in design. This paper uses a new approach for modelling variability in construction by linking relative variability indicators to processes. Mass homebuilding sector was chosen as the scope of the analysis because data is readily available. Numerous simulation experiments were designed by varying size of capacity buffers in front of trade contractors, availability of trade contractors, and level of variability in homebuilding processes. The measurements were shown to lead to an accurate determination of relationships between these factors and production parameters. The variability indicator was found to dramatically affect the tangible performance measures such as home completion rates. This study provides for future analysis of the production homebuilding sector, which may lead to improvements in performance and a faster product delivery to homebuyers.

  5. A new approach for modelling variability in residential construction projects

    Directory of Open Access Journals (Sweden)

    Mehrdad Arashpour

    2013-06-01

    Full Text Available The construction industry is plagued by long cycle times caused by variability in the supply chain. Variations or undesirable situations are the result of factors such as non-standard practices, work site accidents, inclement weather conditions and faults in design. This paper uses a new approach for modelling variability in construction by linking relative variability indicators to processes. Mass homebuilding sector was chosen as the scope of the analysis because data is readily available. Numerous simulation experiments were designed by varying size of capacity buffers in front of trade contractors, availability of trade contractors, and level of variability in homebuilding processes. The measurements were shown to lead to an accurate determination of relationships between these factors and production parameters. The variability indicator was found to dramatically affect the tangible performance measures such as home completion rates. This study provides for future analysis of the production homebuilding sector, which may lead to improvements in performance and a faster product delivery to homebuyers. 

  6. Design, Construction, and Modeling of a 252Cf Neutron Irradiator

    Directory of Open Access Journals (Sweden)

    Blake C. Anderson

    2016-01-01

    Full Text Available Neutron production methods are an integral part of research and analysis for an array of applications. This paper examines methods of neutron production, and the advantages of constructing a radioisotopic neutron irradiator assembly using 252Cf. Characteristic neutron behavior and cost-benefit comparative analysis between alternative modes of neutron production are also examined. The irradiator is described from initial conception to the finished design. MCNP modeling shows a total neutron flux of 3 × 105 n/(cm2·s in the irradiation chamber for a 25 μg source. Measurements of the gamma-ray and neutron dose rates near the external surface of the irradiator assembly are 120 μGy/h and 30 μSv/h, respectively, during irradiation. At completion of the project, total material, and labor costs remained below $50,000.

  7. 3D design terrain models for construction plans and GPS control of highway construction equipment.

    Science.gov (United States)

    2010-03-01

    Research was conducted with the objectives of 1) identifying and characterizing benefits and technological, institutional, cultural, and : legal impediments associated with adoption of 3D design and construction technologies, identifying strategies t...

  8. Construction of energy-stable Galerkin reduced order models.

    Energy Technology Data Exchange (ETDEWEB)

    Kalashnikova, Irina; Barone, Matthew Franklin; Arunajatesan, Srinivasan; van Bloemen Waanders, Bart Gustaaf

    2013-05-01

    This report aims to unify several approaches for building stable projection-based reduced order models (ROMs). Attention is focused on linear time-invariant (LTI) systems. The model reduction procedure consists of two steps: the computation of a reduced basis, and the projection of the governing partial differential equations (PDEs) onto this reduced basis. Two kinds of reduced bases are considered: the proper orthogonal decomposition (POD) basis and the balanced truncation basis. The projection step of the model reduction can be done in two ways: via continuous projection or via discrete projection. First, an approach for building energy-stable Galerkin ROMs for linear hyperbolic or incompletely parabolic systems of PDEs using continuous projection is proposed. The idea is to apply to the set of PDEs a transformation induced by the Lyapunov function for the system, and to build the ROM in the transformed variables. The resulting ROM will be energy-stable for any choice of reduced basis. It is shown that, for many PDE systems, the desired transformation is induced by a special weighted L2 inner product, termed the %E2%80%9Csymmetry inner product%E2%80%9D. Attention is then turned to building energy-stable ROMs via discrete projection. A discrete counterpart of the continuous symmetry inner product, a weighted L2 inner product termed the %E2%80%9CLyapunov inner product%E2%80%9D, is derived. The weighting matrix that defines the Lyapunov inner product can be computed in a black-box fashion for a stable LTI system arising from the discretization of a system of PDEs in space. It is shown that a ROM constructed via discrete projection using the Lyapunov inner product will be energy-stable for any choice of reduced basis. Connections between the Lyapunov inner product and the inner product induced by the balanced truncation algorithm are made. Comparisons are also made between the symmetry inner product and the Lyapunov inner product. The performance of ROMs constructed

  9. Pressure-Fed LOX/LCH4 Reaction Control System for Spacecraft: Transient Modeling and Thermal Vacuum Hotfire Test Results

    Science.gov (United States)

    Atwell, Matthew J.; Hurlbert, Eric A.; Melcher, J. C.; Morehead, Robert L.

    2017-01-01

    An integrated cryogenic liquid oxygen, liquid methane (LOX/LCH4) reaction control system (RCS) was tested at NASA Glenn Research Center's Plum Brook Station in the Spacecraft Propulsion Research Facility (B-2) under vacuum and thermal vacuum conditions. The RCS is a subsystem of the Integrated Cryogenic Propulsion Test Article (ICPTA), a pressure-fed LOX/LCH4 propulsion system composed of a single 2,800 lbf main engine, two 28 lbf RCS engines, and two 7 lbf RCS engines. Propellants are stored in four 48 inch diameter 5083 aluminum tanks that feed both the main engine and RCS engines in parallel. Helium stored cryogenically in a composite overwrapped pressure vessel (COPV) flows through a heat exchanger on the main engine before being used to pressurize the propellant tanks to a design operating pressure of 325 psi. The ICPTA is capable of simultaneous main engine and RCS operation. The RCS engines utilize a coil-on-plug (COP) ignition system designed for operation in a vacuum environment, eliminating corona discharge issues associated with a high voltage lead. There are two RCS pods on the ICPTA, with two engines on each pod. One of these two engines is a heritage flight engine from Project Morpheus. Its sea level nozzle was removed and replaced by an 85:1 nozzle machined using Inconel 718, resulting in a maximum thrust of 28 lbf under altitude conditions. The other engine is a scaled down version of the 28 lbf engine, designed to match the core and overall mixture ratios as well as other injector characteristics. This engine can produce a maximum thrust of 7 lbf with an 85:1 nozzle that was additively manufactured using Inconel 718. Both engines are film-cooled and capable of limited duration gas-gas and gas-liquid operation, as well as steady-state liquid-liquid operation. Each pod contains one of each version, such that two engines of the same thrust level can be fired as a couple on opposite pods. The RCS feed system is composed of symmetrical 3/8 inch lines

  10. Simulation of Mariner Mars 1971 spacecraft

    Science.gov (United States)

    Ausman, N. E., Jr.; Simon, N. K.; Rodriguez, C. F.

    1971-01-01

    Preparation for the Mariner Mars 1971 mission is reported, including an extensive training program for operations personnel during which the primary source of spacecraft data was a computer program simulating the spacecraft. The objectives of a simulation model for training purposes differed from objectives appropriate to a design or analysis model. Model subsystems were designed to provide realistic telemetry data reflecting changes due both to commands and environmental parameters affecting the spacecraft at various times during the mission. The spacecraft is modeled along two separate functional lines. Boolean operations are concentrated in the spacecraft logic model, which determines the spacecraft state or mode, while mathematical operations or algorithms are executed in computational subsystem models. Although logic parameters are interrogated as a part of each computational pass, actual logic model processing occurs only when a change-of-state input is generated by the operations organization. The program design, some of the special characteristics of each of the modeled subsystems, and how the model was used in support of mission operations training are presented.

  11. Model code for energy conservation in new building construction

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    In response to the recognized lack of existing consensus standards directed to the conservation of energy in building design and operation, the preparation and publication of such a standard was accomplished with the issuance of ASHRAE Standard 90-75 ''Energy Conservation in New Building Design,'' by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., in 1975. This standard addressed itself to recommended practices for energy conservation, using both depletable and non-depletable sources. A model code for energy conservation in building construction has been developed, setting forth the minimum regulations found necessary to mandate such conservation. The code addresses itself to the administration, design criteria, systems elements, controls, service water heating and electrical distribution and use, both for depletable and non-depletable energy sources. The technical provisions of the document are based on ASHRAE 90-75 and it is intended for use by state and local building officials in the implementation of a statewide energy conservation program.

  12. Theoretical Framework and Model Design for Beautiful Countryside Construction in China

    Directory of Open Access Journals (Sweden)

    ZHENG Xiang-qun

    2015-04-01

    Full Text Available In the context of China today, the process of beautiful countryside construction mainly imitates the patterns of‘urbanization’construction. However, this approach leads to the loss of countryside characteristics and the separation of agricultural culture. Therefore, it's urgent to carry out research of the theoretical framework and model design for beautiful countryside construction. In this paper, based on the analysis of the beautiful countryside construction connotation, the basic theory of beautiful countryside construction was summarized in three aspects: rural complex ecosystem model, multi-functionality of rural model and sustainable development evaluation model. The basic idea of the beautiful countryside construction mode was studied. The design method of beautiful countryside construction mode was proposed in three levels: planning, scheming and evaluating. The research results might offer scientific reference for improving the scientific and operational nature of beautiful countryside construction.

  13. Model for setting priority construction project objectives aligned with ...

    African Journals Online (AJOL)

    Mr Ruben Ndihokubwayo, Lecturer, Department of Construction Management and. Quantity Surveying, Cape ... architects, and consulting engineers, requesting them to base their responses on a specific construction project .... financial incentives are designed is to attempt to align the interests of the contractor with those of ...

  14. Risk assessment and model for community-based construction ...

    African Journals Online (AJOL)

    However, the involvement of local communities introduces a number of risks during the execution of projects as the individuals involved may not be conversant with construction and the procedures involved in the procurement processes of projects. The consequences of not assessing and managing construction risks are ...

  15. Teaching Construction: A Design-Based Course Model

    Science.gov (United States)

    Love, Tyler S.; Salgado, Carlos A.

    2016-01-01

    The focus on construction in T&E education has drastically changed. This article presents a series of topics and design-based labs that can be taught at various grade levels to integrate STEM concepts while also increasing students' overall awareness of construction and structural technologies.

  16. Reference Models of Information Systems Constructed with the use of Technologies of Cloud Calculations

    Directory of Open Access Journals (Sweden)

    Darya Sergeevna Simonenkova

    2013-09-01

    Full Text Available The subject of the research is analysis of various models of the information system constructed with the use of technologies of cloud calculations. Analysis of models is required for constructing a new reference model which will be used for develop a security threats model.

  17. Spacecraft momentum control systems

    CERN Document Server

    Leve, Frederick A; Peck, Mason A

    2015-01-01

    The goal of this book is to serve both as a practical technical reference and a resource for gaining a fuller understanding of the state of the art of spacecraft momentum control systems, specifically looking at control moment gyroscopes (CMGs). As a result, the subject matter includes theory, technology, and systems engineering. The authors combine material on system-level architecture of spacecraft that feature momentum-control systems with material about the momentum-control hardware and software. This also encompasses material on the theoretical and algorithmic approaches to the control of space vehicles with CMGs. In essence, CMGs are the attitude-control actuators that make contemporary highly agile spacecraft possible. The rise of commercial Earth imaging, the advances in privately built spacecraft (including small satellites), and the growing popularity of the subject matter in academic circles over the past decade argues that now is the time for an in-depth treatment of the topic. CMGs are augmented ...

  18. Spacecraft Fire Safety Demonstration

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Spacecraft Fire Safety Demonstration project is to develop and conduct large-scale fire safety experiments on an International Space Station...

  19. Spacecraft Material Outgassing Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This compilation of outgassing data of materials intended for spacecraft use were obtained at the Goddard Space Flight Center (GSFC), utilizing equipment developed...

  20. Empirical modelling of ENSO dynamics: construction of optimal complexity models from data

    Science.gov (United States)

    Mukhina, A.; Kondrashov, D.; Mukhin, D.

    2012-04-01

    One of the main problems arising in modelling of data taken from natural system is finding of a phase space suitable for construction of the evolution operator model. The matter is we ususaly deal with strongly high-dimensional behavior and we are forced to construct a model working in some projection of system phase space corresponding to time scales of interest. Selection of optimal projecion is non-trivial problem since there are many ways to reconstruct phase variables from given time series, especially in the case when time series has a form of spatial field depending on time. Actually, it is sort of model selection problem, because, on the one hand, the transformation of data to some phase variables vector can be considered as a part of the model. On the other hand, such an optimization of a phase space makes sense only in relation to the parameterization of the model we use, i.e. representation of evolution operator, so we should find an optimal structure of the model togerther with phase variables vector. In this work we suggest Bayesian approach to this problem: a prior set of the models of different complexity is defined, then posterior probabilities of each model from this set given the data are calculated, and the model corresponding to largest probability is selected. The suggested approach is applied to optimization of EMR-model of ENSO phenomenon elaborated by Kondrashov et. al. This model operates with number of principal EOFs constructed from spatial field of SST in Equatorial Pacific, and has a form of stochastic differential equations (SDE) system with polynomial parameterization of the right-hand part. Optimal values for both the number of EOFs and the order of SDE system are estimated from the time series generated by Jin & Neelin intermediate ENSO model.

  1. Preliminary study on enhancing waste management best practice model in Malaysia construction industry

    Science.gov (United States)

    Jamaludin, Amril Hadri; Karim, Nurulzatushima Abdul; Noor, Raja Nor Husna Raja Mohd; Othman, Nurulhidayah; Malik, Sulaiman Abdul

    2017-08-01

    Construction waste management (CWM) is the practice of minimizing and diverting construction waste, demolition debris, and land-clearing debris from disposal and redirecting recyclable resources back into the construction process. Best practice model means best choice from the collection of other practices that was built for purpose of construction waste management. The practice model can help the contractors in minimizing waste before the construction activities will be started. The importance of minimizing wastage will have direct impact on time, cost and quality of a construction project. This paper is focusing on the preliminary study to determine the factors of waste generation in the construction sites and identify the effectiveness of existing construction waste management practice conducted in Malaysia. The paper will also include the preliminary works of planned research location, data collection method, and analysis to be done by using the Analytical Hierarchy Process (AHP) to help in developing suitable waste management best practice model that can be used in the country.

  2. DISCOURSE MARKERS IN THE LEXICAL CONSTRUCTIONAL MODEL: THE CASE OF THE ‘SO WHAT X’ CONSTRUCTION DISCOURSE MARKERS IN THE LEXICAL CONSTRUCTIONAL MODEL: THE CASE OF THE ‘SO WHAT X’ CONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Alicia Galera Masegosa

    2010-10-01

    Full Text Available This article argues for an alternative analysis of discourse markers to that proposed within relevance-theoretic approaches, which attribute procedural (as opposed to conceptual meaning to these words. This study provides a new perspective that brings together the main contributions of Relevance Theory (RT and those that arise from the Lexical Constructional Model (LCM, thus shedding light on the role of discourse markers within sentence meaning. Rather than offering procedural information, discourse markers activate high-level conceptual mechanisms that help the hearer in his/her choice of the most appropriate interpretation of utterances. Furthermore, the present paper provides a fully-fl edged analysis of discourse markers and their contribution to implicated meaning, fi lling the gaps observable in relevance-theoretic views. Specifically, So and and have been found to be determinant elements in the creation of a new construction, theSo Wh- X? construction, which explains the uncompromising importance of discourse markers in utterance interpretation.This article argues for an alternative analysis of discourse markers to that proposed within relevance-theoretic approaches, which attribute procedural (as opposed to conceptual meaning to these words.This study provides a new perspective that brings together the main contributions of Relevance Theory (RTand those that arise from the Lexical Constructional Model (LCM, thus shedding light on the role of discourse markers within sentence meaning. Rather than offering procedural information, discourse markers activate high-level conceptual mechanisms that help the hearer in his/her choice of the most appropriate interpretation of utterances. Furthermore, the present paper provides a fully-fl edged analysis of discourse markers and their contribution to implicated meaning, fi lling the gaps observable in relevance-theoretic views. Specifically, So and and have been found to be determinant elements in

  3. Spacecraft nonlinear control

    Science.gov (United States)

    Sheen, Jyh-Jong; Bishop, Robert H.

    1992-01-01

    The feedback linearization technique is applied to the problem of spacecraft attitude control and momentum management with control moment gyros (CMGs). The feedback linearization consists of a coordinate transformation, which transforms the system to a companion form, and a nonlinear feedback control law to cancel the nonlinear dynamics resulting in a linear equivalent model. Pole placement techniques are then used to place the closed-loop poles. The coordinate transformation proposed here evolves from three output functions of relative degree four, three, and two, respectively. The nonlinear feedback control law is presented. Stability in a neighborhood of a controllable torque equilibrium attitude (TEA) is guaranteed and this fact is demonstrated by the simulation results. An investigation of the nonlinear control law shows that singularities exist in the state space outside the neighborhood of the controllable TEA. The nonlinear control law is simplified by a standard linearization technique and it is shown that the linearized nonlinear controller provides a natural way to select control gains for the multiple-input, multiple-output system. Simulation results using the linearized nonlinear controller show good performance relative to the nonlinear controller in the neighborhood of the TEA.

  4. Analyzing Spacecraft Telecommunication Systems

    Science.gov (United States)

    Kordon, Mark; Hanks, David; Gladden, Roy; Wood, Eric

    2004-01-01

    Multi-Mission Telecom Analysis Tool (MMTAT) is a C-language computer program for analyzing proposed spacecraft telecommunication systems. MMTAT utilizes parameterized input and computational models that can be run on standard desktop computers to perform fast and accurate analyses of telecommunication links. MMTAT is easy to use and can easily be integrated with other software applications and run as part of almost any computational simulation. It is distributed as either a stand-alone application program with a graphical user interface or a linkable library with a well-defined set of application programming interface (API) calls. As a stand-alone program, MMTAT provides both textual and graphical output. The graphs make it possible to understand, quickly and easily, how telecommunication performance varies with variations in input parameters. A delimited text file that can be read by any spreadsheet program is generated at the end of each run. The API in the linkable-library form of MMTAT enables the user to control simulation software and to change parameters during a simulation run. Results can be retrieved either at the end of a run or by use of a function call at any time step.

  5. Development and implementation of the South African construction excellence model (SACEM)

    CSIR Research Space (South Africa)

    Dlungwana, WS

    2002-04-01

    Full Text Available . The South African Construction Excellence Model (SACEM) is based on the South African Excellence Model (SAEM), an internationally recognised framework for business performance assessment. The model's basic structure, function, benefits and its relationship...

  6. Best practices for system dynamics model design and construction with powersim studio.

    Energy Technology Data Exchange (ETDEWEB)

    Malczynski, Leonard A.

    2011-06-01

    This guide addresses software quality in the construction of Powersim{reg_sign} Studio 8 system dynamics simulation models. It is the result of almost ten years of experience with the Powersim suite of system dynamics modeling tools (Constructor and earlier Studio versions). It is a guide that proposes a common look and feel for the construction of Powersim Studio system dynamics models.

  7. Providing or designing? Constructing models in primary maths education (IF. 0.756)

    NARCIS (Netherlands)

    van Dijk, I.M.A.W.; van Oers, H.J.M.; Terwel, J.

    2003-01-01

    The goal of this exploratory study was to uncover the construction processes which occur when pupils are taught to work with models in primary maths education. Two approaches were studied: 'providing models' versus 'designing models in co-construction'. A qualitative observational study involved two

  8. DISCOURSE MARKERS IN THE LEXICAL CONSTRUCTIONAL MODEL: THE CASE OF THE ‘SO WHAT X’ CONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Alicia Galera Masegosa

    2011-10-01

    Full Text Available This article argues for an alternative analysis of discourse markers to that proposed within relevance-theoretic approaches, which attribute procedural (as opposed to conceptual meaning to these words. This study provides a new perspective that brings together the main contributions of Relevance Theory (RT and those that arise from the Lexical Constructional Model (LCM, thus shedding light on the role of discourse markers within sentence meaning. Rather than offering procedural information, discourse markers activate high-level conceptual mechanisms that help the hearer in his/her choice of the most appropriate interpretation of utterances. Furthermore, the present paper provides a fully-fledged analysis of discourse markers and their contribution to implicated meaning, filling the gaps observable in relevance-theoretic views. Specifically, So and and have been found to be determinant elements in the creation of a new construction, the So Wh- X? construction, which explains the uncompromising importance of discourse markers in utterance interpretation.

  9. A diagnostic model for assessing the knowledge management practices of construction firms

    OpenAIRE

    Kale, Serdar; Karaman, Erkan A.

    2012-01-01

    Knowledge management is rapidly becoming a key organizational capability for creating competitive advantage in the construction industry. The emergence of knowledge management as a key organizational capability for creating competitive advantage poses enormous challenges to executives of construction firms. This paper proposes a model for benchmarking the knowledge management practices of construction firms that can guide and assist construction business executives to meet these challenges. T...

  10. Mechanical Design of Spacecraft

    Science.gov (United States)

    1962-01-01

    In the spring of 1962, engineers from the Engineering Mechanics Division of the Jet Propulsion Laboratory gave a series of lectures on spacecraft design at the Engineering Design seminars conducted at the California Institute of Technology. Several of these lectures were subsequently given at Stanford University as part of the Space Technology seminar series sponsored by the Department of Aeronautics and Astronautics. Presented here are notes taken from these lectures. The lectures were conceived with the intent of providing the audience with a glimpse of the activities of a few mechanical engineers who are involved in designing, building, and testing spacecraft. Engineering courses generally consist of heavily idealized problems in order to allow the more efficient teaching of mathematical technique. Students, therefore, receive a somewhat limited exposure to actual engineering problems, which are typified by more unknowns than equations. For this reason it was considered valuable to demonstrate some of the problems faced by spacecraft designers, the processes used to arrive at solutions, and the interactions between the engineer and the remainder of the organization in which he is constrained to operate. These lecture notes are not so much a compilation of sophisticated techniques of analysis as they are a collection of examples of spacecraft hardware and associated problems. They will be of interest not so much to the experienced spacecraft designer as to those who wonder what part the mechanical engineer plays in an effort such as the exploration of space.

  11. A Model Suggestion to Predict Leverage Ratio for Construction Projects

    OpenAIRE

    Özlem Tüz; Şafak Ebesek

    2013-01-01

    Due to the nature, construction is an industry with high uncertainty and risk. Construction industry carries high leverage ratios. Firms with low equities work in big projects through progress payment system, but in this case, even a small negative in the planned cash flows constitute a major risk for the company.The use of leverage, with a small investment to achieve profit targets large-scale, high-profit, but also brings a high risk with it. Investors may lose all or the portion of th...

  12. Constructing service-oriented architecture adoption maturity matrix using Kano model

    Science.gov (United States)

    Hamzah, Mohd Hamdi Irwan; Baharom, Fauziah; Mohd, Haslina

    2017-10-01

    Commonly, organizations adopted Service-Oriented Architecture (SOA) because it can provide a flexible reconfiguration and can reduce the development time and cost. In order to guide the SOA adoption, previous industry and academia have constructed SOA maturity model. However, there is a limited number of works on how to construct the matrix in the previous SOA maturity model. Therefore, this study is going to provide a method that can be used in order to construct the matrix in the SOA maturity model. This study adapts Kano Model to construct the cross evaluation matrix focused on SOA adoption IT and business benefits. This study found that Kano Model can provide a suitable and appropriate method for constructing the cross evaluation matrix in SOA maturity model. Kano model also can be used to plot, organize and better represent the evaluation dimension for evaluating the SOA adoption.

  13. Applications of building information model (BIM) in Malaysian construction industry

    Science.gov (United States)

    Tahir, M. M.; Haron, N. A.; Alias, A. H.; Al-Jumaa, A. T.; Muhammad, I. B.; Harun, A. N.

    2017-12-01

    Since the introduction of BIM in Malaysia in 2009, the technology adoption rate is slow when compared to other countries of the world. Most of the construction companies in Malaysia have an insight on the BIM concept but are yet to implement it in the management of their construction projects. By the year 2020, the Malaysian government will make BIM mandatory, this makes it important to carry out research on the possible applications of the technology. A qualitative method of enquiry was used for this study in Klang Valley using semistructured interview. The responses received were analysed using Principal component analysis (PCA). The result of the analysis showed that “quantity take-off and estimation”, “clash detection and coordination”, “integration and collaboration of stakeholders”, and “design and visualisation” as the main applications of BIM in Malaysia presently. The implication of this findings is that the Malaysian construction industry productivity is likely to increase to meet the demand of the population through the implementations of BIM. More also, BIM technology is regarded as the future of construction industry, which makes it very important for the industry.

  14. Ergonomic realities of a Biophilic Construction Site Model | Obiozo ...

    African Journals Online (AJOL)

    The psycho-traumatic stress factors arising from a construction site lacking psychosocial value and the presence of nature, results in personal harm to workers, and marginalises their performance, and the harmonious cohesion of a workplace as an integrally beneficial natural environment. The research reported on the ...

  15. A Public Commissioning Maturity Model for Construction Clients

    NARCIS (Netherlands)

    Hermans, M.H.; Volker, L.; Eisma, P.R.

    2014-01-01

    Being a public organization with construction needs, whether they are housing, building or infrastructure related, implies close co-operation and interaction with the supply chain. Substantial research exists that focuses on project related aspects of commissioning and on the role of the

  16. Risk assessment and model for community-based construction ...

    African Journals Online (AJOL)

    It, therefore, becomes necessary to systematically manage uncertainty in community-based construction in order to increase the likelihood of meeting project objectives using necessary risk management strategies. Risk management, which is an iterative process due to the dynamic nature of many risks, follows three main ...

  17. Constructing Approximate Confidence Intervals for Parameters with Structural Equation Models

    Science.gov (United States)

    Cheung, Mike W. -L.

    2009-01-01

    Confidence intervals (CIs) for parameters are usually constructed based on the estimated standard errors. These are known as Wald CIs. This article argues that likelihood-based CIs (CIs based on likelihood ratio statistics) are often preferred to Wald CIs. It shows how the likelihood-based CIs and the Wald CIs for many statistics and psychometric…

  18. Force-dynamic cultural models in a scalar adjectival construction

    DEFF Research Database (Denmark)

    Jensen, Kim Ebensgaard

    Consider the following instances of the scalar adjectival [too ADJ to V]-construction: (1) The tatty furniture betrayed elegant lines, and the windows, too grimy to see through, stretched up ten feet. (COCA 2011 FIC Bk:NeverGentleman) (2) They're too slow to catch a seal in open water. (COCA 2011...

  19. A diagnostic ontological model for damages to historical constructions

    Czech Academy of Sciences Publication Activity Database

    Cacciotti, Riccardo; Blaško, M.; Valach, Jaroslav

    2015-01-01

    Roč. 16, č. 1 (2015), s. 40-48 ISSN 1296-2074 R&D Projects: GA MK(CZ) DF11P01OVV002 Keywords : historical constructions * conservation * ontologies * damage Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 1.533, year: 2015 http://www.sciencedirect.com/science/article/pii/S1296207414000259

  20. Models in the construction of female identity in Nigerian postcolonial ...

    African Journals Online (AJOL)

    Gendered identity in Africa has for centuries been a hotbed of ideological and narrative contestations. While colonial constructions of the African female were generally essentialist and negative in character, early postcolonial African literature also ironically deployed essentialisms and rigid gender binaries to portray African ...

  1. Revamping Spacecraft Operational Intelligence

    Science.gov (United States)

    Hwang, Victor

    2012-01-01

    The EPOXI flight mission has been testing a new commercial system, Splunk, which employs data mining techniques to organize and present spacecraft telemetry data in a high-level manner. By abstracting away data-source specific details, Splunk unifies arbitrary data formats into one uniform system. This not only reduces the time and effort for retrieving relevant data, but it also increases operational visibility by allowing a spacecraft team to correlate data across many different sources. Splunk's scalable architecture coupled with its graphing modules also provide a solid toolset for generating data visualizations and building real-time applications such as browser-based telemetry displays.

  2. Constructing a Measurement in Service Quality for Indian Banks: Structural Equation Modeling Approach

    OpenAIRE

    Anil Kumar; Manoj Kumar Dash

    2013-01-01

    The aim of this paper is to construct a measure in service quality for Indian banks and establishes a causal relationship of service attributes performance with customer satisfaction. The SERVQUAL model is used. The quantification of service quality led to the attempt to construct an index. The index is constructed using Structural Equation Modeling (SEM) and American Customer Satisfaction Index (ACSI) as the underlying frameworks. The analysis is based on data of 200 bank customers from the ...

  3. Modeling the Individual Within the Group: an Interdisciplinary Approach to Collaborative Knowledge Construction

    OpenAIRE

    Lund, Kristine

    2016-01-01

    Constructing knowledge with others is fundamental for all human activity, and many disciplines have sought to understand how the individual, other people, and the context, all influence collaborative knowledge construction, be it individual or group knowledge. The goal of this Habilitation à Diriger des Recherches is to present an analytical model of the relations of the individual to the group in situations of collaborative knowledge construction. The model is inspired by the work of Levinso...

  4. Contemporary state of spacecraft/environment interaction research

    CERN Document Server

    Novikov, L S

    1999-01-01

    Various space environment effects on spacecraft materials and equipment, and the reverse effects of spacecrafts and rockets on space environment are considered. The necessity of permanent updating and perfection of our knowledge on spacecraft/environment interaction processes is noted. Requirements imposed on models of space environment in theoretical and experimental researches of various aspects of the spacecraft/environment interaction problem are formulated. In this field, main problems which need to be solved today and in the nearest future are specified. The conclusion is made that the joint analysis of both aspects of spacecraft/environment interaction problem promotes the most effective solution of the problem.

  5. Model of investment appraisal of high-rise construction with account of cost of land resources

    Science.gov (United States)

    Okolelova, Ella; Shibaeva, Marina; Trukhina, Natalya

    2018-03-01

    The article considers problems and potential of high-rise construction as a global urbanization. The results of theoretical and practical studies on the appraisal of investments in high-rise construction are provided. High-rise construction has a number of apparent upsides in modern terms of development of megapolises and primarily it is economically efficient. Amid serious lack of construction sites, skyscrapers successfully deal with the need of manufacturing, office and living premises. Nevertheless, there are plenty issues, which are related with high-rise construction, and only thorough scrutiny of them allow to estimate the real economic efficiency of this branch. The article focuses on the question of economic efficiency of high-rise construction. The suggested model allows adjusting the parameters of a facility under construction, setting the tone for market value as well as the coefficient for appreciation of the construction net cost, that depends on the number of storey's, in the form of function or discrete values.

  6. Constructing Experience: Event Models from Perception to Action.

    Science.gov (United States)

    Richmond, Lauren L; Zacks, Jeffrey M

    2017-12-01

    Mental representations of everyday experience are rich, structured, and multimodal. In this article we consider the adaptive pressures that led to human construction of such representations, arguing that structured event representations enable cognitive systems to more effectively predict the trajectory of naturalistic everyday activity. We propose an account of how cortical systems and the hippocampus (HPC) interact to construct, maintain, and update event representations. This analysis throws light on recent research on story comprehension, event segmentation, episodic memory, and action planning. It also suggests how the growing science base can be deployed to diagnose impairments in event perception and memory, and to improve memory for everyday events. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Constructing Topic Models of Internet of Things for Information Processing

    OpenAIRE

    Xin, Jie; Cui, Zhiming; Zhang, Shukui; He, Tianxu; Li, Chunhua; Huang, Haojing

    2014-01-01

    Internet of Things (IoT) is regarded as a remarkable development of the modern information technology. There is abundant digital products data on the IoT, linking with multiple types of objects/entities. Those associated entities carry rich information and usually in the form of query records. Therefore, constructing high quality topic hierarchies that can capture the term distribution of each product record enables us to better understand users’ search intent and benefits tasks such as taxon...

  8. Quantifying uncertainty of geological 3D layer models, constructed with a-priori geological expertise

    NARCIS (Netherlands)

    Gunnink, J.J.; Maljers, D.; Hummelman, J.

    2010-01-01

    Uncertainty quantification of geological models that are constructed with additional geological expert-knowledge is not straightforward. To construct sound geological 3D layer models we use a lot of additional knowledge, with an uncertainty that is hard to quantify. Examples of geological expert

  9. Refinement-Based Student Modeling and Automated Bug Library Construction.

    Science.gov (United States)

    Baffes, Paul; Mooney, Raymond

    1996-01-01

    Discussion of student modeling and intelligent tutoring systems focuses on the development of the ASSERT algorithm (Acquiring Stereotypical Student Errors by Refining Theories). Topics include overlay modeling; bug libraries (databases of student misconceptions); dynamic modeling; refinement-based modeling; and experimental results from tests at…

  10. Profile construction in experimental choice designs for mixed logit models

    NARCIS (Netherlands)

    Sandor, Z; Wedel, M

    2002-01-01

    A computationally attractive model for the analysis of conjoint choice experiments is the mixed multinomial logit model, a multinomial logit model in which it is assumed that the coefficients follow a (normal) distribution across subjects. This model offers the advantage over the standard

  11. Electrolysis Propulsion for Spacecraft Applications

    Science.gov (United States)

    deGroot, Wim A.; Arrington, Lynn A.; McElroy, James F.; Mitlitsky, Fred; Weisberg, Andrew H.; Carter, Preston H., II; Myers, Blake; Reed, Brian D.

    1997-01-01

    Electrolysis propulsion has been recognized over the last several decades as a viable option to meet many satellite and spacecraft propulsion requirements. This technology, however, was never used for in-space missions. In the same time frame, water based fuel cells have flown in a number of missions. These systems have many components similar to electrolysis propulsion systems. Recent advances in component technology include: lightweight tankage, water vapor feed electrolysis, fuel cell technology, and thrust chamber materials for propulsion. Taken together, these developments make propulsion and/or power using electrolysis/fuel cell technology very attractive as separate or integrated systems. A water electrolysis propulsion testbed was constructed and tested in a joint NASA/Hamilton Standard/Lawrence Livermore National Laboratories program to demonstrate these technology developments for propulsion. The results from these testbed experiments using a I-N thruster are presented. A concept to integrate a propulsion system and a fuel cell system into a unitized spacecraft propulsion and power system is outlined.

  12. Chaos in attitude dynamics of spacecraft

    CERN Document Server

    Liu, Yanzhu

    2013-01-01

    Attitude dynamics is the theoretical basis of attitude control of spacecrafts in aerospace engineering. With the development of nonlinear dynamics, chaos in spacecraft attitude dynamics has drawn great attention since the 1990's. The problem of the predictability and controllability of the chaotic attitude motion of a spacecraft has a practical significance in astronautic science. This book aims to summarize basic concepts, main approaches, and recent progress in this area. It focuses on the research work of the author and other Chinese scientists in this field, providing new methods and viewpoints in the investigation of spacecraft attitude motion, as well as new mathematical models, with definite engineering backgrounds, for further analysis. Professor Yanzhu Liu was the Director of the Institute of Engineering Mechanics, Shanghai Jiao Tong University, China. Dr. Liqun Chen is a Professor at the Department of Mechanics, Shanghai University, China.

  13. Single reusable spacecraft

    Data.gov (United States)

    National Aeronautics and Space Administration — Design of a my single person reusable spacecraft. It can carry one person and it has to be dropped from an aircraft at an altitude of 40,000 - 45,000 feet. Can be...

  14. Statistical models of summer rainshowers derived from fine-scale radar observations. [for spacecraft microwave communications attenuation

    Science.gov (United States)

    Konrad, T. G.

    1978-01-01

    A statistical modeling of rain cell characteristics is presented; the modeling is based on high-resolution radar measurements of the cell structure. The analysis of the fine-scale three-dimensional structure of summer rainshowers in the mid-Atlantic region leads to statistical descriptions of the rain cells in terms of a variety of physical cell parameters. Core reflectivity profiles, contour area, and altitude extent of the cells have been determined along with the frequency of occurrence for various storm classes and categories. The statistical descriptions of the rain cells for the mid-Atlantic region were compared to descriptions for other areas, and the similarities and differences are described. Simplified models of rain cells based on the statistical descriptions are developed for the different rain categories as a function of frequency of occurrence.

  15. DEFINING AND CONSTRUCTING THE TEACHING MODEL OF ENTREPRENEUR EDUCATION BASED ON ENTREPRENEURIAL INTENTION MODEL

    Directory of Open Access Journals (Sweden)

    Henry Pribadi

    2005-01-01

    Full Text Available Concept of entrepreneurship has been widely debated whether to be an entrepreneur one need to get formal entrepreneurial education or not. Most of the formal entrepreneur education yield the same flaw, which is the lack of teaching soft skill and building the necessary entrepreneurship characteristics. Intention-based models of entrepreneurship education try to fill the gap by focusing the education on the human intention of becoming entrepreneur by defining four model of entrepreneurship education. An empirical research is conducted to show simple application on defining and understanding the model where the result could be used for giving some insight on constructing the appropriate model for entrepreneurship education in the future.

  16. On the construction of a regional atmospheric climate model

    DEFF Research Database (Denmark)

    Christensen, J. H.; Van Meijgaard, E.

    1992-01-01

    A Regional Atmospheric Climate Model which combines the physical parameterization package of the General Circulation or Climate Model (ECHAM) used at the Max Planck Institute for Meteorology in Hamburg, and the dynamics package of the Nordic - Dutch - Irish Limited Area Model (HIRLAM), has been...

  17. Modeling social influence through network autocorrelation : constructing the weight matrix

    NARCIS (Netherlands)

    Leenders, Roger Th. A. J.

    Many physical and social phenomena are embedded within networks of interdependencies, the so-called 'context' of these phenomena. In network analysis, this type of process is typically modeled as a network autocorrelation model. Parameter estimates and inferences based on autocorrelation models,

  18. A methodology for constructing the calculation model of scientific spreadsheets

    NARCIS (Netherlands)

    Vos, de M.; Wielemaker, J.; Schreiber, G.; Wielinga, B.; Top, J.L.

    2015-01-01

    Spreadsheets models are frequently used by scientists to analyze research data. These models are typically described in a paper or a report, which serves as single source of information on the underlying research project. As the calculation workflow in these models is not made explicit, readers are

  19. Modelling a Global EPCM (Engineering, Procurement and Construction Management Enterprise

    Directory of Open Access Journals (Sweden)

    Sekhar Chattopadhyay

    2010-03-01

    Full Text Available This paper investigates the applicability of enterprise architectures in the context of current business environment by examining the application of Purdue Enterprise Reference Architecture to WorleyParsons, a global engineering, procurement and construction management enterprise, under the backdrop of a similar study carried out on Fluor Daniel during mid-nineties of the last century. The outcome of this study recommends the need for new enterprise architecture, the People-Centric Enterprise Architecture that not only focuses on human dimension in modern enterprises as the central thread, but also includes more business characteristics of the enterprise other than engineerings.

  20. Spacecraft Dynamics Should be Considered in Kalman Filter Attitude Estimation

    Science.gov (United States)

    Yang, Yaguang; Zhou, Zhiqiang

    2016-01-01

    Kalman filter based spacecraft attitude estimation has been used in some high-profile missions and has been widely discussed in literature. While some models in spacecraft attitude estimation include spacecraft dynamics, most do not. To our best knowledge, there is no comparison on which model is a better choice. In this paper, we discuss the reasons why spacecraft dynamics should be considered in the Kalman filter based spacecraft attitude estimation problem. We also propose a reduced quaternion spacecraft dynamics model which admits additive noise. Geometry of the reduced quaternion model and the additive noise are discussed. This treatment is more elegant in mathematics and easier in computation. We use some simulation example to verify our claims.

  1. Two-dimensiosnal electron beam charging model for polymer films. M.S. Thesis; [spacecraft charging, geosynchronous satellites

    Science.gov (United States)

    Reeves, R. D.; Balmain, K. G.

    1981-01-01

    A two dimensional model was developed to describe the charging of thin polymer films exposed to a uniform mon-energetic electron beam. The study was motivated by observed anomalous behavior of geosynchronous satellites which was attributed to electrical discharges associated with the differential charging of satellite surfaces of magnetospheric electrons. Electric fields both internal and external to the irradiated specimen were calculated at steady state in order to identify regions of high electrical stress. Particular emphasis was placed on evaluating the charging characteristics near the material's edge. The model was used to identify and quantify the effects of some of the experimental parameters notably: beam energy; beam angle of incidence; beam current density; material thickness; and material width. Simulations of the following situations were also conducted: positive or negative precharging over part of the surface; a central gap in the material; and a discontinuity in the material's thickness.

  2. Research on network information security model and system construction

    OpenAIRE

    Wang Haijun

    2016-01-01

    It briefly describes the impact of large data era on China’s network policy, but also brings more opportunities and challenges to the network information security. This paper reviews for the internationally accepted basic model and characteristics of network information security, and analyses the characteristics of network information security and their relationship. On the basis of the NIST security model, this paper describes three security control schemes in safety management model and the...

  3. Construction of orthodontic setup models on a computer.

    Science.gov (United States)

    Kihara, Takuya; Tanimoto, Kotaro; Michida, Masahiko; Yoshimi, Yuki; Nagasaki, Toshikazu; Murayama, Takeshi; Tanne, Kazuo; Nikawa, Hiroki

    2012-06-01

    Orthodontic setup models are usually limited to the display of teeth, with no information about the roots. The purpose of this article is to present a method for visualizing the tooth roots in setup models by integrating information from cone-beam computed tomography and a laser scanner. The reproducibility of the integration was evaluated. The records of 5 patients were used in this study. Three-dimensional digital models were generated from the dental casts. Tooth models were generated from the cone-beam computed tomography slices. The 3-dimensional models were superimposed on the crowns of the teeth in the tooth models and integrated. The integrated 3-dimensional tooth model and 3-dimensional setup model were registered. The reproducibility of the integration was evaluated for each tooth. Unpaired Student t tests were performed on the data between the anterior and posterior teeth, and between the right and left teeth. The discrepancy among the integrated 3-dimensional models at the final positions after we used this technique was 0.025 ± 0.007 mm. There was a significant difference in the distance between the anterior and posterior teeth (P <0.05). However, the average distances between the anterior and posterior teeth were small: 0.023 ± 0.007 and 0.028 ± 0.007 mm, respectively. No significant difference was found between the right and left teeth (P = 0.831). The methods presented in this study provide a reproducible visualization of tooth roots in virtual setup models by registering accurate crown models to cone-beam computed tomography scans. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  4. Building Information Modeling for Managing Design and Construction

    DEFF Research Database (Denmark)

    Berard, Ole Bengt

    outcomes, such as building defects, schedule delays, and budget overruns are related. Research in other fields indicates a relationship between information management and the performance and efficiency of organizations. This has led to the assumption that better information will eventually lead to a better...... in the field of information systems. Design information quality is defined as conformance of the design information supplied by the design team to a contractor’s specifications for the planning and execution of a construction project. The following eight criteria have been identified in order to describe......, or outdated design information. * Precision – accurate geometry and unambiguous requirements for the scope. * Availability – effort to securely access current design information. * Distribution – effort to manage, share, and route design information. * Flexibility – effort to transform, extract, or update...

  5. A Model-Based Approach to Constructing Music Similarity Functions

    Science.gov (United States)

    West, Kris; Lamere, Paul

    2006-12-01

    Several authors have presented systems that estimate the audio similarity of two pieces of music through the calculation of a distance metric, such as the Euclidean distance, between spectral features calculated from the audio, related to the timbre or pitch of the signal. These features can be augmented with other, temporally or rhythmically based features such as zero-crossing rates, beat histograms, or fluctuation patterns to form a more well-rounded music similarity function. It is our contention that perceptual or cultural labels, such as the genre, style, or emotion of the music, are also very important features in the perception of music. These labels help to define complex regions of similarity within the available feature spaces. We demonstrate a machine-learning-based approach to the construction of a similarity metric, which uses this contextual information to project the calculated features into an intermediate space where a music similarity function that incorporates some of the cultural information may be calculated.

  6. Designing and Validating a Model for Measuring Innovation Capacity Construct

    Directory of Open Access Journals (Sweden)

    Mahmood Doroodian

    2014-01-01

    Full Text Available In today’s rapid changing and highly competitive business environment, innovation is broadly recognized as a powerful competitive weapon. Innovation is a dynamic process that needs continuous, evolving, and mastered management. Thus, companies need to monitor and measure their innovation capacity to manage the innovation process. Yet, there is lack of a psychometrically valid scale for innovation capacity construct in the current innovation literature. The purpose of this paper is to develop a reliable and valid scale of measurement for innovation capacity. To test its unidimensionality, reliability, and several components of validity, we used data collected from 175 small- and medium-sized enterprises (SMEs in Iran and performed a series of analyses. The reliability measures, exploratory and confirmatory factor analyses, and several components of validity tests strongly support a four-dimensional scale for measuring innovation capacity. The dimensions are knowledge and technology management, idea management, project development, and commercialization capabilities.

  7. A model for the construction of elementary concepts

    Science.gov (United States)

    von Glasersfeld, Ernst

    1999-03-01

    In his paper Les épistémologies constructivistes: Un nouveau commencement (Sciences de la Société, n°40, 1997), Jean-Louis Le Moigne poses the question: "Le rêve d'une connaissance autoréférentielle se fondant sur elle-même, est sans doute fascinant … Mais est-il scientifiquement raisonnable?". Building on the work of Jean Piaget, I shall try to show through a developmental analysis of elementary, scientifically relevant concepts, such as `change', `object permanence', `space', and `time', that the notion of the thinking subject's construction of knowledge constitutes a more reasonable foundation for science than the traditional belief in the representation of objective reality.

  8. Construction and Research of System Identifiable Mathematical Models

    OpenAIRE

    Robertas Janickas

    2011-01-01

    Paper discusses about control and data acquisition, processing, visualization, which must be adapted to the investigation and examination of identification process. A description of the device, the functionality and customization possibilities are presented. The relevant experimental model and its characteristics are obtained for measurement, control results using this model.Article in Lithuanian

  9. Construction and Research of System Identifiable Mathematical Models

    Directory of Open Access Journals (Sweden)

    Robertas Janickas

    2011-08-01

    Full Text Available Paper discusses about control and data acquisition, processing, visualization, which must be adapted to the investigation and examination of identification process. A description of the device, the functionality and customization possibilities are presented. The relevant experimental model and its characteristics are obtained for measurement, control results using this model.Article in Lithuanian

  10. Personal Construct Psychology Model of School Counselling Delivery

    Science.gov (United States)

    Truneckova, Deborah; Viney, Linda L.

    2012-01-01

    With increasing focus on the mental health of young people by schools, greater attention is directed to the responsiveness and effectiveness of models of psychological practice in schools. A model will be presented with a coherent theoretical structure within which the school counsellor can understand the diverse psychological symptoms and…

  11. Formation of the high-energy ion population in the earth's magnetotail: spacecraft observations and theoretical models

    Directory of Open Access Journals (Sweden)

    A. V. Artemyev

    2014-10-01

    Full Text Available We investigate the formation of the high-energy (E ∈ [20,600] keV ion population in the earth's magnetotail. We collect statistics of 4 years of Interball / Tail observations (1995–1998 in the vicinity of the neutral plane in the magnetotail region (X RE, |Y| ≤ 20 RE in geocentric solar magnetospheric (GSM system. We study the dependence of high-energy ion spectra on the thermal-plasma parameters (the temperature Ti and the amplitude of bulk velocity vi and on the magnetic-field component Bz. The ion population in the energy range E ∈ [20,600] keV can be separated in the thermal core and the power-law tail with the slope (index ~ −4.5. Fluxes of the high-energy ion population increase with the growth of Bz, vi and especially Ti, but spectrum index seems to be independent on these parameters. We have suggested that the high-energy ion population is generated by small scale transient processes, rather than by the global reconfiguration of the magnetotail. We have proposed the relatively simple and general model of ion acceleration by transient bursts of the electric field. This model describes the power-law energy spectra and predicts typical energies of accelerated ions.

  12. Fractionated Spacecraft Architectures Seeding Study

    National Research Council Canada - National Science Library

    Mathieu, Charlotte; Weigel, Annalisa

    2006-01-01

    The report introduces the concept of spacecraft fractionation, which transforms a traditional monolithic spacecraft into a network of elements where a free-flying payload module is supported by nearby...

  13. Constructing Business Models around Identity : Tensions in Architectural Firms

    NARCIS (Netherlands)

    Bos-De Vos, M.; Volker, L.; Chan, Paul W; Neilson, Christopher J.

    2017-01-01

    Architectural firms experience difficulties to establish healthy and sustainable business models as they have to reconcile the often-competing value systems that they are based upon. Organizational members continuously negotiate professional values and beliefs with the firm's commercial goals,

  14. A geometric construction of traveling waves in a bioremediation model

    NARCIS (Netherlands)

    Beck, M.A.; Doelman, A.; Kaper, T.J.

    2006-01-01

    Bioremediation is a promising technique for cleaning contaminated soil. We study an idealized bioremediation model involving a substrate (contaminant to be removed), electron acceptor (added nutrient), and microorganisms in a one-dimensional soil column. Using geometric singular perturbation theory,

  15. Modelling, simulation and construction of a dc/dc boost power converter: a school experimental system

    International Nuclear Information System (INIS)

    Silva-Ortigoza, R; Marciano-Melchor, M; Silva-Ortigoza, G; Hernández-Guzmán, V M; Saldaña-González, G; Marcelino-Aranda, M

    2012-01-01

    We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders the feasible introduction of this equipment in undergraduate laboratories. (paper)

  16. A Construction of Multisender Authentication Codes with Sequential Model from Symplectic Geometry over Finite Fields

    Directory of Open Access Journals (Sweden)

    Shangdi Chen

    2014-01-01

    Full Text Available Multisender authentication codes allow a group of senders to construct an authenticated message for a receiver such that the receiver can verify authenticity of the received message. In this paper, we construct multisender authentication codes with sequential model from symplectic geometry over finite fields, and the parameters and the maximum probabilities of deceptions are also calculated.

  17. Toward Intelligent Assessment: An Integration of Constructed Response Testing, Artificial Intelligence, and Model-Based Measurement.

    Science.gov (United States)

    Bennett, Randy Elliot

    A new assessment conception is described that integrates constructed-response testing, artificial intelligence, and model-based measurement. The conception incorporates complex constructed-response items for their potential to increase the validity, instructional utility, and credibility of standardized tests. Artificial intelligence methods are…

  18. A Model-Based Approach to Constructing Music Similarity Functions

    Directory of Open Access Journals (Sweden)

    Lamere Paul

    2007-01-01

    Full Text Available Several authors have presented systems that estimate the audio similarity of two pieces of music through the calculation of a distance metric, such as the Euclidean distance, between spectral features calculated from the audio, related to the timbre or pitch of the signal. These features can be augmented with other, temporally or rhythmically based features such as zero-crossing rates, beat histograms, or fluctuation patterns to form a more well-rounded music similarity function. It is our contention that perceptual or cultural labels, such as the genre, style, or emotion of the music, are also very important features in the perception of music. These labels help to define complex regions of similarity within the available feature spaces. We demonstrate a machine-learning-based approach to the construction of a similarity metric, which uses this contextual information to project the calculated features into an intermediate space where a music similarity function that incorporates some of the cultural information may be calculated.

  19. Voxel-based model construction from colored tomographic images

    International Nuclear Information System (INIS)

    Loureiro, Eduardo Cesar de Miranda

    2002-07-01

    This work presents a new approach in the construction of voxel-based phantoms that was implemented to simplify the segmentation process of organs and tissues reducing the time used in this procedure. The segmentation process is performed by painting tomographic images and attributing a different color for each organ or tissue. A voxel-based head and neck phantom was built using this new approach. The way as the data are stored allows an increasing in the performance of the radiation transport code. The program that calculates the radiation transport also works with image files. This capability allows image reconstruction showing isodose areas, under several points of view, increasing the information to the user. Virtual X-ray photographs can also be obtained allowing that studies could be accomplished looking for the radiographic techniques optimization assessing, at the same time, the doses in organs and tissues. The accuracy of the program here presented, called MCvoxEL, that implements this new approach, was tested by comparison to results from two modern and well-supported Monte Carlo codes. Dose conversion factors for parallel X-ray exposure were also calculated. (author)

  20. [Construction of competency model of 'excellent doctor' in Chinese medicine].

    Science.gov (United States)

    Jin, Aning; Tian, Yongquan; Zhao, Taiyang

    2014-05-01

    To evaluate outstanding and ordinary persons from personal characteristics using competency as the important criteria, which is the future direction of medical education reform. We carried on a behavior event interview about famous doctors of old traditional Chinese medicine, compiled competency dictionary, proceed control prediction test. SPSS and AMOS were used to be data analysis tools on statistics. We adopted the model of peer assessment and contrast to carry out empirical research. This project has carried on exploratory factor analysis and confirmatory factor analysis, established a "5A" competency model which include moral ability, thinking ability, communication ability, learning and practical ability. Competency model of "excellent doctor" in Chinese medicine has been validated, with good reliability and validity, and embodies the characteristics of traditional Chinese medicine personnel training, with theoretical and practical significance for excellence in medicine physician training.

  1. The construction and application of didactic models in Biochemistry teaching

    Directory of Open Access Journals (Sweden)

    Maximiliano de Souza Zierer

    2017-10-01

    Full Text Available This work describes how to build and use didactic models as a teaching resource to a more creative teaching in Biochemistry. Students are organized into groups to discuss the creation, planning and execution of models. Previously, the teacher guides the use of various materials for preparation and encourages the use of low cost materials. The day of the activity, held in the classroom, students build their models and are evaluated orally by the teacher about the functions or processes represented. At the end of class, we propose the presentation by each group, plus a general discussion about them. We find that that this methodology makes the classroom an environment highly conducive to creative expression, allowing students to develop their potential and making them effective learning, meaningful and longer lasting when compared to traditional teaching methods.

  2. A constructive model potential method for atomic interactions

    Science.gov (United States)

    Bottcher, C.; Dalgarno, A.

    1974-01-01

    A model potential method is presented that can be applied to many electron single centre and two centre systems. The development leads to a Hamiltonian with terms arising from core polarization that depend parametrically upon the positions of the valence electrons. Some of the terms have been introduced empirically in previous studies. Their significance is clarified by an analysis of a similar model in classical electrostatics. The explicit forms of the expectation values of operators at large separations of two atoms given by the model potential method are shown to be equivalent to the exact forms when the assumption is made that the energy level differences of one atom are negligible compared to those of the other.

  3. Biomass Scenario Model Scenario Library: Definitions, Construction, and Description

    Energy Technology Data Exchange (ETDEWEB)

    Inman, D.; Vimmerstedt, L.; Bush, B.; Peterson, S.

    2014-04-01

    Understanding the development of the biofuels industry in the United States is important to policymakers and industry. The Biomass Scenario Model (BSM) is a system dynamics model of the biomass-to-biofuels system that can be used to explore policy effects on biofuels development. Because of the complexity of the model, as well as the wide range of possible future conditions that affect biofuels industry development, we have not developed a single reference case but instead developed a set of specific scenarios that provide various contexts for our analyses. The purpose of this report is to describe the scenarios that comprise the BSM scenario library. At present, we have the following policy-focused scenarios in our library: minimal policies, ethanol-focused policies, equal access to policies, output-focused policies, technological diversity focused, and the point-of-production- focused. This report describes each scenario, its policy settings, and general insights gained through use of the scenarios in analytic studies.

  4. A Theoretical Model for Meaning Construction through Constructivist Concept Learning

    DEFF Research Database (Denmark)

    Badie, Farshad

    The central focus of this Ph.D. research is on ‘Logic and Cognition’ and, more specifically, this research covers the quintuple (Logic and Logical Philosophy, Philosophy of Education, Educational Psychology, Cognitive Science, Computer Science). The most significant contributions of this Ph...... of ‘learning’, ‘mentoring’, and ‘knowledge’ within learning and knowledge acquisition systems. Constructivism as an epistemology and as a model of knowing and, respectively as a theoretical model of learning builds up the central framework of this research....

  5. Construction of radiation - induced metastasis model in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Kuk; Jang, Su Jin; Kang, Sung Wook; Kim, Jae Sung; Hwang, Sang Gu; Kang, Joo Hyun [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2011-05-15

    In treatment of cancer, distant metastases are important limiting factor because an estimated 50% of all cancer patients will develop metastases, and the metastases are major causing of cancer treatment failure. Recently a few reports indicated {gamma}-radiation induced an increase of invasiveness of several cancer cells. In this study, we had tried to show the possibility that radiation could also induce metastasis in vivo system. To prove our hypothesis, we constructed primary tumor by using C6-TL transfectant cell line expressing HSV1-tk and firefly luciferase (fLuc), and then {gamma}-radiation was treated to xenografts locally. Treatment of {gamma}-radiation to primary C6-TL xenografts of mice reduced size of xenografts and elongated survival of mice than those of mock control mice. But we also show that {gamma}-radiation treatment was followed by the growth of dormant metastases in various organs including lung and intestine after 2-4 weeks of {gamma}-radiation treatment. When bioluminescence imaging indicated growth of tumor in organs in mice, we sacrificed the mice and repeat acquired bioluminescence imaging after repeatedly. These images presented tumor growth locations exactly in organs. Because metastatic tumor candidates have morphology of foci, biopsies were performed for histological analysis or PCR analysis to confirm metastases. In most foci, histological analysis indicated several features of typical cancer tissue and PCR analysis showed present of fLuc gene in metastases. Detection of fLuc gene in metastases indicated these foci were originated from primary C6-TL xenografts, and the results suggest that {gamma}-radiation could promote metastasis in vivo as well as in vitro system. Although we need to understand changes of intracellular signaling or physiological phenomena of the radiation-induced metastasis yet, these results also imply that {gamma}-radiation treatment only to cancer patients need to pay attention carefully, and development of new

  6. Case-Based Modeling for Learning: Socially Constructed Skill Development

    Science.gov (United States)

    Lyons, Paul; Bandura, Randall P.

    2018-01-01

    Purpose: Grounded on components of experiential learning theory (ELT) and self-regulation of learning (SRL) theory, augmented by elements of action theory and script development, the purpose of this paper is to demonstrate the case-based modeling (CBM) instructional approach that stimulates learning in groups or teams. CBM is related to individual…

  7. Model for setting priority construction project objectives aligned with ...

    African Journals Online (AJOL)

    A comprehensive model based on priority project objectives aligned with monetary incentives, and agreed upon by built environment stakeholders was developed. A web survey was adopted to send out a questionnaire to nationwide participants, including contractors, quantity surveyors, project managers, architects, and ...

  8. Building challenge : international education model for construction education

    NARCIS (Netherlands)

    Stern, G.P. (Glenn); Bazen, J.C. (Jacques); Gavrikov, D.S. (Dennis)

    2016-01-01

    http://dx.doi.org/10.14261/postit/DB158B96-42E6-4619-AB9259AD8729C0AC In 2015 and 2016, Saxion University of Applied Sciences organized the 2nd and 3rd edition of the Regional Innovation and Entrepreneurship Conference (RIEC).   The Building challenge is a new education model in which

  9. Constructing Self-Modeling Videos: Procedures and Technology

    Science.gov (United States)

    Collier-Meek, Melissa A.; Fallon, Lindsay M.; Johnson, Austin H.; Sanetti, Lisa M. H.; Delcampo, Marisa A.

    2012-01-01

    Although widely recommended, evidence-based interventions are not regularly utilized by school practitioners. Video self-modeling is an effective and efficient evidence-based intervention for a variety of student problem behaviors. However, like many other evidence-based interventions, it is not frequently used in schools. As video creation…

  10. Constructive Models of Discrete and Continuous Physical Phenomena

    Science.gov (United States)

    2014-02-08

    time. The hardware description language VHDL has a related model of time, where time is a member of N×N, and the second value is used in a manner...behaviors. Tech. Rep. RR 95–52, rev. RR (96–56), I3S, April 1996. 4. ARMSTRONG, J. R., AND GRAY, F. G. VHDL Design Representation and Synthesis, sec- ond

  11. 3D engineered models for highway construction : the Iowa experience.

    Science.gov (United States)

    2015-06-01

    3D engineered modeling is a relatively new and developing technology that can provide numerous bene ts to owners, engineers, : contractors, and the general public. This manual is for highway agencies that are considering or are in the process of s...

  12. Construction and Updating of Event Models in Auditory Event Processing

    Science.gov (United States)

    Huff, Markus; Maurer, Annika E.; Brich, Irina; Pagenkopf, Anne; Wickelmaier, Florian; Papenmeier, Frank

    2018-01-01

    Humans segment the continuous stream of sensory information into distinct events at points of change. Between 2 events, humans perceive an event boundary. Present theories propose changes in the sensory information to trigger updating processes of the present event model. Increased encoding effort finally leads to a memory benefit at event…

  13. Constructive Lower Bounds on Model Complexity of Shallow Perceptron Networks

    Czech Academy of Sciences Publication Activity Database

    Kůrková, Věra

    2018-01-01

    Roč. 29, č. 7 (2018), s. 305-315 ISSN 0941-0643 R&D Projects: GA ČR GA15-18108S Institutional support: RVO:67985807 Keywords : shallow and deep networks * model complexity and sparsity * signum perceptron networks * finite mappings * variational norms * Hadamard matrices Subject RIV: IN - Informatics, Computer Science Impact factor: 2.505, year: 2016

  14. A multi-agent safety response model in the construction industry.

    Science.gov (United States)

    Meliá, José L

    2015-01-01

    The construction industry is one of the sectors with the highest accident rates and the most serious accidents. A multi-agent safety response approach allows a useful diagnostic tool in order to understand factors affecting risk and accidents. The special features of the construction sector can influence the relationships among safety responses along the model of safety influences. The purpose of this paper is to test a model explaining risk and work-related accidents in the construction industry as a result of the safety responses of the organization, the supervisors, the co-workers and the worker. 374 construction employees belonging to 64 small Spanish construction companies working for two main companies participated in the study. Safety responses were measured using a 45-item Likert-type questionnaire. The structure of the measure was analyzed using factor analysis and the model of effects was tested using a structural equation model. Factor analysis clearly identifies the multi-agent safety dimensions hypothesized. The proposed safety response model of work-related accidents, involving construction specific results, showed a good fit. The multi-agent safety response approach to safety climate is a useful framework for the assessment of organizational and behavioral risks in construction.

  15. The MSAT spacecraft of Telesat Mobile Inc.

    Science.gov (United States)

    Bertenyi, E.

    The MSAT spacecraft of the Canadian mobile satellite operator, Telesat Mobile Inc. (TMI) is described. When launched in 1994, the large geostationary MSAT spacecraft which is currently under construction by Hughes Aircraft Co. and Spar Aerospace Ltd. will enable TMI to provide mobile and transportable communications services to its customers even in the most remote parts of the North American continent. The main elements of TMI's mobile satellite system (described in a companion paper) are the space segment and the ground segment. TMI's space segment will employ one of two nearly identical satellites, one of which will be owned and operated by TMI, the other by the U.S. mobile satellite operator, American Mobile Satellite Corporation (AMSC). The two companies are participating in a joint spacecraft procurement in order to reduce the nonrecurring costs and to ensure system compatibility between the two systems; and they have also agreed to provide in-orbit backup to each other in the event of a catastrophic satellite failure. The program status, performance requirements, main parameters, and configuration of the MSAT spacecraft are reviewed. The major features of the communications subsystem are discussed in some detail, and a brief summary is presented of the spacecraft service module. Key technology items include the L-band RF power amplifier, which must operate with a high DC to RF power efficiency and generate low intermodulation when loaded with multi-carrier signals; and the large diameter deployable L-band antenna. The development status and expected performance of these spacecraft components is examined.

  16. Evolutionary Game Model Study of Construction Green Supply Chain Management under the Government Intervention

    Science.gov (United States)

    Xing, Yuanzhi; Deng, Xiaoyi

    2017-11-01

    The paper first has defined the concepts of green supply chain management and evolution game theory, and pointed out the characteristics of green supply chain management in construction. The main participants and key links of the construction green supply chain management are determined by constructing the organization framework. This paper established the evolutionary game model between construction enterprises and recycling enterprises for the green supply chain closed-loop structure. The waste recycling evolutionary stability equilibrium solution is obtained to explore the principle and effective scope of government policy intervention. This paper put forward the relevant countermeasures to the green supply chain management in construction recycling stage from the government point of view. The conclusion has reference value and guidance to the final product construction enterprises, recycling enterprises and the government during green supply chain.

  17. Decision support model for selecting and evaluating suppliers in the construction industry

    Directory of Open Access Journals (Sweden)

    Fernando Schramm

    2012-12-01

    Full Text Available A structured evaluation of the construction industry's suppliers, considering aspects which make their quality and credibility evident, can be a strategic tool to manage this specific supply chain. This study proposes a multi-criteria decision model for suppliers' selection from the construction industry, as well as an efficient evaluation procedure for the selected suppliers. The model is based on SMARTER (Simple Multi-Attribute Rating Technique Exploiting Ranking method and its main contribution is a new approach to structure the process of suppliers' selection, establishing explicit strategic policies on which the company management system relied to make the suppliers selection. This model was applied to a Civil Construction Company in Brazil and the main results demonstrate the efficiency of the proposed model. This study allowed the development of an approach to Construction Industry which was able to provide a better relationship among its managers, suppliers and partners.

  18. Waste generated in high-rise buildings construction: a quantification model based on statistical multiple regression.

    Science.gov (United States)

    Parisi Kern, Andrea; Ferreira Dias, Michele; Piva Kulakowski, Marlova; Paulo Gomes, Luciana

    2015-05-01

    Reducing construction waste is becoming a key environmental issue in the construction industry. The quantification of waste generation rates in the construction sector is an invaluable management tool in supporting mitigation actions. However, the quantification of waste can be a difficult process because of the specific characteristics and the wide range of materials used in different construction projects. Large variations are observed in the methods used to predict the amount of waste generated because of the range of variables involved in construction processes and the different contexts in which these methods are employed. This paper proposes a statistical model to determine the amount of waste generated in the construction of high-rise buildings by assessing the influence of design process and production system, often mentioned as the major culprits behind the generation of waste in construction. Multiple regression was used to conduct a case study based on multiple sources of data of eighteen residential buildings. The resulting statistical model produced dependent (i.e. amount of waste generated) and independent variables associated with the design and the production system used. The best regression model obtained from the sample data resulted in an adjusted R(2) value of 0.694, which means that it predicts approximately 69% of the factors involved in the generation of waste in similar constructions. Most independent variables showed a low determination coefficient when assessed in isolation, which emphasizes the importance of assessing their joint influence on the response (dependent) variable. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Take it NP-easy: Bounded model construction for duration calculus

    DEFF Research Database (Denmark)

    Fränzle, Martin

    2002-01-01

    Following the recent successes of bounded model-checking, we reconsider the problem of constructing models of discrete-time Duration Calculus formulae. While this problem is known to be non-elementary when arbitrary length models are considered [Hansen94], it turns out to be only NP-complete when...... constrained to bounded length. As a corollary we obtain that model construction is in NP for the formulae actually encountered in case studies using Duration Calculus, as these have a certain small-model property. First experiments with a prototype implementation of the procedures demonstrate a competitive...

  20. Constructing an integrated model of the antecedents of adolescent smoking.

    Science.gov (United States)

    Wilkinson, Dawn; Abraham, Charles

    2004-09-01

    Reviews have called for integrative, theoretically informed models of the 'hundreds of associations' (Miller & Slap, 1989, p. 131) between psychosocial measures and adolescent smoking (e. g. Tyas & Pederson, 1998). Such a model was tested. A prospective, classroom-based survey measuring previously identified correlates of smoking allowed comparison of the strength of relationships between antecedents and smoking status six months later. The prospective sample included 225 13 to 14-year-olds. Measures of behaviour-specific cognitions derived from the Theory of Planned Behaviour (TPB)-as well as personality, self-esteem, parental support and parental control, sociodemographic factors, and descriptive norms-were included. Relationships between antecedents were explored using path analyses. High initial rates of smoking were observed. Of the variance in smoking six months later, 56% was explained by seven direct predictors: intention, perceived ease of smoking, estimated number of friends smoking, percentage of older brothers smoking, self-esteem, extraversion and car access. Results emphasize the importance of behaviour-specific cognitions specified by the TPB but suggest that other factors, including extraversion and self-esteem, need to be included in models of the antecedents of smoking. The findings also imply that some antecedents, such as parental support, may indirectly influence adolescent smoking through their effect on other variables.

  1. Construction of a Cyber Attack Model for Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Varuttamaseni, Athi; Bari, Robert A.; Youngblood, Robert

    2017-05-01

    The consideration of how one compromised digital equipment can impact neighboring equipment is critical to understanding the progression of cyber attacks. The degree of influence that one component may have on another depends on a variety of factors, including the sharing of resources such as network bandwidth or processing power, the level of trust between components, and the inclusion of segmentation devices such as firewalls. The interactions among components via mechanisms that are unique to the digital world are not usually considered in traditional PRA. This means potential sequences of events that may occur during an attack may be missed if one were to only look at conventional accident sequences. This paper presents a method where, starting from the initial attack vector, the progression of a cyber attack can be modeled. The propagation of the attack is modeled by considering certain attributes of the digital components in the system. These attributes determine the potential vulnerability of a component to a class of attack and the capability gained by the attackers once they are in control of the equipment. The use of attributes allows similar components (components with the same set of attributes) to be modeled in the same way, thereby reducing the computing resources required for analysis of large systems.

  2. Evaluation on the efficiency of the construction sector companies in Malaysia with data envelopment analysis model

    Science.gov (United States)

    Weng Hoe, Lam; Jinn, Lim Shun; Weng Siew, Lam; Hai, Tey Kim

    2018-04-01

    In Malaysia, construction sector is essential parts in driving the development of the Malaysian economy. Construction industry is an economic investment and its relationship with economic development is well posited. However, the evaluation on the efficiency of the construction sectors companies listed in Kuala Lumpur Stock Exchange (KLSE) with Data Analysis Envelopment (DEA) model have not been actively studied by the past researchers. Hence the purpose of this study is to examine the financial performance the listed construction sectors companies in Malaysia in the year of 2015. The results of this study show that the efficiency of construction sectors companies can be obtained by using DEA model through ratio analysis which defined as the ratio of total outputs to total inputs. This study is significant because the inefficient companies are identified for potential improvement.

  3. Challenges of the expansive use of Building Information Modeling (BIM in construction projects

    Directory of Open Access Journals (Sweden)

    Hannele Kerosuo

    2015-06-01

    Full Text Available Building information modeling (BIM is an emerging modeling technology which challenges existing work procedures and practices in the construction industry. In this article we study the challenges, problems and potential expansions of BIM as a tool in the design, construction and operation of buildings. For this purpose the interfaces between different parties are examined in Finnish construction projects. The methodological approach of the study is cultural-historical activity theory, according to which a new artifact becomes a mediating instrument when the participatory subjects reconfigure the entire activity. The implementation of BIM is now spreading from the design activity to other phases of the construction projects, but its use is still limited in the projects' other three interfaces. BIM is an evolving set of software developed for various purposes which is locally 'combined' to fit the circumstances and capabilities of the stakeholders of the construction process.

  4. Robust Spacecraft Component Detection in Point Clouds.

    Science.gov (United States)

    Wei, Quanmao; Jiang, Zhiguo; Zhang, Haopeng

    2018-03-21

    Automatic component detection of spacecraft can assist in on-orbit operation and space situational awareness. Spacecraft are generally composed of solar panels and cuboidal or cylindrical modules. These components can be simply represented by geometric primitives like plane, cuboid and cylinder. Based on this prior, we propose a robust automatic detection scheme to automatically detect such basic components of spacecraft in three-dimensional (3D) point clouds. In the proposed scheme, cylinders are first detected in the iteration of the energy-based geometric model fitting and cylinder parameter estimation. Then, planes are detected by Hough transform and further described as bounded patches with their minimum bounding rectangles. Finally, the cuboids are detected with pair-wise geometry relations from the detected patches. After successive detection of cylinders, planar patches and cuboids, a mid-level geometry representation of the spacecraft can be delivered. We tested the proposed component detection scheme on spacecraft 3D point clouds synthesized by computer-aided design (CAD) models and those recovered by image-based reconstruction, respectively. Experimental results illustrate that the proposed scheme can detect the basic geometric components effectively and has fine robustness against noise and point distribution density.

  5. About the Big Graphs Arising when Forming the Diagnostic Models in a Reconfigurable Computing Field of Functional Monitoring and Diagnostics System of the Spacecraft Onboard Control Complex

    Directory of Open Access Journals (Sweden)

    L. V. Savkin

    2015-01-01

    Full Text Available One of the problems in implementation of the multipurpose complete systems based on the reconfigurable computing fields (RCF is the problem of optimum redistribution of logicalarithmetic resources in growing scope of functional tasks. Irrespective of complexity, all of them are transformed into an orgraph, which functional and topological structure is appropriately imposed on the RCF based, as a rule, on the field programmable gate array (FPGA.Due to limitation of the hardware configurations and functions realized by means of the switched logical blocks (SLB, the abovementioned problem becomes even more critical when there is a need, within the strictly allocated RCF fragment, to realize even more complex challenge in comparison with the problem which was solved during the previous computing step. In such cases it is possible to speak about graphs of big dimensions with respect to allocated RCF fragment.The article considers this problem through development of diagnostic algorithms to implement diagnostics and control of an onboard control complex of the spacecraft using RCF. It gives examples of big graphs arising with respect to allocated RCF fragment when forming the hardware levels of a diagnostic model, which, in this case, is any hardware-based algorithm of diagnostics in RCF.The article reviews examples of arising big graphs when forming the complicated diagnostic models due to drastic difference in formation of hardware levels on closely located RCF fragments. It also pays attention to big graphs emerging when the multichannel diagnostic models are formed.Three main ways to solve the problem of big graphs with respect to allocated RCF fragment are given. These are: splitting the graph into fragments, use of pop-up windows with relocating and memorizing intermediate values of functions of high hardware levels of diagnostic models, and deep adaptive update of diagnostic model.It is shown that the last of three ways is the most efficient

  6. Network design and operational modelling for construction green supply chain management

    Directory of Open Access Journals (Sweden)

    Pengfei Zhou Dong Chen

    2013-01-01

    Full Text Available Based on studying organizational structure of Construction Green Supply Chain Management (CGSCM, a mathematical programming model of CGSCM was proposed. The model aimed to maximize the aggregate profits of normalized construction logistics, the reverse logistics and the environmental performance. Numerical experiments show that the proposed approach can improve the aggregate profit effectively. In addition, return ratio, subsidies from governmental organizations, and environmental performance were analyzed for CGSCM performance. Herein, the proper return, subsidy and control strategy could optimize construction green supply chain.

  7. Constructing warm inflationary model in brane–antibrane system

    Energy Technology Data Exchange (ETDEWEB)

    Setare, M.R., E-mail: rezakord@ipm.ir [Department of Science, Campus of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Sepehri, A., E-mail: alireza.sepehri@uk.ac.ir [Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Kamali, V., E-mail: Vkamali@basu.ac.ir [Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamedan, 65178 (Iran, Islamic Republic of)

    2014-07-30

    Recently, various observational data predicted a possibility that inflation may naturally occur in a warm region. In this scenario, radiation is produced during the inflation epoch and reheating is avoided. The main question arises as to what is the origin of warm inflation in 4D universe? We answer this question in brane–antibrane system. We propose a model that allows all cosmological parameters like the scale factor a, the Hubble parameter H and phantom energy density depend on the equation of state parameter in transverse dimension between two branes. Thus, an enhancement in these parameters can be a signature of some evolutions in extra dimension. In our model, the expansion of 4D universe is controlled by the separation distance between branes and evolves from non-phantom phase to phantom one. Consequently, phantom-dominated era of the universe accelerates and ends up in big-rip singularity. Also, we show that as the tachyon potential increases, the effect of interaction between branes on the 4D universe expansion becomes systematically more effective, because at higher energies there exist more channels for flowing energy from extra dimension to other four dimensions. Finally, we test our model against WMAP and Planck data and obtain the ripping time. According to experimental data, N≃50 case leads to n{sub s}≃0.96, where N and n{sub s} are the number e-folds and the spectral index respectively. This standard case may be found in 0.01

  8. Mental model construction in the "EarthView" classroom

    Science.gov (United States)

    Tallon, Rosaleen Jude

    EarthView Explorer is a CD-ROM developed to supplement topics covered in middle and high school earth science courses. The objective was to provide students with the opportunity to explore real scientific data using an interface that maximized flexibility in retrieval and analysis, while providing a consistent visual framework for students to use during learning. This exploratory case study of three suburban high school earth science classes examined the interaction of a teacher and his students with EarthView software to begin to understand its effects on teaching and learning. Observations, student journals, pre- and post-questions, and interviews were analyzed. In addition, this study explored the potential of mental model drawing to demonstrate students' mental images of the Earth including its component subsystems and related processes acquired through EarthView. A rubric was developed to assess diagrams on their ability to illustrate parts, connections, and the underlying mechanism of a system and to rate student groups as super, master, apprentice, and novice model builders. This research demonstrated that EarthView software influenced two aspects of learning. Students acquired a substantial amount of earth science content knowledge and were able to exercise science process skills such as graphing data, recognizing patterns, correlating and controlling variables, developing hypotheses, making inferences and forming generalizations. Students were able to "rediscover" various concepts and theories in much the same way as scientists. This "rediscovery" approach fostered by EarthView changed the nature of the classroom The teacher assumed the role of expert, guide, and facilitator. The student assumed the role of investigator. Topics that had been taught previously in a more traditional manner were turned over to students who learned by exploring, asking questions, sampling, gathering and interpreting data. Student mental model diagrams provided a means of

  9. Innovation evaluation model for macro-construction sector companies: A study in Spain.

    Science.gov (United States)

    Zubizarreta, Mikel; Cuadrado, Jesús; Iradi, Jon; García, Harkaitz; Orbe, Aimar

    2017-04-01

    The innovativeness of the traditional construction sector, composed of construction companies or contractors, is not one of its strong points. Likewise, its poor productivity in comparison with other sectors, such as manufacturing, has historically been criticized. Similar features are found in the Spanish traditional construction sector, which it has been described as not very innovative. However, certain characteristics of the sector may explain this behavior; the companies invest in R+D less than in other sectors and release fewer patents, so traditional innovation evaluation indicators do not reflect the true extent of its innovative activity. While previous research has focused on general innovation evaluation models, limited research has been done regarding innovation evaluation in the macro-construction sector, which includes, apart from the traditional construction companies or contractors, all companies related to the infrastructure life-cycle. Therefore, in this research an innovation evaluation model has been developed for macro-construction sector companies and is applied in the Spanish case. The model may be applied to the macro-construction sector companies in other countries, requiring the adaption of the model to the specific characteristics of the sector in that country, in consultation with a panel of experts at a national level. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Propellant-free Spacecraft Relative Maneuvering via Atmospheric Differential Drag

    Science.gov (United States)

    2015-07-06

    vectorized form Rp Pearson correlation coefficient Re Earth mean radius S Spacecraft cross- wind section area for chaser and target spacecraft...trajectories are modeled using Simulink in the initialization part of the simulation (prior to running STK). The simulation architecture can be seen in...F., Romano, M., and Bevilacqua, R., “Lyapunov-Based Thrusters’ Selection for Spacecraft Control: Analysis and Experimentation,” AIAA Journal of

  11. Modeling Signal-Noise Processes Supports Student Construction of a Hierarchical Image of Sample

    Science.gov (United States)

    Lehrer, Richard

    2017-01-01

    Grade 6 (modal age 11) students invented and revised models of the variability generated as each measured the perimeter of a table in their classroom. To construct models, students represented variability as a linear composite of true measure (signal) and multiple sources of random error. Students revised models by developing sampling…

  12. Construction and updating of event models in auditory event processing.

    Science.gov (United States)

    Huff, Markus; Maurer, Annika E; Brich, Irina; Pagenkopf, Anne; Wickelmaier, Florian; Papenmeier, Frank

    2018-02-01

    Humans segment the continuous stream of sensory information into distinct events at points of change. Between 2 events, humans perceive an event boundary. Present theories propose changes in the sensory information to trigger updating processes of the present event model. Increased encoding effort finally leads to a memory benefit at event boundaries. Evidence from reading time studies (increased reading times with increasing amount of change) suggest that updating of event models is incremental. We present results from 5 experiments that studied event processing (including memory formation processes and reading times) using an audio drama as well as a transcript thereof as stimulus material. Experiments 1a and 1b replicated the event boundary advantage effect for memory. In contrast to recent evidence from studies using visual stimulus material, Experiments 2a and 2b found no support for incremental updating with normally sighted and blind participants for recognition memory. In Experiment 3, we replicated Experiment 2a using a written transcript of the audio drama as stimulus material, allowing us to disentangle encoding and retrieval processes. Our results indicate incremental updating processes at encoding (as measured with reading times). At the same time, we again found recognition performance to be unaffected by the amount of change. We discuss these findings in light of current event cognition theories. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  13. Distributed Spacecraft Control Architectures

    Science.gov (United States)

    Carpenter, James Russell; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    A fundamental issue for estimation and control of distributed systems such as formation flying spacecraft is the information exchange architecture. In centralized schemes, each subordinate need only share its measurement data with a central hub, and the subordinates depend on the center to direct their actions. In decentralized schemes, all nodes participate in the data exchange, so that each has the same in by formation as the center, and may thereby self-direct the same action that the center would have commanded, assuming all share a common goal. This talk compares and contrasts the centralized and decentralized schemes in the context of autonomously maintaining a distributed satellite formation.

  14. On the possibility on constructing covariant chromomagnetic field models

    International Nuclear Information System (INIS)

    Cabo, A.; Penaranda, S.; Martinez, R.

    1995-03-01

    Expressions for SO(4) invariant euclidean QCD generating functionals are introduced which should produce non-vanishing gluon condensates. Their investigation is started here by initially considering the loop expansion of the corresponding effective action searching for a description differing from the usual perturbation theory. At this level, we consider special free propagators showing a sort or off-diagonal long range order. The calculation of the polarization tensor leads to a gluon mass term which is proportional to the squared root of the also finite value for 2 >. The summation of all the one-loop contributions to the energy having only mass insertions, indicates the spontaneous generation of the condensate from the perturbative grounds state in a way resembling the similar effect in the case of the chromomagnetic field models. This initial inspection suggests the need for a closer investigation which will be considered elsewhere. (author). 22 refs

  15. Using Gaussian Processes to Construct Flexible Models of Stellar Spectra

    Science.gov (United States)

    Czekala, Ian

    2018-01-01

    The use of spectra is fundamental to astrophysical fields ranging from exoplanets to stars to galaxies. In spite of this ubiquity, or perhaps because of it, there are a plethora of use cases that do not yet have physics-based forward models that can fit high signal-to-noise data to within the observational noise. These inadequacies result in subtle but systematic residuals not captured by any model, which complicates and biases parameter inference. Fortunately, the now-prevalent collection and archiving of large spectral datasets also provides an opening for empirical, data-driven approaches. We introduce one example of a time-series dataset of high-resolution stellar spectra, as is commonly delivered by planet-search radial velocity instruments like TRES, HIRES, and HARPS. Measurements of radial velocity variations of stars and their companions are essential for stellar and exoplanetary study; these measurements provide access to the fundamental physical properties that dictate all phases of stellar evolution and facilitate the quantitative study of planetary systems. In observations of a (spatially unresolved) spectroscopic binary star, one only ever records the composite sum of the spectra from the primary and secondary stars, complicating photospheric analysis of each individual star. Our technique “disentangles” the composite spectra by treating each underlying stellar spectrum as a Gaussian process, whose posterior predictive distribution is inferred simultaneously with the orbital parameters. To demonstrate the potential of this technique, we deploy it on red-optical time-series spectra of the mid-M-dwarf eclipsing binary LP661-13, which was recently discovered by the MEarth project. We successfully reconstruct the primary and secondary stellar spectra and report orbital parameters with improved precision compared to traditional radial velocity analysis techniques.

  16. Exploring Interface Problems in Taiwan’s Construction Projects Using Structural Equation Modeling

    Directory of Open Access Journals (Sweden)

    Chien-Liang Lin

    2017-05-01

    Full Text Available Construction projects are complex systems that inherently contain complex interface problems. This study explored the root causes of interface problems in construction projects using structural equation modeling. This technique is a systematic approach that combines factor analysis and path analysis to investigate the causal relationships among multidimensional factors. The literature on construction interface problems was reviewed, and a questionnaire survey was conducted in Taiwan to identify 27 initial factors that cause interface problems in three dimensions: owner, design, and construction. Then, a series of structural equation models (SEMs was developed to further explore the root causes of the interface problems and their causal relationships. This study has three main findings: (1 poor design causes interface problems; (2 ineffective communication and coordination among the owner, design, and construction dimensions are the main factors that cause construction interface problems; and (3 a lack of communication and coordination has a greater influence on the construction dimension than on the owner and design dimensions. The above findings can be used as important references and sustainable management strategies for academia and decision-makers in the construction industry.

  17. Building information modelling (BIM) after ten years: Malaysian construction players’ perception of BIM

    Science.gov (United States)

    Latiffi, A. Ahmad; Brahim, J.; Fathi, M. S.

    2017-08-01

    Building Information Modelling (BIM) concept has expanded widely in many countries for more than a decade with its role of improving current practices in construction projects. However, the understanding of BIM differs among construction players, depending on how construction players utilize the concept in their projects. Therefore, this paper aims to explore the understanding of BIM concept among construction players in the Malaysian construction industry. A literature review on BIM concept and semi-structured interviews with construction players in BIM such as client, civil and structural (C&S) engineer and mechanical and electrical (M&E) engineer, quantity surveyor (QS), contractor, facilities manager and BIM consultant have been conducted in order to achieve this study’s the aim. The results show that the understanding of BIM concept among the construction players is limited to BIM as a process and technology. It is important for the construction players to improve their understanding of BIM as it can be used to enhance performance and productivity of construction projects.

  18. Calibration models for density borehole logging - construction report

    International Nuclear Information System (INIS)

    Engelmann, R.E.; Lewis, R.E.; Stromswold, D.C.

    1995-10-01

    Two machined blocks of magnesium and aluminum alloys form the basis for Hanford's density models. The blocks provide known densities of 1.780 ± 0.002 g/cm 3 and 2.804 ± 0.002 g/cm 3 for calibrating borehole logging tools that measure density based on gamma-ray scattering from a source in the tool. Each block is approximately 33 x 58 x 91 cm (13 x 23 x 36 in.) with cylindrical grooves cut into the sides of the blocks to hold steel casings of inner diameter 15 cm (6 in.) and 20 cm (8 in.). Spacers that can be inserted between the blocks and casings can create air gaps of thickness 0.64, 1.3, 1.9, and 2.5 cm (0.25, 0.5, 0.75 and 1.0 in.), simulating air gaps that can occur in actual wells from hole enlargements behind the casing

  19. Model construction of “earning money by taking photos”

    Science.gov (United States)

    Yang, Jingmei

    2018-03-01

    In the era of information, with the increasingly developed network, “to earn money by taking photos” is a self-service model under the mobile Internet. The user downloads the APP, registers as a member of the APP, and then takes a task that needs to take photographs from the APP and earns the reward of the task on the APP. The article uses the task data and membership information data of an already completed project, including the member’s location and reputation value. On the basis of reasonable assumption, the data was processed with the MATLAB, SPSS and Excel software. This article mainly studied problems of the function relationship between the task performance, task position (GPS latitude and GPS longitude) and task price of users, analyzed the project’s task pricing rules and the reasons why the task is not completed, and applied multivariate regression function and GeoQ software to analyze the data, studied the task pricing rules, applied the chart method to solve the complex data, clear and easy to understand, and also reality simulation is applied to analyze why the tasks are not completed. Also, compared with the previous program, a new task pricing program is designed for the project to obtain the confidence level by means of the SPSS software, to estimate the reasonable range of the task pricing, predict and design a new pricing program on the reasonable price range.

  20. Improving Traditional Building Repair Construction Quality Using Historic Building Information Modeling Concept

    Science.gov (United States)

    Wu, T. C.; Lin, Y. C.; Hsu, M. F.; Zheng, N. W.; Chen, W. L.

    2013-07-01

    In addition to the repair construction project following the repair principles contemplated by heritage experts, the construction process should be recorded and measured at any time for monitoring to ensure the quality of repair. The conventional construction record methods mostly depend on the localized shooting of 2D digital images coupled with text and table for illustration to achieve the purpose of monitoring. Such methods cannot fully and comprehensively record the 3D spatial relationships in the real world. Therefore, the construction records of traditional buildings are very important but cannot function due to technical limitations. This study applied the 3D laser scanning technology to establish a 3D point cloud model for the repair construction of historical buildings. It also broke down the detailed components of the 3D point cloud model by using the concept of the historic building information modeling, and established the 3D models of various components and their attribute data in the 3DGIS platform database. In the construction process, according to the time of completion of each stage as developed on the construction project, this study conducted the 3D laser scanning and database establishment for each stage, also applied 3DGIS spatial information and attribute information comparison and analysis to propose the analysis of differences in completion of various stages for improving the traditional building repair construction quality. This method helps to improve the quality of repair construction work of tangible cultural assets of the world. The established 3DGIS platform can be used as a power tool for subsequent management and maintenance.

  1. IMPROVING TRADITIONAL BUILDING REPAIR CONSTRUCTION QUALITY USING HISTORIC BUILDING INFORMATION MODELING CONCEPT

    Directory of Open Access Journals (Sweden)

    T. C. Wu

    2013-07-01

    Full Text Available In addition to the repair construction project following the repair principles contemplated by heritage experts, the construction process should be recorded and measured at any time for monitoring to ensure the quality of repair. The conventional construction record methods mostly depend on the localized shooting of 2D digital images coupled with text and table for illustration to achieve the purpose of monitoring. Such methods cannot fully and comprehensively record the 3D spatial relationships in the real world. Therefore, the construction records of traditional buildings are very important but cannot function due to technical limitations. This study applied the 3D laser scanning technology to establish a 3D point cloud model for the repair construction of historical buildings. It also broke down the detailed components of the 3D point cloud model by using the concept of the historic building information modeling, and established the 3D models of various components and their attribute data in the 3DGIS platform database. In the construction process, according to the time of completion of each stage as developed on the construction project, this study conducted the 3D laser scanning and database establishment for each stage, also applied 3DGIS spatial information and attribute information comparison and analysis to propose the analysis of differences in completion of various stages for improving the traditional building repair construction quality. This method helps to improve the quality of repair construction work of tangible cultural assets of the world. The established 3DGIS platform can be used as a power tool for subsequent management and maintenance.

  2. Construction of a digital elevation model: methods and parallelization

    International Nuclear Information System (INIS)

    Mazzoni, Christophe

    1995-01-01

    The aim of this work is to reduce the computation time needed to produce the Digital Elevation Models (DEM) by using a parallel machine. It is made in collaboration between the French 'Institut Geographique National' (IGN) and the Laboratoire d'Electronique de Technologie et d'Instrumentation (LETI) of the French Atomic Energy Commission (CEA). The IGN has developed a system which provides DEM that is used to produce topographic maps. The kernel of this system is the correlator, a software which automatically matches pairs of homologous points of a stereo-pair of photographs. Nevertheless the correlator is expensive In computing time. In order to reduce computation time and to produce the DEM with same accuracy that the actual system, we have parallelized the IGN's correlator on the OPENVISION system. This hardware solution uses a SIMD (Single Instruction Multiple Data) parallel machine SYMPATI-2, developed by the LETI that is involved in parallel architecture and image processing. Our analysis of the implementation has demonstrated the difficulty of efficient coupling between scalar and parallel structure. So we propose solutions to reinforce this coupling. In order to accelerate more the processing we evaluate SYMPHONIE, a SIMD calculator, successor of SYMPATI-2. On an other hand, we developed a multi-agent approach for what a MIMD (Multiple Instruction, Multiple Data) architecture is available. At last, we describe a Multi-SIMD architecture that conciliates our two approaches. This architecture offers a capacity to apprehend efficiently multi-level treatment image. It is flexible by its modularity, and its communication network supplies reliability that interest sensible systems. (author) [fr

  3. Modeling the factors affecting unsafe behavior in the construction industry from safety supervisors' perspective.

    Science.gov (United States)

    Khosravi, Yahya; Asilian-Mahabadi, Hassan; Hajizadeh, Ebrahim; Hassanzadeh-Rangi, Narmin; Bastani, Hamid; Khavanin, Ali; Mortazavi, Seyed Bagher

    2014-01-01

    There can be little doubt that the construction is the most hazardous industry in the worldwide. This study was designed to modeling the factors affecting unsafe behavior from the perspective of safety supervisors. The qualitative research was conducted to extract a conceptual model. A structural model was then developed based on a questionnaire survey (n=266) by two stage Structural Equation Model (SEM) approach. An excellent confirmed 12-factors structure explained about 62% of variances unsafe behavior in the construction industry. A good fit structural model indicated that safety climate factors were positively correlated with safety individual factors (Pconstruction workers' engagement in safe or unsafe behavior. In order to improve construction safety performance, more focus on the workplace condition is required.

  4. Automating Trend Analysis for Spacecraft Constellations

    Science.gov (United States)

    Davis, George; Cooter, Miranda; Updike, Clark; Carey, Everett; Mackey, Jennifer; Rykowski, Timothy; Powers, Edward I. (Technical Monitor)

    2001-01-01

    missions such as DRACO with the intent that mission operations costs be significantly reduced. The goal of the Constellation Spacecraft Trend Analysis Toolkit (CSTAT) project is to serve as the pathfinder for a fully automated trending system to support spacecraft constellations. The development approach to be taken is evolutionary. In the first year of the project, the intent is to significantly advance the state of the art in current trending systems through improved functionality and increased automation. In the second year, the intent is to add an expert system shell, likely through the adaptation of an existing commercial-off-the-shelf (COTS) or government-off-the-shelf (GOTS) tool to implement some level of the trending intelligence that humans currently provide in manual operations. In the third year, the intent is to infuse the resulting technology into a near-term constellation or formation-flying mission to test it and gain experience in automated trending. The lessons learned from the real missions operations experience will then be used to improve the system, and to ultimately incorporate it into a fully autonomous, closed-loop mission operations system that is truly capable of supporting large constellations. In this paper, the process of automating trend analysis for spacecraft constellations will be addressed. First, the results of a survey on automation in spacecraft mission operations in general, and in trending systems in particular will be presented to provide an overview of the current state of the art. Next, a rule-based model for implementing intelligent spacecraft subsystem trending will be then presented, followed by a survey of existing COTS/GOTS tools that could be adapted for implementing such a model. The baseline design and architecture of the CSTAT system will be presented. Finally, some results obtained from initial software tests and demonstrations will be presented.

  5. Proceedings of the Spacecraft Charging Technology Conference: Executive Summary

    Science.gov (United States)

    Pike, C. P.; Whipple, E. C., Jr.; Stevens, N. J.; Minges, M. L.; Lehn, W. L.; Bunn, M. H.

    1977-01-01

    Aerospace environments are reviewed in reference to spacecraft charging. Modelling, a theoretical scheme which can be used to describe the structure of the sheath around the spacecraft and to calculate the charging currents within, is discussed. Materials characterization is considered for experimental determination of the behavior of typical spacecraft materials when exposed to simulated geomagnetic substorm conditions. Materials development is also examined for controlling and minimizing spacecraft charging or at least for distributing the charge in an equipotential manner, using electrical conductive surfaces for materials exposed to space environment.

  6. 8th Spacecraft Charging Technology Conference

    Science.gov (United States)

    Minor, J. L. (Compiler)

    2004-01-01

    The 8th Spacecraft Charging Technology Conference was held in Huntsville, Alabama, October 20-24, 2003. Hosted by NASA s Space Environments and Effects (SEE) Program and co-sponsored by the Air Force Research Laboratory (AFRL) and the European Space Agency (ESA), the 2003 conference saw attendance from eleven countries with over 65 oral papers and 18 poster papers. Presentation topics highlighted the latest in spacecraft charging mitigation techniques and on-orbit investigations, including: Plasma Propulsion and Tethers; Ground Testing Techniques; Interactions of Spacecraft and Systems With the Natural and Induced Plasma Environment; Materials Characterizations; Models and Computer Simulations; Environment Specifications; Current Collection and Plasma Probes in Space Plasmas; On-Orbit Investigations. A round-table discussion of international standards regarding electrostatic discharge (ESD) testing was also held with the promise of continued discussions in the off years and an official continuation at the next conference.

  7. Large Scale Experiments on Spacecraft Fire Safety

    DEFF Research Database (Denmark)

    Urban, David L.; Ruff, Gary A.; Minster, Olivier

    2012-01-01

    structure. As a result, the prediction of the behaviour of fires in reduced gravity is at present not validated. To address this gap in knowledge, a collaborative international project, Spacecraft Fire Safety, has been established with its cornerstone being the development of an experiment (Fire Safety 1...... to ensure the carrier vehicle does not sustain damage, the absence of a crew removes the need for strict containment of combustion products. This will facilitate the possibility of examin-ing fire behaviour on a scale that is relevant to spacecraft fire safety and will provide unique data for fire model...... validation. This unprecedented opportunity will expand the understanding of the fundamentals of fire behaviour in spacecraft. The experiment is being developed by an international topical team that is collaboratively defining the experiment requirements and performing supporting analysis, experimentation...

  8. a Quadtree Organization Construction and Scheduling Method for Urban 3d Model Based on Weight

    Science.gov (United States)

    Yao, C.; Peng, G.; Song, Y.; Duan, M.

    2017-09-01

    The increasement of Urban 3D model precision and data quantity puts forward higher requirements for real-time rendering of digital city model. Improving the organization, management and scheduling of 3D model data in 3D digital city can improve the rendering effect and efficiency. This paper takes the complexity of urban models into account, proposes a Quadtree construction and scheduling rendering method for Urban 3D model based on weight. Divide Urban 3D model into different rendering weights according to certain rules, perform Quadtree construction and schedule rendering according to different rendering weights. Also proposed an algorithm for extracting bounding box extraction based on model drawing primitives to generate LOD model automatically. Using the algorithm proposed in this paper, developed a 3D urban planning&management software, the practice has showed the algorithm is efficient and feasible, the render frame rate of big scene and small scene are both stable at around 25 frames.

  9. A QUADTREE ORGANIZATION CONSTRUCTION AND SCHEDULING METHOD FOR URBAN 3D MODEL BASED ON WEIGHT

    Directory of Open Access Journals (Sweden)

    C. Yao

    2017-09-01

    Full Text Available The increasement of Urban 3D model precision and data quantity puts forward higher requirements for real-time rendering of digital city model. Improving the organization, management and scheduling of 3D model data in 3D digital city can improve the rendering effect and efficiency. This paper takes the complexity of urban models into account, proposes a Quadtree construction and scheduling rendering method for Urban 3D model based on weight. Divide Urban 3D model into different rendering weights according to certain rules, perform Quadtree construction and schedule rendering according to different rendering weights. Also proposed an algorithm for extracting bounding box extraction based on model drawing primitives to generate LOD model automatically. Using the algorithm proposed in this paper, developed a 3D urban planning&management software, the practice has showed the algorithm is efficient and feasible, the render frame rate of big scene and small scene are both stable at around 25 frames.

  10. Spacecraft Attitude Control in Hamiltonian Framework

    DEFF Research Database (Denmark)

    Wisniewski, Rafal

    2000-01-01

    The objective of this paper is to give a design scheme for attitude control algorithms of a generic spacecraft. Along with the system model formulated in the Hamilton's canonical form the algorithm uses information about a required potential energy and a dissipative term. The control action...

  11. Using the factor of curves model to evaluate associations among multiple family constructs over time.

    Science.gov (United States)

    Isiordia, Marilu; Conger, Rand; Robins, Richard W; Ferrer, Emilio

    2017-12-01

    Research in family psychology often focuses on understanding how multiple familial constructs develop over time. To examine these developmental processes, researchers frequently use a multivariate latent growth model (LGM) in which univariate LGMs are specified for each individual construct and then correlations are examined between the slopes and intercepts of different pairs of constructs. However, if the developmental associations among the constructs are hypothesized to derive from a higher-order common "cause" or factor, then a more appropriate model is the factor of curves (FOCUS) model. In this paper, we describe the FOCUS model for assessing the covariation among multiple developmental measures over time. We use empirical data to illustrate the benefits of the FOCUS model for testing whether a common factor, family academic orientation, is responsible for the interrelations among parental school perception, parental educational involvement, and children's academic competence from elementary school to high school. Results support that a higher-order family academic orientation construct can be used to characterize the developmental associations among parental school perception, parental educational involvement, and children's academic competence over time. We emphasize the importance of selecting a statistical model that matches one's theory of developmental change. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  12. Construction and Quantification of the One Top model of the Fire Events PSA

    International Nuclear Information System (INIS)

    Kang, Dae Il; Lee, Yoon Hwan; Han, Sang Hoon

    2008-01-01

    KAERI constructed the one top model of the fire events PSA for Ulchin Unit 3 and 4 by using the 'mapping technique'. The mapping technique was developed for the construction and quantification of external events PSA models with a one top model for an internal events PSA. With 'AIMS', the mapping technique can be implemented by the construction of mapping tables. The mapping tables include fire rooms, fire ignition frequency, related initiating events, fire transfer events, and the internal PSA basic events affected by a fire. The constructed one top fire PSA model is based on previously conducted fire PSA results for Ulchin Unit 3 and 4. In this paper, we introduce the construction procedure and quantification results of the one top model of the fire events PSA by using the mapping technique. As the one top model of the fire events PSA developed in this study is based on the previous study, we also introduce the previous fire PSA approach focused on quantification

  13. The Dangling model in the construction of compound sentences with regard to verb tenses

    Directory of Open Access Journals (Sweden)

    Mahmoud Mehravaran

    2016-02-01

    the mistakes of some of the grammars. This research project has for the first time introduced constructive models of compound sentences in a comprehensive research taking in to account the tense of the verbs. The primary question in this research project is which kind of sentences can be considered as compound and what is the constructive of such a sentence? When defining a compound sentences, grammarians either shave the same beliefs or differ in their ideas. But all grammarians agree to the fact that a compound sentences has more than one verb. Different definitions are due to different criteria adapted in constructing a compound sentences. To construct a noun, and adjective, a verb and a sentence we should take similar and precise criteria to our consideration. In the grammatical units of noun, adjectives, and verbs construction means connecting two or more parts that can convey one similar meaning and its parts are dependent upon one another.  In the construction of compound sentences there must be the same criteria so that its applications can be truly recognized and identified just like the previously mentioned grammatical units. The first step to arrive at a criterion in defining and identifying compound sentences, is to separate this discussion from connective sentences that are relate to each other with connectives are called connective sentences. But sentences which are constructed with dependent making connectives and their parts are dependent upon one another are called compound sentences. Therefore the signs of compound sentences with regard to constructions and the meaning of criterion are as follows: 1 They have more than one verb. 2 The consistence of two or more dependent phrases. 3 Phrases construct a complete sentences all together and convey one similar message. 4 One of the phrases is the main clause and the other one is the subordinate one. 5 The phrases or subordinate clauses can be related to one of the major parts and they can take a

  14. The Dangling model in the construction of compound sentences with regard to verb tenses

    Directory of Open Access Journals (Sweden)

    Mahmoud Mehravaran

    2016-01-01

    the mistakes of some of the grammars. This research project has for the first time introduced constructive models of compound sentences in a comprehensive research taking in to account the tense of the verbs. The primary question in this research project is which kind of sentences can be considered as compound and what is the constructive of such a sentence? When defining a compound sentences, grammarians either shave the same beliefs or differ in their ideas. But all grammarians agree to the fact that a compound sentences has more than one verb. Different definitions are due to different criteria adapted in constructing a compound sentences. To construct a noun, and adjective, a verb and a sentence we should take similar and precise criteria to our consideration. In the grammatical units of noun, adjectives, and verbs construction means connecting two or more parts that can convey one similar meaning and its parts are dependent upon one another.  In the construction of compound sentences there must be the same criteria so that its applications can be truly recognized and identified just like the previously mentioned grammatical units. The first step to arrive at a criterion in defining and identifying compound sentences, is to separate this discussion from connective sentences that are relate to each other with connectives are called connective sentences. But sentences which are constructed with dependent making connectives and their parts are dependent upon one another are called compound sentences. Therefore the signs of compound sentences with regard to constructions and the meaning of criterion are as follows: 1 They have more than one verb. 2 The consistence of two or more dependent phrases. 3 Phrases construct a complete sentences all together and convey one similar message. 4 One of the phrases is the main clause and the other one is the subordinate one. 5 The phrases or subordinate clauses can be related to one of the major parts and they can take a

  15. Application of 3-Dimensional Printing Technology to Construct an Eye Model for Fundus Viewing Study

    OpenAIRE

    Xie, Ping; Hu, Zizhong; Zhang, Xiaojun; Li, Xinhua; Gao, Zhishan; Yuan, Dongqing; Liu, Qinghuai

    2014-01-01

    Objective To construct a life-sized eye model using the three-dimensional (3D) printing technology for fundus viewing study of the viewing system. Methods We devised our schematic model eye based on Navarro's eye and redesigned some parameters because of the change of the corneal material and the implantation of intraocular lenses (IOLs). Optical performance of our schematic model eye was compared with Navarro's schematic eye and other two reported physical model eyes using the ZEMAX optical ...

  16. Utilization of building information modeling in infrastructure’s design and construction

    Science.gov (United States)

    Zak, Josef; Macadam, Helen

    2017-09-01

    Building Information Modeling (BIM) is a concept that has gained its place in the design, construction and maintenance of buildings in Czech Republic during recent years. This paper deals with description of usage, applications and potential benefits and disadvantages connected with implementation of BIM principles in the preparation and construction of infrastructure projects. Part of the paper describes the status of BIM implementation in Czech Republic, and there is a review of several virtual design and construction practices in Czech Republic. Examples of best practice are presented from current infrastructure projects. The paper further summarizes experiences with new technologies gained from the application of BIM related workflows. The focus is on the BIM model utilization for the machine control systems on site, quality assurance, quality management and construction management.

  17. FlightDynLib: An Object-Oriented Model Component Library for Constructing Multi-Disciplinary Aircraft Dynamics Models

    OpenAIRE

    Looye, G.; Hecker, S.; Kier, T.; Reschke, C.

    2005-01-01

    In this paper a model component library for developing multi-disciplinary aircraft flight dynamics models is presented, named FlightDynLib. This library is based on the object-oriented modelling language Modelica that has been designed for modelling of large scale multi-physics systems. The flight dynamics library allows for graphical construction of comlex rigid as well as flexible aircraft dynamics models and is fully compatible with other available libraries for electronics, thermodynamics...

  18. Application and study of 3D visualization model on nuclear power plant construction

    Science.gov (United States)

    Guo, Depeng; Pu, Chenghao; Li, Maolin; Zhang, Wenguang; Zhao, Jing; Arlia, Laura Alejandra

    2017-04-01

    3-D visualization model is an advanced tool which addresses a digital expression to the project entity and functional characteristics by integrating the relative engineering data. Construction units lead this technique in the equipment installation activities of the first unit of AP1000 Nuclear Power Plant Project in the world. 3-D technique proved its advantages in construction scheme preparation, second design, collision simulation, construction logic, etc. Through the introduction of the main characteristics and superiority of this technique, the solution and suggestions for some project insufficiencies have been proposed. This will represent a benefit for its application in the future.

  19. Collaborative Management of Complex Major Construction Projects: AnyLogic-Based Simulation Modelling

    Directory of Open Access Journals (Sweden)

    Na Zhao

    2016-01-01

    Full Text Available Complex supply chain system collaborative management of major construction projects effectively integrates the different participants in the construction project. This paper establishes a simulation model based on AnyLogic to reveal the collaborative elements in the complex supply chain management system and the modes of action as well as the transmission problems of the intent information. Thus it is promoting the participants to become an organism with coordinated development and coevolution. This study can help improve the efficiency and management of the complex system of major construction projects.

  20. Model Configuration and Innovative Design of College Students’ Ecological Civilization Construction

    Science.gov (United States)

    Chengwen, Yang

    2018-02-01

    This study is based on Marxist eco-civilization thought, combining with Eco management theory, puts forward solutions for college students’ ecological civilization construction. The paper based on the perspective of ecological management theory to analyze the main elements of eco-civilization construction of college students, mainly including five categories. In view of above-mentioned analyze, constructed the model of college students’ eco-civilization which is based on the theory of eco-management, and put forward on concrete methods to improve it.

  1. Why a Train Set Helps Participants Co-Construct Meaning in Business Model Innovation

    DEFF Research Database (Denmark)

    Beuthel, Maria Rosa; Buur, Jacob

    In this position paper we show how participants in an innovation workshop employ tangible material – a toy train set – to co-construct understandings of a new business model. In multidisciplinary teams the process of developing new terms and concepts together is crucial for work to progress. Every...... to understand how they construct a concept. We observe that the final result of the workshop is indeed innovative and is co-constructed by all group members. We discuss why the toy train works: It keeps both hands and mind busy, it allows silent participation, and it expands the vocabulary of the discussion....

  2. Model and Algorithm for Substantiating Solutions for Organization of High-Rise Construction Project

    Science.gov (United States)

    Anisimov, Vladimir; Anisimov, Evgeniy; Chernysh, Anatoliy

    2018-03-01

    In the paper the models and the algorithm for the optimal plan formation for the organization of the material and logistical processes of the high-rise construction project and their financial support are developed. The model is based on the representation of the optimization procedure in the form of a non-linear problem of discrete programming, which consists in minimizing the execution time of a set of interrelated works by a limited number of partially interchangeable performers while limiting the total cost of performing the work. The proposed model and algorithm are the basis for creating specific organization management methodologies for the high-rise construction project.

  3. Enhanced Explicit Semantic Analysis for Product Model Retrieval in Construction Industry

    OpenAIRE

    Liu, Han; Liu, Yu-Shen; Pauwels, Pieter; Guo, Hongling; Gu, Ming

    2017-01-01

    With the rapidly growing number of online product models in construction industry, there is an urgent need for developing effective domain-specific information retrieval methods. Explicit semantic analysis (ESA) is a method that automatically extracts concept-based features from human knowledge repositories for semantic retrieval. This avoids the requirement of constructing and maintaining an explicitly formalized ontology. However, since domain-specific knowledge repositories are relatively ...

  4. ANALYSIS OF FUNNELS EVALUATION MODEL BY THE “CONSTRUCTION-SOIL” SYSTEM

    Directory of Open Access Journals (Sweden)

    A. S. Koretskiy

    2010-04-01

    Full Text Available Recently in the European countries the designs of flexible pipes and pipe bridges, the bearing capacity of which is provided by passive resistance of soil, have found more applications. The paper presents an analysis of existing models for calculating flexible pipes working as a system «construction-soil». The numerical example for calculating such construction design using software package SCAD is given.

  5. Expanding the Work Phases Model: User and Expert Involvement in the Construction of Online Specialised Dictionaries

    DEFF Research Database (Denmark)

    Leroyer, Patrick

    The purpose of this article is to establish new proposals for the lexicographic process and the involvement of experts and users in the construction of online specialised dictionaries. It is argued that the ENeL action should also have a view to the development of innovative theories...... and methodologies for the construction of online specialised dictionaries, and a new model for user and expert involvement is proposed....

  6. BARRIERS AND CHALLENGES OF BUILDING INFORMATION MODELLING IMPLEMENTATION IN JORDANIAN CONSTRUCTION INDUSTRY

    OpenAIRE

    Mohammed A.KA. AL-Btoush*, Ahmad Tarmizi Haron

    2017-01-01

    Construction companies are faced with the need to innovatively integrate the construction process and address project development challenges. One way of doing that is the integration of building information modelling (BIM) in the building design and development cycles. However, due to the lack of clear understanding and the absence of a holistic implementation guideline, many companies are unable to fully achieve BIM potentials or implement BIM in their project and building lifecycle. BIM imp...

  7. An Integrated Framework for Process-Driven Model Construction in Disease Ecology and Animal Health.

    Science.gov (United States)

    Mancy, Rebecca; Brock, Patrick M; Kao, Rowland R

    2017-01-01

    Process models that focus on explicitly representing biological mechanisms are increasingly important in disease ecology and animal health research. However, the large number of process modelling approaches makes it difficult to decide which is most appropriate for a given disease system and research question. Here, we discuss different motivations for using process models and present an integrated conceptual analysis that can be used to guide the construction of infectious disease process models and comparisons between them. Our presentation complements existing work by clarifying the major differences between modelling approaches and their relationship with the biological characteristics of the epidemiological system. We first discuss distinct motivations for using process models in epidemiological research, identifying the key steps in model design and use associated with each. We then present a conceptual framework for guiding model construction and comparison, organised according to key aspects of epidemiological systems. Specifically, we discuss the number and type of disease states, whether to focus on individual hosts (e.g., cows) or groups of hosts (e.g., herds or farms), how space or host connectivity affect disease transmission, whether demographic and epidemiological processes are periodic or can occur at any time, and the extent to which stochasticity is important. We use foot-and-mouth disease and bovine tuberculosis in cattle to illustrate our discussion and support explanations of cases in which different models are used to address similar problems. The framework should help those constructing models to structure their approach to modelling decisions and facilitate comparisons between models in the literature.

  8. Item Construction Using Reflective, Formative, or Rasch Measurement Models: Implications for Group Work

    Science.gov (United States)

    Peterson, Christina Hamme; Gischlar, Karen L.; Peterson, N. Andrew

    2017-01-01

    Measures that accurately capture the phenomenon are critical to research and practice in group work. The vast majority of group-related measures were developed using the reflective measurement model rooted in classical test theory (CTT). Depending on the construct definition and the measure's purpose, the reflective model may not always be the…

  9. Videogame Construction by Engineering Students for Understanding Modelling Processes: The Case of Simulating Water Behaviour

    Science.gov (United States)

    Pretelín-Ricárdez, Angel; Sacristán, Ana Isabel

    2015-01-01

    We present some results of an ongoing research project where university engineering students were asked to construct videogames involving the use of physical systems models. The objective is to help them identify and understand the elements and concepts involved in the modelling process. That is, we use game design as a constructionist approach…

  10. Dynamic Processes of Conceptual Change: Analysis of Constructing Mental Models of Chemical Equilibrium.

    Science.gov (United States)

    Chiu, Mei-Hung; Chou, Chin-Cheng; Liu, Chia-Ju

    2002-01-01

    Investigates students' mental models of chemical equilibrium using dynamic science assessments. Reports that students at various levels have misconceptions about chemical equilibrium. Involves 10th grade students (n=30) in the study doing a series of hands-on chemical experiments. Focuses on the process of constructing mental models, dynamic…

  11. Measurement of Dispositional Affect: Construct Validity and Convergence with a Circumplex Model of Affect.

    Science.gov (United States)

    Huelsman, Timothy J.; Furr, R. Michael; Nemanick, Richard C., Jr.

    2003-01-01

    Examined the issue of construct validity of several existing measures of affect and their fit with the circumplex model. Analyses demonstrate that data collected using the four scales studied are characterized by generally good concurrent and discriminant validity. Data are in partial agreement with the proposed circumflex model of affect. (SLD)

  12. Identifying Multiple Levels of Discussion-Based Teaching Strategies for Constructing Scientific Models

    Science.gov (United States)

    Williams, Grant; Clement, John

    2015-01-01

    This study sought to identify specific types of discussion-based strategies that two successful high school physics teachers using a model-based approach utilized in attempting to foster students' construction of explanatory models for scientific concepts. We found evidence that, in addition to previously documented dialogical strategies that…

  13. On Promoting the Construction of Model Province of National Rural Informationization in Hubei

    Directory of Open Access Journals (Sweden)

    Pengfei Zhang

    2014-04-01

    Full Text Available The construction of model province of national rural informationization, which needs more departments jointly and participants, is a systematic, socialized major project. Hubei provincial government, standing in the angle of planning the province's economic and social development as a whole, proposes the “one Yuan multi-level” development strategy and it has laid a solid foundation to make Hubei province become the construction pilot provinces of “model province of national rural informationization”. In the construction of model province of rural informationization, the open and inclusive concept is of great significance to realize national long-term goals and make the rural information service sustained and long efficient. At the same time, each department and each participation main body coordinate with each other, which realize the integration of rural information service resources and prevent rural information service from redundant and inefficient investment. Therefore, in the construction of model province of national rural informationization, Hubei province need to uphold the open and inclusive concept, further emancipate the mind, and complement each other. It should strengthen organizational leadership, complete the top planning and design, strengthen the department coordination, innovate information services operating mechanism, strengthen integration of information resources and integrated application of service platform, strengthen the system construction and examination management, strengthen the propaganda guidance, and further promote each work of model province carried out smoothly and orderly.

  14. Development of Deflection Prediction Model for Concrete Block Pavement Considering the Block Shapes and Construction Patterns

    Directory of Open Access Journals (Sweden)

    Wuguang Lin

    2016-01-01

    Full Text Available Concrete block pavement (CBP is distinct from typical concrete or asphalt pavements. It is built by using individual blocks with unique construction patterns forming a discrete surface layer to bear traffic loadings. The surface structure of CBP varies depending on the block shapes and construction patterns, so it is hard to apply a general equivalent elastic modulus estimation method to define the surface structural strength. In this study, FEM analysis and dynamic loading test were carried out to develop a deflection prediction model for CBP considering the block shapes and construction patterns. Based on the analysis results, it was found that block shapes did not have much effect on load distribution, whereas construction patterns did. By applying the deflection prediction model to the rutting model for CBP proposed by Sun, the herringbone bond pattern showed the best performance comparing with stretcher bond or basket weave bond pattern. As the load repetition increased to 1.2 million, the rutting depth of CBP constructed by herringbone bond pattern was 2 mm smaller than those constructed by the other two patterns.

  15. Development of the “quality-efficiency” model of construction investment projects for road construction on the basis of sustainable growth

    Science.gov (United States)

    Uvarova, Svetlana; Belyaeva, Svetlana; Myshovskaya, Lyudmila

    2017-10-01

    The urgency of the problem to improve the quality of the road construction is due to the need to stimulate demand for toll travel, increase efficiency of construction and investment projects and reduce the cost of resources as well as negative impact on the environment. The authors state levels and criteria of quality for the construction products on the basis of the semantic analysis, that allowed to structure the quality elements of the road construction object. Taking into account justified quality parameters, standard technical basis for building sector is systemized and directions for its optimization are suggested. There is developed a model to estimate the efficiency level of construction and investment projects in terms of quality which is carried out through the construction projects of toll roads.

  16. Study of the two-dimensional Hubbard model at half-filling through constructive methods; Etude du modele de Hubbard bidimensionnel a demi remplissage par des methodes constructives

    Energy Technology Data Exchange (ETDEWEB)

    Afchain, St

    2005-02-15

    The Hubbard model is the simplest model to describe the behaviour of fermions on a network, it takes into account only fermion scattering and only interactions with other fermions located on the same site. Half-filling means that the total number of fermions is equal to half the number of sites. In the first chapter we show how we can pass trough successive approximations from a very general Hamiltonian to the Hubbard Hamiltonian. The second chapter is dedicated to the passage from the Hamiltonian formalism to the Grassmanian functional formalism. The main idea is to show that the correlation functions of the Hamiltonian approach can be described through fermionic functional integrals which implies the possibility of speaking of the model in terms of field theory. The chapter 3 deals with the main constructive techniques that allow the strict and consistent construction of models inside the frame of field theory. We show by proving the violation of a condition concerning self-energy, that the two-dimensional Hubbard model at half-filling has not the behaviour of a Fermi liquid in the Landau's interpretation. (A.C.)

  17. Moving Low-Carbon Construction Industry in Jiangsu Province: Evidence from Decomposition and Decoupling Models

    Directory of Open Access Journals (Sweden)

    Rongrong Li

    2017-06-01

    Full Text Available The carbon dioxide (CO2 emissions caused by the global construction industry account for 36% of the world’s total carbon emissions, and 50% of China’s total carbon emissions. The carbon emissions from Jiangsu Province’s construction industry account for approximately 16% of the total emissions of the Chinese construction industry. Taking the construction industry in Jiangsu Province as our study object, therefore, this paper introduces the Intergovernmental Panel on Climate Change (IPCC carbon emission accounting method as a means to measure the total CO2 emissions of the Jiangsu Province construction industry. Specifically, we examine the period from 2005 to 2013. Based on the Tapio decoupling model, we analyze the decoupling state between the CO2 emissions of the construction industry in Jiangsu Province and the province’s economic growth. Our paper also employs the Logarithmic Mean Divisia Index (LMDI approach, in order to conduct a decomposition analysis of those factors that influenced the changes in the level of CO2 emissions during the studied period. According to the results of our research, during the period from 2005 to 2013, the CO2 emission levels caused by the construction industry in Jiangsu Province experienced a significant increase. The cumulative total CO2 emissions reached 402.85 million tons. During most of the years covered by our study, an expansive negative decoupling state existed between the level of CO2 emissions and the output value of Jiangsu’s construction industry. These periods were interspersed with either a weak decoupling state in some years or a strong decoupling state in other years. The indirect carbon emission intensity effect and the industry scale effect were the main factors influencing the increases in the construction industry’s CO2 emissions. At the conclusion of our paper, we put forward policy suggestions, with the objective of promoting the de-carbonization of the construction industry

  18. A probabilistic method for constructing wave time-series at inshore locations using model scenarios

    Science.gov (United States)

    Long, Joseph W.; Plant, Nathaniel G.; Dalyander, P. Soupy; Thompson, David M.

    2014-01-01

    Continuous time-series of wave characteristics (height, period, and direction) are constructed using a base set of model scenarios and simple probabilistic methods. This approach utilizes an archive of computationally intensive, highly spatially resolved numerical wave model output to develop time-series of historical or future wave conditions without performing additional, continuous numerical simulations. The archive of model output contains wave simulations from a set of model scenarios derived from an offshore wave climatology. Time-series of wave height, period, direction, and associated uncertainties are constructed at locations included in the numerical model domain. The confidence limits are derived using statistical variability of oceanographic parameters contained in the wave model scenarios. The method was applied to a region in the northern Gulf of Mexico and assessed using wave observations at 12 m and 30 m water depths. Prediction skill for significant wave height is 0.58 and 0.67 at the 12 m and 30 m locations, respectively, with similar performance for wave period and direction. The skill of this simplified, probabilistic time-series construction method is comparable to existing large-scale, high-fidelity operational wave models but provides higher spatial resolution output at low computational expense. The constructed time-series can be developed to support a variety of applications including climate studies and other situations where a comprehensive survey of wave impacts on the coastal area is of interest.

  19. A software complex intended for constructing applied models and meta-models on the basis of mathematical programming principles

    Directory of Open Access Journals (Sweden)

    Михаил Юрьевич Чернышов

    2013-12-01

    Full Text Available A software complex (SC elaborated by the authors on the basis of the language LMPL and representing a software tool intended for synthesis of applied software models and meta-models constructed on the basis of mathematical programming (MP principles is described. LMPL provides for an explicit form of declarative representation of MP-models, presumes automatic constructing and transformation of models and the capability of adding external software packages. The following software versions of the SC have been implemented: 1 a SC intended for representing the process of choosing an optimal hydroelectric power plant model (on the principles of meta-modeling and 2 a SC intended for representing the logic-sense relations between the models of a set of discourse formations in the discourse meta-model.

  20. Programming While Construction of Engineering 3D Models of Complex Geometry

    Science.gov (United States)

    Kheyfets, A. L.

    2017-11-01

    The capabilities of geometrically accurate computational 3D models construction with the use of programming are presented. The construction of models of an architectural arch and a glo-boid worm gear is considered as an example. The models are designed in the AutoCAD pack-age. Three programs of construction are given. The first program is for designing a multi-section architectural arch. The control of the arch’s geometry by impacting its main parameters is shown. The second program is for designing and studying the working surface of a globoid gear’s worm. The article shows how to make the animation for this surface’s formation. The third program is for formation of a worm gear cavity surface. The cavity formation dynamics is studied. The programs are written in the AutoLisp programming language. The program texts are provided.

  1. JOMAR - A model for accounting the environmental loads from building constructions

    Energy Technology Data Exchange (ETDEWEB)

    Roenning, Anne; Nereng, Guro; Vold, Mie; Bjoerberg, Svein; Lassen, Niels

    2008-07-01

    The objective for this project was to develop a model as a basis for calculation of environmental profile for whole building constructions, based upon data from databases and general LCA software, in addition to the model structure from the Nordic project on LCC assessment of buildings. The model has been tested on three building constructions; timber based, flexible and heavy as well as heavy. Total energy consumption and emissions contributing to climate change are calculated in a total life cycle perspective. The developed model and exemplifying case assessments have shown that a holistic model including operation phase is both important and possible to implement. The project has shown that the operation phase causes the highest environmental loads when it comes to the exemplified impact categories. A suggestion on further development of the model along two different axes in collaboration with a broader representation from the building sector is given in the report (author)(tk)

  2. Factors Influencing Implementation of OHSAS 18001 in Indian Construction Organizations: Interpretive Structural Modeling Approach.

    Science.gov (United States)

    Rajaprasad, Sunku Venkata Siva; Chalapathi, Pasupulati Venkata

    2015-09-01

    Construction activity has made considerable breakthroughs in the past two decades on the back of increases in development activities, government policies, and public demand. At the same time, occupational health and safety issues have become a major concern to construction organizations. The unsatisfactory safety performance of the construction industry has always been highlighted since the safety management system is neglected area and not implemented systematically in Indian construction organizations. Due to a lack of enforcement of the applicable legislation, most of the construction organizations are forced to opt for the implementation of Occupational Health Safety Assessment Series (OHSAS) 18001 to improve safety performance. In order to better understand factors influencing the implementation of OHSAS 18001, an interpretive structural modeling approach has been applied and the factors have been classified using matrice d'impacts croises-multiplication appliqué a un classement (MICMAC) analysis. The study proposes the underlying theoretical framework to identify factors and to help management of Indian construction organizations to understand the interaction among factors influencing in implementation of OHSAS 18001. Safety culture, continual improvement, morale of employees, and safety training have been identified as dependent variables. Safety performance, sustainable construction, and conducive working environment have been identified as linkage variables. Management commitment and safety policy have been identified as the driver variables. Management commitment has the maximum driving power and the most influential factor is safety policy, which states clearly the commitment of top management towards occupational safety and health.

  3. AN ANALYSIS OF ACCIDENT TRENDS AND MODELING OF SAFETY INDICES IN AN INDIAN CONSTRUCTION ORGANIZATION

    Directory of Open Access Journals (Sweden)

    Sunku Venkata Siva Rajaprasad

    2016-09-01

    Full Text Available Construction industry has been recognized as a hazardous industry in many countries due to distinct nature of execution of works.The accident rate in construction sector is high all over the world due to dynamic nature of work activities. Occurrence of accidents and its severity in construction industry is several times higher than the manufacturing industries. The study was limited to a major construction organization in India to examine the trends in construction accidents for the period 2008-2014. In India, safety performance is gauged basing on safety indices; frequency, severity and incidence rates. It is not practicable to take decisions or to implement safety strategies on the basis of indices. The data used for this study was collected from a leading construction organization involved in execution of major construction activities all over India and abroad. The multiple regression method was adopted to model the pattern of safety indices wise .The pattern showed that significant relationships exist between the three safety indices and the related independent variables.

  4. Investigation on the Expansion of Urban Construction Land Use Based on the CART-CA Model

    Directory of Open Access Journals (Sweden)

    Yongxiang Yao

    2017-05-01

    Full Text Available Change in urban construction land use is an important factor when studying urban expansion. Many scholars have combined cellular automata (CA with data mining algorithms to perform relevant simulation studies. However, the parameters for rule extraction are difficult to determine and the rules are simplex, and together, these factors tend to introduce excessive fitting problems and low modeling accuracy. In this paper, we propose a method to extract the transformation rules for a CA model based on the Classification and Regression Tree (CART. In this method, CART is used to extract the transformation rules for the CA. This method first adopts the CART decision tree using the bootstrap algorithm to mine the rules from the urban land use while considering the factors that impact the geographic spatial variables in the CART regression procedure. The weights of individual impact factors are calculated to generate a logistic regression function that reflects the change in urban construction land use. Finally, a CA model is constructed to simulate and predict urban construction land expansion. The urban area of Xinyang City in China is used as an example for this experimental research. After removing the spatial invariant region, the overall simulation accuracy is 81.38% and the kappa coefficient is 0.73. The results indicate that by using the CART decision tree to train the impact factor weights and extract the rules, it can effectively increase the simulation accuracy of the CA model. From convenience and accuracy perspectives for rule extraction, the structure of the CART decision tree is clear, and it is very suitable for obtaining the cellular rules. The CART-CA model has a relatively high simulation accuracy in modeling urban construction land use expansion, it provides reliable results, and is suitable for use as a scientific reference for urban construction land use expansion.

  5. New Flexible Models and Design Construction Algorithms for Mixtures and Binary Dependent Variables

    OpenAIRE

    Ruseckaite, Aiste

    2017-01-01

    markdownabstractThis thesis discusses new mixture(-amount) models, choice models and the optimal design of experiments. Two chapters of the thesis relate to the so-called mixture, which is a product or service whose ingredients’ proportions sum to one. The thesis begins by introducing mixture models in the choice context and develops new optimal design construction algorithms for choice experiments involving mixtures. Building further, varying the total amount of a mixture, and not only its i...

  6. System Dynamics Model and Simulation of Employee Work-Family Conflict in the Construction Industry

    Science.gov (United States)

    Wu, Guangdong; Duan, Kaifeng; Zuo, Jian; Yang, Jianlin; Wen, Shiping

    2016-01-01

    The construction industry is a demanding work environment where employees’ work-family conflict is particularly prominent. This conflict has a significant impact on job and family satisfaction and performance of employees. In order to analyze the dynamic evolution of construction industry employee’s work-family conflict between work and family domains, this paper constructs a bi-directional dynamic model framework of work-family conflict by referring to the relevant literature. Consequently, a system dynamics model of employee’s work-family conflict in the construction industry is established, and a simulation is conducted. The simulation results indicate that construction industry employees experience work interference with family conflict (WIFC) levels which are significantly greater than the family interference with work conflict (FIWC) levels. This study also revealed that improving work flexibility and organizational support can have a positive impact on the satisfaction and performance of construction industry employees from a work and family perspective. Furthermore, improving family support can only significantly improve employee job satisfaction. PMID:27801857

  7. System Dynamics Model and Simulation of Employee Work-Family Conflict in the Construction Industry.

    Science.gov (United States)

    Wu, Guangdong; Duan, Kaifeng; Zuo, Jian; Yang, Jianlin; Wen, Shiping

    2016-10-28

    The construction industry is a demanding work environment where employees' work-family conflict is particularly prominent. This conflict has a significant impact on job and family satisfaction and performance of employees. In order to analyze the dynamic evolution of construction industry employee's work-family conflict between work and family domains, this paper constructs a bi-directional dynamic model framework of work-family conflict by referring to the relevant literature. Consequently, a system dynamics model of employee's work-family conflict in the construction industry is established, and a simulation is conducted. The simulation results indicate that construction industry employees experience work interference with family conflict (WIFC) levels which are significantly greater than the family interference with work conflict (FIWC) levels. This study also revealed that improving work flexibility and organizational support can have a positive impact on the satisfaction and performance of construction industry employees from a work and family perspective. Furthermore, improving family support can only significantly improve employee job satisfaction.

  8. System Dynamics Model and Simulation of Employee Work-Family Conflict in the Construction Industry

    Directory of Open Access Journals (Sweden)

    Guangdong Wu

    2016-10-01

    Full Text Available The construction industry is a demanding work environment where employees’ work-family conflict is particularly prominent. This conflict has a significant impact on job and family satisfaction and performance of employees. In order to analyze the dynamic evolution of construction industry employee’s work-family conflict between work and family domains, this paper constructs a bi-directional dynamic model framework of work-family conflict by referring to the relevant literature. Consequently, a system dynamics model of employee’s work-family conflict in the construction industry is established, and a simulation is conducted. The simulation results indicate that construction industry employees experience work interference with family conflict (WIFC levels which are significantly greater than the family interference with work conflict (FIWC levels. This study also revealed that improving work flexibility and organizational support can have a positive impact on the satisfaction and performance of construction industry employees from a work and family perspective. Furthermore, improving family support can only significantly improve employee job satisfaction.

  9. Computational model-informed design and bioprinting of cell-patterned constructs for bone tissue engineering.

    Science.gov (United States)

    Carlier, Aurélie; Skvortsov, Gözde Akdeniz; Hafezi, Forough; Ferraris, Eleonora; Patterson, Jennifer; Koç, Bahattin; Van Oosterwyck, Hans

    2016-05-17

    Three-dimensional (3D) bioprinting is a rapidly advancing tissue engineering technology that holds great promise for the regeneration of several tissues, including bone. However, to generate a successful 3D bone tissue engineering construct, additional complexities should be taken into account such as nutrient and oxygen delivery, which is often insufficient after implantation in large bone defects. We propose that a well-designed tissue engineering construct, that is, an implant with a specific spatial pattern of cells in a matrix, will improve the healing outcome. By using a computational model of bone regeneration we show that particular cell patterns in tissue engineering constructs are able to enhance bone regeneration compared to uniform ones. We successfully bioprinted one of the most promising cell-gradient patterns by using cell-laden hydrogels with varying cell densities and observed a high cell viability for three days following the bioprinting process. In summary, we present a novel strategy for the biofabrication of bone tissue engineering constructs by designing cell-gradient patterns based on a computational model of bone regeneration, and successfully bioprinting the chosen design. This integrated approach may increase the success rate of implanted tissue engineering constructs for critical size bone defects and also can find a wider application in the biofabrication of other types of tissue engineering constructs.

  10. A Fractionated Spacecraft System Assessment Tool Based on Lifecycle Simulation Under Uncertainty

    NARCIS (Netherlands)

    Yao, W.; Chen, X.; Zhao, Y.; Van Tooren, M.J.L.

    2012-01-01

    To comprehensively assess fractionated spacecraft, an assessment tool is developed based on lifecycle simulation under uncertainty driven by modular evolutionary stochastic models. First, fractionated spacecraft nomenclature and architecture are clarified, and assessment criteria are analyzed. The

  11. Developing a system dynamics model to analyse environmental problem in construction site

    Science.gov (United States)

    Haron, Fatin Fasehah; Hawari, Nurul Nazihah

    2017-11-01

    This study aims to develop a system dynamics model at a construction site to analyse the impact of environmental problem. Construction sites may cause damages to the environment, and interference in the daily lives of residents. A proper environmental management system must be used to reduce pollution, enhance bio-diversity, conserve water, respect people and their local environment, measure performance and set targets for the environment and sustainability. This study investigates the damaging impact normally occur during the construction stage. Environmental problem will cause costly mistake in project implementation, either because of the environmental damages that are likely to arise during project implementation, or because of modification that may be required subsequently in order to make the action environmentally acceptable. Thus, findings from this study has helped in significantly reducing the damaging impact towards environment, and improve the environmental management system performance at construction site.

  12. High-rise construction in the Russian economy: modeling of management decisions

    Science.gov (United States)

    Miroshnikova, Tatyana; Taskaeva, Natalia

    2018-03-01

    The growth in the building industry, particularly in residential high-rise construction, is having considerable influence on the country's economic development. The scientific hypothesis of the research is that the execution of town-planning programs of high-rise construction depends to a large extent on the management of the provision of material resources for the construction of a millionth city, while the balance model is the most important tool for establishing and determining the ratio between supply and demand for material resources. In order to improve the efficiency of high-rise building management, it is proposed to develop a methodology for managing the provision of construction of large cities with material resources.

  13. A two-phase moisture transport model accounting for sorption hysteresis in layered porous building constructions

    DEFF Research Database (Denmark)

    Johannesson, Björn; Janz, Mårten

    2009-01-01

    and exhibits different transport properties. A successful model of such a case may shred light on the performance of different constructions with regards to, for example, mould growth and freeze thaw damages. For this purpose a model has been developed which is based on a two phase flow, vapor and liquid water......, with account also to sorption hysteresis. The different materials in the considered layered construction are assigned different properties, i.e. vapor and liquid water diffusivities and boundary (wetting and drying) sorption curves. Further, the scanning behavior between wetting and drying boundary curves...

  14. Ontologies to Support RFID-Based Link between Virtual Models and Construction Components

    DEFF Research Database (Denmark)

    Sørensen, Kristian Birch; Christiansson, Per; Svidt, Kjeld

    2010-01-01

    as the foundation for information sharing between trading partners, reuse of data from one phase in construction to the next, integration of process and product models with enterprise resource planning (ERP) systems, easy access of information, communication of data through networks, reading of data stored...... of errors, it gives a better production basis, and it improves clarity and enhances communication compared to traditional 2D drafting methods. However, there is still much unutilized potential in the virtual models, especially for use in the construction and operation phases. A digital link between...

  15. Modelling of project cash flow on construction projects in Malang city

    Science.gov (United States)

    Djatmiko, Bambang

    2017-09-01

    Contractors usually prepare a project cash flow (PCF) on construction projects. The flow of cash in and cash out within a construction project may vary depending on the owner, contract documents, and construction service providers who have their own authority. Other factors affecting the PCF are down payment, termyn, progress schedule, material schedule, equipment schedule, manpower schedules, and wages of workers and subcontractors. This study aims to describe the cash inflow and cash outflow based on the empirical data obtained from contractors, develop a PCF model based on Halpen & Woodhead's PCF model, and investigate whether or not there is a significant difference between the Halpen & Woodhead's PCF model and the empirical PCF model. Based on the researcher's observation, the PCF management has never been implemented by the contractors in Malang in serving their clients (owners). The research setting is in Malang City because physical development in all field and there are many new construction service providers. The findings in this current study are summarised as follows: 1) Cash in included current assets (20%), owner's down payment (20%), termyin I (5%-25%), termyin II (20%), termyin III (25%), termyin IV (25%) and retention (5%). Cash out included direct cost (65%), indirect cost (20%), and profit + informal cost(15%), 2)the construction work involving the empirical PCF model in this study was started with the funds obtained from DP or current assets and 3) The two models bear several similarities in the upward trends of direct cost, indirect cost, Pro Ic, progress billing, and S-curve. The difference between the two models is the occurrence of overdraft in the Halpen and Woodhead's PCF model only.

  16. Null motion strategy for spacecraft large angle agile maneuvering using hybrid actuators

    Science.gov (United States)

    Wu, Yun-Hua; Han, Feng; Hua, Bing; Chen, Zhi-Ming

    2017-11-01

    Control Moment Gyro (CMG) and Reaction Wheel (RW) generally serve in different spacecraft control tasks due to their unique characteristics, such as large output torque and control accuracy, respectively. The major concerns in using of CMG and RW are singularity and saturation, which could make spacecraft uncontrollable. RW as singularity escape equipment is adopted to construct hybrid actuator system named CMG & RW (CMGRW) to enhance and improve the spacecraft attitude performance as well as the CMG's. First, the attitude dynamic model of the spacecraft equipped with hybrid actuators is established and the corresponding singularity is analyzed thoroughly. Then null motion in CMGRW is further argued and proved feasible for both elliptical and hyperbolic singularities escape. A new performance index in terms of CMG and RW state is proposed, followed by a steering logic using gradient method with a feasible null motion vector to drive the hybrid actuator system to feasible states. Numerical simulations with initial conditions considering CMG singularity and RW saturation are selected to demonstrate the excellent performance of the hybrid actuators during the entire large angle agile maneuvering process, resulting in a group of feasible final states of the CMGRW that serves as great initial conditions for the next agile maneuvering.

  17. Establishing a common ground for the use of structural equation modelling for construction related research studies

    Directory of Open Access Journals (Sweden)

    Ayodeji Emmanuel Oke

    2012-09-01

    Full Text Available The use of structural equation modelling (SEM for research studies in construction related field has been on the increase over the years. The essence of this study is not to compare the level of usage of SEM with other modelling methods, neither is it to examine its extent of adoption in construction management - as this has been researched in previous works - but to arrive at a common ground for future construction related research works, based on the findings and recommendations from existing studies on the subject of SEM. Research materials within and outside the field of construction management were reviewed and it was discovered that SEM using AMOS (covariance approach is the most appropriate method for construction research studies. This is not just because it is the most available of the software programs, but because of the numerous benefits and advantages highlighted from previous studies. The study also recommended appropriate sample size as well as cut-off value for various required goodness-of-fit tests of SEM model.

  18. Power Grid Construction Project Portfolio Optimization Based on Bi-level programming model

    Science.gov (United States)

    Zhao, Erdong; Li, Shangqi

    2017-08-01

    As the main body of power grid operation, county-level power supply enterprises undertake an important emission to guarantee the security of power grid operation and safeguard social power using order. The optimization of grid construction projects has been a key issue of power supply capacity and service level of grid enterprises. According to the actual situation of power grid construction project optimization of county-level power enterprises, on the basis of qualitative analysis of the projects, this paper builds a Bi-level programming model based on quantitative analysis. The upper layer of the model is the target restriction of the optimal portfolio; the lower layer of the model is enterprises’ financial restrictions on the size of the enterprise project portfolio. Finally, using a real example to illustrate operation proceeding and the optimization result of the model. Through qualitative analysis and quantitative analysis, the bi-level programming model improves the accuracy and normative standardization of power grid enterprises projects.

  19. Printed Spacecraft Separation System

    Energy Technology Data Exchange (ETDEWEB)

    Dehoff, Ryan R [ORNL; Holmans, Walter [Planetary Systems Corporation

    2016-10-01

    In this project Planetary Systems Corporation proposed utilizing additive manufacturing (3D printing) to manufacture a titanium spacecraft separation system for commercial and US government customers to realize a 90% reduction in the cost and energy. These savings were demonstrated via “printing-in” many of the parts and sub-assemblies into one part, thus greatly reducing the labor associated with design, procurement, assembly and calibration of mechanisms. Planetary Systems Corporation redesigned several of the components of the separation system based on additive manufacturing principles including geometric flexibility and the ability to fabricate complex designs, ability to combine multiple parts of an assembly into a single component, and the ability to optimize design for specific mechanical property targets. Shock absorption was specifically targeted and requirements were established to attenuate damage to the Lightband system from shock of initiation. Planetary Systems Corporation redesigned components based on these requirements and sent the designs to Oak Ridge National Laboratory to be printed. ORNL printed the parts using the Arcam electron beam melting technology based on the desire for the parts to be fabricated from Ti-6Al-4V based on the weight and mechanical performance of the material. A second set of components was fabricated from stainless steel material on the Renishaw laser powder bed technology due to the improved geometric accuracy, surface finish, and wear resistance of the material. Planetary Systems Corporation evaluated these components and determined that 3D printing is potentially a viable method for achieving significant cost and savings metrics.

  20. A model for evaluating the social performance of construction waste management

    International Nuclear Information System (INIS)

    Yuan Hongping

    2012-01-01

    Highlights: ► Scant attention is paid to social performance of construction waste management (CWM). ► We develop a model for assessing the social performance of CWM. ► With the model, the social performance of CWM can be quantitatively simulated. - Abstract: It has been determined by existing literature that a lot of research efforts have been made to the economic performance of construction waste management (CWM), but less attention is paid to investigation of the social performance of CWM. This study therefore attempts to develop a model for quantitatively evaluating the social performance of CWM by using a system dynamics (SD) approach. Firstly, major variables affecting the social performance of CWM are identified and a holistic system for assessing the social performance of CWM is formulated in line with feedback relationships underlying these variables. The developed system is then converted into a SD model through the software iThink. An empirical case study is finally conducted to demonstrate application of the model. Results of model validation indicate that the model is robust and reasonable to reflect the situation of the real system under study. Findings of the case study offer helpful insights into effectively promoting the social performance of CWM of the project investigated. Furthermore, the model exhibits great potential to function as an experimental platform for dynamically evaluating effects of management measures on improving the social performance of CWM of construction projects.

  1. Group theoretical construction of two-dimensional models with infinite sets of conservation laws

    International Nuclear Information System (INIS)

    D'Auria, R.; Regge, T.; Sciuto, S.

    1980-01-01

    We explicitly construct some classes of field theoretical 2-dimensional models associated with symmetric spaces G/H according to a general scheme proposed in an earlier paper. We treat the SO(n + 1)/SO(n) and SU(n + 1)/U(n) case, giving their relationship with the O(n) sigma-models and the CP(n) models. Moreover, we present a new class of models associated to the SU(n)/SO(n) case. All these models are shown to possess an infinite set of local conservation laws. (orig.)

  2. Protecting Spacecraft Fragments from Exposure to Small Debris

    Directory of Open Access Journals (Sweden)

    V. V. Zelentsov

    2015-01-01

    less than 4 ... 5 km/s, at higher speeds particles breaks through them. As a result, a cloud is formed. It consists of fragments, destroying particle, and debris split-off from the obstacle. For reliable protection the sandwich panels are used. Shield design comprises two panels: the first panel being multi-layer and the second one being single-layer. The task of the first panel is to provide the maximum fragmented particle and reduce its speed. The second panel protects the structure from the cloud fragments resulting from breakdown of the first panel. The European module "Columbus” that is part of the ISS and transport vehicle ATV have the protective shield of the similar construction. The shield consists of "aluminum sheet with 2 mm thickness; filler - Kevlar + Nextel + epoxy resin, thermal insulation; the second panel comprises aluminum sheet of 3 mm thickness.Modeling and experiments show high efficiency of steel mesh as a protective shield. Spacecraft design consists, mainly, of aluminum alloys therefore space debris is from the same material. At collision with steel mesh a particle is decelerated and destroyed. Therefore, timeRushan ability of the particle significantly decreases. The second layer, opposing to the impact of high-speed particles, is foam metal (foam-Lumina. It is successfully used in the automotive engineering. Ballistic fabric (such as Kevlar is capable to protect from the effect of the fragmentation cloud.

  3. THE MODELLING OF ORGANIZATIONAL STRUCTURES OF MANAGEMENT BY REALIZING INVESTMENT CONSTRUCTION PROJECTS

    Directory of Open Access Journals (Sweden)

    Олег Александрович КУЧМА

    2016-03-01

    Full Text Available The authors consider the modeling of organizational structures by virtue of interaction between the basic participants by realizing of investment construction projects. This process is directed at the complex analysis of a problem of quality management by creating of building goods taking into account modern project management tendencies. The topicality of problem is obvious as by realizing of investment construction projects there is a liberal share of uncompleted projects, and in the completed projects actual values considerably exceed budgeted capital expenditures. The introduced model allows managing the project per quality system in all phases of the investment construction project‘s life cycle. It promotes refinement of building goods, improves the rate of successfully completed projects with actual values near budgeted.

  4. A Bibliometric Review on Risk Management and Building Information Modeling for International Construction

    Directory of Open Access Journals (Sweden)

    Tsenguun Ganbat

    2018-01-01

    Full Text Available International construction is complicated and involves high risks. However, with the development of technological innovation, Building Information Modeling (BIM emerged and seems to be able to address certain risks. To understand BIM applications in risk management for international construction, a state-of-the-art review is required. Therefore, this paper aims to identify the research trends and opportunities for risk management in BIM-enabled international construction by reviewing 526 peer-reviewed journal articles for the years 2007–2017. Thus five steps of bibliometric analysis were conducted based on the proposed frameworks of BIM risk management in international construction (BIM-RM-INTL. The results show that the popularization of BIM not only attracts all stakeholders’ interests but also brings some risks. For example, financial factors are hard to detect and control through BIM, information loss during transmission stands out, and BIM has no unified standards and regulations for international construction. The research has mapped existing research results and their relationships for future risk management in BIM-enabled international construction.

  5. Construction and Application Research of Isomap-RVM Credit Assessment Model

    Directory of Open Access Journals (Sweden)

    Guangrong Tong

    2015-01-01

    Full Text Available Credit assessment is the basis and premise of credit risk management systems. Accurate and scientific credit assessment is of great significance to the operational decisions of shareholders, corporate creditors, and management. Building a good and reliable credit assessment model is key to credit assessment. Traditional credit assessment models are constructed using the support vector machine (SVM combined with certain traditional dimensionality reduction algorithms. When constructing such a model, the dimensionality reduction algorithms are first applied to reduce the dimensions of the samples, so as to prevent the correlation of the samples’ characteristic index from being too high. Then, machine learning of the samples will be conducted using the SVM, in order to carry out classification assessment. To further improve the accuracy of credit assessment methods, this paper has introduced more cutting-edge algorithms, applied isometric feature mapping (Isomap for dimensionality reduction, and used the relevance vector machine (RVM for credit classification. It has constructed an Isomap-RVM model and used it to conduct financial analysis of China's listed companies. The empirical analysis shows that the credit assessment accuracy of the Isomap-RVM model is significantly higher than that of the Isomap-SVM model and slightly higher than that of the PCA-RVM model. It can correctly identify the credit risks of listed companies.

  6. Remote Spacecraft Attitude Control by Coulomb Charging

    Science.gov (United States)

    Stevenson, Daan

    The possibility of inter-spacecraft collisions is a serious concern at Geosynchronous altitudes, where many high-value assets operate in proximity to countless debris objects whose orbits experience no natural means of decay. The ability to rendezvous with these derelict satellites would enable active debris removal by servicing or repositioning missions, but docking procedures are generally inhibited by the large rotational momenta of uncontrolled satellites. Therefore, a contactless means of reducing the rotation rate of objects in the space environment is desired. This dissertation investigates the viability of Coulomb charging to achieve such remote spacecraft attitude control. If a servicing craft imposes absolute electric potentials on a nearby nonspherical debris object, it will impart electrostatic torques that can be used to gradually arrest the object's rotation. In order to simulate the relative motion of charged spacecraft with complex geometries, accurate but rapid knowledge of the Coulomb interactions is required. To this end, a new electrostatic force model called the Multi-Sphere Method (MSM) is developed. All aspects of the Coulomb de-spin concept are extensively analyzed and simulated using a system with simplified geometries and one dimensional rotation. First, appropriate control algorithms are developed to ensure that the nonlinear Coulomb torques arrest the rotation with guaranteed stability. Moreover, the complex interaction of the spacecraft with the plasma environment and charge control beams is modeled to determine what hardware requirements are necessary to achieve the desired electric potential levels. Lastly, the attitude dynamics and feedback control development is validated experimentally using a scaled down terrestrial testbed. High voltage power supplies control the potential on two nearby conductors, a stationary sphere and a freely rotating cylinder. The nonlinear feedback control algorithms developed above are implemented to

  7. Gaining Modelling and Mathematical Experience by Constructing Virtual Sensory Systems in Maze-Videogames

    Science.gov (United States)

    Sacristán, Ana Isabel; Pretelín-Ricárdez, Angel

    2017-01-01

    This work is part of a research project that aims to enhance engineering students' learning of how to apply mathematics in modelling activities of real-world situations, through the construction (design and programming) of videogames. We want also for students to relate their mathematical knowledge with other disciplines (e.g., physics, computer…

  8. A construction kit for modeling the security of M-Commerce applications

    OpenAIRE

    Reif, Wolfgang

    2004-01-01

    A construction kit for modeling the security of M-Commerce applications / Dominik Haneberg, Wolfgang Reif, Kurt Stenzel. - In: Applying formal methods : testing, performance and M/E commerce ; FORTE 2004 Workshops The FormEMC ..., Toledo, Spain, October 1 - 2, 2004 ; proceedings / Manuel Núñez ... (ed.). - Berlin u. a : Springer, 2004. - S. 72-85. - (Lecture notes in computer science ; 3236)

  9. Prototype Development of an ICT System to Support Construction Management Based on Virtual Models and RFID

    DEFF Research Database (Denmark)

    Sørensen, Kristian Birch; Christiansson, Per; Svidt, Kjeld

    2009-01-01

    early example) of an ICT system was carried out to identify and formalise user needs in relation to construction management based on virtual models and radio frequency identification (RFID). The prototype was developed to support working processes in real-time project progress management, quality...

  10. Mixed Methods Study Using Constructive Learning Team Model for Secondary Mathematics Teachers

    Science.gov (United States)

    Ritter, Kristy L.

    2010-01-01

    The constructive learning team model for secondary mathematics teachers (CLTM) was created to provide students with learning opportunities and experiences that address deficiencies in oral and written communication, logical processes and analysis, mathematical operations, independent learning, teamwork, and technology utilization. This study…

  11. Relations between Minuchin's Structural Family Model and Kohut's Self-Psychology Constructs.

    Science.gov (United States)

    Perosa, Linda

    1996-01-01

    Examines relationship between structural family model and self-psychology constructs. College women (n=164) completed the Structural Family Interaction Scale-Revised (SFIS-R), the Parental Relations Inventory, and the Goal Instability and Superiority scales from the Self-Expression Inventory. Indicated that women raised in families with strong…

  12. Construct validation and the Rasch model: functional ability of healthy elderly people

    DEFF Research Database (Denmark)

    Avlund, K; Kreiner, S; Schultz-Larsen, K

    1993-01-01

    in the county of Copenhagen. Functional ability was measured with the traditional activities of daily living and with a classification system developed specially for healthy elderly people. Construct validity was tested by the Rasch model for item analysis, addressing specifically the internal validity...

  13. THREE-DIMENSIONAL GEOFILTRATIONAL MODEL OF THE ROGUN HYDRO POWER PLANT CONSTRUCTION SITE

    Directory of Open Access Journals (Sweden)

    Khokhotva Sergey Nikolaevich

    2017-05-01

    Full Text Available The article deals with technique of creation and results of calculations of the three-dimensional geofiltrational model of the Rogun HPP construction site. When performing works on creation of the Rogun HPP three-dimensional geofiltration model, geological and hydrogeological conditions of the Rogun HPP construction site were analyzed. They showed that the construction site consists mostly of fractured rocks of various weathering degrees. In terms of preservation, four preservation zones were identified in the rock mass. These zones define the features of hydrogeological conditions that have emerged in the area of construction. Calculation results illustrated the absence of seepage areas on the lower slope of dam; this is the indication of normal operation of the dam impervious circuit. The drainage system of the underground hydropower plant has a high efficiency. Operation of the drainage galleries complex leads to a significant reduction of piezometric pressure on roofs of the machine and transformer halls. Above the underground structures a completely drained area is formed. Completed forecast calculations on geofiltration model of the Rogun hydropower plant determine the hydrostatic pressure and piezometric pressure at any point of the modeled area. These data can be used as loads while designing of lining of underground workings.

  14. Multivariate Effect Size Estimation: Confidence Interval Construction via Latent Variable Modeling

    Science.gov (United States)

    Raykov, Tenko; Marcoulides, George A.

    2010-01-01

    A latent variable modeling method is outlined for constructing a confidence interval (CI) of a popular multivariate effect size measure. The procedure uses the conventional multivariate analysis of variance (MANOVA) setup and is applicable with large samples. The approach provides a population range of plausible values for the proportion of…

  15. Software for Engineering Simulations of a Spacecraft

    Science.gov (United States)

    Shireman, Kirk; McSwain, Gene; McCormick, Bernell; Fardelos, Panayiotis

    2005-01-01

    Spacecraft Engineering Simulation II (SES II) is a C-language computer program for simulating diverse aspects of operation of a spacecraft characterized by either three or six degrees of freedom. A functional model in SES can include a trajectory flight plan; a submodel of a flight computer running navigational and flight-control software; and submodels of the environment, the dynamics of the spacecraft, and sensor inputs and outputs. SES II features a modular, object-oriented programming style. SES II supports event-based simulations, which, in turn, create an easily adaptable simulation environment in which many different types of trajectories can be simulated by use of the same software. The simulation output consists largely of flight data. SES II can be used to perform optimization and Monte Carlo dispersion simulations. It can also be used to perform simulations for multiple spacecraft. In addition to its generic simulation capabilities, SES offers special capabilities for space-shuttle simulations: for this purpose, it incorporates submodels of the space-shuttle dynamics and a C-language version of the guidance, navigation, and control components of the space-shuttle flight software.

  16. Construction of a mouse model of factor VIII deficiency by gene targeting

    Energy Technology Data Exchange (ETDEWEB)

    Bi, L.; Lawler, A.; Gearhart, J. [Univ. of Pennsylvania School of Medicine, Philadelphia, PA (United States)] [and others

    1994-09-01

    To develop a small animal model of hemophilia A for gene therapy experiments, we set out to construct a mouse model for factor VIII deficiency by gene targeting. First, we screened a mouse liver cDNA library using a human FVIII cDNA probe. We cloned a 2.6 Kb partial mouse factor VIII cDNA which extends from 800 base pairs of the 3{prime} end of exon 14 to the 5{prime} end of exon 26. A mouse genomic library made from strain 129 was then screened to obtain genomic fragments covering the exons desired for homologous recombination. Two genomic clones were obtained, and one covering exon 15 through 22 was used for gene targeting. To make gene targeting constructs, a 5.8 Kb genomic DNA fragment covering exons 15 to 19 of the mouse FVIII gene was subcloned, and the neo expression cassette was inserted into exons 16 and 17 separately by different strategies. These two constructs were named MFVIIIC-16 and MFVIIIC-17. The constructs were linearized and transfected into strain 129 mouse ES cells by electroporation. Factor VIII gene-knockout ES cell lines were selected by G-418 and screened by genomic Southern blots. Eight exon 16 targeted cell lines and five exon 17 targeted cell lines were obtained. Three cell lines from each construct were injected into blastocysts and surgically transferred into foster mothers. Multiple chimeric mice with 70-90% hair color derived from the ES-cell genotype were seen with both constructs. Germ line transmission of the ES-cell genotype has been obtained for the MFVIIIC-16 construct, and multiple hemophilia A carrier females have been identified. Factor VIII-deficient males will be conceived soon.

  17. Modeling the sustainable development of innovation in transport construction based on the communication approach

    Science.gov (United States)

    Revunova, Svetlana; Vlasenko, Vyacheslav; Bukreev, Anatoly

    2017-10-01

    The article proposes the models of innovative activity development, which is driven by the formation of “points of innovation-driven growth”. The models are based on the analysis of the current state and dynamics of innovative development of construction enterprises in the transport sector and take into account a number of essential organizational and economic changes in management. The authors substantiate implementing such development models as an organizational innovation that has a communication genesis. The use of the communication approach to the formation of “points of innovation-driven growth” allowed the authors to apply the mathematical tools of the graph theory in order to activate the innovative activity of the transport industry in the region. As a result, the authors have proposed models that allow constructing an optimal mechanism for the formation of “points of innovation-driven growth”.

  18. Design and construction of a large reinforced concrete containment model to be tested to failure

    International Nuclear Information System (INIS)

    Ucciferro, J.J.; Horschel, D.S.

    1987-01-01

    The US Nuclear Regulatory Commission is investigating the performance of LWR containments subjected to severe accidents. This work is being performed by the Containment Integrity Division at Sandia National Laboratories (Sandia). The latest research effort involves the testing of a 1/6-scale reinforced concrete containment model. The containment, which was designed and constructed by United Engineers and Constructors, is the largest and most complex model of its kind. The design and construction of the containment model are the subject of this paper. The objective of the containment model tests is to generate data that can be used to qualify methods for reliably predicting the response of LWR containment buildings to severe accident loads. The data recorded during testing include deformations and leakage past sealing surfaces, as well as strains and displacements of the containment shell

  19. Application of Building Information Modeling (3D and 4D in Construction Sector in Iraq

    Directory of Open Access Journals (Sweden)

    Kadhim Raheem Erzaij

    2017-10-01

    Full Text Available Building Information Modeling (BIM is becoming a great known established collaboration process in Architecture, Engineering, and Construction (AEC industry. In various cases in many countries, potential benefits and competitive advantages have been reported. However, despite the potentials and benefits of BIM technologies, it is not applied in the construction sector in Iraq just like many other countries of the world. The purpose of this research is to understand the uses and benefits of BIM for construction projects in Iraq. This purpose has been done by establishing a framework to application of BIM and identifying the benefits of this technology that would convince stakeholders for adopting BIM in the construction sector in Iraq. Through this research, the use of this technology has been clarified by using the proposed framework (application Revit software and linking it with the MS Project and Navisworks Manage software on the case study to identify the important benefits to be the beginning to apply the Building Information Modeling technology in the construction sector in Iraq. The research results indicated that such proposed framework can greatly improve the performance of the current state of project management through improving the project quality, cost saving and time-saving.

  20. [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

  1. An Integrated Framework for Process-Driven Model Construction in Disease Ecology and Animal Health

    Directory of Open Access Journals (Sweden)

    Rebecca Mancy

    2017-09-01

    Full Text Available Process models that focus on explicitly representing biological mechanisms are increasingly important in disease ecology and animal health research. However, the large number of process modelling approaches makes it difficult to decide which is most appropriate for a given disease system and research question. Here, we discuss different motivations for using process models and present an integrated conceptual analysis that can be used to guide the construction of infectious disease process models and comparisons between them. Our presentation complements existing work by clarifying the major differences between modelling approaches and their relationship with the biological characteristics of the epidemiological system. We first discuss distinct motivations for using process models in epidemiological research, identifying the key steps in model design and use associated with each. We then present a conceptual framework for guiding model construction and comparison, organised according to key aspects of epidemiological systems. Specifically, we discuss the number and type of disease states, whether to focus on individual hosts (e.g., cows or groups of hosts (e.g., herds or farms, how space or host connectivity affect disease transmission, whether demographic and epidemiological processes are periodic or can occur at any time, and the extent to which stochasticity is important. We use foot-and-mouth disease and bovine tuberculosis in cattle to illustrate our discussion and support explanations of cases in which different models are used to address similar problems. The framework should help those constructing models to structure their approach to modelling decisions and facilitate comparisons between models in the literature.

  2. Constructing a Computer Model of the Human Eye Based on Tissue Slice Images

    OpenAIRE

    Dai, Peishan; Wang, Boliang; Bao, Chunbo; Ju, Ying

    2010-01-01

    Computer simulation of the biomechanical and biological heat transfer in ophthalmology greatly relies on having a reliable computer model of the human eye. This paper proposes a novel method on the construction of a geometric model of the human eye based on tissue slice images. Slice images were obtained from an in vitro Chinese human eye through an embryo specimen processing methods. A level set algorithm was used to extract contour points of eye tissues while a principle component analysi...

  3. Project Management Life Cycle Models to Improve Management in High-rise Construction

    Science.gov (United States)

    Burmistrov, Andrey; Siniavina, Maria; Iliashenko, Oksana

    2018-03-01

    The paper describes a possibility to improve project management in high-rise buildings construction through the use of various Project Management Life Cycle Models (PMLC models) based on traditional and agile project management approaches. Moreover, the paper describes, how the split the whole large-scale project to the "project chain" will create the factor for better manageability of the large-scale buildings project and increase the efficiency of the activities of all participants in such projects.

  4. METHODOLOGICAL ASPECTS OF CLASSIFICATION OF INVESTMENT MODELS APPLICABLE TO CONSTRUCTION PROJECTS

    OpenAIRE

    Yaskova Natalya Yurevna; Moskvichev Danil Vasilevich

    2012-01-01

    The paper covers the identification of basic investment models applicable to construction projects. They are needed to substantiate the transformation of the investment system, to identify the numerical values of the investment process, and to solve the problems that prevent the efficiency improvement of the investment system. As a result of the analysis, the authors have identified sixteen models that differ in the mode of investment, investment targets, types of investees, in...

  5. Project Management Life Cycle Models to Improve Management in High-rise Construction

    Directory of Open Access Journals (Sweden)

    Burmistrov Andrey

    2018-01-01

    Full Text Available The paper describes a possibility to improve project management in high-rise buildings construction through the use of various Project Management Life Cycle Models (PMLC models based on traditional and agile project management approaches. Moreover, the paper describes, how the split the whole large-scale project to the "project chain" will create the factor for better manageability of the large-scale buildings project and increase the efficiency of the activities of all participants in such projects.

  6. Time-optimal spacecraft attitude maneuver path planning under boundary and pointing constraints

    Science.gov (United States)

    Wu, Changqing; Xu, Rui; Zhu, Shengying; Cui, Pingyuan

    2017-08-01

    The rapid large angle attitude maneuver capability of spacecraft is required during many space missions. This paper addresses the challenge of time-optimal spacecraft attitude maneuver under boundary and pointing constraints. From the perspective of the optimal time, the constrained attitude maneuver problem is summarized as an optimum path-planning problem. To address this problem, a metaheuristic maneuver path planning method is proposed, Angular velocity-Time Coding Differential Evolution (ATDE). In the ATDE method, the angular velocity and time are coded for attitude maneuver modeling, which increases the number of variables and results in a high-dimensional problem. In order to deal with this problem, differential evolution is employed to perform variation and evolution. The boundary and pointing constraints are constructed into the fitness function for path evaluation. Finally, numerical simulations for the different cases were performed to validate the feasibility and effectiveness of the proposed method.

  7. Evaluating measurement of dynamic constructs: defining a measurement model of derivatives.

    Science.gov (United States)

    Estabrook, Ryne

    2015-03-01

    While measurement evaluation has been embraced as an important step in psychological research, evaluating measurement structures with longitudinal data is fraught with limitations. This article defines and tests a measurement model of derivatives (MMOD), which is designed to assess the measurement structure of latent constructs both for analyses of between-person differences and for the analysis of change. Simulation results indicate that MMOD outperforms existing models for multivariate analysis and provides equivalent fit to data generation models. Additional simulations show MMOD capable of detecting differences in between-person and within-person factor structures. Model features, applications, and future directions are discussed. (c) 2015 APA, all rights reserved).

  8. An efficient model construction strategy to simulate microalgal lutein photo-production dynamic process.

    Science.gov (United States)

    Del Rio-Chanona, Ehecatl A; Fiorelli, Fabio; Zhang, Dongda; Ahmed, Nur R; Jing, Keju; Shah, Nilay

    2017-11-01

    Lutein is a high-value bioproduct synthesized by microalga Desmodesmus sp. It has great potential for the food, cosmetics, and pharmaceutical industries. However, in order to enhance its productivity and to fulfil its ever-increasing global market demand, it is vital to construct accurate models capable of simulating the entire behavior of the complicated dynamics of the underlying biosystem. To this aim, in this study two highly robust artificial neural networks (ANNs) are designed for the first time. Contrary to conventional ANNs, these networks model the rate of change of the dynamic system, which makes them highly relevant in practice. Different strategies are incorporated into the current research to guarantee the accuracy of the constructed models, which include determining the optimal network structure through a hyper-parameter selection framework, generating significant amounts of artificial data sets by embedding random noise of appropriate size, and rescaling model inputs through standardization. Based on experimental verification, the high accuracy and great predictive power of the current models for long-term dynamic bioprocess simulation in both real-time and offline frameworks are thoroughly demonstrated. This research, therefore, paves the way to significantly facilitate the future investigation of lutein bioproduction process control and optimization. In addition, the model construction strategy developed in this research has great potential to be directly applied to other bioprocesses. Biotechnol. Bioeng. 2017;114: 2518-2527. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. A Bayesian method for construction of Markov models to describe dynamics on various time-scales.

    Science.gov (United States)

    Rains, Emily K; Andersen, Hans C

    2010-10-14

    The dynamics of many biological processes of interest, such as the folding of a protein, are slow and complicated enough that a single molecular dynamics simulation trajectory of the entire process is difficult to obtain in any reasonable amount of time. Moreover, one such simulation may not be sufficient to develop an understanding of the mechanism of the process, and multiple simulations may be necessary. One approach to circumvent this computational barrier is the use of Markov state models. These models are useful because they can be constructed using data from a large number of shorter simulations instead of a single long simulation. This paper presents a new Bayesian method for the construction of Markov models from simulation data. A Markov model is specified by (τ,P,T), where τ is the mesoscopic time step, P is a partition of configuration space into mesostates, and T is an N(P)×N(P) transition rate matrix for transitions between the mesostates in one mesoscopic time step, where N(P) is the number of mesostates in P. The method presented here is different from previous Bayesian methods in several ways. (1) The method uses Bayesian analysis to determine the partition as well as the transition probabilities. (2) The method allows the construction of a Markov model for any chosen mesoscopic time-scale τ. (3) It constructs Markov models for which the diagonal elements of T are all equal to or greater than 0.5. Such a model will be called a "consistent mesoscopic Markov model" (CMMM). Such models have important advantages for providing an understanding of the dynamics on a mesoscopic time-scale. The Bayesian method uses simulation data to find a posterior probability distribution for (P,T) for any chosen τ. This distribution can be regarded as the Bayesian probability that the kinetics observed in the atomistic simulation data on the mesoscopic time-scale τ was generated by the CMMM specified by (P,T). An optimization algorithm is used to find the most

  10. Applying total interpretive structural modeling to study factors affecting construction labour productivity

    Directory of Open Access Journals (Sweden)

    Sayali Shrikrishna Sandbhor

    2014-03-01

    Full Text Available Construction sector has always been dependent on manpower. Most of the activities carried out on any construction site are labour intensive. Since productivity of any project depends directly on productivity of labour, it is a prime responsibility of the employer to enhance labour productivity. Measures to improve the same depend on analysis of positive and negative factors affecting productivity. Major attention should be given to factors that decrease the productivity of labour. Factor analysis thus is an integral part of any study aiming to improve productivity.  Interpretive structural modeling is a methodology for identifying and summarizing relationships among factors which define an issue or problem. It provides a means to arrange the factors in an order as per their complexity. This study attempts to use the latest version of interpretive structural modeling i.e. total interpretive structural modeling to analyze factors negatively affecting construction labour productivity. It establishes interpretive relationship among these factors facilitating improvement in the overall productivity of construction site.

  11. The Functional Model Approach to the Consulting for Vertically - Integrated Construction Group

    Directory of Open Access Journals (Sweden)

    Pimenova Anna

    2016-01-01

    Full Text Available Managerial decision making in the framework of functional modeling of the consulting process have a direct effect on other business - processes of vertically - integrated group of construction companies. As a result, the experience of consulting companies tends to be used for the making managerial solutions. Consultancy is known as one of the most complicated types of buisiness process. It requires a huge and deep examines and researches of targeting area, therefore need to be provided with special methodology, included internal standards of the consulting companies. Correct methodological support, planning process and implementation of managerial solutions should be based on the survey of the direct and inverse connections and interdependence of all group’s business – processes. Functional - process modeling of the vertically - integrated construction group could be considered as an instrument of examination and analysis of the issue how the managerial solution impact on the business-process for the construction group functioning. The main result of the research is the formalized process-oriented model – prototype of the business - processes of vertically - integrated group of construction companies.

  12. A mathematical model for fluid shear-sensitive 3D tissue construct development.

    Science.gov (United States)

    Liu, Dan; Chua, Chee-Kai; Leong, Kah-Fai

    2013-01-01

    This research studies dynamic culture for 3D tissue construct development with computational fluid dynamics. It proposes a mathematical model to evaluate the impact of flow rates and flow shear stress on cell growth in 3D constructs under perfusion. The modeling results show that dynamic flow, even at flow rate as low as 0.002 cm/s, can support much better mass exchange, higher cell number, and more even cell and nutrient distribution compared to static culture. Higher flow rate can further improve nutrient supply and mass exchange in the construct, promoting better nutritious environment and cell proliferation compared to lower flow rate. In addition, consideration of flow shear stress predicts much higher cell number in the construct compared to that without shear consideration. While the nutrient can dominate shear stress in influencing cell proliferation, the shear effect increases with flow rate. The proposed model helps tissue engineers better understand the cell-flow relationship at the molecular level during dynamic culture.

  13. Spacecraft early design validation using formal methods

    International Nuclear Information System (INIS)

    Bozzano, Marco; Cimatti, Alessandro; Katoen, Joost-Pieter; Katsaros, Panagiotis; Mokos, Konstantinos; Nguyen, Viet Yen; Noll, Thomas; Postma, Bart; Roveri, Marco

    2014-01-01

    The size and complexity of software in spacecraft is increasing exponentially, and this trend complicates its validation within the context of the overall spacecraft system. Current validation methods are labor-intensive as they rely on manual analysis, review and inspection. For future space missions, we developed – with challenging requirements from the European space industry – a novel modeling language and toolset for a (semi-)automated validation approach. Our modeling language is a dialect of AADL and enables engineers to express the system, the software, and their reliability aspects. The COMPASS toolset utilizes state-of-the-art model checking techniques, both qualitative and probabilistic, for the analysis of requirements related to functional correctness, safety, dependability and performance. Several pilot projects have been performed by industry, with two of them having focused on the system-level of a satellite platform in development. Our efforts resulted in a significant advancement of validating spacecraft designs from several perspectives, using a single integrated system model. The associated technology readiness level increased from level 1 (basic concepts and ideas) to early level 4 (laboratory-tested)

  14. Stability analysis of spacecraft power systems

    Science.gov (United States)

    Halpin, S. M.; Grigsby, L. L.; Sheble, G. B.; Nelms, R. M.

    1990-01-01

    The problems in applying standard electric utility models, analyses, and algorithms to the study of the stability of spacecraft power conditioning and distribution systems are discussed. Both single-phase and three-phase systems are considered. Of particular concern are the load and generator models that are used in terrestrial power system studies, as well as the standard assumptions of load and topological balance that lead to the use of the positive sequence network. The standard assumptions regarding relative speeds of subsystem dynamic responses that are made in the classical transient stability algorithm, which forms the backbone of utility-based studies, are examined. The applicability of these assumptions to a spacecraft power system stability study is discussed in detail. In addition to the classical indirect method, the applicability of Liapunov's direct methods to the stability determination of spacecraft power systems is discussed. It is pointed out that while the proposed method uses a solution process similar to the classical algorithm, the models used for the sources, loads, and networks are, in general, more accurate. Some preliminary results are given for a linear-graph, state-variable-based modeling approach to the study of the stability of space-based power distribution networks.

  15. Determination of Realistic Fire Scenarios in Spacecraft

    Science.gov (United States)

    Dietrich, Daniel L.; Ruff, Gary A.; Urban, David

    2013-01-01

    This paper expands on previous work that examined how large a fire a crew member could successfully survive and extinguish in the confines of a spacecraft. The hazards to the crew and equipment during an accidental fire include excessive pressure rise resulting in a catastrophic rupture of the vehicle skin, excessive temperatures that burn or incapacitate the crew (due to hyperthermia), carbon dioxide build-up or accumulation of other combustion products (e.g. carbon monoxide). The previous work introduced a simplified model that treated the fire primarily as a source of heat and combustion products and sink for oxygen prescribed (input to the model) based on terrestrial standards. The model further treated the spacecraft as a closed system with no capability to vent to the vacuum of space. The model in the present work extends this analysis to more realistically treat the pressure relief system(s) of the spacecraft, include more combustion products (e.g. HF) in the analysis and attempt to predict the fire spread and limiting fire size (based on knowledge of terrestrial fires and the known characteristics of microgravity fires) rather than prescribe them in the analysis. Including the characteristics of vehicle pressure relief systems has a dramatic mitigating effect by eliminating vehicle overpressure for all but very large fires and reducing average gas-phase temperatures.

  16. Internal Mass Motion for Spacecraft Dynamics and Control

    National Research Council Canada - National Science Library

    Hall, Christopher D

    2008-01-01

    We present a detailed description of the application of a noncanonical Hamiltonian formulation to the modeling, analysis, and simulation of the dynamics of gyrostat spacecraft with internal mass motion...

  17. Nuclear radiation environment analysis for thermoelectric outer planet spacecraft

    Science.gov (United States)

    Davis, H. S.; Koprowski, E. F.

    1972-01-01

    Neutron and gamma ray transport calculations were performed using Monte Carlo methods and a three-dimensional geometric model of the spacecraft. The results are compared with similar calculations performed for an earlier design.

  18. An Estimation of Construction and Demolition Debris in Seoul, Korea: Waste Amount, Type, and Estimating Model.

    Science.gov (United States)

    Seo, Seongwon; Hwang, Yongwoo

    1999-08-01

    Construction and demolition (C&D) debris is generated at the site of various construction activities. However, the amount of the debris is usually so large that it is necessary to estimate the amount of C&D debris as accurately as possible for effective waste management and control in urban areas. In this paper, an effective estimation method using a statistical model was proposed. The estimation process was composed of five steps: estimation of the life span of buildings; estimation of the floor area of buildings to be constructed and demolished; calculation of individual intensity units of C&D debris; and estimation of the future C&D debris production. This method was also applied in the city of Seoul as an actual case, and the estimated amount of C&D debris in Seoul in 2021 was approximately 24 million tons. Of this total amount, 98% was generated by demolition, and the main components of debris were concrete and brick.

  19. [A competency model of rural general practitioners: theory construction and empirical study].

    Science.gov (United States)

    Yang, Xiu-Mu; Qi, Yu-Long; Shne, Zheng-Fu; Han, Bu-Xin; Meng, Bei

    2015-04-01

    To perform theory construction and empirical study of the competency model of rural general practitioners. Through literature study, job analysis, interviews, and expert team discussion, the questionnaire of rural general practitioners competency was constructed. A total of 1458 rural general practitioners were surveyed by the questionnaire in 6 central provinces. The common factors were constructed using the principal component method of exploratory factor analysis and confirmatory factor analysis. The influence of the competency characteristics on the working performance was analyzed using regression equation analysis. The Cronbach 's alpha coefficient of the questionnaire was 0.974. The model consisted of 9 dimensions and 59 items. The 9 competency dimensions included basic public health service ability, basic clinical skills, system analysis capability, information management capability, communication and cooperation ability, occupational moral ability, non-medical professional knowledge, personal traits and psychological adaptability. The rate of explained cumulative total variance was 76.855%. The model fitting index were Χ(2)/df 1.88, GFI=0.94, NFI=0.96, NNFI=0.98, PNFI=0.91, RMSEA=0.068, CFI=0.97, IFI=0.97, RFI=0.96, suggesting good model fitting. Regression analysis showed that the competency characteristics had a significant effect on job performance. The rural general practitioners competency model provides reference for rural doctor training, rural order directional cultivation of medical students, and competency performance management of the rural general practitioners.

  20. Gravity Probe B spacecraft description

    International Nuclear Information System (INIS)

    Bennett, Norman R; Burns, Kevin; Katz, Russell; Kirschenbaum, Jon; Mason, Gary; Shehata, Shawky

    2015-01-01

    The Gravity Probe B spacecraft, developed, integrated, and tested by Lockheed Missiles and Space Company and later Lockheed Martin Corporation, consisted of structures, mechanisms, command and data handling, attitude and translation control, electrical power, thermal control, flight software, and communications. When integrated with the payload elements, the integrated system became the space vehicle. Key requirements shaping the design of the spacecraft were: (1) the tight mission timeline (17 months, 9 days of on-orbit operation), (2) precise attitude and translational control, (3) thermal protection of science hardware, (4) minimizing aerodynamic, magnetic, and eddy current effects, and (5) the need to provide a robust, low risk spacecraft. The spacecraft met all mission requirements, as demonstrated by dewar lifetime meeting specification, positive power and thermal margins, precision attitude control and drag-free performance, reliable communications, and the collection of more than 97% of the available science data. (paper)

  1. Spacecraft Power Monitor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I project will develop the Spacecraft Power Monitor (SPM) which will use non-intrusive electrical monitoring (NEMO). NEMO transforms the power...

  2. Spacecraft on a Chip Development

    Data.gov (United States)

    National Aeronautics and Space Administration — This project lays the groundwork for the future development of a spacecraft on a chip implementation (SCOC), which would combine the electronics for multiple...

  3. Spacecraft Cabin Particulate Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design, build and test an optical extinction monitor for the detection of spacecraft cabin particulates. This monitor will be sensitive to particle...

  4. Application of dynamic uncertain causality graph in spacecraft fault diagnosis: Multi-conditions

    Science.gov (United States)

    Yao, Quanying; Zhang, Qin; Liu, Peng; Yang, Ping; Wang, Xiaochen; Zhu, Ma

    2017-03-01

    Intelligent diagnosis system is applied to fault diagnosis in spacecraft. Dynamic Uncertain Causality Graph (DUCG) is a new probability graphic model with many advantages. In this paper, DUGG is applied to fault diagnosis in spacecraft: introducing conditional functional events into ordinary DUCG to deal with spacecraft multi-conditions. Now, DUCG has been tested in 16 typical faults with 100% diagnosis accuracy.

  5. A Quantized State Approach to On-line Simulation for Spacecraft Autonomy

    DEFF Research Database (Denmark)

    Alminde, Lars; Stoustrup, Jakob; Bendtsen, Jan Dimon

    2006-01-01

    Future space applications will require an increased level of operational autonomy. This calls for declarative methods for spacecraft state estimation and control, so that the spacecraft engineer can focus on modeling the spacecraft rather than implementing all details of the on-line system...

  6. Construction cost prediction model for conventional and sustainable college buildings in North America

    Directory of Open Access Journals (Sweden)

    Othman Subhi Alshamrani

    2017-03-01

    Full Text Available The literature lacks in initial cost prediction models for college buildings, especially comparing costs of sustainable and conventional buildings. A multi-regression model was developed for conceptual initial cost estimation of conventional and sustainable college buildings in North America. RS Means was used to estimate the national average of construction costs for 2014, which was subsequently utilized to develop the model. The model could predict the initial cost per square feet with two structure types made of steel and concrete. The other predictor variables were building area, number of floors and floor height. The model was developed in three major stages, such as preliminary diagnostics on data quality, model development and validation. The developed model was successfully tested and validated with real-time data.

  7. Constructing an Efficient Self-Tuning Aircraft Engine Model for Control and Health Management Applications

    Science.gov (United States)

    Armstrong, Jeffrey B.; Simon, Donald L.

    2012-01-01

    Self-tuning aircraft engine models can be applied for control and health management applications. The self-tuning feature of these models minimizes the mismatch between any given engine and the underlying engineering model describing an engine family. This paper provides details of the construction of a self-tuning engine model centered on a piecewise linear Kalman filter design. Starting from a nonlinear transient aerothermal model, a piecewise linear representation is first extracted. The linearization procedure creates a database of trim vectors and state-space matrices that are subsequently scheduled for interpolation based on engine operating point. A series of steady-state Kalman gains can next be constructed from a reduced-order form of the piecewise linear model. Reduction of the piecewise linear model to an observable dimension with respect to available sensed engine measurements can be achieved using either a subset or an optimal linear combination of "health" parameters, which describe engine performance. The resulting piecewise linear Kalman filter is then implemented for faster-than-real-time processing of sensed engine measurements, generating outputs appropriate for trending engine performance, estimating both measured and unmeasured parameters for control purposes, and performing on-board gas-path fault diagnostics. Computational efficiency is achieved by designing multidimensional interpolation algorithms that exploit the shared scheduling of multiple trim vectors and system matrices. An example application illustrates the accuracy of a self-tuning piecewise linear Kalman filter model when applied to a nonlinear turbofan engine simulation. Additional discussions focus on the issue of transient response accuracy and the advantages of a piecewise linear Kalman filter in the context of validation and verification. The techniques described provide a framework for constructing efficient self-tuning aircraft engine models from complex nonlinear

  8. Dynamic processes of conceptual change: Analysis of constructing mental models of chemical equilibrium

    Science.gov (United States)

    Chiu, Mei-Hung; Chou, Chin-Cheng; Liu, Chia-Ju

    2002-10-01

    The purpose of this study was to investigate students' mental models of chemical equilibrium using dynamic science assessments. Research in chemical education has shown that students at various levels have misconceptions about chemical equilibrium. According to Chi's theory of conceptual change, the concept of chemical equilibrium has constraint-based features (e.g., random, simultaneous, uniform activities) that might prevent students from deeply understanding the nature of the concept of chemical equilibrium. In this study, we examined how students learned and constructed their mental models of chemical equilibrium in a cognitive apprenticeship context. Thirty 10th-grade students participated in the study: 10 in a control group and 20 in a treatment group. Both groups were presented with a series of hands-on chemical experiments. The students in the treatment group were instructed based on the main features of cognitive apprenticeship (CA), such as coaching, modeling, scaffolding, articulation, reflection, and exploration. However, the students in the control group (non-CA group) learned from the tutor without explicit CA support. The results revealed that the CA group significantly outperformed the non-CA group. The students in the CA group were capable of constructing the mental models of chemical equilibrium - including dynamic, random activities of molecules and interactions between molecules in the microworld - whereas the students in the non-CA group failed to construct similar correct mental models of chemical equilibrium. The study focuses on the process of constructing mental models, on dynamic changes, and on the actions of students (such as self-monitoring/self-correction) who are learning the concept of chemical equilibrium. Also, we discuss the implications for science education.

  9. Integrating building information modeling and health and safety for onsite construction.

    Science.gov (United States)

    Ganah, Abdulkadir; John, Godfaurd A

    2015-03-01

    Health and safety (H&S) on a construction site can either make or break a contractor, if not properly managed. The usage of Building Information Modeling (BIM) for H&S on construction execution has the potential to augment practitioner understanding of their sites, and by so doing reduce the probability of accidents. This research explores BIM usage within the construction industry in relation to H&S communication. In addition to an extensive literature review, a questionnaire survey was conducted to gather information on the embedment of H&S planning with the BIM environment for site practitioners. The analysis of responses indicated that BIM will enhance the current approach of H&S planning for construction site personnel. From the survey, toolbox talk will have to be integrated with the BIM environment, because it is the predominantly used procedure for enhancing H&S issues within construction sites. The advantage is that personnel can visually understand H&S issues as work progresses during the toolbox talk onsite.

  10. Artificial Intelligence Techniques for Controlling Spacecraft Power System

    OpenAIRE

    Hanaa T. El-Madany; Faten H. Fahmy; Ninet M. A. El-Rahman; Hassen T. Dorrah

    2011-01-01

    Advancements in the field of artificial intelligence (AI) made during this decade have forever changed the way we look at automating spacecraft subsystems including the electrical power system. AI have been used to solve complicated practical problems in various areas and are becoming more and more popular nowadays. In this paper, a mathematical modeling and MATLAB–SIMULINK model for the different components of the spacecraft power system is presented. Also, a control sys...

  11. Making the error-controlling algorithm of observable operator models constructive.

    Science.gov (United States)

    Zhao, Ming-Jie; Jaeger, Herbert; Thon, Michael

    2009-12-01

    Observable operator models (OOMs) are a class of models for stochastic processes that properly subsumes the class that can be modeled by finite-dimensional hidden Markov models (HMMs). One of the main advantages of OOMs over HMMs is that they admit asymptotically correct learning algorithms. A series of learning algorithms has been developed, with increasing computational and statistical efficiency, whose recent culmination was the error-controlling (EC) algorithm developed by the first author. The EC algorithm is an iterative, asymptotically correct algorithm that yields (and minimizes) an assured upper bound on the modeling error. The run time is faster by at least one order of magnitude than EM-based HMM learning algorithms and yields significantly more accurate models than the latter. Here we present a significant improvement of the EC algorithm: the constructive error-controlling (CEC) algorithm. CEC inherits from EC the main idea of minimizing an upper bound on the modeling error but is constructive where EC needs iterations. As a consequence, we obtain further gains in learning speed without loss in modeling accuracy.

  12. [Construction of the addiction prevention core competency model for preventing addictive behavior in adolescents].

    Science.gov (United States)

    Park, Hyun Sook; Jung, Sun Young

    2013-12-01

    This study was done to provide fundamental data for the development of competency reinforcement programs to prevent addictive behavior in adolescents through the construction and examination of an addiction prevention core competency model. In this study core competencies for preventing addictive behavior in adolescents through competency modeling were identified, and the addiction prevention core competency model was developed. It was validated methodologically. Competencies for preventing addictive behavior in adolescents as defined by the addiction prevention core competency model are as follows: positive self-worth, self-control skill, time management skill, reality perception skill, risk coping skill, and positive communication with parents and with peers or social group. After construction, concurrent cross validation of the addiction prevention core competency model showed that this model was appropriate. The study results indicate that the addiction prevention core competency model for the prevention of addictive behavior in adolescents through competency modeling can be used as a foundation for an integral approach to enhance adolescent is used as an adjective and prevent addictive behavior. This approach can be a school-centered, cost-efficient strategy which not only reduces addictive behavior in adolescents, but also improves the quality of their resources.

  13. Valuation of real options : construction of a model to evaluate real investment projects

    OpenAIRE

    Rutgerson, Mette Rørvik

    2008-01-01

    In this thesis I use two existing models to construct a model that can evaluate the exploration phase and the production phase of a real investment project simultaneously. I assume that the value of the production phase is the value of the outcome of an exploration project and can therefore make a model that combines the two phases. I assume that the exploration phase has on-going investment costs until completion and that the time to completion is uncertain. I allow the exploration project t...

  14. Integrated controls-structures design methodology development for a class of flexible spacecraft

    Science.gov (United States)

    Maghami, P. G.; Joshi, S. M.; Walz, J. E.; Armstrong, E. S.

    1990-01-01

    Future utilization of space will require large space structures in low-Earth and geostationary orbits. Example missions include: Earth observation systems, personal communication systems, space science missions, space processing facilities, etc., requiring large antennas, platforms, and solar arrays. The dimensions of such structures will range from a few meters to possibly hundreds of meters. For reducing the cost of construction, launching, and operating (e.g., energy required for reboosting and control), it will be necessary to make the structure as light as possible. However, reducing structural mass tends to increase the flexibility which would make it more difficult to control with the specified precision in attitude and shape. Therefore, there is a need to develop a methodology for designing space structures which are optimal with respect to both structural design and control design. In the current spacecraft design practice, it is customary to first perform the structural design and then the controller design. However, the structural design and the control design problems are substantially coupled and must be considered concurrently in order to obtain a truly optimal spacecraft design. For example, let C denote the set of the 'control' design variables (e.g., controller gains), and L the set of the 'structural' design variables (e.g., member sizes). If a structural member thickness is changed, the dynamics would change which would then change the control law and the actuator mass. That would, in turn, change the structural model. Thus, the sets C and L depend on each other. Future space structures can be roughly divided into four mission classes. Class 1 missions include flexible spacecraft with no articulated appendages which require fine attitude pointing and vibration suppression (e.g., large space antennas). Class 2 missions consist of flexible spacecraft with articulated multiple payloads, where the requirement is to fine-point the spacecraft and each

  15. Enhancing mindful coordination in fragmented utility construction practices: by developing, implementing and evaluating virtual design and construction models

    NARCIS (Netherlands)

    olde Scholtenhuis, Léon Luc

    2015-01-01

    Municipalities cope with a growth in number of utility network owners and subsurface network size. Simultaneously, the multiple utility owners involved in subsurface construction work need to align plans to cope with tight deadlines and imposed spatial constraints. This research hones in on this

  16. Constructing Markov State Models to elucidate the functional conformational changes of complex biomolecules

    KAUST Repository

    Wang, Wei

    2017-10-06

    The function of complex biomolecular machines relies heavily on their conformational changes. Investigating these functional conformational changes is therefore essential for understanding the corresponding biological processes and promoting bioengineering applications and rational drug design. Constructing Markov State Models (MSMs) based on large-scale molecular dynamics simulations has emerged as a powerful approach to model functional conformational changes of the biomolecular system with sufficient resolution in both time and space. However, the rapid development of theory and algorithms for constructing MSMs has made it difficult for nonexperts to understand and apply the MSM framework, necessitating a comprehensive guidance toward its theory and practical usage. In this study, we introduce the MSM theory of conformational dynamics based on the projection operator scheme. We further propose a general protocol of constructing MSM to investigate functional conformational changes, which integrates the state-of-the-art techniques for building and optimizing initial pathways, performing adaptive sampling and constructing MSMs. We anticipate this protocol to be widely applied and useful in guiding nonexperts to study the functional conformational changes of large biomolecular systems via the MSM framework. We also discuss the current limitations of MSMs and some alternative methods to alleviate them.

  17. An Algorithm for Modelling the Impact of the Judicial Conflict-Resolution Process on Construction Investment

    Directory of Open Access Journals (Sweden)

    Andrej Bugajev

    2018-01-01

    Full Text Available In this article, the modelling of the judicial conflict-resolution process is considered from a construction investor’s point of view. Such modelling is important for improving the risk management for construction investors and supporting sustainable city development by supporting the development of rules regulating the construction process. Thus, this raises the problem of evaluation of different decisions and selection of the optimal one followed by distribution extraction. First, the example of such a process is analysed and schematically represented. Then, it is formalised as a graph, which is described in the form of a decision graph with cycles. We use some natural problem properties and provide the algorithm to convert this graph into a tree. Then, we propose the algorithm to evaluate profits for different scenarios with estimation of time, which is done by integration of an average daily costs function. Afterwards, the optimisation problem is solved and the optimal investor strategy is obtained—this allows one to extract the construction project profit distribution, which can be used for further analysis by standard risk (and other important information-evaluation techniques. The overall algorithm complexity is analysed, the computational experiment is performed and conclusions are formulated.

  18. Identifying critical success factors (CSFs) of implementing building information modeling (BIM) in Malaysian construction industry

    Science.gov (United States)

    Yaakob, Mazri; Ali, Wan Nur Athirah Wan; Radzuan, Kamaruddin

    2016-08-01

    Building Information Modeling (BIM) is defined as existing from the earliest concept to demolition and it involves creating and using an intelligent 3D model to inform and communicate project decisions. This research aims to identify the critical success factors (CSFs) of BIM implementation in Malaysian construction industry. A literature review was done to explore previous BIM studies on definitions and history of BIM, construction issues, application of BIM in construction projects as well as benefits of BIM. A series of interviews with multidisciplinary Malaysian construction experts will be conducted purposely for data collection process guided by the research design and methodology approach of this study. The analysis of qualitative data from the process will be combined with criteria identified in the literature review in order to identify the CSFs. Finally, the CSFs of BIM implementation will be validated by further Malaysian industrialists during a workshop. The validated CSFs can be used as a term of reference for both Malaysian practitioners and academics towards measuring BIM effectiveness level in their organizations.

  19. Distributed hydrological modelling of the Senegal river basin - model construction and validation

    DEFF Research Database (Denmark)

    Andersen, J.; Refsgaard, J.C.; Jensen, Karsten Høgh

    2001-01-01

    with different levels of calibration were constructed and rigorous validation tests conducted. Calibration against one station and internal validation against eight additional stations revealed significant shortcomings for some of the upstream tributaries, particularly in the semi-arid zone of the river basin...

  20. CAD CONSTRUCTION METHOD OF 3D BUILDING MODELS FOR GIS ANALYSIS

    Directory of Open Access Journals (Sweden)

    P. Boguslawski

    2012-07-01

    Full Text Available Buildings are often modelled as two-dimensional (2D footprints which are extruded to simple cubes. Buildings are also represented as more complex objects with roofs, facades, etc. – in this case they are polyhedra, sometimes of a complex shape. These allow for visualisation and analysis of a wide area like a city, but micro-scale analysis of interiors is not possible. An example can be rescue operation simulation where information about the internal structure of a building and the external terrain is crucial to improve the response time. It demands a three-dimensional (3D model where each room is represented as a separate element; there are also doors, windows, walls and other objects that have to be included. Even complex geometrical models can be easily constructed using Computer-Aided Design (CAD systems. However, lack of semantic information and topological relations makes such models poor choices for GIS analysis. With the new dual half-edge (DHE data structure and a set of Euler operators a 3D model can be built as in CAD systems, and represented as a cell complex. Construction of non-manifold objects is also possible. An advantage of the DHE is simplicity – only edges and nodes are used. Because of the 3D duality implemented in the structure volumes (cells and faces are also present in the model. The geometry of a model is constructed explicitly by using Euler operators: connections between elements are created automatically, and semantic information is represented with attributes which can be assigned to any element of the model.

  1. Constructing set-valued fundamental diagrams from jamiton solutions in second order traffic models

    KAUST Repository

    Seibold, Benjamin

    2013-09-01

    Fundamental diagrams of vehicular traiic ow are generally multivalued in the congested ow regime. We show that such set-valued fundamental diagrams can be constructed systematically from simple second order macroscopic traiic models, such as the classical Payne-Whitham model or the inhomogeneous Aw-Rascle-Zhang model. These second order models possess nonlinear traveling wave solutions, called jamitons, and the multi-valued parts in the fundamental diagram correspond precisely to jamiton-dominated solutions. This study shows that transitions from function-valued to set-valued parts in a fundamental diagram arise naturally in well-known second order models. As a particular consequence, these models intrinsically reproduce traiic phases. © American Institute of Mathematical Sciences.

  2. Construction of risk prediction model of type 2 diabetes mellitus based on logistic regression

    Directory of Open Access Journals (Sweden)

    Li Jian

    2017-01-01

    Full Text Available Objective: to construct multi factor prediction model for the individual risk of T2DM, and to explore new ideas for early warning, prevention and personalized health services for T2DM. Methods: using logistic regression techniques to screen the risk factors for T2DM and construct the risk prediction model of T2DM. Results: Male’s risk prediction model logistic regression equation: logit(P=BMI × 0.735+ vegetables × (−0.671 + age × 0.838+ diastolic pressure × 0.296+ physical activity× (−2.287 + sleep ×(−0.009 +smoking ×0.214; Female’s risk prediction model logistic regression equation: logit(P=BMI ×1.979+ vegetables× (−0.292 + age × 1.355+ diastolic pressure× 0.522+ physical activity × (−2.287 + sleep × (−0.010.The area under the ROC curve of male was 0.83, the sensitivity was 0.72, the specificity was 0.86, the area under the ROC curve of female was 0.84, the sensitivity was 0.75, the specificity was 0.90. Conclusion: This study model data is from a compared study of nested case, the risk prediction model has been established by using the more mature logistic regression techniques, and the model is higher predictive sensitivity, specificity and stability.

  3. Usefulness Of Three-Dimensional Printing Models for Patients with Stoma Construction

    Directory of Open Access Journals (Sweden)

    Tetsuro Tominaga

    2016-04-01

    Full Text Available The use of patient-specific organ models in three-dimensional printing systems could be helpful for the education of patients and medical students. The aim of this study was to clarify whether the use of patient-specific stoma models is helpful for patient education. From January 2014 to September 2014, 5 patients who underwent colorectal surgery and for whom a temporary or permanent stoma had been created were involved in this study. Three-dimensional stoma models and three-dimensional face plates were created. The patients’ ages ranged from 59 to 81 years. Four patients underwent stoma construction because of rectal cancer, and 1 underwent stoma construction because of colon stenosis secondary to recurrent cancer. All patients were educated about their stoma and potential stoma-associated problems using three-dimensional stoma models, and all practiced cutting face plates using three-dimensional face plates. The models were also used during medical staff conferences to discuss current issues. All patients understood their problems and finally became self-reliant. The recent availability of three-dimensional printers has enabled the creation of many organ models, and full-scale stoma and face plate models are now available for patient education on cutting an appropriately individualized face plate. Thus, three-dimensional printers could enable fewer skin problems than are currently associated with daily stomal care.

  4. Vulnerability assessment of groundwater-dependent ecosystems based on integrated groundwater flow modell construction

    Science.gov (United States)

    Tóth, Ádám; Simon, Szilvia; Galsa, Attila; Havril, Timea; Monteiro Santos, Fernando A.; Müller, Imre; Mádl-Szőnyi, Judit

    2017-04-01

    Groundwater-dependent ecosystems (GDEs) are highly influenced by the amount of groundwater, seasonal variation of precipitation and consequent water table fluctuation and also the anthropogenic activities. They can be regarded as natural surface manifestations of the flowing groundwater. The preservation of environment and biodiversity of these GDEs is an important issue worldwide, however, the water management policy and action plan could not be constructed in absense of proper hydrogeological knowledge. The concept of gravity-driven regional groundwater flow could aid the understanding of flow pattern and interpretation of environmental processes and conditions. Unless the required well data are available, the geological-hydrogeological numerical model of the study area cannot be constructed based only on borehole information. In this case, spatially continuous geophysical data can support groundwater flow model building: systematically combined geophysical methods can provide model input. Integration of lithostratigraphic, electrostratigraphic and hydrostratigraphic information could aid groundwater flow model construction: hydrostratigraphic units and their hydraulic behaviour, boundaries and geometry can be obtained. Groundwater-related natural manifestations, such as GDEs, can be explained with the help of the revealed flow pattern and field mapping of features. Integrated groundwater flow model construction for assessing the vulnerability of GDEs was presented via the case study of the geologically complex area of Tihany Peninsula, Hungary, with the aims of understanding the background and occurrence of groundwater-related environmental phenomena, surface water-groundwater interaction, and revealing the potential effect of anthropogenic activity and climate change. In spite of its important and protected status, fluid flow model of the area, which could support water management and natural protection policy, had not been constructed previously. The 3D

  5. MODELING TRENDS OF INVESTMENT AND CONSTRUCTION ACTIVITIES OF THE RUSSIAN FEDERATION

    Directory of Open Access Journals (Sweden)

    Geraskina Inna Nikolaevna

    2017-11-01

    Full Text Available Subject: the results of the study are particularly relevant in the modern system of cyclical crisis generated by the change of Kondratieff’s long waves of economic development and technological structures. From the point of view of synergetics, these processes have the ability to trigger a new order having spontaneous transformation due to endogenous factors. Qualitatively predictable fluctuations in the socio-economic environment and management may lead to self-organization and sustainable development of the economic system. Construction and investment activity of Russia in the majority of cases was investigated by economists without a detailed understanding of system characteristics, inherent properties and laws, which are identified from the results of economic-mathematical modeling. Research objectives: 1. Timely and qualitative prediction of moments of crisis in the investment and construction activities of Russia; 2. Modeling of management activities for the purpose of transitioning to the desired path of development of economic system; 3. Creation of a model that is simple enough for practical use by economists and the use of public data sets in it; studying influence of the bifurcation diagram at a certain time and bypassing the critical points of the system that lead to undesirable outcome. Materials and methods: approximation of the statistical data sets, regression analysis, phase analysis, differential modeling. Results: The authors developed a mathematical model that allows us to use statistical data on investment and construction activities and accurately forecast the chances of recession of the system, and also identify the sensitivity of order parameters to the dynamics of control variables, bifurcation states and behavior of the object under certain management conditions. Conclusions: the paper presents an approach to modeling and forecasting the trends of development of complex cyclic and stochastic subsystem of the national

  6. Using Model Building in Structural Engineering to Enhance Understanding of Construction Principles and Methods

    Directory of Open Access Journals (Sweden)

    Niall Holmes

    2013-05-01

    Full Text Available This paper presents a new model building exercise in a second year module in the Department of Civil & Structural Engineering in the Dublin Institute of Technology (DIT. The activity aimed to improve students’ understanding of structural engineering, construction principles and methods. It allowed students to practically apply lecture material and construct a scaled model giving them an opportunity to study and visualise a real structure and generate their own ideas on how it should be assembled within a constructivist active learning environment. As a result, lectures were found to be more interactive and students more engaged in the discussions and provided a pathway to bridge the gap between theory (presented in lectures and the reality of their professions, which can aid them in their graduate careers. It is hoped that this type of active learning can be used in other engineering programmes to improve student understanding and as an opportunity to better apply lecture material to the real world.

  7. Construction of 6D supersymmetric field models in N = (1 , 0) harmonic superspace

    Science.gov (United States)

    Buchbinder, I. L.; Pletnev, N. G.

    2015-03-01

    We consider the six-dimensional hypermultiplet, vector and tensor multiplet models in (1, 0) harmonic superspace and discuss the corresponding superfield actions. The actions for free (2, 0) tensor multiplet and for interacting vector/tensor multiplet system are constructed. Using the superfield formulation of the hypermultiplet coupled to the vector/tensor system we develop an approach to calculation of the one-loop superfield effective action and find its divergent structure.

  8. Construction of 6D supersymmetric field models in N=(1,0 harmonic superspace

    Directory of Open Access Journals (Sweden)

    I.L. Buchbinder

    2015-03-01

    Full Text Available We consider the six-dimensional hypermultiplet, vector and tensor multiplet models in (1,0 harmonic superspace and discuss the corresponding superfield actions. The actions for free (2,0 tensor multiplet and for interacting vector/tensor multiplet system are constructed. Using the superfield formulation of the hypermultiplet coupled to the vector/tensor system we develop an approach to calculation of the one-loop superfield effective action and find its divergent structure.

  9. A conceptual green business model for construction companies: An empirical evaluation

    OpenAIRE

    Abuzeinab, Amal

    2013-01-01

    PhD study Construction companies are being challenged to adopt a greener approach to meet client needs and to gain or sustain business competiveness with the phenomenon like green market growing. However, the relation between environmental performance and economic value creation is often indirect and hard to quantify. Consequently new concepts have been called for to appreciate opportunities offered by environmental sustainability. Of these, the business model concept provides a better und...

  10. The construction of next-generation matrices for compartmental epidemic models.

    Science.gov (United States)

    Diekmann, O; Heesterbeek, J A P; Roberts, M G

    2010-06-06

    The basic reproduction number (0) is arguably the most important quantity in infectious disease epidemiology. The next-generation matrix (NGM) is the natural basis for the definition and calculation of (0) where finitely many different categories of individuals are recognized. We clear up confusion that has been around in the literature concerning the construction of this matrix, specifically for the most frequently used so-called compartmental models. We present a detailed easy recipe for the construction of the NGM from basic ingredients derived directly from the specifications of the model. We show that two related matrices exist which we define to be the NGM with large domain and the NGM with small domain. The three matrices together reflect the range of possibilities encountered in the literature for the characterization of (0). We show how they are connected and how their construction follows from the basic model ingredients, and establish that they have the same non-zero eigenvalues, the largest of which is the basic reproduction number (0). Although we present formal recipes based on linear algebra, we encourage the construction of the NGM by way of direct epidemiological reasoning, using the clear interpretation of the elements of the NGM and of the model ingredients. We present a selection of examples as a practical guide to our methods. In the appendix we present an elementary but complete proof that (0) defined as the dominant eigenvalue of the NGM for compartmental systems and the Malthusian parameter r, the real-time exponential growth rate in the early phase of an outbreak, are connected by the properties that (0) > 1 if and only if r > 0, and (0) = 1 if and only if r = 0.

  11. SSC superconducting dipole magnet cryostat magnet cryostat model style B construction experience

    International Nuclear Information System (INIS)

    Engler, N.H.; Bossert, R.C.; Carson, J.A.; Gonczy, J.D.; Larson, E.T.; Nicol, T.H.; Niemann, R.C.; Sorenson, D.; Zink, R.

    1989-01-01

    A program to upgrade the full scale SSC dipole magnet cryostat model function and assembly methods has resulted in a series of dipole magnets designated as style B construction. New design features and assembly techniques have produced a magnet and cryostat assembly that is the basis for Phase I of the SSC dipole magnet industrialization program. Details of the assembly program, assembly experience, and comparison to previous assembly experiences are presented. Improvements in magnet assembly techniques are also evaluated. 6 refs., 5 figs

  12. Constructing unified models based on E sub 8 in ten dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Kapetanakis, D. (Technische Univ. Muenchen, Garching (Germany). Fakultaet fuer Physik); Zoupanos, G. (European Organization for Nuclear Research, Geneva (Switzerland))

    1992-10-01

    We examine the virtues and difficulties of the attempts to construct realistic four-dimensional models from a gauge theory based on E{sub 8} and defined in ten dimensions. The four-dimensional theories are obtained using the coset space dimensional reduction scheme. Some of our points and in particular the proposed mechanism for supersymmetry breaking might be useful in other dimensional reduction schemes. (orig.).

  13. Specification, construction, and exact reduction of state transition system models of biochemical processes.

    Science.gov (United States)

    Bugenhagen, Scott M; Beard, Daniel A

    2012-10-21

    Biochemical reaction systems may be viewed as discrete event processes characterized by a number of states and state transitions. These systems may be modeled as state transition systems with transitions representing individual reaction events. Since they often involve a large number of interactions, it can be difficult to construct such a model for a system, and since the resulting state-level model can involve a huge number of states, model analysis can be difficult or impossible. Here, we describe methods for the high-level specification of a system using hypergraphs, for the automated generation of a state-level model from a high-level model, and for the exact reduction of a state-level model using information from the high-level model. Exact reduction is achieved through the automated application to the high-level model of the symmetry reduction technique and reduction by decomposition by independent subsystems, allowing potentially significant reductions without the need to generate a full model. The application of the method to biochemical reaction systems is illustrated by models describing a hypothetical ion-channel at several levels of complexity. The method allows for the reduction of the otherwise intractable example models to a manageable size.

  14. Cytochrome P450 Activity in Ex Vivo Cornea Models and a Human Cornea Construct.

    Science.gov (United States)

    Kölln, Christian; Reichl, Stephan

    2016-07-01

    The pharmacokinetic behaviors of novel ophthalmic drugs are often preliminarily investigated in preclinical studies using ex vivo animal cornea or corneal cell culture models. During transcorneal passage, topically applied drugs may be affected by drug metabolizing enzymes. The knowledge regarding the functional expression of metabolic enzymes in corneal tissue is marginal; thus, the aim of this study was to investigate cytochrome P450 activity in an organotypic three-dimensional human cornea construct and to compare it with porcine and rabbit corneas, which are commonly used ex vivo cornea models. The total cytochrome P450 activity was determined by measuring the transformation of 7-ethoxycoumarin. Furthermore, the expression of the cytochrome P450 enzyme 2D6 (CYP2D6) was investigated at the protein level using immunohistochemistry and western blotting. CYP2D6 activity measurements were performed using a d-luciferin-based assay. In summary, similar levels of the total cytochrome P450 activity were identified in all 3 cornea models. The protein expression of CYP2D6 was confirmed in the human cornea construct and porcine cornea, whereas the signals in the rabbit cornea were weak. The analysis of the CYP2D6 activity indicated similar values for the human cornea construct and porcine cornea; however, a distinctly lower activity was observed in the rabbit cornea. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  15. Development of Hybrid Model for Estimating Construction Waste for Multifamily Residential Buildings Using Artificial Neural Networks and Ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    Dongoun Lee

    2016-09-01

    Full Text Available Due to the increasing costs of construction waste disposal, an accurate estimation of the amount of construction waste is a key factor in a project’s success. Korea has been burdened by increasing construction waste as a consequence of the growing number of construction projects and a lack of construction waste management (CWM strategies. One of the problems associated with predicting the amount of waste is that there are no suitable estimation strategies currently available. Therefore, we developed a hybrid estimation model to predict the quantity and cost of waste in the early stage of construction. The proposed approach can be used to address cost overruns and improve CWM in the subsequent stages of construction. The proposed hybrid model uses artificial neural networks (ANNs and ant colony optimization (ACO. It is expected to provide an accurate waste estimate by applying historical data from multifamily residential buildings.

  16. A model for evaluating the social performance of construction waste management.

    Science.gov (United States)

    Yuan, Hongping

    2012-06-01

    It has been determined by existing literature that a lot of research efforts have been made to the economic performance of construction waste management (CWM), but less attention is paid to investigation of the social performance of CWM. This study therefore attempts to develop a model for quantitatively evaluating the social performance of CWM by using a system dynamics (SD) approach. Firstly, major variables affecting the social performance of CWM are identified and a holistic system for assessing the social performance of CWM is formulated in line with feedback relationships underlying these variables. The developed system is then converted into a SD model through the software iThink. An empirical case study is finally conducted to demonstrate application of the model. Results of model validation indicate that the model is robust and reasonable to reflect the situation of the real system under study. Findings of the case study offer helpful insights into effectively promoting the social performance of CWM of the project investigated. Furthermore, the model exhibits great potential to function as an experimental platform for dynamically evaluating effects of management measures on improving the social performance of CWM of construction projects. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Design based Investigation on Construction of Mathematical Modelling Problems: Example of Financial Content

    Directory of Open Access Journals (Sweden)

    Melike TURAL SÖNMEZ

    2017-12-01

    Full Text Available The purpose of this study is to examine the construction of mathematical modelling problems process in the content of financial literacy. It is also aimed to create design proposals for construction of mathematical modelling problems. A design based research method was used in this study. The participants were three seventh grade students, six finance experts and nine mathematics education experts. Data collection tools were transcription of video and tapes group discussions, presentations and worksheets during mathematical modelling activities, and participant experts’ feedback form about mathematical modelling problems. There were three stages in this study. First stage was application of preliminary study. This stage gave information about convenience of problems to grade level, students’ timing for solution of problems, clarity of problems and students’ background about content. In second stage, finance experts commented on convenience of mathematical modelling problems to financial literacy standards. In third stage, mathematics education experts commented on convenience of problems to students’ grade level, mathematical modelling principles and seventh grade mathematics lesson objectives. They also gave suggestion on progress. The frequency value of theme in feedback forms was calculated and experts’ expressions were given as citation. It was given suggestion about stages and application of the design guide

  18. Construction of an exactly solvable model of the many-body problem

    Energy Technology Data Exchange (ETDEWEB)

    Zettili, N. [King Fahd Univ. of Petrolium and Minerals, Dhahran (Saudi Arabia). Dept. of Phys.]|[Institut de Physique, Universite de Blida, Blida (Algeria); Bouayad, N. [Institut de Physique, Universite de Blida, Blida (Algeria)

    1996-11-11

    We propose here a new model for the many-body problem that can be solved exactly through the diagonalization of its Hamiltonian. This model, which is founded on a Lie algebra, serves as a useful tool for testing the accuracy of many-body approximation methods. The model consists of a one-dimensional system of two distinguishable sets of fermions interacting via a schematic two-body force. We construct this model`s Hamiltonian by means of vector operators that are the generators of an SO(2,1) group and which satisfy a Lie algebra. We incorporate into the Hamiltonian a symmetry that yields a constant of the motion which, in turn, renders the size of the Hamiltonian matrix finite. The diagonalization of this finitely dimensional matrix gives the exact values of the energy spectrum. (orig.).

  19. Use of measurement theory for operationalization and quantification of psychological constructs in systems dynamics modelling

    Science.gov (United States)

    Fitkov-Norris, Elena; Yeghiazarian, Ara

    2016-11-01

    The analytical tools available to social scientists have traditionally been adapted from tools originally designed for analysis of natural science phenomena. This article discusses the applicability of systems dynamics - a qualitative based modelling approach, as a possible analysis and simulation tool that bridges the gap between social and natural sciences. After a brief overview of the systems dynamics modelling methodology, the advantages as well as limiting factors of systems dynamics to the potential applications in the field of social sciences and human interactions are discussed. The issues arise with regards to operationalization and quantification of latent constructs at the simulation building stage of the systems dynamics methodology and measurement theory is proposed as a ready and waiting solution to the problem of dynamic model calibration, with a view of improving simulation model reliability and validity and encouraging the development of standardised, modular system dynamics models that can be used in social science research.

  20. Constructing a Travel Risks’ Evaluation Model for Tour Freelancers Based on the ANP Approach

    Directory of Open Access Journals (Sweden)

    Chin-Tsai Lin

    2016-01-01

    Full Text Available This study constructs a new travel risks’ evaluation model for freelancers to evaluate and select tour groups by considering the interdependencies of the evaluation criteria used. First of all, the proposed model adopts the Nominal Group Technique (NGT to identify suitable evaluation criteria for evaluating travel risks. Six evaluation criteria and 18 subcriteria are obtained. The six evaluation criteria are financial risk, transportation risk, social risk, hygiene risk, sightseeing spot risk, and general risk for freelancer tour groups. Secondly, the model uses the analytic network process (ANP to determine the relative weight of the criteria. Finally, examples of group package tours (GPTs are used to demonstrate the travel risk evaluation process for this model. The results show that the Tokyo GPT is the best group tour. The proposed model helps freelancers to effectively evaluate travel risks and decision-making, making it highly applicable to academia and tour groups.

  1. Construction of Target Controllable Image Segmentation Model Based on Homotopy Perturbation Technology

    Directory of Open Access Journals (Sweden)

    Shu-Li Mei

    2013-01-01

    Full Text Available Based on the basic idea of the homotopy perturbation method which was proposed by Jihuan He, a target controllable image segmentation model and the corresponding multiscale wavelet numerical method are constructed. Using the novel model, we can get the only right object from the multiobject images, which is helpful to avoid the oversegmentation and insufficient segmentation. The solution of the variational model is the nonlinear PDEs deduced by the variational approach. So, the bottleneck of the variational model on image segmentation is the lower efficiency of the algorithm. Combining the multiscale wavelet interpolation operator and HPM, a semianalytical numerical method can be obtained, which can improve the computational efficiency and accuracy greatly. The numerical results on some images segmentation show that the novel model and the numerical method are effective and practical.

  2. Atomicrex—a general purpose tool for the construction of atomic interaction models

    Science.gov (United States)

    Stukowski, Alexander; Fransson, Erik; Mock, Markus; Erhart, Paul

    2017-07-01

    We introduce atomicrex, an open-source code for constructing interatomic potentials as well as more general types of atomic-scale models. Such effective models are required to simulate extended materials structures comprising many thousands of atoms or more, because electronic structure methods become computationally too expensive at this scale. atomicrex covers a wide range of interatomic potential types and fulfills many needs in atomistic model development. As inputs, it supports experimental property values as well as ab initio energies and forces, to which models can be fitted using various optimization algorithms. The open architecture of atomicrex allows it to be used in custom model development scenarios beyond classical interatomic potentials while thanks to its Python interface it can be readily integrated e.g., with electronic structure calculations or machine learning algorithms.

  3. Penalising Model Component Complexity: A Principled, Practical Approach to Constructing Priors

    KAUST Repository

    Simpson, Daniel

    2017-04-06

    In this paper, we introduce a new concept for constructing prior distributions. We exploit the natural nested structure inherent to many model components, which defines the model component to be a flexible extension of a base model. Proper priors are defined to penalise the complexity induced by deviating from the simpler base model and are formulated after the input of a user-defined scaling parameter for that model component, both in the univariate and the multivariate case. These priors are invariant to repa-rameterisations, have a natural connection to Jeffreys\\' priors, are designed to support Occam\\'s razor and seem to have excellent robustness properties, all which are highly desirable and allow us to use this approach to define default prior distributions. Through examples and theoretical results, we demonstrate the appropriateness of this approach and how it can be applied in various situations.

  4. Application of 3-dimensional printing technology to construct an eye model for fundus viewing study.

    Science.gov (United States)

    Xie, Ping; Hu, Zizhong; Zhang, Xiaojun; Li, Xinhua; Gao, Zhishan; Yuan, Dongqing; Liu, Qinghuai

    2014-01-01

    To construct a life-sized eye model using the three-dimensional (3D) printing technology for fundus viewing study of the viewing system. We devised our schematic model eye based on Navarro's eye and redesigned some parameters because of the change of the corneal material and the implantation of intraocular lenses (IOLs). Optical performance of our schematic model eye was compared with Navarro's schematic eye and other two reported physical model eyes using the ZEMAX optical design software. With computer aided design (CAD) software, we designed the 3D digital model of the main structure of the physical model eye, which was used for three-dimensional (3D) printing. Together with the main printed structure, polymethyl methacrylate(PMMA) aspherical cornea, variable iris, and IOLs were assembled to a physical eye model. Angle scale bars were glued from posterior to periphery of the retina. Then we fabricated other three physical models with different states of ammetropia. Optical parameters of these physical eye models were measured to verify the 3D printing accuracy. In on-axis calculations, our schematic model eye possessed similar size of spot diagram compared with Navarro's and Bakaraju's model eye, much smaller than Arianpour's model eye. Moreover, the spherical aberration of our schematic eye was much less than other three model eyes. While in off- axis simulation, it possessed a bit higher coma and similar astigmatism, field curvature and distortion. The MTF curves showed that all the model eyes diminished in resolution with increasing field of view, and the diminished tendency of resolution of our physical eye model was similar to the Navarro's eye. The measured parameters of our eye models with different status of ametropia were in line with the theoretical value. The schematic eye model we designed can well simulate the optical performance of the human eye, and the fabricated physical one can be used as a tool in fundus range viewing research.

  5. Computer modeling of the stress-strain state of welded construction

    Science.gov (United States)

    Nurguzhin, Marat; Danenova, Gulmira; Akhmetzhanov, Talgat

    2017-11-01

    At the present time the maintenance of the welded construction serviceability over normative service life is provided by the maintenance system on the basis of the guiding documents according to the concept of "fail safe". However, technology factors relating to welding such as high residual stresses and significant plastic strains are not considered in the guiding documents. The design procedure of the stressed-strained state of welded constructions is suggested in the paper. The procedure investigates welded constructions during welding and the external load using the program ANSYS. In this paper, the model of influence of the residual stress strain state on the factor of stress intensity is proposed. The calculation method of the residual stressed-strained state (SSS) taking into account the phase transition is developed by the authors. Melting and hardening of a plate material during heating and cooling is considered. The thermomechanical problem of heating a plate by a stationary heat source is solved. The setup of the heating spot center on distance (190 mm) from the crack top in a direction of its propagation leads to the fact that the value of total factor of stress intensity will considerably decrease under action of the specified residual compressing stresses. It can lower the speed of the crack propagation to zero. The suggested method of survivability maintenance can be applied during operation with the purpose of increasing the service life of metal constructions up to running repair of technological machines.

  6. Decentering and Related Constructs: A Critical Review and Metacognitive Processes Model

    Science.gov (United States)

    Bernstein, Amit; Hadash, Yuval; Lichtash, Yael; Tanay, Galia; Shepherd, Kathrine; Fresco, David M.

    2016-01-01

    The capacity to shift experiential perspective—from within one’s subjective experience onto that experience—is fundamental to being human. Scholars have long theorized that this metacognitive capacity—which we refer to as decentering—may play an important role in mental health. To help illuminate this mental phenomenon and its links to mental health, we critically examine decentering-related constructs and their respective literatures (e.g., self-distanced perspective, cognitive distancing, cognitive defusion). First, we introduce a novel metacognitive processes model of decentering. Specifically, we propose that, to varying degrees, decentering-related constructs reflect a common mental phenomenon subserved by three interrelated metacognitive processes: meta-awareness, disidentification from internal experience, and reduced reactivity to thought content. Second, we examine extant research linking decentering-related constructs and their underlying metacognitive processes to mental health. We conclude by proposing future directions for research that transcends decentering-related constructs in an effort to advance the field’s understanding of this facet of human experience and its role in (mal)adaptation. PMID:26385999

  7. Entry Location and Entry Timing (ELET Decision Model for International Construction Firms

    Directory of Open Access Journals (Sweden)

    Che Maznah Mat Isa

    2014-09-01

    Full Text Available This paper proposes a model for entry location (EL and entry timing (ET decisions to guide construction firms in accessing targeted international markets.  Neglecting to properly choose the right combination of the entry location and entry timing (ELET decisions can lead to poor performance of the firms’ international ventures.  The sampling frame was from the Malaysian construction firms that have undertaken and completed projects abroad.  Survey questionnaires sent to 115 firms registered with Construction Industry Development Board (CIDB Malaysia, operating in more than 50 countries, achieved a 39.1 per cent response rate. Based on a comprehensive statistical analysis of survey data it was found that the mutually inclusive significant factors that influenced the firms’ ELET decisions were: the firm’s ability to assess market signals and opportunities, international experience, financial capacity, competencies and capabilities (project management, specialist expertise and technology, resources (level of knowledge based on research and development, experience in similar works, financial support from the home country banks, technical complexities of projects and availability of funds for projects.  Hence, the present research builds on and extends the literature on the ELET decisions in a more integrated way. Keywords: Entry location, entry timing, resource-based view, international markets, Malaysian construction firms.

  8. Spacecraft Fire Experiment (Saffire) Development Status

    DEFF Research Database (Denmark)

    Ruff, Gary A.; Urban, David L.; Fernandez-Pello, A. Carlos

    2014-01-01

    The status is presented of a spacecraft fire safety research project that is under development to reduce the uncertainty and risk in the design of spacecraft fire safety systems for exploration missions. The Spacecraft Fire Safety Demonstration Project is developing three Spacecraft Fire Experime...

  9. Constructing a consumption model of fine dining from the perspective of behavioral economics.

    Science.gov (United States)

    Hsu, Sheng-Hsun; Hsiao, Cheng-Fu; Tsai, Sang-Bing

    2018-01-01

    Numerous factors affect how people choose a fine dining restaurant, including food quality, service quality, food safety, and hedonic value. A conceptual framework for evaluating restaurant selection behavior has not yet been developed. This study surveyed 150 individuals with fine dining experience and proposed the use of mental accounting and axiomatic design to construct a consumer economic behavior model. Linear and logistic regressions were employed to determine model correlations and the probability of each factor affecting behavior. The most crucial factor was food quality, followed by service and dining motivation, particularly regarding family dining. Safe ingredients, high cooking standards, and menu innovation all increased the likelihood of consumers choosing fine dining restaurants.

  10. Constructing an everywhere and locally relevant predictive model of the West-African critical zone

    Science.gov (United States)

    Hector, B.; Cohard, J. M.; Pellarin, T.; Maxwell, R. M.; Cappelaere, B.; Demarty, J.; Grippa, M.; Kergoat, L.; Lebel, T.; Mamadou, O.; Mougin, E.; Panthou, G.; Peugeot, C.; Vandervaere, J. P.; Vischel, T.; Vouillamoz, J. M.

    2017-12-01

    Considering water resources and hydrologic hazards, West Africa is among the most vulnerable regions to face both climatic (e.g. with the observed intensification of precipitation) and anthropogenic changes. With +3% of demographic rate, the region experiences rapid land use changes and increased pressure on surface and groundwater resources with observed consequences on the hydrological cycle (water table rise result of the sahelian paradox, increase in flood occurrence, etc.) Managing large hydrosystems (such as transboundary aquifers or rivers basins as the Niger river) requires anticipation of such changes. However, the region significantly lacks observations, for constructing and validating critical zone (CZ) models able to predict future hydrologic regime, but also comprises hydrosystems which encompass strong environmental gradients (e.g. geological, climatic, ecological) with highly different dominating hydrological processes. We address these issues by constructing a high resolution (1 km²) regional scale physically-based model using ParFlow-CLM which allows modeling a wide range of processes without prior knowledge on their relative dominance. Our approach combines multiple scale modeling from local to meso and regional scales within the same theoretical framework. Local and meso-scale models are evaluated thanks to the rich AMMA-CATCH CZ observation database which covers 3 supersites with contrasted environments in Benin (Lat.: 9.8°N), Niger (Lat.: 13.3°N) and Mali (Lat.: 15.3°N). At the regional scale the lack of relevant map of soil hydrodynamic parameters is addressed using remote sensing data assimilation. Our first results show the model's ability to reproduce the known dominant hydrological processes (runoff generation, ET, groundwater recharge…) across the major West-African regions and allow us to conduct virtual experiments to explore the impact of global changes on the hydrosystems. This approach is a first step toward the construction of

  11. A qualitative model construction method of nuclear power plants for effective diagnostic knowledge generation

    International Nuclear Information System (INIS)

    Yoshikawa, Shinji; Endou, Akira; Kitamura, Yoshinobu; Sasajima, Munehiko; Ikeda, Mitsuru; Mizoguchi, Riichiro.

    1994-01-01

    This paper discusses a method to construct a qualitative model of a nuclear power plant, in order to generate effective diagnostic knowledge. The proposed method is to prepare deep knowledge to be provided to a knowledge compiler based upon qualitative reasoning (QR). Necessity of knowledge compilation for nuclear plant diagnosis will be explained first, and conventionally-experienced problems in qualitative reasoning and a proposed method to overcome this problem is shown next, then a sample procedure to build a qualitative nuclear plant model is demonstrated. (author)

  12. Effective method for construction of low-dimensional models for heat transfer process

    Energy Technology Data Exchange (ETDEWEB)

    Blinov, D.G.; Prokopov, V.G.; Sherenkovskii, Y.V.; Fialko, N.M.; Yurchuk, V.L. [National Academy of Sciences of Ukraine, Kiev (Ukraine). Inst. of Engineering Thermophysics

    2004-12-01

    A low-dimensional model based on the method of proper orthogonal decomposition (POD) and the method of polyargumental systems (MPS) for thermal conductivity problems with strongly localized source of heat has been presented. The key aspect of these methods is that they enable to avoid weak points of other projection methods, which consists in a priori choice of basis functions. It enables us to use the MPS method and the POD method as convenient means to construct low-dimensional models of heat and mass transfer problems. (Author)

  13. Construction and analysis of the model of energy metabolism in E. coli.

    Directory of Open Access Journals (Sweden)

    Zixiang Xu

    Full Text Available Genome-scale models of metabolism have only been analyzed with the constraint-based modelling philosophy and there have been several genome-scale gene-protein-reaction models. But research on the modelling for energy metabolism of organisms just began in recent years and research on metabolic weighted complex network are rare in literature. We have made three research based on the complete model of E. coli's energy metabolism. We first constructed a metabolic weighted network using the rates of free energy consumption within metabolic reactions as the weights. We then analyzed some structural characters of the metabolic weighted network that we constructed. We found that the distribution of the weight values was uneven, that most of the weight values were zero while reactions with abstract large weight values were rare and that the relationship between w (weight values and v (flux values was not of linear correlation. At last, we have done some research on the equilibrium of free energy for the energy metabolism system of E. coli. We found that E(out (free energy rate input from the environment can meet the demand of E(ch(in (free energy rate dissipated by chemical process and that chemical process plays a great role in the dissipation of free energy in cells. By these research and to a certain extend, we can understand more about the energy metabolism of E. coli.

  14. Study of the two-dimensional Hubbard model at half-filling through constructive methods

    International Nuclear Information System (INIS)

    Afchain, St.

    2005-02-01

    The Hubbard model is the simplest model to describe the behaviour of fermions on a network, it takes into account only fermion scattering and only interactions with other fermions located on the same site. Half-filling means that the total number of fermions is equal to half the number of sites. In the first chapter we show how we can pass trough successive approximations from a very general Hamiltonian to the Hubbard Hamiltonian. The second chapter is dedicated to the passage from the Hamiltonian formalism to the Grassmanian functional formalism. The main idea is to show that the correlation functions of the Hamiltonian approach can be described through fermionic functional integrals which implies the possibility of speaking of the model in terms of field theory. The chapter 3 deals with the main constructive techniques that allow the strict and consistent construction of models inside the frame of field theory. We show by proving the violation of a condition concerning self-energy, that the two-dimensional Hubbard model at half-filling has not the behaviour of a Fermi liquid in the Landau's interpretation. (A.C.)

  15. Unification and mechanistic detail as drivers of model construction: models of networks in economics and sociology.

    Science.gov (United States)

    Kuorikoski, Jaakko; Marchionni, Caterina

    2014-12-01

    We examine the diversity of strategies of modelling networks in (micro) economics and (analytical) sociology. Field-specific conceptions of what explaining (with) networks amounts to or systematic preference for certain kinds of explanatory factors are not sufficient to account for differences in modelling methodologies. We argue that network models in both sociology and economics are abstract models of network mechanisms and that differences in their modelling strategies derive to a large extent from field-specific conceptions of the way in which a good model should be a general one. Whereas the economics models aim at unification, the sociological models aim at a set of mechanism schemas that are extrapolatable to the extent that the underlying psychological mechanisms are general. These conceptions of generality induce specific biases in mechanistic explanation and are related to different views of when knowledge from different fields should be seen as relevant.

  16. The Study of Role of Transactional Model Constructs in Yazd Teachers of Primary School by Using of Structural Equation Model

    Directory of Open Access Journals (Sweden)

    M. Mohammadi

    2014-12-01

    Full Text Available Background: By considering, transactional model is one of the most comprehensive model for reduction of stress, this study was determined the role of Transactional Model constructs in Yazd teachers of Primary school by using of Structural Equation Model. Methods: This research was a descriptive- analytical. Categorized approach was applied for sampling. A standard questionnaire and the questionnaire planned based on Transactional Model were applied for data collection. Validity (CVR=0.85 and reliability (α=0.87 of instrument confirmed by experts. SPSS15 and LISREL8.8 software were used for data analysis. Results: In this research 200 Yazd teachers of primary schools (average age of 41.70±5.69 were participated. The results of this study showed the effect of stress on secondary appraisal and primary appraisal was -0.87 and 0.84, respectively. Our results also showed an inverse relationship between perceived stress and secondary appraisal also between primary appraisal and coping effort. Also, the results were confirmed validity and good fitness of model, because of the RMSEA=0.0329 and index χ2/df were less than 3. Conclusion: Since the constructs of this model had a significant effect on the stress, it suggests the policies and plans for improvement of these factors.

  17. Pre-operative simulation of periacetabular osteotomy via a three-dimensional model constructed from salt

    Directory of Open Access Journals (Sweden)

    Fukushima Kensuke

    2017-01-01

    Full Text Available Introduction: Periacetabular osteotomy (PAO is an effective joint-preserving procedure for young adults with developmental dysplasia of the hip. Although PAO provides excellent radiographic and clinical results, it is a technically demanding procedure with a distinct learning curve that requires careful 3D planning and, above all, has a number of potential complications. We therefore developed a pre-operative simulation method for PAO via creation of a new full-scale model. Methods: The model was prepared from the patient’s Digital Imaging and Communications in Medicine (DICOM formatted data from computed tomography (CT, for construction and assembly using 3D printing technology. A major feature of our model is that it is constructed from salt. In contrast to conventional models, our model provides a more accurate representation, at a lower manufacturing cost, and requires a shorter production time. Furthermore, our model realized simulated operation normally with using a chisel and drill without easy breakage or fissure. We were able to easily simulate the line of osteotomy and confirm acetabular version and coverage after moving to the osteotomized fragment. Additionally, this model allowed a dynamic assessment that avoided anterior impingement following the osteotomy. Results: Our models clearly reflected the anatomical shape of the patient’s hip. Our models allowed for surgical simulation, making realistic use of the chisel and drill. Our method of pre-operative simulation for PAO allowed for the assessment of accurate osteotomy line, determination of the position of the osteotomized fragment, and prevented anterior impingement after the operation. Conclusion: Our method of pre-operative simulation might improve the safety, accuracy, and results of PAO.

  18. Analytic expressions for the construction of a fire event PSA model

    International Nuclear Information System (INIS)

    Kang, Dae Il; Kim, Kil Yoo; Kim, Dong San; Hwang, Mee Jeong; Yang, Joon Eon

    2016-01-01

    In this study, the changing process of an internal event PSA model to a fire event PSA model is analytically presented and discussed. Many fire PSA models have fire induced initiating event fault trees not shown in an internal event PSA model. Fire-induced initiating fault tree models are developed for addressing multiple initiating event issues. A single fire event within a fire compartment or fire scenario can cause multiple initiating events. As an example, a fire in a turbine building area can cause a loss of the main feed-water and loss of off-site power initiating events. Up to now, there has been no analytic study on the construction of a fire event PSA model using an internal event PSA model with fault trees of initiating events. In this paper, the changing process of an internal event PSA model to a fire event PSA model was analytically presented and discussed. This study results show that additional cutsets can be obtained if the fault trees of initiating events for a fire event PSA model are not exactly developed.

  19. Dynamics and control of Lorentz-augmented spacecraft relative motion

    CERN Document Server

    Yan, Ye; Yang, Yueneng

    2017-01-01

    This book develops a dynamical model of the orbital motion of Lorentz spacecraft in both unperturbed and J2-perturbed environments. It explicitly discusses three kinds of typical space missions involving relative orbital control: spacecraft hovering, rendezvous, and formation flying. Subsequently, it puts forward designs for both open-loop and closed-loop control schemes propelled or augmented by the geomagnetic Lorentz force. These control schemes are entirely novel and represent a significantly departure from previous approaches.

  20. Electromagnetic braking for Mars spacecraft

    Science.gov (United States)

    Holt, A. C.

    1986-01-01

    Aerobraking concepts are being studied to improve performance and cost effectiveness of propulsion systems for Mars landers and Mars interplanetary spacecraft. Access to megawatt power levels (nuclear power coupled to high-storage inductive or capacitive devices) on a manned Mars interplanetary spacecraft may make feasible electromagnetic braking and lift modulation techniques which were previously impractical. Using pulsed microwave and magnetic field technology, potential plasmadynamic braking and hydromagnetic lift modulation techniques have been identified. Entry corridor modulation to reduce loads and heating, to reduce vertical descent rates, and to expand horizontal and lateral landing ranges are possible benefits. In-depth studies are needed to identify specific design concepts for feasibility assessments. Standing wave/plasma sheath interaction techniques appear to be promising. The techniques may require some tailoring of spacecraft external structures and materials. In addition, rapid response guidance and control systems may require the use of structurally embedded sensors coupled to expert systems or to artificial intelligence systems.

  1. Attitude Fusion Techniques for Spacecraft

    DEFF Research Database (Denmark)

    Bjarnø, Jonas Bækby

    of the instrument, and affecting operations during agile and complex spacecraft attitude maneuvers. As such, there exists a theoretical foundation for augmenting the high frequency performance of the μASC instrument, by harnessing the complementary nature of optical stellar reference and inertial sensor technology...... over the entire span of frequencies applicable to spacecraft attitude control systems. Completing the first steps from theoretical possibility towards a proven concept constitutes the primary focus of the project, having necessitated extensive research and development within several diverse technical......Spacecraft platform instability constitutes one of the most significant limiting factors in hyperacuity pointing and tracking applications, yet the demand for accurate, timely and reliable attitude information is ever increasing. The PhD research project described within this dissertation has...

  2. A data-driven approach to reverse engineering customer engagement models: towards functional constructs.

    Science.gov (United States)

    de Vries, Natalie Jane; Carlson, Jamie; Moscato, Pablo

    2014-01-01

    Online consumer behavior in general and online customer engagement with brands in particular, has become a major focus of research activity fuelled by the exponential increase of interactive functions of the internet and social media platforms and applications. Current research in this area is mostly hypothesis-driven and much debate about the concept of Customer Engagement and its related constructs remains existent in the literature. In this paper, we aim to propose a novel methodology for reverse engineering a consumer behavior model for online customer engagement, based on a computational and data-driven perspective. This methodology could be generalized and prove useful for future research in the fields of consumer behaviors using questionnaire data or studies investigating other types of human behaviors. The method we propose contains five main stages; symbolic regression analysis, graph building, community detection, evaluation of results and finally, investigation of directed cycles and common feedback loops. The 'communities' of questionnaire items that emerge from our community detection method form possible 'functional constructs' inferred from data rather than assumed from literature and theory. Our results show consistent partitioning of questionnaire items into such 'functional constructs' suggesting the method proposed here could be adopted as a new data-driven way of human behavior modeling.

  3. Development of OLI+S Entry Decision Model for Construction Firms in International Markets

    Directory of Open Access Journals (Sweden)

    Che Maznah Binti Mat Isa

    2017-12-01

    Full Text Available The paper aims to provide a holistic approach to address how construction firms make decisions covering all three domains (location, timing and mode across country, market, firm and project factors within the Ownership, Locational and Internalisation plus Specialty (OLI+S paradigm. Questionnaires were administered to 62 project managers based on a sampling frame provided by the Construction Industry Development Board Malaysia. The findings provide empirical and theoretical insights on how the OLI+S model addresses firms’ entry decisions to penetrate international markets. It suggests that the ownership-entry decision factors focus on firms’ internal transferable advantages. The locational-entry decision factors emphasise attractiveness of certain locations where firms decided to invest and operate. The internalisation– entry decision factors emphasise the extent to which firms were able to manipulate their internal competitive assets (firm’s resources and capabilities. Finally, the specialty-entry decision factors emphasise on firms’ competency in project management and specialist expertise to handle complex projects based on their previous project experience. An example of construction firms’ unique characteristics, namely, specialty advantages based on the original Dunning’s OLI eclectic paradigm has been adopted. The established OLI+S entry decision model could be investigated to further refine other related internationalisation theory.

  4. A data-driven approach to reverse engineering customer engagement models: towards functional constructs.

    Directory of Open Access Journals (Sweden)

    Natalie Jane de Vries

    Full Text Available Online consumer behavior in general and online customer engagement with brands in particular, has become a major focus of research activity fuelled by the exponential increase of interactive functions of the internet and social media platforms and applications. Current research in this area is mostly hypothesis-driven and much debate about the concept of Customer Engagement and its related constructs remains existent in the literature. In this paper, we aim to propose a novel methodology for reverse engineering a consumer behavior model for online customer engagement, based on a computational and data-driven perspective. This methodology could be generalized and prove useful for future research in the fields of consumer behaviors using questionnaire data or studies investigating other types of human behaviors. The method we propose contains five main stages; symbolic regression analysis, graph building, community detection, evaluation of results and finally, investigation of directed cycles and common feedback loops. The 'communities' of questionnaire items that emerge from our community detection method form possible 'functional constructs' inferred from data rather than assumed from literature and theory. Our results show consistent partitioning of questionnaire items into such 'functional constructs' suggesting the method proposed here could be adopted as a new data-driven way of human behavior modeling.

  5. Management Model for Evaluation and Selection of Engineering Equipment Suppliers for Construction Projects in Iraq

    Directory of Open Access Journals (Sweden)

    Kadhim Raheem Erzaij

    2016-06-01

    Full Text Available Engineering equipment is essential part in the construction project and usually manufactured with long lead times, large costs and special engineering requirements. Construction manager targets that equipment to be delivered in the site need date with the right quantity, appropriate cost and required quality, and this entails an efficient supplier can satisfy these targets. Selection of engineering equipment supplier is a crucial managerial process .it requires evaluation of multiple suppliers according to multiple criteria. This process is usually performed manually and based on just limited evaluation criteria, so better alternatives may be neglected. Three stages of survey comprised number of public and private companies in Iraqi construction sector were employed to identify main criteria and sub criteria for supplier selection and their priorities.The main criteria identified were quality of product, commercial aspect, delivery, reputation and position, and system quality . An effective technique in multiple criteria decision making (MCDM as analytical hierarchy process (AHP have been used to get importance weights of criteria based on experts judgment. Thereafter, a management software system for Evaluation and Selection of Engineering Equipment Suppliers (ESEES has been developed based on the results obtained from AHP. This model was validated in a case study at municipality of Baghdad involved actual cases of selection pumps suppliers for infrastructure projects .According to experts, this model can improve the current process followed in the supplier selection and aid decision makers to adopt better choices in the domain of selection engineering equipment suppliers.

  6. Construction practice

    International Nuclear Information System (INIS)

    Winters, J.; Clelland, J.; Rumble, E.; Sandell, L.

    2007-01-01

    One has elaborated a virtual computer model (VRC) of construction of the AP1000 project reactor to demonstrate its viability, to improve the NPP project making it more easy for construction with simultaneous reduction of time, costs and risk of construction. The approach ensured time sequence of the 3-D visualization of NPP at the construction stages. The VRC ensures optimization of scheme implementation time period and specifies the basic costs. The VRC application offers essential advantages when planning construction of a nuclear power facility [ru

  7. Construction of SPOC-based Learning Model and its Application in Linguistics Teaching

    Directory of Open Access Journals (Sweden)

    Hua Lu

    2018-02-01

    Full Text Available The design of a reasonable learning model must take the new internet age into consideration. Following a contrastive study between MOOCs and SPOCs, a SPOC-based learning model is proposed in this paper. This new learning model consists of four components, the preliminary component composed of anterior analysis and course construction, the restrictive admission component for student number control, the learning procedure component which is subdivided into pre-class session, class session and post-class session, and the evaluation component which includes both online assessment and classroom assessment. This model has its advantages and is shown to be effective through the demonstration of its application in teaching linguistics to college students.

  8. Exploring the Space of Viable Configurations in a Model of Metabolism-Boundary Co-construction.

    Science.gov (United States)

    Agmon, Eran; Gates, Alexander J; Churavy, Valentin; Beer, Randall D

    2016-01-01

    We introduce a spatial model of concentration dynamics that supports the emergence of spatiotemporal inhomogeneities that engage in metabolism-boundary co-construction. These configurations exhibit disintegration following some perturbations, and self-repair in response to others. We define robustness as a viable configuration's tendency to return to its prior configuration in response to perturbations, and plasticity as a viable configuration's tendency to change to other viable configurations. These properties are demonstrated and quantified in the model, allowing us to map a space of viable configurations and their possible transitions. Combining robustness and plasticity provides a measure of viability as the average expected survival time under ongoing perturbation, and allows us to measure how viability is affected as the configuration undergoes transitions. The framework introduced here is independent of the specific model we used, and is applicable for quantifying robustness, plasticity, and viability in any computational model of artificial life that demonstrates the conditions for viability that we promote.

  9. The fully programmable spacecraft: procedural sequencing for JPL deep space missions using VML (Virtual Machine Language)

    Science.gov (United States)

    Grasso, C. A.

    2002-01-01

    This paper lays out language constructs and capabilities, code features, and VML operations development concepts. The ability to migrate to the spacecraft functionality which is more traditionally implemented on the ground is examined.

  10. Structure mapping and semantic integration in a construction-based neurolinguistic model of sentence processing.

    Science.gov (United States)

    Dominey, Peter Ford; Hoen, Michel

    2006-05-01

    The current research provides a theoretical, computational and neurophysiological framework in which particular aspects of sentence comprehension and non-linguistic sequence transformation processing are implemented by a common neural mechanism for structure mapping. The theoretical context is derived from construction grammar theory in which language is considered in terms of a structured inventory of form to meaning mappings. Computationally, the construction grammar concept is implemented in a hybrid neural network model that is derived from functional neuroanatomical studies. In particular, based on data from Hoen et al. (2006, this issue), the generalized structure mapping capability is attributed to a local cortical network that includes Brodmann's area (BA) 44, while the integration of semantic structure into this transformation mechanism relies on BA 45.

  11. Microgravity Flammability Experiments for Spacecraft Fire Safety

    DEFF Research Database (Denmark)

    Legros, Guillaume; Minster, Olivier; Tóth, Balazs

    2012-01-01

    As fire behaviour in manned spacecraft still remains poorly understood, an international topical team has been created to design a validation experiment that has an unprecedented large scale for a microgravity flammability experiment. While the validation experiment is being designed for a re-sup...... validation experiment are crucial to the ultimate goal of the project, which is the development of predictive tools that should be capable of selecting an adaptive response to fire spread in any manned spacecraft.......As fire behaviour in manned spacecraft still remains poorly understood, an international topical team has been created to design a validation experiment that has an unprecedented large scale for a microgravity flammability experiment. While the validation experiment is being designed for a re...... spread, and thus also the modeling thereof, in realistic conditions is described. Some of the parameters governing the flame spread are also identified and their scaling against the dimensions of the test specimen is briefly questioned. Then several of the current and scheduled efforts are presented...

  12. Validation of groundwater flow model using the change of groundwater flow caused by the construction of AESPOE hard rock laboratory

    International Nuclear Information System (INIS)

    Hasegawa, Takuma; Tanaka, Yasuharu

    2004-01-01

    A numerical model based on results during pre-investigation phases was applied to the groundwater flow change caused by the construction of AEspoe HRL. The drawdowns and chloride concentration during tunnel construction were simulated to validate the numerical model. The groundwater flow was induced by inflow from the Baltic Sea to the tunnel through the hydraulic conductor domain (HCD). The time series of tunnel progress and inflow, boundaries of the Baltic Sea, transmissivity and geometry of HCD are therefore important in representing the groundwater flow. The numerical model roughly represented the groundwater flow during tunnel construction. These simulations were effective in validating the numerical model for groundwater flow and solute transport. (author)

  13. CORRECTION OF FAULTY LINES IN MUSCLE MODEL, TO BE USED IN 3D BUILDING NETWORK CONSTRUCTION

    Directory of Open Access Journals (Sweden)

    I. R. Karas

    2012-07-01

    Full Text Available This paper describes the usage of MUSCLE (Multidirectional Scanning for Line Extraction Model for automatic generation of 3D networks in CityGML format (from raster floor plans. MUSCLE (Multidirectional Scanning for Line Extraction Model is a conversion method which was developed to vectorize the straight lines through the raster images including floor plans, maps for GIS, architectural drawings, and machine plans. The model allows user to define specific criteria which are crucial for acquiring the vectorization process. Unlike traditional vectorization process, this model generates straight lines based on a line thinning algorithm, without performing line following-chain coding and vector reduction stages. In this method the nearly vertical lines were obtained by scanning the images horizontally, while the nearly horizontal lines were obtained by scanning the images vertically. In a case where two or more consecutive lines are nearly horizontal or nearly vertical, raster data become unmanageable and the process generates wrongly vectorized lines. In this situation, to obtain the precise lines, the image with the wrongly vectorized lines is diagonally scanned. By using MUSCLE model, the network models are topologically structured in CityGML format. After the generation process, it is possible to perform 3D network analysis based on these models. Then, by using the software that was designed based on the generated models, a geodatabase of the models could be established. This paper presents the correction application in MUSCLE and explains 3D network construction in detail.

  14. Biologically inspired information theory: Adaptation through construction of external reality models by living systems.

    Science.gov (United States)

    Nakajima, Toshiyuki

    2015-12-01

    Higher animals act in the world using their external reality models to cope with the uncertain environment. Organisms that have not developed such information-processing organs may also have external reality models built in the form of their biochemical, physiological, and behavioral structures, acquired by natural selection through successful models constructed internally. Organisms subject to illusions would fail to survive in the material universe. How can organisms, or living systems in general, determine the external reality from within? This paper starts with a phenomenological model, in which the self constitutes a reality model developed through the mental processing of phenomena. Then, the it-from-bit concept is formalized using a simple mathematical model. For this formalization, my previous work on an algorithmic process is employed to constitute symbols referring to the external reality, called the inverse causality, with additional improvements to the previous work. Finally, as an extension of this model, the cognizers system model is employed to describe the self as one of many material entities in a world, each of which acts as a subject by responding to the surrounding entities. This model is used to propose a conceptual framework of information theory that can deal with both the qualitative (semantic) and quantitative aspects of the information involved in biological processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. A hybrid learning method for constructing compact rule-based fuzzy models.

    Science.gov (United States)

    Zhao, Wanqing; Niu, Qun; Li, Kang; Irwin, George W

    2013-12-01

    The Takagi–Sugeno–Kang-type rule-based fuzzy model has found many applications in different fields; a major challenge is, however, to build a compact model with optimized model parameters which leads to satisfactory model performance. To produce a compact model, most existing approaches mainly focus on selecting an appropriate number of fuzzy rules. In contrast, this paper considers not only the selection of fuzzy rules but also the structure of each rule premise and consequent, leading to the development of a novel compact rule-based fuzzy model. Here, each fuzzy rule is associated with two sets of input attributes, in which the first is used for constructing the rule premise and the other is employed in the rule consequent. A new hybrid learning method combining the modified harmony search method with a fast recursive algorithm is hereby proposed to determine the structure and the parameters for the rule premises and consequents. This is a hard mixed-integer nonlinear optimization problem, and the proposed hybrid method solves the problem by employing an embedded framework, leading to a significantly reduced number of model parameters and a small number of fuzzy rules with each being as simple as possible. Results from three examples are presented to demonstrate the compactness (in terms of the number of model parameters and the number of rules) and the performance of the fuzzy models obtained by the proposed hybrid learning method, in comparison with other techniques from the literature.

  16. Spacecraft Surface Charging Handbook

    Science.gov (United States)

    1992-11-01

    discharges however produce replacement currents that can be global. The local effect of punchthrough is illustrated by a small dipole model for the...St’rap I Farda or TEK7103 Scope Power Dipole -- Line tenna To To PA HP05000 and Spectrum X-Y Analyzer Plotter Figure 61. Test setup for surface...Testing Seminar, Los Angeles, CA, p. 77-82, 19817. Levadou, F., "Proprietes Electriques Des Materiaux." Space Environment: Prevention of Risks Related

  17. [Construction and improvement of animal models with different positional osseous metastasis of prostate cancer in vivo].

    Science.gov (United States)

    Bi, Y X; Xiao, M H; Zhang, N N; Li, X Y; Mao, X P; Zhang, K; Zhang, Z R; Zhao, L Y

    2017-08-18

    To provide an important tool for the study of diagnose and treatment of prostate cancer (PCa) osseous metastasis and change of bone stress force on prostate cancer (PCa) osseous metastasis and a platform, which is more congruous to clinical process, for prevention and cure of neoplastic bone metastases, and to carry out the construction and improvement of animal models of PCa with different positional osseous metastasis in vivo. Different gradient concentrations of RM-1 cells were inoculated into the cavity of left femoral bone or lumbar vertebra of mice (C57BL/6) respectively. The change of mouse activity, tumor formation, tumor size and survival time were observed respectively. And the femur tissue and spinal tissue were obtained from the mice after death. The gray value of iconography were measured by imageological examination of femur tissue, and the final histopathological examination were taken to determine the tumor type in both femur and spinal tissue. The tumor growth could be touched at the puncture site in all the mice after inoculated for 7 days. There were no obvious differences in the time of tumorigenesis, the rate of tumor growth and tumor size among the mice in the same group (P>0.05). As the result, the construction femoral bone and lumbar vertebra metastatic models of PCa had been confirmed by iconography and pathology detection. At the same time, the survival time of the mice inoculated with low concentrations of PCa cells was obviously longer than that of high concentrations of PCa cells ( at least 2 weeks longer). The animal models with different positional osseous metastasis (limbs and axial skeleton) of PCa using the same PCa cells (RM-1) had been first constructed successfully in our study. At the same time, a high success rate of construction of PCa animal model with bone metastasis was obtained by femoral bone marrow cavity injection of PCa cells. The rate of tumor growth was rapid, animal survival time was appropriate, and the PCa animal

  18. Snoopy's hybrid simulator: a tool to construct and simulate hybrid biological models.

    Science.gov (United States)

    Herajy, Mostafa; Liu, Fei; Rohr, Christian; Heiner, Monika

    2017-07-28

    Hybrid simulation of (computational) biochemical reaction networks, which combines stochastic and deterministic dynamics, is an important direction to tackle future challenges due to complex and multi-scale models. Inherently hybrid computational models of biochemical networks entail two time scales: fast and slow. Therefore, it is intricate to efficiently and accurately analyse them using only either deterministic or stochastic simulation. However, there are only a few software tools that support such an approach. These tools are often limited with respect to the number as well as the functionalities of the provided hybrid simulation algorithms. We present Snoopy's hybrid simulator, an efficient hybrid simulation software which builds on Snoopy, a tool to construct and simulate Petri nets. Snoopy's hybrid simulator provides a wide range of state-of-the-art hybrid simulation algorithms. Using this tool, a computational model of biochemical networks can be constructed using a (coloured) hybrid Petri net's graphical notations, or imported from other compatible formats (e.g. SBML), and afterwards executed via dynamic or static hybrid simulation. Snoopy's hybrid simulator is a platform-independent tool providing an accurate and efficient simulation of hybrid (biological) models. It can be downloaded free of charge as part of Snoopy from http://www-dssz.informatik.tu-cottbus.de/DSSZ/Software/Snoopy .

  19. Development of a hybrid model to predict construction and demolition waste: China as a case study.

    Science.gov (United States)

    Song, Yiliao; Wang, Yong; Liu, Feng; Zhang, Yixin

    2017-01-01

    Construction and demolition waste (C&DW) is currently a worldwide issue, and the situation is the worst in China due to a rapid increase in the construction industry and the short life span of China's buildings. To create an opportunity out of this problem, comprehensive prevention measures and effective management strategies are urgently needed. One major gap in the literature of waste management is a lack of estimations on future C&DW generation. Therefore, this paper presents a forecasting procedure for C&DW in China that can forecast the quantity of each component in such waste. The proposed approach is based on a GM-SVR model that improves the forecasting effectiveness of the gray model (GM), which is achieved by adjusting the residual series by a support vector regression (SVR) method and a transition matrix that aims to estimate the discharge of each component in the C&DW. Through the proposed method, future C&DW volume are listed and analyzed containing their potential components and distribution in different provinces in China. Besides, model testing process provides mathematical evidence to validate the proposed model is an effective way to give future information of C&DW for policy makers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Construction of In Vivo Fluorescent Imaging of Echinococcus granulosus in a Mouse Model.

    Science.gov (United States)

    Wang, Sibo; Yang, Tao; Zhang, Xuyong; Xia, Jie; Guo, Jun; Wang, Xiaoyi; Hou, Jixue; Zhang, Hongwei; Chen, Xueling; Wu, Xiangwei

    2016-06-01

    Human hydatid disease (cystic echinococcosis, CE) is a chronic parasitic infection caused by the larval stage of the cestode Echinococcus granulosus. As the disease mainly affects the liver, approximately 70% of all identified CE cases are detected in this organ. Optical molecular imaging (OMI), a noninvasive imaging technique, has never been used in vivo with the specific molecular markers of CE. Thus, we aimed to construct an in vivo fluorescent imaging mouse model of CE to locate and quantify the presence of the parasites within the liver noninvasively. Drug-treated protoscolices were monitored after marking by JC-1 dye in in vitro and in vivo studies. This work describes for the first time the successful construction of an in vivo model of E. granulosus in a small living experimental animal to achieve dynamic monitoring and observation of multiple time points of the infection course. Using this model, we quantified and analyzed labeled protoscolices based on the intensities of their red and green fluorescence. Interestingly, the ratio of red to green fluorescence intensity not only revealed the location of protoscolices but also determined the viability of the parasites in vivo and in vivo tests. The noninvasive imaging model proposed in this work will be further studied for long-term detection and observation and may potentially be widely utilized in susceptibility testing and therapeutic effect evaluation.