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Sample records for aided geometric design

  1. Geometric modeling for computer aided design

    NASA Technical Reports Server (NTRS)

    Schwing, James L.

    1993-01-01

    Over the past several years, it has been the primary goal of this grant to design and implement software to be used in the conceptual design of aerospace vehicles. The work carried out under this grant was performed jointly with members of the Vehicle Analysis Branch (VAB) of NASA LaRC, Computer Sciences Corp., and Vigyan Corp. This has resulted in the development of several packages and design studies. Primary among these are the interactive geometric modeling tool, the Solid Modeling Aerospace Research Tool (smart), and the integration and execution tools provided by the Environment for Application Software Integration and Execution (EASIE). In addition, it is the purpose of the personnel of this grant to provide consultation in the areas of structural design, algorithm development, and software development and implementation, particularly in the areas of computer aided design, geometric surface representation, and parallel algorithms.

  2. Geometric modeling for computer aided design

    NASA Technical Reports Server (NTRS)

    Schwing, James L.; Olariu, Stephen

    1995-01-01

    The primary goal of this grant has been the design and implementation of software to be used in the conceptual design of aerospace vehicles particularly focused on the elements of geometric design, graphical user interfaces, and the interaction of the multitude of software typically used in this engineering environment. This has resulted in the development of several analysis packages and design studies. These include two major software systems currently used in the conceptual level design of aerospace vehicles. These tools are SMART, the Solid Modeling Aerospace Research Tool, and EASIE, the Environment for Software Integration and Execution. Additional software tools were designed and implemented to address the needs of the engineer working in the conceptual design environment. SMART provides conceptual designers with a rapid prototyping capability and several engineering analysis capabilities. In addition, SMART has a carefully engineered user interface that makes it easy to learn and use. Finally, a number of specialty characteristics have been built into SMART which allow it to be used efficiently as a front end geometry processor for other analysis packages. EASIE provides a set of interactive utilities that simplify the task of building and executing computer aided design systems consisting of diverse, stand-alone, analysis codes. Resulting in a streamlining of the exchange of data between programs reducing errors and improving the efficiency. EASIE provides both a methodology and a collection of software tools to ease the task of coordinating engineering design and analysis codes.

  3. Geometric modeling for computer aided design

    NASA Technical Reports Server (NTRS)

    Schwing, James L.

    1992-01-01

    The goal was the design and implementation of software to be used in the conceptual design of aerospace vehicles. Several packages and design studies were completed, including two software tools currently used in the conceptual level design of aerospace vehicles. These tools are the Solid Modeling Aerospace Research Tool (SMART) and the Environment for Software Integration and Execution (EASIE). SMART provides conceptual designers with a rapid prototyping capability and additionally provides initial mass property analysis. EASIE provides a set of interactive utilities that simplify the task of building and executing computer aided design systems consisting of diverse, stand alone analysis codes that result in the streamlining of the exchange of data between programs, reducing errors and improving efficiency.

  4. Geometric modeling for computer aided design

    NASA Technical Reports Server (NTRS)

    Schwing, James L.

    1988-01-01

    Research focused on two major areas. The first effort addressed the design and implementation of a technique that allows for the visualization of the real time variation of physical properties. The second effort focused on the design and implementation of an on-line help system with components designed for both authors and users of help information.

  5. Evolution of Geometric Sensitivity Derivatives from Computer Aided Design Models

    NASA Technical Reports Server (NTRS)

    Jones, William T.; Lazzara, David; Haimes, Robert

    2010-01-01

    The generation of design parameter sensitivity derivatives is required for gradient-based optimization. Such sensitivity derivatives are elusive at best when working with geometry defined within the solid modeling context of Computer-Aided Design (CAD) systems. Solid modeling CAD systems are often proprietary and always complex, thereby necessitating ad hoc procedures to infer parameter sensitivity. A new perspective is presented that makes direct use of the hierarchical associativity of CAD features to trace their evolution and thereby track design parameter sensitivity. In contrast to ad hoc methods, this method provides a more concise procedure following the model design intent and determining the sensitivity of CAD geometry directly to its respective defining parameters.

  6. A Study of Computer-Aided Geometric Optical Design.

    DTIC Science & Technology

    1982-10-01

    WAHLSTEDT OCT B2 AFIT/GEP/PH/82D-24 UNCLASSIFIED F /’G 9/2 N smhohmohholi EohhhhhhhhhhhE 1111.2 1 .6 mmiima __’___ MICROCOPY RESOLUTION TEST CHART NATIONAL...The irting point () f the desigri was a Questar 3 inch telescope.. Avidj tional optic:l elements were added and " the design impoved until the desirF...The P|WI? J ) f e the lens is defined as the index of refractioni at ,ither focal point divided by the respective focal length. The power of the lens

  7. CFD-aided cell settler design optimization and scale-up: effect of geometric design and operational variables on separation performance.

    PubMed

    Shen, Yuyi; Yanagimachi, Kurt

    2011-01-01

    The inclined multiplate (lamella) gravity settler has proven to be an effective cell retention device in industrial perfusion cell culture applications. Investigations on the effects of geometric design and operational variables of the cell settler are crucial to understanding how to best improve the settler performance. Maximizing the harvest/perfusion flow rate while minimizing viable cell loss out of the harvest is the primary challenge for optimization of the settler design. This study demonstrated that computational fluid dynamics (CFD) can be utilized to accurately model and evaluate the settler separation performance for near-monodisperse suspensions and therefore aid in the design optimization of the settler under these baseline conditions. With the preferred geometric features that were identified from CFD modeling results, we proposed design guidelines for the scale-up of these multiplate settler systems. With these guidelines and performance verification using the CFD model, a new large-scale settler was designed and fabricated for a perfusion cell culture process using a minimally aggregating production cell line. Perfusion cell culture runs with this particular cell line were performed with this settler, and the CFD model was able to predict the initial ramp-up performance, proving it to be a valuable scale-up design tool for this production process.

  8. Present capabilities and future requirements for computer-aided geometric modeling in the design and manufacture of gas turbine

    NASA Technical Reports Server (NTRS)

    Caille, E.; Propen, M.; Hoffman, A.

    1984-01-01

    Gas turbine engine design requires the ability to rapidly develop complex structures which are subject to severe thermal and mechanical operating loads. As in all facets of the aerospace industry, engine designs are constantly driving towards increased performance, higher temperatures, higher speeds, and lower weight. The ability to address such requirements in a relatively short time frame has resulted in a major thrust towards integrated design/analysis/manufacturing systems. These computer driven graphics systems represent a unique challenge, with major payback opportunities if properly conceived, implemented, and applied.

  9. Computer Aided Geometrical Optics Design.

    DTIC Science & Technology

    1983-12-01

    calculate wavefront aberrations. Zernike polynomials are defined on the unit circle. For exit pupil geometries other than circular, presumably the FALCON...object to the first surface can be specified as any distance but if none is specified, the default value is 10 10 units . The Y-Z plane is taken as the...Figure 2-2. LENS LI SINGLE THIN LENS EXAMPLE SAY 10 SCY -5 TH 50 UNITS CM CV .01 TH 2 SCHOTT BK7 RD 200 TH 500 GLASS 1.0 END Figure 2-2. Single Thin

  10. A responsive finite element method to aid interactive geometric modeling.

    PubMed

    Umetani, N; Takayama, K; Mitani, J; Igarashi, T

    2011-01-01

    Current computer-aided engineering systems use numerical-simulation methods mainly as offline verification tools to reject designs that don't satisfy the required constraints, rather than as tools to guide users toward better designs. However, integrating real-time finite element method (FEM) into interactive geometric modeling can provide user guidance. During interactive editing, real-time feedback from numerical simulation guides users toward an improved design without tedious trial-and-error iterations. Careful reuse of previous computation results, such as meshes and matrices, on the basis of speed and accuracy trade-offs, have helped produce fast FEM analysis during interactive editing. Several 2D example applications and informal user studies show this approach's effectiveness. Such tools could help nonexpert users design objects that satisfy physical constraints and help those users understand the underlying physical properties.

  11. Designing State Aid Formulas

    ERIC Educational Resources Information Center

    Zhao, Bo; Bradbury, Katharine

    2009-01-01

    This paper designs a new equalization-aid formula based on fiscal gaps of local communities. When states are in transition to a new local aid formula, the issue of whether and how to hold existing aid harmless poses a challenge. The authors show that some previous studies and the formulas derived from them give differential weights to existing and…

  12. Polar metals by geometric design

    NASA Astrophysics Data System (ADS)

    Kim, T. H.; Puggioni, D.; Yuan, Y.; Xie, L.; Zhou, H.; Campbell, N.; Ryan, P. J.; Choi, Y.; Kim, J.-W.; Patzner, J. R.; Ryu, S.; Podkaminer, J. P.; Irwin, J.; Ma, Y.; Fennie, C. J.; Rzchowski, M. S.; Pan, X. Q.; Gopalan, V.; Rondinelli, J. M.; Eom, C. B.

    2016-05-01

    Gauss’s law dictates that the net electric field inside a conductor in electrostatic equilibrium is zero by effective charge screening; free carriers within a metal eliminate internal dipoles that may arise owing to asymmetric charge distributions. Quantum physics supports this view, demonstrating that delocalized electrons make a static macroscopic polarization, an ill-defined quantity in metals—it is exceedingly unusual to find a polar metal that exhibits long-range ordered dipoles owing to cooperative atomic displacements aligned from dipolar interactions as in insulating phases. Here we describe the quantum mechanical design and experimental realization of room-temperature polar metals in thin-film ANiO3 perovskite nickelates using a strategy based on atomic-scale control of inversion-preserving (centric) displacements. We predict with ab initio calculations that cooperative polar A cation displacements are geometrically stabilized with a non-equilibrium amplitude and tilt pattern of the corner-connected NiO6 octahedra—the structural signatures of perovskites—owing to geometric constraints imposed by the underlying substrate. Heteroepitaxial thin-films grown on LaAlO3 (111) substrates fulfil the design principles. We achieve both a conducting polar monoclinic oxide that is inaccessible in compositionally identical films grown on (001) substrates, and observe a hidden, previously unreported, non-equilibrium structure in thin-film geometries. We expect that the geometric stabilization approach will provide novel avenues for realizing new multifunctional materials with unusual coexisting properties.

  13. Polar Metals by Geometric Design

    SciTech Connect

    Kim, T. H.; Puggioni, D.; Yuan, Y.; Xie, L.; Zhou, H.; Campbell, N.; Ryan, P. J.; Choi, Y.; Kim, J. -W.; Patzner, J. R.; Ryu, S.; Podkaminer, J. P.; Irwin, J.; Ma, Y.; Fennie, C. J.; Rzchowski, M. S.; Pan, X. Q.; Gopalan, V.; Rondinelli, J. M.; Eom, C. B.

    2016-05-05

    Gauss's law dictates that the net electric field inside a conductor in electrostatic equilibrium is zero by effective charge screening; free carriers within a metal eliminate internal dipoles that may arise owing to asymmetric charge distributions(1). Quantum physics supports this view(2), demonstrating that delocalized electrons make a static macroscopic polarization, an ill-defined quantity in metals(3)-it is exceedingly unusual to find a polar metal that exhibits long-range ordered dipoles owing to cooperative atomic displacements aligned from dipolar interactions as in insulating phases(4). Here we describe the quantum mechanical design and experimental realization of room-temperature polar metals in thin-film ANiO(3) perovskite nickelates using a strategy based on atomic-scale control of inversion-preserving (centric) displacements(5). We predict with ab initio calculations that cooperative polar A cation displacements are geometrically stabilized with a non-equilibrium amplitude and tilt pattern of the corner-connected NiO6 octahedra-the structural signatures of perovskites-owing to geometric constraints imposed by the underlying substrate. Heteroepitaxial thin-films grown on LaAlO3 (111) substrates fulfil the design principles. We achieve both a conducting polar monoclinic oxide that is inaccessible in compositionally identical films grown on (001) substrates, and observe a hidden, previously unreported(6-10), non-equilibrium structure in thin-film geometries. We expect that the geometric stabilization approach will provide novel avenues for realizing new multifunctional materials with unusual coexisting properties.

  14. Salt bridges: geometrically specific, designable interactions.

    PubMed

    Donald, Jason E; Kulp, Daniel W; DeGrado, William F

    2011-03-01

    Salt bridges occur frequently in proteins, providing conformational specificity and contributing to molecular recognition and catalysis. We present a comprehensive analysis of these interactions in protein structures by surveying a large database of protein structures. Salt bridges between Asp or Glu and His, Arg, or Lys display extremely well-defined geometric preferences. Several previously observed preferences are confirmed, and others that were previously unrecognized are discovered. Salt bridges are explored for their preferences for different separations in sequence and in space, geometric preferences within proteins and at protein-protein interfaces, co-operativity in networked salt bridges, inclusion within metal-binding sites, preference for acidic electrons, apparent conformational side chain entropy reduction on formation, and degree of burial. Salt bridges occur far more frequently between residues at close than distant sequence separations, but, at close distances, there remain strong preferences for salt bridges at specific separations. Specific types of complex salt bridges, involving three or more members, are also discovered. As we observe a strong relationship between the propensity to form a salt bridge and the placement of salt-bridging residues in protein sequences, we discuss the role that salt bridges might play in kinetically influencing protein folding and thermodynamically stabilizing the native conformation. We also develop a quantitative method to select appropriate crystal structure resolution and B-factor cutoffs. Detailed knowledge of these geometric and sequence dependences should aid de novo design and prediction algorithms.

  15. Electronic aids to conceptual design

    NASA Technical Reports Server (NTRS)

    Bouchard, Eugene E.

    1990-01-01

    Presented in viewgraph form are techniques to improve the conceptual design of complex systems. The paper discusses theory of design, flexible software tools for computer aided design, and methods for enhancing communication among design teams.

  16. Computer aided airship design

    NASA Technical Reports Server (NTRS)

    Davis, S. J.; Rosenstein, H.

    1975-01-01

    The Comprehensive Airship Sizing and Performance Computer Program (CASCOMP) is described which was developed and used in the design and evaluation of advanced lighter-than-air (LTA) craft. The program defines design details such as engine size and number, component weight buildups, required power, and the physical dimensions of airships which are designed to meet specified mission requirements. The program is used in a comparative parametric evaluation of six advanced lighter-than-air concepts. The results indicate that fully buoyant conventional airships have the lightest gross lift required when designed for speeds less than 100 knots and the partially buoyant concepts are superior above 100 knots. When compared on the basis of specific productivity, which is a measure of the direct operating cost, the partially buoyant lifting body/tilting prop-rotor concept is optimum.

  17. Telerobotic workstation design aid

    NASA Technical Reports Server (NTRS)

    Corker, K.; Hudlicka, E.; Young, D.; Cramer, N.

    1989-01-01

    Telerobot systems are being developed to support a number of space mission applications. In low earth orbit, telerobots and teleoperated manipulators will be used in shuttle operations and space station construction/maintenance. Free flying telerobotic service vehicles will be used at low and geosynchronous orbital operations. Rovers and autonomous vehicles will be equipped with telerobotic devices in planetary exploration. In all of these systems, human operators will interact with the robot system at varied levels during the scheduled operations. The human operators may be in either orbital or ground-based control systems. To assure integrated system development and maximum utility across these systems, designers must be sensitive to the constraints and capabilities that the human brings to system operation and must be assisted in applying these human factors to system development. The simulation and analysis system is intended to serve the needs of system analysis/designers as an integrated workstation in support of telerobotic design.

  18. Computer-aided geometric modeling of the human eye and orbit.

    PubMed

    Parshall, R F

    1991-01-01

    The author advocates, as a long-term development agenda for the profession, a shift in the working methods of medical illustrators from a two-dimensional image processing mode to a computer-aided design and drafting (CADD) mode. Existing CADD technology, which can make short work of the complex graphic construction problems of anatomical visualization, performs virtually all of its manipulations through systematic exercise of graphic geometry which illustrators tend to reduce to an intuitive, almost vestigial supplement to 2D image processing methods. The primary barrier to the immediate use of CADD is a lack of geometric database materials on anatomical component systems of the body. An on-going experimental project in modeling the human eye and orbit, utilizing a Silicon Graphics Iris workstation and Control Data Corporation's Integrated Computerized Engineering and Manufacturing (ICEM) software, exemplifies the preparatory work needed to create such database materials.

  19. Design of geometric phase measurement in EAST Tokamak

    NASA Astrophysics Data System (ADS)

    Lan, Ting; Liu, Haiqing; Liu, Jian; Qin, Hong

    2016-10-01

    The aim of this work is to propose the optimum scheme for geometric phase measurement in EAST Tokamak. On the one hand, the experimental observation of geometric phase in plasma systems is an essential verification of the geometric phase theory by a new experimental technique. On the other hand, the measurement of geometric phase confirms geometric effect as a new system error in the existing diagnostics. The geometric phase in Faraday rotation angle for linearly polarized electromagnetic waves propagating in non-uniform magnetized plasmas is a good candidate for the first identification of geometric phase in plasma. In this work, the theoretical values of geometric phase for the probe beams of EAST Polarimeter-Interferometer (POINT) system are calculated by path integration in parameter space. Several schemes are proposed for the measurement of the geometric phase in POINT system by amplifying the geometric phase and enhancing the diagnostic resolution. To reach the conditions of the designed scheme for geometric phase measurement, the feasibility of replacing individual retro reflectors (RRs) with retro reflector array (RRA) in POINT system is verified experimentally. Corresponding results are beneficial for geometric phase measurement in EAST Tokamak.

  20. Aids to School Bus Design

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Navistar International Transportation Corporation, Chicago, IL, used three separate NASA-developed technologies in the design and testing of their 3000 Series Bus Chassis which was developed expressly for school bus applications. For structural analysis, they used the MSC/NASTRAN program which mathematically analyzes a design and predicts how it will hold up under stress. They also used the SPATE 9000 system for non-contact measurement of stress, load transfer mechanisms, detection of hidden flaws, and monitoring structural changes during fatigue testing. SPATE 9000 was based on infrared stress measurement technology developed by Langley Research Center. They also employed the Wyle Ride Quality Meter, which was developed by Langley to aid in passenger aircraft design by providing an accurate measurement of ride vibration and sound level. These numbers translate into a subjective discomfort level index. These technologies contribute to the company's 45-48 percent share of the school bus chassis market.

  1. CAPRI: A Geometric Foundation for Computational Analysis and Design

    NASA Technical Reports Server (NTRS)

    Haimes, Robert

    2006-01-01

    CAPRI is a software building tool-kit that refers to two ideas; (1) A simplified, object-oriented, hierarchical view of a solid part integrating both geometry and topology definitions, and (2) programming access to this part or assembly and any attached data. A complete definition of the geometry and application programming interface can be found in the document CAPRI: Computational Analysis PRogramming Interface appended to this report. In summary the interface is subdivided into the following functional components: 1. Utility routines -- These routines include the initialization of CAPRI, loading CAD parts and querying the operational status as well as closing the system down. 2. Geometry data-base queries -- This group of functions allow all top level applications to figure out and get detailed information on any geometric component in the Volume definition. 3. Point queries -- These calls allow grid generators, or solvers doing node adaptation, to snap points directly onto geometric entities. 4. Calculated or geometrically derived queries -- These entry points calculate data from the geometry to aid in grid generation. 5. Boundary data routines -- This part of CAPRI allows general data to be attached to Boundaries so that the boundary conditions can be specified and stored within CAPRI s data-base. 6. Tag based routines -- This part of the API allows the specification of properties associated with either the Volume (material properties) or Boundary (surface properties) entities. 7. Geometry based interpolation routines -- This part of the API facilitates Multi-disciplinary coupling and allows zooming through Boundary Attachments. 8. Geometric creation and manipulation -- These calls facilitate constructing simple solid entities and perform the Boolean solid operations. Geometry constructed in this manner has the advantage that if the data is kept consistent with the CAD package, therefore a new design can be incorporated directly and is manufacturable. 9

  2. Creativity and Motivation for Geometric Tasks Designing in Education

    ERIC Educational Resources Information Center

    Rumanová, Lucia; Smiešková, Edita

    2015-01-01

    In this paper we focus on creativity needed for geometric tasks designing, visualization of geometric problems and use of ICT. We present some examples of various problems related to tessellations. Altogether 21 students--pre-service teachers participated in our activity within a geometry course at CPU in Nitra, Slovakia. Our attempt was to…

  3. Generalizations of fuzzy linguistic control points in geometric design

    NASA Astrophysics Data System (ADS)

    Sallehuddin, M. H.; Wahab, A. F.; Gobithaasan, R. U.

    2014-07-01

    Control points are geometric primitives that play an important role in designing the geometry curve and surface. When these control points are blended with some basis functions, there are several geometric models such as Bezier, B-spline and NURBS(Non-Uniform Rational B-Spline) will be produced. If the control points are defined by the theory of fuzzy sets, then fuzzy geometric models are produced. But the fuzzy geometric models can only solve the problem of uncertainty complex. This paper proposes a new definition of fuzzy control points with linguistic terms. When the fuzzy control points with linguistic terms are blended with basis functions, then a fuzzy linguistic geometric model is produced. This paper ends with some numerical examples illustrating linguistic control attributes of fuzzy geometric models.

  4. Computer-aided system design

    NASA Technical Reports Server (NTRS)

    Walker, Carrie K.

    1991-01-01

    A technique has been developed for combining features of a systems architecture design and assessment tool and a software development tool. This technique reduces simulation development time and expands simulation detail. The Architecture Design and Assessment System (ADAS), developed at the Research Triangle Institute, is a set of computer-assisted engineering tools for the design and analysis of computer systems. The ADAS system is based on directed graph concepts and supports the synthesis and analysis of software algorithms mapped to candidate hardware implementations. Greater simulation detail is provided by the ADAS functional simulator. With the functional simulator, programs written in either Ada or C can be used to provide a detailed description of graph nodes. A Computer-Aided Software Engineering tool developed at the Charles Stark Draper Laboratory (CSDL CASE) automatically generates Ada or C code from engineering block diagram specifications designed with an interactive graphical interface. A technique to use the tools together has been developed, which further automates the design process.

  5. EGRAM- ECHELLE SPECTROGRAPH DESIGN AID

    NASA Technical Reports Server (NTRS)

    Dantzler, A. A.

    1994-01-01

    EGRAM aids in the design of spectrographic systems that utilize an echelle-first order cross disperser combination. This optical combination causes a two dimensional echellogram to fall on a detector. EGRAM describes the echellogram with enough detail to allow the user to effectively judge the feasibility of the spectrograph's design. By iteratively altering system parameters, the desired echellogram can be achieved without making a physical model. EGRAM calculates system parameters which are accurate to the first order and compare favorably to results from ray tracing techniques. The spectrographic system modelled by EGRAM consists of an entrance aperture, collimator, echelle, cross dispersion grating, focusing options, and a detector. The system is assumed to be free of aberrations and the echelle, cross disperser, and detector should be planar. The EGRAM program is menu driven and has a HELP facility. The user is prompted for information such as minimum and maximum wavelengths, slit dimensions, ruling frequencies, detector geometry, and angle of incidence. EGRAM calculates the resolving power and range of order numbers covered by the echellogram. A numerical map is also produced. This tabulates the order number, slit bandpass, and high/middle/low wavelengths. EGRAM can also compute the centroid coordinates of a specific wavelength and order (or vice versa). EGRAM is written for interactive execution and is written in Microsoft BASIC A. It has been implemented on an IBM PC series computer operating under DOS. EGRAM was developed in 1985.

  6. Optimization approach for the evaluation of geometric errors in computer-aided inspection

    NASA Astrophysics Data System (ADS)

    Jiang, Guohua

    Geometric dimensioning and tolerancing (GD&T) is a set of standards that defines a clear and concise mathematical language for communicating product definition. A design based on GD&T clearly reflects the functional requirements of a product, provides unique definition of a drawing among design, manufacturing and inspection engineers and conveys the design intention clearly without any ambiguity. The latest version of this standard is ASME Y14.5M-1994. Traditional methods for the inspection of geometric tolerances have been mostly with the use of functional gages and Coordinate Measuring Machines (CMM). Function gages are very expensive and only provide a yes/no result. CMMs have embedded algorithms to verify geometric tolerances according to the design specification. However, it has been shown that these embedded algorithms neither provide accurate evaluation of geometric errors nor do they conform to the ASME standards. High accuracy requirements in the manufacture of precision parts with complex geometries have made accurate evaluation and verification of geometric tolerances very critical. Over the years, researchers have developed many algorithms to evaluate some of the geometric errors. However, there is still a significant lack of evaluation procedures for complex geometric errors. In this dissertation, mathematical models have been built for the evaluation of a certain set of complex geometric characteristics. The concentration has been on the evaluation of 3D feature relating positional error, cylindricity error and straightness error of spatial line. Research has been carried out to understand the mathematical natures of these problems. Based on the research results, efficient solution methodologies have been developed according to the ASME standards. A robust and efficient procedure has also been developed for the identification of candidate datum sets. The proposed procedures have been implemented using the C++ or C programming language. Experimental

  7. Computer-aided design of LSI topology

    NASA Astrophysics Data System (ADS)

    Seliutin, V. A.

    The problems and methods of the computer-aided design of the topology of LSI circuits and computer-aided manufacture of LSI templates are reviewed. Topics discussed include algorithms for the layout of cells and circuit units, algorithms for tracing connections, the design of the topology of matrix LSI, and the topology of functional LSI circuit units based on MIS structures. The discussion also covers the design of the layout of LSI circuits with single-layer commutation, application examples, and the main trends in the computer-aided design of LSI circuits.

  8. Geometric methods for optimal sensor design.

    PubMed

    Belabbas, M-A

    2016-01-01

    The Kalman-Bucy filter is the optimal estimator of the state of a linear dynamical system from sensor measurements. Because its performance is limited by the sensors to which it is paired, it is natural to seek optimal sensors. The resulting optimization problem is however non-convex. Therefore, many ad hoc methods have been used over the years to design sensors in fields ranging from engineering to biology to economics. We show in this paper how to obtain optimal sensors for the Kalman filter. Precisely, we provide a structural equation that characterizes optimal sensors. We furthermore provide a gradient algorithm and prove its convergence to the optimal sensor. This optimal sensor yields the lowest possible estimation error for measurements with a fixed signal-to-noise ratio. The results of the paper are proved by reducing the optimal sensor problem to an optimization problem on a Grassmannian manifold and proving that the function to be minimized is a Morse function with a unique minimum. The results presented here also apply to the dual problem of optimal actuator design.

  9. Geometric methods for optimal sensor design

    PubMed Central

    Belabbas, M.-A.

    2016-01-01

    The Kalman–Bucy filter is the optimal estimator of the state of a linear dynamical system from sensor measurements. Because its performance is limited by the sensors to which it is paired, it is natural to seek optimal sensors. The resulting optimization problem is however non-convex. Therefore, many ad hoc methods have been used over the years to design sensors in fields ranging from engineering to biology to economics. We show in this paper how to obtain optimal sensors for the Kalman filter. Precisely, we provide a structural equation that characterizes optimal sensors. We furthermore provide a gradient algorithm and prove its convergence to the optimal sensor. This optimal sensor yields the lowest possible estimation error for measurements with a fixed signal-to-noise ratio. The results of the paper are proved by reducing the optimal sensor problem to an optimization problem on a Grassmannian manifold and proving that the function to be minimized is a Morse function with a unique minimum. The results presented here also apply to the dual problem of optimal actuator design. PMID:26997885

  10. A computer-aided regulator design.

    NASA Technical Reports Server (NTRS)

    Karmarkar, J. S.; Siljak, D. D.

    1972-01-01

    A unified computer-aided method for the design of linear and nonlinear regulators is discussed. The general mathematical programming approach considered involves the determination of a vector that solves the problem of minimizing the objective function subject to constraints. Classical design problems stated are related to stability design, dominant mode design, and comprehensive design. A computer algorithm is also developed.

  11. Computer Aided Design in Engineering Education.

    ERIC Educational Resources Information Center

    Gobin, R.

    1986-01-01

    Discusses the use of Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) systems in an undergraduate engineering education program. Provides a rationale for CAD/CAM use in the already existing engineering program. Describes the methods used in choosing the systems, some initial results, and warnings for first-time users. (TW)

  12. SIAM Conference on Geometric Design and Computing. Final Technical Report

    SciTech Connect

    2002-03-11

    The SIAM Conference on Geometric Design and Computing attracted 164 domestic and international researchers, from academia, industry, and government. It provided a stimulating forum in which to learn about the latest developments, to discuss exciting new research directions, and to forge stronger ties between theory and applications. Final Report

  13. Computer-aided diagnosis in CT colonography: detection of polyps based on geometric and texture features

    NASA Astrophysics Data System (ADS)

    Yoshida, Hiroyuki; Naeppi, Janne J.; Frimmel, Hans; Dachman, Abraham H.

    2002-05-01

    A computer-aided diagnosis scheme for the detection of colonic polyps in CT colonography has been developed, and its performance has been assessed based on clinical cases with colonoscopy-confirmed polyps. In the scheme, the colon was automatically segmented by use of knowledge-guided segmentation from 3-dimensional isotropic volumes reconstructed from axial CT slices in CT colonography. Polyp candidates are detected by first computing of 3-dimensional geometric features that characterize polyps, and then segmenting of connected components corresponding to suspicious regions by hysteresis thresholding and fuzzy clustering based on these geometric features. False-positive detections are reduced by computation of 3-dimensional texture features characterizing the internal structures of the polyp candidates, followed by application of discriminant analysis to the feature space generated by the geometric and texture features. We applied our scheme to 43 CT colonographic cases with cleansed colon, including 12 polyps larger than 5 mm. In a by-dataset analysis, the CAD scheme yielded a sensitivity of 95% with 1.2 false positives per data set. The false negative was one of the two polyps in a single patient. Consequently, in by-patient analysis, our method yielded 100% sensitivity with 2.0 false positives per patient. The results indicate that our CAD scheme has the potential to detect clinically important polyp cases with a high sensitivity and a relatively low false-positive rate.

  14. Computer Aided Control System Design (CACSD)

    NASA Technical Reports Server (NTRS)

    Stoner, Frank T.

    1993-01-01

    The design of modern aerospace systems relies on the efficient utilization of computational resources and the availability of computational tools to provide accurate system modeling. This research focuses on the development of a computer aided control system design application which provides a full range of stability analysis and control design capabilities for aerospace vehicles.

  15. Photogrammetry and computer-aided piping design

    SciTech Connect

    Keneflick, J.F.; Chirillo, R.D.

    1985-02-18

    Three-dimensional measurements taken from photographs of a plant model can be digitized and linked with computer-aided piping design. This can short-cut the design and construction of new plants and expedite repair and retrofitting projects. Some designers bridge the gap between model and computer by digitizing from orthographic prints obtained via orthography or the laser scanning of model sections. Such valve or fitting then processed is described in this paper. The marriage of photogrammetry and computer-aided piping design can economically produce such numerical drawings.

  16. Uncertainty management in intelligent design aiding systems

    NASA Technical Reports Server (NTRS)

    Brown, Donald E.; Gabbert, Paula S.

    1988-01-01

    A novel approach to uncertainty management which is particularly effective in intelligent design aiding systems for large-scale systems is presented. The use of this approach in the materials handling system design domain is discussed. It is noted that, during any point in the design process, a point value can be obtained for the evaluation of feasible designs; however, the techniques described provide unique solutions for these point values using only the current information about the design environment.

  17. Computer Aided Drug Design: Success and Limitations.

    PubMed

    Baig, Mohammad Hassan; Ahmad, Khurshid; Roy, Sudeep; Ashraf, Jalaluddin Mohammad; Adil, Mohd; Siddiqui, Mohammad Haris; Khan, Saif; Kamal, Mohammad Amjad; Provazník, Ivo; Choi, Inho

    2016-01-01

    Over the last few decades, computer-aided drug design has emerged as a powerful technique playing a crucial role in the development of new drug molecules. Structure-based drug design and ligand-based drug design are two methods commonly used in computer-aided drug design. In this article, we discuss the theory behind both methods, as well as their successful applications and limitations. To accomplish this, we reviewed structure based and ligand based virtual screening processes. Molecular dynamics simulation, which has become one of the most influential tool for prediction of the conformation of small molecules and changes in their conformation within the biological target, has also been taken into account. Finally, we discuss the principles and concepts of molecular docking, pharmacophores and other methods used in computer-aided drug design.

  18. PLAID- A COMPUTER AIDED DESIGN SYSTEM

    NASA Technical Reports Server (NTRS)

    Brown, J. W.

    1994-01-01

    PLAID is a three-dimensional Computer Aided Design (CAD) system which enables the user to interactively construct, manipulate, and display sets of highly complex geometric models. PLAID was initially developed by NASA to assist in the design of Space Shuttle crewstation panels, and the detection of payload object collisions. It has evolved into a more general program for convenient use in many engineering applications. Special effort was made to incorporate CAD techniques and features which minimize the users workload in designing and managing PLAID models. PLAID consists of three major modules: the Primitive Object Generator (BUILD), the Composite Object Generator (COG), and the DISPLAY Processor. The BUILD module provides a means of constructing simple geometric objects called primitives. The primitives are created from polygons which are defined either explicitly by vertex coordinates, or graphically by use of terminal crosshairs or a digitizer. Solid objects are constructed by combining, rotating, or translating the polygons. Corner rounding, hole punching, milling, and contouring are special features available in BUILD. The COG module hierarchically organizes and manipulates primitives and other previously defined COG objects to form complex assemblies. The composite object is constructed by applying transformations to simpler objects. The transformations which can be applied are scalings, rotations, and translations. These transformations may be defined explicitly or defined graphically using the interactive COG commands. The DISPLAY module enables the user to view COG assemblies from arbitrary viewpoints (inside or outside the object) both in wireframe and hidden line renderings. The PLAID projection of a three-dimensional object can be either orthographic or with perspective. A conflict analysis option enables detection of spatial conflicts or collisions. DISPLAY provides camera functions to simulate a view of the model through different lenses. Other

  19. Aids in designing laboratory flumes

    USGS Publications Warehouse

    Williams, Garnett P.

    1971-01-01

    The upsurge of interest in our environment has caused research and instruction in the flow of water along open channels to become increasingly popular in universities and institutes. This, in turn, has brought a greater demand for properly-designed laboratory flumes. Whatever the reason for your interest, designing and building the flume will take a little preparation. You may choose a pattern exactly like a previous design, or you may follow the more time-consuming method of studying several existing flumes and combine the most desirable features of each.

  20. Visions of visualization aids - Design philosophy and observations

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.

    1989-01-01

    Aids for the visualization of high-dimensional scientific or other data must be designed. Simply casting multidimensional data into a two-dimensional or three-dimensional spatial metaphor does not guarantee that the presentation will provide insight or a parsimonious description of phenomena implicit in the data. Useful visualization, in contrast to glitzy, high-tech, computer-graphics imagery, is generally based on preexisting theoretical beliefs concerning the underlying phenomena. These beliefs guide selection and formatting of the plotted variables. Visualization tools are useful for understanding naturally three-dimensional data bases such as those used by pilots or astronauts. Two examples of such aids for spatial maneuvering illustrate that informative geometric distortion may be introduced to assist visualization and that visualization of complex dynamics alone may not be adequate to provide the necessary insight into the underlying processes.

  1. A new elevating metatarsal osteotomy: geometrical design and applications.

    PubMed

    Wagner, Emilio; Ortiz, Cristián; Keller, Andrés; Espinosa, Maximiliano; Arellano, Sergio; de la Fuente, Paulina; Wagner, Pablo

    2013-01-01

    For metatarsalgia and lesser toe deformities, a commonly performed procedure is the Weil osteotomy, which inevitably depresses the metatarsal head, changing the intrinsic muscle axis and generating phalanx extension. The objective of this study is to present a new metatarsal osteotomy that shortens or lengthens and elevates the metatarsal head, the elevating metatarsal osteotomy (EMO), with its geometrical analysis and possible applications. A geometrical model was designed, planning an oblique subcapital osteotomy with slice resection and distal displacement. A trigonometric analysis was done to calculate how to shorten, elevate, or lengthen the metatarsal head. The EMO elevates the head in one-third of the width of the resected slice. Distal and dorsal displacement of the metatarsal head results in an elevation and lengthening of the metatarsal bone (60% elevation and 65% lengthening). Performing an elevating metatarsal osteotomy will lengthen and elevate the metatarsal head, which sometimes is necessary when treating toe deformities and instability.

  2. A rule based computer aided design system

    NASA Technical Reports Server (NTRS)

    Premack, T.

    1986-01-01

    A Computer Aided Design (CAD) system is presented which supports the iterative process of design, the dimensional continuity between mating parts, and the hierarchical structure of the parts in their assembled configuration. Prolog, an interactive logic programming language, is used to represent and interpret the data base. The solid geometry representing the parts is defined in parameterized form using the swept volume method. The system is demonstrated with a design of a spring piston.

  3. Designing a Composable Geometric Toolkit for Versatility in Applications to Simulation Development

    NASA Technical Reports Server (NTRS)

    Reed, Gregory S.; Campbell, Thomas

    2008-01-01

    Conceived and implemented through the development of probabilistic risk assessment simulations for Project Constellation, the Geometric Toolkit allows users to create, analyze, and visualize relationships between geometric shapes in three-space using the MATLAB computing environment. The key output of the toolkit is an analysis of how emanations from one "source" geometry (e.g., a leak in a pipe) will affect another "target" geometry (e.g., another heat-sensitive component). It can import computer-aided design (CAD) depictions of a system to be analyzed, allowing the user to reliably and easily represent components within the design and determine the relationships between them, ultimately supporting more technical or physics-based simulations that use the toolkit. We opted to develop a variety of modular, interconnecting software tools to extend the scope of the toolkit, providing the capability to support a range of applications. This concept of simulation composability allows specially-developed tools to be reused by assembling them in various combinations. As a result, the concepts described here and implemented in this toolkit have a wide range of applications outside the domain of risk assessment. To that end, the Geometric Toolkit has been evaluated for use in other unrelated applications due to the advantages provided by its underlying design.

  4. Designing Visual Aids That Promote Risk Literacy.

    PubMed

    Garcia-Retamero, Rocio; Cokely, Edward T

    2017-02-01

    Background Effective risk communication is essential for informed decision making. Unfortunately, many people struggle to understand typical risk communications because they lack essential decision-making skills. Objective The aim of this study was to review the literature on the effect of numeracy on risk literacy, decision making, and health outcomes, and to evaluate the benefits of visual aids in risk communication. Method We present a conceptual framework describing the influence of numeracy on risk literacy, decision making, and health outcomes, followed by a systematic review of the benefits of visual aids in risk communication for people with different levels of numeracy and graph literacy. The systematic review covers scientific research published between January 1995 and April 2016, drawn from the following databases: Web of Science, PubMed, PsycINFO, ERIC, Medline, and Google Scholar. Inclusion criteria were investigation of the effect of numeracy and/or graph literacy, and investigation of the effect of visual aids or comparison of their effect with that of numerical information. Thirty-six publications met the criteria, providing data on 27,885 diverse participants from 60 countries. Results Transparent visual aids robustly improved risk understanding in diverse individuals by encouraging thorough deliberation, enhancing cognitive self-assessment, and reducing conceptual biases in memory. Improvements in risk understanding consistently produced beneficial changes in attitudes, behavioral intentions, trust, and healthy behaviors. Visual aids were found to be particularly beneficial for vulnerable and less skilled individuals. Conclusion Well-designed visual aids tend to be highly effective tools for improving informed decision making among diverse decision makers. We identify five categories of practical, evidence-based guidelines for heuristic evaluation and design of effective visual aids.

  5. Computer-Aided Design in Further Education.

    ERIC Educational Resources Information Center

    Ingham, Peter, Ed.

    This publication updates the 1982 occasional paper that was intended to foster staff awareness and assist colleges in Great Britain considering the use of computer-aided design (CAD) material in engineering courses. The paper begins by defining CAD and its place in the Integrated Business System with a brief discussion of the effect of CAD on the…

  6. Simulation as an Aid to Experimental Design.

    ERIC Educational Resources Information Center

    Frazer, Jack W.; And Others

    1983-01-01

    Discusses simulation program to aid in the design of enzyme kinetic experimentation (includes sample runs). Concentration versus time profiles of any subset or all nine states of reactions can be displayed with/without simulated instrumental noise, allowing the user to estimate the practicality of any proposed experiment given known instrument…

  7. Computer Code Aids Design Of Wings

    NASA Technical Reports Server (NTRS)

    Carlson, Harry W.; Darden, Christine M.

    1993-01-01

    AERO2S computer code developed to aid design engineers in selection and evaluation of aerodynamically efficient wing/canard and wing/horizontal-tail configurations that includes simple hinged-flap systems. Code rapidly estimates longitudinal aerodynamic characteristics of conceptual airplane lifting-surface arrangements. Developed in FORTRAN V on CDC 6000 computer system, and ported to MS-DOS environment.

  8. Geometric programming prediction of design trends for OMV protective structures

    NASA Technical Reports Server (NTRS)

    Mog, R. A.; Horn, J. R.

    1990-01-01

    The global optimization trends of protective honeycomb structural designs for spacecraft subject to hypervelocity meteroid and space debris are presented. This nonlinear problem is first formulated for weight minimization of the orbital maneuvering vehicle (OMV) using a generic monomial predictor. Five problem formulations are considered, each dependent on the selection of independent design variables. Each case is optimized by considering the dual geometric programming problem. The dual variables are solved for in terms of the generic estimated exponents of the monomial predictor. The primal variables are then solved for by conversion. Finally, parametric design trends are developed for ranges of the estimated regression parameters. Results specify nonmonotonic relationships for the optimal first and second sheet mass per unit areas in terms of the estimated exponents.

  9. Computer-aided detection of polyps in CT colonography based on geometric features

    NASA Astrophysics Data System (ADS)

    Yoshida, Hiroyuki; Masutani, Yoshitaka; MacEneaney, Peter; Dachman, Abraham H.

    2001-05-01

    CT colonography is a promising technique with a long-term goal to provide mass screening for colorectal carcinoma. Colorectal screening by CT colonography requires that the examination be cost-effective. The correct interpretation time is excessive for a screening test. Therefore, a computerized detection method capable of indicating regions of suspicion is attractive as a diagnostic aid for radiologists. We have developed a new CAD scheme for automated detection of polyps based on CT colonographic data sets. Our method characterizes polyps by geometric features of volumetric data including the volumetric shape index and curvedness. Polyps were detected by fuzzy clustering in a feature space generated by the feature values and spatial coordinates, followed by a rule-based test in the feature space. In an analysis of 41 patients, 9 of whom had at least one biopsy-proved polyp, our CAD scheme detected 100% of polyps with 2.5 false positives per patient. Our preliminary result indicates that the CAD scheme is potentially useful for highlighting areas of suspicion in the colon and, therefore, facilitates widespread screening by reducing the reading time substantially.

  10. A common geometric data-base approach for computer-aided manufacturing of wind-tunnel models and theoretical aerodynamic analysis

    NASA Technical Reports Server (NTRS)

    See, M. J.; Cozzolongo, J. V.

    1983-01-01

    A more automated process to produce wind tunnel models using existing facilities is discussed. A process was sought to more rapidly determine the aerodynamic characteristics of advanced aircraft configurations. Such aerodynamic characteristics are determined from theoretical analyses and wind tunnel tests of the configurations. Computers are used to perform the theoretical analyses, and a computer aided manufacturing system is used to fabricate the wind tunnel models. In the past a separate set of input data describing the aircraft geometry had to be generated for each process. This process establishes a common data base by enabling the computer aided manufacturing system to use, via a software interface, the geometric input data generated for the theoretical analysis. Thus, only one set of geometric data needs to be generated. Tests reveal that the process can reduce by several weeks the time needed to produce a wind tunnel model component. In addition, this process increases the similarity of the wind tunnel model to the mathematical model used by the theoretical aerodynamic analysis programs. Specifically, the wind tunnel model can be machined to within 0.008 in. of the original mathematical model. However, the software interface is highly complex and cumbersome to operate, making it unsuitable for routine use. The procurement of an independent computer aided design/computer aided manufacturing system with the capability to support both the theoretical analysis and the manufacturing tasks was recommended.

  11. Design of geometric phase measurement in EAST Tokamak

    NASA Astrophysics Data System (ADS)

    Lan, T.; Liu, H. Q.; Liu, J.; Jie, Y. X.; Wang, Y. L.; Gao, X.; Qin, H.

    2016-07-01

    The optimum scheme for geometric phase measurement in EAST Tokamak is proposed in this paper. The theoretical values of geometric phase for the probe beams of EAST Polarimeter-Interferometer (POINT) system are calculated by path integration in parameter space. Meanwhile, the influences of some controllable parameters on geometric phase are evaluated. The feasibility and challenge of distinguishing geometric effect in the POINT signal are also assessed in detail.

  12. Visions of visualization aids: Design philosophy and experimental results

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.

    1990-01-01

    Aids for the visualization of high-dimensional scientific or other data must be designed. Simply casting multidimensional data into a two- or three-dimensional spatial metaphor does not guarantee that the presentation will provide insight or parsimonious description of the phenomena underlying the data. Indeed, the communication of the essential meaning of some multidimensional data may be obscured by presentation in a spatially distributed format. Useful visualization is generally based on pre-existing theoretical beliefs concerning the underlying phenomena which guide selection and formatting of the plotted variables. Two examples from chaotic dynamics are used to illustrate how a visulaization may be an aid to insight. Two examples of displays to aid spatial maneuvering are described. The first, a perspective format for a commercial air traffic display, illustrates how geometric distortion may be introduced to insure that an operator can understand a depicted three-dimensional situation. The second, a display for planning small spacecraft maneuvers, illustrates how the complex counterintuitive character of orbital maneuvering may be made more tractable by removing higher-order nonlinear control dynamics, and allowing independent satisfaction of velocity and plume impingement constraints on orbital changes.

  13. Geometric design of the best performing auto-rotating wing

    NASA Astrophysics Data System (ADS)

    Liu, Yucen; Vincent, Lionel; Kanso, Eva

    2016-11-01

    Many plants use gravity and aerodynamics to disperse their seeds away from the parent plant. Various seed designs result in different dispersal modes from gliding to auto-rotating. Here, we are interested in understanding the effect of geometric design of auto-rotating seedpods on their aerodynamic performance. As an experimentally tractable surrogate to real seedpods, we investigate auto-rotating paper wings of various shape designs. We compare these designs to a control case consisting of the canonical rectangular wing. Inspired by aerodynamics, we begin by considering the benefit of an elliptical planform, and test the effect of aspect ratio on flight range and descent angle. We find the elliptical planform improves the tumbling rate and the aspect ratio has a positive effect on the flight performance of the wings. We then test two families of more complex shapes: one of tapered planform and one of a planform with sharp tips. We look for an optimal flight performance while constraining either the mass or the maximum length and width of the wing. We find that wings with sharper tips and larger length have higher auto-rotation rates and improved performance. The results imply that both the planform and length of the wing contribute to the wing's flight performance.

  14. CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) Highlights.

    DTIC Science & Technology

    1984-10-01

    AD-Aift 532 CAD/CAN (COMPUTER-AIDED DESIGN /COMPUTER-ADD D7 MANUFACTURING) HIGHLIGHTSMU ARMY INDUSTRIAL BASE ENGINEERING ACTIVITY ROCK ISLAND IL D L...1985 B DISCLAIMER This document presents information for the US Army Materiel Command (AMC) Computer-Alded Design /Computer-Aided Manufacturing...contains summaries of Army Computer-Aided Design (CAD) and . Computer-Aided Manufacturing (CAM) efforts that are either completed or ongoing. The Army CAD

  15. Visual display aid for orbital maneuvering - Design considerations

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Ellis, Stephen R.

    1993-01-01

    This paper describes the development of an interactive proximity operations planning system that allows on-site planning of fuel-efficient multiburn maneuvers in a potential multispacecraft environment. Although this display system most directly assists planning by providing visual feedback to aid visualization of the trajectories and constraints, its most significant features include: (1) the use of an 'inverse dynamics' algorithm that removes control nonlinearities facing the operator, and (2) a trajectory planning technique that separates, through a 'geometric spreadsheet', the normally coupled complex problems of planning orbital maneuvers and allows solution by an iterative sequence of simple independent actions. The visual feedback of trajectory shapes and operational constraints, provided by user-transparent and continuously active background computations, allows the operator to make fast, iterative design changes that rapidly converge to fuel-efficient solutions. The planning tool provides an example of operator-assisted optimization of nonlinear cost functions.

  16. Domain specific software design for decision aiding

    NASA Technical Reports Server (NTRS)

    Keller, Kirby; Stanley, Kevin

    1992-01-01

    McDonnell Aircraft Company (MCAIR) is involved in many large multi-discipline design and development efforts of tactical aircraft. These involve a number of design disciplines that must be coordinated to produce an integrated design and a successful product. Our interpretation of a domain specific software design (DSSD) is that of a representation or framework that is specialized to support a limited problem domain. A DSSD is an abstract software design that is shaped by the problem characteristics. This parallels the theme of object-oriented analysis and design of letting the problem model directly drive the design. The DSSD concept extends the notion of software reusability to include representations or frameworks. It supports the entire software life cycle and specifically leads to improved prototyping capability, supports system integration, and promotes reuse of software designs and supporting frameworks. The example presented in this paper is the task network architecture or design which was developed for the MCAIR Pilot's Associate program. The task network concept supported both module development and system integration within the domain of operator decision aiding. It is presented as an instance where a software design exhibited many of the attributes associated with DSSD concept.

  17. Integrated computer-aided design using minicomputers

    NASA Technical Reports Server (NTRS)

    Storaasli, O. O.

    1980-01-01

    Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), a highly interactive software, has been implemented on minicomputers at the NASA Langley Research Center. CAD/CAM software integrates many formerly fragmented programs and procedures into one cohesive system; it also includes finite element modeling and analysis, and has been interfaced via a computer network to a relational data base management system and offline plotting devices on mainframe computers. The CAD/CAM software system requires interactive graphics terminals operating at a minimum of 4800 bits/sec transfer rate to a computer. The system is portable and introduces 'interactive graphics', which permits the creation and modification of models interactively. The CAD/CAM system has already produced designs for a large area space platform, a national transonic facility fan blade, and a laminar flow control wind tunnel model. Besides the design/drafting element analysis capability, CAD/CAM provides options to produce an automatic program tooling code to drive a numerically controlled (N/C) machine. Reductions in time for design, engineering, drawing, finite element modeling, and N/C machining will benefit productivity through reduced costs, fewer errors, and a wider range of configuration.

  18. Aspects on Transfer of Aided - Design Files

    NASA Astrophysics Data System (ADS)

    Goanta, A. M.; Anghelache, D. G.

    2016-08-01

    At this stage of development of hardware and software, each company that makes design software packages has a certain type of file created and customized in time to distinguish that company from its competitors. Thus today are widely known the DWG files belonging AutoCAD, IPT / IAM belonging to Inventor, PAR / ASM of Solid Edge's, PRT from the NX and so on. Behind every type of file there is a mathematical model which is common to more types of files. A specific aspect of the computer -aided design is that all softwares are working with both individual parts and assemblies, but their approach is different in that some use the same type of file both for each part and for the whole (PRT ), while others use different types of files (IPT / IAM, PAR / ASM, etc.). Another aspect of the computer -aided design is to transfer files between different companies which use different software packages or even the same software package but in different versions. Each of these situations generates distinct issues. Thus, to solve the partial reading by a project different from the native one, transfer files of STEP and IGES type are used

  19. Computer-Aided Drug Design Methods.

    PubMed

    Yu, Wenbo; MacKerell, Alexander D

    2017-01-01

    Computational approaches are useful tools to interpret and guide experiments to expedite the antibiotic drug design process. Structure-based drug design (SBDD) and ligand-based drug design (LBDD) are the two general types of computer-aided drug design (CADD) approaches in existence. SBDD methods analyze macromolecular target 3-dimensional structural information, typically of proteins or RNA, to identify key sites and interactions that are important for their respective biological functions. Such information can then be utilized to design antibiotic drugs that can compete with essential interactions involving the target and thus interrupt the biological pathways essential for survival of the microorganism(s). LBDD methods focus on known antibiotic ligands for a target to establish a relationship between their physiochemical properties and antibiotic activities, referred to as a structure-activity relationship (SAR), information that can be used for optimization of known drugs or guide the design of new drugs with improved activity. In this chapter, standard CADD protocols for both SBDD and LBDD will be presented with a special focus on methodologies and targets routinely studied in our laboratory for antibiotic drug discoveries.

  20. Computer-aided design of the RF-cavity for a high-power S-band klystron

    NASA Astrophysics Data System (ADS)

    Kant, D.; Bandyopadhyay, A. K.; Pal, D.; Meena, R.; Nangru, S. C.; Joshi, L. M.

    2012-08-01

    This article describes the computer-aided design of the RF-cavity for a S-band klystron operating at 2856 MHz. State-of-the-art electromagnetic simulation tools SUPERFISH, CST Microwave studio, HFSS and MAGIC have been used for cavity design. After finalising the geometrical details of the cavity through simulation, it has been fabricated and characterised through cold testing. Detailed results of the computer-aided simulation and cold measurements are presented in this article.

  1. Geometric design of mechanical linkages for contact specifications

    NASA Astrophysics Data System (ADS)

    Robson, Nina Patarinsky

    2008-10-01

    This dissertation focuses on the kinematic synthesis of mechanical linkages in order to guide an end-effortor so that it maintains contact with specified objects in its workspace. Assuming the serial chain does not have full mobility in its workspace, the contact geometry is used to determine the dimensions of the serial chain. The approach to this problem, is to use the relative curvature of the contact of the end-effector with one or more objects to define velocity and acceleration specifications for its movement. This provides kinematic constraints that are used to synthesize the dimensions of the serial chain. The mathematical formulation of the geometric design problem, leads to systems of multivariable polynomial equations, which are solved exactly using sparse matrix resultants and polynomial homotopy methods. The results from this research yield planar RR and 4R linkages that match a specified contact geometry, spatial TS, parallel RRS and perpendicular RRS linkages that have a required acceleration specification. A new strategy for a robot recovery from actuator failures is demonstrated for the Mars Exploratory Rover Arm. In extending this work to spatial serial chains, a new method based on sparse matrix resultants was developed, which solves exact synthesis problems with acceleration constraints. Further the research builds on the theoretical concepts of contact relationships for spatial movement. The connection between kinematic synthesis and contact problems and its extension to spatial synthesis are developed in this dissertation for the first time and are new contributions. The results, which rely upon the use of surface curvature effects to reduce the number of fixtures needed to immobilize an object, find applications in robot grasping and part-fixturing. The recovery strategy, presented in this research is also a new concept. The recognition that it is possible to reconfigure a crippled robotic system to achieve mission critical tasks can guide

  2. Geometric Continuity: A Parametrization Independent Measure of Continuity for Computer Aided Geometric Design

    DTIC Science & Technology

    1985-08-01

    three and four naturally arise in co mputer graphics animation [25]. Thus, it is desirable to define and describe geom etric continuity for higher...motion of an object in an animation system, the GO R model is most appropriate since orientation and 2. AN INTUITIVE APPROACH 10 (a) (b) (c) Figure...Euclidean space have application in animation control, as recently shown by Gabriel & Kajiya [35] and Shoemake [56]. By requiring smoothness of the

  3. Complex transformation field created by geometrical gradient design of NiTi shape memory alloy

    NASA Astrophysics Data System (ADS)

    Bakhtiari, Reza; Shariat, Bashir S.; Motazedian, Fakhrodin; Wu, Zhigang; Zhang, Junsong; Yang, Hong; Liu, Yinong

    Owing to geometrical non-uniformity, geometrically graded shape memory alloy (SMA) structures by design have the ability to exhibit different and novel thermal and mechanical behaviors compared to geometrically uniform conventional SMAs. This paper reports a study of the pseudoelastic behavior of geometrically graded NiTi plates. This geometrical gradient creates partial stress gradient over stress-induced martensitic transformation, providing enlarged stress controlling interval for shape memory actuation. Finite element modeling framework has been established to predict the deformation behavior of such structures in tensile loading cycles, which was validated by experiments. The modeling results show that the transformation mostly propagates along the gradient direction as the loading level increases.

  4. Computer-aided software development process design

    NASA Technical Reports Server (NTRS)

    Lin, Chi Y.; Levary, Reuven R.

    1989-01-01

    The authors describe an intelligent tool designed to aid managers of software development projects in planning, managing, and controlling the development process of medium- to large-scale software projects. Its purpose is to reduce uncertainties in the budget, personnel, and schedule planning of software development projects. It is based on dynamic model for the software development and maintenance life-cycle process. This dynamic process is composed of a number of time-varying, interacting developmental phases, each characterized by its intended functions and requirements. System dynamics is used as a modeling methodology. The resulting Software LIfe-Cycle Simulator (SLICS) and the hybrid expert simulation system of which it is a subsystem are described.

  5. 6-DOF Pose Estimation of a Robotic Navigation Aid by Tracking Visual and Geometric Features

    PubMed Central

    Ye, Cang; Hong, Soonhac; Tamjidi, Amirhossein

    2015-01-01

    This paper presents a 6-DOF Pose Estimation (PE) method for a Robotic Navigation Aid (RNA) for the visually impaired. The RNA uses a single 3D camera for PE and object detection. The proposed method processes the camera’s intensity and range data to estimates the camera’s egomotion that is then used by an Extended Kalman Filter (EKF) as the motion model to track a set of visual features for PE. A RANSAC process is employed in the EKF to identify inliers from the visual feature correspondences between two image frames. Only the inliers are used to update the EKF’s state. The EKF integrates the egomotion into the camera’s pose in the world coordinate system. To retain the EKF’s consistency, the distance between the camera and the floor plane (extracted from the range data) is used by the EKF as the observation of the camera’s z coordinate. Experimental results demonstrate that the proposed method results in accurate pose estimates for positioning the RNA in indoor environments. Based on the PE method, a wayfinding system is developed for localization of the RNA in a home environment. The system uses the estimated pose and the floorplan to locate the RNA user in the home environment and announces the points of interest and navigational commands to the user through a speech interface. Note to Practitioners This work was motivated by the limitations of the existing navigation technology for the visually impaired. Most of the existing methods use a point/line measurement sensor for indoor object detection. Therefore, they lack capability in detecting 3D objects and positioning a blind traveler. Stereovision has been used in recent research. However, it cannot provide reliable depth data for object detection. Also, it tends to produce a lower localization accuracy because its depth measurement error quadratically increases with the true distance. This paper suggests a new approach for navigating a blind traveler. The method uses a single 3D time

  6. CAPRI: Using a Geometric Foundation for Computational Analysis and Design

    NASA Technical Reports Server (NTRS)

    Haimes, Robert

    2002-01-01

    CAPRI (Computational Analysis Programming Interface) is a software development tool intended to make computerized design, simulation and analysis faster and more efficient. The computational steps traditionally taken for most engineering analysis (Computational Fluid Dynamics (CFD), structural analysis, etc.) are: Surface Generation, usually by employing a Computer Aided Design (CAD) system; Grid Generation, preparing the volume for the simulation; Flow Solver, producing the results at the specified operational point; Post-processing Visualization, interactively attempting to understand the results. It should be noted that the structures problem is more tractable than CFD; there are fewer mesh topologies used and the grids are not as fine (this problem space does not have the length scaling issues of fluids). For CFD, these steps have worked well in the past for simple steady-state simulations at the expense of much user interaction. The data was transmitted between phases via files. In most cases, the output from a CAD system could go IGES files. The output from Grid Generators and Solvers do not really have standards though there are a couple of file formats that can be used for a subset of the gridding (i.e. PLOT3D) data formats and the upcoming CGNS). The user would have to patch up the data or translate from one format to another to move to the next step. Sometimes this could take days. Instead of the serial approach to analysis, CAPRI takes a geometry centric approach. CAPRI is a software building tool-kit that refers to two ideas: (1) A simplified, object-oriented, hierarchical view of a solid part integrating both geometry and topology definitions, and (2) programming access to this part or assembly and any attached data. The connection to the geometry is made through an Application Programming Interface (API) and not a file system.

  7. Computer-Aided Socket Design For Amputees

    NASA Astrophysics Data System (ADS)

    Novicov, Aleksey; Foort, James

    1983-07-01

    The fitting of sockets and artificial legs to amputees' stumps is a difficult and lengthy process that can take numerous trials. It has been proposed that most amputees can be fitted with a standard socket shape with minimal changes to the socket. To perform this task, a procedure is being developed at the Medical Engineering Resource Unit for computer aided socket design for amputees. An interactive PASCAL program, operating on a microcomputer, will prompt the operator (or prosthetist) by asking him to determine the condition of the stump. While the operator is inputing this information into the computer, together with a few critical anatomical measurements, a standard socket shape, viewed on the video monitor, will begin to change. Throughout the "shape fitting" procedure, the operator will have the ability to modify the socket shape on the screen with the use of a light pen. It will also be possible to view various cross-sections and different perspectives. The shape fitting procedure continues until a suitable socket shape is designed. Future efforts will focus on transferring the computer designed socket into a physical socket. The overall goal is to provide amputees with a better fit in less time and to objectify socket fitting so that new prosthetists may be easily taught.

  8. [Geometrical dummy used for ergonomic evaluation on early stage cockpit conceptual design].

    PubMed

    Wang, L J; Yuan, X G

    2001-12-01

    Objective. Basing on the need of cockpit ergonomic design, to set up a geometrical dummy. Method. Surface partition of the dummy, source of the curved face data, express of the curved face, degree of freedom of the human joint, coordinate system of the parts, position of the human segment centroid and weight of the human segment were cleared up first, then geometrical dummy was displayed with three-dimensional software. Result. The geometrical dummy could simulate some basic body movements and postures for ergonomic analysis. Conclusion. The geometrical dummy was suitable for present study and engineering design.

  9. Computer-aided design and computer science technology

    NASA Technical Reports Server (NTRS)

    Fulton, R. E.; Voigt, S. J.

    1976-01-01

    A description is presented of computer-aided design requirements and the resulting computer science advances needed to support aerospace design. The aerospace design environment is examined, taking into account problems of data handling and aspects of computer hardware and software. The interactive terminal is normally the primary interface between the computer system and the engineering designer. Attention is given to user aids, interactive design, interactive computations, the characteristics of design information, data management requirements, hardware advancements, and computer science developments.

  10. Engineering Technology Programs Courses Guide for Computer Aided Design and Computer Aided Manufacturing.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Div. of Vocational Education.

    This guide describes the requirements for courses in computer-aided design and computer-aided manufacturing (CAD/CAM) that are part of engineering technology programs conducted in vocational-technical schools in Georgia. The guide is organized in five sections. The first section provides a rationale for occupations in design and in production,…

  11. Density estimation using the trapping web design: A geometric analysis

    USGS Publications Warehouse

    Link, W.A.; Barker, R.J.

    1994-01-01

    Population densities for small mammal and arthropod populations can be estimated using capture frequencies for a web of traps. A conceptually simple geometric analysis that avoid the need to estimate a point on a density function is proposed. This analysis incorporates data from the outermost rings of traps, explaining large capture frequencies in these rings rather than truncating them from the analysis.

  12. Fifth SIAM conference on geometric design 97: Final program and abstracts. Final technical report

    SciTech Connect

    1997-12-31

    The meeting was divided into the following sessions: (1) CAD/CAM; (2) Curve/Surface Design; (3) Geometric Algorithms; (4) Multiresolution Methods; (5) Robotics; (6) Solid Modeling; and (7) Visualization. This report contains the abstracts of papers presented at the meeting. Proceding the conference there was a short course entitled ``Wavelets for Geometric Modeling and Computer Graphics``.

  13. The Effect of Designed Geometry Teaching Lesson to the Candidate Teachers' Van Hiele Geometric Thinking Level

    ERIC Educational Resources Information Center

    Yilmaz, Gül Kaleli; Koparan, Timur

    2016-01-01

    The aim of this study is to find out how designed Geometry Teaching Lesson affects candidate teachers' Van Hiele Geometric Thinking Levels. For that purpose, 14 weeks long study was performed with 44 candidate teachers who were university students in Turkey. Van Hiele Geometric Thinking Test was applied to candidate teachers before and after…

  14. Computer-aided design for metabolic engineering.

    PubMed

    Fernández-Castané, Alfred; Fehér, Tamás; Carbonell, Pablo; Pauthenier, Cyrille; Faulon, Jean-Loup

    2014-12-20

    The development and application of biotechnology-based strategies has had a great socio-economical impact and is likely to play a crucial role in the foundation of more sustainable and efficient industrial processes. Within biotechnology, metabolic engineering aims at the directed improvement of cellular properties, often with the goal of synthesizing a target chemical compound. The use of computer-aided design (CAD) tools, along with the continuously emerging advanced genetic engineering techniques have allowed metabolic engineering to broaden and streamline the process of heterologous compound-production. In this work, we review the CAD tools available for metabolic engineering with an emphasis, on retrosynthesis methodologies. Recent advances in genetic engineering strategies for pathway implementation and optimization are also reviewed as well as a range of bionalytical tools to validate in silico predictions. A case study applying retrosynthesis is presented as an experimental verification of the output from Retropath, the first complete automated computational pipeline applicable to metabolic engineering. Applying this CAD pipeline, together with genetic reassembly and optimization of culture conditions led to improved production of the plant flavonoid pinocembrin. Coupling CAD tools with advanced genetic engineering strategies and bioprocess optimization is crucial for enhanced product yields and will be of great value for the development of non-natural products through sustainable biotechnological processes.

  15. Software For Computer-Aided Design Of Control Systems

    NASA Technical Reports Server (NTRS)

    Wette, Matthew

    1994-01-01

    Computer Aided Engineering System (CAESY) software developed to provide means to evaluate methods for dealing with users' needs in computer-aided design of control systems. Interpreter program for performing engineering calculations. Incorporates features of both Ada and MATLAB. Designed to be flexible and powerful. Includes internally defined functions, procedures and provides for definition of functions and procedures by user. Written in C language.

  16. Issues of a Computer-Aided Design of Hydraulic Jacks

    NASA Astrophysics Data System (ADS)

    Averchenkov, V. I.; Averchenkov, A. V.; Kolyakinand, V. V.; Orekhov, O. D.

    2016-04-01

    The article deals with the issues of a computer-aided design of hydraulic equipment, namely hydraulic jacks. Design principles of the hydraulic jack CAD system are described. In addition, the possibilities for the system improvement and expansion are considered.

  17. Computer-Aided Design and Computer-Aided Manufacturing Hydroxyapatite/Epoxide Acrylate Maleic Compound Construction for Craniomaxillofacial Bone Defects.

    PubMed

    Zhang, Lei; Shen, Shunyao; Yu, Hongbo; Shen, Steve Guofang; Wang, Xudong

    2015-07-01

    The aim of this study was to investigate the use of computer-aided design and computer-aided manufacturing hydroxyapatite (HA)/epoxide acrylate maleic (EAM) compound construction artificial implants for craniomaxillofacial bone defects. Computed tomography, computer-aided design/computer-aided manufacturing and three-dimensional reconstruction, as well as rapid prototyping were performed in 12 patients between 2008 and 2013. The customized HA/EAM compound artificial implants were manufactured through selective laser sintering using a rapid prototyping machine into the exact geometric shapes of the defect. The HA/EAM compound artificial implants were then implanted during surgical reconstruction. Color-coded superimpositions demonstrated the discrepancy between the virtual plan and achieved results using Geomagic Studio. As a result, the HA/EAM compound artificial bone implants were perfectly matched with the facial areas that needed reconstruction. The postoperative aesthetic and functional results were satisfactory. The color-coded superimpositions demonstrated good consistency between the virtual plan and achieved results. The three-dimensional maximum deviation is 2.12 ± 0.65  mm and the three-dimensional mean deviation is 0.27 ± 0.07  mm. No facial nerve weakness or pain was observed at the follow-up examinations. Only 1 implant had to be removed 2 months after the surgery owing to severe local infection. No other complication was noted during the follow-up period. In conclusion, computer-aided, individually fabricated HA/EAM compound construction artificial implant was a good craniomaxillofacial surgical technique that yielded improved aesthetic results and functional recovery after reconstruction.

  18. Computer-aided design development transition for IPAD environment

    NASA Technical Reports Server (NTRS)

    Owens, H. G.; Mock, W. D.; Mitchell, J. C.

    1980-01-01

    The relationship of federally sponsored computer-aided design/computer-aided manufacturing (CAD/CAM) programs to the aircraft life cycle design process, an overview of NAAD'S CAD development program, an evaluation of the CAD design process, a discussion of the current computing environment within which NAAD is developing its CAD system, some of the advantages/disadvantages of the NAAD-IPAD approach, and CAD developments during transition into the IPAD system are discussed.

  19. Artwork Interactive Design System (AIDS) program description

    NASA Technical Reports Server (NTRS)

    Johnson, B. T.; Taylor, J. F.

    1976-01-01

    An artwork interactive design system is described which provides the microelectronic circuit designer/engineer a tool to perform circuit design, automatic layout modification, standard cell design, and artwork verification at a graphics computer terminal using a graphics tablet at the designer/computer interface.

  20. Computer-aided dispatching system design specification

    SciTech Connect

    Briggs, M.G.

    1997-12-16

    This document defines the performance requirements for a graphic display dispatching system to support Hanford Patrol Operations Center. This document reflects the as-built requirements for the system that was delivered by GTE Northwest, Inc. This system provided a commercial off-the-shelf computer-aided dispatching system and alarm monitoring system currently in operations at the Hanford Patrol Operations Center, Building 2721E. This system also provides alarm back-up capability for the Plutonium Finishing Plant (PFP).

  1. 6-DOF Pose Estimation of a Robotic Navigation Aid by Tracking Visual and Geometric Features.

    PubMed

    Ye, Cang; Hong, Soonhac; Tamjidi, Amirhossein

    2015-10-01

    This paper presents a 6-DOF Pose Estimation (PE) method for a Robotic Navigation Aid (RNA) for the visually impaired. The RNA uses a single 3D camera for PE and object detection. The proposed method processes the camera's intensity and range data to estimates the camera's egomotion that is then used by an Extended Kalman Filter (EKF) as the motion model to track a set of visual features for PE. A RANSAC process is employed in the EKF to identify inliers from the visual feature correspondences between two image frames. Only the inliers are used to update the EKF's state. The EKF integrates the egomotion into the camera's pose in the world coordinate system. To retain the EKF's consistency, the distance between the camera and the floor plane (extracted from the range data) is used by the EKF as the observation of the camera's z coordinate. Experimental results demonstrate that the proposed method results in accurate pose estimates for positioning the RNA in indoor environments. Based on the PE method, a wayfinding system is developed for localization of the RNA in a home environment. The system uses the estimated pose and the floorplan to locate the RNA user in the home environment and announces the points of interest and navigational commands to the user through a speech interface.

  2. Computer aids for integrated circuit design at Sandia National Laboratories

    NASA Astrophysics Data System (ADS)

    Brown, G. W.

    A general framework for a hierarchical computer-aided design (CAD) system for VLSI design is described. The system supports both functional and physical design in the area of initial design specification, system synthesis, simulation, mask layout, verification, and documentation. The system is being implemented in phases within a user environment on a DECsystem 20-VAX 11/780 computer network. It supports evolutionary changes as new technologies, design strategies, and application programs are developed.

  3. Novel solutions to low-frequency problems with geometrically designed beam-waveguide systems

    NASA Technical Reports Server (NTRS)

    Imbriale, W. A.; Esquivel, M. S.; Manshadi, F.

    1995-01-01

    The poor low-frequency performance of geometrically designed beam-waveguide (BWG) antennas is shown to be caused by the diffraction phase centers being far from the geometrical optics mirror focus, resulting in substantial spillover and defocusing loss. Two novel solutions are proposed: (1) reposition the mirrors to focus low frequencies and redesign the high frequencies to utilize the new mirror positions, and (2) redesign the input feed system to provide an optimum solution for the low frequency. A novel use of the conjugate phase-matching technique is utilized to design the optimum low-frequency feed system, and the new feed system has been implemented in the JPL research and development BWG as part of a dual S-/X-band (2.3 GHz/8.45 GHz) feed system. The new S-band feed system is shown to perform significantly better than the original geometrically designed system.

  4. Removal of Supernumerary Teeth Utilizing a Computer-Aided Design/Computer-Aided Manufacturing Surgical Guide.

    PubMed

    Jo, Chanwoo; Bae, Doohwan; Choi, Byungho; Kim, Jihun

    2016-11-12

    Supernumerary teeth need to be removed because they can cause various complications. Caution is needed because their removal can cause damage to permanent teeth or tooth germs in the local vicinity. Surgical guides have recently been used in maxillofacial surgery. Because surgical guides are designed through preoperative analysis by computer-aided design software and fabricated using a 3-dimensional printer applying computer-aided manufacturing technology, they increase the accuracy and predictability of surgery. This report describes 2 cases of removal of a mesiodens-1 from a child and 1 from an adolescent-using a surgical guide; these would have been difficult to remove with conventional surgical methods.

  5. Geometric constraints for shape and topology optimization in architectural design

    NASA Astrophysics Data System (ADS)

    Dapogny, Charles; Faure, Alexis; Michailidis, Georgios; Allaire, Grégoire; Couvelas, Agnes; Estevez, Rafael

    2017-02-01

    This work proposes a shape and topology optimization framework oriented towards conceptual architectural design. A particular emphasis is put on the possibility for the user to interfere on the optimization process by supplying information about his personal taste. More precisely, we formulate three novel constraints on the geometry of shapes; while the first two are mainly related to aesthetics, the third one may also be used to handle several fabrication issues that are of special interest in the device of civil structures. The common mathematical ingredient to all three models is the signed distance function to a domain, and its sensitivity analysis with respect to perturbations of this domain; in the present work, this material is extended to the case where the ambient space is equipped with an anisotropic metric tensor. Numerical examples are discussed in two and three space dimensions.

  6. Human factors of intelligent computer aided display design

    NASA Technical Reports Server (NTRS)

    Hunt, R. M.

    1985-01-01

    Design concepts for a decision support system being studied at NASA Langley as an aid to visual display unit (VDU) designers are described. Ideally, human factors should be taken into account by VDU designers. In reality, although the human factors database on VDUs is small, such systems must be constantly developed. Human factors are therefore a secondary consideration. An expert system will thus serve mainly in an advisory capacity. Functions can include facilitating the design process by shortening the time to generate and alter drawings, enhancing the capability of breaking design requirements down into simpler functions, and providing visual displays equivalent to the final product. The VDU system could also discriminate, and display the difference, between designer decisions and machine inferences. The system could also aid in analyzing the effects of designer choices on future options and in ennunciating when there are data available on a design selections.

  7. Computer Program Aids Design Of Impeller Blades

    NASA Technical Reports Server (NTRS)

    Chen, Wei-Chung; Galazin, John V.

    1992-01-01

    Impeller blades for centrifugal turbopumps designed quickly with help of computer program. Generates blade contours and continually subjects them to evaluation. Checks physical parameters to ensure they are compatible with required performance and recycles design if criteria not met. Program written for centrifugal turbomachinery, also adapted to such axial pump components as inducer blades and stator vanes.

  8. Implementation and display of Computer Aided Design (CAD) models in Monte Carlo radiation transport and shielding applications

    SciTech Connect

    Burns, T.J.

    1994-03-01

    An Xwindow application capable of importing geometric information directly from two Computer Aided Design (CAD) based formats for use in radiation transport and shielding analyses is being developed at ORNL. The application permits the user to graphically view the geometric models imported from the two formats for verification and debugging. Previous models, specifically formatted for the radiation transport and shielding codes can also be imported. Required extensions to the existing combinatorial geometry analysis routines are discussed. Examples illustrating the various options and features which will be implemented in the application are presented. The use of the application as a visualization tool for the output of the radiation transport codes is also discussed.

  9. De novo computer-aided design of novel antiviral agents.

    PubMed

    Massarotti, Alberto; Coluccia, Antonio; Sorba, Giovanni; Silvestri, Romano; Brancale, Andrea

    2012-01-01

    Computer-aided drug design techniques have become an integral part of the drug discovery process. In particular, de novo methodologies can be useful to identify putative ligands for a specific target relying only on the structural information of the target itself. Here we discuss the basic de novo approaches available and their application in antiviral drug design.:

  10. Space systems computer-aided design technology

    NASA Technical Reports Server (NTRS)

    Garrett, L. B.

    1984-01-01

    The interactive Design and Evaluation of Advanced Spacecraft (IDEAS) system is described, together with planned capability increases in the IDEAS system. The system's disciplines consist of interactive graphics and interactive computing. A single user at an interactive terminal can create, design, analyze, and conduct parametric studies of earth-orbiting satellites, which represents a timely and cost-effective method during the conceptual design phase where various missions and spacecraft options require evaluation. Spacecraft concepts evaluated include microwave radiometer satellites, communication satellite systems, solar-powered lasers, power platforms, and orbiting space stations.

  11. Microcomputer-Aided Control Systems Design.

    ERIC Educational Resources Information Center

    Roat, S. D.; Melsheimer, S. S.

    1987-01-01

    Describes a single input/single output feedback control system design program for IBM PC and compatible microcomputers. Uses a heat exchanger temperature control loop to illustrate the various applications of the program. (ML)

  12. Program Aids Analysis And Optimization Of Design

    NASA Technical Reports Server (NTRS)

    Rogers, James L., Jr.; Lamarsh, William J., II

    1994-01-01

    NETS/ PROSSS (NETS Coupled With Programming System for Structural Synthesis) computer program developed to provide system for combining NETS (MSC-21588), neural-network application program and CONMIN (Constrained Function Minimization, ARC-10836), optimization program. Enables user to reach nearly optimal design. Design then used as starting point in normal optimization process, possibly enabling user to converge to optimal solution in significantly fewer iterations. NEWT/PROSSS written in C language and FORTRAN 77.

  13. On computer-aided design of aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Sobieszczanski, J. E.; Voigt, S. J.; Fulton, R. E.

    1974-01-01

    Digital computers are being used in many engineering activities to support design work. This paper provides an overview of some of this work as it relates to the design of aerospace vehicles. Discussions are given of some of the complexities of the design process which lead to large design costs and time. A number of important but disjointed computer capabilities have evolved over the years in analysis, optimization, and graphics, and such capabilities aid in addressing the problem of design complexity. Examples of existing computer-aided design (CAD) systems are given and trends for future CAD systems are indicated, as well as their relationship to pertinent data management technology. It is suggested that major gains in design capability will occur through continued development of CAD methodology and that these gains may be accelerated through a large focused effort.

  14. A Novel Paradigm for Computer-Aided Design: TRIZ-Based Hybridization of Topologically Optimized Density Distributions

    NASA Astrophysics Data System (ADS)

    Cardillo, A.; Cascini, G.; Frillici, F. S.; Rotini, F.

    In a recent project the authors have proposed the adoption of Optimization Systems [1] as a bridging element between Computer-Aided Innovation (CAI) and PLM to identify geometrical contradictions [2], a particular case of the TRIZ physical contradiction [3]. A further development of the research [4] has revealed that the solutions obtained from several topological optimizations can be considered as elementary customized modeling features for a specific design task. The topology overcoming the arising geometrical contradiction can be obtained through a manipulation of the density distributions constituting the conflicting pair. Already two strategies of density combination have been identified as capable to solve geometrical contradictions and several others are under extended testing. The paper illustrates the most recent results of the ongoing research mainly related to the extension of the algorithms from 2D to 3D design spaces. The whole approach is clarified by means of two detailed examples, where the proposed technique is compared with classical multi-goal optimization.

  15. Design of Training Aids and Devices.

    ERIC Educational Resources Information Center

    Lumsdaine, Arthur A.

    Training devices should be designed to provide efficient learning conditions, especially guided practice and prompt feedback. These devices can be more useful than their operational equipment counterparts because they facilitate the focusing of learner attention on particular components of a total operation, they make operations visible for study,…

  16. A mathematical formulation for interface-based modular product design with geometric and weight constraints

    NASA Astrophysics Data System (ADS)

    Jung-Woon Yoo, John

    2016-06-01

    Since customer preferences change rapidly, there is a need for design processes with shorter product development cycles. Modularization plays a key role in achieving mass customization, which is crucial in today's competitive global market environments. Standardized interfaces among modularized parts have facilitated computational product design. To incorporate product size and weight constraints during computational design procedures, a mixed integer programming formulation is presented in this article. Product size and weight are two of the most important design parameters, as evidenced by recent smart-phone products. This article focuses on the integration of geometric, weight and interface constraints into the proposed mathematical formulation. The formulation generates the optimal selection of components for a target product, which satisfies geometric, weight and interface constraints. The formulation is verified through a case study and experiments are performed to demonstrate the performance of the formulation.

  17. An Elective Course on Computer-Aided Process Design.

    ERIC Educational Resources Information Center

    Sommerfeld, Jude T.

    1979-01-01

    Describes an undergraduate chemical engineering course which has been offered at the Georgia Institute of Technology. The objectives, structure, instructional materials and content of this course, which emphasizes the structure and usage of computer-aided design systems, are also included. (HM)

  18. Competing Ideologies in Software Design for Computer-Aided Composition.

    ERIC Educational Resources Information Center

    LeBlanc, Paul

    1990-01-01

    Illustrates the ideological foundations of computer-assisted composition (CAC) software by comparing two computer-writing aids: "Grammatik II" and "Interchange." Notes that many of the best CAC programs have come out of the composition classroom. Argues that English departments must support and reward those who work in CAC design. (RS)

  19. The Journal of Computer- Aided Molecular Design: a bibliometric note

    NASA Astrophysics Data System (ADS)

    Willett, Peter

    2012-01-01

    Summarizes the articles in, and the citations to, volumes 2-24 of the Journal of Computer- Aided Molecular Design. The citations to the journal come from almost 2000 different sources that span a very wide range of academic subjects, with the most heavily cited articles being descriptions of software systems and of computational methods.

  20. Information technology aided exploration of system design spaces

    NASA Technical Reports Server (NTRS)

    Feather, Martin S.; Kiper, James D.; Kalafat, Selcuk

    2004-01-01

    We report on a practical application of information technology techniques to aid system engineers effectively explore large design spaces. We make use of heuristic search, visualization and data mining, the combination of which we have implemented wtihin a risk management tool in use at JPL and NASA.

  1. Structure aided design of chimeric antibiotics.

    PubMed

    Karoli, Tomislav; Mamidyala, Sreeman K; Zuegg, Johannes; Fry, Scott R; Tee, Ernest H L; Bradford, Tanya A; Madala, Praveen K; Huang, Johnny X; Ramu, Soumya; Butler, Mark S; Cooper, Matthew A

    2012-04-01

    The rise of antibiotic resistance is of great clinical concern. One approach to reducing the development of resistance is to co-administer two or more antibiotics with different modes of action. However, it can be difficult to control the distribution and pharmacokinetics of two drugs to ensure both concentrations remain within the range of therapeutic efficacy whilst avoiding adverse effects. Hybrid drugs, where two drugs are linked together with a flexible linker, have been explored, but the resultant large, flexible molecules can have poor bioavailability. We have developed a chimeric approach using click chemistry where the pharmacophores of two drugs are overlapped into a single smaller, more drug-like molecule. Design and selection of compounds were assisted by in silico structural docking. We prepared a series of compounds that include candidates showing activity against the targets of both trimethoprim; dihydrofolate reductase, and ciprofloxacin; DNA gyrase and topoisomerase IV. The resultant triazole containing molecules show modest, but broad spectrum activities against drug sensitive and resistant Gram-negative and Gram-positive bacteria, with no observable cytotoxicity.

  2. NEXUS/NASCAD- NASA ENGINEERING EXTENDIBLE UNIFIED SOFTWARE SYSTEM WITH NASA COMPUTER AIDED DESIGN

    NASA Technical Reports Server (NTRS)

    Purves, L. R.

    1994-01-01

    NEXUS, the NASA Engineering Extendible Unified Software system, is a research set of computer programs designed to support the full sequence of activities encountered in NASA engineering projects. This sequence spans preliminary design, design analysis, detailed design, manufacturing, assembly, and testing. NEXUS primarily addresses the process of prototype engineering, the task of getting a single or small number of copies of a product to work. Prototype engineering is a critical element of large scale industrial production. The time and cost needed to introduce a new product are heavily dependent on two factors: 1) how efficiently required product prototypes can be developed, and 2) how efficiently required production facilities, also a prototype engineering development, can be completed. NEXUS extendibility and unification are achieved by organizing the system as an arbitrarily large set of computer programs accessed in a common manner through a standard user interface. The NEXUS interface is a multipurpose interactive graphics interface called NASCAD (NASA Computer Aided Design). NASCAD can be used to build and display two and three-dimensional geometries, to annotate models with dimension lines, text strings, etc., and to store and retrieve design related information such as names, masses, and power requirements of components used in the design. From the user's standpoint, NASCAD allows the construction, viewing, modification, and other processing of data structures that represent the design. Four basic types of data structures are supported by NASCAD: 1) three-dimensional geometric models of the object being designed, 2) alphanumeric arrays to hold data ranging from numeric scalars to multidimensional arrays of numbers or characters, 3) tabular data sets that provide a relational data base capability, and 4) procedure definitions to combine groups of system commands or other user procedures to create more powerful functions. NASCAD has extensive abilities to

  3. BladeCAD: An Interactive Geometric Design Tool for Turbomachinery Blades

    NASA Technical Reports Server (NTRS)

    Miller, Perry L., IV; Oliver, James H.; Miller, David P.; Tweedt, Daniel L.

    1996-01-01

    A new metthodology for interactive design of turbomachinery blades is presented. Software implementation of the meth- ods provides a user interface that is intuitive to aero-designers while operating with standardized geometric forms. The primary contribution is that blade sections may be defined with respect to general surfaces of revolution which may be defined to represent the path of fluid flow through the turbomachine. The completed blade design is represented as a non-uniform rational B-spline (NURBS) surface and is written to a standard IGES file which is portable to most design, analysis, and manufacturing applications.

  4. Robot-aided rehabilitation task design for inner shoulder muscles.

    PubMed

    Pei, Y; Kim, Y; Obinata, G; Genda, E; Stefanov, D

    2012-01-01

    In this paper, we propose a simultaneous design method of motion and external force trajectories for shoulder inner muscles in the robot-aided rehabilitation system, based on a biomechanical analysis of patient's body. The rehabilitation efficiency evaluation function was maximized by Genetic Algorithm (GA), where the structure of spline curves parameters are pre-defined, and the structural parameters are explored to design smooth rehabilitation motion and external force trajectories.

  5. SNL Mechanical Computer Aided Design (MCAD) guide 2007.

    SciTech Connect

    Moore, Brandon; Pollice, Stephanie L.; Martinez, Jack R.

    2007-12-01

    This document is considered a mechanical design best-practice guide to new and experienced designers alike. The contents consist of topics related to using Computer Aided Design (CAD) software, performing basic analyses, and using configuration management. The details specific to a particular topic have been leveraged against existing Product Realization Standard (PRS) and Technical Business Practice (TBP) requirements while maintaining alignment with sound engineering and design practices. This document is to be considered dynamic in that subsequent updates will be reflected in the main title, and each update will be published on an annual basis.

  6. Fresnel Lens Solar Concentrator Design Based on Geometric Optics and Blackbody Radiation Equations

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Jayroe, Robert, Jr.

    1999-01-01

    Fresnel lenses have been used for years as solar concentrators in a variety of applications. Several variables effect the final design of these lenses including: lens diameter, image spot distance from the lens, and bandwidth focused in the image spot. Defining the image spot as the geometrical optics circle of least confusion and applying blackbody radiation equations the spot energy distribution can be determined. These equations are used to design a fresnel lens to produce maximum flux for a given spot size, lens diameter, and image distance. This approach results in significant increases in solar efficiency over traditional single wavelength designs.

  7. Design of macro-filter-lens with simultaneous chromatic and geometric aberration correction.

    PubMed

    Prasad, Dilip K; Brown, Michael S

    2014-01-01

    A macro-filter-lens design that can correct for chromatic and geometric aberrations simultaneously while providing for a long focal length is presented. The filter is easy to fabricate since it involves two spherical surfaces and a planar surface. Chromatic aberration correction is achieved by making all the rays travel the same optical distance inside the filter element (negative meniscus). Geometric aberration is corrected for by the lens element (plano-convex), which makes the output rays parallel to the optic axis. This macro-filter-lens design does not need additional macro lenses and it provides an inexpensive and optically good (aberration compensated) solution for macro imaging of objects not placed close to the camera.

  8. Three-dimensional geometric analysis of the talus for designing talar prosthetics.

    PubMed

    Islam, Kamrul; Dobbe, Ashlee; Duke, Kajsa; El-Rich, Marwan; Dhillon, Sukhvinder; Adeeb, Samer; Jomha, Nadr M

    2014-04-01

    Proper understanding of the complex geometric shape of the talus bone is important for the design of generic talar body prosthetics and restoration of the proper ankle joint function after surgery. To date, all talus implants have been patient-specific with the limitation that complex computer modeling is required to produce a mirrored image from the unaffected opposite side followed by machining a patient-specific prosthesis. To develop an "off-the-shelf" non-custom talar prosthesis, it is important to perform a thorough investigation of the geometric shape of the talus bone. This article addresses the applicability of a scaling approach for investigating the geometric shape and similarity of talus bones. This study used computed tomography scan images of the ankle joints of 27 different subjects to perform the analysis. Results of the deviation analyses showed that the deviation in the articulating surfaces of the talus bones was not excessive in terms of talus size. These results suggest that a proposed range of five implant sizes is possible. Finally, it is concluded that the talus bones of the ankle joints are geometrically similar, and a proposed range of five implant sizes will fit a wide range of subjects. This information may help to develop generic talus implants that might be applicable to patients with a severe talus injury.

  9. The Computer Aided Aircraft-design Package (CAAP)

    NASA Technical Reports Server (NTRS)

    Yalif, Guy U.

    1994-01-01

    The preliminary design of an aircraft is a complex, labor-intensive, and creative process. Since the 1970's, many computer programs have been written to help automate preliminary airplane design. Time and resource analyses have identified, 'a substantial decrease in project duration with the introduction of an automated design capability'. Proof-of-concept studies have been completed which establish 'a foundation for a computer-based airframe design capability', Unfortunately, today's design codes exist in many different languages on many, often expensive, hardware platforms. Through the use of a module-based system architecture, the Computer aided Aircraft-design Package (CAAP) will eventually bring together many of the most useful features of existing programs. Through the use of an expert system, it will add an additional feature that could be described as indispensable to entry level engineers and students: the incorporation of 'expert' knowledge into the automated design process.

  10. Computer Aided Design Of Electrical Machines For Variable Speed Applications.

    NASA Astrophysics Data System (ADS)

    Krishnan, R.; Aravind, S.; Materu, P.

    1987-10-01

    In recent years, the product life cycle has decreased and demands for new products have emerged due to competition, modern industrial needs and rapidly changing technology. This has necessitated changes in design, development and manufacturing processes so as to improve quality and efficiency as well as reducing costs. Computer Aided Design (CAD) helps to meet this challenge in the design evaluation and final product design stages. This paper presents the development of an interactive software for the optimal design of a motor intended for variable speed applications. The use of finite element analysis methods is proposed as an indispensable part of the CAD system for electrical machine design. An illustration of the method is given for the design of a switched reluctance motor.

  11. Bio-inspired design of geometrically interlocked 3D printed joints

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Oliva, Noel; Kumar's Lab Team

    The morphology of the adhesive-adherend interface significantly affects the mechanical behavior of adhesive joints. As seen in some biocomposites like human skull, or the nacre of some bivalve molluscs' shells, a geometrically interlocking architecture of interfaces creates toughening and strengthening mechanisms enhancing the mechanical properties of the joint. In an attempt to characterize this mechanical interlocking mechanism, this study is focused on computational and experimental investigation of a single-lap joint with a very simple geometrically interlocked interface design in which both adherends have a square waveform configuration of the joining surfaces. This square waveform configuration contains a positive and a negative rectangular teeth per cycle in such a way that the joint is symmetric about the mid-bondlength. Both physical tests performed on 3D printed prototypes of joints and computational results indicate that the joints with square waveform design have higher strength and damage tolerance than those of joints with flat interface. In order to identify an optimal design configuration of this interface, a systematic parametric study is conducted by varying the geometric and material properties of the non-flat interface. This work was supported by Lockheed Martin (Award No: 12NZZ1).

  12. Navigation and Alignment Aids Concept of Operations and Supplemental Design Information. Revision A

    NASA Technical Reports Server (NTRS)

    Kelly, Sean M.; Cryan, Scott P.

    2016-01-01

    The IDSS Navigation and Alignment Aids Concept of Operations and Supplemental Design Information document provides supplemental information to the IDSS IDD. The guide provides insight into the navigation and alignment aids design, and how those aids can be utilized by incoming vehicles for proximity operations and docking. The navigation aids are paramount to successful docking.

  13. Computer-aided design of polymers and composites

    NASA Technical Reports Server (NTRS)

    Kaelble, D. H.

    1985-01-01

    This book on computer-aided design of polymers and composites introduces and discusses the subject from the viewpoint of atomic and molecular models. Thus, the origins of stiffness, strength, extensibility, and fracture toughness in composite materials can be analyzed directly in terms of chemical composition and molecular structure. Aspects of polymer composite reliability are considered along with characterization techniques for composite reliability, relations between atomic and molecular properties, computer aided design and manufacture, polymer CAD/CAM models, and composite CAD/CAM models. Attention is given to multiphase structural adhesives, fibrous composite reliability, metal joint reliability, polymer physical states and transitions, chemical quality assurance, processability testing, cure monitoring and management, nondestructive evaluation (NDE), surface NDE, elementary properties, ionic-covalent bonding, molecular analysis, acid-base interactions, the manufacturing science, and peel mechanics.

  14. Computer-aided conceptual design of Air Cushion Vehicles

    NASA Astrophysics Data System (ADS)

    Band, E. G. U.; Lavis, D. R.

    This paper describes the development and use of a computer-aided design tool which has been used to explore preferred options for amphibious Air-Cushion Vehicle (ACV) and Surface-Effect Ship (SES) designs in support of U.S. Navy and U.S. Army programs. The tool, referred to as the ACV Design Synthesis Model (ADSM), is an interactive computer program which provides a description of feasible ACV or SES concepts that could be developed, by a competent design team, to perform the mission described by the input parameters. The paper discusses how the program was used to explore parametrically the design of a range of self-propelled hoverbarges to meet requirements of the U.S. Army Logistics Over the Shore (LOTS) phases of an amphibious landing. Examples of results are presented to illustrate the method used in determining design and performance trade-offs.

  15. RAMCAD (Reliability, Availability and Maintainability in Computer-Aided Design)

    DTIC Science & Technology

    1992-11-01

    documents the Reliability, Availability, and Maintainability in Computer-Aided Design (RAMCAD) Software Development Program which was started in July 1986 ...by General Dynamics Convair Division under a Program Research and Development Announcement (PRDA 86-16-PMRS). This PRDA was issued on May 15, 1986 ...PRDA 86-16-PMRS) was issued on May 15, 1986 , by the Air Force Human Resources ..aboratory (AFHRL, changed to Armstrong Laboratory, Human Resources

  16. Computer-Aided Final Design Cost Estimating System Overview.

    DTIC Science & Technology

    1977-05-01

    laboratory _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ /1— COMPUTER-AIDED FINAL DESIGN • COST ESTIMATING SYSTEM OVERVIEW © by...PROJECT . TASKAAEA~~ WORK UNIT NUMBERSCONSTRUCTION ENGINEERING RESEARCH LABORATORY ~~~~~~~~~ .• . — P.O. Box 4005 ~~ 4A7627~ %T4fldt11 Champa ign , IL 61820...Construction Division (FA), U.S. Army Construction Engineering Re- search Laboratory (CERL), Champaign , IL. The Principal Investigator was Mr. Michael

  17. Analysis on the effect of geometrical design parameters on maximum shear stresses in an electromagnetic micropump

    NASA Astrophysics Data System (ADS)

    Al-Halhouli, A. T.

    2010-02-01

    In this work, the concept of recently introduced electromagnetic pump has been presented. This pump has been proposed for pumping biomedical fluids carrying particles sensitive to shear stresses. Its working concept depends on controlling the rotation of two pistons placed in a circular channel in opposing polarity under the influence of a moving electromagnetic field. Analytical and numerical investigations on the effect of pump geometrical parameters on shear stresses at different boundary conditions are performed. The geometrical parameters include: channel aspect ratio (channel width to height) and channel radius ratio (inner to outer radius). Non-dimensional simple analytical shear stress expressions that are valid for a wide range of geometrical design parameters and variety of fluids are derived. CFD simulations have been used to verify the analytical expressions within the range of studied parameters. Obtained results showed that the analytical models predict the wall maximum shear stresses with an error less than 5% for w / h<=1.0 at high radius ratios and with an error less than10% for Ri / Ro >=0.3. These results help the designer in fabricating the micropump to be suitable for biomedical applications, where saving the particles carried in fluids from damage is of high importance.

  18. GA-Based Computer-Aided Electromagnetic Design of Two-Phase SRM for Compressor Drives

    NASA Astrophysics Data System (ADS)

    Kano, Yoshiaki; Kosaka, Takashi; Matsui, Nobuyuki

    This paper presents an approach to Genetic Algorithm (GA)-based computer-aided autonomous electromagnetic design of 2-phase Switched Reluctance Motor drives. The proposed drive is designed for compressor drives in low-priced refrigerators as an alternative to existing brushless DC motors drives with rare-earth magnets. In the proposed design approach, three GA loops work to optimize the lamination design so as to meet the requirements for the target application under the given constraints while simultaneously fine-tuning the control parameters. To achieve the design optimization within an acceptable CPU-time, the repeated-calculation required to obtain fitness evaluation in the proposed approach does not use FEM, but consists of geometric flux tube-based non-linear magnetic analysis and a dynamic simulator based on an analytical expression of the magnetizing curves obtained from the non-linear magnetic analysis. The design results show the proposed approach can autonomously find a feasible design solution of SRM drive for the target application from huge search space. The experimental studies using a 2-phase 8/6 prototype manufactured in accordance with the optimized design parameters show the validity of the proposed approach.

  19. The Design Manager's Aid for Intelligent Decomposition (DeMAID)

    NASA Technical Reports Server (NTRS)

    Rogers, James L.

    1994-01-01

    Before the design of new complex systems such as large space platforms can begin, the possible interactions among subsystems and their parts must be determined. Once this is completed, the proposed system can be decomposed to identify its hierarchical structure. The design manager's aid for intelligent decomposition (DeMAID) is a knowledge based system for ordering the sequence of modules and identifying a possible multilevel structure for design. Although DeMAID requires an investment of time to generate and refine the list of modules for input, it could save considerable money and time in the total design process, particularly in new design problems where the ordering of the modules has not been defined.

  20. AIDS

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/000594.htm HIV/AIDS To use the sharing features on this page, ... immunodeficiency virus (HIV) is the virus that causes AIDS. When a person becomes infected with HIV, the ...

  1. Computer-aided structural design of a lunar radio telescope

    NASA Technical Reports Server (NTRS)

    Akgul, Ferhat; Gerstle, Walter H.; Johnson, Stewart W.

    1990-01-01

    This paper describes a computer-aided structural design of the main reflector of a fully steerable radio telescope to be located (in the 21st century) on the moon, and presents the results of the structural analysis of the reflector. The reflector is a paraboloid with a surface area of 12,660 sq m and a focal ratio of 0.42. The reflector's surface will be covered by a 5.08 cm-thick sandwich panel made of thin-walled aluminum cells filled with low-density foam. The low weight of the design will be achieved by using graphite-epoxy as the structural material.

  2. Three-Dimensional Computer Aided Design of a Vertical Winnower

    NASA Astrophysics Data System (ADS)

    Bao, Yumei; Lin, Saijia; Weng, Lijie

    The research states home and abroad of the winnowing technology and winnowers are reviewed in brief. For the air duct, the core component of the winnower, the relevant technical parameters in the winnowing process are calculated based on the winnowing principle. The three-dimensional computer aided design (3D-CAD) software Solidworks is applied. The designed vertical winnower is able to separate different raw materials by adjusting the air speed and has been put into practical production to separate the Chinese traditional medicine with high separating effect.

  3. Multidisciplinary Expert-aided Analysis and Design (MEAD)

    NASA Technical Reports Server (NTRS)

    Hummel, Thomas C.; Taylor, James

    1989-01-01

    The MEAD Computer Program (MCP) is being developed under the Multidisciplinary Expert-Aided Analysis and Design (MEAD) Project as a CAD environment in which integrated flight, propulsion, and structural control systems can be designed and analyzed. The MCP has several embedded computer-aided control engineering (CACE) packages, a user interface (UI), a supervisor, a data-base manager (DBM), and an expert system (ES). The supervisor monitors and coordinates the operation of the CACE packages, the DBM; the ES, and the UI. The DBM tracks the control design process. Models created or installed by the MCP are tracked by date and version, and results are associated with the specific model version with which they were generated. The ES is used to relieve the control engineer from tedious and cumbersome tasks in the iterative design process. The UI provides the capability for a novice as well as an expert to utilize the MCP easily and effectively. The MCP version 2(MCP-2.0) is fully developed for flight control system design and analysis. Propulsion system modeling, analysis, and simulation is also supported; the same is true for structural models represented in state-space form. The ultimate goal is to cover the integration of flight, propulsion, and structural control engineering, including all discipline-specific functionality and interfaces. The current MCP-2.0 components and functionality are discussed.

  4. Fresnel lens solar concentrator design based on geometric optics and blackbody radiation equations

    SciTech Connect

    Watson, M.D.; Jayroe, R.R. Jr.

    1999-07-01

    Fresnel lenses have been used for years as solar concentrators in a variety of applications. Several variables affect the final design of these lenses including: lens diameter, image spot distance from the lens, and bandwidth focused in the image spot. Defining the image spot as the geometrical optics circle of least confusion, a set of design equations has been derived to define the groove angles for each groove on the lens. These equations allow the distribution of light by wavelength within the image spot to be calculated. Combining these equations with the blackbody radiation equations power, power distribution, and flux within the image spot can be calculated. In addition, equations have been derived to design a lens to produce maximum flux in a given spot size. Using these equations, a lens may be designed to optimize the spot energy concentration for given energy source.

  5. Fresnel Lens Solar Concentrator Design Based on Geometric Optics and Blackbody Radiation Equations

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Jayroe, Robert

    1998-01-01

    Fresnel lenses have been used for years as solar concentrators in a variety of applications. Several variables effect the final design of these lenses including: lens diameter, image spot distance from the lens, and bandwidth focused in the image spot. Defining the image spot as the geometrical optics circle of least confusion, a set of design equations has been derived to define the groove angles for each groove on the lens. These equations allow the distribution of light by wavelength within the image spot to be calculated. Combining these equations with the blackbody radiation equations, energy distribution, power, and flux within the image spot can be calculated. In addition, equations have been derived to design a lens to produce maximum flux in a given spot size. Using these equations, a lens may be designed to optimize the spot energy concentration for given energy source.

  6. Biomaterial design for specific cellular interactions: Role of surface functionalization and geometric features

    NASA Astrophysics Data System (ADS)

    Kolhar, Poornima

    The areas of drug delivery and tissue engineering have experienced extraordinary growth in recent years with the application of engineering principles and their potential to support and improve the field of medicine. The tremendous progress in nanotechnology and biotechnology has lead to this explosion of research and development in biomedical applications. Biomaterials can now be engineered at a nanoscale and their specific interactions with the biological tissues can be modulated. Various design parameters are being established and researched for design of drug-delivery carriers and scaffolds to be implanted into humans. Nanoparticles made from versatile biomaterial can deliver both small-molecule drugs and various classes of bio-macromolecules, such as proteins and oligonucleotides. Similarly in the field of tissue engineering, current approaches emphasize nanoscale control of cell behavior by mimicking the natural extracellular matrix (ECM) unlike, traditional scaffolds. Drug delivery and tissue engineering are closely connected fields and both of these applications require materials with exceptional physical, chemical, biological, and biomechanical properties to provide superior therapy. In the current study the surface functionalization and the geometric features of the biomaterials has been explored. In particular, a synthetic surface for culture of human embryonic stem cells has been developed, demonstrating the importance of surface functionalization in maintaining the pluripotency of hESCs. In the second study, the geometric features of the drug delivery carriers are investigated and the polymeric nanoneedles mediated cellular permeabilization and direct cytoplasmic delivery is reported. In the third study, the combined effect of surface functionalization and geometric modification of carriers for vascular targeting is enunciated. These studies illustrate how the biomaterials can be designed to achieve various cellular behaviors and control the

  7. Single-tooth dento-osseous osteotomy with a computer-aided design/computer-aided manufacturing surgical guide.

    PubMed

    Kang, Sang-Hoon; Kim, Moon-Key; Lee, Ji-Yeon

    2016-04-01

    This clinical note introduces a method to assist surgeons in performing single-tooth dento-osseous osteotomy. For use in this method, a surgical guide was manufactured using computer-aided design/computer-aided manufacturing technology and was based on preoperative surgical simulation data. This method was highly conducive to successful single-tooth dento-osseous segmental osteotomy.

  8. CAD/CAM (Computer Aided Design/Computer Aided Manufacture). A Brief Guide to Materials in the Library of Congress.

    ERIC Educational Resources Information Center

    Havas, George D.

    This brief guide to materials in the Library of Congress (LC) on computer aided design and/or computer aided manufacturing lists reference materials and other information sources under 13 headings: (1) brief introductions; (2) LC subject headings used for such materials; (3) textbooks; (4) additional titles; (5) glossaries and handbooks; (6)…

  9. Retrofitting a crown to a sleep apnea device by using computer-aided design and computer-aided milling technology.

    PubMed

    Biethman, Rick; Land, Martin F; Hruskocy, Heather; Colgin, Bruce

    2014-07-01

    Retrofitting a new crown to an existing dental device is challenging. The continued evolution of computer-aided design and computer-aided manufacturing (CAD/CAM) significantly simplifies the process. This article demonstrates retrofitting a gold crown to an existing sleep apnea device.

  10. Single-tooth dento-osseous osteotomy with a computer-aided design/computer-aided manufacturing surgical guide

    PubMed Central

    2016-01-01

    This clinical note introduces a method to assist surgeons in performing single-tooth dento-osseous osteotomy. For use in this method, a surgical guide was manufactured using computer-aided design/computer-aided manufacturing technology and was based on preoperative surgical simulation data. This method was highly conducive to successful single-tooth dento-osseous segmental osteotomy. PMID:27162756

  11. Microwave processing of a dental ceramic used in computer-aided design/computer-aided manufacturing.

    PubMed

    Pendola, Martin; Saha, Subrata

    2015-01-01

    Because of their favorable mechanical properties and natural esthetics, ceramics are widely used in restorative dentistry. The conventional ceramic sintering process required for their use is usually slow, however, and the equipment has an elevated energy consumption. Sintering processes that use microwaves have several advantages compared to regular sintering: shorter processing times, lower energy consumption, and the capacity for volumetric heating. The objective of this study was to test the mechanical properties of a dental ceramic used in computer-aided design/computer-aided manufacturing (CAD/CAM) after the specimens were processed with microwave hybrid sintering. Density, hardness, and bending strength were measured. When ceramic specimens were sintered with microwaves, the processing times were reduced and protocols were simplified. Hardness was improved almost 20% compared to regular sintering, and flexural strength measurements suggested that specimens were approximately 50% stronger than specimens sintered in a conventional system. Microwave hybrid sintering may preserve or improve the mechanical properties of dental ceramics designed for CAD/CAM processing systems, reducing processing and waiting times.

  12. Biologically inspired binaural hearing aid algorithms: Design principles and effectiveness

    NASA Astrophysics Data System (ADS)

    Feng, Albert

    2002-05-01

    Despite rapid advances in the sophistication of hearing aid technology and microelectronics, listening in noise remains problematic for people with hearing impairment. To solve this problem two algorithms were designed for use in binaural hearing aid systems. The signal processing strategies are based on principles in auditory physiology and psychophysics: (a) the location/extraction (L/E) binaural computational scheme determines the directions of source locations and cancels noise by applying a simple subtraction method over every frequency band; and (b) the frequency-domain minimum-variance (FMV) scheme extracts a target sound from a known direction amidst multiple interfering sound sources. Both algorithms were evaluated using standard metrics such as signal-to-noise-ratio gain and articulation index. Results were compared with those from conventional adaptive beam-forming algorithms. In free-field tests with multiple interfering sound sources our algorithms performed better than conventional algorithms. Preliminary intelligibility and speech reception results in multitalker environments showed gains for every listener with normal or impaired hearing when the signals were processed in real time with the FMV binaural hearing aid algorithm. [Work supported by NIH-NIDCD Grant No. R21DC04840 and the Beckman Institute.

  13. A Conceptual Design of a Departure Planner Decision Aid

    NASA Technical Reports Server (NTRS)

    Anagnostakis, Ioannis; Idris, Husni R.; Clark, John-Paul; Feron, Eric; Hansman, R. John; Odoni, Amedeo R.; Hall, William D.

    2000-01-01

    Terminal area Air Traffic Management handles both arriving and departing traffic. To date, research work on terminal area operations has focused primarily on the arrival flow and typically departures are taken into account only in an approximate manner. However, arrivals and departures are highly coupled processes especially in the terminal airspace, with complex interactions and sharing of the same airport resources between arrivals and departures taking place in practically every important terminal area. Therefore, the addition of automation aids for departures, possibly in co-operation with existing arrival flow automation systems, could have a profound contribution in enhancing the overall efficiency of airport operations. This paper presents the conceptual system architecture for such an automation aid, the Departure Planner (DP). This architecture can be used as a core in the development of decision-aiding systems to assist air traffic controllers in improving the performance of departure operations and optimize runway time allocation among different operations at major congested airports. The design of such systems is expected to increase the overall efficiency of terminal area operations and yield benefits for all stakeholders involved in Air Traffic Management (ATM) operations, users as well as service providers.

  14. Effect of Random Geometric Uncertainty on the Computational Design of a 3-D Flexible Wing

    NASA Technical Reports Server (NTRS)

    Gumbert, C. R.; Newman, P. A.; Hou, G. J.-W.

    2002-01-01

    The effect of geometric uncertainty due to statistically independent, random, normally distributed shape parameters is demonstrated in the computational design of a 3-D flexible wing. A first-order second-moment statistical approximation method is used to propagate the assumed input uncertainty through coupled Euler CFD aerodynamic / finite element structural codes for both analysis and sensitivity analysis. First-order sensitivity derivatives obtained by automatic differentiation are used in the input uncertainty propagation. These propagated uncertainties are then used to perform a robust design of a simple 3-D flexible wing at supercritical flow conditions. The effect of the random input uncertainties is shown by comparison with conventional deterministic design results. Sample results are shown for wing planform, airfoil section, and structural sizing variables.

  15. Computer Aided Antenna Design and Frequency Selection for HF Communications.

    DTIC Science & Technology

    1984-06-01

    EESIGN ON THE ADPE-.- NIF (GREEN MACHINE) ... .... . . . . . . . 57 E. COMPUTER AIDED DESIGN USING ECAC1S ACCESSIBIE ANTENNA PACKAGE . . . . . . .. 57 F...8217 C8 L4 E-4 W 3a ’H 1 H -g I) - 4 ’ 0-4 =2 E-4 V. E-4 b. m 0 m 4 =- v- -4 3 4 E’- 4 = P4 H - ofC. I- 1 4 = W P4 w 4 I = N = V rq I 0-4 ~ to H W4

  16. Computer aided design and analysis of gear tooth geometry

    NASA Technical Reports Server (NTRS)

    Chang, S. H.; Huston, R. L.

    1987-01-01

    A simulation method for gear hobbing and shaping of straight and spiral bevel gears is presented. The method is based upon an enveloping theory for gear tooth profile generation. The procedure is applicable in the computer aided design of standard and nonstandard tooth forms. An inverse procedure for finding a conjugate gear tooth profile is presented for arbitrary cutter geometry. The kinematic relations for the tooth surfaces of straight and spiral bevel gears are proposed. The tooth surface equations for these gears are formulated in a manner suitable for their automated numerical development and solution.

  17. Computer-aided design of bevel gear tooth surfaces

    NASA Technical Reports Server (NTRS)

    Shuo, Hung Chang; Huston, Ronald L.; Coy, John J.

    1989-01-01

    This paper presents a computer-aided design procedure for generating bevel gears. The development is based on examining a perfectly plastic, cone-shaped gear blank rolling over a cutting tooth on a plane crown rack. The resulting impression on the plastic gear blank is the envelope of the cutting tooth. This impression and envelope thus form a conjugate tooth surface. Equations are presented for the locus of points on the tooth surface. The same procedures are then extended to simulate the generation of a spiral bevel gear. The corresponding governing equations are presented.

  18. Computer aided design of bevel gear tooth surfaces

    NASA Technical Reports Server (NTRS)

    Chang, S. H.; Huston, R. L.; Coy, J. J.

    1989-01-01

    This paper presents a computer-aided design procedure for generating bevel gears. The development is based on examining a perfectly plastic, cone-shaped gear blank rolling over a cutting tooth on a plane crown rack. The resulting impression on the plastic gear blank is the envelope of the cutting tooth. This impression and envelope thus form a conjugate tooth surface. Equations are presented for the locus of points on the tooth surface. The same procedures are then extended to simulate the generation of a spiral bevel gear. The corresponding governing equations are presented.

  19. CATIA - A computer aided design and manufacturing tridimensional system

    NASA Astrophysics Data System (ADS)

    Bernard, F.

    A properietary computer graphics-aided, three-dimensional interactive application (CATIA) design system is described. CATIA employs approximately 100 graphics displays, which are used by some 500 persons engaged in the definition of aircraft structures, structural strength analyses, the kinematic analysis of mobile elements, aerodynamic calculations, the choice of tooling in the machining of aircraft elements, and the programming of robotics. CATIA covers these diverse fields with a single data base. After a description of salient aspects of the system's hardware and software, graphics examples are given of the definition of curves, surfaces, complex volumes, and analytical tasks.

  20. Accelerating Battery Design Using Computer-Aided Engineering Tools: Preprint

    SciTech Connect

    Pesaran, A.; Heon, G. H.; Smith, K.

    2011-01-01

    Computer-aided engineering (CAE) is a proven pathway, especially in the automotive industry, to improve performance by resolving the relevant physics in complex systems, shortening the product development design cycle, thus reducing cost, and providing an efficient way to evaluate parameters for robust designs. Academic models include the relevant physics details, but neglect engineering complexities. Industry models include the relevant macroscopic geometry and system conditions, but simplify the fundamental physics too much. Most of the CAE battery tools for in-house use are custom model codes and require expert users. There is a need to make these battery modeling and design tools more accessible to end users such as battery developers, pack integrators, and vehicle makers. Developing integrated and physics-based CAE battery tools can reduce the design, build, test, break, re-design, re-build, and re-test cycle and help lower costs. NREL has been involved in developing various models to predict the thermal and electrochemical performance of large-format cells and has used in commercial three-dimensional finite-element analysis and computational fluid dynamics to study battery pack thermal issues. These NREL cell and pack design tools can be integrated to help support the automotive industry and to accelerate battery design.

  1. A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication

    PubMed Central

    Bilgin, Mehmet Selim; Baytaroğlu, Ebru Nur; Erdem, Ali; Dilber, Erhan

    2016-01-01

    The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now. PMID:27095912

  2. A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication.

    PubMed

    Bilgin, Mehmet Selim; Baytaroğlu, Ebru Nur; Erdem, Ali; Dilber, Erhan

    2016-01-01

    The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now.

  3. Design and construction of an Offner spectrometer based on geometrical analysis of ring fields.

    PubMed

    Kim, Seo Hyun; Kong, Hong Jin; Lee, Jong Ung; Lee, Jun Ho; Lee, Jai Hoon

    2014-08-01

    A method to obtain an aberration-corrected Offner spectrometer without ray obstruction is proposed. A new, more efficient spectrometer optics design is suggested in order to increase its spectral resolution. The derivation of a new ring equation to eliminate ray obstruction is based on geometrical analysis of the ring fields for various numerical apertures. The analytical design applying this equation was demonstrated using the optical design software Code V in order to manufacture a spectrometer working in wavelengths of 900-1700 nm. The simulation results show that the new concept offers an analytical initial design taking the least time of calculation. The simulated spectrometer exhibited a modulation transfer function over 80% at Nyquist frequency, root-mean-square spot diameters under 8.6 μm, and a spectral resolution of 3.2 nm. The final design and its realization of a high resolution Offner spectrometer was demonstrated based on the simulation result. The equation and analytical design procedure shown here can be applied to most Offner systems regardless of the wavelength range.

  4. New geometric design consistency model based on operating speed profiles for road safety evaluation.

    PubMed

    Camacho-Torregrosa, Francisco J; Pérez-Zuriaga, Ana M; Campoy-Ungría, J Manuel; García-García, Alfredo

    2013-12-01

    To assist in the on-going effort to reduce road fatalities as much as possible, this paper presents a new methodology to evaluate road safety in both the design and redesign stages of two-lane rural highways. This methodology is based on the analysis of road geometric design consistency, a value which will be a surrogate measure of the safety level of the two-lane rural road segment. The consistency model presented in this paper is based on the consideration of continuous operating speed profiles. The models used for their construction were obtained by using an innovative GPS-data collection method that is based on continuous operating speed profiles recorded from individual drivers. This new methodology allowed the researchers to observe the actual behavior of drivers and to develop more accurate operating speed models than was previously possible with spot-speed data collection, thereby enabling a more accurate approximation to the real phenomenon and thus a better consistency measurement. Operating speed profiles were built for 33 Spanish two-lane rural road segments, and several consistency measurements based on the global and local operating speed were checked. The final consistency model takes into account not only the global dispersion of the operating speed, but also some indexes that consider both local speed decelerations and speeds over posted speeds as well. For the development of the consistency model, the crash frequency for each study site was considered, which allowed estimating the number of crashes on a road segment by means of the calculation of its geometric design consistency. Consequently, the presented consistency evaluation method is a promising innovative tool that can be used as a surrogate measure to estimate the safety of a road segment.

  5. Computer aided design environment for the analysis and design of multi-body flexible structures

    NASA Technical Reports Server (NTRS)

    Ramakrishnan, Jayant V.; Singh, Ramen P.

    1989-01-01

    A computer aided design environment consisting of the programs NASTRAN, TREETOPS and MATLAB is presented in this paper. With links for data transfer between these programs, the integrated design of multi-body flexible structures is significantly enhanced. The CAD environment is used to model the Space Shuttle/Pinhole Occulater Facility. Then a controller is designed and evaluated in the nonlinear time history sense. Recent enhancements and ongoing research to add more capabilities are also described.

  6. Parametric Investigation of Radome Analysis Methods. Volume II. Computer-Aided Radome Analysis Using Geometrical Optics and Lorentz Reciprocity.

    DTIC Science & Technology

    1981-02-01

    1977-31 Dnc. 1ciR) GEOMETRICAL OPTICS AND LORENTZ RECIPROCITY S. PERFORMING O1G. REPORT NUMBER 7. AUTHOR(s) S. CONTRACT OR GRANT NUMBER(s) G. K...Huddleston, H. L. Bassett, & J. M. Newton kFOSR-77-3469 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT, TASK Georgia Institute...and H. L. Bassett, "Multi-Purpose Missile (MPM) High Performance Radome Trade-Off and Development Study", Martin Marietta Aerospace, April 1975. 4. G

  7. The application of computer-aided technologies in automotive styling design

    NASA Astrophysics Data System (ADS)

    Zheng, Ze-feng; Zhang, Ji; Zheng, Ying

    2012-04-01

    In automotive industry, outline design is its life and creative design is its soul indeed. Computer-aided technology has been widely used in the automotive industry and more and more attention has been paid. This paper chiefly introduce the application of computer-aided technologies including CAD, CAM and CAE, analyses the process of automotive structural design and describe the development tendency of computer-aided design.

  8. Advances in computer-aided design and computer-aided manufacture technology.

    PubMed

    Calamia, J R

    1994-01-01

    Although the development of computer-aided design (CAD) and computer-aided manufacture (CAM) technology and the benefits of increased productivity became obvious in the automobile and aerospace industries in the 1970s, investigations of this technology's application in the field of dentistry did not begin until the 1980s. Only now are we beginning to see the fruits of this work with the commercial availability of some systems; the potential for this technology seems boundless. This article reviews the recent literature with emphasis on the period from June 1992 to May 1993. This review should familiarize the reader with some of the latest developments in this technology, including a brief description of some systems currently available and the clinical and economical rationale for their acceptance into the dental mainstream. This article concentrates on a particular system, the Cerec (Siemens/Pelton and Crane, Charlotte, NC) system, for three reasons: first, this system has been available since 1985 and, as a result, has a track record of almost 7 years of data. Most of the data have just recently been released and consequently, much of this year's literature on CAD-CAM is monopolized by studies using this system. Second, this system was developed as a mobile, affordable, direct chairside CAD-CAM restorative method. As such, it is of special interest to the dentist who will offer this new technology directly to the patient, providing a one-visit restoration. Third, the author is currently engaged in research using this particular system and has a working knowledge of this system's capabilities.

  9. A digital patient for computer-aided prosthesis design

    PubMed Central

    Colombo, Giorgio; Facoetti, Giancarlo; Rizzi, Caterina

    2013-01-01

    This article concerns the design of lower limb prosthesis, both below and above knee. It describes a new computer-based design framework and a digital model of the patient around which the prosthesis is designed and tested in a completely virtual environment. The virtual model of the patient is the backbone of the whole system, and it is based on a biomechanical general-purpose model customized with the patient's characteristics (e.g. anthropometric measures). The software platform adopts computer-aided and knowledge-guided approaches with the goal of replacing the current development process, mainly hand made, with a virtual one. It provides the prosthetics with a set of tools to design, configure and test the prosthesis and comprehends two main environments: the prosthesis modelling laboratory and the virtual testing laboratory. The first permits the three-dimensional model of the prosthesis to be configured and generated, while the second allows the prosthetics to virtually set up the artificial leg and simulate the patient's postures and movements, validating its functionality and configuration. General architecture and modelling/simulation tools for the platform are described as well as main aspects and results of the experimentation. PMID:24427528

  10. Visualization and modeling of factors influencing visibility in computer-aided crewstation design

    NASA Technical Reports Server (NTRS)

    Arditi, Aries; Azueta, Steven; Larimer, James; Prevost, Michael; Lubin, Jeffrey; Bergen, James

    1992-01-01

    We have developed two modules for use in computer-aided design (CAD) of crewstation environments that enhance the designer's appreciation of factors influencing the pilot's vision and visual processing capacity. The Binocular Optics Module (BOM) is an interactive tool for visualizing geometric aspects of (1) how retinal imagery of the environment changes on the pilot's retinas under conditions of eye and object motion, and (2) how visual capabilities that can be modeled as regions or contours on the retinas, affect spatial perception of the environment. The Visual Performance Module (VPM) contains a signal processing model of human visual discrimination that quantitatively predicts visual discrimination performance. The outputs of the VPM are retinal contours that represent performance probabilities. These contours may be used as inputs to the BOM for visualizing those volumes of space within the crewstation that bound different levels of the pilot's of visual discrimination capability. Used together, the BOM and VPM provide the designer with the opportunity to interactively explore relationships between environmental retinal imagery and visual function, and the ability to factor the pilot's visual capabilities into the earliest phases of crewstation CAD.

  11. Geometrical shape design of nanophotonic surfaces for thin film solar cells.

    PubMed

    Nam, W I; Yoo, Y J; Song, Y M

    2016-07-11

    We present the effect of geometrical parameters, particularly shape, on optical absorption enhancement for thin film solar cells based on crystalline silicon (c-Si) and gallium arsenide (GaAs) using a rigorous coupled wave analysis (RCWA) method. It is discovered that the "sweet spot" that maximizes efficiency of solar cells exists for the design of nanophotonic surfaces. For the case of ultrathin, rod array is practical due to the effective optical resonances resulted from the optimum geometry whereas parabola array is viable for relatively thicker cells owing to the effective graded index profile. A specific value of thickness, which is the median value of other two devices tailored by rod and paraboloid, is optimized by truncated shape structure. It is therefore worth scanning the optimum shape of nanostructures in a given thickness in order to achieve high performance.

  12. Analysis of suitable geometrical parameters for designing a tendon-driven under-actuated mechanical finger

    NASA Astrophysics Data System (ADS)

    Penta, Francesco; Rossi, Cesare; Savino, Sergio

    2016-06-01

    This study aims to optimize the geometrical parameters of an under-actuated mechanical finger by conducting a theoretical analysis of these parameters. The finger is actuated by a flexion tendon and an extension tendon. The considered parameters are the tendon guide positions with respect to the hinges. By applying such an optimization, the correct kinematical and dynamical behavior of the closing cycle of the finger can be obtained. The results of this study are useful for avoiding the snapthrough and the single joint hyperflexion, which are the two breakdowns most frequently observed during experimentation on prototypes. Diagrams are established to identify the optimum values for the tendon guides position of a finger with specified dimensions. The findings of this study can serve as guide for future finger design.

  13. Branching angles of pyramidal cell dendrites follow common geometrical design principles in different cortical areas

    PubMed Central

    Bielza, Concha; Benavides-Piccione, Ruth; López-Cruz, Pedro; Larrañaga, Pedro; DeFelipe, Javier

    2014-01-01

    Unraveling pyramidal cell structure is crucial to understanding cortical circuit computations. Although it is well known that pyramidal cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intracellularly injected cortical pyramidal cells in seven different cortical regions of the frontal, parietal, and occipital cortex of the mouse. We found that, despite the differences in the structure of the pyramidal cells in these distinct functional and cytoarchitectonic cortical areas, there are common design principles that govern the geometry of dendritic branching angles of pyramidal cells in all cortical areas. PMID:25081193

  14. Branching angles of pyramidal cell dendrites follow common geometrical design principles in different cortical areas.

    PubMed

    Bielza, Concha; Benavides-Piccione, Ruth; López-Cruz, Pedro; Larrañaga, Pedro; DeFelipe, Javier

    2014-08-01

    Unraveling pyramidal cell structure is crucial to understanding cortical circuit computations. Although it is well known that pyramidal cell branching structure differs in the various cortical areas, the principles that determine the geometric shapes of these cells are not fully understood. Here we analyzed and modeled with a von Mises distribution the branching angles in 3D reconstructed basal dendritic arbors of hundreds of intracellularly injected cortical pyramidal cells in seven different cortical regions of the frontal, parietal, and occipital cortex of the mouse. We found that, despite the differences in the structure of the pyramidal cells in these distinct functional and cytoarchitectonic cortical areas, there are common design principles that govern the geometry of dendritic branching angles of pyramidal cells in all cortical areas.

  15. Hardware synthesis from DDL. [Digital Design Language for computer aided design and test of LSI

    NASA Technical Reports Server (NTRS)

    Shah, A. M.; Shiva, S. G.

    1981-01-01

    The details of the digital systems can be conveniently input into the design automation system by means of Hardware Description Languages (HDL). The Computer Aided Design and Test (CADAT) system at NASA MSFC is used for the LSI design. The Digital Design Language (DDL) has been selected as HDL for the CADAT System. DDL translator output can be used for the hardware implementation of the digital design. This paper addresses problems of selecting the standard cells from the CADAT standard cell library to realize the logic implied by the DDL description of the system.

  16. NEXUS/NASCAD- NASA ENGINEERING EXTENDIBLE UNIFIED SOFTWARE SYSTEM WITH NASA COMPUTER AIDED DESIGN

    NASA Technical Reports Server (NTRS)

    Purves, L. R.

    1994-01-01

    NEXUS, the NASA Engineering Extendible Unified Software system, is a research set of computer programs designed to support the full sequence of activities encountered in NASA engineering projects. This sequence spans preliminary design, design analysis, detailed design, manufacturing, assembly, and testing. NEXUS primarily addresses the process of prototype engineering, the task of getting a single or small number of copies of a product to work. Prototype engineering is a critical element of large scale industrial production. The time and cost needed to introduce a new product are heavily dependent on two factors: 1) how efficiently required product prototypes can be developed, and 2) how efficiently required production facilities, also a prototype engineering development, can be completed. NEXUS extendibility and unification are achieved by organizing the system as an arbitrarily large set of computer programs accessed in a common manner through a standard user interface. The NEXUS interface is a multipurpose interactive graphics interface called NASCAD (NASA Computer Aided Design). NASCAD can be used to build and display two and three-dimensional geometries, to annotate models with dimension lines, text strings, etc., and to store and retrieve design related information such as names, masses, and power requirements of components used in the design. From the user's standpoint, NASCAD allows the construction, viewing, modification, and other processing of data structures that represent the design. Four basic types of data structures are supported by NASCAD: 1) three-dimensional geometric models of the object being designed, 2) alphanumeric arrays to hold data ranging from numeric scalars to multidimensional arrays of numbers or characters, 3) tabular data sets that provide a relational data base capability, and 4) procedure definitions to combine groups of system commands or other user procedures to create more powerful functions. NASCAD has extensive abilities to

  17. Geometric optimal design of a magneto-rheological brake considering different shapes for the brake envelope

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Lang, V. T.; Nguyen, N. D.; Choi, S. B.

    2014-01-01

    When designing a magneto-rheological brake (MRB), it is well known that the shape of the brake envelope significantly affects the performance characteristics of the brake. In this study, different shapes for the MR brake envelope, such as rectangular, polygonal or spline shape, are considered and the most suitable shape identified. MRBs with different envelope shapes are introduced followed by the derivation of the braking torque based on Bingham-plastic behavior of the magneto-rheological fluid (MRF). Optimization of the design of the MRB with different envelope shapes is then done. The optimization problem is to find the optimal value for the significant geometric dimensions of the MRB that can produce a certain required braking torque while the brake mass is minimized. A finite element analysis integrated with an optimization tool is employed to obtain optimal solutions for the MRBs. From the results, the most suitable shape for the brake envelope is identified and discussed with the reduction of mass. In addition, the results of the analysis are compared with the experimental results to verify the proposed optimal design characteristics.

  18. Converting Between PLY and Ballistic Research Laboratory-Computer-Aided Design (BRL-CAD) File Formats

    DTIC Science & Technology

    2015-02-01

    Converting Between PLY and Ballistic Research Laboratory–Computer-Aided Design (BRL-CAD) File Formats by Rishub Jain ARL-CR-0760...0760 February 2015 Converting Between PLY and Ballistic Research Laboratory–Computer-Aided Design (BRL-CAD) File Formats Rishub Jain US...and Ballistic Research Laboratory–Computer-Aided Design (BRL-CAD) File Formats 5a. CONTRACT NUMBER W911NF-10-2-0076 5b. GRANT NUMBER 5c. PROGRAM

  19. Target Impact Detection Algorithm Using Computer-aided Design (CAD) Model Geometry

    DTIC Science & Technology

    2014-09-01

    UNCLASSIFIED AD-E403 558 Technical Report ARMET-TR-13024 TARGET IMPACT DETECTION ALGORITHM USING COMPUTER-AIDED DESIGN ( CAD ...DETECTION ALGORITHM USING COMPUTER-AIDED DESIGN ( CAD ) MODEL GEOMETRY 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...This report documents a method and algorithm to export geometry from a three-dimensional, computer-aided design ( CAD ) model in a format that can be

  20. Rubber airplane: Constraint-based component-modeling for knowledge representation in computer-aided conceptual design

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1990-01-01

    Viewgraphs on Rubber Airplane: Constraint-based Component-Modeling for Knowledge Representation in Computer Aided Conceptual Design are presented. Topics covered include: computer aided design; object oriented programming; airfoil design; surveillance aircraft; commercial aircraft; aircraft design; and launch vehicles.

  1. Computer-aided drug design at Boehringer Ingelheim

    NASA Astrophysics Data System (ADS)

    Muegge, Ingo; Bergner, Andreas; Kriegl, Jan M.

    2016-09-01

    Computer-Aided Drug Design (CADD) is an integral part of the drug discovery endeavor at Boehringer Ingelheim (BI). CADD contributes to the evaluation of new therapeutic concepts, identifies small molecule starting points for drug discovery, and develops strategies for optimizing hit and lead compounds. The CADD scientists at BI benefit from the global use and development of both software platforms and computational services. A number of computational techniques developed in-house have significantly changed the way early drug discovery is carried out at BI. In particular, virtual screening in vast chemical spaces, which can be accessed by combinatorial chemistry, has added a new option for the identification of hits in many projects. Recently, a new framework has been implemented allowing fast, interactive predictions of relevant on and off target endpoints and other optimization parameters. In addition to the introduction of this new framework at BI, CADD has been focusing on the enablement of medicinal chemists to independently perform an increasing amount of molecular modeling and design work. This is made possible through the deployment of MOE as a global modeling platform, allowing computational and medicinal chemists to freely share ideas and modeling results. Furthermore, a central communication layer called the computational chemistry framework provides broad access to predictive models and other computational services.

  2. Designing of self-deploying origami structures using geometrically misaligned crease patterns.

    PubMed

    Saito, Kazuya; Tsukahara, Akira; Okabe, Yoji

    2016-01-01

    Usually, origami-based morphing structures are designed on the premise of 'rigid folding', i.e. the facets and fold lines of origami can be replaced with rigid panels and ideal hinges, respectively. From a structural mechanics viewpoint, some rigid-foldable origami models are overconstrained and have negative degrees of freedom (d.f.). In these cases, the singularity in crease patterns guarantees their rigid foldability. This study presents a new method for designing self-deploying origami using the geometrically misaligned creases. In this method, some facets are replaced by 'holes' such that the systems become a 1-d.f. mechanism. These perforated origami models can be folded and unfolded similar to rigid-foldable (without misalignment) models because of their d.f. focusing on the removed facets, the holes will deform according to the motion of the frame of the remaining parts. In the proposed method, these holes are filled with elastic parts and store elastic energy for self-deployment. First, a new extended rigid-folding simulation technique is proposed to estimate the deformation of the holes. Next, the proposed method is applied on arbitrary-size quadrilateral mesh origami. Finally, by using the finite-element method, the authors conduct numerical simulations and confirm the deployment capabilities of the models.

  3. Designing of self-deploying origami structures using geometrically misaligned crease patterns

    PubMed Central

    Saito, Kazuya; Tsukahara, Akira; Okabe, Yoji

    2016-01-01

    Usually, origami-based morphing structures are designed on the premise of ‘rigid folding’, i.e. the facets and fold lines of origami can be replaced with rigid panels and ideal hinges, respectively. From a structural mechanics viewpoint, some rigid-foldable origami models are overconstrained and have negative degrees of freedom (d.f.). In these cases, the singularity in crease patterns guarantees their rigid foldability. This study presents a new method for designing self-deploying origami using the geometrically misaligned creases. In this method, some facets are replaced by ‘holes’ such that the systems become a 1-d.f. mechanism. These perforated origami models can be folded and unfolded similar to rigid-foldable (without misalignment) models because of their d.f. focusing on the removed facets, the holes will deform according to the motion of the frame of the remaining parts. In the proposed method, these holes are filled with elastic parts and store elastic energy for self-deployment. First, a new extended rigid-folding simulation technique is proposed to estimate the deformation of the holes. Next, the proposed method is applied on arbitrary-size quadrilateral mesh origami. Finally, by using the finite-element method, the authors conduct numerical simulations and confirm the deployment capabilities of the models. PMID:26997884

  4. 3-D Geometric Modeling for the 21st Century.

    ERIC Educational Resources Information Center

    Ault, Holly K.

    1999-01-01

    Describes new geometric computer models used in contemporary computer-aided design (CAD) software including wire frame, surface, solid, and parametric models. Reviews their use in engineering design and discusses the impact of these new technologies on the engineering design graphics curriculum. (Author/CCM)

  5. Perceptions of the Design of Voice Output Communication Aids

    ERIC Educational Resources Information Center

    Judge, Simon; Townend, Gillian

    2013-01-01

    Background: Voice output communication aids (VOCAs) are a key form of aided communication within the field of augmentative and alternative communication (AAC). In recent years, rapid developments in technology have resulted in an explosion of devices available commercially, yet little research has been conducted into what people who use VOCAs…

  6. DEMAID - A DESIGN MANAGER'S AID FOR INTELLIGENT DECOMPOSITION (SUN VERSION)

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.

    1994-01-01

    Many engineering systems are large and multi-disciplinary. Before the design of new complex systems such as large space platforms can begin, the possible interactions among subsystems and their parts must be determined. Once this is completed the proposed system can be decomposed to identify its hierarchical structure. DeMAID (A Design Manager's Aid for Intelligent Decomposition) is a knowledge-based system for ordering the sequence of modules and identifying a possible multilevel structure for the design problem. DeMAID displays the modules in an N x N matrix format (called a design structure matrix) where a module is any process that requires input and generates an output. (Modules which generate an output but do not require an input, such as an initialization process, are also acceptable.) Although DeMAID requires an investment of time to generate and refine the list of modules for input, it could save a considerable amount of money and time in the total design process, particularly in new design problems where the ordering of the modules has not been defined. The decomposition of a complex design system into subsystems requires the judgement of the design manager. DeMAID reorders and groups the modules based on the links (interactions) among the modules, helping the design manager make decomposition decisions early in the design cycle. The modules are grouped into circuits (the subsystems) and displayed in an N x N matrix format. Feedback links, which indicate an iterative process, are minimized and only occur within a subsystem. Since there are no feedback links among the circuits, the circuits can be displayed in a multilevel format. Thus, a large amount of information is reduced to one or two displays which are stored for later retrieval and modification. The design manager and leaders of the design teams then have a visual display of the design problem and the intricate interactions among the different modules. The design manager could save a substantial

  7. DEMAID - A DESIGN MANAGER'S AID FOR INTELLIGENT DECOMPOSITION (MACINTOSH VERSION)

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.

    1994-01-01

    Many engineering systems are large and multi-disciplinary. Before the design of new complex systems such as large space platforms can begin, the possible interactions among subsystems and their parts must be determined. Once this is completed the proposed system can be decomposed to identify its hierarchical structure. DeMAID (A Design Manager's Aid for Intelligent Decomposition) is a knowledge-based system for ordering the sequence of modules and identifying a possible multilevel structure for the design problem. DeMAID displays the modules in an N x N matrix format (called a design structure matrix) where a module is any process that requires input and generates an output. (Modules which generate an output but do not require an input, such as an initialization process, are also acceptable.) Although DeMAID requires an investment of time to generate and refine the list of modules for input, it could save a considerable amount of money and time in the total design process, particularly in new design problems where the ordering of the modules has not been defined. The decomposition of a complex design system into subsystems requires the judgement of the design manager. DeMAID reorders and groups the modules based on the links (interactions) among the modules, helping the design manager make decomposition decisions early in the design cycle. The modules are grouped into circuits (the subsystems) and displayed in an N x N matrix format. Feedback links, which indicate an iterative process, are minimized and only occur within a subsystem. Since there are no feedback links among the circuits, the circuits can be displayed in a multilevel format. Thus, a large amount of information is reduced to one or two displays which are stored for later retrieval and modification. The design manager and leaders of the design teams then have a visual display of the design problem and the intricate interactions among the different modules. The design manager could save a substantial

  8. DEMAID - A DESIGN MANAGER'S AID FOR INTELLIGENT DECOMPOSITION (SUN VERSION)

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.

    1994-01-01

    Many engineering systems are large and multi-disciplinary. Before the design of new complex systems such as large space platforms can begin, the possible interactions among subsystems and their parts must be determined. Once this is completed the proposed system can be decomposed to identify its hierarchical structure. DeMAID (A Design Manager's Aid for Intelligent Decomposition) is a knowledge-based system for ordering the sequence of modules and identifying a possible multilevel structure for the design problem. DeMAID displays the modules in an N x N matrix format (called a design structure matrix) where a module is any process that requires input and generates an output. (Modules which generate an output but do not require an input, such as an initialization process, are also acceptable.) Although DeMAID requires an investment of time to generate and refine the list of modules for input, it could save a considerable amount of money and time in the total design process, particularly in new design problems where the ordering of the modules has not been defined. The decomposition of a complex design system into subsystems requires the judgement of the design manager. DeMAID reorders and groups the modules based on the links (interactions) among the modules, helping the design manager make decomposition decisions early in the design cycle. The modules are grouped into circuits (the subsystems) and displayed in an N x N matrix format. Feedback links, which indicate an iterative process, are minimized and only occur within a subsystem. Since there are no feedback links among the circuits, the circuits can be displayed in a multilevel format. Thus, a large amount of information is reduced to one or two displays which are stored for later retrieval and modification. The design manager and leaders of the design teams then have a visual display of the design problem and the intricate interactions among the different modules. The design manager could save a substantial

  9. DEMAID - A DESIGN MANAGER'S AID FOR INTELLIGENT DECOMPOSITION (MACINTOSH VERSION)

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.

    1994-01-01

    Many engineering systems are large and multi-disciplinary. Before the design of new complex systems such as large space platforms can begin, the possible interactions among subsystems and their parts must be determined. Once this is completed the proposed system can be decomposed to identify its hierarchical structure. DeMAID (A Design Manager's Aid for Intelligent Decomposition) is a knowledge-based system for ordering the sequence of modules and identifying a possible multilevel structure for the design problem. DeMAID displays the modules in an N x N matrix format (called a design structure matrix) where a module is any process that requires input and generates an output. (Modules which generate an output but do not require an input, such as an initialization process, are also acceptable.) Although DeMAID requires an investment of time to generate and refine the list of modules for input, it could save a considerable amount of money and time in the total design process, particularly in new design problems where the ordering of the modules has not been defined. The decomposition of a complex design system into subsystems requires the judgement of the design manager. DeMAID reorders and groups the modules based on the links (interactions) among the modules, helping the design manager make decomposition decisions early in the design cycle. The modules are grouped into circuits (the subsystems) and displayed in an N x N matrix format. Feedback links, which indicate an iterative process, are minimized and only occur within a subsystem. Since there are no feedback links among the circuits, the circuits can be displayed in a multilevel format. Thus, a large amount of information is reduced to one or two displays which are stored for later retrieval and modification. The design manager and leaders of the design teams then have a visual display of the design problem and the intricate interactions among the different modules. The design manager could save a substantial

  10. 33 CFR 66.05-100 - Designation of navigable waters as State waters for private aids to navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... as State waters for private aids to navigation. 66.05-100 Section 66.05-100 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-100 Designation of navigable waters as State waters for private aids...

  11. 33 CFR 66.05-100 - Designation of navigable waters as State waters for private aids to navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... as State waters for private aids to navigation. 66.05-100 Section 66.05-100 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-100 Designation of navigable waters as State waters for private aids...

  12. 33 CFR 66.05-100 - Designation of navigable waters as State waters for private aids to navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... as State waters for private aids to navigation. 66.05-100 Section 66.05-100 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-100 Designation of navigable waters as State waters for private aids...

  13. 33 CFR 66.05-100 - Designation of navigable waters as State waters for private aids to navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... as State waters for private aids to navigation. 66.05-100 Section 66.05-100 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-100 Designation of navigable waters as State waters for private aids...

  14. 33 CFR 66.05-10 - State waters for private aids to navigation; designations; revisions, and revocations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false State waters for private aids to... Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-10 State waters for private aids to navigation; designations; revisions,...

  15. 33 CFR 66.05-10 - State waters for private aids to navigation; designations; revisions, and revocations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false State waters for private aids to... Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-10 State waters for private aids to navigation; designations; revisions,...

  16. 33 CFR 66.05-10 - State waters for private aids to navigation; designations; revisions, and revocations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false State waters for private aids to... Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-10 State waters for private aids to navigation; designations; revisions,...

  17. 33 CFR 66.05-10 - State waters for private aids to navigation; designations; revisions, and revocations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false State waters for private aids to... Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-10 State waters for private aids to navigation; designations; revisions,...

  18. 33 CFR 66.05-10 - State waters for private aids to navigation; designations; revisions, and revocations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false State waters for private aids to... Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-10 State waters for private aids to navigation; designations; revisions,...

  19. 33 CFR 66.05-100 - Designation of navigable waters as State waters for private aids to navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... as State waters for private aids to navigation. 66.05-100 Section 66.05-100 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-100 Designation of navigable waters as State waters for private aids...

  20. Computational thermodynamics aided design of novel ferritic alloys

    SciTech Connect

    Yang, Ying; Chen, Tianyi; Tan, Lizhen

    2016-06-30

    With the aid of computational thermodynamics, Ni was identified to suppress the liquidus temperature of Fe2Zr and four Fe-Cr-Ni-Zr alloys were designed to study the Ni effect on the phase stability of Fe2Zr laves_phase. These alloys were fabricated through traditional arc-metling, followed by annealing at 1000 C for 336 hours and 700 C for 1275 hours. The microstructure were examined and characterized by SEM BSE image, EDS compositional mapping and point scan, XRD and TEM analysis. The major results were summarized below: 1)For investigated alloys with 12wt% Cr, 3~6wt% Zr and 3~9 wt%Ni, the phases in equilibrium with the BCC phase are C15_Laves phase, Fe23Zr6 phase. The volume fraction of intermetallic phases increases with Ni and Zr contents. 2)Instead of (Fe,Cr)2Zr C14_Laves phase, Ni stabilizes the C15_Laves structure in Fe-Cr-Ni-Zr alloys by substituting Fe and Cr atoms with Ni atoms in the first sublattice. 3)Fe23Zr6, that is metastable in the Fe-Cr-Zr ternary, is also stabilized by Ni addition. 4)Ni7Zr2 phase was observed in samples with high Ni/Zr ratio. Extensive solubility of Fe was identified in the phase. The microstructural and composition results obtained from this study will be incorportated into the the Fe-Cr-Ni-Zr database. The current samples will be subjected to ion irradiaition to be compared with those results for Fe-Cr-Zr alloys. Additional alloys will be designed to form (Fe,Cr,Ni)2Zr nanoprecipitates for further studies.

  1. On designing and evaluating teaching sequences taking geometrical optics as an example

    NASA Astrophysics Data System (ADS)

    Andersson, Björn; Bach, Frank

    2005-03-01

    National assessments and other investigations have drawn attention to the fact that there is considerable room for improvement in science teaching and learning. This article describes, exemplifies, and discusses a research program set up to address this unsatisfactory state of affairs. Briefly, the idea of the program is that researchers in science education and teachers in schools should work together to design teaching sequences and assess how they function in practice, including what the students learn. This work has two aims: first, to generate results of practical use, and second, to contribute to the development of educational science. Results of practical use are presented in the form of teacher's guides, written to be used as tools for generating further knowledge. As a contribution to educational science, attempts are made to formulate content-oriented theories of conditions that are likely to improve learning with understanding. This article describes and discusses how the research program has been implemented in the area of geometrical optics at the upper level (grades 8 and 9) of compulsory school. It is suggested that the idea of content-oriented theories is worth further examination and development and might contribute to strengthening science education as an autonomous discipline.

  2. Geometric design and mechanical behavior of a deployable cylinder with Miura origami

    NASA Astrophysics Data System (ADS)

    Cai, Jianguo; Deng, Xiaowei; Feng, Jian; Zhou, Ya

    2015-12-01

    The folding and deployment of a cylinder with Miura origami patterns are studied in this paper. First, the geometric formulation of the design problem is discussed. Then the loading case of the axial strains and corresponding external nodal loads applied on the vertices of the top polygon during the motion is investigated analytically. The influence of the angle between the diagonal and horizontal fold lines α and β and the number of Miura origami elements n on the dynamic behavior of the basic segment is also discussed. Then the dynamic behavior is analyzed using numerical simulations. Finally, the deployment process of a cylinder with multi-stories is discussed. The numerical results agree well with the analytical predictions. The results show that the range of motion, i.e. the maximal displacement of top nodes, will also increase with the increase of angles α and β. This cylinder, with a smaller n, may have a bistable behavior. When n is larger, the influence of n on the axial strains and external nodal loads is slight. The numerical results agree well with the analytical predictions. Moreover, the deployment of the cylinder with multi-stories is non-uniform, which deploys from the upper story to the lower story.

  3. Computer Aided Design: Instructional Manual. The North Dakota High Technology Mobile Laboratory Project.

    ERIC Educational Resources Information Center

    Cheng, Wan-Lee

    This instructional manual contains 12 learning activity packets for use in a workshop in computer-aided design and drafting (CADD). The lessons cover the following topics: introduction to computer graphics and computer-aided design/drafting; coordinate systems; advance space graphics hardware configuration and basic features of the IBM PC…

  4. [Numerical finite element modeling of custom car seat using computer aided design].

    PubMed

    Huang, Xuqi; Singare, Sekou

    2014-02-01

    A good cushion can not only provide the sitter with a high comfort, but also control the distribution of the hip pressure to reduce the incidence of diseases. The purpose of this study is to introduce a computer-aided design (CAD) modeling method of the buttocks-cushion using numerical finite element (FE) simulation to predict the pressure distribution on the buttocks-cushion interface. The buttock and the cushion model geometrics were acquired from a laser scanner, and the CAD software was used to create the solid model. The FE model of a true seated individual was developed using ANSYS software (ANSYS Inc, Canonsburg, PA). The model is divided into two parts, i.e. the cushion model made of foam and the buttock model represented by the pelvis covered with a soft tissue layer. Loading simulations consisted of imposing a vertical force of 520N on the pelvis, corresponding to the weight of the user upper extremity, and then solving iteratively the system.

  5. Computer-Aided Geometry Modeling

    NASA Technical Reports Server (NTRS)

    Shoosmith, J. N. (Compiler); Fulton, R. E. (Compiler)

    1984-01-01

    Techniques in computer-aided geometry modeling and their application are addressed. Mathematical modeling, solid geometry models, management of geometric data, development of geometry standards, and interactive and graphic procedures are discussed. The applications include aeronautical and aerospace structures design, fluid flow modeling, and gas turbine design.

  6. Investigation of geometric design in piezoelectric microelectromechanical systems diaphragms for ultrasonic energy harvesting

    NASA Astrophysics Data System (ADS)

    Shi, Qiongfeng; Wang, Tao; Kobayashi, Takeshi; Lee, Chengkuo

    2016-05-01

    Acoustic energy transfer (AET) has been widely used for contactless energy delivery to implantable devices. However, most of the energy harvesters (ultrasonic receivers) for AET are macro-scale transducers with large volume and limited operation bandwidth. Here, we propose and investigate two microelectromechanical systems diaphragm based piezoelectric ultrasonic energy harvesters (PUEHs) as an alternative for AET. The proposed PUEHs consist of micro-scale diaphragm array with different geometric parameter design. Diaphragms in PUEH-1 have large length to width ratio to achieve broadband property, while its energy harvesting performance is compromised. Diaphragms in PUEH-2 have smaller length to width ratio and thinner thickness to achieve both broadband property and good energy harvesting performance. Both PUEHs have miniaturized size and wide operation bandwidth that are ideally suitable to be integrated as power source for implantable biomedical devices. PUEH-1 has a merged -6 dB bandwidth of 74.5% with a central frequency of 350 kHz. PUEH-2 has two separate -6 dB bandwidth of 73.7%/30.8% with central frequencies of 285 kHz/650 kHz. They can adapt to various ultrasonic sources with different working frequency spectrum. Maximum output power is 34.3 nW and 84.3 nW for PUEH-1 and PUEH-2 at 1 mW/cm2 ultrasound intensity input, respectively. The associated power density is 0.734 μW/cm2 and 4.1 μW/cm2, respectively. Better energy harvesting performance is achieved for PUEH-2 because of the optimized length to width ratio and thickness design. Both PUEHs offer more alignment flexibility with more than 40% power when they are in the range of the ultrasound transmitter.

  7. DeMAID/GA USER'S GUIDE Design Manager's Aid for Intelligent Decomposition with a Genetic Algorithm

    NASA Technical Reports Server (NTRS)

    Rogers, James L.

    1996-01-01

    Many companies are looking for new tools and techniques to aid a design manager in making decisions that can reduce the time and cost of a design cycle. One tool that is available to aid in this decision making process is the Design Manager's Aid for Intelligent Decomposition (DeMAID). Since the initial release of DEMAID in 1989, numerous enhancements have been added to aid the design manager in saving both cost and time in a design cycle. The key enhancement is a genetic algorithm (GA) and the enhanced version is called DeMAID/GA. The GA orders the sequence of design processes to minimize the cost and time to converge to a solution. These enhancements as well as the existing features of the original version of DEMAID are described. Two sample problems are used to show how these enhancements can be applied to improve the design cycle. This report serves as a user's guide for DeMAID/GA.

  8. An investigation of constraint-based component-modeling for knowledge representation in computer-aided conceptual design

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1990-01-01

    Originally, computer programs for engineering design focused on detailed geometric design. Later, computer programs for algorithmically performing the preliminary design of specific well-defined classes of objects became commonplace. However, due to the need for extreme flexibility, it appears unlikely that conventional programming techniques will prove fruitful in developing computer aids for engineering conceptual design. The use of symbolic processing techniques, such as object-oriented programming and constraint propagation, facilitate such flexibility. Object-oriented programming allows programs to be organized around the objects and behavior to be simulated, rather than around fixed sequences of function- and subroutine-calls. Constraint propagation allows declarative statements to be understood as designating multi-directional mathematical relationships among all the variables of an equation, rather than as unidirectional assignments to the variable on the left-hand side of the equation, as in conventional computer programs. The research has concentrated on applying these two techniques to the development of a general-purpose computer aid for engineering conceptual design. Object-oriented programming techniques are utilized to implement a user-extensible database of design components. The mathematical relationships which model both geometry and physics of these components are managed via constraint propagation. In addition, to this component-based hierarchy, special-purpose data structures are provided for describing component interactions and supporting state-dependent parameters. In order to investigate the utility of this approach, a number of sample design problems from the field of aerospace engineering were implemented using the prototype design tool, Rubber Airplane. The additional level of organizational structure obtained by representing design knowledge in terms of components is observed to provide greater convenience to the program user, and to

  9. Teaching Computer-Aided Design of Fluid Flow and Heat Transfer Engineering Equipment.

    ERIC Educational Resources Information Center

    Gosman, A. D.; And Others

    1979-01-01

    Describes a teaching program for fluid mechanics and heat transfer which contains both computer aided learning (CAL) and computer aided design (CAD) components and argues that the understanding of the physical and numerical modeling taught in the CAL course is essential to the proper implementation of CAD. (Author/CMV)

  10. 23 CFR 636.104 - Does this part apply to all Federal-aid design-build projects?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ENGINEERING AND TRAFFIC OPERATIONS DESIGN-BUILD CONTRACTING General § 636.104 Does this part apply to all Federal-aid design-build projects? The provisions of this part apply to all Federal-aid design-build... 23 Highways 1 2010-04-01 2010-04-01 false Does this part apply to all Federal-aid...

  11. Computer aided design of microcircuits. Citations from the NTIS data base

    NASA Astrophysics Data System (ADS)

    Reed, W. E.

    1980-09-01

    Government sponsored research covering the computer aided design, modeling, layout, and packaging of integrated and other microelectronic circuits are cited. Computer programs and the use of computer graphics are included.

  12. Correction of facial and mandibular asymmetry using a computer aided design/computer aided manufacturing prefabricated titanium implant.

    PubMed

    Watson, Jason; Hatamleh, Muhanad; Alwahadni, Ahed; Srinivasan, Dilip

    2014-05-01

    Patients with significant craniofacial asymmetry may have functional problems associated with their occlusion and aesthetic concerns related to the imbalance in soft and hard tissue profiles. This report details a case of facial asymmetry secondary to left mandible angle deficiency due to undergoing previous radiotherapy. We describe the correction of the bony deformity using computer aided design/computer aided manufacturing custom-made titanium onlay using novel direct metal laser sintering. The direct metal laser sintering onlay proved a very accurate operative fit and showed a good aesthetic correction of the bony defect with no reported complications postoperatively. It is a useful low-morbidity technique, and there is no resorption or associated donor-site complications.

  13. Dual-scan technique for the customization of zirconia computer-aided design/computer-aided manufacturing frameworks.

    PubMed

    Andreiuolo, Rafael Ferrone; Sabrosa, Carlos Eduardo; Dias, Katia Regina H Cervantes

    2013-09-01

    The use of bi-layered all-ceramic crowns has continuously grown since the introduction of computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia cores. Unfortunately, despite the outstanding mechanical properties of zirconia, problems related to porcelain cracking or chipping remain. One of the reasons for this is that ceramic copings are usually milled to uniform thicknesses of 0.3-0.6 mm around the whole tooth preparation. This may not provide uniform thickness or appropriate support for the veneering porcelain. To prevent these problems, the dual-scan technique demonstrates an alternative that allows the restorative team to customize zirconia CAD/CAM frameworks with adequate porcelain thickness and support in a simple manner.

  14. Assessment of Chair-side Computer-Aided Design and Computer-Aided Manufacturing Restorations: A Review of the Literature

    PubMed Central

    Baroudi, Kusai; Ibraheem, Shukran Nasser

    2015-01-01

    Background: This paper aimed to evaluate the application of computer-aided design and computer-aided manufacturing (CAD-CAM) technology and the factors that affect the survival of restorations. Materials and Methods: A thorough literature search using PubMed, Medline, Embase, Science Direct, Wiley Online Library and Grey literature were performed from the year 2004 up to June 2014. Only relevant research was considered. Results: The use of chair-side CAD/CAM systems is promising in all dental branches in terms of minimizing time and effort made by dentists, technicians and patients for restoring and maintaining patient oral function and aesthetic, while providing high quality outcome. Conclusion: The way of producing and placing the restorations made with the chair-side CAD/CAM (CEREC and E4D) devices is better than restorations made by conventional laboratory procedures. PMID:25954082

  15. Fixed-point Design of the Lattice-reduction-aided Iterative Detection and Decoding Receiver for Coded MIMO Systems

    DTIC Science & Technology

    2011-01-01

    REPORT Fixed-point Design of theLattice-reduction-aided Iterative Detection andDecoding Receiver for Coded MIMO Systems 14. ABSTRACT 16. SECURITY...298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 - Fixed-point Design of theLattice-reduction-aided Iterative Detection andDecoding Receiver for Coded ...important, this report illustrates the performance of coded LR aided detectors. 1 Fixed-point Design of the Lattice-reduction-aided Iterative Detection and

  16. Analytical Design Package (ADP2): A computer aided engineering tool for aircraft transparency design

    NASA Technical Reports Server (NTRS)

    Wuerer, J. E.; Gran, M.; Held, T. W.

    1994-01-01

    The Analytical Design Package (ADP2) is being developed as a part of the Air Force Frameless Transparency Program (FTP). ADP2 is an integrated design tool consisting of existing analysis codes and Computer Aided Engineering (CAE) software. The objective of the ADP2 is to develop and confirm an integrated design methodology for frameless transparencies, related aircraft interfaces, and their corresponding tooling. The application of this methodology will generate high confidence for achieving a qualified part prior to mold fabrication. ADP2 is a customized integration of analysis codes, CAE software, and material databases. The primary CAE integration tool for the ADP2 is P3/PATRAN, a commercial-off-the-shelf (COTS) software tool. The open architecture of P3/PATRAN allows customized installations with different applications modules for specific site requirements. Integration of material databases allows the engineer to select a material, and those material properties are automatically called into the relevant analysis code. The ADP2 materials database will be composed of four independent schemas: CAE Design, Processing, Testing, and Logistics Support. The design of ADP2 places major emphasis on the seamless integration of CAE and analysis modules with a single intuitive graphical interface. This tool is being designed to serve and be used by an entire project team, i.e., analysts, designers, materials experts, and managers. The final version of the software will be delivered to the Air Force in Jan. 1994. The Analytical Design Package (ADP2) will then be ready for transfer to industry. The package will be capable of a wide range of design and manufacturing applications.

  17. The Research of Computer Aided Farm Machinery Designing Method Based on Ergonomics

    NASA Astrophysics Data System (ADS)

    Gao, Xiyin; Li, Xinling; Song, Qiang; Zheng, Ying

    Along with agricultural economy development, the farm machinery product type Increases gradually, the ergonomics question is also getting more and more prominent. The widespread application of computer aided machinery design makes it possible that farm machinery design is intuitive, flexible and convenient. At present, because the developed computer aided ergonomics software has not suitable human body database, which is needed in view of farm machinery design in China, the farm machinery design have deviation in ergonomics analysis. This article puts forward that using the open database interface procedure in CATIA to establish human body database which aims at the farm machinery design, and reading the human body data to ergonomics module of CATIA can product practical application virtual body, using human posture analysis and human activity analysis module to analysis the ergonomics in farm machinery, thus computer aided farm machinery designing method based on engineering can be realized.

  18. Interactive computer aided technology, evolution in the design/manufacturing process

    NASA Technical Reports Server (NTRS)

    English, C. H.

    1975-01-01

    A powerful computer-operated three dimensional graphic system and associated auxiliary computer equipment used in advanced design, production design, and manufacturing was described. This system has made these activities more productive than when using older and more conventional methods to design and build aerospace vehicles. With the use of this graphic system, designers are now able to define parts using a wide variety of geometric entities, define parts as fully surface 3-dimensional models as well as "wire-frame" models. Once geometrically defined, the designer is able to take section cuts of the surfaced model and automatically determine all of the section properties of the planar cut, lightpen detect all of the surface patches and automatically determine the volume and weight of the part. Further, his designs are defined mathematically at a degree of accuracy never before achievable.

  19. Computer-Aided Design Of Turbine Blades And Vanes

    NASA Technical Reports Server (NTRS)

    Hsu, Wayne Q.

    1988-01-01

    Quasi-three-dimensional method for determining aerothermodynamic configuration of turbine uses computer-interactive analysis and design and computer-interactive graphics. Design procedure executed rapidly so designer easily repeats it to arrive at best performance, size, structural integrity, and engine life. Sequence of events in aerothermodynamic analysis and design starts with engine-balance equations and ends with boundary-layer analysis and viscous-flow calculations. Analysis-and-design procedure interactive and iterative throughout.

  20. NREL Software Aids Offshore Wind Turbine Designs (Fact Sheet)

    SciTech Connect

    Not Available

    2013-10-01

    NREL researchers are supporting offshore wind power development with computer models that allow detailed analyses of both fixed and floating offshore wind turbines. While existing computer-aided engineering (CAE) models can simulate the conditions and stresses that a land-based wind turbine experiences over its lifetime, offshore turbines require the additional considerations of variations in water depth, soil type, and wind and wave severity, which also necessitate the use of a variety of support-structure types. NREL's core wind CAE tool, FAST, models the additional effects of incident waves, sea currents, and the foundation dynamics of the support structures.

  1. Creation of Anatomically Accurate Computer-Aided Design (CAD) Solid Models from Medical Images

    NASA Technical Reports Server (NTRS)

    Stewart, John E.; Graham, R. Scott; Samareh, Jamshid A.; Oberlander, Eric J.; Broaddus, William C.

    1999-01-01

    Most surgical instrumentation and implants used in the world today are designed with sophisticated Computer-Aided Design (CAD)/Computer-Aided Manufacturing (CAM) software. This software automates the mechanical development of a product from its conceptual design through manufacturing. CAD software also provides a means of manipulating solid models prior to Finite Element Modeling (FEM). Few surgical products are designed in conjunction with accurate CAD models of human anatomy because of the difficulty with which these models are created. We have developed a novel technique that creates anatomically accurate, patient specific CAD solids from medical images in a matter of minutes.

  2. Computer-aided design of stripline ferrite junction circulators

    NASA Technical Reports Server (NTRS)

    Uzdy, Z.

    1980-01-01

    A general design procedure is presented for stripline Y-junction circulators employing solid dielectric between ground planes. The resonator design and impedance matching are derived in a form suitable for computer evaluation. The procedure is applicable to cases where either the circulator bandwidth or the ground plane spacing is specified. An experimental S-band switching circulator design illustrates the technique.

  3. Asymmetric design for Compound Elliptical Concentrators (CEC) and its geometric flux implications

    NASA Astrophysics Data System (ADS)

    Jiang, Lun; Winston, Roland

    2015-08-01

    The asymmetric compound elliptical concentrator (CEC) has been a less discussed subject in the nonimaging optics society. The conventional way of understanding an ideal concentrator is based on maximizing the concentration ratio based on a uniformed acceptance angle. Although such an angle does not exist in the case of CEC, the thermodynamic laws still hold and we can produce concentrators with the maximum concentration ratio allowed by them. Here we restate the problem and use the string method to solve this general problem. Built on the solution, we can discover groups of such ideal concentrators using geometric flux field, or flowline method.

  4. On designing geometric motion planners to solve regulating and trajectory tracking problems for robotic locomotion systems.

    PubMed

    Asnafi, Alireza; Mahzoon, Mojtaba

    2011-09-01

    Based on a geometric fiber bundle structure, a generalized method to solve both regulation and trajectory tracking problems for locomotion systems is presented. The method is especially applied to two case studies of robotic locomotion systems; a three link articulated fish-like robot as a prototype of locomotion systems with symmetry, and the snakeboard as a prototype of mixed locomotion systems. Our results show that although these motion planners have an open loop structure, due to their generalities, they can steer case studies with negligible errors for almost any complicated path.

  5. Methodology for Benefit Analysis of CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) in USN Shipyards.

    DTIC Science & Technology

    1984-03-01

    D-Ri38 398 METHODOLOGY FOR BENEFIT ANALYSIS OF CAD/CAM / (COMPUTER-HIDED DESIGN/COMPUTER-AIDED MANUFACTURING) IN USN SHIPYARDS(U) NAVAL POSTGRADUATE...Monterey, California DT I ~" t • EB3 1984 THESIS METHODOLOGY FOR BENEFIT ANALYSIS OF CAD/CAM IN USN SHIPYARDS by Richard B. Grahlman March 1984 Thesis...REPORT & PERIOD COVERED Methodology for Benefit Analysis of CAD/CAM Mastrch 1984 i in UM Sipyads. PERFORMIANG ORG. REPORT NUM8ER 7- AUHOW11111 4

  6. Feline Immunodeficiency Virus Model for Designing HIV/AIDS Vaccines

    PubMed Central

    Yamamoto, Janet K.; Sanou, Missa P.; Abbott, Jeffrey R.; Coleman, James K.

    2013-01-01

    Feline immunodeficiency virus (FIV) discovered in 1986 is a lentivirus that causes AIDS in domestic cats. FIV is classified into five subtypes (A–E), and all subtypes and circulating intersubtype recombinants have been identified throughout the world. A commercial FIV vaccine, consisting of inactivated subtype-A and –D viruses (Fel-O-Vax FIV, Fort Dodge Animal Health), was released in the United States in 2002. The United States Department of Agriculture approved the commercial release of Fel-O-Vax FIV based on two efficacy trials using 105 laboratory cats and a major safety trial performed on 689 pet cats. The prototype and commercial FIV vaccines had broad prophylactic efficacy against global FIV subtypes and circulating intersubtype recombinants. The mechanisms of cross-subtype efficacy are attributed to FIV-specific T-cell immunity. Findings from these studies are being used to define the prophylactic epitopes needed for an HIV-1 vaccine for humans. PMID:20210778

  7. Geometric optimization of helical tail designs to calibrate swimming velocities of microswimmers

    NASA Astrophysics Data System (ADS)

    Demir, Ebru; Yesilyurt, Serhat

    2014-11-01

    Artificial microswimmers present both a solution and a challenge as alternative tools to be used in medical applications, namely, drug delivery and minimally invasive surgeries. Achieving desired amount of controlled displacement of microswimmers at desired velocities plays an important role in determining the success of such applications. In this study, a non-dimensionalised CFD model is utilised to investigate the effects of various geometrical parameters on swimming velocities of microswimmers with helical tails in cylindrical confinements, such as helix wavelength, helical body thickness, and diameter. To this end, a ``one wavelength long'' helical tail is placed inside a cylindrical channel of the same length with periodic boundary conditions applied to both ends, constituting an infinite helix model. As the channel diameter is kept constant, a parametric study of abovementioned geometric identities is conducted to observe the change in the swimming velocities. Furthermore, effects of helix-channel eccentricity and helix rotation about the longitudinal axis on swimming velocity of a dimensionally optimized helix are investigated to reveal near wall effects. The results are found to be in good agreement with the theoretical models existing in the literature.

  8. Osseo-mechanical induction of extra-cortical plates with reference to their surface properties and geometric designs.

    PubMed

    Coathup, M J; Bates, P; Cool, P; Walker, P S; Blumenthal, N; Cobb, J P; Blunn, G W

    1999-04-01

    The purpose of this investigation was to determine which geometric and surface properties encouraged optimal ingrowth and bonding of bone to an extra-cortical plate. Forty-eight titanium extra-cortical plates were attached onto the left and right femora of adult rabbits. The plates were of six different designs and the osseoconductive effects of four surfaces were examined. A roughened titanium surface, a plasma sprayed HA coating of low crystallinity (57%) and a solution precipitated calcium phosphate coating were compared with a plasma sprayed crystalline hydroxyapatite coating (crystallinity 85%). Thin sections were prepared by grinding and polishing. Bone formation and the interface around the plates were investigated histologically and computer and morphometric analyses were used to quantify new bone formation, bone apposition onto the plate, bone porosity and the condition of the HA coating. The study found that a hydroxyapatite coating (with the exception of the solution precipitated coating) had significantly greater interfacial contact with bone when compared to a roughened titanium surface, and that significantly more bone attached to a crystalline HA coating compared with the HA coating of lower crystallinity although significantly more bone formed in the vicinity of the lower crystalline HA coating. Differences in the bony reaction induced by the various geometric designs were evident and the optimal plate design requires either holes or slots along its length as this encouraged bone ingrowth into the plate.

  9. Design of all-optical, hot-electron current-direction-switching device based on geometrical asymmetry.

    PubMed

    Kumarasinghe, Chathurangi S; Premaratne, Malin; Gunapala, Sarath D; Agrawal, Govind P

    2016-02-18

    We propose a nano-scale current-direction-switching device(CDSD) that operates based on the novel phenomenon of geometrical asymmetry between two hot-electron generating plasmonic nanostructures. The proposed device is easy to fabricate and economical to develop compared to most other existing designs. It also has the ability to function without external wiring in nano or molecular circuitry since it is powered and controlled optically. We consider a such CDSD made of two dissimilar nanorods separated by a thin but finite potential barrier and theoretically derive the frequency-dependent electron/current flow rate. Our analysis takes in to account the quantum dynamics of electrons inside the nanorods under a periodic optical perturbation that are confined by nanorod boundaries, modelled as finite cylindrical potential wells. The influence of design parameters, such as geometric difference between the two nanorods, their volumes and the barrier width on quality parameters such as frequency-sensitivity of the current flow direction, magnitude of the current flow, positive to negative current ratio, and the energy conversion efficiency is discussed by considering a device made of Ag/TiO2/Ag. Theoretical insight and design guidelines presented here are useful for customizing our proposed CDSD for applications such as self-powered logic gates, power supplies, and sensors.

  10. Design of all-optical, hot-electron current-direction-switching device based on geometrical asymmetry

    PubMed Central

    Kumarasinghe, Chathurangi S.; Premaratne, Malin; Gunapala, Sarath D.; Agrawal, Govind P.

    2016-01-01

    We propose a nano-scale current-direction-switching device(CDSD) that operates based on the novel phenomenon of geometrical asymmetry between two hot-electron generating plasmonic nanostructures. The proposed device is easy to fabricate and economical to develop compared to most other existing designs. It also has the ability to function without external wiring in nano or molecular circuitry since it is powered and controlled optically. We consider a such CDSD made of two dissimilar nanorods separated by a thin but finite potential barrier and theoretically derive the frequency-dependent electron/current flow rate. Our analysis takes in to account the quantum dynamics of electrons inside the nanorods under a periodic optical perturbation that are confined by nanorod boundaries, modelled as finite cylindrical potential wells. The influence of design parameters, such as geometric difference between the two nanorods, their volumes and the barrier width on quality parameters such as frequency-sensitivity of the current flow direction, magnitude of the current flow, positive to negative current ratio, and the energy conversion efficiency is discussed by considering a device made of Ag/TiO2/Ag. Theoretical insight and design guidelines presented here are useful for customizing our proposed CDSD for applications such as self-powered logic gates, power supplies, and sensors. PMID:26887286

  11. Design of all-optical, hot-electron current-direction-switching device based on geometrical asymmetry

    NASA Astrophysics Data System (ADS)

    Kumarasinghe, Chathurangi S.; Premaratne, Malin; Gunapala, Sarath D.; Agrawal, Govind P.

    2016-02-01

    We propose a nano-scale current-direction-switching device(CDSD) that operates based on the novel phenomenon of geometrical asymmetry between two hot-electron generating plasmonic nanostructures. The proposed device is easy to fabricate and economical to develop compared to most other existing designs. It also has the ability to function without external wiring in nano or molecular circuitry since it is powered and controlled optically. We consider a such CDSD made of two dissimilar nanorods separated by a thin but finite potential barrier and theoretically derive the frequency-dependent electron/current flow rate. Our analysis takes in to account the quantum dynamics of electrons inside the nanorods under a periodic optical perturbation that are confined by nanorod boundaries, modelled as finite cylindrical potential wells. The influence of design parameters, such as geometric difference between the two nanorods, their volumes and the barrier width on quality parameters such as frequency-sensitivity of the current flow direction, magnitude of the current flow, positive to negative current ratio, and the energy conversion efficiency is discussed by considering a device made of Ag/TiO2/Ag. Theoretical insight and design guidelines presented here are useful for customizing our proposed CDSD for applications such as self-powered logic gates, power supplies, and sensors.

  12. Formal design methods for reliable computer-aided diagnosis: a review.

    PubMed

    Faust, Oliver; Acharya, U Rajendra; Tamura, Toshiyo

    2012-01-01

    Physiological signals, medical images, and biosystems can be used to access the health of a subject and they can support clinicians by improving the diagnosis for treatment purposes. Computer-aided diagnosis (CAD) in healthcare applications can help in automated decision making, visualization and extraction of hidden complex features to aid in the clinical diagnosis. These CAD systems focus on improving the quality of patient care with a minimum of fault due to device failures. In this paper, we argue that a formal and model driven design methodology can lead to systems which meet this requirement. Modeling is not new to CAD, but modeling for systems design is less explored. Therefore, we discuss selected systems design techniques and provide a more concrete design example on computer-aided diagnosis and automated decision making.

  13. Computer-aided methods in bespoke breast prosthesis design and fabrication.

    PubMed

    Eggbeer, D; Evans, P

    2011-01-01

    This case study presents a method of utilizing computer-aided design technologies to provide bespoke, external breast prostheses. The technique is illustrated through a case study of a mastectomy patient. Photogrammetry methods were used to capture the breast form when supported by a brassiere and the unsupported breast and defect side. Computer-aided design techniques were used to generate a digital prosthesis based upon the supported breast shape and with a fitting surface that matched the defect side. Furthermore, a two-part mould was designed and fabricated using rapid prototyping methods. A colour-matched prosthesis was then fabricated in a gel-based, platinum-cured silicone.

  14. CFD Aided Design and Production of Hydraulic Turbines

    NASA Astrophysics Data System (ADS)

    Kaplan, Alper; Cetinturk, Huseyin; Demirel, Gizem; Ayli, Ece; Celebioglu, Kutay; Aradag, Selin; ETU Hydro Research Center Team

    2014-11-01

    Hydraulic turbines are turbo machines which produce electricity from hydraulic energy. Francis type turbines are the most common one in use today. The design of these turbines requires high engineering effort since each turbine is tailor made due to different head and discharge. Therefore each component of the turbine is designed specifically. During the last decades, Computational Fluid Dynamics (CFD) has become very useful tool to predict hydraulic machinery performance and save time and money for designers. This paper describes a design methodology to optimize a Francis turbine by integrating theoretical and experimental fundamentals of hydraulic machines and commercial CFD codes. Specific turbines are designed and manufactured with the help of a collaborative CFD/CAD/CAM methodology based on computational fluid dynamics and five-axis machining for hydraulic electric power plants. The details are presented in this study. This study is financially supported by Turkish Ministry of Development.

  15. Computer-aided design tools for economical MEMS fabrication processes

    NASA Astrophysics Data System (ADS)

    Schneider, Christian; Priebe, Andreas; Brueck, Rainer; Hahn, Kai

    1999-03-01

    Since the early 70s when microsystem technology was first introduce an enormous market for MST-products has been developed. Airbag sensors, micro pumps, ink jet nozzles etc. and the market is just about to start up. Establishing these products for a reasonable price requires mass production. Meanwhile, also computer-based design-tools have been developed in order to reduce the expenses for MST-design. In contrast to other physical design processes like e.g. in micro electronics, MEMS physical design is characterized by the fact that each product requires a tailored sequence of fabrication steps, usually selected from a variety of processing alternatives. The selection from these alternatives is based on economical constraints. Therefore, the design has a strong influence on the money and time spent to take an MST-product to market.

  16. Aiding Design of Wave Energy Converters via Computational Simulations

    NASA Astrophysics Data System (ADS)

    Jebeli Aqdam, Hejar; Ahmadi, Babak; Raessi, Mehdi; Tootkaboni, Mazdak

    2015-11-01

    With the increasing interest in renewable energy sources, wave energy converters will continue to gain attention as a viable alternative to current electricity production methods. It is therefore crucial to develop computational tools for the design and analysis of wave energy converters. A successful design requires balance between the design performance and cost. Here an analytical solution is used for the approximate analysis of interactions between a flap-type wave energy converter (WEC) and waves. The method is verified using other flow solvers and experimental test cases. Then the model is used in conjunction with a powerful heuristic optimization engine, Charged System Search (CSS) to explore the WEC design space. CSS is inspired by charged particles behavior. It searches the design space by considering candidate answers as charged particles and moving them based on the Coulomb's laws of electrostatics and Newton's laws of motion to find the global optimum. Finally the impacts of changes in different design parameters on the power takeout of the superior WEC designs are investigated. National Science Foundation, CBET-1236462.

  17. A New Family of Interpolatory Non-Stationary Subdivision Schemes for Curve Design in Geometric Modeling

    NASA Astrophysics Data System (ADS)

    Conti, Costanza; Romani, Lucia

    2010-09-01

    Univariate subdivision schemes are efficient iterative methods to generate smooth limit curves starting from a sequence of arbitrary points. Aim of this paper is to present and investigate a new family of 6-point interpolatory non-stationary subdivision schemes capable of reproducing important curves of great interest in geometric modeling and engineering applications, if starting from uniformly spaced initial samples. This new family can reproduce conic sections since it is obtained by a parameter depending affine combination of the cubic exponential B-spline symbol generating functions in the space V4,γ = {1,x,etx,e-tx} with t∈{0,s,is|s>0}. Moreover, the free parameter can be chosen to reproduce also other interesting analytic curves by imposing the algebraic conditions for the reproduction of an additional pair of exponential polynomials giving rise to different extensions of the space V4,γ.

  18. A critical overview of analytical aids of design

    SciTech Connect

    Esat, I.

    1996-12-31

    The paper discusses effectiveness of some of the most important analytical tools of design in terms of their relationship to the design integration. The paper finally concludes that the level of integration remains rather superficial and success is only in certain areas relating to the downstream aspects of design. The degree of integration, particularly in the early stages of design activity, such as conceptualization remains very little. More importantly the paper points to the signs of stagnation, despite of phenomenal progress in every aspects of science, in many areas of science and engineering. The main cause of the stagnation is the curse of dimensionality and the complexity. The complexity now effecting every aspects of science and engineering. From the continuum mechanics to scheduling problems, ineffectiveness of the analytical tools of science and engineering becoming too obvious.

  19. WASTE REDUCTION USING COMPUTER-AIDED DESIGN TOOLS

    EPA Science Inventory

    Growing environmental concerns have spurred considerable interest in pollution prevention. In most instances, pollution prevention involves introducing radical changes to the design of processes so that waste generation is minimized.
    Process simulators can be effective tools i...

  20. Computer-Aided Apparel Design in University Curricula.

    ERIC Educational Resources Information Center

    Belleau, Bonnie D.; Bourgeois, Elva B.

    1991-01-01

    As computer-assisted design (CAD) become an integral part of the fashion industry, universities must integrate CAD into the apparel curriculum. Louisiana State University's curriculum enables students to collaborate in CAD problem solving with industry personnel. (SK)

  1. Computer-aided space shuttle orbiter wing design study

    NASA Technical Reports Server (NTRS)

    Phillips, W. P.; Decker, J. P.; Rau, T. R.; Glatt, C. R.

    1974-01-01

    An analytical and experimental investigation has been made to provide a space shuttle orbiter wing design that met the guideline requirements of landing performance, stability, and hypersonic trim for a specified center-of-gravity envelope. The analytical study was facilitated by the use of the Optimal Design Integration system (ODIN) and the experimental part of the investigation was conducted in the Langley low-turbulence pressure tunnel and the Langley continuous-flow hypersonic tunnel.

  2. Accuracy of different types of computer-aided design/computer-aided manufacturing surgical guides for dental implant placement

    PubMed Central

    Geng, Wei; Liu, Changying; Su, Yucheng; Li, Jun; Zhou, Yanmin

    2015-01-01

    Purpose: To evaluate the clinical outcomes of implants placed using different types of computer-aided design/computer-aided manufacturing (CAD/CAM) surgical guides, including partially guided and totally guided templates, and determine the accuracy of these guides Materials and methods: In total, 111 implants were placed in 24 patients using CAD/CAM surgical guides. After implant insertion, the positions and angulations of the placed implants relative to those of the planned ones were determined using special software that matched pre- and postoperative computed tomography (CT) images, and deviations were calculated and compared between the different guides and templates. Results: The mean angular deviations were 1.72 ± 1.67 and 2.71 ± 2.58, the mean deviations in position at the neck were 0.27 ± 0.24 and 0.69 ± 0.66 mm, the mean deviations in position at the apex were 0.37 ± 0.35 and 0.94 ± 0.75 mm, and the mean depth deviations were 0.32 ± 0.32 and 0.51 ± 0.48 mm with tooth- and mucosa-supported stereolithographic guides, respectively (P < .05 for all). The mean distance deviations when partially guided (29 implants) and totally guided templates (30 implants) were used were 0.54 ± 0.50 mm and 0.89 ± 0.78 mm, respectively, at the neck and 1.10 ± 0.85 mm and 0.81 ± 0.64 mm, respectively, at the apex, with corresponding mean angular deviations of 2.56 ± 2.23° and 2.90 ± 3.0° (P > .05 for all). Conclusions: Tooth-supported surgical guides may be more accurate than mucosa-supported guides, while both partially and totally guided templates can simplify surgery and aid in optimal implant placement. PMID:26309497

  3. Using simulation to aid trial design: Ring-vaccination trials

    PubMed Central

    Hitchings, Matt David Thomas; Grais, Rebecca Freeman

    2017-01-01

    Background The 2014–6 West African Ebola epidemic highlights the need for rigorous, rapid clinical trial methods for vaccines. A challenge for trial design is making sample size calculations based on incidence within the trial, total vaccine effect, and intracluster correlation, when these parameters are uncertain in the presence of indirect effects of vaccination. Methods and findings We present a stochastic, compartmental model for a ring vaccination trial. After identification of an index case, a ring of contacts is recruited and either vaccinated immediately or after 21 days. The primary outcome of the trial is total vaccine effect, counting cases only from a pre-specified window in which the immediate arm is assumed to be fully protected and the delayed arm is not protected. Simulation results are used to calculate necessary sample size and estimated vaccine effect. Under baseline assumptions about vaccine properties, monthly incidence in unvaccinated rings and trial design, a standard sample-size calculation neglecting dynamic effects estimated that 7,100 participants would be needed to achieve 80% power to detect a difference in attack rate between arms, while incorporating dynamic considerations in the model increased the estimate to 8,900. This approach replaces assumptions about parameters at the ring level with assumptions about disease dynamics and vaccine characteristics at the individual level, so within this framework we were able to describe the sensitivity of the trial power and estimated effect to various parameters. We found that both of these quantities are sensitive to properties of the vaccine, to setting-specific parameters over which investigators have little control, and to parameters that are determined by the study design. Conclusions Incorporating simulation into the trial design process can improve robustness of sample size calculations. For this specific trial design, vaccine effectiveness depends on properties of the ring

  4. Computer aided optimal design of compressed air energy storage systems

    NASA Astrophysics Data System (ADS)

    Ahrens, F. W.; Sharma, A.; Ragsdell, K. M.

    1980-07-01

    An automated procedure for the design of Compressed Air Energy Storage (CAES) systems is presented. The procedure relies upon modern nonlinear programming algorithms, decomposition theory, and numerical models of the various system components. Two modern optimization methods are employed; BIAS, a Method of Multipliers code and OPT, a Generalized Reduced Gradient code. The procedure is demonstrated by the design of a CAES facility employing the Media, Illinois Galesville aquifer as the reservoir. The methods employed produced significant reduction in capital and operating cost, and in number of aquifer wells required.

  5. Online Design Aid for Evaluating Manure Pit Ventilation Systems to Reduce Entry Risk.

    PubMed

    Manbeck, Harvey B; Hofstetter, Daniel W; Murphy, Dennis J; Puri, Virendra M

    2016-01-01

    On-farm manure storage pits contain both toxic and asphyxiating gases such as hydrogen sulfide, carbon dioxide, methane, and ammonia. Farmers and service personnel occasionally need to enter these pits to conduct repair and maintenance tasks. One intervention to reduce the toxic and asphyxiating gas exposure risk to farm workers when entering manure pits is manure pit ventilation. This article describes an online computational fluid dynamics-based design aid for evaluating the effectiveness of manure pit ventilation systems to reduce the concentrations of toxic and asphyxiating gases in the manure pits. This design aid, developed by a team of agricultural engineering and agricultural safety specialists at Pennsylvania State University, represents the culmination of more than a decade of research and technology development effort. The article includes a summary of the research efforts leading to the online design aid development and describes protocols for using the online design aid, including procedures for data input and for accessing design aid results. Design aid results include gas concentration decay and oxygen replenishment curves inside the manure pit and inside the barns above the manure pits, as well as animated motion pictures of individual gas concentration decay and oxygen replenishment in selected horizontal and vertical cut plots in the manure pits and barns. These results allow the user to assess (1) how long one needs to ventilate the pits to remove toxic and asphyxiating gases from the pit and barn, (2) from which portions of the barn and pit these gases are most and least readily evacuated, and (3) whether or not animals and personnel need to be removed from portions of the barn above the manure pit being ventilated.

  6. Online Design Aid for Evaluating Manure Pit Ventilation Systems to Reduce Entry Risk

    PubMed Central

    Manbeck, Harvey B.; Hofstetter, Daniel W.; Murphy, Dennis J.; Puri, Virendra M.

    2016-01-01

    On-farm manure storage pits contain both toxic and asphyxiating gases such as hydrogen sulfide, carbon dioxide, methane, and ammonia. Farmers and service personnel occasionally need to enter these pits to conduct repair and maintenance tasks. One intervention to reduce the toxic and asphyxiating gas exposure risk to farm workers when entering manure pits is manure pit ventilation. This article describes an online computational fluid dynamics-based design aid for evaluating the effectiveness of manure pit ventilation systems to reduce the concentrations of toxic and asphyxiating gases in the manure pits. This design aid, developed by a team of agricultural engineering and agricultural safety specialists at Pennsylvania State University, represents the culmination of more than a decade of research and technology development effort. The article includes a summary of the research efforts leading to the online design aid development and describes protocols for using the online design aid, including procedures for data input and for accessing design aid results. Design aid results include gas concentration decay and oxygen replenishment curves inside the manure pit and inside the barns above the manure pits, as well as animated motion pictures of individual gas concentration decay and oxygen replenishment in selected horizontal and vertical cut plots in the manure pits and barns. These results allow the user to assess (1) how long one needs to ventilate the pits to remove toxic and asphyxiating gases from the pit and barn, (2) from which portions of the barn and pit these gases are most and least readily evacuated, and (3) whether or not animals and personnel need to be removed from portions of the barn above the manure pit being ventilated. PMID:27303661

  7. Special Technology Area Review on Computer Aided Design

    DTIC Science & Technology

    1993-03-01

    develop MHDL, AHDL , etc., not only to provide a common modeling language but also to support a robust design environment. This would include language...tools are critical. Analog synthesis requirements must be reflected in VHDL and AHDL (Analog Hardware Description Language) standards. The tools should

  8. Computer aided design of jet engine test cell exhaust systems

    SciTech Connect

    Collings, D.

    1982-01-01

    A computerized design procedure that provides a multi-directional analysis of available data is a proven method of developing accurate cost models and performing system trade-offs. The application to the engineering of exhaust silencing systems for jet engine test cells is discused.

  9. Design Principles for Computer-Aided Vocabulary Learning.

    ERIC Educational Resources Information Center

    Goodfellow, Robin

    1994-01-01

    Presents six principles for the design of adaptive computer-assisted language learning (CALL) programs for vocabulary that incorporate a theory describing quality in the learning outcome and linking it to the learner's approach. Highlights include interactivity; general architecture of a software system; and diagnosis and modification. (Contains…

  10. Types of Hearing Aids

    MedlinePlus

    ... Devices Consumer Products Hearing Aids Types of Hearing Aids Share Tweet Linkedin Pin it More sharing options ... some features for hearing aids? What are hearing aids? Hearing aids are sound-amplifying devices designed to ...

  11. Costs incurred by applying computer-aided design/computer-aided manufacturing techniques for the reconstruction of maxillofacial defects.

    PubMed

    Rustemeyer, Jan; Melenberg, Alex; Sari-Rieger, Aynur

    2014-12-01

    This study aims to evaluate the additional costs incurred by using a computer-aided design/computer-aided manufacturing (CAD/CAM) technique for reconstructing maxillofacial defects by analyzing typical cases. The medical charts of 11 consecutive patients who were subjected to the CAD/CAM technique were considered, and invoices from the companies providing the CAD/CAM devices were reviewed for every case. The number of devices used was significantly correlated with cost (r = 0.880; p < 0.001). Significant differences in mean costs were found between cases in which prebent reconstruction plates were used (€3346.00 ± €29.00) and cases in which they were not (€2534.22 ± €264.48; p < 0.001). Significant differences were also obtained between the costs of two, three and four devices, even when ignoring the cost of reconstruction plates. Additional fees provided by statutory health insurance covered a mean of 171.5% ± 25.6% of the cost of the CAD/CAM devices. Since the additional fees provide financial compensation, we believe that the CAD/CAM technique is suited for wide application and not restricted to complex cases. Where additional fees/funds are not available, the CAD/CAM technique might be unprofitable, so the decision whether or not to use it remains a case-to-case decision with respect to cost versus benefit.

  12. Fracture resistance of computer-aided design/computer-aided manufacturing-generated composite resin-based molar crowns.

    PubMed

    Harada, Akio; Nakamura, Keisuke; Kanno, Taro; Inagaki, Ryoichi; Örtengren, Ulf; Niwano, Yoshimi; Sasaki, Keiichi; Egusa, Hiroshi

    2015-04-01

    The aim of this study was to investigate whether different fabrication processes, such as the computer-aided design/computer-aided manufacturing (CAD/CAM) system or the manual build-up technique, affect the fracture resistance of composite resin-based crowns. Lava Ultimate (LU), Estenia C&B (EC&B), and lithium disilicate glass-ceramic IPS e.max press (EMP) were used. Four types of molar crowns were fabricated: CAD/CAM-generated composite resin-based crowns (LU crowns); manually built-up monolayer composite resin-based crowns (EC&B-monolayer crowns); manually built-up layered composite resin-based crowns (EC&B-layered crowns); and EMP crowns. Each type of crown was cemented to dies and the fracture resistance was tested. EC&B-layered crowns showed significantly lower fracture resistance compared with LU and EMP crowns, although there was no significant difference in flexural strength or fracture toughness between LU and EC&B materials. Micro-computed tomography and fractographic analysis showed that decreased strength probably resulted from internal voids in the EC&B-layered crowns introduced by the layering process. There was no significant difference in fracture resistance among LU, EC&B-monolayer, and EMP crowns. Both types of composite resin-based crowns showed fracture loads of >2000 N, which is higher than the molar bite force. Therefore, CAD/CAM-generated crowns, without internal defects, may be applied to molar regions with sufficient fracture resistance.

  13. Experience gained at ZAO Ural Turbine Works with the use of computer-aided design systems

    NASA Astrophysics Data System (ADS)

    Kortenko, V. V.; Valamin, A. E.; Shanturov, D. N.; Sokolov, E. V.; Toibich, S. V.; Glushchenko, A. N.

    2008-08-01

    The results of work accomplished in the field of computer-aided design at ZAO Ural Turbine Works (UTZ) are presented. A concept is described following which the tasks for a specialist’s workstations being developed at the UTZ are solved. Results from solution of problems with the use of modern numerical simulation computer programs for analyzing gas dynamic processes, casting, welding, and strength of complex structures are given. An example is given to show efficient use of a computer-aided design system for shifting an enterprise to a modern level of automation.

  14. Computer Aided Design of Computer Generated Holograms for electron beam fabrication

    NASA Technical Reports Server (NTRS)

    Urquhart, Kristopher S.; Lee, Sing H.; Guest, Clark C.; Feldman, Michael R.; Farhoosh, Hamid

    1989-01-01

    Computer Aided Design (CAD) systems that have been developed for electrical and mechanical design tasks are also effective tools for the process of designing Computer Generated Holograms (CGHs), particularly when these holograms are to be fabricated using electron beam lithography. CAD workstations provide efficient and convenient means of computing, storing, displaying, and preparing for fabrication many of the features that are common to CGH designs. Experience gained in the process of designing CGHs with various types of encoding methods is presented. Suggestions are made so that future workstations may further accommodate the CGH design process.

  15. The development of a spreadsheet-aided-engineering design tool for parachutes

    SciTech Connect

    Waye, D.E.; Whinery, L.D.

    1997-04-01

    A spreadsheet-aided engineering design tool has been developed to assist in the parachute design process. The new tool was developed during FY96 and utilized in the design of the flight termination parachute system for a 1900 lb. payload. Many modifications were made during the initial utilization of this tool. Work on the tool continues as the authors attempt to create an application tool for the parachute engineer.

  16. A New Design Strategy for Observing Lithium Oxide Growth-Evolution Interactions Using Geometric Catalyst Positioning.

    PubMed

    Ryu, Won-Hee; Gittleson, Forrest S; Li, Jinyang; Tong, Xiao; Taylor, André D

    2016-08-10

    Understanding the catalyzed formation and evolution of lithium-oxide products in Li-O2 batteries is central to the development of next-generation energy storage technology. Catalytic sites, while effective in lowering reaction barriers, often become deactivated when placed on the surface of an oxygen electrode due to passivation by solid products. Here we investigate a mechanism for alleviating catalyst deactivation by dispersing Pd catalytic sites away from the oxygen electrode surface in a well-structured anodic aluminum oxide (AAO) porous membrane interlayer. We observe the cross-sectional product growth and evolution in Li-O2 cells by characterizing products that grow from the electrode surface. Morphological and structural details of the products in both catalyzed and uncatalyzed cells are investigated independently from the influence of the oxygen electrode. We find that the geometric decoration of catalysts far from the conductive electrode surface significantly improves the reaction reversibility by chemically facilitating the oxidation reaction through local coordination with PdO surfaces. The influence of the catalyst position on product composition is further verified by ex situ X-ray photoelectron spectroscopy and Raman spectroscopy in addition to morphological studies.

  17. A new design strategy for observing lithium oxide growth-evolution interactions using geometric catalyst positioning

    SciTech Connect

    Ryu, Won -Hee; Gittleson, Forrest S.; Li, Jinyang; Tong, Xiao; Taylor, Andre D.

    2016-06-21

    Understanding the catalyzed formation and evolution of lithium-oxide products in Li-O2 batteries is central to the development of next-generation energy storage technology. Catalytic sites, while effective in lowering reaction barriers, often become deactivated when placed on the surface of an oxygen electrode due to passivation by solid products. Here we investigate a mechanism for alleviating catalyst deactivation by dispersing Pd catalytic sites away from the oxygen electrode surface in a well-structured anodic aluminum oxide (AAO) porous membrane interlayer. We observe the cross-sectional product growth and evolution in Li-O2 cells by characterizing products that grow from the electrode surface. Morphological and structural details of the products in both catalyzed and uncatalyzed cells are investigated independently from the influence of the oxygen electrode. We find that the geometric decoration of catalysts far from the conductive electrode surface significantly improves the reaction reversibility by chemically facilitating the oxidation reaction through local coordination with PdO surfaces. Lastly, the influence of the catalyst position on product composition is further verified by ex situ Xray photoelectron spectroscopy and Raman spectroscopy in addition to morphological studies.

  18. A new design strategy for observing lithium oxide growth-evolution interactions using geometric catalyst positioning

    DOE PAGES

    Ryu, Won -Hee; Gittleson, Forrest S.; Li, Jinyang; ...

    2016-06-21

    Understanding the catalyzed formation and evolution of lithium-oxide products in Li-O2 batteries is central to the development of next-generation energy storage technology. Catalytic sites, while effective in lowering reaction barriers, often become deactivated when placed on the surface of an oxygen electrode due to passivation by solid products. Here we investigate a mechanism for alleviating catalyst deactivation by dispersing Pd catalytic sites away from the oxygen electrode surface in a well-structured anodic aluminum oxide (AAO) porous membrane interlayer. We observe the cross-sectional product growth and evolution in Li-O2 cells by characterizing products that grow from the electrode surface. Morphological andmore » structural details of the products in both catalyzed and uncatalyzed cells are investigated independently from the influence of the oxygen electrode. We find that the geometric decoration of catalysts far from the conductive electrode surface significantly improves the reaction reversibility by chemically facilitating the oxidation reaction through local coordination with PdO surfaces. Lastly, the influence of the catalyst position on product composition is further verified by ex situ Xray photoelectron spectroscopy and Raman spectroscopy in addition to morphological studies.« less

  19. Intelligent Embedded Instruction for Computer-Aided Design (CAD) systems

    DTIC Science & Technology

    1988-10-01

    8217 convenience and according to their individual learning preferences. This benefit is extremely valuable for adult professionals whose needs may be highly...solving problems. Adult designers tend to develop their own personal ways of using CAD software which can optimize a system’s use. This ability has been...average age for subjects with more than 1 year of computer experience was 34 whereas those with less than 2 months of experience averaged 41 years old

  20. Design, fabrication, and testing of contact-aided compliant cellular mechanisms with curved walls

    NASA Astrophysics Data System (ADS)

    Cirone, Samantha A.; Hayes, Gregory R.; Babcox, Brian L.; Frecker, Mary; Adair, James H.; Lesieutre, George A.

    2011-03-01

    Contact-Aided Compliant Cellular Mechanisms (C3M) are compliant cellular structures with integrated contact mechanisms. The focus of the paper is on the design, fabrication, and testing of C3M with curved walls for high strain applications. It is shown that global strains were increased by replacing straight walls with curved walls in the traditional honeycomb structure, while the addition of contact mechanisms increased cell performance via stress relief in some cases. Furthermore, curved walls are beneficial for fabrication at the meso-scale. The basic curved honeycomb cell geometry is defined by a set of variables. These variables were optimized using Matlab and finite element analysis to find the best non-contact and contact-aided curved cell geometries as well as the cell geometry that provides the greatest stress relief. Currently, the most effective contact-aided curved honeycomb cell can withstand global strains approximately 160% greater than the most effective contact-aided, non-curved cell. Four different designs were fabricated via the Lost Mold-Rapid Infiltration Forming (LM-RIF) process. An array of the contact-aided optimized curved cell was then mechanically tested using a custom designed test rig, and the results were found to have a higher modulus of elasticity and lower global strain than the predictions. Despite these discrepancies, a high-strength highstrain cellular structure was developed, for potential use in morphing aircraft applications.

  1. A new design approach based on differential evolution algorithm for geometric optimization of magnetorheological brakes

    NASA Astrophysics Data System (ADS)

    Le-Duc, Thang; Ho-Huu, Vinh; Nguyen-Thoi, Trung; Nguyen-Quoc, Hung

    2016-12-01

    In recent years, various types of magnetorheological brakes (MRBs) have been proposed and optimized by different optimization algorithms that are integrated in commercial software such as ANSYS and Comsol Multiphysics. However, many of these optimization algorithms often possess some noteworthy shortcomings such as the trap of solutions at local extremes, or the limited number of design variables or the difficulty of dealing with discrete design variables. Thus, to overcome these limitations and develop an efficient computation tool for optimal design of the MRBs, an optimization procedure that combines differential evolution (DE), a gradient-free global optimization method with finite element analysis (FEA) is proposed in this paper. The proposed approach is then applied to the optimal design of MRBs with different configurations including conventional MRBs and MRBs with coils placed on the side housings. Moreover, to approach a real-life design, some necessary design variables of MRBs are considered as discrete variables in the optimization process. The obtained optimal design results are compared with those of available optimal designs in the literature. The results reveal that the proposed method outperforms some traditional approaches.

  2. A Functional Level Preprocessor for Computer Aided Digital Design.

    DTIC Science & Technology

    1980-12-01

    the parsing of ucer input, is based on that for the computer language, PASCAL [J2,1J. The procedure is tle author’s original design Each line of input...NIKLAUS WIR~iN. PASCAL -USER:I MANUAL AmD REPORT. NEW YORK, NY: SPRINGER-VERLAG 1978 Li LANCAST17R, DOIN. CMOS CoORBOLK(A. IND)IANAPOLIS, IND): HOWAI(D...34flGS 0151, OtTAll me:;genera ted by SISL, duri -ne iti; last run. Each message is of the foriiat: SutiWur Uk ;L ATLNG M1:SSA(;lE-, )’URIAT NUMBELR, and

  3. Micrometric precision of prosthetic dental crowns obtained by optical scanning and computer-aided designing/computer-aided manufacturing system.

    PubMed

    das Neves, Flávio Domingues; de Almeida Prado Naves Carneiro, Thiago; do Prado, Célio Jesus; Prudente, Marcel Santana; Zancopé, Karla; Davi, Letícia Resende; Mendonça, Gustavo; Soares, Carlos José

    2014-08-01

    The current study evaluated prosthetic dental crowns obtained by optical scanning and a computer-aided designing/computer-aided manufacturing system using micro-computed tomography to compare the marginal fit. The virtual models were obtained with four different scanning surfaces: typodont (T), regular impressions (RI), master casts (MC), and powdered master casts (PMC). Five virtual models were obtained for each group. For each model, a crown was designed on the software and milled from feldspathic ceramic blocks. Micro-CT images were obtained for marginal gap measurements and the data were statistically analyzed by one-way analysis of variance followed by Tukey's test. The mean vertical misfit was T = 62.6 ± 65.2 μm ; MC = 60.4 ± 38.4 μm; PMC = 58.1 ± 38.0 μm, and RI = 89.8 ± 62.8 μm. Considering a percentage of vertical marginal gap of up to 75 μm, the results were T = 71.5%, RI = 49.2%, MC = 69.6%, and PMC = 71.2%. The percentages of horizontal overextension were T = 8.5%, RI = 0%, MC = 0.8%, and PMC = 3.8%. Based on the results, virtual model acquisition by scanning the typodont (simulated mouth) or MC, with or without powder, showed acceptable values for the marginal gap. The higher result of marginal gap of the RI group suggests that it is preferable to scan this directly from the mouth or from MC.

  4. Micrometric precision of prosthetic dental crowns obtained by optical scanning and computer-aided designing/computer-aided manufacturing system

    NASA Astrophysics Data System (ADS)

    das Neves, Flávio Domingues; de Almeida Prado Naves Carneiro, Thiago; do Prado, Célio Jesus; Prudente, Marcel Santana; Zancopé, Karla; Davi, Letícia Resende; Mendonça, Gustavo; Soares, Carlos José

    2014-08-01

    The current study evaluated prosthetic dental crowns obtained by optical scanning and a computer-aided designing/computer-aided manufacturing system using micro-computed tomography to compare the marginal fit. The virtual models were obtained with four different scanning surfaces: typodont (T), regular impressions (RI), master casts (MC), and powdered master casts (PMC). Five virtual models were obtained for each group. For each model, a crown was designed on the software and milled from feldspathic ceramic blocks. Micro-CT images were obtained for marginal gap measurements and the data were statistically analyzed by one-way analysis of variance followed by Tukey's test. The mean vertical misfit was T=62.6±65.2 μm; MC=60.4±38.4 μm; PMC=58.1±38.0 μm, and RI=89.8±62.8 μm. Considering a percentage of vertical marginal gap of up to 75 μm, the results were T=71.5%, RI=49.2%, MC=69.6%, and PMC=71.2%. The percentages of horizontal overextension were T=8.5%, RI=0%, MC=0.8%, and PMC=3.8%. Based on the results, virtual model acquisition by scanning the typodont (simulated mouth) or MC, with or without powder, showed acceptable values for the marginal gap. The higher result of marginal gap of the RI group suggests that it is preferable to scan this directly from the mouth or from MC.

  5. Design and experimental verification of novel six-degree-of freedom geometric error measurement system for linear stage

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Ta; Lin, Wei-Chen; Liu, Chien-Sheng

    2017-05-01

    In this study, a novel and simple measurement system for simultaneously measuring the geometric errors in six-degree-of-freedom (6-DOF) for a moving linear stage of a machine tool is designed and validated. Compared to laser interferometer and laser Doppler systems, this new measurement system is less expensive and capable of multiple functions. The proposed measurement system comprises an optics module, composed of two reflectors and two cubic beam splitters; a sensing module, composed of three two-dimensional position sensitive detectors (PSDs); and a helium-neon (He-Ne) laser. Using skew-ray tracing and a first-order Taylor series expansion, the 6-DOF geometric errors of the moving linear stage, which include translation and rotation errors, are analyzed. A laboratory prototype system is built to verify the effectiveness and accuracy of the proposed measurement system. The experimental results show that the displacement uncertainty and the angular uncertainty of the proposed measurement system are less than 1.2 μm and 0.4″, respectively. Compared with the Renishaw laser interferometer XL-80 laser system, the translational accuracy and the rotational accuracy of the proposed measurement system are less than ±1 μm and ±0.2″, respectively, when the linear stage travels 6 mm.

  6. Computer-Aided Design of RNA Origami Structures.

    PubMed

    Sparvath, Steffen L; Geary, Cody W; Andersen, Ebbe S

    2017-01-01

    RNA nanostructures can be used as scaffolds to organize, combine, and control molecular functionalities, with great potential for applications in nanomedicine and synthetic biology. The single-stranded RNA origami method allows RNA nanostructures to be folded as they are transcribed by the RNA polymerase. RNA origami structures provide a stable framework that can be decorated with functional RNA elements such as riboswitches, ribozymes, interaction sites, and aptamers for binding small molecules or protein targets. The rich library of RNA structural and functional elements combined with the possibility to attach proteins through aptamer-based binding creates virtually limitless possibilities for constructing advanced RNA-based nanodevices.In this chapter we provide a detailed protocol for the single-stranded RNA origami design method using a simple 2-helix tall structure as an example. The first step involves 3D modeling of a double-crossover between two RNA double helices, followed by decoration with tertiary motifs. The second step deals with the construction of a 2D blueprint describing the secondary structure and sequence constraints that serves as the input for computer programs. In the third step, computer programs are used to design RNA sequences that are compatible with the structure, and the resulting outputs are evaluated and converted into DNA sequences to order.

  7. Computer-aided design and three-dimensional printing in the manufacturing of an ocular prosthesis.

    PubMed

    Ruiters, Sébastien; Sun, Yi; de Jong, Stéphan; Politis, Constantinus; Mombaerts, Ilse

    2016-04-27

    Restoring the facial appearance in acquired anophthalmos entails precision fitting of a customised ocular prosthesis. The fabrication is an artisanal process, and is primarily based on an impression of the anophthalmic cavity. This is usually achieved by the impression-moulding method, which, however, may introduce errors, resulting in a poorly fitted prosthesis. We developed a new method in the manufacturing of a customised ocular prosthesis based on computer-aided design and computer-aided manufacturing. An ocular prosthesis, based on a three-dimensional (3D) printed impression-free mould of the anophthalmic cavity, was successfully fitted in a 68-year-old male. To the best of our knowledge, this is the first case of a customised ocular prosthesis designed with the aid of 3D printing.

  8. The Design of a Project to Assess Bilateral Versus Unilateral Hearing Aid Fitting

    PubMed Central

    Arlinger, Stig; Gatehouse, Stuart; Kiessling, Jürgen; Naylor, Graham; Verschuure, Hans; Wouters, Jan

    2008-01-01

    Binaural hearing provides advantages over monaural in several ways, particularly in difficult listening situations. For a person with bilateral hearing loss, the bilateral fitting of hearing aids thus seems like a natural choice. However, surprisingly few studies have been reported in which the additional benefit of bilateral versus unilateral hearing aid use has been investigated based on real-life experiences. Therefore, a project has been designed to address this issue and to find tools to identify people for whom the drawbacks would outweigh the advantages of bilateral fitting. A project following this design is likely to provide reliable evidence concerning differences in benefit between unilateral and bilateral fitting of hearing aids by evaluating correlations between entrance data and outcome measures and final preferences. PMID:18567594

  9. DeMAID/GA an Enhanced Design Manager's Aid for Intelligent Decomposition

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.

    1996-01-01

    Many companies are looking for new tools and techniques to aid a design manager in making decisions that can reduce the time and cost of a design cycle. One tool is the Design Manager's Aid for Intelligent Decomposition (DeMAID). Since the initial public release of DeMAID in 1989, much research has been done in the areas of decomposition, concurrent engineering, parallel processing, and process management; many new tools and techniques have emerged. Based on these recent research and development efforts, numerous enhancements have been added to DeMAID to further aid the design manager in saving both cost and time in a design cycle. The key enhancement, a genetic algorithm (GA), will be available in the next public release called DeMAID/GA. The GA sequences the design processes to minimize the cost and time in converging a solution. The major enhancements in the upgrade of DeMAID to DeMAID/GA are discussed in this paper. A sample conceptual design project is used to show how these enhancements can be applied to improve the design cycle.

  10. Assembly and insertion of a self-fitting hearing aid: design of effective instruction materials.

    PubMed

    Caposecco, Andrea; Hickson, Louise; Meyer, Carly

    2011-12-01

    A self-fitting hearing aid has been proposed as a viable option to meet the need for rehabilitation in areas where audiology services are unreliable. A successful outcome with a self-fitting hearing aid pivots in part on the clarity of the instructions accompanying the device. The aims of this article are (a) to review the literature to determine features that should be incorporated into written health-care materials and factors to consider in the design process when developing written instructions for a target audience of older adults and (b) to apply this information to the development of a set of written instructions as the first step in self-fitting of a hearing aid, assembling four parts and inserting the aid into the ear. The method involved a literature review of published peer reviewed research. The literature revealed four steps in the development of written health-care materials: planning, design, assessment of suitability, and pilot testing. Best practice design principles for each step were applied in the development of instructions for how to assemble and insert a hearing aid. Separate booklets were developed for the left and right aids and the content of each consisted of simple line drawings accompanied by captions. The reading level was Grade 3.5 equivalent and the Flesch Reading Ease Score was 91.1 indicating that the materials were "very easy" to read. It is essential to follow best practice design principles when developing written health-care materials to motivate the reader, maximize comprehension, and increase the likelihood of successful application of the content.

  11. Therapist-Aided Exposure for Women with Lifelong Vaginismus: A Replicated Single-Case Design

    ERIC Educational Resources Information Center

    ter Kuile, Moniek M.; Bulte, Isis; Weijenborg, Philomeen T. M.; Beekman, Aart; Melles, Reinhilde; Onghena, Patrick

    2009-01-01

    Vaginismus is commonly described as a persistent difficulty in allowing vaginal entry of a penis or other object. Lifelong vaginismus occurs when a woman has never been able to have intercourse. A replicated single-case A-B-phase design was used to investigate the effectiveness of therapist-aided exposure for lifelong vaginismus. A baseline period…

  12. The Design, Implementation, and Formative Evaluation of a Classroom Aide Professional Development Training Program

    ERIC Educational Resources Information Center

    Dulfer, Katherine J.

    2013-01-01

    This dissertation focused on the process of designing, implementing, and formatively evaluating an eight week Classroom Aide Professional Development Training Program (CAPD-TP) on behavior management and academic instruction within the context of a New Jersey state approved private special education school for students with behavioral and/or…

  13. Technology and Jobs: Computer-Aided Design. Numerical-Control Machine-Tool Operators. Office Automation.

    ERIC Educational Resources Information Center

    Stanton, Michael; And Others

    1985-01-01

    Three reports on the effects of high technology on the nature of work include (1) Stanton on applications and implications of computer-aided design for engineers, drafters, and architects; (2) Nardone on the outlook and training of numerical-control machine tool operators; and (3) Austin and Drake on the future of clerical occupations in automated…

  14. Gathering Empirical Evidence Concerning Links between Computer Aided Design (CAD) and Creativity

    ERIC Educational Resources Information Center

    Musta'amal, Aede Hatib; Norman, Eddie; Hodgson, Tony

    2009-01-01

    Discussion is often reported concerning potential links between computer-aided designing and creativity, but there is a lack of systematic enquiry to gather empirical evidence concerning such links. This paper reports an indication of findings from other research studies carried out in contexts beyond general education that have sought evidence…

  15. Web-Based Learning in the Computer-Aided Design Curriculum.

    ERIC Educational Resources Information Center

    Sung, Wen-Tsai; Ou, S. C.

    2002-01-01

    Applies principles of constructivism and virtual reality (VR) to computer-aided design (CAD) curriculum, particularly engineering, by integrating network, VR and CAD technologies into a Web-based learning environment that expands traditional two-dimensional computer graphics into a three-dimensional real-time simulation that enhances user…

  16. National Science Foundation 1989 Engineering Senior Design Projects To Aid the Disabled.

    ERIC Educational Resources Information Center

    Enderle, John D., Ed.

    Through the Bioengineering and Research to Aid the Disabled program of the National Science Foundation, design projects were awarded competitively to 16 universities. Senior engineering students at each of the universities constructed custom devices and software for disabled individuals. This compendium contains a description of each project in…

  17. Design of an aid to visual inspection workstation

    NASA Astrophysics Data System (ADS)

    Tait, Robert; Harding, Kevin

    2016-05-01

    Visual Inspection is the most common means for inspecting manufactured parts for random defects such as pits, scratches, breaks, corrosion or general wear. The reason for the need for visual inspection is the very random nature of what might be a defect. Some defects may be very rare, being seen once or twice a year, but May still be critical to part performance. Because of this random and rare nature, even the most sophisticated image analysis programs have not been able to recognize all possible defects. Key to any future automation of inspection is obtaining good sample images of what might be a defect. However, most visual check take no images and consequently generate no digital data or historical record beyond a simple count. Any additional tool to captures such images must be able to do so without taking addition time. This paper outlines the design of a potential visual inspection station that would be compatible with current visual inspection methods, but afford the means for reliable digital imaging and in many cases augmented capabilities to assist the inspection. Considerations in this study included: resolution, depth of field, feature highlighting, and ease of digital capture, annotations and inspection augmentation for repeatable registration as well as operator assistance and training.

  18. Low-floor bus design preferences of walking aid users during simulated boarding and alighting.

    PubMed

    D'souza, Clive; Paquet, Victor; Lenker, James; Steinfeld, Edward; Bareria, Piyush

    2012-01-01

    Low-floor buses represent a significant improvement in accessible public transit for passengers with limited mobility. However, there is still a need for research on the inclusive design of transit buses to identify specific low-floor bus design conditions that are either particularly accommodating or challenging for passengers with functional and mobility impairments. These include doorway locations, seating configuration and the large front wheel-well covers that collectively impact boarding, alighting and interior movement of passengers. Findings from a laboratory study using a static full-scale simulation of a lowfloor bus to evaluate the impact of seating configuration and crowding on interior movement and accessibility for individuals with and without walking aids are presented (n=41). Simulated bus journeys that included boarding, fare payment, seating, and alighting were performed. Results from video observations and subjective assessments showed differences in boarding and alighting performance and users' perceptions of task difficulty. The need for assistive design features (e.g. handholds, stanchions), legroom and stowage space for walking aids was evident. These results demonstrate that specific design conditions in low-floor buses can significantly impact design preference among those who use walking aids. Consideration of ergonomics and inclusive design can therefore be used to improve the design of low-floor buses.

  19. Computer-aided design of a proton pump

    NASA Technical Reports Server (NTRS)

    New, Michael H.; Pohorille, Andrew; Chang, Sherwood (Technical Monitor)

    1997-01-01

    The use of transmembrane proton gradients in energy transduction is an almost universal feature of life on earth. These proton gradients are established and maintained by specialized assemblies of proteins which actively pump protons across membranes. One broad class of proton pumps uses captured light energy to drive the proton pumping. Our goal is to elucidate the minimum structural requirements of a light-driven proton-pump. There are two basic components to a simple light-driven proton pump: a source of photo-generated protons and a "gate-keeper" which prevents these protons from reattaching themselves to their source. A wide variety of molecules in the membrane, even as simple as polycyclic aromatic hydrocarbons, are capable of releasing protons when illuminated. Our work is therefore focused on the design of the "gate-keeper." Our initial model involves a pair of proton acceptors, coupled to each other by a transient water bridge, and supported in the membrane by a small bundle of peptide helices. Upon illumination, the proton source transfers its proton to the:- first acceptor of the gate-keeper. While the reverse reaction is highly probable, all that is needed to ensure irreversibility is a nonvanishing probability that the proton will be transferred to the second acceptor across a transient water bridge. Back transfer of the proton to the first acceptor, and thence to the proton source, is impeded by the free energy required to move the proton uphill towards the. proton source and by the disruption of the transient water bridge. As a prototypical water-bridged proton transfer system, we are studying the transfer of a proton across a water bridge from a formic acid to a formate anion. With a pK(sub alpha), of 3.7. formic acid is a good model for the acidic amino acids glutamate and aspartate which are good candidates for gate-keeper proton acceptors. Simulations of proton transfer reactions in a membrane are complicated by the quantum mechanical nature of

  20. Sensory imbalance as mechanism of orientation disruption in the leafminer, Phyllocnistis citrella: Elucidation by multivariate geometric designs and response surface models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experimental designs developed to address mixtures are ideally suited for many areas of experimental biology including pheromone blend studies because they address the confounding of proportionality and concentration intrinsic to factorial and one-factor-at-a-time designs. Geometric multivariate des...

  1. Multicriteria aided design of integrated heating-cooling energy systems in buildings.

    PubMed

    Mróz, Tomasz M

    2010-08-01

    This paper presents an analysis of the possible application of integrated heating-cooling systems in buildings. The general algorithm of integrated heating-cooling system design aid was formulated. The evaluation criteria of technically acceptable variants were defined. Fossil fuel energy consumption, carbon dioxide emission, investment, and total exploitation cost were identified as the most important factors describing the considered decision problem. The multicriteria decision aid method ELECTRE III was proposed as the decision tool for the choice of the most compromised variant. The proposed method was used for a case study calculation-the choice of an integrated heating-cooling system for an office building.

  2. The theory, design, and operation of the suppressed carrier data-aided tracking receiver

    NASA Technical Reports Server (NTRS)

    Simon, M. K.; Springett, J. C.

    1973-01-01

    A viable, efficient, and easily mechanized carrier regenerating receiver for use in suppressed carrier-tracking system is described. The receiver referred to as a data-aided receiver (DAR) incorporates a data-aided loop (DAL) which provides the required carrier reference signal. The DAL employs the principle of decision feedback and as such is more efficient than other forms of suppressed carrier-tracking loops. The analysis, design, and implementation of the DAR are covered in detail. Performance comparisons and mechanization tradeoffs are made, wherever possible, with discrete carrier systems and other suppressed carrier systems presently in use. Experimental performance verification is given throughout in support of the theory presented.

  3. A novel application of computer-aided design and manufacturing for reduction cranioplasty.

    PubMed

    Dorafshar, Amir; Fisher, Mark; Borsuk, Daniel; Fishman, Elliot; Ahn, Edward

    2014-01-01

    Macrocephaly is a rare presentation of untreated hydrocephalus. In cases where medical management has failed, macrocephaly can be managed with reduction cranioplasty. Traditionally, reduction cranioplasty is highly dependent on intraoperative tailoring of bone segments to obtain the best possible result and involves high risks of associated severe blood loss and mortality. In this clinical report, we describe a patient with hydrocephalus macrocephaly treated with reduction cranioplasty with the innovative use of computer-aided design and manufacturing to reduce intraoperative risks and improve efficiency. We used computer-aided design to plan osteotomy sites and the final positioning of bone segments. We also utilized computer-aided manufacturing to produce cutting guides, positioning guides, and models to increase precision and improve the final positioning of the cranium. Computer-aided design and manufacturing technology has enabled a shift of the planning burden of complicated craniofacial reconstructions from the intraoperative to the preoperative phase. With a completed plan and premade guides and models, it is possible to minimize the risks, improve efficiency, and obtain a precise, aesthetic result.

  4. Geometrical Design of a Scalable Overlapping Planar Spiral Coil Array to Generate a Homogeneous Magnetic Field

    PubMed Central

    Jow, Uei-Ming; Ghovanloo, Maysam

    2014-01-01

    We present a design methodology for an overlapping hexagonal planar spiral coil (hex-PSC) array, optimized for creation of a homogenous magnetic field for wireless power transmission to randomly moving objects. The modular hex-PSC array has been implemented in the form of three parallel conductive layers, for which an iterative optimization procedure defines the PSC geometries. Since the overlapping hex-PSCs in different layers have different characteristics, the worst case coil-coupling condition should be designed to provide the maximum power transfer efficiency (PTE) in order to minimize the spatial received power fluctuations. In the worst case, the transmitter (Tx) hex-PSC is overlapped by six PSCs and surrounded by six other adjacent PSCs. Using a receiver (Rx) coil, 20 mm in radius, at the coupling distance of 78 mm and maximum lateral misalignment of 49.1 mm (1/√3 of the PSC radius) we can receive power at a PTE of 19.6% from the worst case PSC. Furthermore, we have studied the effects of Rx coil tilting and concluded that the PTE degrades significantly when θ > 60°. Solutions are: 1) activating two adjacent overlapping hex-PSCs simultaneously with out-of-phase excitations to create horizontal magnetic flux and 2) inclusion of a small energy storage element in the Rx module to maintain power in the worst case scenarios. In order to verify the proposed design methodology, we have developed the EnerCage system, which aims to power up biological instruments attached to or implanted in freely behaving small animal subjects’ bodies in long-term electrophysiology experiments within large experimental arenas. PMID:24782576

  5. Geometrical Design of a Scalable Overlapping Planar Spiral Coil Array to Generate a Homogeneous Magnetic Field.

    PubMed

    Jow, Uei-Ming; Ghovanloo, Maysam

    2012-12-21

    We present a design methodology for an overlapping hexagonal planar spiral coil (hex-PSC) array, optimized for creation of a homogenous magnetic field for wireless power transmission to randomly moving objects. The modular hex-PSC array has been implemented in the form of three parallel conductive layers, for which an iterative optimization procedure defines the PSC geometries. Since the overlapping hex-PSCs in different layers have different characteristics, the worst case coil-coupling condition should be designed to provide the maximum power transfer efficiency (PTE) in order to minimize the spatial received power fluctuations. In the worst case, the transmitter (Tx) hex-PSC is overlapped by six PSCs and surrounded by six other adjacent PSCs. Using a receiver (Rx) coil, 20 mm in radius, at the coupling distance of 78 mm and maximum lateral misalignment of 49.1 mm (1/√3 of the PSC radius) we can receive power at a PTE of 19.6% from the worst case PSC. Furthermore, we have studied the effects of Rx coil tilting and concluded that the PTE degrades significantly when θ > 60°. Solutions are: 1) activating two adjacent overlapping hex-PSCs simultaneously with out-of-phase excitations to create horizontal magnetic flux and 2) inclusion of a small energy storage element in the Rx module to maintain power in the worst case scenarios. In order to verify the proposed design methodology, we have developed the EnerCage system, which aims to power up biological instruments attached to or implanted in freely behaving small animal subjects' bodies in long-term electrophysiology experiments within large experimental arenas.

  6. Quantum computation using geometric algebra

    NASA Astrophysics Data System (ADS)

    Matzke, Douglas James

    This dissertation reports that arbitrary Boolean logic equations and operators can be represented in geometric algebra as linear equations composed entirely of orthonormal vectors using only addition and multiplication Geometric algebra is a topologically based algebraic system that naturally incorporates the inner and anticommutative outer products into a real valued geometric product, yet does not rely on complex numbers or matrices. A series of custom tools was designed and built to simplify geometric algebra expressions into a standard sum of products form, and automate the anticommutative geometric product and operations. Using this infrastructure, quantum bits (qubits), quantum registers and EPR-bits (ebits) are expressed symmetrically as geometric algebra expressions. Many known quantum computing gates, measurement operators, and especially the Bell/magic operators are also expressed as geometric products. These results demonstrate that geometric algebra can naturally and faithfully represent the central concepts, objects, and operators necessary for quantum computing, and can facilitate the design and construction of quantum computing tools.

  7. Finite Element Model of Oxygen Transport for the Design of Geometrically Complex Microfluidic Devices Used in Biological Studies

    PubMed Central

    Fraser, Graham M.; Goldman, Daniel; Ellis, Christopher G.

    2016-01-01

    Red blood cells play a crucial role in the local regulation of oxygen supply in the microcirculation through the oxygen dependent release of ATP. Since red blood cells serve as an oxygen sensor for the circulatory system, the dynamics of ATP release determine the effectiveness of red blood cells to relate the oxygen levels to the vessels. Previous work has focused on the feasibility of developing a microfluidic system to measure the dynamics of ATP release. The objective was to determine if a steep oxygen gradient could be developed in the channel to cause a rapid decrease in hemoglobin oxygen saturation in order to measure the corresponding levels of ATP released from the red blood cells. In the present study, oxygen transport simulations were used to optimize the geometric design parameters for a similar system which is easier to fabricate. The system is composed of a microfluidic device stacked on top of a large, gas impermeable flow channel with a hole to allow gas exchange. The microfluidic device is fabricated using soft lithography in polydimethyl-siloxane, an oxygen permeable material. Our objective is twofold: (1) optimize the parameters of our system and (2) develop a method to assess the oxygen distribution in complex 3D microfluidic device geometries. 3D simulations of oxygen transport were performed to simulate oxygen distribution throughout the device. The simulations demonstrate that microfluidic device geometry plays a critical role in molecule exchange, for instance, changing the orientation of the short wide microfluidic channel results in a 97.17% increase in oxygen exchange. Since microfluidic devices have become a more prominent tool in biological studies, understanding the transport of oxygen and other biological molecules in microfluidic devices is critical for maintaining a physiologically relevant environment. We have also demonstrated a method to assess oxygen levels in geometrically complex microfluidic devices. PMID:27829071

  8. An approach to simultaneous system design. II - Nonswitching gain and dynamic feedback compensation by algebraic geometric methods

    NASA Technical Reports Server (NTRS)

    Ghosh, Bijoy K.

    1988-01-01

    This paper studies structured uncertainty problems in feedback system design, considers a compact parameterization of the space of linear dynamical systems and introduces 'base points' and 'critical points' as two algebraic-geometric objects that have significance in sensitivity and robustness studies, respectively. Using the Nevanlinna-Pick interpolation theory, the author obtains a necessary and sufficient condition for simultaneous stabilization of a structured one-parameter family of plants. A recent result due to Kharitonov, on the simultaneous stability of a parameterized family of polynomials, leads to a sufficiency condition for simultaneous stabilization of a structured multiparameter family of plants. Furthermore, the author considers 'simultaneous pole placement' of an r-tuple of plants as a means to arbitrarily tune the natural frequencies of a multimode linear dynamical system. The concept of 'nondegenerate' and 'twisted' r-tuples of plants is introduced as the pole placement problem is studied via Schubert enumerative geometry as an intersection problem on the associated Grassmannian. Various other design problems, viz., the strong stabilization problem and the dead beat control problem, are also considered.

  9. Multi-Input/Multi-Output Designated Eigenstructure (MODES): A Computer-Aided Control System Design Program.

    DTIC Science & Technology

    1987-03-01

    must. introduce some tools. The first of these is known as Newton’s Formulas ( Uspensky , 1948: 261). oA 4-32 ’ */ Newton’s Formulas relate the...Academic Press, Inc., 1976. Uspensky , J.V. Theory of Equations. New York: McGraw- Hill Book Company, 1948. Walker, Robert A., et al. "Computer-Aided

  10. Mandibular Reconstruction Using a Custom-Made Titanium Prosthesis: A Case Report on the Use of Virtual Surgical Planning and Computer-Aided Design/Computer-Aided Manufacturing.

    PubMed

    Ow, Andrew; Tan, Winston; Pienkowski, Lukasz

    2016-09-01

    The use of virtual surgical planning and computer-aided design/computer-aided manufacturing has been reported to enhance the planning for the reconstruction of mandibular continuity defects. This case report illustrates the use of this technology in the fabrication of a custom-made titanium prosthesis to restore a segmental mandibular defect. The design specifications and sequence of the custom-made titanium prosthesis are discussed. Although successful in this case, there are limitations in its application and case selection is of vital importance.

  11. Computer-aided analysis and design of the shape rolling process for producing turbine engine airfoils

    NASA Technical Reports Server (NTRS)

    Lahoti, G. D.; Akgerman, N.; Altan, T.

    1978-01-01

    Mild steel (AISI 1018) was selected as model cold rolling material and Ti-6A1-4V and Inconel 718 were selected as typical hot rolling and cold rolling alloys, respectively. The flow stress and workability of these alloys were characterized and friction factor at the roll/workpiece interface was determined at their respective working conditions by conducting ring tests. Computer-aided mathematical models for predicting metal flow and stresses, and for simulating the shape rolling process were developed. These models utilized the upper bound and the slab methods of analysis, and were capable of predicting the lateral spread, roll separating force, roll torque, and local stresses, strains and strain rates. This computer-aided design system was also capable of simulating the actual rolling process, and thereby designing the roll pass schedule in rolling of an airfoil or a similar shape.

  12. A Computer-Aided Approach for Designing Edge-Slot Waveguide Arrays

    NASA Technical Reports Server (NTRS)

    Gosselin, Renee Brian

    2003-01-01

    Traditional techniques for designing resonant edge-slot waveguide arrays have required an iterative trial-and-error process of measuring slot data from several prototypes. Since very little meaningful data has been published, this technology remains relatively immature and prohibitive for many smaller programs that could benefit from some advantages this antenna has to offer. A new Computer-Aided Design technique for designing resonant edge-slot waveguide arrays was used to successfuliy design such an X-band radiometer antenna for the NASA Light Rainfall Radiometer (LRR) instrument. Having the ability to rapidly create such an extremely accurate and efficient antenna design without the need to manufacture prototypes has also enabled inexpensive research that promises to improve the system-level performance of microwave radiometers for upcoming space-flight missions. This paper will present details of the LRR antenna design and describe some other current edge-slot array accomplishments at Goddard Space Flight Center.

  13. Integrating aerodynamic surface modeling for computational fluid dynamics with computer aided structural analysis, design, and manufacturing

    NASA Technical Reports Server (NTRS)

    Thorp, Scott A.

    1992-01-01

    This presentation will discuss the development of a NASA Geometry Exchange Specification for transferring aerodynamic surface geometry between LeRC systems and grid generation software used for computational fluid dynamics research. The proposed specification is based on a subset of the Initial Graphics Exchange Specification (IGES). The presentation will include discussion of how the NASA-IGES standard will accommodate improved computer aided design inspection methods and reverse engineering techniques currently being developed. The presentation is in viewgraph format.

  14. A Simple and Resource-efficient Setup for the Computer-aided Drug Design Laboratory.

    PubMed

    Moretti, Loris; Sartori, Luca

    2016-10-01

    Undertaking modelling investigations for Computer-Aided Drug Design (CADD) requires a proper environment. In principle, this could be done on a single computer, but the reality of a drug discovery program requires robustness and high-throughput computing (HTC) to efficiently support the research. Therefore, a more capable alternative is needed but its implementation has no widespread solution. Here, the realization of such a computing facility is discussed, from general layout to technical details all aspects are covered.

  15. Tools to aid the specification and design of flight software, appendix B

    NASA Technical Reports Server (NTRS)

    Bristow, G.

    1980-01-01

    The tasks that are normally performed during the specification and architecture design stages of software development are identified. Ways that tools could perform, or aid the performance, of such tasks are also identified. Much of the verification and analysis that is suggested is currently rarely performed during these early stages, but it is believed that this analysis should be done as early as possible so as to detect errors as early as possible.

  16. Evolution of facility layout requirements and CAD (computer-aided design) system development

    SciTech Connect

    Jones, M. )

    1990-06-01

    The overall configuration of the Superconducting Super Collider (SSC) including the infrastructure and land boundary requirements were developed using a computer-aided design (CAD) system. The evolution of the facility layout requirements and the use of the CAD system are discussed. The emphasis has been on minimizing the amount of input required and maximizing the speed by which the output may be obtained. The computer system used to store the data is also described.

  17. IDEAS: A multidisciplinary computer-aided conceptual design system for spacecraft

    NASA Technical Reports Server (NTRS)

    Ferebee, M. J., Jr.

    1984-01-01

    During the conceptual development of advanced aerospace vehicles, many compromises must be considered to balance economy and performance of the total system. Subsystem tradeoffs may need to be made in order to satisfy system-sensitive attributes. Due to the increasingly complex nature of aerospace systems, these trade studies have become more difficult and time-consuming to complete and involve interactions of ever-larger numbers of subsystems, components, and performance parameters. The current advances of computer-aided synthesis, modeling and analysis techniques have greatly helped in the evaluation of competing design concepts. Langley Research Center's Space Systems Division is currently engaged in trade studies for a variety of systems which include advanced ground-launched space transportation systems, space-based orbital transfer vehicles, large space antenna concepts and space stations. The need for engineering analysis tools to aid in the rapid synthesis and evaluation of spacecraft has led to the development of the Interactive Design and Evaluation of Advanced Spacecraft (IDEAS) computer-aided design system. The ADEAS system has been used to perform trade studies of competing technologies and requirements in order to pinpoint possible beneficial areas for research and development. IDEAS is presented as a multidisciplinary tool for the analysis of advanced space systems. Capabilities range from model generation and structural and thermal analysis to subsystem synthesis and performance analysis.

  18. Geometrical optics design of a compact range Gregorian subreflector system by the principle of the central ray

    NASA Technical Reports Server (NTRS)

    Clerici, Giancarlo; Burnside, Walter D.

    1989-01-01

    In recent years, the compact range has become very popular for measuring Radar Cross Section (RCS) and antenna patterns. The compact range, in fact, offers several advantages due to reduced size, a controlled environment, and privacy. On the other hand, it has some problems of its own, which must be solved properly in order to achieve high quality measurement results. For example, diffraction from the edges of the main reflector corrupts the plane wave in the target zone and creates spurious scattering centers in RCS measurements. While diffraction can be minimized by using rolled edges, the field of an offset single reflector compact range is corrupted by three other errors: the taper of the reflected field, the cross polarization introduced by the tilt of the feed and the aperture blockage introduced by the feed itself. These three errors can be eliminated by the use of a subreflector system. A properly designed subreflector system offers very little aperture blockage, no cross-polarization introduced and a minimization of the taper of the reflected field. A Gregorian configuration has been adopted in order to enclose the feed and the ellipsoidal subreflector in a lower chamber, which is isolated by absorbers from the upper chamber, where the main parabolic reflector and the target zone are enclosed. The coupling between the two rooms is performed through a coupling aperture. The first cut design for such a subreflector system is performed through Geometrical Optics ray tracing techniques (GO), and is greatly simplified by the use of the concept of the central ray introduced by Dragone. The purpose of the GO design is to establish the basic dimensions of the main reflector and subreflector, the size of the primary and secondary illuminating surfaces, the tilt angles of the subreflector and feed, and estimate the feed beamwidth. At the same time, the shape of the coupling aperture is initially determined.

  19. Design model of computerized personal decision aid for youth: An expert review

    NASA Astrophysics Data System (ADS)

    Sarif, Siti Mahfuzah; Ibrahim, Norfiza; Shiratuddin, Norshuhada

    2016-08-01

    This paper provides a structured review of a design model of a computerized personal decision aid that is intended for youth, named as YouthPDA Design Model. The proposed design model was examined by experts in related areas to ensure the appropriateness of the proposed components and elements, relevancy of the terminologies used, logic of the flow, usability, and practicality of the design model towards development of YouthPDA application. Seven experts from related areas were involved in the evaluation. Discussions on the findings obtained from the expert review are included in this paper. Finally, a revised design model of YouthPDA is proposed as main guidance to develop YouthPDA application.

  20. Metalloporphyrin catalysts for oxygen reduction developed using computer-aided molecular design

    SciTech Connect

    Ryba, G.N.; Hobbs, J.D.; Shelnutt, J.A.

    1996-04-01

    The objective of this project is the development of a new class of metalloporphyrin materials used as catalsyts for use in fuel cell applications. The metalloporphyrins are excellent candidates for use as catalysts at both the anode and cathode. The catalysts reduce oxygen in 1 M potassium hydroxide, as well as in 2 M sulfuric acid. Covalent attachment to carbon supports is being investigated. The computer-aided molecular design is an iterative process, in which experimental results feed back into the design of future catalysts.

  1. Computer-aided design of control systems to meet many requirements

    NASA Technical Reports Server (NTRS)

    Schy, A. A.; Adams, W. M., Jr.; Johnson, K. G.

    1974-01-01

    A method is described for using nonlinear programing in the computer-aided design of airplane control systems. It is assumed that the quality of such systems depends on many criteria. These criteria are included in the constraints vector (instead of attempting to combine them into a single scalar criterion, as is usually done), and the design proceeds through a sequence of nonlinear programing solutions in which the designer varies the specification of sets of requirements levels. The method is applied to design of a lateral stability augmentation system (SAS) for a fighter airplane, in which the requirements vector is chosen from the official handling qualities specifications. Results are shown for several simple SAS configurations designed to obtain desirable handling qualities over all design flight conditions with minimum feedback gains. The choice of the final design for each case is not unique but depends on the designer's decision as to which achievable set of requirements levels represents the best for that system. Results indicate that it may be possible to design constant parameter SAS which can satisfy the most stringent handling qualities requirements for fighter airplanes in all flight conditions. The role of the designer as a decision maker, interacting with the computer program, is discussed. Advantages of this type of designer-computer interaction are emphasized. Desirable extensions of the method are indicated.

  2. Automated a complex computer aided design concept generated using macros programming

    NASA Astrophysics Data System (ADS)

    Rizal Ramly, Mohammad; Asrokin, Azharrudin; Abd Rahman, Safura; Zulkifly, Nurul Ain Md

    2013-12-01

    Changing a complex Computer Aided design profile such as car and aircraft surfaces has always been difficult and challenging. The capability of CAD software such as AutoCAD and CATIA show that a simple configuration of a CAD design can be easily modified without hassle, but it is not the case with complex design configuration. Design changes help users to test and explore various configurations of the design concept before the production of a model. The purpose of this study is to look into macros programming as parametric method of the commercial aircraft design. Macros programming is a method where the configurations of the design are done by recording a script of commands, editing the data value and adding a certain new command line to create an element of parametric design. The steps and the procedure to create a macro programming are discussed, besides looking into some difficulties during the process of creation and advantage of its usage. Generally, the advantages of macros programming as a method of parametric design are; allowing flexibility for design exploration, increasing the usability of the design solution, allowing proper contained by the model while restricting others and real time feedback changes.

  3. Design and fabrication of facial prostheses for cancer patient applying computer aided method and manufacturing (CADCAM)

    NASA Astrophysics Data System (ADS)

    Din, Tengku Noor Daimah Tengku; Jamayet, Nafij; Rajion, Zainul Ahmad; Luddin, Norhayati; Abdullah, Johari Yap; Abdullah, Abdul Manaf; Yahya, Suzana

    2016-12-01

    Facial defects are either congenital or caused by trauma or cancer where most of them affect the person appearance. The emotional pressure and low self-esteem are problems commonly related to patient with facial defect. To overcome this problem, silicone prosthesis was designed to cover the defect part. This study describes the techniques in designing and fabrication for facial prosthesis applying computer aided method and manufacturing (CADCAM). The steps of fabricating the facial prosthesis were based on a patient case. The patient was diagnosed for Gorlin Gotz syndrome and came to Hospital Universiti Sains Malaysia (HUSM) for prosthesis. The 3D image of the patient was reconstructed from CT data using MIMICS software. Based on the 3D image, the intercanthal and zygomatic measurements of the patient were compared with available data in the database to find the suitable nose shape. The normal nose shape for the patient was retrieved from the nasal digital library. Mirror imaging technique was used to mirror the facial part. The final design of facial prosthesis including eye, nose and cheek was superimposed to see the result virtually. After the final design was confirmed, the mould design was created. The mould of nasal prosthesis was printed using Objet 3D printer. Silicone casting was done using the 3D print mould. The final prosthesis produced from the computer aided method was acceptable to be used for facial rehabilitation to provide better quality of life.

  4. Role of computer-aided drug design in modern drug discovery.

    PubMed

    Macalino, Stephani Joy Y; Gosu, Vijayakumar; Hong, Sunhye; Choi, Sun

    2015-09-01

    Drug discovery utilizes chemical biology and computational drug design approaches for the efficient identification and optimization of lead compounds. Chemical biology is mostly involved in the elucidation of the biological function of a target and the mechanism of action of a chemical modulator. On the other hand, computer-aided drug design makes use of the structural knowledge of either the target (structure-based) or known ligands with bioactivity (ligand-based) to facilitate the determination of promising candidate drugs. Various virtual screening techniques are now being used by both pharmaceutical companies and academic research groups to reduce the cost and time required for the discovery of a potent drug. Despite the rapid advances in these methods, continuous improvements are critical for future drug discovery tools. Advantages presented by structure-based and ligand-based drug design suggest that their complementary use, as well as their integration with experimental routines, has a powerful impact on rational drug design. In this article, we give an overview of the current computational drug design and their application in integrated rational drug development to aid in the progress of drug discovery research.

  5. Geometric grid generation

    NASA Technical Reports Server (NTRS)

    Ives, David

    1995-01-01

    This paper presents a highly automated hexahedral grid generator based on extensive geometrical and solid modeling operations developed in response to a vision of a designer-driven one day turnaround CFD process which implies a designer-driven one hour grid generation process.

  6. DeMAID: A Design Manager's Aide for Intelligent Decomposition user's guide

    NASA Technical Reports Server (NTRS)

    Rogers, James L.

    1989-01-01

    A design problem is viewed as a complex system divisible into modules. Before the design of a complex system can begin, the couplings among modules and the presence of iterative loops is determined. This is important because the design manager must know how to group the modules into subsystems and how to assign subsystems to design teams so that changes in one subsystem will have predictable effects on other subsystems. Determining these subsystems is not an easy, straightforward process and often important couplings are overlooked. Moreover, the planning task must be repeated as new information become available or as the design specifications change. The purpose of this research is to develop a knowledge-based tool called the Design Manager's Aide for Intelligent Decomposition (DeMAID) to act as an intelligent advisor for the design manager. DeMaid identifies the subsystems of a complex design problem, orders them into a well-structured format, and marks the couplings among the subsystems to facilitate the use of multilevel tools. DeMAID also provides the design manager with the capability of examining the trade-offs between sequential and parallel processing. This type of approach could lead to a substantial savings or organizing and displaying a complex problem as a sequence of subsystems easily divisible among design teams. This report serves as a User's Guide for the program.

  7. Computer-aided design of high-contact-ratio gears for minimum dynamic load and stress

    NASA Technical Reports Server (NTRS)

    Lin, Hsiang Hsi; Lee, Chinwai; Oswald, Fred B.; Townsend, Dennis P.

    1990-01-01

    A computer aided design procedure is presented for minimizing dynamic effects on high contact ratio gears by modification of the tooth profile. Both linear and parabolic tooth profile modifications of high contact ratio gears under various loading conditions are examined and compared. The effects of the total amount of modification and the length of the modification zone were systematically studied at various loads and speeds to find the optimum profile design for minimizing the dynamic load and the tooth bending stress. Parabolic profile modification is preferred over linear profile modification for high contact ratio gears because of its lower sensitivity to manufacturing errors. For parabolic modification, a greater amount of modification at the tooth tip and a longer modification zone are required. Design charts are presented for high contact ratio gears with various profile modifications operating under a range of loads. A procedure is illustrated for using the charts to find the optimum profile design.

  8. Geometric Mechanics

    NASA Astrophysics Data System (ADS)

    Talman, Richard

    1999-10-01

    Mechanics for the nonmathematician-a modern approach For physicists, mechanics is quite obviously geometric, yet the classical approach typically emphasizes abstract, mathematical formalism. Setting out to make mechanics both accessible and interesting for nonmathematicians, Richard Talman uses geometric methods to reveal qualitative aspects of the theory. He introduces concepts from differential geometry, differential forms, and tensor analysis, then applies them to areas of classical mechanics as well as other areas of physics, including optics, crystal diffraction, electromagnetism, relativity, and quantum mechanics. For easy reference, Dr. Talman treats separately Lagrangian, Hamiltonian, and Newtonian mechanics-exploring their geometric structure through vector fields, symplectic geometry, and gauge invariance respectively. Practical perturbative methods of approximation are also developed. Geometric Mechanics features illustrative examples and assumes only basic knowledge of Lagrangian mechanics. Of related interest . . . APPLIED DYNAMICS With Applications to Multibody and Mechatronic Systems Francis C. Moon A contemporary look at dynamics at an intermediate level, including nonlinear and chaotic dynamics. 1998 (0-471-13828-2) 504 pp. MATHEMATICAL PHYSICS Applied Mathematics for Scientists and Engineers Bruce Kusse and Erik Westwig A comprehensive treatment of the mathematical methods used to solve practical problems in physics and engineering. 1998 (0-471-15431-8) 680 pp.

  9. Modification of planned postoperative occlusion in orthognathic surgery, based on computer-aided design/computer-aided manufacturing-engineered preoperative surgical simulation.

    PubMed

    Kang, Sang-Hoon; Kim, Moon-Key; You, Tae-Kwon; Lee, Ji-Yeon

    2015-01-01

    In orthognathic surgery, it is important to have a planned postoperative occlusion. A 3-dimensional preoperative simulation, based on 3-dimensional optically scanned occlusion data, can predict how the planned postoperative occlusion will affect the maxilla-mandibular relationship that results from orthognathic surgery. In this study we modified the planned postoperative occlusion, based on computer-aided design/computer-aided manufacturing-engineered preoperative surgical simulations. This modification made it possible to resolve the facial asymmetry of the patient successfully with a simple bilateral intraoral vertical ramus osteotomy and no additional maxillary or mandibular surgery.

  10. Mandibular reconstructions using computer-aided design/computer-aided manufacturing: A systematic review of a defect-based reconstructive algorithm.

    PubMed

    Tarsitano, Achille; Del Corso, Giacomo; Ciocca, Leonardo; Scotti, Roberto; Marchetti, Claudio

    2015-11-01

    Modern planning techniques, including computer-aided design/computer-aided manufacturing (CAD-CAM) can be used to plan reconstructive surgery, optimising aesthetic outcomes and functional rehabilitation. However, although many such applications are available, no systematic protocol yet describes the entire reconstructive procedure, which must include virtual planning, custom manufacture, and a reconstructive algorithm. We reviewed current practices in this novel field, analysed case series described in the literature, and developed a new, defect-based reconstructive algorithm. We also evaluated methods of mandibular reconstruction featuring virtual planning, the use of surgical guides, and laser printing of custom titanium bony plates to support composite free flaps, and evaluated their utility.

  11. Breaking the Glass Ceiling: Increasing the Meaningful Involvement of Women Living With HIV/AIDS (MIWA) in the Design and Delivery of HIV/AIDS Services.

    PubMed

    Carter, Allison; Greene, Saara; Nicholson, Valerie; O'Brien, Nadia; Sanchez, Margarite; de Pokomandy, Alexandra; Loutfy, Mona; Kaida, Angela

    2015-01-01

    The meaningful involvement of women living with HIV/AIDS (MIWA) is a key feature of women-centred HIV care, yet little is known about transforming MIWA from principle to practice. Drawing on focus group data from the Canadian HIV Women's Sexual and Reproductive Health Cohort Study (CHIWOS), we explored HIV-positive women's meaningful involvement in the design and delivery of HIV/AIDS services in British Columbia, Canada. In this article, we highlight the benefits and tensions that emerge as women traverse multiple roles as service users and service providers within their care communities, and the impact this has on their access to care and overall health.

  12. The dynamics of orbital maneuvering: Design and evaluation of a visual display aid for human controllers

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Grunwald, Arthur J.

    1990-01-01

    An interactive proximity operations planning system, which allows on-site planning of fuel-efficient, multi-burn maneuvers in a potential multi-spacecraft environment was developed and tested. Though this display system most directly assists planning by providing visual feedback to aid visualization of the trajectories and constraints, its most significant features include an inverse dynamics algorithm that removes control nonlinearities facing the operator and a trajectory planning technique that reduces the order of control and creates, through a geometric spread-sheet the illusion of an inertially stable environment. This synthetic environment provides the user with control of relevant static and dynamic properties of way-points during small orbital changes allowing independent solutions to the normally coupled problems of orbital maneuvering. An experiment was carried out in which experienced operators were required to plan a trajectory to retrieve an object accidently separated from a dual-keel space station. The time required to plan these maneuvers was found to be predicted by the direction of the insertion thrust and did not depend on the point of separation from the space station.

  13. Operator Station Design System - A computer aided design approach to work station layout

    NASA Technical Reports Server (NTRS)

    Lewis, J. L.

    1979-01-01

    The Operator Station Design System is resident in NASA's Johnson Space Center Spacecraft Design Division Performance Laboratory. It includes stand-alone minicomputer hardware and Panel Layout Automated Interactive Design and Crew Station Assessment of Reach software. The data base consists of the Shuttle Transportation System Orbiter Crew Compartment (in part), the Orbiter payload bay and remote manipulator (in part), and various anthropometric populations. The system is utilized to provide panel layouts, assess reach and vision, determine interference and fit problems early in the design phase, study design applications as a function of anthropometric and mission requirements, and to accomplish conceptual design to support advanced study efforts.

  14. Miscellaneous Topics in Computer-Aided Drug Design: Synthetic Accessibility and GPU Computing, and Other Topics

    PubMed Central

    Fukunishi, Yoshifumi; Mashimo, Tadaaki; Misoo, Kiyotaka; Wakabayashi, Yoshinori; Miyaki, Toshiaki; Ohta, Seiji; Nakamura, Mayu; Ikeda, Kazuyoshi

    2016-01-01

    Abstract: Background Computer-aided drug design is still a state-of-the-art process in medicinal chemistry, and the main topics in this field have been extensively studied and well reviewed. These topics include compound databases, ligand-binding pocket prediction, protein-compound docking, virtual screening, target/off-target prediction, physical property prediction, molecular simulation and pharmacokinetics/pharmacodynamics (PK/PD) prediction. Message and Conclusion: However, there are also a number of secondary or miscellaneous topics that have been less well covered. For example, methods for synthesizing and predicting the synthetic accessibility (SA) of designed compounds are important in practical drug development, and hardware/software resources for performing the computations in computer-aided drug design are crucial. Cloud computing and general purpose graphics processing unit (GPGPU) computing have been used in virtual screening and molecular dynamics simulations. Not surprisingly, there is a growing demand for computer systems which combine these resources. In the present review, we summarize and discuss these various topics of drug design. PMID:27075578

  15. Crew aiding and automation: A system concept for terminal area operations, and guidelines for automation design

    NASA Technical Reports Server (NTRS)

    Dwyer, John P.

    1994-01-01

    This research and development program comprised two efforts: the development of guidelines for the design of automated systems, with particular emphasis on automation design that takes advantage of contextual information, and the concept-level design of a crew aiding system, the Terminal Area Navigation Decision Aiding Mediator (TANDAM). This concept outlines a system capable of organizing navigation and communication information and assisting the crew in executing the operations required in descent and approach. In service of this endeavor, problem definition activities were conducted that identified terminal area navigation and operational familiarization exercises addressing the terminal area navigation problem. Both airborne and ground-based (ATC) elements of aircraft control were extensively researched. The TANDAM system concept was then specified, and the crew interface and associated systems described. Additionally, three descent and approach scenarios were devised in order to illustrate the principal functions of the TANDAM system concept in relation to the crew, the aircraft, and ATC. A plan for the evaluation of the TANDAM system was established. The guidelines were developed based on reviews of relevant literature, and on experience gained in the design effort.

  16. Methods and software tools for computer-aided design of the spacecraft guidance, navigation and control systems

    NASA Astrophysics Data System (ADS)

    Somov, Yevgeny; Oparin, Gennady

    2017-01-01

    We shortly present results on development and employment of the software systems for computer-aided design of the spacecraft guidance. navigation and control systems - modeling, synthesis, nonlinear analysis, simulation and graphic mapping of dynamic processes.

  17. Iso-geometric analysis for neutron diffusion problems

    SciTech Connect

    Hall, S. K.; Eaton, M. D.; Williams, M. M. R.

    2012-07-01

    Iso-geometric analysis can be viewed as a generalisation of the finite element method. It permits the exact representation of a wider range of geometries including conic sections. This is possible due to the use of concepts employed in computer-aided design. The underlying mathematical representations from computer-aided design are used to capture both the geometry and approximate the solution. In this paper the neutron diffusion equation is solved using iso-geometric analysis. The practical advantages are highlighted by looking at the problem of a circular fuel pin in a square moderator. For this problem the finite element method requires the geometry to be approximated. This leads to errors in the shape and size of the interface between the fuel and the moderator. In contrast to this iso-geometric analysis allows the interface to be represented exactly. It is found that, due to a cancellation of errors, the finite element method converges more quickly than iso-geometric analysis for this problem. A fuel pin in a vacuum was then considered as this problem is highly sensitive to the leakage across the interface. In this case iso-geometric analysis greatly outperforms the finite element method. Due to the improvement in the representation of the geometry iso-geometric analysis can outperform traditional finite element methods. It is proposed that the use of iso-geometric analysis on neutron transport problems will allow deterministic solutions to be obtained for exact geometries. Something that is only currently possible with Monte Carlo techniques. (authors)

  18. Design of a cervical collar device to facilitate and accelerate implementation of first aid.

    PubMed

    Işık, Hakan; Saraçoğlu, Esra; Harmanci, Hüseyin; Güler, Inan

    2010-08-01

    Frequently there are disasters all over the world-fires, earthquakes, or even some unexpected shocking catastrophes. Hence people injured, or even died. Lifesaving actions begin with the initiation of the chain of survival. With every minute that passes without medical action being taken, the probability of being able to save the patients life decreases by ten percent. After 10 min there is normally no chance of resuscitation being successful. First aid is emergency treatment given before regular medical aid can be obtained. And it is a concept of first hands-on measures performed in a medical emergency by laypersons. The major aim of this study is to develop an easy-feasible cervical collar, for facilitating and accelerating implementation of first aid especially in case of collective injuries. The developed device is different from the cervical collars which are used to treat the neck pain. In the present study, the heartbeat is obtained by detecting pulse with the stethoscope that is a part of the developed device and fixed on the carorid artery. The obtained heartbeat signal has been processed by the electronic control circuit and the used LED has given light according to the patient's life signal. Although there are some disadvantages of the developed system, the precautions for these cases have been taken and the system has been tried to design in order to operate sensibly.

  19. Computer aided process planning and die design in simulation environment in sheet metal forming

    NASA Astrophysics Data System (ADS)

    Tisza, Miklós; Lukács, Zsolt

    2013-12-01

    During the recent 10-15 years, Computer Aided Process Planning and Die Design evolved as one of the most important engineering tools in sheet metal forming, particularly in the automotive industry. This emerging role is strongly emphasized by the rapid development of Finite Element Modeling, as well. The purpose of this paper is to give a general overview about the recent achievements in this very important field of sheet metal forming and to introduce some special results in this development activity. Therefore, in this paper, an integrated process simulation and die design system developed at the University of Miskolc, Department of Mechanical Engineering will be analyzed. The proposed integrated solutions have great practical importance to improve the global competitiveness of sheet metal forming in the very important segment of industry. The concept described in this paper may have specific value both for process planning and die design engineers.

  20. A Novel Computer-Aided Approach for Parametric Investigation of Custom Design of Fracture Fixation Plates

    PubMed Central

    2017-01-01

    The present study proposes an integrated computer-aided approach combining femur surface modeling, fracture evidence recover plate creation, and plate modification in order to conduct a parametric investigation of the design of custom plate for a specific patient. The study allows for improving the design efficiency of specific plates on the patients' femur parameters and the fracture information. Furthermore, the present approach will lead to exploration of plate modification and optimization. The three-dimensional (3D) surface model of a detailed femur and the corresponding fixation plate were represented with high-level feature parameters, and the shape of the specific plate was recursively modified in order to obtain the optimal plate for a specific patient. The proposed approach was tested and verified on a case study, and it could be helpful for orthopedic surgeons to design and modify the plate in order to fit the specific femur anatomy and the fracture information. PMID:28203270

  1. Lithium-ion batteries for hearing aid applications: I. Design and performance

    NASA Astrophysics Data System (ADS)

    Passerini, S.; Owens, B. B.; Coustier, F.

    Rechargeable batteries have been designed for powering hearing aid devices (HAD). The cells, based on the lithium-ion chemistry, were designed in a size that is compatible with the existing HAD. The 10 mA h batteries were tested to characterize the design and the electrochemical performance from the point of view of a typical HAD application. Results are presented for constant-current tests, first-cycle conditions, charge voltage cut-off, rate performance, and cycle life. The pulse capabilities and the preliminary safety tests of the batteries will be presented in a following report. The results of the lithium-ion HAD cells developed in this project are compared with other battery chemistries: lithium-alloy and nickel-metal hydride secondary batteries and Zn-air primary batteries.

  2. Large Advanced Space Systems (LASS) computer-aided design program additions

    NASA Technical Reports Server (NTRS)

    Farrell, C. E.

    1982-01-01

    The LSS preliminary and conceptual design requires extensive iteractive analysis because of the effects of structural, thermal, and control intercoupling. A computer aided design program that will permit integrating and interfacing of required large space system (LSS) analyses is discussed. The primary objective of this program is the implementation of modeling techniques and analysis algorithms that permit interactive design and tradeoff studies of LSS concepts. Eight software modules were added to the program. The existing rigid body controls module was modified to include solar pressure effects. The new model generator modules and appendage synthesizer module are integrated (interfaced) to permit interactive definition and generation of LSS concepts. The mass properties module permits interactive specification of discrete masses and their locations. The other modules permit interactive analysis of orbital transfer requirements, antenna primary beam n, and attitude control requirements.

  3. A Novel Computer-Aided Approach for Parametric Investigation of Custom Design of Fracture Fixation Plates.

    PubMed

    Chen, Xiaozhong; He, Kunjin; Chen, Zhengming

    2017-01-01

    The present study proposes an integrated computer-aided approach combining femur surface modeling, fracture evidence recover plate creation, and plate modification in order to conduct a parametric investigation of the design of custom plate for a specific patient. The study allows for improving the design efficiency of specific plates on the patients' femur parameters and the fracture information. Furthermore, the present approach will lead to exploration of plate modification and optimization. The three-dimensional (3D) surface model of a detailed femur and the corresponding fixation plate were represented with high-level feature parameters, and the shape of the specific plate was recursively modified in order to obtain the optimal plate for a specific patient. The proposed approach was tested and verified on a case study, and it could be helpful for orthopedic surgeons to design and modify the plate in order to fit the specific femur anatomy and the fracture information.

  4. Computer aided design of digital controller for radial active magnetic bearings

    NASA Technical Reports Server (NTRS)

    Cai, Zhong; Shen, Zupei; Zhang, Zuming; Zhao, Hongbin

    1992-01-01

    A five degree of freedom Active Magnetic Bearing (AMB) system is developed which is controlled by digital controllers. The model of the radial AMB system is linearized and the state equation is derived. Based on the state variables feedback theory, digital controllers are designed. The performance of the controllers are evaluated according to experimental results. The Computer Aided Design (CAD) method is used to design controllers for magnetic bearings. The controllers are implemented with a digital signal processing (DSP) system. The control algorithms are realized with real-time programs. It is very easy to change the controller by changing or modifying the programs. In order to identify the dynamic parameters of the controlled magnetic system, a special experiment was carried out. Also, the online Recursive Least Squares (RLS) parameter identification method is studied. It can be realized with the digital controllers. Online parameter identification is essential for the realization of an adaptive controller.

  5. Design of a controlled-brake orthosis for FES-aided gait.

    PubMed

    Goldfarb, M; Durfee, W K

    1996-03-01

    Functional electrical stimulation (FES) is a means of restoring gait to individuals with spinal cord injury, but the performance of most FES-aided gait systems is hampered by the rapid muscle fatigue which results from stimulated muscle contraction and the inadequate control of joint torques necessary to produce desired limb trajectories. The controlled-brake orthosis (CBO) addresses these limitations by utilizing FES in combination with a long-leg brace that contains controllable friction brakes at the knees and hips. A laboratory version of the CBO utilizing computer-controlled magnetic particle brakes at the joints was designed and constructed, and preliminary results with a single spinal cord injury (SCI) subject have demonstrated reduced fatigue and more repeatable gait trajectories when compared to FES-aided gait without the brace. Significant work remains to demonstrate the efficacy of the concept across a wide range of SCI subjects and to design a system which meets appropriate user requirements of size, weight, cosmesis, ease of use and cost. The primary purpose of the paper is to detail the design of the CBO.

  6. Flexibility analysis of biomacromolecules with application to computer-aided drug design.

    PubMed

    Fulle, Simone; Gohlke, Holger

    2012-01-01

    Flexibility characteristics of biomacromolecules can be efficiently determined down to the atomic level by a graph-theoretical technique as implemented in the FIRST (Floppy Inclusion and Rigid Substructure Topology) and ProFlex software packages. The method has been successfully applied to a series of protein and nucleic acid structures. Here, we describe practical guidelines for setting up and performing a flexibility analysis, discuss current bottlenecks of the approach, and provide sample applications as to how this technique can support computer-aided drug design approaches.

  7. User-Friendly, Syntax Directed Input to a Computer Aided Design System.

    DTIC Science & Technology

    1983-06-01

    indepen- dern-. oblems arise in both compu:er aided design and in software development as a result of multipla types cf computz , mUtiple languages...Base CONLAN. Ease CONLAN is defined cy three i- ms , a set of object types and cperations, syntax, and a comPuta-IoL model. It is defined with Primitive...ycsjum on Computer Hardware= DescrT:--c-: -Lanquaqes. ~ p. =-3’EEET73 28. H1Il, F. J., and Petezzcn, J. R., DjZt4- S Lt-= Ms : Hardware O~gan iza,,i.n cand

  8. Extracting dimensional geometric parameters from B-spline surface models of aircraft

    NASA Technical Reports Server (NTRS)

    Jayaram, U.; Myklebust, Arvid; Gelhausen, P.

    1992-01-01

    Research that creates techniques to automatically obtain dimensional geometric parameters from the nonuniform B-spline surface description of an object is presented. These techniques have been implemented successfully in the aircraft design software, ACSYNT, a computer-aided design system for conceptual aircraft design created at Virginia Tech and NASA Ames. The techniques created and implemented in this research are also of significance to general-purpose design.

  9. User's manual: Computer-aided design programs for inductor-energy-storage dc-to-dc electronic power converters

    NASA Technical Reports Server (NTRS)

    Huffman, S.

    1977-01-01

    Detailed instructions on the use of two computer-aided-design programs for designing the energy storage inductor for single winding and two winding dc to dc converters are provided. Step by step procedures are given to illustrate the formatting of user input data. The procedures are illustrated by eight sample design problems which include the user input and the computer program output.

  10. An Automated Tool for Developing Experimental Designs: The Computer-Aided Design Reference for Experiments (CADRE)

    DTIC Science & Technology

    2009-01-01

    survey procedures, and cognitive task analysis), system design methods (e.g., focus groups , design guidelines, specifications, and requirements), and...LABORATORY - HRED ATTN AMSRD ARL HR MZ A DAVISON 199 E 4TH ST STE C TECH PARK BLG 2 FT LEONARD WOOD MO 65473-1949 1 ARMY RSCH LABORATORY

  11. Accelerating Design of Batteries Using Computer-Aided Engineering Tools (Presentation)

    SciTech Connect

    Pesaran, A.; Kim, G. H.; Smith, K.

    2010-11-01

    Computer-aided engineering (CAE) is a proven pathway, especially in the automotive industry, to improve performance by resolving the relevant physics in complex systems, shortening the product development design cycle, thus reducing cost, and providing an efficient way to evaluate parameters for robust designs. Academic models include the relevant physics details, but neglect engineering complexities. Industry models include the relevant macroscopic geometry and system conditions, but simplify the fundamental physics too much. Most of the CAE battery tools for in-house use are custom model codes and require expert users. There is a need to make these battery modeling and design tools more accessible to end users such as battery developers, pack integrators, and vehicle makers. Developing integrated and physics-based CAE battery tools can reduce the design, build, test, break, re-design, re-build, and re-test cycle and help lower costs. NREL has been involved in developing various models to predict the thermal and electrochemical performance of large-format cells and has used in commercial three-dimensional finite-element analysis and computational fluid dynamics to study battery pack thermal issues. These NREL cell and pack design tools can be integrated to help support the automotive industry and to accelerate battery design.

  12. Current Status of Computer-Aided Drug Design for Type 2 Diabetes

    PubMed Central

    Bibi, Shabana; Sakata, Katsumi

    2016-01-01

    Background Diabetes is a metabolic disorder that requires multiple therapeutic approaches. The pancreas loses its functionality to properly produce the insulin hormone in patients with diabetes mellitus. In 2012, more than one million people worldwide died as a result of diabetes, which was the eighth leading cause of death. Objective Most drugs currently available and approved by the U.S. Food and Drug Administration cannot reach an adequate level of glycemic control in diabetic patients, and have many side effects; thus, new classes of compounds are required. Efforts based on computer-aided drug design (CADD) can mine a large number of databases to produce new and potent hits and minimize the requirement of time and dollars for new discoveries. Methods Pharmaceutical sciences have made progress with advances in drug design concepts. Virtual screening of large databases is most compatible with different computational methods such as molecular docking, pharmacophore, quantitative structure-activity relationship, and molecular dynamic simulation. Contribution of these methods in selection of antidiabetic compounds has been discussed. Results The Computer-Aided Drug Design (CADD) approach has contributed to successful discovery of novel anti-diabetic agents. This mini-review focuses on CADD approach on currently approved drugs and new therapeutic agents-in-development that may achieve suitable glucose levels and decrease the risk of hypoglycemia, which is a major obstacle to glucose control and a special concern for therapies that increase insulin levels. Conclusion Drug design and development for type 2 diabetes have been actively studied. However, a large number of antidiabetic drugs are still in early stages of development. The conventional target- and structure-based approaches can be regarded as part of the efforts toward therapeutic mechanism-based drug design for treatment of type 2 diabetes. It is expected that further improvement in CADD approach will

  13. Computer-aided analysis and design of the shape rolling process for producing turbine engine airfoils

    NASA Technical Reports Server (NTRS)

    Lahoti, G. D.; Akgerman, N.; Altan, T.

    1978-01-01

    Mild steel (AISI 1018) was selected as model cold-rolling material and Ti-6Al-4V and INCONEL 718 were selected as typical hot-rolling and cold-rolling alloys, respectively. The flow stress and workability of these alloys were characterized and friction factor at the roll/workpiece interface was determined at their respective working conditions by conducting ring tests. Computer-aided mathematical models for predicting metal flow and stresses, and for simulating the shape-rolling process were developed. These models utilize the upper-bound and the slab methods of analysis, and are capable of predicting the lateral spread, roll-separating force, roll torque and local stresses, strains and strain rates. This computer-aided design (CAD) system is also capable of simulating the actual rolling process and thereby designing roll-pass schedule in rolling of an airfoil or similar shape. The predictions from the CAD system were verified with respect to cold rolling of mild steel plates. The system is being applied to cold and hot isothermal rolling of an airfoil shape, and will be verified with respect to laboratory experiments under controlled conditions.

  14. Computer-aided design and manufacturing in craniomaxillofacial surgery: the new state of the art.

    PubMed

    Levine, Jamie P; Patel, Ashish; Saadeh, Pierre B; Hirsch, David L

    2012-01-01

    The goal of this article was to illustrate the ease in which virtual surgery and computer-aided design and manufacturing can be used by the craniomaxillofacial surgeon to create tremendously accurate postoperative results and provide confidence with even the most complex three-dimensional bony reconstructions. With advancements in software technology and three-dimensional printing, our ability to plan and execute precise bony reconstruction has become a reality. With this technology, guides can be made to ensure exact bony repositioning or replacement. These guides can help guide cutting of the bone and can act as splints to precisely reposition the bone and direct plate placement. With use of these computer-aided design and manufacturing guides and the addition of guidance technology, the position of the bone can be guaranteed intraoperatively. We review our unique and advanced method in approaching some of these problems and illustrate the application of these techniques in mandibular reconstruction, orthognathic surgery, maxillofacial trauma, and temporomandibular joint reconstruction. This technology continues to evolve, and our indications for its application continue to grow. This article represents only a small portion of the types of cases in which these techniques have already been applied.

  15. Computer-aided Molecular Design of Compounds Targeting Histone Modifying Enzymes

    PubMed Central

    Andreoli, Federico; Del Rio, Alberto

    2015-01-01

    Growing evidences show that epigenetic mechanisms play crucial roles in the genesis and progression of many physiopathological processes. As a result, research in epigenetic grew at a fast pace in the last decade. In particular, the study of histone post-translational modifications encountered an extraordinary progression and many modifications have been characterized and associated to fundamental biological processes and pathological conditions. Histone modifications are the catalytic result of a large set of enzyme families that operate covalent modifications on specific residues at the histone tails. Taken together, these modifications elicit a complex and concerted processing that greatly contribute to the chromatin remodeling and may drive different pathological conditions, especially cancer. For this reason, several epigenetic targets are currently under validation for drug discovery purposes and different academic and industrial programs have been already launched to produce the first pre-clinical and clinical outcomes. In this scenario, computer-aided molecular design techniques are offering important tools, mainly as a consequence of the increasing structural information available for these targets. In this mini-review we will briefly discuss the most common types of known histone modifications and the corresponding operating enzymes by emphasizing the computer-aided molecular design approaches that can be of use to speed-up the efforts to generate new pharmaceutically relevant compounds. PMID:26082827

  16. Design and implementation of a bluetooth-based band-aid pulse rate sensor

    NASA Astrophysics Data System (ADS)

    Kumar, Prashanth S.; Oh, Sechang; Rai, Pratyush; Kwon, Hyeokjun; Banerjee, Nilanjan; Varadan, Vijay K.

    2011-04-01

    Remote patient monitoring systems capable of collecting vital patient data such as blood pressure readings, Electrocardiograph (ECG) waveforms, and heart rate can obviate the need for repeated visits to the hospital. Moreover, such systems that continuously monitor the human physiology can provide valuable data to prognosticate the onset of critical health problems. The key to such remote health diagnostics is the design of minimally intrusive, low cost sensors that do not impede a patient's quotidian life but at the same time collect reliable noise free data. To this end, in this paper, we design and implement a Bluetooth-based wireless sensor system with a disposable sensor element and a reusable wireless component that can be worn as a "band-aid". The sensor is a piezoelectric polymer film placed on the wrist in proximity to the radial artery. The band-aid sized sensor allows non-intrusive monitoring of the pulsatile flow of blood in the artery. The sensor, using the Bluetooth module, can communicate with any Bluetooth enabled computer, mobile phone, or PDA. The data collected from the patient can be remotely viewed and analyzed by a physician.

  17. LIFESPAN: A tool for the computer-aided design of longitudinal studies

    PubMed Central

    Brandmaier, Andreas M.; von Oertzen, Timo; Ghisletta, Paolo; Hertzog, Christopher; Lindenberger, Ulman

    2015-01-01

    Researchers planning a longitudinal study typically search, more or less informally, a multivariate space of possible study designs that include dimensions such as the hypothesized true variance in change, indicator reliability, the number and spacing of measurement occasions, total study time, and sample size. The main search goal is to select a research design that best addresses the guiding questions and hypotheses of the planned study while heeding applicable external conditions and constraints, including time, money, feasibility, and ethical considerations. Because longitudinal study selection ultimately requires optimization under constraints, it is amenable to the general operating principles of optimization in computer-aided design. Based on power equivalence theory (MacCallum et al., 2010; von Oertzen, 2010), we propose a computational framework to promote more systematic searches within the study design space. Starting with an initial design, the proposed framework generates a set of alternative models with equal statistical power to detect hypothesized effects, and delineates trade-off relations among relevant parameters, such as total study time and the number of measurement occasions. We present LIFESPAN (Longitudinal Interactive Front End Study Planner), which implements this framework. LIFESPAN boosts the efficiency, breadth, and precision of the search for optimal longitudinal designs. Its initial version, which is freely available at http://www.brandmaier.de/lifespan, is geared toward the power to detect variance in change as specified in a linear latent growth curve model. PMID:25852596

  18. Computer-aided design comparisons of monolithic and hybrid MEM-tunable VCSELs

    NASA Astrophysics Data System (ADS)

    Ochoa, Edward M.; Nelson, Thomas R., Jr.; Blum-Spahn, Olga; Lott, James A.

    2003-07-01

    We report and use our micro-electro-mechanically tunable vertical cavity surface emitting laser (MEM-TVCSEL) computer-aided design methodology to investigate the resonant frequency design space for monolithic and hybrid MEM-TVCSELs. For various initial optical air gap thickness, we examine the sensitivity of monolithic or hybrid MEM-TVCSEL resonant frequency by simulating zero, two, and four percent variations in III-V material growth thickness. As expected, as initial optical airgap increases, tuning range decreases due to less coupling between the active region and the tuning mirror. However, each design has different resonant frequency sensitivity to variations in III-V growth parameters. In particular, since the monolithic design is comprised of III-V material, the shift in all growth thicknesses significantly shifts the resonant frequency response. However, for hybrid MEMTVCSELs, less shift results, since the lower reflector is an Au mirror with reflectivity independent of III-V growth variations. Finally, since the hybrid design is comprised of a MUMPS polysilicon mechanical actuator, pull-in voltage remains independent of the initial optical airgap between the tuning reflector and the III-V material. Conversely, as the initial airgap increases in the monolithic design, the pull-in voltage significantly increases.

  19. Untangling Geometric Ideas

    ERIC Educational Resources Information Center

    Burgess, Claudia R.

    2014-01-01

    Designed for a broad audience, including educators, camp directors, afterschool coordinators, and preservice teachers, this investigation aims to help individuals experience mathematics in unconventional and exciting ways by engaging them in the physical activity of building geometric shapes using ropes. Through this engagement, the author…

  20. Establishment of a Computer-Aided Design (CAD)/Computer-Aided Manufacturing (CAM) Process for the Production of Cold Forged Gears

    DTIC Science & Technology

    1984-01-01

    Continue on reverse side if necessary and Identify by block number) Computer Aided Design/Manufacturing (CAD/CAM), Spur and Helical Gears, Cold Forging...for cold forging spur and helical gears. The geometry of the spur and helical gears has been obtained from the kinematics of the hobbing/shaper machines...or shaping) to cut the electrode for a helical gear die were then computed using the corrections described above. A computer program called GEARDI

  1. Computer aided design and manufacturing of composite propfan blades for a cruise missile wind tunnel model

    NASA Technical Reports Server (NTRS)

    Thorp, Scott A.; Downey, Kevin M.

    1992-01-01

    One of the propulsion concepts being investigated for future cruise missiles is advanced unducted propfans. To support the evaluation of this technology applied to the cruise missile, a joint DOD and NASA test project was conducted to design and then test the characteristics of the propfans on a 0.55-scale, cruise missile model in a NASA wind tunnel. The configuration selected for study is a counterrotating rearward swept propfan. The forward blade row, having six blades, rotates in a counterclockwise direction, and the aft blade row, having six blades, rotates in a clockwise direction, as viewed from aft of the test model. Figures show the overall cruise missile and propfan blade configurations. The objective of this test was to evaluate propfan performance and suitability as a viable propulsion option for next generation of cruise missiles. This paper details the concurrent computer aided design, engineering, and manufacturing of the carbon fiber/epoxy propfan blades as the NASA Lewis Research Center.

  2. Computer-aided design and distributed system technology development for large space structures

    NASA Technical Reports Server (NTRS)

    Armstrong, Ernest S.; Joshi, Suresh M.

    1986-01-01

    Proposed large space structures have many characteristics that make them difficult to analyze and control. They are highly flexible, with components mathematically modeled by partial differential equations or very large systems of ordinary differential equations. They have many resonant frequencies, typically low and closely spaced. Natural damping may be low and/or improperly modeled. Coupled with stringent operational requirements of orientation, shape control, and vibration suppression, and the inability to perform adequate ground testing, these characteristics present an unconventional identification and control design problem to the systems theorist. Some of the research underway within Langley's Spacecraft Control Branch, Guidance and Control Division aimed at developing theory and algorithms to treat large space structures systems identification and control problems is described. The research areas to be considered are computer-aided design algorithms, and systems identification and control of distributed systems.

  3. A multi-criteria decision aid methodology to design electric vehicles public charging networks

    NASA Astrophysics Data System (ADS)

    Raposo, João; Rodrigues, Ana; Silva, Carlos; Dentinho, Tomaz

    2015-05-01

    This article presents a new multi-criteria decision aid methodology, dynamic-PROMETHEE, here used to design electric vehicle charging networks. In applying this methodology to a Portuguese city, results suggest that it is effective in designing electric vehicle charging networks, generating time and policy based scenarios, considering offer and demand and the city's urban structure. Dynamic-PROMETHE adds to the already known PROMETHEE's characteristics other useful features, such as decision memory over time, versatility and adaptability. The case study, used here to present the dynamic-PROMETHEE, served as inspiration and base to create this new methodology. It can be used to model different problems and scenarios that may present similar requirement characteristics.

  4. Solving rational matrix equations in the state space with applications to computer-aided control-system design

    NASA Technical Reports Server (NTRS)

    Packard, A. K.; Sastry, S. S.

    1986-01-01

    A method of solving a class of linear matrix equations over various rings is proposed, using results from linear geometric control theory. An algorithm, successfully implemented, is presented, along with non-trivial numerical examples. Applications of the method to the algebraic control system design methodology are discussed.

  5. Using the Continuum of Design Modelling Techniques to Aid the Development of CAD Modeling Skills in First Year Industrial Design Students

    ERIC Educational Resources Information Center

    Storer, I. J.; Campbell, R. I.

    2012-01-01

    Industrial Designers need to understand and command a number of modelling techniques to communicate their ideas to themselves and others. Verbal explanations, sketches, engineering drawings, computer aided design (CAD) models and physical prototypes are the most commonly used communication techniques. Within design, unlike some disciplines,…

  6. Database Design Methodology and Database Management System for Computer-Aided Structural Design Optimization.

    DTIC Science & Technology

    1984-12-01

    1983). Several researchers Lillehagen and Dokkar (1982), Grabowski, Eigener and Ranch (1978), and Eberlein and Wedekind (1982) have worked on database...Proceedings of International Federation of Information Processing. pp. 335-366. Eberlein, W. and Wedekind , H., 1982, "A Methodology for Embedding Design

  7. Development of a computer-aided design software for dental splint in orthognathic surgery

    PubMed Central

    Chen, Xiaojun; Li, Xing; Xu, Lu; Sun, Yi; Politis, Constantinus; Egger, Jan

    2016-01-01

    In the orthognathic surgery, dental splints are important and necessary to help the surgeon reposition the maxilla or mandible. However, the traditional methods of manual design of dental splints are difficult and time-consuming. The research on computer-aided design software for dental splints is rarely reported. Our purpose is to develop a novel special software named EasySplint to design the dental splints conveniently and efficiently. The design can be divided into two steps, which are the generation of initial splint base and the Boolean operation between it and the maxilla-mandibular model. The initial splint base is formed by ruled surfaces reconstructed using the manually picked points. Then, a method to accomplish Boolean operation based on the distance filed of two meshes is proposed. The interference elimination can be conducted on the basis of marching cubes algorithm and Boolean operation. The accuracy of the dental splint can be guaranteed since the original mesh is utilized to form the result surface. Using EasySplint, the dental splints can be designed in about 10 minutes and saved as a stereo lithography (STL) file for 3D printing in clinical applications. Three phantom experiments were conducted and the efficiency of our method was demonstrated. PMID:27966601

  8. Computer-Aided Molecular Design of Bis-phosphine Oxide Lanthanide Extractants

    DOE PAGES

    McCann, Billy W.; Silva, Nuwan De; Windus, Theresa L.; ...

    2016-02-17

    Computer-aided molecular design and high-throughput screening of viable host architectures can significantly reduce the efforts in the design of novel ligands for efficient extraction of rare earth elements. This paper presents a computational approach to the deliberate design of bis-phosphine oxide host architectures that are structurally organized for complexation of trivalent lanthanides. Molecule building software, HostDesigner, was interfaced with molecular mechanics software, PCModel, providing a tool for generating and screening millions of potential R2(O)P-link-P(O)R2 ligand geometries. The molecular mechanics ranking of ligand structures is consistent with both the solution-phase free energies of complexation obtained with density functional theory and themore » performance of known bis-phosphine oxide extractants. For the case where link is -CH2-, evaluation of the ligand geometry provides the first characterization of a steric origin for the ‘anomalous aryl strengthening’ effect. The design approach has identified a number of novel bis-phosphine oxide ligands that are better organized for lanthanide complexation than previously studied examples.« less

  9. Computer-Aided Molecular Design of Bis-phosphine Oxide Lanthanide Extractants

    SciTech Connect

    McCann, Billy W.; Silva, Nuwan De; Windus, Theresa L.; Gordon, Mark S.; Moyer, Bruce A.; Bryantsev, Vyacheslav S.; Hay, Benjamin P.

    2016-02-17

    Computer-aided molecular design and high-throughput screening of viable host architectures can significantly reduce the efforts in the design of novel ligands for efficient extraction of rare earth elements. This paper presents a computational approach to the deliberate design of bis-phosphine oxide host architectures that are structurally organized for complexation of trivalent lanthanides. Molecule building software, HostDesigner, was interfaced with molecular mechanics software, PCModel, providing a tool for generating and screening millions of potential R2(O)P-link-P(O)R2 ligand geometries. The molecular mechanics ranking of ligand structures is consistent with both the solution-phase free energies of complexation obtained with density functional theory and the performance of known bis-phosphine oxide extractants. For the case where link is -CH2-, evaluation of the ligand geometry provides the first characterization of a steric origin for the ‘anomalous aryl strengthening’ effect. The design approach has identified a number of novel bis-phosphine oxide ligands that are better organized for lanthanide complexation than previously studied examples.

  10. Development of a computer-aided design software for dental splint in orthognathic surgery

    NASA Astrophysics Data System (ADS)

    Chen, Xiaojun; Li, Xing; Xu, Lu; Sun, Yi; Politis, Constantinus; Egger, Jan

    2016-12-01

    In the orthognathic surgery, dental splints are important and necessary to help the surgeon reposition the maxilla or mandible. However, the traditional methods of manual design of dental splints are difficult and time-consuming. The research on computer-aided design software for dental splints is rarely reported. Our purpose is to develop a novel special software named EasySplint to design the dental splints conveniently and efficiently. The design can be divided into two steps, which are the generation of initial splint base and the Boolean operation between it and the maxilla-mandibular model. The initial splint base is formed by ruled surfaces reconstructed using the manually picked points. Then, a method to accomplish Boolean operation based on the distance filed of two meshes is proposed. The interference elimination can be conducted on the basis of marching cubes algorithm and Boolean operation. The accuracy of the dental splint can be guaranteed since the original mesh is utilized to form the result surface. Using EasySplint, the dental splints can be designed in about 10 minutes and saved as a stereo lithography (STL) file for 3D printing in clinical applications. Three phantom experiments were conducted and the efficiency of our method was demonstrated.

  11. Computer-aided design models for broadside-coupled striplines and millimeter-wave suspended substrate microstrip lines

    NASA Astrophysics Data System (ADS)

    Bhartia, Prakash; Pramanick, Protap

    1988-11-01

    Models were derived from the results of conformal transformation on homogeneous stripline, the equivalence of the odd-mode with the quasi-TEM mode of covered microstrip line, and logarithmic regression of spectral-domain results. Effects of finite strip thickness have been taken into account. These models are fully compatible with the needs and trends of computer-aided and programmable-calculator-aided microwave and millimeter-wave integrated circuit design.

  12. Development of the engineering design integration (EDIN) system: A computer aided design development

    NASA Technical Reports Server (NTRS)

    Glatt, C. R.; Hirsch, G. N.

    1977-01-01

    The EDIN (Engineering Design Integration) System which provides a collection of hardware and software, enabling the engineer to perform man-in-the-loop interactive evaluation of aerospace vehicle concepts, was considered. Study efforts were concentrated in the following areas: (1) integration of hardware with the Univac Exec 8 System; (2) development of interactive software for the EDIN System; (3) upgrading of the EDIN technology module library to an interactive status; (4) verification of the soundness of the developing EDIN System; (5) support of NASA in design analysis studies using the EDIN System; (6) provide training and documentation in the use of the EDIN System; and (7) provide an implementation plan for the next phase of development and recommendations for meeting long range objectives.

  13. 23 CFR 636.104 - Does this part apply to all Federal-aid design-build projects?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 23 Highways 1 2011-04-01 2011-04-01 false Does this part apply to all Federal-aid design-build projects? 636.104 Section 636.104 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS DESIGN-BUILD CONTRACTING General § 636.104 Does this part apply to...

  14. Evaluations and geometrical measurements of the human eye in order to establish the design parameters for the customized contact lens

    NASA Astrophysics Data System (ADS)

    Pascu, A. T.; Besnea, D.; Constantin, V.; Spanu, A.; Ciobanu, R.

    2016-08-01

    The paper presents the usual methods and means for geometrical evaluation and measurement for the anterior pole of the eyeball applied in studies conducted on real patients. The results were centralized, evaluated and presented in a summary in the paper. The purpose of the studies is to determine the range of dimensional values of the anterior pole of the human eyeball for the parameterization of the devices and checking tools when manufacturing the contact lenses.

  15. Therapist-aided exposure for women with lifelong vaginismus: a replicated single-case design.

    PubMed

    Ter Kuile, Moniek M; Bulté, Isis; Weijenborg, Philomeen T M; Beekman, Aart; Melles, Reinhilde; Onghena, Patrick

    2009-02-01

    Vaginismus is commonly described as a persistent difficulty in allowing vaginal entry of a penis or other object. Lifelong vaginismus occurs when a woman has never been able to have intercourse. A replicated single-case A-B-phase design was used to investigate the effectiveness of therapist-aided exposure for lifelong vaginismus. A baseline period (Phase A) was contrasted with exposure + follow-up (Phase B), using random switching between phases. The main outcome measure (intercourse ability) was assessed daily for 24 weeks. Ten women participated. The exposure consisted of a maximum of three 2-hr sessions during 1 week at a university hospital. The participant performed vaginal penetration exercises on herself, in the presence of a female therapist. Two follow-up sessions were scheduled over a 5-week period. Nine of the 10 participants reported having intercourse after treatment, and in 5 of the 9, intercourse was possible within the 1st week of treatment. The results remained at 1-year follow-up. Furthermore, exposure was successful in decreasing fear and negative penetration beliefs posttreatment and at 3-month and 1-year follow-ups. Therapist-aided exposure appears to be an effective treatment for lifelong vaginismus.

  16. VIP: A knowledge-based design aid for the engineering of space systems

    NASA Technical Reports Server (NTRS)

    Lewis, Steven M.; Bellman, Kirstie L.

    1990-01-01

    The Vehicles Implementation Project (VIP), a knowledge-based design aid for the engineering of space systems is described. VIP combines qualitative knowledge in the form of rules, quantitative knowledge in the form of equations, and other mathematical modeling tools. The system allows users rapidly to develop and experiment with models of spacecraft system designs. As information becomes available to the system, appropriate equations are solved symbolically and the results are displayed. Users may browse through the system, observing dependencies and the effects of altering specific parameters. The system can also suggest approaches to the derivation of specific parameter values. In addition to providing a tool for the development of specific designs, VIP aims at increasing the user's understanding of the design process. Users may rapidly examine the sensitivity of a given parameter to others in the system and perform tradeoffs or optimizations of specific parameters. A second major goal of VIP is to integrate the existing corporate knowledge base of models and rules into a central, symbolic form.

  17. Antibodies: Computer-Aided Prediction of Structure and Design of Function.

    PubMed

    Sevy, Alexander M; Meiler, Jens

    2014-12-01

    With the advent of high-throughput sequencing, and the increased availability of experimental structures of antibodies and antibody-antigen complexes, comes the improvement of computational approaches to predict the structure and design the function of antibodies and antibody-antigen complexes. While antibodies pose formidable challenges for protein structure prediction and design due to their large size and highly flexible loops in the complementarity-determining regions, they also offer exciting opportunities: the central importance of antibodies for human health results in a wealth of structural and sequence information that-as a knowledge base-can drive the modeling algorithms by limiting the conformational and sequence search space to likely regions of success. Further, efficient experimental platforms exist to test predicted antibody structure or designed antibody function, thereby leading to an iterative feedback loop between computation and experiment. We briefly review the history of computer-aided prediction of structure and design of function in the antibody field before we focus on recent methodological developments and the most exciting application examples.

  18. Microcomputed tomography marginal fit evaluation of computer-aided design/computer-aided manufacturing crowns with different methods of virtual model acquisition.

    PubMed

    das Neves, Flavio Domingues; do Prado, Celio Jesus; Prudente, Marcel Santana; Carneiro, Thiago Almeida Prado Naves; Zancope, Karla; Davi, Leticia Resende; Mendonca, Gustavo; Cooper, Lyndon; Soares, Carlos Jose

    2015-01-01

    This in vitro study used microcomputed tomography to evaluate the marginal fit of crowns fabricated using a chairside computer-aided design/computer-aided manufacturing (CAD/CAM) system with different methods of virtual model acquisition. Crowns were fabricated to fit in a cast containing a single human premolar. Four methods of virtual model acquisition were used: Group 1 (control), digital impressioning of a typodont; Group 2, digital impressioning of a powdered typodont; Group 3, digital impressioning of a regular impression; and Group 4, digital impressioning of a master cast. Statistically significant differences were found between the marginal gap of Group 2 and the other groups (P < 0.05); no differences were found among Groups 1, 3, and 4. The results showed that crowns fabricated using the chairside CAD/CAM system exhibited significantly smaller vertical misfit when a thin layer of powder was applied over the typodont before digital impressioning.

  19. Computer-aided design and computer-aided manufacture (CAD/CAM) system for construction of spinal orthosis for patients with adolescent idiopathic scoliosis.

    PubMed

    Wong, M S

    2011-01-01

    ABSTRACT Spinal orthoses are commonly prescribed to patients with moderate adolescent idiopathic scoliosis (AIS) for prevention of further curve deterioration. In conventional manufacturing method, plaster bandages are used to obtain the patient's body contour and then the plaster cast is rectified manually. With computer-aided design and computer-aided manufacture (CAD/CAM) system, a series of automated processes from body scanning to digital rectification and milling of the positive model can be performed in a fast and accurate fashion. The purpose of this manuscript is to introduce the application of CAD/CAM system to the construction of spinal orthosis for patients with AIS. Based on evidence within the literature, CAD/CAM method can achieve similar clinical outcomes but with higher efficiency than the conventional fabrication method. Therefore, CAD/CAM method should be considered a substitute to the conventional method in fabrication of spinal orthoses for patients with AIS.

  20. CAM - Geometric systems integration

    NASA Astrophysics Data System (ADS)

    Dunlap, G. C.

    The integration of geometric and nongeometric information for efficient use of CAM is examined. Requirements for engineering drawings requested by management are noted to involve large volumes of nongeometric data to define the materials and quantity variables which impinge on the required design, so that the actual design may be the last and smaller step in the CAM process. Geometric classification and coding are noted to offer an alpha/numeric identifier for integrating the engineering design, manufacturing, and quality assurance functions. An example is provided of a turbine gear part coding in terms of polycode and monocode displays, showing a possible covering of more than 10 trillion features. Software is stressed as the key to integration of company-wide data.

  1. Prospective on multiscale simulation of virus-like particles: Application to computer-aided vaccine design.

    PubMed

    Abi Mansour, Andrew; Sereda, Yuriy V; Yang, Jing; Ortoleva, Peter J

    2015-11-04

    Simulations of virus-like particles needed for computer-aided vaccine design highlight the need for new algorithms that accelerate molecular dynamics. Such simulations via conventional molecular dynamics present a practical challenge due to the millions of atoms involved and the long timescales of the phenomena of interest. These phenomena include structural transitions, self-assembly, and interaction with a cell surface. A promising approach for addressing this challenge is multiscale factorization. The approach is distinct from coarse-graining techniques in that it (1) avoids the need for conjecturing phenomenological governing equations for coarse-grained variables, (2) provides simulations with atomic resolution, (3) captures the cross-talk between disturbances at the atomic and the whole virus-like particle scale, and (4) achieves significant speedup over molecular dynamics. A brief review of multiscale factorization method is provided, as is a prospective on its development.

  2. Computer aided solar house design made of ``Guadua`` in Bogota, Colombia

    SciTech Connect

    Lozano, M.C.; Chalfoun, N.V.

    1995-11-01

    Bogota, Colombia, is the third highest capital in South America, its location near the equator assures high altitudes over the horizon and almost 5 hours of daily mean sunshine. Since 1981, efforts for using natural energy instead of nonrenewable fuel have been targeted to Colombia`s residential construction industry. This paper focuses on a computer aided design process for passive solar low-income row housing in Bogota. Thermal comfort for this tropical climate has been achieved through employing ``Guadua,`` a strong bamboo specie,as an alternative wall system to the traditional brick, adobe, or concrete structures. Through computer analysis, several energy conservation and passive solar strategies have been optimized for a case study row housing type common to the region. The load savings compared to a 6 inch CMU house totaled 72%, while the operating cost has been reduced by 71%. Furthermore, this lightweight and inexpensive ``Guadua`` material has reduced the construction cost by 30%.

  3. Alzheimer's disease drug development based on Computer-Aided Drug Design.

    PubMed

    Zeng, Huahui; Wu, Xiangxiang

    2016-10-04

    Alzheimer's disease (AD) is a common neurodegenerative disorder characterized by the excessive deposition of amyloids in the brain. The pathological features mainly include the extracellular amyloid plaques and intracellular neurofibrillary tangles, which are the production of amyloid precursor protein (APP) processed by the α-, β- and γ-secretases. Based on the amyloid cascade hypotheses of AD, a large number of amyloid-β agents and secretase inhibitors against AD have been recently developed by using computational methods. This review article describes pathophysiology of AD and the structure of the Aβ plaques, β- and γ-secretases, and discusses the recent advances in the development of the amyloid agents for AD therapy and diagnosis by using Computer-Aided Drug Design approach.

  4. [Computer aided design and manufacture of the porcelain fused to metal crown].

    PubMed

    Nie, Xin; Cheng, Xiaosheng; Dai, Ning; Yu, Qing; Hao, Guodong; Sun, Quanping

    2009-04-01

    In order to satisfy the current demand for fast and high-quality prosthodontics, we have carried out a research in the fabrication process of the porcelain fused to metal crown on molar with CAD/CAM technology. Firstly, we get the data of the surface mesh on preparation teeth through a 3D-optical grating measuring system. Then, we reconstruct the 3D-model crown with the computer-aided design software which was developed by ourselves. Finally, with the 3D-model data, we produce a metallic crown on a high-speed CNC carving machine. The result has proved that the metallic crown can match the preparation teeth ideally. The fabrication process is reliable and efficient, and the restoration is precise and steady in quality.

  5. Harnessing Polypharmacology with Computer-Aided Drug Design and Systems Biology.

    PubMed

    Wathieu, Henri; Issa, Naiem T; Byers, Stephen W; Dakshanamurthy, Sivanesan

    2016-01-01

    The ascent of polypharmacology in drug development has many implications for disease therapy, most notably in the efforts of drug discovery, drug repositioning, precision medicine and combination therapy. The single- target approach to drug development has encountered difficulties in predicting drugs that are both clinically efficacious and avoid toxicity. By contrast, polypharmacology offers the possibility of a controlled distribution of effects on a biological system. This review addresses possibilities and bottlenecks in the efficient computational application of polypharmacology. The two major areas we address are the discovery and prediction of multiple protein targets using the tools of computer-aided drug design, and the use of these protein targets in predicting therapeutic potential in the context of biological networks. The successful application of polypharmacology to systems biology and pharmacology has the potential to markedly accelerate the pace of development of novel therapies for multiple diseases, and has implications for the intellectual property landscape, likely requiring targeted changes in patent law.

  6. Chemical feedstock from hardwood by organosolv hydrolysis: Computer-aided process design and economic evaluation

    NASA Astrophysics Data System (ADS)

    Nguyen, X. N.

    1982-12-01

    A two stage catalyzed organosolv plant producing ethanol, furfural, acetic acid, and soluble lignin from wood waste was investigated. The GEMS computer system was used to aid the preliminary design and cost estimation of the proposed wood chemical plant. For a plant processing 1000 ovendry tons of wood per day, a capital investment of $66 million and an operating expense of about $20 million per year were estimated. The capital cost calculated compares favorably with other published estimates. Sensitivity analyses of some key factors in the proposed process disclose that the recovery efficiency of ethanol used in the lignin extraction stage is most important in determining the process economics. Ethanol solvent recovery of about 98% is required. At 95% recovery efficiency, conversion to glucose in the acid hydrolysis step above 90% is necessary for the ethanol selling price to be comparable to the current market price.

  7. Validation of space/ground antenna control algorithms using a computer-aided design tool

    NASA Technical Reports Server (NTRS)

    Gantenbein, Rex E.

    1995-01-01

    The validation of the algorithms for controlling the space-to-ground antenna subsystem for Space Station Alpha is an important step in assuring reliable communications. These algorithms have been developed and tested using a simulation environment based on a computer-aided design tool that can provide a time-based execution framework with variable environmental parameters. Our work this summer has involved the exploration of this environment and the documentation of the procedures used to validate these algorithms. We have installed a variety of tools in a laboratory of the Tracking and Communications division for reproducing the simulation experiments carried out on these algorithms to verify that they do meet their requirements for controlling the antenna systems. In this report, we describe the processes used in these simulations and our work in validating the tests used.

  8. Interactive Image Processing As An Aid To Designing Robot Vision Systems

    NASA Astrophysics Data System (ADS)

    Batchelor, B. G.; Cotter, S. M.; Page, G. J.; Hopkins, S. H.

    1983-10-01

    Interactive image processing has proved to be a valuable aid to prototype development for industrial inspection systems. This paper advocates extending its use to exploratory analysis of robot vision applications. Preliminary studies have shown that it is equally effective in this role, although it is not usually possible to achieve the computational speeds needed for real-time control of the robot using a software-based image processor. Its use, as in inspection research, is likely to be limited to algorithm design/selection. The Autoview image processor (British Robotic Systems Ltd.) has recently been interfaced to a Placemate 5 robot (Pendar Robotics Ltd.) and further programmable manipulation devices, including an xy-coordinate table and a stepping turntable are currently being connected. Using these and similar devices, research will be conducted into such tasks as assembly, Dalletisinq and robot-assisted inspection.

  9. Human immunodeficiency virus type 1 subtype C molecular phylogeny: consensus sequence for an AIDS vaccine design?

    PubMed

    Novitsky, V; Smith, U R; Gilbert, P; McLane, M F; Chigwedere, P; Williamson, C; Ndung'u, T; Klein, I; Chang, S Y; Peter, T; Thior, I; Foley, B T; Gaolekwe, S; Rybak, N; Gaseitsiwe, S; Vannberg, F; Marlink, R; Lee, T H; Essex, M

    2002-06-01

    An evolving dominance of human immunodeficiency virus type 1 subtype C (HIV-1C) in the AIDS epidemic has been associated with a high prevalence of HIV-1C infection in the southern African countries and with an expanding epidemic in India and China. Understanding the molecular phylogeny and genetic diversity of HIV-1C viruses may be important for the design and evaluation of an HIV vaccine for ultimate use in the developing world. In this study we analyzed the phylogenetic relationships (i) between 73 non-recombinant HIV-1C near-full-length genome sequences, including 51 isolates from Botswana; (ii) between HIV-1C consensus sequences that represent different geographic subsets; and (iii) between specific isolates and consensus sequences. Based on the phylogenetic analyses of 73 near-full-length genomes, 16 "lineages" (a term that is used hereafter for discussion purposes and does not imply taxonomic standing) were identified within HIV-1C. The lineages were supported by high bootstrap values in maximum-parsimony and neighbor-joining analyses and were confirmed by the maximum-likelihood method. The nucleotide diversity between the 73 HIV-1C isolates (mean value of 8.93%; range, 2.9 to 11.7%) was significantly higher than the diversity of the samples to the consensus sequence (mean value of 4.86%; range, 3.3 to 7.2%, P < 0.0001). The translated amino acid distances to the consensus sequence were significantly lower than distances between samples within all HIV-1C proteins. The consensus sequences of HIV-1C proteins accompanied by amino acid frequencies were presented (that of Gag is presented in this work; those of Pol, Vif, Vpr, Tat, Rev, Vpu, Env, and Nef are presented elsewhere [http://www.aids.harvard.edu/lab_research/concensus_sequence.htm]). Additionally, in the promoter region three NF-kappa B sites (GGGRNNYYCC) were identified within the consensus sequences of the entire set or any subset of HIV-1C isolates. This study suggests that the consensus sequence

  10. Design, development, and evaluation of visual aids for communicating prescription drug instructions to nonliterate patients in rural Cameroon.

    PubMed

    Ngoh, L N; Shepherd, M D

    1997-03-01

    In this study, culturally sensitive visual aids designed to help convey drug information to nonliterate female adults who had a prescription for a solid oral dosage form of antibiotic medications were developed and evaluated. The researchers conceptualized the educational messages while a local artist produced the visual aids. Seventy-eight female ambulatory patients were evaluated for comprehension and compliance with antibiotic prescription instructions. The study was conducted in three health centers in Cameroon, West Africa and followed a pre-test, post-test, and follow-up format for three groups: two experimental, and one control. All participants were randomly assigned to either experimental or control groups, 26 patients to each group. Subjects in the experimental groups received visual aids alone or visual aids plus an Advanced Organizer. A comparison of the three groups showed that subjects in the experimental groups scored significantly higher than the control group in both the comprehension and compliance measures.

  11. Computer-aided design of transformation toughened blast resistant naval hull steels: Part I

    NASA Astrophysics Data System (ADS)

    Saha, A.; Olson, G. B.

    2007-07-01

    A systematic approach to computer-aided materials design has formulated a new class of ultratough, weldable secondary hardened plate steels combining new levels of strength and toughness while meeting processability requirements. A theoretical design concept integrated the mechanism of precipitated nickel-stabilized dispersed austenite for transformation toughening in an alloy strengthened by combined precipitation of M2C carbides and BCC copper both at an optimal ˜3 nm particle size for efficient strengthening. This concept was adapted to plate steel design by employing a mixed bainitic/martensitic matrix microstructure produced by air-cooling after solution-treatment and constraining the composition to low carbon content for weldability. With optimized levels of copper and M2C carbide formers based on a quantitative strength model, a required alloy nickel content of 6.5 wt% was predicted for optimal austenite stability for transformation toughening at the desired strength level of 160 ksi (1,100 MPa) yield strength. A relatively high Cu level of 3.65 wt% was employed to allow a carbon limit of 0.05 wt% for good weldability, without causing excessive solidification microsegregation.

  12. Use of crop simulation modelling to aid ideotype design of future cereal cultivars.

    PubMed

    Rötter, R P; Tao, F; Höhn, J G; Palosuo, T

    2015-06-01

    A major challenge of the 21st century is to achieve food supply security under a changing climate and roughly a doubling in food demand by 2050 compared to present, the majority of which needs to be met by the cereals wheat, rice, maize, and barley. Future harvests are expected to be especially threatened through increased frequency and severity of extreme events, such as heat waves and drought, that pose particular challenges to plant breeders and crop scientists. Process-based crop models developed for simulating interactions between genotype, environment, and management are widely applied to assess impacts of environmental change on crop yield potentials, phenology, water use, etc. During the last decades, crop simulation has become important for supporting plant breeding, in particular in designing ideotypes, i.e. 'model plants', for different crops and cultivation environments. In this review we (i) examine the main limitations of crop simulation modelling for supporting ideotype breeding, (ii) describe developments in cultivar traits in response to climate variations, and (iii) present examples of how crop simulation has supported evaluation and design of cereal cultivars for future conditions. An early success story for rice demonstrates the potential of crop simulation modelling for ideotype breeding. Combining conventional crop simulation with new breeding methods and genetic modelling holds promise to accelerate delivery of future cereal cultivars for different environments. Robustness of model-aided ideotype design can further be enhanced through continued improvements of simulation models to better capture effects of extremes and the use of multi-model ensembles.

  13. Investigation into the development of computer aided design software for space based sensors

    NASA Technical Reports Server (NTRS)

    Pender, C. W.; Clark, W. L.

    1987-01-01

    The described effort is phase one of the development of a Computer Aided Design (CAD) software to be used to perform radiometric sensor design. The software package will be referred to as SCAD and is directed toward the preliminary phase of the design of space based sensor system. The approach being followed is to develop a modern, graphic intensive, user friendly software package using existing software as building blocks. The emphasis will be directed toward the development of a shell containing menus, smart defaults, and interfaces, which can accommodate a wide variety of existing application software packages. The shell will offer expected utilities such as graphics, tailored menus, and a variety of drivers for I/O devices. Following the development of the shell, the development of SCAD is planned as chiefly selection and integration of appropriate building blocks. The phase one development activities have included: the selection of hardware which will be used with SCAD; the determination of the scope of SCAD; the preliminary evaluation of a number of software packages for applicability to SCAD; determination of a method for achieving required capabilities where voids exist; and then establishing a strategy for binding the software modules into an easy to use tool kit.

  14. Comparative study of auxetic geometries by means of computer-aided design and engineering

    NASA Astrophysics Data System (ADS)

    Álvarez Elipe, Juan Carlos; Díaz Lantada, Andrés

    2012-10-01

    Auxetic materials (or metamaterials) are those with a negative Poisson ratio (NPR) and display the unexpected property of lateral expansion when stretched, as well as an equal and opposing densification when compressed. Such geometries are being progressively employed in the development of novel products, especially in the fields of intelligent expandable actuators, shape morphing structures and minimally invasive implantable devices. Although several auxetic and potentially auxetic geometries have been summarized in previous reviews and research, precise information regarding relevant properties for design tasks is not always provided. In this study we present a comparative study of two-dimensional and three-dimensional auxetic geometries carried out by means of computer-aided design and engineering tools (from now on CAD-CAE). The first part of the study is focused on the development of a CAD library of auxetics. Once the library is developed we simulate the behavior of the different auxetic geometries and elaborate a systematic comparison, considering relevant properties of these geometries, such as Poisson ratio(s), maximum volume or area reductions attainable and equivalent Young’s modulus, hoping it may provide useful information for future designs of devices based on these interesting structures.

  15. DNA-based and geometric morphometric analysis to validate species designation: a case study of the subterranean rodent Ctenomys bicolor.

    PubMed

    Stolz, J F B; Gonçalves, G L; Leipnitz, L; Freitas, T R O

    2013-10-25

    The genus Ctenomys (Rodentia: Ctenomyidae) shows several taxonomic inconsistencies. In this study, we used an integrative approach including DNA sequences, karyotypes, and geometric morphometrics to evaluate the taxonomic validity of a nominal species, Ctenomys bicolor, which was described based on only one specimen in 1912 by Miranda Ribeiro, and since then neglected. We sampled near the type locality assigned to this species and collected 10 specimens. A total of 820 base pairs of the cytochrome b gene were sequenced and analyzed together with nine other species and four morphotypes obtained from GenBank. Bayesian analyses showed that C. bicolor is monophyletic and related to the Bolivian-Matogrossense group, a clade that originated about 3 mya. We compared the cranial shape through morphometric geometrics of C. bicolor, including the specimen originally sampled in 1912, with other species representative of the same phylogenetic group (C. boliviensis and C. steinbachi). C. bicolor shows unique skull traits that distinguish it from all other currently known taxa. Our findings confirm that the specimen collected by Miranda Ribeiro is a valid species, and improve the knowledge about Ctenomys in the Amazon region.

  16. Custom-Made Computer-Aided-Design/Computer-Aided-Manufacturing Biphasic Calcium-Phosphate Scaffold for Augmentation of an Atrophic Mandibular Anterior Ridge

    PubMed Central

    Mangano, Francesco Guido; van Noort, Ric; Apresyan, Samvel; Piattelli, Adriano; Macchi, Aldo

    2015-01-01

    This report documents the clinical, radiographic, and histologic outcome of a custom-made computer-aided-design/computer-aided-manufactured (CAD/CAM) scaffold used for the alveolar ridge augmentation of a severely atrophic anterior mandible. Computed tomographic (CT) images of an atrophic anterior mandible were acquired and modified into a 3-dimensional (3D) reconstruction model; this was transferred to a CAD program, where a custom-made scaffold was designed. CAM software generated a set of tool-paths for the manufacture of the scaffold on a computer-numerical-control milling machine into the exact shape of the 3D design. A custom-made scaffold was milled from a synthetic micromacroporous biphasic calcium phosphate (BCP) block. The scaffold closely matched the shape of the defect: this helped to reduce the time for the surgery and contributed to good healing. One year later, newly formed and well-integrated bone was clinically available, and two implants (AnyRidge, MegaGen, Gyeongbuk, South Korea) were placed. The histologic samples retrieved from the implant sites revealed compact mature bone undergoing remodelling, marrow spaces, and newly formed trabecular bone surrounded by residual BCP particles. This study demonstrates that custom-made scaffolds can be fabricated by combining CT scans and CAD/CAM techniques. Further studies on a larger sample of patients are needed to confirm these results. PMID:26064701

  17. Custom-Made Computer-Aided-Design/Computer-Aided-Manufacturing Biphasic Calcium-Phosphate Scaffold for Augmentation of an Atrophic Mandibular Anterior Ridge.

    PubMed

    Mangano, Francesco Guido; Zecca, Piero Antonio; van Noort, Ric; Apresyan, Samvel; Iezzi, Giovanna; Piattelli, Adriano; Macchi, Aldo; Mangano, Carlo

    2015-01-01

    This report documents the clinical, radiographic, and histologic outcome of a custom-made computer-aided-design/computer-aided-manufactured (CAD/CAM) scaffold used for the alveolar ridge augmentation of a severely atrophic anterior mandible. Computed tomographic (CT) images of an atrophic anterior mandible were acquired and modified into a 3-dimensional (3D) reconstruction model; this was transferred to a CAD program, where a custom-made scaffold was designed. CAM software generated a set of tool-paths for the manufacture of the scaffold on a computer-numerical-control milling machine into the exact shape of the 3D design. A custom-made scaffold was milled from a synthetic micromacroporous biphasic calcium phosphate (BCP) block. The scaffold closely matched the shape of the defect: this helped to reduce the time for the surgery and contributed to good healing. One year later, newly formed and well-integrated bone was clinically available, and two implants (AnyRidge, MegaGen, Gyeongbuk, South Korea) were placed. The histologic samples retrieved from the implant sites revealed compact mature bone undergoing remodelling, marrow spaces, and newly formed trabecular bone surrounded by residual BCP particles. This study demonstrates that custom-made scaffolds can be fabricated by combining CT scans and CAD/CAM techniques. Further studies on a larger sample of patients are needed to confirm these results.

  18. Immunophilins and HIV-1 V3 loop for structure-based anti-AIDS drug design.

    PubMed

    Andrianov, Alexander M

    2009-02-01

    The model of the structural complex of cyclophilin A (CycA) belonging to the immunophilins family with the HIV-MN gp120 V3 loop was generated, and the computer-aided design of the immunophilin-derived peptide able to mask the biologically crucial V3 segments was implemented. To this end, the following problems were solved: (i) the NMR-based conformational analysis of the HIV-MN V3 loop was put into effect, and its low energy structure fitting the input experimental observations was determined; (ii) molecular docking of this V3 structure with the X-ray conformation of CycA was carried out, and the energy refining the simulated structural complex was performed; (iii) the matrix of inter-atomic distances for the amino acids of the molecules forming part of the built over-molecular ensemble was computed, the types of interactions responsible for its stabilization were analyzed, and the CycA stretch, which accounts for the binding to V3, was identified; (iv) the most probable 3D structure for this stretch in the unbound state was predicted, and its collation with the X-ray structure for the corresponding site of CycA was performed; (v) the potential energy function and its constituents were studied for the structural complex generated by molecular docking of the V3 loop with the CycA peptide offering the virtual molecule that imitates the CycA segment, making a key contribution to the interactions of the native protein with the HIV-1 principal neutralizing determinant; (vi) as a result of the studies above, the designed molecule was shown to be capable of the efficacious blockading the functionally crucial V3 sites; and (vii) based on the joint analysis of the evidence obtained previously and in the present study, the composition of the peptide cocktail presenting the promising anti-AIDS pharmacological substance was developed. The molecules simulated here by molecular modeling methods may become the first representatives of a new class of the chemical compounds

  19. Capstone: A Geometry-Centric Platform to Enable Physics-Based Simulation and Design of Systems

    DTIC Science & Technology

    2015-10-05

    geometry at runtime for scalable and accurate a-posteriori mesh adaptation. HPCMP CREATE, —Geometric modeling, mesh generation, computer- aided -engineering...organizations as part of the DoD HPCMP CREATETM Program [6]. Index Terms—Geometric modeling, mesh generation, computer- aided -engineering, engineered...needs based on the physics and the requirements of the discretization approach used. While computer- aided -design (CAD) systems have been used

  20. University of Wyoming, College of Engineering, undergraduate design projects to aid Wyoming persons with disabilities.

    PubMed

    Barrett, Steven F; Laurin, Kathy M; Bloom, Janet K Chidester

    2003-01-01

    In Spring 2002 the University of Wyoming received NSF funding from the Division of Bioengineering and Environmental Systems to provide a meaningful design experience for University of Wyoming, College of Engineering students that will directly aid individuals with disabilities within the state of Wyoming. Other universities have participated in this very worthwhile program [1, 2, 3]. To achieve the program purpose, the following objectives were established: Provide engineering students multi-disciplinary, meaningful, community service design projects, Provide persons with disabilities assistive devices to empower them to achieve the maximum individual growth and development and afford them the opportunity to participate in all aspects of life as they choose, Provide engineering students education and awareness on the special needs and challenges of persons with disabilities, and Provide undergraduate engineering students exposure to the biomedical field of engineering. To accomplish these objectives the College of Engineering partnered with three organizations that provide education and service related to disability. Specifically, the college has joined with the Wyoming Institute for Disabilities (WIND) assistive technology program, Wyoming New Options in Technology (WYNOT) and their Sports and Outdoor Assistive Recreation (SOAR) project along with the university's Special Education program. In this paper we will describe how the program was created, developed, and its current status.

  1. Computer-aided roll pass design in rolling of airfoil shapes

    NASA Technical Reports Server (NTRS)

    Akgerman, N.; Lahoti, G. D.; Altan, T.

    1980-01-01

    This paper describes two computer-aided design (CAD) programs developed for modeling the shape rolling process for airfoil sections. The first program, SHPROL, uses a modular upper-bound method of analysis and predicts the lateral spread, elongation, and roll torque. The second program, ROLPAS, predicts the stresses, roll separating force, the roll torque and the details of metal flow by simulating the rolling process, using the slab method of analysis. ROLPAS is an interactive program; it offers graphic display capabilities and allows the user to interact with the computer via a keyboard, CRT, and a light pen. The accuracy of the computerized models was evaluated by (a) rolling a selected airfoil shape at room temperature from 1018 steel and isothermally at high temperature from Ti-6Al-4V, and (b) comparing the experimental results with computer predictions. The comparisons indicated that the CAD systems, described here, are useful for practical engineering purposes and can be utilized in roll pass design and analysis for airfoil and similar shapes.

  2. Mathematical models as aids for design and development of experiments: the case of transgenic mosquitoes.

    PubMed

    Robert, Michael A; Legros, Mathieu; Facchinelli, Luca; Valerio, Laura; Ramsey, Janine M; Scott, Thomas W; Gould, Fred; Lloyd, Alun L

    2012-11-01

    We demonstrate the utility of models as aids in the design and development of experiments aimed at measuring the effects of proposed vector population control strategies. We describe the exploration of a stochastic, age-structured model that simulates field cage experiments that test the ability of a female-killing strain of the mosquito Aedes aegypti (L.) to suppress a wild-type population. Model output predicts that choices of release ratio and population size can impact mean extinction time and variability in extinction time among experiments. We find that unless fitness costs are >80% they will not be detectable in experiments with high release ratios. At lower release ratios, the predicted length of the experiment increases significantly for fitness costs >20%. Experiments with small populations may more accurately reflect field conditions, but extinction can occur even in the absence of a functional female-killing construct because of stochastic effects. We illustrate how the model can be used to explore experimental designs that aim to study the impact of density dependence and immigration; predictions indicate that cage population eradication may not always be obtainable in an operationally realistic time frame. We propose a method to predict the extinction time of a cage population based on the rate of population reduction with the goal of shortening the duration of the experiment. We discuss the model as a tool for exploring and assessing the utility of a wider range of scenarios than would be feasible to test experimentally because of financial and temporal restraints.

  3. Computer-aided design of dry powder inhalers using computational fluid dynamics to assess performance.

    PubMed

    Suwandecha, Tan; Wongpoowarak, Wibul; Srichana, Teerapol

    2016-01-01

    Dry powder inhalers (DPIs) are gaining popularity for the delivery of drugs. A cost effective and efficient delivery device is necessary. Developing new DPIs by modifying an existing device may be the simplest way to improve the performance of the devices. The aim of this research was to produce a new DPIs using computational fluid dynamics (CFD). The new DPIs took advantages of the Cyclohaler® and the Rotahaler®. We chose a combination of the capsule chamber of the Cyclohaler® and the mouthpiece and grid of the Rotahaler®. Computer-aided design models of the devices were created and evaluated using CFD. Prototype models were created and tested with the DPI dispersion experiments. The proposed model 3 device had a high turbulence with a good degree of deagglomeration in the CFD and the experiment data. The %fine particle fraction (FPF) was around 50% at 60 L/min. The mass median aerodynamic diameter was around 2.8-4 μm. The FPF were strongly correlated to the CFD-predicted turbulence and the mechanical impaction parameters. The drug retention in the capsule was only 5-7%. In summary, a simple modification of the Cyclohaler® and Rotahaler® could produce a better performing inhaler using the CFD-assisted design.

  4. A method of computer aided design with self-generative models in NX Siemens environment

    NASA Astrophysics Data System (ADS)

    Grabowik, C.; Kalinowski, K.; Kempa, W.; Paprocka, I.

    2015-11-01

    Currently in CAD/CAE/CAM systems it is possible to create 3D design virtual models which are able to capture certain amount of knowledge. These models are especially useful in an automation of routine design tasks. These models are known as self-generative or auto generative and they can behave in an intelligent way. The main difference between the auto generative and fully parametric models consists in the auto generative models ability to self-organizing. In this case design model self-organizing means that aside from the possibility of making of automatic changes of model quantitative features these models possess knowledge how these changes should be made. Moreover they are able to change quality features according to specific knowledge. In spite of undoubted good points of self-generative models they are not so often used in design constructional process which is mainly caused by usually great complexity of these models. This complexity makes the process of self-generative time and labour consuming. It also needs a quite great investment outlays. The creation process of self-generative model consists of the three stages it is knowledge and information acquisition, model type selection and model implementation. In this paper methods of the computer aided design with self-generative models in NX Siemens CAD/CAE/CAM software are presented. There are the five methods of self-generative models preparation in NX with: parametric relations model, part families, GRIP language application, knowledge fusion and OPEN API mechanism. In the paper examples of each type of the self-generative model are presented. These methods make the constructional design process much faster. It is suggested to prepare this kind of self-generative models when there is a need of design variants creation. The conducted research on assessing the usefulness of elaborated models showed that they are highly recommended in case of routine tasks automation. But it is still difficult to distinguish

  5. A flexible computer aid for conceptual design based on constraint propagation and component-modeling. [of aircraft in three dimensions

    NASA Technical Reports Server (NTRS)

    Kolb, Mark A.

    1988-01-01

    The Rubber Airplane program, which combines two symbolic processing techniques with a component-based database of design knowledge, is proposed as a computer aid for conceptual design. Using object-oriented programming, programs are organized around the objects and behavior to be simulated, and using constraint propagation, declarative statements designate mathematical relationships among all the equation variables. It is found that the additional level of organizational structure resulting from the arrangement of the design information in terms of design components provides greater flexibility and convenience.

  6. Designing of a digital behind-the-ear hearing aid to meet the World Health Organization requirements.

    PubMed

    Bento, Ricardo Ferreira; Penteado, Silvio Pires

    2010-06-01

    Hearing loss is a common health issue that affects nearly 10% of the world population as indicated by many international studies. The hearing impaired typically experience more frustration, anxiety, irritability, depression, and disorientation than those with normal hearing levels. The standard rehabilitation tool for hearing impairment is an electronic hearing aid whose main components are transducers (microphone and receiver) and a digital signal processor. These electronic components are manufactured by supply chain rather than by hearing aid manufacturers. Manufacturers can use custom-designed components or generic off-the-shelf components. These electronic components are available as application-specific or off-the-shelf products, with the former designed for a specific manufacturer and the latter for a generic approach. The choice of custom or generic components will affect the product specifications, pricing, manufacturing, life cycle, and marketing strategies of the product. The World Health Organization is interested in making available to developing countries hearing aids that are inexpensive to purchase and maintain. The hearing aid presented in this article was developed with these specifications in mind together with additional contemporary features such as four channels with wide dynamic range compression, an adjustable compression rate for each channel, four comfort programs, an adaptive feedback manager, and full volume control. This digital hearing aid is fitted using a personal computer with minimal hardware requirements in intuitive three-step fitting software. A trimmer-adjusted version can be developed where human and material resources are scarce.

  7. Designing of a Digital Behind-the-Ear Hearing Aid to Meet the World Health Organization Requirements

    PubMed Central

    Bento, Ricardo Ferreira; Penteado, Silvio Pires

    2010-01-01

    Hearing loss is a common health issue that affects nearly 10% of the world population as indicated by many international studies. The hearing impaired typically experience more frustration, anxiety, irritability, depression, and disorientation than those with normal hearing levels. The standard rehabilitation tool for hearing impairment is an electronic hearing aid whose main components are transducers (microphone and receiver) and a digital signal processor. These electronic components are manufactured by supply chain rather than by hearing aid manufacturers. Manufacturers can use custom-designed components or generic off-the-shelf components. These electronic components are available as application-specific or off-the-shelf products, with the former designed for a specific manufacturer and the latter for a generic approach. The choice of custom or generic components will affect the product specifications, pricing, manufacturing, life cycle, and marketing strategies of the product. The World Health Organization is interested in making available to developing countries hearing aids that are inexpensive to purchase and maintain. The hearing aid presented in this article was developed with these specifications in mind together with additional contemporary features such as four channels with wide dynamic range compression, an adjustable compression rate for each channel, four comfort programs, an adaptive feedback manager, and full volume control. This digital hearing aid is fitted using a personal computer with minimal hardware requirements in intuitive three-step fitting software. A trimmer-adjusted version can be developed where human and material resources are scarce. PMID:20724354

  8. Revision of Electro-Mechanical Drafting Program to Include CAD/D (Computer-Aided Drafting/Design). Final Report.

    ERIC Educational Resources Information Center

    Snyder, Nancy V.

    North Seattle Community College decided to integrate computer-aided design/drafting (CAD/D) into its Electro-Mechanical Drafting Program. This choice necessitated a redefinition of the program through new curriculum and course development. To initiate the project, a new industrial advisory council was formed. Major electronic and recruiting firms…

  9. Prosthetic rehabilitation with an implant-supported fixed prosthesis using computer-aided design and computer-aided manufacturing dental technology for a patient with a mandibulectomy: A clinical report.

    PubMed

    Yoon, Hyung-In; Han, Jung-Suk

    2016-02-01

    The fabrication of dental prostheses with computer-aided design and computer-aided manufacturing shows acceptable marginal fits and favorable treatment outcomes. This clinical report describes the management of a patient who had undergone a mandibulectomy and received an implant-supported fixed prosthesis by using additive manufacturing for the framework and subtractive manufacturing for the monolithic zirconia restorations.

  10. Development of a Geometric Spatial Visualization Tool

    ERIC Educational Resources Information Center

    Ganesh, Bibi; Wilhelm, Jennifer; Sherrod, Sonya

    2009-01-01

    This paper documents the development of the Geometric Spatial Assessment. We detail the development of this instrument which was designed to identify middle school students' strategies and advancement in understanding of four geometric concept domains (geometric spatial visualization, spatial projection, cardinal directions, and periodic patterns)…

  11. Computers in engineering 1983; Proceedings of the International Conference and Exhibit, Chicago, IL, August 7-11, 1983. Volume 1 - Computer-aided design, manufacturing, and simulation

    NASA Astrophysics Data System (ADS)

    Cokonis, T. J.

    The papers presented in this volume provide examples of the impact of computers on present engineering practice and indicate some future trends in computer-aided design, manufacturing, and simulation. Topics discussed include computer-aided design of turbine cycle configuration, managing and development of engineering computer systems, computer-aided manufacturing with robots in the automotive industry, and computer-aided design/analysis techniques of composite materials in the cure phase. Papers are also presented on computer simulation of vehicular propulsion systems, the performance of a hydraulic system simulator in a CAD environment, and computer simulation of hovercraft heave dynamics and control.

  12. An Analysis of Computer Aided Design (CAD) Packages Used at MSFC for the Recent Initiative to Integrate Engineering Activities

    NASA Technical Reports Server (NTRS)

    Smith, Leigh M.; Parker, Nelson C. (Technical Monitor)

    2002-01-01

    This paper analyzes the use of Computer Aided Design (CAD) packages at NASA's Marshall Space Flight Center (MSFC). It examines the effectiveness of recent efforts to standardize CAD practices across MSFC engineering activities. An assessment of the roles played by management, designers, analysts, and manufacturers in this initiative will be explored. Finally, solutions are presented for better integration of CAD across MSFC in the future.

  13. [Design and implementation of GpsOne remote heart disease first-aid system].

    PubMed

    Lin, Hua

    2008-09-01

    This paper introduces how to develop a novel remote heart disease first-aid system with N-tier architecture. The system applies GpsOne communication technology and professional ECG signal collection technology to the embedded SCM. It can provide an accurate location of the patient and his essential ECG details for remote heart disease first-aid.

  14. Cultural Competence in a Group Intervention Designed for Latino Patients Living with HIV/AIDS

    ERIC Educational Resources Information Center

    Acevedo, Vanessa

    2008-01-01

    Although the trajectory of the HIV/AIDS epidemic has changed dramatically over the past 25 years, addressing the psychosocial needs of patients living with HIV/AIDS remains vital. Ensuring the effective delivery of services demands that interventions be rooted in cultural competence and aimed at vulnerable populations. This article describes a…

  15. Does Merit Aid Program Design Matter? A Cross-Cohort Analysis

    ERIC Educational Resources Information Center

    Domina, Thurston

    2014-01-01

    Twenty-one US states currently offer some form of merit-based postsecondary financial aid, although the generosity and eligibility requirements of merit aid programs varies from state to state. This article uses nationally representative data from high school students in the early 1990s and the early 2000s to evaluate the relationship between the…

  16. Design of radial basis function neural network classifier realized with the aid of data preprocessing techniques: design and analysis

    NASA Astrophysics Data System (ADS)

    Oh, Sung-Kwun; Kim, Wook-Dong; Pedrycz, Witold

    2016-05-01

    In this paper, we introduce a new architecture of optimized Radial Basis Function neural network classifier developed with the aid of fuzzy clustering and data preprocessing techniques and discuss its comprehensive design methodology. In the preprocessing part, the Linear Discriminant Analysis (LDA) or Principal Component Analysis (PCA) algorithm forms a front end of the network. The transformed data produced here are used as the inputs of the network. In the premise part, the Fuzzy C-Means (FCM) algorithm determines the receptive field associated with the condition part of the rules. The connection weights of the classifier are of functional nature and come as polynomial functions forming the consequent part. The Particle Swarm Optimization algorithm optimizes a number of essential parameters needed to improve the accuracy of the classifier. Those optimized parameters include the type of data preprocessing, the dimensionality of the feature vectors produced by the LDA (or PCA), the number of clusters (rules), the fuzzification coefficient used in the FCM algorithm and the orders of the polynomials of networks. The performance of the proposed classifier is reported for several benchmarking data-sets and is compared with the performance of other classifiers reported in the previous studies.

  17. Study on Dicyandiamide-Imprinted Polymers with Computer-Aided Design

    PubMed Central

    Liang, Dadong; Wang, Yan; Li, Songyang; Li, Yuqing; Zhang, Miliang; Li, Yang; Tian, Weishuai; Liu, Junbo; Tang, Shanshan; Li, Bo; Jin, Ruifa

    2016-01-01

    With the aid of theoretical calculations, a series of molecularly imprinted polymers (MIPs) were designed and prepared for the recognition of dicyandiamide (DCD) via precipitation polymerization using acetonitrile as the solvent at 333 K. On the basis of the long-range correction method of M062X/6-31G(d,p), we simulated the bonding sites, bonding situations, binding energies, imprinted molar ratios, and the mechanisms of interaction between DCD and the functional monomers. Among acrylamide (AM), N,N’-methylenebisacrylamide (MBA), itaconic acid (IA), and methacrylic acid (MAA), MAA was confirmed as the best functional monomer, because the strongest interaction (the maximum number of hydrogen bonds and the lowest binding energy) occurs between DCD and MAA, when the optimal molar ratios for DCD to the functional monomers were used, respectively. Additionally, pentaerythritol triacrylate (PETA) was confirmed to be the best cross-linker among divinylbenzene (DVB), ethylene glycol dimethacrylate (EGDMA), trimethylolpropane trimethylacrylate (TRIM), and PETA. This is due to the facts that the weakest interaction (the highest binding energy) occurs between PETA and DCD, and the strongest interaction (the lowest binding energy) occurs between PETA and MAA. Depending on the results of theoretical calculations, a series of MIPs were prepared. Among them, the ones prepared using DCD, MAA, and PETA as the template, the functional monomer, and the cross-linker, respectively, exhibited the highest adsorption capacity for DCD. The apparent maximum absorption quantity of DCD on the MIP was 17.45 mg/g. PMID:27792186

  18. Indications for Computer-Aided Design and Manufacturing in Congenital Craniofacial Reconstruction.

    PubMed

    Fisher, Mark; Medina, Miguel; Bojovic, Branko; Ahn, Edward; Dorafshar, Amir H

    2016-09-01

    The complex three-dimensional relationships in congenital craniofacial reconstruction uniquely lend themselves to the ability to accurately plan and model the result provided by computer-aided design and manufacturing (CAD/CAM). The goal of this study was to illustrate indications where CAD/CAM would be helpful in the treatment of congenital craniofacial anomalies reconstruction and to discuss the application of this technology and its outcomes. A retrospective review was performed of all congenital craniofacial cases performed by the senior author between 2010 and 2014. Cases where CAD/CAM was used were identified, and illustrative cases to demonstrate the benefits of CAD/CAM were selected. Preoperative appearance, computerized plan, intraoperative course, and final outcome were analyzed. Preoperative planning enabled efficient execution of the operative plan with predictable results. Risk factors which made these patients good candidates for CAD/CAM were identified and compiled. Several indications, including multisuture and revisional craniosynostosis, facial bipartition, four-wall box osteotomy, reduction cranioplasty, and distraction osteogenesis could benefit most from this technology. We illustrate the use of CAD/CAM for these applications and describe the decision-making process both before and during surgery. We explore why we believe that CAD/CAM is indicated in these scenarios as well as the disadvantages and risks.

  19. The Design and Evaluation of "CAPTools"--A Computer Aided Parallelization Toolkit

    NASA Technical Reports Server (NTRS)

    Yan, Jerry; Frumkin, Michael; Hribar, Michelle; Jin, Haoqiang; Waheed, Abdul; Johnson, Steve; Cross, Jark; Evans, Emyr; Ierotheou, Constantinos; Leggett, Pete; Saini, Subhash (Technical Monitor)

    1998-01-01

    Writing applications for high performance computers is a challenging task. Although writing code by hand still offers the best performance, it is extremely costly and often not very portable. The Computer Aided Parallelization Tools (CAPTools) are a toolkit designed to help automate the mapping of sequential FORTRAN scientific applications onto multiprocessors. CAPTools consists of the following major components: an inter-procedural dependence analysis module that incorporates user knowledge; a 'self-propagating' data partitioning module driven via user guidance; an execution control mask generation and optimization module for the user to fine tune parallel processing of individual partitions; a program transformation/restructuring facility for source code clean up and optimization; a set of browsers through which the user interacts with CAPTools at each stage of the parallelization process; and a code generator supporting multiple programming paradigms on various multiprocessors. Besides describing the rationale behind the architecture of CAPTools, the parallelization process is illustrated via case studies involving structured and unstructured meshes. The programming process and the performance of the generated parallel programs are compared against other programming alternatives based on the NAS Parallel Benchmarks, ARC3D and other scientific applications. Based on these results, a discussion on the feasibility of constructing architectural independent parallel applications is presented.

  20. Study on Dicyandiamide-Imprinted Polymers with Computer-Aided Design.

    PubMed

    Liang, Dadong; Wang, Yan; Li, Songyang; Li, Yuqing; Zhang, Miliang; Li, Yang; Tian, Weishuai; Liu, Junbo; Tang, Shanshan; Li, Bo; Jin, Ruifa

    2016-10-26

    With the aid of theoretical calculations, a series of molecularly imprinted polymers (MIPs) were designed and prepared for the recognition of dicyandiamide (DCD) via precipitation polymerization using acetonitrile as the solvent at 333 K. On the basis of the long-range correction method of M062X/6-31G(d,p), we simulated the bonding sites, bonding situations, binding energies, imprinted molar ratios, and the mechanisms of interaction between DCD and the functional monomers. Among acrylamide (AM), N,N'-methylenebisacrylamide (MBA), itaconic acid (IA), and methacrylic acid (MAA), MAA was confirmed as the best functional monomer, because the strongest interaction (the maximum number of hydrogen bonds and the lowest binding energy) occurs between DCD and MAA, when the optimal molar ratios for DCD to the functional monomers were used, respectively. Additionally, pentaerythritol triacrylate (PETA) was confirmed to be the best cross-linker among divinylbenzene (DVB), ethylene glycol dimethacrylate (EGDMA), trimethylolpropane trimethylacrylate (TRIM), and PETA. This is due to the facts that the weakest interaction (the highest binding energy) occurs between PETA and DCD, and the strongest interaction (the lowest binding energy) occurs between PETA and MAA. Depending on the results of theoretical calculations, a series of MIPs were prepared. Among them, the ones prepared using DCD, MAA, and PETA as the template, the functional monomer, and the cross-linker, respectively, exhibited the highest adsorption capacity for DCD. The apparent maximum absorption quantity of DCD on the MIP was 17.45 mg/g.

  1. Validation of RetroPath, a computer-aided design tool for metabolic pathway engineering.

    PubMed

    Fehér, Tamás; Planson, Anne-Gaëlle; Carbonell, Pablo; Fernández-Castané, Alfred; Grigoras, Ioana; Dariy, Ekaterina; Perret, Alain; Faulon, Jean-Loup

    2014-11-01

    Metabolic engineering has succeeded in biosynthesis of numerous commodity or high value compounds. However, the choice of pathways and enzymes used for production was many times made ad hoc, or required expert knowledge of the specific biochemical reactions. In order to rationalize the process of engineering producer strains, we developed the computer-aided design (CAD) tool RetroPath that explores and enumerates metabolic pathways connecting the endogenous metabolites of a chassis cell to the target compound. To experimentally validate our tool, we constructed 12 top-ranked enzyme combinations producing the flavonoid pinocembrin, four of which displayed significant yields. Namely, our tool queried the enzymes found in metabolic databases based on their annotated and predicted activities. Next, it ranked pathways based on the predicted efficiency of the available enzymes, the toxicity of the intermediate metabolites and the calculated maximum product flux. To implement the top-ranking pathway, our procedure narrowed down a list of nine million possible enzyme combinations to 12, a number easily assembled and tested. One round of metabolic network optimization based on RetroPath output further increased pinocembrin titers 17-fold. In total, 12 out of the 13 enzymes tested in this work displayed a relative performance that was in accordance with its predicted score. These results validate the ranking function of our CAD tool, and open the way to its utilization in the biosynthesis of novel compounds.

  2. Computer-Aided Design of Fragment Mixtures for NMR-Based Screening

    PubMed Central

    Arroyo, Xavier; Goldflam, Michael; Feliz, Miguel; Belda, Ignasi; Giralt, Ernest

    2013-01-01

    Fragment-based drug discovery is widely applied both in industrial and in academic screening programs. Several screening techniques rely on NMR to detect binding of a fragment to a target. NMR-based methods are among the most sensitive techniques and have the further advantage of yielding a low rate of false positives and negatives. However, NMR is intrinsically slower than other screening techniques; thus, to increase throughput in NMR-based screening, researchers often assay mixtures of fragments, rather than single fragments. Herein we present a fast and straightforward computer-aided method to design mixtures of fragments taken from a library that have minimized NMR signal overlap. This approach enables direct identification of one or several active fragments without the need for deconvolution. Our approach entails encoding of NMR spectra into a computer-readable format that we call a fingerprint, and minimizing the global signal overlap through a Monte Carlo algorithm. The scoring function used favors a homogenous distribution of the global signal overlap. The method does not require additional experimental work: the only data required are NMR spectra, which are generally recorded for each compound as a quality control measure before its insertion into the library. PMID:23516512

  3. Impact of computer-aided design and drafting on operator perceptions and performance intentions

    SciTech Connect

    Mandeville, D.E.

    1987-01-01

    The goal of the introduction of computer-aided design and drafting (CADD) technology is to improve engineering quantity and quality outcomes. What is not so obvious is that the manner in which the operator views the CADD job may affect these outcomes. The study found that: (1) the subjects hold job characteristic beliefs about their jobs that are similar to those held by individuals in related professional and technical positions in other organizations; (2) subjects in routine jobs who had little experience with CADD believe that the characteristics of the job with CADD will be less desirable than there present job utilizing manual drafting; however, experienced users believe that there is little difference; (3) the subjects performing technologically routine jobs indicate that quantity and quality of their jobs decreases with CADD, while holders of technologically nonroutine jobs indicate the opposite; (4) significant but weak relationships existed between job characteristic beliefs, attitudes, and job intentions; however, the model relationships and strengths varied when subgroups were analyzed; and (5) the correlation of social referent group beliefs with subject beliefs are significant but weak.

  4. Development of simulation tools for numerical investigation and computer-aided design (CAD) of gyrotrons

    NASA Astrophysics Data System (ADS)

    Damyanova, M.; Sabchevski, S.; Zhelyazkov, I.; Vasileva, E.; Balabanova, E.; Dankov, P.; Malinov, P.

    2016-10-01

    As the most powerful CW sources of coherent radiation in the sub-terahertz to terahertz frequency range the gyrotrons have demonstrated a remarkable potential for numerous novel and prospective applications in the fundamental physical research and the technologies. Among them are powerful gyrotrons for electron cyclotron resonance heating (ECRH) and current drive (ECCD) of magnetically confined plasma in various reactors for controlled thermonuclear fusion (e.g., tokamaks and most notably ITER), high-frequency gyrotrons for sub-terahertz spectroscopy (for example NMR-DNP, XDMR, study of the hyperfine structure of positronium, etc.), gyrotrons for thermal processing and so on. Modelling and simulation are indispensable tools for numerical studies, computer-aided design (CAD) and optimization of such sophisticated vacuum tubes (fast-wave devices) operating on a physical principle known as electron cyclotron resonance maser (ECRM) instability. During the recent years, our research team has been involved in the development of physical models and problem-oriented software packages for numerical analysis and CAD of different gyrotrons in the framework of a broad international collaboration. In this paper we present the current status of our simulation tools (GYROSIM and GYREOSS packages) and illustrate their functionality by results of numerical experiments carried out recently. Finally, we provide an outlook on the envisaged further development of the computer codes and the computational modules belonging to these packages and specialized to different subsystems of the gyrotrons.

  5. A non-linear programming approach to the computer-aided design of regulators using a linear-quadratic formulation

    NASA Technical Reports Server (NTRS)

    Fleming, P.

    1985-01-01

    A design technique is proposed for linear regulators in which a feedback controller of fixed structure is chosen to minimize an integral quadratic objective function subject to the satisfaction of integral quadratic constraint functions. Application of a non-linear programming algorithm to this mathematically tractable formulation results in an efficient and useful computer-aided design tool. Particular attention is paid to computational efficiency and various recommendations are made. Two design examples illustrate the flexibility of the approach and highlight the special insight afforded to the designer.

  6. DEMAID - A DESIGN MANAGER'S AID FOR INTELLIGENT DECOMPOSITION (SGI IRIS VERSION)

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.

    1994-01-01

    Many engineering systems are large and multi-disciplinary. Before the design of new complex systems such as large space platforms can begin, the possible interactions among subsystems and their parts must be determined. Once this is completed the proposed system can be decomposed to identify its hierarchical structure. DeMAID (A Design Manager's Aid for Intelligent Decomposition) is a knowledge-based system for ordering the sequence of modules and identifying a possible multilevel structure for the design problem. DeMAID displays the modules in an N x N matrix format (called a design structure matrix) where a module is any process that requires input and generates an output. (Modules which generate an output but do not require an input, such as an initialization process, are also acceptable.) Although DeMAID requires an investment of time to generate and refine the list of modules for input, it could save a considerable amount of money and time in the total design process, particularly in new design problems where the ordering of the modules has not been defined. The decomposition of a complex design system into subsystems requires the judgement of the design manager. DeMAID reorders and groups the modules based on the links (interactions) among the modules, helping the design manager make decomposition decisions early in the design cycle. The modules are grouped into circuits (the subsystems) and displayed in an N x N matrix format. Feedback links, which indicate an iterative process, are minimized and only occur within a subsystem. Since there are no feedback links among the circuits, the circuits can be displayed in a multilevel format. Thus, a large amount of information is reduced to one or two displays which are stored for later retrieval and modification. The design manager and leaders of the design teams then have a visual display of the design problem and the intricate interactions among the different modules. The design manager could save a substantial

  7. DEMAID - A DESIGN MANAGER'S AID FOR INTELLIGENT DECOMPOSITION (SGI IRIS VERSION)

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.

    1994-01-01

    Many engineering systems are large and multi-disciplinary. Before the design of new complex systems such as large space platforms can begin, the possible interactions among subsystems and their parts must be determined. Once this is completed the proposed system can be decomposed to identify its hierarchical structure. DeMAID (A Design Manager's Aid for Intelligent Decomposition) is a knowledge-based system for ordering the sequence of modules and identifying a possible multilevel structure for the design problem. DeMAID displays the modules in an N x N matrix format (called a design structure matrix) where a module is any process that requires input and generates an output. (Modules which generate an output but do not require an input, such as an initialization process, are also acceptable.) Although DeMAID requires an investment of time to generate and refine the list of modules for input, it could save a considerable amount of money and time in the total design process, particularly in new design problems where the ordering of the modules has not been defined. The decomposition of a complex design system into subsystems requires the judgement of the design manager. DeMAID reorders and groups the modules based on the links (interactions) among the modules, helping the design manager make decomposition decisions early in the design cycle. The modules are grouped into circuits (the subsystems) and displayed in an N x N matrix format. Feedback links, which indicate an iterative process, are minimized and only occur within a subsystem. Since there are no feedback links among the circuits, the circuits can be displayed in a multilevel format. Thus, a large amount of information is reduced to one or two displays which are stored for later retrieval and modification. The design manager and leaders of the design teams then have a visual display of the design problem and the intricate interactions among the different modules. The design manager could save a substantial

  8. Vertical ridge augmentation of the atrophic posterior mandible with custom-made, computer-aided design/computer-aided manufacturing porous hydroxyapatite scaffolds.

    PubMed

    Figliuzzi, Michele; Mangano, Francesco Guido; Fortunato, Leonzio; De Fazio, Rossella; Macchi, Aldo; Iezzi, Giovanna; Piattelli, Adriano; Mangano, Carlo

    2013-05-01

    The present study describes a new protocol for the manufacturing of custom-made hydroxyapatite scaffolds using computer-aided design/computer-aided manufacturing (CAD/CAM), to augment posterior mandibular bone and minimize surgery when severe atrophy is present. Computed tomographic images of an atrophic posterior mandible were acquired and modified into a 3-dimensional (3D) reconstruction model. This model was transferred as a stereolithographic file to a CAD program, where virtual 3D reconstructions of the alveolar ridge were performed, drawing 2 anatomically shaped, custom-made scaffolds. Computer-aided-manufacturing software generated a set of tool-paths for manufacture on a computer-numerical-control milling machine into the exact shape of the 3D projects. Clinically sized, anatomically shaped scaffolds were generated from commercially available porous hydroxyapatite blocks. The custom-made scaffolds well matched the shape of the bone defects and could be easily implanted during surgery. This matching of the shape helped to reduce the time for the operation and contributed to the good healing of the defects. At the 6-month recall, a newly formed and well-integrated bone was observed, completely filling the mandibular posterior defects, and implants were placed, with good primary stability. At the 1-year follow-up examination, the implant-supported restorations showed a good functional and esthetic integration. Although this is an interim report, this study demonstrates that anatomically shaped custom-made scaffolds can be fabricated by combining computed tomographic scans and CAD/CAM techniques. Further studies are needed to confirm these results.

  9. Modeling uncertainty in classification design of a computer-aided detection system

    NASA Astrophysics Data System (ADS)

    Hosseini, Rahil; Dehmeshki, Jamshid; Barman, Sarah; Mazinani, Mahdi; Qanadli, Salah

    2010-03-01

    A computerized image analysis technology suffers from imperfection, imprecision and vagueness of the input data and its propagation in all individual components of the technology including image enhancement, segmentation and pattern recognition. Furthermore, a Computerized Medical Image Analysis System (CMIAS) such as computer aided detection (CAD) technology deals with another source of uncertainty that is inherent in image-based practice of medicine. While there are several technology-oriented studies reported in developing CAD applications, no attempt has been made to address, model and integrate these types of uncertainty in the design of the system components, even though uncertainty issues directly affect the performance and its accuracy. In this paper, the main uncertainty paradigms associated with CAD technologies are addressed. The influence of the vagueness and imprecision in the classification of the CAD, as a second reader, on the validity of ROC analysis results is defined. In order to tackle the problem of uncertainty in the classification design of the CAD, two fuzzy methods are applied and evaluated for a lung nodule CAD application. Type-1 fuzzy logic system (T1FLS) and an extension of it, interval type-2 fuzzy logic system (IT2FLS) are employed as methods with high potential for managing uncertainty issues. The novelty of the proposed classification methods is to address and handle all sources of uncertainty associated with a CAD system. The results reveal that IT2FLS is superior to T1FLS for tackling all sources of uncertainty and significantly, the problem of inter and intra operator observer variability.

  10. An Investigation into Computer Aided Drafting and Design (CADD) in the Saginaw Area from the Viewpoint of Mechanical Drafting and Design Employers.

    ERIC Educational Resources Information Center

    Irwin, John L.

    The extent to which computer-aided drafting and design (CADD) was being used in local businesses in Saginaw, Michigan, was investigated. Focuses of a literature review were types of CADD systems, categories of CADD users, and the symbiotic relationship between industry and education in providing CADD training. The survey questionnaire was…

  11. Geometric auxetics

    PubMed Central

    Borcea, Ciprian; Streinu, Ileana

    2015-01-01

    We formulate a mathematical theory of auxetic behaviour based on one-parameter deformations of periodic frameworks. Our approach is purely geome- tric, relies on the evolution of the periodicity lattice and works in any dimension. We demonstrate its usefulness by predicting or recognizing, without experiment, computer simulations or numerical approximations, the auxetic capabilities of several well-known structures available in the literature. We propose new principles of auxetic design and rely on the stronger notion of expansive behaviour to provide an infinite supply of planar auxetic mechanisms and several new three-dimensional structures. PMID:28360818

  12. Effect of geometric lattice design on optical/electrical properties of transparent silver grid for organic solar cells.

    PubMed

    Lim, Ju Won; Lee, Young Tack; Pandey, Rina; Yoo, Tae-Hee; Sang, Byoung-In; Ju, Byeong-Kwon; Hwang, Do Kyung; Choi, Won Kook

    2014-11-03

    Silver (Ag) grid transparent electrode is one of the most promising transparent conducting electrodes (TCEs) to replace conventional indium tin oxide (ITO). We systematically investigate an effect of geometric lattice modifications on optical and electrical properties of Ag grid electrode. The reference Ag grid with 5 μm width and 100 μm pitch (duty of 0.05) prepared by conventional photo-lithography and lift-off processes shows the sheet resistance of 13.27 Ω/sq, transmittance of 81.1%, and resultant figure of merit (FOM) of 129.05. Three different modified Ag grid electrodes with stripe added-mesh (SAM), triangle-added mesh (TAM), and diagonal-added mesh (DAM) are suggested to improve optical and electrical properties. Although all three of SAM, TAM, and DAM Ag grid electrodes exhibit the lower transmittance values of about 72 - 77%, they showed much decreased sheet resistance of 6 - 8 Ω/sq. As a result, all of the lattice-modified Ag grid electrodes display significant improvement of FOM and the highest value of 171.14 is obtained from DAM Ag grid, which is comparable to that of conventional ITO electrode (175.46). Also, the feasibility of DAM Ag gird electrode for use in organic solar cell is confirmed by finite difference time domain (FDTD) simulations. Unlike a conventional ITO electrode, DAM Ag grid electrode can induce light scattering and trapping due to the diffuse transmission that compensates for the loss in optical transparency, resulting in comparable light absorption in the photo active layer of poly(3-hexylthiophene) (P3HT): [6,6]-phenyl-C61-butyric acid methyl ester (PC₆₀BM). P3HT:PC₆₀BM based OSCs with the DAM Ag grid electrode were fabricated, which also showed the potential for ITO-free transparent electrode.

  13. Computer-Aided Drug Design (CADD): Methodological Aspects and Practical Applications in Cancer Research

    NASA Astrophysics Data System (ADS)

    Gianti, Eleonora

    Computer-Aided Drug Design (CADD) has deservedly gained increasing popularity in modern drug discovery (Schneider, G.; Fechner, U. 2005), whether applied to academic basic research or the pharmaceutical industry pipeline. In this work, after reviewing theoretical advancements in CADD, we integrated novel and stateof- the-art methods to assist in the design of small-molecule inhibitors of current cancer drug targets, specifically: Androgen Receptor (AR), a nuclear hormone receptor required for carcinogenesis of Prostate Cancer (PCa); Signal Transducer and Activator of Transcription 5 (STAT5), implicated in PCa progression; and Epstein-Barr Nuclear Antigen-1 (EBNA1), essential to the Epstein Barr Virus (EBV) during latent infections. Androgen Receptor. With the aim of generating binding mode hypotheses for a class (Handratta, V.D. et al. 2005) of dual AR/CYP17 inhibitors (CYP17 is a key enzyme for androgens biosynthesis and therefore implicated in PCa development), we successfully implemented a receptor-based computational strategy based on flexible receptor docking (Gianti, E.; Zauhar, R.J. 2012). Then, with the ultimate goal of identifying novel AR binders, we performed Virtual Screening (VS) by Fragment-Based Shape Signatures, an improved version of the original method developed in our Laboratory (Zauhar, R.J. et al. 2003), and we used the results to fully assess the high-level performance of this innovative tool in computational chemistry. STAT5. The SRC Homology 2 (SH2) domain of STAT5 is responsible for phospho-peptide recognition and activation. As a keystone of Structure-Based Drug Design (SBDD), we characterized key residues responsible for binding. We also generated a model of STAT5 receptor bound to a phospho-peptide ligand, which was validated by docking publicly known STAT5 inhibitors. Then, we performed Shape Signatures- and docking-based VS of the ZINC database (zinc.docking.org), followed by Molecular Mechanics Generalized Born Surface Area (MMGBSA

  14. Enveloped viruses understood via multiscale simulation: computer-aided vaccine design

    NASA Astrophysics Data System (ADS)

    Shreif, Z.; Adhangale, P.; Cheluvaraja, S.; Perera, R.; Kuhn, R.; Ortoleva, P.

    2008-04-01

    Enveloped viruses are viewed as an opportunity to understand how highly organized and functional biosystems can emerge from a collection of millions of chaotically moving atoms. They are an intermediate level of complexity between macromolecules and bacteria. They are a natural system for testing theories of self-assembly and structural transitions, and for demonstrating the derivation of principles of microbiology from laws of molecular physics. As some constitute threats to human health, a computer-aided vaccine and drug design strategy that would follow from a quantitative model would be an important contribution. However, current molecular dynamics simulation approaches are not practical for modeling such systems. Our multiscale approach simultaneously accounts for the outer protein net and inner protein/genomic core, and their less structured membranous material and host fluid. It follows from a rigorous multiscale deductive analysis of laws of molecular physics. Two types of order parameters are introduced: (1) those for structures wherein constituent molecules retain long-lived connectivity (they specify the nanoscale structure as a deformation from a reference configuration) and (2) those for which there is no connectivity but organization is maintained on the average (they are field variables such as mass density or measures of preferred orientation). Rigorous multiscale techniques are used to derive equations for the order parameters dynamics. The equations account for thermal-average forces, diffusion coefficients, and effects of random forces. Statistical properties of the atomic-scale fluctuations and the order parameters are co-evolved. By combining rigorous multiscale techniques and modern supercomputing, systems of extreme complexity can be modeled.

  15. Enveloped viruses understood via multiscale simulation: computer-aided vaccine design

    NASA Astrophysics Data System (ADS)

    Shreif, Z.; Adhangale, P.; Cheluvaraja, S.; Perera, R.; Kuhn, R.; Ortoleva, P.

    Enveloped viruses are viewed as an opportunity to understand how highly organized and functional biosystems can emerge from a collection of millions of chaotically moving atoms. They are an intermediate level of complexity between macromolecules and bacteria. They are a natural system for testing theories of self-assembly and structural transitions, and for demonstrating the derivation of principles of microbiology from laws of molecular physics. As some constitute threats to human health, a computer-aided vaccine and drug design strategy that would follow from a quantitative model would be an important contribution. However, current molecular dynamics simulation approaches are not practical for modeling such systems. Our multiscale approach simultaneously accounts for the outer protein net and inner protein/genomic core, and their less structured membranous material and host fluid. It follows from a rigorous multiscale deductive analysis of laws of molecular physics. Two types of order parameters are introduced: (1) those for structures wherein constituent molecules retain long-lived connectivity (they specify the nanoscale structure as a deformation from a reference configuration) and (2) those for which there is no connectivity but organization is maintained on the average (they are field variables such as mass density or measures of preferred orientation). Rigorous multiscale techniques are used to derive equations for the order parameters dynamics. The equations account for thermal-average forces, diffusion coefficients, and effects of random forces. Statistical properties of the atomic-scale fluctuations and the order parameters are co-evolved. By combining rigorous multiscale techniques and modern supercomputing, systems of extreme complexity can be modeled.

  16. Report on DOE - industry workshop on Computer-Aided Catalyst Design (CACD)

    SciTech Connect

    Hay, P.J.

    1994-07-01

    Representatives from industry, national laboratories, and the DOE met to review the status of the DOE-sponsored Computer-Aided Catalyst Design (CACD) program and to assess current industrial needs in CACD. Of the 40 participants at the workshop, nearly half were from industry representing 12 companies--Arco Chemical, Amoco Chemical, Biosym, Dow, DuPont, Exxon, Ford, General Motors, Mobil, Monsanto, W.R. Grace and Union Carbide--that included nine of the largest chemical producers in the U.S. representing $61 billion in chemical sales in 1993. An overview of developments in catalyst modeling at the national laboratories was presented, and current CACD-related activities at each of the companies were described by the industrial participants. The CACD program is addressing important industry needs and is having a significant impact despite the current limited scope and budget. The industrial participants urged the program to continue to target specific areas and to encourage collaborative work among the national labs. Industrial participants expressed strong interest in increased interactions with CACD activities at the national labs, where competencies in theory, modeling, and simulation complement the traditional strengths of catalysis expertise in industry. The chemical, refining and automotive industries face continual economic and environmental pressures for now or improved catalytic processes that are more efficient and produce fewer undesirable byproducts. CACD is viewed as an effective means to enhance experimental catalysis research. The industrial participants attested to the importance of developing and applying catalysis modeling capabilities. The companies represented at the meeting had varying degrees of activity in this area, and many already had significant interactions with national labs. As potential users of this technology, they strongly endorsed the work in the CACD program in the development of modeling capabilities.

  17. Combining principles of Cognitive Load Theory and diagnostic error analysis for designing job aids: Effects on motivation and diagnostic performance in a process control task.

    PubMed

    Kluge, Annette; Grauel, Britta; Burkolter, Dina

    2013-03-01

    Two studies are presented in which the design of a procedural aid and the impact of an additional decision aid for process control were assessed. In Study 1, a procedural aid was developed that avoids imposing unnecessary extraneous cognitive load on novices when controlling a complex technical system. This newly designed procedural aid positively affected germane load, attention, satisfaction, motivation, knowledge acquisition and diagnostic speed for novel faults. In Study 2, the effect of a decision aid for use before the procedural aid was investigated, which was developed based on an analysis of diagnostic errors committed in Study 1. Results showed that novices were able to diagnose both novel faults and practised faults, and were even faster at diagnosing novel faults. This research contributes to the question of how to optimally support novices in dealing with technical faults in process control.

  18. Estimation of Nasal Tip Support Using Computer-Aided Design and 3-Dimensional Printed Models

    PubMed Central

    Gray, Eric; Maducdoc, Marlon; Manuel, Cyrus; Wong, Brian J. F.

    2016-01-01

    IMPORTANCE Palpation of the nasal tip is an essential component of the preoperative rhinoplasty examination. Measuring tip support is challenging, and the forces that correspond to ideal tip support are unknown. OBJECTIVE To identify the integrated reaction force and the minimum and ideal mechanical properties associated with nasal tip support. DESIGN, SETTING, AND PARTICIPANTS Three-dimensional (3-D) printed anatomic silicone nasal models were created using a computed tomographic scan and computer-aided design software. From this model, 3-D printing and casting methods were used to create 5 anatomically correct nasal models of varying constitutive Young moduli (0.042, 0.086, 0.098, 0.252, and 0.302 MPa) from silicone. Thirty rhinoplasty surgeons who attended a regional rhinoplasty course evaluated the reaction force (nasal tip recoil) of each model by palpation and selected the model that satisfied their requirements for minimum and ideal tip support. Data were collected from May 3 to 4, 2014. RESULTS Of the 30 respondents, 4 surgeons had been in practice for 1 to 5 years; 9 surgeons, 6 to 15 years; 7 surgeons, 16 to 25 years; and 10 surgeons, 26 or more years. Seventeen surgeons considered themselves in the advanced to expert skill competency levels. Logistic regression estimated the minimum threshold for the Young moduli for adequate and ideal tip support to be 0.096 and 0.154 MPa, respectively. Logistic regression estimated the thresholds for the reaction force associated with the absolute minimum and ideal requirements for good tip recoil to be 0.26 to 4.74 N and 0.37 to 7.19 N during 1- to 8-mm displacement, respectively. CONCLUSIONS AND RELEVANCE This study presents a method to estimate clinically relevant nasal tip reaction forces, which serve as a proxy for nasal tip support. This information will become increasingly important in computational modeling of nasal tip mechanics and ultimately will enhance surgical planning for rhinoplasty. LEVEL OF EVIDENCE

  19. Mirror-image anterior crown fabrication with computer-aided design and rapid prototyping technology: a clinical report.

    PubMed

    Cho, Seok-Hwan; Chang, Won-Gun

    2013-02-01

    This clinical report describes the fabrication of a maxillary central incisor single crown with rapid prototyping (RP) technology. A patient with a recently replaced metal ceramic crown had discomfort due to the nonanatomic lingual contour of the crown. With computer-aided design (CAD) software and rapid prototyping (RP) technology, the shape of the contralateral central incisor was duplicated and reproduced to make a mirror-image for a new crown. The prosthodontic planning and treatment approach are discussed.

  20. Pheromones as mixtures: geometric designs and response surface modeling for optimization of mating disruption of the citrus leafminer Phyllocnistis citrella

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pheromone blends composed of one or more components are mixtures. Mixtures present a unique problem for experiment design when response (e.g., insect attraction to a blend) is a function of proportionality of the blend's components. In mixtures, the ingredients must total to a constant value. Prop...

  1. Fatigue analysis of computer-aided design/computer-aided manufacturing resin-based composite vs. lithium disilicate glass-ceramic.

    PubMed

    Ankyu, Shuhei; Nakamura, Keisuke; Harada, Akio; Hong, Guang; Kanno, Taro; Niwano, Yoshimi; Örtengren, Ulf; Egusa, Hiroshi

    2016-08-01

    Resin-based composite molar crowns made by computer-aided design/computer-aided manufacturing (CAD/CAM) systems have been proposed as an inexpensive alternative to metal-ceramic or all-ceramic crowns. However, there is a lack of scientific information regarding fatigue resistance. This study aimed to analyze the fatigue behavior of CAD/CAM resin-based composite compared with lithium disilicate glass-ceramic. One-hundred and sixty bar-shaped specimens were fabricated using resin-based composite blocks [Lava Ultimate (LU); 3M/ESPE] and lithium disilicate glass-ceramic [IPS e.max press (EMP); Ivoclar/Vivadent]. The specimens were divided into four groups: no treatment (NT); thermal cycling (TC); mechanical cycling (MC); and thermal cycling followed by mechanical cycling (TCMC). Thermal cycling was performed by alternate immersion in water baths of 5°C and 55°C for 5 × 10(4) cycles. Mechanical cycling was performed in a three-point bending test, with a maximum load of 40 N, for 1.2 × 10(6) cycles. In addition, LU and EMP molar crowns were fabricated and subjected to fatigue treatments followed by load-to-failure testing. The flexural strength of LU was not severely reduced by the fatigue treatments. The fatigue treatments did not significantly affect the fracture resistance of LU molar crowns. The results demonstrate the potential of clinical application of CAD/CAM-generated resin-based composite molar crowns in terms of fatigue resistance.

  2. Early, computer-Aided Design/Computer-Aided Modeling Planned, Le Fort I Advancement With Internal Distractors to Treat Severe Maxillary Hypoplasia in Cleft Lip and Palate.

    PubMed

    Chang, Catherine S; Swanson, Jordan; Yu, Jason; Taylor, Jesse A

    2017-04-11

    Traditionally, maxillary hypoplasia in the setting of cleft lip and palate is treated via orthognathic surgery at skeletal maturity, which condemns these patients to abnormal facial proportions during adolescence. The authors sought to determine the safety profile of computer-aided design/computer-aided modeling (CAD/CAM) planned, Le Fort I distraction osteogenesis with internal distractors in select patients presenting at a young age with severe maxillary retrusion. The authors retrospectively reviewed our "early" Le Fort I distraction osteogenesis experience-patients performed for severe maxillary retrusion (≥12 mm underjet), after canine eruption but prior to skeletal maturity-at a single institution. Patient demographics, cleft characteristics, CAD/CAM operative plans, surgical complications, postoperative imaging, and outcomes were analyzed. Four patients were reviewed, with a median age of 12.8 years at surgery (range 8.6-16.1 years). Overall mean advancement was 17.95 + 2.9 mm (range 13.7-19.9 mm) with mean SNA improved 18.4° to 87.4 ± 5.7°. Similarly, ANB improved 17.7° to a postoperative mean of 2.4 ± 3.1°. Mean follow-up was 100.7 weeks, with 3 of 4 patients in a Class I occlusion with moderate-term follow-up; 1 of 4 will need an additional maxillary advancement due to pseudo-relapse. In conclusion, Le Fort I distraction osteogenesis with internal distractors is a safe procedure to treat severe maxillary hypoplasia after canine eruption but before skeletal maturity. Short-term follow-up demonstrates safety of the procedure and relative stability of the advancement. Pseudo-relapse is a risk of the procedure that must be discussed at length with patients and families.

  3. Influence of surface roughness on mechanical properties of two computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic materials.

    PubMed

    Flury, S; Peutzfeldt, A; Lussi, A

    2012-01-01

    The aim of this study was to evaluate the influence of surface roughness on surface hardness (Vickers; VHN), elastic modulus (EM), and flexural strength (FLS) of two computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic materials. One hundred sixty-two samples of VITABLOCS Mark II (VMII) and 162 samples of IPS Empress CAD (IPS) were ground according to six standardized protocols producing decreasing surface roughnesses (n=27/group): grinding with 1) silicon carbide (SiC) paper #80, 2) SiC paper #120, 3) SiC paper #220, 4) SiC paper #320, 5) SiC paper #500, and 6) SiC paper #1000. Surface roughness (Ra/Rz) was measured with a surface roughness meter, VHN and EM with a hardness indentation device, and FLS with a three-point bending test. To test for a correlation between surface roughness (Ra/Rz) and VHN, EM, or FLS, Spearman rank correlation coefficients were calculated. The decrease in surface roughness led to an increase in VHN from (VMII/IPS; medians) 263.7/256.5 VHN to 646.8/601.5 VHN, an increase in EM from 45.4/41.0 GPa to 66.8/58.4 GPa, and an increase in FLS from 49.5/44.3 MPa to 73.0/97.2 MPa. For both ceramic materials, Spearman rank correlation coefficients showed a strong negative correlation between surface roughness (Ra/Rz) and VHN or EM and a moderate negative correlation between Ra/Rz and FLS. In conclusion, a decrease in surface roughness generally improved the mechanical properties of the CAD/CAM ceramic materials tested. However, FLS was less influenced by surface roughness than expected.

  4. Evaluation of three-dimensional position change of the condylar head after orthognathic surgery using computer-aided design/computer-aided manufacturing-made condyle positioning jig.

    PubMed

    Kim, Hyung-Mo; Baek, Seung-Hak; Kim, Tae-Yun; Choi, Jin-Young

    2014-11-01

    This study was performed to evaluate the efficacy of computer-aided design/computer-aided manufacturing (CAM/CAD)-made condyle positioning jig in orthognathic surgery. The sample consisted of 40 mandibular condyles of 20 patients with class III malocclusion who underwent bilateral sagittal split ramus osteotomy with semirigid fixation (6 men and 14 women; mean age, 25 y; mean amount of mandibular setback, 5.8 mm). Exclusion criteria were patients who needed surgical correction of the frontal ramal inclination and had signs and symptoms of the temporomandibular disorder before surgery. Three-dimensional computed tomograms were taken 1 month before the surgery (T1) and 1 day after the surgery (T2). The condylar position was evaluated at the T1 and T2 stages on the axial, frontal, and sagittal aspects in the three-dimensional coordinates. The linear change of the posterior border of the proximal segment of the ramus between T1 and T2 was also evaluated in 30 condyles (15 patients), with the exception of 10 condyles of 5 patients who received mandibular angle reduction surgery. There was no significant difference in the condylar position in the frontal and sagittal aspects (P > 0.05). Although there was a significant difference in the condylar position in the axial aspect (P < 0.01), the amount of difference was less than 1 mm and 1 degree; it can be considered clinically nonsignificant. In the linear change of the posterior border of the proximal segment of the ramus, the mean change was 1.4 mm and 60% of the samples showed a minimal change of less than 1 mm. The results of this study suggest that CAD/CAM-made condyle positioning jig is easy to install and reliable to use in orthognathic surgery.

  5. Shear bond strength of computer-aided design and computer-aided manufacturing feldspathic and nano resin ceramics blocks cemented with three different generations of resin cement

    PubMed Central

    Ab-Ghani, Zuryati; Jaafar, Wahyuni; Foo, Siew Fon; Ariffin, Zaihan; Mohamad, Dasmawati

    2015-01-01

    Aim: To evaluate the shear bond strength between the dentin substrate and computer-aided design and computer-aided manufacturing feldspathic ceramic and nano resin ceramics blocks cemented with resin cement. Materials and Methods: Sixty cuboidal blocks (5 mm × 5 mm × 5 mm) were fabricated in equal numbers from feldspathic ceramic CEREC® Blocs PC and nano resin ceramic Lava™ Ultimate, and randomly divided into six groups (n = 10). Each block was cemented to the dentin of 60 extracted human premolar using Variolink® II/Syntac Classic (multi-steps etch-and-rinse adhesive bonding), NX3 Nexus® (two-steps etch-and-rinse adhesive bonding) and RelyX™ U200 self-adhesive cement. All specimens were thermocycled, and shear bond strength testing was done using the universal testing machine at a crosshead speed of 1.0 mm/min. Data were analyzed using one-way ANOVA. Results: Combination of CEREC® Blocs PC and Variolink® II showed the highest mean shear bond strength (8.71 Mpa), while the lowest of 2.06 Mpa were observed in Lava™ Ultimate and RelyX™ U200. There was no significant difference in the mean shear bond strength between different blocks. Conclusion: Variolink® II cement using multi-steps etch-and-rinse adhesive bonding provided a higher shear bond strength than the self-adhesive cement RelyX U200. The shear bond strength was not affected by the type of blocks used. PMID:26430296

  6. Influence of different luting protocols on shear bond strength of computer aided design/computer aided manufacturing resin nanoceramic material to dentin

    PubMed Central

    Poggio, Claudio; Pigozzo, Marco; Ceci, Matteo; Scribante, Andrea; Beltrami, Riccardo; Chiesa, Marco

    2016-01-01

    Background: The purpose of this study was to evaluate the influence of three different luting protocols on shear bond strength of computer aided design/computer aided manufacturing (CAD/CAM) resin nanoceramic (RNC) material to dentin. Materials and Methods: In this in vitro study, 30 disks were milled from RNC blocks (Lava Ultimate/3M ESPE) with CAD/CAM technology. The disks were subsequently cemented to the exposed dentin of 30 recently extracted bovine permanent mandibular incisors. The specimens were randomly assigned into 3 groups of 10 teeth each. In Group 1, disks were cemented using a total-etch protocol (Scotchbond™ Universal Etchant phosphoric acid + Scotchbond Universal Adhesive + RelyX™ Ultimate conventional resin cement); in Group 2, disks were cemented using a self-etch protocol (Scotchbond Universal Adhesive + RelyX™ Ultimate conventional resin cement); in Group 3, disks were cemented using a self-adhesive protocol (RelyX™ Unicem 2 Automix self-adhesive resin cement). All cemented specimens were placed in a universal testing machine (Instron Universal Testing Machine 3343) and submitted to a shear bond strength test to check the strength of adhesion between the two substrates, dentin, and RNC disks. Specimens were stressed at a crosshead speed of 1 mm/min. Data were analyzed with analysis of variance and post-hoc Tukey's test at a level of significance of 0.05. Results: Post-hoc Tukey testing showed that the highest shear strength values (P < 0.001) were reported in Group 2. The lowest data (P < 0.001) were recorded in Group 3. Conclusion: Within the limitations of this in vitro study, conventional resin cements (coupled with etch and rinse or self-etch adhesives) showed better shear strength values compared to self-adhesive resin cements. Furthermore, conventional resin cements used together with a self-etch adhesive reported the highest values of adhesion. PMID:27076822

  7. Determination of Optimal Parameters for Dual-Layer Cathode of Polymer Electrolyte Fuel Cell Using Computational Intelligence-Aided Design

    PubMed Central

    Chen, Yi; Huang, Weina; Peng, Bei

    2014-01-01

    Because of the demands for sustainable and renewable energy, fuel cells have become increasingly popular, particularly the polymer electrolyte fuel cell (PEFC). Among the various components, the cathode plays a key role in the operation of a PEFC. In this study, a quantitative dual-layer cathode model was proposed for determining the optimal parameters that minimize the over-potential difference and improve the efficiency using a newly developed bat swarm algorithm with a variable population embedded in the computational intelligence-aided design. The simulation results were in agreement with previously reported results, suggesting that the proposed technique has potential applications for automating and optimizing the design of PEFCs. PMID:25490761

  8. Determination of optimal parameters for dual-layer cathode of polymer electrolyte fuel cell using computational intelligence-aided design.

    PubMed

    Chen, Yi; Huang, Weina; Peng, Bei

    2014-01-01

    Because of the demands for sustainable and renewable energy, fuel cells have become increasingly popular, particularly the polymer electrolyte fuel cell (PEFC). Among the various components, the cathode plays a key role in the operation of a PEFC. In this study, a quantitative dual-layer cathode model was proposed for determining the optimal parameters that minimize the over-potential difference η and improve the efficiency using a newly developed bat swarm algorithm with a variable population embedded in the computational intelligence-aided design. The simulation results were in agreement with previously reported results, suggesting that the proposed technique has potential applications for automating and optimizing the design of PEFCs.

  9. End-to-end design consideration of a radar altimeter for terrain-aided navigation

    NASA Astrophysics Data System (ADS)

    Chun, Joohwan; Choi, Sanghyouk; Paek, Inchan; Park, Dongmin; Yoo, Kyungju

    2013-10-01

    We present a preliminary simulation study of an interferometric SAR altimeter for the terrain-aided navigation application. Our simulation includes raw SAR data generation, azimuth compression, leading edge detection of the echo signal, maximum likelihood angle estimation and the Bayesian state estimation. Sour results show that radar altimeter performance can be improved with the feedback loop from the rear-end navigation part.

  10. Design of an Iconic Communication Aid for Individuals in India with Speech and Motion Impairments

    ERIC Educational Resources Information Center

    Bhattacharya, Samit; Basu, Anupam

    2009-01-01

    India is home to a large number of individuals with significant speech and motion impairments. Many of these individuals are children and neo-literates who have little proficiency in their language of communication. In order to cater to such individuals in India, we have developed Sanyog, an icon-based communication aid. Sanyog accepts a sequence…

  11. Enhancing the methanol tolerance of platinum nanoparticles for the cathode reaction of direct methanol fuel cells through a geometric design

    PubMed Central

    Feng, Yan; Ye, Feng; Liu, Hui; Yang, Jun

    2015-01-01

    Mastery over the structure of nanoparticles might be an effective way to enhance their performance for a given application. Herein we demonstrate the design of cage-bell nanostructures to enhance the methanol tolerance of platinum (Pt) nanoparticles while remaining their catalytic activity for oxygen reduction reaction. This strategy starts with the synthesis of core-shell-shell nanoparticles with Pt and silver (Ag) residing respectively in the core and inner shell regions, which are then agitated with saturated sodium chloride (NaCl) solution to eliminate the Ag component from the inner shell region, leading to the formation of bimetallic nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a metal shell with nano-channels, which exhibit superior methanol-tolerant property in catalyzing oxygen reduction reaction due to the different diffusion behaviour of methanol and oxygen in the porous metal shell of cage-bell structured nanoparticles. In particular, the use of remarkably inexpensive chemical agent (NaCl) to promote the formation of cage-bell structured particles containing a wide spectrum of metal shells highlights its engineering merit to produce highly selective electrocatalysts on a large scale for the cathode reaction of direct methanol fuel cells. PMID:26578100

  12. Enhancing the methanol tolerance of platinum nanoparticles for the cathode reaction of direct methanol fuel cells through a geometric design

    NASA Astrophysics Data System (ADS)

    Feng, Yan; Ye, Feng; Liu, Hui; Yang, Jun

    2015-11-01

    Mastery over the structure of nanoparticles might be an effective way to enhance their performance for a given application. Herein we demonstrate the design of cage-bell nanostructures to enhance the methanol tolerance of platinum (Pt) nanoparticles while remaining their catalytic activity for oxygen reduction reaction. This strategy starts with the synthesis of core-shell-shell nanoparticles with Pt and silver (Ag) residing respectively in the core and inner shell regions, which are then agitated with saturated sodium chloride (NaCl) solution to eliminate the Ag component from the inner shell region, leading to the formation of bimetallic nanoparticles with a cage-bell structure, defined as a movable Pt core enclosed by a metal shell with nano-channels, which exhibit superior methanol-tolerant property in catalyzing oxygen reduction reaction due to the different diffusion behaviour of methanol and oxygen in the porous metal shell of cage-bell structured nanoparticles. In particular, the use of remarkably inexpensive chemical agent (NaCl) to promote the formation of cage-bell structured particles containing a wide spectrum of metal shells highlights its engineering merit to produce highly selective electrocatalysts on a large scale for the cathode reaction of direct methanol fuel cells.

  13. A Geometric Approach to Fair Division

    ERIC Educational Resources Information Center

    Barbanel, Julius

    2010-01-01

    We wish to divide a cake among some collection of people (who may have very different notions of the comparative value of pieces of cake) in a way that is both "fair" and "efficient." We explore the meaning of these terms, introduce two geometric tools to aid our analysis, and present a proof (due to Dietrich Weller) that establishes the existence…

  14. Classroom Aids

    ERIC Educational Resources Information Center

    Science Activities: Classroom Projects and Curriculum Ideas, 2007

    2007-01-01

    This article describes 6 aids for science instruction, including (1) the use of fudge to represent lava; (2) the "Living by Chemistry" program, designed to make high school chemistry more accessible to a diverse pool of students without sacrificing content; (3) NOAA and NSTA's online coral reef teaching tool, a new web-based "science toolbox" for…

  15. Floriculture Aide.

    ERIC Educational Resources Information Center

    Martin, Joyce; Looney, Era

    Designed for use in a self-paced, open-entry/open-exit vocational training program for a floriculture aide, this program guide is one of six for teachers of adult women offenders from a correctional institution. Module topic outlines and sample lesson plans are presented on eleven topics: occupational opportunities in the retail florist industry;…

  16. Design Principles for Personalized Decision Aiding: An Application to Tactical Air Force Route Planning.

    DTIC Science & Technology

    1985-07-01

    contingency plans have not been in- corporated in an option, but significant information is likely to become available during its execution. 2.6.1.4...Technology Corporation , 16 September 1983. Riemenschneider, R.A., Rockmore, A.J., and Wikman, T.A.A. Route planning aid: System specification (PAR Report...83-135). New Hartford, NY: PAR Technology Corporation , 31 October 1983. Savage, L.J. The foundations of statistics. NY: Wiley, 1954. Schum, D

  17. Effect of different adhesive strategies on microtensile bond strength of computer aided design/computer aided manufacturing blocks bonded to dentin

    PubMed Central

    Roperto, Renato; Akkus, Anna; Akkus, Ozan; Lang, Lisa; Sousa-Neto, Manoel Damiao; Teich, Sorin; Porto, Thiago Soares

    2016-01-01

    Background: The aim of this study was to determine the microtensile bond strength (μTBS) of ceramic and composite computer aided design-computer aided manufacturing (CAD-CAM) blocks bonded to dentin using different adhesive strategies. Materials and Methods: In this in vitro study, 30 crowns of sound freshly extracted human molars were sectioned horizontally 3 mm above the cementoenamel junction to produce flat dentin surfaces. Ceramic and composite CAD/CAM blocks, size 14, were sectioned into slices of 3 mm thick. Before bonding, CAD/CAM block surfaces were treated according to the manufacturer's instructions. Groups were created based on the adhesive strategy used: Group 1 (GI) - conventional resin cement + total-etch adhesive system, Group 2 (GII) - conventional resin cement + self-etch adhesive system, and Group 3 (GIII) - self-adhesive resin cement with no adhesive. Bonded specimens were stored in 100% humidity for 24h at 37΀C, and then sectioned with a slow-speed diamond saw to obtain 1 mm × 1 mm × 6 mm microsticks. Microtensile testing was then conducted using a microtensile tester. μTBS values were expressed in MPa and analyzed by one-way ANOVA with post hoc (Tukey) test at the 5% significance level. Results: Mean values and standard deviations of μTBS (MPa) were 17.68 (±2.71) for GI/ceramic; 17.62 (±3.99) for GI/composite; 13.61 (±6.92) for GII/composite; 12.22 (±4.24) for GII/ceramic; 7.47 (±2.29) for GIII/composite; and 6.48 (±3.10) for GIII/ceramic; ANOVA indicated significant differences among the adhesive modality and block interaction (P < 0.05), and no significant differences among blocks only, except between GI and GII/ceramic. Bond strength of GIII was consistently lower (P < 0.05) than GI and GII groups, regardless the block used. Conclusion: Cementation of CAD/CAM restorations, either composite or ceramic, can be significantly affected by different adhesive strategies used. PMID:27076825

  18. The Geometric Grids of the Hieratic Numeral.

    NASA Astrophysics Data System (ADS)

    Aboulfotouh, Hossam M. K.

    The paper discusses the geometrical designs of the hieratic numeral signs. It shows the regular-grid-patterns of squares upon which, the shapes of the already decoded hieratic numeral-signs, have been designed. Also, it shows the design of some hieratic numeral signs, based on subdividing the circle; and the hieratic signs of modular notation. It might reveal the basic geometrical level of understanding of anonymous ancient Egyptians who designed them some four thousand years ago.

  19. Using GREENSCOPE Indicators for Sustainable Computer-Aided Process Evaluation and Design

    EPA Science Inventory

    Manufacturing sustainability can be increased by educating those who design, construct, and operate facilities, and by using appropriate tools for process evaluation and design. The U.S. Environmental Protection Agency's GREENSCOPE methodology and tool, for evaluation and design ...

  20. Choosing profile double-sampling designs for survival estimation with application to President's Emergency Plan for AIDS Relief evaluation.

    PubMed

    An, Ming-Wen; Frangakis, Constantine E; Yiannoutsos, Constantin T

    2014-05-30

    Most studies that follow subjects over time are challenged by having some subjects who dropout. Double sampling is a design that selects and devotes resources to intensively pursue and find a subset of these dropouts, then uses data obtained from these to adjust naïve estimates, which are potentially biased by the dropout. Existing methods to estimate survival from double sampling assume a random sample. In limited-resource settings, however, generating accurate estimates using a minimum of resources is important. We propose using double-sampling designs that oversample certain profiles of dropouts as more efficient alternatives to random designs. First, we develop a framework to estimate the survival function under these profile double-sampling designs. We then derive the precision of these designs as a function of the rule for selecting different profiles, in order to identify more efficient designs. We illustrate using data from the United States President's Emergency Plan for AIDS Relief-funded HIV care and treatment program in western Kenya. Our results show why and how more efficient designs should oversample patients with shorter dropout times. Further, our work suggests generalizable practice for more efficient double-sampling designs, which can help maximize efficiency in resource-limited settings.

  1. Computer program for design and performance analysis of navigation-aid power systems. Program documentation. Volume 1: Software requirements document

    NASA Technical Reports Server (NTRS)

    Goltz, G.; Kaiser, L. M.; Weiner, H.

    1977-01-01

    A computer program has been developed for designing and analyzing the performance of solar array/battery power systems for the U.S. Coast Guard Navigational Aids. This program is called the Design Synthesis/Performance Analysis (DSPA) Computer Program. The basic function of the Design Synthesis portion of the DSPA program is to evaluate functional and economic criteria to provide specifications for viable solar array/battery power systems. The basic function of the Performance Analysis portion of the DSPA program is to simulate the operation of solar array/battery power systems under specific loads and environmental conditions. This document establishes the software requirements for the DSPA computer program, discusses the processing that occurs within the program, and defines the necessary interfaces for operation.

  2. A Short Review of Chemical Reaction Database Systems, Computer-Aided Synthesis Design, Reaction Prediction and Synthetic Feasibility.

    PubMed

    Warr, Wendy A

    2014-06-01

    This article is the text for a pedagogical lecture to be given at the Strasbourg Summer School in Chemoinformatics in June 2104. It covers a very wide range of reaction topics including structure and reaction representation, reaction centers, atom-to-atom mapping, reaction retrieval systems, computer-aided synthesis design, retrosynthesis, reaction prediction and synthetic feasibility. In the time available the coverage of each topic can only be cursory; the main usefulness of this article to the research community is the extensive bibliography.

  3. Geometrical Aberration Suppression for Large Aperture Sub-THz Lenses

    NASA Astrophysics Data System (ADS)

    Rachon, M.; Liebert, K.; Siemion, A.; Bomba, J.; Sobczyk, A.; Knap, W.; Coquillat, D.; Suszek, J.; Sypek, M.

    2017-03-01

    Advanced THz setups require high performance optical elements with large numerical apertures and small focal lengths. This is due to the high absorption of humid air and relatively low efficiency of commercially available detectors. Here, we propose a new type of double-sided sub-THz diffractive optical element with suppressed geometrical aberration for narrowband applications (0.3 THz). One side of the element is designed as thin structure in non-paraxial approach which is the exact method, but only for ideally flat elements. The second side will compensate phase distribution differences between ideal thin structure and real volume one. The computer-aided optimization algorithm is performed to design an additional phase distribution of correcting layer assuming volume designing of the first side of the element. The experimental evaluation of the proposed diffractive component created by 3D printing technique shows almost two times larger performance in comparison with uncorrected basic diffractive lens.

  4. Geometrical Aberration Suppression for Large Aperture Sub-THz Lenses

    NASA Astrophysics Data System (ADS)

    Rachon, M.; Liebert, K.; Siemion, A.; Bomba, J.; Sobczyk, A.; Knap, W.; Coquillat, D.; Suszek, J.; Sypek, M.

    2016-11-01

    Advanced THz setups require high performance optical elements with large numerical apertures and small focal lengths. This is due to the high absorption of humid air and relatively low efficiency of commercially available detectors. Here, we propose a new type of double-sided sub-THz diffractive optical element with suppressed geometrical aberration for narrowband applications (0.3 THz). One side of the element is designed as thin structure in non-paraxial approach which is the exact method, but only for ideally flat elements. The second side will compensate phase distribution differences between ideal thin structure and real volume one. The computer-aided optimization algorithm is performed to design an additional phase distribution of correcting layer assuming volume designing of the first side of the element. The experimental evaluation of the proposed diffractive component created by 3D printing technique shows almost two times larger performance in comparison with uncorrected basic diffractive lens.

  5. SU-E-T-461: Impact of the Radiation Sensitivity of Tumor and Geometric Design of the GRID Block On the Clinical Response of Grid Therapy

    SciTech Connect

    Gholami, S; Ay, M.R; Meigooni, A S.; Nedaie, H.A; Longo, F

    2015-06-15

    Purpose: The spatially fractionated radiation therapy (Grid therapy) is a novel technique that has been recently introduced for treatments of the patients with advanced bulky tumors. The purpose of this study is to investigate the effect of the radiation sensitivity of tumor and Grid block design on the clinical response of the Grid therapy. Methods: The Geant4 toolkit is used to simulate a Varian2100C linear accelerator with the block-based Grid. The dose profile has been utilized to calculate the Therapeutic Ratio (TR) and Equivalent Uniform Dose (EUD) for different types of tumors. These calculations were performed with respect to their radiation sensitivities using Linear Quadratic model (LQ). Clinical responses of few hundred patients from different publications that were treated with Grid therapy, have been used to validate correlation between tumor radiation sensitivity and clinical response of Grid therapy. Moreover, the influence of Grid design on clinical response of this radiation technique was investigated with using Monte Carlo simulation of a Grid block with different hole-diameters of 0.5 cm, 0.75 cm, 1.25 cm, and 1.5 cm. The Geometrical Sparing Factor (GSF) was considered to compare the results from different Grid designs. Results: The higher clinical response of Grid therapy for more radio-resistant tumors was confirmed in both theoretical assumptions and clinical outcomes. In addition, the results indicate that the Grid hole diameter have more effect on increasing the TR in comparison with the hole center-to-center distance effect. From this Monte Carlo study, a Grid design with the hole diameter between 1.25 cm and 1.5 cm with GSF value of 0.90 is recommended. Conclusion: Grid Therapy is more effective for more radio-resistant tumors.The optimum results of the Grid therapy depend on selection of the appropriate Grid design.This study is a first step toward clarifying some important aspects in a clinical response of spatially fractionated

  6. Monte Carlo aided design of an improved well-type ionization chamber for low energy brachytherapy sources

    SciTech Connect

    Bohm, Tim D.; Micka, John A.; De Werd, Larry A.

    2007-04-15

    The determination of the air kerma strength of a brachytherapy seed is necessary for effective treatment planning. Well-type ionization chambers are used on site at therapy clinics to determine the air kerma strength of seeds. In this work, an improved well-type ionization chamber for low energy, low dose rate brachytherapy sources is designed using Monte Carlo transport calculations to aid in the design process. The design improvements are the elimination of the air density induced over-response effect seen in other air-communicating chambers for low energy photon sources, and a larger signal strength (response or current) for {sup 103}Pd and {sup 125}I based seeds. A prototype well chamber based on the Monte Carlo aided design but using graphite coated acrylic walls rather than the design basis air equivalent plastic (C-552) walls was constructed and experimentally evaluated. The prototype chamber produced an 85% stronger signal when measuring a commonly used {sup 103}Pd seed and a 26% stronger signal when measuring a commonly used {sup 125}I seed when compared to another commonly used well chamber. The normalized P{sub TP} corrected chamber response is, at most, 1.3% and 2.4% over unity for air densities/pressures corresponding to an elevation of 3048 m (10 000 feet) above sea level for the commonly used {sup 103}Pd and {sup 125}I based seeds respectively. Comparing calculated and measured chamber responses for common {sup 103}Pd and {sup 125}I based brachytherapy seeds show agreement within 0.6% and 0.2%, respectively. We conclude that Monte Carlo transport calculations accurately model the response of this new well chamber and in general can be used to predict the response of well chambers. The prototype chamber built in this work responds as predicted by the Monte Carlo calculations.

  7. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOEpatents

    Hubbell, Earl A.; Lipshutz, Robert J.; Morris, Macdonald S.; Winkler, James L.

    1997-01-01

    An improved set of computer tools for forming arrays. According to one aspect of the invention, a computer system is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files to design and/or generate lithographic masks.

  8. Computer Aided Drug Design Studies in the Discovery of Secondary Metabolites Targeted Against Age-Related Neurodegenerative Diseases.

    PubMed

    Scotti, Luciana; Scotti, Marcus Tullius

    2015-01-01

    Secondary metabolites are plant products that occur usually in differentiated cells, generally not being necessary for the cells themselves, but likely useful for the plant as a whole. Neurodegeneration can be found in many different levels in the neurons, it always begins at the molecular level and progresses toward the systemic levels. Usually, alterations are observed such as decreasing cholinergic impulse, toxicity related to reactive oxygen species (ROS, inflammatory "amyloid plaque" related processes, catecholamine disequilibrium, etc. Computer aided drug design (CADD has become relevant in the drug discovery process; technological advances in the areas of molecular structure characterization, computational science, and molecular biology have contributed to the planning of new drugs against neurodegenerative diseases. This review discusses scientific CADD studies of the secondary metabolites. Flavonoids, alkaloids, and xanthone compounds have been studied by various researchers (as inhibitory ligands in molecular docking; mainly with three enzymes: acetylcholinesterase (AChE; EC 3.1.1.7, butyrylcholinesterase (BChE; EC 3.1.1.8, and monoamine oxidase (MAO; EC 1.4.3.4. In addition, we have applied ligand-based-virtual screening (using Random Forest, associated with structure-based- virtual screening (docking of a small dataset of 469 alkaloids of the Apocynaceae family from an in-house data bank to select structures with potential inhibitory activity against human AChE. This computer-aided drug design study selected certain alkaloids that might be useful in further studies for the treatment of neurological disorders such as Alzheimer's and Parkinson's disease.

  9. Creating Motivating Job Aids.

    ERIC Educational Resources Information Center

    Tilaro, Angie; Rossett, Allison

    1993-01-01

    Explains how to create job aids that employees will be motivated to use, based on a review of pertinent literature and interviews with professionals. Topics addressed include linking motivation with job aids; Keller's ARCS (Attention, Relevance, Confidence, Satisfaction) model of motivation; and design strategies for job aids based on Keller's…

  10. Devolution and grant-in-aid design for the provision of impure public goods.

    PubMed

    Levaggi, Laura; Levaggi, Rosella

    2016-01-01

    Traditional fiscal federalism theory postulates that devolution for the provision of local public goods increases welfare. However, most of the services offered at local level are local impure public goods whose characteristics may prevent devolution from being efficient. Our paper shows that devolution is the optimal choice only for local impure public goods. For an environment characterised by coordination and asymmetry of information problems, we propose the optimal grants-in-aid formula that Central Government should use to reduce welfare losses and we compare it with what suggested by the mainstream literature. Finally, we show under which conditions devolution should be preferred to a centralised solution. From a policy point of view, our paper may explain the heterogeneity in the choices made by countries in terms of devolution in the provision of merit and impure public goods.

  11. Design and implementation of a GPS-aided inertial navigation system for a helicopter UAV

    NASA Astrophysics Data System (ADS)

    Kastelan, David R.

    Helicopter unmanned aerial vehicles (UAVs) benefit from vertical takeoff and landing, hover, low-speed, and cruising flight capabilities. This versatility has the expense of nonlinear, unstable, and underactuated system dynamics. These challenges and numerous potential applications make the helicopter UAV an interesting testbed for nonlinear control. A platform for such development has been established in the Applied Nonlinear Controls Lab (ANCL). A miniature helicopter was augmented with a manual/autonomous takeover system and the ANCL Avionics. This payload contains a global positioning system (GPS) receiver, inertial sensors, and communications and computing hardware. Allan variance analysis of inertial sensor data enabled the derivation of a GPS-aided inertial navigation system that was implemented on the ANCL Avionics. This extended Kalman filter (EKF)-based algorithm estimates vehicle position, velocity, and attitude necessary for system identification tasks and control system feedback. Performance validation of this algorithm was demonstrated in simulation and in experimental ground and flight tests.

  12. Participation of South African youth in the design and development of AIDS photocomics. 1997-98.

    PubMed

    Toroyan, Tamitza; Reddy, Priscilla S

    In response to an increasing incidence in HIV prevalence among South Africa's youth, a group of interdisciplinary professionals have developed a series of photocomics to address issues around HIV/AIDS communication and sexually transmitted diseases. This article examines the theory behind the use of photocomics in health, and the way the stories work to influence behavior. Results from evaluation of the comics support their use as tools with which to increase information and knowledge while role modeling desirable behavior. Lastly, the article describes the participatory process by which youth were involved in the process of developing and producing the comics. This method of developing culturally relevant and appealing health media is recommended for use in future health promotion strategies that seek to transcend a narrower approach of provision of health information and work to address the social factors that influence youth's decision making.

  13. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOEpatents

    Hubbell, Earl A.; Morris, MacDonald S.; Winkler, James L.

    1999-01-05

    An improved set of computer tools for forming arrays. According to one aspect of the invention, a computer system (100) is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files (104) to design and/or generate lithographic masks (110).

  14. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOEpatents

    Hubbell, E.A.; Morris, M.S.; Winkler, J.L.

    1996-11-05

    An improved set of computer tools for forming arrays is disclosed. According to one aspect of the invention, a computer system is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files to design and/or generate lithographic masks. 14 figs.

  15. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOEpatents

    Hubbell, Earl A.; Morris, MacDonald S.; Winkler, James L.

    1996-01-01

    An improved set of computer tools for forming arrays. According to one aspect of the invention, a computer system (100) is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files (104) to design and/or generate lithographic masks (110).

  16. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOEpatents

    Hubbell, E.A.; Lipshutz, R.J.; Morris, M.S.; Winkler, J.L.

    1997-01-14

    An improved set of computer tools for forming arrays is disclosed. According to one aspect of the invention, a computer system is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files to design and/or generate lithographic masks. 14 figs.

  17. Computer-aided engineering system for design of sequence arrays and lithographic masks

    DOEpatents

    Hubbell, E.A.; Morris, M.S.; Winkler, J.L.

    1999-01-05

    An improved set of computer tools for forming arrays is disclosed. According to one aspect of the invention, a computer system is used to select probes and design the layout of an array of DNA or other polymers with certain beneficial characteristics. According to another aspect of the invention, a computer system uses chip design files to design and/or generate lithographic masks. 14 figs.

  18. Hearing Aids

    MedlinePlus

    ... Health Info » Hearing, Ear Infections, and Deafness Hearing Aids On this page: What is a hearing aid? ... the ear through a speaker. How can hearing aids help? Hearing aids are primarily useful in improving ...

  19. Computer-aided design of curved surfaces with automatic model generation

    NASA Technical Reports Server (NTRS)

    Staley, S. M.; Jerard, R. B.; White, P. R.

    1980-01-01

    The design and visualization of three-dimensional objects with curved surfaces have always been difficult. The paper given below describes a computer system which facilitates both the design and visualization of such surfaces. The system enhances the design of these surfaces by virtue of various interactive techniques coupled with the application of B-Spline theory. Visualization is facilitated by including a specially built model-making machine which produces three-dimensional foam models. Thus, the system permits the designer to produce an inexpensive model of the object which is suitable for evaluation and presentation.

  20. Methodology of Computer-Aided Design of Variable Guide Vanes of Aircraft Engines

    ERIC Educational Resources Information Center

    Falaleev, Sergei V.; Melentjev, Vladimir S.; Gvozdev, Alexander S.

    2016-01-01

    The paper presents a methodology which helps to avoid a great amount of costly experimental research. This methodology includes thermo-gas dynamic design of an engine and its mounts, the profiling of compressor flow path and cascade design of guide vanes. Employing a method elaborated by Howell, we provide a theoretical solution to the task of…

  1. Infusion of a Gaming Paradigm into Computer-Aided Engineering Design Tools

    DTIC Science & Technology

    2012-05-03

    iterdisciplinary system design/simularbn environment several gaming concepts such as network-centric multiplayer interactions, detection dfiterferences...into the VTB interdisciplinary system design/simulation environment several gaming concepts such as network-centric multiplayer interactions...simulation speed so that the physics-based gaming environment can operate fast enough for effective human interaction. The multiplayer gaming

  2. Computer-aided optimal design of custom scoliosis braces considering clinical and patient evaluations.

    PubMed

    Visser, Daniel; Xue, Deyi; Ronsky, Janet L; Harder, James; Zernicke, Ronald F

    2012-09-01

    Scoliosis causes an abnormal three dimensional curvature of the spine that is often treated by an orthotic device called brace. The objective of this research was to develop a new approach to automatically identify the optimal design of custom-built brace, based on clinical and patient evaluations. In this approach, torso geometry of the scoliosis patient was achieved using a 3-D imaging system that generated a 3-D torso surface model, which was modified using a custom CAD system to design the 3-D brace surface model. Two design parameters, a translational correction factor and a rotational correction factor, were selected to design the brace geometry from the torso geometry. The 3-D digital brace was evaluated by three clinical evaluation measures (imbalance, rib hump and principal axis angle reduction) and one patient evaluation measure (discomfort). A multi-objective optimization method was employed to identify the optimal design parameters considering both clinical and patient evaluations.

  3. Design and performance analysis of a low-cost aided dead reckoning navigator

    NASA Astrophysics Data System (ADS)

    Gebre-Egziabher, Demoz

    The Federal Aviation Administration is leading the National Airspace System (NAS) modernization effort, in part, by supplanting traditional air traffic services with the Global Positioning System (GPS) aided by the Wide and Local Area Augmentation Systems (WAAS & LAAS). Making GPS the primary-means of navigation will enhance safety, flexibility and efficiency of operations for all aircraft ranging from single engine general aviation aircraft to complex commercial jet-liners. This transformation of the NAS will be gradual and the build-up to a primary-means GPS capability is expected to occur concurrently with the de-commissioning of a significant number of existing ground-based navigational facilities. If an alternate means of navigation is not available during this transition period, temporary interruptions of GPS services due to intentional or unintentional interference could present significant problems for aircraft lacking backup navigation capability. To successfully deal with such outage scenarios, a NAS architecture consisting of a skeletal network of Distance Measuring Equipment (DME) transponders to provide a redundant navigation capability alongside GPS/WAAS during this transition period is proposed. DME range measurements fused with a low cost dead-reckoning system can provide a navigation performance comparable to VOR and LORAN. This navigation scheme allows reducing the number of operational radio-navigation aids while maintaining an adequate coverage for navigation during the transition to a primary-means GPS NAS. The dead-reckoning navigation system is based on the fusion of a single low-end DME receiver with low cost inertial, air-data and magnetic sensors. These sensors are already part of the newer general aviation aircraft's suite of navigation sensors. Estimator architectures for fusing the information from the various sensors is presented. The performance of this navigator depends on the calibration and on-line estimation of sensor errors

  4. The Design of a Survey Instrument to Aid in Identifying Sex Related Barriers to Employment and the Administration of That Instrument to Rural and Urban Employers.

    ERIC Educational Resources Information Center

    Jones, B. Dolores; Mook, Corena

    A project was conducted to design a survey instrument that would help in identifying sex-related barriers to employment and to administer that instrument to employers in both rural and urban counties of Kansas. It was projected that the data derived from the survey could be used to aid in designing vocational education methods and techniques.…

  5. Automotive technicians' training as a community-of-practice: implications for the design of an augmented reality teaching aid.

    PubMed

    Anastassova, Margarita; Burkhardt, Jean-Marie

    2009-07-01

    The paper presents an ergonomic analysis carried out in the early phases of an R&D project. The purpose was to investigate the functioning of today's Automotive Service Technicians (ASTs) training in order to inform the design of an Augmented Reality (AR) teaching aid. The first part of the paper presents a literature review of some major problems encountered by ASTs today. The benefits of AR as technological aid are also introduced. Then, the methodology and the results of two case studies are presented. The first study is based on interviews with trainers and trainees; the second one on observations in real training settings. The results support the assumption that today's ASTs' training could be regarded as a community-of-practice (CoP). Therefore, AR could be useful as a collaboration tool, offering a shared virtual representation of real vehicle's parts, which are normally invisible unless dismantled (e.g. the parts of a hydraulic automatic transmission). We conclude on the methods and the technologies to support the automotive CoP.

  6. Computer-Aided Design of Organic Host Architectures for Selective Chemosensors

    SciTech Connect

    Hay, Benjamin; Bryantsev, Vyacheslav S.

    2009-01-01

    Selective organic hosts provide the foundation for the development of many types of sensors. The deliberate design of host molecules with predetermined selectivity, however, remains a challenge in supramolecular chemistry. To address this issue we have developed a de novo structure-based design approach for the unbiased construction of complementary host architectures. This chapter summarizes recent progress including improvements on a computer software program, HostDesigner, specifically tailored to discover host architectures for small guest molecules. HostDesigner is capable of generating and evaluating millions of candidate structures in minutes on a desktop personal computer, allowing a user to rapidly identify three-dimensional architectures that are structurally organized for binding a targeted guest species. The efficacy of this computational methodology is illustrated with a search for cation hosts containing aliphatic ether oxygen groups and anion hosts containing urea groups.

  7. Preconditioner and convergence study for the Quantum Computer Aided Design (QCAD) nonlinear poisson problem posed on the Ottawa Flat 270 design geometry.

    SciTech Connect

    Kalashnikova, Irina

    2012-05-01

    A numerical study aimed to evaluate different preconditioners within the Trilinos Ifpack and ML packages for the Quantum Computer Aided Design (QCAD) non-linear Poisson problem implemented within the Albany code base and posed on the Ottawa Flat 270 design geometry is performed. This study led to some new development of Albany that allows the user to select an ML preconditioner with Zoltan repartitioning based on nodal coordinates, which is summarized. Convergence of the numerical solutions computed within the QCAD computational suite with successive mesh refinement is examined in two metrics, the mean value of the solution (an L{sup 1} norm) and the field integral of the solution (L{sup 2} norm).

  8. Exploring New Geometric Worlds

    ERIC Educational Resources Information Center

    Nirode, Wayne

    2015-01-01

    When students work with a non-Euclidean distance formula, geometric objects such as circles and segment bisectors can look very different from their Euclidean counterparts. Students and even teachers can experience the thrill of creative discovery when investigating these differences among geometric worlds. In this article, the author describes a…

  9. Garrett County Aids AID

    ERIC Educational Resources Information Center

    Appalachia, 1975

    1975-01-01

    Garrett County, Maryland volunteered to act as a pre-overseas learning laboratory for AID (Agency for International Development) interns who practiced data collection and planning techniques with the help of local citizenry. (JC)

  10. Anticipating needs and designing new items rapidly - a case study for the design of postural aid equipment.

    PubMed

    Prévost, Marie-Claude; Spooner, Daniel

    2012-01-01

    In this case study, designers proactively proposed new product ideas to a client by using an ergonomic approach. This approach differs from a more traditional approach where one works within a specific, clientdefined project. The methodology used included basic ergonomic techniques such as task analysis and information gathering sessions conducted with users. It was adapted so that these enriched user sessions could be conducted within a short time period. After meeting with five users in seven days, designers identified 20 problems that could be tackled and eight design ideas that could be implemented over the short, medium and long term. The ideas encompassed a wide range of potential projects, including physical product improvements, new product lines, Web-site and software improvements and longer term research. Problems identified and ideas generated involved many disciplines including occupational therapy, mechanical engineering, graphical design, software engineering, sales and manufacturing know-how. This wide range was possible because designers were not constrained to specific project scopes and timelines. The client was involved in the idea evaluation process. As a result of this study two new projects were initiated so far.

  11. Opportunities for Russian Nuclear Weapons Institute developing computer-aided design programs for pharmaceutical drug discovery. Final report

    SciTech Connect

    1996-09-23

    The goal of this study is to determine whether physicists at the Russian Nuclear Weapons Institute can profitably service the need for computer aided drug design (CADD) programs. The Russian physicists` primary competitive advantage is their ability to write particularly efficient code able to work with limited computing power; a history of working with very large, complex modeling systems; an extensive knowledge of physics and mathematics, and price competitiveness. Their primary competitive disadvantage is their lack of biology, and cultural and geographic issues. The first phase of the study focused on defining the competitive landscape, primarily through interviews with and literature searches on the key providers of CADD software. The second phase focused on users of CADD technology to determine deficiencies in the current product offerings, to understand what product they most desired, and to define the potential demand for such a product.

  12. Patient flow improvement for an ophthalmic specialist outpatient clinic with aid of discrete event simulation and design of experiment.

    PubMed

    Pan, Chong; Zhang, Dali; Kon, Audrey Wan Mei; Wai, Charity Sue Lea; Ang, Woo Boon

    2015-06-01

    Continuous improvement in process efficiency for specialist outpatient clinic (SOC) systems is increasingly being demanded due to the growth of the patient population in Singapore. In this paper, we propose a discrete event simulation (DES) model to represent the patient and information flow in an ophthalmic SOC system in the Singapore National Eye Centre (SNEC). Different improvement strategies to reduce the turnaround time for patients in the SOC were proposed and evaluated with the aid of the DES model and the Design of Experiment (DOE). Two strategies for better patient appointment scheduling and one strategy for dilation-free examination are estimated to have a significant impact on turnaround time for patients. One of the improvement strategies has been implemented in the actual SOC system in the SNEC with promising improvement reported.

  13. CFD aided optimization of an innovative SCR catalyst design for heavy-duty marine diesel engines

    NASA Astrophysics Data System (ADS)

    Krastev, V. K.; Russo, S.; Verdemare, D.; Recine, G.; Biferale, L.; Falcucci, G.

    2016-06-01

    In this paper, the design of a new system for reducing NOx from exhaust gases from marine engines is shown. The core of the system is represented by the Selective Catalytic Reduction (SCR) reactor, in which the catalyst is made of titanium dioxide nano-fibers functionalized with metal oxides and deposited by electrospinning on a corrugated metal support. Compared to the current monolithic reactor designs, the high specific surface offered by the fibers allows in principle to satisfy the TIER III emission standards, with a consistent saving in the reactor volume. To optimize the reactor design process, a Computational Fluid Dynamics (CFD) model has been developed, alongside experimental measurements and numerical simulations. Results of different configurations are reported and critically assessed.

  14. Current trends in the design of scaffolds for computer-aided tissue engineering.

    PubMed

    Giannitelli, S M; Accoto, D; Trombetta, M; Rainer, A

    2014-02-01

    Advances introduced by additive manufacturing have significantly improved the ability to tailor scaffold architecture, enhancing the control over microstructural features. This has led to a growing interest in the development of innovative scaffold designs, as testified by the increasing amount of research activities devoted to the understanding of the correlation between topological features of scaffolds and their resulting properties, in order to find architectures capable of optimal trade-off between often conflicting requirements (such as biological and mechanical ones). The main aim of this paper is to provide a review and propose a classification of existing methodologies for scaffold design and optimization in order to address key issues and help in deciphering the complex link between design criteria and resulting scaffold properties.

  15. Computer-aided design and activity prediction of leucine aminopeptidase inhibitors

    NASA Astrophysics Data System (ADS)

    Grembecka, J.; Sokalski, W. A.; Kafarski, P.

    2000-08-01

    The Ligand Design (LUDI) approach has been used in order to design leucine aminopeptidase inhibitors, predict their activity and analyze their interactions with the enzyme. The investigation was based on the crystal structure of bovine lens leucine aminopeptidase (LAP) complexed with its inhibitor - the phosphonic acid analogue of leucine (LeuP). More than 50 potential leucine aminopeptidase inhibitors have been obtained, including the most potent aminophosphonic LAP inhibitors with experimentally known activity, which have been the subject of more detailed studies. A reasonable agreement between theoretical and experimental activities has been obtained for most of the studied inhibitors. Our results confirm that LUDI is a powerful tool for the design of enzyme inhibitors as well as in the prediction of their activity. In addition, for inhibitor-active site interactions dominated by the electrostatic effects it is possible to improve binding energy estimates by using a more accurate description of inhibitor charge distribution.

  16. A semi-automatic computer-aided method for surgical template design

    PubMed Central

    Chen, Xiaojun; Xu, Lu; Yang, Yue; Egger, Jan

    2016-01-01

    This paper presents a generalized integrated framework of semi-automatic surgical template design. Several algorithms were implemented including the mesh segmentation, offset surface generation, collision detection, ruled surface generation, etc., and a special software named TemDesigner was developed. With a simple user interface, a customized template can be semi- automatically designed according to the preoperative plan. Firstly, mesh segmentation with signed scalar of vertex is utilized to partition the inner surface from the input surface mesh based on the indicated point loop. Then, the offset surface of the inner surface is obtained through contouring the distance field of the inner surface, and segmented to generate the outer surface. Ruled surface is employed to connect inner and outer surfaces. Finally, drilling tubes are generated according to the preoperative plan through collision detection and merging. It has been applied to the template design for various kinds of surgeries, including oral implantology, cervical pedicle screw insertion, iliosacral screw insertion and osteotomy, demonstrating the efficiency, functionality and generality of our method. PMID:26843434

  17. Computer Aided Instruction for a Course in Boolean Algebra and Logic Design. Final Report (Revised).

    ERIC Educational Resources Information Center

    Roy, Rob

    The use of computers to prepare deficient college and graduate students for courses that build upon previously acquired information would solve the growing problem of professors who must spend up to one third of their class time in review of material. But examination of students who were taught Boolean Algebra and Logic Design by means of Computer…

  18. A dc model for power switching transistors suitable for computer-aided design and analysis

    NASA Technical Reports Server (NTRS)

    Wilson, P. M.; George, R. T., Jr.; Owen, H. A.; Wilson, T. G.

    1979-01-01

    A model for bipolar junction power switching transistors whose parameters can be readily obtained by the circuit design engineer, and which can be conveniently incorporated into standard computer-based circuit analysis programs is presented. This formulation results from measurements which may be made with standard laboratory equipment. Measurement procedures, as well as a comparison between actual and computed results, are presented.

  19. A semi-automatic computer-aided method for surgical template design.

    PubMed

    Chen, Xiaojun; Xu, Lu; Yang, Yue; Egger, Jan

    2016-02-04

    This paper presents a generalized integrated framework of semi-automatic surgical template design. Several algorithms were implemented including the mesh segmentation, offset surface generation, collision detection, ruled surface generation, etc., and a special software named TemDesigner was developed. With a simple user interface, a customized template can be semi- automatically designed according to the preoperative plan. Firstly, mesh segmentation with signed scalar of vertex is utilized to partition the inner surface from the input surface mesh based on the indicated point loop. Then, the offset surface of the inner surface is obtained through contouring the distance field of the inner surface, and segmented to generate the outer surface. Ruled surface is employed to connect inner and outer surfaces. Finally, drilling tubes are generated according to the preoperative plan through collision detection and merging. It has been applied to the template design for various kinds of surgeries, including oral implantology, cervical pedicle screw insertion, iliosacral screw insertion and osteotomy, demonstrating the efficiency, functionality and generality of our method.

  20. Design Considerations in Development of Minicomputer-Based Computer Aided Instructional Hardware Systems.

    ERIC Educational Resources Information Center

    Wells, C. H.

    A minicomputer-based computer-assisted instructional (CAI) system was designed at the University of Texas Medical Branch in an attempt to lower both the excessive hardware costs and the inordinate amount of time required for the preparation of each hour of instructional material associated with traditional CAI systems. A prototype system with an…

  1. Computer-Aided Design Training and Spatial Visualization Ability in Gifted Adolescents.

    ERIC Educational Resources Information Center

    Mack, Warren E.

    1995-01-01

    An experimental group of 20 gifted adolescents received 3 weeks of computer-assisted design (CAD) instruction. Comparison of their scores on Revised Minnesota Paper Form Board test with those of 20 gifted controls showed CAD did not improve spatial visualization ability. Possible causes were differential computer experience, lack of random…

  2. AESOP: A computer-aided design program for linear multivariable control systems

    NASA Technical Reports Server (NTRS)

    Lehtinen, B.; Geyser, L. C.

    1982-01-01

    An interactive computer program (AESOP) which solves quadratic optimal control and is discussed. The program can also be used to perform system analysis calculations such as transient and frequency responses, controllability, observability, etc., in support of the control and filter design computations.

  3. Computer-aided design of peptide near infrared fluorescent probe for tumor diagnosis

    NASA Astrophysics Data System (ADS)

    Zhang, Congying; Gu, Yueqing

    2014-09-01

    Integrin αvβ3 receptors are expressed on activated endothelial cells during neovascularization to maintain tumor growth, so they become hot research tagets in cancer diagnosis. Peptides possess several attractive features when compared to protein and small molecule, such as small size and high structural compatibility with target proteins. Efficient design of high-affinity peptide ligands to Integrin αvβ3 receptors has been an important problem. Designed peptides in silico provide a valuable and high-selectivity peptide, meanwhile decrease the time of drug screening. In this study, we design peptide which can bind with integrin αvβ3 via computer, and then synthesis near infrared fluorescent probe. The characterization of this near infrared fluorescent probe was detected by UV. To investigate the tumor cell targeting of this probe, it was labeled with visible fluorescent dye Rhodamine B (RhB) for microscopy. To evaluate the targeting capability of this near infrared fluorescent probe, mice bearing integrin αvβ3 positive tumor xenografts were used. In vitro cellular experiments indicated that this probe have a clear binding affinity to αvβ3-positive tumor cells. In vivo experiments confirmed the receptor binding specificity of this probe. The peptide of computational design can bind with integrin αvβ3. Combined peptide near-infrared fluorescent probe with imaging technology use for clinical and tumor diagnosis have a greater development in future.

  4. Man-machine interactive system simplifies computer-aided circuit design

    NASA Technical Reports Server (NTRS)

    Bavuso, S. J.

    1970-01-01

    Langley interactive computerized circuit analysis capability /LICCA/ enables designer to draw electronic circuit diagrams on cathode ray tube screen. This information is submitted as input to user-selected circuit analysis program. LICCA accommodates binary logic circuits and circuits with discrete components, and monitors operator's instructions to detect errors.

  5. Computer Aided Design of Ka-Band Waveguide Power Combining Architectures for Interplanetary Spacecraft

    NASA Technical Reports Server (NTRS)

    Vaden, Karl R.

    2006-01-01

    Communication systems for future NASA interplanetary spacecraft require transmitter power ranging from several hundred watts to kilowatts. Several hybrid junctions are considered as elements within a corporate combining architecture for high power Ka-band space traveling-wave tube amplifiers (TWTAs). This report presents the simulated transmission characteristics of several hybrid junctions designed for a low loss, high power waveguide based power combiner.

  6. Computer Aided Design of Microwave Front-End Components and Antennas for Ultrawideband Systems

    NASA Astrophysics Data System (ADS)

    Almalkawi, Mohammad J.

    This dissertation contributes to the development of novel designs, and implementation techniques for microwave front-end components and packaging employing both transmission line theory and classical circuit theory. For compact realization, all the presented components have been implemented using planar microstrip technology. Recently, there has been an increase in the demand for compact microwave front-ends which exhibit advanced functions. Under this trend, the development of multiband front-end components such as antennas with multiple band-notches, dual-band microwave filters, and high-Q reconfigurable filters play a pivotal role for more convenient and compact products. Therefore, the content of this dissertation is composed of three parts. The first part focuses on packaging as an essential process in RF/microwave integration that is used to mitigate unwanted radiations or crosstalk due to the connection traces. In printed circuit board (PCB) interconnects, crosstalk reduction has been achieved by adding a guard trace with/without vias or stitching capacitors that control the coupling between the traces. In this research, a new signal trace configuration to reduce crosstalk without adding additional components or guard traces is introduced. The second part of this dissertation considers the inherent challenges in the design of multiple-band notched ultrawideband antennas that include the integration of multilayer antennas with RF front-ends and the realization of compact size antennas. In this work, a compact UWB antenna with quad band-notched frequency characteristics was designed, fabricated, and tested demonstrating the desired performance. The third part discusses the design of single- and dual-band dual-mode filters exhibiting both symmetric and asymmetric transfer characteristics. In dual-mode filters, the numbers of resonators that determine the order of a filter are reduced by half while maintaining the performance of the actual filter order. Here, in

  7. State-of-the-art technology in modern computer-aided drug design.

    PubMed

    Dalkas, Georgios A; Vlachakis, Dimitrios; Tsagkrasoulis, Dimosthenis; Kastania, Anastasia; Kossida, Sophia

    2013-11-01

    The quest for small drug-like compounds that selectively inhibit the function of biological targets has always been a major focus in the pharmaceutical industry and in academia as well. High-throughput screening of compound libraries requires time, cost and resources. Therefore, the use of alternative methods is necessary for facilitating lead discovery. Computational techniques that dock small molecules into macromolecular targets and predict the affinity and activity of the small molecule are widely used in drug design and discovery, and have become an integral part of the industrial and academic research. In this review, we present an overview of some state-of-the-art technologies in modern drug design that have been developed for expediting the search for novel drug candidates.

  8. Mommy, Daddy--What's AIDS?

    ERIC Educational Resources Information Center

    National Association of Pediatric Nurse Associates and Practitioners, Cherry Hill, NJ.

    This brochure is designed to help parents answer the questions that their children may ask them about Acquired Immune Deficiency Syndrome (AIDS) and the Human Immuno Deficiency Virus (HIV), the virus that causes AIDS. It provides basic information about AIDS and HIV, as well as sources for further information, such as the National AIDS Hotline. It…

  9. Ideal Compliant Joints and Integration of Computer Aided Design and Analysis

    DTIC Science & Technology

    2013-11-17

    follows in subsequent subsections. B-spline surfaces can be defined in the following parametric form (Piegl and Tiller , 1997): jiqj n i m j pi vNuNvu...DESIGN AND ANALYSIS Ashraf M . Hamed 1 Paramsothy Jayakumar 2 Michael D. Letherwood 2 David J. Gorsich 2 Antonio M . Recuero 1...coordinate u defines the local position of the joint definition point on the base element as shown in Fig. 7, while the second one m defines the

  10. ICAM (Integrated Computer-Aided Manufacturing) Manufacturing Cost/Design Guide. Volume 7. Technology Transfer Summary.

    DTIC Science & Technology

    1984-09-01

    agencies only; Test and Evaluation; 14 Sep 84. Other requests must be referred to AFWAL/MLTC, Wright- Patterson AFB, OH 45433. AUTHORITY Air Force...LABORATORY 0 * AIR FORCE WRIGHT AERONAUTICAL LABORATORIES AIR FORCE SYSTEMS COMMAND ’ WRIGHT-PATTERSON AFB, OH 45433 &. ... 7-- , TTD450260000 12 Supt 1984...Design Guide document covers the work performed under Air Force Contract F33b15-79-C-5102 from 1 October 1979 through 31 August 1984. The contract is

  11. Graphene nanoribbons as low band gap donor materials for organic photovoltaics: quantum chemical aided design.

    PubMed

    Osella, Silvio; Narita, Akimitsu; Schwab, Matthias Georg; Hernandez, Yenny; Feng, Xinliang; Müllen, Klaus; Beljonne, David

    2012-06-26

    Graphene nanoribbons (GNRs) are strips of graphene cut along a specific direction that feature peculiar electronic and optical properties owing to lateral confinement effects. We show here by means of (time-dependent) density functional theory calculations that GNRs with properly designed edge structures fulfill the requirements in terms of electronic level alignment with common acceptors (namely, C(60)), solar light harvesting, and singlet-triplet exchange energy to be used as low band gap semiconductors for organic photovoltaics.

  12. Computer Aided Design of Monolithic Microwave and Millimeter Wave Integrated Circuits and Subsystems

    DTIC Science & Technology

    1989-05-01

    been measured for the I pm single and double heterojunction devices. The 0.25 tm devices had a fmax of 85 GHz. Also reported are a new design technique...is taken into account so that the circuit simulator could run efficiently. The high electron mobility transistor, HEMT, has become an important device...improved the charge control models for HEMTs and MISFETs by taking the nonlinear variation into account , and which resulted in more accurate drain

  13. Advanced earth observation spacecraft computer-aided design software: Technical, user and programmer guide

    NASA Technical Reports Server (NTRS)

    Farrell, C. E.; Krauze, L. D.

    1983-01-01

    The IDEAS computer of NASA is a tool for interactive preliminary design and analysis of LSS (Large Space System). Nine analysis modules were either modified or created. These modules include the capabilities of automatic model generation, model mass properties calculation, model area calculation, nonkinematic deployment modeling, rigid-body controls analysis, RF performance prediction, subsystem properties definition, and EOS science sensor selection. For each module, a section is provided that contains technical information, user instructions, and programmer documentation.

  14. An Object-Oriented Computer Aided Design Program for Traditional Control Systems Analysis

    DTIC Science & Technology

    1992-12-01

    Butterworth filter templates, Lag- Lead controller design, discrete QFT, nonlinear QFT, etc. before any of them have to worry about porting to the...because the subtraction of small similar numbers on a computer leads to a loss of significant digits. However, a more computer-optimized numerical...use. Time_DataType = Record TF, FFTF TransFunc; ForceFuncType Integer; DataFileName String; DataFile File of Extended; First, Final, Delta extended

  15. Computer-Aided Construction at Designing Reinforced Concrete Columns as Per Ec

    NASA Astrophysics Data System (ADS)

    Zielińska, M.; Grębowski, K.

    2015-02-01

    The article presents the authors' computer program for designing and dimensioning columns in reinforced concrete structures taking into account phenomena affecting their behaviour and information referring to design as per EC. The computer program was developed with the use of C++ programming language. The program guides the user through particular dimensioning stages: from introducing basic data such as dimensions, concrete class, reinforcing steel class and forces affecting the column, through calculating the creep coefficient taking into account the impact of imperfection depending on the support scheme and also the number of mating members at load shit, buckling length, to generating the interaction curve graph. The final result of calculations provides two dependence points calculated as per methods of nominal stiffness and nominal curvature. The location of those points relative to the limit curve determines whether the column load capacity is assured or has been exceeded. The content of the study describes in detail the operation of the computer program and the methodology and phenomena which are indispensable at designing axially and eccentrically the compressed members of reinforced concrete structures as per the European standards.

  16. Digital-Analog-Hybrid Neural Simulator: A Design-Aid For Custom-VLSI Neurochips

    NASA Astrophysics Data System (ADS)

    Moopenn, Alexander W.; Thakoor, Anilkumar P.; Duong, Tuan A.

    1989-05-01

    A high speed neural network simulator and its use for the dynamics and performance analysis of feedback neural architectures are described. The simulator is based on a semi-parallel, analog-digital hybrid architecture which utilizes digital memories to store synaptic weights and analog hardware for high speed computation. A breadboard system with 8-bit gray scale synapses, designed and built at JPL, is successfully serving as a valuable design test-bed for the development of fully parallel, analog, custom VLSI neurochips, currently underway at JPL. The breadboard hybrid simulator indeed allows a detailed evaluation of hardware potential and limitations in implementing full analog operations in such chips. As an example, the paper presents an analysis of the stability and convergence behavior of a feedback neural network applied to the "Concentrator Assignment Problem" in combinatorial optimization, as studied on the analog-digital hybrid simulator. This has already resulted in a VLSI custom design of a fully parallel, analog neuroprocessor with a powerful "analog prompting" feature, for the high-speed, multiparameter optimization function.

  17. Computer Aided Drug Design for Multi-Target Drug Design: SAR /QSAR, Molecular Docking and Pharmacophore Methods.

    PubMed

    Abdolmaleki, Azizeh; Ghasemi, Jahan B; Ghasemi, Fatemeh

    2017-01-01

    Multi-target drugs against particular multiple targets get better protection, resistance profiles and curative influence by cooperative rules of a key beneficial target with resistance behavior and compensatory elements. Computational techniques can assist us in the efforts to design novel drugs (ligands) with a preferred bioactivity outline and alternative bioactive molecules at an early stage. A number of in silico methods have been explored extensively in order to facilitate the investigation of individual target agents and to propose a selective drug. A different, progressively more significant field which is used to predict the bioactivity of chemical compounds is the data mining method. Some of the previously mentioned methods have been investigated for multi-target drug design (MTDD) to find drug leads interact simultaneously with multiple targets. Several cheminformatics methods and structure-based approaches try to extract information from units working cooperatively in a biomolecular system to fulfill their task. To dominate the difficulties of the experimental specification of ligand-target structures, rational methods, namely molecular docking, SAR and QSAR are vital substitutes to obtain knowledge for each structure in atomic insight. These procedures are logically successful for the prediction of binding affinity and have shown promising potential in facilitating MTDD. Here, we review some of the important features of the multi-target therapeutics discoveries using the computational approach, highlighting the SAR, QSAR, docking and pharmacophore methods to discover interactions between drug-target that could be leveraged for curative benefits. A summary of each, followed by examples of its applications in drug design has been provided. Computational efficiency of each method has been represented according to its main strengths and limitations.

  18. Computer-aided design and custom-made guide in corrective osteotomy for complex femoral deformity.

    PubMed

    Chai, Wei; Xu, Meng; Zhang, Guo-qiang; Zhang, Li-hai; Gou, Wen-long; Ni, Ming; Chen, Ji-ying

    2013-06-01

    Preoperative planning of corrective osteotomy with traditional radiography has limitations in regards to determining the ideal osteotomy location and orientation in three-dimensional femoral deformities. Though a successful operation can be planned preoperatively, intraoperative contingencies might adhere to the procedural plan in the performance of operation. To efficiently perform a planned procedure, proposed is a design to implement three-dimensional reconstruction photography, based on computer-tomography (CT) scan. A custom-made guide was designed to navigate the osteotomy as planned, and additionally, a personalized intramedullary nail was used for fixation after osteotomy. Three-dimensional (3D) photography of deformed femur was established based on the CT dataset and transferred into 3D photography processing software for further planning. Osteotomy planes were designed and adjusted at deformity sites to correct the 3D deformities. The methodology of a custom-made osteotomy guide was introduced in femoral corrective osteotomy, for the first time, to navigate the operation as planned. After the virtual osteotomy and reduction of bone segments, the parameters of a custom-made intramedullary nail were measured for manufacturing. Findings Virtual operation in computer shows complete correction of the 3D deformity. The osteotomy guide, obtained by rapid-prototyping techniques, navigates mimicking surgery on rapid-prototyping model of the involved femur as planned. Internal fixation was achieved using the custom-made intramedullary nail. Interpretation three-dimensional visualization introduces an advantage in preoperative planning for corrective osteotomy of 3D femoral deformity, and the custom-made osteotomy guide is crucial to realize such a deliberate plan during the actual procedures. The internal fixator, such as an intramedullary nail, can be modified or personalized for fixation in unique cases.

  19. Recent developments in the design of specific Matrix Metalloproteinase inhibitors aided by structural and computational studies.

    PubMed

    Rao, B Govinda

    2005-01-01

    It has been 10 years since a 3-dimensional structure of the catalytic domain of a Matrix Metalloprotease (MMP) was revealed for the first time in 1994. More than 80 structures of different MMPs in apo and inhibited forms, determined by X-ray crystallography and NMR methods, have been published by the end of year 2003. A large number of very potent inhibitors have been disclosed in published and patent literature. Several MMP inhibitors entered clinical trials for the treatment of cancer and arthritis. Most of the first generation inhibitors have hydroxamic acid as the Zinc-binding group and have limited specificity. With the failure of these inhibitors in clinical trials, more efforts have been directed to the design of specific inhibitors with different Zn-binding groups in recent years. This review will summarize all the published structural information and focus on the inhibitors that were designed to take advantage of the nonprime side of the MMP active site using structural information and computational analysis. Representative structures from all MMPs are aligned to a target structure to provide a better understanding of the similarities and differences of the active site pockets. This analysis supports the view that the differences in the nonprime side pockets provide better opportunities for designing inhibitors with higher specificity. Published information on all the Zinc-binding groups of MMP inhibitors is reviewed for the first time. Pros and cons of inhibitors with non-hydroxamate Zinc-binding groups in terms of specificity, toxicity and pharmacokinetic properties are discussed.

  20. Biomimicry in Product Design through Materials Selection and Computer Aided Engineering

    NASA Astrophysics Data System (ADS)

    Alexandridis, G.; Tzetzis, D.; Kyratsis, P.

    2016-11-01

    The aim of this study is to demonstrate a 7-step methodology that describes the way nature can act as a source of inspiration for the design and the development of a product. Furthermore, it suggests special computerized tools and methods for the product optimization regarding its environmental impact i.e. material selection, production methods. For validation purposes, a garden chaise lounge that imitates the form of a scorpion was developed as a result for the case study and the presentation of the current methodology.

  1. Development of structural element precedent of technological process in computer-aided design

    NASA Astrophysics Data System (ADS)

    Simonova, L. A.; Egorova, E. I.

    2015-06-01

    Based on the methodology of building of the intelligent system of TP design, a new approach to the transformation of information on structural and technological characteristics of the part and of 3D part model and representation of it in the form of elementary constructive modules structural units of a surface to form automatically alternative TP variants on a complex of qualitative and quantitative criteria. Each constructive surface module is represented in the database of module CAM of the intelligent system for constructing TP with records of all possible transitions.

  2. Computer-aided design of carbon nanotubes with the desired bioactivity and safety profiles.

    PubMed

    Fourches, Denis; Pu, Dongqiuye; Li, Liwen; Zhou, Hongyu; Mu, Qingxin; Su, Gaoxing; Yan, Bing; Tropsha, Alexander

    2016-01-01

    Growing experimental evidences suggest the existence of direct relationships between the surface chemistry of nanomaterials and their biological effects. Herein, we have employed computational approaches to design a set of biologically active carbon nanotubes (CNTs) with controlled protein binding and cytotoxicity. Quantitative structure-activity relationship (QSAR) models were built and validated using a dataset of 83 surface-modified CNTs. A subset of a combinatorial virtual library of 240 000 ligands potentially attachable to CNTs was selected to include molecules that were within the chemical similarity threshold with respect to the modeling set compounds. QSAR models were then employed to virtually screen this subset and prioritize CNTs for chemical synthesis and biological evaluation. Ten putatively active and 10 putatively inactive CNTs decorated with the ligands prioritized by virtual screening for either protein-binding or cytotoxicity assay were synthesized and tested. We found that all 10 putatively inactive and 7 of 10 putatively active CNTs were confirmed in the protein-binding assay, whereas all 10 putatively inactive and 6 of 10 putatively active CNTs were confirmed in the cytotoxicity assay. This proof-of-concept study shows that computational models can be employed to guide the design of surface-modified nanomaterials with the desired biological and safety profiles.

  3. Computer-Aided Design of Carbon Nanotubes with the Desired Bioactivity and Safety Profiles

    PubMed Central

    Fourches, Denis; Pu, Dongqiuye; Li, Liwen; Zhou, Hongyu; Mu, Qingxin; Su, Gaoxing; Yan, Bing; Tropsha, Alexander

    2016-01-01

    Growing experimental evidences suggest the existence of direct relationships between the surface chemistry of nanomaterials and their biological effects. Herein, we have employed computational approaches to design a set of biologically active Carbon Nanotubes (CNTs) with controlled protein binding and cytotoxicity. Quantitative Structure-Activity Relationships (QSAR) models were built and validated using a dataset of 83 surface-modified CNTs. A subset of a combinatorial virtual library of 240,000 ligands potentially attachable to CNTs was selected to include molecules that were within the chemical similarity threshold with respect to the modeling set compounds. QSAR models were then employed to virtually screen this subset and prioritize CNTs for chemical synthesis and biological evaluation. Ten putatively active and ten putatively inactive CNTs decorated with the ligands prioritized by virtual screening for either protein binding or cytotoxicity assays were synthesized and tested. We found that all 10 putatively inactive and 7 out of 10 putatively active CNTs were confirmed in the protein binding assay, whereas all 10 putatively inactive and 6 out of 10 putatively active CNTs were confirmed in the cytotoxicity assay. This proof-of-concept study shows that computational models can be employed to guide the design of surface-modified nanomaterials with the desired biological and safety profiles. PMID:26525350

  4. Computer-aided designing of immunosuppressive peptides based on IL-10 inducing potential

    PubMed Central

    Nagpal, Gandharva; Usmani, Salman Sadullah; Dhanda, Sandeep Kumar; Kaur, Harpreet; Singh, Sandeep; Sharma, Meenu; Raghava, Gajendra P. S.

    2017-01-01

    In the past, numerous methods have been developed to predict MHC class II binders or T-helper epitopes for designing the epitope-based vaccines against pathogens. In contrast, limited attempts have been made to develop methods for predicting T-helper epitopes/peptides that can induce a specific type of cytokine. This paper describes a method, developed for predicting interleukin-10 (IL-10) inducing peptides, a cytokine responsible for suppressing the immune system. All models were trained and tested on experimentally validated 394 IL-10 inducing and 848 non-inducing peptides. It was observed that certain types of residues and motifs are more frequent in IL-10 inducing peptides than in non-inducing peptides. Based on this analysis, we developed composition-based models using various machine-learning techniques. Random Forest-based model achieved the maximum Matthews’s Correlation Coefficient (MCC) value of 0.59 with an accuracy of 81.24% developed using dipeptide composition. In order to facilitate the community, we developed a web server “IL-10pred”, standalone packages and a mobile app for designing IL-10 inducing peptides (http://crdd.osdd.net/raghava/IL-10pred/). PMID:28211521

  5. Modified optimal control pilot model for computer-aided design and analysis

    NASA Technical Reports Server (NTRS)

    Davidson, John B.; Schmidt, David K.

    1992-01-01

    This paper presents the theoretical development of a modified optimal control pilot model based upon the optimal control model (OCM) of the human operator developed by Kleinman, Baron, and Levison. This model is input compatible with the OCM and retains other key aspects of the OCM, such as a linear quadratic solution for the pilot gains with inclusion of control rate in the cost function, a Kalman estimator, and the ability to account for attention allocation and perception threshold effects. An algorithm designed for each implementation in current dynamic systems analysis and design software is presented. Example results based upon the analysis of a tracking task using three basic dynamic systems are compared with measured results and with similar analyses performed with the OCM and two previously proposed simplified optimal pilot models. The pilot frequency responses and error statistics obtained with this modified optimal control model are shown to compare more favorably to the measured experimental results than the other previously proposed simplified models evaluated.

  6. Simplified Evaluation Method of Drive Characteristics for Computer-Aided Design of Switched Reluctance Motors

    NASA Astrophysics Data System (ADS)

    Kano, Yoshiaki; Fubuki, Shingo; Kosaka, Takashi; Matsui, Nobuyuki

    Since Switched Reluctance Motors (SRM) have simple and rugged construction, they are suitable for low-cost variable speed drives in many industrial applications. However, it is rather difficult to design the motor and to predict the drive performance because of high magnetic non-linearity of the motors. Although FEM is useful for the SRM design, one of disadvantages is a long computation time. This paper proposes a simplified and fast evaluation method of the drive characteristics of SRM whose dimensions are given. The proposed method is composed of an analytical expression of magnetizing curvebased modeling approach and a simple non-linear magnetic analysis. At first, the comparative studies using 12/8 SRM show that the calculated current waveform and stiffness characteristic of the proposed modeling approach are in good agreement with those of experiment. Secondly, it is shown that the proposed magnetic analysis provides accurate and extremely fast magnetizing curves computation for the given motor dimensions compared to 3D-FEM. From the standpoints of analytical accuracy and the required computation time, the effectiveness of the proposed method is verified through the comparisons with 3D-FEM using two SRMs with different specifications.

  7. Development of an empirical model to aid in designing airborne infection isolation rooms.

    PubMed

    Hayden, Charles S; Earnest, G Scott; Jensen, Paul A

    2007-03-01

    Airborne infection isolation rooms (AIIRs) house patients with tuberculosis, severe acute respiratory syndrome (SARS), and many other airborne infectious diseases. Currently, facility engineers and designers of heating, ventilation, and air-conditioning (HVAC) systems have few analytical tools to estimate a room's leakage area and establish an appropriate flow differential (DeltaQ) in hospitals, shelters, and other facilities where communicable diseases are present. An accurate estimate of leakage area and selection of DeltaQ is essential for ensuring that there is negative pressure (i.e., pressure differential [DeltaP]) between an AIIR and adjoining areas. National Institute for Occupational Safety and Health (NIOSH) researchers evaluated the relationship between DeltaQ and DeltaP in 67 AIIRs across the United States and in simulated AIIR. Data gathered in the simulated AIIR was used to develop an empirical model describing the relationship between DeltaQ, DeltaP, and leakage area. Data collected in health care facilities showed that the model accurately predicted the leakage area 44 of 48 times. Statistical analysis of the model and experimental validation showed that the model effectively estimated the actual leakage area from -39% to +22% with 90% confidence. The NIOSH model is an effective, cost-cutting tool that can be used by HVAC engineers and designers to estimate leakage area and select an appropriate DeltaQ in AIIRs to reduce the airborne transmission of disease.

  8. Computer-Aided Design of Materials for use under High Temperature Operating Condition

    SciTech Connect

    Rajagopal, K. R.; Rao, I. J.

    2010-01-31

    The procedures in place for producing materials in order to optimize their performance with respect to creep characteristics, oxidation resistance, elevation of melting point, thermal and electrical conductivity and other thermal and electrical properties are essentially trial and error experimentation that tend to be tremendously time consuming and expensive. A computational approach has been developed that can replace the trial and error procedures in order that one can efficiently design and engineer materials based on the application in question can lead to enhanced performance of the material, significant decrease in costs and cut down the time necessary to produce such materials. The work has relevance to the design and manufacture of turbine blades operating at high operating temperature, development of armor and missiles heads; corrosion resistant tanks and containers, better conductors of electricity, and the numerous other applications that are envisaged for specially structured nanocrystalline solids. A robust thermodynamic framework is developed within which the computational approach is developed. The procedure takes into account microstructural features such as the dislocation density, lattice mismatch, stacking faults, volume fractions of inclusions, interfacial area, etc. A robust model for single crystal superalloys that takes into account the microstructure of the alloy within the context of a continuum model is developed. Having developed the model, we then implement in a computational scheme using the software ABAQUS/STANDARD. The results of the simulation are compared against experimental data in realistic geometries.

  9. A New Era for Cancer Target Therapies: Applying Systems Biology and Computer-Aided Drug Design to Cancer Therapies.

    PubMed

    Wong, Yung-Hao; Chiu, Chia-Chiun; Lin, Chih-Lung; Chen, Ting-Shou; Jheng, Bo-Ren; Lee, Yu-Ching; Chen, Jeremy; Chen, Bor-Sen

    In recent years, many systems biology approaches have been used with various cancers. The materials described here can be used to build bases to discover novel cancer therapy targets in connection with computer-aided drug design (CADD). A deeper understanding of the mechanisms of cancer will provide more choices and correct strategies in the development of multiple target drug therapies, which is quite different from the traditional cancer single target therapy. Targeted therapy is one of the most powerful strategies against cancer and can also be applied to other diseases. Due to the large amount of progress in computer hardware and the theories of computational chemistry and physics, CADD has been the main strategy for developing novel drugs for cancer therapy. In contrast to traditional single target therapies, in this review we will emphasize the future direction of the field, i.e., multiple target therapies. Structure-based and ligand-based drug designs are the two main topics of CADD. The former needs both 3D protein structures and ligand structures, while the latter only needs ligand structures. Ordinarily it is estimated to take more than 14 years and 800 million dollars to develop a new drug. Many new CADD software programs and techniques have been developed in recent decades. We conclude with an example where we combined and applied systems biology and CADD to the core networks of four cancers and successfully developed a novel cocktail for drug therapy that treats multiple targets.

  10. A computational pipeline for identifying kinetic motifs to aid in the design and improvement of synthetic gene circuits

    PubMed Central

    2013-01-01

    Background An increasing number of genetic components are available in several depositories of such components to facilitate synthetic biology research, but picking out those that will allow a designed circuit to achieve the specified function still requires multiple cycles of testing. Here, we addressed this problem by developing a computational pipeline to mathematically simulate a gene circuit for a comprehensive range and combination of the kinetic parameters of the biological components that constitute the gene circuit. Results We showed that, using a well-studied transcriptional repression cascade as an example, the sets of kinetic parameters that could produce the specified system dynamics of the gene circuit formed clusters of recurrent combinations, referred to as kinetic motifs, which appear to be associated with both the specific topology and specified dynamics of the circuit. Furthermore, the use of the resulting "handbook" of performance-ranked kinetic motifs in finding suitable circuit components was illustrated in two application scenarios. Conclusions These results show that the computational pipeline developed here can provide a rational-based guide to aid in the design and improvement of synthetic gene circuits. PMID:24564638

  11. Design and development of a decision aid to enhance shared decision making by patients with an asymptomatic abdominal aortic aneurysm

    PubMed Central

    Ubbink, Dirk T; Knops, Anouk M; Molenaar, Sjaak; Goossens, Astrid

    2008-01-01

    Objective To design, develop, and evaluate an evidence-based decision aid (DA) for patients with an asymptomatic abdominal aortic aneurysm (AAA) to inform them about the pros and cons of their treatment options (ie, surgery or watchful observation) and to help them make a shared decision. Methods A multidisciplinary team defined criteria for the desired DA as to design, medical content and functionality, particularly for elderly users. Development was according to the international standard (IPDAS). Fifteen patients with an AAA, who were either treated or not yet treated, evaluated the tool. Results A DA was developed to offer information about the disease, the risks and benefits of surgical treatment and watchful observation, and the individual possibilities and threats based on the patient’s aneurysm diameter and risk profile. The DA was improved and judged favorably by physicians and patients. Conclusion This evidence-based DA for AAA patients, developed according to IPDAS criteria, is likely to be a simple, user-friendly tool to offer patients evidence-based information about the pros and cons of treatment options for AAA, to improve patients’ understanding of the disease and treatment options, and may support decision making based on individual values. PMID:19920978

  12. HIV / AIDS

    MedlinePlus

    ... facebook share with twitter share with linkedin HIV/AIDS HIV, or human immunodeficiency virus, is the virus ... HIV/AIDS. Why Is the Study of HIV/AIDS a Priority for NIAID? Nearly 37 million people ...

  13. Hearing Aids

    MedlinePlus

    ... and Consumer Devices Consumer Products Hearing Aids Hearing Aids Share Tweet Linkedin Pin it More sharing options ... to restrict your daily activities. Properly fitted hearing aids and aural rehabilitation (techniques used to identify and ...

  14. Hearing Aids

    MedlinePlus

    ... Surgery? A Week of Healthy Breakfasts Shyness Hearing Aids KidsHealth > For Teens > Hearing Aids Print A A ... with certain types of hearing loss. How Hearing Aids Help So you went to audiologist and found ...

  15. Aerodynamic heating and surface temperatures on vehicles for computer-aided design studies

    NASA Technical Reports Server (NTRS)

    Dejarnette, F. R.; Kania, L. A.; Chitty, A.

    1983-01-01

    A computer subprogram has been developed to calculate aerodynamic and radiative heating rates and to determine surface temperatures by integrating the heating rates along the trajectory of a vehicle. Convective heating rates are calculated by applying the axisymmetric analogue to inviscid surface streamlines and using relatively simple techniques to calculate laminar, transitional, or turbulent heating rates. Options are provided for the selection of gas model, transition criterion, turbulent heating method, Reynolds Analogy factor, and entropy-layer swallowing effects. Heating rates are compared to experimental data, and the time history of surface temperatures are given for a high-speed trajectory. The computer subprogram is developed for preliminary design and mission analysis where parametric studies are needed at all speeds.

  16. Data Mining-Aided Crystal Engineering for the Design of Transparent Conducting Oxides: Preprint

    SciTech Connect

    Suh, C.; Kim, K.; Berry, J. J.; Lee, J.; Jones, W. B.

    2010-12-01

    The purpose of this paper is to accelerate the pace of material discovery processes by systematically visualizing the huge search space that conventionally needs to be explored. To this end, we demonstrate not only the use of empirical- or crystal chemistry-based physical intuition for decision-making, but also to utilize knowledge-based data mining methodologies in the context of finding p-type delafossite transparent conducting oxides (TCOs). We report on examples using high-dimensional visualizations such as radial visualization combined with machine learning algorithms such as k-nearest neighbor algorithm (k-NN) to better define and visualize the search space (i.e. structure maps) of functional materials design. The vital role of search space generated from these approaches is discussed in the context of crystal chemistry of delafossite crystal structure.

  17. Building a computer-aided design capability using a standard time share operating system

    NASA Technical Reports Server (NTRS)

    Sobieszczanski, J.

    1975-01-01

    The paper describes how an integrated system of engineering computer programs can be built using a standard commercially available operating system. The discussion opens with an outline of the auxiliary functions that an operating system can perform for a team of engineers involved in a large and complex task. An example of a specific integrated system is provided to explain how the standard operating system features can be used to organize the programs into a simple and inexpensive but effective system. Applications to an aircraft structural design study are discussed to illustrate the use of an integrated system as a flexible and efficient engineering tool. The discussion concludes with an engineer's assessment of an operating system's capabilities and desirable improvements.

  18. Table-aided design of the energy-storage reactor in dc-to-dc converters

    NASA Technical Reports Server (NTRS)

    Owen, H. A., Jr.

    1975-01-01

    A new procedure for the selection of magnetic cores for use in energy-storage dc-to-dc power converters which eliminates the need for an automated computer search algorithm and stored data file is presented. The converter configurations included in the procedure are the three commonly encountered single-winding converters for voltage step-up, for current step-up and for voltage step-up/current step-up, and for the two-winding converter for voltage step-up/current step-up. For each converter configuration, three types of controllers are considered - constant-frequency, constant on-time and constant off-time. Using concepts developed from analyses of these converters by considering the transfer of energy by means of an energy-storage inductor or transformer, a special table of parameters calculated from magnetic core data is constructed and leads to a considerably simplified design procedure.

  19. A Pilot Computer-Aided Design and Manufacturing Curriculum that Promotes Engineering

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Elizabeth City State University (ECSU) is located in a community that is mostly rural in nature. The area is economically deprived when compared to the rest of the state. Many businesses lack the computerized equipment and skills needed to propel upward in today's technologically advanced society. This project will close the ever-widening gap between advantaged and disadvantaged workers as well as increase their participation with industry, NASA and/or other governmental agencies. Everyone recognizes computer technology as the catalyst for advances in design, prototyping, and manufacturing or the art of machining. Unprecedented quality control and cost-efficiency improvements are recognized through the use of computer technology. This technology has changed the manufacturing industry with advanced high-tech capabilities needed by NASA. With the ever-widening digital divide, we must continue to provide computer technology to those who are socio-economically disadvantaged.

  20. Pharmacological Targeting of AMP-Activated Protein Kinase and Opportunities for Computer-Aided Drug Design.

    PubMed

    Miglianico, Marie; Nicolaes, Gerry A F; Neumann, Dietbert

    2016-04-14

    As a central regulator of metabolism, the AMP-activated protein kinase (AMPK) is an established therapeutic target for metabolic diseases. Beyond the metabolic area, the number of medical fields that involve AMPK grows continuously, expanding the potential applications for AMPK modulators. Even though indirect AMPK activators are used in the clinics for their beneficial metabolic outcome, the few described direct agonists all failed to reach the market to date, which leaves options open for novel targeting methods. As AMPK is not actually a single molecule and has different roles depending on its isoform composition, the opportunity for isoform-specific targeting has notably come forward, but the currently available modulators fall short of expectations. In this review, we argue that with the amount of available structural and ligand data, computer-based drug design offers a number of opportunities to undertake novel and isoform-specific targeting of AMPK.