Sample records for fuelcell prototype locomotive

  1. Design of master control unit for laboratory prototype of traction converter for locomotives


    Žák, Jan; Peroutka, Zdeněk; Ovaska, Seppo J.


    This paper deals with the prototype of a main traction converter with medium-frequency transformer for AC trolley wire-fed locomotives. The attention is paid to the new master control and diagnostic unit. The designed master control unit has been implemented in the LabVIEW environment. Our master control unit ensures an effective human interface between a user and the control hardware. In this case, the master unit makes possible both extensive control and diagnostic operations of the laborat...

  2. Locomotion

    DEFF Research Database (Denmark)

    Kiehn, Ole; Dougherty, Kimberly


    Locomotion is a complex motor behavior needed by animals and humans to move through the environment. All forms of locomotion, including swimming, flying, walking, running, and hopping, are repetitive motor activities that require the activation of the limb and body muscles in an organized rhythm ...

  3. Commercialization of fuel-cells

    Energy Technology Data Exchange (ETDEWEB)

    Penner, S.S.; Appleby, A.J.; Baker, B.S.; Bates, J.L.; Buss, L.B.; Dollard, W.J.; Farris, P.J.; Gillis, E.A.; Gunsher, J.A.; Khandkar, A.; Krumpelt, M.; O' Sullivan, J.B.; Runte, G.; Savinell, R.F.; Selman, J.R.; Shores, D.A.; Tarman, P.


    This report is an abbreviated version of the ''Report of the DOE Advanced Fuel Cell Commercialization Working Group (AFC2WG),'' released January 1995. We describe fuel-cell commercialization for stationary power applications of phosphoric acid, molten carbonate, solid oxide, and polymer electrolyte membrane fuel cells.

  4. Advanced underground Vehicle Power and Control: The locomotive Research Platform

    Energy Technology Data Exchange (ETDEWEB)

    Vehicle Projects LLC


    Develop a fuelcell mine locomotive with metal-hydride hydrogen storage. Test the locomotive for fundamental limitations preventing successful commercialization of hydride fuelcells in underground mining. During Phase 1 of the DOE-EERE sponsored project, FPI and its partner SNL, completed work on the development of a 14.4 kW fuelcell power plant and metal-hydride energy storage. An existing battery-electric locomotive with similar power requirements, minus the battery module, was used as the base vehicle. In March 2001, Atlas Copco Wagner of Portland, OR, installed the fuelcell power plant into the base vehicle and initiated integration of the system into the vehicle. The entire vehicle returned to Sandia in May 2001 for further development and integration. Initial system power-up took place in December 2001. A revision to the original contract, Phase 2, at the request of DOE Golden Field Office, established Vehicle Projects LLC as the new prime contractor,. Phase 2 allowed industry partners to conduct surface tests, incorporate enhancements to the original design by SNL, perform an extensive risk and safety analysis, and test the fuelcell locomotive underground under representative production mine conditions. During the surface tests one of the fuelcell stacks exhibited reduced power output resulting in having to replace both fuelcell stacks. The new stacks were manufactured with new and improved technology resulting in an increase of the gross power output from 14.4 kW to 17 kW. Further work by CANMET and Hatch Associates, an engineering consulting firm specializing in safety analysis for the mining industry, both under subcontract to Vehicle Projects LLC, established minimum requirements for underground testing. CANMET upgraded the Programmable Logic Control (PLC) software used to monitor and control the fuelcell power plant, taking into account locomotive operator's needs. Battery Electric, a South Africa manufacturer, designed and manufactured (at no cost

  5. Fuel-Cell Structure Prevents Membrane Drying (United States)

    Mcelroy, J.


    Embossed plates direct flows of reactants and coolant. Membrane-type fuel-cell battery has improved reactant flow and heat removal. Compact, lightweight battery produces high current and power without drying of membranes.

  6. Prototyping


    Corsín Jiménez, Alberto


    The prototyping of method calls for, at a minimum, three operations of design: rethinking the proprietary and legal economy of research; rethinking the frontiers that separate those who use methods from those to whom methods are applied to; designing infrastructures of apprenticeships for every problem.

  7. Compact Fuel-Cell System Would Consume Neat Methanol (United States)

    Narayanan, Sekharipuram; Kindler, Andrew; Valdez, Thomas


    In a proposed direct methanol fuel-cell electric-power-generating system, the fuel cells would consume neat methanol, in contradistinction to the dilute aqueous methanol solutions consumed in prior direct methanol fuel-cell systems. The design concept of the proposed fuel-cell system takes advantage of (1) electro-osmotic drag and diffusion processes to manage the flows of hydrogen and water between the anode and the cathode and (2) evaporative cooling for regulating temperature. The design concept provides for supplying enough water to the anodes to enable the use of neat methanol while ensuring conservation of water for the whole fuel-cell system.

  8. Models of Snail Locomotion (United States)

    Chan, Brian; Hosoi, Anette


    All snails move over a thin layer of mucus using periodic deformations of their muscular foot. This unusual mode of locomotion can be modeled as a thin film of viscous fluid sandwiched between a flexible membrane and a rigid substrate. We present theoretical, numerical and experimental studies of locomotion via viscous stresses generated in thin films. Study of snail locomotion led us to design and construct several mechanical models: RoboSnail 1 which mimics snail locomotion incorrectly, but still proves to be a valid propulsion device over a thin viscous fluid layer and RoboSnail 2 which mimics land snails and uses forward-propagating compression waves on the base of the foot. Experimental results from the prototype machines are compared with long wavelength numerical and theoretical models.

  9. Solar-Hydrogen Fuel-Cell Vehicles


    DeLuchi, Mark A.; Ogden, Joan M.


    Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewably grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional or global pollution. Hydrogen FCEVs would combine the best features of battery-powere...

  10. Photo-switchable microbial fuel-cells. (United States)

    Schlesinger, Orr; Dandela, Rambabu; Bhagat, Ashok; Adepu, Raju; Meijler, Michael M; Xia, Lin; Alfonta, Lital


    Regulation of Bio-systems in a clean, simple, and efficient way is important for the design of smart bio-interfaces and bioelectronic devices. Light as a non-invasive mean to control the activity of a protein enables spatial and temporal control far superior to other chemical and physical methods. The ability to regulate the activity of a catalytic enzyme in a biofuel-cell reduces the waste of resources and energy and turns the fuel-cell into a smart and more efficient device for power generation. Here we present a microbial-fuel-cell based on a surface displayed, photo-switchable alcohol dehydrogenase. The enzyme was modified near the active site using non-canonical amino acids and a small photo-reactive molecule, which enables reversible control of enzymatic activity. Depending on the modification site, the enzyme exhibits reversible behavior upon irradiation with UV and visible light, in both biochemical, and electrochemical assays. The change observed in power output of a microbial fuel cell utilizing the modified enzyme was almost five-fold, between inactive and active states. © 2018 Wiley Periodicals, Inc.

  11. Study questions environmental impact of fuel-cell vehicles (United States)

    Stafford, Ned


    Fuel-cell electric vehicles are seen by many as an environmentally friendly technology that can reduce greenhousegas emissions by producing no harmful emissions. But a new study has found that overall a fuel cell electric vehicle has about the same negative environmental impact as a luxury sports car.

  12. Advanced robot locomotion.

    Energy Technology Data Exchange (ETDEWEB)

    Neely, Jason C.; Sturgis, Beverly Rainwater; Byrne, Raymond Harry; Feddema, John Todd; Spletzer, Barry Louis; Rose, Scott E.; Novick, David Keith; Wilson, David Gerald; Buerger, Stephen P.


    This report contains the results of a research effort on advanced robot locomotion. The majority of this work focuses on walking robots. Walking robot applications include delivery of special payloads to unique locations that require human locomotion to exo-skeleton human assistance applications. A walking robot could step over obstacles and move through narrow openings that a wheeled or tracked vehicle could not overcome. It could pick up and manipulate objects in ways that a standard robot gripper could not. Most importantly, a walking robot would be able to rapidly perform these tasks through an intuitive user interface that mimics natural human motion. The largest obstacle arises in emulating stability and balance control naturally present in humans but needed for bipedal locomotion in a robot. A tracked robot is bulky and limited, but a wide wheel base assures passive stability. Human bipedal motion is so common that it is taken for granted, but bipedal motion requires active balance and stability control for which the analysis is non-trivial. This report contains an extensive literature study on the state-of-the-art of legged robotics, and it additionally provides the analysis, simulation, and hardware verification of two variants of a proto-type leg design.



    Vincent RITS


    Air pollution is a major problem in many of China's cities, with SO2, NOx and PM emissions exceeding World Health Organisation's air quality standards. The environmental (dis-) performance of Chinese vehicles contributes largely to this problem. The fuel-cell system represents a technology that could eliminate much of the local air-pollution problem. However, the chances of fuel-cell cars during the next decades are still highly questioned. In this research, the diffusion of fuel-cell cars...

  14. Tuning Nanowires and Nanotubes for Efficient Fuel-Cell Electrocatalysis. (United States)

    Wang, Wei; Lv, Fan; Lei, Bo; Wan, Sheng; Luo, Mingchuan; Guo, Shaojun


    Developing new synthetic methods for the controlled synthesis of Pt-based or non-Pt nanocatalysts with low or no Pt loading to facilitate sluggish cathodic oxygen reduction reaction (ORR) and organics oxidation reactions is the key in the development of fuel-cell technology. Various nanoparticles (NPs), with a range of size, shape, composition, and structure, have shown good potential to catalyze the sluggish cathodic and anodic reactions. In contrast to NPs, one-dimensional (1D) nanomaterials such as nanowires (NWs), and nanotubes (NTs), exhibit additional advantages associated with their anisotropy, unique structure, and surface properties. The prominent characteristics of NWs and NTs include fewer lattice boundaries, a lower number of surface defect sites, and easier electron and mass transport for better electrocatalytic activity and lower vulnerability to dissolution, Ostwald ripening, and aggregation than Pt NPs for enhanced stability. An overview of recent advances in tuning 1D nanostructured Pt-based, Pd-based, or 1D metal-free nanomaterials as advanced electrocatalysts is provided here, for boosting fuel-cell reactions with high activity and stability, including the oxygen reduction reaction (ORR), methanol oxidation reaction (MOR), and ethanol oxidation reaction (EOR). After highlighting the different strategies developed so far for the synthesis of Pt-based 1D nanomaterials with controlled size, shape, and composition, special emphasis is placed on the rational design of diverse NWs and NTs catalysts such as Pt-based NWs or NTs, non-Pt NTs, and carbon NTs with molecular engineering, etc. for enhancing the ORR, MOR, and EOR. Finally, some perspectives are highlighted on the development of more efficient fuel-cell electrocatalysts featuring high stability, low cost, and enhanced performance, which are the key factors in accelerating the commercialization of fuel-cell technology. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. SECA Coal-Based Systems - FuelCell Energy, Inc.

    Energy Technology Data Exchange (ETDEWEB)

    Ayagh, Hossein [Fuelcell Energy, Inc., Danbury, CT (United States)


    The overall goal of this U.S. Department of Energy (DOE) sponsored project is the development of solid oxide fuel cell (SOFC) cell and stack technology suitable for use in highly-efficient, economically-competitive central generation power plant facilities fueled by coal synthesis gas (syngas). This program incorporates the following supporting objectives: • Reduce SOFC-based electrical power generation system cost to $700 or less (2007 dollars) for a greater than 100 MW Integrated Gasification Fuel Cell (IGFC) power plant, exclusive of coal gasification and CO2 separation subsystem costs. • Achieve an overall IGFC power plant efficiency of at least 50%, from coal (higher heating value or HHV) to AC power (exclusive of CO2 compression power requirement). • Reduce the release of CO2 to the environment in an IGFC power plant to no more than 10% of the carbon in the syngas. • Increase SOFC stack reliability to achieve a design life of greater than 40,000 hours. At the inception of the project, the efforts were focused on research, design and testing of prototype planar SOFC power generators for stationary applications. FuelCell Energy, Inc. successfully completed the initial stage of the project by meeting the program metrics, culminating in delivery and testing of a 3 kW system at National Energy Technology Laboratory (NETL). Subsequently, the project was re-aligned into a three phase effort with the main goal to develop SOFC technology for application in coal-fueled power plants with >90% carbon capture. Phase I of the Coal-based efforts focused on cell and stack size scale-up with concurrent enhancement of performance, life, cost, and manufacturing characteristics. Also in Phase I, design and analysis of the baseline (greater than 100 MW) power plant system—including concept identification, system definition, and cost analysis—was conducted. Phase II efforts focused on development of a ≥25 kW SOFC stack tower incorporating

  16. a Fuel-Cell Distributed Energy Resource with Integrated Energy Storage (United States)

    Nikkhajoei, Hassan


    This paper presents a fuel-cell distributed energy resource with integrated energy storage. A compatible power electronic interface to couple the fuel-cell with the grid and/or a local load is introduced. Details of the energy storage module, the power electronic interface and the corresponding controls are described. A control strategy for the power electronic interface is developed to manage the flow of power between the fuel-cell, the energy storage and the grid. A dynamic model for the fuel-cell distributed resource is developed and is used for the systematic design of the distributed resource control system. Performance of the fuel-cell distributed energy resource is evaluated based on digital time-domain simulations in the (Electromagnetic Transient Program) EMTP-RV software environment. Effectiveness of the energy storage module, the compatible interface and the corresponding controls in enhancing the fuel-cell distributed resource performance is verified. The results demonstrate the developed power electronic interface and control strategy provide the fuel-cell with the load-following capability, the plug-and-play feature and high qualities of voltage and power that are required for the microgrid application.

  17. Biological fuel-cell converts sugar into electric power; Biologinen polttokenno muuttaa sokerin saehkoeksi

    Energy Technology Data Exchange (ETDEWEB)

    Kinnunen, L.


    The Automation Technology Laboratory at the Helsinki University of Technology has developed a fuel-cell which produces electric power and water from glucose. The fuel-cell opens new possibilities for utilization of biologically disintegrable matter, e.g. different kinds of carbage, in power generation. The glucose is converted in the reactor by baking yeast into a metabolite, which is feeded into the fuel-cell of volume 55 ml. Graphite, wound into the nickel wire net, is used as anode in the system. Porous graphite is used as cathode. Anode and cathode are separated from each other by ion- exchange membrane, which is penetrable by hydrogen iones, but not by salt solution of the cathode half-cell. The metabolite is oxidized at the anode, donating electrons and hydrogen iones to the ande. The electrones flow through the circuit into the cathode there they react with hydrogen iones and oxygen feeded through the cathode to form water. The fuel-cell, based on direct oxygenation-reduction, has operated without any disturbances for 280 hours. The efficiency, calculated from the heating value of the glucose, is 44 %, which is better than that of the chemical fuel-cells. The disadvantage of the biological reactions is the low speed of them, so the current densities of the cell still remain into the class 2.0 W/m{sup 2}, which is about 1.0 % of that of the developed phosphoric acid fuel-cells

  18. Better Proton-Conducting Polymers for Fuel-Cell Membranes (United States)

    Narayan, Sri; Reddy, Prakash


    Polyoxyphenylene triazole sulfonic acid has been proposed as a basis for development of improved proton-conducting polymeric materials for solid-electrolyte membranes in hydrogen/air fuel cells. Heretofore, the proton-conducting membrane materials of choice have been exemplified by a family of perfluorosulfonic acid-based polymers (Nafion7 or equivalent). These materials are suitable for operation in the temperature of 75 to 85 C, but in order to reduce the sizes and/or increase the energy-conversion efficiencies of fuel-cell systems, it would be desirable to increase temperatures to as high as 120 C for transportation applications, and to as high as 180 C for stationary applications. However, at 120 C and at relative humidity values below 50 percent, the loss of water from perfluorosulfonic acid-based polymer membranes results in fuel-cell power densities too low to be of practical value. Therefore, membrane electrolyte materials that have usefully high proton conductivity in the temperature range of 180 C at low relative humidity and that do not rely on water for proton conduction at 180 C would be desirable. The proposed polyoxyphenylene triazole sulfonic acid-based materials have been conjectured to have these desirable properties. These materials would be free of volatile or mobile acid constituents. The generic molecular structure of these materials is intended to exploit the fact, demonstrated in previous research, that materials that contain ionizable acid and base groups covalently attached to thermally stable polymer backbones exhibit proton conduction even in the anhydrous state.

  19. Development of Underwater Microrobot with Biomimetic Locomotion

    Directory of Open Access Journals (Sweden)

    W. Zhang


    Full Text Available Microrobots have powerful applications in biomedical and naval fields. They should have a compact structure, be easy to manufacture, have efficient locomotion, be driven by low voltage and have a simple control system. To meet these purposes, inspired by the leg of stick insects, we designed a novel type of microrobot with biomimetic locomotion with 1-DOF (degree of freedom legs. The locomotion includes two ionic conducting polymer film (ICPF actuators to realize the 2-DOF motion. We developed several microrobots with this locomotion. Firstly, we review a microrobot, named Walker-1, with 1-DOF motion. And then a new microrobot, named Walker-2, utilizing six ICPF actuators, with 3-DOF motion is introduced. It is 47 mm in diameter and 8 mm in height (in static state. It has 0.61 g of dried weight. We compared the two microrobot prototypes, and the result shows that Walker-2 has some advantages, such as more flexible moving motion, good balance, less water resistance, more load-carrying ability and so on. We also compared it with some insect-inspired microrobots and some microrobots with 1-DOF legs, and the result shows that a microrobot with this novel type of locomotion has some advantages. Its structure has fewer actuators and joints, a simpler control system and is compact. The ICPF actuator decides that it can be driven by low voltage (less than 5 V and move in water. A microrobot with this locomotion has powerful applications in biomedical and naval fields.

  20. Critical assessment of power trains with fuel-cell systems and different fuels (United States)

    Höhlein, B.; von Andrian, S.; Grube, Th; Menzer, R.

    Legal regulations (USA, EU) are a major driving force for intensifying technological developments with respect to the global automobile market. In the future, highly efficient vehicles with very low emission levels will include low-temperature fuel-cell systems (PEFC) as units of electric power trains. With alcohols, ether or hydrocarbons used as fuels for these new electric power trains, hydrogen as PEFC fuel has to be produced on board. These concepts including the direct use of methanol in fuel-cell systems, differ considerably in terms of both their development prospects and the results achieved so far. Based on process engineering analyses for net electricity generation in PEFC-powered power trains, as well as on assumptions for electric power trains and vehicle configurations, different fuel-cell performances and fuel processing units for octane, diesel, methanol, ethanol, propane and dimethylether have been evaluated as fuels. The possible benefits and key challenges for different solutions of power trains with fuel-cell systems/on-board hydrogen production and with direct methanol fuel-cell (DMFC) systems have been assessed. Locally, fuel-cell power trains are almost emission-free and, unlike battery-powered vehicles, their range is comparable to conventional vehicles. Therefore, they have application advantages cases of particularly stringent emission standards requiring zero emission. In comparison to internal combustion engines, using fuel-cell power trains can lead to clear reductions in primary energy demand and global, climate-relevant emissions providing the advantage of the efficiency of the hydrogen/air reaction in the fuel cell is not too drastically reduced by additional conversion steps of on-board hydrogen production, or by losses due to fuel supply provision.

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

    Energy Technology Data Exchange (ETDEWEB)

    Asnafi, Alireza [Hydro-Aeronautical Research Center, Shiraz University, Shiraz, 71348-13668 (Iran, Islamic Republic of); Mahzoon, Mojtaba, E-mail:, E-mail:, E-mail: [Department of Mechanical Engineering, School of Engineering, Shiraz University, Shiraz, 71348-13668 (Iran, Islamic Republic of)


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

  2. Speeding the transition: Designing a fuel-cell hypercar

    Energy Technology Data Exchange (ETDEWEB)

    Williams, B.D.; Moore, T.C.; Lovins, A.B. [Rocky Mountain Inst., Snowmass, CO (United States). Hypercar Center


    A rapid transformation now underway in automotive technology could accelerate the transition to transportation powered by fuel cells. Ultralight, advanced-composite, low-drag, hybrid-electric hypercars--using combustion engines--could be three- to fourfold more efficient and one or two orders of magnitude cleaner than today`s cars, yet equally safe, sporty, desirable, and (probably) affordable. Further, important manufacturing advantages--including low tooling and equipment costs, greater mechanical simplicity, autobody parts consolidation, shorter product cycles, and reduced assembly effort and space--permit a free-market commercialization strategy. This paper discusses a conceptual hypercar powered by a proton-exchange-membrane fuel cell (PEMFC). It outlines the implications of platform physics and component selection for the vehicle`s mass budget and performance. The high fuel-to-traction conversion efficiency of the hypercar platform could help automakers overcome the Achilles` heel of hydrogen-powered vehicles: onboard storage. Moreover, because hypercars would require significantly less tractive power, and even less fuel-cell power, they could adopt fuel cells earlier, before fuel cells` specific cost, mass, and volume have fully matured. In the meantime, commercialization in buildings can help prepare fuel cells for hypercars. The promising performance of hydrogen-fueled PEMFC hypercars suggests important opportunities in infrastructure development for direct-hydrogen vehicles.

  3. The US Molten Carbonate Fuel-Cell development and commercialization effort (United States)

    Williams, Mark C.; Parsons, Edward L., Jr.; Mayfield, M. J.

    The authors discuss the status of molten carbonate fuel-cell (MCFC) development in the US, including the role of the US Department of Energy (DOE) in commercializing MCFC power-plant products for use by gas utility and electric power industries. The authors describe major fundamental stack research issues, as well as MCFC power-plant network and system issues, that need to be resolved before MCFC technology can be commercialized. A significant initiative in MCFC research is the spatial configuration of MCFC stacks into networks in a fuel-cell power plant.

  4. The Characterisation of a PEM Fuel-Cell System with a Focus on UAS Applications (United States)


    and A. Dicks, Fuel cell systems explained. 2nd ed. 2003, John Wiley and Sons Ltd.: Chichester, West Sussex, England. p. 418. Available from...2864. 42. Johnsen, F.A., California students join small circle of revolutionary fuel-cell fliers. NASA Dryden Flight Research Center news, 5

  5. Locomotive Syndrome: Definition and Management


    Nakamura, Kozo; Ogata, Toru


    Locomotive syndrome is a condition of reduced mobility due to impairment of locomotive organs. Since upright bipedal walking involves minutely controlled movement patterns, impairment of any aspect of the locomotive organs has the potential to adversely affect it. In addition to trauma, chronic diseases of the locomotive organs, which progress with repeated bouts of acute exacerbations, are common causes of the locomotive syndrome. In Japan?s super-aging society, many people are likely to exp...

  6. Architectural prototyping

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Christensen, Henrik Bærbak; Hansen, Klaus Marius


    A major part of software architecture design is learning how specific architectural designs balance the concerns of stakeholders. We explore the notion of "architectural prototypes", correspondingly architectural prototyping, as a means of using executable prototypes to investigate stakeholders......' concerns with respect to a system under development. An architectural prototype is primarily a learning and communication vehicle used to explore and experiment with alternative architectural styles, features, and patterns in order to balance different architectural qualities. The use of architectural...... prototypes in the development process is discussed, and we argue that such prototypes can play a role throughout the entire process. The use of architectural prototypes is illustrated by three distinct cases of creating software systems. We argue that architectural prototyping can provide key insights...

  7. Architectural Prototyping

    DEFF Research Database (Denmark)

    Bardram, Jakob; Christensen, Henrik Bærbak; Hansen, Klaus Marius


    A major part of software architecture design is learning how specific architectural designs balance the concerns of stakeholders. We explore the notion of "architectural prototypes", correspondingly architectural prototyping, as a means of using executable prototypes to investigate stakeholders......' concerns with respect to a system under development. An architectural prototype is primarily a learning and communication vehicle used to explore and experiment with alternative architectural styles, features, and patterns in order to balance different architectural qualities. The use of architectural...... prototypes in the development process is discussed, and we argue that such prototypes can play a role throughout the entire process. The use of architectural prototypes is illustrated by three distinct cases of creating software systems. We argue that architectural prototyping can provide key insights...

  8. Solution Prototype

    DEFF Research Database (Denmark)

    Efeoglu, Arkin; Møller, Charles; Serie, Michel


    environment. The solution prototype that is composed from blending product and service prototype has particular impacts on the dualism of DSR’s “Build” and “Evaluate”. Since the mix between product and service prototyping can be varied, there is a demand for a more agile and iterative framework. Van de Ven...

  9. An assessment of the energetic flows in a commercial PEM fuel-cell system

    International Nuclear Information System (INIS)

    Jovan, Vladimir; Perne, Matija; Petrovcic, Janko


    Some primary issues have not yet been fully investigated on the way towards the commercialization of fuel-cell-based systems (FCS), e.g., their actual efficiency, reliability, safety, degradation, maintainability, etc. This article deals with an estimation of the real energetic flows and the corresponding electrical efficiency of a commercial proton-exchange-membrane fuel-cell hydrogen-fed generator set (PEMFCS). The fuel-cell power system considered here is planned to be the source of both electrical and thermal energy in a mobile dwelling container unit with in-built fuel-cell-based cogeneration system, and for the design of a cogeneration unit the actual amount of disposable energy from the PEMFC unit should be estimated. The assessment of the actual energetic flows, the disposable energy and the consequent electrical efficiency of the case-study PEMFCS is carried out using commercial technical data for the PEMFCS.

  10. Compensations during Unsteady Locomotion. (United States)

    Qiao, Mu; Jindrich, Devin L


    Locomotion in a complex environment is often not steady, but the mechanisms used by animals to power and control unsteady locomotion (stability and maneuverability) are not well understood. We use behavioral, morphological, and impulsive perturbations to determine the compensations used during unsteady locomotion. At the level both of the whole-body and of joints, quasi-stiffness models are useful for describing adjustments to the functioning of legs and joints during maneuvers. However, alterations to the mechanics of legs and joints often are distinct for different phases of the step cycle or for specific joints. For example, negotiating steps involves independent changes of leg stiffness during compression and thrust phases of stance. Unsteady locomotion also involves parameters that are not part of the simplest reduced-parameter models of locomotion (e.g., the spring-loaded inverted pendulum) such as moments of the hip joint. Extensive coupling among translational and rotational parameters must be taken into account to stabilize locomotion or maneuver. For example, maneuvers with morphological perturbations (increased rotational inertial turns) involve changes to several aspects of movement, including the initial conditions of rotation and ground-reaction forces. Coupled changes to several parameters may be employed to control maneuvers on a trial-by-trial basis. Compensating for increased rotational inertia of the body during turns is facilitated by the opposing effects of several mechanical and behavioral parameters. However, the specific rules used by animals to control translation and rotation of the body to maintain stability or maneuver have not been fully characterized. We initiated direct-perturbation experiments to investigate the strategies used by humans to maintain stability following center-of-mass (COM) perturbations. When walking, humans showed more resistance to medio-lateral perturbations (lower COM displacement). However, when running, humans

  11. Fuel-cell based power generating system having power conditioning apparatus (United States)

    Mazumder, Sudip K.; Pradhan, Sanjaya K.


    A power conditioner includes power converters for supplying power to a load, a set of selection switches corresponding to the power converters for selectively connecting the fuel-cell stack to the power converters, and another set of selection switches corresponding to the power converters for selectively connecting the battery to the power converters. The power conveners output combined power that substantially optimally meets a present demand of the load.

  12. Prototyping Practice

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette; Tamke, Martin


    and digital prototyping as a particular means of validation and verification. Here, a breadth of physical prototypes take on varying roles, in turn informing, testing and proving the research enquiry. The paper addresses how we can differentiate between these modes of prototyping and how.......This paper examines the role of the prototyping in digital architecture. During the past decade, a new research field has emerged exploring the digital technology’s impact on the way we think, design and build our environment. In this practice the prototype, the pavilion, installation...... or demonstrator, has become a shared research tool. This paper asks how this practice has formed by tracing the different roles of the prototype from ideation and design, to analysis and evaluation. Taking point of departure in CITA’s own prototyping practice, we explore the relationships between physical...

  13. Locomotive Syndrome: Definition and Management. (United States)

    Nakamura, Kozo; Ogata, Toru

    Locomotive syndrome is a condition of reduced mobility due to impairment of locomotive organs. Since upright bipedal walking involves minutely controlled movement patterns, impairment of any aspect of the locomotive organs has the potential to adversely affect it. In addition to trauma, chronic diseases of the locomotive organs, which progress with repeated bouts of acute exacerbations, are common causes of the locomotive syndrome. In Japan's super-aging society, many people are likely to experience locomotive syndrome in the later part of their lives. Exercise intervention is effective in improving motor function, but because the subjects are elderly people with significant degenerative diseases of the locomotor organs, caution should be taken in choosing the type and intensity of exercise. The present review discusses the definition, current burden, diagnosis and interventions pertaining to the locomotive syndrome. The concept and measures are spreading throughout Japan as one of the national health policy targets.

  14. Vibroacoustic characteristics of mine locomotives

    Energy Technology Data Exchange (ETDEWEB)

    Chigirinskii, S.E.; Ponomarev, N.S.; Leiman, Ya.A.


    The paper discusses noise pollution caused by locomotives used for mine haulage in underground mining. Noise pollution in a mine working and at the driver working place is measured. Mechanical vibrations of the floor in the driver cab are also determined. Noise pollution and mechanical vibrations of 3 locomotive types are comparatively evaluated: the AM-8D electric locomotive, the GR-4 inertia-type locomotive and the 1D-8 diesel locomotive. The results of investigations are shown in 2 tables. The inertia-type locomotive causes the most intensive noise pollution. Noise pollution of the diesel locomotive has been successfully suppressed by a system of shock absorbers. The following methods for noise and vibration control are discussed: use of soundproof cabs, damping vibrations at the driver's seat, use of motors with noise abatement systems and shock absorbers. (In Russian)

  15. Collaborative Prototyping

    DEFF Research Database (Denmark)

    Bogers, Marcel; Horst, Willem


    changes, and it detects emerging usability problems through active engagement and experimentation. As such, the collaborative prototype acts as a boundary object to represent, understand, and transform knowledge across functional, hierarchical, and organizational boundaries. Our study also identifies some......This paper presents an inductive study that shows how collaborative prototyping across functional, hierarchical, and organizational boundaries can improve the overall prototyping process. Our combined action research and case study approach provides new insights into how collaborative prototyping...... can provide a platform for prototype-driven problem solving in early new product development (NPD). Our findings have important implications for how to facilitate multistakeholder collaboration in prototyping and problem solving, and more generally for how to organize collaborative and open innovation...

  16. Prototyping Revisited

    DEFF Research Database (Denmark)

    Hansen, Poul H. Kyvsgård; Hansen, Svend Aage; Hansen, Erik


    Until now, prototyping has been developing as a technological discipline. In so it has proven to be a strong means to test specific solutions or physical designs before the launch of a product. The results have been reduced development time and improvement of quality in a broad sense. There are......, however, indications that we should review our perception of prototypes to be broader and to view our application of prototypes in a broader organizational view. This paper presents an initial and explorative review of the changing role of prototypes in product development....

  17. Unikabeton Prototype

    DEFF Research Database (Denmark)

    Søndergaard, Asbjørn; Dombernowsky, Per


    The Unikabeton prototype structure was developed as the finalization of the cross-disciplinary research project Unikabeton, exploring the architectural potential in linking the computational process of topology optimisation with robot fabrication of concrete casting moulds. The project was elabor......The Unikabeton prototype structure was developed as the finalization of the cross-disciplinary research project Unikabeton, exploring the architectural potential in linking the computational process of topology optimisation with robot fabrication of concrete casting moulds. The project...... of Architecture was to develop a series of optimisation experiments, concluding in the design and optimisation of a full scale prototype concrete structure....


    Directory of Open Access Journals (Sweden)

    Vincent RITS


    Scenario analyses confirm the widely claimed need for further technological development, but also find it insufficient. Moreover, it is found that the widespread diffusion of fuel-cell cars in China will first and only take place after 2025. Main conditions are firstly: the removal of technological and economic obstacles, the appearance of an initial niche market and the self-enforcement of diffusion (with consensus among the important actors, driven by the technological development. Secondly: either high price of fossil fuels (energy resource scarcity is required or (very strict environmental regulations by the Chinese government -i.e. a breakthrough of the present policy trend.

  19. Steam Locomotives: a forgotten era

    African Journals Online (AJOL)

    The boiler was not armoured as the idea was that it was bullet proof. The locomotives were arranged into groups of five and for each group there was an engine as standby. As far as can be ascertained, locomotive No 537 was never armoured, but did work draw trains and freight trains during the Anglo-Boer War too.

  20. Fuel-Cell Power Systems Incorporating Mg-Based H2 Generators (United States)

    Kindler, Andrew; Narayan, Sri R.


    Two hydrogen generators based on reactions involving magnesium and steam have been proposed as means for generating the fuel (hydrogen gas) for such fuel-cell power systems as those to be used in the drive systems of advanced motor vehicles. The hydrogen generators would make it unnecessary to rely on any of the hydrogen storage systems developed thus far that are, variously, too expensive, too heavy, too bulky, and/or too unsafe to be practical. The two proposed hydrogen generators are denoted basic and advanced, respectively. In the basic hydrogen generator (see figure), steam at a temperature greater than or equals 330 C would be fed into a reactor charged with magnesium, wherein hydrogen would be released in the exothermic reaction Mg + H2O yields MgO + H2. The steam would be made in a flash boiler. To initiate the reaction, the boiler could be heated electrically by energy borrowed from a storage battery that would be recharged during normal operation of the associated fuel-cell subsystem. Once the reaction was underway, heat from the reaction would be fed to the boiler. If the boiler were made an integral part of the hydrogen-generator reactor vessel, then the problem of transfer of heat from the reactor to the boiler would be greatly simplified. A pump would be used to feed water from a storage tank to the boiler.

  1. Magnetic Material Assessment of a Novel Ultra-High Step-Up Converter with Single Semiconductor Switch and Galvanic Isolation for Fuel-Cell Power System

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen


    Full Text Available In this paper, a novel step-up converter is proposed, which has the particular features of single semiconductor switch, ultra-high conversion ratio, galvanic isolation, and easy control. Therefore, the proposed converter is suitable for the applications of fuel-cell power system. Coupled inductors and switched capacitors are incorporated in the converter to obtain an ultra-high voltage ratio that is much higher than that of a conventional high step-up converter. Even if the turns ratio of coupled inductor and duty ratio are only to be 1 and 0.5, respectively, the converter can readily achieve a voltage gain of up to 18. Owing to this outstanding performance, it can also be applied to any other low voltage source for voltage boosting. In the power stage, only one active switch is used to handle the converter operation. In addition, the leakage energy of the two couple inductors can be totally recycled without any snubber, which simplifies the control mechanism and improves the conversion efficiency. Magnetic material dominates the conversion performance of the converter. Different types of iron cores are discussed for the possibility to serve as a coupled inductor. A 200 W prototype with 400 V output voltage is built to validate the proposed converter. In measurement, it indicates that the highest efficiency can be up to 94%.

  2. Synthesis of digital locomotive receiver of automatic locomotive signaling

    Directory of Open Access Journals (Sweden)

    K. V. Goncharov


    Full Text Available Purpose. Automatic locomotive signaling of continuous type with a numeric coding (ALSN has several disadvantages: a small number of signal indications, low noise stability, high inertia and low functional flexibility. Search for new and more advanced methods of signal processing for automatic locomotive signaling, synthesis of the noise proof digital locomotive receiver are essential. Methodology. The proposed algorithm of detection and identification locomotive signaling codes is based on the definition of mutual correlations of received oscillation and reference signals. For selecting threshold levels of decision element the following criterion has been formulated: the locomotive receiver should maximum set the correct solution for a given probability of dangerous errors. Findings. It has been found that the random nature of the ALSN signal amplitude does not affect the detection algorithm. However, the distribution law and numeric characteristics of signal amplitude affect the probability of errors, and should be considered when selecting a threshold levels According to obtained algorithm of detection and identification ALSN signals the digital locomotive receiver has been synthesized. It contains band pass filter, peak limiter, normalizing amplifier with automatic gain control circuit, analog to digital converter and digital signal processor. Originality. The ALSN system is improved by the way of the transfer of technical means to modern microelectronic element base, more perfect methods of detection and identification codes of locomotive signaling are applied. Practical value. Use of digital technology in the construction of the locomotive receiver ALSN will expand its functionality, will increase the noise immunity and operation stability of the locomotive signal system in conditions of various destabilizing factors.

  3. Artificial locomotion control

    DEFF Research Database (Denmark)

    Azevedo, Christine; Poignet, Philippe; Espiau, Bernard


    This paper concerns the simultaneous synthesis and control of walking gaits for biped robots. The goal is to propose an adaptable and reactive control law for two-legged machines. The problem is addressed with human locomotion as a reference. The starting point of our work is an analysis of human...... walking from descriptive (biomechanics) as well as explicative (neuroscience and physiology) points of view, the objective being to stress the relevant elements for the approach of robot control. The adopted principles are then: no joint trajectory tracking; explicit distinction and integration...... of postural and walking control; use of evolutive optimization objectives; on-line event handling and environment adaptation and anticipation. This leads to the synthesis of an original control scheme based on non-linear model predictive control: Trajectory Free NMPC. The movement is specified implicitly...

  4. Locomotion through Morphosis

    DEFF Research Database (Denmark)

    Larsen, Jørgen Christian

    construction kit called LocoKit, which is intended as a system on which studies on locomotion can be done in a simple way. The simplicity is ob- tained by giving the user the opportunity to build legged robots from a set of small components which allows for adjusting various parameters on the robot, even after...... in nature can be found and tested. These results shows the poten- tial of LocoKit and are nicely in line with the goal of the project. I future development, LocoKit will be improved in such a way that it allows the user to build even more efficient robots than have been build until now....

  5. Self-improving biped locomotion (United States)

    Teixeira, C.; Costa, L.; Santos, C.


    An approach addressing biped locomotion is here introduced. Central Pattern Generators (CPGs) and Dynamic Movement Primitives (DMPs) were combined to easily produce complex trajectories for the joints of a simulated DARwIn-OP. Policy Learning by Weighting Exploration with the Returns (PoWER) was implemented to improve the robot's locomotion through variation of the DMP's parameters. Maximization of the DARwIn-OP's frontal velocity was addressed and results show a velocity improvement of 213%. The results are very promising and demonstrate the approach's flexibility at generating new trajectories for locomotion.

  6. Optimization of fuel-cell tram operation based on two dimension dynamic programming (United States)

    Zhang, Wenbin; Lu, Xuecheng; Zhao, Jingsong; Li, Jianqiu


    This paper proposes an optimal control strategy based on the two-dimension dynamic programming (2DDP) algorithm targeting at minimizing operation energy consumption for a fuel-cell tram. The energy consumption model with the tram dynamics is firstly deduced. Optimal control problem are analyzed and the 2DDP strategy is applied to solve the problem. The optimal tram speed profiles are obtained for each interstation which consist of three stages: accelerate to the set speed with the maximum traction power, dynamically adjust to maintain a uniform speed and decelerate to zero speed with the maximum braking power at a suitable timing. The optimal control curves of all the interstations are connected with the parking time to form the optimal control method of the whole line. The optimized speed profiles are also simplified for drivers to follow.

  7. Cleaning the air and improving health with hydrogen fuel-cell vehicles. (United States)

    Jacobson, M Z; Colella, W G; Golden, D M


    Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

  8. Fundamentals of soft robot locomotion


    Calisti, M.; Picardi, G.; Laschi, C.


    Soft robotics and its related technologies enable robot abilities in several robotics domains including, but not exclusively related to, manipulation, manufacturing, human���robot interaction and locomotion. Although field applications have emerged for soft manipulation and human���robot interaction, mobile soft robots appear to remain in the research stage, involving the somehow conflictual goals of having a deformable body and exerting forces on the environment to achieve locomotion. This p...

  9. Equilibrium products from autothermal processes for generating hydrogen-rich fuel-cell feeds

    Energy Technology Data Exchange (ETDEWEB)

    Semelsberger, T.A.; Brown, L.F.; Borup, R.L.; Inbody, M.A.M.A. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.; Los Alamos National Lab., NM (United States). Engineering Sciences and Applications Div.


    This work presents thermodynamic analyses of autothermal processes using five fuels- natural gas, methanol, ethanol, dimethyl ether, and gasoline. Autothermal processes combine exothermic and endothermic reactions. The processes considered here couple endothermic steam reforming with exothermic oxidation to create hydrogen-rich fuel-cell feeds. Of the fuels treated here, methanol, ethanol, and dimethyl ether are pure compounds. Methane simulates natural gas and a mixture of 7% neopentane, 56% 2,4 dimethyl pentane, 7% cyclohexane, 30% ethyl benzene simulates gasoline. In the computations, sufficient oxygen is fed so the energy generated by the oxidation exactly compensates the energy absorbed by the reforming reactions. The analyses calculate equilibrium product concentrations at temperatures from 300 to 1000 K, pressures from 1 to 5 atm, and water-fuel ratios from 1 to 9 times the stoichiometric value. The thermodynamic calculations in this work say that any of the five fuels, when processed autothermally, can give a product leading to a hydrogen-rich feed for fuel cells. The calculations also show that the oxygen-containing substances (methanol, ethanol, and dimethyl ether) require lower temperatures for effective processing than the non-oxygenated fuels (natural gas and gasoline). Lower reaction temperatures also promote products containing less carbon monoxide, a desirable effect. The presence of significant product CO mandates the choice of optimum conditions, not necessarily conditions that produce the maximum product hydrogen content. Using a simple optimum objective function shows that dimethyl ether has the greatest potential product content, followed by methanol, ethanol, gasoline, and natural gas. The calculations point the way toward rational choices of processes for producing fuel-cell feeds of the necessary quality. (author)

  10. Rapid Prototyping (United States)


    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  11. Dynamic model of oxygen starved proton exchange membrane fuel-cell using hybrid analytical-numerical method (United States)

    Vijayaraghavan, Krishna; DeVaal, Jake; Narimani, Mohammad


    One of the primary life-limiting factors in PEM fuel-cells arises from performance degradation resulting from transfer (crossover) leaks. Transfer leaks result in oxygen starvation and models of fuel cells under oxygen starved conditions would allow for detection of fault inception. This paper develops a unified fuel-cell model for when the fuel-cells can either deliver power (termed driving-mode, and for when the cell absorb power (termed driven-mode) for higher leak rates. The model captures the gradient of the reactants both in the GDL and in the flow channel in addition to capturing the various electro-chemical effects. The response of the model under normal conditions is first validated for normal operation against previously published experiments. The response of the model under oxygen-starved conditions is then validated against simulated leaks in three different cell architectures: a Ballard 9-cell Mk1100 stack where hydrogen is injected into one cell, and a Ballard 10-cell Mk902 stack and 20-cell Mk903 stack where hydrogen is injected into the upstream cathode flow. Finally, the response of the model is also validated against an actual leaky Mk902 cell. The model generally agrees well with the measured cell voltage data for all the above experiments.

  12. Overcoming the Range Limitation of Medium-Duty Battery Electric Vehicles through the use of Hydrogen Fuel-Cells

    Energy Technology Data Exchange (ETDEWEB)

    Wood, E.; Wang, L.; Gonder, J.; Ulsh, M.


    Battery electric vehicles possess great potential for decreasing lifecycle costs in medium-duty applications, a market segment currently dominated by internal combustion technology. Characterized by frequent repetition of similar routes and daily return to a central depot, medium-duty vocations are well positioned to leverage the low operating costs of battery electric vehicles. Unfortunately, the range limitation of commercially available battery electric vehicles acts as a barrier to widespread adoption. This paper describes the National Renewable Energy Laboratory's collaboration with the U.S. Department of Energy and industry partners to analyze the use of small hydrogen fuel-cell stacks to extend the range of battery electric vehicles as a means of improving utility, and presumably, increasing market adoption. This analysis employs real-world vocational data and near-term economic assumptions to (1) identify optimal component configurations for minimizing lifecycle costs, (2) benchmark economic performance relative to both battery electric and conventional powertrains, and (3) understand how the optimal design and its competitiveness change with respect to duty cycle and economic climate. It is found that small fuel-cell power units provide extended range at significantly lower capital and lifecycle costs than additional battery capacity alone. And while fuel-cell range-extended vehicles are not deemed economically competitive with conventional vehicles given present-day economic conditions, this paper identifies potential future scenarios where cost equivalency is achieved.

  13. Origami-based earthworm-like locomotion robots. (United States)

    Fang, Hongbin; Zhang, Yetong; Wang, K W


    Inspired by the morphology characteristics of the earthworms and the excellent deformability of origami structures, this research creates a novel earthworm-like locomotion robot through exploiting the origami techniques. In this innovation, appropriate actuation mechanisms are incorporated with origami ball structures into the earthworm-like robot 'body', and the earthworm's locomotion mechanism is mimicked to develop a gait generator as the robot 'centralized controller'. The origami ball, which is a periodic repetition of waterbomb units, could output significant bidirectional (axial and radial) deformations in an antagonistic way similar to the earthworm's body segment. Such bidirectional deformability can be strategically programmed by designing the number of constituent units. Experiments also indicate that the origami ball possesses two outstanding mechanical properties that are beneficial to robot development: one is the structural multistability in the axil direction that could contribute to the robot control implementation; and the other is the structural compliance in the radial direction that would increase the robot robustness and applicability. To validate the origami-based innovation, this research designs and constructs three robot segments based on different axial actuators: DC-motor, shape-memory-alloy springs, and pneumatic balloon. Performance evaluations reveal their merits and limitations, and to prove the concept, the DC-motor actuation is selected for building a six-segment robot prototype. Learning from earthworms' fundamental locomotion mechanism-retrograde peristalsis wave, seven gaits are automatically generated; controlled by which, the robot could achieve effective locomotion with qualitatively different modes and a wide range of average speeds. The outcomes of this research could lead to the development of origami locomotion robots with low fabrication costs, high customizability, light weight, good scalability, and excellent re-configurability.

  14. Fundamentals of soft robot locomotion. (United States)

    Calisti, M; Picardi, G; Laschi, C


    Soft robotics and its related technologies enable robot abilities in several robotics domains including, but not exclusively related to, manipulation, manufacturing, human-robot interaction and locomotion. Although field applications have emerged for soft manipulation and human-robot interaction, mobile soft robots appear to remain in the research stage, involving the somehow conflictual goals of having a deformable body and exerting forces on the environment to achieve locomotion. This paper aims to provide a reference guide for researchers approaching mobile soft robotics, to describe the underlying principles of soft robot locomotion with its pros and cons, and to envisage applications and further developments for mobile soft robotics. © 2017 The Author(s).

  15. Relation between observed locomotion traits and locomotion score in dairy cows

    NARCIS (Netherlands)

    Schlageter Tello, A.A.; Bokkers, E.A.M.; Groot Koerkamp, P.W.G.; Hertem, van T.; Viazzi, S.; Lokhorst, Kees


    Lameness is still an important problem in modern dairy farming. Human observation of locomotion, by looking at different traits in one go, is used in practice to assess locomotion. The objectives of this article were to determine which individual locomotion traits are most related to locomotion

  16. In Pipe Robot with Hybrid Locomotion System

    Directory of Open Access Journals (Sweden)

    Cristian Miclauş


    Full Text Available The first part of the paper covers aspects concerning in pipe robots and their components, such as hybrid locomotion systems and the adapting mechanisms used. The second part describes the inspection robot that was developed, which combines tracked and wheeled locomotion (hybrid locomotion. The end of the paper presents the advantages and disadvantages of the proposed robot.

  17. Locomotive monitoring system using wireless sensor networks

    CSIR Research Space (South Africa)

    Croucamp, PL


    Full Text Available Theft of cables used for powering a locomotive not only stops the train from functioning but also paralyzes the signalling and monitoring system. This means that information on certain locomotive's cannot be passed onto other locomotives which may...

  18. Thermal expansion coefficient prediction of fuel-cell seal materials from silica sand (United States)

    Hidayat, Nurul; Triwikantoro, Baqiya, Malik A.; Pratapa, Suminar


    This study is focused on the prediction of coefficient of thermal expansion (CTE) of silica-sand-based fuel-cell seal materials (FcSMs) which in principle require a CTE value in the range of 9.5-12 ppm/°C. A semi-quantitative theoretical method to predict the CTE value is proposed by applying the analyzed phase compositions from XRD data and characterized density-porosity behavior. A typical silica sand was milled at 150 rpm for 1 hour followed by heating at 1000 °C for another hour. The sand and heated samples were characterized by means of XRD to perceive the phase composition correlation between them. Rietveld refinement was executed to investigate the weight fraction of the phase contained in the samples, and then converted to volume fraction for composite CTE calculations. The result was applied to predict their potential physical properties for FcSM. Porosity was taken into account in the calculation after which it was directly measured by the Archimedes method.

  19. Highly Zeolite-Loaded Polyvinyl Alcohol Composite Membranes for Alkaline Fuel-Cell Electrolytes

    Directory of Open Access Journals (Sweden)

    Po-Ya Hsu


    Full Text Available Having a secure and stable energy supply is a top priority for the global community. Fuel-cell technology is recognized as a promising electrical energy generation system for the twenty-first century. Polyvinyl alcohol/zeolitic imidazolate framework-8 (PVA/ZIF-8 composite membranes were successfully prepared in this work from direct ZIF-8 suspension solution (0–45.4 wt % and PVA mixing to prevent filler aggregation for direct methanol alkaline fuel cells (DMAFCs. The ZIF-8 fillers were chosen for the appropriate cavity size as a screening aid to allow water and suppress methanol transport. Increased ionic conductivities and suppressed methanol permeabilities were achieved for the PVA/40.5% ZIF-8 composites, compared to other samples. A high power density of 173.2 mW cm−2 was achieved using a KOH-doped PVA/40.5% ZIF-8 membrane in a DMAFC at 60 °C with 1–2 mg cm−2 catalyst loads. As the filler content was raised beyond 45.4 wt %, adverse effects resulted and the DMAFC performance (144.9 mW cm−2 was not improved further. Therefore, the optimal ZIF-8 content was approximately 40.5 wt % in the polymeric matrix. The specific power output was higher (58 mW mg−1 than most membranes reported in the literature (3–18 mW mg−1.

  20. Rapid detection of defects in fuel-cell electrodes using infrared reactive-flow-through technique (United States)

    Das, Prodip K.; Weber, Adam Z.; Bender, Guido; Manak, Austin; Bittinat, Daniel; Herring, Andrew M.; Ulsh, Michael


    As fuel cells become more prominent, new manufacturing and production methods will need to be developed to deal efficiently and effectively with increased demand. One necessary component of this industrial growth is the accurate measurement of the variability in the manufacturing process. In this study, we present a diagnostic system that combines infrared thermography with a reactive-flow-through technique to detect catalyst-loading defects in fuel-cell gas-diffusion electrodes accurately with high spatial and temporal resolutions. Experimental results are compared with model predictions of thermal response with good agreement. Data analysis, operating-condition impacts, and detection limits are explored using both experiments and simulation. Overall, the results demonstrate the potential of this technique to measure defects on the millimeter length scale with temporal resolutions appropriate for use on a web-line. Thus we present the first development stage of a next-generation non-destructive diagnostic tool, which may be amenable to eventual use on roll-to-roll manufacturing lines.

  1. Fuel-cell breathalyser use for field research on alcohol intoxication: an independent psychometric evaluation

    Directory of Open Access Journals (Sweden)

    Jacob G. Sorbello


    Full Text Available Background Several field studies have used fuel-cell breathalysers (FCB to investigate the prevalence of alcohol intoxication. However, there is a lack of evidence evaluating the psychometric properties of these breathalysers outside of the forensic disciplines. Methods The current research describes four studies designed that assess the reliability and validity of portable platinum FCBs for research on alcohol intoxication. Utilising the Alcolizer LE5 breathalyser and, to a lesser degree, the Lifeloc FC-20 and the Lion Intoxilyzer 8000, each study sampled patrons frequenting popular night-time entertainment districts with varying levels of alcohol intoxication. Results Study one and two found excellent test-retest reliability and inter-instrument reliability for FCBs. Study three and four provided evidence to support the convergent validity of the two FCBs (the LE5 with the FC20, and with an evidential breathalyser (i.e., the Lion Intoxilyzer 8000; EB. Discussion A 93–97% agreement rate between breathalyser readings was found across the four studies. Portable FCB are recommended as a reliable and valid instrument for research designs requiring quick alcohol intoxication estimations in large populations. Strategies to enhance reliable and valid readings are provided for field researchers.

  2. Compact methanol reformer test for fuel-cell powered light-duty vehicles (United States)

    Emonts, B.; Bøgild Hansen, J.; Lœgsgaard Jørgensen, S.; Höhlein, B.; Peters, R.

    On-board production of hydrogen from methanol based on a steam reformer in connection with the use of low-temperature fuel-cells (PEMFC) is an attractive option as energy conversion unit for light-duty vehicles. A steam reforming process at higher pressures with an external burner offers advantages in comparison to a steam reformer with integrated partial oxidation in terms of total efficiency for electricity production. The main aim of a common project carried out by the Forschungszentrum Jülich (FZJ), Haldor Topsøe A/S (HTAS) and Siemens AG is to design, to construct and to test a steam reformer reactor concept (HTAS) with external catalytic burner (FZJ) as heat source as well as catalysts for heterogeneously catalyzed hydrogen production (HTAS), concepts for gas treatment (HTAS, FZJ) and a low-temperature fuel cell (Siemens). Based on the experimental results obtained so far concerning methanol reformers, catalytic burners and gas conditioning units, our report describes the total system, a test unit and preliminary test results related to a hydrogen production capacity of 50 kW (LHV) and dynamic operating conditions. This hydrogen production system is aimed at reducing the specific weight (gas cleaning unit fulfill the requirements with high hydrogen permeability and low cost of the noble metal.

  3. Experiments on vibration-driven stick-slip locomotion: A sliding bifurcation perspective (United States)

    Du, Zhouwei; Fang, Hongbin; Zhan, Xiong; Xu, Jian


    Dry friction appears at the contact interface between two surfaces and is the source of stick-slip vibrations. Instead of being a negative factor, dry friction is essential for vibration-driven locomotion system to take effect. However, the dry-friction-induced stick-slip locomotion has not been fully understood in previous research, especially in terms of experiments. In this paper, we experimentally study the stick-slip dynamics of a vibration-driven locomotion system from a sliding bifurcation perspective. To this end, we first design and build a vibration-driven locomotion prototype based on an internal piezoelectric cantilever. By utilizing the mechanical resonance, the small piezoelectric deformation is significantly amplified to drive the prototype to achieve effective locomotion. Through identifying the stick-slip characteristics in velocity histories, we could categorize the system's locomotion into four types and obtain a stick-slip categorization diagram. In each zone of the diagram the locomotion exhibits qualitatively different stick-slip dynamics. Such categorization diagram is actually a sliding bifurcation diagram; crossing from one stick-slip zone to another corresponds to the triggering of a sliding bifurcation. In addition, a simplified single degree-of-freedom model is established, with the rationality of simplification been explained theoretically and numerically. Based on the equivalent model, a numerical stick-slip categorization is also obtained, which shows good agreement with the experiments both qualitatively and quantitatively. To the best of our knowledge, this is the first work that experimentally generates a sliding bifurcation diagram. The obtained stick-slip categorizations deepen our understanding of stick-slip dynamics in vibration-driven systems and could serve as a base for system design and optimization.

  4. Analysis of Hexapod Robot Locomotion

    Directory of Open Access Journals (Sweden)

    Tomas Luneckas


    Full Text Available Hexapod robot locomotion is analyzed. Trajectory forming method for one leg is introduced. Servo angles are expressed using geometric inverse kinematics method. Forming of tripod gait is described and a diagram representing it is presented. Servo control parameters are defined to ensure fluent and versatile robot control. Several servo control methods are presented. After testing robot movement using different servo control methods, gait generation is corrected and control method that meets servo control parameters is chosen.Article in Lithuanian

  5. Scaling laws of aquatic locomotion (United States)

    Sun, BoHua


    In recent years studies of aquatic locomotion have provided some remarkable insights into the many features of fish swimming performances. This paper derives a scaling relation of aquatic locomotion C D( Re)2 = ( Sw)2 and its corresponding log law and power law. For power scaling law, ( Sw)2 = β n Re 2-1/ n , which is valid within the full spectrum of the Reynolds number Re = UL/ν from low up to high, can simply be expressed as the power law of the Reynolds number Re and the swimming number Sw = ωAL/ν as Re ∝ ( Sw)σ, with σ = 2 for creeping flows, σ = 4=3 for laminar flows, σ = 10=9 and σ = 14=13 for turbulent flows. For log law this paper has derived the scaling law as Sw ∝ Re=(ln Re+1:287), which is even valid for a much wider range of the Reynolds number Re. Both power and log scaling relationships link the locomotory input variables that describe the swimmer's gait A; ω via the swimming number Sw to the locomotory output velocity U via the longitudinal Reynolds number Re, and reveal the secret input-output relationship of aquatic locomotion at different scales of the Reynolds number

  6. Emotion through locomotion: gender impact.

    Directory of Open Access Journals (Sweden)

    Samuel Krüger

    Full Text Available Body language reading is of significance for daily life social cognition and successful social interaction, and constitutes a core component of social competence. Yet it is unclear whether our ability for body language reading is gender specific. In the present work, female and male observers had to visually recognize emotions through point-light human locomotion performed by female and male actors with different emotional expressions. For subtle emotional expressions only, males surpass females in recognition accuracy and readiness to respond to happy walking portrayed by female actors, whereas females exhibit a tendency to be better in recognition of hostile angry locomotion expressed by male actors. In contrast to widespread beliefs about female superiority in social cognition, the findings suggest that gender effects in recognition of emotions from human locomotion are modulated by emotional content of actions and opposite actor gender. In a nutshell, the study makes a further step in elucidation of gender impact on body language reading and on neurodevelopmental and psychiatric deficits in visual social cognition.


    Directory of Open Access Journals (Sweden)

    I. V. Zhukovytskyy


    Full Text Available Purpose. The article considers the process of development and improvement of tachometer data collectors for the data-measuring diesel locomotive hydraulic transmission test system, which will give the possibility of obtaining the source data to conduct further studies of the technical condition of diesel locomotive hydraulic transmission. It is supposed to provide a solution to the problem of development and improvement of tachometer data measuring tools of the previously created data-measuring diesel locomotive hydraulic transmission test system, starting out from the possibility of modification of the existing locomotive hydraulic transmission test-bench at the Dnepropetrovsk Diesel Locomotive Repair Plant «Promteplovoz». Methodology. The researchers proposed in the work a method of modifying the existing tachometer sensor of the automated microprocessor system for the locomotive hydraulic transmission test-bench in the conditions of a diesel locomotive repair plant. It is applicable by substantiating the choice of the required tachometer sensor measuring method, as well as by using the necessary hardware and software to accomplish the goal with the ability to integrate into the data-measuring system for diesel locomotive hydraulic transmission testing. Findings. The available equipment of the locomotive hydraulic transmission test-bench allowed for design of the optical type speed sensor based on the existing sensor D-2MMU-2. The factory testing with the use of a sensor prototype resulted in determination of the required and sufficient sampling time for sensor operating microcontroller. Originality. The available equipment of the locomotive hydraulic transmission test-bench allowed for design of the optical type speed sensor based on the existing sensor D-2MMU-2. We developed the operation algorithms for the microcontroller that processes the signals from this sensor. The sensor was factory-tested. According to the data sample obtained

  8. Micro robot prototype for colonoscopy and in vitro experiments. (United States)

    Wang, K; Yan, G


    For actively diagnosing the colon's pathologies micro-invasively or non-invasively, an autonomous prototype of the earthworm-like robot for colonoscopy was designed according to the principle of bionics, and manufactured using precision process technology. In vitro experiments in pig colon were carried out. The micro robot was driven directly by an electromagnetic linear driver. The mobile cells were joined with joints of two degrees of freedom, and the whole body was flexible. The direction of movement and the angle of imaging can be controlled by the shape memory alloy (SMA). In experiments, locomotion efficient and locomotion ability was analysed carefully. Locomotion force and velocity were tested. In vitro experiments in pig colon demonstrated that the micro robot can navigate though the colon by itself reliably and freely, which will be useful for the application of the robot to colonoscopy in the clinic.

  9. Locomotive biofuel study : preliminary study on the use and the effects of biodiesel in locomotives. (United States)


    Section 404 of the Passenger Rail Investment and Improvement Act (PRIIA), 2008, mandated that the Federal Railroad : Administration (FRA) undertake a Locomotive Biofuel Study to investigate the feasibility of using biofuel blends as locomotive : engi...

  10. Characteristics of undulatory locomotion in granular media


    Peng, Zhiwei; Pak, On Shun; Elfring, Gwynn J.


    Undulatory locomotion is ubiquitous in nature and observed in different media, from the swimming of flagellated microorganisms in biological fluids, to the slithering of snakes on land, or the locomotion of sandfish lizards in sand. Despite the similarity in the undulating pattern, the swimming characteristics depend on the rheological properties of different media. Analysis of locomotion in granular materials is relatively less developed compared with fluids partially due to a lack of valida...

  11. Coupling of cytoskeleton functions for fibroblast locomotion

    DEFF Research Database (Denmark)

    Couchman, J R; Lenn, M; Rees, D A


    Using a chick cell phenotype specialised for locomotion with morphometric measurements made possible by modern instrumentation technology, we have reinvestigated motile functions in fibroblast locomotion. Quantitative analysis of rapid fluctuations in cell form and organelle distribution during l...... function of microtubules to direct the flow towards multiple foci on the leading edge, and so determine cell polarity. Such a mechanism of locomotion for fibroblasts has many features consistent with evidence for other cell types, especially amoebae and leukocytes....

  12. Modeling limbless locomotion using ADAMS software Project (United States)

    National Aeronautics and Space Administration — Limbless locomotion has the potential of meeting transportation requirements, particularly in challenging environments. Snakes can traverse a variety of surfaces...

  13. Railroad and locomotive technology roadmap.

    Energy Technology Data Exchange (ETDEWEB)

    Stodolsky, F.; Gaines, L.; Energy Systems


    Railroads are important to the U.S. economy. They transport freight efficiently, requiring less energy and emitting fewer pollutants than other modes of surface transportation. While the railroad industry has steadily improved its fuel efficiency--by 16% over the last decade--more can, and needs to, be done. The ability of locomotive manufacturers to conduct research into fuel efficiency and emissions reduction is limited by the small number of locomotives manufactured annually. Each year for the last five years, the two North American locomotive manufacturers--General Electric Transportation Systems and the Electro-Motive Division of General Motors--have together sold about 800 locomotives in the United States. With such a small number of units over which research costs can be spread, outside help is needed to investigate all possible ways to reduce fuel usage and emissions. Because fuel costs represent a significant portion of the total operating costs of a railroad, fuel efficiency has always been an important factor in the design of locomotives and in the operations of a railroad. However, fuel efficiency has recently become even more critical with the introduction of strict emission standards by the U.S. Environmental Protection Agency, to be implemented in stages (Tiers 0, 1, and 2) between 2000 and 2005. Some of the technologies that could be employed to meet the emission standards may negatively affect fuel economy--by as much as 10-15% when emissions are reduced to Tier 1 levels. Lowering fuel economy by that magnitude would have a serious impact on the cost to the consumer of goods shipped by rail, on the competitiveness of the railroad industry, and on this country's dependence on foreign oil. Clearly, a joint government/industry R&D program is needed to help catalyze the development of advanced technologies that will substantially reduce locomotive engine emissions while also improving train system energy efficiency. DOE convened an industry

  14. BiLBIQ A Biologically Inspired Robot with Walking and Rolling Locomotion

    CERN Document Server

    King, Ralf Simon


    The book ‘BiLBIQ: A biologically inspired Robot with walking and rolling locomotion’ deals with implementing a locomotion behavior observed in the biological archetype Cebrennus villosus to a robot prototype whose structural design needs to be developed.   The biological sample is investigated as far as possible and compared to other evolutional solutions within the framework of nature’s inventions. Current achievements in robotics are examined and evaluated for their relation and relevance to the robot prototype in question. An overview of what is state of the art in actuation ensures the choice of the hardware available and most suitable for this project. Through a constant consideration of the achievement of two fundamentally different ways of locomotion with one and the same structure, a robot design is developed and constructed taking hardware constraints into account. The development of a special leg structure that needs to resemble and replace body elements of the biological archetype is a speci...

  15. Phase coordination and phase-velocity relationship in metameric robot locomotion. (United States)

    Fang, Hongbin; Li, Suyi; Wang, K W; Xu, Jian


    This research proposes a new approach for the control of metameric robot locomotion via phase coordination. Unlike previous studies where global wave-like rules were pre-specified to construct the actuation sequence of segments, this phase coordination method generates robot locomotion by assigning the actuation phase differences between adjacent segments without any global prerequisite rules. To effectively coordinate the phase differences, different symmetry properties are introduced. Optimization is then carried out on various symmetrically coordinated phase-difference patterns to maximize the average steady-state velocity of the robot. It is shown that the maximum average velocity is always achieved when the reflectional symmetry is included in the phase-difference pattern, and the identical-phase-difference (IPD) pattern is preferred for implementation because it reduces the number of independent phase variables to only one without significant loss in locomotion performance. Extensive analytical investigations on the IPD pattern reveal the relationship between the average locomotion velocity and some important parameters. Theoretical findings on the relationship between the average velocity and the phase difference in the IPD pattern are verified via experimental investigations on an 8-segment earthworm-like metameric robot prototype. Finally, this paper reveals an interesting result that the optimized phase-difference pattern can naturally generate peristalsis waves in metameric robot locomotion without global prerequisite wave-like rules.

  16. The investigation of the locomotive boiler material

    International Nuclear Information System (INIS)

    Tucholski, Z.; Wasiak, J.; Bilous, W.; Hajewska, E.


    In the paper, the history of narrow-gauge railway system is described. The other information about the steam locomotive construction, as well as the technical regulations of its construction and exploitation are also done. The results of the studies of the locomotive boiler material are presented. (authors)

  17. 77 FR 21311 - Locomotive Safety Standards (United States)


    ... final rule incorporates existing industry and engineering best practices related to locomotives and... retrospective review requirements of E.O. 13563, trends in locomotive operation, concern about the safe design... sub-assemblies of pneumatic valves, electronic controls and software (referred to as line replaceable...

  18. Rethink! prototyping transdisciplinary concepts of prototyping

    CERN Document Server

    Nagy, Emilia; Stark, Rainer


    In this book, the authors describe the findings derived from interaction and cooperation between scientific actors employing diverse practices. They reflect on distinct prototyping concepts and examine the transformation of development culture in their fusion to hybrid approaches and solutions. The products of tomorrow are going to be multifunctional, interactive systems – and already are to some degree today. Collaboration across multiple disciplines is the only way to grasp their complexity in design concepts. This underscores the importance of reconsidering the prototyping process for the development of these systems, particularly in transdisciplinary research teams. “Rethinking Prototyping – new hybrid concepts for prototyping” was a transdisciplinary project that took up this challenge. The aim of this programmatic rethinking was to come up with a general concept of prototyping by combining innovative prototyping concepts, which had been researched and developed in three sub-projects: “Hybrid P...

  19. Computer Simulations of Composite Electrodes in Solid-Oxide Fuel-Cells

    Energy Technology Data Exchange (ETDEWEB)

    Sunde, Svein


    Fuel cells are devices for converting the combined chemical (free) energy of fuels and oxygen (air) directly to electrical energy without relying on the dynamic action of steam heated by reacting fuel-oxygen mixtures, like in steam turbines, or of the reacting gas mixtures themselves, like in gas turbines. The basic rationale for fuel cells is their high efficiencies as compared to indirect-conversion methods. Fuel cells are currently being considered for a number of applications, among them de-centralised power supply. Fuel cells come in five basic types and are usually classified according to the type of electrolyte used, which in turn to a significant degree limits the options for anode and cathode materials. The solid-oxide fuel-cell (SOFC) , with which this thesis is concerned, is thus named after its oxide electrolyte, typically the oxide-ion conducting material yttria-stabilised zirconia (YSZ). While the cathode of an SOFC is often uniform in chemical composition (or at least intended to be), various problems of delamination, cracking etc. associated with the use of metallic anode electrocatalysts led to the development of composite SOFC anodes. Porous anodes consisting of Ni and YSZ particles in roughly 50/50 wt-% mixtures are now almost standard with any SOFC-development programme. The designer of composite SOFC electrodes is faced with at least three, interrelated questions: (1) What will be the optimum microstructure and composition of the composite electrode? (2) If the structure changes during operation, as is often observed, what will be the consequences for the internal losses in the cell? (3) How do we interpret electrochemical and conductivity measurements with regard to structure and composition? It is the primary purpose of this thesis to provide a framework for modelling the electrochemical and transport properties of composite electrodes for SOFC, and to arrive at some new insights that cannot be offered by experiment alone. Emphasis is put on

  20. System Design and Locomotion of Superball, an Untethered Tensegrity Robot (United States)

    Sabelhaus, Andrew P.; Bruce, Jonathan; Caluwaerts, Ken; Manovi, Pavlo; Firoozi, Roya Fallah; Dobi, Sarah; Agogino, Alice M.; Sunspiral, Vytas


    The Spherical Underactuated Planetary Exploration Robot ball (SUPERball) is an ongoing project within NASA Ames Research Center's Intelligent Robotics Group and the Dynamic Tensegrity Robotics Lab (DTRL). The current SUPERball is the first full prototype of this tensegrity robot platform, eventually destined for space exploration missions. This work, building on prior published discussions of individual components, presents the fully-constructed robot. Various design improvements are discussed, as well as testing results of the sensors and actuators that illustrate system performance. Basic low-level motor position controls are implemented and validated against sensor data, which show SUPERball to be uniquely suited for highly dynamic state trajectory tracking. Finally, SUPERball is shown in a simple example of locomotion. This implementation of a basic motion primitive shows SUPERball in untethered control.

  1. Continuum limbed robots for locomotion (United States)

    Mutlu, Alper

    This thesis focuses on continuum robots based on pneumatic muscle technology. We introduce a novel approach to use these muscles as limbs of lightweight legged robots. The flexibility of the continuum legs of these robots offers the potential to perform some duties that are not possible with classical rigid-link robots. Potential applications are as space robots in low gravity, and as cave explorer robots. The thesis covers the fabrication process of continuum pneumatic muscles and limbs. It also provides some new experimental data on this technology. Afterwards, the designs of two different novel continuum robots - one tripod, one quadruped - are introduced. Experimental data from tests using the robots is provided. The experimental results are the first published example of locomotion with tripod and quadruped continuum legged robots. Finally, discussion of the results and how far this technology can go forward is presented.

  2. Locomotive track detection for underground (United States)

    Ma, Zhonglei; Lang, Wenhui; Li, Xiaoming; Wei, Xing


    In order to improve the PC-based track detection system, this paper proposes a method to detect linear track for underground locomotive based on DSP + FPGA. Firstly, the analog signal outputted from the camera is sampled by A / D chip. Then the collected digital signal is preprocessed by FPGA. Secondly, the output signal of FPGA is transmitted to DSP via EMIF port. Subsequently, the adaptive threshold edge detection, polar angle and radius constrain based Hough transform are implemented by DSP. Lastly, the detected track information is transmitted to host computer through Ethernet interface. The experimental results show that the system can not only meet the requirements of real-time detection, but also has good robustness.

  3. Dynamic similarity in granular locomotion (United States)

    Kamrin, Ken; Slonaker, James; Zhang, Qiong


    To model the flow of granular media with high accuracy, a number of subtleties arise and complex constitutive relations are needed to address them. However, making certain rheological simplifications produces a framework that is simple enough to obtain global rule-sets that can be used to aid in design without having to solve any partial differential equations or perform discrete element simulations. This talk will show how reduced-order rule-sets such as the Resistive Force Theory can be obtained from a basic frictional plasticity model, and how plasticity can further be used to produce a family of scaling laws in granular locomotion reminiscent of `wind tunnel' scaling laws in fluid dynamics. These are verified with experiments and numerical simulations.

  4. Mechanisms of Protrusion and Cell Locomotion (United States)

    Keller, Hansuli

    Earlier models explaining cell locomotion are briefly reviewed. Then, a model explaining locomotion of non-adhesive Walker carcinosarcoma cells is proposed based on the following data: 1) Walker carcinosarcoma cells, which normally form lamellipodia, can produce forces for movement by at least two distinct actin-based mechanisms, 2) Lamellipodial motility is driven by local actin polymerization, but lamellipodia and actin-based mechanisms (polymerization or contraction) at the front are redundant for locomotion, 3) actomyosin-dependent contraction at the rear (body and/or uropod) is sufficient and necessary for locomotion, 4) fluid pressure can generate protrusion (blebs), 5) an intact cortical layer at the front tends to reduce the speed of locomotion, 6) there is no biologically significant difference in the efficiency of locomotion (speed, persistence, net displacement) of migrating cells showing either lamellipodia, blebs or no morphologically recognizable protrusions, 7) polymerized actin is concentrated in the cortical actin layer. Myosin IIA is preferentially associated with the actin cortex at the rear part of the cell. The data suggest that actomyosin-based contraction in the form of cortical contraction generates protrusion and locomotion in Walker carcinosarcoma cells as previously described in Amoebae. The role of actomyosin-dependent contraction and of fluid-driven mechanisms in other metazoan tissue cell lines is discussed.

  5. 49 CFR 230.21 - Steam locomotive number change. (United States)


    ... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive number change. 230.21 Section 230... Recordkeeping Requirements § 230.21 Steam locomotive number change. When a steam locomotive number is changed, the steam locomotive owner and/or operator must reflect the change in the upper right-hand corner of...

  6. Performance of raters to assess locomotion in dairy cattle

    NARCIS (Netherlands)

    Schlageter Tello, A.A.


    Abstract Locomotion scoring systems are procedures used to evaluate the quality of cows’ locomotion. When scoring locomotion, raters focus their attention on gait and posture traits that are described in the protocol. Using these traits, raters assign a locomotion score to

  7. 49 CFR 229.121 - Locomotive cab noise. (United States)


    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locomotive cab noise. 229.121 Section 229.121... § 229.121 Locomotive cab noise. (a) Performance standards for locomotives. (1) When tested for static noise in accordance with paragraph (a)(3) of this section, all locomotives of each design or model that...

  8. Locomotive Assignment Problem with Heterogeneous Vehicle Fleet and Hiring External Locomotives

    Directory of Open Access Journals (Sweden)

    Dušan Teichmann


    Full Text Available This paper focuses on solving the problem of how to assign locomotives to assembled trains optimally. To solve the problem, linear programming is applied. The situation we model in the paper occurs in the conditions of a transport operator that provides rail transport in the Czech Republic. In the paper, an extended locomotive assignment problem is modeled; the transport operator can use different classes of the locomotives to serve individual connections, some connections must be served by a predefined locomotive class, and the locomotives can be allocated to several depots at the beginning. The proposed model also takes into consideration the fact that some connections can be served by the locomotives of external transport companies or operators. The presented model is applied to a real example in order to test its functionality.

  9. Modeling limbless locomotion using ADAMS software (United States)

    National Aeronautics and Space Administration — Until now, the methods used by probes or humans for locomotion on planetary surfaces have typically been restricted to variations of wheeled motion. As human...

  10. Locomotive to Automobile Baseline Crash Tests (United States)


    Four Locomotive to Automobile Crash tests were performed by the Dynamic Science Division of Ultrasystems at DOT's High Speed Ground Test Center under contract to the Transportation Systems Center, which is conducting the work for the Federal Railroad...

  11. Issues in Locomotive Crew Management and Scheduling (United States)


    This study explores matters related to the scheduling and management of locomotive crews, particularly as they : might contribute to fatigue and stress. It describes how crews are scheduled currently, why there is so much : unpredictability in schedu...

  12. Phenomenological theory of current-producing processes at the solid oxide electrolyte/gas electrode interface: steady-state polarization of fuel-cell electrodes

    International Nuclear Information System (INIS)

    Murygin, I.V.; Chebotin, V.N.


    The polarization of fuel-cell electrodes (mixtures CO + CO 2 and H 2 + H 2 O) in systems with solid oxide electrolytes is discussed. The theory is based upon a process model where the electrode reaction zone can spread along the line of three-phase contact by diffusion of reaction partners and products across the electrolyte/electrode and electrolyte/gas interface

  13. Characterization of undulatory locomotion in granular media (United States)

    Peng, Zhiwei; Pak, On Shun; Elfring, Gwynn


    Undulatory locomotion is ubiquitous in nature, from the swimming of flagellated microorganisms in biological fluids, to the slithering of snakes on land, or the locomotion of sandfish lizards in sand. Analysis of locomotion in granular materials is relatively less developed compared with fluids partially due to a lack of validated force models but a recently proposed resistive force theory (RFT) in granular media has been shown useful in studying the locomotion of a sand-swimming lizard. Here we employ this model to investigate the swimming characteristics of an undulating slender filament of both finite and infinite length. For infinite swimmers, similar to results in viscous fluids, the sawtooth waveform is found to be optimal for propulsion speed at a given power consumption. We also compare the swimming characteristics of sinusoidal and sawtooth swimmers with swimming in viscous fluids. More complex swimming dynamics emerge when the assumption of an infinite swimmer is removed. In particular, we characterize the effects of drifting and pitching in terms of propulsion speed and efficiency for a finite sinusoidal swimmer. The results complement our understanding of undulatory locomotion and provide insights into the effective design of locomotive systems in granular media.

  14. Characteristics of undulatory locomotion in granular media (United States)

    Peng, Zhiwei; Pak, On Shun; Elfring, Gwynn J.


    Undulatory locomotion is ubiquitous in nature and observed in different media, from the swimming of flagellated microorganisms in biological fluids, to the slithering of snakes on land, or the locomotion of sandfish lizards in sand. Despite the similarity in the undulating pattern, the swimming characteristics depend on the rheological properties of different media. Analysis of locomotion in granular materials is relatively less developed compared with fluids partially due to a lack of validated force models but recently a resistive force theory in granular media has been proposed and shown useful in studying the locomotion of a sand-swimming lizard. Here we employ the proposed model to investigate the swimming characteristics of a slender filament, of both finite and infinite length, undulating in a granular medium and compare the results with swimming in viscous fluids. In particular, we characterize the effects of drifting and pitching in terms of propulsion speed and efficiency for a finite sinusoidal swimmer. We also find that, similar to Lighthill's results using resistive force theory in viscous fluids, the sawtooth swimmer is the optimal waveform for propulsion speed at a given power consumption in granular media. The results complement our understanding of undulatory locomotion and provide insights into the effective design of locomotive systems in granular media.

  15. Push-Pull Locomotion for Vehicle Extrication (United States)

    Creager, Colin M.; Johnson, Kyle A.; Plant, Mark; Moreland, Scott J.; Skonieczny, Krzysztof


    For applications in which unmanned vehicles must traverse unfamiliar terrain, there often exists the risk of vehicle entrapment. Typically, this risk can be reduced by using feedback from on-board sensors that assess the terrain. This work addressed the situations where a vehicle has already become immobilized or the desired route cannot be traversed using conventional rolling. Specifically, the focus was on using push-pull locomotion in high sinkage granular material. Push-pull locomotion is an alternative mode of travel that generates thrust through articulated motion, using vehicle components as anchors to push or pull against. It has been revealed through previous research that push-pull locomotion has the capacity for generating higher net traction forces than rolling, and a unique optical flow technique indicated that this is the result of a more efficient soil shearing method. It has now been found that pushpull locomotion results in less sinkage, lower travel reduction, and better power efficiency in high sinkage material as compared to rolling. Even when starting from an "entrapped" condition, push-pull locomotion was able to extricate the test vehicle. It is the authors' recommendation that push-pull locomotion be considered as a reliable back-up mode of travel for applications where terrain entrapment is a possibility.

  16. Rapid Prototyping Laboratory (United States)

    Federal Laboratory Consortium — The ARDEC Rapid Prototyping (RP) Laboratory was established in December 1992 to provide low cost RP capabilities to the ARDEC engineering community. The Stratasys,...

  17. Fabrication and Prototyping Lab (United States)

    Federal Laboratory Consortium — Purpose: The Fabrication and Prototyping Lab for composite structures provides a wide variety of fabrication capabilities critical to enabling hands-on research and...

  18. The dynamics of quadrupedal locomotion. (United States)

    Pandy, M G; Kumar, V; Berme, N; Waldron, K J


    This paper presents a dynamical analysis of quadrupedal locomotion, with specific reference to an adult Nubian goat. Measurements of ground reaction forces and limb motion are used to assess variations in intersegmental forces, joint moments, and instantaneous power for three discernible gaits: walking, running, and jumping. In each case, inertial effects of the torso are shown to dominate to the extent that lower-extremity contributions may be considered negligible. Footforces generated by the forelimbs exceed those exerted by the hindlimbs; and, in general, ground reactions increase with speed. The shoulder and hip dominate mechanical energy production during walking, while the knee plays a more significant role in running. In both cases, however, the elbow absorbs energy, and by so doing functions primarily as a damping (control) element. As opposed to either walking or running, jumping requires total horizontal retardation of the body's center of mass. In this instance, generating the necessary vertical thrust amounts to energy absorption at all joints of the lower extremities.

  19. The PS locomotive runs again

    CERN Document Server


    Over forty years ago, the PS train entered service to steer the magnets of the accelerator into place... ... a service that was resumed last Tuesday. Left to right: Raymond Brown (CERN), Claude Tholomier (D.B.S.), Marcel Genolin (CERN), Gérard Saumade (D.B.S.), Ingo Ruehl (CERN), Olivier Carlier (D.B.S.), Patrick Poisot (D.B.S.), Christian Recour (D.B.S.). It is more than ten years since people at CERN heard the rumbling of the old PS train's steel wheels. Last Tuesday, the locomotive came back into service to be tested. It is nothing like the monstrous steel engines still running on conventional railways -just a small electric battery-driven vehicle employed on installing the magnets for the PS accelerator more than 40 years ago. To do so, it used the tracks that run round the accelerator. In fact, it is the grandfather of the LEP monorail. After PS was commissioned in 1959, the little train was used more and more rarely. This is because magnets never break down, or hardly ever! In fact, the loc...

  20. Robot locomotion on weak ground (United States)

    Qian, Feifei; Li, Chen; Umbanhowar, Paul; Goldman, Daniel


    Natural substrates like sand, soil, and leaf litter vary widely in penetration resistance. Little is known about how animals (and increasingly robots) respond to this variation. To address this deficit, we built an air fluidized bed trackway, in which we control penetration resistance of 1mm granular substrates down to zero by increasing the upward flow rate, Q , to the fluidization transition. Using a 2 . 5 kg bio-inspired hexapedal robot as our model locomotor, we systematically study how locomotion performance (average forward speed, v) varies with penetration resistance, limb kinematics, and foot morphology. Average robot speed decreases with increasing Q, and decreases faster for robots with higher leg frequency or narrower leg width. A previously developed model, which captured the robot's performance on granular media with Q = 0 , also captures the observed performance for weakened states with Q > 0 . A single dimensionless control parameter from the model, which combines gait and ground parameters, determines v for all penetration resistances. Our ground control technique and modeling approach provide a way to probe and understand the limits of locomotor performance on yielding substrates.

  1. Architectures of prototypes and architectural prototyping

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius; Christensen, Michael; Sandvad, Elmer


    This paper reports from experience obtained through development of a prototype of a global customer service system in a project involving a large shipping company and a university research group. The research group had no previous knowledge of the complex business of shipping and had never worked...... sessions with users, - evolve over a long period of time to contain more functionality - allow for 6-7 developers working intensively in parallel. Explicit focus on the software architecture and letting the architecture evolve with the prototype played a major role in resolving these conflicting...... constraints. Specifically allowing explicit restructuring phases when the architecture became problematic showed to be crucial.  ...

  2. Design and experimental gait analysis of a multi-segment in-pipe robot inspired by earthworm's peristaltic locomotion (United States)

    Fang, Hongbin; Wang, Chenghao; Li, Suyi; Xu, Jian; Wang, K. W.


    This paper reports the experimental progress towards developing a multi-segment in-pipe robot inspired by earthworm's body structure and locomotion mechanism. To mimic the alternating contraction and elongation of a single earthworm's segment, a robust, servomotor based actuation mechanism is developed. In each robot segment, servomotor-driven cords and spring steel belts are utilized to imitate the earthworm's longitudinal and circular muscles, respectively. It is shown that the designed segment can contract and relax just like an earthworm's body segment. The axial and radial deformation of a single segment is measured experimentally, which agrees with the theoretical predictions. Then a multisegment earthworm-like robot is fabricated by assembling eight identical segments in series. The locomotion performance of this robot prototype is then extensively tested in order to investigate the correlation between gait design and dynamic locomotion characteristics. Based on the principle of retrograde peristalsis wave, a gait generator is developed for the multi-segment earthworm-like robot, following which gaits of the robot can be constructed. Employing the generated gaits, the 8-segment earthworm-like robot can successfully perform both horizontal locomotion and vertical climb in pipes. By changing gait parameters, i.e., with different gaits, locomotion characteristics including average speed and anchor slippage can be significantly tailored. The proposed actuation method and prototype of the multi-segment in-pipe robot as well as the gait generator provide a bionic realization of earthworm's locomotion with promising potentials in various applications such as pipeline inspection and cleaning.

  3. Relationship between osteology and aquatic locomotion in birds: determining modes of locomotion in extinct Ornithurae. (United States)

    Hinić-Frlog, S; Motani, R


    The evolutionary history of aquatic invasion in birds would be incomplete without incorporation of extinct species. We show that aquatic affinities in fossil birds can be inferred by multivariate analysis of skeletal features and locomotion of 245 species of extant birds. Regularized discriminant analyses revealed that measurements of appendicular skeletons successfully separated diving birds from surface swimmers and flyers, while also discriminating among different underwater modes of swimming. The high accuracy of this method allows detection of skeletal characteristics that are indicative of aquatic locomotion and inference of such locomotion in bird species with insufficient behavioural information. Statistical predictions based on the analyses confirm qualitative assessments for both foot-propelled (Hesperornithiformes) and wing-propelled (Copepteryx) underwater locomotion in fossil birds. This is the first quantitative inference of underwater modes of swimming in fossil birds, enabling future studies of locomotion in extinct birds and evolutionary transitions among locomotor modes in avian lineage.


    NARCIS (Netherlands)

    Belikov, Andrey; Williams, Owen; Droge, Bob; Tsyganov, Andrey; Boxhoorn, Danny; McFarland, John; Verdoes Kleijn, Gijs; Valentijn, E; Altieri, Bruno; Dabin, Christophe; Pasian, F.; Osuna, Pedro; Soille, P.; Marchetti, P.G.


    The Euclid Archive System prototype is a functional information system which is used to address the numerous challenges in the development of fully functional data processing system for Euclid. The prototype must support the highly distributed nature of the Euclid Science Ground System, with Science

  5. EPCiR prototype

    DEFF Research Database (Denmark)


    A prototype of a residential pervasive computing platform based on OSGi involving among other a mock-up of an health care bandage.......A prototype of a residential pervasive computing platform based on OSGi involving among other a mock-up of an health care bandage....

  6. Cooperative Prototyping Experiments

    DEFF Research Database (Denmark)

    Bødker, Susanne; Grønbæk, Kaj


    This paper describes experiments with a design technique that we denote cooperative prototyping. The experiments consider design of a patient case record system for municipal dental clinics in which we used HyperCard, an off the shelf programming environment for the Macintosh. In the ecperiments we...... tried to achieve a fluent work-like evaluation of prototypes where users envisioned future work with a computer tool, at the same time as we made on-line modifications of prototypes in cooperation with the users when breakdown occur in their work-like evaluation. The experiments showed...... that it was possible to make a number of direct manipulation changes of prototypes in cooperation with the users, in interplay with their fluent work-like evaluation of these. However, breakdown occurred in the prototyping process when we reached the limits of the direct manipulation support for modification. From...


    Directory of Open Access Journals (Sweden)

    F. Becker


    Full Text Available Models, simulations and experimental setups of resonant inspection robots are presented. The goal is to show ways to cope with the new requirements and to use the given chances to create novel mobile robots. For the creation of a directed motion the vibration behavior of simple beams and plates is used. It is possible to design robots for 2-dimesnional locomotion which are characterized by a light weight, small size, relative simple design and the ability to create controllable motion using only one actuator. Different types of actuators for micro robots are presented and compared. Furthermore the dynamical behavior of a piezoelectric bending actuator under elastic boundary conditions is investigated and a model for the motion of the locomotion-generating limbs is presented. The comparison with experiments and prototypes shows that the results of the analytical and computational models agree 

  8. Development of locomotion in a subsocial spider. (United States)

    Ahn, Soon Kil; Kim, Kil Won


    Following consumption of their mother, the subsocial spider Amaurobius ferox remain together, exhibiting distinctive behaviours in response to intruders into the natal nest. We examined the ontogeny and characteristics of locomotory behaviours in A. ferox during this post-maternal social period. Locomotion of the spiderlings, elicited by the introduction of a cricket larva into the natal web, fell into two categories: 'abrupt locomotion' (AL) and 'ordinary locomotion' (OL). AL involved rapid and linear movement, whereas OL involved slower motion, not necessarily in a straight line. Both types of locomotion varied with spiderling age. AL appeared for only a limited period of time whereas the frequency of OL increased linearly over time. AL occurred more collectively than OL: the percentage of participants in a bout of locomotion was 18.67±17.71% vs. 10.22±9.33%. The collective tendency of AL increased up until the seventh day and then decreased, whereas that of OL progressively decreased. The direction of AL responses to the intruder did not vary over time; however, for OL, movements towards increased in frequency over time. Locomotory responses also varied with the intensity of intruder movement. Including transient behaviours, the chronology of different behaviours suggests that behavioural development in A. ferox involves maternal influences and weakens group cohesion and collective tendency. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Towards autonomous locomotion: CPG-based control of smooth 3D slithering gait transition of a snake-like robot. (United States)

    Bing, Zhenshan; Cheng, Long; Chen, Guang; Röhrbein, Florian; Huang, Kai; Knoll, Alois


    Snake-like robots with 3D locomotion ability have significant advantages of adaptive travelling in diverse complex terrain over traditional legged or wheeled mobile robots. Despite numerous developed gaits, these snake-like robots suffer from unsmooth gait transitions by changing the locomotion speed, direction, and body shape, which would potentially cause undesired movement and abnormal torque. Hence, there exists a knowledge gap for snake-like robots to achieve autonomous locomotion. To address this problem, this paper presents the smooth slithering gait transition control based on a lightweight central pattern generator (CPG) model for snake-like robots. First, based on the convergence behavior of the gradient system, a lightweight CPG model with fast computing time was designed and compared with other widely adopted CPG models. Then, by reshaping the body into a more stable geometry, the slithering gait was modified, and studied based on the proposed CPG model, including the gait transition of locomotion speed, moving direction, and body shape. In contrast to sinusoid-based method, extensive simulations and prototype experiments finally demonstrated that smooth slithering gait transition can be effectively achieved using the proposed CPG-based control method without generating undesired locomotion and abnormal torque.

  10. Passive appendages aid locomotion through symmetry breaking (United States)

    Bagheri, Shervin; Lacis, Ugis; Mazzino, Andrea; Kellay, Hamid; Brosse, Nicolas; Lundell, Fredrik; Ingremeau, Francois


    Plants and animals use plumes, barbs, tails, feathers, hairs, fins, and other types of appendages to aid locomotion. Despite their enormous variation, passive appendages may contribute to locomotion by exploiting the same physical mechanism. We present a new mechanism that applies to body appendages surrounded by a separated flow, which often develops behind moving bodies larger than a few millimeters. We use theory, experiments, and numerical simulations to show that bodies with protrusions turn and drift by exploiting a symmetry-breaking instability similar to the instability of an inverted pendulum. Our model explains why the straight position of an appendage in flowing fluid is unstable and how it stabilizes either to the left or right of the incoming fluid flow direction. The discovery suggests a new mechanism of locomotion that may be relevant for certain organisms; for example, how plumed seeds may drift without wind and how motile animals may passively reorient themselves.

  11. Numerical simulation of human biped locomotion

    International Nuclear Information System (INIS)

    Ishiguro, Misako; Fujisaki, Masahide


    This report describes the numerical simulation of the motion of human-like robot which is one of the research theme of human acts simulation program (HASP) begun at the Computing Center of JAERI in 1987. The purpose of the theme is to model the human motion using robotics kinematic/kinetic equations and to get the joint angles as the solution. As the first trial, we treat the biped locomotion (walking) which is the most fundamental human motion. We implemented a computer program on FACOM M-780 computer, where the program is originated from the book of M. Vukobratovic in Yugoslavia, and made a graphic program to draw a walking shot sequence. Mainly described here are the mathematical model of the biped locomotion, implementation method of the computer program, input data for basic walking pattern, computed results and its validation, and graphic representation of human walking image. Literature survey on robotics equation and biped locomotion is also included. (author)

  12. Correlation engine prototype

    CERN Document Server

    Pose, V


    The CERN monitoring prototype, part of the fabric management work package (WP4) of the DataGrid project, task Monitoring, collects monitoring data from farm nodes in CERN into a central monitoring database. Performing correlations on the data in the monitoring database should help to foresee exceptions on individual nodes or node groups and to analyze performance of the farm. The Correlation Engine Prototype has been developed to provide easy adding of new correlations of monitoring data and actions triggered in case of exceptions. The current prototype is written in Perl. The results of the correlation engine can be accessed through a web-interface.

  13. PRMS Data Warehousing Prototype (United States)

    Guruvadoo, Eranna K.


    Project and Resource Management System (PRMS) is a web-based, mid-level management tool developed at KSC to provide a unified enterprise framework for Project and Mission management. The addition of a data warehouse as a strategic component to the PRMS is investigated through the analysis, design and implementation processes of a data warehouse prototype. As a proof of concept, a demonstration of the prototype with its OLAP's technology for multidimensional data analysis is made. The results of the data analysis and the design constraints are discussed. The prototype can be used to motivate interest and support for an operational data warehouse.

  14. A model for nematode locomotion in soil (United States)

    Hunt, H. William; Wall, Diana H.; DeCrappeo, Nicole; Brenner, John S.


    Locomotion of nematodes in soil is important for both practical and theoretical reasons. We constructed a model for rate of locomotion. The first model component is a simple simulation of nematode movement among finite cells by both random and directed behaviours. Optimisation procedures were used to fit the simulation output to data from published experiments on movement along columns of soil or washed sand, and thus to estimate the values of the model's movement coefficients. The coefficients then provided an objective means to compare rates of locomotion among studies done under different experimental conditions. The second component of the model is an equation to predict the movement coefficients as a function of controlling factors that have been addressed experimentally: soil texture, bulk density, water potential, temperature, trophic group of nematode, presence of an attractant or physical gradient and the duration of the experiment. Parameters of the equation were estimated by optimisation to achieve a good fit to the estimated movement coefficients. Bulk density, which has been reported in a minority of published studies, is predicted to have an important effect on rate of locomotion, at least in fine-textured soils. Soil sieving, which appears to be a universal practice in laboratory studies of nematode movement, is predicted to negatively affect locomotion. Slower movement in finer textured soils would be expected to increase isolation among local populations, and thus to promote species richness. Future additions to the model that might improve its utility include representing heterogeneity within populations in rate of movement, development of gradients of chemical attractants, trade-offs between random and directed components of movement, species differences in optimal temperature and water potential, and interactions among factors controlling locomotion.

  15. Analysis of fuel cell hybrid locomotives (United States)

    Miller, Arnold R.; Peters, John; Smith, Brian E.; Velev, Omourtag A.

    Led by Vehicle Projects LLC, an international industry-government consortium is developing a 109 t, 1.2 MW road-switcher locomotive for commercial and military railway applications. As part of the feasibility and conceptual-design analysis, a study has been made of the potential benefits of a hybrid power plant in which fuel cells comprise the prime mover and a battery or flywheel provides auxiliary power. The potential benefits of a hybrid power plant are: (i) enhancement of transient power and hence tractive effort; (ii) regenerative braking; (iii) reduction of capital cost. Generally, the tractive effort of a locomotive at low speed is limited by wheel adhesion and not by available power. Enhanced transient power is therefore unlikely to benefit a switcher locomotive, but could assist applications that require high acceleration, e.g. subway trains with all axles powered. In most cases, the value of regeneration in locomotives is minimal. For low-speed applications such as switchers, the available kinetic energy and the effectiveness of traction motors as generators are both minimal. For high-speed heavy applications such as freight, the ability of the auxiliary power device to absorb a significant portion of the available kinetic energy is low. Moreover, the hybrid power plant suffers a double efficiency penalty, namely, losses occur in both absorbing and then releasing energy from the auxiliary device, which result in a net storage efficiency of no more than 50% for present battery technology. Capital cost in some applications may be reduced. Based on an observed locomotive duty cycle, a cost model shows that a hybrid power plant for a switcher may indeed reduce capital cost. Offsetting this potential benefit are the increased complexity, weight and volume of the power plant, as well as 20-40% increased fuel consumption that results from lower efficiency. Based on this analysis, the consortium has decided to develop a pure fuel cell road-switcher locomotive

  16. Large and limbless: the locomotion of snakes (United States)

    Hu, David


    In efforts to understand snake locomotion, we consider one of their various gaits. By contracting and extending their bodies unidirectionally like a slinky, large snakes propel themselves in a straight line. In a combined experimental and theoretical investigation, we here report on the dynamics of a boa constrictor alongside the analysis of an n-linked extensible crawler model. Constraints on their locomotion are quantified and discussed, such as the elasticity, frictional anisotropy and abrasive wear of their skin. Also presented are certain snake behaviors that culminate in their tying themselves into knots.

  17. Locomotion of Paramecium in patterned environments (United States)

    Park, Eun-Jik; Eddins, Aja; Kim, Junil; Yang, Sung; Jana, Saikat; Jung, Sunghwan


    Ciliary organisms like Paramecium Multimicronucleatum locomote by synchronized beating of cilia that produce metachronal waves over their body. In their natural environments they navigate through a variety of environments especially surfaces with different topology. We study the effects of wavy surfaces patterned on the PDMS channels on the locomotive abilities of Paramecium by characterizing different quantities like velocity amplitude and wavelength of the trajectories traced. We compare this result with the swimming characteristics in straight channels and draw conclusions about the effects of various patterned surfaces.


    Directory of Open Access Journals (Sweden)

    S. V. Myamlin


    Full Text Available Purpose. To determine the dynamic qualities of the mainline freight locomotives characterizing the safe motion in tangent and curved track sections at all operational speeds, one needs a whole set of studies, which includes a selection of the design scheme, development of the corresponding mathematical model of the locomotive spatial fluctuations, construction of the computer calculation program, conducting of the theoretical and then experimental studies of the new designs. In this case, one should compare the results with existing designs. One of the necessary conditions for the qualitative improvement of the traction rolling stock is to define the parameters of its running gears. Among the issues related to this problem, an important place is occupied by the task of determining the locomotive dynamic properties on the stage of projection, taking into account the selected technical solutions in the running gear design. Methodology. The mathematical modeling studies are carried out by the numerical integration method of the dynamic loading for the mainline locomotive using the software package «Dynamics of Rail Vehicles » («DYNRAIL». Findings. As a result of research for the improvement of locomotive running gear design it can be seen that the creation of the modern locomotive requires from engineers and scientists the realization of scientific and technical solutions. The solutions enhancing design speed with simultaneous improvement of the traction, braking and dynamic qualities to provide a simple and reliable design, especially the running gear, reducing the costs for maintenance and repair, low initial cost and operating costs for the whole service life, high traction force when starting, which is as close as possible to the ultimate force of adhesion, the ability to work in multiple traction mode and sufficient design speed. Practical Value. The generalization of theoretical, scientific and methodological, experimental studies aimed

  19. LHC prototype magnet

    CERN Multimedia


    1.5 metre superconducting magnet. This prototype magnet for the LHC was cooled to a few degrees above absolute zero, which allowed it to obtain the world record for the highest magnetic field for an accelerator magnet in 1991.

  20. Ceramic subsurface marker prototypes

    Energy Technology Data Exchange (ETDEWEB)

    Lukens, C.E. [Rockwell International Corp., Richland, WA (United States). Rockwell Hanford Operations


    The client submitted 5 sets of porcelain and stoneware subsurface (radioactive site) marker prototypes (31 markers each set). The following were determined: compressive strength, thermal shock resistance, thermal crazing resistance, alkali resistance, color retention, and chemical resistance.

  1. Locomotive Schedule Optimization for Da-qin Heavy Haul Railway


    Su, Ruiye; Zhou, Leishan; Tang, Jinjin


    The main difference between locomotive schedule of heavy haul railways and that of regular rail transportation is the number of locomotives utilized for one train. One heavy-loaded train usually has more than one locomotive, but a regular train only has one. This paper develops an optimization model for the multilocomotive scheduling problem (MLSP) through analyzing the current locomotive schedule of Da-qin Railway. The objective function of our paper is to minimize the total number of utiliz...

  2. 21st Century Locomotive Technology: Quarterly Technical Status Report 9 DOE/AL68284-TSR09

    Energy Technology Data Exchange (ETDEWEB)

    Lembit Salasoo; Paul Houpt; Jennifer Topinka; Anthony Furman


    Locomotive-scale single cylinder engine with common rail fuel injection data was gathered to explore the fuel consumption and particulate matter emissions entitlement. A structured experiment on thermal spray application of polymer based compressor abradables was begun. Turbine performance improvements were found due to metallic abradables coatings. Hybrid energy storage battery ripple current and long-term cycling tests have been performed. Final track test of advanced energy management system was performed. Fuel optimization computational methods have been enhanced, and a prototype real-time graphic interface developed.

  3. 49 CFR 230.101 - Steam locomotive driving journal boxes. (United States)


    ... 49 Transportation 4 2010-10-01 2010-10-01 false Steam locomotive driving journal boxes. 230.101... Locomotives and Tenders Running Gear § 230.101 Steam locomotive driving journal boxes. (a) Driving journal boxes. Driving journal boxes shall be maintained in a safe and suitable condition for service. Not more...

  4. Relation between observed locomotion traits and locomotion score in dairy cows. (United States)

    Schlageter-Tello, Andrés; Bokkers, Eddie A M; Groot Koerkamp, Peter W G; Van Hertem, Tom; Viazzi, Stefano; Romanini, Carlos E B; Halachmi, Ilan; Bahr, Claudia; Berckmans, Daniël; Lokhorst, Kees


    Lameness is still an important problem in modern dairy farming. Human observation of locomotion, by looking at different traits in one go, is used in practice to assess locomotion. The objectives of this article were to determine which individual locomotion traits are most related to locomotion scores in dairy cows, and whether experienced raters are capable of scoring these individual traits consistently. Locomotion and 5 individual locomotion traits (arched back, asymmetric gait, head bobbing, reluctance to bear weight, and tracking up) were scored independently on a 5-level scale for 58 videos of different cows. Videos were shown to 10 experienced raters in 2 different scoring sessions. Relations between locomotion score and traits were estimated by 3 logistic regression models aiming to calculate the size of the fixed effects on the probability of scoring a cow in 1 of the 5 levels of the scale (model 1) and the probability of classifying a cow as lame (locomotion score ≥3; model 2) or as severely lame (locomotion score ≥4; model 3). Fixed effects were rater, session, traits, and interactions among fixed effects. Odds ratios were calculated to estimate the relative probability to classify a cow as lame when an altered (trait score ≥3) or severely altered trait (trait score ≥4) was present. Overall intrarater and interrater reliability and agreement were calculated as weighted kappa coefficient (κw) and percentage of agreement, respectively. Specific intrarater and interrater agreement for individual levels within a 5-level scale were calculated. All traits were significantly related to the locomotion score when scored with a 5-level scale and when classified as (severely) lame or nonlame. Odds ratios for altered and severely altered traits were 10.8 and 14.5 for reluctance to bear weight, 6.5 and 7.2 for asymmetric gait, and 4.8 and 3.2 for arched back, respectively. Raters showed substantial variation in reliability and agreement values when scoring

  5. 49 CFR 210.9 - Movement of a noise defective locomotive, rail car, or consist of a locomotive and rail cars. (United States)


    ... 49 Transportation 4 2010-10-01 2010-10-01 false Movement of a noise defective locomotive, rail car, or consist of a locomotive and rail cars. 210.9 Section 210.9 Transportation Other Regulations... locomotive, rail car, or consist of a locomotive and rail cars. A locomotive, rail car, or consist of a...

  6. 76 FR 2199 - Locomotive Safety Standards (United States)


    ... existing regulations. The proposal incorporates existing industry and engineering best practices related to... Overview of Proposed Requirements Trends in locomotive operation, concern about the safe design of... used many of the same sub-assemblies of pneumatic valves, electronic controls and software (referred to...

  7. Locomotion of C elegans in structured environments (United States)

    Majmudar, Trushant; Keaveny, Eric; Shelley, Michael; Zhang, Jun


    Undulatory locomotion of microorganisms like soil-dwelling worms and sperm, in structured environments, is ubiquitous in nature. They navigate complex environments consisting of fluids and obstacles, negotiating hydrodynamic effects and geometrical constraints. Here we report experimental observations on the locomotion of C elegans swimming in arrays of micro-pillars in square lattices, with different lattice spacing. We observe that the worm employs a number of different locomotion strategies depending on the lattice spacing. As observed previously in the literature, we uncover regimes of enhanced locomotion, where the velocity is much higher than the free-swimming velocity. In addition, we also observe changes in frequency, velocity, and the gait of the worm as a function of lattice spacing. We also track the worm over time and find that it exhibits super-diffusive behavior and covers a larger area by utilizing the obstacles. These results may have significant impact on the foraging behavior of the worm in its natural environment. Our experimental approach, in conjunction with modeling and simulations, allows us to disentangle the effects of structure and hydrodynamics for an undulating microorganism.

  8. Evidence for Motor Simulation in Imagined Locomotion (United States)

    Kunz, Benjamin R.; Creem-Regehr, Sarah H.; Thompson, William B.


    A series of experiments examined the role of the motor system in imagined movement, finding a strong relationship between imagined walking performance and the biomechanical information available during actual walking. Experiments 1 through 4 established the finding that real and imagined locomotion differ in absolute walking time. We then tested…

  9. Muscle spindle and fusimotor activity in locomotion. (United States)

    Ellaway, Peter H; Taylor, Anthony; Durbaba, Rade


    Mammals may exhibit different forms of locomotion even within a species. A particular form of locomotion (e.g. walk, run, bound) appears to be selected by supraspinal commands, but the precise pattern, i.e. phasing of limbs and muscles, is generated within the spinal cord by so-called central pattern generators. Peripheral sense organs, particularly the muscle spindle, play a crucial role in modulating the central pattern generator output. In turn, the feedback from muscle spindles is itself modulated by static and dynamic fusimotor (gamma) neurons. The activity of muscle spindle afferents and fusimotor neurons during locomotion in the cat is reviewed here. There is evidence for some alpha-gamma co-activation during locomotion involving static gamma motoneurons. However, both static and dynamic gamma motoneurons show patterns of modulation that are distinct from alpha motoneuron activity. It has been proposed that static gamma activity may drive muscle spindle secondary endings to signal the intended movement to the central nervous system. Dynamic gamma motoneuron drive appears to prime muscle spindle primary endings to signal transitions in phase of the locomotor cycle. These findings come largely from reduced animal preparations (decerebrate) and require confirmation in freely moving intact animals. © 2015 Anatomical Society.

  10. Morphological self stabilization of locomotion gaits: illustration on a few examples from bio-inspired locomotion


    Chevallereau , Christine; Boyer , Frédéric; Porez , Mathieu; Mauny , Johan; Aoustin , Yannick


    International audience; — To a large extent, robotics locomotion can be viewed as cyclic motions, named gaits. Due to the high complexity of the locomotion dynamics, to find the control laws that ensure an expected gait and its stability with respect to external perturbations, is a challenging issue for feedback control. To address this issue, a promising way is to take inspiration from animals that intensively exploit the interactions of the passive degrees of freedom of their body with thei...

  11. Locomotive Schedule Optimization for Da-qin Heavy Haul Railway

    Directory of Open Access Journals (Sweden)

    Ruiye Su


    Full Text Available The main difference between locomotive schedule of heavy haul railways and that of regular rail transportation is the number of locomotives utilized for one train. One heavy-loaded train usually has more than one locomotive, but a regular train only has one. This paper develops an optimization model for the multilocomotive scheduling problem (MLSP through analyzing the current locomotive schedule of Da-qin Railway. The objective function of our paper is to minimize the total number of utilized locomotives. The MLSP is nondeterministic polynomial (NP hard. Therefore, we convert the multilocomotive traction problem into a single-locomotive traction problem. Then, the single-locomotive traction problem (SLTP can be converted into an assignment problem. The Hungarian algorithm is applied to solve the model and obtain the optimal locomotive schedule. We use the variance of detention time of locomotives at stations to evaluate the stability of locomotive schedule. In order to evaluate the effectiveness of the proposed optimization model, case studies for 20 kt and 30 kt heavy-loaded combined trains on Da-qin Railway are both conducted. Compared to the current schedules, the optimal schedules from the proposed models can save 62 and 47 locomotives for 20 kt and 30 kt heavy-loaded combined trains, respectively. Therefore, the effectiveness of the proposed model and its solution algorithm are both valid.

  12. Development of a Novel Locomotion Algorithm for Snake Robot

    International Nuclear Information System (INIS)

    Khan, Raisuddin; Billah, Md Masum; Watanabe, Mitsuru; Shafie, A A


    A novel algorithm for snake robot locomotion is developed and analyzed in this paper. Serpentine is one of the renowned locomotion for snake robot in disaster recovery mission to overcome narrow space navigation. Several locomotion for snake navigation, such as concertina or rectilinear may be suitable for narrow spaces, but is highly inefficient if the same type of locomotion is used even in open spaces resulting friction reduction which make difficulties for snake movement. A novel locomotion algorithm has been proposed based on the modification of the multi-link snake robot, the modifications include alterations to the snake segments as well elements that mimic scales on the underside of the snake body. Snake robot can be able to navigate in the narrow space using this developed locomotion algorithm. The developed algorithm surmount the others locomotion limitation in narrow space navigation

  13. Effects of locomotion extend throughout the mouse early visual system. (United States)

    Erisken, Sinem; Vaiceliunaite, Agne; Jurjut, Ovidiu; Fiorini, Matilde; Katzner, Steffen; Busse, Laura


    Neural responses in visual cortex depend not only on sensory input but also on behavioral context. One such context is locomotion, which modulates single-neuron activity in primary visual cortex (V1). How locomotion affects neuronal populations across cortical layers and in precortical structures is not well understood. We performed extracellular multielectrode recordings in the visual system of mice during locomotion and stationary periods. We found that locomotion influenced activity of V1 neurons with a characteristic laminar profile and shaped the population response by reducing pairwise correlations. Although the reduction of pairwise correlations was restricted to cortex, locomotion slightly but consistently increased firing rates and controlled tuning selectivity already in the dorsolateral geniculate nucleus (dLGN) of the thalamus. At the level of the eye, increases in locomotion speed were associated with pupil dilation. These findings document further, nonmultiplicative effects of locomotion, reaching earlier processing stages than cortex. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. From prototype to product

    DEFF Research Database (Denmark)

    Andersen, Tariq Osman; Bansler, Jørgen P.; Kensing, Finn


    This paper delves into the challenges of engaging patients, clinicians and industry stakeholders in the participatory design of an mHealth platform for patient-clinician collaboration. It follows the process from the development of a research prototype to a commercial software product. In particu......This paper delves into the challenges of engaging patients, clinicians and industry stakeholders in the participatory design of an mHealth platform for patient-clinician collaboration. It follows the process from the development of a research prototype to a commercial software product....... In particular, we draw attention to four major challenges of (a) aligning the different concerns of patients and clinicians, (b) designing according to clinical accountability, (c) ensuring commercial interest, and (d) dealing with regulatory constraints when prototyping safety critical health Information...

  15. ComfortPower. Design, construction and evaluation of a combined fuel-cell and heat pump system

    Energy Technology Data Exchange (ETDEWEB)

    Silversand, Fredrik (Catator AB, Lund (Sweden))


    Catator AB has constructed, commissioned and evaluated a combined fuel-cell and heat-pump system (ComfortPower). The basic idea behind the project was to demonstrate the possibility to achieve ultrahigh thermal efficiencies when combining fuel-cell technologies and heat pumps. Moreover, the system should provide a great flexibility with respect to the fuel mix and should in addition to heat provide surplus electricity and cooling. The system was built on a HT-PEM platform (high temperature polymer electrolyte fuel cell from Serenergy a/s), which was operated by Catators proprietary Optiformer technology. The power generator was combined with a heat pump module (F1145-5, 230 V), supplied by Nibe. The system was packaged into a cabinet (1.65 x 0.6 x 0.6 m) comprising the power module, the heat pump, all necessary balance-of-plant components and the control system. The power output from the fuel-cell system was around 1.35 kW, which enabled operation of the heat pump compressor. By utilizing surplus heat energy from the fuel cell it was possible to achieve a favourable operation point in the heat pump system, resulting in a high overall COP (coefficient of performance). The heat output from the system was as high as 10 kW whereas 6 kW cooling could be provided. The thermal efficiencies measured in experiments were normally around 200%, calculated on the lower heating value of the fuel. A number of fuels have been investigated in the fuel cell system, including both gaseous (natural gas/LPG) and liquid fuels (alcohols and kerosene). Indeed, the system has a wide fuel flexibility, which opens up for a variety of applications in campus villages and buildings. This study has demonstrated the possibility to reduce the carbon dioxide footprint by a factor of 2 over conventional boilers in heating applications. In addition the unit can be operated on a variety of fuels and can produce cooling and electricity in addition to heat. A fully working system has been designed

  16. Prototyping a Smart City

    DEFF Research Database (Denmark)

    Korsgaard, Henrik; Brynskov, Martin

    In this paper, we argue that by approaching the so-called Smart City as a design challenge, and an interaction design perspective, it is possible to both uncover existing challenges in the interplay between people, technology and society, as well as prototype possible futures. We present a case...... in which we exposed data about the online communication between the citizens and the municipality on a highly visible media facade, while at the same time prototyped a tool that enabled citizens to report ‘bugs’ within the city....

  17. Prototyping the Future (United States)


    Advanced Ceramics Research (ACR) of Tucson, Arizona, researches transforming scientific concepts into technological achievement. Through the SBIR (Small Business Innovative Research) program, ACR developed a high pressure and temperature fused deposition system, a prototyping system that is known as extrusion freeform fabrication. This system is useful in manufacturing prosthetics. ACR also developed a three-dimensional rapid prototyping process in which physical models are quickly created directly from computer generated models. Marshall Space Flight Center also contracted ACR to fabricate a set of ceramic engines to be appraised for a solar thermal rocket engine test program.

  18. [Job stress in locomotive attendants in a locomotive depot and related influencing factors]. (United States)

    Kang, L; Jia, X C; Lu, F; Zhou, W H; Chen, R


    Objective: To investigate the current status of job stress in locomotive attendants in a locomotive depot and related influencing factors. Methods: From 2012 to 2013, cluster sampling was used to select 1500 locomotive attendants in a locomotive depot in Zhengzhou Railway Bureau as respondents.The contents of the investigation included general data and occupational information.A job satisfaction questionnaire was used to investigate the degree of satisfaction, a depression scale was used to investigate the frequency of symptoms, and a daily stress scale was used to investigate the frequency of fatigue and stress. Results: There was a significant difference in depression score between locomotive attendants with different ages, working years, degrees of education, working situations of spouse, total monthly family incomes, numbers of times of attendanceat night, monthly numbers of times of attendance,ormonthly attendance times( P job satisfaction score between locomotive attendants with different ages,working years, degrees of education, working situations of spouse, total monthly family incomes, numbers of times of attendance at night, monthly attendance times,or ways to work( P job satisfaction( β =1.546)and monthly number of times of attendance,working years,attendance time at night,and degree of education were negatively correlated with job satisfaction( β =-0.185,-0.097,-0.020,and -1.106); monthly number of times of attendance andcommute time were positively correlated with depression( β =0.243 and 0.029); attendance time at night,working situation of spouse,commute time,monthly number of times of attendance,degree of education,and working years were positively correlated with daily stress( β =0.006,0.473,0.010,0.043,0.585, and 0.028). Conclusion: Number of times of attendance, attendance time,working years,and spouse are influencing factors for job stress in locomotive attendants. Improvement in work process and care for their personal life help to reduce

  19. Cockroft Walton accelerator prototype

    International Nuclear Information System (INIS)

    Hutapea, Sumihar.


    Prototype of a Cockroft Walton generator using ceramic and plastic capacitors is discussed. Compared to the previous generator, the construction and components are much more improved. Pralon is used for the high voltage insulation column and plastic is used as a dielectric material for the high voltage capacitor. Cockroft Walton generator is used as a high tension supply for an accelerator. (author)

  20. LEP vacuum chamber, prototype

    CERN Multimedia

    CERN PhotoLab


    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  1. Rapid Prototyping Reconsidered (United States)

    Desrosier, James


    Continuing educators need additional strategies for developing new programming that can both reduce the time to market and lower the cost of development. Rapid prototyping, a time-compression technique adapted from the high technology industry, represents one such strategy that merits renewed evaluation. Although in higher education rapid…

  2. MIND performance and prototyping

    International Nuclear Information System (INIS)

    Cervera-Villanueva, A.


    The performance of MIND (Magnetised Iron Neutrino Detector) at a neutrino factory has been revisited in a new analysis. In particular, the low neutrino energy region is studied, obtaining an efficiency plateau around 5 GeV for a background level below 10 -3 . A first look has been given into the detector optimisation and prototyping

  3. Rapid Prototyping in PVS (United States)

    Munoz, Cesar A.; Butler, Ricky (Technical Monitor)


    PVSio is a conservative extension to the PVS prelude library that provides basic input/output capabilities to the PVS ground evaluator. It supports rapid prototyping in PVS by enhancing the specification language with built-in constructs for string manipulation, floating point arithmetic, and input/output operations.

  4. Cost Effective Prototyping (United States)

    Wickman, Jerry L.; Kundu, Nikhil K.


    This laboratory exercise seeks to develop a cost effective prototype development. The exercise has the potential of linking part design, CAD, mold development, quality control, metrology, mold flow, materials testing, fixture design, automation, limited parts production and other issues as related to plastics manufacturing.

  5. Courthouse Prototype Building

    Energy Technology Data Exchange (ETDEWEB)

    Malhotra, Mini [ORNL; New, Joshua Ryan [ORNL; Im, Piljae [ORNL


    As part of DOE's support of ANSI/ASHRAE/IES Standard 90.1 and IECC, researchers at Pacific Northwest National Laboratory (PNNL) apply a suite of prototype buildings covering 80% of the commercial building floor area in the U.S. for new construction. Efforts have started on expanding the prototype building suite to cover 90% of the commercial building floor area in the U.S., by developing prototype models for additional building types including place of worship, public order and safety, public assembly. Courthouse is courthouse is a sub-category under the “Public Order and Safety" building type category; other sub-categories include police station, fire station, and jail, reformatory or penitentiary.ORNL used building design guides, databases, and documented courthouse projects, supplemented by personal communication with courthouse facility planning and design experts, to systematically conduct research on the courthouse building and system characteristics. This report documents the research conducted for the courthouse building type and proposes building and system characteristics for developing a prototype building energy model to be included in the Commercial Building Prototype Model suite. According to the 2012 CBECS, courthouses occupy a total of 436 million sqft of floor space or 0.5% of the total floor space in all commercial buildings in the US, next to fast food (0.35%), grocery store or food market (0.88%), and restaurant or cafeteria (1.2%) building types currently included in the Commercial Prototype Building Model suite. Considering aggregated average, courthouse falls among the larger with a mean floor area of 69,400 sqft smaller fuel consumption intensity building types and an average of 94.7 kBtu/sqft compared to 77.8 kBtu/sqft for office and 80 kBtu/sqft for all commercial buildings.Courthouses range in size from 1000 sqft to over a million square foot building gross square feet and 1 courtroom to over 100 courtrooms. Small courthouses

  6. Locomotion control of hybrid cockroach robots (United States)

    Sanchez, Carlos J.; Chiu, Chen-Wei; Zhou, Yan; González, Jorge M.; Vinson, S. Bradleigh; Liang, Hong


    Natural systems retain significant advantages over engineered systems in many aspects, including size and versatility. In this research, we develop a hybrid robotic system using American (Periplaneta americana) and discoid (Blaberus discoidalis) cockroaches that uses the natural locomotion and robustness of the insect. A tethered control system was firstly characterized using American cockroaches, wherein implanted electrodes were used to apply an electrical stimulus to the prothoracic ganglia. Using this approach, larger discoid cockroaches were engineered into a remotely controlled hybrid robotic system. Locomotion control was achieved through electrical stimulation of the prothoracic ganglia, via a remotely operated backpack system and implanted electrodes. The backpack consisted of a microcontroller with integrated transceiver protocol, and a rechargeable battery. The hybrid discoid roach was able to walk, and turn in response to an electrical stimulus to its nervous system with high repeatability of 60%. PMID:25740855

  7. Using entropy measures to characterize human locomotion. (United States)

    Leverick, Graham; Szturm, Tony; Wu, Christine Q


    Entropy measures have been widely used to quantify the complexity of theoretical and experimental dynamical systems. In this paper, the value of using entropy measures to characterize human locomotion is demonstrated based on their construct validity, predictive validity in a simple model of human walking and convergent validity in an experimental study. Results show that four of the five considered entropy measures increase meaningfully with the increased probability of falling in a simple passive bipedal walker model. The same four entropy measures also experienced statistically significant increases in response to increasing age and gait impairment caused by cognitive interference in an experimental study. Of the considered entropy measures, the proposed quantized dynamical entropy (QDE) and quantization-based approximation of sample entropy (QASE) offered the best combination of sensitivity to changes in gait dynamics and computational efficiency. Based on these results, entropy appears to be a viable candidate for assessing the stability of human locomotion.

  8. Advances in rapid prototyping

    Energy Technology Data Exchange (ETDEWEB)

    Atwood, C.L.; McCarty, G.D.; Pardo, B.T.; Bryce, E.A.


    Recent advances in stereolithography and selective laser sintering have had a significant impact on the overall quality of parts produced using these rapid prototyping processes. The development and implementation of 3D System`s QuickCast{trademark} resin and software for building investment casting patterns have proven to be major steps toward fabricating highly accurate patterns with very good surface finishes. Sandia uses patterns generated from rapid prototyping processes to reduce the cycle time and cost of fabricating prototype parts in support of a Sandia National Laboratories managed program called FASTCAST. As participants in the Beta test program for QuickCast{trademark} resin and software, they experienced a steep learning curve and were able to build accurate parts in a short period of time. It is now possible, using this technology, to produce highly accurate prototype parts as well as acceptable firs article and small lots size production parts. They use the Selective Laser Sintering (SLS) process to fabricate prototype wax patterns for investment casting. DTM Corporation recently introduced the use of their polycarbonate material for fabricating investment casting patterns. The polycarbonate material is processed significantly faster, with improved strength, dimensional stability, and without a support structure during the build process. Sandia is currently changing from investment casting wax to polycarbonate for the fabrication of investment casting patterns using the SLS process. This presentation will focus on the successes with these new materials from the standpoints of application, accuracy, surface finish, and post processing. Also presented will be examples of parts manufactured by these processes.

  9. Serpentine locomotion through elastic energy release


    Dal Corso, Francesco; Misseroni, Diego; Pugno, Nicola; Movchan, A. B.; Movchan, N. V.; Bigoni, Davide


    A model for serpentine locomotion is derived from a novel perspective based on concepts from configurational mechanics. The motion is realized through the release of the elastic energy of a deformable rod, sliding inside a frictionless channel, which represents a snake moving against lateral restraints. A new formulation is presented, correcting previous results and including situations never analysed so far, as in the cases when the serpent's body lies only partially inside the restraining c...

  10. Exotendons for assistance of human locomotion

    Directory of Open Access Journals (Sweden)

    van den Bogert Antonie J


    Full Text Available Abstract Background Powered robotic exoskeletons for assistance of human locomotion are currently under development for military and medical applications. The energy requirements for such devices are excessive, and this has become a major obstacle for practical applications. Legged locomotion in many animals, however, is very energy efficient. We propose that poly-articular elastic mechanisms are a major contributor to the economy of locomotion in such specialized animals. Consequently, it should be possible to design unpowered assistive devices that make effective use of similar mechanisms. Methods A passive assistive technology is presented, based on long elastic cords attached to an exoskeleton and guided by pulleys placed at the joints. A general optimization procedure is described for finding the best geometrical arrangement of such "exotendons" for assisting a specific movement. Optimality is defined either as minimal residual joint moment or as minimal residual joint power. Four specific exotendon systems with increasing complexity are considered. Representative human gait data were used to optimize each of these four systems to achieve maximal assistance for normal walking. Results The most complex exotendon system, with twelve pulleys per limb, was able to reduce the joint moments required for normal walking by 71% and joint power by 74%. A simpler system, with only three pulleys per limb, could reduce joint moments by 46% and joint power by 47%. Conclusion It is concluded that unpowered passive elastic devices can substantially reduce the muscle forces and the metabolic energy needed for walking, without requiring a change in movement. When optimally designed, such devices may allow independent locomotion in patients with large deficits in muscle function.

  11. On the rules for aquatic locomotion (United States)

    Saadat, M.; Fish, F. E.; Domel, A. G.; Di Santo, V.; Lauder, G. V.; Haj-Hariri, H.


    We present unifying rules governing the efficient locomotion of swimming fish and marine mammals. Using scaling and dimensional analysis, supported by new experimental data, we show that efficient locomotion occurs when the values of the Strouhal (St) number St (=f A /U ) and A*(=A /L ) , two nondimensional numbers that relate forward speed U , tail-beat amplitude A , tail-beat frequency f , and the length of the swimmer L are bound to the tight ranges of 0.2-0.4 and 0.1-0.3, respectively. The tight range of 0.2-0.4 for the St number has previously been associated with optimal thrust generation. We show that the St number alone is insufficient to achieve optimal aquatic locomotion, and an additional condition on A* is needed. More importantly, we show that when swimming at minimal power consumption, the Strouhal number of a cruising swimmer is predetermined solely by the shape and drag characteristics of the swimmer. We show that diverse species of fish and cetaceans cruise indeed with the St number and A* predicted by our theory. Our findings provide a physical explanation as to why fast aquatic swimmers cruise with a relatively constant tail-beat amplitude of approximately 20% of the body length, and their swimming speed is nearly proportional to their tail-beat frequency.

  12. Neurobiology of Caenorhabditis elegans Locomotion: Where Do We Stand? (United States)

    Gjorgjieva, Julijana; Biron, David; Haspel, Gal


    Animals use a nervous system for locomotion in some stage of their life cycle. The nematode Caenorhabditis elegans, a major animal model for almost all fields of experimental biology, has long been used for detailed studies of genetic and physiological locomotion mechanisms. Of its 959 somatic cells, 302 are neurons that are identifiable by lineage, location, morphology, and neurochemistry in every adult hermaphrodite. Of those, 75 motoneurons innervate body wall muscles that provide the thrust during locomotion. In this Overview, we concentrate on the generation of either forward- or backward-directed motion during crawling and swimming. We describe locomotion behavior, the parts constituting the locomotion system, and the relevant neuronal connectivity. Because it is not yet fully understood how these components combine to generate locomotion, we discuss competing hypotheses and models. PMID:26955070

  13. Serotonin Influences Locomotion in the Nudibranch Mollusc Melibe leonina




    Serotonin (5-HT) influences locomotion in many animals, from flatworms to mammals. This study examined the effects of 5-HT on locomotion in the nudibranch mollusc Melibe leonina (Gould, 1852). M. leonina exhibits two modes of locomotion, crawling and swimming. Animals were bath-immersed in a range of concentrations of 5-HT or injected with various 5-HT solutions into the hemolymph and then monitored for locomotor activity. In contrast to other gastropods studied, M. leonina showed no signific...

  14. Software evolution in prototyping


    Berzins, V.; Qi, Lu


    This paper proposes a model of software changes for supporting the evolution of software prototypes. The software evolution steps are decomposed into primitive substeps that correspond to monotonic specification changes. This structure is used to rearrange chronological derivation sequences into structures containing only meaning-preserving changes. The authors indicate how this structure can be used to automatically combine different changes to a specification. A set of examples illustrates ...

  15. A contribution about ferrofluid based flow manipulation and locomotion systems

    International Nuclear Information System (INIS)

    Zimmermann, K; Zeidis, I; Bohm, V; Popp, J


    With the background of developing apedal bionic inspired locomotion systems for future application fields like autonomous (swarm) robots, medical engineering and inspection systems, this article presents a selection of locomotion systems with bifluidic flow control using ferrofluid. By controlling the change of shape, position and pressure of the ferrofluid in a secondary low viscous fluid by magnetic fields locomotion of objects or the ferrofluid itself can be realised. The locomotion of an object is caused in the first example by a ferrofluid generated flow of the secondary fluid and in the second and third case by the direct alteration of the ferrofluid position.

  16. A contribution about ferrofluid based flow manipulation and locomotion systems

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, K; Zeidis, I; Bohm, V; Popp, J [TU Ilmenau, Fak. f. Maschinenbau, FG Technische Mechanik, Max-Planck-Ring 12, 98693 Ilmenau (Germany)], E-mail:, E-mail:


    With the background of developing apedal bionic inspired locomotion systems for future application fields like autonomous (swarm) robots, medical engineering and inspection systems, this article presents a selection of locomotion systems with bifluidic flow control using ferrofluid. By controlling the change of shape, position and pressure of the ferrofluid in a secondary low viscous fluid by magnetic fields locomotion of objects or the ferrofluid itself can be realised. The locomotion of an object is caused in the first example by a ferrofluid generated flow of the secondary fluid and in the second and third case by the direct alteration of the ferrofluid position.

  17. LFP Oscillations in the Mesencephalic Locomotor Region during Voluntary Locomotion

    Directory of Open Access Journals (Sweden)

    Brian R. Noga


    Full Text Available Oscillatory rhythms in local field potentials (LFPs are thought to coherently bind cooperating neuronal ensembles to produce behaviors, including locomotion. LFPs recorded from sites that trigger locomotion have been used as a basis for identification of appropriate targets for deep brain stimulation (DBS to enhance locomotor recovery in patients with gait disorders. Theta band activity (6–12 Hz is associated with locomotor activity in locomotion-inducing sites in the hypothalamus and in the hippocampus, but the LFPs that occur in the functionally defined mesencephalic locomotor region (MLR during locomotion have not been determined. Here we record the oscillatory activity during treadmill locomotion in MLR sites effective for inducing locomotion with electrical stimulation in rats. The results show the presence of oscillatory theta rhythms in the LFPs recorded from the most effective MLR stimulus sites (at threshold ≤60 μA. Theta activity increased at the onset of locomotion, and its power was correlated with the speed of locomotion. In animals with higher thresholds (>60 μA, the correlation between locomotor speed and theta LFP oscillations was less robust. Changes in the gamma band (previously recorded in vitro in the pedunculopontine nucleus (PPN, thought to be a part of the MLR were relatively small. Controlled locomotion was best achieved at 10–20 Hz frequencies of MLR stimulation. Our results indicate that theta and not delta or gamma band oscillation is a suitable biomarker for identifying the functional MLR sites.

  18. The need for speed in rodent locomotion analyses. (United States)

    Batka, Richard J; Brown, Todd J; Mcmillan, Kathryn P; Meadows, Rena M; Jones, Kathryn J; Haulcomb, Melissa M


    Locomotion analysis is now widely used across many animal species to understand the motor defects in disease, functional recovery following neural injury, and the effectiveness of various treatments. More recently, rodent locomotion analysis has become an increasingly popular method in a diverse range of research. Speed is an inseparable aspect of locomotion that is still not fully understood, and its effects are often not properly incorporated while analyzing data. In this hybrid manuscript, we accomplish three things: (1) review the interaction between speed and locomotion variables in rodent studies, (2) comprehensively analyze the relationship between speed and 162 locomotion variables in a group of 16 wild-type mice using the CatWalk gait analysis system, and (3) develop and test a statistical method in which locomotion variables are analyzed and reported in the context of speed. Notable results include the following: (1) over 90% of variables, reported by CatWalk, were dependent on speed with an average R(2) value of 0.624, (2) most variables were related to speed in a nonlinear manner, (3) current methods of controlling for speed are insufficient, and (4) the linear mixed model is an appropriate and effective statistical method for locomotion analyses that is inclusive of speed-dependent relationships. Given the pervasive dependency of locomotion variables on speed, we maintain that valid conclusions from locomotion analyses cannot be made unless they are analyzed and reported within the context of speed. © 2014 Wiley Periodicals, Inc.

  19. LFP Oscillations in the Mesencephalic Locomotor Region during Voluntary Locomotion. (United States)

    Noga, Brian R; Sanchez, Francisco J; Villamil, Luz M; O'Toole, Christopher; Kasicki, Stefan; Olszewski, Maciej; Cabaj, Anna M; Majczyński, Henryk; Sławińska, Urszula; Jordan, Larry M


    Oscillatory rhythms in local field potentials (LFPs) are thought to coherently bind cooperating neuronal ensembles to produce behaviors, including locomotion. LFPs recorded from sites that trigger locomotion have been used as a basis for identification of appropriate targets for deep brain stimulation (DBS) to enhance locomotor recovery in patients with gait disorders. Theta band activity (6-12 Hz) is associated with locomotor activity in locomotion-inducing sites in the hypothalamus and in the hippocampus, but the LFPs that occur in the functionally defined mesencephalic locomotor region (MLR) during locomotion have not been determined. Here we record the oscillatory activity during treadmill locomotion in MLR sites effective for inducing locomotion with electrical stimulation in rats. The results show the presence of oscillatory theta rhythms in the LFPs recorded from the most effective MLR stimulus sites (at threshold ≤60 μA). Theta activity increased at the onset of locomotion, and its power was correlated with the speed of locomotion. In animals with higher thresholds (>60 μA), the correlation between locomotor speed and theta LFP oscillations was less robust. Changes in the gamma band (previously recorded in vitro in the pedunculopontine nucleus (PPN), thought to be a part of the MLR) were relatively small. Controlled locomotion was best achieved at 10-20 Hz frequencies of MLR stimulation. Our results indicate that theta and not delta or gamma band oscillation is a suitable biomarker for identifying the functional MLR sites.

  20. A prototype analysis of vengeance

    NARCIS (Netherlands)

    Elshout, Maartje; Nelissen, Rob; van Beest, Ilja


    The authors examined the concept of vengeance from a prototype perspective. In 6 studies, the prototype structure of vengeance was mapped. Sixty-nine features of vengeance were identified (Study 1), and rated on centrality (Study 2). Further studies confirmed the prototype structure. Compared to

  1. MITRE sensor layer prototype (United States)

    Duff, Francis; McGarry, Donald; Zasada, David; Foote, Scott


    The MITRE Sensor Layer Prototype is an initial design effort to enable every sensor to help create new capabilities through collaborative data sharing. By making both upstream (raw) and downstream (processed) sensor data visible, users can access the specific level, type, and quantities of data needed to create new data products that were never anticipated by the original designers of the individual sensors. The major characteristic that sets sensor data services apart from typical enterprise services is the volume (on the order of multiple terabytes) of raw data that can be generated by most sensors. Traditional tightly coupled processing approaches extract pre-determined information from the incoming raw sensor data, format it, and send it to predetermined users. The community is rapidly reaching the conclusion that tightly coupled sensor processing loses too much potentially critical information.1 Hence upstream (raw and partially processed) data must be extracted, rapidly archived, and advertised to the enterprise for unanticipated uses. The authors believe layered sensing net-centric integration can be achieved through a standardize-encapsulate-syndicateaggregate- manipulate-process paradigm. The Sensor Layer Prototype's technical approach focuses on implementing this proof of concept framework to make sensor data visible, accessible and useful to the enterprise. To achieve this, a "raw" data tap between physical transducers associated with sensor arrays and the embedded sensor signal processing hardware and software has been exploited. Second, we encapsulate and expose both raw and partially processed data to the enterprise within the context of a service-oriented architecture. Third, we advertise the presence of multiple types, and multiple layers of data through geographic-enabled Really Simple Syndication (GeoRSS) services. These GeoRSS feeds are aggregated, manipulated, and filtered by a feed aggregator. After filtering these feeds to bring just the type

  2. Morphological self stabilization of locomotion gaits: illustration on a few examples from bio-inspired locomotion. (United States)

    Chevallereau, Christine; Boyer, Frédéric; Porez, Mathieu; Mauny, Johan; Aoustin, Yannick


    To a large extent, robotics locomotion can be viewed as cyclic motions, named gaits. Due to the high complexity of the locomotion dynamics, to find the control laws that ensure an expected gait and its stability with respect to external perturbations, is a challenging issue for feedback control. To address this issue, a promising way is to take inspiration from animals that intensively exploit the interactions of the passive degrees of freedom of their body with their physical surroundings, to outsource the high-level exteroceptive feedback control to low-level proprioceptive ones. In this case, passive interactions can ensure most of the expected control goals. In this article, we propose a methodological framework to study the role of morphology in the design of locomotion gaits and their stability. This framework ranges from modelling to control aspects, and is illustrated through three examples from bio-inspired locomotion: a three-dimensional micro air vehicle in hovering flight, a pendular planar climber and a bipedal planar walker. In these three cases, we will see how simple considerations based on the morphology of the body can ensure the existence of passive stable gaits without requiring any high-level control.

  3. Guiding locomotion in complex dynamic environments

    Directory of Open Access Journals (Sweden)

    Brett R Fajen


    Full Text Available Locomotion in complex dynamic environments is an integral part of many daily activities, including walking in crowded spaces, driving on busy roadways, and playing sports. Many of the tasks that humans perform in such environments involve interactions with moving objects -- that is, they require people to coordinate their own movement with the movements of other objects. A widely adopted framework for research on the detection, avoidance, and interception of moving objects is the bearing angle model, according to which observers move so as to keep the bearing angle of the object constant for interception and varying for obstacle avoidance. The bearing angle model offers a simple, parsimonious account of visual control but has several significant limitations and does not easily scale up to more complex tasks. In this paper, I introduce an alternative account of how humans choose actions and guide locomotion in the presence of moving objects. I show how the new approach addresses the limitations of the bearing angle model and accounts for a variety of behaviors involving moving objects, including (1 choosing whether to pass in front of or behind a moving obstacle, (2 perceiving whether a gap between a pair of moving obstacles is passable, (3 avoiding a collision while passing through single or multiple lanes of traffic, (4 coordinating speed and direction of locomotion during interception, (5 simultaneously intercepting a moving target while avoiding a stationary or moving obstacle, and (6 knowing whether to abandon the chase of a moving target. I also summarize data from recent studies that support the new approach.

  4. Mechanical aspects of legged locomotion control. (United States)

    Koditschek, Daniel E; Full, Robert J; Buehler, Martin


    We review the mechanical components of an approach to motion science that enlists recent progress in neurophysiology, biomechanics, control systems engineering, and non-linear dynamical systems to explore the integration of muscular, skeletal, and neural mechanics that creates effective locomotor behavior. We use rapid arthropod terrestrial locomotion as the model system because of the wealth of experimental data available. With this foundation, we list a set of hypotheses for the control of movement, outline their mathematical underpinning and show how they have inspired the design of the hexapedal robot, RHex.

  5. Serpentine Locomotion Articulated Chain: ANA II

    Directory of Open Access Journals (Sweden)

    A. M. Cardona


    Full Text Available When humanity faces challenges in solving problems beyond their technical resources, and has no foundation to solve a problem, engineering must search for an answer developing new concepts and innovative frameworks to excel these limitations and travel beyond our capabilities. This project “Serpentine locomotion articulated chain: ANA II” is a self-contained robot built to evaluate the behavior of the platform being capable of serpentine movements, in a modular chain mechanical design, based on a master/slave architecture.

  6. Viscous streaming for locomotion and transport (United States)

    Gazzola, Mattia; Parthasarathy, Tejaswin


    Rectified and oscillatory flows associated with vibrating boundaries have been employed in a variety of tasks, especially in microfluidics. The associated fluid mechanics is well known in the case of simple geometries, cylinders in particular, yet little is known in the case of active, complex systems. Motivated by potential applications in swimming mini-bots, we established an accurate and robust computational framework to investigate the flow behavior associated with oscillations of multiple and deforming shapes with an emphasis on streaming assisted locomotion and transport systems.

  7. Intraspecific variation in aerobic and anaerobic locomotion

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Tirsgård, Bjørn; Cordero, Gerardo A.


    Intraspecific variation and trade-off in aerobic and anaerobic traits remain poorly understood in aquatic locomotion. Using gilthead sea bream (Sparus aurata) and Trinidadian guppy (Poecilia reticulata), both axial swimmers, this study tested four hypotheses: (1) gait transition from steady...... to unsteady (i.e., burst-assisted) swimming is associated with anaerobic metabolism evidenced as excess post exercise oxygen consumption (EPOC); (2) variation in swimming performance (critical swimming speed; U crit) correlates with metabolic scope (MS) or anaerobic capacity (i.e., maximum EPOC); (3...

  8. Prototypes as Platforms for Participation

    DEFF Research Database (Denmark)

    Horst, Willem

    The development of interactive products in industry is an activity involving different disciplines – such as different kinds of designers, engineers, marketers and managers – in which prototypes play an important role. On the one hand, prototypes can be powerful boundary objects and an effective...... that invite the participation of different stakeholders based on my involvement in the development process of an interactive product in industry. I demonstrate that involving non-designers in the making and shaping of the prototype enables them to take active part in the reflective learning process...... prototype can be staged as a live prototype in collaborative prototyping workshops to both make and evaluate it with internal and external stakeholders, which effectively turns the prototype into a platform for participation. Overall, this work contributes to the interaction design research literature...

  9. OPAL Jet Chamber Prototype

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

  10. Nightshade Prototype Experiments (Silverleaf)

    Energy Technology Data Exchange (ETDEWEB)

    Danielson, Jeremy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bauer, Amy L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    The Red Sage campaign is a series of subcritical dynamic plutonium experiments designed to measure ejecta. Nightshade, the first experiments in Red Sage scheduled for fiscal year 2019, will measure the amount of ejecta emission into vacuum from a double-­shocked plutonium surface. To address the major technical risks in Nightshade, a Level 2 milestone was developed for fiscal year 2016. Silverleaf, a series of four experiments, was executed at the Los Alamos National Laboratory in July and August 2016 to demonstrate a prototype of the Nightshade package and to satisfy this Level 2 milestone. This report is documentation that Red Sage Level 2 milestone requirements were successfully met.

  11. AMS Prototyping Activities (United States)

    Burleigh, Scott


    This slide presentation reviews the activity around the Asynchronous Message Service (AMS) prototype. An AMS reference implementation has been available since late 2005. It is aimed at supporting message exchange both in on-board environments and over space links. The implementation incoroporates all mandatory elements of the draft recommendation from July 2007: (1) MAMS, AMS, and RAMS protocols. (2) Failover, heartbeats, resync. (3) "Hooks" for security, but no cipher suites included in the distribution. The performance is reviewed, and a Benchmark latency test over VxWorks Message Queues is shown as histograms of a count vs microseconds per 1000-byte message

  12. Prototyping Augmented Reality

    CERN Document Server

    Mullen, Tony


    Learn to create augmented reality apps using Processing open-source programming language Augmented reality (AR) is used all over, and you may not even realize it. Smartphones overlay data onto live camera views to show homes for sale, restaurants, or historical sites. American football broadcasts use AR to show the invisible first-down line on the field to TV viewers. Nike and Budweiser, among others, have used AR in ads. Now, you can learn to create AR prototypes using 3D data, Processing open-source programming language, and other languages. This unique book is an easy-to-follow guide on how

  13. Combining Bio-inspired Sensing with Bio-inspired Locomotion

    DEFF Research Database (Denmark)

    Shaikh, Danish; Hallam, John; Christensen-Dalsgaard, Jakob

    In this paper we present a preliminary Braitenberg vehicle–like approach to combine bio-inspired audition with bio-inspired quadruped locomotion in simulation. Locomotion gaits of the salamander–like robot Salamandra robotica are modified by a lizard’s peripheral auditory system model...

  14. The Determination of the Asynchronous Traction Motor Characteristics of Locomotive

    Directory of Open Access Journals (Sweden)

    Pavel Grigorievich Kolpakhchyan


    Full Text Available The article deals with the problem of the locomotive asynchronous traction motor control with the AC diesel-electric transmission. The limitations of the torque of the traction motor when powered by the inverter are determined. The recommendations to improve the use of asynchronous traction motor of locomotives with the AC diesel-electric transmission are given.

  15. 49 CFR 232.105 - General requirements for locomotives. (United States)


    ... locomotives. (a) The air brake equipment on a locomotive shall be in safe and suitable condition for service... set pressure at any service application with the brakes control valve in the freight position. If such... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER...

  16. Locomotive emissions measurements for various blends of biodiesel fuel. (United States)


    The objective of this project was to assess the effects of various blends of biodiesel on locomotive engine exhaust emissions. The : emission tests were conducted on two locomotive models, a Tier 2 EMD SD70ACe and a Tier 1 Plus GE Dash9-44CW, using t...


    Directory of Open Access Journals (Sweden)

    S. V. Pylypenko


    Full Text Available In the article the results of dynamic running and traction-energy tests of the electric locomotive VL40U are presented. In accordance with the test results a conclusion about the suitability of electric locomotive of such a type for operation with trains containing up to 15 passenger coaches inclusive is made.

  18. Architectures of soft robotic locomotion enabled by simple mechanical principles. (United States)

    Zhu, Liangliang; Cao, Yunteng; Liu, Yilun; Yang, Zhe; Chen, Xi


    In nature, a variety of limbless locomotion patterns flourish, from the small or basic life forms (Escherichia coli, amoebae, etc.) to the large or intelligent creatures (e.g., slugs, starfishes, earthworms, octopuses, jellyfishes, and snakes). Many bioinspired soft robots based on locomotion have been developed in the past few decades. In this work, based on the kinematics and dynamics of two representative locomotion modes (i.e., worm-like crawling and snake-like slithering), we propose a broad set of innovative designs for soft mobile robots through simple mechanical principles. Inspired by and going beyond the existing biological systems, these designs include 1-D (dimensional), 2-D, and 3-D robotic locomotion patterns enabled by the simple actuation of continuous beams. We report herein over 20 locomotion modes achieving various locomotion functions, including crawling, rising, running, creeping, squirming, slithering, swimming, jumping, turning, turning over, helix rolling, wheeling, etc. Some are able to reach high speed, high efficiency, and overcome obstacles. All these locomotion strategies and functions can be integrated into a simple beam model. The proposed simple and robust models are adaptive for severe and complex environments. These elegant designs for diverse robotic locomotion patterns are expected to underpin future deployments of soft robots and to inspire a series of advanced designs.

  19. Locomotion With Loads: Practical Techniques for Predicting Performance Outcomes (United States)


    COVERED 15Apr2014 - 14Apr2015 4. TITLE AND SUBTITLE Locomotion With Loads: Practical Techniques for Predicting Performance Outcomes 5a., 1982; Kram & Taylor, 1990) that the mass- specific metabolic cost of locomotion varies in a systematic manner with the linear dimensions of the

  20. Locomotion Induced by Spatial Restriction in Adult Drosophila. (United States)

    Xiao, Chengfeng; Robertson, R Meldrum


    Drosophila adults display an unwillingness to enter confined spaces but the behaviors induced by spatial restriction in Drosophila are largely unknown. We developed a protocol for high-throughput analysis of locomotion and characterized features of locomotion in a restricted space. We observed intense and persistent locomotion of flies in small circular arenas (diameter 1.27 cm), whereas locomotion was greatly reduced in large circular arenas (diameter 3.81 cm). The increased locomotion induced by spatial restriction was seen in male flies but not female flies, indicating sexual dimorphism of the response to spatial restriction. In large arenas, male flies increased locomotion in arenas previously occupied by male but not female individuals. In small arenas, such pre-conditioning had no effect on male flies, which showed intense and persistent locomotion similar to that seen in fresh arenas. During locomotion with spatial restriction, wildtype Canton-S males traveled slower and with less variation in speed than the mutant w1118 carrying a null allele of white gene. In addition, wildtype flies showed a stronger preference for the boundary than the mutant in small arenas. Genetic analysis with a series of crosses revealed that the white gene was not associated with the phenotype of boundary preference in wildtype flies.

  1. Coordination of locomotion with voluntary movements in humans

    NARCIS (Netherlands)

    Ivanenko, Yuri P; Cappellini, Germana; Dominici, Nadia; Poppele, Richard E; Lacquaniti, Francesco


    Muscle activity occurring during human locomotion can be accounted for by five basic temporal activation patterns in a variety of locomotion conditions. Here, we examined how these activation patterns interact with muscle activity required for a voluntary movement. Subjects produced a voluntary

  2. Ciliary Locomotion in Varying Viscosity Flow (United States)

    Eastham, Patrick; Shoele, Kourosh


    Ciliary locomotion is a common method of transportation employed by bacteria. They must be able to move through their environment at will to seek nutrients as well as avoid dangers. While research into bacteria motility has received considerable attention, very little has been done to consider the effects of a spatially-varying viscosity environment on swimming. This presentation will discuss recent research into how bacteria can take advantage of nutrient-dependent viscosity to generate an asymmetric stress field around their body, potentially increasing free-swimming velocity. First, we analytically show that asymptotically small variations in viscosity due to nutrient concentrations can affect the free-swimming velocity of a bacteria. Then we extend our study to fully nonlinear coupling between nutrient concentration and viscosity and employ the Finite Element method to solve a system containing a convection-diffusion equation for nutrient concentration as well as Stokes flow for stress distribution on the swimmer. We will discuss how the free-swimming velocity profile changes for various nutrient Pecletnumbers and ciliary locomotion modes.

  3. Environmental engineering simplifies subterranean locomotion control (United States)

    Gravish, Nick; Monaenkova, Darya; Goodisman, Michael A. D.; Goldman, Daniel I.


    We hypothesize that ants engineer habitats which reduce locomotion control requirements. We studied tunnel construction, and locomotion, in fire ants (Solenopsis invicta, body length L = 0 . 35 +/- 0 . 05). In their daily life, ants forage for food above ground and return resources to the nest. This steady-state tunnel traffic enables high-throughput biomechanics studies of tunnel climbing. In a laboratory experiment we challenged fire ants to climb through 8 cm long glass tunnels (D = 0.1 - 0.9 cm) that separated a nest from an open arena with food and water. During ascending and descending climbs we induced falls by a motion-activated rapid, short, downward translation of the tunnels. Normalized tunnel diameter (D / L) determined the ability of ants to rapidly recover from perturbations. Fall arrest probability was unity for small D / L , and zero for large D / L . The transition from successful to unsuccessful arrest occurred at D / L = 1 . 4 +/- 0 . 3 . Through X-Ray computed tomography study we show that the diameter of ant-excavated tunnels is independent of soil-moisture content (studied from 1-20%) and particle size (50-595 μm diameter), and has a mean value of D / L = 1 . 06 +/- 0 . 23 . Thus fire ants construct tunnels of diameter near the onset of fall instability.

  4. Proprioceptive Actuation Design for Dynamic Legged locomotion (United States)

    Kim, Sangbae; Wensing, Patrick; Biomimetic Robotics Lab Team

    Designing an actuator system for highly-dynamic legged locomotion exhibited by animals has been one of the grand challenges in robotics research. Conventional actuators designed for manufacturing applications have difficulty satisfying challenging requirements for high-speed locomotion, such as the need for high torque density and the ability to manage dynamic physical interactions. It is critical to introduce a new actuator design paradigm and provide guidelines for its incorporation in future mobile robots for research and industry. To this end, we suggest a paradigm called proprioceptive actuation, which enables highly- dynamic operation in legged machines. Proprioceptive actuation uses collocated force control at the joints to effectively control contact interactions at the feet under dynamic conditions. In the realm of legged machines, this paradigm provides a unique combination of high torque density, high-bandwidth force control, and the ability to mitigate impacts through backdrivability. Results show that the proposed design provides an impact mitigation factor that is comparable to other quadruped designs with series springs to handle impact. The paradigm is shown to enable the MIT Cheetah to manage the application of contact forces during dynamic bounding, with results given down to contact times of 85ms and peak forces over 450N. As a result, the MIT Cheetah achieves high-speed 3D running up to 13mph and jumping over an 18-inch high obstacle. The project is sponsored by DARPA M3 program.

  5. Reversibility in locomotion in granular media (United States)

    Savoie, William; Goldman, Daniel


    A recent study of a self-deforming robot [Hatton et al., PRL, 2013] demonstrated that slow movement in dry granular media resembles locomotion in low Re fluids, in part because inertia is dominated by friction. The study indicated that granular swimming was kinematically reversible, a surprise because yielding in granular flow is irreversible. To investigate if reciprocal motions lead to net displacements in granular swimmers, in laboratory experiments, we study the locomotion of a robotic ``scallop'' consisting of a square body with two flipper-like limbs controlled to flap forward and backward symmetrically (a flap cycle). The body is constrained by linear bearings to allow motion in only one dimension. We vary the the flapping frequency f, the body/flipper burial depth d, and the number of flaps N in a deep bed of 6 mm diameter plastic spheres. Over a range of f and d, the N = 1 cycle produces net translation of the body; however for large N, a cycle produces no net translation. We conclude that symmetric strokes in granular swimming are irreversible at the onset of self-deformation, but become asymptotically reversible. work supported by NSF and ARL.

  6. DataCollection Prototyping

    CERN Multimedia

    Beck, H.P.

    DataCollection is a subsystem of the Trigger, DAQ & DCS project responsible for the movement of event data from the ROS to the High Level Triggers. This includes data from Regions of Interest (RoIs) for Level 2, building complete events for the Event Filter and finally transferring accepted events to Mass Storage. It also handles passing the LVL1 RoI pointers and the allocation of Level 2 processors and load balancing of Event Building. During the last 18 months DataCollection has developed a common architecture for the hardware and software required. This involved a radical redesign integrating ideas from separate parts of earlier TDAQ work. An important milestone for this work, now achieved, has been to demonstrate this subsystem in the so-called Phase 2A Integrated Prototype. This prototype comprises the various TDAQ hardware and software components (ROSs, LVL2, etc.) under the control of the TDAQ Online software. The basic functionality has been demonstrated on small testbeds (~8-10 processing nodes)...

  7. OMS FDIR: Initial prototyping (United States)

    Taylor, Eric W.; Hanson, Matthew A.


    The Space Station Freedom Program (SSFP) Operations Management System (OMS) will automate major management functions which coordinate the operations of onboard systems, elements and payloads. The objectives of OMS are to improve safety, reliability and productivity while reducing maintenance and operations cost. This will be accomplished by using advanced automation techniques to automate much of the activity currently performed by the flight crew and ground personnel. OMS requirements have been organized into five task groups: (1) Planning, Execution and Replanning; (2) Data Gathering, Preprocessing and Storage; (3) Testing and Training; (4) Resource Management; and (5) Caution and Warning and Fault Management for onboard subsystems. The scope of this prototyping effort falls within the Fault Management requirements group. The prototyping will be performed in two phases. Phase 1 is the development of an onboard communications network fault detection, isolation, and reconfiguration (FDIR) system. Phase 2 will incorporate global FDIR for onboard systems. Research into the applicability of expert systems, object-oriented programming, fuzzy sets, neural networks and other advanced techniques will be conducted. The goals and technical approach for this new SSFP research project are discussed here.

  8. Live Piloting and Prototyping

    Directory of Open Access Journals (Sweden)

    Francesca Rizzo


    Full Text Available This paper presents current trends in service design research concerning large scale projects aimed at generating changes at a local scale. The strategy adopted to achieve this, is to co-design solutions including future users in the development process, prototyping and testing system of products and services before their actual implementation. On the basis of experience achieved in the European Project Life 2.0, this paper discusses which methods and competencies are applied in the development of these projects, eliciting the lessons learnt especially from the piloting phase in which the participatory design (PD approach plays a major role. In the first part, the topic is introduced jointly with the theoretical background where the user center design and participatory design methods are presented; then the Life 2.0 project development is described; finally the experience is discussed from a service design perspective, eliciting guidelines for piloting and prototyping services in a real context of use. The paper concludes reflecting on the designers’ role and competencies needed in this process.

  9. Reduction and identification for hybrid dynamical models of terrestrial locomotion (United States)

    Burden, Samuel A.; Sastry, S. Shankar


    The study of terrestrial locomotion has compelling applications ranging from design of legged robots to development of novel prosthetic devices. From a first-principles perspective, the dynamics of legged locomotion seem overwhelmingly complex as nonlinear rigid body dynamics couple to a granular substrate through viscoelastic limbs. However, a surfeit of empirical data demonstrates that animals use a small fraction of their available degrees-of-freedom during locomotion on regular terrain, suggesting that a reduced-order model can accurately describe the dynamical variation observed during steady-state locomotion. Exploiting this emergent phenomena has the potential to dramatically simplify design and control of micro-scale legged robots. We propose a paradigm for studying dynamic terrestrial locomotion using empirically-validated reduced{order models.

  10. Different forms of locomotion in the spinal lamprey. (United States)

    Hsu, Li-Ju; Orlovsky, Grigori N; Zelenin, Pavel V


    Forward locomotion has been extensively studied in different vertebrate animals, and the principal role of spinal mechanisms in the generation of this form of locomotion has been demonstrated. Vertebrate animals, however, are capable of other forms of locomotion, such as backward walking and swimming, sideward walking, and crawling. Do the spinal mechanisms play a principal role in the generation of these forms of locomotion? We addressed this question in lampreys, which are capable of five different forms of locomotion - fast forward swimming, slow forward swimming, backward swimming, forward crawling, and backward crawling. To induce locomotion in lampreys spinalised at the second gill level, we used either electrical stimulation of the spinal cord at different rostrocaudal levels, or tactile stimulation of specific cutaneous receptive fields from which a given form of locomotion could be evoked in intact lampreys. We found that any of the five forms of locomotion could be evoked in the spinal lamprey by electrical stimulation of the spinal cord, and some of them by tactile stimulation. These results suggest that spinal mechanisms in the lamprey, in the absence of phasic supraspinal commands, are capable of generating the basic pattern for all five forms of locomotion observed in intact lampreys. In spinal lampreys, the direction of swimming did not depend on the site of spinal cord stimulation, but on the stimulation strength. The direction of crawling strongly depended on the body configuration. The spinal structures presumably activated by spinal cord stimulation and causing different forms of locomotion are discussed. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. 40 CFR 1033.515 - Discrete-mode steady-state emission tests of locomotives and locomotive engines. (United States)


    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Discrete-mode steady-state emission... Procedures § 1033.515 Discrete-mode steady-state emission tests of locomotives and locomotive engines. This... a warm-up followed by a sequence of nominally steady-state discrete test modes, as described in...

  12. HTS machine laboratory prototype

    DEFF Research Database (Denmark)

    High Temperature Superconducting (HTS) electrical machines have the potential to offer outstanding technical performance with regards to efficiency and power density. However, the industry needs to address a large number of challenges in the attempt to harvest the full potential of HTS machines....... Among others a few stand out, e.g. reliability and efficiency of thermal insulation and cooling systems; optimized torque transfer elements and current leads; commercial availability and competitiveness of HTS material etc. Also, HTS conductors lack standardization due to their rapid development where...... many of HTS properties are not known and need to be tested with a specific purpose in mind not just for different types of HTS conductors but also for the same type of HTS conductors made by different manufactures. To address some of these challenges, we have constructed a laboratory prototype HTS...

  13. Brachial Plexus Blocker Prototype

    Directory of Open Access Journals (Sweden)

    Stéphanie Coelho Monteiro


    Full Text Available Although the area of surgical simulation has been the subject of study in recent years, it is still necessary to develop artificial experimental models with a perspective to dismiss the use of biological models. Since this makes the simulators more real, transferring the environment of the health professional to a physical or virtual reality, an anesthetic prototype has been developed, where the motor response is replicated when the brachial plexus is subjected to a proximal nervous stimulus. Using action-research techniques, with this simulator it was possible to validate that the human nerve response can be replicated, which will aid the training of health professionals, reducing possible risks in a surgical environment.

  14. Prototype Stilbene Neutron Collar

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shumaker, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Snyderman, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Verbeke, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wong, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    A neutron collar using stilbene organic scintillator cells for fast neutron counting is described for the assay of fresh low enriched uranium (LEU) fuel assemblies. The prototype stilbene collar has a form factor similar to standard He-3 based collars and uses an AmLi interrogation neutron source. This report describes the simulation of list mode neutron correlation data on various fuel assemblies including some with neutron absorbers (burnable Gd poisons). Calibration curves (doubles vs 235U linear mass density) are presented for both thermal and fast (with Cd lining) modes of operation. It is shown that the stilbene collar meets or exceeds the current capabilities of He-3 based neutron collars. A self-consistent assay methodology, uniquely suited to the stilbene collar, using triples is described which complements traditional assay based on doubles calibration curves.

  15. Prototyping user displays using CLIPS (United States)

    Kosta, Charles P.; Miller, Ross; Krolak, Patrick; Vesty, Matt


    CLIPS is being used as an integral module of a rapid prototyping system. The prototyping system consists of a display manager for object browsing, a graph program for displaying line and bar charts, and a communications server for routing messages between modules. A CLIPS simulation of a physical model provides dynamic control of the user's display. Currently, a project is well underway to prototype the Advanced Automation System (AAS) for the Federal Aviation Administration.

  16. Mobile prototyping with Axure 7

    CERN Document Server

    Hacker, Will


    This book is a step-by-step tutorial which includes hands-on examples and downloadable Axure files to get you started with mobile prototyping immediately. You will learn how to develop an application from scratch, and will be guided through each and every step.If you are a mobile-centric developer/designer, or someone who would like to take their Axure prototyping skills to the next level and start designing and testing mobile prototypes, this book is ideal for you. You should be familiar with prototyping and Axure specifically, before you read this book.

  17. Three-Dimensional Modeling of a Robotic Fish Based on Real Carp Locomotion

    Directory of Open Access Journals (Sweden)

    Gonca Ozmen Koca


    Full Text Available This work focuses on developing a complete non-linear dynamic model comprising entirely kinematic and hydrodynamic effects of Carangiform locomotion based on the Lagrange approach by adapting the parameters and behaviors of a real carp. In order to imitate biological features, swimming patterns of a real carp for forward, turning and up-down motions are analyzed by using the Kineova 8.20 software. The proportional optimum link lengths according to actual size, swimming speed, flapping frequency, proportional physical parameters and different swimming motions of the real carp are investigated with the designed robotic fish model. Three-dimensional (3D locomotion is evaluated by tracking two trajectories in a MATLAB environment. A Reaching Law Control (RLC approach for inner loop (Euler angles-speed control and a guidance system for the outer loop (orientation control are proposed to provide an effective closed-loop control performance. In order to illustrate the 3D performance of the proposed closed loop control system in a virtual reality platform, the designed robotic fish model is also implemented using the Virtual Reality Modeling Language (VRML. Simulation and experimental analysis show that the proposed model gives us significant key solutions to design a fish-like robotic prototype.

  18. Interlimb Coordination in Body-Weight Supported Locomotion: A Pilot Study (United States)

    Seiterle, Stefan; Susko, Tyler; Artemiadis, Panagiotis K.; Riener, Robert; Krebs, Hermano Igo


    Locomotion involves complex neural networks responsible for automatic and volitional actions. During locomotion, motor strategies can rapidly compensate for any obstruction or perturbation that could interfere with forward progression. In this pilot study, we examined the contribution of interlimb pathways for evoking muscle activation patterns in the contralateral limb when a unilateral perturbation was applied and in the case where body weight was externally supported. In particular, the latency of neuromuscular responses was measured, while the stimulus to afferent feedback was limited. The pilot experiment was conducted with six healthy young subjects. It employed the MIT-Skywalker (beta-prototype), a novel device intended for gait therapy. Subjects were asked to walk on the split-belt treadmill, while a fast unilateral perturbation was applied mid-stance by unexpectedly lowering one side of the split-treadmill walking surfaces. Subject's weight was externally supported via the body-weight support system consisting of an underneath bicycle seat and the torso was stabilized via a loosely fitted chest harness. Both the weight support and the chest harness limited the afferent feedback. The unilateral perturbations evoked changes in the electromyographic activity of the non-perturbed contralateral leg. The latency of all muscle responses exceeded 100 ms, which precludes the conjecture that spinal cord alone is responsible for the perturbation response. It suggests the role of supraspinal or midbrain level pathways at the inter-leg coordination during gait. PMID:25990210

  19. Dynamics of underwater legged locomotion: modeling and experiments on an octopus-inspired robot. (United States)

    Calisti, M; Corucci, F; Arienti, A; Laschi, C


    This paper studies underwater legged locomotion (ULL) by means of a robotic octopus-inspired prototype and its associated model. Two different types of propulsive actions are embedded into the robot model: reaction forces due to leg contact with the ground and hydrodynamic forces such as the drag arising from the sculling motion of the legs. Dynamic parameters of the model are estimated by means of evolutionary techniques and subsequently the model is exploited to highlight some distinctive features of ULL. Specifically, the separation between the center of buoyancy (CoB)/center of mass and density affect the stability and speed of the robot, whereas the sculling movements contribute to propelling the robot even when its legs are detached from the ground. The relevance of these effects is demonstrated through robotic experiments and model simulations; moreover, by slightly changing the position of the CoB in the presence of the same feed-forward activation, a number of different behaviors (i.e. forward and backward locomotion at different speeds) are achieved.

  20. Fish Locomotion: Recent Advances and New Directions (United States)

    Lauder, George V.


    Research on fish locomotion has expanded greatly in recent years as new approaches have been brought to bear on a classical field of study. Detailed analyses of patterns of body and fin motion and the effects of these movements on water flow patterns have helped scientists understand the causes and effects of hydrodynamic patterns produced by swimming fish. Recent developments include the study of the center-of-mass motion of swimming fish and the use of volumetric imaging systems that allow three-dimensional instantaneous snapshots of wake flow patterns. The large numbers of swimming fish in the oceans and the vorticity present in fin and body wakes support the hypothesis that fish contribute significantly to the mixing of ocean waters. New developments in fish robotics have enhanced understanding of the physical principles underlying aquatic propulsion and allowed intriguing biological features, such as the structure of shark skin, to be studied in detail.

  1. Slipping slender bodies and enhanced flagellar locomotion (United States)

    Man, Yi; Lauga, Eric


    In the biological world, many cells exploit slender appendages to swim, include numerous species of bacteria, algae and spermatozoa. A classical method to describe the flow field around such appendages is slender-body theory (SBT), which is often used to study flagellar motility in Newtonian fluids. However, biology environments are often rheologically complex due to the presence of polymers. These polymers generically phase-separate near rigid boundaries where low-viscosity fluid layers lead to effective slip on the surface. In this talk, we present an analytical derivation of SBT in the case where the no-slip boundary condition on the appendage is replaced by a Navier slip boundary condition. Our results demonstrate in particular a systematic reduction of the resistance coefficient of the slender filaments in their tangential direction, which leads to enhanced flagellar locomotion.

  2. Coupling of cytoskeleton functions for fibroblast locomotion

    DEFF Research Database (Denmark)

    Couchman, J R; Lenn, M; Rees, D A


    the cells to lose control of shape and organelle distribution even though forward protrusion continued unaffected. Cytoplasmic displacements shown by marker mitochondria correlated with adjacent fluctuations at the leading edge, and drug treatments which increased the amplitude of mitochondrial movements...... caused visible protrusions in projected positions at the leading edge. We conclude that fibroblast locomotion may be driven coordinately by a common set of motility mechanisms and that this coordination may be lost as a result of physical or pharmacological disturbance. Taking our evidence with results...... from other Laboratories, we propose the following cytoskeleton functions. (i) Protrusive activity, probably based on solation--gelation cycles of the actin based cytoskeleton and membrane recycling which provides cellular and membrane components for streaming through the cell body to the leading edge...

  3. Collective locomotion of non-swimmers (United States)

    Lauga, Eric; Bartolo, Denis


    To achieve propulsion at low Reynolds number, a swimmer (e.g. a biological cell such as a bacterium, or a spermatozoon) must deform its shape in time in a way that is not invariant under time-reversal symmetry (non-reciprocal); this is Purcell's scallop theorem. We show here explicitly that there is no many-scallop theorem. Two active bodies undergoing reciprocal deformations - and therefore incapable of swimming when considered separately - can exploit hydrodynamic interaction to swim. If the bodies are polar, we also show that they experience effective long-range interactions. We derive our results analytically for a minimal dimers model, and generalize them to more complex geometries on the basis of symmetry and scaling arguments. Furthermore, we explain how such cooperative locomotion can be realized experimentally by shaking a collection of soft particles with a homogeneous external field, thereby making non-swimmers swim.

  4. Soft Snakes: Construction, Locomotion, and Control (United States)

    Branyan, Callie; Courier, Taylor; Fleming, Chloe; Remaley, Jacquelin; Hatton, Ross; Menguc, Yigit

    We fabricated modular bidirectional silicone pneumatic actuators to build a soft snake robot, applying geometric models of serpenoid swimmers to identify theoretically optimal gaits to realize serpentine locomotion. With the introduction of magnetic connections and elliptical cross-sections in fiber-reinforced modules, we can vary the number of continuum segments in the snake body to achieve more supple serpentine motion in a granular media. The performance of these gaits is observed using a motion capture system and efficiency is assessed in terms of pressure input and net displacement. These gaits are optimized using our geometric soap-bubble method of gait optimization, demonstrating the applicability of this tool to soft robot control and coordination.

  5. Embodied Sensorimotor Interaction for Hexapod Locomotion

    DEFF Research Database (Denmark)

    Ambe, Yuichi; Aoi, Shinya; Nachstedt, Timo


    is still unclear. Recent studies in biology suggest that a functional motor output during walking is formed by the interaction between central pattern generators (CPGs) and sensory feedbacks. In this paper, we investigate the dynamics of a hexapod robot model whose legs are driven by distributed...... oscillators with a local sensory feedback from neuromechanical point of view. This feedback changes the oscillation period of the oscillator depending solely on the timing of the contact between the foot and the ground. The results of dynamic simulations and real robot experiments show that due to the local...... sensory feedback the robot produces continuous stable gaits depending on the locomotion speed as a result of self-organization, one of which are similar to those of insects. These results reveal that the neuromechanical interaction induced by the local sensory feedback plays an important role...

  6. Locomotion in simulated microgravity: gravity replacement loads (United States)

    McCrory, Jean L.; Baron, Heidi A.; Balkin, Sandy; Cavanagh, Peter R.


    BACKGROUND: When an astronaut walks or runs on a treadmill in microgravity, a subject load device (SLD) is used to return him or her back to the treadmill belt. The gravity replacement load (GRL) in the SLD is transferred, via a harness, to the pelvis and/or the shoulders. This research compared comfort and ground reaction forces during treadmill running in a microgravity locomotion simulator at GRLs of 60%, 80%, and 100% of body weight (BW). Two harness designs (shoulder springs only (SSO) and waist and shoulder springs (WSS)) were used. HYPOTHESES: 1) The 100% BW gravity replacement load conditions would be comfortably tolerated and would result in larger ground reaction forces and loading rates than the lower load conditions, and 2) the WSS harness would be more comfortable than the SSO harness. METHODS: Using the Penn State Zero Gravity Locomotion Simulator (ZLS), 8 subjects ran at 2.0 m x s(-1) (4.5 mph) for 3 min at each GRL setting in each harness. Subjective ratings of harness comfort, ground reaction forces, and GRL data were collected during the final minute of exercise. RESULTS: The 100% BW loading conditions were comfortably tolerated (2.3 on a scale of 0-10), although discomfort increased as the GRL increased. There were no overall differences in perceived comfort between the two harnesses. The loading rates (27.1, 33.8, 39.1 BW x s(-1)) and the magnitudes of the first (1.0, 1.4, 1.6 BW) and second (1.3, 1.7, 1.9 BW) peaks of the ground reaction force increased with increasing levels (60, 80, 100% BW respectively) of GRL. CONCLUSIONS: Subjects were able to tolerate a GRL of 100% BW well. The magnitude of the ground reaction force peaks and the loading rate is directly related to the magnitude of the GRL.

  7. In-pipe micromachine locomotion via the inertial stepping principle

    Energy Technology Data Exchange (ETDEWEB)

    Yum, Young Jin [University of Ulsan, Ulsan (Korea, Republic of); Hwang, Han Sub [Suweon Science College, Suweon (Korea, Republic of); Kelemen, Michal; Maxim, Vladislav; Frankovsky, Peter [Technical University of Kosice, Kosice (Slovakia)


    This paper discusses an in-pipe inspection micromachine intended for locomotion inside a small diameter pipe. The micromachine locomotion is based on the inertial stepping principle, which utilizes the drive force of the two-body impact. The in-pipe micromachine contacts the pipe through the elastic bristles installed on the in-pipe machine and in two lines and crossways with respect to the micromachine axle. The paper describes the principle of locomotion and the dynamics by which the unknown of both the parameters and the relations are experimentally identified. Based on the results, a simulation model was created, and the results of the simulations were compared with experimental results.

  8. A survey report for the turning of biped locomotion robot

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Ichiro; Takanishi, Atsuo [Waseda Univ., Tokyo (Japan); Kume, Etsuo


    A mechanical design study of biped locomotion robots is going on at JAERI within the scope of the Human Acts Simulation Program (HASP). The design study at JAERI is of an arbitrarily mobile robot for inspection of nuclear facilities. A survey has been performed for collecting useful information from already existing biped locomotion robots. This is a survey report for the turning of biped locomotion robot: the WL-10R designed and developed at Waseda University. This report includes the control method of turning, machine model and control system. (author).

  9. 49 CFR 230.90 - Draw gear between steam locomotive and tender. (United States)


    ... 49 Transportation 4 2010-10-01 2010-10-01 false Draw gear between steam locomotive and tender. 230... Steam Locomotives and Tenders Draw Gear and Draft Systems § 230.90 Draw gear between steam locomotive and tender. (a) Maintenance and testing. The draw gear between the steam locomotive and tender...

  10. Window prototypes during the project

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe


    The conditions for the PASSYS test and the results of the measurements on one of the aerogel window prototypes are described.......The conditions for the PASSYS test and the results of the measurements on one of the aerogel window prototypes are described....

  11. Rapid prototyping: een veelbelovende methode

    NARCIS (Netherlands)

    Haverman, T.M.; Karagozoglu, K.H.; Prins, H.; Schulten, E.A.J.M.; Forouzanfar, T.


    Rapid prototyping is a method which makes it possible to produce a three-dimensional model based on two-dimensional imaging. Various rapid prototyping methods are available for modelling, such as stereolithography, selective laser sintering, direct laser metal sintering, two-photon polymerization,

  12. Rapid prototyping in medical sciences

    Directory of Open Access Journals (Sweden)

    Ákos Márk Horváth


    Full Text Available Even if it sound a bit incredible rapid prototyping (RPT as production method has been used for decades in other professions. Nevertheless medical science just started discover the possibilities of this technology and use the offered benefits of 3D printing. In this paper authors have investigated the pharmaceutical usage of rapid prototyping.

  13. LISA phasemeter development: Advanced prototyping

    Energy Technology Data Exchange (ETDEWEB)

    Bykov, Iouri; Delgado, Juan Jose Esteban; Garcia Marin, Antonio Francisco; Heinzel, Gerhard; Danzmann, Karsten, E-mail: Iouri.bykov@aei.mpg.d [Institute for Gravitational Physics of the Leibniz University Hannover and Max Planck Institute for Gravitational Physics (Albert Einstein Institute) (Germany)


    We present the status of our investigations on the LISA Phasemeter. The new prototype is based on a custom-designed breadboard with four high-speed ADC and two DAC channels, extended readout capabilities and a large FPGA (field programmable gate array). The required main functionalities and performance of the prototype have been demonstrated in laboratory conditions.

  14. Role model and prototype matching

    DEFF Research Database (Denmark)

    Lykkegaard, Eva; Ulriksen, Lars


    Previous research has found that young people’s prototypes of science students and scientists affect their inclination to choose tertiary STEM programs (Science, Technology, Engineering and Mathematics). Consequently, many recruitment initiatives include role models to challenge these prototypes......’ meetings with the role models affected their thoughts concerning STEM students and attending university. The regular self-to-prototype matching process was shown in real-life role-models meetings to be extended to a more complex three-way matching process between students’ self-perceptions, prototype...... images and situation-specific conceptions of role models. Furthermore, the study underlined the positive effect of prolonged role-model contact, the importance of using several role models and that traditional school subjects catered more resistant prototype images than unfamiliar ones did...

  15. Virtual Prototyping at CERN (United States)

    Gennaro, Silvano De

    The VENUS (Virtual Environment Navigation in the Underground Sites) project is probably the largest Virtual Reality application to Engineering design in the world. VENUS is just over one year old and offers a fully immersive and stereoscopic "flythru" of the LHC pits for the proposed experiments, including the experimental area equipment and the surface models that are being prepared for a territorial impact study. VENUS' Virtual Prototypes are an ideal replacement for the wooden models traditionally build for the past CERN machines, as they are generated directly from the EUCLID CAD files, therefore they are totally reliable, they can be updated in a matter of minutes, and they allow designers to explore them from inside, in a one-to-one scale. Navigation can be performed on the computer screen, on a stereoscopic large projection screen, or in immersive conditions, with an helmet and 3D mouse. By using specialised collision detection software, the computer can find optimal paths to lower each detector part into the pits and position it to destination, letting us visualize the whole assembly probess. During construction, these paths can be fed to a robot controller, which can operate the bridge cranes and build LHC almost without human intervention. VENUS is currently developing a multiplatform VR browser that will let the whole HEP community access LHC's Virtual Protoypes over the web. Many interesting things took place during the conference on Virtual Reality. For more information please refer to the Virtual Reality section.

  16. UA1 prototype detector

    CERN Multimedia


    Prototype of UA1 central detector inside a plexi tube. The UA1 experiment ran at CERN's Super Proton Synchrotron and made the Nobel Prize winning discovery of W and Z particles in 1983. The UA1 central detector was crucial to understanding the complex topology of proton-antiproton events. It played a most important role in identifying a handful of Ws and Zs among billions of collisions. The detector was essentially a wire chamber - a 6-chamber cylindrical assembly 5.8 m long and 2.3 m in diameter, the largest imaging drift chamber of its day. It recorded the tracks of charged particles curving in a 0.7 Tesla magnetic field, measuring their momentum, the sign of their electric charge and their rate of energy loss (dE/dx). Atoms in the argon-ethane gas mixture filling the chambers were ionised by the passage of charged particles. The electrons which were released drifted along an electric field shaped by field wires and were collected on sense wires. The geometrical arrangement of the 17000 field wires and 6...

  17. Space Warfighting Construct: Prototyping (United States)

    Teehan, R. F.; Anttonen, J. S.; Stein, J. M.; Stearns, J. A.

    Space is undergoing a period of great change, as the barriers to entry are lowering in every arena. Launch to any orbit is becoming more routine and feasible thanks to industry innovation, the rise of small- and cubesats, and the use of ESPA rings enabling “freight trains to GEO.” With more regular rides to space, there is a concomitant rise in the capability for space qualification, technology validation and verification, and all types of experimentation in both the space and ground segments. The types of architectures that commercial and government agencies develop is being influenced because space is becoming more accessible. Whereas current architectures are designed to have four to six satellites perform a mission, in the future that same mission may be distributed among dozens, hundreds, or even thousands of satellites. This changing landscape is something of a double-edged sword for Space Situational Awareness (SSA): safety of flight becomes a heightened concern, but the opportunities for the entire community to innovate, prototype, and ultimately provide novel, robust solutions have never been greater.

  18. Dynamic Locomotion With Four and Six-Legged Robots

    National Research Council Canada - National Science Library

    Buehler, M; Saranli, U; Papadopoulos, D; Koditschek, D


    .... The Scout II quadruped runs on flat ground in a bounding gait, and was motivated by an effort to understand the minimal mechanical design and control complexity for dynamically stable locomotion...

  19. Hybrid Locomotive for Energy Savings and Reduced Emissions (United States)


    Norfolk Southern Corporation (NS) and Pennsylvania State University tested several different battery systems in hybrid locomotives. Advanced lithium-ion battery technology was the only kind that displayed the capacity to perform in heavy switching or...

  20. A sensory-driven controller for quadruped locomotion. (United States)

    Ferreira, César; Santos, Cristina P


    Locomotion of quadruped robots has not yet achieved the harmony, flexibility, efficiency and robustness of its biological counterparts. Biological research showed that spinal reflexes are crucial for a successful locomotion in the most varied terrains. In this context, the development of bio-inspired controllers seems to be a good way to move toward an efficient and robust robotic locomotion, by mimicking their biological counterparts. This contribution presents a sensory-driven controller designed for the simulated Oncilla quadruped robot. In the proposed reflex controller, movement is generated through the robot's interactions with the environment, and therefore, the controller is solely dependent on sensory information. The results show that the reflex controller is capable of producing stable quadruped locomotion with a regular stepping pattern. Furthermore, it is capable of dealing with slopes without changing the parameters and with small obstacles, overcoming them successfully. Finally, system robustness was verified by adding noise to sensors and actuators and also delays.

  1. Vibrational Locomotion Enabling Subsurface Exploration of Unconsolidated Regolith Project (United States)

    National Aeronautics and Space Administration — The idea of vibrational locomotion is based on vibrational-fluidization in ISRU reactor systems, which has proven very effective for regolith mixing. The vibrating...

  2. Test requirements of locomotive fuel tank blunt impact tests (United States)


    The Federal Railroad Administrations Office of Research : and Development is conducting research into passenger : locomotive fuel tank crashworthiness. A series of impact tests : are planned to measure fuel tank deformation under two types : of dy...

  3. Crawling beneath the free surface: Water snail locomotion


    Lee, Sungyon; Bush, John W. M.; Hosoi, A. E.; Lauga, Eric


    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being g...

  4. Design of Mine Locomotive System Based on CAN Bus


    Li Yuanhong; Zhang Quanzhu; Zhang Wenshan


    Based on CAN bus, this paper studies the system control and management system of locomotive in mine, analyzes the working principle of locomotive system, gives the CAN bus scheme, hardware circuit design and CAN communication protocol, and implements long-distance, high-reliability communication function and remote monitoring function. Experiments show that the auxiliary system based on CAN bus control easier, operation more secure, as well as improving the control performance and service lif...

  5. Locomotion in Lymphocytes is Altered by Differential PKC Isoform Expression (United States)

    Sundaresan, A.; Risin, D.; Pellis, N. R.


    Lymphocyte locomotion is critical for proper elicitation of the immune response. Locomotion of immune cells via the interstitium is essential for optimal immune function during wound healing, inflammation and infection. There are conditions which alter lymphocyte locomotion and one of them is spaceflight. Lymphocyte locomotion is severely inhibited in true spaceflight (true microgravity) and in rotating wall vessel culture (modeled microgravity). When lymphocytes are activated prior to culture in modeled microgravity, locomotion is not inhibited and the levels are comparable to those of static cultured lymphocytes. When a phorbol ester (PMA) is used in modeled microgravity, lymphocyte locomotion is restored by 87%. This occurs regardless if PMA is added after culture in the rotating wall vessel or during culture. Inhibition of DNA synthesis also does not alter restoration of lymphocyte locomotion by PMA. PMA is a direct activator of (protein kinase C) PKC . When a calcium ionophore, ionomycin is used it does not possess any restorative properties towards locomotion either alone or collectively with PMA. Since PMA brings about restoration without help from calcium ionophores (ionomycin), it is infer-red that calcium independent PKC isoforms are involved. Changes were perceived in the protein levels of PKC 6 where levels of the protein were downregulated at 24,72 and 96 hours in untreated rotated cultures (modeled microgravity) compared to untreated static (1g) cultures. At 48 hours there is an increase in the levels of PKC & in the same experimental set up. Studies on transcriptional and translational patterns of calcium independent isoforms of PKC such as 8 and E are presented in this study.

  6. Development of Electrolysis System Powered by Solar-Cell Array to Supply Hydrogen Gas for Fuel-Cell Energy Resource Systems (United States)

    Priambodo, Purnomo Sidi; Yusivar, Feri; Subiantoro, Aries; Gunawan, Ridwan


    The huge demand of energy worldwide and the depletion of fossil based energy, is a strong reason to rapidly develop any kind of renewable energy resources, which has economical advantages and zero pollution effect. One of the renewable energy technologies aimed in this paper is the generation of electric-energy based on fuel-cell technology, where the input hydrogen (H2) gas is supplied by electrolysis system powered by renewable energy system based on solar cell. In this paper, the authors explain the development of electrolysis system which is powered by solar cell array to supply hydrogen for fuel-cell system. The authors explain in detail how to design an efficient electrolysis system to obtain high ratio conversion of electric energy to hydrogen gas volume. It includes the explanation of the usage of multiple anodes with a single cathode for many solar cell inputs in a single electrolysis system. Hereinafter this is referred as multiple anode electrolysis system. This multiple anode electrolysis system makes the management of hydrogen gas becomes more efficient and effective by using only a single hydrogen gas storage system. This paper also explain the careful design of the resistance value of the electrolysis system to protect or avoid the solar cell panel to deliver excessive current to the electrolysis system which can cause damage on the solar cell panel. Moreover, the electrolyte volume detector is applied on the system as a tool to measure the electrolyte concentration to assure the system resistance is still in the allowed range. Further, the hydrogen gas produced by electrolysis system is stored into the gas storage which consists of silica-gel purifier, first stage low pressure gas bottle, vacuum pump, and second stage high pressure gas bottle. In the first step, the pump will vacuum the first bottle. The first bottle will collect the hydrogen from the electrolysis system through the silica gel to get rid of water vapor. When the first bottle

  7. Multi-modal locomotion: from animal to application

    International Nuclear Information System (INIS)

    Lock, R J; Burgess, S C; Vaidyanathan, R


    The majority of robotic vehicles that can be found today are bound to operations within a single media (i.e. land, air or water). This is very rarely the case when considering locomotive capabilities in natural systems. Utility for small robots often reflects the exact same problem domain as small animals, hence providing numerous avenues for biological inspiration. This paper begins to investigate the various modes of locomotion adopted by different genus groups in multiple media as an initial attempt to determine the compromise in ability adopted by the animals when achieving multi-modal locomotion. A review of current biologically inspired multi-modal robots is also presented. The primary aim of this research is to lay the foundation for a generation of vehicles capable of multi-modal locomotion, allowing ambulatory abilities in more than one media, surpassing current capabilities. By identifying and understanding when natural systems use specific locomotion mechanisms, when they opt for disparate mechanisms for each mode of locomotion rather than using a synergized singular mechanism, and how this affects their capability in each medium, similar combinations can be used as inspiration for future multi-modal biologically inspired robotic platforms. (topical review)

  8. Serotonin influences locomotion in the nudibranch mollusc Melibe leonina. (United States)

    Lewis, Stefanie L; Lyons, Deborah E; Meekins, Tiffanie L; Newcomb, James M


    Serotonin (5-HT) influences locomotion in many animals, from flatworms to mammals. This study examined the effects of 5-HT on locomotion in the nudibranch mollusc Melibe leonina (Gould, 1852). M. leonina exhibits two modes of locomotion, crawling and swimming. Animals were bath-immersed in a range of concentrations of 5-HT or injected with various 5-HT solutions into the hemolymph and then monitored for locomotor activity. In contrast to other gastropods studied, M. leonina showed no significant effect of 5-HT on the distance crawled or the speed of crawling. However, the highest concentration (10(-3) mol l(-1) for bath immersion and 10(-5) mol l(-1) for injection) significantly increased the time spent swimming and the swimming speed. The 5-HT receptor antagonist methysergide inhibited the influence of 5-HT on the overall amount of swimming but not on swimming speed. These results suggest that 5-HT influences locomotion at the behavioral level in M. leonina. In conjunction with previous studies on the neural basis of locomotion in M. leonina, these results also suggest that this species is an excellent model system for investigating the 5-HT modulation of locomotion.

  9. Limited locomotive ability relaxed selective constraints on molluscs mitochondrial genomes. (United States)

    Sun, Shao'e; Li, Qi; Kong, Lingfeng; Yu, Hong


    Mollusca are the second largest phylum in the animal kingdom with different types of locomotion. Some molluscs are poor-migrating, while others are free-moving or fast-swimming. Most of the energy required for locomotion is provided by mitochondria via oxidative phosphorylation. Here, we conduct a comparative genomic analysis of 256 molluscs complete mitochondrial genomes and evaluate the role of energetic functional constraints on the protein-coding genes, providing a new insight into mitochondrial DNA (mtDNA) evolution. The weakly locomotive molluscs, compared to strongly locomotive molluscs, show significantly higher Ka/Ks ratio, which suggest they accumulated more nonsynonymous mutations in mtDNA and have experienced more relaxed evolutionary constraints. Eleven protein-coding genes (CoxI, CoxII, ATP6, Cytb, ND1-6, ND4L) show significant difference for Ka/Ks ratios between the strongly and weakly locomotive groups. The relaxation of selective constraints on Atp8 arise in the common ancestor of bivalves, and the further relaxation occurred in marine bivalves lineage. Our study thus demonstrates that selective constraints relevant to locomotive ability play an essential role in evolution of molluscs mtDNA.

  10. A subset of interneurons required for Drosophila larval locomotion. (United States)

    Yoshikawa, Shingo; Long, Hong; Thomas, John B


    Efforts to define the neural circuits generating locomotor behavior have produced an initial understanding of some of the components within the spinal cord, as well as a basic understanding of several invertebrate motor pattern generators. However, how these circuits are assembled during development is poorly understood. We are defining the neural circuit that generates larval locomotion in the genetically tractable fruit fly Drosophila melanogaster to study locomotor circuit development. Forward larval locomotion involves a stereotyped posterior-to-anterior segmental translocation of body wall muscle contraction and is generated by a relatively small number of identified muscles, motor and sensory neurons, plus an unknown number of the ~270 bilaterally-paired interneurons per segment of the 1st instar larva. To begin identifying the relevant interneurons, we have conditionally inactivated synaptic transmission of interneuron subsets and assayed for the effects on locomotion. From this screen we have identified a subset of 25 interneurons per hemisegment, called the lateral locomotor neurons (LLNs), that are required for locomotion. Both inactivation and constitutive activation of the LLNs disrupt locomotion, indicating that patterned output of the LLNs is required. By expressing a calcium indicator in the LLNs, we found that they display a posterior-to-anterior wave of activity within the CNS corresponding to the segmental translocation of the muscle contraction wave. Identification of the LLNs represents the first step toward elucidating the circuit generating larval locomotion. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Water surface locomotion in tropical canopy ants. (United States)

    Yanoviak, S P; Frederick, D N


    Upon falling onto the water surface, most terrestrial arthropods helplessly struggle and are quickly eaten by aquatic predators. Exceptions to this outcome mostly occur among riparian taxa that escape by walking or swimming at the water surface. Here we document sustained, directional, neustonic locomotion (i.e. surface swimming) in tropical arboreal ants. We dropped 35 species of ants into natural and artificial aquatic settings in Peru and Panama to assess their swimming ability. Ten species showed directed surface swimming at speeds >3 body lengths s(-1), with some swimming at absolute speeds >10 cm s(-1). Ten other species exhibited partial swimming ability characterized by relatively slow but directed movement. The remaining species showed no locomotory control at the surface. The phylogenetic distribution of swimming among ant genera indicates parallel evolution and a trend toward negative association with directed aerial descent behavior. Experiments with workers of Odontomachus bauri showed that they escape from the water by directing their swimming toward dark emergent objects (i.e. skototaxis). Analyses of high-speed video images indicate that Pachycondyla spp. and O. bauri use a modified alternating tripod gait when swimming; they generate thrust at the water surface via synchronized treading and rowing motions of the contralateral fore and mid legs, respectively, while the hind legs provide roll stability. These results expand the list of facultatively neustonic terrestrial taxa to include various species of tropical arboreal ants. © 2014. Published by The Company of Biologists Ltd.

  12. Sensory modulation of movement, posture and locomotion. (United States)

    Saradjian, A H


    During voluntary movement, there exists a well known functional sensory attenuation of afferent inputs, which allows us to discriminate between information related to our own movements and those arising from the external environment. This attenuation or 'gating' prevents some signals from interfering with movement elaboration and production. However, there are situations in which certain task-relevant sensory inputs may not be gated. This review begins by identifying the prevalent findings in the literature with specific regard to the somatosensory modality, and reviews the many cases of classical sensory gating phenomenon accompanying voluntary movement and their neural basis. This review also focuses on the newer axes of research that demonstrate that task-specific sensory information may be disinhibited or even facilitated during engagement in voluntary actions. Finally, a particular emphasis will be placed on postural and/or locomotor tasks involving strong somatosensory demands, especially for the setting of the anticipatory postural adjustments observed prior the initiation of locomotion. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  13. Analysis of Ada as a prototyping language (United States)

    Holloway, C. Michael


    This paper examines the suitability of Ada as a language for developing software prototypes. The differences between software prototypes and traditional engineering prototypes are discussed; the approaches to software prototyping are identified. Ada's potential as a language for prototyping is evaluated according to the writability, expressiveness, and flexibility of the language; Ada is found to be inadequate as a prototyping language because it lacks writability and expressiveness. Possible approaches to improving the expressiveness of the language are discussed.

  14. Learning Axure RP interactive prototypes

    CERN Document Server

    Krahenbuhl, John Henry


    If you are a user experience professional, designer, information architect, or business analyst who wants to gain interactive prototyping skills with Axure, then this book is ideal for you. Some familiarity with Axure is preferred but not essential.

  15. Digital Prototyping of Milk Products

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Nielsen, Otto Højager Attermann; Skytte, Jacob Lercke


    the extension. This work was (in part) financed by the Centre for Imaging Food Quality project which is funded by the Danish Council for Strategic Research (contract no 09-067039) within the Programme Commission on Health, Food and Welfare. This work was also in part financed by the Digital Prototypes project......Digital prototyping has revolutionised the automotive industry by providing designers and engineers with digital models of their products that enable virtual product design, visualisation, and simulation [1]. However, digital prototyping does not exist in the food industry as the colloidal nature...... of most foods make them much more challenging to visualise and simulate realistically. We present models and methods that take steps toward digital prototyping of milk products and other food colloids. To simulate the dynamics of liquid products that only exist digitally, we use deformable simplicial...

  16. Architectural Prototyping in Industrial Practice

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius


    Architectural prototyping is the process of using executable code to investigate stakeholders’ software architecture concerns with respect to a system under development. Previous work has established this as a useful and cost-effective way of exploration and learning of the design space of a system......, in addressing issues regarding quality attributes, in addressing architectural risks, and in addressing the problem of knowledge transfer and conformance. Little work has been reported so far on the actual industrial use of architectural prototyping. In this paper, we report from an ethnographical study...... prototypes include end-user or business related functionality rather than purely architectural functionality. Based on these observations we provide recommendations for effective industrial architectural prototyping....

  17. Develop Prototype Microwave Interferometry Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Tringe, J. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Converse, M. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kane, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    A prototype microwave interferometer was created at NSTec to characterize moving conductive fronts in upcoming experiments. The interferometer is capable of operation in the ~26-40 GHz band, and interrogating fronts with more than 1 W of power.


    Directory of Open Access Journals (Sweden)

    S. V. Myamlin


    Full Text Available Purpose. The paper is devoted to dynamic characteristics evaluation of the locomotive with prospective design and determination the feasibility of its use on the Ukrainian railways. Methodology. The methods of mathematical and computer modeling of the dynamics of railway vehicles, as well as methods for the numerical integration of systems of ordinary nonlinear differential equations were used to solve the problem. Findings. The calculated diagram of a locomotive on three-axle bogies was built to solve the problem, and it is a system of rigid bodies connected by various elements of rheology. The mathematical model of the locomotive movement, allowing studying its spatial vibrations at driving on straight and curved sections of the track with random irregularities in plan and profile was developed with use of this calculated diagram. At compiling the mathematical model took into account both geometric (nonlinearity profile of the wheel roll surface and physical nonlinearity of the system (the work forces of dry friction, nonlinearity characteristics of interaction forces between wheels and rails. The multivariate calculations, which allowed assessing the dynamic qualities of the locomotive at its movement along straight and curved sections of the track, were realized with the use of computer modeling. The smoothness movement indicators of the locomotive in horizontal and vertical planes, frame strength, coefficients of vertical dynamics in the first and second stages of the suspension, the load factor of resistance against the derailment of the wheel from the rail were determined at the period of research. In addition, a comparison of the obtained results with similar characteristics is widely used on the Ukrainian railways in six-axle locomotive TE 116. The influence of speed and technical state of the track on the locomotive traffic safety was determined.Originality. A mathematical model of the spatial movement of a six-axle locomotive with


    Directory of Open Access Journals (Sweden)

    I. V. Zhukovytskyy


    Full Text Available Purpose. The article describes the process of developing the information-measuring test system of diesel locomotives hydraulic transmission, which gives the possibility to obtain baseline data to conduct further studies for the determination of the technical condition of diesel locomotives hydraulic transmission. The improvement of factory technology of post-repair tests of hydraulic transmissions by automating the existing hydraulic transmission test stands according to the specifications of the diesel locomotive repair enterprises was analyzed. It is achieved based on a detailed review of existing foreign information-measuring test systems for hydraulic transmission of diesel locomotives, BelAZ earthmover, aircraft tug, slag car, truck, BelAZ wheel dozer, some brands of tractors, etc. The problem for creation the information-measuring test systems for diesel locomotive hydraulic transmission is being solved, starting in the first place from the possibility of automation of the existing test stand of diesel locomotives hydraulic transmission at Dnipropetrovsk Diesel Locomotive Repair Plant "Promteplovoz". Methodology. In the work the researchers proposed the method to create a microprocessor automated system of diesel locomotives hydraulic transmission stand testing in the locomotive plant conditions. It acts by justifying the selection of the necessary sensors, as well as the application of the necessary hardware and software for information-measuring systems. Findings. Based on the conducted analysis there was grounded the necessity of improvement the plant hydraulic transmission stand testing by creating a microprocessor testing system, supported by the experience of developing such systems abroad. Further research should be aimed to improve the accuracy and frequency of data collection by adopting the more modern and reliable sensors in tandem with the use of filtering software for electromagnetic and other interference. Originality. The

  20. Problems of locomotive wheel wear in fleet replacement

    Directory of Open Access Journals (Sweden)

    L.P. Lingaytis


    Full Text Available Purpose. To conduct a research and find out the causes of defects appearing on the wheel thread of freight locomotives 2М62 and SIEMENS ER20CF. Methodology. To find the ways to solve this problem comparing the locomotive designs and their operating conditions. Findings. After examining the nature of the wheel wear the main difference was found: in locomotives of the 2M62 line wears the wheel flange, and in the locomotives SIEMENS ER20CF – the tread surface. After installation on the 2M62 locomotive the lubrication system of flanges their wear rate significantly decreased. On the new freight locomotives SIEMENS ER20CF the flange lubrication systems of the wheel set have been already installed at the factory, however the wheel thread is wearing. As for locomotives 2M62, and on locomotives SIEMENS ER20CF most wear profile skating wheels of the first wheel set. On both locomotive lines the 2М62 and the SIEMENS ER20CF the tread profile of the first wheel set most of all is subject to the wear. After reaching the 170 000 km run, the tread surface of some wheels begins to crumble. There was a suspicion that the reason for crumb formation of the wheel surface may be insufficient or excessive wheel hardness or its chemical composition. In order to confirm or deny this suspicion the following studies were conducted: the examination of the rim surface, the study of the wheel metal hardness and the document analysis of the wheel production and their comparison with the results of wheel hardness measurement. Practical value. The technical condition of locomotives is one of the bases of safety and reliability of the rolling stock. The reduction of the wheel wear significantly reduces the operating costs of railway transport. After study completion it was found that there was no evidence to suggest that the ratio of the wheel-rail hardness could be the cause of the wheel surface crumbling.

  1. Fast-prototyping of VLSI

    International Nuclear Information System (INIS)

    Saucier, G.; Read, E.


    Fast-prototyping will be a reality in the very near future if both straightforward design methods and fast manufacturing facilities are available. This book focuses, first, on the motivation for fast-prototyping. Economic aspects and market considerations are analysed by European and Japanese companies. In the second chapter, new design methods are identified, mainly for full custom circuits. Of course, silicon compilers play a key role and the introduction of artificial intelligence techniques sheds a new light on the subject. At present, fast-prototyping on gate arrays or on standard cells is the most conventional technique and the third chapter updates the state-of-the art in this area. The fourth chapter concentrates specifically on the e-beam direct-writing for submicron IC technologies. In the fifth chapter, a strategic point in fast-prototyping, namely the test problem is addressed. The design for testability and the interface to the test equipment are mandatory to fulfill the test requirement for fast-prototyping. Finally, the last chapter deals with the subject of education when many people complain about the lack of use of fast-prototyping in higher education for VLSI

  2. The origin of the selectivity and activity of ruthenium-cluster catalysts for fuel-cell feed-gas purification: a gas-phase approach. (United States)

    Lang, Sandra M; Bernhardt, Thorsten M; Krstić, Marjan; Bonačić-Koutecký, Vlasta


    Gas-phase ruthenium clusters Ru(n)(+) (n=2-6) are employed as model systems to discover the origin of the outstanding performance of supported sub-nanometer ruthenium particles in the catalytic CO methanation reaction with relevance to the hydrogen feed-gas purification for advanced fuel-cell applications. Using ion-trap mass spectrometry in conjunction with first-principles density functional theory calculations three fundamental properties of these clusters are identified which determine the selectivity and catalytic activity: high reactivity toward CO in contrast to inertness in the reaction with CO2; promotion of cooperatively enhanced H2 coadsorption and dissociation on pre-formed ruthenium carbonyl clusters, that is, no CO poisoning occurs; and the presence of Ru-atom sites with a low number of metal-metal bonds, which are particularly active for H2 coadsorption and activation. Furthermore, comprehensive theoretical investigations provide mechanistic insight into the CO methanation reaction and discover a reaction route involving the formation of a formyl-type intermediate. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Hybrid Locomotion Evaluation for a Novel Amphibious Spherical Robot

    Directory of Open Access Journals (Sweden)

    Huiming Xing


    Full Text Available We describe the novel, multiply gaited, vectored water-jet, hybrid locomotion-capable, amphibious spherical robot III (termed ASR-III featuring a wheel-legged, water-jet composite driving system incorporating a lifting and supporting wheel mechanism (LSWM and mechanical legs with a water-jet thruster. The LSWM allows the ASR-III to support the body and slide flexibly on smooth (flat terrain. The composite driving system facilitates two on-land locomotion modes (sliding and walking and underwater locomotion mode with vectored thrusters, improving adaptability to the amphibious environment. Sliding locomotion improves the stability and maneuverability of ASR-III on smooth flat terrain, whereas walking locomotion allows ASR-III to conquer rough terrain. We used both forward and reverse kinematic models to evaluate the walking and sliding gait efficiency. The robot can also realize underwater locomotion with four vectored water-jet thrusters, and is capable of forward motion, heading angle control and depth control. We evaluated LSWM efficiency and the sliding velocities associated with varying extensions of the LSWM. To explore gait stability and mobility, we performed on-land experiments on smooth flat terrain to define the optimal stride length and frequency. We also evaluated the efficacy of waypoint tracking when the sliding gait was employed, using a closed-loop proportional-integral-derivative (PID control mechanism. Moreover, experiments of forward locomotion, heading angle control and depth control were conducted to verify the underwater performance of ASR-III. Comparison of the previous robot and ASR-III demonstrated the ASR-III had better amphibious motion performance.

  4. Human Locomotion in Hypogravity: From Basic Research to Clinical Applications

    Directory of Open Access Journals (Sweden)

    Francesco Lacquaniti


    Full Text Available We have considerable knowledge about the mechanisms underlying compensation of Earth gravity during locomotion, a knowledge obtained from physiological, biomechanical, modeling, developmental, comparative, and paleoanthropological studies. By contrast, we know much less about locomotion and movement in general under sustained hypogravity. This lack of information poses a serious problem for human space exploration. In a near future humans will walk again on the Moon and for the first time on Mars. It would be important to predict how they will move around, since we know that locomotion and mobility in general may be jeopardized in hypogravity, especially when landing after a prolonged weightlessness of the space flight. The combination of muscle weakness, of wearing a cumbersome spacesuit, and of maladaptive patterns of locomotion in hypogravity significantly increase the risk of falls and injuries. Much of what we currently know about locomotion in hypogravity derives from the video archives of the Apollo missions on the Moon, the experiments performed with parabolic flight or with body weight support on Earth, and the theoretical models. These are the topics of our review, along with the issue of the application of simulated hypogravity in rehabilitation to help patients with deambulation problems. We consider several issues that are common to the field of space science and clinical rehabilitation: the general principles governing locomotion in hypogravity, the methods used to reduce gravity effects on locomotion, the extent to which the resulting behavior is comparable across different methods, the important non-linearities of several locomotor parameters as a function of the gravity reduction, the need to use multiple methods to obtain reliable results, and the need to tailor the methods individually based on the physiology and medical history of each person.

  5. Human Locomotion in Hypogravity: From Basic Research to Clinical Applications (United States)

    Lacquaniti, Francesco; Ivanenko, Yury P.; Sylos-Labini, Francesca; La Scaleia, Valentina; La Scaleia, Barbara; Willems, Patrick A.; Zago, Myrka


    We have considerable knowledge about the mechanisms underlying compensation of Earth gravity during locomotion, a knowledge obtained from physiological, biomechanical, modeling, developmental, comparative, and paleoanthropological studies. By contrast, we know much less about locomotion and movement in general under sustained hypogravity. This lack of information poses a serious problem for human space exploration. In a near future humans will walk again on the Moon and for the first time on Mars. It would be important to predict how they will move around, since we know that locomotion and mobility in general may be jeopardized in hypogravity, especially when landing after a prolonged weightlessness of the space flight. The combination of muscle weakness, of wearing a cumbersome spacesuit, and of maladaptive patterns of locomotion in hypogravity significantly increase the risk of falls and injuries. Much of what we currently know about locomotion in hypogravity derives from the video archives of the Apollo missions on the Moon, the experiments performed with parabolic flight or with body weight support on Earth, and the theoretical models. These are the topics of our review, along with the issue of the application of simulated hypogravity in rehabilitation to help patients with deambulation problems. We consider several issues that are common to the field of space science and clinical rehabilitation: the general principles governing locomotion in hypogravity, the methods used to reduce gravity effects on locomotion, the extent to which the resulting behavior is comparable across different methods, the important non-linearities of several locomotor parameters as a function of the gravity reduction, the need to use multiple methods to obtain reliable results, and the need to tailor the methods individually based on the physiology and medical history of each person. PMID:29163225

  6. Stabilization of cat paw trajectory during locomotion. (United States)

    Klishko, Alexander N; Farrell, Bradley J; Beloozerova, Irina N; Latash, Mark L; Prilutsky, Boris I


    We investigated which of cat limb kinematic variables during swing of regular walking and accurate stepping along a horizontal ladder are stabilized by coordinated changes of limb segment angles. Three hypotheses were tested: 1) animals stabilize the entire swing trajectory of specific kinematic variables (performance variables); and 2) the level of trajectory stabilization is similar between regular and ladder walking and 3) is higher for forelimbs compared with hindlimbs. We used the framework of the uncontrolled manifold (UCM) hypothesis to quantify the structure of variance of limb kinematics in the limb segment orientation space across steps. Two components of variance were quantified for each potential performance variable, one of which affected it ("bad variance," variance orthogonal to the UCM, VORT) while the other one did not ("good variance," variance within the UCM, VUCM). The analysis of five candidate performance variables revealed that cats during both locomotor behaviors stabilize 1) paw vertical position during the entire swing (VUCM > VORT, except in mid-hindpaw swing of ladder walking) and 2) horizontal paw position in initial and terminal swing (except for the entire forepaw swing of regular walking). We also found that the limb length was typically stabilized in midswing, whereas limb orientation was not (VUCM ≤ VORT) for both limbs and behaviors during entire swing. We conclude that stabilization of paw position in early and terminal swing enables accurate and stable locomotion, while stabilization of vertical paw position in midswing helps paw clearance. This study is the first to demonstrate the applicability of the UCM-based analysis to nonhuman movement. Copyright © 2014 the American Physiological Society.

  7. Stabilization of cat paw trajectory during locomotion (United States)

    Klishko, Alexander N.; Farrell, Bradley J.; Beloozerova, Irina N.; Latash, Mark L.


    We investigated which of cat limb kinematic variables during swing of regular walking and accurate stepping along a horizontal ladder are stabilized by coordinated changes of limb segment angles. Three hypotheses were tested: 1) animals stabilize the entire swing trajectory of specific kinematic variables (performance variables); and 2) the level of trajectory stabilization is similar between regular and ladder walking and 3) is higher for forelimbs compared with hindlimbs. We used the framework of the uncontrolled manifold (UCM) hypothesis to quantify the structure of variance of limb kinematics in the limb segment orientation space across steps. Two components of variance were quantified for each potential performance variable, one of which affected it (“bad variance,” variance orthogonal to the UCM, VORT) while the other one did not (“good variance,” variance within the UCM, VUCM). The analysis of five candidate performance variables revealed that cats during both locomotor behaviors stabilize 1) paw vertical position during the entire swing (VUCM > VORT, except in mid-hindpaw swing of ladder walking) and 2) horizontal paw position in initial and terminal swing (except for the entire forepaw swing of regular walking). We also found that the limb length was typically stabilized in midswing, whereas limb orientation was not (VUCM ≤ VORT) for both limbs and behaviors during entire swing. We conclude that stabilization of paw position in early and terminal swing enables accurate and stable locomotion, while stabilization of vertical paw position in midswing helps paw clearance. This study is the first to demonstrate the applicability of the UCM-based analysis to nonhuman movement. PMID:24899676

  8. Locomotive syndrome in the elderly: translation, cultural adaptation, and Brazilian validation of the tool 25-Question Geriatric Locomotive Function Scale. (United States)

    Tavares, Daniela Regina Brandão; Santos, Fania Cristina

    The term Locomotive Syndrome refers to conditions in which the elderly are at high risk of inability to ambulate due to problems in locomotor system. For Locomotive Syndrome screening, the 25-Question Geriatric Locomotive Function Scale was created. The objective here was to translate, adapt culturally to Brazil, and study the psychometric properties of 25-Question Geriatric Locomotive Function Scale. The translation and cultural adaptation of 25-Question Geriatric Locomotive Function Scale were carried out, thus resulting in GLFS 25-P, whose psychometric properties were analyzed in a sample of 100 elderly subjects. Sociodemographic data on pain, falls, self-perceived health and basic and instrumental functionalities were determined. GLFS 25-P was applied three times: in one same day by two interviewers, and after 15 days, again by the first interviewer. GLFS 25-P showed a high internal consistency value according to Cronbach's alpha coefficient (0.942), and excellent reproducibility, according to intraclass correlation, with interobserver and intraobserver values of 97.6% and 98.4%, respectively (p<0.01). Agreements for each item of the instrument were considerable (between 0.248 and 0.673), according to Kappa statistic. In its validation, according to the Pearson's coefficient, regular and good correlations were obtained for the basic (BADL) and instrumental (IADL) activities of daily living, respectively (p<0.01). Statistically significant associations with chronic pain (p<0.001), falls (p=0.02) and self-perceived health (p<0.001) were found. A multivariate analysis showed a significantly higher risk of Locomotive Syndrome in the presence of chronic pain (OR 15.92, 95% CI 3.08-82.27) and with a worse self-perceived health (OR 0.23, 95% CI 0.07-0.79). GLFS 25-P proved to be a reliable and valid tool in Locomotive Syndrome screening for the elderly population. Copyright © 2016. Published by Elsevier Editora Ltda.

  9. Obstacle Avoidance in Groping Locomotion of a Humanoid Robot

    Directory of Open Access Journals (Sweden)

    Masahiro Ohka


    Full Text Available This paper describes the development of an autonomous obstacle-avoidance method that operates in conjunction with groping locomotion on the humanoid robot Bonten-Maru II. Present studies on groping locomotion consist of basic research in which humanoid robot recognizes its surroundings by touching and groping with its arm on the flat surface of a wall. The robot responds to the surroundings by performing corrections to its orientation and locomotion direction. During groping locomotion, however, the existence of obstacles within the correction area creates the possibility of collisions. The objective of this paper is to develop an autonomous method to avoid obstacles in the correction area by applying suitable algorithms to the humanoid robot's control system. In order to recognize its surroundings, six-axis force sensors were attached to both robotic arms as end effectors for force control. The proposed algorithm refers to the rotation angle of the humanoid robot's leg joints due to trajectory generation. The algorithm relates to the groping locomotion via the measured groping angle and motions of arms. Using Bonten-Maru II, groping experiments were conducted on a wall's surface to obtain wall orientation data. By employing these data, the humanoid robot performed the proposed method autonomously to avoid an obstacle present in the correction area. Results indicate that the humanoid robot can recognize the existence of an obstacle and avoid it by generating suitable trajectories in its legs.

  10. Two-fluid model for locomotion under self-confinement (United States)

    Reigh, Shang Yik; Lauga, Eric


    The bacterium Helicobacter pylori causes ulcers in the stomach of humans by invading mucus layers protecting epithelial cells. It does so by chemically changing the rheological properties of the mucus from a high-viscosity gel to a low-viscosity solution in which it may self-propel. We develop a two-fluid model for this process of swimming under self-generated confinement. We solve exactly for the flow and the locomotion speed of a spherical swimmer located in a spherically symmetric system of two Newtonian fluids whose boundary moves with the swimmer. We also treat separately the special case of an immobile outer fluid. In all cases, we characterize the flow fields, their spatial decay, and the impact of both the viscosity ratio and the degree of confinement on the locomotion speed of the model swimmer. The spatial decay of the flow retains the same power-law decay as for locomotion in a single fluid but with a decreased magnitude. Independent of the assumption chosen to characterize the impact of confinement on the actuation applied by the swimmer, its locomotion speed always decreases with an increase in the degree of confinement. Our modeling results suggest that a low-viscosity region of at least six times the effective swimmer size is required to lead to swimming with speeds similar to locomotion in an infinite fluid, corresponding to a region of size above ≈25 μ m for Helicobacter pylori.

  11. Prototypes in engineering design: Definitions and strategies

    DEFF Research Database (Denmark)

    Jensen, Lasse Skovgaard; Özkil, Ali Gürcan; Mortensen, Niels Henrik


    By reviewing literature, we investigate types, purposes and definitions of prototypes. There is no overarching definition of a prototype, but we identify five categories of prototypes in litterature. We further synthesize and reference previous work to create an overview of aspects in prototyping...

  12. Engineering prototypes for theta-pinch devices

    International Nuclear Information System (INIS)

    Hansborough, L.D.; Hammer, C.F.; Hanks, K.W.; McDonald, T.E.; Nunnally, W.C.


    Past, present, and future engineering prototypes for theta-pinch plasma-physics devices at Los Alamos Scientific Laboratory are discussed. Engineering prototypes are designed to test and evaluate all components under system conditions expected on actual plasma-physics experimental devices. The importance of engineering prototype development increases as the size and complexity of the plasma-physics device increases. Past experiences with the Scyllac prototype and the Staged Theta-Pinch prototype are discussed and evaluated. The design of the proposed Staged Scyllac prototype and the Large Staged Scyllac implosion prototype assembly are discussed

  13. Coupler dynamic performance analysis of heavy haul locomotives (United States)

    Ma, Weihua; Luo, Shihui; Song, Rongrong


    In this paper, a train dynamic model was developed to study the dynamic performance of heavy haul locomotives, taking into account the use of different coupler and buffer systems under conditions of severe longitudinal coupler compressive forces. The model consists of four locomotives each having 38 independent degrees of freedom and one dummy freight vehicle connected to each other by couplers and buffers. Simulation results showed that the longitudinal coupler compressive forces withstood by large rotation angle couplers with coupler shoulders were larger than those withstood by small rotation angle couplers. The results obtained for the large rotation angle coupler model showed that it had higher safety curve negotiation speeds. Due to the smaller static impedance, it was found that large capacity elastic clay (or cement) buffers cannot satisfy the requirement of heavy haul locomotives during cycle braking in long heavy downgraded tracks; the use of friction clay buffers can solve this problem.

  14. Postural dependence of human locomotion during gait initiation. (United States)

    Mille, Marie-Laure; Simoneau, Martin; Rogers, Mark W


    The initiation of human walking involves postural motor actions for body orientation and balance stabilization that must be effectively integrated with locomotion to allow safe and efficient transport. Our ability to coordinately adapt these functions to environmental or bodily changes through error-based motor learning is essential to effective performance. Predictive compensations for postural perturbations through anticipatory postural adjustments (APAs) that stabilize mediolateral (ML) standing balance normally precede and accompany stepping. The temporal sequencing between these events may involve neural processes that suppress stepping until the expected stability conditions are achieved. If so, then an unexpected perturbation that disrupts the ML APAs should delay locomotion. This study investigated how the central nervous system (CNS) adapts posture and locomotion to perturbations of ML standing balance. Healthy human adults initiated locomotion while a resistance force was applied at the pelvis to perturb posture. In experiment 1, using random perturbations, step onset timing was delayed relative to the APA onset indicating that locomotion was withheld until expected stability conditions occurred. Furthermore, stepping parameters were adapted with the APAs indicating that motor prediction of the consequences of the postural changes likely modified the step motor command. In experiment 2, repetitive postural perturbations induced sustained locomotor aftereffects in some parameters (i.e., step height), immediate but rapidly readapted aftereffects in others, or had no aftereffects. These results indicated both rapid but transient reactive adaptations in the posture and gait assembly and more durable practice-dependent changes suggesting feedforward adaptation of locomotion in response to the prevailing postural conditions. Copyright © 2014 the American Physiological Society.

  15. Dedicated Hippocampal Inhibitory Networks for Locomotion and Immobility. (United States)

    Arriaga, Moises; Han, Edward B


    Network activity is strongly tied to animal movement; however, hippocampal circuits selectively engaged during locomotion or immobility remain poorly characterized. Here we examined whether distinct locomotor states are encoded differentially in genetically defined classes of hippocampal interneurons. To characterize the relationship between interneuron activity and movement, we used in vivo , two-photon calcium imaging in CA1 of male and female mice, as animals performed a virtual-reality (VR) track running task. We found that activity in most somatostatin-expressing and parvalbumin-expressing interneurons positively correlated with locomotion. Surprisingly, nearly one in five somatostatin or one in seven parvalbumin interneurons were inhibited during locomotion and activated during periods of immobility. Anatomically, the somata of somatostatin immobility-activated neurons were smaller than those of movement-activated neurons. Furthermore, immobility-activated interneurons were distributed across cell layers, with somatostatin-expressing cells predominantly in stratum oriens and parvalbumin-expressing cells mostly in stratum pyramidale. Importantly, each cell's correlation between activity and movement was stable both over time and across VR environments. Our findings suggest that hippocampal interneuronal microcircuits are preferentially active during either movement or immobility periods. These inhibitory networks may regulate information flow in "labeled lines" within the hippocampus to process information during distinct behavioral states. SIGNIFICANCE STATEMENT The hippocampus is required for learning and memory. Movement controls network activity in the hippocampus but it's unclear how hippocampal neurons encode movement state. We investigated neural circuits active during locomotion and immobility and found interneurons were selectively active during movement or stopped periods, but not both. Each cell's response to locomotion was consistent across time

  16. Axure RP 6 Prototyping Essentials

    CERN Document Server

    Schwartz, Ezra


    Axure RP 6 Prototyping Essentials is a detailed, practical primer on the leading rapid prototyping tool. Short on jargon and high on concepts, real-life scenarios and step-by-step guidance through hands-on examples, this book will show you how to integrate Axure into your UX workflow. This book is written for UX practitioners, business analysts, product managers, and anyone else who is involved in UX projects. The book assumes that you have no or very little familiarity with Axure. It will help you if you are evaluating the tool for an upcoming project or are required to quickly get up to spee

  17. Soft swimming: exploiting deformable interfaces for low reynolds number locomotion. (United States)

    Trouilloud, Renaud; Yu, Tony S; Hosoi, A E; Lauga, Eric


    Reciprocal movement cannot be used for locomotion at low Reynolds number in an infinite fluid or near a rigid surface. Here we show that this limitation is relaxed for a body performing reciprocal motions near a deformable interface. Using physical arguments and scaling relationships, we show that the nonlinearities arising from reciprocal flow-induced interfacial deformation rectify the periodic motion of the swimmer, leading to locomotion. Such a strategy can be used to move toward, away from, and parallel to any deformable interface as long as the length scales involved are smaller than intrinsic scales, which we identify. A macroscale experiment of flapping motion near a free surface illustrates this new result.

  18. Economic aspects of advanced coal-fired gas turbine locomotives (United States)

    Liddle, S. G.; Bonzo, B. B.; Houser, B. C.


    Increases in the price of such conventional fuels as Diesel No. 2, as well as advancements in turbine technology, have prompted the present economic assessment of coal-fired gas turbine locomotive engines. A regenerative open cycle internal combustion gas turbine engine may be used, given the development of ceramic hot section components. Otherwise, an external combustion gas turbine engine appears attractive, since although its thermal efficiency is lower than that of a Diesel engine, its fuel is far less expensive. Attention is given to such a powerplant which will use a fluidized bed coal combustor. A life cycle cost analysis yields figures that are approximately half those typical of present locomotive engines.

  19. Decoding the organization of spinal circuits that control locomotion (United States)

    Kiehn, Ole


    Unravelling the functional operation of neuronal networks and linking cellular activity to specific behavioural outcomes are among the biggest challenges in neuroscience. In this broad field of research, substantial progress has been made in studies of the spinal networks that control locomotion. Through united efforts using electrophysiological and molecular genetic network approaches and behavioural studies in phylogenetically diverse experimental models, the organization of locomotor networks has begun to be decoded. The emergent themes from this research are that the locomotor networks have a modular organization with distinct transmitter and molecular codes and that their organization is reconfigured with changes to the speed of locomotion or changes in gait. PMID:26935168

  20. A Specific Population of Reticulospinal Neurons Controls the Termination of Locomotion


    Juvin, Laurent; Grätsch, Swantje; Trillaud-Doppia, Emilie; Gariépy, Jean-François; Büschges, Ansgar; Dubuc, Réjean


    Locomotion requires the proper sequencing of neural activity to start, maintain, and stop it. Recently, brainstem neurons were shown to specifically stop locomotion in mammals. However, the cellular properties of these neurons and their activity during locomotion are still unknown. Here, we took advantage of the lamprey model to characterize the activity of a cell population that we now show to be involved in stopping locomotion. We find that these neurons display a burst of spikes that coinc...

  1. Encapsulation of polymer photovoltaic prototypes

    DEFF Research Database (Denmark)

    Krebs, Frederik C


    A simple and efficient method for the encapsulation of polymer and organic photovoltaic prototypes is presented. The method employs device preparation on glass substrates with subsequent sealing using glass fiber reinforced thermosetting epoxy (prepreg) against a back plate. The method allows...

  2. Joint Battlespace Infosphere Repository Prototype

    National Research Council Canada - National Science Library

    McCabe, Patrick


    .... The approach was to leverage in-house research and development for repository design and core service definition as points of departure for a far term design. Several repository software packages were evaluated to aid in the definition of the design space for the JBI repository prototype.

  3. NMS Prototype development final report

    International Nuclear Information System (INIS)

    Lepetich, J.E.


    Program for development of NMS prototype for LAMPF consisted of 5 tasks: crystal procurement specification, inspection/evaluation of CsI crystals, design/fabrication of crystal housing, design/fabrication of PMT shields, and packaging of crystals in the housing

  4. Facial Prototype Formation in Children. (United States)

    Inn, Donald; And Others

    This study examined memory representation as it is exhibited in young children's formation of facial prototypes. In the first part of the study, researchers constructed images of faces using an Identikit that provided the features of hair, eyes, mouth, nose, and chin. Images were varied systematically. A series of these images, called exemplar…

  5. 49 CFR 223.17 - Identification of equipped locomotives, passenger cars and cabooses. (United States)


    ... cars and cabooses. 223.17 Section 223.17 Transportation Other Regulations Relating to Transportation...-LOCOMOTIVES, PASSENGER CARS AND CABOOSES Specific Requirements § 223.17 Identification of equipped locomotives, passenger cars and cabooses. Each locomotive, passenger car and caboose that is fully equipped with glazing...

  6. Prototyping of user interfaces for mobile applications

    CERN Document Server

    Bähr, Benjamin


    This book investigates processes for the prototyping of user interfaces for mobile apps, and describes the development of new concepts and tools that can improve the prototype driven app development in the early stages. It presents the development and evaluation of a new requirements catalogue for prototyping mobile app tools that identifies the most important criteria such tools should meet at different prototype-development stages. This catalogue is not just a good point of orientation for designing new prototyping approaches, but also provides a set of metrics for a comparing the performance of alternative prototyping tools. In addition, the book discusses the development of Blended Prototyping, a new approach for prototyping user interfaces for mobile applications in the early and middle development stages, and presents the results of an evaluation of its performance, showing that it provides a tool for teamwork-oriented, creative prototyping of mobile apps in the early design stages.

  7. Prototype Effect and the Persuasiveness of Generalizations. (United States)

    Dahlman, Christian; Sarwar, Farhan; Bååth, Rasmus; Wahlberg, Lena; Sikström, Sverker

    An argument that makes use of a generalization activates the prototype for the category used in the generalization. We conducted two experiments that investigated how the activation of the prototype affects the persuasiveness of the argument. The results of the experiments suggest that the features of the prototype overshadow and partly overwrite the actual facts of the case. The case is, to some extent, judged as if it had the features of the prototype instead of the features it actually has. This prototype effect increases the persuasiveness of the argument in situations where the audience finds the judgment more warranted for the prototype than for the actual case (positive prototype effect), but decreases persuasiveness in situations where the audience finds the judgment less warranted for the prototype than for the actual case (negative prototype effect).

  8. Prototype diagnosis of psychiatric syndromes (United States)



    The method of diagnosing patients used since the early 1980s in psychiatry, which involves evaluating each of several hundred symptoms for their presence or absence and then applying idiosyncratic rules for combining them for each of several hundred disorders, has led to great advances in research over the last 30 years. However, its problems have become increasingly apparent, particularly for clinical practice. An alternative approach, designed to maximize clinical utility, is prototype matching. Instead of counting symptoms of a disorder and determining whether they cross an arbitrary cutoff, the task of the diagnostician is to gauge the extent to which a patient’s clinical presentation matches a paragraph-length description of the disorder using a simple 5-point scale, from 1 (“little or no match”) to 5 (“very good match”). The result is both a dimensional diagnosis that captures the extent to which the patient “has” the disorder and a categorical diagnosis, with ratings of 4 and 5 corresponding to presence of the disorder and a rating of 3 indicating “subthreshold” or “clinically significant features”. The disorders and criteria woven into the prototypes can be identified empirically, so that the prototypes are both scientifically grounded and clinically useful. Prototype diagnosis has a number of advantages: it better captures the way humans naturally classify novel and complex stimuli; is clinically helpful, reliable, and easy to use in everyday practice; facilitates both dimensional and categorical diagnosis and dramatically reduces the number of categories required for classification; allows for clinically richer, empirically derived, and culturally relevant classification; reduces the gap between research criteria and clinical knowledge, by allowing clinicians in training to learn a small set of standardized prototypes and to develop richer mental representations of the disorders over time through clinical experience; and can help

  9. Small-scale soft-bodied robot with multimodal locomotion (United States)

    Hu, Wenqi; Lum, Guo Zhan; Mastrangeli, Massimo; Sitti, Metin


    Untethered small-scale (from several millimetres down to a few micrometres in all dimensions) robots that can non-invasively access confined, enclosed spaces may enable applications in microfactories such as the construction of tissue scaffolds by robotic assembly, in bioengineering such as single-cell manipulation and biosensing, and in healthcare such as targeted drug delivery and minimally invasive surgery. Existing small-scale robots, however, have very limited mobility because they are unable to negotiate obstacles and changes in texture or material in unstructured environments. Of these small-scale robots, soft robots have greater potential to realize high mobility via multimodal locomotion, because such machines have higher degrees of freedom than their rigid counterparts. Here we demonstrate magneto-elastic soft millimetre-scale robots that can swim inside and on the surface of liquids, climb liquid menisci, roll and walk on solid surfaces, jump over obstacles, and crawl within narrow tunnels. These robots can transit reversibly between different liquid and solid terrains, as well as switch between locomotive modes. They can additionally execute pick-and-place and cargo-release tasks. We also present theoretical models to explain how the robots move. Like the large-scale robots that can be used to study locomotion, these soft small-scale robots could be used to study soft-bodied locomotion produced by small organisms.

  10. Using Computational and Mechanical Models to Study Animal Locomotion (United States)

    Miller, Laura A.; Goldman, Daniel I.; Hedrick, Tyson L.; Tytell, Eric D.; Wang, Z. Jane; Yen, Jeannette; Alben, Silas


    Recent advances in computational methods have made realistic large-scale simulations of animal locomotion possible. This has resulted in numerous mathematical and computational studies of animal movement through fluids and over substrates with the purpose of better understanding organisms’ performance and improving the design of vehicles moving through air and water and on land. This work has also motivated the development of improved numerical methods and modeling techniques for animal locomotion that is characterized by the interactions of fluids, substrates, and structures. Despite the large body of recent work in this area, the application of mathematical and numerical methods to improve our understanding of organisms in the context of their environment and physiology has remained relatively unexplored. Nature has evolved a wide variety of fascinating mechanisms of locomotion that exploit the properties of complex materials and fluids, but only recently are the mathematical, computational, and robotic tools available to rigorously compare the relative advantages and disadvantages of different methods of locomotion in variable environments. Similarly, advances in computational physiology have only recently allowed investigators to explore how changes at the molecular, cellular, and tissue levels might lead to changes in performance at the organismal level. In this article, we highlight recent examples of how computational, mathematical, and experimental tools can be combined to ultimately answer the questions posed in one of the grand challenges in organismal biology: “Integrating living and physical systems.” PMID:22988026

  11. Decoding bipedal locomotion from the rat sensorimotor cortex

    NARCIS (Netherlands)

    Rigosa, J.; Panarese, A.; Dominici, N.; Friedli, L.; van den Brand, R.; Carpaneto, J.; DiGiovanna, J.; Courtine, G.; Micera, S.


    Objective. Decoding forelimb movements from the firing activity of cortical neurons has been interfaced with robotic and prosthetic systems to replace lost upper limb functions in humans. Despite the potential of this approach to improve locomotion and facilitate gait rehabilitation, decoding lower

  12. Locomotion and basicranial anatomy in primates and marsupials. (United States)

    Villamil, Catalina I


    There is ongoing debate in paleoanthropology about whether and how the anatomy of the cranium, and especially the cranial base, is evolving in response to locomotor and postural changes. However, the majority of studies focus on two-dimensional data, which fails to capture the complexity of cranial anatomy. This study tests whether three-dimensional cranial base anatomy is linked to locomotion or to other factors in primates (n = 473) and marsupials (n = 231). Results indicate that although there is a small effect of locomotion on cranial base anatomy in primates, this is not the case in marsupials. Instead, facial anatomy likely drives variation in cranial base anatomy in both primates and marsupials, with additional roles for body size and brain size. Although some changes to foramen magnum position and orientation are phylogenetically useful among the hominoids, they do not necessarily reflect locomotion or positional behavior. The interplay between locomotion, posture, and facial anatomy in primates requires further investigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Energetic extremes in aquatic locomotion by coral reef fishes. (United States)

    Fulton, Christopher J; Johansen, Jacob L; Steffensen, John F


    Underwater locomotion is challenging due to the high friction and resistance imposed on a body moving through water and energy lost in the wake during undulatory propulsion. While aquatic organisms have evolved streamlined shapes to overcome such resistance, underwater locomotion has long been considered a costly exercise. Recent evidence for a range of swimming vertebrates, however, has suggested that flapping paired appendages around a rigid body may be an extremely efficient means of aquatic locomotion. Using intermittent flow-through respirometry, we found exceptional energetic performance in the Bluelined wrasse Stethojulis bandanensis, which maintains tuna-like optimum cruising speeds (up to 1 metre s(-1)) while using 40% less energy than expected for their body size. Displaying an exceptional aerobic scope (22-fold above resting), streamlined rigid-body posture, and wing-like fins that generate lift-based thrust, S. bandanensis literally flies underwater to efficiently maintain high optimum swimming speeds. Extreme energetic performance may be key to the colonization of highly variable environments, such as the wave-swept habitats where S. bandanensis and other wing-finned species tend to occur. Challenging preconceived notions of how best to power aquatic locomotion, biomimicry of such lift-based fin movements could yield dramatic reductions in the power needed to propel underwater vehicles at high speed.

  14. Scaling in Theropod Dinosaurs: Femoral Bone Strength and Locomotion II (United States)

    Lee, Scott


    In the second paper of this series, the effect of transverse femoral stresses due to locomotion in theropod dinosaurs of different sizes was examined for the case of an unchanging leg geometry. Students are invariably thrilled to learn about theropod dinosaurs, and this activity applies the concepts of torque and stress to the issue of theropod…

  15. Scaling in Theropod Dinosaurs: Femoral Bone Strength and Locomotion (United States)

    Lee, Scott


    In our first article on scaling in theropod dinosaurs, the longitudinal stress in the leg bones due to supporting the weight of the animal was studied and found not to control the dimensions of the femur. As a continuation of our study of elasticity in dinosaur bones, we now examine the transverse stress in the femur due to locomotion and find…

  16. Energetic extremes in aquatic locomotion by coral reef fishes.

    Directory of Open Access Journals (Sweden)

    Christopher J Fulton

    Full Text Available Underwater locomotion is challenging due to the high friction and resistance imposed on a body moving through water and energy lost in the wake during undulatory propulsion. While aquatic organisms have evolved streamlined shapes to overcome such resistance, underwater locomotion has long been considered a costly exercise. Recent evidence for a range of swimming vertebrates, however, has suggested that flapping paired appendages around a rigid body may be an extremely efficient means of aquatic locomotion. Using intermittent flow-through respirometry, we found exceptional energetic performance in the Bluelined wrasse Stethojulis bandanensis, which maintains tuna-like optimum cruising speeds (up to 1 metre s(-1 while using 40% less energy than expected for their body size. Displaying an exceptional aerobic scope (22-fold above resting, streamlined rigid-body posture, and wing-like fins that generate lift-based thrust, S. bandanensis literally flies underwater to efficiently maintain high optimum swimming speeds. Extreme energetic performance may be key to the colonization of highly variable environments, such as the wave-swept habitats where S. bandanensis and other wing-finned species tend to occur. Challenging preconceived notions of how best to power aquatic locomotion, biomimicry of such lift-based fin movements could yield dramatic reductions in the power needed to propel underwater vehicles at high speed.

  17. Dynamics and locomotion of flexible foils in a frictional environment (United States)

    Wang, Xiaolin; Alben, Silas


    Over the past few decades, oscillating flexible foils have been used to study the physics of organismal propulsion in different fluid environments. Here, we extend this work to a study of flexible foils in a frictional environment. When the foil is oscillated by heaving at one end but is not free to locomote, the dynamics change from periodic to non-periodic and chaotic as the heaving amplitude increases or the bending rigidity decreases. For friction coefficients lying in a certain range, the transition passes through a sequence of N-periodic and asymmetric states before reaching chaotic dynamics. Resonant peaks are damped and shifted by friction and large heaving amplitudes, leading to bistable states. When the foil is free to locomote, the horizontal motion smoothes the resonant behaviours. For moderate frictional coefficients, steady but slow locomotion is obtained. For large transverse friction and small tangential friction corresponding to wheeled snake robots, faster locomotion is obtained. Travelling wave motions arise spontaneously, and move with horizontal speeds that scale as transverse friction coefficient to the power 1/4 and input power that scales as the transverse friction coefficient to the power 5/12. These scalings are consistent with a boundary layer form of the solutions near the foil's leading edge.

  18. 49 CFR 231.30 - Locomotives used in switching service. (United States)


    ... classification of cars according to commodity or destination; assembling of cars for train movements; changing... locomotives built after March 31, 1977. (5) Material. (i) Steel or other material of equivalent or better... March 31, 1977, each vertical handhold must— (i) Be constructed of wrought iron, steel or other material...

  19. Energetic Extremes in Aquatic Locomotion by Coral Reef Fishes (United States)

    Fulton, Christopher J.; Johansen, Jacob L.; Steffensen, John F.


    Underwater locomotion is challenging due to the high friction and resistance imposed on a body moving through water and energy lost in the wake during undulatory propulsion. While aquatic organisms have evolved streamlined shapes to overcome such resistance, underwater locomotion has long been considered a costly exercise. Recent evidence for a range of swimming vertebrates, however, has suggested that flapping paired appendages around a rigid body may be an extremely efficient means of aquatic locomotion. Using intermittent flow-through respirometry, we found exceptional energetic performance in the Bluelined wrasse Stethojulis bandanensis, which maintains tuna-like optimum cruising speeds (up to 1 metre s−1) while using 40% less energy than expected for their body size. Displaying an exceptional aerobic scope (22-fold above resting), streamlined rigid-body posture, and wing-like fins that generate lift-based thrust, S. bandanensis literally flies underwater to efficiently maintain high optimum swimming speeds. Extreme energetic performance may be key to the colonization of highly variable environments, such as the wave-swept habitats where S. bandanensis and other wing-finned species tend to occur. Challenging preconceived notions of how best to power aquatic locomotion, biomimicry of such lift-based fin movements could yield dramatic reductions in the power needed to propel underwater vehicles at high speed. PMID:23326566

  20. Application of flywheel energy storage for heavy haul locomotives

    International Nuclear Information System (INIS)

    Spiryagin, Maksym; Wolfs, Peter; Szanto, Frank; Sun, Yan Quan; Cole, Colin; Nielsen, Dwayne


    Highlights: • A novel design for heavy haul locomotive equipped with a flywheel energy storage system is proposed. • The integrated intelligent traction control system was developed. • A flywheel energy storage system has been tested through a simulation process. • The developed hybrid system was verified using an existing heavy haul railway route. • Fuel efficiency analysis confirms advantages of the hybrid design. - Abstract: At the present time, trains in heavy haul operations are typically hauled by several diesel-electric locomotives coupled in a multiple unit. This paper studies the case of a typical consist of three Co–Co diesel-electric locomotives, and considers replacing one unit with an alternative version, with the same design parameters, except that the diesel-electric plant is replaced with flywheel energy storage equipment. The intelligent traction and energy control system installed in this unit is integrated into the multiple-unit control to allow redistribution of the power between all units. In order to verify the proposed design, a three-stage investigation has been performed as described in this paper. The initial stage studies a possible configuration of the flywheel energy storage system by detailed modelling of the proposed intelligent traction and energy control system. The second stage includes the investigation and estimation of possible energy flows using a longitudinal train dynamics simulation. The final stage compares the conventional and the proposed locomotive configurations considering two parameters: fuel efficiency and emissions reduction.

  1. Physical fitness, nutritional habits and daily locomotive action of 12 ...

    African Journals Online (AJOL)

    Objective. The purpose of this study was to examine the differences in physical fitness, daily nutritional habits and locomotive behaviour among pupils with varying body mass index (BMI) in the 5th and 6th grades of primary school. Design. The sample consisted of 480 pupils (229 boys and 251 girls), who participated in ...

  2. Transmembrane channel-like (tmc) gene regulates Drosophila larval locomotion. (United States)

    Guo, Yanmeng; Wang, Yuping; Zhang, Wei; Meltzer, Shan; Zanini, Damiano; Yu, Yue; Li, Jiefu; Cheng, Tong; Guo, Zhenhao; Wang, Qingxiu; Jacobs, Julie S; Sharma, Yashoda; Eberl, Daniel F; Göpfert, Martin C; Jan, Lily Yeh; Jan, Yuh Nung; Wang, Zuoren


    Drosophila larval locomotion, which entails rhythmic body contractions, is controlled by sensory feedback from proprioceptors. The molecular mechanisms mediating this feedback are little understood. By using genetic knock-in and immunostaining, we found that the Drosophila melanogaster transmembrane channel-like (tmc) gene is expressed in the larval class I and class II dendritic arborization (da) neurons and bipolar dendrite (bd) neurons, both of which are known to provide sensory feedback for larval locomotion. Larvae with knockdown or loss of tmc function displayed reduced crawling speeds, increased head cast frequencies, and enhanced backward locomotion. Expressing Drosophila TMC or mammalian TMC1 and/or TMC2 in the tmc-positive neurons rescued these mutant phenotypes. Bending of the larval body activated the tmc-positive neurons, and in tmc mutants this bending response was impaired. This implicates TMC's roles in Drosophila proprioception and the sensory control of larval locomotion. It also provides evidence for a functional conservation between Drosophila and mammalian TMCs.

  3. Neurovascular coupling and decoupling in the cortex during voluntary locomotion. (United States)

    Huo, Bing-Xing; Smith, Jared B; Drew, Patrick J


    Hemodynamic signals are widely used to infer neural activity in the brain. We tested the hypothesis that hemodynamic signals faithfully report neural activity during voluntary behaviors by measuring cerebral blood volume (CBV) and neural activity in the somatosensory cortex and frontal cortex of head-fixed mice during locomotion. Locomotion induced a large and robust increase in firing rate and gamma-band (40-100 Hz) power in the local field potential in the limb representations in somatosensory cortex, and was accompanied by increases in CBV, demonstrating that hemodynamic signals are coupled with neural activity in this region. However, in the frontal cortex, CBV did not change during locomotion, but firing rate and gamma-band power both increased, indicating a decoupling of neural activity from the hemodynamic signal. These results show that hemodynamic signals are not faithful indicators of the mean neural activity in the frontal cortex during locomotion; thus, the results from fMRI and other hemodynamic imaging methodologies for studying neural processes must be interpreted with caution. Copyright © 2014 the authors 0270-6474/14/3410975-07$15.00/0.

  4. Locomotion in Stroke Subjects: Interactions between Unaffected and Affected Sides (United States)

    Kloter, Evelyne; Wirz, Markus; Dietz, Volker


    The aim of this study was to evaluate the sensorimotor interactions between unaffected and affected sides of post-stroke subjects during locomotion. In healthy subjects, stimulation of the tibial nerve during the mid-stance phase is followed by electromyography responses not only in the ipsilateral tibialis anterior, but also in the proximal arm…

  5. Using Jacqueline Woodson's "Locomotion" with Middle School Readers (United States)

    Napoli, Mary; Ritholz, Emily Rose


    Motivation is an essential component in developing a love of reading in middle level struggling students. For these readers, novels in verse bridge the gap to more challenging pieces of literature. In this article, Title One students explored Locomotion by Jacqueline Woodson and learned that they, too, are poets. (Contains 9 figures.)

  6. A Method for Locomotion Mode Identification Using Muscle Synergies. (United States)

    Afzal, Taimoor; Iqbal, Kamran; White, Gannon; Wright, Andrew B


    Active lower limb transfemoral prostheses have enabled amputees to perform different locomotion modes such as walking, stair ascent, stair descent, ramp ascent and ramp descent. To achieve seamless mode transitions, these devices either rely on neural information from the amputee's residual limbs or sensors attached to the prosthesis to identify the intended locomotion modes or both. We present an approach for classification of locomotion modes based on the framework of muscle synergies underlying electromyography signals. Neural information at the critical instances (e.g., heel contact and toe-off) was decoded for this purpose. Non-negative matrix factorization was used to extract the muscles synergies from the muscle feature matrix. The estimation of the neural command was done using non-negative least squares. The muscle synergy approach was compared with linear discriminant analysis (LDA), support vector machine (SVM), and neural network (NN) and was tested on seven able-bodied subjects. There was no significant difference ( p > 0.05 ) in transitional and steady state classification errors during stance phase. The muscle synergy approach performed significantly better ( ) than NN and LDA during swing phase while results were similar to SVM. These results suggest that the muscle synergy approach can be used to discriminate between locomotion modes involving transitions.

  7. Tractable Quantification of Metastability for Robust Bipedal Locomotion (United States)


    Mathematics GPA 4.0/4.0 2007-2011 Sabanci University, Istanbul B.S. in Mechatronics Engineering Minor in Mathematics GPA 3.88/4.0 Major GPA: 3.96/4.00...on Mechatronics (ICM), pages 997-1002, April 2011. viii Abstract Tractable Quantification of Metastability for Robust Bipedal Locomotion by Cenk Oguz

  8. Using computational and mechanical models to study animal locomotion. (United States)

    Miller, Laura A; Goldman, Daniel I; Hedrick, Tyson L; Tytell, Eric D; Wang, Z Jane; Yen, Jeannette; Alben, Silas


    Recent advances in computational methods have made realistic large-scale simulations of animal locomotion possible. This has resulted in numerous mathematical and computational studies of animal movement through fluids and over substrates with the purpose of better understanding organisms' performance and improving the design of vehicles moving through air and water and on land. This work has also motivated the development of improved numerical methods and modeling techniques for animal locomotion that is characterized by the interactions of fluids, substrates, and structures. Despite the large body of recent work in this area, the application of mathematical and numerical methods to improve our understanding of organisms in the context of their environment and physiology has remained relatively unexplored. Nature has evolved a wide variety of fascinating mechanisms of locomotion that exploit the properties of complex materials and fluids, but only recently are the mathematical, computational, and robotic tools available to rigorously compare the relative advantages and disadvantages of different methods of locomotion in variable environments. Similarly, advances in computational physiology have only recently allowed investigators to explore how changes at the molecular, cellular, and tissue levels might lead to changes in performance at the organismal level. In this article, we highlight recent examples of how computational, mathematical, and experimental tools can be combined to ultimately answer the questions posed in one of the grand challenges in organismal biology: "Integrating living and physical systems."

  9. Prototypical Rod Consolidation Demonstration Project

    International Nuclear Information System (INIS)


    The objective of Phase 3 of the Prototypical Rod consolidation Demonstration Project (PRCDP) was to procure, fabricate, assemble, and test the Prototypical Rod consolidation System as described in the NUS Phase 2 Final Design Report. This effort required providing the materials, components, and fabricated parts which makes up all of the system equipment. In addition, it included the assembly, installation, and setup of this equipment at the Cold Test Facility. During the Phase 3 effort the system was tested on a component, subsystem, and system level. This volume 1, discusses the PRCDP Phase 3 Test Program that was conducted by the HALLIBURTON NUS Environmental Corporation under contract AC07-86ID12651 with the United States Department of Energy. This document, Volume 1, Book 1 discusses the following topics: the background of the project; test program description; summary of tests and test results; problem evaluation; functional requirements confirmation; recommendations; and completed test documentation for tests performed in Phase 3

  10. Prototypical Rod Consolidation Demonstration Project

    International Nuclear Information System (INIS)


    The objective of Phase 3 of the Prototypical Rod consolidation Demonstration Project (PRCDP) was to procure, fabricate, assemble, and test the Prototypical Rod consolidation System as described in the NUS Phase 2 Final Design Report. This effort required providing the materials, components, and fabricated parts which makes up all of the system equipment. In addition, it included the assembly, installation, and setup of this equipment at the Cold Test Facility. During the Phase 3 effort the system was tested on a component, subsystem, and system level. This volume 1, discusses the PRCDP Phase 3 Test Program that was conducted by the HALLIBURTON NUS Environmental Corporation under contract AC07-86ID12651 with the United States Department of Energy. This document, Volume 1, Book 9 discusses the following topics: Integrated System Normal Operations Test Results and Analysis Report; Integrated System Off-Normal Operations Test Results and Analysis Report; and Integrated System Maintenance Operations Test Results and Analysis Report

  11. Customer-experienced rapid prototyping (United States)

    Zhang, Lijuan; Zhang, Fu; Li, Anbo


    In order to describe accurately and comprehend quickly the perfect GIS requirements, this article will integrate the ideas of QFD (Quality Function Deployment) and UML (Unified Modeling Language), and analyze the deficiency of prototype development model, and will propose the idea of the Customer-Experienced Rapid Prototyping (CE-RP) and describe in detail the process and framework of the CE-RP, from the angle of the characteristics of Modern-GIS. The CE-RP is mainly composed of Customer Tool-Sets (CTS), Developer Tool-Sets (DTS) and Barrier-Free Semantic Interpreter (BF-SI) and performed by two roles of customer and developer. The main purpose of the CE-RP is to produce the unified and authorized requirements data models between customer and software developer.

  12. Prototypical Rod Consolidation Demonstration Project

    International Nuclear Information System (INIS)


    The objective of Phase 3 of the Prototypical Rod consolidation Demonstration Project (PRCDP) was to procure, fabricate, assemble, and test the Prototypical Rod consolidation System as described in the NUS Phase 2 Final Design Report. This effort required providing the materials, components, and fabricated parts which makes up all of the system equipment. In addition, it included the assembly, installation, and setup of this equipment at the Cold Test Facility. During the Phase 3 effort the system was tested on a component, subsystem, and system level. This volume 1, discusses the PRCDP Phase 3 Test Program that was conducted by the HALLIBURTON NUS Environmental Corporation under contract AC07-86ID12651 with the United States Department of Energy. This document, Volume 1, Book 2 discusses the following topics: Fuel Rod Extraction System Test Results and Analysis Reports and Clamping Table Test Results and Analysis Reports

  13. Prototype of sun projector device (United States)

    Ihsan; Dermawan, B.


    One way to introduce astronomy to public, including students, can be handled by solar observation. The widely held device for this purpose is coelostat and heliostat. Besides using filter attached to a device such as telescope, it is safest to use indirect way for observing the Sun. The main principle of the indirect way is deflecting the sun light and projecting image of the sun on a screen. We design and build a simple and low-cost astronomical device, serving as a supplement to increase public service, especially for solar observation. Without using any digital and intricate supporting equipment, people can watch and relish image of the Sun in comfortable condition, i.e. in a sheltered or shady place. Here we describe a design and features of our prototype of the device, which still, of course, has some limitations. In the future, this prototype can be improved for more efficient and useful applications.

  14. Prototyping the PANDA Barrel DIRC

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, C., E-mail: [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Kalicy, G.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwiening, J.; Traxler, M.; Zühlsdorf, M. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany); Dodokhov, V.Kh. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Britting, A.; Eyrich, W.; Lehmann, A. [Friedrich Alexander-University of Erlangen-Nuremberg, Erlangen (Germany); and others


    The design of the Barrel DIRC detector for the future PANDA experiment at FAIR contains several important improvements compared to the successful BABAR DIRC, such as focusing and fast timing. To test those improvements as well as other design options a prototype was build and successfully tested in 2012 with particle beams at CERN. The prototype comprises a radiator bar, focusing lens, mirror, and a prism shaped expansion volume made of synthetic fused silica. An array of micro-channel plate photomultiplier tubes measures the location and arrival time of the Cherenkov photons with sub-nanosecond resolution. The development of a fast reconstruction algorithm allowed to tune construction details of the detector setup with test beam data and Monte-Carlo simulations.

  15. JUNO PMT system and prototyping (United States)

    Wang, Zhimin; JUNO Collaboration


    The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose underground experiment and the largest liquid scintillator (LS) detector going for neutrino mass hierarchy, precise neutrino oscillation parameter measurement and studies of other rare processes, including but not limited to, solar neutrino, geo-neutrino, supernova neutrinos and the diffuse supernova neutrinos background. The 20” PMT system with ∼17000 high quantum efficiency tubes, including Hamamatsu 20” and newly developed MCP 20” tubes, is one of the keys of JUNO experiment for better energy resolution, good detector response etc. We are doing prototypes for PMTs, detectors to study/understand more detailed characteristics of the future detector. Here plans to give you a full view about the JUNO PMT system and its prototyping, including the PMT system layout, PMT testing system design, PMT water proof potting with electronics, installation ideas and the basics PMT performance.

  16. A locomotion intent prediction system based on multi-sensor fusion. (United States)

    Chen, Baojun; Zheng, Enhao; Wang, Qining


    Locomotion intent prediction is essential for the control of powered lower-limb prostheses to realize smooth locomotion transitions. In this research, we develop a multi-sensor fusion based locomotion intent prediction system, which can recognize current locomotion mode and detect locomotion transitions in advance. Seven able-bodied subjects were recruited for this research. Signals from two foot pressure insoles and three inertial measurement units (one on the thigh, one on the shank and the other on the foot) are measured. A two-level recognition strategy is used for the recognition with linear discriminate classifier. Six kinds of locomotion modes and ten kinds of locomotion transitions are tested in this study. Recognition accuracy during steady locomotion periods (i.e., no locomotion transitions) is 99.71% ± 0.05% for seven able-bodied subjects. During locomotion transition periods, all the transitions are correctly detected and most of them can be detected before transiting to new locomotion modes. No significant deterioration in recognition performance is observed in the following five hours after the system is trained, and small number of experiment trials are required to train reliable classifiers.

  17. DOE's annealing prototype demonstration projects

    International Nuclear Information System (INIS)

    Warren, J.; Nakos, J.; Rochau, G.


    One of the challenges U.S. utilities face in addressing technical issues associated with the aging of nuclear power plants is the long-term effect of plant operation on reactor pressure vessels (RPVs). As a nuclear plant operates, its RPV is exposed to neutrons. For certain plants, this neutron exposure can cause embrittlement of some of the RPV welds which can shorten the useful life of the RPV. This RPV embrittlement issue has the potential to affect the continued operation of a number of operating U.S. pressurized water reactor (PWR) plants. However, RPV material properties affected by long-term irradiation are recoverable through a thermal annealing treatment of the RPV. Although a dozen Russian-designed RPVs and several U.S. military vessels have been successfully annealed, U.S. utilities have stated that a successful annealing demonstration of a U.S. RPV is a prerequisite for annealing a licensed U.S. nuclear power plant. In May 1995, the Department of Energy's Sandia National Laboratories awarded two cost-shared contracts to evaluate the feasibility of annealing U.S. licensed plants by conducting an anneal of an installed RPV using two different heating technologies. The contracts were awarded to the American Society of Mechanical Engineers (ASME) Center for Research and Technology Development (CRTD) and MPR Associates (MPR). The ASME team completed its annealing prototype demonstration in July 1996, using an indirect gas furnace at the uncompleted Public Service of Indiana's Marble Hill nuclear power plant. The MPR team's annealing prototype demonstration was scheduled to be completed in early 1997, using a direct heat electrical furnace at the uncompleted Consumers Power Company's nuclear power plant at Midland, Michigan. This paper describes the Department's annealing prototype demonstration goals and objectives; the tasks, deliverables, and results to date for each annealing prototype demonstration; and the remaining annealing technology challenges

  18. Prototype Morphing Fan Nozzle Demonstrated (United States)

    Lee, Ho-Jun; Song, Gang-Bing


    Ongoing research in NASA Glenn Research Center's Structural Mechanics and Dynamics Branch to develop smart materials technologies for aeropropulsion structural components has resulted in the design of the prototype morphing fan nozzle shown in the photograph. This prototype exploits the potential of smart materials to significantly improve the performance of existing aircraft engines by introducing new inherent capabilities for shape control, vibration damping, noise reduction, health monitoring, and flow manipulation. The novel design employs two different smart materials, a shape-memory alloy and magnetorheological fluids, to reduce the nozzle area by up to 30 percent. The prototype of the variable-area fan nozzle implements an overlapping spring leaf assembly to simplify the initial design and to provide ease of structural control. A single bundle of shape memory alloy wire actuators is used to reduce the nozzle geometry. The nozzle is subsequently held in the reduced-area configuration by using magnetorheological fluid brakes. This prototype uses the inherent advantages of shape memory alloys in providing large induced strains and of magnetorheological fluids in generating large resistive forces. In addition, the spring leaf design also functions as a return spring, once the magnetorheological fluid brakes are released, to help force the shape memory alloy wires to return to their original position. A computerized real-time control system uses the derivative-gain and proportional-gain algorithms to operate the system. This design represents a novel approach to the active control of high-bypass-ratio turbofan engines. Researchers have estimated that such engines will reduce thrust specific fuel consumption by 9 percent over that of fixed-geometry fan nozzles. This research was conducted under a cooperative agreement (NCC3-839) at the University of Akron.

  19. Energy-based control for a biologically inspired hexapod robot with rolling locomotion

    Directory of Open Access Journals (Sweden)

    Takuma Nemoto


    Full Text Available This paper presents an approach to control rolling locomotion on the level ground with a biologically inspired hexapod robot. For controlling rolling locomotion, a controller which can compensate energy loss with rolling locomotion of the hexapod robot is designed based on its dynamic model. The dynamic model describes the rolling locomotion which is limited to planar one by an assumption that the hexapod robot does not fall down while rolling and influences due to collision and contact with the ground, and it is applied for computing the mechanical energy of the hexapod robot and a plant for a numerical simulation. The numerical simulation of the rolling locomotion on the level ground verifies the effectiveness of the proposed controller. The simulation results show that the hexapod robot can perform the rolling locomotion with the proposed controller. In conclusion, it is shown that the proposed control approach is effective in achieving the rolling locomotion on the level ground.

  20. Printing of Titanium implant prototype

    International Nuclear Information System (INIS)

    Wiria, Florencia Edith; Shyan, John Yong Ming; Lim, Poon Nian; Wen, Francis Goh Chung; Yeo, Jin Fei; Cao, Tong


    Dental implant plays an important role as a conduit of force and stress to flow from the tooth to the related bone. In the load sharing between an implant and its related bone, the amount of stress carried by each of them directly related to their stiffness or modulus. Hence, it is a crucial issue for the implant to have matching mechanical properties, in particular modulus, between the implant and its related bone. Titanium is a metallic material that has good biocompatibility and corrosion resistance. Whilst the modulus of the bulk material is still higher than that of bone, it is the lowest among all other commonly used metallic implant materials, such as stainless steel or cobalt alloy. Hence it is potential to further reduce the modulus of pure Titanium by engineering its processing method to obtain porous structure. In this project, porous Titanium implant prototype is fabricated using 3-dimensional printing. This technique allows the flexibility of design customization, which is beneficial for implant fabrication as tailoring of implant size and shape helps to ensure the implant would fit nicely to the patient. The fabricated Titanium prototype had a modulus of 4.8-13.2 GPa, which is in the range of natural bone modulus. The compressive strength achieved was between 167 to 455 MPa. Subsequent cell culture study indicated that the porous Titanium prototype had good biocompatibility and is suitable for bone cell attachment and proliferation.

  1. Development of Prototype Reactive Armor Tile (United States)


    Final Technical Status Report For DOTC 10-01-INIT-017 Development of Prototype Reactive Armor Tile Reporting Period: 13 May 2015 Ordnance...Final 3. DATES COVERED 4. TITLE AND SUBTITLE Final Report: Development of Prototype Reactive Armor Tile 5a. CONTRACT NUMBER OTA # W15QKN-09-9...NOTES 14. ABSTRACT Prototyping efforts performed for Development of Prototype Reactive Armor Tile 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF


    Directory of Open Access Journals (Sweden)

    L. V. Ursulyak


    Full Text Available Purpose. To compare the operational characteristics of freight diesel-electric locomotives ER20CF and 2М62м, which are operated with Lithuanian Railways. Important problems on traction calculations are considered in this article. In this article the critical tasks of traction calculations are solved. It is the main computational tool in the rational functioning, planning and development of railways: determination of the estimated weight of the rolling stock, the diagrams construction of specific resultant forces of a train, the permitted speed definition of the train on the slopes, curves of train traffic construction on the section. Methodology. Using the rules and methods of traction calculations the analysis of the basic operational characteristics of the modernized freight diesel-electric locomotive 2М62m and freight passenger dual locomotive 2ER20CF was held. The maximum weight of the train set, the track structure on a high-speed ascent through the use of kinetic energy (with traction and without traction, technical speed, acceleration force and the value of the smallest radius curve are selected as controlled parameters. During the calculations it was considered that the trains were formed of a fully loaded four-axle gondola cars, model 112-119 (feature-606 with axle load of 23.5 t; the motion was carried out on the continuous welded rail track; the front of the train set is a dual locomotive 2ER20CF or two locomotive 2М62м. Longitudinal profile of the road on the route Vilnus–KlF was analyzed for the choice of theoretical rise. Inspection concerning the possibility of overcoming the high-speed rise was performed with an analytical method, based on the use of the kinetic energy accumulated by the overcoming of «light» elements of the profile. Findings. In the calculations, the maximum weight of the train set taking into account theoretical rise was analyzed. The inspection of the theoretical weight of the train set on a reliable

  3. Implicit face prototype learning from geometric information. (United States)

    Or, Charles C-F; Wilson, Hugh R


    There is evidence that humans implicitly learn an average or prototype of previously studied faces, as the unseen face prototype is falsely recognized as having been learned (Solso & McCarthy, 1981). Here we investigated the extent and nature of face prototype formation where observers' memory was tested after they studied synthetic faces defined purely in geometric terms in a multidimensional face space. We found a strong prototype effect: The basic results showed that the unseen prototype averaged from the studied faces was falsely identified as learned at a rate of 86.3%, whereas individual studied faces were identified correctly 66.3% of the time and the distractors were incorrectly identified as having been learned only 32.4% of the time. This prototype learning lasted at least 1 week. Face prototype learning occurred even when the studied faces were further from the unseen prototype than the median variation in the population. Prototype memory formation was evident in addition to memory formation of studied face exemplars as demonstrated in our models. Additional studies showed that the prototype effect can be generalized across viewpoints, and head shape and internal features separately contribute to prototype formation. Thus, implicit face prototype extraction in a multidimensional space is a very general aspect of geometric face learning. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Prototypes in engineering design: Definitions and strategies

    DEFF Research Database (Denmark)

    Jensen, Lasse Skovgaard; Özkil, Ali Gürcan; Mortensen, Niels Henrik


    strategies. Due to rapid changes and progressions in the use of prototypes, we conclude conclude that there is a need for more holistic and overview generating research about prototyping. This for product developers to properly manage, select and apply the optimal prototyping process....

  5. Field Data Logger Prototype for Power Converters

    DEFF Research Database (Denmark)

    Chaudhary, Sanjay; Ghimire, Pramod; Thøgersen, Paul Bach


    and subsequent analysis of the data. This paper presents the development of a low cost prototype field data logger prototype using Raspberry PI and industrial sensors. The functionalities of the data logger prototype are described. An online rainflow count algorithm has been implemented as well....

  6. Fuel-cell technology for vehicular applications; L`introduzione delle pile a combustibile nel settore dei trasporti: proposte, standard e normative per sistemi di bordo ed impianti

    Energy Technology Data Exchange (ETDEWEB)

    Ciancia, A.; Pede, G.; Marmigi, R. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dip. Energia


    The fuel-cell technology applied to engines for vehicular applications grants broad margins of convenience over any known alternative engine for what concerns the compliance with any present and foreseeable environmental and energy saving regulations. On the other hand, the use of hydrogen produced on board from fuels or stored as a liquid or a gas, raises new problems from the point of view of safety regulations and standards both in the design and use of vehicles and in the fuel production and distribution. The present work is aimed at pointing out the above main safety problems, describes the technical-choices together with their technical grounds, in the framework of the italian and U E standards and regulations. The report is then made up of three parts. The initial section where the on board storage of the fuel from technical-economical point of view is discussed. with particular reference to the compressed hydrogen, the second describing the regulations and standards holding in the field of on board pressure equipment and reporting the ongoing ENEA`s activities in the field. The final part is devoted to the distribution and supply of the fuels to the fuel cell powered electric vehicles. [Italiano] La tecnologia delle celle a combustibile, impiegata nella realizzazione dei propulsori dei veicoli elettrici, conferisce ad essi ampi margini di vantaggio su ogni altro tipo di motorizzazione per quanto riguarda le attuali e prevedibili future normative ambientali e di risparmio energetico. Il presente rapporto si propone di evidenziare alcuni tra questi problemi ed esporre e motivare le soluzioni tecniche previste nell`ambito degli specifici programmi dell`ENEA, in un contesto normativo di riferimento nazionale e comunitario. Il rapporto si compone pertanto di tre parti: una parte iniziale dove e` affrontato dal punto di vista tecnico-economico il problema del trasporto del combustibile a bordo con particolare riferimento all`idrogeno compresso, una seconda in cui

  7. Spinal corollary discharge modulates motion sensing during vertebrate locomotion. (United States)

    Chagnaud, Boris P; Banchi, Roberto; Simmers, John; Straka, Hans


    During active movements, neural replicas of the underlying motor commands may assist in adapting motion-detecting sensory systems to an animal's own behaviour. The transmission of such motor efference copies to the mechanosensory periphery offers a potential predictive substrate for diminishing sensory responsiveness to self-motion during vertebrate locomotion. Here, using semi-isolated in vitro preparations of larval Xenopus, we demonstrate that shared efferent neural pathways to hair cells of vestibular endorgans and lateral line neuromasts express cyclic impulse bursts during swimming that are directly driven by spinal locomotor circuitry. Despite common efferent innervation and discharge patterns, afferent signal encoding at the two mechanosensory peripheries is influenced differentially by efference copy signals, reflecting the different organization of body/water motion-detecting processes in the vestibular and lateral line systems. The resultant overall gain reduction in sensory signal encoding in both cases, which likely prevents overstimulation, constitutes an adjustment to increased stimulus magnitudes during locomotion.

  8. Biorobotics: using robots to emulate and investigate agile locomotion. (United States)

    Ijspeert, Auke J


    The graceful and agile movements of animals are difficult to analyze and emulate because locomotion is the result of a complex interplay of many components: the central and peripheral nervous systems, the musculoskeletal system, and the environment. The goals of biorobotics are to take inspiration from biological principles to design robots that match the agility of animals, and to use robots as scientific tools to investigate animal adaptive behavior. Used as physical models, biorobots contribute to hypothesis testing in fields such as hydrodynamics, biomechanics, neuroscience, and prosthetics. Their use may contribute to the design of prosthetic devices that more closely take human locomotion principles into account. Copyright © 2014, American Association for the Advancement of Science.

  9. The coal-fired gas turbine locomotive - A new look (United States)

    Liddle, S. G.; Bonzo, B. B.; Purohit, G. P.


    Advances in turbomachine technology and novel methods of coal combustion may have made possible the development of a competitive coal fired gas turbine locomotive engine. Of the combustor, thermodynamic cycle, and turbine combinations presently assessed, an external combustion closed cycle regenerative gas turbine with a fluidized bed coal combustor is judged to be the best suited for locomotive requirements. Some merit is also discerned in external combustion open cycle regenerative systems and internal combustion open cycle regenerative gas turbine systems employing a coal gasifier. The choice of an open or closed cycle depends on the selection of a working fluid and the relative advantages of loop pressurization, with air being the most attractive closed cycle working fluid on the basis of cost.

  10. The Perceived Naturalness of Virtual Walking Speeds during WIP Locomotion

    DEFF Research Database (Denmark)

    Nilsson, Niels Chr.; Serafin, Stefania; Nordahl, Rolf


    It is well established that individuals tend to underestimate visually presented walking speeds when relying on treadmills for virtual walking. However, prior to the present studies this perceptual distortion had not been observed in relation to Walking-in-Place (WIP) locomotion, and a number...... of the factors contributing to the perceptual distortion have yet to be identified. In this paper we present a summary of seven of our studies investigating what factors that influence self-motion perception during virtual walking and two meta-analyses of the findings of the seven studies. The studies relate...... to how gait cycle characteristics, visual display properties, and methodological differences affect speed underestimation during treadmill and WIP locomotion. The studies suggested the following: A significant main effect was found for step frequency; both display and geometric field of view were...

  11. Hybrid control and motion planning of dynamical legged locomotion

    CERN Document Server


    "This book provides a comprehensive presentation of issues and challenges faced by researchers and practicing engineers in motion planning and hybrid control of dynamical legged locomotion. The major features range from offline and online motion planning algorithms to generate desired feasible periodic walking and running motions and tow-level control schemes, including within-stride feedback laws, continuous time update laws and event-based update laws, to asymptotically stabilize the generated desired periodic orbits. This book describes the current state of the art and future directions across all domains of dynamical legged locomotion so that readers can extend proposed motion planning algorithms and control methodologies to other types of planar and 3D legged robots".

  12. Modern power electronics for locomotives; Moderne Leistungselektronik im Lokomotiveinsatz

    Energy Technology Data Exchange (ETDEWEB)

    Bakran, M.M.; Eckel, H.G.; Nagel, A. [Siemens AG, Nuernberg (Germany)


    Locomotives represent a challenging application for high-power electronics in terms of power, voltage-level and operating conditions. The driving forces are the development of semiconductor devices, the corresponding circuit topologies and the resulting drive properties. The transition from GTO to IGBT allowed building more compact converters with a more flexible power rating. This for example made the integration of the auxiliary converter an effective solution. The development of 6.5kV IGBTs made possible easier operation on the 3kV-dc line, however, still with optimized and different solutions for multisystem locomotives. The actual development of semiconductor technology still suggests a further increase in power density. (orig.)

  13. Project management strategies for prototyping breakdowns

    DEFF Research Database (Denmark)

    Granlien, Maren Sander; Pries-Heje, Jan; Baskerville, Richard


    of strategies for coping with escalation in troubled prototyping projects; the framework is based on project management triangle theory and is useful when considering how to manage prototype breakdown and escalation. All strategies were applied in the project case at different points in time. The strategies led......, managing the explorative and iterative aspects of prototyping projects is not a trivial task. We examine the managerial challenges in a small scale prototyping project in the Danish healthcare sector where a prototype breakdown and project escalation occurs. From this study we derive a framework......Prototyping is often presented as a universal solution to many intractable information systems project problems. Prototyping is known to offer at least three advantages (1) provide users with a concrete understanding, (2) eliminate the confusion, (3) cope with uncertainty. On the other hand...

  14. Full-scale locomotive dynamic crash testing and correlations : locomotive consist colliding with steel coil truck at grade crossing (test 3). (United States)


    This report presents the test results and finite element correlations of a full-scale dynamic collision between a locomotive and a highway truck loaded with two heavy steel coils. The locomotive consist was moving at 58 miles per hour before it struc...

  15. Theoretical and experimental study on a compliant flipper-leg during terrestrial locomotion. (United States)

    Fang, Tao; Zhou, Youcheng; Li, Shikun; Xu, Min; Liang, Haiyi; Li, Weihua; Zhang, Shiwu


    An amphibious robot with straight compliant flipper-legs can conquer various amphibious environments. The robot can rotate its flipper-legs and utilize their large deflection to walk on rough terrain, and it can oscillate the straight flipper-legs to propel itself underwater. This paper focuses on the dynamics of the compliant straight flipper-legs during terrestrial locomotion by modeling its deformation dynamically with large deflection theory and simulating it to investigate the parameters of locomotion such as trajectory, velocity, and propulsion. To validate the theoretical model of dynamic locomotion, a single-leg experimental platform is used to explore the flipper-legs in motion with various structural and kinematic parameters. Furthermore, a robotic platform mounting with four compliant flipper-legs is also developed and used to experiment with locomotion. The trajectories of the rotating axle of the compliant flipper-leg during locomotion were approximately coincidental in simulation and in experiments. The speed of locomotion and cost of transport during locomotion were explored and analyzed. The performance of different types of compliant flipper-legs during locomotion shows that varying the degrees of stiffness will have a significant effect on their locomotion. The dynamic model and analysis of the compliant flipper-leg for terrestrial locomotion facilitates the ability of amphibious robots to conquer complex environments.

  16. FY97 ICCS prototype specification

    International Nuclear Information System (INIS)

    Woodruff, J.


    The ICCS software team will implement and test two iterations of their software product during FY97. This document specifies the products to be delivered in that first prototype and projects the direction that the second prototype will take. Detailed specification of the later iteration will be written when the results of the first iteration are complete. The selection of frameworks to be implemented early is made on a basis of risk analysis from the point of view of future development in the ICCS project. The prototype will address risks in integration of object- oriented components, in refining our development process, and in emulation testing for FEP devices. This document is a specification that identifies products and processes to undertake for resolving these risks. The goals of this activity are to exercise our development process at a modest scale and to probe our architecture plan for fundamental limits and failure modes. The product of the iterations will be the framework software which will be useful in future ICCS code. Thus the FY97 products are intended for internal usage by the ICCS team and for demonstration to the FEP software developers of the strategy for integrating supervisory software with FEP computers. This will be the first of several expected iterations of the software development process and the performance measurements that ICCS will demonstrate, intended to support confidence in our ability to meet project RAM goals. The design of the application software is being carried out in a separate WBS 1.5.2 activity. The design activity has as its FY97 product a series of Software Design Documents that will specify the functionality of the controls software of ICCS. During the testing of this year''s prototypes, the application functionality needed for test will be provided by sample maintenance controls. These are early precursors of controls that can be used for low level device control. Since the devices under test will be represented by

  17. Mechanical Prototyping and Manufacturing Internship (United States)

    Grenfell, Peter


    The internship was located at the Johnson Space Center (JSC) Innovation Design Center (IDC), which is a facility where the JSC workforce can meet and conduct hands-on innovative design, fabrication, evaluation, and testing of ideas and concepts relevant to NASA's mission. The tasks of the internship included mechanical prototyping design and manufacturing projects in service of research and development as well as assisting the users of the IDC in completing their manufacturing projects. The first project was to manufacture hatch mechanisms for a team in the Systems Engineering and Project Advancement Program (SETMAP) hexacopter competition. These mechanisms were intended to improve the performance of the servomotors and offer an access point that would also seal to prevent cross-contamination. I also assisted other teams as they were constructing and modifying their hexacopters. The success of this competition demonstrated a proof of concept for aerial reconnaissance and sample return to be potentially used in future NASA missions. I also worked with Dr. Kumar Krishen to prototype an improved thermos and a novel, portable solar array. Computer-aided design (CAD) software was used to model the parts for both of these projects. Then, 3D printing as well as conventional techniques were used to produce the parts. These prototypes were then subjected to trials to determine the success of the designs. The solar array is intended to work in a cluster that is easy to set up and take down and doesn't require powered servomechanisms. It could be used terrestrially in areas not serviced by power grids. Both projects improve planetary exploration capabilities to future astronauts. Other projects included manufacturing custom rail brackets for EG-2, assisting engineers working on underwater instrument and tool cases for the NEEMO project, and helping to create mock-up parts for Space Center Houston. The use of the IDC enabled efficient completion of these projects at

  18. The ATLAS IBL BOC prototype (United States)

    Schroer, N.


    The Pixel Detector of the ATLAS experiment at CERN will be upgraded with an Insertable B-Layer (IBL) in 2013. To handle the data readout the currently used VME card pairs consisting of a back of crate card (BOC) and a read out driver (ROD) are being redesigned. This paper presents details of the hardware design of the new BOC prototype, which takes advantage from modern FPGA technology and commercial optical modules and abandons the need for a variety of custom components used on the old card. Also the throughput is four times higher and additional features are implemented.

  19. The ATLAS IBL BOC Prototype

    CERN Document Server

    Schroer, N; Bruschi, M; Dantone, I; Dopke, J; Falchieri, D; Flick, T; Gabrielli, A; Grosse-Knetter, J; Heim, T; Joseph, J; Krieger, N; Kugel, A; Morettini, P; Neumann, M; Polini, A; Rizzi, M; Travaglini, R; Zannoli, S; Zoccoli, A


    The pixel detector of the ATLAS experiment at CERN will be upgraded with an additional layer (IBL) in 2013. To handle the data readout the currently used VME card pairs consisting of a back of crate card (BOC) and a read out driver (ROD) are being redesigned. This paper presents details of the hardware design of the new BOC prototype, which takes advantage from modern FPGA technology and commercial optical modules and abandons the need for a variety of custom components used on the old card. Also the throughput is four times higher and additional features are implemented.

  20. Phalangeal joints kinematics in ostrich (Struthio camelus) locomotion on sand (United States)

    Han, Dianlei; Wan, Haijin; Li, Xiujuan; Luo, Gang; Xue, Shuliang; Ma, Songsong; Yang, Mingming; Li, Jianqiao


    In ostriches, the toes are the only body parts that contact loose sand surfaces. Thus, toe interphalangeal joint motions may play vital biomechanical roles. However, there is little research on ostrich phalangeal joint movements while walking or running on sand. The results from the three-dimensional motion track analysis system Simi Motion show that gait pattern has no significant effect on the key indicators (angles at touch-down, mid-stance, lift-off and range of motion) of the toe joint angles. The motion of the toe phalanges when walking and running on sand is basically the same. The ground medium is the key factor that changes the toe postures adopted by ostriches during the stance phase in slow to fast locomotion. The 3rd toe and the 4th toe are connected by the interphalangeal ligament, and the motions of the MTP3 and MTP4 joints are highly synchronized on a loose sand substrate. The 3rd toe and 4th toe are coupled to maintain static balance in slow locomotion and dynamic balance in fast locomotion. In addition, the gait pattern has a marked effect on the range of forward displacement of the toenail (YTN). The ostrich toenail plays an important role in preventing slip and provides traction at push-off in a sandy environment. The metatarsophalangeal joint plays an important role in energy saving during fast locomotion on loose sand substrates. Simulation reveals that the particle velocity field, particle force field and sand particle disturbance in the running gait are denser than those in the walking gait. PMID:29489844

  1. Dynamic Locomotion and Whole-Body Control for Compliant Humanoids


    Hopkins, Michael Anthony


    With the ability to navigate natural and man-made environments and utilize standard human tools, humanoid robots have the potential to transform emergency response and disaster relief applications by serving as first responders in hazardous scenarios. Such applications will require major advances in humanoid control, enabling robots to traverse difficult, cluttered terrain with both speed and stability. To advance the state of the art, this dissertation presents a complete dynamic locomotion ...

  2. Brief anesthesia, but not voluntary locomotion, significantly alters cortical temperature (United States)

    Shirey, Michael J.; Kudlik, D'Anne E.; Huo, Bing-Xing; Greene, Stephanie E.; Drew, Patrick J.


    Changes in brain temperature can alter electrical properties of neurons and cause changes in behavior. However, it is not well understood how behaviors, like locomotion, or experimental manipulations, like anesthesia, alter brain temperature. We implanted thermocouples in sensorimotor cortex of mice to understand how cortical temperature was affected by locomotion, as well as by brief and prolonged anesthesia. Voluntary locomotion induced small (∼0.1°C) but reliable increases in cortical temperature that could be described using a linear convolution model. In contrast, brief (90-s) exposure to isoflurane anesthesia depressed cortical temperature by ∼2°C, which lasted for up to 30 min after the cessation of anesthesia. Cortical temperature decreases were not accompanied by a concomitant decrease in the γ-band local field potential power, multiunit firing rate, or locomotion behavior, which all returned to baseline within a few minutes after the cessation of anesthesia. In anesthetized animals where core body temperature was kept constant, cortical temperature was still >1°C lower than in the awake animal. Thermocouples implanted in the subcortex showed similar temperature changes under anesthesia, suggesting these responses occur throughout the brain. Two-photon microscopy of individual blood vessel dynamics following brief isoflurane exposure revealed a large increase in vessel diameter that ceased before the brain temperature significantly decreased, indicating cerebral heat loss was not due to increased cerebral blood vessel dilation. These data should be considered in experimental designs recording in anesthetized preparations, computational models relating temperature and neural activity, and awake-behaving methods that require brief anesthesia before experimental procedures. PMID:25972579

  3. The role of vortices in animal locomotion in fluids

    Directory of Open Access Journals (Sweden)

    Dvořák R.


    Full Text Available The aim of this paper is to show the significance of vortices in animal locomotion in fluids on two deliberately chosen examples. The first example concerns lift generation by bird and insect wings, the second example briefly mentiones swimming and walking on water. In all the examples, the vortices generated by the moving animal impart the necessary momentum to the surrounding fluid, the reaction to which is the force moving or lifting the animal.

  4. Performance analysis of jump-gliding locomotion for miniature robotics. (United States)

    Vidyasagar, A; Zufferey, Jean-Christohphe; Floreano, Dario; Kovač, M


    Recent work suggests that jumping locomotion in combination with a gliding phase can be used as an effective mobility principle in robotics. Compared to pure jumping without a gliding phase, the potential benefits of hybrid jump-gliding locomotion includes the ability to extend the distance travelled and reduce the potentially damaging impact forces upon landing. This publication evaluates the performance of jump-gliding locomotion and provides models for the analysis of the relevant dynamics of flight. It also defines a jump-gliding envelope that encompasses the range that can be achieved with jump-gliding robots and that can be used to evaluate the performance and improvement potential of jump-gliding robots. We present first a planar dynamic model and then a simplified closed form model, which allow for quantification of the distance travelled and the impact energy on landing. In order to validate the prediction of these models, we validate the model with experiments using a novel jump-gliding robot, named the 'EPFL jump-glider'. It has a mass of 16.5 g and is able to perform jumps from elevated positions, perform steered gliding flight, land safely and traverse on the ground by repetitive jumping. The experiments indicate that the developed jump-gliding model fits very well with the measured flight data using the EPFL jump-glider, confirming the benefits of jump-gliding locomotion to mobile robotics. The jump-glide envelope considerations indicate that the EPFL jump-glider, when traversing from a 2 m height, reaches 74.3% of optimal jump-gliding distance compared to pure jumping without a gliding phase which only reaches 33.4% of the optimal jump-gliding distance. Methods of further improving flight performance based on the models and inspiration from biological systems are presented providing mechanical design pathways to future jump-gliding robot designs.

  5. Nigral Glutamatergic Neurons Control the Speed of Locomotion. (United States)

    Ryczko, Dimitri; Grätsch, Swantje; Schläger, Laura; Keuyalian, Avo; Boukhatem, Zakaria; Garcia, Claudia; Auclair, François; Büschges, Ansgar; Dubuc, Réjean


    The mesencephalic locomotor region (MLR) plays a crucial role in locomotor control. In vertebrates, stimulation of the MLR at increasing intensities elicits locomotion of growing speed. This effect has been presumed to result from higher brain inputs activating the MLR like a dimmer switch. Here, we show in lampreys ( Petromyzon marinus ) of either sex that incremental stimulation of a region homologous to the mammalian substantia nigra pars compacta (SNc) evokes increasing activation of MLR cells with a graded increase in the frequency of locomotor movements. Neurons co-storing glutamate and dopamine were found to project from the primal SNc to the MLR. Blockade of glutamatergic transmission largely diminished MLR cell responses and locomotion. Local blockade of D 1 receptors in the MLR decreased locomotor frequency, but did not disrupt the SNc-evoked graded control of locomotion. Our findings revealed the presence of a glutamatergic input to the MLR originating from the primal SNc that evokes graded locomotor movements. SIGNIFICANCE STATEMENT The mesencephalic locomotor region (MLR) plays a crucial role in the control of locomotion. It projects downward to reticulospinal neurons that in turn activate the spinal locomotor networks. Increasing the intensity of MLR stimulation produces a growing activation of reticulospinal cells and a progressive increase in the speed of locomotor movements. Since the discovery of the MLR some 50 years ago, it has been presumed that higher brain regions activate the MLR in a graded fashion, but this has not been confirmed yet. Here, using a combination of techniques from cell to behavior, we provide evidence of a new glutamatergic pathway activating the MLR in a graded fashion, and consequently evoking a progressive increase in locomotor output. Copyright © 2017 the authors 0270-6474/17/379759-12$15.00/0.

  6. Locomotion Efficiency Optimization of Biologically Inspired Snake Robots


    Eleni Kelasidi; Mansoureh Jesmani; Kristin Y. Pettersen; Jan Tommy Gravdahl


    Snake robots constitute bio-inspired solutions that have been studied due to their ability to move in challenging environments where other types of robots, such as wheeled or legged robots, usually fail. In this paper, we consider both land-based and swimming snake robots. One of the principal concerns of the bio-inspired snake robots is to increase the motion efficiency in terms of the forward speed by improving the locomotion methods. Furthermore, energy efficiency becomes a crucial challen...

  7. Central Pattern Generator for Locomotion: Anatomical, Physiological and Pathophysiological Considerations

    Directory of Open Access Journals (Sweden)

    Pierre A. Guertin


    Full Text Available This article provides a perspective on major innovations over the past century in research on the spinal cord and, specifically, on specialized spinal circuits involved in the control of rhythmic locomotor pattern generation and modulation. Pioneers such as Charles Sherrington and Thomas Graham Brown have conducted experiments in the early twentieth century that changed our views of the neural control of locomotion. Their seminal work supported subsequently by several decades of evidence has led to the conclusion that walking, flying and swimming are largely controlled by a network of spinal neurons generally referred to as the central pattern generator (CPG for locomotion. It has been subsequently demonstrated across all vertebrate species examined, from lampreys to humans, that this CPG is capable, under some conditions, to self-produce, even in absence of descending or peripheral inputs, basic rhythmic and coordinated locomotor movements. Recent evidence suggests, in turn, that plasticity changes of some CPG elements may contribute to the development of specific pathophysiological conditions associated with impaired locomotion or spontaneous locomotor-like movements. This article constitutes a comprehensive review summarizing key findings on the CPG as well as on its potential role in Restless Leg Syndrome (RLS, Periodic Leg Movement (PLM, and Alternating Leg Muscle Activation (ALMA. Special attention will be paid to the role of the CPG in a recently identified, and uniquely different neurological disorder, called the Uner Tan Syndrome.

  8. Enhanced Caenorhabditis elegans locomotion in a structured microfluidic environment.

    Directory of Open Access Journals (Sweden)

    Sungsu Park

    Full Text Available BACKGROUND: Behavioral studies of Caenorhabditis elegans traditionally are done on the smooth surface of agar plates, but the natural habitat of C. elegans and other nematodes is the soil, a complex and structured environment. In order to investigate how worms move in such environments, we have developed a technique to study C. elegans locomotion in microstructures fabricated from agar. METHODOLOGY/PRINCIPAL FINDINGS: When placed in open, liquid-filled, microfluidic chambers containing a square array of posts, we discovered that worms are capable of a novel mode of locomotion, which combines the fast gait of swimming with the more efficient movements of crawling. When the wavelength of the worms matched the periodicity of the post array, the microstructure directed the swimming and increased the speed of C. elegans ten-fold. We found that mutants defective in mechanosensation (mec-4, mec-10 or mutants with abnormal waveforms (unc-29 did not perform this enhanced locomotion and moved much more slowly than wild-type worms in the microstructure. CONCLUSION/SIGNIFICANCE: These results show that the microstructure can be used as a behavioral screen for mechanosensory and uncoordinated mutants. It is likely that worms use mechanosensation in the movement and navigation through heterogeneous environments.

  9. Chimpanzee ankle and foot joint kinematics: Arboreal versus terrestrial locomotion. (United States)

    Holowka, Nicholas B; O'Neill, Matthew C; Thompson, Nathan E; Demes, Brigitte


    Many aspects of chimpanzee ankle and midfoot joint morphology are believed to reflect adaptations for arboreal locomotion. However, terrestrial travel also constitutes a significant component of chimpanzee locomotion, complicating functional interpretations of chimpanzee and fossil hominin foot morphology. Here we tested hypotheses of foot motion and, in keeping with general assumptions, we predicted that chimpanzees would use greater ankle and midfoot joint ranges of motion during travel on arboreal supports than on the ground. We used a high-speed motion capture system to measure three-dimensional kinematics of the ankle and midfoot joints in two male chimpanzees during three locomotor modes: terrestrial quadrupedalism on a flat runway, arboreal quadrupedalism on a horizontally oriented tree trunk, and climbing on a vertically oriented tree trunk. Chimpanzees used relatively high ankle joint dorsiflexion angles during all three locomotor modes, although dorsiflexion was greatest in arboreal modes. They used higher subtalar joint coronal plane ranges of motion during terrestrial and arboreal quadrupedalism than during climbing, due in part to their use of high eversion angles in the former. Finally, they used high midfoot inversion angles during arboreal locomotor modes, but used similar midfoot sagittal plane kinematics across all locomotor modes. The results indicate that chimpanzees use large ranges of motion at their various ankle and midfoot joints during both terrestrial and arboreal locomotion. Therefore, we argue that chimpanzee foot anatomy enables a versatile locomotor repertoire, and urge caution when using foot joint morphology to reconstruct arboreal behavior in fossil hominins. © 2017 Wiley Periodicals, Inc.

  10. Control method for biped locomotion robots based on ZMP information

    Energy Technology Data Exchange (ETDEWEB)

    Kume, Etsuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment


    The Human Acts Simulation Program (HASP) started as a ten year program of Computing and Information Systems Center (CISC) at Japan Atomic Energy Research Institute (JAERI) in 1987. A mechanical design study of biped locomotion robots for patrol and inspection in nuclear facilities is being performed as an item of the research scope. One of the goals of our research is to design a biped locomotion robot for practical use in nuclear facilities. So far, we have been studying for several dynamic walking patterns. In conventional control methods for biped locomotion robots, the program control is used based on preset walking patterns, so it dose not have the robustness such as a dynamic change of walking pattern. Therefore, a real-time control method based on dynamic information of the robot states is necessary for the high performance of walking. In this study a new control method based on Zero Moment Point (ZMP) information is proposed as one of real-time control methods. The proposed method is discussed and validated based on the numerical simulation. (author).

  11. Virtual Prototyping of RF Weapons (United States)

    Cartwright, Keith


    We are attempting to perform virtual prototyping of RF systems, from pulse power through to antennas, with the ICEPIC (Improved Concurrent Electromagnetic Particle-in-Cell) HPC software that we have developed over the past several years with funding from AFOSR. This code simulates from first principles (Maxwell's equations and Lorenz's force law) the electrodynamics and charged particle dynamics of the RF-producing part of the system. Such simulations require major computational resources. In the past, we have simulated GigaWatt-class sources that have already been built in the laboratory including the relativistic klystron oscillator (RKO) and the magnetically insulated line oscillator (MILO). Our simulations have uncovered undesirable features of these sources, and have led us to suggest ways to improve them. We are now taking the next step in our evolution towards true virtual prototyping. We have begun to simulate the relativistic magnetron before it is been built at our lab. The details of the device that will eventually be built, including the geometric structure and the externally generated magnetic field distribution, will be based on our simulations. In this paper, we present results from ICEPIC simulations that lead to the improvement of the RKO and MILO as well as predicted characteristics the relativistic magnetron that we plan to build in the fall of 2002.

  12. Prototypical Rod Consolidation Demonstration Project

    International Nuclear Information System (INIS)


    The objective of Phase 3 of the Prototypical Rod consolidation Demonstration Project (PRCDP) was to procure, fabricate, assemble, and test the Prototypical Rod consolidation System as described in the NUS Phase 2 Final Design Report. This effort required providing the materials, components, and fabricated parts which makes up all of the system equipment. In addition, it included the assembly, installation, and setup of this equipment at the Cold Test Facility. During the Phase 3 effort the system was tested on a component, subsystem, and system level. This volume 1, discusses the PRCDP Phase 3 Test Program that was conducted by the HALLIBURTON NUS Environmental Corporation under contract AC07-86ID12651 with the United States Department of Energy. This document, Volume 1, Book 5 discusses the following topics: Lower Cutting System Test Results and Analysis Report; NFBC Loading System Test Results and Analysis Report; Robotic Bridge Transporter Test Results and Analysis Report; RM-10A Remotec Manipulator Test Results and Analysis Report; and Manipulator Transporter Test Results and Analysis Report

  13. Low-friction nanojoint prototype (United States)

    Vlassov, Sergei; Oras, Sven; Antsov, Mikk; Butikova, Jelena; Lõhmus, Rünno; Polyakov, Boris


    High surface energy of individual nanostructures leads to high adhesion and static friction that can completely hinder the operation of nanoscale systems with movable parts. For instance, silver or gold nanowires cannot be moved on silicon substrate without plastic deformation. In this paper, we experimentally demonstrate an operational prototype of a low-friction nanojoint. The movable part of the prototype is made either from a gold or silver nano-pin produced by laser-induced partial melting of silver and gold nanowires resulting in the formation of rounded bulbs on their ends. The nano-pin is then manipulated into the inverted pyramid (i-pyramids) specially etched in a Si wafer. Due to the small contact area, the nano-pin can be repeatedly tilted inside an i-pyramid as a rigid object without noticeable deformation. At the same time in the absence of external force the nanojoint is stable and preserves its position and tilt angle. Experiments are performed inside a scanning electron microscope and are supported by finite element method simulations.

  14. Design of railway obstacle detection prototype

    CSIR Research Space (South Africa)

    Xungu, Sipho A


    Full Text Available Locomotives are at risk to collisions and derailment due to obstacles on the track. Trains do not have the ability to steer around obstacles, they are confined to the track and depend on stopping to avoid hazards. These accidents often result...

  15. Lack of adaptation during prolonged split-belt locomotion in the intact and spinal cat. (United States)

    Kuczynski, Victoria; Telonio, Alessandro; Thibaudier, Yann; Hurteau, Marie-France; Dambreville, Charline; Desrochers, Etienne; Doelman, Adam; Ross, Declan; Frigon, Alain


    During split-belt locomotion in humans where one leg steps faster than the other, the symmetry of step lengths and double support periods of the slow and fast legs is gradually restored. When returning to tied-belt locomotion, there is an after-effect, with a reversal in the asymmetry observed in the early split-belt period, indicating that the new pattern was stored within the central nervous system. In this study, we investigated if intact and spinal-transected cats show a similar pattern of adaptation to split-belt locomotion by measuring kinematic variables and electromyography before, during and after 10 min of split-belt locomotion. The results show that cats do not adapt to prolonged split-belt locomotion. Our results suggest an important physiological difference in how cats and humans respond to prolonged asymmetric locomotion. In humans, gait adapts to prolonged walking on a split-belt treadmill, where one leg steps faster than the other, by gradually restoring the symmetry of interlimb kinematic variables, such as double support periods and step lengths, and by reducing muscle activity (EMG, electromyography). The adaptation is also characterized by reversing the asymmetry of interlimb variables observed during the early split-belt period when returning to tied-belt locomotion, termed an after-effect. To determine if cats adapt to prolonged split-belt locomotion and to assess if spinal locomotor circuits participate in the adaptation, we measured interlimb variables and EMG in intact and spinal-transected cats before, during and after 10 min of split-belt locomotion. In spinal cats, only the hindlimbs performed stepping with the forelimbs stationary. In intact and spinal cats, step lengths and double support periods were, on average, symmetric, during tied-belt locomotion. They became asymmetric during split-belt locomotion and remained asymmetric throughout the split-belt period. Upon returning to tied-belt locomotion, symmetry was immediately restored

  16. Pectoral fin locomotion in batoid fishes: undulation versus oscillation. (United States)

    Rosenberger, L J


    This study explores the dichotomy between undulatory (passing multiple waves down the fin or body) and oscillatory (flapping) locomotion by comparing the kinematics of pectoral fin locomotion in eight species of batoids (Dasyatis americana, D. sabina, D. say, D. violacea, Gymnura micrura, Raja eglanteria, Rhinobatos lentiginosus and Rhinoptera bonasus) that differ in their swimming behavior, phylogenetic position and lifestyle. The goals of this study are to describe and compare the pectoral fin locomotor behavior of the eight batoid species, to clarify how fin movements change with swimming speed for each species and to analyze critically the undulation/oscillation continuum proposed by Breder using batoids as an example. Kinematic data were recorded for each species over a range of swimming velocities (1-3 disc lengths s(-1)). The eight species in this study vary greatly in their swimming modes. Rhinobatos lentiginosus uses a combination of axial-based and pectoral-fin-based undulation to move forward through the water, with primary thrust generated by the tail. The pectoral fins are activated in short undulatory bursts for increasing swimming speed and for maneuvering. Raja eglanteria uses a combination of pectoral and pelvic locomotion, although only pectoral locomotion is analyzed here. The other six species use pectoral locomotion exclusively to propel themselves through the water. Dasyatis sabina and D. say have the most undulatory fins with an average of 1.3 waves per fin length, whereas Rhinoptera bonasus has the most oscillatory fin behavior with 0.4 waves per fin length. The remaining species range between these two extremes in the degree of undulation present on their fins. There is an apparent trade-off between fin-beat frequency and amplitude. Rhinoptera bonasus has the lowest frequency and the highest fin amplitude, whereas Rhinobatos lentiginosus has the highest frequency and the lowest amplitude among the eight species examined. The kinematic

  17. Association of Mode of Locomotion and Independence in Locomotion With Long-Term Outcomes After Spinal Cord Injury (United States)

    Krause, James; Carter, Rickey E; Brotherton, Sandra


    Background/Objective: To explore the association of mode of locomotion (ambulation vs wheelchair use) and independence in locomotion (independent vs require assistance) with health, participation, and subjective well-being (SWB) after spinal cord injury (SCI). Research Design: Secondary analysis was conducted on survey data collected from 2 rehabilitation hospitals in the Midwest and a specialty hospital in the southeastern United States. The 1,493 participants were a minimum of 18 years of age and had traumatic SCI of at least 1 year duration at enrollment. Main Outcome Measures: Three sets of outcome measures were used: SWB, participation, and health. SWB was measured by 8 scales and a measure of depressive symptoms, participation by 3 items, health by general health ratings, days in poor health, hospitalizations, and treatments. Results: Small but significant associations were observed between independence in locomotion and every outcome. Ambulation was associated with greater participation but a mixed pattern of favorable and unfavorable health and SWB outcomes. Supplemental analyses were conducted on those who ambulated but who were dependent on others to do so (n = 117), because this group reported poor outcomes in several areas. Individuals who were independent in wheelchair use reported substantially better outcomes than nonwheelchair users and those dependent on others in wheelchair use. Conclusions: Although ambulation is often a recovery goal, individuals with SCI who ambulate do not uniformly report better outcomes than wheelchair users, and those who depend on others for assistance with ambulation may experience a unique set of problems. PMID:19810625

  18. Deliverable 2.1.3 ISISEMD Integrated Prototype

    DEFF Research Database (Denmark)

    Peterson, Carrie Beth


    D-2.1.3 - ISISEMD Integrated Prototype This deliverable accompanies the prototype platform of ISISEMD. It contains a description of the prototype of the ISISEMD platform......D-2.1.3 - ISISEMD Integrated Prototype This deliverable accompanies the prototype platform of ISISEMD. It contains a description of the prototype of the ISISEMD platform...

  19. The Relationship between Locomotive Syndrome and Depression in Community-Dwelling Elderly People


    Misa Nakamura; Hiroshi Hashizume; Sachiko Nomura; Ryohei Kono; Hirotoshi Utsunomiya


    Locomotive syndrome (LS) is a concept that refers to the condition of people requiring healthcare services because of problems associated with locomotion. Depression is a major psychiatric disease among the elderly, in addition to dementia. The purpose of this study was to determine the association between LS and depression. The study participants were 224 healthy elderly volunteers living in a rural area in Japan. LS was defined as scores ≥ 16 on the 25-question Geriatric Locomotive Function...

  20. Closing the Loop: Integrating Body, Muscle and Environment with Locomotion Central Pattern Generators (United States)


    between the neural circuitry, body, and fluid environment for swimming locomotion , where the lamprey serves as a model system1,2,3,4,5,6,7,8. Our...REPORT Final Report: Closing the Loop: Integrating Body, Muscle and Environment with Locomotion Central Pattern Generators 14. ABSTRACT 16. SECURITY...CLASSIFICATION OF: The role of sensory feedback is a central question in understanding vertebrate locomotion . Sensory feedback related to movement of

  1. LEP vacuum chamber, early prototype

    CERN Multimedia

    CERN PhotoLab


    The structure of LEP, with long bending magnets and little access to the vacuum chamber between them, required distributed pumping. This is an early prototype for the LEP vacuum chamber, made from extruded aluminium. The main opening is for the beam. The small channel to the right is for cooling water, to carry away the heat deposited by the synchroton radiation from the beam. The 4 slots in the channel to the left house the strip-shaped ion-getter pumps (see 7810255). The ion-getter pumps depended on the magnetic field of the bending magnets, too low at injection energy for the pumps to function well. Also, a different design was required outside the bending magnets. This design was therefore abandoned, in favour of a thermal getter pump (see 8301153 and 8305170).

  2. Rendering for machine vision prototyping (United States)

    Reiner, Jacek


    Machine Vision systems for manufacturing quality inspection are interdisciplinary solutions including lighting, optics, cameras, image processing, segmentation, feature analysis, classification as well as integration with manufacturing process. The design and optimization of the above systems, especially image acquisition setup is mainly driven by experiment. This requires deep know-how and well equipped laboratory, which does not guarantee the optimal development process and results. This paper proposes novel usage of rendering, originating from 3D computer graphics, for machine vision prototyping and optimization. The invented technique and physically-based rendering aids selection or optimization of luminaires, tolerancing of mechanical construction and object handling, robustness predetermination or surface flaw simulation. The rendering setup utilizes mesh modeling, bump and normal mapping and light distribution sharpening with IES data files. The performed light simulation experiments for metal surfaces (face surface of bearing rollers) are validated.

  3. Hadron therapy information sharing prototype

    CERN Document Server

    Roman, Faustin Laurentiu; Kanellopoulos, Vassiliki; Amoros, Gabriel; Davies, Jim; Dosanjh, Manjit; Jena, Raj; Kirkby, Norman; Peach, Ken; Salt, Jose


    The European PARTNER project developed a prototypical system for sharing hadron therapy data. This system allows doctors and patients to record and report treatment-related events during and after hadron therapy. It presents doctors and statisticians with an integrated view of adverse events across institutions, using open-source components for data federation, semantics, and analysis. There is a particular emphasis upon semantic consistency, achieved through intelligent, annotated form designs. The system as presented is ready for use in a clinical setting, and amenable to further customization. The essential contribution of the work reported here lies in the novel data integration and reporting methods, as well as the approach to software sustainability achieved through the use of community-supported open-source components.

  4. Prototype of industrial electrons accelerator

    International Nuclear Information System (INIS)

    Lopez, V.H.; Valdovinos, A.M.


    The interest and the necessity of Mexico's industry in the use of irradiation process has been increased in the last years. As examples are the irradiation of combustion gases (elimination of NO x and SO 2 ) and the polymer cross-linking between others. At present time at least twelve enterprises require immediately of them which have been contacted by electron accelerators suppliers of foreign countries. The first project step consisted in to identify the electrons accelerator type that in can be constructed in Mexico with the major number of possible equipment, instruments, components and acquisition materials local and useful for the major number of users. the characteristics of the accelerator prototype are: accelerator type transformer with multiple secondary insulated and rectifier circuits with a potential of 0.8 MV of voltage, the second step it consisted in an economic study that permitted to demonstrate the economic feasibility of its construction. (Author)

  5. PEP-II prototype klystron

    International Nuclear Information System (INIS)

    Fowkes, W.R.; Caryotakis, G.; Lee, T.G.; Pearson, C.; Wright, E.L.


    A 540-kW continuous-wave (cw) klystron operating at 476 MHz was developed for use as a power source for testing PEP-II rf accelerating cavities and rf windows. It also serves as a prototype for a 1.2 MW cw klystron presently being developed as a potential rf source for asymmetric colliding ring use. The design incorporates the concepts and many of the parts used in the original 353 MHz PEP klystron developed sixteen years ago. The superior computer simulation codes available today result in improved performance with the cavity frequencies, drift lengths, and output circuit optimized for the higher frequency.The design and operating results of this tube are described with particular emphasis on the factors which affect efficiency and stability

  6. Prototype moving-ring reactor

    International Nuclear Information System (INIS)

    Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.


    We have completed a design of the Prototype Moving-Ring Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma (Compact Toroids). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three burn stations. Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for 1/3 of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power

  7. Prototype international quality assurance program

    International Nuclear Information System (INIS)

    Broadway, J.A.; Chambless, D.A.; Sapozhnikov, Yu.A.; Kalmykov, S.N.


    The international community presently lacks the ability to determine the quality and credibility of environmental measurements that is required to make sound decisions in matters related to international security, public health, and investment-related considerations. The ultimate goal of the work described in this article is to develop a credible information base including measurement capability for determination of environmental contamination and the potential for proliferation of material components of chemical or nuclear weapons. This study compared the accuracy obtained by six Russian and six U.S. laboratories for samples representative of classes of trace metals, dioxing-furans, and radioactive substances. The results obtained in this work indicate that current estimates for laboratory accuracy are likely overly optimistic. The weaknesses discovered by this prototype U.S. - Russia study also exist within the broader international community of laboratories. Further work is proposed to address the urgent need for the international community to improve performance evaluations for analytical measurements. (author)


    Directory of Open Access Journals (Sweden)

    Yu. V. Zelenko


    Full Text Available Purpose.The success of the traffic on the railways of Ukraine depends on the number and the operational fleet of electric locomotives. Today, the locomotive depot exploit physically and morally outdated locomotives that have low reliability. Modernization of electric locomotives is not economically justified. The aim of this study is to improve the safety of the traction rolling stock by the frequency analysis of dynamical systems, which allows conducting the calculation of the natural (of resonant frequencies of the design and related forms of vibrations.Methodology.The study was conducted by methods of analytical mechanics and mathematical modeling of operating loads of freight locomotive when driving at different speeds on the straight and curved track sections. The theoretical value of the work is the technique of choice of constructive schemes and rational parameters of perspective electric locomotive taking into account the electric inertia ratios and stiffness coefficients of Lagrange second-order equations.Findings. The problems of theoretical research and the development of a mathematical model of the spatial electric vibrations are solved. The theoretical studies of the effect of inertia ratios and stiffness coefficients on the dynamic values and the parameter values of electric locomotive undercarriages are presented.Originality.The set of developed regulations and obtained results is a practical solution to selecting rational parameters of bogies of the freight mainline locomotive for railways of Ukraine. A concept of choice of constructive scheme and rational parameters of perspective locomotive is formulated. It is developed the method of calculation of spatial electric locomotive oscillations to determine its dynamic performance. The software complex for processing the data of experimental studies of dynamic parameters of electric locomotive and comparing the results of the theoretical calculations with the data of full

  9. Acquiring Efficient Locomotion in a Simulated Quadruped through Evolving Random and Predefined Neural Networks

    DEFF Research Database (Denmark)

    Veenstra, Frank; Struck, Alexander; Krauledat, Matthias


    The acquisition and optimization of dynamically stable locomotion is important to engender fast and energy efficient locomotion in animals. Conventional optimization strategies tend to have difficulties in acquiring dynamically stable gaits in legged robots. In this paper, an evolving neural...... network (ENN) was implemented with the aim to optimize the locomotive behavior of a four-legged simulated robot. In the initial generation, individuals had neural networks (NNs) that were either predefined or randomly initialized. Additional investigations show that the efficiency of applying additional...... optimize a locomotive strategy for a simulated quadruped....

  10. The Yucca Mountain Project Prototype Testing Program

    International Nuclear Information System (INIS)


    The Yucca Mountain Project is conducting a Prototype Testing Program to ensure that the Exploratory Shaft Facility (ESF) tests can be completed in the time available and to develop instruments, equipment, and procedures so the ESF tests can collect reliable and representative site characterization data. This report summarizes the prototype tests and their status and location and emphasizes prototype ESF and surface tests, which are required in the early stages of the ESF site characterization tests. 14 figs

  11. Rapid prototyping using CBCT: an initial experience

    International Nuclear Information System (INIS)

    Yovchev, D.; Deliverska, E.; Indjova, J.; Ugrinov, R.


    This report presents a case of fibrous dysplasia in the left lower jaw of a 12-year-old girl, scanned with CBCT. On the basis of CBCT scan a model of affected jaw was produced using a rapid-prototyping three-dimensional printer. The case demonstrates the possibility to get a prototype by CBCT data. Prototypes can be used to support the diagnosis, planning, training (students and postgraduates) and to obtain informed consent from the patient.

  12. A prototype for JDEM science data processing

    International Nuclear Information System (INIS)

    Gottschalk, Erik E


    Fermilab is developing a prototype science data processing and data quality monitoring system for dark energy science. The purpose of the prototype is to demonstrate distributed data processing capabilities for astrophysics applications, and to evaluate candidate technologies for trade-off studies. We present the architecture and technical aspects of the prototype, including an open source scientific execution and application development framework, distributed data processing, and publish/subscribe message passing for quality control.

  13. Prototype calorimeters for the NA3 experiment

    CERN Multimedia


    The NA3 Experiment was set-up on the North Area of the SPS by the CERN/ Ecole Polytechnique/College de France/ Orsay/Saclay Collaboration, to study high transverse momentum leptons and hadrons from hadron collisions. The calorimeters measured the energy of hadrons (prototype on the right) and leptons (prototype on the left). They used a new type of plastic scintillator (plexipop). (see CERN Courier of November 1975) energy (prototype on the right)

  14. Sexuality of Disabled Athletes Depending on the Form of Locomotion

    Directory of Open Access Journals (Sweden)

    Plinta Ryszard


    Full Text Available The main purpose of this study was to determine sexuality of disabled athletes depending on the form of locomotion. The study included 170 disabled athletes, aged between 18 and 45. The entire population was divided into 3 research groups depending on the form of locomotion: moving on wheelchairs (n=52, on crutches (n=29 and unaided (n=89. The research tool was a questionnaire voluntarily and anonymously completed by the respondents of the research groups. The questionnaire was composed of a general part concerning the socio-demographic conditions, medical history, health problems, a part dedicated to physical disability as well as the Polish version of the International Index of Erectile Function (IIEF and the Female Sexual Function Index (FSFI evaluating sexual life. STATISTICA 10.0 for Windows was used in the statistical analysis. Subjects moving on crutches were significantly older than ones moving on wheelchairs and unaided (34.41 ±11.00 vs. 30.49 ±10.44 and 27.99 ±10.51 years, respectively (p=0.018. Clinically significant erectile dysfunctions were most often diagnosed in athletes moving on wheelchairs (70.27%, followed by athletes moving on crutches and moving unaided (60% and 35.42%, respectively; p=0.048. Clinical sexual dysfunctions were diagnosed on a similar level among all female athletes. It was concluded that the form of locomotion may determine sexuality of disabled men. Males on wheelchair revealed the worst sexual functioning. Female athletes moving on wheelchairs, on crutches and moving unaided were comparable in the aspect of their sexual life.

  15. Benefit of "Push-pull" Locomotion for Planetary Rover Mobility (United States)

    Creager, Colin M.; Moreland, Scott Jared; Skonieczny, K.; Johnson, K.; Asnani, V.; Gilligan, R.


    As NASAs exploration missions on planetary terrains become more aggressive, a focus on alternative modes of locomotion for rovers is necessary. In addition to climbing steep slopes, the terrain in these extreme environments is often unknown and can be extremely hard to traverse, increasing the likelihood of a vehicle or robot becoming damaged or immobilized. The conventional driving mode in which all wheels are either driven or free-rolling is very efficient on flat hard ground, but does not always provide enough traction to propel the vehicle through soft or steep terrain. This paper presents an alternative mode of travel and investigates the fundamental differences between these locomotion modes. The methods of push-pull locomotion discussed can be used with articulated wheeled vehicles and are identified as walking or inchinginch-worming. In both cases, the braked non-rolling wheels provide increased thrust. An in-depth study of how soil reacts under a rolling wheel vs. a braked wheel was performed by visually observing the motion of particles beneath the surface. This novel technique consists of driving or dragging a wheel in a soil bin against a transparent wall while high resolution, high-rate photographs are taken. Optical flow software was then used to determine shearing patterns in the soil. Different failure modes were observed for the rolling and braked wheel cases. A quantitative comparison of inching vs. conventional driving was also performed on a full-scale vehicle through a series of drawbar pull tests in the Lunar terrain strength simulant, GRC-1. The effect of tire stiffness was also compared; typically compliant tires provide better traction when driving in soft soil, however its been observed that rigid wheels may provide better thrust when non-rolling. Initial tests indicate up to a possible 40 increase in pull force capability at high slip when inching vs. rolling.

  16. Lightweight Multifunctional Planetary Probe for Extreme Environment Exploration and Locomotion (United States)

    Bayandor, Javid (Principal Investigator); Schroeder, Kevin; Samareh, Jamshid


    The demand to explore new worlds requires the development of advanced technologies that enable landed science on uncertain terrains or in hard to reach locations. As a result, contemporary Entry, Descent, Landing, (EDL) and additional locomotion (EDLL) profiles are becoming increasingly more complex, with the introduction of lifting/guided entries, hazard avoidance on descent, and a plethora of landing techniques including airbags and the skycrane maneuver. The inclusion of each of these subsystems into a mission profile is associated with a substantial mass penalty. This report explores the new all-in-one entry vehicle concept, TANDEM, a new combined EDLL concept, and compares it to the current state of the art EDL systems. The explored system is lightweight and collapsible and provides the capacity for lifting/guided entry, guided descent, hazard avoidance, omnidirectional impact protection and surface locomotion without the aid of any additional subsystems. This Phase I study explored: 1. The capabilities and feasibility of the TANDEM concept as an EDLL vehicle. 2. Extensive impact analysis to ensure mission success in unfavorable landing conditions, and safe landing in Tessera regions. 3. Development of a detailed design for a conceptual mission to Venus. As a result of our work it was shown that: 1. TANDEM provides additional benefits over the Adaptive, Deployable Entry Placement Technology (ADEPT) including guided descent and surface locomotion, while reducing the mass by 38% compared to the ADEPT-VITaL mission. 2. Demonstrated that the design of tensegrity structures, and TANDEM specifically, grows linearly with an increase in velocity, which was previously unknown. 3. Investigation of surface impact revealed a promising results that suggest a properly configured TANDEM vehicle can safely land and preform science in the Tessera regions, which was previously labeled by the Decadal Survey as, largely inaccessible despite its high scientific interest. This work

  17. Partly shared spinal cord networks for locomotion and scratching. (United States)

    Berkowitz, Ari; Hao, Zhao-Zhe


    Animals produce a variety of behaviors using a limited number of muscles and motor neurons. Rhythmic behaviors are often generated in basic form by networks of neurons within the central nervous system, or central pattern generators (CPGs). It is known from several invertebrates that different rhythmic behaviors involving the same muscles and motor neurons can be generated by a single CPG, multiple separate CPGs, or partly overlapping CPGs. Much less is known about how vertebrates generate multiple, rhythmic behaviors involving the same muscles. The spinal cord of limbed vertebrates contains CPGs for locomotion and multiple forms of scratching. We investigated the extent of sharing of CPGs for hind limb locomotion and for scratching. We used the spinal cord of adult red-eared turtles. Animals were immobilized to remove movement-related sensory feedback and were spinally transected to remove input from the brain. We took two approaches. First, we monitored individual spinal cord interneurons (i.e., neurons that are in between sensory neurons and motor neurons) during generation of each kind of rhythmic output of motor neurons (i.e., each motor pattern). Many spinal cord interneurons were rhythmically activated during the motor patterns for forward swimming and all three forms of scratching. Some of these scratch/swim interneurons had physiological and morphological properties consistent with their playing a role in the generation of motor patterns for all of these rhythmic behaviors. Other spinal cord interneurons, however, were rhythmically activated during scratching motor patterns but inhibited during swimming motor patterns. Thus, locomotion and scratching may be generated by partly shared spinal cord CPGs. Second, we delivered swim-evoking and scratch-evoking stimuli simultaneously and monitored the resulting motor patterns. Simultaneous stimulation could cause interactions of scratch inputs with subthreshold swim inputs to produce normal swimming, acceleration

  18. Biodiesel fuel costs and environmental issues when powering railway locomotives

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, Abdul; Ziemer, Norbert; Tatara, Robert; Moraga, Reinaldo; Mirman, Clifford; Vohra, Promod


    Issues for adopting biodiesel fuel, instead of petrodiesel, to power railroad locomotives are engine performance and emissions, fuel infrastructure, and fuel cost. These are evaluated for B2 through B100 blends. Biodiesel's solvent action on fuel systems is addressed. With biodiesel, hydrocarbon, carbon monoxide, and particulate emissions are unchanged or reduced. Nitrogen oxides are elevated but it is believed that engine alterations can minimize these emissions. A Transportation Model, using data from a major railway, has demonstrated that refueling depots can be fully supplied with biodiesel at a pricing premium of 1% to 26%, depending on blend and geographical location.

  19. Human-robot interaction strategies for walker-assisted locomotion

    CERN Document Server

    Cifuentes, Carlos A


    This book presents the development of a new multimodal human-robot interface for testing and validating control strategies applied to robotic walkers for assisting human mobility and gait rehabilitation. The aim is to achieve a closer interaction between the robotic device and the individual, empowering the rehabilitation potential of such devices in clinical applications. A new multimodal human-robot interface for testing and validating control strategies applied to robotic walkers for assisting human mobility and gait rehabilitation is presented. Trends and opportunities for future advances in the field of assistive locomotion via the development of hybrid solutions based on the combination of smart walkers and biomechatronic exoskeletons are also discussed. .

  20. Designing presence for real locomotion in immersive virtual environments

    DEFF Research Database (Denmark)

    Turchet, Luca


    This paper describes a framework for designing systems for real locomotion in virtual environments (VEs) in order to achieve an intense sense of presence. The main outcome of the present research is a list of design features that the virtual reality technology should have in order to achieve...... that allows VE designers to evaluate the maturity of their systems and to pinpoint directions for future developments. A survey analysis was performed using the proposed framework, which involved three case studies to determine how many features of the proposed framework were present and their status...

  1. Energy Efficiency of Robot Locomotion Increases Proportional to Weight

    DEFF Research Database (Denmark)

    Larsen, Jørgen Christian; Støy, Kasper


    The task of producing steady, stable and energy efficient locomotion in legged robots with the ability to walk in un- known terrain have for many years been a big challenge in robotics. This work is focusing on how different robots build from the modular robotic system, LocoKit by Larsen et. la [3......], performs compared to animals, and also on the similari- ties between robots an animals. This work shows, that there in robots exist the same connection between cost of trans- port and the weight of the robots as is true for animals....

  2. Energy Efficiency of Robot Locomotion Increases Proportional to Weight

    DEFF Research Database (Denmark)

    Larsen, J. C.; Stoy, K.


    The task of producing steady, stable and energy efficient locomotion in legged robots with the ability to walk in unknown terrain have for many years been a big challenge in robotics. This work is focusing on how different robots build from the modular robotic system, LocoKit by Larsen et al. [1......], performs compared to animals, and also on the similarities between robots an animals. This work shows, that there in robots exist the same connection between cost of transport and the weight of the robots as is true for animals. (C) Selection and peer-review under responsibility of FET11 conference...

  3. Improvement of fuel injection system of locomotive diesel engine. (United States)

    Li, Minghai; Cui, Hongjiang; Wang, Juan; Guan, Ying


    The traditional locomotive diesels are usually designed for the performance of rated condition and much fuel will be consumed. A new plunger piston matching parts of fuel injection pump and injector nozzle matching parts were designed. The experimental results of fuel injection pump test and diesel engine show that the fuel consumption rate can be decreased a lot in the most of the working conditions. The forced lubrication is adopted for the new injector nozzle matching parts, which can reduce failure rate and increase service life. The design has been patented by Chinese State Patent Office.

  4. Biomechanical Analysis of Treadmill Locomotion on the International Space Station (United States)

    De Witt, J. K.; Fincke, R. S.; Guilliams, M. E.; Ploutz-Snyder, L. L.


    Treadmill locomotion exercise is an important aspect of ISS exercise countermeasures. It is widely believed that an optimized treadmill exercise protocol could offer benefits to cardiovascular and bone health. If training heart rate is high enough, treadmill exercise is expected to lead to improvements in aerobic fitness. If impact or bone loading forces are high enough, treadmill exercise may be expected to contribute to improved bone outcomes. Ground-based research suggests that joint loads increase with increased running speed. However, it is unknown if increases in locomotion speed results in similar increases in joint loads in microgravity. Although data exist regarding the biomechanics of running and walking in microgravity, a majority were collected during parabolic flight or during investigations utilizing a microgravity analog. The Second Generation Treadmill (T2) has been in use on the International Space Station (ISS) and records the ground reaction forces (GRF) produced by crewmembers during exercise. Biomechanical analyses will aid in understanding potential differences in typical gait motion and allow for modeling of the human body to determine joint and muscle forces during exercise. By understanding these mechanisms, more appropriate exercise prescriptions can be developed that address deficiencies. The objective of this evaluation is to collect biomechanical data from crewmembers during treadmill exercise prior to and during flight. The goal is to determine if locomotive biomechanics differ between normal and microgravity environments and to determine how combinations of subject load and speed influence joint loading during in-flight treadmill exercise. Further, the data will be used to characterize any differences in specific bone and muscle loading during locomotion in these two gravitational conditions. This project maps to the HRP Integrated Research Plan risks including Risk of Bone Fracture (Gap B15), Risk of Early Onset Osteoporosis Due to

  5. Rapid Prototyping in Instructional Design: Creating Competencies (United States)

    Fulton, Carolyn D.


    Instructional designers working in rapid prototyping environments currently do not have a list of competencies that help to identify the knowledge, skills, and attitudes (KSAs) required in these workplaces. This qualitative case study used multiple cases in an attempt to identify rapid prototyping competencies required in a rapid prototyping…

  6. Gamification in a Prototype Household Energy Game

    NARCIS (Netherlands)

    Fijnheer, J.D.L.; van Oostendorp, H.; Veltkamp, R.C.


    Research where gamification is used to influence household energy consumption is an emerging field. This paper reviews design features of the prototype Powersaver Game. The aim of this game is to influence household energy consumption in the long-term. The evaluation of the design of the prototype,

  7. Virtual Video Prototyping of Pervasive Healthcare Systems

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Bossen, Claus; Madsen, Kim Halskov


    Virtual studio technology enables the mixing of physical and digital 3D objects and thus expands the way of representing design ideas in terms of virtual video prototypes, which offers new possibilities for designers by combining elements of prototypes, mock-ups, scenarios, and conventional video...

  8. Virtual Video Prototyping for Healthcare Systems

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Bossen, Claus; Lykke-Olesen, Andreas


    Virtual studio technology enables the mixing of physical and digital 3D objects and thus expands the way of representing design ideas in terms of virtual video prototypes, which offers new possibilities for designers by combining elements of prototypes, mock-ups, scenarios, and conventional video...

  9. Rapid Prototyping of Mobile Learning Games (United States)

    Federley, Maija; Sorsa, Timo; Paavilainen, Janne; Boissonnier, Kimo; Seisto, Anu


    This position paper presents the first results of an on-going project, in which we explore rapid prototyping method to efficiently produce digital learning solutions that are commercially viable. In this first phase, rapid game prototyping and an iterative approach was tested as a quick and efficient way to create learning games and to evaluate…

  10. Wireless Augmented Reality Prototype (WARP) (United States)

    Devereaux, A. S.


    Initiated in January, 1997, under NASA's Office of Life and Microgravity Sciences and Applications, the Wireless Augmented Reality Prototype (WARP) is a means to leverage recent advances in communications, displays, imaging sensors, biosensors, voice recognition and microelectronics to develop a hands-free, tetherless system capable of real-time personal display and control of computer system resources. Using WARP, an astronaut may efficiently operate and monitor any computer-controllable activity inside or outside the vehicle or station. The WARP concept is a lightweight, unobtrusive heads-up display with a wireless wearable control unit. Connectivity to the external system is achieved through a high-rate radio link from the WARP personal unit to a base station unit installed into any system PC. The radio link has been specially engineered to operate within the high- interference, high-multipath environment of a space shuttle or space station module. Through this virtual terminal, the astronaut will be able to view and manipulate imagery, text or video, using voice commands to control the terminal operations. WARP's hands-free access to computer-based instruction texts, diagrams and checklists replaces juggling manuals and clipboards, and tetherless computer system access allows free motion throughout a cabin while monitoring and operating equipment.

  11. Full-scale locomotive dynamic collision testing and correlations : offset collisions between a locomotive and a covered hopper car (test 4). (United States)


    This report presents the test results and finite element correlations of a full-scale dynamic collision test with rail vehicles as part of the Federal Railroad Administrations research program on improved crashworthiness of locomotive structures. ...

  12. Fast muscle function in the European eel (Anguilla anguilla, L.) : during aquatic and terrestrial locomotion

    NARCIS (Netherlands)

    Ellerby, D.J.; Spierts, I.L.Y.; Altringham, J.D.


    Eels are capable of locomotion both in water and on land using undulations of the body axis. Axial undulations are powered by the lateral musculature. Differences in kinematics and the underlying patterns of fast muscle activation are apparent between locomotion in these two environments. The change

  13. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers. (United States)


    ... boilers. 230.20 Section 230.20 Transportation Other Regulations Relating to Transportation (Continued... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... maintained for the life of the boiler. (See appendix B of this part.) (b) Welded and riveted repairs to...

  14. Compressed stability analysis of the coupler and buffer system of heavy-haul locomotives (United States)

    Zhang, Zhichao; Li, Gu; Chu, Gaofeng; Zu, Honglin; Kennedy, David


    This paper develops a locomotive dynamic model to study the coupler compressed stability and locomotive running safety under severe longitudinal compressive forces, taking into account a new model of the flattened pin coupler and buffer system employed by heavy-haul locomotives. In this new model, the arc surface contact friction element is built up for the first time to simulate the compressed contact friction process between the arc surfaces of the coupler tail and the following plate. An improved nonlinear mathematical model of buffers and a coupler rotation angle stop element are also included. After validating the presented locomotive dynamic model by comparing its calculated results with test data, simulations are carried out to analyse the influences of the coupler-tail arc surface and locomotive secondary suspension parameters on the coupler compressed stability and locomotive running safety. Results indicate that the friction coefficient and the arc radius of the coupler-tail arc surfaces have a remarkable influence, and that the locomotive secondary lateral stop and lateral stiffness also have a significant effect. Optimising these parameters could significantly improve the coupler compressed stability and locomotive running safety. Finally, a real example of Chinese heavy-haul trains is shown to confirm the importance of the coupler-tail contact friction action.

  15. 49 CFR 210.29 - Operation standards (moving locomotives and rail cars). (United States)


    ... cars). 210.29 Section 210.29 Transportation Other Regulations Relating to Transportation (Continued... REGULATIONS Inspection and Testing § 210.29 Operation standards (moving locomotives and rail cars). The operation standards for the noise emission levels of moving locomotives, rail cars, or consists of...

  16. Design and analysis of an optimal hopper for use in resonance-based locomotion

    NARCIS (Netherlands)

    Wanders, Ivor; Folkertsma, Gerrit Adriaan; Stramigioli, Stefano

    Quadrupedal running is an efficient form of locomotion found in nature, which serves as an inspiration for robotics. We believe that a resonance-based approach is the path towards energy-efficient legged locomotion and running robots. The first step in working towards this goal is creating an

  17. Differential gating of thalamo-cortical signals by reticular nucleus of thalamus during locomotion (United States)

    Marlinski, Vladimir; Sirota, Mikhail G.; Beloozerova, Irina N.


    SUMMARY The thalamic reticular nucleus (RE) provides inhibition to the dorsal thalamus, and forms a crucial interface between thalamo-cortical and cortico-thalamic signals. Whereas there has been significant interest in the role of the RE in organizing thalamo-cortical signaling, information on the activity of the RE in the awake animal is scant. Here we investigated the activity of neurons within the ‘motor’ compartment of the RE in the awake, unrestrained cat during simple locomotion on a flat surface and complex locomotion along a horizontal ladder that required visual control of stepping. The activity of 88% of neurons in this region was modulated during locomotion. Neurons with receptive fields on the shoulder were located dorsally in the nucleus and had regular discharges; during locomotion they had relatively low activity and modest magnitudes of stride-related modulation, and their group activity was distributed over the stride. In contrast, neurons with receptive fields on the wrist/paw were located more ventrally, often discharged sleep-type bursts during locomotion, were very active and profoundly modulated, and their group activity was concentrated in the swing and end of stance. 75% of RE neurons had different activity during the two locomotion tasks. We conclude that during locomotion the RE differentially gates thalamo-cortical signals transmitted during different phases of the stride, in relation to different parts of the limb, and the type of locomotion task. PMID:23136421


    NARCIS (Netherlands)


    The development of the nervous system is determined by an interaction between genetic and epigenetic factors. We investigated the possible role of proprioceptive afferent input in the development of locomotion in the rat. Kinematic analysis of locomotion in normal rats reveals a marked transition

  19. 49 CFR 1242.22 - Shop buildings-locomotives (account XX-19-24). (United States)


    ... 49 Transportation 9 2010-10-01 2010-10-01 false Shop buildings-locomotives (account XX-19-24). 1242.22 Section 1242.22 Transportation Other Regulations Relating to Transportation (Continued) SURFACE... Structures § 1242.22 Shop buildings—locomotives (account XX-19-24). Separate common expenses according to...

  20. A Reconfigurable Omnidirectional Soft Robot Based on Caterpillar Locomotion. (United States)

    Zou, Jun; Lin, Yangqiao; Ji, Chen; Yang, Huayong


    A pneumatically powered, reconfigurable omnidirectional soft robot based on caterpillar locomotion is described. The robot is composed of nine modules arranged as a three by three matrix and the length of this matrix is 154 mm. The robot propagates a traveling wave inspired by caterpillar locomotion, and it has all three degrees of freedom on a plane (X, Y, and rotation). The speed of the robot is about 18.5 m/h (two body lengths per minute) and it can rotate at a speed of 1.63°/s. The modules have neodymium-iron-boron (NdFeB) magnets embedded and can be easily replaced or combined into other configurations. Two different configurations are presented to demonstrate the possibilities of the modular structure: (1) by removing some modules, the omnidirectional robot can be reassembled into a form that can crawl in a pipe and (2) two omnidirectional robots can crawl close to each other and be assembled automatically into a bigger omnidirectional robot. Omnidirectional motion is important for soft robots to explore unstructured environments. The modular structure gives the soft robot the ability to cope with the challenges of different environments and tasks.

  1. Ground reaction force adaptations to tripedal locomotion in dogs. (United States)

    Fuchs, A; Goldner, B; Nolte, I; Schilling, N


    To gain insight into the adaptive mechanisms to tripedal locomotion and increase understanding of the biomechanical consequences of limb amputation, this study investigated kinetic and temporal gait parameters in dogs before and after the loss of a hindlimb was simulated. Nine clinically sound Beagle dogs trotted on an instrumented treadmill and the ground reaction forces as well as the footfall patterns were compared between quadrupedal and tripedal locomotion. Stride and stance durations decreased significantly in all limbs when the dogs ambulated tripedally, while relative stance duration increased. Both vertical and craniocaudal forces were significantly different in the remaining hindlimb. In the forelimbs, propulsive force increased in the contralateral and decreased in the ipsilateral limb, while the vertical forces were unchanged (except for mean force in the contralateral limb). Bodyweight was shifted to the contralateral and cranial body side so that each limb bore ~33% of the dog's bodyweight. The observed changes in the craniocaudal forces and the vertical impulse ratio between the fore- and hindlimbs suggest that a nose-up pitching moment occurs during the affected limb pair's functional step. To regain pitch balance for a given stride cycle, a nose-down pitching moment is exerted when the intact limb pair supports the body. These kinetic changes indicate a compensatory mechanism in which the unaffected diagonal limb pair is involved. Therefore, the intact support pair of limbs should be monitored closely in canine hindlimb amputees. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Data-driven stochastic modelling of zebrafish locomotion. (United States)

    Zienkiewicz, Adam; Barton, David A W; Porfiri, Maurizio; di Bernardo, Mario


    In this work, we develop a data-driven modelling framework to reproduce the locomotion of fish in a confined environment. Specifically, we highlight the primary characteristics of the motion of individual zebrafish (Danio rerio), and study how these can be suitably encapsulated within a mathematical framework utilising a limited number of calibrated model parameters. Using data captured from individual zebrafish via automated visual tracking, we develop a model using stochastic differential equations and describe fish as a self propelled particle moving in a plane. Based on recent experimental evidence of the importance of speed regulation in social behaviour, we extend stochastic models of fish locomotion by introducing experimentally-derived processes describing dynamic speed regulation. Salient metrics are defined which are then used to calibrate key parameters of coupled stochastic differential equations, describing both speed and angular speed of swimming fish. The effects of external constraints are also included, based on experimentally observed responses. Understanding the spontaneous dynamics of zebrafish using a bottom-up, purely data-driven approach is expected to yield a modelling framework for quantitative investigation of individual behaviour in the presence of various external constraints or biological assays.

  3. Reciprocal locomotion of dense swimmers in Stokes flow

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Rodriguez, David [Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Lauga, Eric [Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0411 (United States)], E-mail:, E-mail:


    Due to the kinematic reversibility of Stokes flow, a body executing a reciprocal motion (a motion in which the sequence of body configurations remains identical under time reversal) cannot propel itself in a viscous fluid in the limit of negligible inertia; this result is known as Purcell's scallop theorem. In this limit, the Reynolds numbers based on the fluid inertia and on the body inertia are all zero. Previous studies characterized the breakdown of the scallop theorem with fluid inertia. In this paper we show that, even in the absence of fluid inertia, certain dense bodies undergoing reciprocal motion are able to swim. Using Lorentz's reciprocal theorem, we first derive the general differential equations that govern the locomotion kinematics of a dense swimmer. We demonstrate that no reciprocal swimming is possible if the body motion consists only of tangential surface deformation (squirming). We then apply our general formulation to compute the locomotion of four simple swimmers, each with a different spatial asymmetry, that perform normal surface deformations. We show that the resulting swimming speeds (or rotation rates) scale as the first power of a properly defined 'swimmer Reynolds number', demonstrating thereby a continuous breakdown of the scallop theorem with body inertia.

  4. Contact enhancement of locomotion in spreading cell colonies (United States)

    D'Alessandro, Joseph; Solon, Alexandre P.; Hayakawa, Yoshinori; Anjard, Christophe; Detcheverry, François; Rieu, Jean-Paul; Rivière, Charlotte


    The dispersal of cells from an initially constrained location is a crucial aspect of many physiological phenomena, ranging from morphogenesis to tumour spreading. In such processes, cell-cell interactions may deeply alter the motion of single cells, and in turn the collective dynamics. While contact phenomena like contact inhibition of locomotion are known to come into play at high densities, here we focus on the little explored case of non-cohesive cells at moderate densities. We fully characterize the spreading of micropatterned colonies of Dictyostelium discoideum cells from the complete set of individual trajectories. From data analysis and simulation of an elementary model, we demonstrate that contact interactions act to speed up the early population spreading by promoting individual cells to a state of higher persistence, which constitutes an as-yet unreported contact enhancement of locomotion. Our findings also suggest that the current modelling paradigm of memoryless active particles may need to be extended to account for the history-dependent internal state of motile cells.

  5. Locomotion and drag in wet and dry granular media (United States)

    Goldman, Daniel; Kuckuk, Robyn; Sharpe, Sarah


    Many animals move within substrates such as soil and dry sand; the resistive properties of such granular materials (GM) can depend on water content and compaction, but little is known about how such parameters affect locomotion or the relevant physics of drag and penetration. We developed a system to create homogeneous wet GM of varying moisture content and compaction in quantities sufficient to study the burial and subsurface locomotion of the Ocellated skink (C. ocellatus) a desert-generalist lizard. X-ray imaging revealed that in wet and dry GM the lizard slowly buried (~ 30 seconds) propagating a wave from head to tail, while moving in a start-stop motion. During forward movement, the head oscillated, and the forelimb on the convex side of the body propelled the animal. Although body kinematics (and ``slip'') were similar in both substrates, the burial depth was smaller in wet GM. Penetration and drag force experiments on smooth cylinders revealed that wet GM was ~ 3 × more resistive than dry GM, suggesting that during burial the lizard operated near its maximum force producing capability and was thus constrained by environmental properties. work supported by NSF PoLS.

  6. Spatial assignment of emissions using a new locomotive emissions model. (United States)

    Gould, Gregory M; Niemeier, Deb A


    Estimates of fuel use and air pollutant emissions from freight rail currently rely highly on aggregate methods and largely obsolete data which offer little insight into contemporary air quality problems. Because the freight industry is for the most part privately held and data are closely guarded for competitive reasons, the challenge is to produce robust estimates using current reporting requirements, while accurately portraying the spatial nature of freight rail impacts. This research presents a new spatially resolved model for estimating air pollutant emissions (hydrocarbons, carbon monoxide, nitrogen oxides, particulate matter less than 10 μm in diameter, sulfur dioxide, and carbon dioxide) from locomotives. Emission estimates are based on track segment level data including track grade, type of train traffic (bulk, intermodal, or manifest) and the local locomotive fleet (EPA tier certification level and fuel efficiency). We model the California Class I freight rail system and compare our results to regional estimates from the California Air Resources Board and to estimates following U.S. Environmental Protection Agency guidance. We find that our results vary considerably from the other methods depending on the region or corridor analyzed. We also find large differences in fuel and emission intensity for individual rail corridors.

  7. Crawling beneath the free surface: Water snail locomotion (United States)

    Lee, Sungyon; Bush, John W. M.; Hosoi, A. E.; Lauga, Eric


    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being generated by the undulation of the snail foot that is separated from the free surface by a thin layer of mucus. Here, a lubrication model is used to describe the mucus flow in the limit of small-amplitude interfacial deformations. By assuming the shape of the snail foot to be a traveling sine wave and the mucus to be Newtonian, an evolution equation for the interface shape is obtained and the resulting propulsive force on the snail is calculated. This propulsive force is found to be nonzero for moderate values of the capillary number but vanishes in the limits of high and low capillary number. Physically, this force arises because the snail's foot deforms the free surface, thereby generating curvature pressures and lubrication flows inside the mucus layer that couple to the topography of the foot.

  8. Hopping locomotion at different gravity: metabolism and mechanics in humans. (United States)

    Pavei, Gaspare; Minetti, Alberto E


    Previous literature on the effects of low gravity on the mechanics and energetics of human locomotion already dealt with walking, running, and skipping. The aim of the present study is to obtain a comprehensive view on that subject by including measurements of human hopping in simulated low gravity, a gait often adopted in many Apollo Missions and documented in NASA footage. Six subjects hopped at different speeds at terrestrial, Martian, and Lunar gravity on a treadmill while oxygen consumption and 3D body kinematic were sampled. Results clearly indicate that hopping is too metabolically expensive to be a sustainable locomotion on Earth but, similarly to skipping (and running), its economy greatly (more than ×10) increases at lower gravity. On the Moon, the metabolic cost of hopping becomes even lower than that of walking, skipping, and running, but the general finding is that gaits with very different economy on Earth share almost the same economy on the Moon. The mechanical reasons for such a decrease in cost are discussed in the paper. The present data, together with previous findings, will allow also to predict the aerobic traverse range/duration of astronauts when getting far from their base station on low gravity planets. Copyright © 2016 the American Physiological Society.

  9. Effects of wearing lower leg compression sleeves on locomotion economy. (United States)

    Kurz, Eduard; Anders, Christoph


    The purpose of this investigation was to assess the effect of compression sleeves on muscle activation cost during locomotion. Twenty-two recreationally active men (age: 25 ± 3 years) ran on a treadmill at four different speeds (ordered sequence of 2.8, 3.3, 2.2, and 3.9 m/s). The tests were performed without (control situation, CON) and while wearing specially designed lower leg compression sleeves (SL). Myoelectric activity of five lower leg muscles (tibialis anterior, fibularis longus, lateral and medial head of gastrocnemius, and soleus) was captured using Surface EMG. To assess muscle activation cost, the cumulative muscle activity per distance travelled (CMAPD) of the CON and SL situations was determined. Repeated measures analyses of variance were performed separately for each muscle. The analyses revealed a reduced lower leg muscle activation cost with respect to test situation for SL for all muscles (p  0.18). The respective significant reductions of CMAPD values during SL ranged between 4% and 16% and were largest at 2.8 m/s. The findings presented point towards an improved muscle activation cost while wearing lower leg compression sleeves during locomotion that have potential to postpone muscle fatigue.

  10. Locomotion and Grasping impairment in preschoolers with autism spectrum disorder

    Directory of Open Access Journals (Sweden)

    Francesca Fulceri


    Full Text Available Objective: To investigate expressiveness of motor impairment in autism spectrum disorder (ASD and its correlation with developmental and clinical features of ASD. Method: Thirty-five male preschoolers with ASD completed the Peabody Developmental Motor Scales-2 (PDMS-2; Folio and Fewell, 2000 and underwent a multidisciplinary assessment including medical examination, standardized assessment of cognitive abilities, administration of Autism_Diagnostic_Observation_Schedule (ADOS and a parent interview about adaptive skills. Results: Results revealed a substantial impairment in locomotion and grasping skills. Both fine and gross motor skills were significantly correlated with non verbal IQ and adaptive behaviours (p<0.01 but not with chronological age or ADOS scores. Children with weaker motor skills have greater cognitive and adaptive behaviours deficits. Conclusions: Motor development in ASD can be detected at preschool age and locomotion and grasping skills are substantially the most impaired area. These findings support the need to assess motor skills in preschoolers with ASD in addition to other developmental skill areas. Along with the increasingly acknowledged importance of motor skills for subsequent social, cognitive, and communicative development our findings support the need to consider motor intervention as a key area in therapeutic program to improve outcome in preschoolers with ASD.

  11. Hybrid magnetic mechanism for active locomotion based on inchworm motion

    International Nuclear Information System (INIS)

    Kim, Sung Hoon; Hashi, Shuichiro; Ishiyama, Kazushi


    Magnetic robots have been studied in the past. Insect-type micro-robots are used in various biomedical applications; researchers have developed inchworm micro-robots for endoscopic use. A biological inchworm has a looping locomotion gait. However, most inchworm micro-robots depend on a general bending, or bellows, motion. In this paper, we introduce a new robotic mechanism using magnetic force and torque control in a rotating magnetic field for a looping gait. The proposed robot is controlled by the magnetic torque, attractive force, and body mechanisms (two stoppers, flexible body, and different frictional legs). The magnetic torque generates a general bending motion. In addition, the attractive force and body mechanisms produce the robot’s looping motion within a rotating magnetic field and without the use of an algorithm for field control. We verified the device’s performance and analyzed the motion through simulations and various experiments. The robot mechanism can be applied to active locomotion for various medical robots, such as wireless endoscopes. (technical note)

  12. Controlling legs for locomotion-insights from robotics and neurobiology. (United States)

    Buschmann, Thomas; Ewald, Alexander; von Twickel, Arndt; Büschges, Ansgar


    Walking is the most common terrestrial form of locomotion in animals. Its great versatility and flexibility has led to many attempts at building walking machines with similar capabilities. The control of walking is an active research area both in neurobiology and robotics, with a large and growing body of work. This paper gives an overview of the current knowledge on the control of legged locomotion in animals and machines and attempts to give walking control researchers from biology and robotics an overview of the current knowledge in both fields. We try to summarize the knowledge on the neurobiological basis of walking control in animals, emphasizing common principles seen in different species. In a section on walking robots, we review common approaches to walking controller design with a slight emphasis on biped walking control. We show where parallels between robotic and neurobiological walking controllers exist and how robotics and biology may benefit from each other. Finally, we discuss where research in the two fields diverges and suggest ways to bridge these gaps.

  13. Fluid Flow Simulation and Energetic Analysis of Anomalocarididae Locomotion (United States)

    Mikel-Stites, Maxwell; Staples, Anne


    While an abundance of animal locomotion simulations have been performed modeling the motions of living arthropods and aquatic animals, little quantitative simulation and reconstruction of gait parameters has been done to model the locomotion of extinct animals, many of which bear little physical resemblance to their modern descendants. To that end, this project seeks to analyze potential swimming patterns used by the anomalocaridid family, (specifically Anomalocaris canadensis, a Cambrian Era aquatic predator), and determine the most probable modes of movement. This will serve to either verify or cast into question the current assumed movement patterns and properties of these animals and create a bridge between similar flexible-bodied swimmers and their robotic counterparts. This will be accomplished by particle-based fluid flow simulations of the flow around the fins of the animal, as well as an energy analysis of a variety of sample gaits. The energy analysis will then be compared to the extant information regarding speed/energy use curves in an attempt to determine which modes of swimming were most energy efficient for a given range of speeds. These results will provide a better understanding of how these long-extinct animals moved, possibly allowing an improved understanding of their behavioral patterns, and may also lead to a novel potential platform for bio-inspired underwater autonomous vehicles (UAVs).

  14. Jumping robots: a biomimetic solution to locomotion across rough terrain. (United States)

    Armour, Rhodri; Paskins, Keith; Bowyer, Adrian; Vincent, Julian; Megill, William; Bomphrey, Richard


    This paper introduces jumping robots as a means to traverse rough terrain; such terrain can pose problems for traditional wheeled, tracked and legged designs. The diversity of jumping mechanisms found in nature is explored to support the theory that jumping is a desirable ability for a robot locomotion system to incorporate, and then the size-related constraints are determined from first principles. A series of existing jumping robots are presented and their performance summarized. The authors present two new biologically inspired jumping robots, Jollbot and Glumper, both of which incorporate additional locomotion techniques of rolling and gliding respectively. Jollbot consists of metal hoop springs forming a 300 mm diameter sphere, and when jumping it raises its centre of gravity by 0.22 m and clears a height of 0.18 m. Glumper is of octahedral shape, with four 'legs' that each comprise two 500 mm lengths of CFRP tube articulating around torsion spring 'knees'. It is able to raise its centre of gravity by 1.60 m and clears a height of 1.17 m. The jumping performance of the jumping robot designs presented is discussed and compared against some specialized jumping animals. Specific power output is thought to be the performance-limiting factor for a jumping robot, which requires the maximization of the amount of energy that can be stored together with a minimization of mass. It is demonstrated that this can be achieved through optimization and careful materials selection.

  15. A Specific Population of Reticulospinal Neurons Controls the Termination of Locomotion

    Directory of Open Access Journals (Sweden)

    Laurent Juvin


    Full Text Available Locomotion requires the proper sequencing of neural activity to start, maintain, and stop it. Recently, brainstem neurons were shown to specifically stop locomotion in mammals. However, the cellular properties of these neurons and their activity during locomotion are still unknown. Here, we took advantage of the lamprey model to characterize the activity of a cell population that we now show to be involved in stopping locomotion. We find that these neurons display a burst of spikes that coincides with the end of swimming activity. Their pharmacological activation ends ongoing swimming, whereas the inactivation of these neurons dramatically impairs the rapid termination of swimming. These neurons are henceforth referred to as stop cells, because they play a crucial role in the termination of locomotion. Our findings contribute to the fundamental understanding of motor control and provide important details about the cellular mechanisms involved in locomotor termination.

  16. [The concept and definition of locomotive syndrome in a super-aged society]. (United States)

    Nakamura, Kozo; Yoshimura, Noriko; Akune, Toru; Ogata, Toru; Tanaka, Sakae


    The population of elderly individuals who need nursing care is rapidly increasing in Japan. Locomotive syndrome involves a decrease in mobility due to locomotive organ dysfunction, and increases risk for dependency on nursing care service. Because gait speed and chair stand time are correlated with such risks, patients with locomotive syndrome are assessed using brief methods such as the two-step test, which involves dividing the maximum stride length by the height of the patient, and the stand-up test, which involves standing on one or both legs at different heights. One leg standing and squatting are recommended as beneficial locomotive home exercises. Locomotive syndrome has been recognized widely in Japan, and included in the National Health Promotion Movement (2013-2022).

  17. 21st Century Locomotive Technology: 2003 Annual Technical Status Report DOE/AL68284-TSR03

    Energy Technology Data Exchange (ETDEWEB)

    Lembit Salasoo


    The 21st Century Locomotive program objective is to develop 25% more efficient freight locomotives by 2010. Diesel engine-related research addresses advanced fuel injection, electric turbocharger and abradable seals. Assembly of a common rail fuel injection test system is underway, and a CFD combustion model has been validated. An electrically assisted turbocharger has been constructed and operated, meeting the generator mode design rating. System characterization and optimization is ongoing. Candidate abradable seal materials have been identified and test coupons prepared. Locomotive system-related research addresses capturing, storing and utilizing regenerative braking energy in a hybrid locomotive, and fuel optimization control. Hybrid locomotive energy storage requirements have been identified and studies on specific energy storage solutions are in progress. Energy management controls have been defined and testing initiated. Train and track parameter identification necessary for fuel optimization has been demonstrated.

  18. A Specific Population of Reticulospinal Neurons Controls the Termination of Locomotion. (United States)

    Juvin, Laurent; Grätsch, Swantje; Trillaud-Doppia, Emilie; Gariépy, Jean-François; Büschges, Ansgar; Dubuc, Réjean


    Locomotion requires the proper sequencing of neural activity to start, maintain, and stop it. Recently, brainstem neurons were shown to specifically stop locomotion in mammals. However, the cellular properties of these neurons and their activity during locomotion are still unknown. Here, we took advantage of the lamprey model to characterize the activity of a cell population that we now show to be involved in stopping locomotion. We find that these neurons display a burst of spikes that coincides with the end of swimming activity. Their pharmacological activation ends ongoing swimming, whereas the inactivation of these neurons dramatically impairs the rapid termination of swimming. These neurons are henceforth referred to as stop cells, because they play a crucial role in the termination of locomotion. Our findings contribute to the fundamental understanding of motor control and provide important details about the cellular mechanisms involved in locomotor termination. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  19. Multibody system dynamics for bio-inspired locomotion: from geometric structures to computational aspects. (United States)

    Boyer, Frédéric; Porez, Mathieu


    This article presents a set of generic tools for multibody system dynamics devoted to the study of bio-inspired locomotion in robotics. First, archetypal examples from the field of bio-inspired robot locomotion are presented to prepare the ground for further discussion. The general problem of locomotion is then stated. In considering this problem, we progressively draw a unified geometric picture of locomotion dynamics. For that purpose, we start from the model of discrete mobile multibody systems (MMSs) that we progressively extend to the case of continuous and finally soft systems. Beyond these theoretical aspects, we address the practical problem of the efficient computation of these models by proposing a Newton-Euler-based approach to efficient locomotion dynamics with a few illustrations of creeping, swimming, and flying.

  20. Can Clinical Assessment of Locomotive Body Function Explain Gross Motor Environmental Performance in Cerebral Palsy? (United States)

    Sanz Mengibar, Jose Manuel; Santonja-Medina, Fernando; Sanchez-de-Muniain, Paloma; Canteras-Jordana, Manuel


    Gross Motor Function Classification System has discriminative purposes but does not assess short-term therapy goals. Locomotion Stages (LS) classify postural body functions and independent activity components. Assessing the relation between Gross Motor Function Classification System level and Locomotion Stages will make us understand if clinical assessment can explain and predict motor environmental performance in cerebral palsy. A total of 462 children were assessed with both scales. High reliability and strong negative correlation (-0.908) for Gross Motor Function Classification System and Locomotion Stages at any age was found. Sensitivity was 83%, and specificity and positive predictive value were 100% within the same age range. Regression analysis showed detailed probabilities for the realization of the Gross Motor Function Classification System depending on the Locomotion Stages and the age group. Postural body function measure with Locomotion Stages is reliable, sensitive, and specific for gross motor function and able to predict environmental performance. © The Author(s) 2015.

  1. Identification of a brainstem circuit regulating visual cortical state in parallel with locomotion. (United States)

    Lee, A Moses; Hoy, Jennifer L; Bonci, Antonello; Wilbrecht, Linda; Stryker, Michael P; Niell, Cristopher M


    Sensory processing is dependent upon behavioral state. In mice, locomotion is accompanied by changes in cortical state and enhanced visual responses. Although recent studies have begun to elucidate intrinsic cortical mechanisms underlying this effect, the neural circuits that initially couple locomotion to cortical processing are unknown. The mesencephalic locomotor region (MLR) has been shown to be capable of initiating running and is associated with the ascending reticular activating system. Here, we find that optogenetic stimulation of the MLR in awake, head-fixed mice can induce both locomotion and increases in the gain of cortical responses. MLR stimulation below the threshold for overt movement similarly changed cortical processing, revealing that MLR's effects on cortex are dissociable from locomotion. Likewise, stimulation of MLR projections to the basal forebrain also enhanced cortical responses, suggesting a pathway linking the MLR to cortex. These studies demonstrate that the MLR regulates cortical state in parallel with locomotion. Copyright © 2014 Elsevier Inc. All rights reserved.


    Directory of Open Access Journals (Sweden)

    B. Ye. Bodnar


    Full Text Available Purpose. The article describes the most common methods for determining the locomotive traction force. Solving the tasks of traction calculations involves determination of the forces influencing the train at every point of the way. When choosing a rational trajectory of the train motion and the development of operational regulations of train driving it is necessary to determine the actual value of the locomotive traction force. Considering various factors, power value of traction electric motor of locomotive may have significant differences. Advancement of the operational definition system of the locomotive traction force during the calculations by electrical parameters of traction electric motor with regard to uneven load of wheel-motor block is the purpose of the article. Methodology. The method of determining the traction force of locomotives and diesel locomotives with electric transmission, which is based on primary data acquisition of traction electric engines of direct current behavior, was proposed. Sensors and their integration into the electrical circuitry of the locomotive in order to get the data in digital form and for operational calculation of the each traction motor mode and the definition of locomotive traction force are presented. Findings. The experimental investigation of the system of locomotive traction force determination with the electric traction motor ED-105 was offered. A comparison of electrical and mechanical power of the electric motor was conducted. Originality. The system of locomotives power operational definition, which takes into account the variable electro-mechanical factors of wheel and motor blocks and increases the accuracy of the calculations, was proposed. Practical value. The system is a part of an onboard complex in definition of energy-efficient regimes for trains movement and provides the definition of accelerating and decelerating forces.

  3. Cholinergic mechanisms in spinal locomotion-potential target for rehabilitation approaches. (United States)

    Jordan, Larry M; McVagh, J R; Noga, B R; Cabaj, A M; Majczyński, H; Sławińska, Urszula; Provencher, J; Leblond, H; Rossignol, Serge


    Previous experiments implicate cholinergic brainstem and spinal systems in the control of locomotion. Our results demonstrate that the endogenous cholinergic propriospinal system, acting via M2 and M3 muscarinic receptors, is capable of consistently producing well-coordinated locomotor activity in the in vitro neonatal preparation, placing it in a position to contribute to normal locomotion and to provide a basis for recovery of locomotor capability in the absence of descending pathways. Tests of these suggestions, however, reveal that the spinal cholinergic system plays little if any role in the induction of locomotion, because MLR-evoked locomotion in decerebrate cats is not prevented by cholinergic antagonists. Furthermore, it is not required for the development of stepping movements after spinal cord injury, because cholinergic agonists do not facilitate the appearance of locomotion after spinal cord injury, unlike the dramatic locomotion-promoting effects of clonidine, a noradrenergic α-2 agonist. Furthermore, cholinergic antagonists actually improve locomotor activity after spinal cord injury, suggesting that plastic changes in the spinal cholinergic system interfere with locomotion rather than facilitating it. Changes that have been observed in the cholinergic innervation of motoneurons after spinal cord injury do not decrease motoneuron excitability, as expected. Instead, the development of a "hyper-cholinergic" state after spinal cord injury appears to enhance motoneuron output and suppress locomotion. A cholinergic suppression of afferent input from the limb after spinal cord injury is also evident from our data, and this may contribute to the ability of cholinergic antagonists to improve locomotion. Not only is a role for the spinal cholinergic system in suppressing locomotion after SCI suggested by our results, but an obligatory contribution of a brainstem cholinergic relay to reticulospinal locomotor command systems is not confirmed by our experiments.

  4. Prototypical versus contemporary Mediterranean Diet. (United States)

    Rizza, W; De Gara, L; Antonelli Incalzi, R; Pedone, C


    To investigate the evolution of the Mediterranean Diet (MD) in a delimited area of Southern Italy, by comparing the diet adopted 60-70 years ago (Prototypical Mediterranean Diet, PMD) with the contemporary one (Contemporary Mediterranean Diet, CMD), and to verify to what extent they fitted the recommendations of the Italian and the USDA dietary guidelines. We recruited a total of 106 participants, divided in two groups. PMD group included 52 women aged >80 years, with a good cognitive function and full independence in basic and instrumental activities of daily living. CMD group included 20 men and 34 women aged 50-60 years. Food intake was assessed by administering the EPIC food frequency questionnaire to each participant, and an additional survey to the PMD subjects only. Both PMD and CMD showed adequate intakes of macronutrients, although some deficiencies related to micronutrient requirements were evident. CMD showed a slightly greater use of animal products, processed and sugary foods, and higher intakes of simple sugars, animal proteins (49.6 vs 28.3 g/day), animal lipids (37.8 vs 20.1 g/day), saturated fats (25.0 vs 15.8 g/day) and cholesterol (305.0 vs 258.5 g/day). PMD showed many similarities to the original version of the MD in terms of macronutrients distribution and food choices. The documented evolution of the dietary habits over a 70 years timespan suggests that nowadays Mediterranean regions adhere less strictly to the original MD, although nutrients intakes are adequate to LARN and USDA recommendations. Copyright © 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

  5. 49 CFR Appendix B to Part 240 - Procedures for Submission and Approval of Locomotive Engineer Qualification Programs (United States)


    ... Locomotive Engineer Qualification Programs B Appendix B to Part 240 Transportation Other Regulations Relating... QUALIFICATION AND CERTIFICATION OF LOCOMOTIVE ENGINEERS Pt. 240, App. B Appendix B to Part 240—Procedures for Submission and Approval of Locomotive Engineer Qualification Programs This appendix establishes procedures...

  6. Review on CNC-Rapid Prototyping (United States)

    Z, M. Nafis O.; Y, Nafrizuan M.; A, Munira M.; J, Kartina


    This article reviewed developments of Computerized Numerical Control (CNC) technology in rapid prototyping process. Rapid prototyping (RP) can be classified into three major groups; subtractive, additive and virtual. CNC rapid prototyping is grouped under the subtractive category which involves material removal from the workpiece that is larger than the final part. Richard Wysk established the use of CNC machines for rapid prototyping using sets of 2½-D tool paths from various orientations about a rotary axis to machine parts without refixturing. Since then, there are few developments on this process mainly aimed to optimized the operation and increase the process capabilities to stand equal with common additive type of RP. These developments include the integration between machining and deposition process (hybrid RP), adoption of RP to the conventional machine and optimization of the CNC rapid prototyping process based on controlled parameters. The article ended by concluding that the CNC rapid prototyping research area has a vast space for improvement as in the conventional machining processes. Further developments and findings will enhance the usage of this method and minimize the limitation of current approach in building a prototype.

  7. Review on CNC-Rapid Prototyping

    International Nuclear Information System (INIS)

    M Nafis O Z; Nafrizuan M Y; Munira M A; Kartina J


    This article reviewed developments of Computerized Numerical Control (CNC) technology in rapid prototyping process. Rapid prototyping (RP) can be classified into three major groups; subtractive, additive and virtual. CNC rapid prototyping is grouped under the subtractive category which involves material removal from the workpiece that is larger than the final part. Richard Wysk established the use of CNC machines for rapid prototyping using sets of 2½-D tool paths from various orientations about a rotary axis to machine parts without refixturing. Since then, there are few developments on this process mainly aimed to optimized the operation and increase the process capabilities to stand equal with common additive type of RP. These developments include the integration between machining and deposition process (hybrid RP), adoption of RP to the conventional machine and optimization of the CNC rapid prototyping process based on controlled parameters. The article ended by concluding that the CNC rapid prototyping research area has a vast space for improvement as in the conventional machining processes. Further developments and findings will enhance the usage of this method and minimize the limitation of current approach in building a prototype.

  8. Prototype-Incorporated Emotional Neural Network. (United States)

    Oyedotun, Oyebade K; Khashman, Adnan


    Artificial neural networks (ANNs) aim to simulate the biological neural activities. Interestingly, many ''engineering'' prospects in ANN have relied on motivations from cognition and psychology studies. So far, two important learning theories that have been subject of active research are the prototype and adaptive learning theories. The learning rules employed for ANNs can be related to adaptive learning theory, where several examples of the different classes in a task are supplied to the network for adjusting internal parameters. Conversely, the prototype-learning theory uses prototypes (representative examples); usually, one prototype per class of the different classes contained in the task. These prototypes are supplied for systematic matching with new examples so that class association can be achieved. In this paper, we propose and implement a novel neural network algorithm based on modifying the emotional neural network (EmNN) model to unify the prototype- and adaptive-learning theories. We refer to our new model as ``prototype-incorporated EmNN''. Furthermore, we apply the proposed model to two real-life challenging tasks, namely, static hand-gesture recognition and face recognition, and compare the result to those obtained using the popular back-propagation neural network (BPNN), emotional BPNN (EmNN), deep networks, an exemplar classification model, and k-nearest neighbor.

  9. Evaluation of a prototype infrasound system

    International Nuclear Information System (INIS)

    Whitaker, R.; Sandoval, T.; Breding, D.; Kromer, D.


    Under Department of Energy sponsorship, Sandia National Laboratories and Los Alamos National Laboratory cooperated to develop a prototype infrasonic array, with associated documentation, that could be used as part of the International Monitoring System. The United States Government or foreign countries could procure commercially available systems based on this prototype to fulfill their Comprehensive Test Ban Treaty (CTBT) obligations. The prototype is a four-element array in a triangular layout as recommended in CD/NTB/WP.224 with an element at each corner and one in the center. The prototype test configuration utilize an array spacing of 1 km. The prototype infrasound system has the following objectives: (1) Provide a prototype that reliably acquires and transmits near real-time infrasonic data to facilitate the rapid location and identification of atmospheric events. (2) Provide documentation that could be used by the United States and foreign countries to procure infrasound systems commercially to fulfill their CTBT responsibilities. Infrasonic monitoring is an effective, low cost technology for detecting atmospheric explosions. The low frequency components of explosion signals propagate to long ranges (few thousand kilometers) where they can be detected with an array of sensors. Los Alamos National Laboratory's expertise in infrasound systems and phenomenology when combined with Sandia's expertise in providing verification quality system for treaty monitoring make an excellent team to provide the prototype infrasound sensor system. By September 1997, the prototype infrasound system will have been procured, integrated, evaluated and documented. Final documentation will include a system requirements document, an evaluation report and a hardware design document. The hardware design document will describe the various hardware components used in the infrasound prototype and their interrelationships

  10. [Rapid prototyping: a very promising method]. (United States)

    Haverman, T M; Karagozoglu, K H; Prins, H-J; Schulten, E A J M; Forouzanfar, T


    Rapid prototyping is a method which makes it possible to produce a three-dimensional model based on two-dimensional imaging. Various rapid prototyping methods are available for modelling, such as stereolithography, selective laser sintering, direct laser metal sintering, two-photon polymerization, laminated object manufacturing, three-dimensional printing, three-dimensional plotting, polyjet inkjet technology,fused deposition modelling, vacuum casting and milling. The various methods currently being used in the biomedical sector differ in production, materials and properties of the three-dimensional model which is produced. Rapid prototyping is mainly usedforpreoperative planning, simulation, education, and research into and development of bioengineering possibilities.

  11. The equine neck and its function during movement and locomotion. (United States)

    Zsoldos, Rebeka R; Licka, Theresia F


    During both locomotion and body movements at stance, the head and neck of the horse are a major craniocaudal and lateral balancing mechanism employing input from the visual, vestibular and proprioceptive systems. The function of the equine neck has recently become the focus of several research groups; this is probably also feeding on an increase of interest in the equine neck in equestrian sports, with a controversial discussion of specific neck positions such as maximum head and neck flexion. The aim of this review is to offer an overview of new findings on the structures and functions of the equine neck, illustrating their interplay. The movement of the neck is based on intervertebral motion, but it is also an integral part of locomotion; this is illustrated by the different neck conformations in the breeds of horses used for various types of work. The considerable effect of the neck movement and posture onto the whole trunk and even the limbs is transmitted via bony, ligamentous and muscular structures. Also, the fact that the neck position can easily be influenced by the rider and/or by the employment of training aids makes it an important avenue for training of new movements of the neck as well as the whole horse. Additionally, the neck position also affects the cervical spinal cord as well as the roots of the spinal nerves; besides the commonly encountered long-term neurological effects of cervical vertebral disorders, short-term changes of neural and muscular function have also been identified in the maximum flexion of the cranial neck and head position. During locomotion, the neck stores elastic energy within the passive tissues such as ligaments, joint capsules and fasciae. For adequate stabilisation, additional muscle activity is necessary; this is learned and requires constant muscle training as it is essential to prevent excessive wear and tear on the vertebral joints and also repetitive or single trauma to the spinal nerves and the spinal cord. The


    Directory of Open Access Journals (Sweden)

    D. M. Kozachenko


    Full Text Available Purpose. At the present time, Ukraine's mainline railway transport is entirely in state ownership. Ukraine has undertaken to implement the European Union Directives providing of non-discriminatory access to the railway infrastructure of independent carriers. A considerable quantity of options significantly affects the working conditions of carriers that do not depend on Ukrzaliznytsia. One of the tasks that arises when performing transportation by independent carriers is the organization of private locomotives operation and their servicing by engine crews. The purpose of the article is to evaluate the technical characteristic of the private locomotives usage in order to perform goods traffic in the direction of sea ports. Methodology. The researches were carried out on the basis of methods for organizing the operational work of railways and methods of traction calculations. Findings. The paper highlights the problem of goods traffic organization to seaports by independent carriers. It determines the requirements for equipment for diesel locomotives and electric locomotives depending on the distance of transportation. Permissible distances that can be served by engine crews in performing the requirements for the duration of their continuous operation were also determined. Schemes of infrastructure objects location for the locomotives and engine crews operation have been developed. It was established that diesel locomotives of independent carriers will be able to serve transportation between loading and unloading stations up to 822 km, and electric locomotives up to 1000 km with the construction of the main part of the locomotive infrastructure at the port station. The performed calculations show the potential coverage of rail transportation to sea ports by independent carriers with the use of its own locomotive infrastructure. To define more exactly the haul length of train servicing by locomotives and locomotives by engine crews, it is necessary

  13. On the neutron jet prototype

    International Nuclear Information System (INIS)

    Cherkasov, A.S.


    Full text: Fast neutrons are proposed to use, in a deep space, as a recoil mass for low-thrust nuclear fission (or fusion) rocket engine instead of hydrogen heated in nuclear reactor up to 2300 - 2700 o C [1, 2]. In particularly, such neutron engines with a long-term operation as well as nuclear powerful or micro-explosions can be used for ensuring of the astronomical safety for the Earth from asteroids in diameter more 50 m. For production of attractive force of 9.81N the propellant expenditure of hydrogen jet with the system specific impulse of ∼ 9000 m s -1 is ∼ 94 kg a day. For fast 1.8 MeV-neutron jet - 45.8 g per day (directed or collimated neutron fluxes). J=10 16 cm -2 s -1 if a cross-section of rocket nozzle is 1m 2 [2]. So, to produce powerful directed or collimated fast neutron fluxes high intensity controlled neutron sources are required (they are, basically, the novel high-flux research reactors, for example, HFRR (Osaka University, Japan), 400 MW (th) and ψ=10 16 cm -2 s -1 ). The most suitable neutron jet prototype is the B-2 facility of the fast reactor BR-5 (SSC RF Obninsk, Russia). This is a 'mono directional disk' with a diameter of 0.25 m; for neutrons with energies > (2, 3) MeV the collimated neutron flux is 10 10 cm -2 s -1 at the reactor power of 5 MW [3]. The intensification of fast neutron fluences may be up to ∼ 21 for the volume fast neutron source (the fast reactor with a diameter of ∼ 0.8 m) and ∼ 39 for point one by using an iron reflecting tube one side of which is closed (end wall - the effects of a n eutron searchlight ) [4]. The thickness of walls is 40 cm [5]. The additional intensification is possible by using 6 LiD-thermal neutron-flux converter into ∼ 14 MeV-neutrons from (dT), ( 6 LiT)-fusion reactions [6

  14. Characterization of Prototype LSST CCDs

    Energy Technology Data Exchange (ETDEWEB)



    The ambitious science goals of the Large Synoptic Survey Telescope (LSST) will be achieved in part by a wide-field imager that will achieve a new level of performance in terms of area, speed, and sensitivity. The instrument performance is dominated by the focal plane sensors, which are now in development. These new-generation sensors will make use of advanced semiconductor technology and will be complemented by a highly integrated electronics package located inside the cryostat. A test laboratory has been set up at Brookhaven National Laboratory (BNL) to characterize prototype sensors and to develop test and assembly techniques for eventual integration of production sensors and electronics into modules that will form the final focal plane. As described in [1], the key requirements for LSST sensors are wideband quantum efficiency (QE) extending beyond lpm in the red, control of point spread function (PSF), and fast readout using multiple amplifiers per chip operated in parallel. In addition, LSST's fast optical system (f71.25) places severe constraints on focal plane flatness. At the chip level this involves packaging techniques to minimize warpage of the silicon die, and at the mosaic level careful assembly and metrology to achieve a high coplanarity of the sensor tiles. In view of the long lead time to develop the needed sensor technology, LSST undertook a study program with several vendors to fabricate and test devices which address the most critical performance features [2]. The remainder of this paper presents key results of this study program. Section 2 summarizes the sensor requirements and the results of design optimization studies, and Section 3 presents the sensor development plan. In Section 4 we describe the test bench at BNL. Section 5 reports measurement results obtained to date oh devices fabricated by several vendors. Section 6 presents a summary of the paper and an outlook for the future work. We present characterization methods and results on

  15. Presentation Trainer Prototype 1.0

    NARCIS (Netherlands)

    Börner, Dirk; Specht, Marcus


    This software sketch comprises the first prototype of the presentation trainer. The application uses the Microsoft Kinect sensor and was built using the Processing 1.5.1 development environment. Available under the GNU LGPL licence version 3 or higher.

  16. Power test for first prototype LIBO module

    CERN Multimedia

    Laurent Guiraud


    The Linac Booster (LIBO) is a prototype machine for producing particle beams for cancer therapy. Hadron therapy techniques are able to reach deep tumours with less damage to surrounding tissue than with conventional radiotherapy.

  17. Norcal Prototype LNG Truck Fleet: Final Results

    Energy Technology Data Exchange (ETDEWEB)


    U.S. DOE and National Renewable Energy Laboratory evaluated Norcal Waste Systems liquefied natural gas (LNG) waste transfer trucks. Trucks had prototype Cummins Westport ISXG engines. Report gives final evaluation results.

  18. Gesture recognition for an exergame prototype

    NARCIS (Netherlands)

    Gacem, Brahim; Vergouw, Robert; Verbiest, Harm; Cicek, Emrullah; Kröse, Ben; van Oosterhout, Tim; Bakkes, S.C.J.


    We will demonstrate a prototype exergame aimed at the serious domain of elderly fitness. The exergame incorporates straightforward means to gesture recognition, and utilises a Kinect camera to obtain 2.5D sensory data of the human user.

  19. Homogeneity of Prototypical Attributes in Soccer Teams

    Directory of Open Access Journals (Sweden)

    Christian Zepp


    Full Text Available Research indicates that the homogeneous perception of prototypical attributes influences several intragroup processes. The aim of the present study was to describe the homogeneous perception of the prototype and to identify specific prototypical subcategories, which are perceived as homogeneous within sport teams. The sample consists of N = 20 soccer teams with a total of N = 278 athletes (age M = 23.5 years, SD = 5.0 years. The results reveal that subcategories describing the cohesiveness of the team and motivational attributes are mentioned homogeneously within sport teams. In addition, gender, identification, team size, and the championship ranking significantly correlate with the homogeneous perception of prototypical attributes. The results are discussed on the basis of theoretical and practical implications.

  20. System design document for the INFLO prototype. (United States)


    This report documents the high level System Design Document (SDD) for the prototype development and : demonstration of the Intelligent Network Flow Optimization (INFLO) application bundle, with a focus on the Speed : Harmonization (SPD-HARM) and Queu...

  1. A prototype threshold Cherenkov counter for DIRAC

    CERN Document Server

    Bragadireanu, M; Cima, E; Dulach, B; Gianotti, P; Guaraldo, C; Iliescu, M A; Lanaro, A; Levi-Sandri, P; Petrascu, C; Girolami, B; Groza, L; Kulikov, A; Kuptsov, A; Topilin, N; Trusov, S


    We have designed, built and tested a gas threshold Cherenkov counter as prototype for a larger counter foreseen for use in the DIRAC experiment, at CERN. We describe the performances of the counter on a test beam.

  2. Building a better snail: Lubrication and adhesive locomotion (United States)

    Chan, Brian; Balmforth, N. J.; Hosoi, A. E.


    Many gastropods, such as slugs and snails, crawl via an unusual mechanism known as adhesive locomotion. We investigate this method of propulsion using two mathematical models: one for direct waves and one for retrograde waves. We then test the effectiveness of both proposed mechanisms by constructing two mechanical crawlers. Each crawler uses a different mechanical strategy to move on a thin layer of viscous fluid. The first uses a flexible flapping sheet to generate lubrication pressures in a Newtonian fluid, which in turn propel the mechanical snail. The second generates a wave of compression on a layer of Laponite, a non-Newtonian, finite-yield stress fluid with characteristics similar to those of snail mucus. This second design can climb smooth vertical walls and perform an inverted traverse.

  3. Bipedal locomotion: toward unified concepts in robotics and neuroscience. (United States)

    Azevedo, Christine; Espiau, Bernard; Amblard, Bernard; Assaiante, Christine


    This review is the result of a joint reflection carried out by researchers in the fields of robotics and automatic control on the one hand and neuroscience on the other, both trying to answer the same question: what are the functional bases of bipedal locomotion and how can they be controlled? The originality of this work is to synthesize the two approaches in order to take advantage of the knowledge concerning the adaptability and reactivity performances of humans and of the rich tools and formal concepts available in biped robotics. Indeed, we claim that the theoretical framework of robotics can enhance our understanding of human postural control by formally expressing the experimental concepts used in neuroscience. Conversely, biological knowledge of human posture and gait can inspire biped robot design and control. Therefore, both neuroscientists and roboticists should find useful information in this paper.

  4. Dynamic control of biped locomotion robot using optimal regulator

    Energy Technology Data Exchange (ETDEWEB)

    Sano, Akihito; Furusho, Junji


    For moving in indoor space, it is generally recognized that biped locomotion is suitable. This paper proposes a hierarchical control strategy for the lower level where the position control or the force control at each joint is implemented. In the upper level control, the robot motion is divided into a sagittal plane and a lateral plane. We applied the optimal control algorithm to the motion control in the lateral plane in order to improve the robustness of the control system. The effects of these control schemes are shown by the experiments using the new walking robot BLR-G 1 and the parallel calculation system. BLR-G 1 has 9 degrees of freedom and equips the foot-pressure-sensors and a rate gyroscope. Complete dynamic walking is realized, in which the cycle for each step is about 1.0 second.

  5. Prototype_Matematikforløb_Sct-Hans

    DEFF Research Database (Denmark)

    Davidsen, Helle Munkholm; Sørensen, Kirsten Bonde; Klitø, Nanna Breinholt


    Forløbet udgør en prototype på et matematikforløb til 8. klasse, som er udviklet til at styrke og fastholde elevers motivation for læring. Formålet med denne prototype er at styrke motivationen for læring gennem synlige læringsmål, faglig differentiering og elevernes medbestemmelse. Didaktisk mål...

  6. Prototype_Danskforløb_Sct.Hans

    DEFF Research Database (Denmark)

    Davidsen, Helle Munkholm; Sørensen, Kirsten Bonde; Klitø, Nanna Breinholt


    Forløbet udgør en prototype på et danskforløb til 4. klasse, som er udviklet til at styrke og fastholde elevers motivation for læring. Formålet med denne prototype er at styrke motivationen for læring gennem synlige læringsmål, faglig differentiering og elevernes medbestemmelse. Didaktisk mål: at...

  7. Implementation of a blockchain workflow management prototype


    Fridgen, Gilbert; Sablowsky, Bernd; Urbach, Nils


    Blockchain technology offers huge potential to various industries and application areas. In a joint applied research project, Fraunhofer Institute for Applied Information Technology (FIT) together with Norddeutsche Landesbank (NORD/LB) identified (inter-company) workflow management as a promising application area and developed a Blockchain prototype for a documentary letter of credit in the international shipping business. In addition to the projects explicit outcome a Blockchain prototype an...

  8. Rapid Prototyping: Technologies, Materials and Advances


    Dudek P.; Rapacz-Kmita A.


    In the context of product development, the term rapid prototyping (RP) is widely used to describe technologies which create physical prototypes directly from digital data. Recently, this technology has become one of the fastest-growing methods of manufacturing parts. The paper provides brief notes on the creation of composites using RP methods, such as stereolithography, selective laser sintering or melting, laminated object modelling, fused deposition modelling or three-dimensional printing....

  9. Progress in Additive Manufacturing and Rapid Prototyping


    Kruth, Jean-Pierre; Leu, MC; Nakagawa, T


    Rapid prototyping generally refers to techniques that produce shaped parts by gradual creation or addition of solid material, therein differing fundamentally from forming and material removal manufacturing techniques. This paper tries to summarize one decade of research and developments in rapid prototyping. The first part surveys some general economical and technological trends. The second part of the paper goes into some more details on a process-by-process basis.

  10. Relating appendicular skeletal variation of sigmodontine rodents to locomotion modes in a phylogenetic context. (United States)

    Carvalho Coutinho, Ludmilla; Alves de Oliveira, João


    Sigmodontinae rodents constitute the second-largest subfamily among mammals. Alongside the taxonomic diversity, they are also ecologically diverse, exhibiting a wide array of locomotion modes, with semifossorial, terrestrial, semiaquatic, scansorial, arboreal, and saltatorial forms. To understand the ecomorphologic aspects that allow these rodents to display such locomotion diversity, we analyzed 35 qualitative characters of the appendicular skeleton (humerus, ulna, radius, scapula, femur, tibia, ilium, ischium and pubis) in 795 specimens belonging to 64 species, 34 genera and 10 tribes, representing all locomotion modes assigned to this subfamily. We performed a statistical analysis based upon the coefficient of trait differentiation to test the congruence of character states and the different locomotion modes. We also mapped characters states in a molecular phylogeny in order to reconstruct ancestral states and to evaluate how appendicular characters evolved within main lineages of Sigmodontinae radiation under a phylogenetic framework. The statistical analyses revealed six characters related to specific locomotion modes, except terrestrial. The mapping and parsimony ancestral states reconstruction identified two characters with phylogenetical signal and eight characters that are exclusively or more frequently recorded in certain modes of locomotion, four of them also detected by the statistical analysis. Notwithstanding the documented morphological variation, few changes characterize the transition to each of the locomotion modes, at least regarding the appendicular skeleton. This finding corroborates previous results that showed that sigmodontines exhibit an all-purpose appendicular morphology that allows them to use and explore a great variety of habitats. © 2017 Anatomical Society.

  11. Self-generated sounds of locomotion and ventilation and the evolution of human rhythmic abilities. (United States)

    Larsson, Matz


    It has been suggested that the basic building blocks of music mimic sounds of moving humans, and because the brain was primed to exploit such sounds, they eventually became incorporated in human culture. However, that raises further questions. Why do genetically close, culturally well-developed apes lack musical abilities? Did our switch to bipedalism influence the origins of music? Four hypotheses are raised: (1) Human locomotion and ventilation can mask critical sounds in the environment. (2) Synchronization of locomotion reduces that problem. (3) Predictable sounds of locomotion may stimulate the evolution of synchronized behavior. (4) Bipedal gait and the associated sounds of locomotion influenced the evolution of human rhythmic abilities. Theoretical models and research data suggest that noise of locomotion and ventilation may mask critical auditory information. People often synchronize steps subconsciously. Human locomotion is likely to produce more predictable sounds than those of non-human primates. Predictable locomotion sounds may have improved our capacity of entrainment to external rhythms and to feel the beat in music. A sense of rhythm could aid the brain in distinguishing among sounds arising from discrete sources and also help individuals to synchronize their movements with one another. Synchronization of group movement may improve perception by providing periods of relative silence and by facilitating auditory processing. The adaptive value of such skills to early ancestors may have been keener detection of prey or stalkers and enhanced communication. Bipedal walking may have influenced the development of entrainment in humans and thereby the evolution of rhythmic abilities.

  12. Trunk orientation causes asymmetries in leg function in small bird terrestrial locomotion. (United States)

    Andrada, Emanuel; Rode, Christian; Sutedja, Yefta; Nyakatura, John A; Blickhan, Reinhard


    In contrast to the upright trunk in humans, trunk orientation in most birds is almost horizontal (pronograde). It is conceivable that the orientation of the heavy trunk strongly influences the dynamics of bipedal terrestrial locomotion. Here, we analyse for the first time the effects of a pronograde trunk orientation on leg function and stability during bipedal locomotion. For this, we first inferred the leg function and trunk control strategy applied by a generalized small bird during terrestrial locomotion by analysing synchronously recorded kinematic (three-dimensional X-ray videography) and kinetic (three-dimensional force measurement) quail locomotion data. Then, by simulating quail gaits using a simplistic bioinspired numerical model which made use of parameters obtained in in vivo experiments with real quail, we show that the observed asymmetric leg function (left-skewed ground reaction force and longer leg at touchdown than at lift-off) is necessary for pronograde steady-state locomotion. In addition, steady-state locomotion becomes stable for specific morphological parameters. For quail-like parameters, the most common stable solution is grounded running, a gait preferred by quail and most of the other small birds. We hypothesize that stability of bipedal locomotion is a functional demand that, depending on trunk orientation and centre of mass location, constrains basic hind limb morphology and function, such as leg length, leg stiffness and leg damping. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  13. Fossils, feet and the evolution of human bipedal locomotion. (United States)

    Harcourt-Smith, W E H; Aiello, L C


    We review the evolution of human bipedal locomotion with a particular emphasis on the evolution of the foot. We begin in the early twentieth century and focus particularly on hypotheses of an ape-like ancestor for humans and human bipedal locomotion put forward by a succession of Gregory, Keith, Morton and Schultz. We give consideration to Morton's (1935) synthesis of foot evolution, in which he argues that the foot of the common ancestor of modern humans and the African apes would be intermediate between the foot of Pan and Hylobates whereas the foot of a hypothetical early hominin would be intermediate between that of a gorilla and a modern human. From this base rooted in comparative anatomy of living primates we trace changing ideas about the evolution of human bipedalism as increasing amounts of postcranial fossil material were discovered. Attention is given to the work of John Napier and John Robinson who were pioneers in the interpretation of Plio-Pleistocene hominin skeletons in the 1960s. This is the period when the wealth of evidence from the southern African australopithecine sites was beginning to be appreciated and Olduvai Gorge was revealing its first evidence for Homo habilis. In more recent years, the discovery of the Laetoli footprint trail, the AL 288-1 (A. afarensis) skeleton, the wealth of postcranial material from Koobi Fora, the Nariokotome Homo ergaster skeleton, Little Foot (Stw 573) from Sterkfontein in South Africa, and more recently tantalizing material assigned to the new and very early taxa Orrorin tugenensis, Ardipithecus ramidus and Sahelanthropus tchadensis has fuelled debate and speculation. The varying interpretations based on this material, together with changing theoretical insights and analytical approaches, is discussed and assessed in the context of new three-dimensional morphometric analyses of australopithecine and Homo foot bones, suggesting that there may have been greater diversity in human bipedalism in the earlier phases

  14. Natural Translating Locomotion Modulates Cortical Activity at Action Observation

    Directory of Open Access Journals (Sweden)

    Thierry Pozzo


    Full Text Available The present study verified if the translational component of locomotion modulated cortical activity recorded at action observation. Previous studies focusing on visual processing of biological motion mainly presented point light walker that were fixed on a spot, thus removing the net translation toward a goal that yet remains a critical feature of locomotor behavior. We hypothesized that if biological motion recognition relies on the transformation of seeing in doing and its expected sensory consequences, a significant effect of translation compared to centered displays on sensorimotor cortical activity is expected. To this aim, we explored whether EEG activity in the theta (4–8 Hz, alpha (8–12 Hz, beta 1 (14–20 Hz and beta 2 (20–32 Hz frequency bands exhibited selectivity as participants viewed four types of stimuli: a centered walker, a centered scrambled, a translating walker and a translating scrambled. We found higher theta synchronizations for observed stimulus with familiar shape. Higher power decreases in the beta 1 and beta 2 bands, indicating a stronger motor resonance was elicited by translating compared to centered stimuli. Finally, beta bands modulation in Superior Parietal areas showed that the translational component of locomotion induced greater motor resonance than human shape. Using a Multinomial Logistic Regression classifier we found that Dorsal-Parietal and Inferior-Frontal regions of interest (ROIs, constituting the core of action-observation system, were the only areas capable to discriminate all the four conditions, as reflected by beta activities. Our findings suggest that the embodiment elicited by an observed scenario is strongly mediated by horizontal body displacement.

  15. Undulatory locomotion of finite filaments: lessons from Caenorhabditis elegans

    International Nuclear Information System (INIS)

    Berman, R S; Kenneth, O; Sznitman, J; Leshansky, A M


    Undulatory swimming is a widespread propulsion strategy adopted by many small-scale organisms including various single-cell eukaryotes and nematodes. In this work, we report a comprehensive study of undulatory locomotion of a finite filament using (i) approximate resistive force theory (RFT) assuming a local nature of hydrodynamic interaction between the filament and the surrounding viscous liquid and (ii) particle-based numerical computations taking into account the intra-filament hydrodynamic interaction. Using the ubiquitous model of a propagating sinusoidal waveform, we identify the limit of applicability of the RFT and determine the optimal propulsion gait in terms of (i) swimming distance per period of undulation and (ii) hydrodynamic propulsion efficiency. The occurrence of the optimal swimming gait maximizing hydrodynamic efficiency at finite wavelength in particle-based computations diverges from the prediction of the RFT. To compare the model swimmer powered by sine wave undulations to biological undulatory swimmers, we apply the particle-based approach to study locomotion of the model organism nematode Caenorhabditis elegans using the swimming gait extracted from experiments. The analysis reveals that even though the amplitude and the wavenumber of undulations are similar to those determined for the best performing sinusoidal swimmer, C. elegans overperforms the latter in terms of both displacement and hydrodynamic efficiency. Further comparison with other undulatory microorganisms reveals that many adopt waveforms with characteristics similar to the optimal model swimmer, yet real swimmers still manage to beat the best performing sine-wave swimmer in terms of distance covered per period. Overall our results underline the importance of further waveform optimization, as periodic undulations adopted by C. elegans and other organisms deviate considerably from a simple sine wave. (paper)

  16. Adaptive Gaze Strategies for Locomotion with Constricted Visual Field

    Directory of Open Access Journals (Sweden)

    Colas N. Authié


    Full Text Available In retinitis pigmentosa (RP, loss of peripheral visual field accounts for most difficulties encountered in visuo-motor coordination during locomotion. The purpose of this study was to accurately assess the impact of peripheral visual field loss on gaze strategies during locomotion, and identify compensatory mechanisms. Nine RP subjects presenting a central visual field limited to 10–25° in diameter, and nine healthy subjects were asked to walk in one of three directions—straight ahead to a visual target, leftward and rightward through a door frame, with or without obstacle on the way. Whole body kinematics were recorded by motion capture, and gaze direction in space was reconstructed using an eye-tracker. Changes in gaze strategies were identified in RP subjects, including extensive exploration prior to walking, frequent fixations of the ground (even knowing no obstacle was present, of door edges, essentially of the proximal one, of obstacle edge/corner, and alternating door edges fixations when approaching the door. This was associated with more frequent, sometimes larger rapid-eye-movements, larger movements, and forward tilting of the head. Despite the visual handicap, the trajectory geometry was identical between groups, with a small decrease in walking speed in RPs. These findings identify the adaptive changes in sensory-motor coordination, in order to ensure visual awareness of the surrounding, detect changes in spatial configuration, collect information for self-motion, update the postural reference frame, and update egocentric distances to environmental objects. They are of crucial importance for the design of optimized rehabilitation procedures.

  17. Visual control of trunk translation and orientation during locomotion. (United States)

    Anson, E; Agada, P; Kiemel, T; Ivanenko, Y; Lacquaniti, F; Jeka, J


    Previous studies have suggested distinct control of gait characteristics in the anterior-posterior (AP) and medial-lateral (ML) directions in response to visual input. Responses were larger to a ML visual stimulus, suggesting that vision plays a larger role in stabilizing gait in the ML direction. Here, we investigated responses of the trunk during locomotion to determine whether a similar direction dependence is observed. We hypothesized that translation of the trunk would show a similar ML dependence on vision, but that angular deviations of the trunk would show equivalent responses in all directions. Subjects stood or walked on a treadmill at 5 km/h while viewing a virtual wall of white triangles that moved in either the AP or ML direction according to a broadband input stimulus. Frequency response functions between the visual scene motion and trunk kinematics revealed that trunk translation gain was larger across all frequencies during walking compared with standing. Trunk orientation responses were not different from standing at very low frequencies; however, at high frequencies, trunk orientation gain was much higher during walking. Larger gains in response to ML visual scene motion were found for all trunk movements. Higher gains in the ML direction while walking suggest that visual feedback may contribute more to the stability of trunk movements in the ML direction. Vision modified trunk movement behavior on both a slow (translation) and fast (orientation) time scale suggesting a priority for minimizing angular deviations of the trunk. Overall, trunk responses to visual input were consistent with the theme that control of locomotion requires higher-level sensory input to maintain stability in the ML direction.

  18. Investigating the role of implicit prototypes in the prototype willingness model. (United States)

    Howell, Jennifer L; Ratliff, Kate A


    One useful theory to predict health behavior is the prototype-willingness model (PWM), which posits that people are more willing to engage in behavior to the extent that they have a positive view of the prototypical person who performs that behavior. The goal of the present research is to test whether adding an implicit measure of prototype favorability might improve explanatory power in the PWM. Two studies examined whether implicit prototype favorability uniquely predicted White women's intentions to engage in healthy sun behavior over the next 3-6 months, and their willingness to engage in risky sun behavior, should the opportunity arise. The results suggested that implicit prototype favorability, particularly implicit prototypes of those who engage in risky UV-related behaviors, uniquely predicted intentions to engage in healthy sun behavior and willingness to engage in risky sun behavior in the PWM.

  19. Field evaluation of prototype electrofibrous filters

    International Nuclear Information System (INIS)

    Kuhl, W.D.; Bergman, W.; Biermann, A.H.; Lum, B.Y.


    New prototype electrofibrous filters were designed, built and evaluated in laboratory tests and in field installations. Two prototypes were designed for use in nuclear ventilation ducts as prefilters to HEPA filters. One prototype is designed to be a permanent component of the ventilation system while the other is a disposable unit. The disposable electrofibrous prefilter was installed in the exhaust stream of a glove box in which barrels of uranium turnings are burned. Preliminary tests show the disposal prefilter is effectively prolonging the HEPA filter life. An earlier prototype of the rolling prefilter was upgraded to meet the increased requirements for installation in a nuclear facility. This upgraded prototype was evaluated in the fire test facility at LLNL and shown to be effective in protecting HEPA filters from plugging under the most severe smoke conditions. The last prototype described in this report is a recirculating air filter. After demonstrating a high performance in laboratory tests the unit was shipped to Savannah River where it is awaiting installation in a Pu fuel fabrication facility. An analysis of the particulate problem in Savannah River indicates that four recirculating air filter will save $172,000 per year in maintenance costs

  20. MPACT Fast Neutron Multiplicity System Prototype Development

    Energy Technology Data Exchange (ETDEWEB)

    D.L. Chichester; S.A. Pozzi; J.L. Dolan; M.T. Kinlaw; S.J. Thompson; A.C. Kaplan; M. Flaska; A. Enqvist; J.T. Johnson; S.M. Watson


    This document serves as both an FY2103 End-of-Year and End-of-Project report on efforts that resulted in the design of a prototype fast neutron multiplicity counter leveraged upon the findings of previous project efforts. The prototype design includes 32 liquid scintillator detectors with cubic volumes 7.62 cm in dimension configured into 4 stacked rings of 8 detectors. Detector signal collection for the system is handled with a pair of Struck Innovative Systeme 16-channel digitizers controlled by in-house developed software with built-in multiplicity analysis algorithms. Initial testing and familiarization of the currently obtained prototype components is underway, however full prototype construction is required for further optimization. Monte Carlo models of the prototype system were performed to estimate die-away and efficiency values. Analysis of these models resulted in the development of a software package capable of determining the effects of nearest-neighbor rejection methods for elimination of detector cross talk. A parameter study was performed using previously developed analytical methods for the estimation of assay mass variance for use as a figure-of-merit for system performance. A software package was developed to automate these calculations and ensure accuracy. The results of the parameter study show that the prototype fast neutron multiplicity counter design is very nearly optimized under the restraints of the parameter space.

  1. Measurement of black carbon emissions from in-use diesel-electric passenger locomotives in California (United States)

    Tang, N. W.; Kirchstetter, T.; Martien, P. T.; Apte, J.


    Black carbon (BC) emission factors were measured for a California commuter rail line fleet of diesel-electric passenger locomotives (Caltrain). The emission factors are based on BC and carbon dioxide (CO2) concentrations in the exhaust plumes of passing locomotives, which were measured from pedestrian overpasses using portable analyzers. Each of the 29 locomotives in the fleet was sampled on 4-20 separate occasions at different locations to characterize different driving modes. The average emission factor expressed as g BC emitted per kg diesel consumed was 0.87 ± 0.66 g kg-1 (±1 standard deviation, n = 362 samples). BC emission factors tended to be higher for accelerating locomotives traveling at higher speeds with engines in higher notch settings. Higher fuel-based BC emission factors (g kg-1) were measured for locomotives equipped with separate "head-end" power generators (SEP-HEPs), which power the passenger cars, while higher time-based emission factors (g h-1) were measured for locomotives without SEP-HEPs, whose engines are continuously operated at high speeds to provide both head-end and propulsion power. PM10 emission factors, estimated assuming a BC/PM10 emission ratio of 0.6 and a typical power output-to-fuel consumption ratio, were generally in line with the Environmental Protection Agency's locomotive exhaust emission standards. Per passenger mile, diesel-electric locomotives in this study emit only 20% of the CO2 emitted by typical gasoline-powered light-duty vehicles (i.e., cars). However, the reduction in carbon footprint (expressed in terms of CO2 equivalents) due to CO2 emissions avoidance from a passenger commuting by train rather than car is appreciably offset by the locomotive's higher BC emissions.

  2. [The significance of exercises and sports in the locomotive syndrome prevention. (United States)

    Ishibashi, Hideaki

    In Japan, the world's fastest aging country, the locomotive syndrome that shows a decrease in the mobility due to dysfunctions of the locomotor organs is a major risk factor of long-term care need in the old age. Exercises and sports habits are well reviewed to lead to the improvement and maintenance of motor function, and exercises are also useful in the prevention of a number of musculoskeletal diseases. In addition, several trials with the exercise intervention indicated improvement in motor function, suggesting exercises could prevent the locomotive syndrome. In future, prevalence of exercise habits may lead to decrease the prevalence of locomotive syndrome, resulting in elongation of the healthy life span.

  3. Salicylic acid-dependent gene expression is activated by locomotion mucus of different molluscan herbivores. (United States)

    Meldau, Stefan; Kästner, Julia; von Knorre, Dietrich; Baldwin, Ian T


    Slugs and snails specifically secrete mucus to aid their locomotion. This mucus is the contact material between molluscan herbivores and plants. We have recently shown that the locomotion mucus of the slug Deroceras reticulatum contains salicylic acid (SA).(1) When applied to wounded leaves of Arabidopsis thaliana this mucus induces the activity of the SA-responsive pathogenesis related 1 (PR1) promotor1. Here we analyzed PR1 promotor activity in response to treatments with locomotion mucus of eight slugs and snails. Although none of the mucus contained SA, their application still elicited PR1 promotor activity. These data provide further insights into the complex interactions between molluscan herbivores and plants.

  4. A survey report for the design of biped locomotion robot: the WL-12 (Waseda Leg-12)

    Energy Technology Data Exchange (ETDEWEB)

    Takanishi, Atsuo; Kato, Ichiro [Waseda Univ., Tokyo (Japan); Kume, Etsuo


    A mechanical design study of biped locomotion robots is going on at JAERI within the scope of the Human Acts Simulation Program (HASP). The design study at JAERI is of an arbitrarily mobile robot for inspection of nuclear facilities. A survey has been performed for collecting useful information from already existing biped locomotion robots. This is a survey report of the biped locomotion robot: the WL-12 designed and developed at Waseda University. This report includes the mechanical model and control system designs. (author).

  5. The New Era of Virtual Reality Locomotion: A Systematic Literature Review of Techniques and a Proposed Typology

    Directory of Open Access Journals (Sweden)

    Costas Boletsis


    Full Text Available The latest technical and interaction advancements that took place in the Virtual Reality (VR field have marked a new era, not only for VR, but also for VR locomotion. Although the latest advancements in VR locomotion have raised the interest of both researchers and users in analyzing and experiencing current VR locomotion techniques, the field of research on VR locomotion, in its new era, is still uncharted. In this work, VR locomotion is explored through a systematic literature review investigating empirical studies of VR locomotion techniques from 2014–2017. The review analyzes the VR locomotion techniques that have been studied, their interaction-related characteristics and the research topics that were addressed in these studies. Thirty-six articles were identified as relevant to the literature review, and the analysis of the articles resulted in 73 instances of 11 VR locomotion techniques, such as real-walking, walking-in-place, point and teleport, joystick-based locomotion, and more. Results showed that since the VR revival, the focus of VR locomotion research has been on VR technology and various technological aspects, overshadowing the investigation of user experience. From an interaction perspective, the majority of the utilized and studied VR locomotion techniques were found to be based on physical interaction, exploiting physical motion cues for navigation in VR environments. A significant contribution of the literature review lies in the proposed typology for VR locomotion, introducing four distinct VR locomotion types: motion-based, room scale-based, controller-based and teleportation-based locomotion.

  6. Prototype superconducting magnet for the FFAG accelerator

    International Nuclear Information System (INIS)

    Obana, T.; Ogitsu, T.; Yamamoto, A.; Yoshimoto, M.; Mori, Y.; Fujii, T.; Iwasa, M.; Orikasa, T.


    A study of a superconducting magnet for the Fixed Field Alternating Gradient (FFAG) accelerator has been performed. The FFAG accelerator requires static magnetic field, and it is suitable for superconducting magnet applications, because problems associated with time varying magnetic field such as eddy current loss can be eliminated. The superconducting magnet, which can generate high magnetic field, is possible to realize a higher beam energy with a given accelerator size or the size to be smaller for a given beam energy. The FFAG accelerator magnet is demanded to have a complicated nonlinear magnetic field with high accuracy. As a first prototype superconducting coil, the coil configuration which consists of left-right asymmetric cross-section and large aperture has been designed. The prototype coil has been successfully developed by using a 6-axis Computer Numerical Control (CNC) winding machine. The magnetic field of the prototype coil has been demonstrated in warm measurement. As a consequence, the technical feasibility has been verified with the prototype coil development and the performance test. In addition, the technology components developed in the prototype coil have a possibility to transfer to a fusion magnet

  7. Close encounters of the prototype kind

    CERN Multimedia


    CERN is building a new control centre for the operation of its entire accelerator complex and technical infrastructure. The prototype console for the new centre has just been installed and tested. Close encounters of the prototype kind CERN is building a new control centre for the operation of its entire accelerator complex and technical infrastructure. The prototype console for the new centre has just been installed and tested. The prototype of the control consoles that will be at the heart of the future CERN Control Centre (CCC) has just been installed in the Roy Billinge Room in Building 354. Until now, there have been four separate control rooms for the CERN accelerators and technical infrastructure. The CCC, which will be located on the Prévessin site, will bring them all together in a single room. The Centre will consist of 40 consoles for four different areas (LHC, SPS, PS complex and technical infrastructure). The prototype was tested by the technicians for a month. Following installation and con...

  8. A multi-perspective review of microbial fuel-cells for wastewater treatment: Bio-electro-chemical, microbiologic and modeling aspects (United States)

    Capodaglio, Andrea G.; Molognoni, Daniele; Pons, Anna Vilajeliu


    Microbial Fuel Cells (MFCs) represent a still novel technology for the recovery of energy and resources through wastewater treatment. Although the technology is quite appealing, due its potential benefits, its practical application is still hampered by several drawbacks, such as systems instability (especially when attempting to scale-up reactors from laboratory prototype), internally competing microbial reactions, and limited power generation. This paper is an attempt to address several of the operational issues related to MFCs application to wastewater treatment, in particular when dealing with simultaneous organic matter and nitrogen pollution control. Reactor configuration, operational schemes, electrochemical and microbiological characterization, optimization methods and modelling strategies are reviewed and discussed with a multidisciplinary, multi-perspective approach. The conclusions drawn herein can be of practical interest for all MFC researchers dealing with domestic or industrial wastewater treatment..

  9. LSTM-Based Temperature Prediction for Hot-Axles of Locomotives

    Directory of Open Access Journals (Sweden)

    Luo Can


    Full Text Available The reliability of locomotives plays a central role for the smooth operation of railway systems. Hot-axle failures are one of the most commonly found problems leading to locomotive accidents. Since the operating status of the locomotive axle bearings can be distinctly reflected by the axle temperatures, online temperature monitoring has become an essential way to detect hot-axle failures. In this work, we explore the feasibility of predict the hot-axle failures by identifying the temperature from predicted nominal values. We propose a data-driven approach based on the Long Short-Term Memory (LSTM network to predict the sensor temperature for axle bearings. The effectiveness of the prediction model was validated with operation data collected from commercial locomotives. With a prediction accuracy is within a few percent, the proposed techniques can be used as a dynamic reference for hot-axle monitoring.

  10. Kinematics and the Implementation of a Modular Caterpillar Robot in Trapezoidal Wave Locomotion

    Directory of Open Access Journals (Sweden)

    Hongxing Wei


    Full Text Available With the development of bionic engineering, research into bionic robots has become a popular topic. In this field, the design of robotic mechanisms to realize the locomotion of insects forms a significant research branch. The current paper presents a caterpillar robotic mechanism that is composed of our newly-developed self-assembly modular robots (Sambot. A trapezoidal wave locomotion gait is planned for the caterpillar mechanism and the kinematics equations are established and solved analytically for such locomotion. The variations of the kinematics quantities are illustrated and discussed. The variation of the jump of the angular acceleration indicates that it is better to apply the trapezoidal wave gait to low velocity situations. Finally, the obtained data of the kinematics quantities is used to perform the gait control locomotion experiment and the errors of the experimental data are analysed in depth.

  11. The Effects of Natural Locomotion on Maneuvering Task Performance in Virtual and Real Environments

    National Research Council Canada - National Science Library

    Unguder, Eray


    This thesis investigates human performance differences on maneuvering tasks in virtual and real spaces when a natural locomotion technique is used as opposed to an abstraction through a device such as a...

  12. 49 CFR 222.21 - When must a locomotive horn be used? (United States)


    ... or lead cab car shall be sounded when such locomotive or lead cab car is approaching a public highway... equipped with automatic flashing lights and gates and the gates are fully lowered; or (2) There are no...


    Directory of Open Access Journals (Sweden)

    A. M. Muha


    Full Text Available In the article the structural reliability of different variants of structured schemes of the steady-state converter for traction drive of promising multi-system electric locomotives with asynchronous traction engines is compared.

  14. Physiological aspects of legged terrestrial locomotion the motor and the machine

    CERN Document Server

    Cavagna, Giovanni


    This book offers a succinct but comprehensive description of the mechanics of muscle contraction and legged terrestrial locomotion. It describes on the one hand how the fundamental properties of muscle tissue affect the mechanics of locomotion, and on the other, how the mechanics of locomotion modify the mechanism of muscle operation under different conditions. Further, the book reports on the design and results of experiments conducted with two goals. The first was to describe the physiological function of muscle tissue (which may be considered as the “motor”) contracting at a constant length, during shortening, during lengthening, and under a condition that occurs most frequently in the back-and-forth movement of the limbs during locomotion, namely the stretch-shortening cycle of the active muscle. The second objective was to analyze the interaction between the motor and the “machine” (the skeletal lever system) during walking and running in different scenarios with respect to speed, step frequency,...

  15. Locomotive fuel vapor reclamation system field evaluation and cost-benefit analysis : draft final report. (United States)


    This report summarizes the results of the work performed to install a diesel vapor reclamation unit (DVRU) on an SD70 MAC : locomotive of BNSF Railways and its performance evaluation during freight railroad service. One complete DVRU with several : s...

  16. Arousal and locomotion make distinct contributions to cortical activity patterns and visual encoding (United States)

    Vinck, Martin; Batista-Brito, Renata; Knoblich, Ulf; Cardin, Jessica A.


    Spontaneous and sensory-evoked cortical activity is highly state-dependent, yet relatively little is known about transitions between distinct waking states. Patterns of activity in mouse V1 differ dramatically between quiescence and locomotion, but this difference could be explained by either motor feedback or a change in arousal levels. We recorded single cells and local field potentials from area V1 in mice head-fixed on a running wheel and monitored pupil diameter to assay arousal. Using naturally occurring and induced state transitions, we dissociated arousal and locomotion effects in V1. Arousal suppressed spontaneous firing and strongly altered the temporal patterning of population activity. Moreover, heightened arousal increased the signal-to-noise ratio of visual responses and reduced noise correlations. In contrast, increased firing in anticipation of and during movement was attributable to locomotion effects. Our findings suggest complementary roles of arousal and locomotion in promoting functional flexibility in cortical circuits. PMID:25892300

  17. Locomotion concerns with moral usefulness: When liberals endorse binding moral foundations. (United States)

    Cornwell, James F M; Higgins, E Tory


    Moral Foundations Theory has provided a framework for understanding the endorsement of different moral beliefs. Our research investigated whether there are other reasons to endorse moral foundations in addition to epistemic concerns; specifically, the perceived social usefulness of moral foundations. In Study 1, we demonstrate that those showing stronger locomotion concerns for controlling movement tend toward a higher endorsement of binding foundations, and that this effect is stronger among political liberals who otherwise do not typically endorse these foundations. In Study 2, we show that priming participants with assessment concerns (emphasizing truth) rather than locomotion concerns (emphasizing control) reduces the response variance among liberals and also removes the association between locomotion and the binding foundations. In Study 3, we directly ask participants to focus on moral truth versus moral usefulness, with moral truth replicating the Study 2 effect of assessment priming, and moral usefulness replicating the effect of locomotion priming.


    Directory of Open Access Journals (Sweden)

    P. O. Loza


    Full Text Available The methods of determination of equivalent load current in tests of electric locomotive traction engines without forced ventilation with use of the results of qualification test of engines of certain types are offered in the article.


    Directory of Open Access Journals (Sweden)

    A. Y. Kuzyshyn


    Full Text Available Purpose. When locomotives move in curved sections of the railway track, horizontal forces arise, which lead to pressing the ridge of the wheel pair to the railway track. The article is aimed to develop a method for determining the frame force acting on the bogie from the side of body of the locomotive section using the current methodology of calculating the lateral force. It is also aimed to determine the basic parameters that influence the value of the frame force. It is necessary to construct the dependencies of the frame force on the travel time of electric locomotive in the corresponding curve changing these parameters. Methodology. As is known, the electric locomotive is a multimass mechanical system. We will assume that this system consists of seven bodies: a body, two frames of carriages and four wheel sets. To determine the lateral force acting on the rail from the wheelset one need to solve differential equations of motion of locomotive bogie in curves of small radius. Using the equations of kinetostatics for wheelset one should come to determining the frame force acting on the car bogie from the side of body of the locomotive section. The nominal geometric and mass parameters of parts and components of electric locomotive are taken in the calculations. The curve radius, the length of transition curve, the length of circular curve, the longitudinal slope of railway track and other parameters are fixed values. Findings. There were obtained calculated values of the frame force of electric locomotive VL80 acting on the bogie from the side of body of the locomotive section. Based on the obtained results there were built the dependencies of frame force on the travel time of electric locomotive on the corresponding curve when changing the speed and corresponding elevation of the outer rail. Originality. On the basis of the existing methodology for calculating the lateral force it was developed the method for determining the frame force acting

  20. Profile and genetic parameters of dairy cattle locomotion score and lameness across lactation. (United States)

    Kougioumtzis, A; Valergakis, G E; Oikonomou, G; Arsenos, G; Banos, G


    This study investigated the profile of locomotion score and lameness before the first calving and throughout the first (n=237) and second (n=66) lactation of 303 Holstein cows raised on a commercial farm. Weekly heritability estimates of locomotion score and lameness, and their genetic and phenotypic correlations with milk yield, body condition score, BW and reproduction traits were derived. Daughter future locomotion score and lameness predictions from their sires��� breeding values for conformation traits were also calculated. First-lactation cows were monitored weekly from 6 weeks before calving to the end of lactation. Second-lactation cows were monitored weekly throughout lactation. Cows were locomotion scored on a scale from one (sound) to five (severely lame); a score greater than or equal to two defined presence of lameness. Cows��� weekly body condition score and BW was also recorded. These records were matched to corresponding milk yield records, where the latter were 7-day averages on the week of inspection. The total number of repeated records amounted to 12 221. Data were also matched to the farm���s reproduction database, from which five traits were derived. Statistical analyses were based on uni- and bivariate random regression models. The profile analysis showed that locomotion and lameness problems in first lactation were fewer before and immediately after calving, and increased as lactation progressed. The profile of the two traits remained relatively constant across the second lactation. Highest heritability estimates were observed in the weeks before first calving (0.66 for locomotion score and 0.54 for lameness). Statistically significant genetic correlations were found for first lactation weekly locomotion score and lameness with body condition score, ranging from ���0.31 to ���0.65 and from ���0.44 to ���0.76, respectively, suggesting that cows genetically pre-disposed for high body condition score

  1. Prototype design of an engineer collision protection system (United States)


    This research program was sponsored by the Federal Railroad Administration (FRA) Office of Research and Development in support of the advancement of improved safety standards for passenger rail vehicles. In a train collision, the cab or locomotive en...

  2. Kinematics and the Implementation of a Modular Caterpillar Robot in Trapezoidal Wave Locomotion


    Hongxing Wei; Yuanyang Cui; Haiyuan Li; Jindong Tan; Yong Guan; Yong-Dong Li


    With the development of bionic engineering, research into bionic robots has become a popular topic. In this field, the design of robotic mechanisms to realize the locomotion of insects forms a significant research branch. The current paper presents a caterpillar robotic mechanism that is composed of our newly-developed self-assembly modular robots (Sambot). A trapezoidal wave locomotion gait is planned for the caterpillar mechanism and the kinematics equations are established and solved analy...

  3. Development of generalized dynamic model of oscillations of cylinder case of diesel engine of locomotive

    Directory of Open Access Journals (Sweden)

    Irina YUTKINA


    Full Text Available An engineering method of design, worked out by the authors, is considered in the paper. It allows to carry out design of amplitude-frequency specter and vibration loading of cylinder cases of the diesel engine of locomotive with account of cavitation-erosion damage. Offered method of design of parameters of cavitation-erosion damage may be used in design of new structures of diesel engines of locomotives and systems of cooling.

  4. Inferring Characteristics of Sensorimotor Behavior by Quantifying Dynamics of Animal Locomotion (United States)

    Leung, KaWai

    Locomotion is one of the most well-studied topics in animal behavioral studies. Many fundamental and clinical research make use of the locomotion of an animal model to explore various aspects in sensorimotor behavior. In the past, most of these studies focused on population average of a specific trait due to limitation of data collection and processing power. With recent advance in computer vision and statistical modeling techniques, it is now possible to track and analyze large amounts of behavioral data. In this thesis, I present two projects that aim to infer the characteristics of sensorimotor behavior by quantifying the dynamics of locomotion of nematode Caenorhabditis elegans and fruit fly Drosophila melanogaster, shedding light on statistical dependence between sensing and behavior. In the first project, I investigate the possibility of inferring noxious sensory information from the behavior of Caenorhabditis elegans. I develop a statistical model to infer the heat stimulus level perceived by individual animals from their stereotyped escape responses after stimulation by an IR laser. The model allows quantification of analgesic-like effects of chemical agents or genetic mutations in the worm. At the same time, the method is able to differentiate perturbations of locomotion behavior that are beyond affecting the sensory system. With this model I propose experimental designs that allows statistically significant identification of analgesic-like effects. In the second project, I investigate the relationship of energy budget and stability of locomotion in determining the walking speed distribution of Drosophila melanogaster during aging. The locomotion stability at different age groups is estimated from video recordings using Floquet theory. I calculate the power consumption of different locomotion speed using a biomechanics model. In conclusion, the power consumption, not stability, predicts the locomotion speed distribution at different ages.

  5. Ergonomics of locomotive design in South African Gold and Platinum mines.

    CSIR Research Space (South Africa)

    Smith, JR


    Full Text Available , a practical strategy was devised for the improvement of the current fleet. Aspects covered during the study included: • analysis of the locomotive operator tasks. • identification of the ergonomics aspects and mechanical engineering... to determine reach, posture, field of view and control locations for the operator. • determining the design modifications, which would improve the overall operation of the mine locomotives in South African gold and platinum mines • formu...

  6. Signals from the ventrolateral thalamus to the motor cortex during locomotion (United States)

    Marlinski, Vladimir; Nilaweera, Wijitha U.; Zelenin, Pavel V.; Sirota, Mikhail G.


    The activity of the motor cortex during locomotion is profoundly modulated in the rhythm of strides. The source of modulation is not known. In this study we examined the activity of one of the major sources of afferent input to the motor cortex, the ventrolateral thalamus (VL). Experiments were conducted in chronically implanted cats with an extracellular single-neuron recording technique. VL neurons projecting to the motor cortex were identified by antidromic responses. During locomotion, the activity of 92% of neurons was modulated in the rhythm of strides; 67% of cells discharged one activity burst per stride, a pattern typical for the motor cortex. The characteristics of these discharges in most VL neurons appeared to be well suited to contribute to the locomotion-related activity of the motor cortex. In addition to simple locomotion, we examined VL activity during walking on a horizontal ladder, a task that requires vision for correct foot placement. Upon transition from simple to ladder locomotion, the activity of most VL neurons exhibited the same changes that have been reported for the motor cortex, i.e., an increase in the strength of stride-related modulation and shortening of the discharge duration. Five modes of integration of simple and ladder locomotion-related information were recognized in the VL. We suggest that, in addition to contributing to the locomotion-related activity in the motor cortex during simple locomotion, the VL integrates and transmits signals needed for correct foot placement on a complex terrain to the motor cortex. PMID:21994259

  7. Extensor motoneurone properties are altered immediately before and during fictive locomotion in the adult decerebrate rat. (United States)

    MacDonell, C W; Power, K E; Chopek, J W; Gardiner, K R; Gardiner, P F


    This study examined motoneurone properties during fictive locomotion in the adult rat for the first time. Fictive locomotion was induced via electrical stimulation of the mesencephalic locomotor region in decerebrate adult rats under neuromuscular blockade to compare basic and rhythmic motoneurone properties in antidromically identified extensor motoneurones during: (1) quiescence, before and after fictive locomotion; (2) the 'tonic' period immediately preceding locomotor-like activity, whereby the amplitude of peripheral flexor (peroneal) and extensor (tibial) nerves are increased but alternation has not yet occurred; and (3) locomotor-like episodes. Locomotion was identified by alternating flexor-extensor nerve activity, where the motoneurone either produced membrane oscillations consistent with a locomotor drive potential (LDP) or did not display membrane oscillation during alternating nerve activity. Cells producing LDPs were referred to as such, while those that did not were referred to as 'idle' motoneurones. LDP and idle motoneurones during locomotion had hyperpolarized spike threshold (Vth ; LDP: 3.8 mV; idle: 5.8 mV), decreased rheobase and an increased discharge rate (LDP: 64%; idle: 41%) during triangular ramp current injection even though the frequency-current slope was reduced by 70% and 55%, respectively. Modulation began in the tonic period immediately preceding locomotion, with a hyperpolarized Vth and reduced rheobase. Spike frequency adaptation did not occur in spiking LDPs or firing generated from sinusoidal current injection, but occurred during a sustained current pulse during locomotion. Input conductance showed no change. Results suggest motoneurone modulation occurs across the pool and is not restricted to motoneurones engaged in locomotion. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  8. Bone-free: soft mechanics for adaptive locomotion. (United States)

    Trimmer, B A; Lin, Huai-ti


    Muscular hydrostats (such as mollusks), and fluid-filled animals (such as annelids), can exploit their constant-volume tissues to transfer forces and displacements in predictable ways, much as articulated animals use hinges and levers. Although larval insects contain pressurized fluids, they also have internal air tubes that are compressible and, as a result, they have more uncontrolled degrees of freedom. Therefore, the mechanisms by which larval insects control their movements are expected to reveal useful strategies for designing soft biomimetic robots. Using caterpillars as a tractable model system, it is now possible to identify the biomechanical and neural strategies for controlling movements in such highly deformable animals. For example, the tobacco hornworm, Manduca sexta, can stiffen its body by increasing muscular tension (and therefore body pressure) but the internal cavity (hemocoel) is not iso-barometric, nor is pressure used to directly control the movements of its limbs. Instead, fluid and tissues flow within the hemocoel and the body is soft and flexible to conform to the substrate. Even the gut contributes to the biomechanics of locomotion; it is decoupled from the movements of the body wall and slides forward within the body cavity at the start of each step. During crawling the body is kept in tension for part of the stride and compressive forces are exerted on the substrate along the axis of the caterpillar, thereby using the environment as a skeleton. The timing of muscular activity suggests that crawling is coordinated by proleg-retractor motoneurons and that the large segmental muscles produce anterograde waves of lifting that do not require precise timing. This strategy produces a robust form of locomotion in which the kinematics changes little with orientation. In different species of caterpillar, the presence of prolegs on particular body segments is related to alternative kinematics such as "inching." This suggests a mechanism for the

  9. Mobile Prototyping Platforms for Remote Engineering Applications

    Directory of Open Access Journals (Sweden)

    Karsten Henke


    Full Text Available This paper describes a low-cost mobile communication platform as a universal rapid-prototyping system, which is based on the Quadrocopter concept. At the Integrated Hardware and Software Systems Group at the Ilmenau University of Technology these mobile platforms are used to motivate bachelor and master students to study Computer Engineering sciences. This could be done by increasing their interest in technical issues, using this platform as integral part of a new ad-hoc lab to demonstrate different aspects in the area of Mobile Communication as well as universal rapid prototyping nodes to investigate different mechanisms for self-organized mobile communication systems within the International Graduate School on Mobile Communications. Beside the three fields of application, the paper describes the current architecture concept of the mobile prototyping platform as well as the chosen control mechanism and the assigned sensor systems to fulfill all the required tasks.

  10. Lightweight composite fighting cover prototype development program

    Energy Technology Data Exchange (ETDEWEB)

    Wrenn, G.E. Jr.; Frame, B.J.; Gwaltney, R.C.; Akerman, M.A.


    The U.S. Army Field Assistance Science and Technology Program requested Oak Ridge National Laboratory (ORNL) to demonstrate the use of lightweight composite materials in construction of overhead covers for reinforced infantry fighting positions. In recent years, ORNL researchers have designed and tested several concepts for lightweight ballistic protection structures, and they have developed numerous prototype composite structures for military and civilian applications. In the current program, composite panel designs and materials are tested and optimized to meet anticipated static and dynamic load conditions for the overhead cover structure. Ten prototype composite covers were built at ORNL for use in Army field tests. Each composite cover has a nominal surface area of 12 ft[sup 2] and a nominal weight of 8 lb. Four of the prototypes are made with folding sections to improve their handling characteristics. The composite covers exhibit equivalent performance in Army field tests to covers made with conventional materials that weigh four times as much.


    Energy Technology Data Exchange (ETDEWEB)

    Thomas A. Ulrich; Roger Lew; Ronald L. Boring; Ken Thomas


    A computerized operator support system (COSS) is proposed for use in nuclear power plants to assist control room operators in addressing time-critical plant upsets. A COSS is a collection of technologies to assist operators in monitoring overall plant performance and making timely, informed decisions on appropriate control actions for the projected plant condition. A prototype COSS was developed in order to demonstrate the concept and provide a test bed for further research. The prototype is based on four underlying elements consisting of a digital alarm system, computer-based procedures, piping and instrumentation diagram system representations, and a recommender module for mitigation actions. The initial version of the prototype is now operational at the Idaho National Laboratory using the Human System Simulation Laboratory.

  12. Specification of a commercial SFAT device prototype

    International Nuclear Information System (INIS)

    Tiitta, A.; Pitkaenen, V.; Tarvainen, M.


    The project for the development of the Spent Fuel Attribute Tester (SFAT) under the Task-A-563 of the Finnish Support Programme has proceeded to the prototype design phase. Radiation data of the AFR Storage (TVO KPA-Store) of the TVO Power Company, Finland, relevant to the optimal design of the measurement geometry has been measured and will be shortly reported. The requirements and constraints imposed to this kind of device by the user (IAEA), nuclear safety authorities (represented by STUK) and the nuclear power companies (represented by TVO) have been worked out. The feasibility of a design that can be approved by all parties has been established. The specifications relevant for the design for the design of a commercial SFAT prototype, will be given. Considerations as for the operation procedure, maintenance and safety will be made. Finally, some recommendations for the further advancement of the SFAT prototype project will be given. (orig.). (1 ref., 5 figs., 2 tabs.)

  13. Generalizing Prototype Theory: A Formal Quantum Framework (United States)

    Aerts, Diederik; Broekaert, Jan; Gabora, Liane; Sozzo, Sandro


    Theories of natural language and concepts have been unable to model the flexibility, creativity, context-dependence, and emergence, exhibited by words, concepts and their combinations. The mathematical formalism of quantum theory has instead been successful in capturing these phenomena such as graded membership, situational meaning, composition of categories, and also more complex decision making situations, which cannot be modeled in traditional probabilistic approaches. We show how a formal quantum approach to concepts and their combinations can provide a powerful extension of prototype theory. We explain how prototypes can interfere in conceptual combinations as a consequence of their contextual interactions, and provide an illustration of this using an intuitive wave-like diagram. This quantum-conceptual approach gives new life to original prototype theory, without however making it a privileged concept theory, as we explain at the end of our paper. PMID:27065436

  14. HSI Prototypes for Human Systems Simulation Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Jokstad, Håkon [Idaho National Lab. (INL), Idaho Falls, ID (United States); McDonald, Rob [Idaho National Lab. (INL), Idaho Falls, ID (United States)


    This report describes in detail the design and features of three Human System Interface (HSI) prototypes developed by the Institutt for Energiteknikk (IFE) in support of the U.S. Department of Energy’s Light Water Reactor Sustainability Program under Contract 128420 through Idaho National Laboratory (INL). The prototypes are implemented for the Generic Pressurized Water Reactor simulator and installed in the Human Systems Simulation Laboratory at INL. The three prototypes are: 1) Power Ramp display 2) RCS Heat-up and Cool-down display 3) Estimated time to limit display The power ramp display and the RCS heat-up/cool-down display are designed to provide good visual indications to the operators on how well they are performing their task compared to their target ramp/heat-up/cool-down rate. The estimated time to limit display is designed to help operators restore levels or pressures before automatic or required manual actions are activated.

  15. Licensing management system prototype system design

    International Nuclear Information System (INIS)

    Immerman, W.H.; Arcuni, A.A.; Elliott, J.M.; Chapman, L.D.


    This report is a design document for a prototype implementation of a licensing management system (LMS) as defined in SAND83-7080. It describes the concept of operations for full implementation of an LMS in accordance with the previously defined functional requirements. It defines a subset of a full LMS suitable for meeting prototype implementation goals, and proposes a system design for this subset. The report describes overall system design considerations consistent with, but more explicit than the general characteristics required by the LMS functional definition. A high level design is presented for just those functions selected for prototype implementation. The report also provides a data element dictionary describing the structured logical data elements required to implement the selected functions

  16. A Versatile Prototyping System for Capacitive Sensing

    Directory of Open Access Journals (Sweden)

    Daniel HRACH


    Full Text Available This paper presents a multi-purpose and easy to handle rapid prototyping platform that has been designed for capacitive measurement systems. The core of the prototype platform is a Digital Signal Processor board that allows for the entire data acquisition, data (pre- processing and storage, and communication with any host computer. The platform is running on uCLinux operating system and features the possibility of a fast design and evaluation of capacitive sensor developments. To show the practical benefit of the prototyping platform, three exemplary applications are presented. For all applications, the platform is just plugged to the electrode structure of the sensor front-end without the need for analogue signal pre-conditioning.

  17. Prototype Hanford Surface Barrier: Design basis document

    International Nuclear Information System (INIS)

    Myers, D.R.; Duranceau, D.A.


    The Hanford Site Surface Barrier Development Program (BDP) was organized in 1985 to develop the technology needed to provide a long-term surface barrier capability for the Hanford Site and other arid sites. This document provides the basis of the prototype barrier. Engineers and scientists have momentarily frozen evolving barrier designs and incorporated the latest findings from BDP tasks. The design and construction of the prototype barrier has required that all of the various components of the barrier be brought together into an integrated system. This integration is particularly important because some of the components of the protective barreir have been developed independently of other barreir components. This document serves as the baseline by which future modifications or other barrier designs can be compared. Also, this document contains the minutes of meeting convened during the definitive design process in which critical decisions affecting the prototype barrier's design were made and the construction drawings

  18. Generalizing Prototype Theory: A Formal Quantum Framework

    Directory of Open Access Journals (Sweden)

    Diederik eAerts


    Full Text Available Theories of natural language and concepts have been unable to model the flexibility, creativity, context-dependence, and emergence, exhibited by words, concepts and their combinations. The mathematical formalism of quantum theory has instead been successful in capturing these phenomena such as graded membership, situational meaning, composition of categories, and also more complex decision making situations, which cannot be modeled in traditional probabilistic approaches. We show how a formal quantum approach to concepts and their combinations can provide a powerful extension of prototype theory. We explain how prototypes can interfere in conceptual combinations as a consequence of their contextual interactions, and provide an illustration of this using an intuitive wave-like diagram. This quantum-conceptual approach gives new life to original prototype theory, without however making it a privileged concept theory, as we explain at the end of our paper.

  19. Locomotion of inchworm-inspired robot made of smart soft composite (SSC)

    International Nuclear Information System (INIS)

    Wang, Wei; Lee, Jang-Yeob; Rodrigue, Hugo; Song, Sung-Hyuk; Ahn, Sung-Hoon; Chu, Won-Shik


    A soft-bodied robot made of smart soft composite with inchworm-inspired locomotion capable of both two-way linear and turning movement has been proposed, developed, and tested. The robot was divided into three functional parts based on the different functions of the inchworm: the body, the back foot, and the front foot. Shape memory alloy wires were embedded longitudinally in a soft polymer to imitate the longitudinal muscle fibers that control the abdominal contractions of the inchworm during locomotion. Each foot of the robot has three segments with different friction coefficients to implement the anchor and sliding movement. Then, utilizing actuation patterns between the body and feet based on the looping gait, the robot achieves a biomimetic inchworm gait. Experiments were conducted to evaluate the robot’s locomotive performance for both linear locomotion and turning movement. Results show that the proposed robot’s stride length was nearly one third of its body length, with a maximum linear speed of 3.6 mm s −1 , a linear locomotion efficiency of 96.4%, a maximum turning capability of 4.3 degrees per stride, and a turning locomotion efficiency of 39.7%. (paper)

  20. Crouching to fit in: the energetic cost of locomotion in tunnels. (United States)

    Horner, Angela M; Hanna, Jandy B; Biknevicius, Audrone R


    Animals that are specialized for a particular habitat or mode of locomotion often demonstrate locomotor efficiency in a focal environment when compared to a generalist species. However, measurements of these focal habitats or behaviors are often difficult or impossible to do in the field. In this study, the energetics and kinematics of simulated tunnel locomotion by two unrelated semi-fossorial mammals, the ferret and degu, were analyzed using open-flow respirometry and digital video. Animals were trained to move inside of normal (unconstrained, overground locomotion) and height-decreased (simulated tunnel, adjusted to tolerance limits for each species) Plexiglas chambers that were mounted flush onto a treadmill. Both absolute and relative tunnel performance differed between the species; ferrets tolerated a tunnel height that forced them to crouch at nearly 25% lower hip height than in an unconstrained condition, whereas degus would not perform on the treadmill past a ∼9% reduction in hip height. Both ferrets and degus exhibited significantly higher metabolic rates and cost of transport (CoT) values when moving in the tunnel condition relative to overground locomotion. When comparing CoT values across small (locomotion, whereas degus were very close to the line of best fit. Although tunnel locomotion requires a more striking change in posture for ferrets, ferrets are more efficient locomotors in both conditions than mammals of similar mass. © 2016. Published by The Company of Biologists Ltd.

  1. The medial preoptic area modulates cocaine-induced locomotion in male rats. (United States)

    Will, Ryan G; Martz, Julia R; Dominguez, Juan M


    Cocaine-induced locomotion is mediated by dopamine in the nucleus accumbens (NAc). Recent evidence indicates that the medial preoptic area (mPOA), a region in the rostral hypothalamus, modulates cocaine-induced dopamine in the NAc. Specifically, rats with lesions of the mPOA experienced a greater increase in dopamine following cocaine administration than rats with sham lesions. Whether the mPOA similarly influences cocaine-induced locomotion is not known. Here we examined whether radiofrequency or neurotoxic lesions of the mPOA in male rats influence changes in locomotion that follow cocaine administration. Locomotion was measured following cocaine administration in male rats with neurotoxic, radiofrequency, or sham lesions of the mPOA. Results indicate that bilateral lesions of the mPOA facilitated cocaine-induced locomotion. This facilitation was independent of lesion type, as increased locomotion was observed with either approach. These findings support a role for the mPOA as an integral region in the processing of cocaine-induced behavioral response, in this case locomotor activity. Published by Elsevier B.V.

  2. The leg stiffnesses animals use may improve the stability of locomotion. (United States)

    Shen, ZhuoHua; Seipel, Justin


    Despite a wide diversity of running animals, their leg stiffness normalized by animal size and weight (a relative leg stiffness) resides in a narrow range between 7 and 27. Here we determine if the stability of locomotion could be a driving factor for the tight distribution of animal leg stiffness. We simulated an established physics-based model (the actuated Spring-Loaded Inverted Pendulum model) of animal running and found that, with the same energetic cost, perturbations to locomotion are optimally corrected when relative leg stiffness is within the biologically observed range. Here we show that the stability of locomotion, in combination with energetic cost, could be a significant factor influencing the nearly universally observed animal relative leg stiffness range. The energetic cost of locomotion has been widely acknowledged as influencing the evolution of physiology and locomotion behaviors. Specifically, its potential importance for relative leg stiffness has been demonstrated. Here, we demonstrate that stability of locomotion may also be a significant factor influencing relative leg stiffness. Published by Elsevier Ltd.

  3. Prototype ion source for JT-60 neutral beam injectors

    International Nuclear Information System (INIS)

    Akiba, M.


    A prototype ion source for JT-60 neutral beam injectors has been fabricated and tested. Here, we review the construction of the prototype ion source and report the experimental results about the source characteristics that has been obtained at this time. The prototype ion source is now installed at the prototype unit of JT-60 neutral beam injection units and the demonstration of the performances of the ion source and the prototype unit has just started

  4. The NA48 liquid krypton prototype calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Barr, G.D.; Buchholz, P.; Carosi, R.; Coward, D.; Cundy, D.; Doble, N.; Gatignon, L.; Gonidec, A.; Hallgren, B.; Kesseler, G.; Lacourt, A.; Laverriere, G.; Linser, G.; Mast, M.; Schilly, P.; Schinzel, D.; Seidl, W.; Taureg, H.; Wahl, H.; Wicht, P. (CERN, Geneva (Switzerland)); Bertanza, L.; Bigi, A.; Calafiura, P.; Casali, R.; Cerri, C.; Fantechi, R.; Gennaro, G.; Gorini, B.; Mannelli, I.; Marzulli, V.; Pierazzini, G.; Schiuma, D.; Sergiampietri, F. (INFN, Pisa (Italy) Scuola Normale, Pisa (Italy) Univ. Pisa (Italy)); Bederede, D.; Debeer, M.; Debu, P.; Peyaud, B. (CE-Saclay-DAPNIA, 91 - Gif-sur-Yvette (France)); Kreutz, A. (Univ. Gesamthochschule Siegen (Germany)); Griesmayer, E.; Markytan, M.; Neuhofer, G.; Pernicka, M.; Taurok, A.; Viehhauser, G.; Wulz, C.E. (Oesterreichische Akademie der Wissenschaften, Inst. fuer Hochenergiephysik, Vienna (Austria)); Cagliari-Cambridge-CERN-Dubna-Edingburgh-Ferrara-Mainz-Perugia-Pisa-Saclay-Siegen-Torino-Vienna Collaboration


    The NA48 experiment for a precision measurement of the CP violation parameter element of'/element of in K[sup 0][yields]2[pi] decays will require a fast electromagnetic calorimeter with excellent energy and time resolution. A quasi homogeneous calorimeter using liquid krypton and a fast readout with 40 MHz FADCs is proposed. A prototype with 400 kg of liquid krypton was built and tested in an electron beam. Results for the energy, space and time resolution of this prototype are given. (orig.).

  5. User prototypes as partly unconscious communication

    DEFF Research Database (Denmark)

    Glasemann, Marie; Kanstrup, Anne Marie


    In this paper, we introduce user prototypes as a technique that supports users’ articulation of emotions relevant for design: dreams, fears, motivations – their feelings and aspirations. Following Bateson’s writings about communication through art, we consider user prototypes as “partly unconscious...... communication” and propose to analyze them by focusing on the emotional articulations integrated in the users’ design language. We illustrate this with an example from a design research project on designing learning technology for young diabetics. The example shows how young people with diabetes can express...

  6. Rapid Prototyping: Technologies, Materials and Advances

    Directory of Open Access Journals (Sweden)

    Dudek P.


    Full Text Available In the context of product development, the term rapid prototyping (RP is widely used to describe technologies which create physical prototypes directly from digital data. Recently, this technology has become one of the fastest-growing methods of manufacturing parts. The paper provides brief notes on the creation of composites using RP methods, such as stereolithography, selective laser sintering or melting, laminated object modelling, fused deposition modelling or three-dimensional printing. The emphasis of this work is on the methodology of composite fabrication and the variety of materials used in these technologies.

  7. From research plots to prototype biomass plantations

    Energy Technology Data Exchange (ETDEWEB)

    Kenney, W.A.; Vanstone, B.J.; Gambles, R.L.; Zsuffa, L. [Univ. of Toronto, Ontario (Canada)


    The development of biomass energy plantations is now expanding from the research plot phase into the next level of development at larger scale plantings. This is necessary to provide: more accurate information on biomass yields, realistic production cost figures, venues to test harvesting equipment, demonstration sites for potential producers, and a supply of feedstock for prototype conversion facilities. The paper will discuss some of these objectives and some of the challenges encountered in the scale-up process associated with a willow prototype plantation project currently under development in Eastern Canada.

  8. Video prototype of the interactive operating theatre

    DEFF Research Database (Denmark)


    theatre. Based on the findings from our field work, we have built the ActiveTheatre, a C&A prototype. ActiveTheatre is built to support collaboration in and around the operating theatre, to capture events instead of automatically capturing eve- rything, and to be integrated with existing applications...... already present in the operation theatre. The ActiveTheatre prototype has been developed in close co- operation with surgeons and nurses at a local hospital. The work on the proto- type and our initial evaluations have provided an insight into how to design, capture and access applications that are going...

  9. Modelling and Control of the Wavestar Prototype

    DEFF Research Database (Denmark)

    Hansen, Rico Hjerm; Kramer, Morten M.


    Algorithm (WPEA), applied to the full-scale Wavestar Prototype for maximizing energy extraction. The WPEA is optimized based on simulations of the point absorbers in different sea states. Hence, a presentation of a hydrodynamic model of the Wavestar is included in the paper. A simplified Power Take-Off (PTO......) is also added to the model, enabling the optimization of the WPEA to take into account the PTO constraints of PTO bandwidth and force limitations. The predicted results of the optimized WPEA are compared to real measurements from theWavestar Prototype, showing good compliance....

  10. RK-TBA prototype RF source

    International Nuclear Information System (INIS)

    Houck, T.; Anderson, D.; Giordano, G.


    A prototype rf power source based on the Relativistic Klystron Two-Beam Accelerator (RK-TBA) concept is being constructed at the Lawrence Berkeley National Laboratory to study physics, engineering, and costing issues. The prototype is described and compared to a full scale design appropriate for driving the Next Linear Collider (NLC). Specific details of the induction core tests and pulsed power system are presented. The 1-MeV, 1.2-kA induction gun currently under construction is also described in detail

  11. Prototype of an excimer laser for microprocessing (United States)

    Iwanejko, Leszek; Pokora, Ludwik J.; Wolinski, Wieslaw L.


    The paper presents a brief description of a prototype of a XeC1 excimer laser for micraprocessing of materials. The planned main parameters of the laserare as follows: wavelength . . . . . . . . . . . . . . . . . . . . . . . . . 308 nm -''energyofapulse. . . . . . . . . . . . . lOOmJ -pulseduration (FWHM) . . . . . . . . . . . . . . . 2Ons repetition frequency . . . . . . . . . . . . . . 1O Hz peak power of a pulse . . . . . . . . . . . . . . . 5 MW With respect to currently carrried works with the prototype we show only preliminary results of testing of a laser head. The obtained maximum laser pulse energy exceeded 90 ml. However it should be pointed out that this value was obtained without any opt i mi z at i on of the 1 aser.

  12. The prototype of radioactive ion source

    CERN Document Server

    Aleksandrov, A V; Kot, N K; Andrighetto, A; Stroe, L


    The design and experimental results of the RIB source prototype are presented.A source will have the container of sup 2 sup 3 sup 5 U compounds heated up to 2200-2500 degree C. Vapors of uranium fission obtained when the ion source is irradiated by the high-energy neutron flux, are then ionized and extracted from the source. In the experiments with the prototype loaded by sup 1 sup 2 C the source working temperature 2700 degree C was reached, the carbon ion current 10 nA was obtained. The total operation time of more than 100 hours with no performance degradation was demonstrated.

  13. Bristle-Bots: a model system for locomotion and swarming (United States)

    Giomi, Luca; Hawley-Weld, Nico; Mahadevan, L.


    The term swarming describes the ability of a group of similarly sized organisms to move coherently in space and time. This behavior is ubiquitous among living systems: it occurs in sub-cellular systems, bacteria, insects, fish, birds, pedestrians and in general in nearly any group of individuals endowed with the ability to move and sense. Here we address the problem of the origin of collective behavior in systems of self-propelled agents whose only social capability is given by aligning contact interactions. Our model system consists of a collection of Bristle-Bots, simple automata made from a toothbrush and the vibrating device of a cellular phone. When Bristle-Bots are confined in a limited space, increasing their number drives a transition from a disordered and uncoordinated motion to an organized collective behavior. This can occur through the formation of a swirling cluster of robots or a collective dynamical arrest, according to the type of locomotion implemented in the single devices. It is possible to move between these two major regimes by adjusting a single construction parameter.

  14. Energy expenditure for thermoregulation and locomotion in emperor penguins. (United States)

    Pinshow, B; Fedak, M A; Battles, D R; Schmidt-Nielsen, K


    During the antarctic winter emperor penguins (Aptenodytes forsteri) spend up to four mo fasting while they breed at rookeries 80 km or more from the sea, huddling close together in the cold. This breeding cycle makes exceptional demands on their energy reserves, and we therefore studied their thermoregulation and locomotion. Rates of metabolism were measured in five birds (mean body mass, 23.37 kg) at ambient temperatures ranging from 25 to -47 degrees C. Between 20 and -10 degrees C the metabolic rate (standard metabolic rate (SMR)) remained neraly constant, about 42.9 W. Below -10 degrees C metabolic rate increased lineraly with decreasing ambient temperature and at -47 degrees C it was 70% above the SMR. Mean thermal conductance below -10 degrees C was 1.57 W m-2 degrees C-1. Metabolic rate during treadmill walking increased linearly with increasing speed. Our data suggest that walking 200 km (from the sea to the rookery and back) requires less than 15% of the energy reserves of a breeding male emperor penguin initially weighing 35 kg. The high energy requirement for thermoregulation (about 85%) would, in the absence of huddling, probably exceed the total energy reserves.

  15. A jump persistent turning walker to model zebrafish locomotion. (United States)

    Mwaffo, Violet; Anderson, Ross P; Butail, Sachit; Porfiri, Maurizio


    Zebrafish are gaining momentum as a laboratory animal species for the investigation of several functional and dysfunctional biological processes. Mathematical models of zebrafish behaviour are expected to considerably aid in the design of hypothesis-driven studies by enabling preliminary in silico tests that can be used to infer possible experimental outcomes without the use of zebrafish. This study is motivated by observations of sudden, drastic changes in zebrafish locomotion in the form of large deviations in turn rate. We demonstrate that such deviations can be captured through a stochastic mean reverting jump diffusion model, a process that is commonly used in financial engineering to describe large changes in the price of an asset. The jump process-based model is validated on trajectory data of adult subjects swimming in a shallow circular tank obtained from an overhead camera. Through statistical comparison of the empirical distribution of the turn rate against theoretical predictions, we demonstrate the feasibility of describing zebrafish as a jump persistent turning walker. The critical role of the jump term is assessed through comparison with a simplified mean reversion diffusion model, which does not allow for describing the heavy-tailed distributions observed in the fish turn rate. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  16. The forward undulatory locomotion of Ceanorhabditis elegans in viscoelastic fluids (United States)

    Shen, Amy; Ulrich, Xialing


    Caenorhabditis elegans is a soil dwelling roundworm that has served as model organisms for studying a multitude of biological and engineering phenomena. We study the undulatory locomotion of nematode in viscoelastic fluids with zero-shear viscosity varying from 0.03-75 Pa .s and relaxation times ranging from 0-350 s. We observe that the averaged normalized wavelength of swimming worm is essentially the same as that in Newtonian fluids. The undulatory frequency f shows the same reduction rate with respect to zero-shear viscosity in viscoelastic fluids as that found in the Newtonian fluids, meaning that the undulatory frequency is mainly controlled by the fluid viscosity. However, the moving speed Vm of the worm shows more distinct dependence on the elasticity of the fluid and exhibits a 4% drop with each 10-fold increase of the Deborah number De, a dimensionless number characterizing the elasticity of a fluid. To estimate the swimming efficiency coefficient and the ratio K =CN /CL of resistive coefficients of the worm in various viscoelastic fluids, we show that whereas it would take the worm around 7 periods to move a body length in a Newtonian fluid, it would take 27 periods to move a body length in a highly viscoelastic fluid.

  17. Modeling posture-dependent leg actuation in sagittal plane locomotion

    International Nuclear Information System (INIS)

    Schmitt, J; Clark, J


    The spring loaded inverted pendulum template has been shown to accurately model the steady locomotion dynamics of a variety of running animals, and has served as the inspiration for an entire class of dynamic running robots. While the template models the leg dynamics by an energy-conserving spring, insects and animals have structures that dissipate, store and produce energy during a stance phase. Recent investigations into the spring-like properties of limbs, as well as animal response to drop-step perturbations, suggest that animals use their legs to manage energy storage and dissipation, and that this management is important for gait stability. In this paper, we extend our previous analysis of control of the spring loaded inverted pendulum template via changes in the leg touch-down angle to include energy variations during the stance phase. Energy variations are incorporated through leg actuation that varies the force-free leg length during the stance phase, yet maintains qualitatively correct force and velocity profiles. In contrast to the partially asymptotically stable gaits identified in previous analyses, incorporating energy and leg angle variations in this manner produces complete asymptotic stability. Drop-step perturbation simulations reveal that the control strategy is rather robust, with gaits recovering from drops of up to 30% of the nominal hip height.

  18. Reinforcement learning of periodical gaits in locomotion robots (United States)

    Svinin, Mikhail; Yamada, Kazuyaki; Ushio, S.; Ueda, Kanji


    Emergence of stable gaits in locomotion robots is studied in this paper. A classifier system, implementing an instance- based reinforcement learning scheme, is used for sensory- motor control of an eight-legged mobile robot. Important feature of the classifier system is its ability to work with the continuous sensor space. The robot does not have a prior knowledge of the environment, its own internal model, and the goal coordinates. It is only assumed that the robot can acquire stable gaits by learning how to reach a light source. During the learning process the control system, is self-organized by reinforcement signals. Reaching the light source defines a global reward. Forward motion gets a local reward, while stepping back and falling down get a local punishment. Feasibility of the proposed self-organized system is tested under simulation and experiment. The control actions are specified at the leg level. It is shown that, as learning progresses, the number of the action rules in the classifier systems is stabilized to a certain level, corresponding to the acquired gait patterns.

  19. Markerless 3D motion capture for animal locomotion studies

    Directory of Open Access Journals (Sweden)

    William Irvin Sellers


    Full Text Available Obtaining quantitative data describing the movements of animals is an essential step in understanding their locomotor biology. Outside the laboratory, measuring animal locomotion often relies on video-based approaches and analysis is hampered because of difficulties in calibration and often the limited availability of possible camera positions. It is also usually restricted to two dimensions, which is often an undesirable over-simplification given the essentially three-dimensional nature of many locomotor performances. In this paper we demonstrate a fully three-dimensional approach based on 3D photogrammetric reconstruction using multiple, synchronised video cameras. This approach allows full calibration based on the separation of the individual cameras and will work fully automatically with completely unmarked and undisturbed animals. As such it has the potential to revolutionise work carried out on free-ranging animals in sanctuaries and zoological gardens where ad hoc approaches are essential and access within enclosures often severely restricted. The paper demonstrates the effectiveness of video-based 3D photogrammetry with examples from primates and birds, as well as discussing the current limitations of this technique and illustrating the accuracies that can be obtained. All the software required is open source so this can be a very cost effective approach and provides a methodology of obtaining data in situations where other approaches would be completely ineffective.

  20. An Adaptive Classification Strategy for Reliable Locomotion Mode Recognition

    Directory of Open Access Journals (Sweden)

    Ming Liu


    Full Text Available Algorithms for locomotion mode recognition (LMR based on surface electromyography and mechanical sensors have recently been developed and could be used for the neural control of powered prosthetic legs. However, the variations in input signals, caused by physical changes at the sensor interface and human physiological changes, may threaten the reliability of these algorithms. This study aimed to investigate the effectiveness of applying adaptive pattern classifiers for LMR. Three adaptive classifiers, i.e., entropy-based adaptation (EBA, LearnIng From Testing data (LIFT, and Transductive Support Vector Machine (TSVM, were compared and offline evaluated using data collected from two able-bodied subjects and one transfemoral amputee. The offline analysis indicated that the adaptive classifier could effectively maintain or restore the performance of the LMR algorithm when gradual signal variations occurred. EBA and LIFT were recommended because of their better performance and higher computational efficiency. Finally, the EBA was implemented for real-time human-in-the-loop prosthesis control. The online evaluation showed that the applied EBA effectively adapted to changes in input signals across sessions and yielded more reliable prosthesis control over time, compared with the LMR without adaptation. The developed novel adaptive strategy may further enhance the reliability of neurally-controlled prosthetic legs.