Science.gov

Sample records for modular linear drive

  1. Modular droplet actuator drive

    NASA Technical Reports Server (NTRS)

    Pollack, Michael G. (Inventor); Paik, Philip (Inventor)

    2011-01-01

    A droplet actuator drive including a detection apparatus for sensing a property of a droplet on a droplet actuator; circuitry for controlling the detection apparatus electronically coupled to the detection apparatus; a droplet actuator cartridge connector arranged so that when a droplet actuator cartridge electronically is coupled thereto: the droplet actuator cartridge is aligned with the detection apparatus; and the detection apparatus can sense the property of the droplet on a droplet actuator; circuitry for controlling a droplet actuator coupled to the droplet actuator connector; and the droplet actuator circuitry may be coupled to a processor.

  2. Linear Back-Drive Differentials

    NASA Technical Reports Server (NTRS)

    Waydo, Peter

    2003-01-01

    Linear back-drive differentials have been proposed as alternatives to conventional gear differentials for applications in which there is only limited rotational motion (e.g., oscillation). The finite nature of the rotation makes it possible to optimize a linear back-drive differential in ways that would not be possible for gear differentials or other differentials that are required to be capable of unlimited rotation. As a result, relative to gear differentials, linear back-drive differentials could be more compact and less massive, could contain fewer complex parts, and could be less sensitive to variations in the viscosities of lubricants. Linear back-drive differentials would operate according to established principles of power ball screws and linear-motion drives, but would utilize these principles in an innovative way. One major characteristic of such mechanisms that would be exploited in linear back-drive differentials is the possibility of designing them to drive or back-drive with similar efficiency and energy input: in other words, such a mechanism can be designed so that a rotating screw can drive a nut linearly or the linear motion of the nut can cause the screw to rotate. A linear back-drive differential (see figure) would include two collinear shafts connected to two parts that are intended to engage in limited opposing rotations. The linear back-drive differential would also include a nut that would be free to translate along its axis but not to rotate. The inner surface of the nut would be right-hand threaded at one end and left-hand threaded at the opposite end to engage corresponding right- and left-handed threads on the shafts. A rotation and torque introduced into the system via one shaft would drive the nut in linear motion. The nut, in turn, would back-drive the other shaft, creating a reaction torque. Balls would reduce friction, making it possible for the shaft/nut coupling on each side to operate with 90 percent efficiency.

  3. Modular PM Motor Drives for Automotive Traction Applications

    SciTech Connect

    Su, G.J.

    2001-10-29

    This paper presents modular permanent magnet (PM) motor drives for automotive traction applications. A partially modularized drive system consisting of a single PM motor and multiple inverters is described. The motor has multiple three-phase stator winding sets and each winding set is driven with a separate three-phase inverter module. A truly modularized inverter and motor configuration based on an axial-gap PM motor is then introduced, in which identical PM motor modules are mounted on a common shaft and each motor module is powered by a separate inverter module. The advantages of the modular approach for both inverter and motor include: (1) power rating scalability--one design meets different power requirements by simply stacking an adequate number of modules, thus avoiding redesigning and reducing the development cost, (2) increased fault tolerance, and (3) easy repairing. A prototype was constructed by using two inverters and an axial-gap PM motor with two sets of three-phase stat or windings, and it is used to assist the diesel engine in a hybrid electric vehicle converted from a Chevrolet Suburban. The effect of different pulse-width-modulation strategies for both motoring and regenerative modes on current control is analyzed. Torque and regenerative control algorithms are implemented with a digital signal processor. Analytical and initial testing results are included in the paper.

  4. Affine Vertex Operator Algebras and Modular Linear Differential Equations

    NASA Astrophysics Data System (ADS)

    Arike, Yusuke; Kaneko, Masanobu; Nagatomo, Kiyokazu; Sakai, Yuichi

    2016-05-01

    In this paper, we list all affine vertex operator algebras of positive integral levels whose dimensions of spaces of characters are at most 5 and show that a basis of the space of characters of each affine vertex operator algebra in the list gives a fundamental system of solutions of a modular linear differential equation. Further, we determine the dimensions of the spaces of characters of affine vertex operator algebras whose numbers of inequivalent simple modules are not exceeding 20.

  5. Can computational efficiency alone drive the evolution of modularity in neural networks?

    PubMed Central

    Tosh, Colin R.

    2016-01-01

    Some biologists have abandoned the idea that computational efficiency in processing multipart tasks or input sets alone drives the evolution of modularity in biological networks. A recent study confirmed that small modular (neural) networks are relatively computationally-inefficient but large modular networks are slightly more efficient than non-modular ones. The present study determines whether these efficiency advantages with network size can drive the evolution of modularity in networks whose connective architecture can evolve. The answer is no, but the reason why is interesting. All simulations (run in a wide variety of parameter states) involving gradualistic connective evolution end in non-modular local attractors. Thus while a high performance modular attractor exists, such regions cannot be reached by gradualistic evolution. Non-gradualistic evolutionary simulations in which multi-modularity is obtained through duplication of existing architecture appear viable. Fundamentally, this study indicates that computational efficiency alone does not drive the evolution of modularity, even in large biological networks, but it may still be a viable mechanism when networks evolve by non-gradualistic means. PMID:27573614

  6. Proceedings of the international conference on maglev and linear drives

    SciTech Connect

    Not Available

    1986-01-01

    This book contains papers presented at a conference on Maglev and linear drives. Topics covered include: Development of superconducting magnets for the Canadian electrodynamic Maglev vehicle; Power supply system to drive HSST - Expo '86; and Thrust and levitation force characteristics of linear synchronous motors.

  7. Split-Stirling-cycle displacer linear-electric drive

    NASA Technical Reports Server (NTRS)

    Ackermann, R. A.; Bhate, S. K.; Byrne, D. V.

    1983-01-01

    The retrofit of a 1/4-W split-Stirling cooler with a linear driven on the displacer was achieved and its performance characterized. The objective of this work was to demonstrate that a small linear motor could be designed to meet the existing envelope specifications of the cooler and that an electric linear drive on the displacer could improve the cooler's reliability and performance. The paper describes the characteristics of this motor and presents cooler test results.

  8. High reliability linear drive device for artificial hearts

    NASA Astrophysics Data System (ADS)

    Ji, Jinghua; Zhao, Wenxiang; Liu, Guohai; Shen, Yue; Wang, Fangqun

    2012-04-01

    In this paper, a new high reliability linear drive device, termed as stator-permanent-magnet tubular oscillating actuator (SPM-TOA), is proposed for artificial hearts (AHs). The key is to incorporate the concept of two independent phases into this linear AH device, hence achieving high reliability operation. The fault-tolerant teeth are employed to provide the desired decoupling phases in magnetic circuit. Also, as the magnets and the coils are located in the stator, the proposed SPM-TOA takes the definite advantages of robust mover and direct-drive capability. By using the time-stepping finite element method, the electromagnetic characteristics of the proposed SPM-TOA are analyzed, including magnetic field distributions, flux linkages, back- electromotive forces (back-EMFs) self- and mutual inductances, as well as cogging and thrust forces. The results confirm that the proposed SPM-TOA meets the dimension, weight, and force requirements of the AH drive device.

  9. An open source 3-d printed modular micro-drive system for acute neurophysiology.

    PubMed

    Patel, Shaun R; Ghose, Kaushik; Eskandar, Emad N

    2014-01-01

    Current, commercial, electrode micro-drives that allow independent positioning of multiple electrodes are expensive. Custom designed solutions developed by individual laboratories require fabrication by experienced machinists working in well equipped machine shops and are therefore difficult to disseminate into widespread use. Here, we present an easy to assemble modular micro-drive system for acute primate neurophysiology (PriED) that utilizes rapid prototyping (3-d printing) and readily available off the shelf-parts. The use of 3-d printed parts drastically reduces the cost of the device, making it available to labs without the resources of sophisticated machine shops. The direct transfer of designs from electronic files to physical parts also gives researchers opportunities to easily modify and implement custom solutions to specific recording needs. We also demonstrate a novel model of data sharing for the scientific community: a publicly available repository of drive designs. Researchers can download the drive part designs from the repository, print, assemble and then use the drives. Importantly, users can upload their modified designs with annotations making them easily available for others to use. PMID:24736691

  10. An Open Source 3-D Printed Modular Micro-Drive System for Acute Neurophysiology

    PubMed Central

    Eskandar, Emad N.

    2014-01-01

    Current, commercial, electrode micro-drives that allow independent positioning of multiple electrodes are expensive. Custom designed solutions developed by individual laboratories require fabrication by experienced machinists working in well equipped machine shops and are therefore difficult to disseminate into widespread use. Here, we present an easy to assemble modular micro-drive system for acute primate neurophysiology (PriED) that utilizes rapid prototyping (3-d printing) and readily available off the shelf-parts. The use of 3-d printed parts drastically reduces the cost of the device, making it available to labs without the resources of sophisticated machine shops. The direct transfer of designs from electronic files to physical parts also gives researchers opportunities to easily modify and implement custom solutions to specific recording needs. We also demonstrate a novel model of data sharing for the scientific community: a publicly available repository of drive designs. Researchers can download the drive part designs from the repository, print, assemble and then use the drives. Importantly, users can upload their modified designs with annotations making them easily available for others to use. PMID:24736691

  11. General Linear Rf-Current Drive Calculation in Toroidal Plasma

    NASA Astrophysics Data System (ADS)

    Smirnov, A. P.; Harvey, R. W.; Prater, R.

    2009-04-01

    A new general linear calculation of RF current drive has been implemented in the GENRAY all-frequencies RF ray tracing code. This is referred to as the ADJ-QL package, and is based on the Karney, et al. [1] relativistic Green function calculator, ADJ, generalized to non-circular plasmas in toroidal geometry, and coupled with full, bounce-averaged momentum-space RF quasilinear flux [2] expressions calculated at each point along the RF ray trajectories. This approach includes momentum conservation, polarization effects and the influence of trapped electrons. It is assumed that the electron distribution function remains close to a relativistic Maxwellian function. Within the bounds of these assumptions, small banana width, toroidal geometry and low collisionality, the calculation is applicable for all-frequencies RF electron current drive including electron cyclotron, lower hybrid, fast waves and electron Bernstein waves. GENRAY ADJ-QL calculations of the relativistic momentum-conserving current drive have been applied in several cases: benchmarking of electron cyclotron current drive in ITER against other code results; and electron Bernstein and high harmonic fast wave current drive in NSTX. The impacts of momentum conservation on the current drive are also shown for these cases.

  12. Pulsatile blood pump with a linear drive actuator.

    PubMed

    Fukunaga, Kazuyoshi; Homma, Akihiko; Funakubo, Akio; Tatsumi, Eisuke; Taenaka, Yoshiyuki; Kitamura, Soichiro; Fukui, Yasuhiro

    2007-01-01

    The main purpose of this study was to develop an implantable direct-electromagnetic left ventricular assist system driven by a linear actuator (linear LVAS). The linear LVAS is a pulsatile pump with a pusher plate that is driven directly by a linear oscillatory actuator (LOA) without any movement converters. This prototype pump unit with a LOA was 100 mm in diameter, 50 mm in thickness, and weighed 740 g. The full-fill/full-eject driving method was applied to the control algorithm. In addition, a mechanism to detect and release sucking was realized to overcome this problem that accompanies the active-filling type of VAS. The performance of the linear LVAS was evaluated in a long-term animal experiment using a goat (56 kg). The goat survived for 42 days. The reason why we terminated this experiment was that thrombus was found in the pump. There was no frictional debris found around the LOA. The linear LVAS did not exhibit electrical or mechanical problems during the first animal experiment. PMID:17574509

  13. Linear micromechanical stepping drive for pinhole array positioning

    NASA Astrophysics Data System (ADS)

    Endrödy, Csaba; Mehner, Hannes; Grewe, Adrian; Hoffmann, Martin

    2015-05-01

    A compact linear micromechanical stepping drive for positioning a 7 × 5.5 mm2 optical pinhole array is presented. The system features a step size of 13.2 µm and a full displacement range of 200 µm. The electrostatic inch-worm stepping mechanism shows a compact design capable of positioning a payload 50% of its own weight. The stepping drive movement, step sizes and position accuracy are characterized. The actuated pinhole array is integrated in a confocal chromatic hyperspectral imaging system, where coverage of the object plane, and therefore the useful picture data, can be multiplied by 14 in contrast to a non-actuated array.

  14. Oscillating-Linear-Drive Vacuum Compressor for CO2

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Shimko, Martin

    2005-01-01

    A vacuum compressor has been designed to compress CO2 from approximately equal to 1 psia (approximately equal to 6.9 kPa absolute pressure) to approximately equal to 75 psia (approximately equal to 0.52 MPa), to be insensitive to moisture, to have a long operational life, and to be lightweight, compact, and efficient. The compressor consists mainly of (1) a compression head that includes hydraulic diaphragms, a gas-compression diaphragm, and check valves; and (2) oscillating linear drive that includes a linear motor and a drive spring, through which compression force is applied to the hydraulic diaphragms. The motor is driven at the resonance vibrational frequency of the motor/spring/compression-head system, the compression head acting as a damper that takes energy out of the oscillation. The net effect of the oscillation is to cause cyclic expansion and contraction of the gas-compression diaphragm, and, hence, of the volume bounded by this diaphragm. One-way check valves admit gas into this volume from the low-pressure side during expansion and allow the gas to flow out to the high-pressure side during contraction. Fatigue data and the results of diaphragm stress calculations have been interpreted as signifying that the compressor can be expected to have an operational life of greater than 30 years with a confidence level of 99.9 percent.

  15. Non-Linear Analysis of the Modular Coil Windings for the National Compact Stellarator Experiment

    SciTech Connect

    Freudenberg, K.D.; Williamson, D.E.; Fan, H.M.; Myatt, L

    2005-05-15

    A non linear FEA study has been performed on the modular coils of the National Compact Stellarator Experiment (NCSX). The modular coils provide the primary magnetic field within NCSX and consist of flexible cable conductor wound on a cast and machined winding form and vacuum impregnated with epoxy. Eighteen coils and associated winding forms are connected at assembly into a toroidal shell structure. The purpose of this study was to evaluate the structural response of the windings and shell structure during cooldown and normal operation. Two separate software packages were used for the study, and two independent analyses were undertaken. The first analysis performed with Pro/Mechanica, examined both the response of the modular coils to magnetic pressure and thermal effects during a 2 Tesla pulse. Modeled items included a portion of the shell structure the winding packs, and a set of 48 'pseudo clamps'. The so called 'pseudo clamps' are represented simply by blocks of material that are restrained in their respective normal directions and have properties which mimic the stiffness of the spring washers of the actual preload clamps. The winding pack is free to slide on the shell structure and is restrained only by the clamps. A second model, including the complete shell structure of all three coils, was studied with the FEA program ANSYS. Contact regions defined in both Pro/Mechanica and Ansys allow the winding to slide and detach form the shell structure. The two analyses are compared for parameters such as winding/structure gap, overall displacement, equivalent stress and principle strain values.

  16. Directional selection can drive the evolution of modularity in complex traits

    PubMed Central

    Melo, Diogo; Marroig, Gabriel

    2015-01-01

    Modularity is a central concept in modern biology, providing a powerful framework for the study of living organisms on many organizational levels. Two central and related questions can be posed in regard to modularity: How does modularity appear in the first place, and what forces are responsible for keeping and/or changing modular patterns? We approached these questions using a quantitative genetics simulation framework, building on previous results obtained with bivariate systems and extending them to multivariate systems. We developed an individual-based model capable of simulating many traits controlled by many loci with variable pleiotropic relations between them, expressed in populations subject to mutation, recombination, drift, and selection. We used this model to study the problem of the emergence of modularity, and hereby show that drift and stabilizing selection are inefficient at creating modular variational structures. We also demonstrate that directional selection can have marked effects on the modular structure between traits, actively promoting a restructuring of genetic variation in the selected population and potentially facilitating the response to selection. Furthermore, we give examples of complex covariation created by simple regimes of combined directional and stabilizing selection and show that stabilizing selection is important in the maintenance of established covariation patterns. Our results are in full agreement with previous results for two-trait systems and further extend them to include scenarios of greater complexity. Finally, we discuss the evolutionary consequences of modular patterns being molded by directional selection. PMID:25548154

  17. A Medium-Voltage Motor Drive with a Modular Multilevel PWM Inverter Part II. Startup Method and Performance

    NASA Astrophysics Data System (ADS)

    Nishimura, Kazutoshi; Hagiwara, Makoto; Akagi, Hirofumi

    This paper presents a medium-voltage motor drive with a modular multilevel PWM inverter, and focuses on a startup method and its performance. It is formed by six modular arms, each of which consists of a cascaded stack of multiple bidirectional chopper-cells. The frequency of the dominant ac-voltage fluctuation is equal to the motor (inverter) frequency. These fluctuations occur in the dc capacitor of each chopper-cell, and the magnitude of the fluctuation is inversely proportional to the motor frequency. Because of the increased voltage fluctuation in low-frequency regions, the so-called “volt-per-hertz control” cannot be applied in motor starting. The startup method proposed in this paper is suitable for a motor drive with the modular multilevel PWM inverter. It enables the motor to produce a startup torque loaded on the motor at an initial amplitude and a fixed frequency of the inverter while taking into account constraints on the motor current and the ac-voltage fluctuation. The validity of the startup method as well as the startup performance is confirmed by experiment and simulation.

  18. A 400 KHz line rate 2048 pixel modular SWIR linear array for earth observation applications

    NASA Astrophysics Data System (ADS)

    Anchlia, Ankur; Vinella, Rosa M.; Wouters, Kristof; Gielen, Daphne; Hooylaerts, Peter; Deroo, Pieter; Ruythooren, Wouter; van der Zanden, Koen; Vermeiren, Jan; Merken, Patrick

    2015-10-01

    In this paper, we report about a family of linear imaging FPAs sensitive in the [0.9 - 1.7um] band, developed for high speed applications such as LIDAR, wavelength references and OCT analyzers and also for earth observation applications. Fast linear FPAs can also be used in a wide variety of terrestrial applications, including high speed sorting, electro- and photo-luminesce and medical applications. The arrays are based on a modular ROIC design concept: modules of 512 pixels are stitched during fabrication to achieve 512, 1024 and 2048 pixel arrays. In principle, this concept can be extended to any multiple of 512 pixels, the limiting factor being the pixel yield of long InGaAs arrays and the CTE differences in the hybrid setup. Each 512-pixel module has its own on-chip digital sequencer, analog readout chain and 4 output buffers. This modular concept enables a long-linear array to run at a high line rate of 400 KHz irrespective of the array length, which limits the line rate in a traditional linear array. The pixel has a pitch of 12.5um. The detector frontend is based on CTIA (Capacitor Trans-impedance Amplifier), having 5 selectable integration capacitors giving full well from 62x103e- (gain0) to 40x106e- (gain4). An auto-zero circuit limits the detector bias non-uniformity to 5-10mV across broad intensity levels, limiting the input referred dark signal noise to 20e-rms for Tint=3ms at room temperature. An on-chip CDS that follows the CTIA facilitates removal of Reset/KTC noise, CTIA offsets and most of the 1/f noise. The measured noise of the ROIC is 35e-rms in gain0. At a master clock rate of 60MHz and a minimum integration time of 1.4us, the FPAs reach the highest line rate of 400 KHz.

  19. Linear hydraulic drive system for a Stirling engine

    SciTech Connect

    Walsh, M.M.

    1984-02-21

    A hydraulic drive system operating from the periodic pressure wave produced by a Stirling engine along a first axis thereof and effecting transfer of power from the Stirling engine to a load apparatus therefor and wherein the movable, or working member of the load apparatus is reciprocatingly driven along an axis substantially at right angles to the first axis to achieve an arrangement of a Stirling engine and load apparatus assembly which is much shorter and the components of the load apparatus more readily accessible. 2 figs.

  20. Linear hydraulic drive system for a Stirling engine

    DOEpatents

    Walsh, Michael M.

    1984-02-21

    A hydraulic drive system operating from the periodic pressure wave produced by a Stirling engine along a first axis thereof and effecting transfer of power from the Stirling engine to a load apparatus therefor and wherein the movable, or working member of the load apparatus is reciprocatingly driven along an axis substantially at right angles to the first axis to achieve an arrangement of a Stirling engine and load apparatus assembly which is much shorter and the components of the load apparatus more readily accessible.

  1. 13th International Conference on Magnetically Levitated Systems and Linear Drives

    SciTech Connect

    Not Available

    1993-09-01

    This report contains short papers on research being conducted throughout the world on magnetically levitated systems, mainly consisting of trains, and magnetic linear drives. These papers have been index separately elsewhere on the data base.

  2. Computer Synthesis Approaches of Hyperboloid Gear Drives with Linear Contact

    NASA Astrophysics Data System (ADS)

    Abadjiev, Valentin; Kawasaki, Haruhisa

    2014-09-01

    The computer design has improved forming different type software for scientific researches in the field of gearing theory as well as performing an adequate scientific support of the gear drives manufacture. Here are attached computer programs that are based on mathematical models as a result of scientific researches. The modern gear transmissions require the construction of new mathematical approaches to their geometric, technological and strength analysis. The process of optimization, synthesis and design is based on adequate iteration procedures to find out an optimal solution by varying definite parameters. The study is dedicated to accepted methodology in the creation of soft- ware for the synthesis of a class high reduction hyperboloid gears - Spiroid and Helicon ones (Spiroid and Helicon are trademarks registered by the Illinois Tool Works, Chicago, Ill). The developed basic computer products belong to software, based on original mathematical models. They are based on the two mathematical models for the synthesis: "upon a pitch contact point" and "upon a mesh region". Computer programs are worked out on the basis of the described mathematical models, and the relations between them are shown. The application of the shown approaches to the synthesis of commented gear drives is illustrated.

  3. Nonlinear response of a linear chain to weak driving

    NASA Astrophysics Data System (ADS)

    Hennig, D.; Mulhern, C.; Burbanks, A. D.; Schimansky-Geier, L.

    2014-01-01

    We study the escape of a chain of coupled units over the barrier of a metastable potential. It is demonstrated that a very weak external driving field with a suitably chosen frequency suffices to accomplish speedy escape. The latter requires passage through a transition state, the formation of which is triggered by permanent feeding of energy from a phonon background into humps of localized energy and elastic interaction of the arising breather solutions. In fact, cooperativity between the units of the chain entailing coordinated energy transfer is shown to be crucial for enhancing the rate of escape in an extremely effective and low-energy cost way where the effects of entropic localization and breather coalescence conspire.

  4. Improved linear ultrasonic motor performance with square-wave based driving-tip trajectory

    NASA Astrophysics Data System (ADS)

    Le, Adam Y.; Mills, James K.; Benhabib, Beno

    2015-03-01

    This paper proposes the application of a non-sinusoidal periodic excitation voltage to induce a near-square-wave driving tip trajectory in linear ultrasonic motors (LUSMs). A square-wave-based trajectory can deliver superior frictional force to the moving stage in the forward stroke of the driving tip motion and reduced frictional force during the return stroke. This would reduce lost power in the periodic driving tip motion, thereby, increasing the output force and power of the LUSM. An implementation procedure is suggested to achieve the near-square-wave driving tip trajectory. The proposed approach is illustrated through realistic finite-element-based simulations using a bimodal LUSM configuration.

  5. Linear Stepper Actuation Driving Drop Resonance and Modifying Hysteresis.

    PubMed

    Katariya, Mayur; Huynh, So Hung; McMorran, Darren; Lau, Chun Yat; Muradoglu, Murat; Ng, Tuck Wah

    2016-08-23

    In this work, 2 μL water drops are placed on substrates that are created to have a circular hydrophilic region bounded by superhydrophobicity so that they exhibit high contact angles. When the substrate is translated by a linear stepper actuator, the random force components present in the actuator are shown to cause the drop to rock resonantly. When the substrate is translated downward at inclination angles of up to 6° with respect to the horizontal, the contact angle hysteresis increases progressively to a limiting condition. When the substrate is moved up at inclined angles, alternatively, the contact angle hysteresis increases initially to the limiting condition before it is progressively restored to its static state. These behaviors are accounted for by the reversible micro-Cassie to Wenzel wetting state transformations that are made possible by the hierarchical microscale and nanoscale structures present in the superhydrophobic regions. PMID:27479030

  6. Hedgehog-dependent proliferation drives modular growth during morphogenesis of a dermal bone

    PubMed Central

    Huycke, Tyler R.; Eames, B. Frank; Kimmel, Charles B.

    2012-01-01

    In the developing skeleton, dermal bone morphogenesis includes the balanced proliferation, recruitment and differentiation of osteoblast precursors, yet how bones acquire unique morphologies is unknown. We show that Hedgehog (Hh) signaling mediates bone shaping during early morphogenesis of the opercle (Op), a well characterized dermal bone of the zebrafish craniofacial skeleton. ihha is specifically expressed in a local population of active osteoblasts along the principal growing edge of the bone. Mutational studies show that Hh signaling by this osteoblast population is both necessary and sufficient for full recruitment of pre-osteoblasts into the signaling population. Loss of ihha function results in locally reduced proliferation of pre-osteoblasts and consequent reductions in recruitment into the osteoblast pool, reduced bone edge length and reduced outgrowth. Conversely, hyperactive Hh signaling in ptch1 mutants causes opposite defects in proliferation and growth. Time-lapse microscopy of early Op morphogenesis using transgenically labeled osteoblasts demonstrates that ihha-dependent bone development is not only region specific, but also begins exactly at the onset of a second phase of morphogenesis, when the early bone begins to reshape into a more complex form. These features strongly support a hypothesis that dermal bone development is modular, with different gene sets functioning at specific times and locations to pattern growth. The Hh-dependent module is not limited to this second phase of bone growth: during later larval development, the Op is fused along the dysmorphic edge to adjacent dermal bones. Hence, patterning within a module may include adjacent regions of functionally related bones and might require that signaling pathways function over an extended period of development. PMID:22627283

  7. Solar receiver heliostat reflector having a linear drive and position information system

    DOEpatents

    Horton, Richard H.

    1980-01-01

    A heliostat for a solar receiver system comprises an improved drive and control system for the heliostat reflector assembly. The heliostat reflector assembly is controllably driven in a predetermined way by a light-weight drive system so as to be angularly adjustable in both elevation and azimuth to track the sun and efficiently continuously reflect the sun's rays to a focal zone, i.e., heat receiver, which forms part of a solar energy utilization system, such as a solar energy fueled electrical power generation system. The improved drive system includes linear stepping motors which comprise low weight, low cost, electronic pulse driven components. One embodiment comprises linear stepping motors controlled by a programmed, electronic microprocessor. Another embodiment comprises a tape driven system controlled by a position control magnetic tape.

  8. Comparative Finite Element Method Analysis of Spiroid Worm Gear Drives Having Arched Profile and Having Linear Profile in Axial Section

    NASA Astrophysics Data System (ADS)

    Bodzás, Sándor; Dudás, Illés

    2014-12-01

    With the knowledge of the advantageous characteristics of the cylindrical worm gear drives having arched profile in axial section and the conical worm gear drives having linear profile in axial section, a new geometric type conical worm gear drive has been designed and then manufactured, that is the conical worm gear drive having arched profile in axial section. Beside similar charging and marginal conditions in case of the same geometric spiroid worm gear drives having arched profile and having linear profile in axial section we have done comparative finite element method analysis for awarding of the strains, deformations and stresses of this gear drives.

  9. A superconducting linear motor drive for a positive displacement bellows pump for use in the g-2 cryogenics system

    SciTech Connect

    Green, M.A.

    1994-10-01

    Forced two-phase cooling of indirectly cooled magnets requires circulation of liquid helium through the magnet cooling channel. A bellows helium pump is one possible way of providing helium flow to a magnet cooling system. Since the bellows type of helium pump is immersed in liquid helium, a superconducting linear motor drive appears to be an attractive option. This report describes a linear motor drive that employs oriented permanent magnet materials such as samarium-cobalt as the stator magnet system and a superconducting loud speaker voice coil type of drive as the armature of the linear motor. This report examines drive motor requirements for a helium pump.

  10. Function projective synchronization in partially linear drive-response chaotic systems

    NASA Astrophysics Data System (ADS)

    Zhang, Rong; Xu, Zhen-Yuan

    2010-12-01

    This paper gives the definition of function projective synchronization with less conservative demand for a scaling function, and investigates the function projective synchronization in partially linear drive-response chaotic systems. Based on the Lyapunov stability theory, it has been shown that the function projective synchronization with desired scaling function can be realized by simple control law. Moreover it does not need scaling function to be differentiable, bounded and non-vanished. The numerical simulations are provided to verify the theoretical result.

  11. Highly linear silicon traveling wave Mach-Zehnder carrier depletion modulator based on differential drive.

    PubMed

    Streshinsky, Matthew; Ayazi, Ali; Xuan, Zhe; Lim, Andy Eu-Jin; Lo, Guo-Qiang; Baehr-Jones, Tom; Hochberg, Michael

    2013-02-11

    We present measurements of the nonlinear distortions of a traveling-wave silicon Mach-Zehnder modulator based on the carrier depletion effect. Spurious free dynamic range for second harmonic distortion of 82 dB·Hz(1/2) is seen, and 97 dB·Hz(2/3) is measured for intermodulation distortion. This measurement represents an improvement of 20 dB over the previous best result in silicon. We also show that the linearity of a silicon traveling wave Mach-Zehnder modulator can be improved by differentially driving it. These results suggest silicon may be a suitable platform for analog optical applications. PMID:23481838

  12. Device with Functions of Linear Motor and Non-contact Power Collector for Wireless Drive

    NASA Astrophysics Data System (ADS)

    Fujii, Nobuo; Mizuma, Tsuyoshi

    The authors propose a new apparatus with functions of propulsion and non-contact power collection for a future vehicle which can run like an electric vehicle supplied from the onboard battery source in most of the root except near stations. The batteries or power-capacitors are non-contact charged from the winding connected with commercial power on ground in the stations etc. The apparatus has both functions of linear motor and transformer, and the basic configuration is a wound-secondary type linear induction motor (LIM). In the paper, the wound type LIM with the concentrated single-phase winding for the primary member on the ground is dealt from the viewpoint of low cost arrangement. The secondary winding is changed to the single-phase connection for zero thrust in the transformer operation, and the two-phase connection for the linear motor respectively. The change of connection is done by the special converter for charge and linear drive on board. The characteristics are studied analytically.

  13. Controllability of Free-piston Stirling Engine/linear Alternator Driving a Dynamic Load

    NASA Technical Reports Server (NTRS)

    Kankam, M. David; Rauch, Jeffrey S.

    1994-01-01

    This paper presents the dynamic behavior of a Free-Piston Stirling Engine/linear alternator (FPSE/LA) driving a single-phase fractional horse-power induction motor. The controllability and dynamic stability of the system are discussed by means of sensitivity effects of variations in system parameters, engine controller, operating conditions, and mechanical loading on the induction motor. The approach used expands on a combined mechanical and thermodynamic formulation employed in a previous paper. The application of state-space technique and frequency domain analysis enhances understanding of the dynamic interactions. Engine-alternator parametric sensitivity studies, similar to those of the previous paper, are summarized. Detailed discussions are provided for parametric variations which relate to the engine controller and system operating conditions. The results suggest that the controllability of a FPSE-based power system is enhanced by proper operating conditions and built-in controls.

  14. Thrust and normal force characteristics analysis of linear synchronous motor for direct drive conveyer

    NASA Astrophysics Data System (ADS)

    Zhu, Yu-wu; Kim, Do-sun; Cho, Yun-hyun

    2007-12-01

    The problem in improving the high positioning precision of permanent magnet linear synchronous motor (PMLSM) for direct drive conveyer is the large detent force, which contains two components: one is the cogging force caused by the interaction between the permanent magnet (PM) and the iron core, the other is the end effect caused by the finite mover length. In this paper a force compensator in the field oriented control (FOC) algorithm is employed to reduce this detent force, so the thrust and the normal force characteristics analysis of PMLSM are of the most importance. First the characteristics of the thrust and the normal force are simulated by finite element method (FEM), and the relation of the thrust and the normal force to the q-axis current is analyzed. Then the components of detent force are defined by Fourier series using the curve fitting method, and compensated by injecting the instantaneous currents using the FOC method. Finally the dynamic characteristics of this PMLSM for direct drive conveyer are investigated, and the numerical results are reported to validate the effectiveness of this proposed method.

  15. Development of an ultrasonic linear motor with ultra-positioning capability and four driving feet.

    PubMed

    Zhu, Cong; Chu, Xiangcheng; Yuan, Songmei; Zhong, Zuojin; Zhao, Yanqiang; Gao, Shuning

    2016-12-01

    This paper presents a novel linear piezoelectric motor which is suitable for rapid ultra-precision positioning. The finite element analysis (FEA) was applied for optimal design and further analysis, then experiments were conducted to investigate its performance. By changing the input signal, the proposed motor was found capable of working in the fast driving mode as well as in the precision positioning mode. When working in the fast driving mode, the motor acts as an ultrasonic motor with maximum no-load speed up to 181.2mm/s and maximum thrust of 1.7N at 200Vp-p. Also, when working in precision positioning mode, the motor can be regarded as a flexible hinge piezoelectric actuator with arbitrary motion in the range of 8μm. The measurable minimum output displacement was found to be 0.08μm, but theoretically, can be even smaller. More importantly, the motor can be quickly and accurately positioned in a large stroke. PMID:27479230

  16. Torque linearizing hardware for the electric joint motors of a direct-drive robot

    NASA Astrophysics Data System (ADS)

    Muir, P. F.; Bryan, J. R.

    Many emerging high-performance robot control algorithms require the command of the joint torques, yet no known commercial robots provide such a capability. We describe the design, development, testing, and application of a VMEbus-based torque linearizing joint interface board (JIB). One JIB resides between the robot control processor and each joint motor amplifier. The JIB provides the control processor with the capability to read the motor position and apply accurate motor torques. The torque command capability derives from the application of a 128k x 8 EPROM lookup table for each motor phase. Because joint motor torque is dependent upon the torque command and the motor position, the hardware is designed to utilize the torque command and the current motor position as the address to retrieve the proper pulse-width for the PWM motor amplifier. The table look-up cycle operates independently of the robot controller at a 40KHz rate to provide constant joint torque as the motor rotates. We identify the proper table entries by an automated in situ data collection procedure. Static torque generation results show that the torque deviations are reduced from as much as 76 percent to below 5 percent for each of the three direct-drive motors (two are variable reluctance motors and one is brushless DC) on an AdeptTwo robot. These torque deviations are reduced below 2.5 percent if only the upper 90 percent of the torque range is considered. The torque deviations of the non-direct-drive joint are reduced by 50 percent. Dynamic robot edge following experiments show that the robot speed of operation can be more than doubled for a given applied force accuracy by utilizing the joint torque linearizing boards.

  17. Torque linearizing hardware for the electric joint motors of a direct-drive robot

    SciTech Connect

    Muir, P.F.; Bryan, J.R.

    1991-01-01

    Many emerging high-performance robot control algorithms require the command of the joint torques; yet no known commercial robots provide such a capability. In this paper, we describe the design, development, testing and application of a VMEbus-based torque linearizing joint interface board (JIB). One JIB resides between the robot control processor and each joint motor amplifier. The JIB provides the control processor with the capability to read the motor position and apply accurate motor torques. The torque command capability derives from the application of a 128k {times} 8 EPROM lookup table for each motor phase. Because joint motor torque is dependent upon the torque command and the motor position, the hardware is designed to utilize the torque command and the current motor position as the address to retrieve the proper pulse-width for the PWM motor amplifier. The table look-up cycle operates independently of the robot controller at a 40KHz rate to provide constant joint torque as the motor rotates. We identify the proper table entries by an automated in situ data collection procedure. Static torque generation results show that the torque deviations are reduced from as much as 76% to below 5% for each of the three direct-drive motors (two are variable reluctance motors and one is brushless DC) on an AdeptTwo robot. These torque deviations are reduced below 2.5% if only the upper 90% of the torque range is considered. The torque deviations of the non-direct-drive joint are reduced by 50%. Dynamic robot edge following experiments show that the robot speed of operation can be more than doubled for a given applied force accuracy by utilizing the joint torque linearizing boards. 8 refs.

  18. Torque linearizing hardware for the electric joint motors of a direct-drive robot

    SciTech Connect

    Muir, P.F.; Bryan, J.R.

    1991-12-31

    Many emerging high-performance robot control algorithms require the command of the joint torques; yet no known commercial robots provide such a capability. In this paper, we describe the design, development, testing and application of a VMEbus-based torque linearizing joint interface board (JIB). One JIB resides between the robot control processor and each joint motor amplifier. The JIB provides the control processor with the capability to read the motor position and apply accurate motor torques. The torque command capability derives from the application of a 128k {times} 8 EPROM lookup table for each motor phase. Because joint motor torque is dependent upon the torque command and the motor position, the hardware is designed to utilize the torque command and the current motor position as the address to retrieve the proper pulse-width for the PWM motor amplifier. The table look-up cycle operates independently of the robot controller at a 40KHz rate to provide constant joint torque as the motor rotates. We identify the proper table entries by an automated in situ data collection procedure. Static torque generation results show that the torque deviations are reduced from as much as 76% to below 5% for each of the three direct-drive motors (two are variable reluctance motors and one is brushless DC) on an AdeptTwo robot. These torque deviations are reduced below 2.5% if only the upper 90% of the torque range is considered. The torque deviations of the non-direct-drive joint are reduced by 50%. Dynamic robot edge following experiments show that the robot speed of operation can be more than doubled for a given applied force accuracy by utilizing the joint torque linearizing boards. 8 refs.

  19. Linear motor drive system for continuous-path closed-loop position control of an object

    DOEpatents

    Barkman, William E.

    1980-01-01

    A precision numerical controlled servo-positioning system is provided for continuous closed-loop position control of a machine slide or platform driven by a linear-induction motor. The system utilizes filtered velocity feedback to provide system stability required to operate with a system gain of 100 inches/minute/0.001 inch of following error. The filtered velocity feedback signal is derived from the position output signals of a laser interferometer utilized to monitor the movement of the slide. Air-bearing slides mounted to a stable support are utilized to minimize friction and small irregularities in the slideway which would tend to introduce positioning errors. A microprocessor is programmed to read command and feedback information and converts this information into the system following error signal. This error signal is summed with the negative filtered velocity feedback signal at the input of a servo amplifier whose output serves as the drive power signal to the linear motor position control coil.

  20. Novel concept for driving the linear compressor of a micro-miniature split Stirling cryogenic cooler

    NASA Astrophysics Data System (ADS)

    Maron, V.; Veprik, A.; Finkelstein, L.; Vilenchik, H.; Ziv, I.; Pundak, N.

    2009-05-01

    New methods of carrying out homeland security and antiterrorist operations call for the development of a new generation of mechanically cooled, portable, battery powered infrared imagers, relying on micro-miniature Stirling cryogenic coolers of rotary or linear types. Since split Stirling linearly driven micro-miniature cryogenic coolers have inherently longer life spans, low vibration export and better aural stealth as compared to their rotary driven rivals, they are more suitable for the above applications. The performance of such cryogenic coolers depends strongly on the efficacy of their electronic drivers. In a traditional approach, the PWM power electronics produce the fixed frequency tonal driving voltage/current, the magnitude of which is modulated via a PID control law so as to maintain the desired focal plane array temperature. The disadvantage of such drivers is that they draw high ripple current from the system's power bus. This results in the need for an oversized DC power supply (battery packs) and power electronic components, low efficiency due to excessive conductive losses and high residual electromagnetic interference which in turn degrades the performance of other systems connected to the same power bus. Without either an active line filter or large and heavy passive filtering, other electronics can not be powered from the same power bus, unless they incorporate heavy filtering at their inputs. The authors present the results of a feasibility study towards developing a novel "pumping" driver consuming essentially constant instant battery power/current without making use of an active or passive filter. In the tested setup, the driver relies on a bidirectional controllable bridge, invertible with the driving frequency, and a fast regulated DC/DC converter which maintains a constant level of current consumed from the DC power supply and thus operates in input current control mode. From the experimental results, the steady-state power consumed by the

  1. NDT and SHM of Carbon Fiber Composites using Linear Drive MWM-Arrays

    NASA Technical Reports Server (NTRS)

    Washabaugh, Andrew; Martin, Christopher; Lyons, Robert; Grundy, David; Goldfine, Neil; Russell, Richard; Wincheski, Russell

    2012-01-01

    Carbon fiber composites are used in a wide range of structural applications due to their excellent specific strength and stiffness. However, the anisotropic mechanical and electrical properties associated with the fibers within each composite layer present challenges, and opportunities, for Nondestructive Testing (NDT) methods used to characterize and assess the structure condition. This includes composite condition after manufacture (such as fiber orientation and density, porosity, delamination, and bond strength) and during usage (such as damage from impact, fiber breakage, thermal exposure or applied stress). Ultrasonic and thermographic methods can address some of these challenges, but eddy current methods provide an alternative method for composite structures that contain a conducting material, such as carbon fibers or a metallic liner. This presentation reviews recent advances in the development of eddy current sensors and arrays for carbon fiber composite NDT and Structural Health Monitoring (SHM) applications. The focus is on eddy current sensor constructs with linear drive windings, such as MWM -Arrays, that induce currents primarily within the linear fibers of the composite. By combining this type of sensor construct with micromechanical models that relate composite constituent properties to measurable sensor responses, insight is obtained into the volumetric distribution of electrical properties within the composite and the associated manufacturing, damage, or strain conditions. With knowledge of the fiber layup, this MWM-Array technology is able to detect damage and strain/stress as a function of depth and fiber orientation. This work has been funded by NASA, NA V AIR and the Army for applications ranging from composite overwrapped pressure vessels (COPVs) to aircraft structures and rotorcraft blades. This presentation will specifically present background on the MWM-Array technology, results from the micromechanical modeling effort, and results from

  2. Quasi-linear modeling of lower hybrid current drive in ITER and DEMO

    NASA Astrophysics Data System (ADS)

    Cardinali, A.; Cesario, R.; Panaccione, L.; Santini, F.; Amicucci, L.; Castaldo, C.; Ceccuzzi, S.; Mirizzi, F.; Tuccillo, A. A.

    2015-12-01

    First pass absorption of the Lower Hybrid waves in thermonuclear devices like ITER and DEMO is modeled by coupling the ray tracing equations with the quasi-linear evolution of the electron distribution function in 2D velocity space. As usually assumed, the Lower Hybrid Current Drive is not effective in a plasma of a tokamak fusion reactor, owing to the accessibility condition which, depending on the density, restricts the parallel wavenumber to values greater than n∥crit and, at the same time, to the high electron temperature that would enhance the wave absorption and then restricts the RF power deposition to the very periphery of the plasma column (near the separatrix). In this work, by extensively using the "raystar" code, a parametric study of the propagation and absorption of the LH wave as function of the coupled wave spectrum (as its width, and peak value), has been performed very accurately. Such a careful investigation aims at controlling the power deposition layer possibly in the external half radius of the plasma, thus providing a valuable aid to the solution of how to control the plasma current profile in a toroidal magnetic configuration, and how to help the suppression of MHD mode that can develop in the outer part of the plasma. This analysis is useful not only for exploring the possibility of profile control of a pulsed operation reactor as well as the tearing mode stabilization, but also in order to reconsider the feasibility of steady state regime for DEMO.

  3. Non-linear effects in electron cyclotron current drive applied for the stabilization of neoclassical tearing modes

    NASA Astrophysics Data System (ADS)

    Ayten, B.; Westerhof, E.; the ASDEX Upgrade Team

    2014-07-01

    Due to the smallness of the volumes associated with the flux surfaces around the O-point of a magnetic island, the electron cyclotron power density applied inside the island for the stabilization of neoclassical tearing modes (NTMs) can exceed the threshold for non-linear effects as derived previously by Harvey et al (1989 Phys. Rev. Lett. 62 426). We study the non-linear electron cyclotron current drive (ECCD) efficiency through bounce-averaged, quasi-linear Fokker-Planck calculations in the magnetic geometry as created by the islands. The calculations are performed for the parameters of a typical NTM stabilization experiment on ASDEX Upgrade. A particular feature of these experiments is that the rays of the EC wave beam propagate tangential to the flux surfaces in the power deposition region. The calculations show significant non-linear effects on the ECCD efficiency, when the ECCD power is increased from its experimental value of 1 MW to a larger value of 4 MW. The nonlinear effects are largest in the case of locked islands or when the magnetic island rotation period is longer than the collisional time scale. The non-linear effects result in an overall reduction of the current drive efficiency for this case with absorption of the EC power on the low-field side of the electron cyclotron resonance layer. As a consequence of the non-linear effects, also the stabilizing effect of the ECCD on the island is reduced from linear expectations.

  4. Quasi-linear modeling of lower hybrid current drive in ITER and DEMO

    SciTech Connect

    Cardinali, A. Cesario, R.; Panaccione, L.; Santini, F.; Amicucci, L.; Castaldo, C.; Ceccuzzi, S.; Mirizzi, F.; Tuccillo, A. A.

    2015-12-10

    First pass absorption of the Lower Hybrid waves in thermonuclear devices like ITER and DEMO is modeled by coupling the ray tracing equations with the quasi-linear evolution of the electron distribution function in 2D velocity space. As usually assumed, the Lower Hybrid Current Drive is not effective in a plasma of a tokamak fusion reactor, owing to the accessibility condition which, depending on the density, restricts the parallel wavenumber to values greater than n{sub ∥crit} and, at the same time, to the high electron temperature that would enhance the wave absorption and then restricts the RF power deposition to the very periphery of the plasma column (near the separatrix). In this work, by extensively using the “ray{sup star}” code, a parametric study of the propagation and absorption of the LH wave as function of the coupled wave spectrum (as its width, and peak value), has been performed very accurately. Such a careful investigation aims at controlling the power deposition layer possibly in the external half radius of the plasma, thus providing a valuable aid to the solution of how to control the plasma current profile in a toroidal magnetic configuration, and how to help the suppression of MHD mode that can develop in the outer part of the plasma. This analysis is useful not only for exploring the possibility of profile control of a pulsed operation reactor as well as the tearing mode stabilization, but also in order to reconsider the feasibility of steady state regime for DEMO.

  5. Proceedings of the IEEE international conference on Maglev and linear drives

    SciTech Connect

    Not Available

    1987-01-01

    These proceedings collect papers on linear induction motors and magnetic levitation. Topics include: linear induction propulsion, eddy current analysis of cryostat outer vessel in superconductive magnetically levitated vehicles, dynamics of maglev vehicles, and high-speed maglev trains.

  6. Engineering non-linear resonator mode interactions in circuit QED by continuous driving: Manipulation of a photonic quantum memory

    NASA Astrophysics Data System (ADS)

    Reagor, Matthew; Pfaff, Wolfgang; Heeres, Reinier; Ofek, Nissim; Chou, Kevin; Blumoff, Jacob; Leghtas, Zaki; Touzard, Steven; Sliwa, Katrina; Holland, Eric; Albert, Victor V.; Frunzio, Luigi; Devoret, Michel H.; Jiang, Liang; Schoelkopf, Robert J.

    2015-03-01

    Recent advances in circuit QED have shown great potential for using microwave resonators as quantum memories. In particular, it is possible to encode the state of a quantum bit in non-classical photonic states inside a high-Q linear resonator. An outstanding challenge is to perform controlled operations on such a photonic state. We demonstrate experimentally how a continuous drive on a transmon qubit coupled to a high-Q storage resonator can be used to induce non-linear dynamics of the resonator. Tailoring the drive properties allows us to cancel or enhance non-linearities in the system such that we can manipulate the state stored in the cavity. This approach can be used to either counteract undesirable evolution due to the bare Hamiltonian of the system or, ultimately, to perform logical operations on the state encoded in the cavity field. Our method provides a promising pathway towards performing universal control for quantum states stored in high-coherence resonators in the circuit QED platform.

  7. Pile Driving

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Machine-oriented structural engineering firm TERA, Inc. is engaged in a project to evaluate the reliability of offshore pile driving prediction methods to eventually predict the best pile driving technique for each new offshore oil platform. Phase I Pile driving records of 48 offshore platforms including such information as blow counts, soil composition and pertinent construction details were digitized. In Phase II, pile driving records were statistically compared with current methods of prediction. Result was development of modular software, the CRIPS80 Software Design Analyzer System, that companies can use to evaluate other prediction procedures or other data bases.

  8. Non-Linear Effects on the LH Wave Coupling in Tore Supra and Impact on the LH Current Drive Efficiency

    SciTech Connect

    Ekedahl, A.; Frincu, B.; Goniche, M.; Hillairet, J.; Petrzilka, V.

    2009-11-26

    A strong, non-linear degradation of the Lower Hybrid (LH) wave coupling in Tore Supra can be observed when the LH launcher is screened on both sides by additional side limiters, such as side protections of adjacent Ion Cyclotron (IC) antennas. The power reflection coefficient (RC) at the LH grill mouth is estimated to increase from {approx}20% at low power density (<1 MW/m{sup 2}) up to >40% at high power density (>10 MW/m{sup 2}). Such large RC (>40%) is unacceptably high, in particular for long durations. The screening by the additional side limiters reduces the connection length in front of the LH grill, which results in lower {lambda}{sub n}, {lambda}{sub T}, n{sub e} and T{sub e} at the grill. However, the reduction in ne alone is not enough to explain the non-linear behaviour. Modelling with a code that takes into account a ponderomotive force potential [1], depleting the electron density in front of the grill, shows consistent results. In full non-inductive current drive scenarios, the observed degradation in LH coupling is measurable on the LH current drive efficiency, through the increase in coupled LH power required to maintain V{sub Loop} = 0. These results demonstrate thus the importance of being able to control the LH coupling conditions, in order to optimize the efficiency and power handling of LH systems.

  9. DNA-programmed modular assembly of cyclic and linear nanoarrays for the synthesis of two-dimensional conducting polymers.

    PubMed

    Chen, Wen; Schuster, Gary B

    2012-01-18

    Nanometer-scale arrays of conducting polymers were prepared on scaffolds of self-assembling DNA modules. A series of DNA oligomers was prepared, each containing six 2,5-bis(2-thienyl)pyrrole (SNS) monomer units linked covalently to N4 atoms of alternating cytosines placed between leading and trailing 12-nucleobase recognition sequences. These DNA modules were encoded so the recognition sequences would uniquely associate through Watson-Crick assembly to form closed-cycle or linear arrays of aligned SNS monomers. The melting behavior and electrophoretic migration of these assemblies showed cooperative formation of multicomponent arrays containing two to five DNA modules (i.e., 12-30 SNS monomers). The treatment of these arrays with horseradish peroxidase and H(2)O(2) resulted in oxidative polymerization of the SNS monomers with concomitant ligation of the DNA modules. The resulting cyclic and linear arrays exhibited chemical and optical properties typical of conducting thiophene-like polymers, with a red-end absorption beyond 1250 nm. AFM images of the cyclic array containing 18 SNS units revealed highly regular 10 nm diameter objects. PMID:22242713

  10. Drive control and position measurement of RailCab vehicles driven by linear motors

    NASA Astrophysics Data System (ADS)

    Pottharst, Andreas; Henke, Christian; Schneider, Tobias; Böcker, Joachim; Grotstollen, Horst

    2006-11-01

    The novel railway system RailCab makes use of autonomous vehicles which are driven by an AC linear motor. Depending on the track-side motor part, long-stator or short-stator operations are possible. The paper deals with the operation of the doubly-fed induction motor which is used for motion control and for transferring the energy required onboard the vehicle. This type of linear motor synchronization of the traveling fields generated by the stationary primary and moving secondary windings is an important and demanding task because the instantaneous positions of the vehicle or the primary traveling wave must be determined with high accuracy. The paper shows how this task is solved at the moment and what improvements are under development.

  11. Induction Motor Drive System Based on Linear Active Disturbance Rejection Controller

    NASA Astrophysics Data System (ADS)

    Liu, Liying; Zhang, Yongli; Yao, Qingmei

    It is difficult to establish an exact mathematical model for the induction motor and the robustness is poor of the vector control system using PI regulator. This paper adopts the linear active disturbance rejection controller (LADRC) to control inductor motor. LADRC doesn't need the exact mathematical model of motor and it can not only estimate but also compensate the general disturbance that includes the coupling items in model of motor and parameters perturbations by linear extended state observer (LESO), so the rotor flux and torque fully decouple. As a result, the performance is improved. To prove the above control scheme, the proposed control system has been simulated in MATLAB/SIMULINK, and the comparison was made with PID. Simulation results show that LADRC' has better performance and robustness than PID.

  12. Calibration of non-contact incremental linear encoders using a macro-micro dual-drive high-precision comparator

    NASA Astrophysics Data System (ADS)

    Yu, Haoyu; Liu, Hongzhong; Li, Xuan; Ye, Guoyong; Shi, Yongsheng; Yin, Lei; Jiang, Weitao; Chen, Bangdao; Liu, Xiaokang

    2015-09-01

    The accuracy of a linear encoder is determined by encoder-specific errors, which consist of both long-range and cyclic errors. Generally, it is difficult to measure the two errors of a non-contact incremental linear encoder with a large measuring range and small signal period in one measurement because of the contradiction between long travel range and high resolution. To resolve this issue, a prototype high-precision interferometric comparator with a macro-micro dual-drive system is presented. The measurement and motion resolution of the comparator are 1 nm and 3 nm, respectively. A measuring range of 320 mm is realized and the theoretical maximum range of the comparator is 2 m. The comparator mainly includes a high-accuracy aerostatic linear-motion stage, a constant displacement ratio piezoelectric-driven stage, two laser interferometers, a 6-DOF grating pair position adjustment devices and a PC-based data processor. The measurable linear movement is afforded, respectively, by the long-stroke stage and the piezoelectric-driven stage for the long-range error and cyclic error measurement. The movement can be measured by the encoder and then be calibrated by the corresponding laser interferometer. In the experiment, the accuracy of a non-contact incremental linear encoder with a 20 μm-long signal period and 320 mm measuring range proposed by our team was calibrated after proper mounting. The long-range error is measured to be 3.123 μm, and the cyclic error is within  ±0.159 μm, which matches well with the theoretical estimation given by  ±0.145 μm. The measurement uncertainties are estimated and the results confirm the effectiveness and feasibility of the proposed scheme and instruments.

  13. The use of linear superconducting electron accelerator for subcritical reactor driving

    NASA Astrophysics Data System (ADS)

    Guk, I. S.; Dovbnya, A. N.; Kononenko, S. G.; Peev, F. A.; Tarasenko, A. S.; van der Wiel, M.; Botman, J. I. M.

    2008-12-01

    At the National Science Centre, Kharkiv Institute of Physics and Technology (NSC KIPT) the possibility of creating an installation with a subcritical reactor driven by an electron accelerator is examined. To obtain the maximal stream of neutrons from a neutron-producing target at a minimal density of energy emission, the electron energy should be in the range of 100-200 MeV and the size of the target should be as large as possible. Other important requirements are beam continuity with time and long-term stability of the accelerator parameters. The variants of using the superconducting linear accelerator on the basis of a TESLA accelerating structure as of subcritical reactor driver are considered. The basic design parameters and characteristics of this installation are presented.

  14. Modular entanglement.

    PubMed

    Gualdi, Giulia; Giampaolo, Salvatore M; Illuminati, Fabrizio

    2011-02-01

    We introduce and discuss the concept of modular entanglement. This is the entanglement that is established between the end points of modular systems composed by sets of interacting moduli of arbitrarily fixed size. We show that end-to-end modular entanglement scales in the thermodynamic limit and rapidly saturates with the number of constituent moduli. We clarify the mechanisms underlying the onset of entanglement between distant and noninteracting quantum systems and its optimization for applications to quantum repeaters and entanglement distribution and sharing. PMID:21405382

  15. Amplitude modulation drive to rectangular-plate linear ultrasonic motors with vibrators dimensions 8 mm x 2.16 mm X 1 mm.

    PubMed

    Ming, Yang; Hanson, Ben; Levesley, Martin C; Walker, Peter G; Watterson, Kevin G

    2006-12-01

    In this paper, to exploit the contribution from not only the stators but also from other parts of miniature ultrasonic motors, an amplitude modulation drive is proposed to drive a miniature linear ultrasonic motor consisting of two rectangular piezoelectric ceramic plates. Using finite-element software, the first longitudinal and second lateral-bending frequencies of the vibrator are shown to be very close when its dimensions are 8 mm x 2.16 mm x 1 mm. So one single frequency power should be able to drive the motor. However, in practice the motor is found to be hard to move with a single frequency power because of its small vibration amplitudes and big frequency difference between its longitudinal and bending resonance, which is induced by the boundary condition variation. To drive the motor effectively, an amplitude modulation drive is used by superimposing two signals with nearly the same frequencies, around the resonant frequency of the vibrators of the linear motor. When the amplitude modulation frequency is close to the resonant frequency of the vibrator's surroundings, experimental results show that the linear motor can move back and forward with a maximum thrust force (over 0.016 N) and a maximum velocity (over 50 mm/s). PMID:17186925

  16. Modular invariant inflation

    NASA Astrophysics Data System (ADS)

    Kobayashi, Tatsuo; Nitta, Daisuke; Urakawa, Yuko

    2016-08-01

    Modular invariance is a striking symmetry in string theory, which may keep stringy corrections under control. In this paper, we investigate a phenomenological consequence of the modular invariance, assuming that this symmetry is preserved as well as in a four dimensional (4D) low energy effective field theory. As a concrete setup, we consider a modulus field T whose contribution in the 4D effective field theory remains invariant under the modular transformation and study inflation drived by T. The modular invariance restricts a possible form of the scalar potenntial. As a result, large field models of inflation are hardly realized. Meanwhile, a small field model of inflation can be still accomodated in this restricted setup. The scalar potential traced during the slow-roll inflation mimics the hilltop potential Vht, but it also has a non-negligible deviation from Vht. Detecting the primordial gravitational waves predicted in this model is rather challenging. Yet, we argue that it may be still possible to falsify this model by combining the information in the reheating process which can be determined self-completely in this setup.

  17. Characterising the interaction of individual-wheel drives with traction by linear parameter-varying model: a method for analysing the role of traction in torsional vibrations in wheel drives and active damping

    NASA Astrophysics Data System (ADS)

    Zhun Yeap, Khang; Müller, Steffen

    2016-02-01

    A model-based approach for characterising the interaction of individual-wheel drives with traction is contributed in this article. The primary aim is to investigate the influence of traction on torsional vibration behaviour in the drive train. The essence of this approach lies in reformulating the nonlinear traction behaviour into its differential form, which enables an analytical description of this interaction in its linear parameter-varying model equivalence. Analytical statements on the vibration behaviour for different driving scenarios are inferred from this model and validated with measurement samples from a high-performance electric road vehicle. Subsequent influences of traction on the performance of active damping of torsional vibrations are derived from this model.

  18. Dual-drive LiNbO3 interferometric Mach-Zehnder architecture with extended linear regime for high peak-to-average OFDM-based communication systems.

    PubMed

    Morant, Maria; Llorente, Roberto; Hauden, Jerome; Quinlan, Terence; Mottet, Alexandre; Walker, Stuart

    2011-12-12

    A dual-drive LiNbO(3) architecture modulator with chirp management is proposed and developed offering SFDR > 25 dB in a 1.4 V bias excursion compared to only 0.5 V bias excursion in a conventional Mach-Zehnder electro-optical modulator (MZ-EOM). The architecture effectively extends the linear regime and enables the optical transmission of wireless systems employing orthogonal division multiplexing (OFDM) modulation such as ultra-wide band (UWB) which require high linearity over a broad frequency range due to their high peak-to-average power ratio (PARP). Radio-over-fiber UWB transmission in a passive optical network is experimentally demonstrated employing this technique, exhibiting an enhancement of 2.2 dB in EVM after 57 km SSMF when the dual-drive developed modulator is employed. PMID:22274055

  19. Modular shield

    DOEpatents

    Snyder, Keith W.

    2002-01-01

    A modular system for containing projectiles has a sheet of material including at least a polycarbonate layer held by a metal frame having a straight frame member corresponding to each straight edge of the sheet. Each frame member has a U-shaped shield channel covering and holding a straight edge of the sheet and an adjacent U-shaped clamp channel rigidly held against the shield channel. A flexible gasket separates each sheet edge from its respective shield channel; and each frame member is fastened to each adjacent frame member only by clamps extending between adjacent clamp channels.

  20. Modular Certification

    NASA Technical Reports Server (NTRS)

    Rushby, John; Miner, Paul S. (Technical Monitor)

    2002-01-01

    Airplanes are certified as a whole: there is no established basis for separately certifying some components, particularly software-intensive ones, independently of their specific application in a given airplane. The absence of separate certification inhibits the development of modular components that could be largely "precertified" and used in several different contexts within a single airplane, or across many different airplanes. In this report, we examine the issues in modular certification of software components and propose an approach based on assume-guarantee reasoning. We extend the method from verification to certification by considering behavior in the presence of failures. This exposes the need for partitioning, and separation of assumptions and guarantees into normal and abnormal cases. We then identify three classes of property that must be verified within this framework: safe function, true guarantees, and controlled failure. We identify a particular assume-guarantee proof rule (due to McMillan) that is appropriate to the applications considered, and formally verify its soundness in PVS.

  1. Effect of driving frequency on non-linear coupling between ultrasound transducer and target under inspection in Sonic Infrared Imaging

    NASA Astrophysics Data System (ADS)

    Song, Yuyang; Han, Xiaoyan

    2014-09-01

    Sonic Infrared (IR) Imaging, also referred as vibrothermography, is a novel Nondestructive Evaluation (NDE) technology to find cracks through infrared imaging of vibration-induced crack heating. The vibration source plays an important role in the detection of cracks. In this paper, the effect of driving frequency on the ultrasound vibration to the thermal imaging is presented. The research is organized by using different frequency system and coupling materials on the same aluminum bar sample. The analysis is conducted by combination of the vibration waveforms with the IR images and signals. Correlation analysis between the acoustic energy and the thermal energy in the crack is discussed as well.

  2. Design of high-power radio-frequency drive loops for operation into 425-MHz linear accelerators

    SciTech Connect

    Liska, D.; Dauelsberg, L.

    1988-04-01

    Recent designs for ultra high-frequency (UHF) band accelerators have prompted the need for high-powered drive loops compatible with the peak and average power needs of the accelerator tanks. Two such loops have ben developed in the Accelerator Technology (AT) Division at Los Alamos and are now part of the general accelerator inventory. One loop is of small size, appropriate for radio-frequency quadrupole (RFQ) injector-accelerators, and is rated at 500-kW peak, 2-ms pulse length and 5% duty factor. The other loop is a 1-MW design, physically larger, also rated at 2-ms pulse length and 5% duty factor. The 1-MW drive loop uses a flat-disk ceramic window. The 500-kW loop as developed can use either a flat disk window or a special lambda2 window module available from Oak Ridge National Laboratory (ORNL). The purpose of this note is to describe the design of these loops and the tests performed on them so that they might be used by design engineers with appropriate applications.

  3. Modular Robotic Vehicle

    NASA Technical Reports Server (NTRS)

    Borroni-Bird, Christopher E. (Inventor); Vitale, Robert L. (Inventor); Lee, Chunhao J. (Inventor); Ambrose, Robert O. (Inventor); Bluethmann, William J. (Inventor); Junkin, Lucien Q. (Inventor); Lutz, Jonathan J. (Inventor); Guo, Raymond (Inventor); Lapp, Anthony Joseph (Inventor); Ridley, Justin S. (Inventor)

    2015-01-01

    A modular robotic vehicle includes a chassis, driver input devices, an energy storage system (ESS), a power electronics module (PEM), modular electronic assemblies (eModules) connected to the ESS via the PEM, one or more master controllers, and various embedded controllers. Each eModule includes a drive wheel containing a propulsion-braking module, and a housing containing propulsion and braking control assemblies with respective embedded propulsion and brake controllers, and a mounting bracket covering a steering control assembly with embedded steering controllers. The master controller, which is in communication with each eModule and with the driver input devices, communicates with and independently controls each eModule, by-wire, via the embedded controllers to establish a desired operating mode. Modes may include a two-wheel, four-wheel, diamond, and omni-directional steering modes as well as a park mode. A bumper may enable docking with another vehicle, with shared control over the eModules of the vehicles.

  4. Modular robot

    DOEpatents

    Ferrante, T.A.

    1997-11-11

    A modular robot may comprise a main body having a structure defined by a plurality of stackable modules. The stackable modules may comprise a manifold, a valve module, and a control module. The manifold may comprise a top surface and a bottom surface having a plurality of fluid passages contained therein, at least one of the plurality of fluid passages terminating in a valve port located on the bottom surface of the manifold. The valve module is removably connected to the manifold and selectively fluidically connects the plurality of fluid passages contained in the manifold to a supply of pressurized fluid and to a vent. The control module is removably connected to the valve module and actuates the valve module to selectively control a flow of pressurized fluid through different ones of the plurality of fluid passages in the manifold. The manifold, valve module, and control module are mounted together in a sandwich-like manner and comprise a main body. A plurality of leg assemblies are removably connected to the main body and are removably fluidically connected to the fluid passages in the manifold so that each of the leg assemblies can be selectively actuated by the flow of pressurized fluid in different ones of the plurality of fluid passages in the manifold. 12 figs.

  5. Modular robot

    DOEpatents

    Ferrante, Todd A.

    1997-01-01

    A modular robot may comprise a main body having a structure defined by a plurality of stackable modules. The stackable modules may comprise a manifold, a valve module, and a control module. The manifold may comprise a top surface and a bottom surface having a plurality of fluid passages contained therein, at least one of the plurality of fluid passages terminating in a valve port located on the bottom surface of the manifold. The valve module is removably connected to the manifold and selectively fluidically connects the plurality of fluid passages contained in the manifold to a supply of pressurized fluid and to a vent. The control module is removably connected to the valve module and actuates the valve module to selectively control a flow of pressurized fluid through different ones of the plurality of fluid passages in the manifold. The manifold, valve module, and control module are mounted together in a sandwich-like manner and comprise a main body. A plurality of leg assemblies are removably connected to the main body and are removably fluidically connected to the fluid passages in the manifold so that each of the leg assemblies can be selectively actuated by the flow of pressurized fluid in different ones of the plurality of fluid passages in the manifold.

  6. Managing in an age of modularity.

    PubMed

    Baldwin, C Y; Clark, K B

    1997-01-01

    Modularity is a familiar principle in the computer industry. Different companies can independently design and produce components, suck as disk drives or operating software, and those modules will fit together into a complex and smoothly functioning product because the module makers obey a given set of design rules. Modularity in manufacturing is already common in many companies. But now a number of them are beginning to extend the approach into the design of their products and services. Modularity in design should tremendously boost the rate of innovation in many industries as it did in the computer industry. As businesses as diverse as auto manufacturing and financial services move toward modular designs, the authors say, competitive dynamics will change enormously. No longer will assemblers control the final product: suppliers of key modules will gain leverage and even take on responsibility for design rules. Companies will compete either by specifying the dominant design rules (as Microsoft does) or by producing excellent modules (as disk drive maker Quantum does). Leaders in a modular industry will control less, so they will have to watch the competitive environment closely for opportunities to link up with other module makers. They will also need to know more: engineering details that seemed trivial at the corporate level may now play a large part in strategic decisions. Leaders will also become knowledge managers internally because they will need to coordinate the efforts of development groups in order to keep them focused on the modular strategies the company is pursuing. PMID:10170333

  7. Optimal Network Modularity for Information Diffusion

    NASA Astrophysics Data System (ADS)

    Nematzadeh, Azadeh; Ferrara, Emilio; Flammini, Alessandro; Ahn, Yong-Yeol

    2014-08-01

    We investigate the impact of community structure on information diffusion with the linear threshold model. Our results demonstrate that modular structure may have counterintuitive effects on information diffusion when social reinforcement is present. We show that strong communities can facilitate global diffusion by enhancing local, intracommunity spreading. Using both analytic approaches and numerical simulations, we demonstrate the existence of an optimal network modularity, where global diffusion requires the minimal number of early adopters.

  8. Modular weapon control unit

    SciTech Connect

    Boccabella, M.F.; McGovney, G.N.

    1997-01-01

    The goal of the Modular Weapon Control Unit (MWCU) program was to design and develop a reconfigurable weapon controller (programmer/sequencer) that can be adapted to different weapon systems based on the particular requirements for that system. Programmers from previous systems are conceptually the same and perform similar tasks. Because of this commonality and the amount of re-engineering necessary with the advent of every new design, the idea of a modular, adaptable system has emerged. Also, the controller can be used in more than one application for a specific weapon system. Functionality has been divided into a Processor Module (PM) and an Input/Output Module (IOM). The PM will handle all operations that require calculations, memory, and timing. The IOM will handle interfaces to the rest of the system, input level shifting, output drive capability, and detection of interrupt conditions. Configuration flexibility is achieved in two ways. First, the operation of the PM is determined by a surface mount Read-Only Memory (ROM). Other surface-mount components can be added or neglected as necessary for functionality. Second, IOMs consist of configurable input buffers, configurable output drivers, and configurable interrupt generation. Further, these modules can be added singly or in groups to a Processor Module to achieve the required I/O configuration. The culmination of this LDRD was the building of both Processor Module and Input/Output Module. The MWCU was chosen as a test system to evaluate Low-Temperature Co-fired Ceramic (LTCC) technology, desirable for high component density and good thermal characteristics.

  9. Modern Schools? Think Modular!

    ERIC Educational Resources Information Center

    Jackson, Lisa M.

    1998-01-01

    Examines how modular educational facilities can provide a viable alternative in building construction when speed and safety are key construction issues. Explains the durability of modular structures, their adherence to building codes, and the flexibility that they provide in design and appearance. The advantages to permanent modular construction…

  10. Portable modular detection system

    DOEpatents

    Brennan, James S.; Singh, Anup; Throckmorton, Daniel J.; Stamps, James F.

    2009-10-13

    Disclosed herein are portable and modular detection devices and systems for detecting electromagnetic radiation, such as fluorescence, from an analyte which comprises at least one optical element removably attached to at least one alignment rail. Also disclosed are modular detection devices and systems having an integrated lock-in amplifier and spatial filter and assay methods using the portable and modular detection devices.

  11. Modular design attitude control system

    NASA Technical Reports Server (NTRS)

    Chichester, F. D.

    1984-01-01

    A sequence of single axismodels and a series of reduced state linear observers of minimum order are used to reconstruct inaccessible variables pertaining to the modular attitude control of a rigid body flexible suspension model of a flexible spacecraft. The single axis models consist of two, three, four, and five rigid bodies, each interconnected by a flexible shaft passing through the mass centers of the bodies. Modal damping is added to each model. Reduced state linear observers are developed for synthesizing the inaccessible modal state variables for each modal model.

  12. Modular approach to achieving the next-generation X-ray light source

    NASA Astrophysics Data System (ADS)

    Biedron, S. G.; Milton, S. V.; Freund, H. P.

    2001-12-01

    A modular approach to the next-generation light source is described. The "modules" include photocathode, radio-frequency, electron guns and their associated drive-laser systems, linear accelerators, bunch-compression systems, seed laser systems, planar undulators, two-undulator harmonic generation schemes, high-gain harmonic generation systems, nonlinear higher harmonics, and wavelength shifting. These modules will be helpful in distributing the next-generation light source to many more laboratories than the current single-pass, high-gain free-electron laser designs permit, due to both monetary and/or physical space constraints.

  13. Computing an upper bound of modularity

    NASA Astrophysics Data System (ADS)

    Miyauchi, Atsushi; Miyamoto, Yuichiro

    2013-07-01

    Modularity proposed by Newman and Girvan is a quality function for community detection. Numerous heuristics for modularity maximization have been proposed because the problem is NP-hard. However, the accuracy of these heuristics has yet to be properly evaluated because computational experiments typically use large networks whose optimal modularity is unknown. In this study, we propose two powerful methods for computing a nontrivial upper bound of modularity. More precisely, our methods can obtain the optimal value of a linear programming relaxation of the standard integer linear programming for modularity maximization. The first method modifies the traditional row generation approach proposed by Grötschel and Wakabayashi to shorten the computation time. The second method is based on a row and column generation. In this method, we first solve a significantly small subproblem of the linear programming and iteratively add rows and columns. Owing to the speed and memory efficiency of these proposed methods, they are suitable for large networks. In particular, the second method consumes exceedingly small memory capacity, enabling us to compute the optimal value of the linear programming for the Power Grid network (consisting of 4941 vertices and 6594 edges) on a standard desktop computer.

  14. A 15 MHz bandwidth, 60 Vpp, low distortion power amplifier for driving high power piezoelectric transducers.

    PubMed

    Capineri, Lorenzo

    2014-10-01

    This paper presents the design and the realization of a linear power amplifier with large bandwidth (15 MHz) capable of driving low impedance ultrasonic transducers. The output current driving capability (up to 5 A) and low distortion makes it suitable for new research applications using high power ultrasound in the medical and industrial fields. The electronic design approach is modular so that the characteristics can be scaled according to specific applications and implementation details for the circuit layout are reported. Finally the characterization of the power amplifier module is presented. PMID:25362428

  15. Modularity of Prosthetic Implants.

    PubMed

    Barrack

    1994-01-01

    The vast majority of total-joint-replacement components currently utilized are modular to some degree. Modularity reduces inventory and increases the surgeon's options in both primary and revision total-joint arthroplasty. Use of a modular interface, however, increases the risk of fretting, wear debris, and dissociation and mismatching of components. The use of modular heads in total hip replacement is firmly established. The occurrence of corrosion and fretting has been recognized, and most manufacturers have improved the quality of the interface to minimize these problems. Modular polyethylene liners also offer advantages, particularly in revision procedures, where the option of additional screw fixation remains important. Many uncemented acetabular components are inserted without screws, which may generate renewed interest in one-piece factory-preassembled components. The conformity, locking mechanism, and nonarticular interface of modular acetabular components have all been studied and improved. Modular tibial components offer additional flexibility in the performance of total knee replacement but introduce the risk of dissociation and increased polyethylene wear; in revision procedures, modularity provides a valuable option for dealing with bone loss and an additional method of fixation by means of press-fit stems. Modular humeral components offer a significant advantage with limited apparent risk; however, longer clinical experience is required to assess potential problems. PMID:10708990

  16. Full characterization of modular values for finite-dimensional systems

    NASA Astrophysics Data System (ADS)

    Ho, Le Bin; Imoto, Nobuyuki

    2016-06-01

    Kedem and Vaidman obtained a relationship between the spin-operator modular value and its weak value for specific coupling strengths [14]. Here we give a general expression for the modular value in the n-dimensional Hilbert space using the weak values up to (n - 1)th order of an arbitrary observable for any coupling strength, assuming non-degenerated eigenvalues. For two-dimensional case, it shows a linear relationship between the weak value and the modular value. We also relate the modular value of the sum of observables to the weak value of their product.

  17. Small Modular Biomass Systems

    SciTech Connect

    2002-12-01

    This fact sheet provides information about modular biomass systems. Small modular biomass systems can help supply electricity to rural areas, businesses, and the billions of people who live without power worldwide. These systems use locally available biomass fuels such as wood, crop waste, animal manures, and landfill gas.

  18. Modular Buildings Buying Guide.

    ERIC Educational Resources Information Center

    Morris, Susan

    1991-01-01

    Suggests that child care program directors who are expanding their programs or opening new child care centers investigate the possibility of renting, leasing, or purchasing a modular building. Discusses the advantages of modular buildings over conventional building construction or rented space in an occupied building. Provides information about…

  19. Modular avionic architectures

    NASA Astrophysics Data System (ADS)

    Trujillo, Edward

    The author presents an analysis revealing some of the salient features of modular avionics. A decomposition of the modular avionics concept is performed, highlighting some of the key features of such architectures. Several layers of architecture can be found in such concepts, including those relating to software structure, communication, and supportability. Particular emphasis is placed on the layer relating to partitioning, which gives rise to those features of integration, modularity, and commonality. Where integration is the sharing of common tasks or items to gain efficiency and flexibility, modularity is the partitioning of a system into reconfigurable and maintainable items, and commonality is partitioning to maximize the use of identical items across the range of applications. Two architectures, MASA (Modular Avionics System Architecture) and Pave Pillar, are considered in particular.

  20. Modular Spectrometers in the Undergraduate Chemistry Laboratory

    NASA Astrophysics Data System (ADS)

    Bernazzani, Paul; Paquin, Francine

    2001-06-01

    A rapid evolution of fiber-optic and computer technology led to the concept of modular spectrometers. The Ocean Optics S2000 series of spectroscopic instruments, based on a 2048-element linear CCD-array, are examples of such equipment. We have introduced two of these modular systems into our undergraduate laboratory courses, for experiments that serve as an introduction to signal processing. The Ocean Optics spectrometers have proven to be both rapid and inexpensive and have improved the quality of learning of our students.

  1. Electric versus hydraulic drives

    SciTech Connect

    Not Available

    1983-01-01

    This volume records the proceedings of a conference organised by the Engineering Manufacturing Industries Division of the Institution of Mechanical Engineers. Topics considered include high performance position control - a review of the current state of developments; hydrostatic drives - present and future; electric drives - present and future trends; electrical and hydraulic drives for heavy industrial robots; the development of an electro-mechanical tilt system for the advanced passenger train; industrial hydraulic ring mains - effective or efficient. the comparison of performance of servo feed-drive systems; overhead crane drives; the future of d.c. servodrives; the choice of actuator for military systems; linear electro-hydraulic actuators; and actuation for industrial robots.

  2. A 15 MHz bandwidth, 60 V{sub pp}, low distortion power amplifier for driving high power piezoelectric transducers

    SciTech Connect

    Capineri, Lorenzo

    2014-10-01

    This paper presents the design and the realization of a linear power amplifier with large bandwidth (15 MHz) capable of driving low impedance ultrasonic transducers. The output current driving capability (up to 5 A) and low distortion makes it suitable for new research applications using high power ultrasound in the medical and industrial fields. The electronic design approach is modular so that the characteristics can be scaled according to specific applications and implementation details for the circuit layout are reported. Finally the characterization of the power amplifier module is presented.

  3. A modular BLSS simulation model

    NASA Technical Reports Server (NTRS)

    Rummel, John D.; Volk, Tyler

    1987-01-01

    A bioregenerative life support system (BLSS) for extraterrestrial use will be faced with coordination problems more acute than those in any ecosystem found on Earth. A related problem in BLSS design is providing an interface between the various life support processors, one that will allow for their coordination while still allowing for system expansion. A modular model is presented of a BLSS that interfaces system processors only with the material storage reservoirs, allowing those reservoirs to act as the principal buffers in the system and thus minimizing difficulties with processor coordination. The modular nature of the model allows independent development of the detailed submodels that exist within the model framework. Using this model, BLSS dynamics were investigated under normal conditions and under various failure modes. Partial and complete failures of various components, such as the waste processors or the plants themselves, drive transient responses in the model system, allowing the examination of the effectiveness of the system reservoirs as buffers. The results from simulations help to determine control strategies and BLSS design requirements. An evolved version could be used as an interactive control aid in a future BLSS.

  4. Diversity and Unity of Modularity

    ERIC Educational Resources Information Center

    Seok, Bongrae

    2006-01-01

    Since the publication of Fodor's (1983) The Modularity of Mind, there have been quite a few discussions of cognitive modularity among cognitive scientists. Generally, in those discussions, modularity means a property of specialized cognitive processes or a domain-specific body of information. In actuality, scholars understand modularity in many…

  5. Modular tokamak magnetic system

    DOEpatents

    Yang, Tien-Fang

    1988-01-01

    A modular tokamak system comprised of a plurality of interlocking moldules. Each module is comprised of a vacuum vessel section, a toroidal field coil, moldular saddle coils which generate a poloidal magnetic field and ohmic heating coils.

  6. Modularity in signaling systems

    NASA Astrophysics Data System (ADS)

    Del Vecchio, Domitilla

    2012-08-01

    Modularity is a property by which the behavior of a system does not change upon interconnection. It is crucial for understanding the behavior of a complex system from the behavior of the composing subsystems. Whether modularity holds in biology is an intriguing and largely debated question. In this paper, we discuss this question taking a control system theory view and focusing on signaling systems. In particular, we argue that, despite signaling systems being constituted of structural modules, such as covalent modification cycles, modularity does not hold in general. As in any engineering system, impedance-like effects, called retroactivity, appear at interconnections and alter the behavior of connected modules. We further argue that while signaling systems have evolved sophisticated ways to counter-act retroactivity and enforce modularity, retroactivity may also be exploited to finely control the information processing of signaling pathways. Testable predictions and experimental evidence are discussed with their implications.

  7. Modular avionics packaging standardization

    NASA Astrophysics Data System (ADS)

    Austin, M.; McNichols, J. K.

    The Modular Avionics Packaging (MAP) Program for packaging future military avionics systems with the objective of improving reliability, maintainability, and supportability, and reducing equipment life cycle costs is addressed. The basic MAP packaging concepts called the Standard Avionics Module, the Standard Enclosure, and the Integrated Rack are summarized, and the benefits of modular avionics packaging, including low risk design, technology independence with common functions, improved maintainability and life cycle costs are discussed. Progress made in MAP is briefly reviewed.

  8. Modularity and mental architecture.

    PubMed

    Robbins, Philip

    2013-11-01

    Debates about the modularity of cognitive architecture have been ongoing for at least the past three decades, since the publication of Fodor's landmark book The Modularity of Mind. According to Fodor, modularity is essentially tied to informational encapsulation, and as such is only found in the relatively low-level cognitive systems responsible for perception and language. According to Fodor's critics in the evolutionary psychology camp, modularity simply reflects the fine-grained functional specialization dictated by natural selection, and it characterizes virtually all aspects of cognitive architecture, including high-level systems for judgment, decision making, and reasoning. Though both of these perspectives on modularity have garnered support, the current state of evidence and argument suggests that a broader skepticism about modularity may be warranted. WIREs Cogn Sci 2013, 4:641-649. doi: 10.1002/wcs.1255 CONFLICT OF INTEREST: The author has declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website. PMID:26304269

  9. The impact of the non-linearity of the radiant flux on the thermal load of the color conversion elements in phosphor converted LEDs under different current driving schemes.

    PubMed

    Wenzl, Franz P; Sommer, Christian; Hartmann, Paul; Pachler, Peter; Hoschopf, Hans; Langer, Gregor; Fulmek, Paul; Nicolics, Johann

    2013-05-01

    For a systematic approach to improve the reliability and the white light quality of phosphor converted light-emitting diodes (LEDs) it is imperative to gain a better understanding of the individual parameters that affect color temperature constancy and maintenance. By means of a combined optical and thermal simulation procedure, in this contribution we give a comprehensive discussion on the impact of different current driving schemes on the thermal load of the color conversion elements (CCEs) of phosphor converted LEDs. We show that on the one hand a decreasing duty cycle under pulse width modulation driving conditions may cause a notable temperature variation and on the other hand also effects due to the non-linearity between the blue radiant flux and the current have to be considered for the thermal load of the CCEs. PMID:24104432

  10. Derivatives of Siegel modular forms and exponential functions

    NASA Astrophysics Data System (ADS)

    Bertrand, D.; Zudilin, W. W.

    2001-08-01

    We show that the differential field generated by Siegel modular forms and the differential field generated by exponentials of polynomials are linearly disjoint over \\mathbb C. Combined with our previous work [3], this provides a complete multidimensional extension of Mahler's theorem on the transcendence degree of the field generated by the exponential function and the derivatives of a modular function. We give two proofs of our result, one purely algebraic, the other analytic, but both based on arguments from differential algebra and on the stability under the action of the symplectic group of the differential field generated by rational and modular functions.

  11. Self Evolving Modular Network

    NASA Astrophysics Data System (ADS)

    Tokunaga, Kazuhiro; Kawabata, Nobuyuki; Furukawa, Tetsuo

    We propose a novel modular network called the Self-Evolving Modular Network (SEEM). The SEEM has a modular network architecture with a graph structure and these following advantages: (1) new modules are added incrementally to allow the network to adapt in a self-organizing manner, and (2) graph's paths are formed based on the relationships between the models represented by modules. The SEEM is expected to be applicable to evolving functions of an autonomous robot in a self-organizing manner through interaction with the robot's environment and categorizing large-scale information. This paper presents the architecture and an algorithm for the SEEM. Moreover, performance characteristic and effectiveness of the network are shown by simulations using cubic functions and a set of 3D-objects.

  12. Symmetric modular torsatron

    DOEpatents

    Rome, J.A.; Harris, J.H.

    1984-01-01

    A fusion reactor device is provided in which the magnetic fields for plasma confinement in a toroidal configuration is produced by a plurality of symmetrical modular coils arranged to form a symmetric modular torsatron referred to as a symmotron. Each of the identical modular coils is helically deformed and comprise one field period of the torsatron. Helical segments of each coil are connected by means of toroidally directed windbacks which may also provide part of the vertical field required for positioning the plasma. The stray fields of the windback segments may be compensated by toroidal coils. A variety of magnetic confinement flux surface configurations may be produced by proper modulation of the winding pitch of the helical segments of the coils, as in a conventional torsatron, winding the helix on a noncircular cross section and varying the poloidal and radial location of the windbacks and the compensating toroidal ring coils.

  13. Modular optical detector system

    DOEpatents

    Horn, Brent A.; Renzi, Ronald F.

    2006-02-14

    A modular optical detector system. The detector system is designed to detect the presence of molecules or molecular species by inducing fluorescence with exciting radiation and detecting the emitted fluorescence. Because the system is capable of accurately detecting and measuring picomolar concentrations it is ideally suited for use with microchemical analysis systems generally and capillary chromatographic systems in particular. By employing a modular design, the detector system provides both the ability to replace various elements of the detector system without requiring extensive realignment or recalibration of the components as well as minimal user interaction with the system. In addition, the modular concept provides for the use and addition of a wide variety of components, including optical elements (lenses and filters), light sources, and detection means, to fit particular needs.

  14. Modular architecture for robotics and teleoperation

    DOEpatents

    Anderson, Robert J.

    1996-12-03

    Systems and methods for modularization and discretization of real-time robot, telerobot and teleoperation systems using passive, network based control laws. Modules consist of network one-ports and two-ports. Wave variables and position information are passed between modules. The behavior of each module is decomposed into uncoupled linear-time-invariant, and coupled, nonlinear memoryless elements and then are separately discretized.

  15. Modular biowaste monitoring system

    NASA Technical Reports Server (NTRS)

    Fogal, G. L.

    1975-01-01

    The objective of the Modular Biowaste Monitoring System Program was to generate and evaluate hardware for supporting shuttle life science experimental and diagnostic programs. An initial conceptual design effort established requirements and defined an overall modular system for the collection, measurement, sampling and storage of urine and feces biowastes. This conceptual design effort was followed by the design, fabrication and performance evaluation of a flight prototype model urine collection, volume measurement and sampling capability. No operational or performance deficiencies were uncovered as a result of the performance evaluation tests.

  16. Criteria for software modularization

    NASA Technical Reports Server (NTRS)

    Card, David N.; Page, Gerald T.; Mcgarry, Frank E.

    1985-01-01

    A central issue in programming practice involves determining the appropriate size and information content of a software module. This study attempted to determine the effectiveness of two widely used criteria for software modularization, strength and size, in reducing fault rate and development cost. Data from 453 FORTRAN modules developed by professional programmers were analyzed. The results indicated that module strength is a good criterion with respect to fault rate, whereas arbitrary module size limitations inhibit programmer productivity. This analysis is a first step toward defining empirically based standards for software modularization.

  17. Fault tolerant linear actuator

    DOEpatents

    Tesar, Delbert

    2004-09-14

    In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.

  18. The Evolution of Modular Construction.

    ERIC Educational Resources Information Center

    American School & University, 1993

    1993-01-01

    Explores how the myths of modular construction for schools began; also discusses the advances made in steel and modular construction. The major advantages of using permanent modular construction for schools are highlighted, including its rapid construction, use of standard building materials, financial flexibility, and durability. (GR)

  19. Modular multimorphic kinematic arm structure and pitch and yaw joint for same

    DOEpatents

    Martin, H. Lee; Williams, Daniel M.; Holt, W. Eugene

    1989-01-01

    A multimorphic kinematic manipulator arm is provided with seven degrees of freedom and modular kinematic redundancy through identical pitch/yaw, shoulder, elbow and wrist joints and a wrist roll device at the wrist joint, which further provides to the manipulator arm an obstacle avoidance capability. The modular pitch/yaw joints are traction drive devices which provide backlash free operation with smooth torque transmission and enhanced rigidity. A dual input drive arrangement is provided for each joint resulting in a reduction of the load required to be assumed by each drive and providing selective pitch and yaw motions by control of the relative rotational directions of the input drive.

  20. Current Control Method to Achieve Wide-Range Power Driving for Linear Synchronous Motor with Half-Wave-Rectified Self-Excitation

    NASA Astrophysics Data System (ADS)

    Hirayama, Tadashi; Higuchi, Tsuyoshi

    In a previous paper, we proposed a novel linear synchronous motor with half-wave-rectified self-excitation. The long-stator-type linear synchronous motor was built, and its performance was verified by performing experiments. This paper presents a new current control method for the linear synchronous motor for achieving a wide range of speeds and high-power operations. First, we propose the current control method for high-thrust operation in the constant-thrust region. This operation is realized by using a reluctance thrust resulting from the saliency of the linear synchronous motor. Furthermore, we propose a control method that maximizes the ratio of the thrust to the voltage; this method can be used to expand the operating range. Wide-range-speed operation can be achieved by applying this new control method along with field-weakening control. The thrust and operation characteristics of the proposed control methods are estimated by performing experiments and an electric and magnetic coupled analysis.

  1. Modular Perspectives on Bilingualism.

    ERIC Educational Resources Information Center

    Francis, Norbert

    2002-01-01

    This research review traces the current discussion on models of bilingualism to the contributions of Vygotsky and Luria. Proposes that a modular approach to studying the different aspects of bilingual development promises to chart a course toward finding a broader common ground around research findings and interpretations that appear to be…

  2. State Librarianship: Modular Curriculum.

    ERIC Educational Resources Information Center

    Robbins, Jane; Powell, Anne

    This modular curriculum on state librarianship is designed to be used as a basis for a full-length library science course, instructional segments of several courses, continuing education courses, or workshops. The 20 curriculum modules cover the many facets of state libraries and their activities--history, functions, social and political…

  3. Modularity in robotic systems

    NASA Technical Reports Server (NTRS)

    Tesar, Delbert; Butler, Michael S.

    1989-01-01

    Most robotic systems today are designed one at a time, at a high cost of time and money. This wasteful approach has been necessary because the industry has not established a foundation for the continued evolution of intelligent machines. The next generation of robots will have to be generic, versatile machines capable of absorbing new technology rapidly and economically. This approach is demonstrated in the success of the personal computer, which can be upgraded or expanded with new software and hardware at virtually every level. Modularity is perceived as a major opportunity to reduce the 6 to 7 year design cycle time now required for new robotic manipulators, greatly increasing the breadth and speed of diffusion of robotic systems in manufacturing. Modularity and its crucial role in the next generation of intelligent machines are the focus of interest. The main advantages that modularity provides are examined; types of modules needed to create a generic robot are discussed. Structural modules designed by the robotics group at the University of Texas at Austin are examined to demonstrate the advantages of modular design.

  4. MRV - Modular Robotic Vehicle

    NASA Technical Reports Server (NTRS)

    Ridley, Justin; Bluethmann, Bill

    2015-01-01

    The Modular Robotic Vehicle, or MRV, completed in 2013, was developed at the Johnson Space Center in order to advance technologies which have applications for future vehicles both in space and on Earth. With seating for two people, MRV is a fully electric vehicle modeled as a "city car", suited for busy urban environments.

  5. Sequenced drive for rotary valves

    DOEpatents

    Mittell, Larry C.

    1981-01-01

    A sequenced drive for rotary valves which provides the benefits of applying rotary and linear motions to the movable sealing element of the valve. The sequenced drive provides a close approximation of linear motion while engaging or disengaging the movable element with the seat minimizing wear and damage due to scrubbing action. The rotary motion of the drive swings the movable element out of the flowpath thus eliminating obstruction to flow through the valve.

  6. iDriving (Intelligent Driving)

    SciTech Connect

    Malikopoulos, Andreas

    2012-09-17

    iDriving identifies the driving style factors that have a major impact on fuel economy. An optimization framework is used with the aim of optimizing a driving style with respect to these driving factors. A set of polynomial metamodels is constructed to reflect the responses produced in fuel economy by changing the driving factors. The optimization framework is used to develop a real-time feedback system, including visual instructions, to enable drivers to alter their driving styles in responses to actual driving conditions to improve fuel efficiency.

  7. iDriving (Intelligent Driving)

    Energy Science and Technology Software Center (ESTSC)

    2012-09-17

    iDriving identifies the driving style factors that have a major impact on fuel economy. An optimization framework is used with the aim of optimizing a driving style with respect to these driving factors. A set of polynomial metamodels is constructed to reflect the responses produced in fuel economy by changing the driving factors. The optimization framework is used to develop a real-time feedback system, including visual instructions, to enable drivers to alter their driving stylesmore » in responses to actual driving conditions to improve fuel efficiency.« less

  8. Small Modular Reactors (468th Brookhaven Lecture)

    SciTech Connect

    Bari, Robert

    2011-04-20

    With good reason, much more media attention has focused on nuclear power plants than solar farms, wind farms, or hydroelectric plants during the past month and a half. But as nations around the world demand more energy to power everything from cell phone batteries to drinking water pumps to foundries, nuclear plants are the only non-greenhouse-gas producing option that can be built to operate almost anywhere, and can continue to generate power during droughts, after the sun sets, and when winds die down. To supply this demand for power, designers around the world are competing to develop more affordable nuclear reactors of the future: small modular reactors. Brookhaven Lab is working with DOE to ensure that these reactors are designed to be safe for workers, members of surrounding communities, and the environment and to ensure that the radioactive materials and technology will only be used for peaceful purposes, not weapons. In his talk, Bari will discuss the advantages and challenges of small modular reactors and what drives both international and domestic interest in them. He will also explain how Brookhaven Lab and DOE are working to address the challenges and provide a framework for small modular reactors to be commercialized.

  9. Modular integrated video system

    SciTech Connect

    Gaertner, K.J.; Heaysman, B.; Holt, R.; Sonnier, C.

    1986-01-01

    The Modular Integrated Video System (MIVS) is intended to provide a simple, highly reliable closed circuit television (CCTV) system capable of replacing the IAEA Twin Minolta Film Camera Systems in those safeguards facilities where mains power is readily available, and situations where it is desired to have the CCTV camera separated from the CCTV recording console. This paper describes the MIVS and the Program Plan which is presently being followed for the development, testing, and implementation of the system.

  10. Base drive circuit

    DOEpatents

    Lange, A.C.

    1995-04-04

    An improved base drive circuit having a level shifter for providing bistable input signals to a pair of non-linear delays. The non-linear delays provide gate control to a corresponding pair of field effect transistors through a corresponding pair of buffer components. The non-linear delays provide delayed turn-on for each of the field effect transistors while an associated pair of transistors shunt the non-linear delays during turn-off of the associated field effect transistor. 2 figures.

  11. Base drive circuit

    DOEpatents

    Lange, Arnold C.

    1995-01-01

    An improved base drive circuit (10) having a level shifter (24) for providing bistable input signals to a pair of non-linear delays (30, 32). The non-linear delays (30, 32) provide gate control to a corresponding pair of field effect transistors (100, 106) through a corresponding pair of buffer components (88, 94). The non-linear delays (30, 32) provide delayed turn-on for each of the field effect transistors (100, 106) while an associated pair of transistors (72, 80) shunt the non-linear delays (30, 32) during turn-off of the associated field effect transistor (100, 106).

  12. Impaired Driving

    MedlinePlus

    ... Risk Factors BAC Effects Prevention Additional Resources How big is the problem? In 2014, 9,967 people ... Driving: A Threat to Everyone (October 2011) Additional Data Drunk Driving State Data and Maps Motor Vehicle ...

  13. Drugged Driving

    MedlinePlus

    ... Infographics » Drugged Driving Drugged Driving Email Facebook Twitter Text Description of Infographic Top Right Figure : In 2009, ... crash than those who don't smoke. Bottom Text: Develop Social Strategies Offer to be a designated ...

  14. Modular high speed counter employing edge-triggered code

    DOEpatents

    Vanstraelen, G.F.

    1993-06-29

    A high speed modular counter (100) utilizing a novel counting method in which the first bit changes with the frequency of the driving clock, and changes in the higher order bits are initiated one clock pulse after a 0'' to 1'' transition of the next lower order bit. This allows all carries to be known one clock period in advance of a bit change. The present counter is modular and utilizes two types of standard counter cells. A first counter cell determines the zero bit. The second counter cell determines any other higher order bit. Additional second counter cells are added to the counter to accommodate any count length without affecting speed.

  15. Modular high speed counter employing edge-triggered code

    DOEpatents

    Vanstraelen, Guy F.

    1993-06-29

    A high speed modular counter (100) utilizing a novel counting method in which the first bit changes with the frequency of the driving clock, and changes in the higher order bits are initiated one clock pulse after a "0" to "1" transition of the next lower order bit. This allows all carries to be known one clock period in advance of a bit change. The present counter is modular and utilizes two types of standard counter cells. A first counter cell determines the zero bit. The second counter cell determines any other higher order bit. Additional second counter cells are added to the counter to accommodate any count length without affecting speed.

  16. Standardized Modular Power Interfaces for Future Space Explorations Missions

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard

    2015-01-01

    Earlier studies show that future human explorations missions are composed of multi-vehicle assemblies with interconnected electric power systems. Some vehicles are often intended to serve as flexible multi-purpose or multi-mission platforms. This drives the need for power architectures that can be reconfigured to support this level of flexibility. Power system developmental costs can be reduced, program wide, by utilizing a common set of modular building blocks. Further, there are mission operational and logistics cost benefits of using a common set of modular spares. These benefits are the goals of the Advanced Exploration Systems (AES) Modular Power System (AMPS) project. A common set of modular blocks requires a substantial level of standardization in terms of the Electrical, Data System, and Mechanical interfaces. The AMPS project is developing a set of proposed interface standards that will provide useful guidance for modular hardware developers but not needlessly constrain technology options, or limit future growth in capability. In 2015 the AMPS project focused on standardizing the interfaces between the elements of spacecraft power distribution and energy storage. The development of the modular power standard starts with establishing mission assumptions and ground rules to define design application space. The standards are defined in terms of AMPS objectives including Commonality, Reliability-Availability, Flexibility-Configurability and Supportability-Reusability. The proposed standards are aimed at assembly and sub-assembly level building blocks. AMPS plans to adopt existing standards for spacecraft command and data, software, network interfaces, and electrical power interfaces where applicable. Other standards including structural encapsulation, heat transfer, and fluid transfer, are governed by launch and spacecraft environments and bound by practical limitations of weight and volume. Developing these mechanical interface standards is more difficult but

  17. New realities of modular construction

    SciTech Connect

    Duty, J.M. Jr. ); Fisher, D. ); Lewis, W.W. )

    1993-12-01

    Modular construction has both advantages and disadvantages. Advantages are safety, reduction of construction time and faster plant startup time, reduced labor cost, weather friendliness, increased quality and efficiency, simultaneous production capability, testing ease and fewer interruptions to an operating plant. Disadvantages are transportation costs, module size limitations, transportation-accessibility needs, increased engineering effort, and offloading and setting needs. These pros and cons were identified by a Construction Industry Institute (C2) task force established in 1989 to assess modular construction strengths and weaknesses. Objective: develop a decision-support tool to evaluate a project's suitability for modularization. The task force first had to learn what drivers influence modularization and then develop a set of characteristics of the ideal project for modularization. To help in this research, academics from the University of Houston and Purdue University developed MODEX, an expert system which became the decision-support tool. The paper first discusses the myths of modularization and then describes MODEX.

  18. Hosing Instability of the Drive Electron Beam in the E157 Plasma-Wakefield Acceleration Experiment at the Stanford Linear Accelerator

    SciTech Connect

    Blue, Brent Edward; /SLAC /UCLA

    2005-10-10

    In the plasma-wakefield experiment at SLAC, known as E157, an ultra-relativistic electron beam is used to both excite and witness a plasma wave for advanced accelerator applications. If the beam is tilted, then it will undergo transverse oscillations inside of the plasma. These oscillations can grow exponentially via an instability know as the electron hose instability. The linear theory of electron-hose instability in a uniform ion column predicts that for the parameters of the E157 experiment (beam charge, bunch length, and plasma density) a growth of the centroid offset should occur. Analysis of the E157 data has provided four critical results. The first was that the incoming beam did have a tilt. The tilt was much smaller than the radius and was measured to be 5.3 {micro}m/{delta}{sub z} at the entrance of the plasma (IP1.) The second was the beam centroid oscillates in the ion channel at half the frequency of the beam radius (betatron beam oscillations), and these oscillations can be predicted by the envelope equation. Third, up to the maximum operating plasma density of E157 ({approx}2 x 10{sup 14} cm{sup -3}), no growth of the centroid offset was measured. Finally, time-resolved data of the beam shows that up to this density, no significant growth of the tail of the beam (up to 8ps from the centroid) occurred even though the beam had an initial tilt.

  19. Robotic hand with modular extensions

    DOEpatents

    Salisbury, Curt Michael; Quigley, Morgan

    2015-01-20

    A robotic device is described herein. The robotic device includes a frame that comprises a plurality of receiving regions that are configured to receive a respective plurality of modular robotic extensions. The modular robotic extensions are removably attachable to the frame at the respective receiving regions by way of respective mechanical fuses. Each mechanical fuse is configured to trip when a respective modular robotic extension experiences a predefined load condition, such that the respective modular robotic extension detaches from the frame when the load condition is met.

  20. Development of a modularized seating system to actively manage interface pressure.

    PubMed

    Yu, Chung-Huang; Chou, Tung-Yu; Chen, Cheng-Huan; Chen, Poyin; Wang, Fu-Cheng

    2014-01-01

    Pressure ulcers can be a fatal complication. Many immobile wheelchair users face this threat. Current passive and active cushions do reduce the incidence of pressure ulcers and they have different merits. We proposed an active approach to combine their advantages which is based on the concept that the interface pressure can be changed with different supporting shapes. The purpose of this paper is to verify the proposed approach. With practical applications in mind, we have developed a modular system whose support surface is composed by height-adjustable support elements. Each four-element module was self-contained and composed of force sensors, position sensors, linear actuators, signal conditioners, driving circuits, and signal processors. The modules could be chained and assembled together easily to form different-sized support surfaces. Each support element took up a 3 cm × 3 cm supporting area. The displacement resolution was less than 0.1 mm and the force sensor error was less than 1% in the 2000 g range. Each support element of the system could provide 49 N pushing force (408 mmHg over the 3 cm × 3 cm area) at a speed of 2.36 mm/s. Several verification tests were performed to assess the whole system's feasibility. Further improvements and clinical applications were discussed. In conclusion, this modularized system is capable of actively managing interface pressure in real time. PMID:25098206

  1. Development of a Modularized Seating System to Actively Manage Interface Pressure

    PubMed Central

    Yu, Chung-Huang; Chou, Tung-Yu; Chen, Cheng-Huan; Chen, Poyin; Wang, Fu-Cheng

    2014-01-01

    Pressure ulcers can be a fatal complication. Many immobile wheelchair users face this threat. Current passive and active cushions do reduce the incidence of pressure ulcers and they have different merits. We proposed an active approach to combine their advantages which is based on the concept that the interface pressure can be changed with different supporting shapes. The purpose of this paper is to verify the proposed approach. With practical applications in mind, we have developed a modular system whose support surface is composed by height-adjustable support elements. Each four-element module was self-contained and composed of force sensors, position sensors, linear actuators, signal conditioners, driving circuits, and signal processors. The modules could be chained and assembled together easily to form different-sized support surfaces. Each support element took up a 3 cm × 3 cm supporting area. The displacement resolution was less than 0.1 mm and the force sensor error was less than 1% in the 2000 g range. Each support element of the system could provide 49 N pushing force (408 mmHg over the 3 cm × 3 cm area) at a speed of 2.36 mm/s. Several verification tests were performed to assess the whole system's feasibility. Further improvements and clinical applications were discussed. In conclusion, this modularized system is capable of actively managing interface pressure in real time. PMID:25098206

  2. Column generation algorithms for exact modularity maximization in networks.

    PubMed

    Aloise, Daniel; Cafieri, Sonia; Caporossi, Gilles; Hansen, Pierre; Perron, Sylvain; Liberti, Leo

    2010-10-01

    Finding modules, or clusters, in networks currently attracts much attention in several domains. The most studied criterion for doing so, due to Newman and Girvan [Phys. Rev. E 69, 026113 (2004)], is modularity maximization. Many heuristics have been proposed for maximizing modularity and yield rapidly near optimal solution or sometimes optimal ones but without a guarantee of optimality. There are few exact algorithms, prominent among which is a paper by Xu [Eur. Phys. J. B 60, 231 (2007)]. Modularity maximization can also be expressed as a clique partitioning problem and the row generation algorithm of Grötschel and Wakabayashi [Math. Program. 45, 59 (1989)] applied. We propose to extend both of these algorithms using the powerful column generation methods for linear and non linear integer programming. Performance of the four resulting algorithms is compared on problems from the literature. Instances with up to 512 entities are solved exactly. Moreover, the computing time of previously solved problems are reduced substantially. PMID:21230350

  3. Modular biometric system

    NASA Astrophysics Data System (ADS)

    Hsu, Charles; Viazanko, Michael; O'Looney, Jimmy; Szu, Harold

    2009-04-01

    Modularity Biometric System (MBS) is an approach to support AiTR of the cooperated and/or non-cooperated standoff biometric in an area persistent surveillance. Advanced active and passive EOIR and RF sensor suite is not considered here. Neither will we consider the ROC, PD vs. FAR, versus the standoff POT in this paper. Our goal is to catch the "most wanted (MW)" two dozens, separately furthermore ad hoc woman MW class from man MW class, given their archrivals sparse front face data basis, by means of various new instantaneous input called probing faces. We present an advanced algorithm: mini-Max classifier, a sparse sample realization of Cramer-Rao Fisher bound of the Maximum Likelihood classifier that minimize the dispersions among the same woman classes and maximize the separation among different man-woman classes, based on the simple feature space of MIT Petland eigen-faces. The original aspect consists of a modular structured design approach at the system-level with multi-level architectures, multiple computing paradigms, and adaptable/evolvable techniques to allow for achieving a scalable structure in terms of biometric algorithms, identification quality, sensors, database complexity, database integration, and component heterogenity. MBS consist of a number of biometric technologies including fingerprints, vein maps, voice and face recognitions with innovative DSP algorithm, and their hardware implementations such as using Field Programmable Gate arrays (FPGAs). Biometric technologies and the composed modularity biometric system are significant for governmental agencies, enterprises, banks and all other organizations to protect people or control access to critical resources.

  4. Modular gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    A gearing system using modular gear bearing components. Each component is composed of a core, one or more modules attached to the core and two or more fastening modules rigidly attaching the modules to the core. The modules, which are attached to the core, may consist of gears, rollers or gear bearing components. The core orientation affects the orientation of the modules attached to the core. This is achieved via the keying arrangement of the core and the component modules that attach to the core. Such an arrangement will also facilitate the phase tuning of gear modules with respect to the core and other gear modules attached to the core.

  5. Modular space station facilities.

    NASA Technical Reports Server (NTRS)

    Parker, P. J.

    1973-01-01

    The modular space station will operate as a general purpose laboratory (GPL). In addition, the space station will be able to support many attached or free-flying research and application modules that would be dedicated to specific projects like astronomy or earth observations. The GPL primary functions have been organized into functional laboratories including an electrical/electronics laboratory, a mechanical sciences laboratory, an experiment and test isolation laboratory, a hard data process facility, a data evaluation facility, an optical sciences laboratory, a biomedical and biosciences laboratory, and an experiment/secondary command and control center.

  6. Network-based modular latent structure analysis

    PubMed Central

    2014-01-01

    Background High-throughput expression data, such as gene expression and metabolomics data, exhibit modular structures. Groups of features in each module follow a latent factor model, while between modules, the latent factors are quasi-independent. Recovering the latent factors can shed light on the hidden regulation patterns of the expression. The difficulty in detecting such modules and recovering the latent factors lies in the high dimensionality of the data, and the lack of knowledge in module membership. Methods Here we describe a method based on community detection in the co-expression network. It consists of inference-based network construction, module detection, and interacting latent factor detection from modules. Results In simulations, the method outperformed projection-based modular latent factor discovery when the input signals were not Gaussian. We also demonstrate the method's value in real data analysis. Conclusions The new method nMLSA (network-based modular latent structure analysis) is effective in detecting latent structures, and is easy to extend to non-linear cases. The method is available as R code at http://web1.sph.emory.edu/users/tyu8/nMLSA/. PMID:25435002

  7. Modular Wideband Active Vibration Absorber

    NASA Technical Reports Server (NTRS)

    Smith, David R.; Zewari, Wahid; Lee, Kenneth Y.

    1999-01-01

    A comparison of space experiments with previous missions shows a common theme. Some of the recent experiments are based on the scientific fundamentals of instruments of prior years. However, the main distinguishing characteristic is the embodiment of advances in engineering and manufacturing in order to extract clearer and sharper images and extend the limits of measurement. One area of importance to future missions is providing vibration free observation platforms at acceptable costs. It has been shown by researchers that vibration problems cannot be eliminated by passive isolation techniques alone. Therefore, various organizations have conducted research in the area of combining active and passive vibration control techniques. The essence of this paper is to present progress in what is believed to be a new concept in this arena. It is based on the notion that if one active element in a vibration transmission path can provide a reasonable vibration attenuation, two active elements in series may provide more control options and better results. The paper presents the functions of a modular split shaft linear actuator developed by NASA's Goddard Space Flight Center and University of Massachusetts Lowell. It discusses some of the control possibilities facilitated by the device. Some preliminary findings and problems are also discussed.

  8. Modular antenna design study

    NASA Technical Reports Server (NTRS)

    Ribble, J. W.

    1981-01-01

    The mechanical design of a modular antenna concept was developed sufficiently to allow manufacture of a working demonstration model of a module, to predict mass properties, and to make performance estimates for antenna reflectors composed of these modules. The primary features of this concept are: (1) each module is an autonomous structural element which can be attached to adjacent modules through a three point connection; (2) the upper surface is a folding hexagonal truss plate mechanism which serves as the supporting structure for a reflective surface; and (3) the entire truss and surface can be folded into a cylindrical envelope in which all truss elements are essentially parallel. The kinematic studies and engineering demonstration model fully verified the deployment kinematics, stowing philosophy, and deployment sequencing for large antenna modules. It was established that such modules can be stowed in packages as small as 25 cm in diameter, using 1.27 cm diameter structural tubes. The development activity indicates that this deployable modular approach towards building large structures in space will support erection of 450 m apertures for operation up to 3 GHz with a single space shuttle flight.

  9. Terpene Biosynthesis: Modularity Rules

    PubMed Central

    Oldfield, Eric; Lin, Fu-Yang

    2013-01-01

    Terpenes are the largest class of small molecule natural products on Earth, and the most abundant by mass. Here, we summarize recent developments in elucidating the structure and function of the proteins involved in their biosynthesis. There are 6 main building blocks or modules (α,β,γ,δ,ε and ζ) that make up the structures of these enzymes: the αα and αδ head-to-tail trans-prenyl transferases that produce trans-isoprenoid diphosphates from C5 precursors; the ε head-to-head prenyl transferases that convert these diphosphates into the tri-and tetra-terpene precursors of sterols, hopanoids and carotenoids; the βγ di- and tri-terpene synthases; the ζ head-to-tail cis-prenyl transferases that produce the cis-isoprenoid diphosphates involved in bacterial cell wall biosynthesis, and finally the α, αβ and αβγ terpene synthases that produce plant terpenes, with many of these modular enzymes having originated from ancestral α and β domain proteins. We also review progress in determining the structure and function of the two 4Fe-4S reductases involved in formation of the C5 diphosphates in many bacteria, where again, highly modular structures are found. PMID:22105807

  10. Modular reflector concept study

    NASA Technical Reports Server (NTRS)

    Vaughan, D. H.

    1981-01-01

    A study was conducted to evaluate the feasibility of space erecting a 100 meter paraboloidal radio frequency reflector by joining a number of individually deployed structural modules. Three module design concepts were considered: (1) the deployable cell module (DCM); (2) the modular paraboloidal erectable truss antenna (Mod-PETA); and (3) the modular erectable truss antenna (META). With the space shuttle (STS) as the launch system, the methodology of packaging and stowing in the orbiter, and of dispensing, deploying and joining, in orbit, were studied and the necessary support equipment identified. The structural performance of the completed reflectors was evaluated and their overall operational capability and feasibility were evaluated and compared. The potential of the three concepts to maintain stable shape in the space environment was determined. Their ability to operate at radio frequencies of 1 GHz and higher was assessed assuming the reflector surface to consist of a number of flat, hexagonal facets. A parametric study was performed to determine figure degradation as a function of reflector size, flat facet size, and f/D ratio.

  11. Modular robotic architecture

    NASA Astrophysics Data System (ADS)

    Smurlo, Richard P.; Laird, Robin T.

    1991-03-01

    The development of control architectures for mobile systems is typically a task undertaken with each new application. These architectures address different operational needs and tend to be difficult to adapt to more than the problem at hand. The development of a flexible and extendible control system with evolutionary growth potential for use on mobile robots will help alleviate these problems and if made widely available will promote standardization and cornpatibility among systems throughout the industry. The Modular Robotic Architecture (MRA) is a generic control systern that meets the above needs by providing developers with a standard set of software hardware tools that can be used to design modular robots (MODBOTs) with nearly unlimited growth potential. The MODBOT itself is a generic creature that must be customized by the developer for a particular application. The MRA facilitates customization of the MODBOT by providing sensor actuator and processing modules that can be configured in almost any manner as demanded by the application. The Mobile Security Robot (MOSER) is an instance of a MODBOT that is being developed using the MRA. Navigational Sonar Module RF Link Control Station Module hR Link Detection Module Near hR Proximi Sensor Module Fluxgate Compass and Rate Gyro Collision Avoidance Sonar Module Figure 1. Remote platform module configuration of the Mobile Security Robot (MOSER). Acoustical Detection Array Stereoscopic Pan and Tilt Module High Level Processing Module Mobile Base 566

  12. Modular radiochemistry synthesis system

    SciTech Connect

    Satyamurthy, Nagichettiar; Barrio, Jorge R; Amarasekera, Bernard; Van Dam, R. Michael; Olma, Sebastian; Williams, Dirk; Eddings, Mark A; Shen, Clifton Kwang-Fu

    2015-02-10

    A modular chemical production system includes multiple modules for performing a chemical reaction, particularly of radiochemical compounds, from a remote location. One embodiment comprises a reaction vessel including a moveable heat source with the position thereof relative to the reaction vessel being controllable from a remote position. Alternatively the heat source may be fixed in location and the reaction vial is moveable into and out of the heat source. The reaction vessel has one or more sealing plugs, the positioning of which in relationship to the reaction vessel is controllable from a remote position. Also the one or more reaction vessel sealing plugs can include one or more conduits there through for delivery of reactants, gases at atmospheric or an elevated pressure, inert gases, drawing a vacuum and removal of reaction end products to and from the reaction vial, the reaction vial with sealing plug in position being operable at elevated pressures. The modular chemical production system is assembled from modules which can each include operating condition sensors and controllers configured for monitoring and controlling the individual modules and the assembled system from a remote position. Other modules include, but are not limited to a Reagent Storage and Delivery Module, a Cartridge Purification Module, a Microwave Reaction Module, an External QC/Analysis/Purification Interface Module, an Aliquotting Module, an F-18 Drying Module, a Concentration Module, a Radiation Counting Module, and a Capillary Reactor Module.

  13. Modular radiochemistry synthesis system

    SciTech Connect

    Satyamurthy, Nagichettiar; Barrio, Jorge R.; Amarasekera, Bernard; Van Dam, R. Michael; Olma, Sebastian; Williams, Dirk; Eddings, Mark; Shen, Clifton Kwang-Fu

    2015-12-15

    A modular chemical production system includes multiple modules for performing a chemical reaction, particularly of radiochemical compounds, from a remote location. One embodiment comprises a reaction vessel including a moveable heat source with the position thereof relative to the reaction vessel being controllable from a remote position. Alternatively the heat source may be fixed in location and the reaction vial is moveable into and out of the heat source. The reaction vessel has one or more sealing plugs, the positioning of which in relationship to the reaction vessel is controllable from a remote position. Also the one or more reaction vessel sealing plugs can include one or more conduits there through for delivery of reactants, gases at atmospheric or an elevated pressure, inert gases, drawing a vacuum and removal of reaction end products to and from the reaction vial, the reaction vial with sealing plug in position being operable at elevated pressures. The modular chemical production system is assembled from modules which can each include operating condition sensors and controllers configured for monitoring and controlling the individual modules and the assembled system from a remote position. Other modules include, but are not limited to a Reagent Storage and Delivery Module, a Cartridge Purification Module, a Microwave Reaction Module, an External QC/Analysis/Purification Interface Module, an Aliquotting Module, an F-18 Drying Module, a Concentration Module, a Radiation Counting Module, and a Capillary Reactor Module.

  14. Modular Finite Element Methods Library Version: 1.0

    Energy Science and Technology Software Center (ESTSC)

    2010-06-22

    MFEM is a general, modular library for finite element methods. It provides a variety of finite element spaces and bilinear/linear forms in 2D and 3D. MFEM also includes classes for dealing with various types of meshes and their refinement.

  15. Advanced Modular Inverter Technology Development

    SciTech Connect

    Adam Szczepanek

    2006-02-04

    was to design and validate new gate drive circuits to provide the capability of high temp operation. The new power stages and controls were later validated through extensive performance, durability and environmental tests. To further validate the design, two power stages and controls were integrated into a grid-tied load bank test fixture, a real application for field-testing. This fixture was designed to test motor drives with PWM output up to 50kW. In the second part of this program the new control topology based on sub-phases control and interphase transformer technology was successfully developed and validated. The main advantage of this technology is to reduce magnetic mass, loss and current ripple. This report summarizes the results of the advanced modular inverter technology development and details: (1) Power stage development and fabrication (2) Power stage validation testing (3) Grid-tied test fixture fabrication and initial testing (4) Interphase transformer technology development

  16. Quantum modular forms, mock modular forms, and partial theta functions

    NASA Astrophysics Data System (ADS)

    Kimport, Susanna

    Defined by Zagier in 2010, quantum modular forms have been the subject of an explosion of recent research. Many of these results are aimed at discovering examples of these functions, which are defined on the rational numbers and have "nice" modularity properties. Though the subject is in its early stages, numerous results (including Zagier's original examples) show these objects naturally arising from many areas of mathematics as limits of other modular-like functions. One such family of examples is due to Folsom, Ono, and Rhoades, who connected these new objects to partial theta functions (introduced by Rogers in 1917) and mock modular forms (about which there is a rich theory, whose origins date back to Ramanujan in 1920). In this thesis, we build off of the work of Folsom, Ono, and Rhoades by providing an infinite family of quantum modular forms of arbitrary positive half-integral weight. Further, this family of quantum modular forms "glues" mock modular forms to partial theta functions and is constructed from a so-called "universal" mock theta function by extending a method of Eichler and Zagier (originally defined for holomorphic Jacobi forms) into a non-holomorphic setting. In addition to the infinite family, we explore the weight 1/2 and 3/2 functions in more depth. For both of these weights, we are able to explicitly write down the quantum modular form, as well as the corresponding "errors to modularity," which can be shown to be Mordell integrals of specific theta functions and, as a consequence, are real-analytic functions. Finally, we turn our attention to the partial theta functions associated with these low weight examples. Berndt and Kim provide asymptotic expansions for a certain class of partial theta functions as q approaches 1 radially within the unit disk. Here, we extend this work to not only obtain asymptotic expansions for this class of functions as q approaches any root of unity, but also for a certain class of derivatives of these functions

  17. Spacecraft Modularity for Serviceable Satellites

    NASA Technical Reports Server (NTRS)

    Rossetti, Dino; Keer, Beth; Panek, John; Ritter, Bob; Reed, Benjamin; Cepollina, Frank

    2015-01-01

    Spacecraft modularity has been a topic of interest at NASA since the 1970s, when the Multi-­-Mission Modular Spacecraft (MMS) was developed at the Goddard Space Flight Center. Since then, modular concepts have been employed for a variety of spacecraft and, as in the case of the Hubble Space Telescope (HST) and the International Space Station (ISS), have been critical to the success of on-­- orbit servicing. Modularity is even more important for future robotic servicing. Robotic satellite servicing technologies under development by NASA can extend mission life and reduce lifecycle cost and risk. These are optimized when the target spacecraft is designed for servicing, including advanced modularity. This paper will explore how spacecraft design, as demonstrated by the Reconfigurable Operational spacecraft for Science and Exploration (ROSE) spacecraft architecture, and servicing technologies can be developed in parallel to fully take advantage of the promise of both.

  18. Spacecraft Modularity for Serviceable Satellites

    NASA Technical Reports Server (NTRS)

    Reed, Benjamin B.; Rossetti, Dino; Keer, Beth; Panek, John; Cepollina, Frank; Ritter, Robert

    2015-01-01

    Spacecraft modularity has been a topic of interest at NASA since the 1970s, when the Multi-Mission Modular Spacecraft (MMS) was developed at the Goddard Space Flight Center. Since then, modular concepts have been employed for a variety of spacecraft and, as in the case of the Hubble Space Telescope (HST) and the International Space Station (ISS), have been critical to the success of on-orbit servicing. Modularity is even more important for future robotic servicing. Robotic satellite servicing technologies under development by NASA can extend mission life and reduce life-cycle cost and risk. These are optimized when the target spacecraft is designed for servicing, including advanced modularity. This paper will explore how spacecraft design, as demonstrated by the Reconfigurable Operational spacecraft for Science and Exploration (ROSE) spacecraft architecture, and servicing technologies can be developed in parallel to fully take advantage of the promise of both.

  19. Modular Flooring System

    NASA Technical Reports Server (NTRS)

    Thate, Robert

    2012-01-01

    The modular flooring system (MFS) was developed to provide a portable, modular, durable carpeting solution for NASA fs Robotics Alliance Project fs (RAP) outreach efforts. It was also designed to improve and replace a modular flooring system that was too heavy for safe use and transportation. The MFS was developed for use as the flooring for various robotics competitions that RAP utilizes to meet its mission goals. One of these competitions, the FIRST Robotics Competition (FRC), currently uses two massive rolls of broadloom carpet for the foundation of the arena in which the robots are contained during the competition. The area of the arena is approximately 30 by 72 ft (approximately 9 by 22 m). This carpet is very cumbersome and requires large-capacity vehicles, and handling equipment and personnel to transport and deploy. The broadloom carpet sustains severe abuse from the robots during a regular three-day competition, and as a result, the carpet is not used again for competition. Similarly, broadloom carpets used for trade shows at convention centers around the world are typically discarded after only one use. This innovation provides a green solution to this wasteful practice. Each of the flooring modules in the previous system weighed 44 lb (.20 kg). The improvements in the overall design of the system reduce the weight of each module by approximately 22 lb (.10 kg) (50 %), and utilize an improved "module-to-module" connection method that is superior to the previous system. The MFS comprises 4-by-4-ft (.1.2-by- 1.2-m) carpet module assemblies that utilize commercially available carpet tiles that are bonded to a lightweight substrate. The substrate surface opposite from the carpeted surface has a module-to-module connecting interface that allows for the modules to be connected, one to the other, as the modules are constructed. This connection is hidden underneath the modules, creating a smooth, co-planar flooring surface. The modules are stacked and strapped

  20. The modular power subsystem for the multimission modular spacecraft

    NASA Technical Reports Server (NTRS)

    Harris, D. W.

    1978-01-01

    The block diagram, subsystems, and components of the modular power subsystem for the multimission modular spacecraft (MMS) are described. The basic design studies were guided by considerations of cost, efficiency, simplicity, and flexibility to serve a variety of missions. Components discussed are the power regulator unit, the power control unit, the signal conditioning assembly, bus protection assembly, and the 20 Ah and 50 Ah batteries. The plan for the modular power subsystem protoflight module tests is shown. The testing has four phases: (1) component level tests, (2) subsystem integration and initial performance test, (3) subsystem protoflight environmental tests, and (4) subsystem final performance tests, qualification/acceptance review and delivery.

  1. Modular electronics packaging system

    NASA Technical Reports Server (NTRS)

    Hunter, Don J. (Inventor)

    2001-01-01

    A modular electronics packaging system includes multiple packaging slices that are mounted horizontally to a base structure. The slices interlock to provide added structural support. Each packaging slice includes a rigid and thermally conductive housing having four side walls that together form a cavity to house an electronic circuit. The chamber is enclosed on one end by an end wall, or web, that isolates the electronic circuit from a circuit in an adjacent packaging slice. The web also provides a thermal path between the electronic circuit and the base structure. Each slice also includes a mounting bracket that connects the packaging slice to the base structure. Four guide pins protrude from the slice into four corresponding receptacles in an adjacent slice. A locking element, such as a set screw, protrudes into each receptacle and interlocks with the corresponding guide pin. A conduit is formed in the slice to allow electrical connection to the electronic circuit.

  2. Modular error embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.; Ettinger, J. Mark

    1999-01-01

    A method of embedding auxiliary information into the digital representation of host data containing noise in the low-order bits. The method applies to digital data representing analog signals, for example digital images. The method reduces the error introduced by other methods that replace the low-order bits with auxiliary information. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user through use of a digital key. The modular error embedding method includes a process to permute the order in which the host data values are processed. The method doubles the amount of auxiliary information that can be added to host data values, in comparison with bit-replacement methods for high bit-rate coding. The invention preserves human perception of the meaning and content of the host data, permitting the addition of auxiliary data in the amount of 50% or greater of the original host data.

  3. Modular Optical PDV System

    SciTech Connect

    Araceli Rutkowski, David Esquibel

    2008-12-11

    A modular optical photon Doppler velocimetry (PDV) detector system has been developed by using readily available optical components with a 20-GHz Miteq optical detector into eight channels of single-wide modules integrated into a 3U rack unit (1U = 1.75 inches) with a common power supply. Optical fibers were precisely trimmed, welded, and timed within each unit. This system has been used to collect dynamic velocity data on various physics experiments. An optical power meter displays the laser input power to the module and optical power at the detector. An adjustable micro-electromechanical system (MEMS) optical attenuator is used to adjust the amount of unshifted light entering the detector. Front panel LEDs show the presence of power to the module. A fully loaded chassis with eight channels consumes 45 watts of power. Each chassis requires 1U spacing above and below for heat management. Modules can be easily replaced.

  4. Modular arctic structures system

    SciTech Connect

    Reusswig, G. H.

    1984-12-04

    A modular and floatable offshore exploration and production platform system for use in shallow arctic waters is disclosed. A concrete base member is floated to the exploration or production site, and ballated into a predredged cavity. The cavity and base are sized to provide a stable horizontal base 30 feet below the mean water/ice plane. An exploration or production platform having a massive steel base is floated to the site and ballasted into position on the base. Together, the platform, base and ballast provide a massive gravity structure that is capable of resisting large ice and wave forces that impinge on the structure. The steel platform has a sloping hourglass profile to deflect horizontal ice loads vertically, and convert the horizontal load to a vertical tensile stress, which assists in breaking the ice as it advances toward the structure.

  5. Modular small hydro configuration

    NASA Astrophysics Data System (ADS)

    1981-09-01

    Smaller sites (those under 750 kilowatts) which previously were not attractive to develop using equipment intended for application at larger scale sites, were the focal point in the conception of a system which utilizes standard industrial components which are generally available within short procurement times. Such components were integrated into a development scheme for sites having 20 feet to 150 feet of head. The modular small hydro configuration maximizes the use of available components and minimizes modification of existing civil works. A key aspect of the development concept is the use of a vertical turbine multistage pump, used in the reverse mode as a hydraulic turbine. The configuration allows for automated operation and control of the hydroelectric facilities with sufficient flexibility for inclusion of potential hydroelectric sites into dispersed storage and generation (DSG) utility grid systems.

  6. Modular Chemical Descriptor Language (MCDL): Stereochemical modules

    SciTech Connect

    Gakh, Andrei A; Burnett, Michael N; Trepalin, Sergei V.; Yarkov, Alexander V

    2011-01-01

    In our previous papers we introduced the Modular Chemical Descriptor Language (MCDL) for providing a linear representation of chemical information. A subsequent development was the MCDL Java Chemical Structure Editor which is capable of drawing chemical structures from linear representations and generating MCDL descriptors from structures. In this paper we present MCDL modules and accompanying software that incorporate unique representation of molecular stereochemistry based on Cahn-Ingold-Prelog and Fischer ideas in constructing stereoisomer descriptors. The paper also contains additional discussions regarding canonical representation of stereochemical isomers, and brief algorithm descriptions of the open source LINDES, Java applet, and Open Babel MCDL processing module software packages. Testing of the upgraded MCDL Java Chemical Structure Editor on compounds taken from several large and diverse chemical databases demonstrated satisfactory performance for storage and processing of stereochemical information in MCDL format.

  7. Some new modular equations and their applications

    NASA Astrophysics Data System (ADS)

    Yi, Jinhee; Sim, Hyo Seob

    2006-07-01

    Ramanujan derived 23 beautiful eta-function identities, which are certain types of modular equations. We found more than 70 of certain types of modular equations by using Garvan's Maple q-series package. In this paper, we prove some new modular equations which we found by employing the theory of modular form and we give some applications for them.

  8. Distracted driving

    MedlinePlus

    ... stay safe with a cell phone in the car. ... for Disease Control and Prevention Injury Prevention & Control. Motor Vehicle Safety. www.cdc.gov/motorvehiclesafety/distracted_driving . Accessed May ...

  9. Driving Safely

    MedlinePlus

    ... drivers’ flexibility and coordination, and reduced driving errors. S l Hand grip strengthening to help you hold on to the steering wheel l Shoulder and upper arm flexibility exercises to make ...

  10. Distracted Driving

    MedlinePlus

    ... combines all three types of distraction. 3 How big is the problem? Deaths In 2013, 3,154 ... European countries. More A CDC study analyzed 2011 data on distracted driving, including talking on a cell ...

  11. Modular Arithmetic in the Marketplace.

    ERIC Educational Resources Information Center

    Gallian, Joseph A.; Winters, Steven

    1988-01-01

    Several schemes use modular arithmetic to append a check digit to product identification numbers for error detection. Some schemes are discussed, including ones for money orders and library books. Then a foolproof method is presented. (MNS)

  12. The evolutionary origins of modularity.

    PubMed

    Clune, Jeff; Mouret, Jean-Baptiste; Lipson, Hod

    2013-03-22

    A central biological question is how natural organisms are so evolvable (capable of quickly adapting to new environments). A key driver of evolvability is the widespread modularity of biological networks--their organization as functional, sparsely connected subunits--but there is no consensus regarding why modularity itself evolved. Although most hypotheses assume indirect selection for evolvability, here we demonstrate that the ubiquitous, direct selection pressure to reduce the cost of connections between network nodes causes the emergence of modular networks. Computational evolution experiments with selection pressures to maximize network performance and minimize connection costs yield networks that are significantly more modular and more evolvable than control experiments that only select for performance. These results will catalyse research in numerous disciplines, such as neuroscience and genetics, and enhance our ability to harness evolution for engineering purposes. PMID:23363632

  13. The evolutionary origins of modularity

    PubMed Central

    Clune, Jeff; Mouret, Jean-Baptiste; Lipson, Hod

    2013-01-01

    A central biological question is how natural organisms are so evolvable (capable of quickly adapting to new environments). A key driver of evolvability is the widespread modularity of biological networks—their organization as functional, sparsely connected subunits—but there is no consensus regarding why modularity itself evolved. Although most hypotheses assume indirect selection for evolvability, here we demonstrate that the ubiquitous, direct selection pressure to reduce the cost of connections between network nodes causes the emergence of modular networks. Computational evolution experiments with selection pressures to maximize network performance and minimize connection costs yield networks that are significantly more modular and more evolvable than control experiments that only select for performance. These results will catalyse research in numerous disciplines, such as neuroscience and genetics, and enhance our ability to harness evolution for engineering purposes. PMID:23363632

  14. Fluid cooled vehicle drive module

    DOEpatents

    Beihoff, Bruce C.; Radosevich, Lawrence D.; Meyer, Andreas A.; Gollhardt, Neil; Kannenberg, Daniel G.

    2005-11-15

    An electric vehicle drive includes a support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support, in conjunction with other packaging features may form a shield from both external EM/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  15. Spacecraft Modularity for Serviceable Satellites

    NASA Technical Reports Server (NTRS)

    Rossetti, Dino; Keer, Beth; Panek, John; Reed, Benjamin; Cepollina, Frank; Ritter, Robert

    2015-01-01

    Satellite servicing has been a proven capability of NASA since the first servicing missions in the 1980s with astronauts on the space shuttle. This capability enabled the on-orbit assembly of the International Space Station (ISS) and saved the Hubble Space Telescope (HST) mission following the discovery of the flawed primary mirror. The effectiveness and scope of servicing opportunities, especially using robotic servicers, is a function of how cooperative a spacecraft is. In this paper, modularity will be presented as a critical design aspect for a spacecraft that is cooperative from a servicing perspective. Different features of modularity are discussed using examples from HST and the Multimission Modular Spacecraft (MMS) program from the 1980s and 1990s. The benefits of modularity will be presented including those directly related to servicing and those outside of servicing including reduced costs and increased flexibility. The new Reconfigurable Operational spacecraft for Science and Exploration (ROSE) concept is introduced as an affordable implementation of modularity that provides cost savings and flexibility. Key aspects of the ROSE architecture are discussed such as the module design and the distributed avionics architecture. The ROSE concept builds on the experience from MMS and due to its modularity, would be highly suitable as a future client for on-orbit servicing.

  16. The modularity of pollination networks

    PubMed Central

    Olesen, Jens M.; Bascompte, Jordi; Dupont, Yoko L.; Jordano, Pedro

    2007-01-01

    In natural communities, species and their interactions are often organized as nonrandom networks, showing distinct and repeated complex patterns. A prevalent, but poorly explored pattern is ecological modularity, with weakly interlinked subsets of species (modules), which, however, internally consist of strongly connected species. The importance of modularity has been discussed for a long time, but no consensus on its prevalence in ecological networks has yet been reached. Progress is hampered by inadequate methods and a lack of large datasets. We analyzed 51 pollination networks including almost 10,000 species and 20,000 links and tested for modularity by using a recently developed simulated annealing algorithm. All networks with >150 plant and pollinator species were modular, whereas networks with <50 species were never modular. Both module number and size increased with species number. Each module includes one or a few species groups with convergent trait sets that may be considered as coevolutionary units. Species played different roles with respect to modularity. However, only 15% of all species were structurally important to their network. They were either hubs (i.e., highly linked species within their own module), connectors linking different modules, or both. If these key species go extinct, modules and networks may break apart and initiate cascades of extinction. Thus, species serving as hubs and connectors should receive high conservation priorities. PMID:18056808

  17. Modular Approach to Spintronics

    PubMed Central

    Camsari, Kerem Yunus; Ganguly, Samiran; Datta, Supriyo

    2015-01-01

    There has been enormous progress in the last two decades, effectively combining spintronics and magnetics into a powerful force that is shaping the field of memory devices. New materials and phenomena continue to be discovered at an impressive rate, providing an ever-increasing set of building blocks that could be exploited in designing transistor-like functional devices of the future. The objective of this paper is to provide a quantitative foundation for this building block approach, so that new discoveries can be integrated into functional device concepts, quickly analyzed and critically evaluated. Through careful benchmarking against available theory and experiment we establish a set of elemental modules representing diverse materials and phenomena. These elemental modules can be integrated seamlessly to model composite devices involving both spintronic and nanomagnetic phenomena. We envision the library of modules to evolve both by incorporating new modules and by improving existing modules as the field progresses. The primary contribution of this paper is to establish the ground rules or protocols for a modular approach that can build a lasting bridge between materials scientists and circuit designers in the field of spintronics and nanomagnetics. PMID:26066079

  18. Modular Isotopic Thermoelectric Generator

    SciTech Connect

    Schock, Alfred

    1981-04-03

    Advanced RTG concepts utilizing improved thermoelectric materials and converter concepts are under study at Fairchild for DOE. The design described here is based on DOE's newly developed radioisotope heat source, and on an improved silicon-germanium material and a multicouple converter module under development at Syncal. Fairchild's assignment was to combine the above into an attractive power system for use in space, and to assess the specific power and other attributes of that design. The resultant design is highly modular, consisting of standard RTG slices, each producing ~24 watts at the desired output voltage of 28 volt. Thus, the design could be adapted to various space missions over a wide range of power levels, with little or no redesign. Each RTG slice consists of a 250-watt heat source module, eight multicouple thermoelectric modules, and standard sections of insulator, housing, radiator fins, and electrical circuit. The design makes it possible to check each thermoelectric module for electrical performance, thermal contact, leaktightness, and performance stability, after the generator is fully assembled; and to replace any deficient modules without disassembling the generator or perturbing the others. The RTG end sections provide the spring-loaded supports required to hold the free-standing heat source stack together during launch vibration. Details analysis indicates that the design offers a substantial improvement in specific power over the present generator of RTGs, using the same heat source modules. There are three copies in the file.

  19. Modular Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

    2016-01-01

    High-efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRGs) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high-specific-power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTGs). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and the Department of Energy (DOE) called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered, which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provided about 50 to 450 W of direct current (DC) to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator, which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific

  20. Modular Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

    2015-01-01

    High efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRG) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high specific power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTG). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and DOE called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provide about 50 to 450 watts DC to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific power may be slightly lower than the ASRG and

  1. Phage-bacteria infection networks: From nestedness to modularity

    NASA Astrophysics Data System (ADS)

    Flores, Cesar O.; Valverde, Sergi; Weitz, Joshua S.

    2013-03-01

    Bacteriophages (viruses that infect bacteria) are the most abundant biological life-forms on Earth. However, very little is known regarding the structure of phage-bacteria infections. In a recent study we re-evaluated 38 prior studies and demonstrated that phage-bacteria infection networks tend to be statistically nested in small scale communities (Flores et al 2011). Nestedness is consistent with a hierarchy of infection and resistance within phages and bacteria, respectively. However, we predicted that at large scales, phage-bacteria infection networks should be typified by a modular structure. We evaluate and confirm this hypothesis using the most extensive study of phage-bacteria infections (Moebus and Nattkemper 1981). In this study, cross-infections were evaluated between 215 marine phages and 286 marine bacteria. We develop a novel multi-scale network analysis and find that the Moebus and Nattkemper (1981) study, is highly modular (at the whole network scale), yet also exhibits nestedness and modularity at the within-module scale. We examine the role of geography in driving these modular patterns and find evidence that phage-bacteria interactions can exhibit strong similarity despite large distances between sites. CFG acknowledges the support of CONACyT Foundation. JSW holds a Career Award at the Scientific Interface from the Burroughs Wellcome Fund and acknowledges the support of the James S. McDonnell Foundation

  2. Metastring theory and modular space-time

    NASA Astrophysics Data System (ADS)

    Freidel, Laurent; Leigh, Robert G.; Minic, Djordje

    2015-06-01

    String theory is canonically accompanied with a space-time interpretation which determines S-matrix-like observables, and connects to the standard physics at low energies in the guise of local effective field theory. Recently, we have introduced a reformulation of string theory which does not rely on an a priori space-time interpretation or a pre-assumption of locality. This metastring theory is formulated in such a way that stringy symmetries (such as T-duality) are realized linearly. In this paper, we study metastring theory on a flat background and develop a variety of technical and interpretational ideas. These include a formulation of the moduli space of Lorentzian worldsheets, a careful study of the symplectic structure and consequently consistent closed and open boundary conditions, and the string spectrum and operator algebra. What emerges from these studies is a new quantum notion of space-time that we refer to as a quantum Lagrangian or equivalently a modular space-time. This concept embodies the standard tenets of quantum theory and implements in a precise way a notion of relative locality. The usual string backgrounds (non-compact space-time along with some toroidally compactified spatial directions) are obtained from modular space-time by a limiting procedure that can be thought of as a correspondence limit.

  3. Designing linear systolic arrays

    SciTech Connect

    Kumar, V.K.P.; Tsai, Y.C. . Dept. of Electrical Engineering)

    1989-12-01

    The authors develop a simple mapping technique to design linear systolic arrays. The basic idea of the technique is to map the computations of a certain class of two-dimensional systolic arrays onto one-dimensional arrays. Using this technique, systolic algorithms are derived for problems such as matrix multiplication and transitive closure on linearly connected arrays of PEs with constant I/O bandwidth. Compared to known designs in the literature, the technique leads to modular systolic arrays with constant hardware in each PE, few control lines, lexicographic data input/output, and improved delay time. The unidirectional flow of control and data in this design assures implementation of the linear array in the known fault models of wafer scale integration.

  4. Modular multimorphic kinematic arm structure and pitch and yaw joint for same

    DOEpatents

    Martin, H.L.; Williams, D.M.; Holt, W.E.

    1987-04-21

    A multimorphic kinematic manipulator arm is provided with seven degrees of freedom and modular kinematic redundancy through identical pitch/yaw, shoulder, elbow and wrist joints and a wrist roll device at the wrist joint, which further provides to the manipulator arm an obstacle avoidance capability. The modular pitch/yaw joints are traction drive devices which provide backlash free operation with smooth torque transmission and enhanced rigidity. A dual input drive arrangement is provided for each joint resulting in a reduction of the load required to be assumed by each drive means and providing selective pitch and yaw motions by control of the relative rotational directions of the input drive means. 12 figs.

  5. Product modular design incorporating preventive maintenance issues

    NASA Astrophysics Data System (ADS)

    Gao, Yicong; Feng, Yixiong; Tan, Jianrong

    2016-03-01

    Traditional modular design methods lead to product maintenance problems, because the module form of a system is created according to either the function requirements or the manufacturing considerations. For solving these problems, a new modular design method is proposed with the considerations of not only the traditional function related attributes, but also the maintenance related ones. First, modularity parameters and modularity scenarios for product modularity are defined. Then the reliability and economic assessment models of product modularity strategies are formulated with the introduction of the effective working age of modules. A mathematical model used to evaluate the difference among the modules of the product so that the optimal module of the product can be established. After that, a multi-objective optimization problem based on metrics for preventive maintenance interval different degrees and preventive maintenance economics is formulated for modular optimization. Multi-objective GA is utilized to rapidly approximate the Pareto set of optimal modularity strategy trade-offs between preventive maintenance cost and preventive maintenance interval difference degree. Finally, a coordinate CNC boring machine is adopted to depict the process of product modularity. In addition, two factorial design experiments based on the modularity parameters are constructed and analyzed. These experiments investigate the impacts of these parameters on the optimal modularity strategies and the structure of module. The research proposes a new modular design method, which may help to improve the maintainability of product in modular design.

  6. Direct drive field actuator motors

    DOEpatents

    Grahn, A.R.

    1998-03-10

    A positive-drive field actuator motor is described which includes a stator carrying at least one field actuator which changes in dimension responsive to application of an energy field, and at least one drive shoe movable by the dimensional changes of the field actuator to contact and move a rotor element with respect to the stator. Various embodiments of the motor are disclosed, and the rotor element may be moved linearly or arcuately. 62 figs.

  7. Direct drive field actuator motors

    DOEpatents

    Grahn, Allen R.

    1998-01-01

    A positive-drive field actuator motor including a stator carrying at least one field actuator which changes in dimension responsive to application of an energy field, and at least one drive shoe movable by the dimensional changes of the field actuator to contact and move a rotor element with respect to the stator. Various embodiments of the motor are disclosed, and the rotor element may be moved linearly or arcuately.

  8. LEGO: A modular accelerator design code

    SciTech Connect

    Cai, Y.; Donald, M.; Irwin, J.; Yan, Y.

    1997-08-01

    An object-oriented accelerator design code has been designed and implemented in a simple and modular fashion. It contains all major features of its predecessors: TRACY and DESPOT. All physics of single-particle dynamics is implemented based on the Hamiltonian in the local frame of the component. Components can be moved arbitrarily in the three dimensional space. Several symplectic integrators are used to approximate the integration of the Hamiltonian. A differential algebra class is introduced to extract a Taylor map up to arbitrary order. Analysis of optics is done in the same way both for the linear and nonlinear case. Currently, the code is used to design and simulate the lattices of the PEP-II. It will also be used for the commissioning.

  9. Coevolution, modularity and human disease.

    PubMed

    Fraser, Hunter B

    2006-12-01

    The concepts of coevolution and modularity have been studied separately for decades. Recent advances in genomics have led to the first systematic studies in each of these fields at the molecular level, resulting in several important discoveries. Both coevolution and modularity appear to be pervasive features of genomic data from all species studied to date, and their presence can be detected in many types of datasets, including genome sequences, gene expression data, and protein-protein interaction data. Moreover, the combination of these two ideas might have implications for our understanding of many aspects of biology, ranging from the general architecture of living systems to the causes of various human diseases. PMID:17005391

  10. Portable or Modular? There Is a Difference....

    ERIC Educational Resources Information Center

    Morton, Mike

    2002-01-01

    Describes differences between two types of school facilities: portable (prebuilt, temporary wood structure installed on site) and modular (method of construction for permanent buildings). Provides details of modular construction. (PKP)

  11. Modularity-maximizing graph communities via mathematical programming

    NASA Astrophysics Data System (ADS)

    Agarwal, G.; Kempe, D.

    2008-12-01

    In many networks, it is of great interest to identify communities, unusually densely knit groups of individuals. Such communities often shed light on the function of the networks or underlying properties of the individuals. Recently, Newman suggested modularity as a natural measure of the quality of a network partitioning into communities. Since then, various algorithms have been proposed for (approximately) maximizing the modularity of the partitioning determined. In this paper, we introduce the technique of rounding mathematical programs to the problem of modularity maximization, presenting two novel algorithms. More specifically, the algorithms round solutions to linear and vector programs. Importantly, the linear programing algorithm comes with an a posteriori approximation guarantee: by comparing the solution quality to the fractional solution of the linear program, a bound on the available “room for improvement” can be obtained. The vector programming algorithm provides a similar bound for the best partition into two communities. We evaluate both algorithms using experiments on several standard test cases for network partitioning algorithms, and find that they perform comparably or better than past algorithms, while being more efficient than exhaustive techniques.

  12. Modular Building Institute. 2003 Educational Showcase.

    ERIC Educational Resources Information Center

    Roman, Michael; Robert, Laurie; Reynolds, Pamela; Ulrey, Bill; Crawford, Doug; Shield, Tom; Soenksen, Steven

    "Commercial Modular Construction Magazine" regularly contains articles where the use of modular schools and classrooms is highlighted. This document contains a selection of those articles, including: (1) "Relocatable Classrooms Come of Age" (Michael Roman); (2) "Systems Building" (Laurie Robert); (3) "Realizing Modular's Merits" (Michael Roman);…

  13. Evolution and the Modularity of Mindreading.

    ERIC Educational Resources Information Center

    Moore, Chris

    1996-01-01

    Reviews Baron-Cohen's study of autism and an explanatory theory called modularity of mindreading, which proposed a domain-specific modular psychological model based on evolutionary, developmental, psychopathological, and neurobiological considerations. Enumerates problems with the modularity approach and emphasized the evolution of domain general…

  14. 48 CFR 3417.70 - Modular contracting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Modular contracting. 3417... REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Modular Contracting 3417.70 Modular contracting. (a) FSA—May incrementally conduct successive procurements of modules of...

  15. Modularity in Cognition: Framing the Debate

    ERIC Educational Resources Information Center

    Barrett, H. Clark; Kurzban, Robert

    2006-01-01

    Modularity has been the subject of intense debate in the cognitive sciences for more than 2 decades. In some cases, misunderstandings have impeded conceptual progress. Here the authors identify arguments about modularity that either have been abandoned or were never held by proponents of modular views of the mind. The authors review arguments that…

  16. The Modular Mind and Intrapersonal Communication Processes.

    ERIC Educational Resources Information Center

    Stacks, Don W.

    Based on a prior model on modularity of the brain, a new modular model of intrapersonal communication was developed which focuses on brain processing, encompassing both the structures and the functions of those structures in the creation of messages. The modular mind is a bio-social model of communication which presupposes a relationship between…

  17. Rapidly Deployed Modular Telemetry System

    NASA Technical Reports Server (NTRS)

    Varnavas, Kosta A. (Inventor); Sims, William Herbert, III (Inventor)

    2013-01-01

    The present invention is a telemetry system, and more specifically is a rapidly deployed modular telemetry apparatus which utilizes of SDR technology and the FPGA programming capability to reduce the number of hardware components and programming required to deploy a telemetry system.

  18. Induction in a Modular Learner.

    ERIC Educational Resources Information Center

    Carroll, Susanne E.

    2002-01-01

    Presents a theory of inductive learning--Autonomous Induction Theory--a form of induction that takes place within the autonomous and modular representational systems of the language faculty. Argues that Autonomous Induction Theory is constrained enough to be taken seriously as a plausible approach to explaining second language acquisition.…

  19. Modularity and stability in ecological communities

    PubMed Central

    Grilli, Jacopo; Rogers, Tim; Allesina, Stefano

    2016-01-01

    Networks composed of distinct, densely connected subsystems are called modular. In ecology, it has been posited that a modular organization of species interactions would benefit the dynamical stability of communities, even though evidence supporting this hypothesis is mixed. Here we study the effect of modularity on the local stability of ecological dynamical systems, by presenting new results in random matrix theory, which are obtained using a quaternionic parameterization of the cavity method. Results show that modularity can have moderate stabilizing effects for particular parameter choices, while anti-modularity can greatly destabilize ecological networks. PMID:27337386

  20. Quasispecies Theory for Evolution of Modularity

    PubMed Central

    Park, Jeong-Man; Niestemski, Liang Ren; Deem, Michael W.

    2015-01-01

    Biological systems are modular, and this modularity evolves over time and in different environments. A number of observations have been made of increased modularity in biological systems under increased environmental pressure. We here develop a quasispecies theory for the dynamics of modularity in populations of these systems. We show how the steady-state fitness in a randomly changing environment can be computed. We derive a fluctuation dissipation relation for the rate of change of modularity and use it to derive a relationship between rate of environmental changes and rate of growth of modularity. We also find a principle of least action for the evolved modularity at steady state. Finally, we compare our predictions to simulations of protein evolution and find them to be consistent. PMID:25679649

  1. Hybrid interior point training of modular neural networks.

    PubMed

    Szymanski, P T; Lemmon, M; Bett, C J

    1998-03-01

    Modular neural networks use a single gating neuron to select the outputs of a collection of agent neurons. Expectation-maximization (EM) algorithms provide one way of training modular neural networks to approximate non-linear functionals. This paper introduces a hybrid interior-point (HIP) algorithm for training modular networks. The HIP algorithm combines an interior-point linear programming (LP) algorithm with a Newton-Raphson iteration in such a way that the computational efficiency of the interior point LP methods is preserved. The algorithm is formally proven to converge asymptotically to locally optimal networks with a total computational cost that scales in a polynomial manner with problem size. Simulation experiments show that the HIP algorithm produces networks whose average approximation error is better than that of EM-trained networks. These results also demonstrate that the computational cost of the HIP algorithm scales at a slower rate than the EM-procedure and that, for small-size networks, the total computational costs of both methods are comparable. PMID:12662833

  2. Dementia and driving

    MedlinePlus

    ... not drive at times of the day when traffic is heaviest. Do not drive when the weather is bad. Do not drive long distances. Drive only on roads the person is used to. Caregivers should try to lessen ...

  3. Modular Stellarator Fusion Reactor concept

    SciTech Connect

    Miller, R.L.; Krakowski, R.A.

    1981-08-01

    A preliminary conceptual study is made of the Modular Stellarator Reactor (MSR). A steady-state ignited, DT-fueled, magnetic fusion reactor is proposed for use as a central electric-power station. The MSR concept combines the physics of the classic stellarator confinement topology with an innovative, modular-coil design. Parametric tradeoff calculations are described, leading to the selection of an interim design point for a 4-GWt plant based on Alcator transport scaling and an average beta value of 0.04 in an l = 2 system with a plasma aspect ratio of 11. The physics basis of the design point is described together with supporting magnetics, coil-force, and stress computations. The approach and results presented herein will be modified in the course of ongoing work to form a firmer basis for a detailed conceptual design of the MSR.

  4. Modular hydrodam: concept definition study

    SciTech Connect

    Not Available

    1981-07-01

    The purpose of this investigation was to explore the potential for developing economical new ultra low-head (6 to 10 ft) sites using an innovative concept known as the Modular Hydrodam (MH). This concept combines the benefits of shop fabrication, installation of equipment in truck transportable, waterproof power modules, and prefabricated gate sections that can be located between the power modules. The size and weight of the power module permits it to be fully assembled and checked out in the manufacturer's shop. The module can then be broken down into four pieces and shipped by truck to the site. Once in place, concrete ballast will be added, as necessary, to prevent flotation. The following aspects were investigated: tubular and cross flow turbines; modularized components; the use of a cable support system for horizontal stability of the dam and powerhouse; and construction in the wet as well as in the dry.

  5. Modular industrial robots as the tool of process automation in robotized manufacturing cells

    NASA Astrophysics Data System (ADS)

    Gwiazda, A.; Banas, W.; Sekala, A.; Foit, K.; Hryniewicz, P.; Kost, G.

    2015-11-01

    Recently the number of designed modular machine was increased. The term modular machine is used to denote different types of machinery, equipment and production lines, which are created using modular elements. Modular could be both mechanic elements, and drives, as well as control systems. This method of machine design is more and more popular because it allows obtaining flexible and relatively cheap solutions. So it is worth to develop the concept of modularity in next areas of application. The advantages of modular solutions are: simplification of the structure, standardization of components, and faster assembly process of the complete machine Additional advantages, which is particularly important for manufacturers, are shorter manufacturing times, longer production series and reduced manufacturing costs. Modular designing is also the challenge for designers and the need for a new approach to the design process, to the starting process and to the exploitation process. The purpose for many manufacturers is the standardization of the components used for creating the finished products. This purpose could be realized by the application of standard modules which could be combined together in different ways to create the desired particular construction as much as possible in accordance with the order. This solution is for the producer more favorable than the construction of a large machine whose configuration must be matched to each individual order. In the ideal case each module has its own control system and the full functionality of the modular machine is obtained due to the mutual cooperation of all modules. Such a solution also requires the modular components which create the modular machine are equipped with interfaces compatible one with another to facilitate their communication. The individual components of the machine could be designed, manufactured and used independently and production management task could be divided into subtasks. They could be also

  6. Multidimensional bioseparation with modular microfluidics

    DOEpatents

    Chirica, Gabriela S.; Renzi, Ronald F.

    2013-08-27

    A multidimensional chemical separation and analysis system is described including a prototyping platform and modular microfluidic components capable of rapid and convenient assembly, alteration and disassembly of numerous candidate separation systems. Partial or total computer control of the separation system is possible. Single or multiple alternative processing trains can be tested, optimized and/or run in parallel. Examples related to the separation and analysis of human bodily fluids are given.

  7. High density modular avionics packaging

    NASA Astrophysics Data System (ADS)

    Poradish, F.

    Requirements and design configurations for high density modular avionics packaging are examined, with particular attention given to new hardware trends, the design of high-density standard modules (HDSM's), and HDSM requirements. The discussion of the HDSM's covers thermal management, system testability, power supply, and performance specifications. The general design of an integrated HDSM demonstration system currently under construction is briefly described, and some test data are presented.

  8. CAMAC modular programmable function generator

    SciTech Connect

    Turner, G.W.; Suehiro, S.; Hendricks, R.W.

    1980-12-01

    A CAMAC modular programmable function generator has been developed. The device contains a 1024 word by 12-bit memory, a 12-bit digital-to-analog converter with a 600 ns settling time, an 18-bit programmable frequency register, and two programmable trigger output registers. The trigger registers can produce programmed output logic transitions at various (binary) points in the output function curve, and are used to synchronize various other data acquisition devices with the function curve.

  9. Deinterlacing using modular neural network

    NASA Astrophysics Data System (ADS)

    Woo, Dong H.; Eom, Il K.; Kim, Yoo S.

    2004-05-01

    Deinterlacing is the conversion process from the interlaced scan to progressive one. While many previous algorithms that are based on weighted-sum cause blurring in edge region, deinterlacing using neural network can reduce the blurring through recovering of high frequency component by learning process, and is found robust to noise. In proposed algorithm, input image is divided into edge and smooth region, and then, to each region, one neural network is assigned. Through this process, each neural network learns only patterns that are similar, therefore it makes learning more effective and estimation more accurate. But even within each region, there are various patterns such as long edge and texture in edge region. To solve this problem, modular neural network is proposed. In proposed modular neural network, two modules are combined in output node. One is for low frequency feature of local area of input image, and the other is for high frequency feature. With this structure, each modular neural network can learn different patterns with compensating for drawback of counterpart. Therefore it can adapt to various patterns within each region effectively. In simulation, the proposed algorithm shows better performance compared with conventional deinterlacing methods and single neural network method.

  10. Modular microrobot for swimming in heterogeneous environments

    NASA Astrophysics Data System (ADS)

    Cheang, U. Kei; Meshkati, Meshkati; Fu, Henry; Kim, Minjun; Drexel University Team; University of Nevada, Reno Team

    2015-11-01

    One of the difficulties in navigating in vivo is to overcome many types of environments. This includes blood vessels of different diameters, fluids with different mechanical properties, and physical barriers. Inspired by conventional modular robotics, we demonstrate modular microrobotics using magnetic particles as the modular units to change size and shape through docking and undocking. Much like the vast variety of microorganisms navigating many different bio-environments, modular microswimmers have the ability to dynamically adapt different environments by reconfiguring the swimmers' physical characteristics. We model the docking as magnetic assembly and undocking mechanisms as deformation by hydrodynamic forces. We characterize the swimming capability of the modular microswimmer with different size and shapes. Finally, we demonstrate modular microrobotics by assembling a three-bead microswimmer into a nine-bead microswimmer, and then disassemble it into several independently swimming microswimmers..

  11. Intelligent CAD approach for modular design

    NASA Astrophysics Data System (ADS)

    Ouyang, Miao-an; Li, Chenggang; Zhong, Yifang; Yu, Jun; Zhou, Ji

    1996-03-01

    In this paper, the technology of Artificial Intelligence is introduced into a modular design and manufacturing for machine tools. The authors present a methodology to realize the modular conceptual design combined with traditional CAD, and develop an intelligent machine tools modular conceptual system. The problem-solving strategies are described in detail. The design model and system architecture are set up. Techniques and their incorporation of expert system, case-based reasoning and artificial neural networks are clarified.

  12. Modular, Hierarchical Learning By Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Baldi, Pierre F.; Toomarian, Nikzad

    1996-01-01

    Modular and hierarchical approach to supervised learning by artificial neural networks leads to neural networks more structured than neural networks in which all neurons fully interconnected. These networks utilize general feedforward flow of information and sparse recurrent connections to achieve dynamical effects. The modular organization, sparsity of modular units and connections, and fact that learning is much more circumscribed are all attractive features for designing neural-network hardware. Learning streamlined by imitating some aspects of biological neural networks.

  13. High performance backplane components for modular avionics

    NASA Astrophysics Data System (ADS)

    Groves-Kirkby, C. J.; Goodwin, M. J.; Hall, J. P.; Glynn, G.; Hankey, J.; Salik, M. D.; Goodfellow, R. C.; Jibb, D. J.

    1994-10-01

    The design and development of optoelectronic transceiver and optical pathway components for application in a modular avionics backplane demonstrator system are described and initial performance results are presented.

  14. Using collective variables to drive molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Fiorin, Giacomo; Klein, Michael L.; Hénin, Jérôme

    2013-12-01

    A software framework is introduced that facilitates the application of biasing algorithms to collective variables of the type commonly employed to drive massively parallel molecular dynamics (MD) simulations. The modular framework that is presented enables one to combine existing collective variables into new ones, and combine any chosen collective variable with available biasing methods. The latter include the classic time-dependent biases referred to as steered MD and targeted MD, the temperature-accelerated MD algorithm, as well as the adaptive free-energy biases called metadynamics and adaptive biasing force. The present modular software is extensible, and portable between commonly used MD simulation engines.

  15. Development of a Direct Drive Permanent Magnet Generator for Small Wind Turbines

    SciTech Connect

    Chertok, Allan; Hablanian, David; McTaggart, Paul; DOE Project Officer - Keith Bennett

    2004-11-16

    In this program, TIAX performed the conceptual design and analysis of an innovative, modular, direct-drive permanent magnet generator (PMG) for use in small wind turbines that range in power rating from 25 kW to 100 kW. TIAX adapted an approach that has been successfully demonstrated in high volume consumer products such as direct-drive washing machines and portable generators. An electromagnetic model was created and the modular PMG design was compared to an illustrative non-modular design. The resulting projections show that the modular design can achieve significant reductions in size, weight, and manufacturing cost without compromising efficiency. Reducing generator size and weight can also lower the size and weight of other wind turbine components and hence their manufacturing cost.

  16. Modular and Orthogonal Synthesis of Hybrid Polymers and Networks

    PubMed Central

    Liu, Shuang; Dicker, Kevin T.; Jia, Xinqiao

    2015-01-01

    Biomaterials scientists strive to develop polymeric materials with distinct chemical make-up, complex molecular architectures, robust mechanical properties and defined biological functions by drawing inspirations from biological systems. Salient features of biological designs include (1) repetitive presentation of basic motifs; and (2) efficient integration of diverse building blocks. Thus, an appealing approach to biomaterials synthesis is to combine synthetic and natural building blocks in a modular fashion employing novel chemical methods. Over the past decade, orthogonal chemistries have become powerful enabling tools for the modular synthesis of advanced biomaterials. These reactions require building blocks with complementary functionalities, occur under mild conditions in the presence of biological molecules and living cells and proceed with high yield and exceptional selectivity. These chemistries have facilitated the construction of complex polymers and networks in a step-growth fashion, allowing facile modulation of materials properties by simple variations of the building blocks. In this review, we first summarize features of several types of orthogonal chemistries. We then discuss recent progress in the synthesis of step growth linear polymers, dendrimers and networks that find application in drug delivery, 3D cell culture and tissue engineering. Overall, orthogonal reactions and modulular synthesis have not only minimized the steps needed for the desired chemical transformations but also maximized the diversity and functionality of the final products. The modular nature of the design, combined with the potential synergistic effect of the hybrid system, will likely result in novel hydrogel matrices with robust structures and defined functions. PMID:25572255

  17. Portable and modularized fluorometer based on optical fiber

    NASA Astrophysics Data System (ADS)

    Yue, WeiWei; Zhang, Lei; Guo, ZhenYa; Jiang, ShouZhen; Bai, ChengJie

    2015-02-01

    A portable and modularized fluorometer based on optical fiber was proposed in this work. The fluorometer included a light emitter diode (LED) light source module (LSM), a sample cell module (SCM), an optical-electrical converter module (OCM) and a signal process module (SAM). The LEDs in LSM were driven by a constant current source to provide stable exciting light with different wavelength. The OCM included a modularized optical filter and used a photomultiplier tube (PMT) to detect fluorescence signal. The SCM was used to locate sample cuvette and could be connected by optical fibers with the LSM and OCM. Via modularized design, the LSM and OCM could both selected and replaced based on different fluorescence dyes. In order to improve the detecting dynamic range of the fluorometer, the SAM could control the light intensity of LED source in LSM, to control the gain of PMT in OCM, and particularly, four channel signal acquisition circuits with different gain were constructed to collect fluorescence signal simultaneously. Fluorescein isothiocyanate (FITC) was selected as sample to test the fluorometer. The fluorometer has shown a high sensitivity with FITC concentration of 10ng/mL and presented a good linearity from 10 ng/mL to 10 μg/mL.

  18. Metal band drives in spacecraft mechanisms

    NASA Technical Reports Server (NTRS)

    Maus, Daryl

    1993-01-01

    Transmitting and changing the characteristics of force and stroke is a requirement in nearly all mechanisms. Examples include changing linear to rotary motion, providing a 90 deg change in direction, and amplifying stroke or force. Requirements for size, weight, efficiency and reliability create unique problems in spacecraft mechanisms. Flexible metal band and cam drive systems provide powerful solutions to these problems. Band drives, rack and pinion gears, and bell cranks are compared for effectiveness. Band drive issues are discussed including materials, bend radius, fabrication, attachment and reliability. Numerous mechanisms are shown which illustrate practical applications of band drives.

  19. Evaporation mitigation by floating modular devices

    NASA Astrophysics Data System (ADS)

    Hassan, M. M.; Peirson, W. L.

    2016-05-01

    Prolonged periods of drought and consequent evaporation from open water bodies in arid parts of Australia continue to be a threat to water availability for agricultural production. Over many parts of Australia, the annual average evaporation exceeds the annual precipitation by more than 5 times. Given its significance, it is surprising that no evaporation mitigation technique has gained widespread adoption to date. High capital and maintenance costs of manufactured products are a significant barrier to implementation. The use of directly recycled clean plastic containers as floating modular devices to mitigate evaporation has been investigated for the first time. A six-month trial at an arid zone site in Australia of this potential cost effective solution has been undertaken. The experiment was performed using clean conventional drinking water bottles as floating modules on the open water surface of 240-L tanks with three varying degrees of covering (nil, 34% and 68%). A systematic reduction in evaporation is demonstrated during the whole study period that is approximately linearly proportional to the covered surface. These results provide a potential foundation for robust evaporation mitigation with the prospect of implementing a cost-optimal design.

  20. Learning modular policies for robotics.

    PubMed

    Neumann, Gerhard; Daniel, Christian; Paraschos, Alexandros; Kupcsik, Andras; Peters, Jan

    2014-01-01

    A promising idea for scaling robot learning to more complex tasks is to use elemental behaviors as building blocks to compose more complex behavior. Ideally, such building blocks are used in combination with a learning algorithm that is able to learn to select, adapt, sequence and co-activate the building blocks. While there has been a lot of work on approaches that support one of these requirements, no learning algorithm exists that unifies all these properties in one framework. In this paper we present our work on a unified approach for learning such a modular control architecture. We introduce new policy search algorithms that are based on information-theoretic principles and are able to learn to select, adapt and sequence the building blocks. Furthermore, we developed a new representation for the individual building block that supports co-activation and principled ways for adapting the movement. Finally, we summarize our experiments for learning modular control architectures in simulation and with real robots. PMID:24966830

  1. Compact stellarators with modular coils

    PubMed Central

    Garabedian, P. R.

    2000-01-01

    Compact stellarator designs with modular coils and only two or three field periods are now available; these designs have both good stability and quasiaxial symmetry providing adequate transport for a magnetic fusion reactor. If the bootstrap current assumes theoretically predicted values a three field period configuration is optimal, but if that net current turns out to be lower, a device with two periods and just 12 modular coils might be better. There are also attractive designs with quasihelical symmetry and four or five periods whose properties depend less on the bootstrap current. Good performance requires that there be a satisfactory magnetic well in the vacuum field, which is a property lacking in a stellarator-tokamak hybrid that has been proposed for a proof of principle experiment. In this paper, we present an analysis of stability for these configurations that is based on a mountain pass theorem asserting that, if two solutions of the problem of magnetohydrodynamic equilibrium can be found, then there has to be an unstable solution. We compare results of our theory of equilibrium, stability, and transport with recently announced measurements from the large LHD experiment in Japan. PMID:10899993

  2. Optimal multi-community network modularity for information diffusion

    NASA Astrophysics Data System (ADS)

    Wu, Jiaocan; Du, Ruping; Zheng, Yingying; Liu, Dong

    2016-02-01

    Studies demonstrate that community structure plays an important role in information spreading recently. In this paper, we investigate the impact of multi-community structure on information diffusion with linear threshold model. We utilize extended GN network that contains four communities and analyze dynamic behaviors of information that spreads on it. And we discover the optimal multi-community network modularity for information diffusion based on the social reinforcement. Results show that, within the appropriate range, multi-community structure will facilitate information diffusion instead of hindering it, which accords with the results derived from two-community network.

  3. Effects of Modularity, Certification Session and Re-Sits on Examination Performance

    ERIC Educational Resources Information Center

    Vidal Rodeiro, Carmen L.; Nadas, Rita

    2012-01-01

    General Certificates of Secondary Education, known as GCSEs, are organised into modules which can be assessed at the end of the course (linear route) or at different points throughout the course (modular route). This research investigates students' performance in English and mathematics in each assessment route and the effects of certification…

  4. The modular class of a Dirac map

    NASA Astrophysics Data System (ADS)

    Caseiro, Raquel

    2016-06-01

    In this paper we study the modular classes of Dirac manifolds and of Dirac maps, and we discuss their basic properties. We apply these results to explain the relationship between the modular classes of the various structures involved in the reduction of a Poisson manifold under the action of a Poisson-Lie group.

  5. Modular interdependency in complex dynamical systems.

    PubMed

    Watson, Richard A; Pollack, Jordan B

    2005-01-01

    Herbert A. Simon's characterization of modularity in dynamical systems describes subsystems as having dynamics that are approximately independent of those of other subsystems (in the short term). This fits with the general intuition that modules must, by definition, be approximately independent. In the evolution of complex systems, such modularity may enable subsystems to be modified and adapted independently of other subsystems, whereas in a nonmodular system, modifications to one part of the system may result in deleterious side effects elsewhere in the system. But this notion of modularity and its effect on evolvability is not well quantified and is rather simplistic. In particular, modularity need not imply that intermodule dependences are weak or unimportant. In dynamical systems this is acknowledged by Simon's suggestion that, in the long term, the dynamical behaviors of subsystems do interact with one another, albeit in an "aggregate" manner--but this kind of intermodule interaction is omitted in models of modularity for evolvability. In this brief discussion we seek to unify notions of modularity in dynamical systems with notions of how modularity affects evolvability. This leads to a quantifiable measure of modularity and a different understanding of its effect on evolvability. PMID:16197673

  6. Teachers' Perceptions of Modular Technology Education Laboratories

    ERIC Educational Resources Information Center

    Harris, Kara S.

    2005-01-01

    The purpose of this study was to examine teachers' perceptions concerning the modular technology approach to teaching technology education in Georgia. The study addressed the following basic research question: What do teachers in Georgia perceive to be the main advantages and drawbacks to teaching technology education in a modular environment…

  7. Twisted Cyclic Cohomology and Modular Fredholm Modules

    NASA Astrophysics Data System (ADS)

    Rennie, Adam; Sitarz, Andrzej; Yamashita, Makoto

    2013-07-01

    Connes and Cuntz showed in [Comm. Math. Phys. 114 (1988), 515-526] that suitable cyclic cocycles can be represented as Chern characters of finitely summable semifinite Fredholm modules. We show an analogous result in twisted cyclic cohomology using Chern characters of modular Fredholm modules. We present examples of modular Fredholm modules arising from Podleś spheres and from SUq(2).

  8. Modular Construction: The Wave of the Future.

    ERIC Educational Resources Information Center

    Savage, Chuck

    1989-01-01

    Modular construction of school buildings offers speed of construction, with 100 percent contractor responsibility for the completed structures. Under negotiated terms, modular projects can be purchased outright or through long-term leasing arrangements that provide ownership at the end of the lease period. (MLF)

  9. Magnetostrictive direct drive motors

    NASA Technical Reports Server (NTRS)

    Naik, Dipak; Dehoff, P. H.

    1992-01-01

    A new rare earth alloy, Terfenol-D, combines low frequency operation and extremely high energy density with high magnetostriction. Its material properties make it suitable as a drive element for actuators requiring high output torque. The high strains, the high forces and the high controllability of Terfenol alloys provide a powerful and challenging basis for new ways to generate motion in actuators. Two prototypes of motors using Terfenol-D rods were developed at NASA Goddard. The basic principles of operation are provided of the motor along with other relevant details. A conceptual design of a torque limiting safety clutch/brake under development is illustrated. Also, preliminary design drawings of a linear actuator using Terfenol-D is shown.

  10. Anti- (conjugate) linearity

    NASA Astrophysics Data System (ADS)

    Uhlmann, Armin

    2016-03-01

    This is an introduction to antilinear operators. In following Wigner the terminus antilinear is used as it is standard in Physics. Mathematicians prefer to say conjugate linear. By restricting to finite-dimensional complex-linear spaces, the exposition becomes elementary in the functional analytic sense. Nevertheless it shows the amazing differences to the linear case. Basics of antilinearity is explained in sects. 2, 3, 4, 7 and in sect. 1.2: Spectrum, canonical Hermitian form, antilinear rank one and two operators, the Hermitian adjoint, classification of antilinear normal operators, (skew) conjugations, involutions, and acq-lines, the antilinear counterparts of 1-parameter operator groups. Applications include the representation of the Lagrangian Grassmannian by conjugations, its covering by acq-lines. As well as results on equivalence relations. After remembering elementary Tomita-Takesaki theory, antilinear maps, associated to a vector of a two-partite quantum system, are defined. By allowing to write modular objects as twisted products of pairs of them, they open some new ways to express EPR and teleportation tasks. The appendix presents a look onto the rich structure of antilinear operator spaces.

  11. Linear Accelerators

    SciTech Connect

    Sidorin, Anatoly

    2010-01-05

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  12. Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Sidorin, Anatoly

    2010-01-01

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  13. The emergence of modularity in biological systems

    NASA Astrophysics Data System (ADS)

    Lorenz, Dirk M.; Jeng, Alice; Deem, Michael W.

    2011-06-01

    In this review, we discuss modularity and hierarchy in biological systems. We review examples from protein structure, genetics, and biological networks of modular partitioning of the geometry of biological space. We review theories to explain modular organization of biology, with a focus on explaining how biology may spontaneously organize to a structured form. That is, we seek to explain how biology nucleated from among the many possibilities in chemistry. The emergence of modular organization of biological structure will be described as a symmetry-breaking phase transition, with modularity as the order parameter. Experimental support for this description will be reviewed. Examples will be presented from pathogen structure, metabolic networks, gene networks, and protein-protein interaction networks. Additional examples will be presented from ecological food networks, developmental pathways, physiology, and social networks.

  14. Design of a reconfigurable modular manipulator system

    NASA Technical Reports Server (NTRS)

    Schmitz, D.; Kanade, T.

    1987-01-01

    Using manipulators with a fixed configuration for specific tasks is appropriate when the task requirements are known beforehand. However, in less predictable situations, such as an outdoor construction site or aboard a space station, a manipulator system requires a wide range of capabilities, probably beyond the limitations of a single, fixed-configuration manipulator. To fulfill this need, researchers have been working on a Reconfigurable Modular Manipulator System (RMMS). Researchers have designed and are constructing a prototype RMMS. The prototype currently consists of two joint modules and four link modules. The joints utilize a conventional harmonic drive and torque motor actuator, with a small servo amplifier included in the assembly. A brushless resolver is used to sense the joint position and velocity. For coupling the modules together, a standard electrical connector and V-band clamps for mechanical connection are used, although more sophisticated designs are under way for future versions. The joint design yields an output torque to 50 ft-lbf at joint speeds up to 1 radian/second. The resolver and associated electronics have resolutions of 0.0001 radians, and absolute accuracies of plus or minus 0.001 radians. Manipulators configured from these prototype modules will have maximum reaches in the 0.5 to 2 meter range. The real-time RMMS controller consists of a Motorola 68020 single-board computer which will perform real time servo control and path planning of the manipulator. This single board computer communicates via shared memory with a SUN3 workstation, which serves as a software development system and robot programming environment. Researchers have designed a bus communication network to provide multiplexed communication between the joint modules and the computer controller. The bus supports identification of modules, sensing of joint states, and commands to the joint actuator. This network has sufficient bandwidth to allow servo sampling rates in

  15. Small Modular Reactors: Institutional Assessment

    SciTech Connect

    Joseph Perkowski, Ph.D.

    2012-06-01

    ? Objectives include, among others, a description of the basic development status of “small modular reactors” (SMRs) focused primarily on domestic activity; investigation of the domestic market appeal of modular reactors from the viewpoints of both key energy sector customers and also key stakeholders in the financial community; and consideration of how to proceed further with a pro-active "core group" of stakeholders substantially interested in modular nuclear deployment in order to provide the basis to expedite design/construction activity and regulatory approval. ? Information gathering was via available resources, both published and personal communications with key individual stakeholders; published information is limited to that already in public domain (no confidentiality); viewpoints from interviews are incorporated within. Discussions at both government-hosted and private-hosted SMR meetings are reflected herein. INL itself maintains a neutral view on all issues described. Note: as per prior discussion between INL and CAP, individual and highly knowledgeable senior-level stakeholders provided the bulk of insights herein, and the results of those interviews are the main source of the observations of this report. ? Attachment A is the list of individual stakeholders consulted to date, including some who provided significant earlier assessments of SMR institutional feasibility. ? Attachments B, C, and D are included to provide substantial context on the international status of SMR development; they are not intended to be comprehensive and are individualized due to the separate nature of the source materials. Attachment E is a summary of the DOE requirements for winning teams regarding the current SMR solicitation. Attachment F deserves separate consideration due to the relative maturity of the SMART SMR program underway in Korea. Attachment G provides illustrative SMR design features and is intended for background. Attachment H is included for overview

  16. BESST: A Miniature, Modular Radiometer

    NASA Technical Reports Server (NTRS)

    Warden, Robert; Good, William; Baldwin-Stevens, Erik

    2010-01-01

    A new radiometer assembly has been developed that incorporates modular design principles in order to provide flexibility and versatility. The assembly, shown in Figure 1, is made up of six modules plus a central cubical frame. A small thermal imaging detector is used to determine the temperature of remote objects. To improve the accuracy of the temperature reading, frequent calibration is required. The detector must view known temperature targets before viewing the remote object. Calibration is achieved by using a motorized fold mirror to select the desired scene the detector views. The motor steps the fold mirror through several positions, which allows the detector to view the calibration targets or the remote object. The details, features, and benefits of the radiometer are described in this paper.

  17. Modular, object-oriented redesign of a large-scale Monte Carlo neutron transport program

    SciTech Connect

    Moskowitz, B.S.

    2000-02-01

    This paper describes the modular, object-oriented redesign of a large-scale Monte Carlo neutron transport program. This effort represents a complete 'white sheet of paper' rewrite of the code. In this paper, the motivation driving this project, the design objectives for the new version of the program, and the design choices and their consequences will be discussed. The design itself will also be described, including the important subsystems as well as the key classes within those subsystems.

  18. Extended Driving Impairs Nocturnal Driving Performances

    PubMed Central

    Sagaspe, Patricia; Taillard, Jacques; Åkerstedt, Torbjorn; Bayon, Virginie; Espié, Stéphane; Chaumet, Guillaume; Bioulac, Bernard; Philip, Pierre

    2008-01-01

    Though fatigue and sleepiness at the wheel are well-known risk factors for traffic accidents, many drivers combine extended driving and sleep deprivation. Fatigue-related accidents occur mainly at night but there is no experimental data available to determine if the duration of prior driving affects driving performance at night. Participants drove in 3 nocturnal driving sessions (3–5am, 1–5am and 9pm–5am) on open highway. Fourteen young healthy men (mean age [±SD] = 23.4 [±1.7] years) participated Inappropriate line crossings (ILC) in the last hour of driving of each session, sleep variables, self-perceived fatigue and sleepiness were measured. Compared to the short (3–5am) driving session, the incidence rate ratio of inappropriate line crossings increased by 2.6 (95% CI, 1.1 to 6.0; P<.05) for the intermediate (1–5am) driving session and by 4.0 (CI, 1.7 to 9.4; P<.001) for the long (9pm–5am) driving session. Compared to the reference session (9–10pm), the incidence rate ratio of inappropriate line crossings were 6.0 (95% CI, 2.3 to 15.5; P<.001), 15.4 (CI, 4.6 to 51.5; P<.001) and 24.3 (CI, 7.4 to 79.5; P<.001), respectively, for the three different durations of driving. Self-rated fatigue and sleepiness scores were both positively correlated to driving impairment in the intermediate and long duration sessions (P<.05) and increased significantly during the nocturnal driving sessions compared to the reference session (P<.01). At night, extended driving impairs driving performances and therefore should be limited. PMID:18941525

  19. Osmotrophy in modular Ediacara organisms

    PubMed Central

    Laflamme, Marc; Xiao, Shuhai; Kowalewski, Michał

    2009-01-01

    The Ediacara biota include macroscopic, morphologically complex soft-bodied organisms that appear globally in the late Ediacaran Period (575–542 Ma). The physiology, feeding strategies, and functional morphology of the modular Ediacara organisms (rangeomorphs and erniettomorphs) remain debated but are critical for understanding their ecology and phylogeny. Their modular construction triggered numerous hypotheses concerning their likely feeding strategies, ranging from micro-to-macrophagus feeding to photoautotrophy to osmotrophy. Macrophagus feeding in rangeomorphs and erniettomorphs is inconsistent with their lack of oral openings, and photoautotrophy in rangeomorphs is contradicted by their habitats below the photic zone. Here, we combine theoretical models and empirical data to evaluate the feasibility of osmotrophy, which requires high surface area to volume (SA/V) ratios, as a primary feeding strategy of rangeomorphs and erniettomorphs. Although exclusively osmotrophic feeding in modern ecosystems is restricted to microscopic bacteria, this study suggests that (i) fractal branching of rangeomorph modules resulted in SA/V ratios comparable to those observed in modern osmotrophic bacteria, and (ii) rangeomorphs, and particularly erniettomorphs, could have achieved osmotrophic SA/V ratios similar to bacteria, provided their bodies included metabolically inert material. Thus, specific morphological adaptations observed in rangeomorphs and erniettomorphs may have represented strategies for overcoming physiological constraints that typically make osmotrophy prohibitive for macroscopic life forms. These results support the viability of osmotrophic feeding in rangeomorphs and erniettomorphs, help explain their taphonomic peculiarities, and point to the possible importance of earliest macroorganisms for cycling dissolved organic carbon that may have been present in abundance during Ediacaran times. PMID:19706530

  20. MODULAR MANIPULATOR FOR ROBOTICS APPLICATIONS

    SciTech Connect

    Joseph W. Geisinger, Ph.D.

    2001-07-31

    ARM Automation, Inc. is developing a framework of modular actuators that can address the DOE's wide range of robotics needs. The objective of this effort is to demonstrate the effectiveness of this technology by constructing a manipulator from these actuators within a glovebox for Automated Plutonium Processing (APP). At the end of the project, the system of actuators was used to construct several different manipulator configurations, which accommodate common glovebox tasks such as repackaging. The modular nature and quickconnects of this system simplify installation into ''hot'' boxes and any potential modifications or repair therein. This work focused on the development of self-contained robotic actuator modules including the embedded electronic controls for the purpose of building a manipulator system. Both of the actuators developed under this project contain the control electronics, sensors, motor, gear train, wiring, system communications and mechanical interfaces of a complete robotics servo device. Test actuators and accompanying DISC{trademark}s underwent validation testing at The University of Texas at Austin and ARM Automation, Inc. following final design and fabrication. The system also included custom links, an umbilical cord, an open architecture PC-based system controller, and operational software that permitted integration into a completely functional robotic manipulator system. The open architecture on which this system is based avoids proprietary interfaces and communication protocols which only serve to limit the capabilities and flexibility of automation equipment. The system was integrated and tested in the contractor's facility for intended performance and operations. The manipulator was tested using the full-scale equipment and process mock-ups. The project produced a practical and operational system including a quantitative evaluation of its performance and cost.

  1. Circuit models and three-dimensional electromagnetic simulations of a 1-MA linear transformer driver stage

    NASA Astrophysics Data System (ADS)

    Rose, D. V.; Miller, C. L.; Welch, D. R.; Clark, R. E.; Madrid, E. A.; Mostrom, C. B.; Stygar, W. A.; Lechien, K. R.; Mazarakis, M. A.; Langston, W. L.; Porter, J. L.; Woodworth, J. R.

    2010-09-01

    A 3D fully electromagnetic (EM) model of the principal pulsed-power components of a high-current linear transformer driver (LTD) has been developed. LTD systems are a relatively new modular and compact pulsed-power technology based on high-energy density capacitors and low-inductance switches located within a linear-induction cavity. We model 1-MA, 100-kV, 100-ns rise-time LTD cavities [A. A. Kim , Phys. Rev. ST Accel. Beams 12, 050402 (2009)PRABFM1098-440210.1103/PhysRevSTAB.12.050402] which can be used to drive z-pinch and material dynamics experiments. The model simulates the generation and propagation of electromagnetic power from individual capacitors and triggered gas switches to a radially symmetric output line. Multiple cavities, combined to provide voltage addition, drive a water-filled coaxial transmission line. A 3D fully EM model of a single 1-MA 100-kV LTD cavity driving a simple resistive load is presented and compared to electrical measurements. A new model of the current loss through the ferromagnetic cores is developed for use both in circuit representations of an LTD cavity and in the 3D EM simulations. Good agreement between the measured core current, a simple circuit model, and the 3D simulation model is obtained. A 3D EM model of an idealized ten-cavity LTD accelerator is also developed. The model results demonstrate efficient voltage addition when driving a matched impedance load, in good agreement with an idealized circuit model.

  2. Size reduction of complex networks preserving modularity

    SciTech Connect

    Arenas, A.; Duch, J.; Fernandez, A.; Gomez, S.

    2008-12-24

    The ubiquity of modular structure in real-world complex networks is being the focus of attention in many trials to understand the interplay between network topology and functionality. The best approaches to the identification of modular structure are based on the optimization of a quality function known as modularity. However this optimization is a hard task provided that the computational complexity of the problem is in the NP-hard class. Here we propose an exact method for reducing the size of weighted (directed and undirected) complex networks while maintaining invariant its modularity. This size reduction allows the heuristic algorithms that optimize modularity for a better exploration of the modularity landscape. We compare the modularity obtained in several real complex-networks by using the Extremal Optimization algorithm, before and after the size reduction, showing the improvement obtained. We speculate that the proposed analytical size reduction could be extended to an exact coarse graining of the network in the scope of real-space renormalization.

  3. Coaxial Redundant Drives

    NASA Technical Reports Server (NTRS)

    Brissette, R.

    1983-01-01

    Harmonic drives allow redundancy and high out put torque in small package. If main drive fails, standby drive takes over and produces torque along same axis as main drive. Uses include power units in robot for internal pipeline inspection, manipulators in deep submersible probes or other applications in which redundancy protects against costly failures.

  4. Electrical drive for automobile

    SciTech Connect

    Fobbs, H.

    1980-09-16

    Electrical apparatus for driving an automobile is described that is comprised of a dc motor operationally connected to the rear axle through a drive shaft with the motor energized from storage batteries and recharged from alternators coupled to the drive shaft adjacent a clutch at the rear end of the automobile through an auxiliary drive shaft.

  5. A parallel and modular deformable cell Car-Parrinello code

    NASA Astrophysics Data System (ADS)

    Cavazzoni, Carlo; Chiarotti, Guido L.

    1999-12-01

    We have developed a modular parallel code implementing the Car-Parrinello [Phys. Rev. Lett. 55 (1985) 2471] algorithm including the variable cell dynamics [Europhys. Lett. 36 (1994) 345; J. Phys. Chem. Solids 56 (1995) 510]. Our code is written in Fortran 90, and makes use of some new programming concepts like encapsulation, data abstraction and data hiding. The code has a multi-layer hierarchical structure with tree like dependences among modules. The modules include not only the variables but also the methods acting on them, in an object oriented fashion. The modular structure allows easier code maintenance, develop and debugging procedures, and is suitable for a developer team. The layer structure permits high portability. The code displays an almost linear speed-up in a wide range of number of processors independently of the architecture. Super-linear speed up is obtained with a "smart" Fast Fourier Transform (FFT) that uses the available memory on the single node (increasing for a fixed problem with the number of processing elements) as temporary buffer to store wave function transforms. This code has been used to simulate water and ammonia at giant planet conditions for systems as large as 64 molecules for ˜50 ps.

  6. A Modular Approach to Redundant Robot Control

    SciTech Connect

    Anderson, R.J.

    1997-12-01

    This paper describes a modular approach for computing redundant robot kinematics. First some conventional redundant control methods are presented and shown to be `passive control laws`, i.e. they can be represented by a network consisting of passive elements. These networks are then put into modular form by applying scattering operator techniques. Additional subnetwork modules can then be added to further shape the motion. Modules for obstacle detection, joint limit avoidance, proximity sensing, and for imposing nonlinear velocity constraints are presented. The resulting redundant robot control system is modular, flexible and robust.

  7. Modular standards for emerging avionics technologies

    NASA Astrophysics Data System (ADS)

    Radcliffe, B.; Boaz, J.

    The present investigation is concerned with modular standards for the integration of new avionics technologies into production aircraft, taking into account also major retrofit programs. It is pointed out that avionics systems are about to undergo drastic changes in the partitioning of functions and judicious sharing of resources. These changes have the potential to significantly improve reliability and maintainability, and to reduce costs. Attention is given to a definition of the modular avionics concept, the existing module program, the development approach, development progress on the modular avionics standard, and the future of avionics installation standards.

  8. Solar array drive system

    NASA Technical Reports Server (NTRS)

    Berkopec, F. D.; Sturman, J. C.; Stanhouse, R. W.

    1976-01-01

    A solar array drive system consisting of a solar array drive mechanism and the corresponding solar array drive electronics is being developed. The principal feature of the solar array drive mechanism is its bidirectional capability which enables its use in mechanical redundancy. The solar array drive system is of a widely applicable design. This configuration will be tested to determine its acceptability for generic mission sets. Foremost of the testing to be performed is the testing for extended duration.

  9. Modular Buildings: A Quick, Quality Solution for Schools.

    ERIC Educational Resources Information Center

    School Planning & Management, 2001

    2001-01-01

    Highlights the history of the modular classroom industry and emergence of the Modular Building Institute. Analyzes the differences between temporary portable classrooms and permanent modular additions. Also examines the possible influence of modular classrooms on future facility design and the ways that educational facilities officials are saving…

  10. Modular optimization code package: MOZAIK

    NASA Astrophysics Data System (ADS)

    Bekar, Kursat B.

    This dissertation addresses the development of a modular optimization code package, MOZAIK, for geometric shape optimization problems in nuclear engineering applications. MOZAIK's first mission, determining the optimal shape of the D2O moderator tank for the current and new beam tube configurations for the Penn State Breazeale Reactor's (PSBR) beam port facility, is used to demonstrate its capabilities and test its performance. MOZAIK was designed as a modular optimization sequence including three primary independent modules: the initializer, the physics and the optimizer, each having a specific task. By using fixed interface blocks among the modules, the code attains its two most important characteristics: generic form and modularity. The benefit of this modular structure is that the contents of the modules can be switched depending on the requirements of accuracy, computational efficiency, or compatibility with the other modules. Oak Ridge National Laboratory's discrete ordinates transport code TORT was selected as the transport solver in the physics module of MOZAIK, and two different optimizers, Min-max and Genetic Algorithms (GA), were implemented in the optimizer module of the code package. A distributed memory parallelism was also applied to MOZAIK via MPI (Message Passing Interface) to execute the physics module concurrently on a number of processors for various states in the same search. Moreover, dynamic scheduling was enabled to enhance load balance among the processors while running MOZAIK's physics module thus improving the parallel speedup and efficiency. In this way, the total computation time consumed by the physics module is reduced by a factor close to M, where M is the number of processors. This capability also encourages the use of MOZAIK for shape optimization problems in nuclear applications because many traditional codes related to radiation transport do not have parallel execution capability. A set of computational models based on the

  11. A Modular, IGBT Driven, Ignitron Switched, Optically Controlled Power Supply

    NASA Astrophysics Data System (ADS)

    Carroll, Evan; von der Linden, Jens; You, Setthivoine

    2013-10-01

    An experiment to investigate the dynamics of canonical flux tubes at the University of Washington uses two high energy pulsed power supplies to generate and sustain the plasma discharge. A modular 240 μF , 12 kV DC capacitor based power supply, discharged by ignitron, has been developed specifically for this application. Design considerations include minimizing inductance, rapid switching, fast rise times, and electrically isolated control. An optically coupled front panel and fast IGBT ignitron drive circuit, sequenced manually or by software, control the charge and discharge of the power supply. A complete, sequenced charge/discharge has been successfully tested with a dummy load, producing a peak current of 100 kA and a rise time of 25 μs . This work was sponsored in part by the US DOE Grant DE-SC0010340.

  12. Linear Collisions

    ERIC Educational Resources Information Center

    Walkiewicz, T. A.; Newby, N. D., Jr.

    1972-01-01

    A discussion of linear collisions between two or three objects is related to a junior-level course in analytical mechanics. The theoretical discussion uses a geometrical approach that treats elastic and inelastic collisions from a unified point of view. Experiments with a linear air track are described. (Author/TS)

  13. Modular, Intelligent Power Systems for Space Exploration

    NASA Technical Reports Server (NTRS)

    Button, Robert

    2006-01-01

    NASA's new Space Exploration Initiative demands that vehicles, habitats, and rovers achieve unprecedented levels of reliability, safety, effectiveness, and affordability. Modular and intelligent electrical power systems are critical to achieving those goals. Modular electrical power systems naturally increase reliability and safety through built-in fault tolerance. These modular systems also enable standardization across a multitude of systems, thereby greatly increasing affordability of the programs. Various technologies being developed to support this new paradigm for space power systems will be presented. Examples include the use of digital control in power electronics to enable better performance and advanced modularity functions such as distributed, master-less control and series input power conversion. Also, digital control and robust communication enables new levels of power system control, stability, fault detection, and health management. Summary results from recent development efforts are presented along with expected future technology development needs required to support NASA's ambitious space exploration goals.

  14. Modular Solar Electric Power (MSEP) Systems (Presentation)

    SciTech Connect

    Hassani, V.

    2000-06-18

    This presentation discusses the development and deployment of Modular Solar Electric Power (MSEP) systems, the feasibility of application of existing binary power cycles to solar trough technology, and identification of next action items.

  15. Modular biowaste monitoring system conceptual design

    NASA Technical Reports Server (NTRS)

    Fogal, G. L.

    1974-01-01

    The objective of the study was to define requirements and generate a conceptual design for a Modular Biowaste Monitoring System for specifically supporting shuttle life science experimental and diagnostic programs.

  16. Modular digital holographic fringe data processing system

    NASA Technical Reports Server (NTRS)

    Downward, J. G.; Vavra, P. C.; Schebor, F. S.; Vest, C. M.

    1985-01-01

    A software architecture suitable for reducing holographic fringe data into useful engineering data is developed and tested. The results, along with a detailed description of the proposed architecture for a Modular Digital Fringe Analysis System, are presented.

  17. COMPONENT VERSION IN MODULAR TOTAL HIP REVISION

    PubMed Central

    Kopec, Michael A.; Pemberton, Aaron; Milbrandt, Joseph C.; Allan, Gordon

    2009-01-01

    Morphologic changes of the proximal femur make revision total hip arthroplasty challenging. Metaphyseal retroversion and diaphyseal varus are common in this scenario. Twenty-one total hip revisions using a modular femoral prosthesis were examined by obtaining three radiographs (A/P, surgical lateral, and true lateral of the femur) to assemble CAD models for determining the range of modular component positioning. An average of femoral neck anteversion was observed. Seventeen of 21 cases (81%) had retroverted metaphyseal segments (−23.2°+/−17.4°) and/or varus stems (−32.1°+/−13.0°). Neck anteversion averaged 21.4°(+/−10.0°). One of 21 cases (5%) resulted in component orientation similar to a non-modular prosthesis. Modular components provide options to accommodate proximal femoral remodeling not afforded by monobloc stems in total hip revision surgery. PMID:19742077

  18. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... modular transmitter must have their own shielding. The physical crystal and tuning capacitors may be... shielded. The physical crystal and tuning capacitors may be located external to the shielded radio...

  19. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... modular transmitter must have their own shielding. The physical crystal and tuning capacitors may be... shielded. The physical crystal and tuning capacitors may be located external to the shielded radio...

  20. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... modular transmitter must have their own shielding. The physical crystal and tuning capacitors may be... shielded. The physical crystal and tuning capacitors may be located external to the shielded radio...

  1. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... modular transmitter must have their own shielding. The physical crystal and tuning capacitors may be... shielded. The physical crystal and tuning capacitors may be located external to the shielded radio...

  2. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... modular transmitter must have their own shielding. The physical crystal and tuning capacitors may be... shielded. The physical crystal and tuning capacitors may be located external to the shielded radio...

  3. A 3-d modular gripper design tool

    SciTech Connect

    Brown, R.G.; Brost, R.C.

    1997-01-01

    Modular fixturing kits are precisely machined sets of components used for flexible, short-turnaround construction of fixtures for a variety of manufacturing purposes. A modular vise is a parallel-jaw vise, where each jaw is a modular fixture plate with a regular grid of precisely positioned holes. A modular vise can be used to locate and hold parts for machining, assembly, and inspection tasks. To fixture a part, one places pins in some of the holes so that when the vise is closed, the part is reliably located and completely constrained. The modular vise concept can be adapted easily to the design of modular parallel-jaw grippers for robots. By attaching a grid plate to each jaw of a parallel-jaw gripper, the authors gain the ability to easily construct high-quality grasps for a wide variety of parts from a standard set of hardware. Wallack and Canny developed a previous algorithm for planning planar grasp configurations for the modular vise. In this paper, the authors expand this work to produce a 3-d fixture/gripper design tool. They describe several analyses added to the planar algorithm to improve its utility, including a three-dimensional grasp quality metric based on geometric and force information, three-dimensional geometric loading analysis, and inter-gripper interference analysis to determine the compatibility of multiple grasps for handing the part from one gripper to another. Finally, the authors describe two applications which combine the utility of modular vise-style grasping with inter-gripper interference: The first is the design of a flexible part-handling subsystem for a part cleaning workcell under development at Sandia National Laboratories; the second is the automatic design of grippers that support the assembly of multiple products on a single assembly line.

  4. Additional Drive Circuitry for Piezoelectric Screw Motors

    NASA Technical Reports Server (NTRS)

    Smythe, Robert; Palmer, Dean; Gursel, Yekta; Reder, Leonard; Savedra, Raymond

    2004-01-01

    Modules of additional drive circuitry have been developed to enhance the functionality of a family of commercially available positioning motors (Picomotor . or equivalent) that provide linear motion controllable, in principle, to within increments .30 nm. A motor of this type includes a piezoelectric actuator that turns a screw. Unlike traditional piezoelectrically actuated mechanisms, a motor of this type does not rely on the piezoelectric transducer to hold position: the screw does not turn except when the drive signal is applied to the actuator.

  5. Direct-drive field actuator motors

    DOEpatents

    Grahn, Allen R.

    1995-01-01

    A high-torque, low speed, positive-drive field actuator motor including a stator carrying at least one field actuator which changes in dimension responsive to application of an energy field, and at least one drive shoe movable by the dimensional changes of the field actuator to contact and move a rotor element with respect to the stator. Various embodiments of the motor are disclosed, and the rotor element may be moved linearly or arcuately.

  6. Direct-drive field actuator motors

    DOEpatents

    Grahn, A.R.

    1995-07-11

    A high-torque, low speed, positive-drive field actuator motor is disclosed including a stator carrying at least one field actuator which changes in dimension responsive to application of an energy field, and at least one drive shoe movable by the dimensional changes of the field actuator to contact and move a rotor element with respect to the stator. Various embodiments of the motor are disclosed, and the rotor element may be moved linearly or arcuately. 37 figs.

  7. Development of a building block design of modular photovoltaic concentrator array fields

    SciTech Connect

    Carmichael, D.C.; Alexander, G.; Noel, G.T.; Scurlock, L.D.; Huss, W.R.; Stickford, G.H.

    1983-08-01

    To reduce the balance-of-system (BOS) costs and site-specific design costs for photovoltaic concentrator array fields, a modular Building Block design has been developed for installing array fields of each of two available concentrator collectors. The array-field subsystems and requirements incorporated in the design analyses include site preparation, foundations, electrical wiring, grounding, lightning protection, electromagnetic interference provisions, and tracking and controls. The Building Block designs developed minimize these array-field BOS costs and serve as standardized units to be used in multiples to construct array fields of various sizes. The detailed drawings and construction specifications prepared for the designs require only minimal design modification and cost for adaption to a specific site and application. The two concentrator collectors for which the modular array-field designs were developed are the linear-focus Fresnel-lens array manufactured by E-Systems, Inc., and the point-focus Fresnel-lens array manufactured by Martin Marietta Aerospace Corporation. Both designs are two-axis tracking and passively cooled. The developed Building Block designs are immediately applicable and reduce the array-field BOS costs and site-specific design costs to a fraction of those experienced in previous installations. The estimated array-field BOS costs (in 1982 dollars) using these modular designs are $0.78/W for the modular field based on the E-Systems array and $1.18/W for the modular field based on the Martin-Marietta array.

  8. A 3-d modular gripper design tool

    SciTech Connect

    Brown, R.G.; Brost, R.C.

    1997-02-01

    Modular fixturing kits are sets of components used for flexible, rapid construction of fixtures. A modular vise is a parallel-jaw vise, each jaw of which is a modular fixture plate with a regular grid of precisely positioned holes. To fixture a part, one places pins in some of the holes so that when the vise is closed, the part is reliably located and completely constrained. The modular vise concept can be adapted easily to the design of modular parallel-jaw grippers for robots. By attaching a grid-plate to each jaw of a parallel-jaw gripper, one gains the ability to easily construct high-quality grasps for a wide variety of parts from a standard set of hardware. Wallack and Canny developed an algorithm for planning planar grasp configurations for the modular vise. In this paper, the authors expand this work to produce a 3-d fixture/gripper design tool. They describe several analyses they have added to the planar algorithm, including a 3-d grasp quality metric based on force information, 3-d geometric loading analysis, and inter-gripper interference analysis. Finally, the authors describe two applications of their code. One of these is an internal application at Sandia, while the other shows a potential use of the code for designing part of an agile assembly line.

  9. Test stations: a modular approach

    NASA Astrophysics Data System (ADS)

    Capone, Benjamin R.; Remillard, Paul; Everett, Jonathan E.

    1996-06-01

    Recent requests for test stations to characterize and evaluate thermal and visible imaging systems have shown remarkable similarities. They contain the usual request for target patterns for the measurement of MRTD, NETD, SiTF for the infrared thermal imager and similar patterns for measuring CTF and SNR for the visible imager. The combined systems almost invariably include some type of laser designator/rangefinder in the total package requiring the need for LOS registration among the various individual units. Similarities also exist in that the requests are for large collimator apertures and focal lengths for projecting the desired signals into the unit under test apertures. Diversified Optical Products, Inc. has developed and is continually improving test station hardware and software to provide modularity in design and versatility in operation while satisfying individual test requirements and maintaining low cost. A high emissivity, DSP controlled, high slew rate, low cost, blackbody source with excellent uniformity and stability has been produced to function as the driver for thermal image target projectors. Several types of sources for producing energy in the visible portion of the spectrum have been evaluated. Software for selection of targets, sources, focus and auto- collimation has been developed and tested.

  10. Theory for the Emergence of Modularity in Complex Systems

    NASA Astrophysics Data System (ADS)

    Deem, Michael; Park, Jeong-Man

    2013-03-01

    Biological systems are modular, and this modularity evolves over time and in different environments. A number of observations have been made of increased modularity in biological systems under increased environmental pressure. We here develop a theory for the dynamics of modularity in these systems. We find a principle of least action for the evolved modularity at long times. In addition, we find a fluctuation dissipation relation for the rate of change of modularity at short times. We discuss a number of biological and social systems that can be understood with this framework. The modularity of the protein-protein interaction network increases when yeast are exposed to heat shock, and the modularity of the protein-protein networks in both yeast and E. coli appears to have increased over evolutionary time. Food webs in low-energy, stressful environments are more modular than those in plentiful environments, arid ecologies are more modular during droughts, and foraging of sea otters is more modular when food is limiting. The modularity of social networks changes over time: stock brokers instant messaging networks are more modular under stressful market conditions, criminal networks are more modular under increased police pressure, and world trade network modularity has decreased