WorldWideScience

Sample records for auxiliary navigation mechanism

  1. Mechanical (turbines and auxiliary equipment)

    CERN Document Server

    Sherry, A; Cruddace, AE

    2013-01-01

    Modern Power Station Practice, Volume 3: Mechanical (Turbines and Auxiliary Equipment) focuses on the development of turbines and auxiliary equipment used in power stations in Great Britain. Topics covered include thermodynamics and steam turbine theory; turbine auxiliary systems such as lubrication systems, feed water heating systems, and the condenser and cooling water plants. Miscellaneous station services, and pipework in power plants are also described. This book is comprised of five chapters and begins with an overview of thermodynamics and steam turbine theory, paying particular attenti

  2. Auxiliary nRules of Quantum Mechanics

    OpenAIRE

    Mould, Richard A

    2005-01-01

    Standard quantum mechanics makes use of four auxiliary rules that allow the Schrodinger solutions to be related to laboratory experience, such as the Born rule that connects square modulus to probability. These rules (here called the sRules) lead to some unacceptable results. They do not allow the primary observer to be part of the system. They do not allow individual observations (as opposed to ensembles) to be part of the system. They make a fundamental distinction between microscopic and m...

  3. Auxiliary nRules of Quantum Mechanics

    CERN Document Server

    Mould, R A

    2005-01-01

    Standard quantum mechanics makes use of four auxiliary rules that allow the Schrodinger solutions to be related to laboratory experience, such as the Born rule that connects square modulus to probability. These rules (here called the sRules) lead to some unacceptable results. They do not allow the primary observer to be part of the system. They do not allow individual observations (as opposed to ensembles) to be part of the system. They make a fundamental distinction between microscopic and macroscopic things, and they are ambiguous in their description of secondary observers such as Schrodingers cat. The nRules are an alternative set of auxiliary rules that avoid the above difficulties. In this paper we look at a wide range of representative experiments showing that the nRules adequately relate the Schrodinger solutions to empirical experience. This suggests that the sRules should be abandoned in favor of the more satisfactory nRules, or a third auxiliary rule-set called the oRules. Keywords: brain states, c...

  4. Sensory mechanisms of animal orientation and navigation

    OpenAIRE

    Muheim, R.; Boström, J.; Åkesson, S.; Liedvogel, M

    2014-01-01

    Although questions such as 'How do animals find their way, and how do they sense and process this information in the brain?' have been asked for centuries , the field of animal orientation and navigation has seen an immense leap forward in the past few decades. Moreover, our understanding has also expanded considerably regarding the molecular and physiological mechanisms of the different compasses and cues used by animals for orientation and navigation (Åkesson et al., Chapter 9, and Svensson...

  5. Navigational Mechanisms of Migrating Monarch Butterflies

    OpenAIRE

    Reppert, Steven M.; Gegear, Robert J; Merlin, Christine

    2010-01-01

    Recent studies of the iconic fall migration of monarch butterflies have illuminated the mechanisms behind the navigation south, using a time-compensated sun compass. Skylight cues, such as the sun itself and polarized light, are processed through both eyes and likely integrated in the brain’s central complex, the presumed site of the sun compass. Time compensation is provided by circadian clocks that have a distinctive molecular mechanism and that reside in the antennae. Monarchs may also use...

  6. Navigational mechanisms of migrating monarch butterflies.

    Science.gov (United States)

    Reppert, Steven M; Gegear, Robert J; Merlin, Christine

    2010-09-01

    Recent studies of the iconic fall migration of monarch butterflies have illuminated the mechanisms behind their southward navigation while using a time-compensated sun compass. Skylight cues, such as the sun itself and polarized light, are processed through both eyes and are probably integrated in the brain's central complex, the presumed site of the sun compass. Time compensation is provided by circadian clocks that have a distinctive molecular mechanism and that reside in the antennae. Monarchs might also use a magnetic compass because they possess two cryptochromes that have the molecular capability for light-dependent magnetoreception. Multiple genomic approaches are now being used with the aim of identifying navigation genes. Monarch butterflies are thus emerging as an excellent model organism in which to study the molecular and neural basis of long-distance migration. PMID:20627420

  7. New bionic navigation algorithm based on the visual navigation mechanism of bees

    Science.gov (United States)

    Huang, Yufeng; Liu, Yi; Liu, Jianguo

    2015-04-01

    Through some research on visual navigation mechanisms of flying insects especially honeybees, a novel navigation algorithm integrating entropy flow with Kalman filter has been introduced in this paper. Concepts of entropy image and entropy flow are also introduced, which can characterize topographic features and measure changes of the image respectively. To characterize texture feature and spatial distribution of an image, a new concept of contrast entropy image has been presented in this paper. Applying the contrast entropy image to the navigation algorithm to test its' performance of navigation and comparing with simulation results of intensity entropy image, a conclusion that contrast entropy image performs better and more robust in navigation has been made.

  8. Generation of Enhanced and Robust bipartite optomechanical entanglement via an auxiliary qubit induced quadratic mechanical nonlinearity

    CERN Document Server

    Chakraborty, Subhadeep

    2016-01-01

    We present a scheme for obtaining steady-state optomechanical entanglement in an optomechanical system, in which the mechanical mirror is perturabatively coupled to an auxiliary qubit. The coupling between the mechanical oscillator and the single qubit results in a quadratic mechanical nonlinear term in the Hamiltonian describing the system. We find that the mechanical nonlinearity not only enhances the degree of optomechanical entanglement but also generate it at a considerably lower optomechanical coupling strength. We observe that the degree of entanglement decreases monotonically with increasing temperature. However, the maximum temperature up to which entanglement persists increase with increasing nonlinear amplitude. Thus, the bipartite entanglement in presence of the mechanical nonlinearity becomes more robust against thermal phonon fluctuations.

  9. A flexible navigation mechanism for complex data models

    OpenAIRE

    Oleg Burlaca

    2010-01-01

    The paper presents a way to build flexible navigation tools over a big dataset of well structured data models. The mechanism is underpinned by a search engine that is used to slice and dice the database. By applying a series of consecutive groupings, the result of a search query can be organized in a hierarchical structure and browsed using traditional user interface controls.

  10. Enhanced Mechanisms for Navigation and Tracking Services in Smart Phones

    Directory of Open Access Journals (Sweden)

    L.-C. Chen

    2013-03-01

    Full Text Available Combining Global Positioning System (GPS and Short Message Service (SMS, this paper develops a realisticsystem, called Mobile Navigation and Tracking System (MNTS, to provide navigation and target tracking services.MNTS is an Android based mobile application which integrated many enhanced mechanisms for navigation andtarget tracking services. MNTS not only provides users with the GPS navigation capability, but also supports QuickResponse (QR code decoding, nearby scenic spot searching, friend positioning and target tracking. In targettracking, MNTS utilizing SMS mainly adopts two proposed novel approaches: location prediction and dynamicthreshold to reduce the number of short message transmissions while maintaining location accuracy within anacceptable range. Location prediction utilizes the current target’s location, moving speed, bearing to predict its nextlocation. When the distance between the predicted location and the actual location exceeds a threshold, the targetsends a short message to the tracker to update the actual location. Based on the movement speed of the target,the threshold is dynamically adjusted to balance the location accuracy and the number of short messages.Furthermore, as MNTS is free and open-source software, service providers or developers can easily extend theirown services based on this system.

  11. A flexible navigation mechanism for complex data models

    Directory of Open Access Journals (Sweden)

    Oleg Burlaca

    2010-07-01

    Full Text Available The paper presents a way to build flexible navigation tools over a big dataset of well structured data models. The mechanism is underpinned by a search engine that is used to slice and dice the database. By applying a series of consecutive groupings, the result of a search query can be organized in a hierarchical structure and browsed using traditional user interface controls.

  12. Adaptive information interactive mechanism for multi-UAV visual navigation

    Science.gov (United States)

    Liu, Hui; Dai, Qionghai

    2012-06-01

    Multi-unmanned aerial vehicle (UAV) cooperative communication for visual navigation has recently generated significant concern. It has large amounts of visual information to be transmitted and processed among UAVs with realtime requirements. And the UAV clusters have self-organized, time-varying and high dynamic characteristics. Considering the above conditions, we propose an adaptive information interactive mechanism (AIIM) for multi-UAV visual navigation. In the mechanism, the function modules for UAV inter-communication interface are designed, the mobility-based link lifetime is established and the information interactive protocol is presented. Thus we combine the mobility of UAVs with the corresponding communication requirements to make effective information interaction for UAVs. Task-oriented distributed control is adopted to improve the collaboration flexibility in the multi-UAV visual navigation system. In order to timely obtain the necessary visual information, each UAV can cooperate with other relevant UAVs which meet some certain terms such as situation, task or environmental conditions. Simulation results are presented to show the validity of the proposed mechanism in terms of end-to-end delay and links stability.

  13. Clean Development Mechanism PDD Guidebook: Navigating the Pitfalls; 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    2008-04-15

    This guidebook is designed to help readers navigate the pitfalls of preparing a Project Design Document (PDD) for Clean Development Mechanism (CDM) projects. This second edition also aims at helping project developers to navigate the pitfalls of preparing a Monitoring Report and be better prepared to face the verification process. The purpose of a PDD is to prepare project information for relevant stakeholders. These stakeholders include the investment community, the Designated Operating Entity (DOE) performing validation of the project, the CDM Executive Board (EB), the Designated National Authorities (DNA) of the involved countries and the local population. The PDD, together with the validation report and the approval letter of the DNA, are the basis for the registration of the project and its recognition as a credible CDM project. The PDD is about the project's design--that is, how the project intends to reduce greenhouse gas (GHG) emissions below those levels that would otherwise have been emitted1. Each and every CDM project is unique, from the project design to the application of even the simplest baseline methodology. Some of the projects submitted for validation may be very efficient in reducing emissions and score well in terms of economic, social and environmental benefits, but may still not qualify as CDM projects. Experience has shown that the information needed to judge the suitability of a project for the CDM is vast and can take months to assemble. Also, the time required to assemble relevant information increases with the number and diversity of stakeholders involved and the complexity of the information itself. The objective of the verification of emissions reduction is the review and ex post determination of the monitored emission reductions that have occurred during a specified verification period. The verification is about the project's reality--that is, how the project has been implemented as described in the registered PDD and is

  14. Auxiliary systems

    International Nuclear Information System (INIS)

    For a undisturbed reactor operation, the various Auxiliary and Ancillary Systems must function perfectly with the Reactor Coolant System together. While the Auxiliary Systems are directly connected to the Reactor Coolant System and therefore have contact with the Reactor Coolant, the Ancillary Systems perform tasks which do not directly influence reactor operation and in part are necessary exclusively for environment protection. The design criteria of the individual systems are a result of these tasks, especially in relation to availability, operational readiness and probability of failure. (orig.)

  15. Clean development mechanism PDD guidebook: Navigating the pitfalls

    Energy Technology Data Exchange (ETDEWEB)

    Kamel, S. (ed.)

    2005-11-01

    This guidebook is designed to help readers navigate the pitfalls of preparing a Project Design Document (PDD) for Clean Development Mechanism (CDM) projects. The purpose of a PDD is to prepare project information for relevant stakeholders. These stakeholders include the investment community, the Designated Operating Entity (DOE) performing validation of the project, the CDM Executive Board (EB), the Designated National Authorities (DNA) of the involved countries and the local population. The PDD, together with the validation report and the approval letter of the DNA, are the basis for the registration of the project and its recognition as a credible CDM project. The PDD is about the project's design that is, how the project intends to reduce greenhouse gas (GHG) emissions below those levels that would otherwise have been emitted. Each and every CDM project is unique, from the project design to the application of even the simplest baseline methodology. Some of the projects submitted for validation may be very efficient in reducing emissions and score well in terms of economic, social and environmental benefits, but may still not qualify as CDM projects. Experience has shown that the information needed to judge a suitability of a project for the CDM is vast and can take months to assemble. Also, the time required to assemble relevant information increases with the number and diversity of stakeholders involved and the complexity of the information itself. This guidebook is based on a review of all PDDs submitted to DNV for validation. The advice given and the pitfalls described in this guidebook are, therefore, based on day-to-day, hands-on experience and real instances of mistakes made in submissions. In summary, then, this guidebook takes a practical stance: it is concerned with the practical issues of how to get projects through the validation process. It will help those submitting a PDD by: 1) Describing the most common and costly mistakes made in the process

  16. Amblypygids: Model Organisms for the Study of Arthropod Navigation Mechanisms in Complex Environments?

    Science.gov (United States)

    Wiegmann, Daniel D; Hebets, Eileen A; Gronenberg, Wulfila; Graving, Jacob M; Bingman, Verner P

    2016-01-01

    Navigation is an ideal behavioral model for the study of sensory system integration and the neural substrates associated with complex behavior. For this broader purpose, however, it may be profitable to develop new model systems that are both tractable and sufficiently complex to ensure that information derived from a single sensory modality and path integration are inadequate to locate a goal. Here, we discuss some recent discoveries related to navigation by amblypygids, nocturnal arachnids that inhabit the tropics and sub-tropics. Nocturnal displacement experiments under the cover of a tropical rainforest reveal that these animals possess navigational abilities that are reminiscent, albeit on a smaller spatial scale, of true-navigating vertebrates. Specialized legs, called antenniform legs, which possess hundreds of olfactory and tactile sensory hairs, and vision appear to be involved. These animals also have enormous mushroom bodies, higher-order brain regions that, in insects, integrate contextual cues and may be involved in spatial memory. In amblypygids, the complexity of a nocturnal rainforest may impose navigational challenges that favor the integration of information derived from multimodal cues. Moreover, the movement of these animals is easily studied in the laboratory and putative neural integration sites of sensory information can be manipulated. Thus, amblypygids could serve as model organisms for the discovery of neural substrates associated with a unique and potentially sophisticated navigational capability. The diversity of habitats in which amblypygids are found also offers an opportunity for comparative studies of sensory integration and ecological selection pressures on navigation mechanisms. PMID:27014008

  17. Amblypygids: Model Organisms for the Study of Arthropod Navigation Mechanisms in Complex Environments?

    Directory of Open Access Journals (Sweden)

    Daniel D Wiegmann

    2016-03-01

    Full Text Available Navigation is an ideal behavioral model for the study of sensory system integration and the neural substrates associated with complex behavior. For this broader purpose, however, it may be profitable to develop new model systems that are both tractable and sufficiently complex to ensure that information derived from a single sensory modality and path integration are inadequate to locate a goal. Here, we discuss some recent discoveries related to navigation by amblypygids, nocturnal arachnids that inhabit the tropics and sub-tropics. Nocturnal displacement experiments under the cover of a tropical rainforest reveal that these animals possess navigational abilities that are reminiscent, albeit on a smaller spatial scale, of true-navigating vertebrates. Specialized legs, called antenniform legs, which possess hundreds of olfactory and tactile sensory hairs, and vision appear to be involved. These animals also have enormous mushroom bodies, higher-order brain regions that, in insects, integrate contextual cues and may be involved in spatial memory. In amblypygids, the complexity of a nocturnal rainforest may impose navigational challenges that favor the integration of information derived from multimodal cues. Moreover, the movement of these animals is easily studied in the laboratory and putative neural integration sites of sensory information can be manipulated. Thus, amblypygids could serve as a model system for the discovery of neural substrates associated with a unique and potentially sophisticated navigational capability. The diversity of habitats in which amblypygids are found also offers an opportunity for comparative studies of sensory integration and ecological selection pressures on navigation mechanisms.

  18. Mechanism analysis and countermeasures for the Farley-Tihange phenomenon of nuclear auxiliary pipes

    International Nuclear Information System (INIS)

    Due to thermal fatigue, Farley-Tihange phenomenon frequently appears on the downstream area filled with cold and heat water of the residual heat removal heat-exchange equipment and the base metal and welding joint of the RIS and RRA pipes connected with the main coolant pipe directly in nuclear power plants in operation worldwide, which brings unacceptable defects, even worse induces LOCA. This article summarizes the recurrent position and potential risks of the Farley-Tihange phenomenon, establishes the fault tree of its failure causes, analyses failure mechanism and models of heat fatigue, presents systematically countermeasures including in-operation supervision, shutdown non-destructive monitoring, emergency maintenance preparedness and so on. (authors)

  19. Challenges for identifying the neural mechanisms that support spatial navigation: the impact of spatial scale

    Directory of Open Access Journals (Sweden)

    Thomas eWolbers

    2014-08-01

    Full Text Available Spatial navigation is a fascinating behavior that is essential for our everyday lives. It involves nearly all sensory systems, it requires numerous parallel computations, and it engages multiple memory systems. One of the key problems in this field pertains to the question of reference frames: spatial information such as direction or distance can be coded egocentrically - relative to an observer - or allocentrically - in a reference frame independent of the observer. While many studies have associated striatal and parietal circuits with egocentric coding and entorhinal/hippocampal circuits with allocentric coding, this strict dissociation is not in line with a growing body of experimental data. In this review, we discuss some of the problems that can arise when studying the neural mechanisms that are presumed to support different spatial reference frames. We argue that the scale of space in which a navigation task takes place plays a crucial role in determining the processes that are being recruited. This has important implications, particularly for the inferences that can be made from animal studies in small scale space about the neural mechanisms supporting human spatial navigation in large (environmental spaces. Furthermore, we argue that many of the commonly used tasks to study spatial navigation and the underlying neuronal mechanisms involve different types of reference frames, which can complicate the interpretation of neurophysiological data.

  20. Effects of auxiliary source connections in multichip power module

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon;

    2016-01-01

    Auxiliary source bond wires and connections are widely used to in the power module with paralleled MOSFETs or IGBTs. This paper investigates the working mechanism and the effects of the auxiliary source connections in multichip power modules. It reveals that the auxiliary source connections cannot...

  1. A Neural Path Integration Mechanism for Adaptive Vector Navigation in Autonomous Agents

    DEFF Research Database (Denmark)

    Goldschmidt, Dennis; Dasgupta, Sakyasingha; Wörgötter, Florentin;

    2015-01-01

    simulated sixlegged artificial agent. Input signals from an allothetic compass and odometry are sustained through leaky neural integrator circuits, which are then used to compute the home vector by local excitation-global inhibition interactions. The home vector is computed and represented in circular...... arrays of neurons, where compass directions are population-coded and linear displacements are rate-coded. The mechanism allows for robust homing behavior in the presence of external sensory noise. The emergent behavior of the controlled agent does not only show a robust solution for the problem of......Animals show remarkable capabilities in navigating their habitat in a fully autonomous and energy-efficient way. In many species, these capabilities rely on a process called path integration, which enables them to estimate their current location and to find their way back home after long...

  2. Auxiliary verbs in Dinka

    DEFF Research Database (Denmark)

    Andersen, Torben

    2007-01-01

    Dinka, a Western Nilotic language, has a class of auxiliary verbs which is remarkable in the following four respects: (i) It is unusually large, comprising some 20 members; (ii) it is grammatically homogeneous in terms of both morphology and syntax; (iii) most of the auxiliary verbs correspond to...

  3. Autonomous control for mechanically stable navigation of microscale implants in brain tissue to record neural activity.

    Science.gov (United States)

    Anand, Sindhu; Kumar, Swathy Sampath; Muthuswamy, Jit

    2016-08-01

    Emerging neural prosthetics require precise positional tuning and stable interfaces with single neurons for optimal function over a lifetime. In this study, we report an autonomous control to precisely navigate microscale electrodes in soft, viscoelastic brain tissue without visual feedback. The autonomous control optimizes signal-to-noise ratio (SNR) of single neuronal recordings in viscoelastic brain tissue while maintaining quasi-static mechanical stress conditions to improve stability of the implant-tissue interface. Force-displacement curves from microelectrodes in in vivo rodent experiments are used to estimate viscoelastic parameters of the brain. Using a combination of computational models and experiments, we determined an optimal movement for the microelectrodes with bidirectional displacements of 3:2 ratio between forward and backward displacements and a inter-movement interval of 40 s for minimizing mechanical stress in the surrounding brain tissue. A regulator with the above optimal bidirectional motion for the microelectrodes in in vivo experiments resulted in significant reduction in the number of microelectrode movements (0.23 movements/min) and longer periods of stable SNR (53 % of the time) compared to a regulator using a conventional linear, unidirectional microelectrode movement (with 1.48 movements/min and stable SNR 23 % of the time). PMID:27457752

  4. Interplay of directional navigation mechanisms as a function of near-goal distance: experiments with the house mouse.

    Science.gov (United States)

    Alyan, S H; Jander, R

    1997-12-01

    Mice (Mus musculus) that shuttle between their nest and an outside goal use different navigation mechanisms, depending on their distance from the nest. This was studied by rotating directional cues and the mice relative to one another. Close to home (20-50 cm) mice choose path integration and orientation by beacon, while farther away from the nest distal landmark orientation becomes more important. The larger the beacon is at the home site, the greater is the distance over which it is used as a directional cue. As mice head towards their nest, they demonstrate a tendency to home by means of distal landmarks at large distances, and by means of path integration or guided beacon integration at smaller distances. This space related sequence in the use of orientation mechanisms is the reverse from the temporal sequence (stages) of learning mechanisms employed when first learning to navigate home (Alyan and Jander, 1994). PMID:24896857

  5. Mechanism of back siltation in navigation channel in Dinh An Estuary, Vietnam

    Institute of Scientific and Technical Information of China (English)

    Viet-Thanh NGUYEN; Jin-hai ZHENG; Ji-sheng ZHANG

    2013-01-01

    The Dinh An Estuary is one of the Nine Dragon estuaries of the Mekong River. An international navigation channel was built in the estuary for vessels traveling from the South China Sea to the southwestern area of Vietnam and then to Phnom Penh, Cambodia. The morphological evolution of the navigation channel is complicated and unstable. The back siltation intensity in the navigation channel has largely increased and been concentrated in the curvature segments of the channel since 1980. In this study, based on simulation results and measured data, five key factors that influence the back siltation in the navigation channel were systematically analyzed. These factors included the increasing elevation gap between the channel and the nearby seabed, the disadvantageous hydrodynamic conditions, sediment transport, mixing of saltwater and freshwater, and wave effects in the navigation channel. It is shown that the back siltation to a large extent results from the low current velocity of the secondary ocean circulation, which often occurs in the curvature segments of the channel. Suspended sediment also settles in the channel due to the decrease of the current velocity and the sediment transport capacity when flow passes through the channel. The changes of hydrodynamic conditions are responsible for the majority of the severe siltation in the curvature segments of the navigation channel.

  6. Cryptochromes define a novel circadian clock mechanism in monarch butterflies that may underlie sun compass navigation.

    Science.gov (United States)

    Zhu, Haisun; Sauman, Ivo; Yuan, Quan; Casselman, Amy; Emery-Le, Myai; Emery, Patrick; Reppert, Steven M

    2008-01-01

    The circadian clock plays a vital role in monarch butterfly (Danaus plexippus) migration by providing the timing component of time-compensated sun compass orientation, a process that is important for successful navigation. We therefore evaluated the monarch clockwork by focusing on the functions of a Drosophila-like cryptochrome (cry), designated cry1, and a vertebrate-like cry, designated cry2, that are both expressed in the butterfly and by placing these genes in the context of other relevant clock genes in vivo. We found that similar temporal patterns of clock gene expression and protein levels occur in the heads, as occur in DpN1 cells, of a monarch cell line that contains a light-driven clock. CRY1 mediates TIMELESS degradation by light in DpN1 cells, and a light-induced TIMELESS decrease occurs in putative clock cells in the pars lateralis (PL) in the brain. Moreover, monarch cry1 transgenes partially rescue both biochemical and behavioral light-input defects in cry(b) mutant Drosophila. CRY2 is the major transcriptional repressor of CLOCK:CYCLE-mediated transcription in DpN1 cells, and endogenous CRY2 potently inhibits transcription without involvement of PERIOD. CRY2 is co-localized with clock proteins in the PL, and there it translocates to the nucleus at the appropriate time for transcriptional repression. We also discovered CRY2-positive neural projections that oscillate in the central complex. The results define a novel, CRY-centric clock mechanism in the monarch in which CRY1 likely functions as a blue-light photoreceptor for entrainment, whereas CRY2 functions within the clockwork as the transcriptional repressor of a negative transcriptional feedback loop. Our data further suggest that CRY2 may have a dual role in the monarch butterfly's brain-as a core clock element and as an output that regulates circadian activity in the central complex, the likely site of the sun compass. PMID:18184036

  7. Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae;

    2016-01-01

    Deep generative models parameterized by neural networks have recently achieved state-of-the-art performance in unsupervised and semi-supervised learning. We extend deep generative models with auxiliary variables which improves the variational approximation. The auxiliary variables leave the...... generative model unchanged but make the variational distribution more expressive. Inspired by the structure of the auxiliary variable we also propose a model with two stochastic layers and skip connections. Our findings suggest that more expressive and properly specified deep generative models converge...... faster with better results. We show state-of-the-art performance within semi-supervised learning on MNIST (0.96%), SVHN (16.61%) and NORB (9.40%) datasets....

  8. CAREM-25. Auxiliary systems

    International Nuclear Information System (INIS)

    CAREM is an innovative PWR reactor whose prototype will be of small power generation capacity (100 M Wt, about 25 M We). CAREM design is based on light water integrated reactor with slightly enriched uranium. In this work, a summary of the functions and most relevant design characteristics of main auxiliary systems associated to the chain of heat removal and physicochemical - radiological treatment of the cooling fluids of the CAREM-25 prototype is presented. Even though these auxiliary systems of the reactor are not safety system, they fulfill functions related with the nuclear safety at different operative modes of the reactor. (author)

  9. CAREM-25. Auxiliary systems

    International Nuclear Information System (INIS)

    CAREM is an innovative PWR reactor whose prototype will be of small power generation capacity (100MWt, about 25MWe).CAREM design is based on light water integrated reactor with slightly enriched uranium.In this work, a summary of the functions and most relevant design characteristics of main auxiliary systems associated to the chain of heat removal and physicochemical - radiological treatment of the cooling fluids of the CAREM-25 prototype is presented.Even though these auxiliary systems of the reactor are not safety system, they fulfill functions related with the nuclear safety at different operative modes of the reactor

  10. Auxiliary building structures

    International Nuclear Information System (INIS)

    Five types of auxiliary structures are described such as were used during the construction of the Dukovany nuclear power plant, namely a portable staircase tower, a stable staircase tower, mobile tower scaffolding, mobile scaffolding on a crane track and a scaffold cradle. Basic technical data for all types of scaffolding are given. (Pu)

  11. PS auxiliary magnet

    CERN Multimedia

    1974-01-01

    Units of the PS auxiliary magnet system. The picture shows how the new dipoles, used for vertical and horizontal high-energy beam manipulation, are split for installation and removal so that it is not necessary to break the accelerator vacuum. On the right, adjacent to the sector valve and the windings of the main magnet, is an octupole of the set.

  12. Operation auxiliary system (SAO)

    International Nuclear Information System (INIS)

    This work presents an auxiliary system for nuclear power plants operation (SAO). The development purpose consisted in a computing supervision system to be installed at different sites of a reactor, mainly in the control room. The inclusion of this system to a nuclear power plant minimizes the possibility of human error for the facility operation. (Author)

  13. Cryptochromes define a novel circadian clock mechanism in monarch butterflies that may underlie sun compass navigation.

    Directory of Open Access Journals (Sweden)

    Haisun Zhu

    2008-01-01

    Full Text Available The circadian clock plays a vital role in monarch butterfly (Danaus plexippus migration by providing the timing component of time-compensated sun compass orientation, a process that is important for successful navigation. We therefore evaluated the monarch clockwork by focusing on the functions of a Drosophila-like cryptochrome (cry, designated cry1, and a vertebrate-like cry, designated cry2, that are both expressed in the butterfly and by placing these genes in the context of other relevant clock genes in vivo. We found that similar temporal patterns of clock gene expression and protein levels occur in the heads, as occur in DpN1 cells, of a monarch cell line that contains a light-driven clock. CRY1 mediates TIMELESS degradation by light in DpN1 cells, and a light-induced TIMELESS decrease occurs in putative clock cells in the pars lateralis (PL in the brain. Moreover, monarch cry1 transgenes partially rescue both biochemical and behavioral light-input defects in cry(b mutant Drosophila. CRY2 is the major transcriptional repressor of CLOCK:CYCLE-mediated transcription in DpN1 cells, and endogenous CRY2 potently inhibits transcription without involvement of PERIOD. CRY2 is co-localized with clock proteins in the PL, and there it translocates to the nucleus at the appropriate time for transcriptional repression. We also discovered CRY2-positive neural projections that oscillate in the central complex. The results define a novel, CRY-centric clock mechanism in the monarch in which CRY1 likely functions as a blue-light photoreceptor for entrainment, whereas CRY2 functions within the clockwork as the transcriptional repressor of a negative transcriptional feedback loop. Our data further suggest that CRY2 may have a dual role in the monarch butterfly's brain-as a core clock element and as an output that regulates circadian activity in the central complex, the likely site of the sun compass.

  14. Dental Auxiliary Occupations. Interim Report.

    Science.gov (United States)

    Kingston, Richard D.

    As part of a dental auxiliaries project, a Dental Auxiliary National Technical Advisory Committee was established, and its major undertaking was to assist in the development of a functional inventory for each of the three dental auxiliary occupations (dental assisting, dental hygiene, and dental laboratory technology). The analysis consisted of…

  15. Cryptochromes define a novel circadian clock mechanism in monarch butterflies that may underlie sun compass navigation.

    OpenAIRE

    Haisun Zhu; Ivo Sauman; Quan Yuan; Amy Casselman; Myai Emery-Le; Patrick Emery; Reppert, Steven M.

    2008-01-01

    The circadian clock plays a vital role in monarch butterfly (Danaus plexippus) migration by providing the timing component of time-compensated sun compass orientation, a process that is important for successful navigation. We therefore evaluated the monarch clockwork by focusing on the functions of a Drosophila-like cryptochrome (cry), designated cry1, and a vertebrate-like cry, designated cry2, that are both expressed in the butterfly and by placing these genes in the context of other releva...

  16. Linear Look-ahead in Conjunctive Cells: An Entorhinal Mechanism for Vector-Based Navigation

    Directory of Open Access Journals (Sweden)

    John L Kubie

    2012-04-01

    Full Text Available The crisp organization of the firing bumps of entorhinal grid cells and conjunctive cells leads to the notion that the entorhinal cortex may compute linear navigation routes. Specifically, we propose a process, termed linear look-ahead, by which a stationary animal could compute a series of locations in the direction it is facing. We speculate that this computation could be achieved through learned patterns of connection strengths among entorhinal neurons. This paper has three sections. First, we describe the minimal grid cell properties that will be built into our network. Specifically, the network relies of rigid modules of neurons, where all members have identical grid scale and orientation, but differ in spatial phase. Additionally, these neurons must be densely interconnected with synapses that are modifiable early in the animal’s life. Second, we investigate whether plasticity during short bouts of locomotion could induce patterns of connections amongst grid cells or conjunctive cells. Finally, we run a simulation to test whether the learned connection patterns can exhibit linear look-ahead. Our results are straightforward. A simulated 30-minute walk produces weak strengthening of synapses between grid cells that do not support linear look-ahead. Similar training in a conjunctive-cell module produces a small subset of very strong connections between cells. These strong pairs have three properties: The pre- and post-synaptic cells have similar heading direction. The cell pairs have neighboring grid bumps. Finally, the spatial offset of firing bumps of the cell pair is in the direction of the common heading preference. Such a module can produce strong and accurate linear look ahead starting in any location and extending in any direction. We speculate that this process may: 1. compute linear paths to goals; 2. update grid cell firing during navigation; and 3. stabilize the rigid modules of grid cells and conjunctive cells.

  17. Navigation systems

    OpenAIRE

    Ocepek, Marjan

    2013-01-01

    In this thesis we present different navigation systems which may be used also in surveying. Map as a basis of navigation is described at the beginning. Next, we focus on navigation based on celestial bodies. We present basic terms such as navigation and orientation and describe some primitive methods, which had been used for orientation without compass. We present two important time keeping instruments that facilitated the process of position determination, the chronometer and chronograph, an...

  18. WMO Selected, Supplemenatary, Auxiliary Ships

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World Meteorological Organization International List of Selected, Supplementary and Auxiliary Ships, recognized as Publication 47. 1973-1998 editions, gathered from...

  19. Characterisation of skiers’ mechanics, course setting and terrain geomorphology in World Cup Alpine Skiing using global navigation satellite systems: Injury risk, performance and methodological aspects

    OpenAIRE

    Gilgien, Matthias

    2014-01-01

    This study was undertaken to characterize course setting, terrain geomorphology and skier mechanics in World Cup (WC) alpine skiing. Since there was no existing appropriate methodology to capture skier mechanics across large capture volumes under WC racing conditions in speed disciplines, a novel method was invented. The method was based on a global navigation satellite system (GNSS) and was tailored to assess position, velocity, acceleration and external forces while causing m...

  20. Improving Energy Efficiency of Auxiliaries

    International Nuclear Information System (INIS)

    The summaries of this report are: Economics Ultimately Dictates Direction; Electric Auxiliaries Provide Solid Benefits. The Impact on Vehicle Architecture Will be Important; Integrated Generators With Combined With Turbo Generators Can Meet the Electrical Demands of Electric Auxiliaries; Implementation Will Follow Automotive 42V Transition; Availability of Low Cost Hardware Will Slow Implementation; Industry Leadership and Cooperation Needed; Standards and Safety Protocols Will be Important. Government Can Play an Important Role in Expediting: Funding Technical Development; Incentives for Improving Fuel Economy; Developing Standards, Allowing Economy of Scale; and Providing Safety Guidelines

  1. Solid Oxide Fuel Cell Auxiliary Power Unit

    International Nuclear Information System (INIS)

    Solid Oxide Fuel Cell (SOFC) is an attractive, efficient, clean source of power for transportation, military, and stationary applications. Delphi has pioneered its application as an auxiliary Power Unit (APU) for transportation. Delphi is also interested in marketing this technology for stationary applications. Its key advantages are high efficiency and compatibility with gasoline, natural gas and diesel fuel. It's consistent with mechanizations that support the trend to low emissions. Delphi is committed to working with customers and partners to bring this novel technology to market

  2. Hydraulic turbines and auxiliary equipment

    Energy Technology Data Exchange (ETDEWEB)

    Luo Gaorong [Organization of the United Nations, Beijing (China). International Centre of Small Hydroelectric Power Plants

    1995-07-01

    This document presents a general overview on hydraulic turbines and auxiliary equipment, emphasizing the turbine classification, in accordance with the different types of turbines, standard turbine series in China, turbine selection based on the basic data required for the preliminary design, general hill model curves, chart of turbine series and the arrangement of application for hydraulic turbines, hydraulic turbine testing, and speed regulating device.

  3. Turbine generator and its auxiliaries

    International Nuclear Information System (INIS)

    The turbine generator and its auxiliary systems in Tarapur Atomic Power Station (TAPS) have been performing well and further their performance and availability has increased due to timely assessment of the problems anticipated in the systems by a close co-ordination among the concerned staff. Continued efforts are on for further improvements. (author)

  4. Computer navigation vs conventional mechanical jig technique in hip resurfacing arthroplasty: a meta-analysis based on 7 studies.

    Science.gov (United States)

    Liu, Hao; Li, Lin; Gao, Wei; Wang, Meilin; Ni, Chunhui

    2013-01-01

    The studies on the accuracy of femoral component in hip resurfacing arthroplasty with the help of computer-assisted navigation were not consistent. This study aims to assess at the functional outcomes after computer navigation in hip resurfacing arthroplasty by systematically reviewing and meta-analyzing the data, which were searched up to December 2011 in PubMed, MEDLINE, EMBASE, MetaMed, EBSCO HOST, and the Web site of Google scholar. Totally, 197 articles about hip resurfacing arthroplasty were collected; finally, 7 articles met the inclusion criteria and were included in this meta-analysis (520 patients with 555 hip resurfacing arthroplasty). The odds ratio for the number of outliers was 0.155 (95% confidence interval, 0.048-0.498; P < .003). In conclusion, this meta-analysis suggests that the computer-assisted navigation system makes the femoral component positioning in hip resurfacing arthroplasty easier and more precise. PMID:22771091

  5. NAVIGATOR (FER)

    International Nuclear Information System (INIS)

    The NAVIGATOR concept is based on the negative-ion-grounded 500 keV/20 MW neutral beam injection system (NBI system), which has been proposed and studied at JAERI. The NAVIGATOR concept contains two categories; one is the NAVIGATOR machine as a tokamak reactor, and the other is the NAVIGATOR philosphy as a quiding principle in fusion research. The NAVIGATOR concept should be applied in a phased approach to and beyond the operating goal for the FER (Fusion Experimental Reactor, the next generation tokamak machine in Japan). The mission of the FER is to realize self-ignition and a long controlled burn of about 800 seconds and to develop and test fusion technologies, including the tritiumfuel cycle, superconducting magnet, remote maintenance and breeding blanket test modules. The NAVIGATOR concept is composed of three major elements, that is, reliable operation scenarios, reliable maintenability and suffiecient flexibility of the reactor. The NAVIGATOR concept well supports the ideas of phased operation and phased construction of the FER, which will result in the reduction technological risk. (author). 4 refs.; 3 figs

  6. Ecodesign Navigator

    DEFF Research Database (Denmark)

    Simon, M; Evans, S.; McAloone, Timothy Charles; Sweatman, A.; Bhamra, T.; Poole, S.

    The Ecodesign Navigator is the product of a three-year research project called DEEDS - DEsign for Environment Decision Support. The initial partners were Manchester Metropolitan University, Cranfield University, Engineering 6 Physical Sciences Resaech Council, Electrolux, ICL, and the Industry...

  7. 45 CFR 707.10 - Auxiliary aids.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Auxiliary aids. 707.10 Section 707.10 Public Welfare Regulations Relating to Public Welfare (Continued) COMMISSION ON CIVIL RIGHTS ENFORCEMENT OF... § 707.10 Auxiliary aids. (a) The Agency shall furnish appropriate auxiliary aids where necessary...

  8. 7 CFR 15b.37 - Auxiliary aids.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Auxiliary aids. 15b.37 Section 15b.37 Agriculture... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Other Aid, Benefits, or Services § 15b.37 Auxiliary aids... appropriate auxiliary aids to persons with impaired sensory, manual, or speaking skills, where necessary...

  9. The Marginalized Auxiliary Particle Filter

    OpenAIRE

    Fritsche, Carsten; Schön, Thomas; Klein, Anja

    2010-01-01

    In this paper we are concerned with nonlinear systems subject to a conditionally linear, Gaussian sub-structure. This structure is often exploited in high-dimensional state estimation problems using the marginalized (aka Rao-Blackwellized) particle filter. The main contribution in the present work is to show how an efficient filter can be derived by exploiting this structure within the auxiliary particle filter. Based on a multisensor aircraft tracking example, the superior performance of the...

  10. Performance analysis of a Passive Auxiliary Feedwater System in APR+

    International Nuclear Information System (INIS)

    The Advanced Power Reactor Plus (APR+), which is a GEN III+ reactor based on the APR1400, is being developed in Korea. In order to enhance the safety of the APR+, a passive auxiliary feedwater system (PAFS) has been adopted in the APR+. The PAFS replaces the conventional active auxiliary feedwater system (AFWS) by introducing a natural driving force mechanism while maintaining the system function of cooling the primary side and removing the decay heat. The purpose of this paper is to evaluate the performance of the PAFS under design basis events using best-estimated thermalhydraulic codes

  11. Mechanical analysis of an auxiliary piping elbow

    International Nuclear Information System (INIS)

    This study was undertaken following the trough-wall cracking of a safety injection line elbow (Bugey PWR Unit 3, November 11, 1983). Its objective is to evaluate the stress distribution in the elbow, under the various loadings applied to the pipe, in order to explain the cracking. These loadings are modelized using in situ carried measurements and conclusions from the laboratory survey (global pipe displacements, thermal stratification of the internal fluid ...). A finite element stress analysis (by piping and 3D computer codes) allowed us to compare the various effects of these loadings on the elbow cracking. This work has contributed to the improvement in the reliability of this piping in complement of the modifications which are carried out in operating plants to prevent these defects. (orig.)

  12. Radio frequency auxiliary heating systems design in ITER

    International Nuclear Information System (INIS)

    A combination of radio frequency (RF) auxiliary heating systems will provide at least one half of the required 100 MW of auxiliary power in ITER. Five of the 20 equatorial ports are assigned to RF heating systems. Recent work has focused on developing an integrated equatorial port-plug design concept for all of the RF auxiliary heating systems as well as other equatorial port systems such as diagnostics. Common features of the design approach include the use of identical interfaces to services such as cooling water, vacuum, mechanical connection to the vessel, and maintenance. Based on the integrated port concept, a high level of design integration has been achieved for the RF heating systems. Implementation of the integrated design concept has been accomplished without significantly affecting the individual system performance and with limited impact on the torus layout. (author)

  13. Hovercraft auxiliary power units (APUs)

    Energy Technology Data Exchange (ETDEWEB)

    Russell, B.J.

    1983-08-01

    Auxiliary power units (APU) manufactured by British firms for use in hovercraft are characterized. Both diesel and gas-turbine APUs are found to be well suited to the demands of this application. The design features, dimensions, performance data, and installation requirements are discussed for the SS 90, SS 923, DA-1, BA-1, HM 5, and Gevaudan 9 APUs, as well as the TRS 18 gas-turbine smoke generator. The progress made in improving the fuel efficiency of gas turbines and reducing the weight of diesel engines is considered significant.

  14. Perfects, resultatives and auxiliaries in early English

    OpenAIRE

    McFadden, Thomas; Alexiadou, Artemis

    2008-01-01

    In this paper, we will argue for a novel analysis of the auxiliary alternation in Early English, its development and subsequent loss which has broader consequences for the way that auxiliary selection is looked at cross-linguistically. We will present evidence that the choice of auxiliaries accompanying past participles in Early English differed in several significant respects from that in the familiar modern European languages. Specifically, while the construction with have became a full-fle...

  15. Auxiliary feedwater system aging study

    International Nuclear Information System (INIS)

    This report documents the results of a Phase I follow-on study of the Auxiliary Feedwater (AFW) System that has been conducted for the US Regulatory Commission's Nuclear Plant Aging research Program. The Phase I study found a number of significant AFW System functions that are not being adequately tested by conventional test methods and some that are actually being degraded by conventional testing. Thus, it was decided that this follow-on study would focus on these testing omissions nd equipment degradation. The deficiencies in current monitoring and operating practice are categorized and evaluated. Areas of component degradation caused by current practice are discussed. Recommendations are made for improved diagnostic methods and test procedures

  16. Auxiliary bearing design and rotor dynamics analysis of blower fan for HTR-10

    International Nuclear Information System (INIS)

    The electromagnetic bearing instead of ordinary mechanical bearing was chosen to support the rotor in the blower fan system with helium of 10 MW high temperature gas-cooled test reactor (HTR-10), and the auxiliary bearing was applied in the HTR-10 as the backup protector. When the electromagnetic bearing doesn't work suddenly for the power broken, the auxiliary bearing is used to support the falling rotor with high rotating speed. The rotor system will be protected by the auxiliary bearing. The design of auxiliary bearing is the ultimate safeguard for the system. This rotor is vertically mounted to hold the blower fan. The rotor's length is about 1.5 m, its weight is about 240 kg and the rotating speed is about 5400 r/min. Auxiliary bearing design and rotor dynamics analysis are very important for the design of blower fan to make success. The research status of the auxiliary bearing was summarized in the paper. A sort of auxiliary bearing scheme was proposed. MSC.Marc was selected to analyze the vibration mode and the natural frequency of the rotor. The scheme design of auxiliary bearing and analysis result of rotor dynamics offer the important theoretical base for the protector design and control system of electromagnetic bearing of the blower fan. (authors)

  17. 47 CFR 73.1675 - Auxiliary antennas.

    Science.gov (United States)

    2010-10-01

    ... Class A TV licensees may request a decrease from the authorized facility's ERP in the license application. An FM, TV or Class A TV licensee may also increase the ERP of the auxiliary facility in a license... licensed main facility as an auxiliary facility with an ERP less than or equal to the ERP specified on...

  18. Auxiliary full-disc telescope for the European Solar Telescope

    Czech Academy of Sciences Publication Activity Database

    Sobotka, Michal; Klvaňa, Miroslav; Melich, Zbyněk; Rail, Zdeněk; Bettonvil, F.; Gelly, B.

    Bellingham : SPIE, 2010 - (McLean, I.), 77351Z-1-77351Z-8 ISBN 9780819482259. - (Proceedings of SPIE. 7735). [Ground-based and Airborne Instrumentation for Astronomy III. San Diego (US), 27.06.2010-02.07.2010] Grant ostatní: EU(XE) 212482 Institutional research plan: CEZ:AV0Z10030501; CEZ:AV0Z20430508 Keywords : auxiliary full-disc telescope * principal functions Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  19. Resolution of concerns in auxiliary feedwater piping

    International Nuclear Information System (INIS)

    Auxiliary feedwater piping systems at pressurized water reactor (PWR) nuclear power plants have experienced unanticipated operating conditions during plant operation. These unanticipated conditions have included plant events involving backleakage through check valves, temperatures in portions of the auxiliary feedwater piping system that exceed design conditions, and the occurrence of unanticipated severe fluid transients. The impact of these events has had an adverse effect at some nuclear stations on plant operation, installed plant components and hardware, and design basis calculations. Beaver Valley Unit 2, a three loop pressurized water reactor nuclear plant, has observed anomalies with the auxiliary feedwater system since the unit went operational in 1987. The consequences of these anomalies and plant events have been addressed and resolved for Beaver Valley Unit 2 by performing engineering and construction activities. These activities included pipe stress, pipe support and pipe rupture analysis, the monitoring of auxiliary feedwater system temperature and pressure, and the modification to plant piping, supports, valves, structures and operating procedures

  20. The dynamic responses of the soil-auxiliary buildings structure interaction system

    International Nuclear Information System (INIS)

    The dynamic responses of the soil-auxiliary buildings structure interaction system in the nuclear power plant are concerned. The main distinguished feature of this study is that the extreme un-symmetry of the auxiliary buildings and reactor containment are considered. A Synthetical mechanical model for study is established. Finally, the analysis of the dynamic response of the Qinshan Nuclear Power Plant structure is taken as a simple example of applying this method and the numerical results are given

  1. Indirect combustion noise of auxiliary power units

    Science.gov (United States)

    Tam, Christopher K. W.; Parrish, Sarah A.; Xu, Jun; Schuster, Bill

    2013-08-01

    Recent advances in noise suppression technology have significantly reduced jet and fan noise from commercial jet engines. This leads many investigators in the aeroacoustics community to suggest that core noise could well be the next aircraft noise barrier. Core noise consists of turbine noise and combustion noise. There is direct combustion noise generated by the combustion processes, and there is indirect combustion noise generated by the passage of combustion hot spots, or entropy waves, through constrictions in an engine. The present work focuses on indirect combustion noise. Indirect combustion noise has now been found in laboratory experiments. The primary objective of this work is to investigate whether indirect combustion noise is also generated in jet and other engines. In a jet engine, there are numerous noise sources. This makes the identification of indirect combustion noise a formidable task. Here, our effort concentrates exclusively on auxiliary power units (APUs). This choice is motivated by the fact that APUs are relatively simple engines with only a few noise sources. It is, therefore, expected that the chance of success is higher. Accordingly, a theoretical model study of the generation of indirect combustion noise in an Auxiliary Power Unit (APU) is carried out. The cross-sectional areas of an APU from the combustor to the turbine exit are scaled off to form an equivalent nozzle. A principal function of a turbine in an APU is to extract mechanical energy from the flow stream through the exertion of a resistive force. Therefore, the turbine is modeled by adding a negative body force to the momentum equation. This model is used to predict the ranges of frequencies over which there is a high probability for indirect combustion noise generation. Experimental spectra of internal pressure fluctuations and far-field noise of an RE220 APU are examined to identify anomalous peaks. These peaks are possible indirection combustion noise. In the case of the

  2. Navigation Lights - USACE IENC

    Data.gov (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  3. 46 CFR 58.01-35 - Main propulsion auxiliary machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Main propulsion auxiliary machinery. 58.01-35 Section 58... AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-35 Main propulsion auxiliary machinery. Auxiliary machinery vital to the main propulsion system must be provided in duplicate unless the...

  4. Universal navigation on smartphones

    CERN Document Server

    Karimi, Hassan A

    2011-01-01

    Universal navigation is accessible primarily through smart phones providing users with navigation information regardless of the environment (i.e., outdoor or indoor). ""Universal Navigation for Smart Phones"" provide the most up-to-date navigation technologies and systems for both outdoor and indoor navigation. It also provides a comparison of the similarities and differences between outdoor and indoor navigation systems from both a technological stand point and user's perspective. All aspects of navigation systems including geo-positioning, wireless communication, databases, and functions wil

  5. Builtin vs. auxiliary detection of extrapolation risk.

    Energy Technology Data Exchange (ETDEWEB)

    Munson, Miles Arthur; Kegelmeyer, W. Philip,

    2013-02-01

    A key assumption in supervised machine learning is that future data will be similar to historical data. This assumption is often false in real world applications, and as a result, prediction models often return predictions that are extrapolations. We compare four approaches to estimating extrapolation risk for machine learning predictions. Two builtin methods use information available from the classification model to decide if the model would be extrapolating for an input data point. The other two build auxiliary models to supplement the classification model and explicitly model extrapolation risk. Experiments with synthetic and real data sets show that the auxiliary models are more reliable risk detectors. To best safeguard against extrapolating predictions, however, we recommend combining builtin and auxiliary diagnostics.

  6. Navigation in surgery

    OpenAIRE

    Mezger, Uli; Jendrewski, Claudia; Bartels, Michael

    2013-01-01

    Introduction “Navigation in surgery” spans a broad area, which, depending on the clinical challenge, can have different meanings. Over the past decade, navigation in surgery has evolved beyond imaging modalities and bulky systems into the rich networking of the cloud or devices that are pocket-sized. Discussion This article will review various aspects of navigation in the operating room and beyond. This includes a short history of navigation, the evolution of surgical navigation, as well as t...

  7. Apollo Onboard Navigation Techniques

    Science.gov (United States)

    Interbartolo, Michael

    2009-01-01

    This viewgraph presentation reviews basic navigation concepts, describes coordinate systems and identifies attitude determination techniques including Primary Guidance, Navigation and Control System (PGNCS) IMU management and Command and Service Module Stabilization and Control System/Lunar Module (LM) Abort Guidance System (AGS) attitude management. The presentation also identifies state vector determination techniques, including PGNCS coasting flight navigation, PGNCS powered flight navigation and LM AGS navigation.

  8. Nuclear reactors with auxiliary boiler circuit

    International Nuclear Information System (INIS)

    A gas-cooled nuclear reactor has a main circulatory system for the gaseous coolant incorporating one or more main energy converting units, such as gas turbines, and an auxiliary circulatory system for the gaseous coolant incorporating at least one steam generating boiler arranged to be heated by the coolant after its passage through the reactor core to provide steam for driving an auxiliary steam turbine, such an arrangement providing a simplified start-up procedure also providing emergency duties associated with long term heat removal on reactor shut down

  9. Transport in Auxiliary Heated NSTX Discharges

    International Nuclear Information System (INIS)

    The NSTX spherical torus (ST) provides a unique platform to investigate magnetic confinement in auxiliary-heated plasmas at low aspect ratio. Auxiliary power is routinely coupled to ohmically heated plasmas by deuterium neutral-beam injection (NBI) and by high-harmonic fast waves (HHFW) launch. While theory predicts both techniques to preferentially heat electrons, experiment reveals the electron temperature is greater than the ion temperature during HHFW, but the electron temperature is less than the ion temperature during NBI. In the following we present the experimental data and the results of transport analyses

  10. A New Navigation Strategy in Hypermedia Integral Ware Authoring System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    After analyzing the general navigation mechanisms and discussing the knowledge point card linking model which is the base of the navigation mechanism used in the Hypermedia Integral ware Authoring System(HIAS), the paper presents a new navigation strategy in HIAS. And the application trend of HIAS is discussed at last.

  11. Vacuum switchgear for power station auxiliary switchboards

    International Nuclear Information System (INIS)

    Sizewell B is the first UK power station in which vacuum switchgear is used for the auxiliary switchboards. Previously the 3.3kV, 6.6kV or 11kV switchgear has used air-break circuit breakers and fused air-break contactors, known as motor starting devices or fused switching devices (FSD). The use of vacuum interrupters is therefore a new technology in this application, although it has been established in the UK distribution network and in industrial installations from the mid 1970s. Vacuum switchgear was already in use in the USA for power station auxiliary switchgear at the time that it was proposed for Sizewell B. The Sizewell B high voltage auxiliary switchgear comprises eight Unit and Station Auxiliary Switchboards at 3.3kV and 11kV, and four 3.3kV Essential Switchboards for the essential safety related circuits, making a total of 65 circuit breakers plus FSD panels. (Author)

  12. Curricular Guidelines for Dental Auxiliary Radiology.

    Science.gov (United States)

    Journal of Dental Education, 1981

    1981-01-01

    AADS curricular guidelines suggest objectives for these areas of dental auxiliary radiology: physical principles of X-radiation in dentistry, related radiobiological concepts, principles of radiologic health, radiographic technique, x-ray films and intensifying screens, factors contributing to film quality, darkroom, and normal variations in…

  13. Window-mounted auxiliary solar heater

    Science.gov (United States)

    Anthony, K. G.; Herndon, E. P.

    1977-01-01

    System uses hot-air collectors, no thermal storage, and fan with thermostat switches. At cost of heating efficiency, unit could be manufactured and sold at price allowing immediate entry to market as auxiliary heating system. Its simplicity allows homeowner installation, and maintenance is minimal.

  14. Auxiliary power unit for moving a vehicle

    Science.gov (United States)

    Akasam, Sivaprasad; Johnson, Kris W.; Johnson, Matthew D.; Slone, Larry M.; Welter, James Milton

    2009-02-03

    A power system is provided having at least one traction device and a primary power source configured to power the at least one traction device. In addition, the power system includes an auxiliary power source also configured to power the at least one traction device.

  15. 单轴旋转式惯导系统误差抑制机理分析%The analysis of error control mechanism for single-axis rotation inertial navigation system

    Institute of Scientific and Technical Information of China (English)

    高贤志; 王丹

    2012-01-01

    It is significantly important to improve the performance of inertial navigation system navigation by controlling the negative effects on inertial navigation system for inertial measurement units. This paper analyses the error equations of the inertial navigation system, makes a focus on the inertial components accumulation effect on symmetrical position error, analyses the automatic constant error compensation mechanism of the inertial navigation system, and then discusses the error depressing of inertial components constant error, the scale factor error cased by rotating. Finally, the simulation for single-axis rotation mechanism validates the theory analysis.%提高惯导系统对于惯性器件误差负面影响的抑制能力,对于改善系统的导航精度具有重要意义.本文对惯导系统误差方程进行分析,重点讨论对称位置上惯性器件误差的积累效果,系统地研究了单轴旋转调制对捷联惯性导航系统惯性器件误差的自动补偿机理,详细分析了单轴旋转对惯性器件常值误差、标度因数误差的抑制情况.对单轴旋转调制方案进行仿真,验证了理论分析的正确性.

  16. Optical Navigation System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is for a flexible navigation system for deep space operations that does not require GPS measurements. The navigation solution is computed using an...

  17. Learning for Autonomous Navigation

    Science.gov (United States)

    Angelova, Anelia; Howard, Andrew; Matthies, Larry; Tang, Benyang; Turmon, Michael; Mjolsness, Eric

    2005-01-01

    Robotic ground vehicles for outdoor applications have achieved some remarkable successes, notably in autonomous highway following (Dickmanns, 1987), planetary exploration (1), and off-road navigation on Earth (1). Nevertheless, major challenges remain to enable reliable, high-speed, autonomous navigation in a wide variety of complex, off-road terrain. 3-D perception of terrain geometry with imaging range sensors is the mainstay of off-road driving systems. However, the stopping distance at high speed exceeds the effective lookahead distance of existing range sensors. Prospects for extending the range of 3-D sensors is strongly limited by sensor physics, eye safety of lasers, and related issues. Range sensor limitations also allow vehicles to enter large cul-de-sacs even at low speed, leading to long detours. Moreover, sensing only terrain geometry fails to reveal mechanical properties of terrain that are critical to assessing its traversability, such as potential for slippage, sinkage, and the degree of compliance of potential obstacles. Rovers in the Mars Exploration Rover (MER) mission have got stuck in sand dunes and experienced significant downhill slippage in the vicinity of large rock hazards. Earth-based off-road robots today have very limited ability to discriminate traversable vegetation from non-traversable vegetation or rough ground. It is impossible today to preprogram a system with knowledge of these properties for all types of terrain and weather conditions that might be encountered.

  18. Auxiliary field formulation of supersymmetric nonlinear sigma models

    International Nuclear Information System (INIS)

    Two dimensional N=2 supersymmetric nonlinear sigma models on hermitian symmetric spaces are formulated in terms of the auxiliary superfields. If we eliminate auxiliary vector and chiral superfields, they give D- and F- term constraints to define the target manifolds. The integration over auxiliary vector superfields, which can be performed exactly, is equivalent to the elimination of the auxiliary fields by the use of the classical equations of motion. (author)

  19. Auxiliary-Arc Electrodes for MHD Systems

    International Nuclear Information System (INIS)

    The important role of electrode phenomena in the operation of magneto aerodynamic machines is well known. In particular, the voltage drops which occur in the boundary layer in the immediate neighbourhood of the electrode may reduce the output of the apparatus. These voltage drops are caused partly by the increased resistance presented by the boundary layer in the neighbourhood of the electrode when the latter is appreciably colder than the gas, and partly by the fact that the electrode is not at a temperature sufficient to be emissive. Auxiliary-arc electrodes that have been constructed and tested seem to provide a solution both of the cold boundary layer problem and of the cathode emissivity problem. For this purpose an arc is established between a refractory metal cathode placed behind and clear of the generator wall and an anode forming part of the wall. The arc column can be activated by a rotational movement under the effect of a magnetic field, which may be that of the machine itself. The mechanical arrangement of the electrodes is such that, with a weak flow of gas (argon for example), it is possible to maintain a protective atmosphere around the arc cathode, while the arc anode is strongly cooled by the wall. The gas flow also has the effect of forcing the arc column towards the stream, thus increasing the conductivity of the boundary layer. Furthermore, the arc column behaves as a virtual cathode, from which a sizeable electron current can be extracted. Electrodes constructed on this principle have been tested on gas streams composed of fuel-oil combustion products. By using them as cathodes it has been possible to extract a current of 5 A without the voltage drop between the electrode and the gas exceeding 10 V. Comparative tests have been carried out with cooled metal electrodes, in which case the voltage drop is of the order of 120 V. The arc electrodes tested have operated for several hours without any apparent damage. In spite of the energy which has

  20. Aircraft Instrument, Fire Protection, Warning, Communication, Navigation and Cabin Atmosphere Control System (Course Outline), Aviation Mechanics 3 (Air Frame): 9067.04.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This document presents an outline for a 135-hour course designed to familiarize the student with manipulative skills and theoretical knowledge concerning aircraft instrument systems like major flight and engine instruments; fire protection and fire fighting systems; warning systems and navigation systems; aircraft cabin control systems, such as…

  1. Radar and electronic navigation

    CERN Document Server

    Sonnenberg, G J

    2013-01-01

    Radar and Electronic Navigation, Sixth Edition discusses radar in marine navigation, underwater navigational aids, direction finding, the Decca navigator system, and the Omega system. The book also describes the Loran system for position fixing, the navy navigation satellite system, and the global positioning system (GPS). It reviews the principles, operation, presentations, specifications, and uses of radar. It also describes GPS, a real time position-fixing system in three dimensions (longitude, latitude, altitude), plus velocity information with Universal Time Coordinated (UTC). It is accur

  2. Research on Web Navigations

    Directory of Open Access Journals (Sweden)

    Qian Zhongsheng

    2011-10-01

    Full Text Available Web applications employ various new languages, technologies, and programming models to implement applications with very high quality requirements. In building Web applications, three types of models must be considered, which are conceptual model, navigation model and presentation model. Navigation problems are significant among them that must be confronted. This work illuminates three different classifications of Web navigations as well as their feature, analyzes and compares various popular Web navigation models. Moreover, it also presents and suggests some guidelines for Web navigation design based on Web development design pattern experiences.

  3. Modified Darboux transformations with foreign auxiliary equations

    International Nuclear Information System (INIS)

    We construct a new type of first-order Darboux transformations for the stationary Schroedinger equation. In contrast to the conventional case, our Darboux transformations support arbitrary (foreign) auxiliary equations. We show that among other applications, our formalism can be used to systematically construct Darboux transformations for Schroedinger equations with energy-dependent potentials, including a recent result (Lin et al., 2007) as a special case. -- Highlights: → We generalize the Darboux transformation for the Schroedinger equation. → By admitting arbitrary auxiliary functions, we provide a new tool for generating solutions. → As a special case we recover a recent result on energy-dependent potentials. → We extend the latter result to very general energy-dependence.

  4. An Intelligent Auxiliary Vacuum Brake System

    OpenAIRE

    Tong, Chia-Chang; Lin, Jhih-Yu; Li, Shih-Fan; Li, Jiun-Yi

    2009-01-01

    The purpose of this paper focuses on designing an intelligent, compact, reliable, and robust auxiliary vacuum brake system (VBS) with Kalman filter and self-diagnosis scheme. All of the circuit elements in the designed system are integrated into one programmable system-on-chip (PSoC) with entire computational algorithms implemented by software. In this system, three main goals are achieved: (a) Kalman filter and hysteresis controller algorithms are employed within PSoC chip by software to sur...

  5. Auxiliary facilities on nuclear ship 'MUTSU'

    International Nuclear Information System (INIS)

    The nuclear ship 'MUTSU' has been moored at SEKINEHAMA, MUTU City in AOMORI Prefecture and several tests and works are being carried out on the ship. The construction of the auxiliary facilities for these works on the ship was completed in safety in August 1988. After that the facilities have fulfilled their function. The outlines of design, fabrication and construction of the facilities are described in this paper. (author)

  6. New Massive Supergravity and Auxiliary Fields

    CERN Document Server

    Bergshoeff, Eric A; Parra, Lorena; Rosseel, Jan; Yin, Yihao; Zojer, Thomas

    2013-01-01

    We construct a supersymmetric formulation of linearized New Massive Gravity without introducing higher derivatives. Instead, we introduce supersymmetrically a set of bosonic and fermionic auxiliary fields which, upon elimination by their equations of motion, introduce fourth-order derivative terms for the metric and third-order derivative terms for the gravitino. Our construction requires an off-shell formulation of the three-dimensional supersymmetric massive Fierz--Pauli theory. We discuss the non-linear extension of our results.

  7. Engine Auxiliary System Guideline: Cooling Systems

    OpenAIRE

    Kela, Suvi

    2015-01-01

    The thesis was done for Wärtsilä Technical Services organization. The assignment was to consolidate a guideline for cooling systems as an engine auxiliary system covering the Wärtsilä 4-stroke engines currently in production. The guideline was to include information considering both marine and power plants installations. The sources of information were internal documentation from Wärtsilä, literature review and discussions with Wärtsilä cooling system experts. The guideline includes informati...

  8. Modelling group navigation: transitive social structures improve navigational performance.

    Science.gov (United States)

    Flack, Andrea; Biro, Dora; Guilford, Tim; Freeman, Robin

    2015-07-01

    Collective navigation demands that group members reach consensus on which path to follow, a task that might become more challenging when the group's members have different social connections. Group decision-making mechanisms have been studied successfully in the past using individual-based modelling, although many of these studies have neglected the role of social connections between the group's interacting members. Nevertheless, empirical studies have demonstrated that individual recognition, previous shared experiences and inter-individual familiarity can influence the cohesion and the dynamics of the group as well as the relative spatial positions of specific individuals within it. Here, we use models of collective motion to study the impact of social relationships on group navigation by introducing social network structures into a model of collective motion. Our results show that groups consisting of equally informed individuals achieve the highest level of accuracy when they are hierarchically organized with the minimum number of preferred connections per individual. We also observe that the navigational accuracy of a group will depend strongly on detailed aspects of its social organization. More specifically, group navigation does not only depend on the underlying social relationships, but also on how much weight leading individuals put on following others. Also, we show that groups with certain social structures can compensate better for an increased level of navigational error. The results have broader implications for studies on collective navigation and motion because they show that only by considering a group's social system can we fully elucidate the dynamics and advantages of joint movements. PMID:26063820

  9. Self-start of auxiliary electric motors at the site with 440MW units

    International Nuclear Information System (INIS)

    Technique for calculating electric motors in self-start modes with provision for their mechanical charateristics is given. Recommendations on switching off individual electric motors during self-start of both single and all sections of NPP 440 MW unit auxiliaries to restore quickly bus voltage are presented

  10. Auxiliary field Monte-Carlo study of the QCD phase diagram at strong coupling

    CERN Document Server

    Ohnishi, Akira; Nakano, Takashi Z

    2012-01-01

    We investigate the QCD phase diagram in the strong coupling limit by using a newly developed auxiliary field Monte-Carlo (AFMC) method. Starting from an effective action in the leading order of the 1/g^2 and 1/d expansion with one species of unrooted staggered fermion, we solve the many-body problem exactly by introducing the auxiliary fields and integrating out the temporal links and quark fields. We have a sign problem in AFMC, which is different from the original one in finite density lattice QCD. For low momentum auxiliary field modes, a complex phase cancellation mechanism exists, and the sign problem is not serious on a small lattice. Compared with the mean field results, the transition temperature is found to be reduced by around 10 % and the hadron phase is found to be extended in the larger chemical potential direction by around 20 %, as observed in the monomer-dimer-polymer (MDP) simulations.

  11. Olfaction Contributes to Pelagic Navigation in a Coastal Shark

    OpenAIRE

    Nosal, Andrew P.; Chao, Yi; Farrara, John D.; Chai, Fei; Hastings, Philip A.

    2016-01-01

    How animals navigate the constantly moving and visually uniform pelagic realm, often along straight paths between distant sites, is an enduring mystery. The mechanisms enabling pelagic navigation in cartilaginous fishes are particularly understudied. We used shoreward navigation by leopard sharks (Triakis semifasciata) as a model system to test whether olfaction contributes to pelagic navigation. Leopard sharks were captured alongshore, transported 9 km offshore, released, and acoustically tr...

  12. Navigating the Internet.

    OpenAIRE

    Powsner, S M; Roderer, N K

    1994-01-01

    Navigating any complex set of information resources requires tools for both browsing and searching. A number of tools are available today for using Internet resources, and more are being developed. This article reviews existing navigational tools, including two developed at the Yale University School of Medicine, and points out their strengths and weaknesses. A major shortcoming of the present Internet navigation methods is the lack of controlled descriptions of the available resources. As a ...

  13. Indoor wayfinding and navigation

    CERN Document Server

    2015-01-01

    Due to the widespread use of navigation systems for wayfinding and navigation in the outdoors, researchers have devoted their efforts in recent years to designing navigation systems that can be used indoors. This book is a comprehensive guide to designing and building indoor wayfinding and navigation systems. It covers all types of feasible sensors (for example, Wi-Fi, A-GPS), discussing the level of accuracy, the types of map data needed, the data sources, and the techniques for providing routes and directions within structures.

  14. [Hospital auxiliary staff, between polyvalence and invisibility].

    Science.gov (United States)

    Veissier, Pascale

    2016-01-01

    Often underestimated, hospital auxiliary staff carry out on a daily basis a professional activity that may be difficult to define and/or recognize. What does their work consist in and what are the boundaries of the scope of their activity? Faced with a growing rate of absenteeism among these members of staff in a nursing home for elderly people attached to a hospital, an issue emerges: does the content of their professional activity have an impact on the causes and evolution of this phenomenon? PMID:26976318

  15. System Study: Auxiliary Feedwater 1998–2013

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2014-12-31

    This report presents an unreliability evaluation of the auxiliary feedwater (AFW) system at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2013 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10-year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the AFW results.

  16. System Study: Auxiliary Feedwater 1998-2014

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.

    2015-12-01

    This report presents an unreliability evaluation of the auxiliary feedwater (AFW) system at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the AFW results.

  17. Auxiliary fields in the geometrical relativistic particle dynamics

    International Nuclear Information System (INIS)

    We describe how to construct the dynamics of relativistic particles, following either timelike or null curves, by means of an auxiliary variables method instead of the standard theory of deformations for curves. There are interesting physical particle models governed by actions that involve higher order derivatives of the embedding functions of the worldline. We point out that the mechanical content of such models can be extracted wisely from a lower order action, which can be performed by implementing in the action a finite number of constraints that involve the geometrical relationship structures inherent to a curve and by using a covariant formalism. We emphasize our approach for null curves. For such systems, the natural time parameter is a pseudo-arclength whose properties resemble those of the standard proper time. We illustrate the formalism by applying it to some models for relativistic particles

  18. Auxiliary fields in the geometrical relativistic particle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Amador, A; Bagatella, N; Rojas, E [Departamento de Fisica, Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico); Cordero, R [Departamento de Fisica, Escuela Superior de Fisica y Matematicas del I.P.N, Edificio 9, 07738 Mexico D.F (Mexico)], E-mail: aramador@gmail.com, E-mail: nbagatella@uv.mx, E-mail: cordero@esfm.ipn.mx, E-mail: efrojas@uv.mx

    2008-03-21

    We describe how to construct the dynamics of relativistic particles, following either timelike or null curves, by means of an auxiliary variables method instead of the standard theory of deformations for curves. There are interesting physical particle models governed by actions that involve higher order derivatives of the embedding functions of the worldline. We point out that the mechanical content of such models can be extracted wisely from a lower order action, which can be performed by implementing in the action a finite number of constraints that involve the geometrical relationship structures inherent to a curve and by using a covariant formalism. We emphasize our approach for null curves. For such systems, the natural time parameter is a pseudo-arclength whose properties resemble those of the standard proper time. We illustrate the formalism by applying it to some models for relativistic particles.

  19. Auxiliary pattern for cell-based OPC

    Science.gov (United States)

    Kahng, Andrew B.; Park, Chul-Hong

    2006-10-01

    The runtime of model-based optical proximity correction (OPC) tools has grown unacceptably with each successive technology generation, and has emerged as one of the major bottlenecks for turnaround time (TAT) of IC data preparation and manufacturing. The cell-based OPC approach improves runtime by performing OPC once per cell definition as opposed to once per cell instantiation in the layout. However, cell-based OPC does not comprehend inter-cell optical interactions that affect feature printability in a layout context. In this work, we propose auxiliary pattern-enabled cell-based OPC which can minimize the CD differences between cell-based OPC and model-based OPC. To enable effective insertion of auxiliary pattern (AP) in the design, we also propose a post-placement optimization of a standard cell block with respect to detailed placement. By dynamic programming-based placement perturbation, we achieve 100% AP applicability in designs with placement utilizations of cell-based OPC with AP can match gate edge placement error (EPE) count of model-based OPC within 4%. This is an improvement of 90%, on average, over cell-based OPC without APs. The AP-based OPC approach can reduce OPC runtimes versus model-based OPC by up to 40X in our benchmark designs. We can also achieve reduction of GDSII file size and ORC runtimes due to hierarchy maintenance of cell-based OPC.

  20. Navigation Using Inertial Sensors

    OpenAIRE

    Groves, P. D.

    2015-01-01

    This tutorial provides an introduction to navigation using inertial sensors, explaining the underlying principles. Topics covered include accelerometer and gyro technology and their characteristics, strapdown inertial navigation, attitude determination, integration and alignment, zero updates, motion constraints, pedestrian dead reckoning using step detection, and fault detection.

  1. Visual navigation for an autonomous mobile vehicle

    OpenAIRE

    Peterson, Kevin Robert

    1992-01-01

    Approved for public release; distribution is unlimited Image understanding for a mobile robotic vehicle is an important and complex task for ensuring safe navigation and extended autonomous operations. The goal of this work is to implement a working vision-based navigation control mechanism within a known environment onboard the autonomous mobile vehicle Yamabico-II. Although installing a working hardware system was not accomplished, the image processing, model description, pattern match...

  2. Algorithms for vehicle navigation

    OpenAIRE

    Storandt, Sabine

    2012-01-01

    Nowadays, navigation systems are integral parts of most cars. They allow the user to drive to a preselected destination on the shortest or quickest path by giving turn-by-turn directions. To fulfil this task the navigation system must be aware of the current position of the vehicle at any time, and has to compute the optimal route to the destination on that basis. Both of these subproblems have to be solved frequently, because the navigation system must react immediately if the vehicle leaves...

  3. Dynamic analysis of reactor auxiliary buildings

    International Nuclear Information System (INIS)

    A review of structural methods of generalized use in the dynamic analysis of Auxiliary Buildings and similar structures of Nuclear Power Plants is presented. Emphasis is placed on the structural response to blast and seismic loading studied from a global view point. Alternative models for the representation of both element and global stiffnesses are discussed. The assumption of rigid floor behaviour for lateral force excitation is studied. Advantages of using multi-stick models are referred and illustrated. The occurrence of torsional motions on the response is examined. The study evidences the importance of the low aspect ratio of these structures and shows its influence on parameters currently used in design of conventional buildings. (Author)

  4. Brane worlds in gravity with auxiliary fields

    International Nuclear Information System (INIS)

    Recently, Pani et al. explored a new theory of gravity by adding nondynamical fields, i.e., gravity with auxiliary fields (Phys Rev D 88:121502, 2013). In this gravity theory, higher-order derivatives of matter fields generically appear in the field equations. In this paper we extend this theory to any dimensions and discuss the thick braneworld model in five dimensions. Domain wall solutions are obtained numerically. The stability of the brane system under tensor perturbations is analyzed. We find that the system is stable under tensor perturbations and the gravity zero mode is localized on the brane. Therefore, the four-dimensional Newtonian potential can be realized on the brane. (orig.)

  5. Brane worlds in gravity with auxiliary fields

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Bin; Liu, Yu-Xiao; Yang, Ke [Lanzhou University, Institute of Theoretical Physics, Lanzhou (China)

    2015-02-01

    Recently, Pani et al. explored a new theory of gravity by adding nondynamical fields, i.e., gravity with auxiliary fields (Phys Rev D 88:121502, 2013). In this gravity theory, higher-order derivatives of matter fields generically appear in the field equations. In this paper we extend this theory to any dimensions and discuss the thick braneworld model in five dimensions. Domain wall solutions are obtained numerically. The stability of the brane system under tensor perturbations is analyzed. We find that the system is stable under tensor perturbations and the gravity zero mode is localized on the brane. Therefore, the four-dimensional Newtonian potential can be realized on the brane. (orig.)

  6. Grammaticalization: The development of some English modal auxiliaries

    Directory of Open Access Journals (Sweden)

    Leonardo Véliz Campos

    2007-01-01

    Full Text Available This paper approaches the topic of Grammaticalization from a diachronic perspective, with particular emphasis on the development of some English modal auxiliaries. The first part contextualizes the topic within the filed of Cognitive Linguistics; the second, deals with a brief description of lexical and grammatical items. The third part of the paper provides some crucial information on the history of Grammaticalization. A final section outlines some of the mechanisms involved in the process of Grammaticalization together with the analysis of some English modal auxiliaries and the importance of it in when studying and understanding English as a foreign language.En éste articulo se hace una reseña de un perspectiva diacrónica a un tema llamado Gramaticalización, con particular énfasis en el desarrollo de algunos de los verbos auxiliares modales en Inglés. En la primera parte se contextualiza el tema en el campo de los estudios de la Lingüística Cognitiva y, en la segunda, se aborda la distinción entre categorías léxicas y categorías gramaticales en una breve descripción. En la tercera parte se entrega información acerca de la historia del proceso de gramaticalización. La sección final plantea algunos de los mecanismos que son parte del proceso de gramaticalización, junto con un análisis de algunos verbos auxiliares modales en inglés que resultan ser de suma importancia en el estudio y la comprensión del inglés como lengua extranjera.

  7. Restricted Navigation Areas - USACE IENC

    Data.gov (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  8. Dedicated auxiliary power units for Hybrid Electric Vehicles

    NARCIS (Netherlands)

    Mourad, S.; Weijer, C.J.T. van de

    1998-01-01

    The use of a dedicated auxiliary power unit is essential to utilize the potential that hybrid vehicles offer for efficient and ultra-clean transportation. An example of a hybrid project at the TNO Road-Vehicles Research Institute shows the development and the results of a dedicated auxiliary power u

  9. 47 CFR 80.290 - Auxiliary receiving antenna.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Auxiliary receiving antenna. 80.290 Section 80... antenna. An auxiliary receiving antenna must be provided when necessary to avoid unauthorized interruption or reduced efficiency of the required watch because the normal receiving antenna is not...

  10. The German and English Auxiliary Systems and Complex Predicates

    Science.gov (United States)

    McCormick, Terrence C.

    1976-01-01

    This paper explores the auxiliary systems of English and German and the use of the auxiliary verbs in various complex predicate structures in the two languages. It aims at alleviating two types of problems in learning German involving governing patterns and ordering problems in clauses. (CHK)

  11. Spatial cognition and navigation

    Science.gov (United States)

    Aretz, Anthony J.

    1989-01-01

    An experiment that provides data for the development of a cognitive model of pilot flight navigation is described. The experiment characterizes navigational awareness as the mental alignment of two frames of reference: (1) the ego centered reference frame that is established by the forward view out of the cockpit and (2) the world centered reference frame that is established by the aircraft's location on a map. The data support a model involving at least two components: (1) the perceptual encoding of the navigational landmarks and (2) the mental rotation of the map's world reference frame into alignment with the ego centered reference frame. The quantitative relationships of these two factors are provided as possible inputs for a computational model of spatial cognition during flight navigation.

  12. Symmetric Synchronous Collaborative Navigation

    OpenAIRE

    Gerosa, Luca; Giordani, Alessandra; Ronchetti, Marco

    2004-01-01

    Synchronous collaborative navigation is a form of social navigation where users virtually share a web browser. In this paper, we present a symmetric, proxy-based architecture where each user can take the lead and guide others in visiting web sites, without the need for a special browser or other software. We show how we have applied this scheme to a problem-solving-oriented e-learning system.

  13. Simulative technology for auxiliary fuel tank separation in a wind tunnel

    Institute of Scientific and Technical Information of China (English)

    Ma Xin; Liu Wei; Chen Ling; Li Xiao; Jia Zhenyuan; Shang Zhiliang

    2016-01-01

    In this paper, we propose a simulative experimental system in wind tunnel conditions for the separation of auxiliary fuel tanks from an aircraft. The experimental system consists of a simulative release mechanism, a scaled model and a pose measuring system. A new release mechanism was designed to ensure stability of the separation. Scaled models of the auxiliary fuel tank were designed and their moment of inertia was adjusted by installing counterweights inside the model. Pose param-eters of the scaled model were measured and calculated by a binocular vision system. Additionally, in order to achieve high brightness and high signal-to-noise ratio of the images in the dark enclosed wind tunnel, a new high-speed image acquisition method based on miniature self-emitting units was pre-sented. Accuracy of the pose measurement system and repeatability of the separation mechanism were verified in the laboratory. Results show that the position precision of the pose measurement system can reach 0.1 mm, the precision of the pitch and yaw angles is less than 0.1? and that of the roll angle can be up to 0.3?. Besides, repeatability errors of models’ velocity and angular velocity controlled by the release mechanism remain small, satisfying the measurement requirements. Finally, experiments for the separation of auxiliary fuel tanks were conducted in the laboratory.

  14. Beginnings of Satellite Navigation

    Directory of Open Access Journals (Sweden)

    Miljenko Solarić

    2008-05-01

    Full Text Available The first satellite navigation system called the Navy Navigation Satellite System (NNSS or TRANSIT was planned in the USA in 1958. It consisted of 5-6 artificial Earth satellites, was set in motion for the USA military in 1964, and in 1967 for civilian purposes. The frequency shift of received radio waves emitted from the satellite and caused by the Doppler effect was measured. The TRANSIT satellite speed of approaching or moving away was derived from that; the TRANSIT satellites emmited also their own coordinates. Then the ship's position was determined by an intersection of three hyperboloids, which were determined from differences of distances in three time intervals. Maintenance of this navigation system was stopped in 1996, but it is still being used in the USA Navy for exploring the ionosphere. Furthermore, results of Doppler measurements in international projects at the Hvar Observatory from 1982 and 1983. This was the first time in Croatia and the former country that the coordinates of the Hvar Observatory were determined in the unique world coordinate system WGS'72. The paper ends with a brief representation of the Tsiklon Doppler navigation system produced in the former Soviet Union, and there is a list of some of numerous produced and designed satellite navigation systems.Ključne riječi

  15. Auxiliary Heating Systems for the Ignitor Project

    Science.gov (United States)

    Sassi, M.; Mantovani, S.; Coppi, B.

    2013-10-01

    Auxiliary plasma heating systems directed at extending the range of plasma regimes that can be accessed by Ohmic heating only are important components of the Ignitor machine. In order to affect the entire plasma column an appropriate ICRH systemhas been designed and components of it have been tested. The adoption of a 280 GHz system affecting, by ECRH, the outer edge of the plasma column has been proposed in order to influence temperature and density profiles in this important region. The ICRH system will operate over the range 80-120 MHz, consistent with magnetic fields in the range 9-13 T. The maximum delivered power goes from 8 MW (at 80 MHz) to 6 MW (at 120 MHz) distributed over 4 ports. A full size prototype of the VTL between the port flange and the antenna straps, with the external support and precise guiding system has been constructed. The innovative quick latching system located at the end of the coaxial cable has been successfully tested, providing perfect interference with the spring Be-Cu electrical contacts. Vacuum levels of 10-6, compatible with the limit of material degassing, and electrical tests up to 12 kV without discharges have been obtained. Special attention was given to the finishing of the inox surfaces, and to the TIG welds. U.S. DOE sponsored.

  16. Aging assessment of auxiliary feedwater pumps

    International Nuclear Information System (INIS)

    ORNL is conducting aging assessments of auxiliary feedwater pumps to provide recommendations for monitoring and assessing the severity of time-dependent degradation as well as to recommend maintenance and replacement practices. Cornerstones of these activities are the identification of failure modes and causes and ranking of causes. Failure modes and causes of interest are those due to aging and service wear. Design details, functional requirements, and operating experience data were used to identify failure modes and causes and to rank the latter. Based on this input, potentially useful inspection, surveillance, and condition monitoring methods that are currently available for use or in the developmental stage were examined and recommendations made. The methods selected are listed and discussed in terms of use and information to be obtained. Relationships between inspection, surveillance, and monitoring and maintenance practices entered prominently into maintenance recommendations. These recommendations, therefore, embrace predictive as well as corrective and preventative maintenance practices. The recommendations are described, inspection details are discussed, and periodic inspection and maintenance interval guidelines are given. Surveillance testing at low-flow conditions is also discussed. It is shown that this type of testing can lead to accelerated aging

  17. Orbiter Auxiliary Power Unit Flight Support Plan

    Science.gov (United States)

    Guirl, Robert; Munroe, James; Scott, Walter

    1990-01-01

    This paper discussed the development of an integrated Orbiter Auxiliary Power Unit (APU) and Improved APU (IAPU) Flight Suuport Plan. The plan identifies hardware requirements for continued support of flight activities for the Space Shuttle Orbiter fleet. Each Orbiter vehicle has three APUs that provide power to the hydraulic system for flight control surface actuation, engine gimbaling, landing gear deployment, braking, and steering. The APUs contain hardware that has been found over the course of development and flight history to have operating time and on-vehicle exposure time limits. These APUs will be replaced by IAPUs with enhanced operating lives on a vehicle-by-vehicle basis during scheduled Orbiter modification periods. This Flight Support Plan is used by program management, engineering, logistics, contracts, and procurement groups to establish optimum use of available hardware and replacement quantities and delivery requirements for APUs until vehicle modifications and incorporation of IAPUs. Changes to the flight manifest and program delays are evaluated relative to their impact on hardware availability.

  18. Coordinating sensing and local navigation

    Science.gov (United States)

    Slack, Marc G.

    1991-07-01

    Based on Navigation Templates (or NaTs), this work presents a new paradigm for local navigation which addresses the noisy and uncertain nature of sensor data. Rather than creating a new navigation plan each time the robot's perception of the world changes, the technique incorporates perceptual changes directly into the existing navigation plan. In this way, the robot's navigation plan is quickly and continuously modified, resulting in actions that remain coordinated with its changing perception of the world.

  19. Auxiliary signal processing system for a multiparameter radar

    Science.gov (United States)

    Chandrasekar, V.; Gray, G. R.; Caylor, I. J.

    1993-01-01

    The design of an auxiliary signal processor for a multiparameter radar is described with emphasis on low cost, quick development, and minimum disruption of radar operations. The processor is based around a low-cost digital signal processor card and personal computer controller. With the use of such a concept, an auxiliary processor was implemented for the NCAR CP-2 radar during a 1991 summer field campaign and allowed measurement of additional polarimetric parameters, namely, the differential phase and the copolar cross correlation. Sample data are presented from both the auxiliary and existing radar signal processors.

  20. Syntactic Analyses for Parallel Grammars Auxiliaries and Genitive NPs

    CERN Document Server

    Butt, M; Rohrer, C; Butt, Miriaam; Fortman, Christian; Rohrer, Christian

    1996-01-01

    This paper focuses on two disparate aspects of German syntax from the perspective of parallel grammar development. As part of a cooperative project, we present an innovative approach to auxiliaries and multiple genitive NPs in German. The LFG-based implementation presented here avoids unnessary structural complexity in the representation of auxiliaries by challenging the traditional analysis of auxiliaries as raising verbs. The approach developed for multiple genitive NPs provides a more abstract, language independent representation of genitives associated with nominalized verbs. Taken together, the two approaches represent a step towards providing uniformly applicable treatments for differing languages, thus lightening the burden for machine translation.

  1. Mobile Robot Navigation

    DEFF Research Database (Denmark)

    Andersen, Jens Christian

    2007-01-01

    . The research is now progressing towards autonomous robots which will be able to assist us in our daily life. One of the enabling technologies is navigation, and navigation is the subject of this thesis. Navigation of an autonomous robot is concerned with the ability of the robot to direct itself from...... validation of the implemented solutions and the ability of the methods to solve real world problems. The amount of software needed by an autonomous robot can be overwhelming. Software reuse and distributed development are therefore important issues. The thesis describes a new component architecture......Abstract Robots will soon take part in everyone’s daily life. In industrial production this has been the case for many years, but up to now the use of mobile robots has been limited to a few and isolated applications like lawn mowing, surveillance, agricultural production and military applications...

  2. Navigating Distributed Services

    DEFF Research Database (Denmark)

    Beute, Berco

    2002-01-01

    , to a situation where they are distributedacross the Internet. The second trend is the shift from a virtual environment that solelyconsists of distributed documents to a virtual environment that consists of bothdistributed documents and distributed services. The third and final trend is theincreasing...... diversity of devices used to access information on the Internet.The focal point of the thesis is an initial exploration of the effects of the trends onusers as they navigate the virtual environment of distributed documents and services.To begin the thesis uses scenarios as a heuristic device to identify and...... analyse themain effects of the trends. This is followed by an exploration of theory of navigationInformation Spaces, which is in turn followed by an overview of theories, and the stateof the art in navigating distributed services. These explorations of both theory andpractice resulted in a large number of...

  3. Designs for remote inspection of the ALMR Reactor Vessel Auxiliary Cooling System (RVACS)

    International Nuclear Information System (INIS)

    One of the most important safety systems in General Electric's (GI) Advanced Liquid Metal Reactor (ALMR) is the Reactor Vessel Auxiliary Cooling System (RVACS). Because of high temperature, radiation, and restricted space conditions, GI desired methods to remotely inspect the RVACS, emissive coatings, and reactor vessel welds during normal refueling operations. The DOE/NE Robotics for Advanced Reactors program formed a team to evaluate the ALMR design for remote inspection of the RVACS. Conceptual designs for robots to perform the required inspection tasks were developed by the team. Design criteria for these remote systems included robot deployment, power supply, navigation, environmental hardening of components, tether management, communication with an operator, sensing, and failure recovery. The operation of the remote inspection concepts were tested using 3-D simulation models of the ALMR. In addition, the team performed an extensive technology review of robot components that could survive the environmental conditions in the RVACS

  4. Designs for remote inspection of the ALMR Reactor Vessel Auxiliary Cooling System (RVACS)

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, F.J. (Oak Ridge National Lab., TN (United States)); Carroll, D.G. (General Electric Co., San Jose, CA (United States)); Chen, C. (Tennessee Univ., Knoxville, TN (United States)); Crane, C.; Dalton, R. (Florida Univ., Gainesville, FL (United States)); Taylor, J.R. (Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)); Tosunoglu, S. (Texas Univ., Austin, TX (United States))

    1993-01-01

    One of the most important safety systems in General Electric's (GI) Advanced Liquid Metal Reactor (ALMR) is the Reactor Vessel Auxiliary Cooling System (RVACS). Because of high temperature, radiation, and restricted space conditions, GI desired methods to remotely inspect the RVACS, emissive coatings, and reactor vessel welds during normal refueling operations. The DOE/NE Robotics for Advanced Reactors program formed a team to evaluate the ALMR design for remote inspection of the RVACS. Conceptual designs for robots to perform the required inspection tasks were developed by the team. Design criteria for these remote systems included robot deployment, power supply, navigation, environmental hardening of components, tether management, communication with an operator, sensing, and failure recovery. The operation of the remote inspection concepts were tested using 3-D simulation models of the ALMR. In addition, the team performed an extensive technology review of robot components that could survive the environmental conditions in the RVACS.

  5. Mariner 9 navigation

    Science.gov (United States)

    Neil, W. J.; Jordan, J. F.; Zielenbach, J. W.; Wong, S. K.; Mitchell, R. T.; Webb, W. A.; Koskela, P. E.

    1973-01-01

    A final, comprehensive description of the navigation of Mariner 9-the first U.S. spacecraft to orbit another planet is provided. The Mariner 9 navigation function included not only precision flight path control but also pointing of the spacecraft's scientific instruments mounted on a two degree of freedom scan platform. To the extent appropriate, each section describes the perflight analyses on which the operational strategies and performance predictions were based. Inflight results are then discussed and compared with the preflight predictions. Postflight analyses, which were primarily concerned with developing a thorough understanding of unexpected in-flight results, are also presented.

  6. The attack navigator

    DEFF Research Database (Denmark)

    Probst, Christian W.; Willemson, Jan; Pieters, Wolter

    2016-01-01

    The need to assess security and take protection decisions is at least as old as our civilisation. However, the complexity and development speed of our interconnected technical systems have surpassed our capacity to imagine and evaluate risk scenarios. This holds in particular for risks that are...... caused by the strategic behaviour of adversaries. Therefore, technology-supported methods are needed to help us identify and manage these risks. In this paper, we describe the attack navigator: a graph-based approach to security risk assessment inspired by navigation systems. Based on maps of a socio...

  7. 46 CFR 182.620 - Auxiliary means of steering.

    Science.gov (United States)

    2010-10-01

    ... TONS) MACHINERY INSTALLATION Steering Systems § 182.620 Auxiliary means of steering. (a) Except as... personnel hazards during normal or heavy weather operation. (b) A suitable hand tiller may be acceptable...

  8. Dynamic navigation simulation of an articulated multi-link arm for in-vessel inspection tasks in a Tokamak

    International Nuclear Information System (INIS)

    This paper is part of the remote handling (RH) activities towards preparedness for the future fusion machines. The aim of the R and D program performed is to demonstrate the feasibility of the inspection tasks inside the Vacuum Vessel. Due to the toroidal geometry and huge dimensions of the Vacuum Vessel, there is an inevitable need of a precise and fast automated articulated inspection system that can perform the required inspection tasks without damaging the surface and to maintain the machine availability for the maximum time. When considering generic Tokamak relevant conditions, the set of major challenges for the Remote Equipment is to sustain the severe operating conditions: ultra high vacuum, temperature and tritium level. The limited number of machine access ports and the very constrained environment complicate the introduction of a robot into the machine. The Multi Link inspection arm is required to be deployed in the bounded environment inside the Tokamak Vessel. This paper presents the development of software for implementation of autonomous navigation motion control algorithms based design simulations for the inspection Arm for routine inspection tasks, navigation to the targeted coordinates inside the Vessel, clash avoidance and to perform other auxiliary mechanical tasks. The software is also capable to store the joints and frame locations at every interval which can be used for the real time control application. The developed software has the flexibility to work with any number of links and joints. (author)

  9. GPS INTEGRATED NAVIGATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Swati R. Dhabarde

    2012-06-01

    Full Text Available In my project I am developing a computer program that willsimulate and explain the need of technology and advance systemfor any person moving or navigating in a car (or any vehicle.Every person in day to day life requires some navigation for theproper working of his work .it is the human nature that ever mantakes some guidance about some or another work without guidancethe job taken by a human being will be completed properly or notis not known. So, for a proper working of your decided scheduleyou should know everything about the place where you live. Youdo know and if you ought to know then you can use “EmergencyNavigation System”.‘Emergency Navigation System’ is specialized softwarewhich is able to track the current position (of any person drivingvehicles and tell the path and other detailed information aboutyour destination. If there are occurrences of multiple paths to thesame destination then it can show the shortest one among them.

  10. Evaluation of the pressure loads generated by hydrogen explosion in auxiliary nuclear building

    International Nuclear Information System (INIS)

    Full text of publication follows: In the framework of nuclear safety, a hydrogen leaks in the auxiliary nuclear building would raise a explosion hazard. A local ignition of the combustible mixture would give birth initially to a slow flame, rapidly accelerated by obstacles. This flame acceleration is responsible for high pressure loads that can damage the auxiliary building and destroy safety equipments in it. In this paper, we evaluate the pressure loads generated by an hydrogen explosion for both bounding and realistic explosion scenarios. The bounding scenarios use stoichiometric hydrogen-air mixtures and the realistic scenarios correspond to hydrogen leaks with mass flow rate varying between 1 g/s and 9 g/s. For every scenario, the impact of the ignition location and ignition time are investigated. The hydrogen dispersion and explosion are computed using the TONUS code. The dispersion model used is based on a finite element solver and the explosion is simulated by a structured finite volumes EULER equation solver and the combustion model CREBCOM which simulates the hydrogen/air turbulent flame propagation, taking into account 3D complex geometry and reactants concentration gradients. The pressure loads computed are then used to investigate the occurrence of a mechanical failure of the tanks located in the auxiliary nuclear building and containing radioactive fluids. The EUROPLEXUS code is used to perform 3D mechanical calculations because the loads are non uniform and of rather short deviation. (authors)

  11. Bayesian auxiliary variable models for binary and multinomial regression

    OpenAIRE

    Holmes, C C; HELD, L.

    2006-01-01

    In this paper we discuss auxiliary variable approaches to Bayesian binary and multinomial regression. These approaches are ideally suited to automated Markov chain Monte Carlo simulation. In the first part we describe a simple technique using joint updating that improves the performance of the conventional probit regression algorithm. In the second part we discuss auxiliary variable methods for inference in Bayesian logistic regression, including covariate set uncertainty. Fina...

  12. A Parallel Auxiliary Grid AMG Method for GPU

    OpenAIRE

    Wang, Lu; Hu, Xiaozhe; Cohen, Jonathan; Xu, Jinchao

    2012-01-01

    In this paper, we develop a new parallel auxiliary grid algebraic multigrid (AMG) method to leverage the power of graphic processing units (GPUs). In the construction of the hierarchical coarse grid, we use a simple and fixed coarsening procedure based on a region quadtree generated from an auxiliary grid. This allows us to explicitly control the sparsity patterns and operator complexities of the AMG solver. This feature provides (nearly) optimal load balancing and predictable communication p...

  13. Operating experiences and degradation detection for auxiliary feedwater systems

    International Nuclear Information System (INIS)

    A study of Pressurized Water Reactor Auxiliary Feedwater (AFW) Systems has been conducted by Oak Ridge National Laboratory (ORNL) under the auspices of the Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. The results of the study are documented in NUREG/CR-5404, Vol. 1, Auxiliary Feedwater System Aging Study. The study reviewed historical failure experience and current monitoring practices for the AFW System. This paper provides an overview of the study approach and results

  14. New braneworld models in the presence of auxiliary fields

    CERN Document Server

    Bazeia, D; Menezes, R; Moreira, D C

    2014-01-01

    We study braneworld models in the presence of auxiliary fields. We use the first-order framework to investigate several distinct possibilities, where the standard braneworld scenario changes under the presence of the parameter that controls the auxiliary fields introduced to modify Einstein's equation. The results add to previous ones, to show that the minimal modification that we investigate contributes to change quantitatively the thick braneworld profile, although no new qualitative effect is capable of being induced by the minimal modification here considered.

  15. Alphabet Sizes of Auxiliary Variables in Canonical Inner Bounds

    OpenAIRE

    Jana, Soumya

    2008-01-01

    Alphabet size of auxiliary random variables in our canonical description is derived. Our analysis improves upon estimates known in special cases, and generalizes to an arbitrary multiterminal setup. The salient steps include decomposition of constituent rate polytopes into orthants, translation of a hyperplane till it becomes tangent to the achievable region at an extreme point, and derivation of minimum auxiliary alphabet sizes based on Caratheodory's theorem.

  16. Progress on radio frequency auxiliary heating system designs in ITER

    International Nuclear Information System (INIS)

    ITER will require over 100 MW of auxiliary power for heating, on- and off-axis current drive, accessing the H-mode, and plasma shut-down. The Electron Cyclotron Range of Frequencies (ECRF) and Ion Cyclotron Range of Frequencies (ICRF) are two forms of Radio Frequency (RF) auxiliary power being developed for these applications. Design concepts for both the ECRF and ICRF systems are presented, key features and critical design issues are discussed, and projected performances outlined

  17. SEPP-ZVS High Frequency Inverter Incorporating Auxiliary Switch

    Science.gov (United States)

    Ogiwara, Hiroyuki; Itoi, Misao; Nakaoka, Mutsuo

    This paper presents a novel circuit topology to attain ZVS operation of a high frequency inverter over a wide range output power regulation using a PWM control technique by connecting an auxiliary switch to the conventional single ended push-pull (SEPP) ZVS high frequency inverter. A switching current is injected into the main switches via the auxiliary switch only during the short period between its turn-on and off times to supply a current required for its ZVS operation.

  18. Soft switching DC/DC converter using auxiliary circuits

    OpenAIRE

    Jaroslav Dudrik; Vladimír Ruščin

    2008-01-01

    A novel auxiliary circuit for full-bridge PWMDC/DC converter with controlled secondary side rectifieris presented in this paper. Zero-current turn-on for allpower switches of the inverter is achieved for full loadrange from no-load to short circuit by using controlledrectifier and auxiliary circuit on the secondary side.Modified phase shift PWM control strategy is used for theconverter. The principle of operation is explained andanalyzed and the simulation results are presented.

  19. Photoplus: auxiliary information for printed images based on distributed source coding

    Science.gov (United States)

    Samadani, Ramin; Mukherjee, Debargha

    2008-01-01

    A printed photograph is difficult to reuse because the digital information that generated the print may no longer be available. This paper describes a mechanism for approximating the original digital image by combining a scan of the printed photograph with small amounts of digital auxiliary information kept together with the print. The auxiliary information consists of a small amount of digital data to enable accurate registration and color-reproduction, followed by a larger amount of digital data to recover residual errors and lost frequencies by distributed Wyner-Ziv coding techniques. Approximating the original digital image enables many uses, including making good quality reprints from the original print, even when they are faded many years later. In essence, the print itself becomes the currency for archiving and repurposing digital images, without requiring computer infrastructure.

  20. Chemical compass for bird navigation

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Hore, Peter J.; Ritz, Thorsten;

    2014-01-01

    Migratory birds travel spectacular distances each year, navigating and orienting by a variety of means, most of which are poorly understood. Among them is a remarkable ability to perceive the intensity and direction of the Earth's magnetic field. Biologically credible mechanisms for the detection...... other relies on the quantum spin dynamics of transient photoinduced radical pairs. Originally suggested by Schulten in 1978 as the basis of the avian magnetic compass sensor, this mechanism gained support from the subsequent observation that the compass is light-dependent. The radical pair hypothesis...... began to attract increased interest following the proposal in 2000 that free radical chemistry could occur in the bird's retina initiated by photoexcitation of cryptochrome, a specialized photoreceptor protein. In the present paper we review the important physical and chemical constraints on a possible...

  1. The development of a passive auxiliary feedwater system in APR+

    International Nuclear Information System (INIS)

    The Advanced Power Reactor Plus (APR+) is being developed in Korea. APR+ is a GEN III+ reactor on the basis of the APR1400. To meet the requirements of GEN III+ reactors, the economics and the safety of the APR+ are further enhanced. One of the basic principles of APR+ safety systems is the adoption of hybrid safety systems. Passive safety systems replace the current active safety systems from an economic point of view. The passive aux. feedwater system (PAFS) is one of the passive safety features adopted in the APR+. The PAFS replaces the conventional active auxiliary feedwater system by introducing a natural driving force mechanism while maintaining the system's basic Junction of cooling down the primary side and removing the decay heat. In order to satisfy the single failure criterion, the PAFS is composed of two independent trains. Each train has one steam condensing heat exchanger of 100% capability and one PCCT (Passive Condensation Cooling water Tank) of 100% capability. Basic design is underway and separate effect tests and integral effect tests will be performed to demonstrate the performance of the PAFS. (authors)

  2. Research on Temperature Modeling of Strapdown Inertial Navigation System

    Science.gov (United States)

    Huang, XiaoJuan; Zhao, LiJian; Xu, RuXiang; Yang, Heng

    2016-02-01

    Strapdown inertial navigation system with laser gyro has been deployed in space tracking ship and compared with the conventional platform inertial navigation system, it has substantial advantage in performance, accuracy and stabilization. Environmental and internal temperature affects the gyro, accelerator, electrical circuits and mechanical structure significantly but the existing temperature compensation model is not accurate enough especially when there is a big temperature change.

  3. Migration, Orientation and Navigation: Magnetic Compasses in Insects

    Science.gov (United States)

    The use of magnetic information for orientation and navigation is a widespread phenomenon in animals. In contrast to navigational systems in vertebrates, our understanding of the mechanisms underlying the insect magnetic perception and use of the information is at an early stage. Some insects use ma...

  4. Improved Line Tracking System for Autonomous Navigation of High-Speed Vehicle

    Directory of Open Access Journals (Sweden)

    Yahya Zare Khafri

    2012-07-01

    Full Text Available Line tracking navigation is one of the most widely techniques used in the robot navigation. In this paper, a customized line tracking system is proposed for autonomous navigation of high speed vehicles. In the presented system, auxiliary information -in addition to the road path- is added to the tracking lines such as locations of turn and intersections in the real roads. Moreover, the geometric position of line sensors is re-designed enables the high rate sensing with higher reliability. Finally, a light-weight navigation algorithm is proposed allow the high-speed movement using a reasonable processing power. This system is implemented on a MIPS-based embedded processor and experimental results with this embedded system show more than 98% accuracy at 200km/h with a 1GHz processor is viable.

  5. Revision of IMO Model Course 3.17 Maritime English. Focus on Maritime English to Auxiliary Personnel

    Directory of Open Access Journals (Sweden)

    L. Martes

    2015-09-01

    Full Text Available Under the Manila 2010 amendments to the STCW , all crew members on board cruise vessels, mainly those assisting passengers during emergency situations and not only, “should be able to communicate safety-related issues in English or in the language spoken by the passengers and other personnel on board.” Having in view that navigational and safety communications from ship to shore and vice versa, ship to ship, and on board ships must be precise, simple and unambiguous, so as to avoid confusion and error, besides the need to standardize the language used, there is a growing demand of developing communication skills in English, especially for personnel working on cruise vessels, but also on RORO vessels, yachts and small passenger vessels. This is the reason why we have designed, developed and are already delivering the “Maritime English for Auxiliary Personnel" course in Specialized Maritime English to auxiliary personnel working on board cruise vessels to develop their ability to communicate with passengers, mainly during an emergency. The course covers the specific language used to describe the parts of ships, organisation on board ships, all essential safety-related matters and work-specific topics. It also reflects the situations in which auxiliary personnel need to communicate, with each other, with other crew members and with shore side authorities. The final goal of this course is to improve fluency in spoken English in real life situations which, of course, can be both routine and non-routine.

  6. Inland Electronic Navigational Charts (IENC)

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — These Inland Electronic Navigational Charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  7. Nautical Navigation Aids (NAVAID) Locations

    Data.gov (United States)

    Department of Homeland Security — Structures intended to assist a navigator to determine position or safe course, or to warn of dangers or obstructions to navigation. This dataset includes lights,...

  8. 30 CFR 57.8534 - Shutdown or failure of auxiliary fans.

    Science.gov (United States)

    2010-07-01

    ... auxiliary fan failure due to malfunction, accident, power failure, or other such unplanned or unscheduled... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Shutdown or failure of auxiliary fans. 57.8534... Ventilation Underground Only § 57.8534 Shutdown or failure of auxiliary fans. (a) Auxiliary fans installed...

  9. A PPS Sampling Scheme Using Harmonic Mean of An Auxiliary Variable

    OpenAIRE

    L.N. Sahoo; Dalabehera, M.; A.K. Mangaraj

    2012-01-01

    We consider a probability proportional to size sampling scheme by using harmonic mean of an auxiliary variable, when the correlation between study variable and auxiliary variable is highly negative. This is achieved by considering inverse transformation of the auxiliary variable and then utilizing the transformed auxiliary variable values at the design stage of the survey operation in selecting a sample.

  10. Navigation in Virtual Environment

    Czech Academy of Sciences Publication Activity Database

    Mikeš, Stanislav; Haindl, Michal; Holub, Radek

    Vienna: Austrian Computer Society, 2008 - (R. Sablatnig and J. Hemsley and P. Krammerer and E. Zolda and J. Stockinger), s. 111-118 ISBN 978-3-85403-238-0. [2nd International Conference EVA. Vienna (AT), 25.08.2008-28.08.2008] R&D Projects: GA AV ČR 1ET400750407; GA MŠk 1M0572; GA ČR GA102/08/0593 Grant ostatní: GA MŠk(CZ) 2C06019 Institutional research plan: CEZ:AV0Z10750506 Keywords : Virtual Reality * Navigation Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2008/RO/mikes-haindl-holub-navigation%20in%20virtual%20environment.pdf

  11. Mobile Robot Navigation

    OpenAIRE

    Andersen, Jens Christian; Ravn, Ole; Andersen, Nils Axel

    2007-01-01

    Robotter vil om få år blive en del af vores daglige liv. Inden for produktionsindustrien har det allerede være tilfældet i mange år, men anvendelsen af mobile robotter har hidtil været henvist til isolerede områder som græsslåning, overvågning, landbrugsproduktion og militære funktioner. Fremskridt i forskningen gør, at robotter vil kunne assistere os i mange af vore daglige gøremål i en ikke så fjern fremtid. En af de teknologier, der skal gøre dette muligt, er navigation, og navigation er e...

  12. VLTI First Fringes with Two Auxiliary Telescopes at Paranal

    Science.gov (United States)

    2005-03-01

    . Moreover, these moving ultra-high precision telescopes, each weighing 33 tonnes, fulfill very stringent mechanical stability requirements: "The telescopes are unique in the world", says Bertrand Koehler, the VLTI AT Project Manager. "After being relocated to a new position, the telescope is repositioned to a precision better than one tenth of a millimetre - that is, the size of a human hair! The image of the star is stabilized to better than thirty milli-arcsec - this is how we would see an object of the same size as one of the VLT enclosures on the Moon. Finally, the path followed by the light inside the telescope after bouncing on ten mirrors is stable to better than a few nanometres, which is the size of about one hundred atoms." A World Premiere ESO PR Photo 07e/05 ESO PR Photo 07e/05 "First Fringes" with two ATs [Preview - JPEG: 400 x 559 pix - 61k] [Normal - JPEG: 800 x 1134 pix - 357k] Caption: ESO PR Photo 07e/05 The "First Fringes" obtained with the first two VLTI Auxiliary Telescopes, as seen on the computer screen during the observation. The fringe pattern arises when the light beams from the two 1.8-m telescopes are brought together inside the VINCI instrument. The pattern itself contains information about the angular extension of the observed object, here the 6th-magnitude star HD62082. The fringes are acquired by moving a mirror back and forth around the position of equal path length for the two telescopes. One such scan can be seen in the third row window. This pattern results from the raw interferometric signals (the last two rows) after calibration and filtering using the photometric signals (the 4th and 5th row). The first two rows show the spectrum of the fringe pattern signal. More details about the interpretation of this pattern is given in Appendix A of PR 06/01. The possibility to move the ATs around and thus to perform observations with a large number of different telescope configurations ensures a great degree of flexibility, unique for an optical

  13. Self-navigating robot

    Science.gov (United States)

    Thompson, A. M.

    1978-01-01

    Rangefinding equipment and onboard navigation system determine best route from point to point. Research robot has two TV cameras and laser for scanning and mapping its environment. Path planner finds most direct, unobstructed route that requires minimum expenditure of energy. Distance is used as measure of energy expense, although other measures such as time or power consumption (which would depend on the topography of the path) may be used.

  14. Navigating stories in films

    OpenAIRE

    Salway, Andrew; Xu, Yan

    2005-01-01

    This report describes the transformation of feature films into hypervideo by representing their story structures using plot unties. Plot units represent cause-effect relationships between characters’ affect states and the events in a story. We use plot units to structure hypervideo links between intervals of video data. We have manually analysed two full-length feature films in terms of plot units. A system was developed to store and edit data about plot units and to navigate films by followi...

  15. Invisible Navigation (or Impossible?).

    OpenAIRE

    Özcan, Oğuzhan; O'Neil, Mary Lou

    2013-01-01

    Abstract: This article introduces an experimental artwork on moving mobile interfaces. It aims to answer the question: Is it possible to navigate a part of a large image composition, moving a smaller interface of a mobile device in a certain direction such as left and right, back and forth or up and down? The article then outlines the new concept of “Invisible (or impossible) Navigation” and discusses the output of artistic practices which address the “Labyrinth of Art”.

  16. Navigational Query Languages

    OpenAIRE

    Surinx, Dimitri

    2013-01-01

    In this thesis we introduce navigational query languages on graphs. Path queries in our languages are built over several operators: identity, union, composition, projection, coprojection, converse, transitive closure, diversity, intersection and difference. The smallest language we will consider only contains the first 3 operators, while the largest language contains all operators. For these query languages we will characterize their complete relative expressive power, i.e., we will compare t...

  17. Multisensor robot navigation system

    Science.gov (United States)

    Persa, Stelian; Jonker, Pieter P.

    2002-02-01

    Almost all robot navigation systems work indoors. Outdoor robot navigation systems offer the potential for new application areas. The biggest single obstacle to building effective robot navigation systems is the lack of accurate wide-area sensors for trackers that report the locations and orientations of objects in an environment. Active (sensor-emitter) tracking technologies require powered-device installation, limiting their use to prepared areas that are relative free of natural or man-made interference sources. The hybrid tracker combines rate gyros and accelerometers with compass and tilt orientation sensor and DGPS system. Sensor distortions, delays and drift required compensation to achieve good results. The measurements from sensors are fused together to compensate for each other's limitations. Analysis and experimental results demonstrate the system effectiveness. The paper presents a field experiment for a low-cost strapdown-IMU (Inertial Measurement Unit)/DGPS combination, with data processing for the determination of 2-D components of position (trajectory), velocity and heading. In the present approach we have neglected earth rotation and gravity variations, because of the poor gyroscope sensitivities of our low-cost ISA (Inertial Sensor Assembly) and because of the relatively small area of the trajectory. The scope of this experiment was to test the feasibility of an integrated DGPS/IMU system of this type and to develop a field evaluation procedure for such a combination.

  18. Navigation in virtual environments

    Science.gov (United States)

    Arthur, Erik; Hancock, Peter A.; Telke, Susan

    1996-06-01

    Virtual environments show great promise in the area of training. ALthough such synthetic environments project homeomorphic physical representations of real- world layouts, it is not known how individuals develop models to match such environments. To evaluate this process, the present experiment examined the accuracy of triadic representations of objects having learned them previously under different conditions. The layout consisted of four different colored spheres arranged on a flat plane. These objects could be viewed in either a free navigation virtual environment condition (NAV) or a single body position virtual environment condition. The first condition allowed active exploration of the environment while the latter condition allowed the participant only a passive opportunity to observe form a single viewpoint. These viewing conditions were a between-subject variable with ten participants randomly assigned to each condition. Performance was assessed by the response latency to judge the accuracy of a layout of three objects over different rotations. Results showed linear increases in response latency as the rotation angle increased from the initial perspective in SBP condition. The NAV condition did not show a similar effect of rotation angle. These results suggest that the spatial knowledge acquisition from virtual environments through navigation is similar to actual navigation.

  19. Organization and scheduling of auxiliary components and large equipments erection and control

    International Nuclear Information System (INIS)

    The first part of this paper deals with the installation of auxiliary systems. FRAMATOME divides NSSS site construction activities into the following 3 packages: main primary system, electricity and instrumentation and control, and auxiliary systems. This paper presents an analysis of the organisation of auxiliary system installation with particular reference to piping. The term ''auxiliary systems'' covers all NSSS mechanical and electrical equipment with the exception of heavy Reactor Coolant System components (reactor, fuel, associated handling equipment and cooling loops). FRAMATOME, with the help of its associates working on the French nuclear programme, has been able to develop efficient methods of organisation as a result of the wide experience gained. The main field involved is that of piping, for which computerized task analysis, scheduling and follow-up methods have been developed. The second part deals with large components installation. The normal sequence of welding operations for the assembly of the reactor coolant loops of a PWR power plant begins with the simultaneous welding of hot and cold leg piping and is completed by the welding of the crossover leg between the steam generator and the reactor coolant pump, thus ''closing'' the loop. This is the traditional method. FRAMATOME has developed a different method whereby installation of the reactor coolant loops begins with the welding of the steam generator - reactor coolant pump connection. This is the ''crossover leg'' method. This report presents a description of both methods followed by the results of a comparative study of technical considerations and schedules; in conclusion, charts are presented to assist in pre-selection of the method which is best suited to the on-site delivery schedule of Reactor Coolant System components

  20. Accuracy of marker-assisted selection with auxiliary traits

    Indian Academy of Sciences (India)

    P Narain

    2003-09-01

    Genetic information on molecular markers is increasingly being used in plant and animal improvement programmes particularly as indirect means to improve a metric trait by selection either on an individual basis or on the basis of an index incorporating such information. This paper examines the utility of an index of selection that not only combines phenotypic and molecular information on the trait under improvement but also combines similar information on one or more auxiliary traits. The accuracy of such a selection procedure has been theoretically studied for sufficiently large populations so that the effects of detected quantitative trait loci can be perfectly estimated. The theory is illustrated numerically by considering one auxiliary trait. It is shown that the use of an auxiliary trait improves the selection accuracy; and, hence, the relative efficiency of index selection compared to individual selection which is based on the same intensity of selection. This is particularly so for higher magnitudes of residual genetic correlation and environmental correlation having opposite signs, lower values of the proportion of genetic variation in the main trait associated with the markers, negligible proportion of genetic variation in the auxiliary trait associated with the markers, and lower values of the heritability of the main trait but higher values of the heritability of the auxiliary trait.

  1. Integrated navigation method based on inertial navigation system and Lidar

    Science.gov (United States)

    Zhang, Xiaoyue; Shi, Haitao; Pan, Jianye; Zhang, Chunxi

    2016-04-01

    An integrated navigation method based on the inertial navigational system (INS) and Lidar was proposed for land navigation. Compared with the traditional integrated navigational method and dead reckoning (DR) method, the influence of the inertial measurement unit (IMU) scale factor and misalignment was considered in the new method. First, the influence of the IMU scale factor and misalignment on navigation accuracy was analyzed. Based on the analysis, the integrated system error model of INS and Lidar was established, in which the IMU scale factor and misalignment error states were included. Then the observability of IMU error states was analyzed. According to the results of the observability analysis, the integrated system was optimized. Finally, numerical simulation and a vehicle test were carried out to validate the availability and utility of the proposed INS/Lidar integrated navigational method. Compared with the test result of a traditional integrated navigation method and DR method, the proposed integrated navigational method could result in a higher navigation precision. Consequently, the IMU scale factor and misalignment error were effectively compensated by the proposed method and the new integrated navigational method is valid.

  2. 煤矿井下综采工作面巡查机器人磁迹导航的研究%Research of Magnetic Tracking Navigation of Patrolling Robot on Fully Mechanized Coal Face of Coal Mine Underground

    Institute of Scientific and Technical Information of China (English)

    朱红秀; 石红伟; 姜川; 贾瑞清; 郭文骏; 费雷; 解轲; 李玲辉

    2011-01-01

    提出了一种煤矿井下综采工作面自主移动巡查机器人磁迹导航方案;通过实验确定了该机器人的磁轨材料和磁传感器分别为条状强磁磁铁和MS-324型干簧管,以轮式机器人采集煤矿井下图像信息为例,确定了干簧管在机器人上的安装位置及工作过程.实验结果表明,该机器人在中间2个干簧管之间的距离为40 mm时能稳定行走.%The paper proposed a scheme of magnetic tracking navigation of autonomous mobile patrolling robot on fully mechanized coal face of coal mine underground. The scheme defines magnetic tracking material and magnetic sensor of the robot as stripy magnet with high intensity magnetic and model MS-324 tongue tube through experiment, it defines installing position and working process of the tongue tube of the robot with example of collecting underground image information by wheeled robot. The experiment result showed that the robot can moves stably when distances between two tongue tubes are 40 mm.

  3. Design Characteristics of the Passive Auxiliary Feedwater System in APR+

    International Nuclear Information System (INIS)

    The passive auxiliary feedwater system (PAFS) is a typical passive safety system implemented for the APR+. The auxiliary feedwater system (AFWS) in the APR1400, which is the reference plant of the APR+, consists of two motor driven pumps, two turbine driven pumps, two water storage tanks, and related pipes and valves. The AFWS feeds emergency water to steam generators to cool down the reactor coolant system when the main feedwater is lost. To enhance the safety, the PAFS replaces the AFWS with a passive condensation heat exchanger (PCHX), a passive condensation cooling tank (PCCT), and a few valves and pipes in the APR+ design. In this paper, we propose the design requirements and conceptual design of the PAFS in order to evaluate the operability of the PAFS, to develop the APR+'s general arrangements for the auxiliary building, and to identify the important parameters to be quantified by experiments

  4. Auxiliary bearing design considerations for gas cooled reactors

    International Nuclear Information System (INIS)

    The need to avoid contamination of the primary system, along with other perceived advantages, has led to the selection of electromagnetic bearings (EMBs) in most ongoing commercial-scale gas cooled reactor (GCR) designs. However, one implication of magnetic bearings is the requirement to provide backup support to mitigate the effects of failures or overload conditions. The demands on these auxiliary or 'catcher' bearings have been substantially escalated by the recent development of direct Brayton cycle GCR concepts. Conversely, there has been only limited directed research in the area of auxiliary bearings, particularly for vertically oriented turbomachines. This paper explores the current state-of-the-art for auxiliary bearings and the implications for current GCR designs. (author)

  5. 33 CFR 401.53 - Obstructing navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Obstructing navigation. 401.53 Section 401.53 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.53...

  6. Control algorithms for autonomous robot navigation

    International Nuclear Information System (INIS)

    This paper examines control algorithm requirements for autonomous robot navigation outside laboratory environments. Three aspects of navigation are considered: navigation control in explored terrain, environment interactions with robot sensors, and navigation control in unanticipated situations. Major navigation methods are presented and relevance of traditional human learning theory is discussed. A new navigation technique linking graph theory and incidental learning is introduced

  7. Control algorithms for autonomous robot navigation

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, C.C.

    1985-09-20

    This paper examines control algorithm requirements for autonomous robot navigation outside laboratory environments. Three aspects of navigation are considered: navigation control in explored terrain, environment interactions with robot sensors, and navigation control in unanticipated situations. Major navigation methods are presented and relevance of traditional human learning theory is discussed. A new navigation technique linking graph theory and incidental learning is introduced.

  8. Understanding satellite navigation

    CERN Document Server

    Acharya, Rajat

    2014-01-01

    This book explains the basic principles of satellite navigation technology with the bare minimum of mathematics and without complex equations. It helps you to conceptualize the underlying theory from first principles, building up your knowledge gradually using practical demonstrations and worked examples. A full range of MATLAB simulations is used to visualize concepts and solve problems, allowing you to see what happens to signals and systems with different configurations. Implementation and applications are discussed, along with some special topics such as Kalman Filter and Ionosphere. W

  9. Navigating Hypermasculine Terrains

    DEFF Research Database (Denmark)

    Henriksen, Ann-Karina Eske

    2015-01-01

    The study addresses how young women navigate urban terrains that are characterized by high levels of interpersonal aggression and crime. It is argued that young women apply a range of gendered tactics to establish safety and social mastery, and that these are framed by the limits and possibilities...... imposed by a street-based hypermasculine script. The analysis rests on an ethnographic study among 25 young Danish women aged 13 to 23 experienced in engaging in street-based physical violence. The study suggests that explorations of female tactics can provide a useful method of analysis for understanding...

  10. China Satellite Navigation Conference

    CERN Document Server

    Liu, Jingnan; Fan, Shiwei; Wang, Feixue

    2016-01-01

    These Proceedings present selected research papers from CSNC2016, held during 18th-20th May in Changsha, China. The theme of CSNC2016 is Smart Sensing, Smart Perception. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou System (BDS) especially. They are divided into 12 topics to match the corresponding sessions in CSNC2016, which broadly covered key topics in GNSS. Readers can learn about the BDS and keep abreast of the latest advances in GNSS techniques and applications.

  11. Modular neural network and classical reinforcement learning for autonomous robot navigation: inhibiting undesirable behaviors

    OpenAIRE

    Antonelo, Eric; Baerveldt, Albert-Jan; Rögnvaldsson, Thorsteinn; Figueiredo, Mauricio

    2006-01-01

    Classical reinforcement learning mechanisms and a modular neural network are unified for conceiving an intelligent autonomous system for mobile robot navigation. The conception aims at inhibiting two common navigation deficiencies: generation of unsuitable cyclic trajectories and ineffectiveness in risky configurations. Distinct design apparatuses are considered for tackling these navigation difficulties, for instance: 1) neuron parameter for memorizing neuron activities (also functioning as ...

  12. Improving Semi-Supervised Learning with Auxiliary Deep Generative Models

    DEFF Research Database (Denmark)

    Maaløe, Lars; Sønderby, Casper Kaae; Sønderby, Søren Kaae;

    Deep generative models based upon continuous variational distributions parameterized by deep networks give state-of-the-art performance. In this paper we propose a framework for extending the latent representation with extra auxiliary variables in order to make the variational distribution more...... expressive for semi-supervised learning. By utilizing the stochasticity of the auxiliary variable we demonstrate how to train discriminative classifiers resulting in state-of-the-art performance within semi-supervised learning exemplified by an 0.96% error on MNIST using 100 labeled data points. Furthermore...

  13. Auxiliary tensor fields for Sp(2,R) self-duality

    CERN Document Server

    Ivanov, Evgeny A; Zupnik, Boris M

    2014-01-01

    The coset Sp(2,R)/U(1) is parametrized by two real scalar fields. We generalize the formalism of auxiliary tensor (bispinor) fields in U(1) self-dual nonlinear models of abelian gauge fields to the case of Sp(2,R) self-duality. In this new formulation, Sp(2,R) duality of the nonlinear scalar-gauge equations of motion is equivalent to an Sp(2,R) invariance of the auxiliary interaction. We derive this result in two different ways, aiming at its further application to supersymmetric theories. We also consider an extension to interactions with higher derivatives.

  14. Bispinor Auxiliary Fields in Duality-Invariant Electrodynamics Revisited

    OpenAIRE

    Ivanov, E. A.; Zupnik, B. M.

    2012-01-01

    Motivated by a recent progress in studying the duality-symmetric models of nonlinear electrodynamics, we revert to the auxiliary tensorial (bispinor) field formulation of the O(2) duality proposed by us in arXiv:hep-th/0110074, arXiv:hep-th/0303192. In this approach, the entire information about the given duality-symmetric system is encoded in the O(2) invariant interaction Lagrangian which is a function of the auxiliary fields V_{\\alpha\\beta}, \\bar V_{\\dot \\alpha\\dot \\beta}. We extend this s...

  15. TMI-2 auxiliary building elevator shaft and pit decontamination

    International Nuclear Information System (INIS)

    Decontamination of the elevator pit and shaft in the auxiliary building at Three Mile Island Unit 2 (TMI-2) was performed to remove high radiation and contamination levels which prevented personnel from utilizing the elevator. The radiation and contamination levels in the TMI-2 auxiliary building elevator shaft have been reduced to the point where plant personnel are again permitted to ride in the elevator without a radiation work permit, with the exception of access to the 281-ft (basement) level. Based on the declassification and expanded use of the elevator, the task goal has been met. The tax expended 16.16 man-rem and 621 man-hours

  16. Vanishing auxiliary variables in PPS sampling - with applications in microscopy

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute; Jensen, Eva B. Vedel

    auxiliary variables are a common phenomenon in microscopy and, accordingly, part of the population is not accessible, using PPS sampling. We propose a modification of the design, for which an optimal solution can be found, using a model assisted approach. The optimal design has independent interest in......Recently, non-uniform sampling has been suggested in microscopy to increase efficiency. More precisely, sampling proportional to size (PPS) has been introduced where the probability of sampling a unit in the population is proportional to the value of an auxiliary variable. Unfortunately, vanishing...

  17. A linguistic and navigational knowledge approach to text navigation

    OpenAIRE

    Couto, Javier; Minel, Jean-Luc

    2008-01-01

    We present an approach to text navigation conceived as a cognitive process exploiting linguistic information present in texts. We claim that the navigational knowledge in-volved in this process can be modeled in a declarative way with the Sextant language. Since Sextant refers exhaustively to specific linguistic phenomena, we have defined a customized text representation. These dif-ferent components are implemented in the text navigation system NaviTexte. Two ap-plications of NaviTexte are de...

  18. PARTICULAR AUXILIARY FEATURES OF DIMENSIONAL THEORY

    Directory of Open Access Journals (Sweden)

    Vardanyan Gumedin Surenovich

    2012-10-01

    Full Text Available New approach to selection of the principal measurement units system, different from the one used in the conventional dimensional theory, is proposed in the article. The new approach expands the capacities of dimensional analysis in the resolution of problems of deformable solid mechanics.

  19. PARTICULAR AUXILIARY FEATURES OF DIMENSIONAL THEORY

    OpenAIRE

    Vardanyan Gumedin Surenovich

    2012-01-01

    New approach to selection of the principal measurement units system, different from the one used in the conventional dimensional theory, is proposed in the article. The new approach expands the capacities of dimensional analysis in the resolution of problems of deformable solid mechanics.

  20. PT-symmetric quantum models living in an auxiliary Pontryagin space

    Czech Academy of Sciences Publication Activity Database

    Znojil, Miloslav

    2012-01-01

    Roč. 2, č. 2 (2012), s. 102-109. ISSN 2159-5291. [21st International Workshop on Operator Theory and its Applications IWOTA 2010. Berlin, 12.07.2010-16.07.2010] R&D Projects: GA MŠk LC06002; GA ČR GAP203/11/1433 Institutional research plan: CEZ:AV0Z10480505 Keywords : quantum mechanics * Hermitizations of observables * auxiliary Krein and Pontryagin spaces * Jacobi-matrix Hamiltonians * Dieudonn´e equation Subject RIV: BE - Theoretical Physics http://arxiv.org/pdf/1110.1218v1.pdf

  1. Ego-motion based on EM for bionic navigation

    Science.gov (United States)

    Yue, Xiaofeng; Wang, L. J.; Liu, J. G.

    2015-12-01

    Researches have proved that flying insects such as bees can achieve efficient and robust flight control, and biologists have explored some biomimetic principles regarding how they control flight. Based on those basic studies and principles acquired from the flying insects, this paper proposes a different solution of recovering ego-motion for low level navigation. Firstly, a new type of entropy flow is provided to calculate the motion parameters. Secondly, EKF, which has been used for navigation for some years to correct accumulated error, and estimation-Maximization, which is always used to estimate parameters, are put together to determine the ego-motion estimation of aerial vehicles. Numerical simulation on MATLAB has proved that this navigation system provides more accurate position and smaller mean absolute error than pure optical flow navigation. This paper has done pioneering work in bionic mechanism to space navigation.

  2. 33 CFR 207.185 - Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation. 207.185 Section 207.185 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION...

  3. Development of KALIMER auxiliary sodium and cover gas management system

    International Nuclear Information System (INIS)

    The objectives of this report are to develop and to describe the auxiliary liquid metal and cover gas management systems of KALIMER. the system includes following system: (1) Auxiliary liquid metal system (2) Inert gas receiving and processing system (3) Impurity monitoring and analysis system. Auxiliary liquid metal and cover gas management system of KALIMER was developed. Functions of each systems and design basis were describes. The auxiliary liquid metal system receives, transfers, and purifies all sodium used in the plant. The system furnishes the required sodium quantity at the pressure, temperature, flow rate, and purity specified by the interfacing system. The intermediated sodium processing subsystem (ISPS) provides continuous purification of IHTS sodium, as well as performs the initial fill operation for both the IHTS and reactor vessel. The primary sodium processing subsystem provides purification (cold trapping) for sodium used in the reactor vessel. The inert gas receiving and processing (IGRP) system provides liquefied and ambient gas storage, delivers inert gases of specified composition and purity at regulated flow rates and pressures to points of usage throughout the KALIMER, and accepts the contaminated gases through its vacuum facilities for storage and transfer to the gas radwaste system. Three gases are used in the KALIMER: helium, argon, and nitrogen. 11 tabs., 12 figs. (Author)

  4. PWR auxiliary systems, safety and emergency systems, accident analysis, operation

    International Nuclear Information System (INIS)

    The author presents a description of PWR auxiliary systems like volume control, boric acid control, coolant purification, -degassing, -storage and -treatment system and waste processing systems. Residual heat removal systems, emergency systems and containment designs are discussed. As an accident analysis the author gives a survey over malfunctions and disturbances in the field of reactor operations. (TK)

  5. Auxiliary-field quantum Monte Carlo methods in nuclei

    CERN Document Server

    Alhassid, Y

    2016-01-01

    Auxiliary-field quantum Monte Carlo methods enable the calculation of thermal and ground state properties of correlated quantum many-body systems in model spaces that are many orders of magnitude larger than those that can be treated by conventional diagonalization methods. We review recent developments and applications of these methods in nuclei using the framework of the configuration-interaction shell model.

  6. Power consumption of the ASCV and auxiliary equipment

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Pedersen, Jørgen Kaas

    1998-01-01

    Operating an ASCV requires power - to cover the losses in the ASCV itself and to run auxiliary equipment. It is necessary to take this power consumption into account when considering the economical aspects of installing an ASCV.Field measurements of this consumption of the ASCV in Rejsby Hede are...

  7. 40 CFR 1033.510 - Auxiliary power units.

    Science.gov (United States)

    2010-07-01

    ... locomotive is equipped with an auxiliary power unit (APU) that operates during an idle shutdown mode, you must account for the APU's emissions rates as specified in this section, unless the APU is part of an... emission rate (g/hr) as specified in § 1033.530. Add the APU emission rate (g/hr) that you determine...

  8. Green Propulsion Auxiliary Power Unit Demonstration at MSFC

    Science.gov (United States)

    Robinson, Joel W.

    2014-01-01

    MSFC has embarked on use of green propellant replacement of hydrazine for a variety of applications. This paper focused on activities for auxiliary power unit but MSFC is actively investigating use of green propellants for thruster applications. MSFC is interested in partnership with the international community to address the infusion of green propellant into greater use.

  9. Continuous Market Engineering - Focusing Agent Behavior, Interfaces, and Auxiliary Services

    OpenAIRE

    Kranz, Tobias Theodor

    2015-01-01

    Electronic markets spread out amongst business entities as well as private individuals. Albeit numerous approaches on developing electronic markets exist, a unified approach targeting market development, redesign, and refinement has been lacking. This thesis studies the potential of continuously improving electronic markets. Thereby, the experiments? design focuses on Agent Behavior, Interfaces, and Auxiliary Services and thus unveils the potential of continuously improving electronic markets.

  10. Regulation of Glutamate Receptors by Their Auxiliary Subunits

    OpenAIRE

    Tomita, Susumu

    2010-01-01

    Glutamate receptors are major excitatory receptors in the brain. Recent findings have established auxiliary subunits of glutamate receptors as critical modulators of synaptic transmission, synaptic plasticity and neurological disorder. The elucidation of the molecular rules governing glutamate receptors and subunits will improve our understanding of synapses and of neural-circuit regulation in the brain.

  11. Light wire auxiliaries with pre-adjusted edgewise appliance to control individual incisor torque

    Directory of Open Access Journals (Sweden)

    Sharanya Sabrish

    2015-01-01

    The use of light wire auxiliaries have definite advantages and hence should be a part of our armamentarium to handle such cases. Light wire auxiliaries offer us a biomechanically superior and economical alternative to apply torque forces on incisors.

  12. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    Analytical Method of Auxiliary Sources solutions for plane wave scattering by circular impedance cylinders are derived by transformation of the exact eigenfunction series solutions employing the Hankel function wave transformation. The analytical Method of Auxiliary Sources solution thus obtained...

  13. Introductory Course on Satellite Navigation

    Science.gov (United States)

    Giger, Kaspar; Knogl, J. Sebastian

    2012-01-01

    Satellite navigation is widely used for personal navigation and more and more in precise and safety-critical applications. Thus, the subject is suited for attracting the interest of young people in science and engineering. The practical applications allow catching the students' attention for the theoretical background. Educational material on the…

  14. Improvement of stability of sinusoidally driven atmospheric pressure plasma jet using auxiliary bias voltage

    OpenAIRE

    Hyun-Jin Kim; Jae Young Kim; Jae Hyun Kim; Dong Ha Kim; Duck-Sik Lee; Choon-Sang Park; Hyung Dal Park; Bhum Jae Shin; Heung-Sik Tae

    2015-01-01

    In this study, we have proposed the auxiliary bias pulse scheme to improve the stability of atmospheric pressure plasma jets driven by an AC sinusoidal waveform excitation source. The stability of discharges can be significantly improved by the compensation of irregular variation in memory voltage due to the effect of auxiliary bias pulse. From the parametric study, such as the width, voltage, and onset time of auxiliary bias pulse, it has been demonstrated that the auxiliary bias pulse plays...

  15. Autonomous Spacecraft Navigation With Pulsars

    CERN Document Server

    Becker, Werner; Jessner, Axel

    2013-01-01

    An external reference system suitable for deep space navigation can be defined by fast spinning and strongly magnetized neutron stars, called pulsars. Their beamed periodic signals have timing stabilities comparable to atomic clocks and provide characteristic temporal signatures that can be used as natural navigation beacons, quite similar to the use of GPS satellites for navigation on Earth. By comparing pulse arrival times measured on-board a spacecraft with predicted pulse arrivals at a reference location, the spacecraft position can be determined autonomously and with high accuracy everywhere in the solar system and beyond. The unique properties of pulsars make clear already today that such a navigation system will have its application in future astronautics. In this paper we describe the basic principle of spacecraft navigation using pulsars and report on the current development status of this novel technology.

  16. Increasing the Cruise Range and Reducing the Capital Cost of Electric Vehicles by Integrating Auxiliary Unit with the Traction Drive

    OpenAIRE

    N. Satheesh Kumar

    2016-01-01

    Poor cruise performance of Electric Vehicles (EVs) continues to be the primary reason that impends their market penetration. Adding more battery to extend the cruise range is not a viable solution as it increases the structural weight and capital cost of the EV. Simulations identified that a vehicle spends on average 15% of its total time in braking, signifying an immense potential of the utilization of regenerative braking mechanism. Based on the analysis, a 3 kW auxiliary electrical unit co...

  17. A Convergent Method of Auxiliary Sources for Two-Dimensional Impedance Scatterers With Edges

    DEFF Research Database (Denmark)

    Karamehmedovic, Mirza; Breinbjerg, Olav

    2001-01-01

    A modification to the Method of Auxiliary Sources (MAS) is introduced which renders the method operational for two-dimensional impedance scatterers with edges. The modification consists in letting the auxiliary surface converge to the scatterer physical surface for increasing number of auxiliary ...

  18. 14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine tests in auxiliary power unit (APU... Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which... in operation, and remain stopped during operation of the engine as an auxiliary power unit (“APU...

  19. BE, DO, and Modal Auxiliaries of 3-Year-Old African American English Speakers

    Science.gov (United States)

    Newkirk-Turner, Brandi L.; Oetting, Janna B.; Stockman, Ida J.

    2014-01-01

    Purpose: This study examined African American English--speaking children's use of BE, DO, and modal auxiliaries. Method: The data were based on language samples obtained from 48 three-year-olds. Analyses examined rates of marking by auxiliary type, auxiliary surface form, succeeding element, and syntactic construction and by a number of child…

  20. Navigation sensors and systems in GNSS degraded and denied environments

    Institute of Scientific and Technical Information of China (English)

    George T. Schmidt

    2015-01-01

    Position, velocity, and timing (PVT) signals from the Global Positioning System (GPS) are used throughout the world but the availability and reliability of these signals in all environments has become a subject of concern for both civilian and military applications. This presentation sum-marizes recent advances in navigation sensor technology, including GPS, inertial, and other navi-gation aids that address these concerns. Also addressed are developments in sensor integration technology with several examples described, including the Bluefin-21 system mechanization.

  1. Cues indicating location in pigeon navigation.

    Science.gov (United States)

    Beason, Robert C; Wiltschko, Wolfgang

    2015-10-01

    Domesticated Rock Pigeons (Columba livia f. domestica) have been selected for returning home after being displaced. They appear to use many of the physical cue sources available in the natural environment for Map-and-Compass navigation. Two compass mechanisms that have been well documented in pigeons are a time-compensated sun compass and a magnetic inclination compass. Location-finding, or map, mechanisms have been more elusive. Visual landmarks, magnetic fields, odors, gravity and now also infrasound have been proposed as sources of information on location. Even in highly familiar locations, pigeons appear to neither use nor need landmarks and can even return to the loft while wearing frosted lenses. Direct and indirect evidence indicates magnetic field information influences pigeon navigation in ways that are consistent with magnetic map components. The role of odors is unclear; it might be motivational in nature rather than navigational. The influence of gravity must be further analyzed. Experiments with infrasound have been interpreted in the sense that they provide information on the home direction, but this hypothesis is inconsistent with the Map-and-Compass Model. All these factors appear to be components of a multifactorial system, with the pigeons being opportunistic, preferring those cues that prove most suitable in their home region. This has made understanding the roles of individual cues challenging. PMID:26149606

  2. Molecular basis for differential modulation of BK channel voltage-dependent gating by auxiliary γ subunits.

    Science.gov (United States)

    Li, Qin; Fan, Fei; Kwak, Ha Rim; Yan, Jiusheng

    2015-06-01

    Large conductance Ca(2+)- and voltage-activated potassium (BK) channels are comprised of pore-forming α subunits and various regulatory auxiliary subunits. The BK channel auxiliary γ (BKγ) subunits are a newly identified class of proteins containing an extracellular leucine-rich repeat domain (LRRD), a single transmembrane (TM) segment, and a short cytoplasmic C-terminal tail (C-tail). Although each of the four BKγ proteins shifts the voltage dependence of BK channel activation in a hyperpolarizing direction, they show markedly different efficacies, mediating shifts over a range of 15-145 mV. Analyses of chimeric BKγ subunits created by swapping individual structural elements, and of BKγ deletion and substitution mutants, revealed that differential modulation of BK gating by the four BKγ subunits depends on a small region consisting of the TM segment and the adjacent intracellular cluster of positively charged amino acids. The γ1 and γ2 TM segments contributed approximately -100 mV, and the γ1 and γ3 C-tails contributed approximately -40 mV, to shifting the voltage dependence of BK channel activation, whereas the γ3 and γ4 TM segments and the γ2 and γ4 C-tails contributed much less. The large extracellular LRRDs were mainly functionally interchangeable, although the γ1 LRRD was slightly less effective at enhancing (or slightly more effective at attenuating) the shift in BK channel voltage-dependent gating toward hyperpolarizing potentials than those of the other BKγ subunits. Analysis of mutated BKγ subunits revealed that juxta-membrane clusters of positively charged amino acids determine the functions of the γ1 and γ3 C-tails. Therefore, the modulatory functions of BKγ subunits are coarse- and fine-tuned, respectively, through variations in their TM segments and in the adjacent intracellular positively charged regions. Our results suggest that BK channel modulation by auxiliary γ subunits depends on intra- and/or juxta-membrane mechanisms

  3. Contracted auxiliary Gaussian basis integral and derivative evaluation.

    Science.gov (United States)

    Giese, Timothy J; York, Darrin M

    2008-02-14

    The rapid evaluation of two-center Coulomb and overlap integrals between contracted auxiliary solid harmonic Gaussian functions is examined. Integral expressions are derived from the application of Hobson's theorem and Dunlap's product and differentiation rules of the spherical tensor gradient operator. It is shown that inclusion of the primitive normalization constants greatly simplifies the calculation of contracted functions corresponding to a Gaussian multipole expansion of a diffuse charge density. Derivative expressions are presented and it is shown that chain rules are avoided by expressing the derivatives as a linear combination of auxiliary integrals involving no more than five terms. Calculation of integrals and derivatives requires the contraction of a single vector corresponding to the monopolar result and its scalar derivatives. Implementation of the method is discussed and comparison is made with a Cartesian Gaussian-based method. The current method is superior for the evaluation of both integrals and derivatives using either primitive or contracted functions. PMID:18282025

  4. The auxiliary system design retrofits of the different coolant pump

    International Nuclear Information System (INIS)

    The coolant pump auxiliary systems retrofits are introduced in detail according to the different type of coolant pumps. The retrofit reasons of the chemical and volume control system, component cooling water system, Nuclear Nitrogen Storage and Distribution System, Vent and drain system, etc. are investigated. The most extraordinary change takes place in the chemical and volume control system and cooling water system. The charging flow temperature of re- generative heat exchanger and discharge flow of charging pump will be changed according to the difference coolant pump seal flow distribution. The commercial CFD software Flow master is employed to validate the charging capability. The other auxiliary systems' retrofits are also introduced in the end of this paper. (authors)

  5. Aging assessment of PWR [Pressurized Water Reactor] Auxiliary Feedwater Systems

    International Nuclear Information System (INIS)

    In support of the Nuclear Regulatory Commission's Nuclear Plant Aging Research (NPAR) Program, Oak Ridge National Laboratory is conducting a review of Pressurized Water Reactor Auxiliary Feedwater Systems. Two of the objectives of the NPAR Program are to identify failure modes and causes and identify methods to detect and track degradation. In Phase I of the Auxiliary Feedwater System study, a detailed review of system design and operating and surveillance practices at a reference plant is being conducted to determine failure modes and to provide an indication of the ability of current monitoring methods to detect system degradation. The extent to which current practices are contributing to aging and service wear related degradation is also being assessed. This paper provides a description of the study approach, examples of results, and some interim observations and conclusions. 1 fig., 1 tab

  6. An Analytical Method of Auxiliary Sources Solution for Plane Wave Scattering by Impedance Cylinders - A Reference Solution for the Numerical Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2004-01-01

    To facilitate the validation of the numerical Method of Auxiliary Sources an analytical Method of Auxiliary Sources solution is derived in this paper. The Analytical solution is valid for transverse magnetic, and electric, plane wave scattering by circular impedance Cylinders, and it is derived by...... singularities at different positions away from the origin. The transformation necessitates a truncation of the wave transformation but the inaccuracy introduced hereby is shown to be negligible. The analytical Method of Auxiliary Sources solution is employed as a reference to investigate the accuracy of the...... numerical Method of Auxiliary Sources for a range of scattering configurations....

  7. Lunar Navigation Architecture Design Considerations

    Science.gov (United States)

    D'Souza, Christopher; Getchius, Joel; Holt, Greg; Moreau, Michael

    2009-01-01

    The NASA Constellation Program is aiming to establish a long-term presence on the lunar surface. The Constellation elements (Orion, Altair, Earth Departure Stage, and Ares launch vehicles) will require a lunar navigation architecture for navigation state updates during lunar-class missions. Orion in particular has baselined earth-based ground direct tracking as the primary source for much of its absolute navigation needs. However, due to the uncertainty in the lunar navigation architecture, the Orion program has had to make certain assumptions on the capabilities of such architectures in order to adequately scale the vehicle design trade space. The following paper outlines lunar navigation requirements, the Orion program assumptions, and the impacts of these assumptions to the lunar navigation architecture design. The selection of potential sites was based upon geometric baselines, logistical feasibility, redundancy, and abort support capability. Simulated navigation covariances mapped to entry interface flightpath- angle uncertainties were used to evaluate knowledge errors. A minimum ground station architecture was identified consisting of Goldstone, Madrid, Canberra, Santiago, Hartebeeshoek, Dongora, Hawaii, Guam, and Ascension Island (or the geometric equivalent).

  8. Auxiliary representations of Lie algebras and the BRST constructions

    International Nuclear Information System (INIS)

    The method of construction of auxiliary representations for a given Lie algebra is discussed in the framework of the BRST approach. The corresponding BRST charge turns out to be nonhermitian. This problem is solved by the introduction of the additional kernel operator in the definition of the scalar product in the Fock space. The existence of the kernel operator is proved for any Lie algebra

  9. Auxiliary Field Meson Model at Finite Temperature and Density

    CERN Document Server

    Kouno, H; Kashiwa, K; Hamada, M; Tokudome, H; Matsuzaki, M; Yahiro, M

    2005-01-01

    Starting from many quark interactions, we construct a nonlinear sigma-omega model at finite temperature and density. The mesons are introduced as auxiliary fields. Effective quark-meson couplings are strongly related to effective meson masses, since they are derived simultaneously from the original many quark interactions. In this model, even if the effective omega-meson mass decreases due to the partial chiral restoration, the equation of state (EOS) of nuclear matter can become soft.

  10. Contracted auxiliary Gaussian basis integral and derivative evaluation

    OpenAIRE

    Giese, Timothy J.; York, Darrin M.

    2008-01-01

    The rapid evaluation of 2-center Coulomb and overlap integrals between contracted auxiliary solid harmonic Gaussian functions is examined. Integral expressions are derived from the application of Hobson’s theorem and Dunlap’s product and differentiation rules of the spherical tensor gradient operator. It is shown that inclusion of the primitive normalization constants greatly simplifies the calculation of contracted functions corresponding to a Gaussian multipole expansion of a diffuse charge...

  11. A simplified model for scheduling services on auxiliary bus lines

    OpenAIRE

    Codina Sancho, Esteve; Montero Mercadé, Lídia

    2014-01-01

    In this paper, a mathematical programming based model is described to assist with the schedule of services for a set of auxiliary bus lines that operate alleviating a disruption of the regular transportation system during a given time period. In contrast to other models, considered static, service schedules are set taking into account demand fluctuations that may happen in that time period. Passenger flows are represented with a multi-commodity structure and disseminate throug...

  12. A magnetorheological clutch for efficient automotive auxiliary device actuation

    OpenAIRE

    F. Bucchi; Forte, P; F. Frendo; R. Squarcini

    2013-01-01

    In this paper the results of a project funded by Regione Toscana aimed at reducing the power absorption of auxiliary devices in vehicles are presented. In particular the design, testing and application of a magnetorheological clutch (MR) is proposed, aimed at disengaging the vacuum pump, which draws in air from the power-brake booster chamber, in order to reduce the device power absorption. Several clutch preliminary studies done to choose the clutch geometry and the magnetic field supply are...

  13. Mixed Bayesian Networks with Auxiliary Variables for Automatic Speech Recognition

    OpenAIRE

    Stephenson, Todd Andrew; Magimai.-Doss, Mathew; Bourlard, Hervé

    2001-01-01

    Standard hidden Markov models (HMMs), as used in automatic speech recognition (ASR), calculate their emission probabilities by an artificial neural network (ANN) or a Gaussian distribution conditioned on the hidden state variable, considering the emissions independent of any other variable in the model. Recent work showed the benefit of conditioning the emission distributions on a discrete auxiliary variable, which is observed in training and hidden in recognition. Related work has shown the ...

  14. Enhancing Sentence Relation Modeling with Auxiliary Character-level Embedding

    OpenAIRE

    Li, Peng; Huang, Heng

    2016-01-01

    Neural network based approaches for sentence relation modeling automatically generate hidden matching features from raw sentence pairs. However, the quality of matching feature representation may not be satisfied due to complex semantic relations such as entailment or contradiction. To address this challenge, we propose a new deep neural network architecture that jointly leverage pre-trained word embedding and auxiliary character embedding to learn sentence meanings. The two kinds of word seq...

  15. Navigable networks as Nash equilibria of navigation games

    Science.gov (United States)

    Gulyás, András; Bíró, József J.; Kőrösi, Attila; Rétvári, Gábor; Krioukov, Dmitri

    2015-07-01

    Common sense suggests that networks are not random mazes of purposeless connections, but that these connections are organized so that networks can perform their functions well. One function common to many networks is targeted transport or navigation. Here, using game theory, we show that minimalistic networks designed to maximize the navigation efficiency at minimal cost share basic structural properties with real networks. These idealistic networks are Nash equilibria of a network construction game whose purpose is to find an optimal trade-off between the network cost and navigability. We show that these skeletons are present in the Internet, metabolic, English word, US airport, Hungarian road networks, and in a structural network of the human brain. The knowledge of these skeletons allows one to identify the minimal number of edges, by altering which one can efficiently improve or paralyse navigation in the network.

  16. A greedy-navigator approach to navigable city plans

    CERN Document Server

    Lee, Sang Hoon

    2012-01-01

    We use a set of four theoretical navigability indices for street maps to investigate the shape of the resulting street networks, if they are grown by optimizing these indices. The indices compare the performance of simulated navigators (having a partial information about the surroundings, like humans in many real situations) to the performance of optimally navigating individuals. We show that our simple greedy shortcut construction strategy generates the emerging structures that are different from real road network, but not inconceivable. The resulting city plans, for all navigation indices, share common qualitative properties such as the tendency for triangular blocks to appear, while the more quantitative features, such as degree distributions and clustering, are characteristically different depending on the type of metrics and routing strategies. We show that it is the type of metrics used which determines the overall shapes characterized by structural heterogeneity, but the routing schemes contribute to m...

  17. Neoclassical offset toroidal velocity and auxiliary ion heating in tokamaks

    Science.gov (United States)

    Lazzaro, E.

    2016-05-01

    In conditions of ideal axisymmetry, for a magnetized plasma in a generic bounded domain, necessarily toroidal, the uniform absorption of external energy (e.g., RF or any isotropic auxiliary heating) cannot give rise to net forces or torques. Experimental evidence on contemporary tokamaks shows that the near central absorption of RF heating power (ICH and ECH) and current drive in presence of MHD activity drives a bulk plasma rotation in the co- I p direction, opposite to the initial one. Also the appearance of classical or neoclassical tearing modes provides a nonlinear magnetic braking that tends to clamp the rotation profile at the q-rational surfaces. The physical origin of the torque associated with P RF absorption could be due the effects of asymmetry in the equilibrium configuration or in power deposition, but here we point out also an effect of the response of the so-called neoclassical offset velocity to the power dependent heat flow increment. The neoclassical toroidal viscosity due to internal magnetic kink or tearing modes tends to relax the plasma rotation to this asymptotic speed, which in absence of auxiliary heating is of the order of the ion diamagnetic velocity. It can be shown by kinetic and fluid calculations, that the absorption of auxiliary power by ions modifies this offset proportionally to the injected power thereby forcing the plasma rotation in a direction opposite to the initial, to large values. The problem is discussed in the frame of the theoretical models of neoclassical toroidal viscosity.

  18. Bayesian Analysis of Geostatistical Models With an Auxiliary Lattice

    KAUST Repository

    Park, Jincheol

    2012-04-01

    The Gaussian geostatistical model has been widely used for modeling spatial data. However, this model suffers from a severe difficulty in computation: it requires users to invert a large covariance matrix. This is infeasible when the number of observations is large. In this article, we propose an auxiliary lattice-based approach for tackling this difficulty. By introducing an auxiliary lattice to the space of observations and defining a Gaussian Markov random field on the auxiliary lattice, our model completely avoids the requirement of matrix inversion. It is remarkable that the computational complexity of our method is only O(n), where n is the number of observations. Hence, our method can be applied to very large datasets with reasonable computational (CPU) times. The numerical results indicate that our model can approximate Gaussian random fields very well in terms of predictions, even for those with long correlation lengths. For real data examples, our model can generally outperform conventional Gaussian random field models in both prediction errors and CPU times. Supplemental materials for the article are available online. © 2012 American Statistical Association, Institute of Mathematical Statistics, and Interface Foundation of North America.

  19. Generating Selected Color using RGB, Auxiliary Lights, and Simplex Search

    Directory of Open Access Journals (Sweden)

    Kim HyungTae

    2015-01-01

    Full Text Available A mixed light source generates various colors, with the potential to adjust intensities of multiple LEDs, which makes it possible to generate arbitrary colors. Currently, PCs and OSs provide color selection windows that can obtain the RGB or HSL color coordinates of a user’s selection. Mixed light sources are usually composed of LEDs in the primary colors, with LEDs in auxiliary colors such as white and yellow used in a few cases. When using auxiliary color LEDs, the number of LED inputs, the dimming levels, is larger than the number of elements in the color coordinate, which causes an under-determined problem. This study proposed how to determine the dimming levels of LEDs based on the selected color. Commercial LEDs have di_erent optical power values and impure color coordinates, even if they are RGB. Hence, the characteristics of the LEDs were described using a linear model derived from the tri-stimulus values (an XYZ color coordinate model and dimming levels. Color mixing models were derived for the arbitrary number of auxiliary color LEDs. The under-determined problem was solved using a simplex search method without an inverse matrix operation. The proposed method can be applied to a machine vision system and an RGBW light mixer for semiconductor inspection. The dimming levels, obtained using the proposed method were better than derived using other methods.

  20. Navigation/Prop Software Suite

    Science.gov (United States)

    Bruchmiller, Tomas; Tran, Sanh; Lee, Mathew; Bucker, Scott; Bupane, Catherine; Bennett, Charles; Cantu, Sergio; Kwong, Ping; Propst, Carolyn

    2012-01-01

    Navigation (Nav)/Prop software is used to support shuttle mission analysis, production, and some operations tasks. The Nav/Prop suite containing configuration items (CIs) resides on IPS/Linux workstations. It features lifecycle documents, and data files used for shuttle navigation and propellant analysis for all flight segments. This suite also includes trajectory server, archive server, and RAT software residing on MCC/Linux workstations. Navigation/Prop represents tool versions established during or after IPS Equipment Rehost-3 or after the MCC Rehost.

  1. Discovery of Individual User Navigation Styles

    OpenAIRE

    Herder, E.; Juvina, I.

    2004-01-01

    Individual differences have been shown to lead to different navigation styles. In this paper we present a pilot study that aims at finding predictors for users’ vulnerability to experience disorientation that can be gathered unobtrusively and in real-time. We identified two navigation styles that we called flimsy navigation and laborious navigation that together predict users’ perceived disorientation. Our findings suggest that adaptive navigation support that addresses these navigation style...

  2. A navigational guidance system in the human brain.

    Science.gov (United States)

    Spiers, Hugo J; Maguire, Eleanor A

    2007-01-01

    Finding your way in large-scale space requires knowing where you currently are and how to get to your goal destination. While much is understood about the neural basis of one's current position during navigation, surprisingly little is known about how the human brain guides navigation to goals. Computational accounts argue that specific brain regions support navigational guidance by coding the proximity and direction to the goal, but empirical evidence for such mechanisms is lacking. Here, we scanned subjects with functional magnetic resonance imaging as they navigated to goal destinations in a highly accurate virtual simulation of a real city. Brain activity was then analyzed in combination with metric measures of proximity and direction to goal destinations that were derived from each individual subject's coordinates at every second of navigation. We found that activity in the medial prefrontal cortex was positively correlated, and activity in a right subicular/entorhinal region was negatively correlated with goal proximity. By contrast, activity in bilateral posterior parietal cortex was correlated with egocentric direction to goals. Our results provide empirical evidence for a navigational guidance system in the human brain, and define more precisely the contribution of these three brain regions to human navigation. In addition, these findings may also have wider implications for how the brain monitors and integrates different types of information in the service of goal-directed behavior in general. PMID:17492693

  3. Navigating "Assisted Dying".

    Science.gov (United States)

    Schipper, Harvey

    2016-02-01

    Carter is a bellwether decision, an adjudication on a narrow point of law whose implications are vast across society, and whose impact may not be realized for years. Coupled with Quebec's Act Respecting End-of-life Care it has sharply changed the legal landscape with respect to actively ending a person's life. "Medically assisted dying" will be permitted under circumstances, and through processes, which have yet to be operationally defined. This decision carries with it moral assumptions, which mean that it will be difficult to reach a unifying consensus. For some, the decision and Act reflect a modern acknowledgement of individual autonomy. For others, allowing such acts is morally unspeakable. Having opened the Pandora's Box, the question becomes one of navigating a tolerable societal path. I believe it is possible to achieve a workable solution based on the core principle that "medically assisted dying" should be a very rarely employed last option, subject to transparent ongoing review, specifically as to why it was deemed necessary. My analysis is based on 1. The societal conditions in which have fostered demand for "assisted dying", 2. Actions in other jurisdictions, 3. Carter and Quebec Bill 52, 4. Political considerations, 5. Current medical practice. Leading to a series of recommendations regarding. 1. Legislation and regulation, 2. The role of professional regulatory agencies, 3. Medical professions education and practice, 4. Public education, 5. Health care delivery and palliative care. Given the burden of public opinion, and the legal steps already taken, a process for assisted-dying is required. However, those legal and regulatory steps should only be considered a necessary and defensive first step in a two stage process. The larger goal, the second step, is to drive the improvement of care, and thus minimize assisted-dying. PMID:27169205

  4. Navigation System of Marks Areas - USACE IENC

    Data.gov (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  5. Comparison of auxiliary feedwater and EDRS operation during natural circulation of MRX

    International Nuclear Information System (INIS)

    The MRX is an integral type ship reactor with 100 MWt power, which is designed by Japan Atomic Energy Research Institute. It is characterized by integral type PWR, in-vessel type control rod drive mechanism, water-filled containment vessel and passive decay heat removal system. Marine reactor should have high passive safety. Therefore, in this study, we simulated the loss of flow accident to verify the passive decay heat removal by natural circulation using RETRAN-03 code. auxiliary feed water systems are used for decay heat removal mechanism and results are compared with the loss of flow accident analysis using emergency decay heat removal system by JAERI. Results are very similar to case of EDRS 1 loop operation in JAERI analysis and decay heat is successfully removed by natural circulation

  6. Seismic response of base isolated auxiliary building with age related degradation

    International Nuclear Information System (INIS)

    The aging of an isolator affects not only the mechanical properties of the isolator but also the dynamic properties of the upper structure, such as the change in stiffness, deformation capacity, load bearing capacity, creep, and damping. Therefore, the seismic response of base isolated structures will change with time. The floor response in the base isolated nuclear power plants (NPPs) can be particularly changed because of the change in stiffness and damping for the isolator. The increased seismic response due to the aging of isolator can cause mechanical problems for many equipment located in the NPPs. Therefore, it is necessary to evaluate the seismic response of base isolated NPPs with age related degradation. In this study, the seismic responses for a base isolated auxiliary building of SHIN KORI 3 and 4 with age related degradation were investigated using a nonlinear time history analysis. Floor response spectrums (FRS) were presented with time for identifying the change in seismic demand under the aging of isolator

  7. Determination of intersecting curve between two surfaces of revolution with parallel axes by use of auxiliary planes and auxiliary spheres

    Directory of Open Access Journals (Sweden)

    Obradović Ratko

    2002-01-01

    Full Text Available In this paper the space intersecting curve between two surfaces of revolution with parallel axes of surfaces have been determined. Two mathematical models for determination of intersecting curve between two surfaces of revolution have been formed: auxiliary planes have been used in the first mathematical model and auxiliary spheres have been used in the second model (Obradović 2000. In the first case each auxiliary plane intersected with each surface of revolution on circle and two points of intersecting curve are obtained as intersecting points between these two circles. In the second case centres of two locks of auxiliary spheres are put on axes of surfaces of revolution (centre of first lock is on axis of the first surface of revolution and centre of second lock is on axis of the second surface of revolution on saine z coordinate (when axes of surfaces of revolution are parallel with z axis of coordinate system. First lock sphere intersects the first surface of revolution on w1 parallels and second lock corresponding sphere intersects the second surface of revolution on w2 circles. It is possible to find a relationship that for selected radius of the first lock sphere can determine the radius of second lock sphere and real points of intersecting curve have been determined by use of these two spheres. The points of intersecting curve between two surfaces of revolution are obtained by intersection between w1 circles from the first surface with w2 circles from the second surface (Obradović 2000.

  8. Radio Navigation Waveform Experiment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is installing the Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT) onto the truss of the International Space Station to demonstrate...

  9. NOAA Electronic Navigational Charts (ENC)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of Coast Survey (OCS) has been involved in the development of a NOAA Electronic Navigational Chart (NOAA ENC) suite to support the marine transportation...

  10. Increasing the Cruise Range and Reducing the Capital Cost of Electric Vehicles by Integrating Auxiliary Unit with the Traction Drive

    Directory of Open Access Journals (Sweden)

    N. Satheesh Kumar

    2016-01-01

    Full Text Available Poor cruise performance of Electric Vehicles (EVs continues to be the primary reason that impends their market penetration. Adding more battery to extend the cruise range is not a viable solution as it increases the structural weight and capital cost of the EV. Simulations identified that a vehicle spends on average 15% of its total time in braking, signifying an immense potential of the utilization of regenerative braking mechanism. Based on the analysis, a 3 kW auxiliary electrical unit coupled with the traction drive during braking events increases the recoverable energy by 8.4%. In addition, the simulation revealed that, on average, the energy drawn from the battery is reduced by 3.2% when traction drive is integrated with the air-conditioning compressor (an auxiliary electrical load. A practical design solution of the integrated unit is also included in the paper. Based on the findings, it is evident that the integration of an auxiliary unit with the traction drive results in enhancing the energy capturing capacity of the regenerative braking mechanism and decreases the power consumed from the battery. Further, the integrated unit boosts other advantages such as reduced material cost, improved reliability, and a compact and lightweight design.

  11. Experimental study on the operational and the cooling performance of the APR+ passive auxiliary feedwater system

    International Nuclear Information System (INIS)

    The passive auxiliary feedwater system (PAFS) is one of the advanced safety features adopted in the APR+ which is intended to completely replace the conventional active auxiliary feedwater system. The PAFS cools down the steam generator secondary side and eventually removes the decay heat from the reactor core by introducing a natural driving force mechanism; i.e., condensing steam in nearly-horizontal U-tubes submerged inside the passive condensation cooling tank (PCCT). With an aim of validating the cooling and operational performance of the PAFS, the separate effect test, PASCAL (PAFS Condensing Heat Removal Assessment Loop), is being performed to experimentally investigate the condensation heat transfer and natural convection phenomena in the PAFS. A single nearly-horizontal U-tube whose dimension is same as the prototypic U-tube of the APR+ PAFS is simulated in the PASCAL test. By performing the PASCAL test, the major thermal-hydraulic parameters such as local/overall heat transfer coefficients, fluid temperature inside the tube, wall temperature of the tube, and pool temperature distribution in the PCCT were produced not only to evaluate the current condensation heat transfer model but also to present database for the safety analysis related with the PAFS. (authors)

  12. Experimental program for validation of cooling and operational performance of the APR+ Passive auxiliary feedwater system

    International Nuclear Information System (INIS)

    PAFS (Passive Auxiliary Feedwater System) is one of the advanced passive safety systems adopted in the APR+ (Advanced Power Reactor plus), which is intended to completely replace the conventional active auxiliary feedwater system. PAFS cools down the steam generator's secondary side, and eventually removes the decay heat from the reactor core by introducing a natural driving force mechanism; i.e., condensing steam in nearly horizontal U-tubes submerged inside the passive condensation cooling tank (PCCT). With an aim of validating the cooling and operational performance of the PAFS, an experimental program is in progress at KAERI (Korea Atomic Energy Research Institute), which is composed of two kinds of tests; the separate effect test and the integral effect test. The separate effect test, PASCAL (PAFS Condensing Heat Removal Assessment Loop), is in progress to experimentally investigate the condensation heat transfer and natural convection phenomena in PAFS. The integral effect test is being performed to confirm the operational performance of the PAFS coupled with the other reactor coolant systems (RCS) using the thermal hydraulic integral effect test facility, ATLAS (Advanced Thermal hydraulic test Loop for Accident Simulation). This paper summarizes the up to date experimental results of the separate effect test and the integral effect test for PAFS from a cooling and operational performance point of view

  13. Roles of HIV-1 auxiliary proteins in viral pathogenesis and host-pathogen interactions

    Institute of Scientific and Technical Information of China (English)

    Lin LI; Hai Shan LI; C.David PAUZA; Michael BUKRINSKY; Richard Y ZHAO

    2005-01-01

    Active host-pathogen interactions take place during infection of human immunodeficiency virus type 1 (HIV-1).Outcomes of these interactions determine the efficiency of viral infection and subsequent disease progression. HIV-infected cells respond to viral invasion with various defensive strategies such as innate, cellular and humoral immune antiviral mechanisms. On the other hand, the virus has also developed various offensive tactics to suppress these host cellular responses. Among many of the viral offensive strategies, HIV- 1 viral auxiliary proteins (Tat, Rev, Nef, Vif, Vpr and Vpu) play important roles in the host-pathogen interaction and thus have significant impacts on the outcome of HIV infection. One of the best examples is the interaction of Vif with a host cytidine deaminase APOBEC3G. Although specific roles of other auxiliary proteins are not as well described as Vif-APOBEC3G interaction, it is the goal of this brief review to summarize some of the preliminary findings with the hope to stimulate further discussion and investigation in this exhilarating area of research.

  14. FLASH LIDAR Based Relative Navigation

    Science.gov (United States)

    Brazzel, Jack; Clark, Fred; Milenkovic, Zoran

    2014-01-01

    Relative navigation remains the most challenging part of spacecraft rendezvous and docking. In recent years, flash LIDARs, have been increasingly selected as the go-to sensors for proximity operations and docking. Flash LIDARS are generally lighter and require less power that scanning Lidars. Flash LIDARs do not have moving parts, and they are capable of tracking multiple targets as well as generating a 3D map of a given target. However, there are some significant drawbacks of Flash Lidars that must be resolved if their use is to be of long-term significance. Overcoming the challenges of Flash LIDARs for navigation-namely, low technology readiness level, lack of historical performance data, target identification, existence of false positives, and performance of vision processing algorithms as intermediaries between the raw sensor data and the Kalman filter-requires a world-class testing facility, such as the Lockheed Martin Space Operations Simulation Center (SOSC). Ground-based testing is a critical step for maturing the next-generation flash LIDAR-based spacecraft relative navigation. This paper will focus on the tests of an integrated relative navigation system conducted at the SOSC in January 2014. The intent of the tests was to characterize and then improve the performance of relative navigation, while addressing many of the flash LIDAR challenges mentioned above. A section on navigation performance and future recommendation completes the discussion.

  15. Vision Based Autonomous Robot Navigation Algorithms and Implementations

    CERN Document Server

    Chatterjee, Amitava; Nirmal Singh, N

    2013-01-01

    This book is devoted to the theory and development of autonomous navigation of mobile robots using computer vision based sensing mechanism. The conventional robot navigation systems, utilizing traditional sensors like ultrasonic, IR, GPS, laser sensors etc., suffer several drawbacks related to either the physical limitations of the sensor or incur high cost. Vision sensing has emerged as a popular alternative where cameras can be used to reduce the overall cost, maintaining high degree of intelligence, flexibility and robustness. This book includes a detailed description of several new approaches for real life vision based autonomous navigation algorithms and SLAM. It presents the concept of how subgoal based goal-driven navigation can be carried out using vision sensing. The development concept of vision based robots for path/line tracking using fuzzy logic is presented, as well as how a low-cost robot can be indigenously developed in the laboratory with microcontroller based sensor systems. The book descri...

  16. Optimal Intermittent Reorientation in Insect Navigation

    Science.gov (United States)

    Peleg, Orit; Mahadevan, Lakshminarayanan; Applied Math Lab Team

    2015-03-01

    The process of navigation is often accompanied by several cognitive demanding activities, such as motor control, locomotion planning, and multi-sensory acquisition and integration. Organisms with limited cognitive resources must therefore multitask and develop optimal schemes to dynamically allocate resources to the different tasks. An extreme example of task alternations during navigation is the hallmark of ball rolling dung beetles. The beetles need to roll their dung-ball along a straight path away from the dung pile where intense competition occurs. Before initiating a roll, dung beetles climb on top of the ball and rotate about their vertical axis. This action serves as an orientation mechanism that allows them to set an initial bearing, and to regain this bearing if they experience an unintentional disturbance along the way. We developed a model inspired by the beetle's navigational scheme, where an agent performs a random walk intermittent by reorientation events, in which its heading direction is corrected. We show that the resultant paths are a characteristic of correlated diffusion in short time scale, and biased diffusion in the long time scale. We identify optimal alternation schemes and characterize their robustness upon introducing noisy sensory acquisition and rough environmental conditions.

  17. 33 CFR 66.10-15 - Aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Aids to navigation. 66.10-15 Section 66.10-15 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Uniform State Waterway Marking System § 66.10-15 Aids to navigation....

  18. Comment: ``On the computation of molecular auxiliary functions and ”

    Indian Academy of Sciences (India)

    Frank E Harris

    2003-10-01

    Guseinov, Mamedov, Kara and Orbay (Pramana – J. Phys. 56, 691 (2001)) propose methods for evaluating the molecular auxiliary functions () and () for the range 17 ≤ ≤ 60 and 25 ≤ ≤ 60. However, their procedure for () is not new, and that for () is less efficient for their target range than another well-known method. Their approach does have merit for smaller non-zero values of . Two minor errors in table 1 of their paper are also identified.

  19. Exploring requirements for indoor navigation systems

    OpenAIRE

    Ni, Chunxiao

    2013-01-01

    Indoor navigation has been a subject in ubiquitous computing domain in the past decade. Recently many studies focus on exploring user requirements for indoor navigation systems and make effort in developing effective interactive systems to support indoor navigation. This study aims to find which kind of spatial representation and what orientation cues common users prefer to use for indoor navigation. An experiment was performed to examine the navigation effectiveness and user satisfaction wit...

  20. Homing pigeons only navigate in air with intact environmental odours : A test of the olfactory activation hypothesis with GPS data loggers

    OpenAIRE

    Anna Gagliardo; Paolo Ioalè; Caterina Filannino; Martin Wikelski

    2011-01-01

    A large body of evidence has shown that anosmic pigeons are impaired in their navigation. However, the role of odours in navigation is still subject to debate. While according to the olfactory navigation hypothesis homing pigeons possess a navigational map based on the distribution of environmental odours, the olfactory activation hypothesis proposes that odour perception is only needed to activate a navigational mechanism based on cues of another nature. Here we tested experimentally whether...

  1. Fuel handling machine and auxiliary systems for a fuel handling cell

    International Nuclear Information System (INIS)

    This working report is an update for as well as a supplement to an earlier fuel handling machine design (Kukkola and Roennqvist 2006). A focus in the earlier design proposal was primarily on the selection of a mechanical structure and operating principle for the fuel handling machine. This report introduces not only a fuel handling machine design but also auxiliary fuel handling cell equipment and its operation. An objective of the design work was to verify the operating principles of and space allocations for fuel handling cell equipment. The fuel handling machine is a remote controlled apparatus capable of handling intensely radiating fuel assemblies in the fuel handling cell of an encapsulation plant. The fuel handling cell is air tight space radiation-shielded with massive concrete walls. The fuel handling machine is based on a bridge crane capable of traveling in the handling cell along wall tracks. The bridge crane has its carriage provided with a carousel type turntable having mounted thereon both fixed and telescopic masts. The fixed mast has a gripper movable on linear guides for the transfer of fuel assemblies. The telescopic mast has a manipulator arm capable of maneuvering equipment present in the fuel handling cell, as well as conducting necessary maintenance and cleaning operations or rectifying possible fault conditions. The auxiliary fuel handling cell systems consist of several subsystems. The subsystems include a service manipulator, a tool carrier for manipulators, a material hatch, assisting winches, a vacuum cleaner, as well as a hose reel. With the exception of the vacuum cleaner, the devices included in the fuel handling cell's auxiliary system are only used when the actual encapsulation process is not ongoing. The malfunctions of mechanisms or actuators responsible for the motion actions of a fuel handling machine preclude in a worst case scenario the bringing of the fuel handling cell and related systems to a condition appropriate for

  2. Olfaction Contributes to Pelagic Navigation in a Coastal Shark.

    Science.gov (United States)

    Nosal, Andrew P; Chao, Yi; Farrara, John D; Chai, Fei; Hastings, Philip A

    2016-01-01

    How animals navigate the constantly moving and visually uniform pelagic realm, often along straight paths between distant sites, is an enduring mystery. The mechanisms enabling pelagic navigation in cartilaginous fishes are particularly understudied. We used shoreward navigation by leopard sharks (Triakis semifasciata) as a model system to test whether olfaction contributes to pelagic navigation. Leopard sharks were captured alongshore, transported 9 km offshore, released, and acoustically tracked for approximately 4 h each until the transmitter released. Eleven sharks were rendered anosmic (nares occluded with cotton wool soaked in petroleum jelly); fifteen were sham controls. Mean swimming depth was 28.7 m. On average, tracks of control sharks ended 62.6% closer to shore, following relatively straight paths that were significantly directed over spatial scales exceeding 1600 m. In contrast, tracks of anosmic sharks ended 37.2% closer to shore, following significantly more tortuous paths that approximated correlated random walks. These results held after swimming paths were adjusted for current drift. This is the first study to demonstrate experimentally that olfaction contributes to pelagic navigation in sharks, likely mediated by chemical gradients as has been hypothesized for birds. Given the similarities between the fluid three-dimensional chemical atmosphere and ocean, further research comparing swimming and flying animals may lead to a unifying paradigm explaining their extraordinary navigational abilities. PMID:26735492

  3. PERFORMANCE CHARACTERISTIC MEMS-BASED IMUs FOR UAVs NAVIGATION

    Directory of Open Access Journals (Sweden)

    H. A. Mohamed

    2015-08-01

    Full Text Available Accurate 3D reconstruction has become essential for non-traditional mapping applications such as urban planning, mining industry, environmental monitoring, navigation, surveillance, pipeline inspection, infrastructure monitoring, landslide hazard analysis, indoor localization, and military simulation. The needs of these applications cannot be satisfied by traditional mapping, which is based on dedicated data acquisition systems designed for mapping purposes. Recent advances in hardware and software development have made it possible to conduct accurate 3D mapping without using costly and high-end data acquisition systems. Low-cost digital cameras, laser scanners, and navigation systems can provide accurate mapping if they are properly integrated at the hardware and software levels. Unmanned Aerial Vehicles (UAVs are emerging as a mobile mapping platform that can provide additional economical and practical advantages. However, such economical and practical requirements need navigation systems that can provide uninterrupted navigation solution. Hence, testing the performance characteristics of Micro-Electro-Mechanical Systems (MEMS or low cost navigation sensors for various UAV applications is important research. This work focuses on studying the performance characteristics under different manoeuvres using inertial measurements integrated with single point positioning, Real-Time-Kinematic (RTK, and additional navigational aiding sensors. Furthermore, the performance of the inertial sensors is tested during Global Positioning System (GPS signal outage.

  4. Performance Characteristic Mems-Based IMUs for UAVs Navigation

    Science.gov (United States)

    Mohamed, H. A.; Hansen, J. M.; Elhabiby, M. M.; El-Sheimy, N.; Sesay, A. B.

    2015-08-01

    Accurate 3D reconstruction has become essential for non-traditional mapping applications such as urban planning, mining industry, environmental monitoring, navigation, surveillance, pipeline inspection, infrastructure monitoring, landslide hazard analysis, indoor localization, and military simulation. The needs of these applications cannot be satisfied by traditional mapping, which is based on dedicated data acquisition systems designed for mapping purposes. Recent advances in hardware and software development have made it possible to conduct accurate 3D mapping without using costly and high-end data acquisition systems. Low-cost digital cameras, laser scanners, and navigation systems can provide accurate mapping if they are properly integrated at the hardware and software levels. Unmanned Aerial Vehicles (UAVs) are emerging as a mobile mapping platform that can provide additional economical and practical advantages. However, such economical and practical requirements need navigation systems that can provide uninterrupted navigation solution. Hence, testing the performance characteristics of Micro-Electro-Mechanical Systems (MEMS) or low cost navigation sensors for various UAV applications is important research. This work focuses on studying the performance characteristics under different manoeuvres using inertial measurements integrated with single point positioning, Real-Time-Kinematic (RTK), and additional navigational aiding sensors. Furthermore, the performance of the inertial sensors is tested during Global Positioning System (GPS) signal outage.

  5. Modeling of anomalous Wtb interactions in single top quark events using auxiliary fields

    CERN Document Server

    Boos, E; Dudko, L; Perfilov, M

    2016-01-01

    A method to simulate anomalous fermion-boson interactions in Wtb vertex is presented with a minimal set of simulated samples of single top quark events at the LHC energies. In proposed method additional auxiliary vector fields corresponding to the Standard Model gauge fields are implemented for each type of the anomalous vertex structure. The method allows to simulate a manifestation of anomalous gauge couplings in two approaches used in experimental analyses either keeping only the linear order contributions in the anomalous couplings or keeping all contributions in numerators and denominators as appeared in matrix elements. All the single top quark production mechanisms, $t$-, $s$- and associative tW-channels are considered. The correctness of the proposed method is demonstrated.

  6. 印染助剂中的环境激素%Environmental hormone in textile auxiliary

    Institute of Scientific and Technical Information of China (English)

    张海婴; 赵婷; 袁碧云; 李蔚文

    2014-01-01

    Problem of environmental hormone is another global environmental problem that cannot be ignored besides the depletion of ozone layer and greenhouse effect. The classification, characteristics, action mechanism and harms of hormone to environment were introduced, and environmental hormone problem caused by textile auxiliary and the related analysis methods were emphatically discussed.%环境激素问题是继臭氧层破坏和温室效应之后又一大不可忽视的世界环境问题。介绍了环境激素的种类、特点、作用机理、危害,重点介绍了纺织染整助剂中的环境激素问题及其检测技术。

  7. Søgning og navigation

    DEFF Research Database (Denmark)

    Grauballe, Henning; Strunck, Kirsten Marie

    6 udvalgte testposter undersøges i 97 danske folkebibliotekers webkataloger med henblik på at afdække, hvordan disse testposters kontrollerede data udnyttes som hyperlinks til navigation og til videresøgning på ”Noget der ligner”. Undersøgelsen viser, at webkatalogerne især fokuserer på at udnytte...... opstillingsdata og udvalgte emnedata til navigation. Dermed udnyttes det samlede potentiale i de kontrollerede data ikke til at imødekomme brugernes forventninger til navigation ved hjælp af hyperlinks på Web’en. Undersøgelsen indikerer desuden, at der er en tæt sammenhæng mellem det konkrete bibliotekssystem...

  8. GPS Navigation and Tracking Device

    Directory of Open Access Journals (Sweden)

    Yahya Salameh Khraisat

    2011-10-01

    Full Text Available Since the introduction of GPS Navigation systems in the marketplace, consumers and businesses have been coming up with innovative ways to use the technology in their everyday life. GPS Navigation and Tracking systems keep us from getting lost when we are in strange locations, they monitor children when they are away from home, keep track of business vehicles and can even let us know where a philandering partner is at all times. Because of this we attend to build a GPS tracking device to solve the mentioned problems. Our work consists of the GPS module that collects data from satellites and calculates the position information before transmitting them to the user’s PC (of Navigation system or observers (of Tracking System using wireless technology (GSM.

  9. 20--500 watt AMTEC auxiliary electric power system

    Energy Technology Data Exchange (ETDEWEB)

    Ivanenok, J.F. III; Sievers, R.K. [Advanced Modular Power Systems, Inc., Ann Arbor, MI (United States)

    1996-12-31

    Numerous design studies have been completed on Alkali Metal Thermal to Electric Converter (AMTEC) power systems for space applications demonstrating their substantial increase in performance. Recently design studies have been initiated to couple AMTEC power conversion with fossil fueled combustion systems. This paper describes the results of a Phase 1 SBIR effort to design an innovative, efficient, reliable, long life AMTEC Auxiliary Electric Power System (AEPS) for remote site applications (20--500 watts). The concept uses high voltage AMTEC cells, each containing 7 to 9 small electrolyte tubes, integrated with a combustor and recuperator. These multi-tube AMTEC cells are low cost, reliable, long life static converters. AMTEC technology is ideal for auxiliary electric power supplies that must operate reliably over a broad range of temperatures, fuel sources, power levels, and operational specifications. The simplicity, efficiency (20% systems) and modularity of this technology allow it to fill applications as varied as light-weight backpacks, remote site power supplies, and military base power. Phase 1 demonstrated the feasibility of a 20% system design, and showed that the development needs to focus on identifying long life AMTEC cell components, determining the AMTEC cell and system reliability, and demonstrating that a 20 watt AMTEC system is 3--5 times more efficient than existing systems for the same application.

  10. Assembly auxiliary system for narrow cabins of spacecraft

    Science.gov (United States)

    Liu, Yi; Li, Shiqi; Wang, Junfeng

    2015-09-01

    Due to the narrow space and complex structure of spacecraft cabin, the existing asssembly systems can not well suit for the assembly process of cabin products. This paper aims to introduce an assembly auxiliary system for cabin products. A hierarchical-classification method is proposed to re-adjust the initial assembly relationship of cabin into a new hierarchical structure for efficient assembly planning. An improved ant colony algorithm based on three assembly principles is established for searching a optimizational assembly sequence of cabin parts. A mixed reality assembly environment is constructed with enhanced information to promote interaction efficiency of assembly training and guidance. Based on the machine vision technology, the inspection of left redundant objects and measurement of parts distance in inner cabin are efficiently performed. The proposed system has been applied to the assembly work of a spacecraft cabin with 107 parts, which includes cabin assembly planning, assembly training and assembly quality inspection. The application result indicates that the proposed system can be an effective assistant tool to cabin assembly works and provide an intuitive and real assembly experience for workers. This paper presents an assembly auxiliary system for spacecraft cabin products, which can provide technical support to the spacecraft cabin assembly industry.

  11. Surgical navigation in oral implantology.

    Science.gov (United States)

    Miller, Robert J; Bier, Jurgen

    2006-03-01

    The ability to generate 3-dimensional volumetric images of the maxillofacial area has allowed surgeons to evaluate anatomy before surgery and plan for the placement of implants in ideal positions. However, the ability to transfer that information to surgical reality has been the most challenging part of implant dentistry. With the advent of computer-assisted surgery, the surgeon may now navigate through the entire implant procedure with extremely high accuracy. A new portable laptop navigated system for oral implantology is discussed as an adjunct for complex implant cases. PMID:16569960

  12. Observability of Inertial Navigation System

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    To improve the observability of strapdown inertial navigation system and the effectiveness of Kalman filter in the navigation system, the method of estimating the observability is analyzed based on eigenvalues and eigenvectors which are proved to be availabe, on this basis two-position alignment technigue is applied. The simulation shows that two-position alignment really makes the system's observability change from being incomplete to being complete, and the test method based on eigenvalues and eigenvectors is available to determine the observability of every state vector.

  13. Navigation with a visual memory

    OpenAIRE

    Remazeilles, Anthony

    2004-01-01

    This work deals with autonomous robotic navigation. A robotic system that moves on its own must be able to localise itself in the environment, so as to define a path to follow, and also to control its motion in order to reach a desired position. A vision based-approach is chosen, by onsidering robotic systems with an on-board camera. The navigation space is represented in a topological way by an image database acquired during a learning step. Thus, the robot localisation is directly related t...

  14. Energy confinement scaling in tokamaks: some implications of recent experiments with ohmic and strong auxiliary heating

    International Nuclear Information System (INIS)

    Recent results from confinement scaling experiments on tokamaks with ohmic and strong auxiliary heating are reviewed. An attempt is made to draw these results together into a low-density ohmic confinement scaling law, and a scaling law for confinement with auxiliary heating. The auxiliary heating confinement law may also serve to explain the saturation in tau/sub E/ vs anti n/sub e/ observed in some ohmic heating density scaling experiments

  15. Use of Auxiliary Electrode to Prevent Alkalinization of Soil in Electrokinetic Remediation

    OpenAIRE

    Mori, Yuki; Wada, Shin-ichiro

    2004-01-01

    We devised an improved electrokinetic remendiatioin method in whoch an auxiliary electrode was placed at the cathode-side end of the soil to be treated. The electric potential difference between tne anode and the auxiliary electrode was fixed constant whole that between the cathode and the auxiloary electode was controlled to make the auxiliary electode function as a secondary anode. To test the performance of the method, we carried out a bench scale remediatioin experiment on cadmium-contam...

  16. Modifications and addition of an auxiliary feedwater pump to SONGS [San Onofre nuclear generating station] 1

    International Nuclear Information System (INIS)

    This paper discusses the recent modifications and equipment additions to the auxiliary feedwater (AFW) system at San Onofre nuclear generating station (SONGS) Unit 1. As a result of the Three Mile Island accident, several modifications to the AFW system were required. The addition of a third auxiliary feedwater pump was necessary to allow auxiliary feedwater operation following a main steam-line break concurrent with a single active failure

  17. Engineering satellite-based navigation and timing global navigation satellite systems, signals, and receivers

    CERN Document Server

    Betz, J

    2016-01-01

    This book describes the design and performance analysis of satnav systems, signals, and receivers. It also provides succinct descriptions and comparisons of all the world’s satnav systems. Its comprehensive and logical structure addresses all satnav signals and systems in operation and being developed. Engineering Satellite-Based Navigation and Timing: Global Navigation Satellite Systems, Signals, and Receivers provides the technical foundation for designing and analyzing satnav signals, systems, and receivers. Its contents and structure address all satnav systems and signals: legacy, modernized, and new. It combines qualitative information with detailed techniques and analyses, providing a comprehensive set of insights and engineering tools for this complex multidisciplinary field. Part I describes system and signal engineering including orbital mechanics and constellation design, signal design principles and underlying considerations, link budgets, qua tifying receiver performance in interference, and e...

  18. Basal ganglia contributions to adaptive navigation.

    Science.gov (United States)

    Mizumori, Sheri J Y; Puryear, Corey B; Martig, Adria K

    2009-04-12

    The striatum has long been considered to be selectively important for nondeclarative, procedural types of memory. This stands in contrast with spatial context processing that is typically attributed to hippocampus. Neurophysiological evidence from studies of the neural mechanisms of adaptive navigation reveals that distinct neural systems such as the striatum and hippocampus continuously process task relevant information regardless of the current cognitive strategy. For example, both striatal and hippocampal neural representations reflect spatial location, directional heading, reward, and egocentric movement features of a test situation in an experience-dependent way, and independent of task demands. Thus, continual parallel processing across memory systems may be the norm rather than the exception. It is suggested that neuromodulators, such as dopamine, may serve to differentially regulate learning-induced neural plasticity mechanisms within these memory systems such that the most successful form of neural processing exerts the strongest control over response selection functions. In this way, dopamine may serve to optimize behavioral choices in the face of changing environmental demands during navigation. PMID:19056429

  19. The constructional conception of the effectiveness of navigational service rising for navigation on inland water routes

    OpenAIRE

    I. V. Tykhonov

    2010-01-01

    Constructional conception of rising of the effectiveness of navigational service on inland water routes is described. The article demonstrates that using of this conception and informational recourses permit to raise the effectiveness of navigational service of safety of navigation

  20. Celestial navigation in a nutshell

    CERN Document Server

    Schlereth, Hewitt

    2000-01-01

    Celestial Navigation in a Nutshell demonstrates how to take sights by the sun, moon, stars, and planets, discussing the advantages and disadvantages of each method. The reader is taken carefully through several examples and situational illustrations, making this a most effective self-teaching guide. Common errors are reviewed and several tips on how to improve accuracy are given.

  1. Conceptual Grounds of Navigation Safety

    Directory of Open Access Journals (Sweden)

    Vladimir Torskiy

    2016-04-01

    Full Text Available The most important global problem being solved by the whole world community nowadays is to provide sustainable mankind development. Recent research in the field of sustainable development states that civilization safety is impossible without transfer sustainable development. At the same time, sustainable development (i.e. preservation of human culture and biosphere is impossible as a system that serves to meet economical, cultural, scientific, recreational and other human needs without safety. Safety plays an important role in sustainable development goals achievement. An essential condition of effective navigation functioning is to provide its safety. The “prescriptive” approach to the navigation safety, which is currently used in the world maritime field, is based on long-term experience and ship accidents investigation results. Thus this approach acted as an the great fact in reduction of number of accidents at sea. Having adopted the International Safety Management Code all the activities connected with navigation safety problems solution were transferred to the higher qualitative level. Search and development of new approaches and methods of ship accidents prevention during their operation have obtained greater importance. However, the maritime safety concept (i.e. the different points on ways, means and methods that should be used to achieve this goal hasn't been formed and described yet. The article contains a brief review of the main provisions of Navigation Safety Conceptions, which contribute to the number of accidents and incidents at sea reduction.

  2. Olfactory Orientation and Navigation in Humans.

    Science.gov (United States)

    Jacobs, Lucia F; Arter, Jennifer; Cook, Amy; Sulloway, Frank J

    2015-01-01

    Although predicted by theory, there is no direct evidence that an animal can define an arbitrary location in space as a coordinate location on an odor grid. Here we show that humans can do so. Using a spatial match-to-sample procedure, humans were led to a random location within a room diffused with two odors. After brief sampling and spatial disorientation, they had to return to this location. Over three conditions, participants had access to different sensory stimuli: olfactory only, visual only, and a final control condition with no olfactory, visual, or auditory stimuli. Humans located the target with higher accuracy in the olfaction-only condition than in the control condition and showed higher accuracy than chance. Thus a mechanism long proposed for the homing pigeon, the ability to define a location on a map constructed from chemical stimuli, may also be a navigational mechanism used by humans. PMID:26083337

  3. Olfactory Orientation and Navigation in Humans.

    Directory of Open Access Journals (Sweden)

    Lucia F Jacobs

    Full Text Available Although predicted by theory, there is no direct evidence that an animal can define an arbitrary location in space as a coordinate location on an odor grid. Here we show that humans can do so. Using a spatial match-to-sample procedure, humans were led to a random location within a room diffused with two odors. After brief sampling and spatial disorientation, they had to return to this location. Over three conditions, participants had access to different sensory stimuli: olfactory only, visual only, and a final control condition with no olfactory, visual, or auditory stimuli. Humans located the target with higher accuracy in the olfaction-only condition than in the control condition and showed higher accuracy than chance. Thus a mechanism long proposed for the homing pigeon, the ability to define a location on a map constructed from chemical stimuli, may also be a navigational mechanism used by humans.

  4. Navigation system for interstitial brachytherapy

    International Nuclear Information System (INIS)

    The purpose of the stud was to develop a computed tomography (CT) based electromagnetic navigation system for interstitial brachytherapy. This is especially designed for situations when needles have to be positioned adjacent to or within critical anatomical structures. In such instances interactive 3D visualisation of the needle positions is essential. The material consisted of a Polhemus electromagnetic 3D digitizer, a Pentium 200 MHz laptop and a voice recognition for continuous speech. In addition, we developed an external reference system constructed of Perspex which could be positioned above the tumour region and attached to the patient using a non-invasive fixation method. A specially designed needle holder and patient bed were also developed. Measurements were made on a series of phantoms in order to study the efficacy and accuracy of the navigation system. The mean navigation accuracy of positioning the 20.0 cm length metallic needles within the phantoms was in the range 2.0-4.1 mm with a maximum of 5.4 mm. This is an improvement on the accuracy of a CT-guided technique which was in the range 6.1-11.3 mm with a maximum of 19.4 mm. The mean reconstruction accuracy of the implant geometry was 3.2 mm within a non-ferromagnetic environment. We found that although the needles were metallic this did not have a significant influence. We also found for our experimental setups that the CT table and operation table non-ferromagnetic parts had no significant influence on the navigation accuracy. This navigation system will be a very useful clinical tool for interstitial brachytherapy applications, particularly when critical structures have to be avoided. It also should provide a significant improvement on our existing technique

  5. Influence of a screening navigation program on social inequalities in health beliefs about colorectal cancer screening.

    Science.gov (United States)

    Vallet, Fanny; Guillaume, Elodie; Dejardin, Olivier; Guittet, Lydia; Bouvier, Véronique; Mignon, Astrid; Berchi, Célia; Salinas, Agnès; Launoy, Guy; Christophe, Véronique

    2016-08-01

    The aim of the study was to test whether a screening navigation program leads to more favorable health beliefs and decreases social inequalities in them. The selected 261 noncompliant participants in a screening navigation versus a usual screening program arm had to respond to health belief measures inspired by the Protection Motivation Theory. Regression analyses showed that social inequalities in perceived efficacy of screening, favorable attitude, and perceived facility were reduced in the screening navigation compared to the usual screening program. These results highlight the importance of health beliefs to understand the mechanism of screening navigation programs in reducing social inequalities. PMID:25549659

  6. "Self-assisted" amoeboid navigation in complex environments.

    Directory of Open Access Journals (Sweden)

    Inbal Hecht

    Full Text Available BACKGROUND: Living cells of many types need to move in response to external stimuli in order to accomplish their functional tasks; these tasks range from wound healing to immune response to fertilization. While the directional motion is typically dictated by an external signal, the actual motility is also restricted by physical constraints, such as the presence of other cells and the extracellular matrix. The ability to successfully navigate in the presence of obstacles is not only essential for organisms, but might prove relevant in the study of autonomous robotic motion. METHODOLOGY/PRINCIPAL FINDINGS: We study a computational model of amoeboid chemotactic navigation under differing conditions, from motion in an obstacle-free environment to navigation between obstacles and finally to moving in a maze. We use the maze as a simple stand-in for a motion task with severe constraints, as might be expected in dense extracellular matrix. Whereas agents using simple chemotaxis can successfully navigate around small obstacles, the presence of large barriers can often lead to agent trapping. We further show that employing a simple memory mechanism, namely secretion of a repulsive chemical by the agent, helps the agent escape from such trapping. CONCLUSIONS/SIGNIFICANCE: Our main conclusion is that cells employing simple chemotactic strategies will often be unable to navigate through maze-like geometries, but a simple chemical marker mechanism (which we refer to as "self-assistance" significantly improves success rates. This realization provides important insights into mechanisms that might be employed by real cells migrating in complex environments as well as clues for the design of robotic navigation strategies. The results can be extended to more complicated multi-cellular systems and can be used in the study of mammalian cell migration and cancer metastasis.

  7. 33 CFR 401.54 - Interference with navigation aids.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Interference with navigation aids. 401.54 Section 401.54 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION... with navigation aids. (a) Aids to navigation shall not be interfered with or used as moorings. (b)...

  8. 33 CFR 67.35-10 - Private aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Private aids to navigation. 67.35-10 Section 67.35-10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION AIDS TO NAVIGATION ON ARTIFICIAL ISLANDS AND FIXED STRUCTURES Applications §...

  9. 33 CFR 100.45 - Establishment of aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Establishment of aids to navigation. 100.45 Section 100.45 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... navigation. The District Commander will establish and maintain only those aids to navigation necessary...

  10. Interaction region design and auxiliary detector systems for an EIC

    Directory of Open Access Journals (Sweden)

    Petti R.

    2016-01-01

    Full Text Available There are a number of exciting physics opportunities at a future electron-ion collider facility. One possible design for such a facility is eRHIC, where the current RHIC facility located at Brookhaven National Lab would be transformed into an electron-ion collider. It is imperative for a seamless integration of auxiliary detector systems into the interaction region design to have a machine that meets the needs for the planned physics analyses, as well as take into account the space constraints due to the tunnel geometry and the necessary beam line elements. In this talk, we describe the current ideas for integrating a luminosity detector, electron polarimeter, roman pots, and a low Q2-tagger into the interaction region for eRHIC.

  11. Parent formulations, frame-like Lagrangians, and generalized auxiliary fields

    CERN Document Server

    Grigoriev, Maxim

    2012-01-01

    We elaborate on the recently proposed Lagrangian parent formulation. In particular, we identify a natural choice of the allowed field configurations ensuring the equivalence of the parent and the starting point Lagrangians. We also analyze the structure of the generalized auxiliary fields employed in the parent formulation and establish the relationship between the parent Lagrangian and the recently proposed Lagrange structure for the unfolded dynamics. As an illustration of the parent formalism a systematic derivation of the frame-like Lagrangian for totally symmetric fields starting from the Fronsdal one is given. We also present a concise and manifestly sp(2)-symmetric form of the off-shell constraints and gauge symmetries for AdS space symmetric fields at the nonlinear level.

  12. Auxiliary quasi-resonant dc tank electrical power converter

    Science.gov (United States)

    Peng, Fang Z.

    2006-10-24

    An auxiliary quasi-resonant dc tank (AQRDCT) power converter with fast current charging, voltage balancing (or charging), and voltage clamping circuits is provided for achieving soft-switched power conversion. The present invention is an improvement of the invention taught in U.S. Pat. No. 6,111,770, herein incorporated by reference. The present invention provides faster current charging to the resonant inductor, thus minimizing delay time of the pulse width modulation (PWM) due to the soft-switching process. The new AQRDCT converter includes three tank capacitors or power supplies to achieve the faster current charging and minimize the soft-switching time delay. The new AQRDCT converter further includes a voltage balancing circuit to charge and discharge the three tank capacitors so that additional isolated power supplies from the utility line are not needed. A voltage clamping circuit is also included for clamping voltage surge due to the reverse recovery of diodes.

  13. Glycosyl dithiocarbamates: β-selective couplings without auxiliary groups.

    Science.gov (United States)

    Padungros, Panuwat; Alberch, Laura; Wei, Alexander

    2014-03-21

    In this article, we evaluate glycosyl dithiocarbamates (DTCs) with unprotected C2 hydroxyls as donors in β-linked oligosaccharide synthesis. We report a mild, one-pot conversion of glycals into β-glycosyl DTCs via DMDO oxidation with subsequent ring opening by DTC salts, which can be generated in situ from secondary amines and CS2. Glycosyl DTCs are readily activated with Cu(I) or Cu(II) triflate at low temperatures and are amenable to reiterative synthesis strategies, as demonstrated by the efficient construction of a tri-β-1,6-linked tetrasaccharide. Glycosyl DTC couplings are highly β-selective despite the absence of a preexisting C2 auxiliary group. We provide evidence that the directing effect is mediated by the C2 hydroxyl itself via the putative formation of a cis-fused bicyclic intermediate. PMID:24548247

  14. Learning Deep Representation for Face Alignment with Auxiliary Attributes.

    Science.gov (United States)

    Zhang, Zhanpeng; Luo, Ping; Loy, Chen Change; Tang, Xiaoou

    2016-05-01

    In this study, we show that landmark detection or face alignment task is not a single and independent problem. Instead, its robustness can be greatly improved with auxiliary information. Specifically, we jointly optimize landmark detection together with the recognition of heterogeneous but subtly correlated facial attributes, such as gender, expression, and appearance attributes. This is non-trivial since different attribute inference tasks have different learning difficulties and convergence rates. To address this problem, we formulate a novel tasks-constrained deep model, which not only learns the inter-task correlation but also employs dynamic task coefficients to facilitate the optimization convergence when learning multiple complex tasks. Extensive evaluations show that the proposed task-constrained learning (i) outperforms existing face alignment methods, especially in dealing with faces with severe occlusion and pose variation, and (ii) reduces model complexity drastically compared to the state-of-the-art methods based on cascaded deep model. PMID:27046839

  15. Bistable energy harvesting enhancement with an auxiliary linear oscillator

    International Nuclear Information System (INIS)

    Recent work has indicated that linear vibrational energy harvesters with an appended degree-of-freedom (DOF) may be advantageous for introducing new dynamic forms to extend the operational bandwidth. Given the additional interest in bistable harvester designs, which exhibit a propitious snap through effect from one stable state to the other, it is a logical extension to explore the influence of an added DOF to a bistable system. However, bistable snap through is not a resonant phenomenon, which tempers the presumption that the dynamics induced by an additional DOF on bistable designs would inherently be beneficial as for linear systems. This paper presents two analytical formulations to assess the fundamental and superharmonic steady-state dynamics of an excited bistable energy harvester to which is attached an auxiliary linear oscillator. From an energy harvesting perspective, the model predicts that the additional linear DOF uniformly amplifies the bistable harvester response magnitude and generated power for excitation frequencies less than the attachment’s resonance while improved power density spans a bandwidth below this frequency. Analyses predict bandwidths having co-existent responses composed of a unique proportion of fundamental and superharmonic dynamics. Experiments validate key analytical predictions and observe the ability for the coupled system to develop an advantageous multi-harmonic interwell response when the initial conditions are insufficient for continuous high-energy orbit at the excitation frequency. Overall, the addition of an auxiliary linear oscillator to a bistable harvester is found to be an effective means of enhancing the energy harvesting performance and robustness. (paper)

  16. A proposal on auxiliary business insurance for peritoneal dialysis treatment

    Institute of Scientific and Technical Information of China (English)

    WANG Juan; WANG Tao; FANG Ji-qian

    2008-01-01

    Background The peritoneal dialysis (PD) therapy for end stage renal disease (ESRD) is expensive. The main reason for non-acceptance onto dialysis programs is the great cost. In the present study, we design an auxiliary business insurance program to provide the potential ESRD patients who have no access to governmental medical insurance or can not afford the remaining part besides the limited reimbursement for peritoneal dialysis therapy.Methods The information applied in this study was extracted from the medical records of 641 PD patients, who were treated in two dialysis centers of the first and the third teaching hospitals of the Peking University respectively. A collective risk model was employed to estimate the expenses on PD therapy. Survival analyses were performed to obtain the average survival time of PD patients and the average length of time from the onset of the primary disease to the beginning of PD. An annuity method was used to determine the pure premium.Results For chronic nephritis, diabetes mellitus and hyperpietic as primary diseases, the mean survival time ± standard errors were (55.1±3.7) months, (38.9±3.2) months and (61.4±4.6) months respectively, and they were significantly different from each other (all P=0.000). The expenses of whole PD therapy were 242 159.05 Yuan, 182 525.02 Yuan and 284 579.24 Yuan respectively.Conclusions An auxiliary business insurance for PD patients was designed with the pure premium for any individual who had chronic nephritis, diabetes mellitus or hyperpietic as primary disease was RMB 35.94 Yuan/year, 87.73Yuan/year or 7.71 Yuan/year respectively without considering the additional premium for coping with the business expenditures and accidental risks.

  17. Navigation in Cross-cultural business relationships

    DEFF Research Database (Denmark)

    Andersen, Poul Houman

    2001-01-01

    Cross-cultural business navigation concerns the process of handling the complexity of several interacting cultural spheres of influence......Cross-cultural business navigation concerns the process of handling the complexity of several interacting cultural spheres of influence...

  18. Evolutionary Fuzzy Control and Navigation for Two Wheeled Robots Cooperatively Carrying an Object in Unknown Environments.

    Science.gov (United States)

    Juang, Chia-Feng; Lai, Min-Ge; Zeng, Wan-Ting

    2015-09-01

    This paper presents a method that allows two wheeled, mobile robots to navigate unknown environments while cooperatively carrying an object. In the navigation method, a leader robot and a follower robot cooperatively perform either obstacle boundary following (OBF) or target seeking (TS) to reach a destination. The two robots are controlled by fuzzy controllers (FC) whose rules are learned through an adaptive fusion of continuous ant colony optimization and particle swarm optimization (AF-CACPSO), which avoids the time-consuming task of manually designing the controllers. The AF-CACPSO-based evolutionary fuzzy control approach is first applied to the control of a single robot to perform OBF. The learning approach is then applied to achieve cooperative OBF with two robots, where an auxiliary FC designed with the AF-CACPSO is used to control the follower robot. For cooperative TS, a rule for coordination of the two robots is developed. To navigate cooperatively, a cooperative behavior supervisor is introduced to select between cooperative OBF and cooperative TS. The performance of the AF-CACPSO is verified through comparisons with various population-based optimization algorithms for the OBF learning problem. Simulations and experiments verify the effectiveness of the approach for cooperative navigation of two robots. PMID:25398185

  19. 29 CFR Appendix II to Part 1918 - Tables for Selected Miscellaneous Auxiliary Gear (Mandatory)

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Tables for Selected Miscellaneous Auxiliary Gear (Mandatory) II Appendix II to Part 1918 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND.... 1918, App. II Appendix II to Part 1918—Tables for Selected Miscellaneous Auxiliary Gear...

  20. How Does Dissociation between Written and Oral Forms Affect Reading: Evidence from Auxiliary Verbs in Arabic

    Science.gov (United States)

    Ibrahim, Raphiq

    2011-01-01

    In Arabic, auxiliary verbs are necessary in the written language, but absent from the oral language. This is contrary to languages such as English and French in which auxiliary verbs are mandatory in both written and oral languages. This fact was exploited to examine if dissociation between written and oral forms affects reading measures like…

  1. Modal Auxiliaries and Their Semantic Functions Used by Advanced EFL Learners

    Science.gov (United States)

    Torabiardakani, Najmeh; Khojasteh, Laleh; Shokrpour, Nasrin

    2015-01-01

    Since modal auxiliary verbs have been proved to be one of the most troublesome grammatical structures in English, the researchers of this study decided to do an analysis on the ways in which advanced EFL Iranian students use modal auxiliaries focusing specially on nine modals' semantic functions. Consequently, was conducted based on the following…

  2. Auxiliary space preconditioners for linear elasticity based on generalized finite element methods

    OpenAIRE

    Brannick, James; Cho, Durkbin

    2010-01-01

    We construct and analyze a preconditioner of the linear elastiity system discretized by conforming linear finite elements in the framework of the auxiliary space method. The auxiliary space preconditioner is based on discretization of a scalar elliptic equation with Generalized Finite Element Method.

  3. Indirect assessment of web navigation success

    OpenAIRE

    Gwizdka, Jacek; Spence, Ian

    2005-01-01

    Despite much research on hypertext and web navigation, relatively little is known about the relationship between web navigation strategies and success. We present two exploratory studies designed to explore the relationships between several web navigation metrics that are based on similarity to an optimal path to predict task success. The data suggest that the relationships between these measures depend on the particular web navigation task.

  4. Sniffing Around for Providing Navigation Assistance

    OpenAIRE

    Herder, E.

    2004-01-01

    In this paper we describe an approach to adaptive navigation assistance that is meant to enhance a user’s information scent. The navigation assistance is composed of a combination of predictive user navigation modeling and common information retrieval methods. Besides assistance in forward browsing, the assistant helps users in deciding when to switch to searching or backtracking, while taking their navigation preferences into account.

  5. Novel Environmental Features for Robust Multisensor Navigation

    OpenAIRE

    Walter, D. J.; Groves, P. D.; Mason, R J; Harrison, J.; J. Woodward; Wright, P

    2013-01-01

    Many navigation techniques have now become so reliant on GNSS that there is no back up when there is limited or no signal reception. If there is interference, intentional or otherwise, with the signal, navigation could be lost or become misleading [1]. Other navigation techniques harness different technologies such as Wi-Fi [2], eLoran and inertial navigation. However, each of these techniques has its own limitations, such as coverage, degradation in urban areas or solution drift [3]. Therefo...

  6. Navigation based on symbolic space models

    OpenAIRE

    Baras, Karolina; Moreira, Adriano; Meneses, Filipe

    2010-01-01

    Existing navigation systems are very appropriate for car navigation, but lack support for convenient pedestrian navigation and cannot be used indoors due to GPS limitations. In addition, the creation and the maintenance of the required models are costly and time consuming, and are usually based on proprietary data structures. In this paper we describe a navigation system based on a human inspired symbolic space model. We argue that symbolic space models are much easier...

  7. Observability during planetary approach navigation

    Science.gov (United States)

    Bishop, Robert H.; Burkhart, P. Daniel; Thurman, Sam W.

    1993-01-01

    The objective of the research is to develop an analytic technique to predict the relative navigation capability of different Earth-based radio navigation measurements. In particular, the problem is to determine the relative ability of geocentric range and Doppler measurements to detect the effects of the target planet gravitational attraction on the spacecraft during the planetary approach and near-encounter mission phases. A complete solution to the two-dimensional problem has been developed. Relatively simple analytic formulas are obtained for range and Doppler measurements which describe the observability content of the measurement data along the approach trajectories. An observability measure is defined which is based on the observability matrix for nonlinear systems. The results show good agreement between the analytic observability analysis and the computational batch processing method.

  8. Literal grid map models for animal navigation: Assumptions and predictions.

    Science.gov (United States)

    Turner, Rebecca M; Walker, Michael M; Postlethwaite, Claire M

    2016-09-01

    Many animals can navigate from unfamiliar locations to a familiar target location with no outward route information or direct sensory contact with the target or any familiar landmarks. Several models have been proposed to explain this phenomenon, one possibility being a literal interpretation of a grid map. In this paper we systematically compare four such models, which we label: Correct Bicoordinate navigation, both Target and Release site based, Approximate Bicoordinate navigation, and Directional navigation. Predictions of spatial patterns of initial orientation errors and efficiencies depend on a combination of assumptions about the navigation mechanism and the geometry of the environmental coordinate fields used as model inputs. When coordinates axes are orthogonal at the target the predictions from the Correct Bicoordinate (Target based) model and Approximate Bicoordinate model are identical. However, if the coordinate axes are non-orthogonal different regional patterns of initial orientation errors and efficiencies can be expected from these two models. Field anomalies produce high magnitudes of orientation errors close to the target, while region-wide nonlinearity leads to orientation errors increasing with distance from the target. In general, initial orientation error patterns are more useful for distinguishing between different assumption combinations than efficiencies. We discuss how consideration of model predictions may be helpful in the design of experiments. PMID:27266672

  9. Navigation and geo-tracking system of UAV EO payload

    Science.gov (United States)

    Chen, Ying; Zhen, Kang; Xue, Yuanyuan; Zhang, Xiajiang; Li, Yingjuan; Tang, Chao

    2016-01-01

    A multi-function system based on inertial measurement unit (IMU) is introduced, which can fulfill navigation, attitude measurement of LOS in payload, platform stabilization and tracking control. The IMU is integrated with electro-optical sensors and a laser range finder on gimbals, which performs attitude calculation and navigation by constructing navigation coordinates in a mathematic platform, and the platform navigation information is obtained by transformation matrix between platform and gimbal coordinates. The platform comprising of gyros, electro-optical sensors and servo mechanism is capable of stabilizing line of sight and could be used to geo-tracking in the relevant field of view (FOV).The system can determine geography coordinates of the host platform and target only with navigation information and laser ranging data. The geo-tracking system always locked the target image at the center of FOV by calculating spatial geometry and adjusting LOS attitude. This tracking is different from TV tracking and geographical reference image tracking, which may be influenced by fog and obscurant. When the UAV is flying over urban or mountain areas for rescue missions, it can avoid the loss of targets due to strong maneuver or LOS obscuration, and reduce the operation load and improve rescue efficiency.

  10. Odor supported place cell model and goal navigation in rodents

    DEFF Research Database (Denmark)

    Kulvicius, Tomas; Tamosiunaite, Minija; Ainge, James; Dudchenko, Paul; Wörgötter, Florentin

    2008-01-01

    Experiments with rodents demonstrate that visual cues play an important role in the control of hippocampal place cells and spatial navigation. Nevertheless, rats may also rely on auditory, olfactory and somatosensory stimuli for orientation. It is also known that rats can track odors or self-gene......-generated olfactory cues, together with a mixed navigation strategy, improves goal directed navigation.......-generated scent marks to find a food source. Here we model odor supported place cells by using a simple feed-forward network and analyze the impact of olfactory cues on place cell formation and spatial navigation. The obtained place cells are used to solve a goal navigation task by a novel mechanism based on self......-marking by odor patches combined with a Q-learning algorithm. We also analyze the impact of place cell remapping on goal directed behavior when switching between two environments. We emphasize the importance of olfactory cues in place cell formation and show that the utility of environmental and self...

  11. 06421 Abstracts Collection -- Robot Navigation

    OpenAIRE

    Fekete, Sándor; Fleischer, Rudolf; Klein, Rolf; Lopez-Ortiz, Alejandro

    2007-01-01

    From 15.10.06 to 20.10.06, the Dagstuhl Seminar 06421 ``Robot Navigation''generate automatically was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the...

  12. Interplanetary spacecraft navigation using pulsars

    OpenAIRE

    Deng, X. P.; Hobbs, G.; You, X. P.; M. T. Li; Keith, M. J.; Shannon, R. M.; Coles, W.; Manchester, R. N.; J.H. Zheng; Yu, X. Z.; Gao, D.; Wu, X; Chen, D.

    2013-01-01

    We demonstrate how observations of pulsars can be used to help navigate a spacecraft travelling in the solar system. We make use of archival observations of millisecond pulsars from the Parkes radio telescope in order to demonstrate the effectiveness of the method and highlight issues, such as pulsar spin irregularities, which need to be accounted for. We show that observations of four millisecond pulsars every seven days using a realistic X-ray telescope on the spacecraft throughout a journe...

  13. Safety effects of navigation systems.

    OpenAIRE

    2009-01-01

    Increasing numbers of drivers are using navigation systems in their cars. The advantages to the user are obvious: you can get to your destination via the fastest and shortest route. This reduces stress and exposure to other traffic. However, there are also some (unintended) negative effects. For example, using the system while driving can distract your attention from other traffic. The system sometimes directs traffic through small centres of habitation or along unsuitable roads. Moreover, ti...

  14. Robotic perception for autonomous navigation

    OpenAIRE

    Furlan,

    2014-01-01

    This thesis presents the research work the author carried on during his PhD on the topic of robotic perception for autonomous navigation. In particular, the efforts focus on the Self-Localization, Scene Understanding and Object Detection and Tracking problems, proposing for each of these three topics one or more approaches that present an improvement over the state-of-the-art. In some cases the proposed approaches mutually exploit the generated information to improve the quality of the final ...

  15. 06421 Executive Summary -- Robot Navigation

    OpenAIRE

    Fekete, Sándor; Fleischer, Rudolf; Klein, Rolf; Lopez-Ortiz, Alejandro

    2007-01-01

    For quite a number of years, researchers from various fields have studied problems motivated by Robot Navigation. People in Online Algorithms have developed strategies that can deal with the inherent lack of information an autonomous robot encounters, as it sets out to perform a task in an unknown environment. Computational Geometers have obtained many results on the efficient planning of collision-free motions, and on visibility problems. Scientists and engineers in Robotics have perfected r...

  16. Orientation and navigation in birds

    OpenAIRE

    Bouwman, H.

    1998-01-01

    How birds orientate and navigate over long distances, remains one of the subjects of ornithology eliciting much interest. Birds use combinations of different sources of information to find direction and position. Some of these are the geomagnetic field, celestial bodies, mosaic and gradient maps, sound, smell, idiotetic information and others. Different species use different combinations of sources. This ability is partially inherent and partially learned.

  17. Orientation and navigation in birds

    Directory of Open Access Journals (Sweden)

    H. Bouwman

    1998-07-01

    Full Text Available How birds orientate and navigate over long distances, remains one of the subjects of ornithology eliciting much interest. Birds use combinations of different sources of information to find direction and position. Some of these are the geomagnetic field, celestial bodies, mosaic and gradient maps, sound, smell, idiotetic information and others. Different species use different combinations of sources. This ability is partially inherent and partially learned.

  18. Navigation in diagnosis and therapy

    International Nuclear Information System (INIS)

    Image-guided navigation for surgery and other therapeutic interventions has grown in importance in recent years. During image-guided navigation a target is detected, localized and characterized for diagnosis and therapy. Thus, images are used to select, plan, guide and evaluate therapy, thereby reducing invasiveness and improving outcomes. A shift from traditional open surgery to less-invasive image-guided surgery will continue to impact the surgical marketplace. Increases in the speed and capacity of computers and computer networks have enabled image-guided interventions. Key elements in image navigation systems are pre-operative 3D imaging (or real-time image acquisition), a graphical display and interactive input devices, such as surgical instruments with light emitting diodes (LEDs). CT and MRI, 3D imaging devices, are commonplace today and 3D images are useful in complex interventions such as radiation oncology and surgery. For example, integrated surgical imaging workstations can be used for frameless stereotaxy during neurosurgical interventions. In addition, imaging systems are being expanded to include decision aids in diagnosis and treatment. Electronic atlases, such as Voxel Man or others derived from the Visible Human Project, combine a set of image data with non-image knowledge such as anatomic labels. Robot assistants and magnetic guidance technology are being developed for minimally invasive surgery and other therapeutic interventions. Major progress is expected at the interface between the disciplines of radiology and surgery where imaging, intervention and informatics converge

  19. Pharmacological evidence is consistent with a prominent role of spatial memory in complex navigation.

    Science.gov (United States)

    Roth, Timothy C; Krochmal, Aaron R

    2016-02-10

    The ability to learn about the spatial environment plays an important role in navigation, migration, dispersal, and foraging. However, our understanding of both the role of cognition in the development of navigation strategies and the mechanisms underlying these strategies is limited. We tested the hypothesis that complex navigation is facilitated by spatial memory in a population of Chrysemys picta that navigate with extreme precision (±3.5 m) using specific routes that must be learned prior to age three. We used scopolamine, a muscarinic acetylcholine receptor antagonist, to manipulate the cognitive spatial abilities of free-living turtles during naturally occurring overland movements. Experienced adults treated with scopolamine diverted markedly from their precise navigation routes. Naive juveniles lacking experience (and memory) were not affected by scopolamine, and thereby served as controls for perceptual or non-spatial cognitive processes associated with navigation. Further, neither adult nor juvenile movement was affected by methylscopolamine, a form of scopolamine that does not cross the blood-brain barrier, a control for the peripheral effects of scopolamine. Together, these results are consistent with a role of spatial cognition in complex navigation and highlight a cellular mechanism that might underlie spatial cognition. Overall, our findings expand our understanding of the development of complex cognitive abilities of vertebrates and the neurological mechanisms of navigation. PMID:26865305

  20. Navigation.

    Science.gov (United States)

    Wellman, Bruce; Lipton, Laura

    2000-01-01

    Teachers' quests for more data-based planning, problem solving, and decision making often stumble against limited capacities for engaging in thoughtful interactions, with groups typically lacking process tools, collaborative communication skills, and reflective habits. This article presents a three-phase model for guiding data-driven dialogue in…

  1. Cooperative navigation and localization for multiple UUVs

    Science.gov (United States)

    Zhang, Li-Chuan; Xu, De-Min; Liu, Ming-Yong; Yan, Wei-Sheng

    2009-09-01

    The authors proposed a moving long baseline algorithm based on the extended Kalman filter (EKF) for cooperative navigation and localization of multi-unmanned underwater vehicles (UUVs). Research on cooperative navigation and localization for multi-UUVs is important to solve navigation problems that restrict long and deep excursions. The authors investigated improvements in navigation accuracy. In the moving long base line (MLBL) structure, the master UUV is equipped with a high precision navigation system as a node of the moving long baseline, and the slave UUV is equipped with a low precision navigation system. They are both equipped with acoustic devices to measure relative location. Using traditional triangulation methods to calculate the position of the slave UUV may cause a faulty solution. An EKF was designed to solve this, combining the proprioceptive and exteroceptive sensors. Research results proved that the navigational accuracy is improved significantly with the MLBL method based on EKF.

  2. Ligand-Enabled β-C–H Arylation of Alpha-Amino Acids Using a Simple and Practical Auxiliary

    OpenAIRE

    Chen, Gang; Shigenari, Toshihiko; Jain, Pankaj; Zhang, Zhipeng; Jin, Zhong; He, Jian; Li, Suhua; Mapelli, Claudio; Miller, Michael M.; Poss, Michael A.; Scola, Paul M.; Yeung, Kap-Sun; Yu, Jin-Quan

    2015-01-01

    Pd-catalyzed β-C–H functionalizations of carboxylic acid derivatives using an auxiliary as a directing group have been extensively explored in the past decade. In comparison to the most widely used auxiliaries in asymmetric synthesis, the simplicity and practicality of the auxiliaries developed for C–H activation remains to be improved. We previously developed a simple N-methoxyamide auxiliary to direct β-C–H activation, albeit this system was not compatible with carboxylic acids containing α...

  3. Mechanics

    CERN Document Server

    Hartog, J P Den

    1961-01-01

    First published over 40 years ago, this work has achieved the status of a classic among introductory texts on mechanics. Den Hartog is known for his lively, discursive and often witty presentations of all the fundamental material of both statics and dynamics (and considerable more advanced material) in new, original ways that provide students with insights into mechanical relationships that other books do not always succeed in conveying. On the other hand, the work is so replete with engineering applications and actual design problems that it is as valuable as a reference to the practicing e

  4. Spatial navigation in young versus older adults

    Directory of Open Access Journals (Sweden)

    Ivana Gazova

    2013-12-01

    Full Text Available Older age is associated with changes in the brain, including the medial temporal lobe, which may result in mild spatial navigation deficits, especially in allocentric navigation. The aim of the study was to characterize the profile of real-space allocentric (world-centered, hippocampus dependent and egocentric (body-centered, parietal lobe dependent navigation and learning in young vs. older adults, and to assess a possible influence of gender. We recruited healthy participants without cognitive deficits on standard neuropsychological testing, white matter lesions or pronounced hippocampal atrophy: 24 young participants (18-26 years old and 44 older participants stratified as participants 60-70 years old (n=24 and participants 71-84 years old (n=20. All underwent spatial navigation testing in the real-space human analog of the Morris Water Maze, which has the advantage of assessing separately allocentric and egocentric navigation and learning. Of the 8 consecutive trials, trials 2-8 were used to reduce bias by a rebound effect (more dramatic changes in performance between trials 1 and 2 relative to subsequent trials. The participants who were 71-84 years old (p< .001, but not those 60-70 years old, showed deficit in allocentric navigation compared to the young participants. There were no differences in egocentric navigation. All three groups showed spatial learning effect (p´s ≤.01. There were no gender differences in spatial navigation and learning. The linear regression limited to older participants showed linear (β=0.30, p=.045 and quadratic (β=0.30, p=.046 effect of age on allocentric navigation. There was no effect of age on egocentric navigation. These results demonstrate that navigation deficits in older age may be limited to allocentric navigation, whereas egocentric navigation and learning may remain preserved. This specific pattern of spatial navigation impairment may help differentiate normal aging from prodromal Alzheimer

  5. Tribological changes on SS304 stainless steel induced by nitrogen plasma immersion ion implantation with and without auxiliary heating

    International Nuclear Information System (INIS)

    In order to achieve quite thick treated layers with reasonable thickness uniformity in SS304 steel, the plasma immersion ion implantation (PIII) process was run in high-temperature, up to 350 deg. C, to induce high thermal diffusion but avoid the white layer formation. In these experiments, we heated the sample-holder with a shielded resistive wire properly wound around it and subjected the SS samples to nitrogen glow discharge PIII with relatively low voltages (10 kV) in different temperatures. We also treated the SS samples by the traditional PIII method, slowly increasing the high voltage pulse intensities, until 14 kV at the end of processing, reaching temperatures of up to 350 deg. C. These modes of treatments were compared with respect to nitrogen implantation profiles, X-ray diffraction, tribology and mechanical properties. X-ray diffraction results indicated a much higher efficiency of auxiliary heated PIII mode compared to the ordinary PIII. Very prominent γN peaks were observed for the first mode, indicating large concentration of nitrogen in thick layers, confirmed by the nitrogen profiles measured by GDOS and AES. Improved mechanical and tribological properties were obtained for SS304 samples treated by the PIII with auxiliary heating, more than for ordinary PIII. Hardness was enhanced by up to 2.77 times, as seen by nanoindentation tests.

  6. Tribological changes on SS304 stainless steel induced by nitrogen plasma immersion ion implantation with and without auxiliary heating

    Energy Technology Data Exchange (ETDEWEB)

    Mello, C.B., E-mail: carina@plasma.inpe.br [Laboratorio Associado de Plasma, INPE, Sao Jose dos Campos, SP (Brazil); Laboratorio Associado de Sensores e Materiais, INPE, Sao Jose dos Campos, SP (Brazil); Ueda, M. [Laboratorio Associado de Plasma, INPE, Sao Jose dos Campos, SP (Brazil); Lepienski, C.M. [Depto. de Fisica, Universidade Federal do Parana, Curitiba, PR (Brazil); Reuther, H. [Research Center Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Dresden (Germany)

    2009-12-15

    In order to achieve quite thick treated layers with reasonable thickness uniformity in SS304 steel, the plasma immersion ion implantation (PIII) process was run in high-temperature, up to 350 deg. C, to induce high thermal diffusion but avoid the white layer formation. In these experiments, we heated the sample-holder with a shielded resistive wire properly wound around it and subjected the SS samples to nitrogen glow discharge PIII with relatively low voltages (10 kV) in different temperatures. We also treated the SS samples by the traditional PIII method, slowly increasing the high voltage pulse intensities, until 14 kV at the end of processing, reaching temperatures of up to 350 deg. C. These modes of treatments were compared with respect to nitrogen implantation profiles, X-ray diffraction, tribology and mechanical properties. X-ray diffraction results indicated a much higher efficiency of auxiliary heated PIII mode compared to the ordinary PIII. Very prominent {gamma}{sub N} peaks were observed for the first mode, indicating large concentration of nitrogen in thick layers, confirmed by the nitrogen profiles measured by GDOS and AES. Improved mechanical and tribological properties were obtained for SS304 samples treated by the PIII with auxiliary heating, more than for ordinary PIII. Hardness was enhanced by up to 2.77 times, as seen by nanoindentation tests.

  7. Balancing direct and indirect sources of navigational information in a leaderless model of collective animal movement.

    Science.gov (United States)

    Codling, Edward A; Bode, Nikolai W F

    2016-04-01

    Navigation is an important movement process that enables individuals and groups of animals to find targets in space at different spatio-temporal scales. Earlier studies have shown how being in a group can confer navigational advantages to individuals, either through following more experienced leaders or through the pooling of many inaccurate compasses, a process known as the 'many wrongs principle'. However, the exact mechanisms for how information is transferred and used within the group in order to improve both individual- and group-level navigational performance are not fully understood. Here we explore the relative weighting that should be given to different sources of navigational information by an individual within a navigating group at each step of the movement process. Specifically, we consider a direct goal-oriented source of navigational information such as the individual׳s own imperfect knowledge of the target (a 'noisy compass') alongside two indirect sources of navigational information: the previous movement directions of neighbours in the group (social information) and, for the first time in this context, the previous movement direction of the individual (persistence). We assume that all individuals are equal in their abilities and that direct navigational information is prone to higher errors than indirect information. Using computer simulations, we show that in such situations giving a high weighting to either type of indirect navigational information can serve to significantly improve the navigation success of groups. Crucially, we also show that if the quality of social information is reduced, e.g. by an individual׳s limited cognitive abilities, the best navigational strategy for groups assigns a considerable weighting to persistence, a behaviour that is neither social, nor directly aimed at navigating. PMID:26801875

  8. A Corpus-Based Study on the Use of Past Tense Auxiliary "Be" in Argumentative Essays of Malaysian ESL Learners

    Science.gov (United States)

    Manokaran, Janaki; Ramalingam, Chithra; Adriana, Karen

    2013-01-01

    This research is a corpus-based study of secondary and college ESL Malaysian learner's written work by identifying and classifying the types of errors in the Past Tense Auxiliary "Be". This research studied the past tense auxiliary "be", types of past tense auxiliary "be" errors and frequency of past tense auxiliary…

  9. Analysis of a potential two phase flow instability in a PWR passive auxiliary feedwater system

    International Nuclear Information System (INIS)

    The APR+ incorporates a passive auxiliary feedwater system (PAFS). The PAFS is comprised of two separate mechanical divisions. Each division is a closed loop which is aligned to feed condensed water to its corresponding steam generator (SG), and is equipped with one passive condensation heat exchanger (PCHX), some associated isolation/drain/vent valves, check valves, instrumentation and control, and pipes. The PAFS is designed to start its operation after reactor trip and maintain its function of residual heat removal for 8 hours or longer without AC power or operator action, and to ensure a subsequent cooldown of RCS to the shutdown cooling entry conditions. During the PAFS operation mode, steam in the SG secondary side moves up due to buoyancy force and passes through the main steam line, and then flows into the PCHX where steam is condensed inside the tubes of which the outer wall surfaces are cooled by the water stored in a condensation cooling tank. The condensate is passively fed into the SG economizer by gravity. Because a natural circulation loop is susceptible to two phase flow instability, it is requisite to confirm the PAFS is designed adequately to avoid the potential challenges to its operational safety due to the instability. This paper addresses an analytical model for assessing if the loop has possible thermal and fluid mechanical characteristics which could lead to an undesirable unstable or oscillating water level in the APR+ PAFS

  10. Improvement on the auxiliary total artificial heart (ATAH) left chamber design.

    Science.gov (United States)

    Andrade, Aron; Fonseca, Jeison; Legendre, Daniel; Nicolosi, Denys; Biscegli, Jose; Pinotti, Marcos; Ohashi, Yukio; Nosé, Yukihiko

    2003-05-01

    The auxiliary total artificial heart (ATAH) is an electromechanically driven artificial heart with reduced dimensions, which is able to be implanted in the right thoracic or abdominal cavities of an average human patient without removing the natural heart or the heart neurohumoral inherent control mechanism for the arterial pressure. This device uses a brushless direct current motor and a mechanical actuator (roller screw) to move two diaphragms. The ATAH's beating frequency is regulated through the change of the left preload, based on Frank-Starling's law, assisting the native heart in obtaining adequate blood flow. The ATAH left and right stroke volumes are 38 ml and 34 ml, respectively, giving approximately 5 L/min of cardiac output at 160 bpm. Flow visualization studies were performed in critical areas on the ATAH left chamber. A closed circuit loop was used with water and glycerin (37%) at 25 degrees C. Amberlite particles (80 mesh) were illuminated by a 1 mm planar helium-neon laser light. With left mean preload fixed at 10 mm Hg and the afterload at 100 mm Hg, the heart rate varied from 60 to 200 bpm. Two porcine valves were used on the inlet and outlet ports. The flow pattern images were obtained using a color micro-camera and a video recorder. Subsequently, these images were digitized using a PC computer. A persistent stagnant flow was detected in the left chamber inlet port. After improvement on the left chamber design, this stagnant flow disappeared. PMID:12752207

  11. Seismic qualification of PWR plant auxiliary feedwater systems

    Energy Technology Data Exchange (ETDEWEB)

    Lu, S.C.; Tsai, N.C.

    1983-08-01

    The NRC Standard Review Plan specifies that the auxiliary feedwater (AFW) system of a pressurized water reactor (PWR) is a safeguard system that functions in the event of a Safe Shutdown Earthquake (SSE) to remove the decay heat via the steam generator. Only recently licensed PWR plants have an AFW system designed to the current Standard Review Plan specifications. The NRC devised the Multiplant Action Plan C-14 in order to make a survey of the seismic capability of the AFW systems of operating PWR plants. The purpose of this survey is to enable the NRC to make decisions regarding the need of requiring the licensees to upgrade the AFW systems to an SSE level of seismic capability. To implement the first phase of the C-14 plan, the NRC issued a Generic Letter (GL) 81-14 to all operating PWR licensees requesting information on the seismic capability of their AFW systems. This report summarizes Lawrence Livermore National Laboratory's efforts to assist the NRC in evaluating the status of seismic qualification of the AFW systems in 40 PWR plants, by reviewing the licensees' responses to GL 81-14.

  12. Practical auxiliary basis implementation of Rung 3.5 functionals.

    Science.gov (United States)

    Janesko, Benjamin G; Scalmani, Giovanni; Frisch, Michael J

    2014-07-21

    Approximate exchange-correlation functionals for Kohn-Sham density functional theory often benefit from incorporating exact exchange. Exact exchange is constructed from the noninteracting reference system's nonlocal one-particle density matrix γ(r(->), r(->)'). Rung 3.5 functionals attempt to balance the strengths and limitations of exact exchange using a new ingredient, a projection of γ(r(->), r(->)') onto a semilocal model density matrix γ(SL)(ρ(r(->)), ∇ρ(r(->)), r(->) - r(->)'). γSL depends on the electron density ρ(r(->) at reference point r(->), and is closely related to semilocal model exchange holes. We present a practical implementation of Rung 3.5 functionals, expanding the r(->) - r(->)' dependence of γSL in an auxiliary basis set. Energies and energy derivatives are obtained from 3D numerical integration as in standard semilocal functionals. We also present numerical tests of a range of properties, including molecular thermochemistry and kinetics, geometries and vibrational frequencies, and bandgaps and excitation energies. Rung 3.5 functionals typically provide accuracy intermediate between semilocal and hybrid approximations. Nonlocal potential contributions from γSL yield interesting successes and failures for band structures and excitation energies. The results enable and motivate continued exploration of Rung 3.5 functional forms. PMID:25053297

  13. Seismic qualification of PWR plant auxiliary feedwater systems

    International Nuclear Information System (INIS)

    The NRC Standard Review Plan specifies that the auxiliary feedwater (AFW) system of a pressurized water reactor (PWR) is a safeguard system that functions in the event of a Safe Shutdown Earthquake (SSE) to remove the decay heat via the steam generator. Only recently licensed PWR plants have an AFW system designed to the current Standard Review Plan specifications. The NRC devised the Multiplant Action Plan C-14 in order to make a survey of the seismic capability of the AFW systems of operating PWR plants. The purpose of this survey is to enable the NRC to make decisions regarding the need of requiring the licensees to upgrade the AFW systems to an SSE level of seismic capability. To implement the first phase of the C-14 plan, the NRC issued a Generic Letter (GL) 81-14 to all operating PWR licensees requesting information on the seismic capability of their AFW systems. This report summarizes Lawrence Livermore National Laboratory's efforts to assist the NRC in evaluating the status of seismic qualification of the AFW systems in 40 PWR plants, by reviewing the licensees' responses to GL 81-14

  14. A magnetorheological clutch for efficient automotive auxiliary device actuation

    Directory of Open Access Journals (Sweden)

    F. Bucchi

    2013-01-01

    Full Text Available In this paper the results of a project funded by Regione Toscana aimed at reducing the power absorption of auxiliary devices in vehicles are presented. In particular the design, testing and application of a magnetorheological clutch (MR is proposed, aimed at disengaging the vacuum pump, which draws in air from the power-brake booster chamber, in order to reduce the device power absorption. Several clutch preliminary studies done to choose the clutch geometry and the magnetic field supply are illustrated. The final choice consisted in an MR clutch with permanent magnet, which satisfied size, torque and fail-safe specifications. The clutch characteristics, in terms of torque versus slip, were obtained experimentally for three different clutch prototypes on an ad-hoc developed test bench.As result of a preliminary simulation, a comparison between the power absorption of a current production vacuum pump, an innovative vacuum pump and both vacuum pumps coupled with the MR clutch is presented. The New European Driving Cycle is considered for simulating the vacuum pump operation both in urban and highway driving. Results show that the use of the innovative vacuum pump reduces the device consumption of about 35%, whereas the use of MR clutch coupled with the innovative vacuum pump reduces it up to about 44% in urban driving and 50% in highway driving.

  15. Green Propulsion Auxiliary Power Unit Demonstration at MSFC

    Science.gov (United States)

    Robinson, Joel W.

    2014-01-01

    In 2012, the National Aeronautics & Space Administration (NASA) Space Technology Mission Directorate (STMD) began the process of building an integrated technology roadmap, including both technology pull and technology push strategies. Technology Area 1 (TA-01)1 for Launch Propulsion Systems is one of fourteen TAs that provide recommendations for the overall technology investment strategy and prioritization of NASA's space technology activities. Identified within TA-01 was the need for a green propulsion auxiliary power unit (APU) for hydraulic power by 2015. Engineers led by the author at the Marshall Space Flight Center (MSFC) have been evaluating green propellant alternatives and have begun the development of an APU test bed to demonstrate the feasibility of use. NASA has residual APU assets remaining from the retired Space Shuttle Program. Likewise, the F-16 Falcon fighter jet also uses an Emergency Power Unit (EPU) that has similar characteristics to the NASA hardware. Both EPU and APU components have been acquired for testing at MSFC. This paper will summarize the status of the testing efforts of green propellant from the Air Force Research Laboratory (AFRL) propellant AFM315E based on hydroxyl ammonium nitrate (HAN) with these test assets.

  16. Emergency Navigation without an Infrastructure

    Directory of Open Access Journals (Sweden)

    Erol Gelenbe

    2014-08-01

    Full Text Available Emergency navigation systems for buildings and other built environments, such as sport arenas or shopping centres, typically rely on simple sensor networks to detect emergencies and, then, provide automatic signs to direct the evacuees. The major drawbacks of such static wireless sensor network (WSN-based emergency navigation systems are the very limited computing capacity, which makes adaptivity very difficult, and the restricted battery power, due to the low cost of sensor nodes for unattended operation. If static wireless sensor networks and cloud-computing can be integrated, then intensive computations that are needed to determine optimal evacuation routes in the presence of time-varying hazards can be offloaded to the cloud, but the disadvantages of limited battery life-time at the client side, as well as the high likelihood of system malfunction during an emergency still remain. By making use of the powerful sensing ability of smart phones, which are increasingly ubiquitous, this paper presents a cloud-enabled indoor emergency navigation framework to direct evacuees in a coordinated fashion and to improve the reliability and resilience for both communication and localization. By combining social potential fields (SPF and a cognitive packet network (CPN-based algorithm, evacuees are guided to exits in dynamic loose clusters. Rather than relying on a conventional telecommunications infrastructure, we suggest an ad hoc cognitive packet network (AHCPN-based protocol to adaptively search optimal communication routes between portable devices and the network egress nodes that provide access to cloud servers, in a manner that spares the remaining battery power of smart phones and minimizes the time latency. Experimental results through detailed simulations indicate that smart human motion and smart network management can increase the survival rate of evacuees and reduce the number of drained smart phones in an evacuation process.

  17. 33 CFR 162.240 - Tongass Narrows, Alaska; navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Tongass Narrows, Alaska; navigation. 162.240 Section 162.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.240...

  18. 33 CFR 401.97 - Closing procedures and ice navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Closing procedures and ice navigation. 401.97 Section 401.97 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Navigation...

  19. Determination of the thermal loadings affecting the auxiliary lines of the reactor coolant system in French PWR plants

    International Nuclear Information System (INIS)

    The various incidents, imputed to thermal fatigue, which occurred throughout the world on the auxiliary lines of Reactor Coolant System (SIS, RHR, CVC), led EDF to urge a research program in order to determine the origins and the consequences of these problems for the French nuclear power plants. In 1992, following the crossing crack discovered at Dampierre 2 on the un-isolable part of a Safety Injection System pipe, a program of instrumentation was defined and is described in this paper. Among the objectives, two of the principal goals were to determine the thermal loadings really supported by the various lines and to highlight the thermal hydraulic phenomena affecting them. Indeed, in order to explain the discovered damages, it was essential to know the real thermal loadings to compare them with those of design and to carry out mechanical calculations of resistance to thermal fatigue. The instrumentations installed on the 900 MW units enabled to check the resistance with the fatigue of all the auxiliary lines in spite of significant differences between the real loadings and those envisaged at the design. They contributed to the knowledge improvement on the local thermal hydraulic phenomena but the incidents at Dampierre 1 showed that this knowledge is still imperfect. The results of these instrumentations are also used for the design of the future units by the use of the feedback of several cycles of acquisition on the 900 MW units, but also 1300 MW and 1450 MW since similar instrumentations were installed on the auxiliary lines in Golfech 2 and Chooz B1

  20. An experimental study on the validation of cooling capability for the Passive Auxiliary Feedwater System (PAFS) condensation heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seok; Bae, Byoung-Uhn; Cho, Yun-Je; Park, Yu-Sun; Kang, Kyoung-Ho [Thermal Hydraulics Safety Research Division, Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of); Yun, Byong-Jo, E-mail: bjyun@pusan.ac.kr [School of Mechanical Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan, 609-735 (Korea, Republic of)

    2013-07-15

    Highlights: • PAFS is designed to replace a conventional active Auxiliary Feedwater System. • A SET facility is constructed for investigating the thermal-hydraulic behavior of the PAFS system. • Experimental results proved that the PCHX design satisfied the heat removal requirements. • Results of the MARS-KS code provided a conservative prediction of the heat transfer phenomena. -- Abstract: The Passive Auxiliary Feedwater System (PAFS) is one of the advanced safety features adopted in the Advanced Power Reactor Plus (APR+). PAFS is designed to replace a conventional active Auxiliary Feedwater System (AFWS). The PAFS cools down the steam generator secondary side and eventually removes the decay heat from the reactor core by a natural circulation mechanism, i.e., condensing steam in nearly horizontal U-tubes submerged inside a pool. A separate effect test facility was constructed with the aim of validating the cooling and operational performance of the PAFS. The PAFS Condensing Heat Removal Assessment Loop (PASCAL) was constructed by simulating a single Passive Condensation Heat Exchanger (PCHX) tube submerged in the Passive Condensation Cooling Tank (PCCT) according to the volumetric scaling methodology. Quasi-steady state (SS) test cases and PCCT level decrease (PL) were sequentially performed with the steam generator heater power set at 540 kW to investigate the thermal-hydraulic behavior of the PAFS system and the characteristics of the natural circulation in the loop. The experimental results proved that the current PCHX design satisfied the heat removal requirement for cooling down the reactor core during an accident condition. Therefore, the PAFS can replace a conventional active AFWS in the APR+ by utilizing the two-phase natural circulation flow. The Multi-dimensional Analysis of Reactor Safety, KINS Standard Version (MARS-KS), a thermal hydraulic system analysis code, was utilized to validate the present experimental data. The results of the MARS

  1. An experimental study on the validation of cooling capability for the Passive Auxiliary Feedwater System (PAFS) condensation heat exchanger

    International Nuclear Information System (INIS)

    Highlights: • PAFS is designed to replace a conventional active Auxiliary Feedwater System. • A SET facility is constructed for investigating the thermal-hydraulic behavior of the PAFS system. • Experimental results proved that the PCHX design satisfied the heat removal requirements. • Results of the MARS-KS code provided a conservative prediction of the heat transfer phenomena. -- Abstract: The Passive Auxiliary Feedwater System (PAFS) is one of the advanced safety features adopted in the Advanced Power Reactor Plus (APR+). PAFS is designed to replace a conventional active Auxiliary Feedwater System (AFWS). The PAFS cools down the steam generator secondary side and eventually removes the decay heat from the reactor core by a natural circulation mechanism, i.e., condensing steam in nearly horizontal U-tubes submerged inside a pool. A separate effect test facility was constructed with the aim of validating the cooling and operational performance of the PAFS. The PAFS Condensing Heat Removal Assessment Loop (PASCAL) was constructed by simulating a single Passive Condensation Heat Exchanger (PCHX) tube submerged in the Passive Condensation Cooling Tank (PCCT) according to the volumetric scaling methodology. Quasi-steady state (SS) test cases and PCCT level decrease (PL) were sequentially performed with the steam generator heater power set at 540 kW to investigate the thermal-hydraulic behavior of the PAFS system and the characteristics of the natural circulation in the loop. The experimental results proved that the current PCHX design satisfied the heat removal requirement for cooling down the reactor core during an accident condition. Therefore, the PAFS can replace a conventional active AFWS in the APR+ by utilizing the two-phase natural circulation flow. The Multi-dimensional Analysis of Reactor Safety, KINS Standard Version (MARS-KS), a thermal hydraulic system analysis code, was utilized to validate the present experimental data. The results of the MARS

  2. Youth Mobilisation as Social Navigation

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2010-01-01

    This article sheds light on the mobilisation of young people into conflict. It argues that warfare constitutes a terrain of possibility for urban youth in Guinea‑Bissau, and shows how they navigate war as an event by tactically manoeuvring within the social ties and options that arise in such sit...

  3. S-glutathionylation of an auxiliary subunit confers redox sensitivity to Kv4 channel inactivation.

    Directory of Open Access Journals (Sweden)

    Henry H Jerng

    Full Text Available Reactive oxygen species (ROS regulate ion channels, modulate neuronal excitability, and contribute to the etiology of neurodegenerative disorders. ROS differentially suppress fast "ball-and-chain" N-type inactivation of cloned Kv1 and Kv3 potassium channels but not of Kv4 channels, likely due to a lack of reactive cysteines in Kv4 N-termini. Recently, we discovered that N-type inactivation of Kv4 channel complexes can be independently conferred by certain N-terminal variants of Kv4 auxiliary subunits (DPP6a, DPP10a. Here, we report that both DPP6a and DPP10a, like Kv subunits with redox-sensitive N-type inactivation, contain a highly conserved cysteine in their N-termini (Cys-13. To test if N-type inactivation mediated by DPP6a or DPP10a is redox sensitive, Xenopus oocyte recordings were performed to examine the effects of two common oxidants, tert-butyl hydroperoxide (tBHP and diamide. Both oxidants markedly modulate DPP6a- or DPP10a-conferred N-type inactivation of Kv4 channels, slowing the overall inactivation and increasing the peak current. These functional effects are fully reversed by the reducing agent dithiothreitol (DTT and appear to be due to a selective modulation of the N-type inactivation mediated by these auxiliary subunits. Mutation of DPP6a Cys-13 to serine eliminated the tBHP or diamide effects, confirming the importance of Cys-13 to the oxidative regulation. Biochemical studies designed to elucidate the underlying molecular mechanism show no evidence of protein-protein disulfide linkage formation following cysteine oxidation. Instead, using a biotinylated glutathione (BioGEE reagent, we discovered that oxidation by tBHP or diamide leads to S-glutathionylation of Cys-13, suggesting that S-glutathionylation underlies the regulation of fast N-type inactivation by redox. In conclusion, our studies suggest that Kv4-based A-type current in neurons may show differential redox sensitivity depending on whether DPP6a or DPP10a is highly

  4. S-glutathionylation of an auxiliary subunit confers redox sensitivity to Kv4 channel inactivation.

    Science.gov (United States)

    Jerng, Henry H; Pfaffinger, Paul J

    2014-01-01

    Reactive oxygen species (ROS) regulate ion channels, modulate neuronal excitability, and contribute to the etiology of neurodegenerative disorders. ROS differentially suppress fast "ball-and-chain" N-type inactivation of cloned Kv1 and Kv3 potassium channels but not of Kv4 channels, likely due to a lack of reactive cysteines in Kv4 N-termini. Recently, we discovered that N-type inactivation of Kv4 channel complexes can be independently conferred by certain N-terminal variants of Kv4 auxiliary subunits (DPP6a, DPP10a). Here, we report that both DPP6a and DPP10a, like Kv subunits with redox-sensitive N-type inactivation, contain a highly conserved cysteine in their N-termini (Cys-13). To test if N-type inactivation mediated by DPP6a or DPP10a is redox sensitive, Xenopus oocyte recordings were performed to examine the effects of two common oxidants, tert-butyl hydroperoxide (tBHP) and diamide. Both oxidants markedly modulate DPP6a- or DPP10a-conferred N-type inactivation of Kv4 channels, slowing the overall inactivation and increasing the peak current. These functional effects are fully reversed by the reducing agent dithiothreitol (DTT) and appear to be due to a selective modulation of the N-type inactivation mediated by these auxiliary subunits. Mutation of DPP6a Cys-13 to serine eliminated the tBHP or diamide effects, confirming the importance of Cys-13 to the oxidative regulation. Biochemical studies designed to elucidate the underlying molecular mechanism show no evidence of protein-protein disulfide linkage formation following cysteine oxidation. Instead, using a biotinylated glutathione (BioGEE) reagent, we discovered that oxidation by tBHP or diamide leads to S-glutathionylation of Cys-13, suggesting that S-glutathionylation underlies the regulation of fast N-type inactivation by redox. In conclusion, our studies suggest that Kv4-based A-type current in neurons may show differential redox sensitivity depending on whether DPP6a or DPP10a is highly expressed

  5. PNP: mining of profile navigational patterns

    Science.gov (United States)

    Li, Hua-Fu; Shan, Man-Kwan

    2002-03-01

    Web usage mining is a key knowledge discovery research and as such has been well researched. So far, this research has focused mainly on databases containing access log data only. However, many real-world databases contain users profile data and current solutions for this situation are still insufficient. In this paper we have a large database containing of user profile information together with user web-pages navigation patterns. The user profile data includes quantitative attributes, such as salary or age, and categorical attributes, such as sex or marital status. We introduce the concept of profile navigation patterns, which discusses the problem of relating user profile information to navigational behavior. An example of such profile navigation pattern might be 20% of married people between age 25 and 30 have the similar navigational behavior , where a, c, h, i, l are web pages in a web site. The navigation patterns may contain the generic traversal behavior, e.g. trend to backward moves, cycles etc. The objective of mining profile navigation patterns is to identify browser profile for web personalization. We give an algorithm for mining such profile navigation patterns. Our method (algorithm PNP) can discover profile navigation patterns efficiently. We also present new inclination measurements to identify the interesting profile navigational patterns. Experimental results show the efficiency and scalability of PNP.

  6. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207.169 Section 207.169 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE...

  7. Intelligent navigation and multivehicle coordination

    Science.gov (United States)

    McKay, Mark D.; Anderson, Matthew O.; Kinoshita, Robert A.; Flann, Nicholas S.

    1999-07-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) and Utah State University's Center for Self-Organizing and Intelligent Systems have developed a team of autonomous robotic vehicles. This paper discusses the development of a strategy that uses a sophisticated, highly intelligent sensor platform to allow centralized coordination between smaller and inexpensive robots. The three components of the multi-agent cooperative scheme are small-scale robots, large-scale robots, and the central control station running a mission and path- planning software. The smaller robots are used for activities where the probability of loss increases, such as Unexploded Ordnance (UXO) or mine detonation. The research is aimed at building simple, inexpensive multi-agent vehicles and an intelligent navigation and multi-vehicle coordination system suitable for UXO, environmental remediation or mine detection. These simplified robots are capable of conducting hunting missions using low-cost positioning sensors and intelligent algorithms. Additionally, a larger sensor-rich intelligent system capable of transporting smaller units to outlying remote sites has been developed. The larger system interfaces to the central control station and provides navigation assistance to multiple low-cost vehicles. Finally, mission and path-planning software serves as the operator control unit, allowing central data collection, map creation and tracking, and an interface to the larger system as well as each smaller unit. The power of this scheme is the ability to scale to the appropriate level for the complexity of the mission.

  8. Optic flow and autonomous navigation.

    Science.gov (United States)

    Campani, M; Giachetti, A; Torre, V

    1995-01-01

    Many animals, especially insects, compute and use optic flow to control their motion direction and to avoid obstacles. Recent advances in computer vision have shown that an adequate optic flow can be computed from image sequences. Therefore studying whether artificial systems, such as robots, can use optic flow for similar purposes is of particular interest. Experiments are reviewed that suggest the possible use of optic flow for the navigation of a robot moving in indoor and outdoor environments. The optic flow is used to detect and localise obstacles in indoor scenes, such as corridors, offices, and laboratories. These routines are based on the computation of a reduced optic flow. The robot is usually able to avoid large obstacles such as a chair or a person. The avoidance performances of the proposed algorithm critically depend on the optomotor reaction of the robot. The optic flow can be used to understand the ego-motion in outdoor scenes, that is, to obtain information on the absolute velocity of the moving vehicle and to detect the presence of other moving objects. A critical step is the correction of the optic flow for shocks and vibrations present during image acquisition. The results obtained suggest that optic flow can be successfully used by biological and artificial systems to control their navigation. Moreover, both systems require fast and accurate optomotor reactions and need to compensate for the instability of the viewed world. PMID:7617428

  9. Spatial Database Modeling for Indoor Navigation Systems

    Science.gov (United States)

    Gotlib, Dariusz; Gnat, Miłosz

    2013-12-01

    For many years, cartographers are involved in designing GIS and navigation systems. Most GIS applications use the outdoor data. Increasingly, similar applications are used inside buildings. Therefore it is important to find the proper model of indoor spatial database. The development of indoor navigation systems should utilize advanced teleinformation, geoinformatics, geodetic and cartographical knowledge. The authors present the fundamental requirements for the indoor data model for navigation purposes. Presenting some of the solutions adopted in the world they emphasize that navigation applications require specific data to present the navigation routes in the right way. There is presented original solution for indoor data model created by authors on the basis of BISDM model. Its purpose is to expand the opportunities for use in indoor navigation.

  10. Autonomous Robot Navigation based on Visual Landmarks

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    autonomous navigation and self-localization using automatically selected landmarks. The thesis investigates autonomous robot navigation and proposes a new method which benefits from the potential of the visual sensor to provide accuracy and reliability to the navigation process while relying on naturally...... update of the estimated robot position while the robot is moving. In order to make the system autonomous, both acquisition and observation of landmarks have to be carried out automatically. The thesis consequently proposes a method for learning and navigation of a working environment and it explores......The use of landmarks for robot navigation is a popular alternative to having a geometrical model of the environment through which to navigate and monitor self-localization. If the landmarks are defined as special visual structures already in the environment then we have the possibility of fully...

  11. INS/CNS/GNSS integrated navigation technology

    CERN Document Server

    Quan, Wei; Gong, Xiaolin; Fang, Jiancheng

    2015-01-01

    This book not only introduces the principles of INS, CNS and GNSS, the related filters and semi-physical simulation, but also systematically discusses the key technologies needed for integrated navigations of INS/GNSS, INS/CNS, and INS/CNS/GNSS, respectively. INS/CNS/GNSS integrated navigation technology has established itself as an effective tool for precise positioning navigation, which can make full use of the complementary characteristics of different navigation sub-systems and greatly improve the accuracy and reliability of the integrated navigation system. The book offers a valuable reference guide for graduate students, engineers and researchers in the fields of navigation and its control. Dr. Wei Quan, Dr. Jianli Li, Dr. Xiaolin Gong and Dr. Jiancheng Fang are all researchers at the Beijing University of Aeronautics and Astronautics.

  12. Indoor inertial waypoint navigation for the blind.

    Science.gov (United States)

    Riehle, Timothy H; Anderson, Shane M; Lichter, Patrick A; Whalen, William E; Giudice, Nicholas A

    2013-01-01

    Indoor navigation technology is needed to support seamless mobility for the visually impaired. This paper describes the construction and evaluation of an inertial dead reckoning navigation system that provides real-time auditory guidance along mapped routes. Inertial dead reckoning is a navigation technique coupling step counting together with heading estimation to compute changes in position at each step. The research described here outlines the development and evaluation of a novel navigation system that utilizes information from the mapped route to limit the problematic error accumulation inherent in traditional dead reckoning approaches. The prototype system consists of a wireless inertial sensor unit, placed at the users' hip, which streams readings to a smartphone processing a navigation algorithm. Pilot human trials were conducted assessing system efficacy by studying route-following performance with blind and sighted subjects using the navigation system with real-time guidance, versus offline verbal directions. PMID:24110904

  13. Pb-17Li auxiliary and purification systems: design of the auxiliary Pb-Li loop for helium cooled lithium lead test blanket module

    International Nuclear Information System (INIS)

    This technical report describes the Pb-17Li auxiliary system proposed for Helium Cooled Lithium Lead (HCLL) Test Blanket Module (TBM) that will be installed and tested in ITER. The Pb-17Li auxiliary should ensure feeding and circulation of Pb-17Li liquid metal in this breeding blanket and removal of tritium produced by a nuclear reaction in TBM. The container with the Pb-17Li auxiliary system (dimensions HxLxW: 2.315 m x 2.19 m x 1.6 m) will be placed as close as possible to the TBM to prevent tritium permeation from the connection piping. The report describes developed design of the Pb-17Li auxiliary system that is from the functional point of view divided into the following parts: main circuit, detritization unit and cold trap, dosing and sampling systems, heating and cooling systems, and shielding and insulation. The Pb-17Li circuit is a closed loop with forced circulation of Pb-17Li. From the tank that, at the same time, is a Pb-17Li storage tank, liquid metal is pumped into the TBM where tritium is produced. The flow velocity in the Pb-17Li system will be controlled in the range of 0.1 to 1 kg/s. Pb-17Li outlet temperature from the TBM is 550 deg C. Tritium is removed from Pb-17Li in a detritiation unit. Corrosion products and impurities are removed in a cold trap. Design of the key system components as well as their structure material are described. The technical report determines and describes the Pb-17Li auxiliary system operating modes such as filling, start-up, operation at nominal parameters, shut-down, emergency operation and sampling. Also, the limits and terms of the Pb-17Li auxiliary system safe operation are defined. Requirements for the Pb-17Li auxiliary system installation, testing and maintenance are discussed. In conclusion, recommendations for further developments of the Pb-17Li auxiliary system are proposed. (author)

  14. Practical auxiliary basis implementation of Rung 3.5 functionals

    Energy Technology Data Exchange (ETDEWEB)

    Janesko, Benjamin G., E-mail: b.janesko@tcu.edu [Department of Chemistry, Texas Christian University, Fort Worth, Texas 76129 (United States); Scalmani, Giovanni; Frisch, Michael J. [Gaussian, Inc., 340 Quinnipiac St., Bldg. 40, Wallingford, Connecticut 06492 (United States)

    2014-07-21

    Approximate exchange-correlation functionals for Kohn-Sham density functional theory often benefit from incorporating exact exchange. Exact exchange is constructed from the noninteracting reference system's nonlocal one-particle density matrix γ(r{sup -vector},r{sup -vector}′). Rung 3.5 functionals attempt to balance the strengths and limitations of exact exchange using a new ingredient, a projection of γ(r{sup -vector},r{sup -vector} ′) onto a semilocal model density matrix γ{sub SL}(ρ(r{sup -vector}),∇ρ(r{sup -vector}),r{sup -vector}−r{sup -vector} ′). γ{sub SL} depends on the electron density ρ(r{sup -vector}) at reference point r{sup -vector}, and is closely related to semilocal model exchange holes. We present a practical implementation of Rung 3.5 functionals, expanding the r{sup -vector}−r{sup -vector} ′ dependence of γ{sub SL} in an auxiliary basis set. Energies and energy derivatives are obtained from 3D numerical integration as in standard semilocal functionals. We also present numerical tests of a range of properties, including molecular thermochemistry and kinetics, geometries and vibrational frequencies, and bandgaps and excitation energies. Rung 3.5 functionals typically provide accuracy intermediate between semilocal and hybrid approximations. Nonlocal potential contributions from γ{sub SL} yield interesting successes and failures for band structures and excitation energies. The results enable and motivate continued exploration of Rung 3.5 functional forms.

  15. Green Propulsion Auxiliary Power Unit Demonstration at MSFC

    Science.gov (United States)

    Robinson, Joel W.; Beckel, Steve

    2014-01-01

    In 2012, the National Aeronautics & Space Administration (NASA) Space Technology Mission Directorate (STMD) began the process of building an integrated technology roadmap, including both technology pull and technology push strategies. Technology Area 1 (TA-01) for Launch Propulsion Systems is one of fourteen TA's that provide recommendations for the overall technology investment strategy and prioritization of NASA's space technology activities. Identified within TA-01 was the need for a green propulsion auxiliary power unit (APU) for hydraulic power by 2015. Engineers led by the author at the Marshall Space Flight Center (MSFC) have been evaluating green propellant alternatives and have begun the development of an APU testbed to demonstrate the feasibility of use. NASA has residual APU assets remaining from the retired Space Shuttle Program. Likewise, the F-16 Falcon fighter jet also uses an Emergency Power Unit (EPU) that has similar characteristics to the NASA hardware. Both EPU's and APU components have been acquired for testing at MSFC. In concert with this effort, ATK has been developing green propellant technology based on the Swedish Space Corp ECAPS LMP-103S propellant. Propellant blending and test facilities have been established at ATK's Elkton MD facility with the intent to provide suitable propellant blends for application to green APU systems as well as thrusters. This paper will summarize the status of the testing efforts with ATK for use of the green propellant LMP-103S based on ammonium dinitramide and use of the Air Force Research Laboratory (AFRL) propellant AF-M315E based on hydroxyl ammonium nitrate with these test assets.

  16. Compact propane fuel processor for auxiliary power unit application

    Science.gov (United States)

    Dokupil, M.; Spitta, C.; Mathiak, J.; Beckhaus, P.; Heinzel, A.

    With focus on mobile applications a fuel cell auxiliary power unit (APU) using liquefied petroleum gas (LPG) is currently being developed at the Centre for Fuel Cell Technology (Zentrum für BrennstoffzellenTechnik, ZBT gGmbH). The system is consisting of an integrated compact and lightweight fuel processor and a low temperature PEM fuel cell for an electric power output of 300 W. This article is presenting the current status of development of the fuel processor which is designed for a nominal hydrogen output of 1 k Wth,H2 within a load range from 50 to 120%. A modular setup was chosen defining a reformer/burner module and a CO-purification module. Based on the performance specifications, thermodynamic simulations, benchmarking and selection of catalysts the modules have been developed and characterised simultaneously and then assembled to the complete fuel processor. Automated operation results in a cold startup time of about 25 min for nominal load and carbon monoxide output concentrations below 50 ppm for steady state and dynamic operation. Also fast transient response of the fuel processor at load changes with low fluctuations of the reformate gas composition have been achieved. Beside the development of the main reactors the transfer of the fuel processor to an autonomous system is of major concern. Hence, concepts for packaging have been developed resulting in a volume of 7 l and a weight of 3 kg. Further a selection of peripheral components has been tested and evaluated regarding to the substitution of the laboratory equipment.

  17. Ocean Surface Topography Mission (OSTM) /Jason-2: Auxiliary Files (NODC Accession 0044983)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession contains the data descriptions for the OSTM/Jason-2 Auxiliary data files, which is served through the NOAA/NESDIS Comprehensive Large Array-data...

  18. [Laser navigation guided cleft lip repair].

    Science.gov (United States)

    Bing, Shi

    2016-06-01

    A new method using the ideal mid-facial line as the navigating reference was introduced to improve the outcome of cleft lip repair. Using the verticle coordinate crossing the middle point of the intercanthus line, surgeons could observe and correct the distortion of the fine structures in labial-nasal area. This laser projecting mid-facial-line navigation was repeatable, while not interfere the operating. In conclusion, generalizing laser navigation is a valuable supplementary for cleft lip repair. PMID:27526442

  19. Konzeption und Implementierung eines Quellcode-Navigators

    OpenAIRE

    Lu, Leiqin

    2004-01-01

    The Bauhaus project supports program understanding on both architectural level and source code level, which requires a graphical user interface tool for source code navigation. In this thesis a source code navigator is designed and implemented as part of the Bauhaus toolkit. The source code navigator cooperates with other tools in the Bauhaus toolkit. In particular, it is fully integrated with Gravis, the tool for architectural view, to provide an integrated environment for program unders...

  20. Global navigation satellite systems and their applications

    CERN Document Server

    Madry, Scott

    2015-01-01

    Dr. Madry, one of the world's leading experts in the field, provides in a condensed form a quick yet comprehensive overview of satellite navigation. This book concisely addresses the latest technology, the applications, the regulatory issues, and the strategic implications of satellite navigation systems. This assesses the strengths and weaknesses of satellite navigation networks and review of all the various national systems now being deployed and the motivation behind the proliferation of these systems.

  1. Research on integrated navigation method for AUV

    Institute of Scientific and Technical Information of China (English)

    GUO Zhen; SUN Feng

    2005-01-01

    The principles of the SINS/DVL integrated navigation system are introduced, and the compass status accuracy is compared. When the heading is changed, the dead reckoning algorithm using the heading information of the SINS (Strapdown inertial navigation systems) and DVL (doppler velocity log) is adopted to substitute the SINS/DVL integrated system. The simulation results show that the method can improve the accuracy of integrated navigation system when AUV (autonomous underwater vehicle) is in motion.

  2. Memory consolidation of landmarks in good navigators.

    Science.gov (United States)

    Janzen, Gabriele; Jansen, Clemens; van Turennout, Miranda

    2008-01-01

    Landmarks play an important role in successful navigation. To successfully find your way around an environment, navigationally relevant information needs to be stored and become available at later moments in time. Evidence from functional magnetic resonance imaging (fMRI) studies shows that the human parahippocampal gyrus encodes the navigational relevance of landmarks. In the present event-related fMRI experiment, we investigated memory consolidation of navigationally relevant landmarks in the medial temporal lobe after route learning. Sixteen right-handed volunteers viewed two film sequences through a virtual museum with objects placed at locations relevant (decision points) or irrelevant (nondecision points) for navigation. To investigate consolidation effects, one film sequence was seen in the evening before scanning, the other one was seen the following morning, directly before scanning. Event-related fMRI data were acquired during an object recognition task. Participants decided whether they had seen the objects in the previously shown films. After scanning, participants answered standardized questions about their navigational skills, and were divided into groups of good and bad navigators, based on their scores. An effect of memory consolidation was obtained in the hippocampus: Objects that were seen the evening before scanning (remote objects) elicited more activity than objects seen directly before scanning (recent objects). This increase in activity in bilateral hippocampus for remote objects was observed in good navigators only. In addition, a spatial-specific effect of memory consolidation for navigationally relevant objects was observed in the parahippocampal gyrus. Remote decision point objects induced increased activity as compared with recent decision point objects, again in good navigators only. The results provide initial evidence for a connection between memory consolidation and navigational ability that can provide a basis for successful

  3. Cognitive adaptations for gathering-related navigation in humans

    Science.gov (United States)

    Krasnow, Max M.; Truxaw, Danielle; Gaulin, Steven J.C.; New, Joshua; Ozono, Hiroki; Uono, Shota; Ueno, Taiji; Minemoto, Kazusa

    2013-01-01

    Current research increasingly suggests that spatial cognition in humans is accomplished by many specialized mechanisms, each designed to solve a particular adaptive problem. A major adaptive problem for our hominin ancestors, particularly females, was the need to efficiently gather immobile foods which could vary greatly in quality, quantity, spatial location and temporal availability. We propose a cognitive model of a navigational gathering adaptation in humans and test its predictions in samples from the US and Japan. Our results are uniformly supportive: the human mind appears equipped with a navigational gathering adaptation that encodes the location of gatherable foods into spatial memory. This mechanism appears to be chronically active in women and activated under explicit motivation in men. PMID:23833551

  4. Robotics_MobileRobot Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Robots and rovers exploring planets need to autonomously navigate to specified locations. Advanced Scientific Concepts, Inc. (ASC) and the University of Minnesota...

  5. Lunar Autonomous Automatic Surface Navigation System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA GRC Laboratory need for navigation capabilities to provide location awareness, precision position fixing, best heading, and traverse path...

  6. Navigation and Ancillary Information Facility's SPICE

    Data.gov (United States)

    National Aeronautics and Space Administration — The Navigation and Ancillary Information Facility (NAIF), acting under the directions of NASA's Planetary Science Division, has built an information system named...

  7. Hybrid Guidance System for Relative Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA architectures and missions will involve many distributed platforms that must work together. This in turn requires guidance, navigation and control...

  8. Auxiliary heating of a theta-pinch plasma by radial magnetoacoustic standing waves

    International Nuclear Information System (INIS)

    Auxiliary heating of a linear theta-pinch plasma column by an externally driven radial magnetoacoustic oscillation has been experimentally investigated. The axial field of the theta pinch was modulated in time at the frequency of the plasma's fundamental radial magnetoacoustic oscillation. The dissipation in the plasma column was sufficient to transfer into the plasma at least 9% of the energy stored in the auxiliary capacitor bank used to drive the oscillation

  9. Simulation of the effect of auxiliary ties used in the construction of Mallorca Cathedral

    OpenAIRE

    Bourgeois, Julien

    2013-01-01

    The thesis is oriented on the study of Mallorca Cathedral taking into account its construction process and, particularly, the influence of iron ties used as auxiliary devices during the construction. Some previous studies (Roca et al., 2013, 2012) have presented some possible hypotheses about the construction process of this gothic cathedral. This study complements the previous results by considering the possibility of the adoption of auxiliary ties, since some evidences of their ...

  10. Integral effect test on operational performance of the PAFS (Passive Auxiliary Feedwater System) for a FLB (Feedwater Line Break) accident

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Byoung Uhn; Kim, Seok; Park, Yu Sun; Kim, Bok Deuk; Kang, Kyoung Ho [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    PAFS (Passive Auxiliary Feedwater System) is one of the advanced safety features adopted in the APR+, which is intended to completely replace a conventional active auxiliary feedwater system. It cools down the steam generator secondary side and eventually removes the decay heat from the reactor core by adopting a natural convection mechanism; i.e., condensing steam in the PCHX (Passive Condensation Heat Exchanger) submerged inside the PCCT (Passive Condensate Cooling Tank). The test facility, ATLAS PAFS, was constructed to experimentally investigate the thermal hydraulic behavior in the primary and secondary systems of the APR+ during the transient when the PAFS is actuated. Among the anticipated accidents with the PAFS actuation, the FLB (Feedwater Line Break) was considered as the most important accident in evaluating the cooling capability of the PAFS, during the development of PIRT (Phenomena Identification and Ranking Table) of the PAFS. In this study, the PAFS FLB EC 01 test was performed to simulate a break on the pipe connected to the SG 1 economizer, which was analyzed as the most severe case in the APR+ SSAR (Standard Safety Analysis Report). The main objectives of this test were not only to provide physical insight into the system response of the APR+ during the FLB accident but also to produce an integral effect test data to validate a thermal hydraulic safety analysis code.

  11. Integral effect test on operational performance of the PAFS (Passive Auxiliary Feedwater System) for a FLB (Feedwater Line Break) accident

    International Nuclear Information System (INIS)

    PAFS (Passive Auxiliary Feedwater System) is one of the advanced safety features adopted in the APR+, which is intended to completely replace a conventional active auxiliary feedwater system. It cools down the steam generator secondary side and eventually removes the decay heat from the reactor core by adopting a natural convection mechanism; i.e., condensing steam in the PCHX (Passive Condensation Heat Exchanger) submerged inside the PCCT (Passive Condensate Cooling Tank). The test facility, ATLAS PAFS, was constructed to experimentally investigate the thermal hydraulic behavior in the primary and secondary systems of the APR+ during the transient when the PAFS is actuated. Among the anticipated accidents with the PAFS actuation, the FLB (Feedwater Line Break) was considered as the most important accident in evaluating the cooling capability of the PAFS, during the development of PIRT (Phenomena Identification and Ranking Table) of the PAFS. In this study, the PAFS FLB EC 01 test was performed to simulate a break on the pipe connected to the SG 1 economizer, which was analyzed as the most severe case in the APR+ SSAR (Standard Safety Analysis Report). The main objectives of this test were not only to provide physical insight into the system response of the APR+ during the FLB accident but also to produce an integral effect test data to validate a thermal hydraulic safety analysis code

  12. Collective Ignorance? A Critical Investigation of Social Navigation Rating Techniques

    OpenAIRE

    2007-01-01

    The usage of collaborative filtering mechanisms has become widespread on the web. But how reliable are such recommendation systems as a basis for making out choices? This thesis starts by compiling a list of known weaknesses of rating scales and written reviews, based on existing work within the field of social navigation and a few other disciplines. Four Norwegian web sites, all implementing collaborative filtering techniques, are then analyzed in relation to the compilation of known weaknes...

  13. Recognising isolated words for mobile robot navigation control

    OpenAIRE

    Zuleika Alezones - Campos; Yeison Baquero-Romero; HenrryBorrero-Guerrero; Marcelo Becker

    2012-01-01

    AbstractUsing computational tools facilitating bio-inspired models has led to developing a system for characterising voice commands for controlling a prototype hexapod mobile robot’s navigation. A software subsystem was set up, as well as another mechanical and electronic subsystem. The software subsystem consisted of a prototype programme written in Java consisting of five modules (obtaining the spoken signal, extracting characteristics, comparing characteristics, defining com-mands for tran...

  14. Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Y.; Wang, W. X.; LeBlanc, B. P.; Guttenfelder, W.; Kaye, S. M.; Ethier, S.; Mazzucato, E.; Bell, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Lee, K. C. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Domier, C. W. [University of California at Davis, Davis, California 95616 (United States); Smith, D. R. [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Yuh, H. [Nova Photonics, Inc., Princeton, New Jersey 08540 (United States)

    2015-11-15

    In this letter, we report the first observation of the fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus eXperiment [Ono et al., Nucl. Fusion 40, 557 (2000)]. The observation was made in a set of RF-heated L-mode plasmas with toroidal magnetic field of 0.55 T and plasma current of 300 kA. It is observed that electron-scale turbulence spectral power (measured with a high-k collective microwave scattering system) decreases significantly following fast cessation of RF heating that occurs in less than 200 μs. The large drop in the turbulence spectral power has a short time delay of about 1–2 ms relative to the RF cessation and happens on a time scale of 0.5–1 ms, much smaller than the energy confinement time of about 10 ms. Power balance analysis shows a factor of about 2 decrease in electron thermal diffusivity after the sudden drop of turbulence spectral power. Measured small changes in equilibrium profiles across the RF cessation are unlikely able to explain this sudden reduction in the measured turbulence and decrease in electron thermal transport, supported by local linear stability analysis and both local and global nonlinear gyrokinetic simulations. The observations imply that nonlocal flux-driven mechanism may be important for the observed turbulence and electron thermal transport.

  15. Auxiliary feedwater system risk-based inspection guide for the Point Beach nuclear power plant

    International Nuclear Information System (INIS)

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the auxiliary feedwater (AFW) system at pressurized water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses existing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify generic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Point Beach was selected as one of a series of plants for study. The product of this effort is a prioritized listing of AFW failures which have occurred at the plant and at other PWRS. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at the Point Beach plant

  16. Auxiliary feedwater system risk-based inspection guide for the Virgil C. Summer Nuclear Power Plant

    International Nuclear Information System (INIS)

    In a study sponsored by the US Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory has developed and applied a methodology for deriving plant-specific risk-based inspection guidance for the emergency/auxiliary feedwater (EFW/AFW) system at press water reactors that have not undergone probabilistic risk assessment (PRA). This methodology uses costing PRA results and plant operating experience information. Existing PRA-based inspection guidance information recently developed for the NRC for various plants was used to identify genetic component failure modes. This information was then combined with plant-specific and industry-wide component information and failure data to identify failure modes and failure mechanisms for the AFW system at the selected plants. Virgil C. Summer plant was selected as one m a series of plants for study. The product of this effort is a priority listing of AFW failures which have occurred at the plant and at other PWRS. This listing is intended for use by NRC inspectors in the preparation of inspection plans addressing AFW risk-important components at Virgil C. Summer plant

  17. Fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    In this letter, we report the first observation of the fast response of electron-scale turbulence to auxiliary heating cessation in National Spherical Torus eXperiment [Ono et al., Nucl. Fusion 40, 557 (2000)]. The observation was made in a set of RF-heated L-mode plasmas with toroidal magnetic field of 0.55 T and plasma current of 300 kA. It is observed that electron-scale turbulence spectral power (measured with a high-k collective microwave scattering system) decreases significantly following fast cessation of RF heating that occurs in less than 200 μs. The large drop in the turbulence spectral power has a short time delay of about 1–2 ms relative to the RF cessation and happens on a time scale of 0.5–1 ms, much smaller than the energy confinement time of about 10 ms. Power balance analysis shows a factor of about 2 decrease in electron thermal diffusivity after the sudden drop of turbulence spectral power. Measured small changes in equilibrium profiles across the RF cessation are unlikely able to explain this sudden reduction in the measured turbulence and decrease in electron thermal transport, supported by local linear stability analysis and both local and global nonlinear gyrokinetic simulations. The observations imply that nonlocal flux-driven mechanism may be important for the observed turbulence and electron thermal transport

  18. Improvement of stability of sinusoidally driven atmospheric pressure plasma jet using auxiliary bias voltage

    Directory of Open Access Journals (Sweden)

    Hyun-Jin Kim

    2015-12-01

    Full Text Available In this study, we have proposed the auxiliary bias pulse scheme to improve the stability of atmospheric pressure plasma jets driven by an AC sinusoidal waveform excitation source. The stability of discharges can be significantly improved by the compensation of irregular variation in memory voltage due to the effect of auxiliary bias pulse. From the parametric study, such as the width, voltage, and onset time of auxiliary bias pulse, it has been demonstrated that the auxiliary bias pulse plays a significant role in suppressing the irregular discharges caused by the irregular variation in memory voltage and stable discharge can be initiated with the termination of the auxiliary bias pulse. As a result of further investigating the effects of the auxiliary pulse scheme on the jet stability under various process conditions such as the distance between the jet head and the counter electrode, and carrier gas flow, the jet stability can be improved by adjusting the amplitude and number of the bias pulse depending on the variations in the process conditions.

  19. Improvement of stability of sinusoidally driven atmospheric pressure plasma jet using auxiliary bias voltage

    Science.gov (United States)

    Kim, Hyun-Jin; Kim, Jae Young; Kim, Jae Hyun; Kim, Dong Ha; Lee, Duck-Sik; Park, Choon-Sang; Park, Hyung Dal; Shin, Bhum Jae; Tae, Heung-Sik

    2015-12-01

    In this study, we have proposed the auxiliary bias pulse scheme to improve the stability of atmospheric pressure plasma jets driven by an AC sinusoidal waveform excitation source. The stability of discharges can be significantly improved by the compensation of irregular variation in memory voltage due to the effect of auxiliary bias pulse. From the parametric study, such as the width, voltage, and onset time of auxiliary bias pulse, it has been demonstrated that the auxiliary bias pulse plays a significant role in suppressing the irregular discharges caused by the irregular variation in memory voltage and stable discharge can be initiated with the termination of the auxiliary bias pulse. As a result of further investigating the effects of the auxiliary pulse scheme on the jet stability under various process conditions such as the distance between the jet head and the counter electrode, and carrier gas flow, the jet stability can be improved by adjusting the amplitude and number of the bias pulse depending on the variations in the process conditions.

  20. Disturbance in the power system caused by auxiliary DC installation failure of switchyard

    Energy Technology Data Exchange (ETDEWEB)

    Mesic, M. [HEP Transmission System Operator, Zagreb (Croatia); Tesnjak, S.; Skok, S. [Zagreb Univ. (Croatia). Faculty of Electrical Engineering and Computing

    2008-07-01

    Auxiliary direct current (DC) installation failures can lead to outages in power plants and compromise the security of power systems. In this study, a simplified stationary model was used to simulate an auxiliary DC installation in a switchyard. The aim of the study was to evaluate new International Electrotechnical Commission (IEC) standards for auxiliary DC installation dimensioning and analysis. Criteria included the dimensioning and selection of batteries; the calculation of conductor heating; voltage drop calculations; conductor squares in relation to permanent currents; and the evaluation of protection elements. The new standards were compared with the previous auxiliary system installation methodology. Results of the study suggested that the new standard has introduced significant improvements in short circuit current calculation. Laboratory tests for the measurement of short circuits showed that the active network has less of an impact on the auxiliary system than previous measuring methods. Alterations to the IEC standard will be required as a result of limitations to the short circuit current and new rectifier technology. Results of the study will be used to develop a new model and scheme for dimensioning and analyzing auxiliary DC installations. 9 refs., 4 tabs., 5 figs.

  1. Autonomous integrated navigation method based on the strapdown inertial navigation system and Lidar

    Science.gov (United States)

    Zhang, Xiaoyue; Lin, Zhili; Zhang, Chunxi

    2014-07-01

    An integrated navigation method based on the strapdown inertial navigation system (SINS) and Doppler Lidar was presented and its validity is demonstrated by practical experiments. A very effective and independent integrated navigation mode is realized that both an inertial navigation system (INS) and Lidar are not interfered with or screened by electromagnetic waves. In our work, the SINS error model was first introduced, and the velocity error model was transformed into body reference coordinates. Then the expression for measurement model of SINS/Lidar integrated navigation was deduced under Lidar reference coordinates. For application of land or vehicle navigation, the expression for the measurement model was simplified, and observation analysis was carried out. Finally, numerical simulation and vehicle test results were carried out to validate the availability and utility of the proposed SINS/Lidar integrated navigation method for land navigation.

  2. Autonomous navigation system and method

    Science.gov (United States)

    Bruemmer, David J. [Idaho Falls, ID; Few, Douglas A. [Idaho Falls, ID

    2009-09-08

    A robot platform includes perceptors, locomotors, and a system controller, which executes instructions for autonomously navigating a robot. The instructions repeat, on each iteration through an event timing loop, the acts of defining an event horizon based on the robot's current velocity, detecting a range to obstacles around the robot, testing for an event horizon intrusion by determining if any range to the obstacles is within the event horizon, and adjusting rotational and translational velocity of the robot accordingly. If the event horizon intrusion occurs, rotational velocity is modified by a proportion of the current rotational velocity reduced by a proportion of the range to the nearest obstacle and translational velocity is modified by a proportion of the range to the nearest obstacle. If no event horizon intrusion occurs, translational velocity is set as a ratio of a speed factor relative to a maximum speed.

  3. TARGET RELATIVE NAVIGATION PERFORMANCE RESULTS FROM SINPLEX: A MINIATURIZED NAVIGATION SYSTEM

    OpenAIRE

    Steffes, Stephen; Theil, Stephan; Dumke, Michael; Heise, David; Krüger, Hans; Sagliano, Marco; Samaan, Malak; Oosterling, Han; Boslooper, Erik; Duivenvoorde, Tom; Schulte, Jan; Söderholm, S.; Skaborn, Daniel; Yanson, Yuriy; Esposito, Marco

    2014-01-01

    The goal of the SINPLEX project is to develop an innovative solution to significantly reduce the mass of the navigation subsystem for exploration missions which include landing and/or rendezvous and capture phases. The system mass is reduced by functionally integrating the navigation sensors, using micro- and nanotechnology to miniaturize electronics and fusing the sensor data within a navigation filter to improve navigation performance. A breadboard system was built and includes ...

  4. A molecular compass for bird navigation

    Science.gov (United States)

    Hore, Peter

    2015-03-01

    Migratory birds travel spectacular distances, navigating and orienting by a variety of means, most of which are poorly understood. Among them is a remarkable ability to perceive the intensity and direction of the Earth's magnetic field. Biologically credible mechanisms for the sensing of such weak fields (25-65 microtesla) are scarce and in recent years just two proposals have emerged as frontrunners. One involves biogenic iron-containing nanoparticles; the other relies on the magnetic sensitivity of short-lived photochemical intermediates known as radical pairs. The latter began to attract attention following the proposal 15 years ago that the necessary physics and chemistry could take place in the bird's retina in specialised photoactive proteins called cryptochromes. The coherent dynamics of the electron-nuclear spin systems of pairs of photo-induced radicals is conjectured to form the basis of the sensing mechanism even though the interaction of an electron spin with the geomagnetic field is six orders of magnitude smaller than the thermal energy. The possibility that slowing decohering, entangled electron spins could form the basis of an important sensory mechanism has qualified radical pair magnetoreception for a place under the umbrella of ``Quantum Biology.'' In this talk, I will introduce the radical pair mechanism, comment on the roles of entanglement and quantum coherence, outline some of the experimental evidence for the cryptochrome hypothesis, and summarize what still needs to be done to determine whether birds (and maybe other animals) really do use a chemical compass to find their way around. This work was supported by grants from DARPA, AFOSR, ERC and the EMF Biological Research Trust.

  5. Mechanics

    CERN Document Server

    Chester, W

    1979-01-01

    When I began to write this book, I originally had in mind the needs of university students in their first year. May aim was to keep the mathematics simple. No advanced techniques are used and there are no complicated applications. The emphasis is on an understanding of the basic ideas and problems which require expertise but do not contribute to this understanding are not discussed. How­ ever, the presentation is more sophisticated than might be considered appropri­ ate for someone with no previous knowledge of the subject so that, although it is developed from the beginning, some previous acquaintance with the elements of the subject would be an advantage. In addition, some familiarity with element­ ary calculus is assumed but not with the elementary theory of differential equations, although knowledge of the latter would again be an advantage. It is my opinion that mechanics is best introduced through the motion of a particle, with rigid body problems left until the subject is more fully developed. Howev...

  6. Indigenous manufacturing realization of twin source and its auxiliary system

    International Nuclear Information System (INIS)

    operation) as well as Vacuum mode (DNB type vacuum immersed operation). The Twin Source shall be manufactured as per ASME guidelines for pressure vessel. Experiments on the Twin Source are foreseen in the near future, as all the auxiliary systems like 180 kW, RF generator system, vacuum vessel with Pumping station, Cooling water system, Data acquisition and control system (DACS) and other power supply systems are already installed in the lab premises. The paper discusses the FEA based engineering design, simplified manufacturing design, manufacturing experience with highlighting quality control and the system integration activities undertaken for the TWIN source test facility. (author)

  7. Improvement of Equipment reliability for Auxiliary Feed Water System

    International Nuclear Information System (INIS)

    According to AP913 ER) of INPO, Number of the event related to equipment is higher than others like external or human performance. In the top 25 systems, Auxiliary feed water system is the seventh highest among systems. AWFS consists of many component and complex system and Main Function of AFWS is to supply feedwater to the steam generators for the removal of heat from the RCS(Reactor Coolant System) in event the main feedwater system is unavailable following a transient or accident. Reliability of component means how well operate on demands and monitoring is necessary to keep track of condition of component. If component performance is lower than the required value, corrective action for failure mode should be done. The objective of this study is focused to improve of AF pump by adding the tasks of SHR(System Health Report) into the task of system engineer walkdown of PMT(Preventive Maintenance Template). Increasing the reliability of AF pump will contribute to improvement of reliability of AFWS. Based on operating history, there was high vibration of AF pump during performance test. In that case, there were a lot of maintenance works for normal operation of AF pump. Vibration problem related pump can't be detected by tasks of SE walkdown because it's not running during normal operation except for surveillance test. CHR(Component Health Report) of AF pump in AFWS can be made from necessary part which means monitoring and functional failure because problem of Stand-by pump can be covered by conducting monitoring and analysis of functional failure. To improve reliability of AF pump, walkdown of PMT and SHR should be conducted both in accordance with surveillance test frequency. Health of AF pump based on operation history can be verified first and then can find out which parts of pump are weak. Finally, weak part can be managed intensively and failure can be reduced according to SE walkdown. But this work can be risky and burdensome because all parts of CHR are not

  8. Waypoint navigation with a vibrotactile waist belt

    NARCIS (Netherlands)

    Erp, J.B.F. van; Veen, H.A.H.C. van; Jansen, C.; Dobbins, T.

    2005-01-01

    Presenting waypoint navigation on a visual display is not suited for all situations. The present experiments investigate if it is feasible to present the navigation information on a tactile display. Important design issue of the display is how direction and distance information must be coded. Import

  9. Blavigator: a navigation aid for blind persons

    OpenAIRE

    José, João; MORENO, M; Pinilla-Dutoit, J.; Rodrigues, J. M. F.; du Buf, J. M. H.

    2012-01-01

    Blavigator (blind navigator) is a vision aid for blind and visuaIIy impaired persons. It supports local navigation by detecting waIkable paths in the immediate vicinity of the user. It guides the user for centering on the path.

  10. Rosetta Star Tracker and Navigation Camera

    DEFF Research Database (Denmark)

    Thuesen, Gøsta

    1998-01-01

    Proposal in response to the Invitation to Tender (ITT) issued by Matra Marconi Space (MSS) for the procurement of the ROSETTA Star Tracker and Navigation Camera.......Proposal in response to the Invitation to Tender (ITT) issued by Matra Marconi Space (MSS) for the procurement of the ROSETTA Star Tracker and Navigation Camera....

  11. Understanding the Social Navigation User Experience

    Science.gov (United States)

    Goecks, Jeremy

    2009-01-01

    A social navigation system collects data from its users--its community--about what they are doing, their opinions, and their decisions, aggregates this data, and provides the aggregated data--community data--back to individuals so that they can use it to guide behavior and decisions. Social navigation systems empower users with the ability to…

  12. Validation of principles for tactile navigation displays

    NARCIS (Netherlands)

    Erp, J.B.F. van; Werkhoven, P.J.

    2006-01-01

    Access to navigation information rapidly becomes standard in many situations, for example through GPS receivers and collision avoidance systems in cars. However, perceiving and processing the information may result in overloading the userÆs visual sense and cognitive resources. Intuitive navigation

  13. Evolved Navigation Theory and Horizontal Visual Illusions

    Science.gov (United States)

    Jackson, Russell E.; Willey, Chela R.

    2011-01-01

    Environmental perception is prerequisite to most vertebrate behavior and its modern investigation initiated the founding of experimental psychology. Navigation costs may affect environmental perception, such as overestimating distances while encumbered (Solomon, 1949). However, little is known about how this occurs in real-world navigation or how…

  14. GPS free navigation inspired by insects through monocular camera and inertial sensors

    Science.gov (United States)

    Liu, Yi; Liu, J. G.; Cao, H.; Huang, Y.

    2015-12-01

    Navigation without GPS and other knowledge of environment have been studied for many decades. Advance technology have made sensors more compact and subtle that can be easily integrated into micro and hand-hold device. Recently researchers found that bee and fruit fly have an effectively and efficiently navigation mechanism through optical flow information and process only with their miniature brain. We present a navigation system inspired by the study of insects through a calibrated camera and other inertial sensors. The system utilizes SLAM theory and can be worked in many GPS denied environment. Simulation and experimental results are presented for validation and quantification.

  15. Enhancing Navigation on Wikipedia with Social Tags

    CERN Document Server

    Zubiaga, Arkaitz

    2012-01-01

    Social tagging has become an interesting approach to improve search and navigation over the actual Web, since it aggregates the tags added by different users to the same resource in a collaborative way. This way, it results in a list of weighted tags describing its resource. Combined to a classical taxonomic classification system such as that by Wikipedia, social tags can enhance document navigation and search. On the one hand, social tags suggest alternative navigation ways, including pivot-browsing, popularity-driven navigation, and filtering. On the other hand, it provides new metadata, sometimes uncovered by documents' content, that can substantially improve document search. In this work, the inclusion of an interface to add user-defined tags describing Wikipedia articles is proposed, as a way to improve article navigation and retrieval. As a result, a prototype on applying tags over Wikipedia is proposed in order to evaluate its effectiveness.

  16. GPS-based navigation for space applications

    Science.gov (United States)

    Champetier, C.; Duhamel, T.; Frezet, M.

    1995-03-01

    We present in this paper a survey of the applications of the GPS (global positioning system) system for spacecraft navigation. The use of the GPS techniques for space missions is a striking example of dual-use of military technology; it can bring vast improvements in performances and, in some cases, for a reduced cost. We only deal in this paper with the functional aspects and performances of GPS uses without addressing the issues of hardware implementation where current developments are leading to an increased miniaturization of the GPS receiver hardware. We start this paper with a general overview of the GPS system and its various uses for space missions. We then focus on four areas where MATRA MARCONI Space has conducted detailed analyses of performances: autonomous navigation for geostationary spacecraft, relative navigation for space rendezvous, differential navigation for landing vehicles, absolute navigation for launchers and reentry vehicles.

  17. Navigation aided surgery for facial fractures

    International Nuclear Information System (INIS)

    A navigation system that has been developed in neurosurgery has recently been applied in the maxillofacial region. We introduced a navigation system (Stealth Station, Medtronic) in the maxillofacial region. As preoperative preparation, CT scanning was performed with a slice of 1 mm. Navigation aided surgery was performed in 11 patients with facial fractures between April 2005 and July 2006. Navigation aided reduction of the bone segment was performed by comparing with the sound site on the screen. Facial symmetry was recovered in 10 of 11 cases. Facial asymmetry in 1 case (midfacial multiple fractures) remained, because the system did not work after the surgeon contacted the reference frame during the operation. The navigation system is useful for repairing facial fractures, especially for verifying facial symmetry. (author)

  18. Risk management model of winter navigation operations.

    Science.gov (United States)

    Valdez Banda, Osiris A; Goerlandt, Floris; Kuzmin, Vladimir; Kujala, Pentti; Montewka, Jakub

    2016-07-15

    The wintertime maritime traffic operations in the Gulf of Finland are managed through the Finnish-Swedish Winter Navigation System. This establishes the requirements and limitations for the vessels navigating when ice covers this area. During winter navigation in the Gulf of Finland, the largest risk stems from accidental ship collisions which may also trigger oil spills. In this article, a model for managing the risk of winter navigation operations is presented. The model analyses the probability of oil spills derived from collisions involving oil tanker vessels and other vessel types. The model structure is based on the steps provided in the Formal Safety Assessment (FSA) by the International Maritime Organization (IMO) and adapted into a Bayesian Network model. The results indicate that ship independent navigation and convoys are the operations with higher probability of oil spills. Minor spills are most probable, while major oil spills found very unlikely but possible. PMID:27207023

  19. Interactive multiview video system with non-complex navigation at the decoder

    CERN Document Server

    Maugey, Thomas

    2012-01-01

    Multiview video with interactive and smooth view switching at the receiver is a challenging application with several issues in terms of effective use of storage and bandwidth resources, reactivity of the system, quality of the viewing experience and system complexity. The classical decoding system for generating virtual views first projects a reference or encoded frame to a given viewpoint and then fills in the holes due to potential occlusions. This last step still constitutes a complex operation with specific software or hardware at the receiver and requires a certain quantity of information from the neighboring frames for insuring consistency between the virtual images. In this work we propose a new approach that shifts most of the burden due to interactivity from the decoder to the encoder, by anticipating the navigation of the decoder and sending auxiliary information that guarantees temporal and interview consistency. This leads to an additional cost in terms of transmission rate and storage, which we m...

  20. Pareto navigation-algorithmic foundation of interactive multi-criteria IMRT planning

    International Nuclear Information System (INIS)

    Inherently, IMRT treatment planning involves compromising between different planning goals. Multi-criteria IMRT planning directly addresses this compromising and thus makes it more systematic. Usually, several plans are computed from which the planner selects the most promising following a certain procedure. Applying Pareto navigation for this selection step simultaneously increases the variety of planning options and eases the identification of the most promising plan. Pareto navigation is an interactive multi-criteria optimization method that consists of the two navigation mechanisms 'selection' and 'restriction'. The former allows the formulation of wishes whereas the latter allows the exclusion of unwanted plans. They are realized as optimization problems on the so-called plan bundle-a set constructed from pre-computed plans. They can be approximately reformulated so that their solution time is a small fraction of a second. Thus, the user can be provided with immediate feedback regarding his or her decisions. Pareto navigation was implemented in the MIRA navigator software and allows real-time manipulation of the current plan and the set of considered plans. The changes are triggered by simple mouse operations on the so-called navigation star and lead to real-time updates of the navigation star and the dose visualizations. Since any Pareto-optimal plan in the plan bundle can be found with just a few navigation operations the MIRA navigator allows a fast and directed plan determination. Besides, the concept allows for a refinement of the plan bundle, thus offering a middle course between single plan computation and multi-criteria optimization. Pareto navigation offers so far unmatched real-time interactions, ease of use and plan variety, setting it apart from the multi-criteria IMRT planning methods proposed so far

  1. Oceanic long-distance navigation: Do experienced migrants use the Earth's magnetic field?

    OpenAIRE

    Åkesson, Susanne; Luschi, P; Papi, F; Broderick, A. C.; Glen, F.; Godley, B. J.; Hays, G.C.

    2001-01-01

    Albatrosses and sea turtles are known to perform extremely long-distance journeys between disparate feeding areas and breeding sites located on small, isolated, oceanic islands or at specific coastal sites. These oceanic journeys, performed mainly over or through apparently featureless mediums, indicate impressive navigational abilities, and the sensory mechanisms used are still largely unknown. This research used three different approaches to investigate whether bi-coordinate navigation base...

  2. Path Integration Working Memory for Multi Task Dead Reckoning and Visual Navigation

    OpenAIRE

    Hasson, Cyril; Gaussier, Philippe

    2010-01-01

    International audience Biologically inspired models for navigation use mechanisms like path integration or sensori-motor learning. This paper describes the use of a proprioceptive working memory to give path integration the potential to store several goals. Then we coupled the path integration working memory to place cell sensori-motor learning to test the potential autonomy this gives to the robot. This navigation architecture intends to combine the benefits of both strategies in order to...

  3. Venous catheterization with ultrasound navigation

    Energy Technology Data Exchange (ETDEWEB)

    Kasatkin, A. A., E-mail: ant-kasatkin@yandex.ru; Nigmatullina, A. R. [Izhevsk State Medical Academy, Kommunarov street, 281, Izhevsk, Russia, 426034 (Russian Federation); Urakov, A. L., E-mail: ant-kasatkin@yandex.ru [Institute of Mechanics Ural Branch of Russian Academy of Sciences, T.Baramzinoy street 34, Izhevsk, Russia, 426067, Izhevsk (Russian Federation); Izhevsk State Medical Academy, Kommunarov street, 281, Izhevsk, Russia, 426034 (Russian Federation)

    2015-11-17

    By ultrasound scanning it was determined that respiratory movements made by chest of healthy and sick person are accompanied by respiratory chest rise of internal jugular veins. During the exhalation of an individual diameter of his veins increases and during the breath it decreases down to the complete disappearing if their lumen. Change of the diameter of internal jugular veins in different phases can influence significantly the results of vein puncture and cauterization in patients. The purpose of this research is development of the method increasing the efficiency and safety of cannulation of internal jugular veins by the ultrasound visualization. We suggested the method of catheterization of internal jugular veins by the ultrasound navigation during the execution of which the puncture of venous wall by puncture needle and the following conduction of J-guide is carried out at the moment of patient’s exhalation. This method decreases the risk of complications development during catheterization of internal jugular vein due to exclusion of perforating wound of vein and subjacent tissues and anatomical structures.

  4. Inertial sensors for smartphones navigation.

    Science.gov (United States)

    Dabove, P; Ghinamo, G; Lingua, A M

    2015-01-01

    The advent of smartphones and tablets, means that we can constantly get information on our current geographical location. These devices include not only GPS/GNSS chipsets but also mass-market inertial platforms that can be used to plan activities, share locations on social networks, and also to perform positioning in indoor and outdoor scenarios. This paper shows the performance of smartphones and their inertial sensors in terms of gaining information about the user's current geographical locatio n considering an indoor navigation scenario. Tests were carried out to determine the accuracy and precision obtainable with internal and external sensors. In terms of the attitude and drift estimation with an updating interval equal to 1 s, 2D accuracies of about 15 cm were obtained with the images. Residual benefits were also obtained, however, for large intervals, e.g. 2 and 5 s, where the accuracies decreased to 50 cm and 2.2 m, respectively. PMID:26753121

  5. Venous catheterization with ultrasound navigation

    Science.gov (United States)

    Kasatkin, A. A.; Urakov, A. L.; Nigmatullina, A. R.

    2015-11-01

    By ultrasound scanning it was determined that respiratory movements made by chest of healthy and sick person are accompanied by respiratory chest rise of internal jugular veins. During the exhalation of an individual diameter of his veins increases and during the breath it decreases down to the complete disappearing if their lumen. Change of the diameter of internal jugular veins in different phases can influence significantly the results of vein puncture and cauterization in patients. The purpose of this research is development of the method increasing the efficiency and safety of cannulation of internal jugular veins by the ultrasound visualization. We suggested the method of catheterization of internal jugular veins by the ultrasound navigation during the execution of which the puncture of venous wall by puncture needle and the following conduction of J-guide is carried out at the moment of patient's exhalation. This method decreases the risk of complications development during catheterization of internal jugular vein due to exclusion of perforating wound of vein and subjacent tissues and anatomical structures.

  6. [Tableting technology of a dry extract from Solidago virgaurea L. with the use of silicified microcrystalline cellulose (Prosolv) and other selected auxiliary substances].

    Science.gov (United States)

    Marczyiński, Zbigniew

    2009-01-01

    Direct tableting is simpler and more cost-effective from the point of view of good manufacturing practice (GMP) than wet granulation or dry compacting. Moreover, the use of dry plant extracts in the process of direct tableting, omitting granulation, decreases the possibility of biological activity loss of active substances. Thus, pharmaceutical industry uses this particular process more and more frequently. Only few therapeutic substances form under compression tablets meeting current requirements. Very often addition of auxiliary substances appears to be indispensable. The aim of this study was to obtain uncoated tablets by the method of direct tableting with the use of selected auxiliary substances. Dry extract from Solidago virgaurea L. was the study material. Shrimp chitosan, silicified microcrystalline cellulose (Prosolv), polyvinylpyrrolidone, calcium carbonate and sodium stearyl fumarate were used as auxiliary substances. Eleven tablet batches were manufactured in a reciprocating instrumented tableting machine (Ewreka). The produced tablets were subjected to morphological tests comprising the tablet size, determination of batching accuracy (determination of mass uniformity of individual tablets), test of mechanical resistance (crushing strength), determination of disintegration time. The statistical hardness of the manufactured tablets was also estimated. Pharmaceutical availability tests were performed of the biologically active substances released from tablets to the acceptor fluid. The study was based on general and detailed regulations of Polish Pharmacopoeia VII (PP VII). The obtained results allow to conclude that the applied auxiliary substances appeared to be useful in adequate proportions in manufacturing tablets containing dry extract from Solidago virgaurea L. The properties of the obtained batches of tablets were in majority consistent with the current requirements. The applied method provides technological reproducibility and high durability of

  7. Vision aided inertial navigation system augmented with a coded aperture

    Science.gov (United States)

    Morrison, Jamie R.

    Navigation through a three-dimensional indoor environment is a formidable challenge for an autonomous micro air vehicle. A main obstacle to indoor navigation is maintaining a robust navigation solution (i.e. air vehicle position and attitude estimates) given the inadequate access to satellite positioning information. A MEMS (micro-electro-mechanical system) based inertial navigation system provides a small, power efficient means of maintaining a vehicle navigation solution; however, unmitigated error propagation from relatively noisy MEMS sensors results in the loss of a usable navigation solution over a short period of time. Several navigation systems use camera imagery to diminish error propagation by measuring the direction to features in the environment. Changes in feature direction provide information regarding direction for vehicle movement, but not the scale of movement. Movement scale information is contained in the depth to the features. Depth-from-defocus is a classic technique proposed to derive depth from a single image that involves analysis of the blur inherent in a scene with a narrow depth of field. A challenge to this method is distinguishing blurriness caused by the focal blur from blurriness inherent to the observed scene. In 2007, MIT's Computer Science and Artificial Intelligence Laboratory demonstrated replacing the traditional rounded aperture with a coded aperture to produce a complex blur pattern that is more easily distinguished from the scene. A key to measuring depth using a coded aperture then is to correctly match the blur pattern in a region of the scene with a previously determined set of blur patterns for known depths. As the depth increases from the focal plane of the camera, the observable change in the blur pattern for small changes in depth is generally reduced. Consequently, as the depth of a feature to be measured using a depth-from-defocus technique increases, the measurement performance decreases. However, a Fresnel zone

  8. Flexibility of continental navigation and migration in European mallards

    DEFF Research Database (Denmark)

    van Toor, Mariëlle L.; Hedenström, Anders; Waldenström, Jonas;

    2013-01-01

    Germany. We followed the movements of the ducks via satellite GPS-tracking and observed their migration decisions during the fall and consecutive spring migration. The control animals released in Ottenby behaved as expected from banding recoveries: they continued migration during the winter and in spring......The ontogeny of continent-wide navigation mechanisms of the individual organism, despite being crucial for the understanding of animal movement and migration, is still poorly understood. Several previous studies, mainly conducted on passerines, indicate that inexperienced, juvenile birds may not...... generally correct for displacement during fall migration. Waterbirds such as the mallard (Anas platyrhynchos, Linnaeus 1758) are more flexible in their migration behavior than most migratory songbirds, but previous experiments with waterbirds have not yet allowed clear conclusions about their navigation...

  9. Synthesis and Validation of Vision Based Spacecraft Navigation

    DEFF Research Database (Denmark)

    Massaro, Alessandro Salvatore

    This dissertation targets spacecraft navigation by means of vision based sensors. The goal is to achieve autonomous, robust and ecient navigation through a multidisciplinary research and development effort, covering the fields of computer vision, electronics, optics and mechanics. The attention...... to the Moon's surface is still prohibitively expensive and not ideal for missions such as cargo delivery. The first part of this book focuses on a lunar landing scenario as case study and discusses software and hardware components for an optimal vision based sensor for precision planetary landing. Computer...... vision techniques are applied to the problems of horizontal velocity estimation, and hazard detection. Experimental implementations are henceforth presented and the results show their potential for integration on a space qualified processing unit. The study concludes with recommendations for key physical...

  10. Environmental practices of the auxiliary companies to the Spanish automobile industry

    Science.gov (United States)

    González-Torre, Pilar L.; González, Beatriz A.; Gupta, Surendra M.

    2005-11-01

    The automobile manufacturing industry plays a very important role in a country's economy. The importance of automobile manufacturing industry lies in its sheer size and complexity in terms of the direct and indirect influence it commands across many other industries. While millions of people are employed in the automobile manufacturing industry, it is estimated that more than two and half times that number are employed in the auxiliary companies that supply parts to the automobile manufacturing companies. The auxiliary companies represent a group of businesses of various sizes, types, and geographical locations, producing a vast variety of products ranging from the very simple to the extremely intricate. In this study, the current environmental practices of management in the core Spanish auxiliary companies that do business with the automobile manufacturing industry (and thus form a large part of the automobile manufacturing industry's supply chain) are investigated. We show that while automobile manufacturing companies are under scrutiny to become more and more environmentally friendly, not only at their manufacturing stage but also at their products' useful and EOL stages, there appears to be no such burden on the auxiliary companies. Our conclusion is based on an elaborate survey conducted during the fall of 2004 of Spanish auxiliary companies with questions about the characteristics, environmental practices and reverse logistics related activities carried out by the companies.

  11. Simplified technique for auxiliary orthotopic liver transplantation using a whole graft

    Science.gov (United States)

    ROCHA-SANTOS, Vinicius; NACIF, Lucas Souto; PINHEIRO, Rafael Soares; DUCATTI, Liliana; ANDRAUS, Wellington; D'ALBURQUERQUE, Luiz Carneiro

    2015-01-01

    Background Acute liver failure is associated with a high mortality rate and the main purposes of treatment are to prevent cerebral edema and infections, which often are responsible for patient death. The orthotopic liver transplantation is the gold standard treatment and improves the 1-year survival. Aim To describe an alternative technique to auxiliary liver transplant on acute liver failure. Method Was performed whole auxiliary liver transplantation as an alternative technique for a partial auxiliary liver transplantation using a whole liver graft from a child removing the native right liver performed a right hepatectomy. The patient met the O´Grady´s criteria and the rational to indicate an auxiliary orthotopic liver transplantation was the acute classification without hemodynamic instability or renal failure in a patient with deterioration in consciousness. Results The procedure improved liver function and decreased intracranial hypertension in the postoperative period. Conclusion This technique can overcome some postoperative complications that are associated with partial grafts. As far as is known, this is the first case of auxiliary orthotopic liver transplantation in Brazil. PMID:26176253

  12. Pulsar Navigation in the Solar System

    CERN Document Server

    Dong, Jiang

    2008-01-01

    The X-ray Pulsar-based Autonomous Navigation(XNAV) were recently tested which use the Crab pulsar (PSR B0531+21) in the USA Experiment on flown by the Navy on the Air Force Advanced Research and Global Observation Satellite (ARGOS) under the Space Test Program. It provide the way that the spacecraft could autonomously determine its position with respect to an inertial origin. Now I analysis the sensitivity of the exist instrument and the signal process to use radio pulsar navigation and discuss the integrated navigation use pulsar,then give the different navigation mission analysis and design process basically which include the space, the airborne, the ship and the land of the planet or the lunar.So the pulsar navigation can give the continuous position in deep spaces, that means we can freedom fly successfully in the solar system use celestial navigation that include pulsar and traditional star sensor.It also can less or abolish the depend of Global Navigation Satellite System which include GPS, GRONSS, Gali...

  13. Space optical navigation techniques: an overview

    Science.gov (United States)

    Rebordão, J. M.

    2013-11-01

    Optical or vision-based navigation is an enabling technology for satellite autonomous navigation associated to different navigation approaches such as cruising, fly-by, terrain relative navigation, landing, rendezvous and docking between spacecrafts, rigidity of multi-satellite constellations. Since 2001, in many different ESA projects, the author and his team (at INETI and currently at FCUL) have been associated to most of the developments of the optical components of autonomous navigation, in cooperation with space primes or GNC subsystems suppliers. A unique experience related to seemingly simple photonic concepts associated to computational vision, photonic noises, camera tradeoffs and system concepts has emerged, and deserves a synthesis especially because some of these concepts are being implemented in the ESA Proba 3 mission and ESA is currently updating the technology in view of forthcoming planetary missions to Jupiter, Jupiter moons and asteroids. It is important to note that the US have already flown several missions relying on autonomous navigation and that NASA experience is at least one decade old. System approaches, sources of difficulty, some tradeoffs in both (and between) hardware and software, critical interface issues between the imaging and GNC (Guidance, Navigation and Control) subsystems, image processing techniques, utilization of apriori or to be estimated information, uncertainties, simulation of the imaging chain and non-cooperative environments will be addressed synthetically for both passive (optical) and active (lidar) systems.

  14. Nuclear burst detection information transfers system based on BD Navigation

    International Nuclear Information System (INIS)

    The article introduces the character of BD Navigation System.The feasibility of using BD Navigation System is analyzed. Nuclear explosion information transmission system based on BD Navigation System is designed and implemented. (authors)

  15. Optimal Control of Mechanical Systems

    Directory of Open Access Journals (Sweden)

    Vadim Azhmyakov

    2007-01-01

    Full Text Available In the present work, we consider a class of nonlinear optimal control problems, which can be called “optimal control problems in mechanics.” We deal with control systems whose dynamics can be described by a system of Euler-Lagrange or Hamilton equations. Using the variational structure of the solution of the corresponding boundary-value problems, we reduce the initial optimal control problem to an auxiliary problem of multiobjective programming. This technique makes it possible to apply some consistent numerical approximations of a multiobjective optimization problem to the initial optimal control problem. For solving the auxiliary problem, we propose an implementable numerical algorithm.

  16. Navigated minimally invasive unicompartmental knee arthroplasty.

    Science.gov (United States)

    Jenny, Jean-Yves; Müller, Peter E; Weyer, R; John, Michael; Weber, Patrick; Ciobanu, Eugène; Schmitz, Andreas; Bacher, Thomas; Neumann, Wolfram; Jansson, Volkmar

    2006-10-01

    Unicompartmental knee arthroplasty (UKA) is an alternative procedure to high tibial osteotomy. This study assessed the procedure using computer navigation to improve implantation accuracy and presents early radiological results of a group of patients implanted with the univation UKA (B. Braun Aesculap, Tuttlingen, Germany) with navigation instrumentation and a minimally invasive approach. The authors concluded that navigated implantation of a UKA using a nonimage-based system improved radiologic accuracy implantation without significant inconvenience and minimal change in the conventional operating technique. PMID:17407935

  17. Navigational Use of Cassini Delta V Telemetry

    Science.gov (United States)

    Roth, Duane C.; Antreasian, Peter G.; Ardalan, Shadan M.; Criddle, Kevin E.; Goodson, Troy; Ionasescu, Rodica; Jones, Jeremy B.; Parcher, Daniel W.; Pelletier, Frederic J.; Thompson, Paul F.; Vaughan, Andrew T.

    2008-01-01

    Telemetry data are used to improve navigation of the Saturn orbiting Cassini spacecraft. Thrust induced delta V's are computed on-board the spacecraft, recorded in telemetry, and downlinked to Earth. This paper discusses how and why the Cassini Navigation team utilizes spacecraft delta V telemetry. Operational changes making this information attractive to the Navigation Team will be briefly discussed, as will spacecraft hardware and software algorithms responsible for the on-board computation. An analysis of past delta V telemetry, providing calibrations and accuracies that can be applied to the estimation of future delta V activity, is described.

  18. INTERACTION SPECIFICITY IN AIR NAVIGATION COMMUNICATION

    Directory of Open Access Journals (Sweden)

    Kateryna Povoroznyk

    2012-09-01

    Full Text Available  The article is about a problem of air navigation communication and the positive influence of interpersonal communication for air navigation specialists. The ability of organizing a dialogue with subject – subject relationship substantially increase professional interaction efficiency. As scientific surveys show a dialogue is not just the form of communication, but an organizing phenomenon that directly influences the quality of air navigation communication, but there is still a gap in the aviation English teaching technics, mainly due to lack of psycho – pedagogical knowledge concerning human factor peculiarities within dialogical relationship framework. The article highlights the possible ways of the problem solution.

  19. Navigating nuclear science: Enhancing analysis through visualization

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, N.H.; Berkel, J. van; Johnson, D.K.; Wylie, B.N.

    1997-09-01

    Data visualization is an emerging technology with high potential for addressing the information overload problem. This project extends the data visualization work of the Navigating Science project by coupling it with more traditional information retrieval methods. A citation-derived landscape was augmented with documents using a text-based similarity measure to show viability of extension into datasets where citation lists do not exist. Landscapes, showing hills where clusters of similar documents occur, can be navigated, manipulated and queried in this environment. The capabilities of this tool provide users with an intuitive explore-by-navigation method not currently available in today`s retrieval systems.

  20. Integration of Omega and satellite navigation systems

    Science.gov (United States)

    Schlachta, Henry B.

    An extensive series of laboratory tests and flight trials has established that the hybrid Omega/VLF/GPS system effectively applies GPS to the enhancement of Omega with a cost-effective operator installation. The accuracy enhancement thus achieved also increases the reliability of navigation and furnishes aviation fuel savings superior to those of Omega, as a result of reduced flight-path wavering. The prospective GPS/GLONASS navigation system currently undergoing definition will be the first certifiable as a sole means on navigation; the Omega/VLF/GPS hybrid can serve as a transitional system.

  1. The Principle and Application of Maser Navigation

    OpenAIRE

    Dong, Jiang

    2008-01-01

    The traditional celestial navigation system (CNS) is used the moon, stars, and planets as celestial guides. Then the star tracker (i.e. track one star or planet or angle between it) and star sensor (i.e. sense many star simultaneous) be used to determine the attitude of the spacecraft. Pulsar navigation also be introduced to CNS. Maser is another interested celestial in radio astronomy which has strong flux density as spectral line. Now we analysis the principle of maser navigation which base...

  2. Functional Techniques in Classical Mechanics

    CERN Document Server

    Gozzi, E

    2001-01-01

    In 1931 Koopman and von Neumann extended previous work of Liouville and provided an operatorial version of Classical Mechanics (CM). In this talk we will review a path-integral formulation of this operatorial version of CM. In particular we will study the geometrical nature of the many auxiliary variables present and of the unexpected universal symmetries generated by the functional technique.

  3. Treatment for chronic daily headache by using auxiliary and alternative methods

    Directory of Open Access Journals (Sweden)

    V. A. Golovacheva

    2015-06-01

    Full Text Available Chronic daily headache (CDH is one of the top 10 causes of adult disability and one of the 5 most common causes of female disability. To treat patients with CDH is one of the most difficult tasks in neurological practice. Difficulties in managing patients with CHD are associated with the high prevalence of comorbid mental disorders, analgesic abuse, pain syndromes at another site, and misconceptions of a patient about his/her disease. A combination of drug and non-drug therapies is the mainstay of the current approach to treating patients with CDH. Standard, alternative, and auxiliary therapies are identified. The paper describes different types of current auxiliary and alternative therapy used in the world’s leading headache centers and clinics. It describes experience with cerebrolysin used as auxiliary and alternative pharmacotherapies for CDH.

  4. The auxiliary elliptic-like equation and the exp-function method

    Indian Academy of Sciences (India)

    Hong Li; Jin-Liang Zhang

    2009-06-01

    The auxiliary equation method is very useful for finding the exact solutions of the nonlinear evolution equations. In this paper, a new idea of finding the exact solutions of the nonlinear evolution equations is introduced. The idea is that the exact solutions of the auxiliary elliptic-like equation are derived using exp-function method, and then the exact solutions of the nonlinear evolution equations are derived with the aid of auxiliary elliptic-like equation. As examples, the RKL models, the high-order nonlinear Schrödinger equation, the Hamilton amplitude equation, the generalized Hirota–Satsuma coupled KdV system and the generalized ZK–BBM equation are investigated and the exact solutions are presented using this method.

  5. Dynamic modelling and response characteristics of a magnetic bearing rotor system with auxiliary bearings

    Science.gov (United States)

    Free, April M.; Flowers, George T.; Trent, Victor S.

    1995-01-01

    Auxiliary bearings are a critical feature of any magnetic bearing system. They protect the soft iron core of the magnetic bearing during an overload or failure. An auxiliary bearing typically consists of a rolling element bearing or bushing with a clearance gap between the rotor and the inner race of the support. The dynamics of such systems can be quite complex. It is desired to develop a rotordynamic model which describes the dynamic behavior of a flexible rotor system with magnetic bearings including auxiliary bearings. The model is based upon an experimental test facility. Some simulation studies are presented to illustrate the behavior of the model. In particular, the effects of introducing sideloading from the magnetic bearing when one coil fails is studied.

  6. Dynamic modelling and response characteristics of a magnetic bearing rotor system including auxiliary bearings

    Science.gov (United States)

    Free, April M.; Flowers, George T.; Trent, Victor S.

    1993-01-01

    Auxiliary bearings are a critical feature of any magnetic bearing system. They protect the soft iron core of the magnetic bearing during an overload or failure. An auxiliary bearing typically consists of a rolling element bearing or bushing with a clearance gap between the rotor and the inner race of the support. The dynamics of such systems can be quite complex. It is desired to develop a rotor-dynamic model and assess the dynamic behavior of a magnetic bearing rotor system which includes the effects of auxiliary bearings. Of particular interest is the effects of introducing sideloading into such a system during failure of the magnetic bearing. A model is developed from an experimental test facility and a number of simulation studies are performed. These results are presented and discussed.

  7. Research of auxiliary supporting means in swimming training of adults, which are afraid of water

    Directory of Open Access Journals (Sweden)

    Liliya Sheyko

    2015-02-01

    Full Text Available Purpose: to consider the possibility of effective teaching swimming adults suffering from hydrophobia, using auxiliary equipment. Materials and Methods: the study involved 37 people aged 22–45 years. Applied: analysis of the educational process of learning to swim, questioning, peer review techniques, teacher observation and experiment, mathematical statistics. Results: this study suggests that the formation of swimming skills is faster and more effective when used the auxiliary equipment. In the experimental group, four swimming styles were mastered by 59% and in the control by 18%. Conclusions: the proposed method of training of adults, with auxiliary equipment, allows to overcome the feelings of fear, accelerates the learning process and improve its efficiency.

  8. Aiming of Kirkpatrick-Baez microscope based on auxiliary optical system

    International Nuclear Information System (INIS)

    An auxiliary optical system has been designed, which can provide precise positioning for aiming Kirkpatrick-Baez (KB) microscope object location. An 8 keV X-ray imaging system by KB microscope with periodic multilayer films has been designed. The field of view and depth of field in the resolution of 5 μm are got, and then the corresponding point and depth of field in diagnostic experiments are calculated. Based on the object-image relations and precision of the KB microscope, an auxiliary visible light imaging system is designed and X-ray imaging experiments are performed, which can achieve equivalent aiming between the visible imaging system and the KB microscope. The results show that ±20 μm vertical axis plane and ±300 μm axial accuracy are achieved through the auxiliary optical path, which can meet the object point positioning requirements of the KB microscope. (authors)

  9. Multicriteria optimization of the investment in the auxiliary services of thermal power plants: A case study

    International Nuclear Information System (INIS)

    Highlights: • A multiobjective optimization model to improve the efficiency of auxiliary services. • Economic (investment and NPV) and energy saving criteria are considered. • Evolutionary multiobjective optimization is used for solving the problem with a DM. • A case study based on a real 1100 MW coal-fired power plant is considered. • Results show very profitable solutions from the economic and energy points of view. - Abstract: Thermal power plants have traditionally operated at rated power as base load, but nowadays they operate at partial loads because of the new situation of the electricity market. These plants have raised their auxiliary services consumption because, in most of the cases, the auxiliaries were not designed to efficiently operate at partial loads. This paper presents a multiple criteria study about the efficiency improvement of the auxiliary services. We consider the economic investment and the net present value, as economic criteria, together with the energy saving criterion. In the multiobjective model proposed, the energy model is validated using several measures taken in a 1100 megawatts coal power plant. Besides, the multiobjective problem associated to the case study considered is solved using evolutionary multiobjective optimization and considering preference information. The results obtained conclude that a significant efficiency improvement of the auxiliary services can be achieved by means of the improvement strategies considered. Indeed, the high net present values reached indicate that the investments required by the different solutions are really profitable from the economic perspective. Therefore, investing money in the efficiency improvement of the auxiliary services represents a very profitable option for improving the operation of power plants at partial loads

  10. Mars Rover Local Navigation And Hazard Avoidance

    Science.gov (United States)

    Wilcox, B. H.; Gennery, D. B.; Mishkin, A. H.

    1989-03-01

    A Mars rover sample return mission has been proposed for the late 1990's. Due to the long speed-of-light delays between Earth and Mars, some autonomy on the rover is highly desirable. JPL has been conducting research in two possible modes of rover operation, Computer-Aided Remote Driving and Semiautonomous Navigation. A recently-completed research program used a half-scale testbed vehicle to explore several of the concepts in semiautonomous navigation. A new, full-scale vehicle with all computational and power resources on-board will be used in the coming year to demonstrate relatively fast semiautonomous navigation. The computational and power requirements for Mars rover local navigation and hazard avoidance are discussed.

  11. Analysis of Ares 1 Ascent Navigation Options

    Science.gov (United States)

    Norris, Lee; Tao, Yee-Chee; Hall, Robert; Chuang, Jason; Whorton, Mark

    2008-01-01

    The paper documents a collaborative analysis of ascent Navigation options for the Ares 1 launch vehicle by the NASA Marshall Space Flight Center (MSFC) and the C. S. Draper Laboratory. The objective of the work was the development of a Navigation concept and supporting requirements which meet the Ares 1 accuracy specification in a manner which is straightforward, reliable, and cost effective. Six primary Navigation architectures were considered. In each case analysis was performed to determine under what conditions the required accuracy at second stage cutoff could be achieved. Those architectures which met the accuracy requirements were then assessed in terms of cost, complexity, and reliability to determine a baseline Navigation approach and the primary supporting requirements.

  12. 5th China Satellite Navigation Conference

    CERN Document Server

    Jiao, Wenhai; Wu, Haitao; Lu, Mingquan

    2014-01-01

    China Satellite Navigation Conference (CSNC) 2014 Proceedings presents selected research papers from CSNC2014, held on 21-23 May in Nanjing, China. The theme of CSNC2014 is 'BDS Application: Innovation, Integration and Sharing'. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou System (BDS) especially. They are divided into 9 topics to match the corresponding sessions in CSNC2014, which broadly covered key topics in GNSS. Readers can learn about the BDS and keep abreast of the latest advances in GNSS techniques and applications.  SUN Jiadong is the Chief Designer of the Compass/ BDS, and the Academician of Chinese Academy of Sciences (CAS); JIAO Wenhai is a researcher at China Satellite Navigation Office; WU Haitao is a professor at Navigation Headquarters, CAS; LU Mingquan is a professor at Department of Electronic Engineering of Tsinghua University.

  13. Indoor magnetic navigation for the blind.

    Science.gov (United States)

    Riehle, Timothy H; Anderson, Shane M; Lichter, Patrick A; Giudice, Nicholas A; Sheikh, Suneel I; Knuesel, Robert J; Kollmann, Daniel T; Hedin, Daniel S

    2012-01-01

    Indoor navigation technology is needed to support seamless mobility for the visually impaired. This paper describes the construction of and evaluation of a navigation system that infers the users' location using only magnetic sensing. It is well known that the environments within steel frame structures are subject to significant magnetic distortions. Many of these distortions are persistent and have sufficient strength and spatial characteristics to allow their use as the basis for a location technology. This paper describes the development and evaluation of a prototype magnetic navigation system consisting of a wireless magnetometer placed at the users' hip streaming magnetic readings to a smartphone processing location algorithms. Human trials were conducted to assess the efficacy of the system by studying route-following performance with blind and sighted subjects using the navigation system for real-time guidance. PMID:23366303

  14. Plenoptic Imager for Automated Surface Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Autonomous and semi-autonomous robotic systems require information about their surroundings in order to navigate properly. A video camera machine vision system can...

  15. NOAA Seamless Raster Navigational Charts (RNC)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Seamless Raster Chart Server provides a seamless collarless mosaic of the NOAA Raster Navigational Charts (RNC). The RNC are a collection of approximately...

  16. Observability analysis of Mars entry integrated navigation

    Science.gov (United States)

    Wang, Liansheng; Xia, Yuanqing

    2015-09-01

    This paper studies three schemes of Mars entry navigation: inertial measurement unit (IMU) based dead reckoning (DR), IMU/orbiter based integrated navigation, and IMU/orbiter/Mars surface beacon (MSB) based integrated navigation. We demonstrate through simulations that first scheme, IMU based DR, produces substantially large state estimation errors. Although these errors are reduced by adding two Mars orbiters, the system is only barely observable. However, by adding two MSBs in above configuration, the position and velocity estimation errors are reduced to the scope of 10 m and 0.5 m/s respectively and the navigation system becomes completely observable. Finally, the estimability of states is investigated; it is observed that velocity variables or velocity variables linear combinations can be estimated better than position variables.

  17. LEO AUTONOMOUS NAVIGATION BASED ON IMAGE MOTION

    Institute of Scientific and Technical Information of China (English)

    DUANFang; LIUJian-ye; YUFeng

    2005-01-01

    A method of LEO autonomous navigation is presented based on the nonlinear satellite velocity relative to the earth. The velocity is detected by a high-speed camera, with the attitude information detected by a star sensor. Compared with traditional autonomous navigation by landmark identification, the satellite velocity relarive to the earth is obtained by correlativity analysis of images. It does not need to recognize ground objects or views. Since it is not necessary to pre-store the database of ground marks, lots of memory space can be saved.The state and observation equations are constructed, and the filtering is processed by the Kalman filter. Simulation results show that the system has high autonomous navigation precision in LEO autonomous navigation.

  18. Navigation with a passive brain based interface

    NARCIS (Netherlands)

    Erp, J.B.F. van; Werkhoven, P.J.; Thurlings, M.E.; Brouwer, A.-M.

    2009-01-01

    In this paper, we describe a Brain Computer Interface (BCI) for navigation. The system is based on detecting brain signals that are elicited by tactile stimulation on the torso indicating the desired direction.

  19. Mars rover local navigation and hazard avoidance

    Science.gov (United States)

    Wilcox, B. H.; Gennery, D. B.; Mishkin, A. H.

    1989-01-01

    A Mars rover sample return mission has been proposed for the late 1990's. Due to the long speed-of-light delays between earth and Mars, some autonomy on the rover is highly desirable. JPL has been conducting research in two possible modes of rover operation, Computer-Aided Remote Driving and Semiautonomous Navigation. A recently-completed research program used a half-scale testbed vehicle to explore several of the concepts in semiautonomous navigation. A new, full-scale vehicle with all computational and power resources on-board will be used in the coming year to demonstrate relatively fast semiautonomous navigation. The computational and power requirements for Mars rover local navigation and hazard avoidance are discussed.

  20. Unifying the PST and the auxiliary tensor field formulations of 4D self-duality

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, E.A., E-mail: eivanov@theor.jinr.ru [Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna, Moscow Region 141980 (Russian Federation); Nurmagambetov, A.J., E-mail: ajn@kipt.kharkov.ua [Akhiezer Institute for Theoretical Physics of NSC KIPT, Kharkov, UA 61108 (Ukraine); Zupnik, B.M., E-mail: zupnik@theor.jinr.ru [Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna, Moscow Region 141980 (Russian Federation)

    2014-04-04

    We unify the Lorentz- and O(2) duality-covariant approach to 4D self-dual theories by Pasti, Sorokin and Tonin (PST) with the formulation involving an auxiliary tensor field. We present the basic features of the new hybrid approach, including symmetries of the relevant generalized PST action. Its salient peculiarity is the unique form of the realization of the PST gauge symmetries. The corresponding transformations do not affect the auxiliary tensor field, which guarantees the self-duality of the nonlinear actions in which the O(2) invariant interactions are constructed out of the tensor field.

  1. Unifying the PST and the auxiliary tensor field formulations of 4D self-duality

    International Nuclear Information System (INIS)

    We unify the Lorentz- and O(2) duality-covariant approach to 4D self-dual theories by Pasti, Sorokin and Tonin (PST) with the formulation involving an auxiliary tensor field. We present the basic features of the new hybrid approach, including symmetries of the relevant generalized PST action. Its salient peculiarity is the unique form of the realization of the PST gauge symmetries. The corresponding transformations do not affect the auxiliary tensor field, which guarantees the self-duality of the nonlinear actions in which the O(2) invariant interactions are constructed out of the tensor field.

  2. Unifying the PST and the auxiliary tensor field formulations of 4D self-duality

    CERN Document Server

    Ivanov, E A; Zupnik, B M

    2014-01-01

    We unify the Lorentz- and O(2) duality-covariant approach to 4D self-dual theories by Pasti, Sorokin and Tonin (PST) with the formulation involving an auxiliary tensor field. We present the basic features of the new hybrid approach, including symmetries of the relevant generalized PST action. Its salient peculiarity is the unique form of the realization of the PST gauge symmetries. The corresponding transformations do not affect the auxiliary tensor field, which guarantees the self-duality of the non-linear actions in which the O(2) invariant interactions are constructed out of the tensor field.

  3. Unifying the PST and the auxiliary tensor field formulations of 4D self-duality

    Science.gov (United States)

    Ivanov, E. A.; Nurmagambetov, A. J.; Zupnik, B. M.

    2014-04-01

    We unify the Lorentz- and O(2) duality-covariant approach to 4D self-dual theories by Pasti, Sorokin and Tonin (PST) with the formulation involving an auxiliary tensor field. We present the basic features of the new hybrid approach, including symmetries of the relevant generalized PST action. Its salient peculiarity is the unique form of the realization of the PST gauge symmetries. The corresponding transformations do not affect the auxiliary tensor field, which guarantees the self-duality of the nonlinear actions in which the O(2) invariant interactions are constructed out of the tensor field.

  4. Auxiliary matrix formalism for interaction representation transformations, optimal control, and spin relaxation theories

    Science.gov (United States)

    Goodwin, D. L.; Kuprov, Ilya

    2015-08-01

    Auxiliary matrix exponential method is used to derive simple and numerically efficient general expressions for the following, historically rather cumbersome, and hard to compute, theoretical methods: (1) average Hamiltonian theory following interaction representation transformations; (2) Bloch-Redfield-Wangsness theory of nuclear and electron relaxation; (3) gradient ascent pulse engineering version of quantum optimal control theory. In the context of spin dynamics, the auxiliary matrix exponential method is more efficient than methods based on matrix factorizations and also exhibits more favourable complexity scaling with the dimension of the Hamiltonian matrix.

  5. Solar combisystems with forecast control to increase the solar fraction and lower the auxiliary energy cost

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Fan, Jianhua;

    2011-01-01

    Solar Combi systems still need quite a lot of auxiliary energy especially in small systems without seasonal storage possibilities. The control of the auxiliary energy input both in time and power is important to utilize as much as possible of the solar energy available from the collectors and also...... energy sources. It can be either direct electric heating elements or a heat pump upgrading ambient energy in the air, ground, solar collector or waste heat from the house. The paper describes system modeling and simulation results. Advanced laboratory experiments are also starting now with three...

  6. [Impact of directly compressed auxiliary materials on powder property of fermented cordyceps powder].

    Science.gov (United States)

    Chen, Li-Hua; Yue, Guo-Chao; Guan, Yong-Mei; Yang, Ming; Zhu, Wei-Feng

    2014-01-01

    To investigate such physical indexes as hygroscopicity, angle of repose, bulk density, fillibility of compression of mixed powder of directly compressed auxiliary materials and fermented cordyceps powder by using micromeritic study methods. The results showed that spray-dried lactose Flowlac100 and microcrystalline cellulose Avicel PH102 had better effect in liquidity and compressibility on fermented cordyceps powder than pregelatinized starch. The study on the impact of directly compressed auxiliary materials on the powder property of fermented cordyceps powder had guiding significant to the research of fermented cordyceps powder tablets, and could provide basis for the development of fermented cordyceps powder tablets. PMID:24754170

  7. Construction Report of Separate Effect Test Facility for Passive Auxiliary Feedwater System (PASCAL)

    International Nuclear Information System (INIS)

    A separate effect test facility for PAFS(Passive Auxiliary Feedwater System, PAFS), PASCAL, was constructed to evaluate the cooling performance of PAFS and the condensation heat transfer models. This report includes the scope of the separate effect tests, the design of PASCAL facility, and measuring principles. From the design and construction of the separate effect test facility, PASCAL facility was composed of the fluid system, the auxiliary system, the measurement system, the electricity system, the control system and the data acquisition system. This report will be utilized to make the experiment procedure and perform the test

  8. MARS calculation of PAFS (passive auxiliary feedwater system) heat exchanger in APR+

    International Nuclear Information System (INIS)

    APR+ (Advanced Power Reactor Plus), the next generation nuclear power plant in Korea, adopts PAFS (Passive Auxiliary Feedwater System) as one of the advanced safety feature. To design the condensation heat exchanger in PAFS, the two-phase flow phenomena in horizontal U-tube and PCCT (Passive Condensate Cooling Tank) were investigated by MARS calculation. By benchmarking with NOKO experimental result, MARS code showed a reasonable capability to quantitatively predict the condensation in horizontal tube heat exchanger. And the design of PAFS heat exchanger was proved to sufficiently remove the decay heat by the condensation heat transfer without any active auxiliary feedwater system

  9. Evaluation of Effect of N2 Gas on the Cooling Capability of Passive Auxiliary Feedwater System

    International Nuclear Information System (INIS)

    Advanced Power Reactor Plus (APR+), a next generation nuclear power plant in Korea, adopts Passive Auxiliary Feedwater System (PAFS) to replace the conventional active auxiliary feedwater system. Because PAFS removes decay heat from the reactor core, it is required to verify the performance of PAFS in postulated accidents cases. In addition, an effect of non-condensable gas such as N2 gas on the heat removal capability of PAFS should be evaluated since the non-condensable gas may deteriorate a condensation heat transfer through the condensation heat exchanger in PAFS. In this study, MARS code is used to evaluate the effect of N2 gas

  10. Outdoor testing of solar water heaters - Effects of load pattern and auxiliary boosting

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, G.L.; Gilliaert, D.; Tebaldi, P. (Commission of the European Communities, Ispra (Italy))

    1992-10-01

    The effect of load draw-off pattern and auxiliary boosting on the performance of vertical and horizontal tank solar water heaters is investigated. The selection of an appropriate load pattern to use in a performance rating test is shown to depend on the type of system. The primary factor governing the dependence of performance on load pattern in single tank systems is conduction between the auxiliary boosted zone and the solar preheat zone. A method of quantifying the effect of conduction in solar tanks is presented.

  11. MARS calculation of PAFS (passive auxiliary feedwater system) heat exchanger in APR+

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Byoung Uhn; Yun, Byong Jo; Bae, Sung Won; Choi, Ki Yong; Song, Chul Hwa [KAERI, Daejeon (Korea, Republic of); Cheon, Jong [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2009-07-01

    APR+ (Advanced Power Reactor Plus), the next generation nuclear power plant in Korea, adopts PAFS (Passive Auxiliary Feedwater System) as one of the advanced safety feature. To design the condensation heat exchanger in PAFS, the two-phase flow phenomena in horizontal U-tube and PCCT (Passive Condensate Cooling Tank) were investigated by MARS calculation. By benchmarking with NOKO experimental result, MARS code showed a reasonable capability to quantitatively predict the condensation in horizontal tube heat exchanger. And the design of PAFS heat exchanger was proved to sufficiently remove the decay heat by the condensation heat transfer without any active auxiliary feedwater system.

  12. Auxiliary matrix formalism for interaction representation transformations, optimal control, and spin relaxation theories

    International Nuclear Information System (INIS)

    Auxiliary matrix exponential method is used to derive simple and numerically efficient general expressions for the following, historically rather cumbersome, and hard to compute, theoretical methods: (1) average Hamiltonian theory following interaction representation transformations; (2) Bloch-Redfield-Wangsness theory of nuclear and electron relaxation; (3) gradient ascent pulse engineering version of quantum optimal control theory. In the context of spin dynamics, the auxiliary matrix exponential method is more efficient than methods based on matrix factorizations and also exhibits more favourable complexity scaling with the dimension of the Hamiltonian matrix

  13. Indoor Navigation Using an iPhone

    OpenAIRE

    Emilsson, André

    2010-01-01

    Indoor navigation could be used in many applications to enhance performance in its specific area. Anything from serious life critical tasks like aiding firefighters or coordinating military attacks to more simple every day use like finding a desired shop in a large supermarket could be considered. Smartphones of today introduce an interesting platform with capabilities like existing, more clumsy, indoor navigation systems. The iPhone 3GS is a powerful smartphone that lets the programmer use i...

  14. Inertial Navigation and Mapping for Autonomous Vehicles

    OpenAIRE

    Skoglund, Martin

    2014-01-01

    Navigation and mapping in unknown environments is an important building block for increased autonomy of unmanned vehicles, since external positioning systems can be susceptible to interference or simply being inaccessible. Navigation and mapping require signal processing of vehicle sensor data to estimate motion relative to the surrounding environment and to simultaneously estimate various properties of the surrounding environment. Physical models of sensors, vehicle motion and external influ...

  15. Electromagnetic tracking and steering for catheter navigation

    OpenAIRE

    O'Donoghue, Kilian

    2014-01-01

    This thesis explores the use of electromagnetics for both steering and tracking of medical instruments in minimally invasive surgeries. The end application is virtual navigation of the lung for biopsy of early stage cancer nodules. Navigation to the peripheral regions of the lung is difficult due to physical dimensions of the bronchi and current methods have low successes rates for accurate diagnosis. Firstly, the potential use of DC magnetic fields for the actuation of catheter devices with ...

  16. Precise laser gyroscope for autonomous inertial navigation

    International Nuclear Information System (INIS)

    Requirements to gyroscopes of strapdown inertial navigation systems for aircraft application are formulated. The construction of a ring helium – neon laser designed for autonomous navigation is described. The processes that determine the laser service life and the relation between the random error of the angular velocity measurement and the surface relief features of the cavity mirrors are analysed. The results of modelling one of the promising approaches to processing the laser gyroscope signals are presented. (laser gyroscopes)

  17. 19 CFR 4.98 - Navigation fees.

    Science.gov (United States)

    2010-04-01

    ... calculated in accordance with § 24.17(d) Customs Regulations (19 CFR 24.17(d)), and be based upon the amount... 19 Customs Duties 1 2010-04-01 2010-04-01 false Navigation fees. 4.98 Section 4.98 Customs Duties... VESSELS IN FOREIGN AND DOMESTIC TRADES General § 4.98 Navigation fees. (a)(1) The Customs Service...

  18. Applying AHP to Web Navigation Design

    OpenAIRE

    Su-Hua Wang; Che-Hung Lin

    2008-01-01

    Due to increasing popularity of the World Wide Web, web-based systems are widely used. Most corporate web sites try to enhance their usability by providing artistic web presentations. However, the design of web sites is not judged solely on an artistic basis. Two of the most important design criteria for web sites are access to web content and navigation architecture. This research proposes a platform for automatically evaluating the quality of web navigation architecture. Because of the hier...

  19. An integrated platform for inertial navigation systems

    Science.gov (United States)

    Dumitrascu, Ana; Tamas, Razvan D.; Caruntu, George; Bobirca, Daniel

    2015-02-01

    In this paper we propose a new configuration for an inertial navigation system (INS), type strap down, designed to be used onboard a ship. The system consists of an inertial navigation unit (IMU), using a 9-axis inertial sensor and pressure and temperature sensors, a GPS module, various interfaces for optimal communication and command, a microcontroller for data processing and computing and a power supply.

  20. VOR area navigation - Techniques and results

    Science.gov (United States)

    Ragsdale, W. A.

    1982-01-01

    Several methods for deriving position from VOR (without DME) have been developed and evaluated in this study. These methods permit navigation to arbitrary waypoints using either two VOR's or one VOR and a clock. These algorithms have been tested in computer simulations and in flight tests. The single VOR method appears to be the most practical and is a candidate for an automated light plane area navigation system, called VORNAV.

  1. Neurobiologically inspired mobile robot navigation and planning

    OpenAIRE

    Mathias Quoy

    2007-01-01

    After a short review of biologically inspired navigation architectures, mainly relying on modeling the hippocampal anatomy, or at least some of its functions, we present a navigation and planning model for mobile robots. This architecture is based on a model of the hippocampal and prefrontal interactions. In particular, the system relies on the definition of a new cell type “transition cells” that encompasses traditional “place cells”.

  2. Neurobiologically Inspired Mobile Robot Navigation and Planning

    OpenAIRE

    Cuperlier, Nicolas; Quoy, Mathias; Gaussier, Philippe

    2007-01-01

    After a short review of biologically inspired navigation architectures, mainly relying on modeling the hippocampal anatomy, or at least some of its functions, we present a navigation and planning model for mobile robots. This architecture is based on a model of the hippocampal and prefrontal interactions. In particular, the system relies on the definition of a new cell type “transition cells” that encompasses traditional “place cells”.

  3. Neurobiologically inspired mobile robot navigation and planning

    Directory of Open Access Journals (Sweden)

    Mathias Quoy

    2007-11-01

    Full Text Available After a short review of biologically inspired navigation architectures, mainly relying on modeling the hippocampal anatomy, or at least some of its functions, we present a navigation and planning model for mobile robots. This architecture is based on a model of the hippocampal and prefrontal interactions. In particular, the system relies on the definition of a new cell type “transition cells” that encompasses traditional “place cells”.

  4. A Real-Time Autonomous Navigation Architecture

    OpenAIRE

    Chen, Gang; Fraichard, Thierry; Martinez-Gomez, Luis

    2007-01-01

    This paper presents a novel navigation architecture for automated car-like vehicles in urban environments. Motion safety is a critical issue in such environments given that they are partially known and highly dynamic with moving objects (other vehicles, pedestrians...). The main feature of the navigation architecture proposed is its ability to make safe motion decisions in real-time, thus taking into account the harsh constraints imposed by the type of environments considered. The architectur...

  5. Autonomous navigation and sign detector learning

    OpenAIRE

    Ellis, Liam; Pugeault, Nicolas; Öfjäll, Kristoffer; Hedborg, Johan; Bowden, Richard; Felsberg, Michael

    2013-01-01

    This paper presents an autonomous robotic system that incorporates novel Computer Vision, Machine Learning and Data Mining algorithms in order to learn to navigate and discover important visual entities. This is achieved within a Learning from Demonstration (LfD) framework, where policies are derived from example state-to-action mappings. For autonomous navigation, a mapping is learnt from holistic image features (GIST) onto control parameters using Random Forest regression. Additionally, vis...

  6. Precise laser gyroscope for autonomous inertial navigation

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, A G; Molchanov, A V; Izmailov, E A [Joint Stock Company ' Moscow Institute of Electromechanics and Automatics' , Moscow (Russian Federation); Chirkin, M V [Ryazan State Radio Engineering University (Russian Federation)

    2015-01-31

    Requirements to gyroscopes of strapdown inertial navigation systems for aircraft application are formulated. The construction of a ring helium – neon laser designed for autonomous navigation is described. The processes that determine the laser service life and the relation between the random error of the angular velocity measurement and the surface relief features of the cavity mirrors are analysed. The results of modelling one of the promising approaches to processing the laser gyroscope signals are presented. (laser gyroscopes)

  7. Effectiveness and Ergonomics of Integrated Navigation System

    OpenAIRE

    Vidan, Pero; Stanivuk, Tatjana; Bielić, Toni

    2012-01-01

    Ergonomics increases the efficiency of people and device interaction. Nowadays, modern navigation bridges are designed in accordance with the requirements of navigators, designers and shipowners, production costs etc. The bridge design, various layouts, instrument arrangements and their capacities etc. have not been fully regulated by the SOLAS convention. The Convention regulates manufacturers’ requirements which refer to accuracy, device sensitivity etc. However, factors that are important ...

  8. Mobility and Navigation among the Yucatec Maya

    OpenAIRE

    Cashdan, Elizabeth; Kramer, Karen L.; Davis, Helen E.; Padilla, Lace; Greaves, Russell D.

    2015-01-01

    Sex differences in range size and navigation are widely reported, with males traveling farther than females, being less spatially anxious, and in many studies navigating more effectively. One explanation holds that these differences are the result of sexual selection, with larger ranges conferring mating benefits on males, while another explanation focuses on greater parenting costs that large ranges impose on reproductive-aged females. We evaluated these arguments with data from a community ...

  9. Location Assurance and Privacy in GNSS Navigation

    OpenAIRE

    Chen, Xihui; Harpes, Carlo; Lenzini, Gabriele; Mauw, Sjouke; Pang, Jun

    2013-01-01

    The growing popularity of location-based services such as GNSS (Global Navigation Satellite System) navigation requires confidence in the reliability of the calculated locations. The exploration of a user’s location also gives rise to severe privacy concerns. Within an ESA (European Space Agency) funded project, we have developed a service that not only verifies the correctness of users’ locations but also enables users to control the accuracy of their revealed locations.

  10. Interactive learning of visual topological navigation

    OpenAIRE

    Filliat, David

    2008-01-01

    International audience We present a topological navigation system that is able to visually recognize the different rooms of an apartment and guide a robot between them. Specifically tailored for small entertainment robots, the system relies on vision only and learns its navigation capabilities incrementally by interacting with a user. This continuous learning strategy makes the system particularly adaptable to environmental lighting and structure modifications. From the computer vision poi...

  11. Neural representation of navigational relevance is rapidly induced and long lasting.

    Science.gov (United States)

    Janzen, Gabriele; Wagensveld, Barbara; van Turennout, Miranda

    2007-04-01

    Successful navigation is facilitated by the presence of landmarks. Previous functional magnetic resonance imaging (fMRI) evidence indicated that the human parahippocampal gyrus automatically distinguishes between landmarks placed at navigationally relevant (decision points) and irrelevant locations (nondecision points). This storage of navigational relevance can provide a neural mechanism underlying successful navigation. However, an efficient wayfinding mechanism requires that important spatial information is learned quickly and maintained over time. The present study investigates whether the representation of navigational relevance is modulated by time and practice. Participants learned 2 film sequences through virtual mazes containing objects at decision and at nondecision points. One maze was shown one time, and the other maze was shown 3 times. Twenty-four hours after study, event-related fMRI data were acquired during recognition of the objects. The results showed that activity in the parahippocampal gyrus was increased for objects previously placed at decision points as compared with objects placed at nondecision points. The decision point effect was not modulated by the number of exposures to the mazes and independent of explicit memory functions. These findings suggest a persistent representation of navigationally relevant information, which is stable after only one exposure to an environment. These rapidly induced and long-lasting changes in object representation provide a basis for successful wayfinding. PMID:16751297

  12. Target Relative Navigation Results from Hardware-in-the-Loop Tests Using the SINPLEX Navigation System

    OpenAIRE

    Steffes, Stephen; Dumke, Michael; Heise, David; Sagliano, Marco; Samaan, Malak; Theil, Stephan

    2014-01-01

    The goal of the SINPLEX project is to develop an innovative solution to significantly reduce the mass of the navigation subsystem for exploration missions which include landing and/or rendezvous and capture phases. The system mass is reduced while still maintaining good navigation performance as compared to a conventional modular system. This is done by functionally integrating the navigation sensors, using micro- and nanotechnology to miniaturize electronics and fusing the sen...

  13. Simulation-based validation of navigation filter software for a shallow water AUV navigation system (SANS)

    OpenAIRE

    Steven, Ruediger.

    1996-01-01

    Navigation filter software is currently being developed for an inertial navigation system without rotating gyros. This system shall replace the navigation system that is currently used in the Phoenix Autonomous Underwater Vehicle of the Naval Postgraduate School. The filter combines acceleration sensors, angular rate sensors, a water speed sensor, a magnetic compass and a GPS system. The harmonization of the sensors is performed by gain matrices. The filter code must be tested for correctness...

  14. The Mathematics of Navigating the Solar System

    Science.gov (United States)

    Hintz, Gerald

    2000-01-01

    In navigating spacecraft throughout the solar system, the space navigator relies on three academic disciplines - optimization, estimation, and control - that work on mathematical models of the real world. Thus, the navigator determines the flight path that will consume propellant and other resources in an efficient manner, determines where the craft is and predicts where it will go, and transfers it onto the optimal trajectory that meets operational and mission constraints. Mission requirements, for example, demand that observational measurements be made with sufficient precision that relativity must be modeled in collecting and fitting (the estimation process) the data, and propagating the trajectory. Thousands of parameters are now determined in near real-time to model the gravitational forces acting on a spacecraft in the vicinity of an irregularly shaped body. Completing these tasks requires mathematical models, analyses, and processing techniques. Newton, Gauss, Lambert, Legendre, and others are justly famous for their contributions to the mathematics of these tasks. More recently, graduate students participated in research to update the gravity model of the Saturnian system, including higher order gravity harmonics, tidal effects, and the influence of the rings. This investigation was conducted for the Cassini project to incorporate new trajectory modeling features in the navigation software. The resulting trajectory model will be used in navigating the 4-year tour of the Saturnian satellites. Also, undergraduate students are determining the ephemerides (locations versus time) of asteroids that will be used as reference objects in navigating the New Millennium's Deep Space 1 spacecraft autonomously.

  15. Sensor fusion for improved indoor navigation

    Science.gov (United States)

    Emilsson, Erika; Rydell, Joakim

    2012-09-01

    A reliable indoor positioning system providing high accuracy has the potential to increase the safety of first responders and military personnel significantly. To enable navigation in a broad range of environments and obtain more accurate and robust positioning results, we propose a multi-sensor fusion approach. We describe and evaluate a positioning system, based on sensor fusion between a foot-mounted inertial measurement unit (IMU) and a camera-based system for simultaneous localization and mapping (SLAM). The complete system provides accurate navigation in many relevant environments without depending on preinstalled infrastructure. The camera-based system uses both inertial measurements and visual data, thereby enabling navigation also in environments and scenarios where one of the sensors provides unreliable data during a few seconds. When sufficient light is available, the camera-based system generally provides good performance. The foot-mounted system provides accurate positioning when distinct steps can be detected, e.g., during walking and running, even in dark or smoke-filled environments. By combining the two systems, the integrated positioning system can be expected to enable accurate navigation in almost all kinds of environments and scenarios. In this paper we present results from initial tests, which show that the proposed sensor fusion improves the navigation solution considerably in scenarios where either the foot-mounted or camera-based system is unable to navigate on its own.

  16. NFC internal: an indoor navigation system.

    Science.gov (United States)

    Ozdenizci, Busra; Coskun, Vedat; Ok, Kerem

    2015-01-01

    Indoor navigation systems have recently become a popular research field due to the lack of GPS signals indoors. Several indoors navigation systems have already been proposed in order to eliminate deficiencies; however each of them has several technical and usability limitations. In this study, we propose NFC Internal, a Near Field Communication (NFC)-based indoor navigation system, which enables users to navigate through a building or a complex by enabling a simple location update, simply by touching NFC tags those are spread around and orient users to the destination. In this paper, we initially present the system requirements, give the design details and study the viability of NFC Internal with a prototype application and a case study. Moreover, we evaluate the performance of the system and compare it with existing indoor navigation systems. It is seen that NFC Internal has considerable advantages and significant contributions to existing indoor navigation systems in terms of security and privacy, cost, performance, robustness, complexity, user preference and commercial availability. PMID:25825976

  17. NFC Internal: An Indoor Navigation System

    Directory of Open Access Journals (Sweden)

    Busra Ozdenizci

    2015-03-01

    Full Text Available Indoor navigation systems have recently become a popular research field due to the lack of GPS signals indoors. Several indoors navigation systems have already been proposed in order to eliminate deficiencies; however each of them has several technical and usability limitations. In this study, we propose NFC Internal, a Near Field Communication (NFC-based indoor navigation system, which enables users to navigate through a building or a complex by enabling a simple location update, simply by touching NFC tags those are spread around and orient users to the destination. In this paper, we initially present the system requirements, give the design details and study the viability of NFC Internal with a prototype application and a case study. Moreover, we evaluate the performance of the system and compare it with existing indoor navigation systems. It is seen that NFC Internal has considerable advantages and significant contributions to existing indoor navigation systems in terms of security and privacy, cost, performance, robustness, complexity, user preference and commercial availability.

  18. Fuzzy Adaptive Cubature Kalman Filter for Integrated Navigation Systems

    Directory of Open Access Journals (Sweden)

    Chien-Hao Tseng

    2016-07-01

    Full Text Available This paper presents a sensor fusion method based on the combination of cubature Kalman filter (CKF and fuzzy logic adaptive system (FLAS for the integrated navigation systems, such as the GPS/INS (Global Positioning System/inertial navigation system integration. The third-degree spherical-radial cubature rule applied in the CKF has been employed to avoid the numerically instability in the system model. In processing navigation integration, the performance of nonlinear filter based estimation of the position and velocity states may severely degrade caused by modeling errors due to dynamics uncertainties of the vehicle. In order to resolve the shortcoming for selecting the process noise covariance through personal experience or numerical simulation, a scheme called the fuzzy adaptive cubature Kalman filter (FACKF is presented by introducing the FLAS to adjust the weighting factor of the process noise covariance matrix. The FLAS is incorporated into the CKF framework as a mechanism for timely implementing the tuning of process noise covariance matrix based on the information of degree of divergence (DOD parameter. The proposed FACKF algorithm shows promising accuracy improvement as compared to the extended Kalman filter (EKF, unscented Kalman filter (UKF, and CKF approaches.

  19. Fuzzy Adaptive Cubature Kalman Filter for Integrated Navigation Systems.

    Science.gov (United States)

    Tseng, Chien-Hao; Lin, Sheng-Fuu; Jwo, Dah-Jing

    2016-01-01

    This paper presents a sensor fusion method based on the combination of cubature Kalman filter (CKF) and fuzzy logic adaptive system (FLAS) for the integrated navigation systems, such as the GPS/INS (Global Positioning System/inertial navigation system) integration. The third-degree spherical-radial cubature rule applied in the CKF has been employed to avoid the numerically instability in the system model. In processing navigation integration, the performance of nonlinear filter based estimation of the position and velocity states may severely degrade caused by modeling errors due to dynamics uncertainties of the vehicle. In order to resolve the shortcoming for selecting the process noise covariance through personal experience or numerical simulation, a scheme called the fuzzy adaptive cubature Kalman filter (FACKF) is presented by introducing the FLAS to adjust the weighting factor of the process noise covariance matrix. The FLAS is incorporated into the CKF framework as a mechanism for timely implementing the tuning of process noise covariance matrix based on the information of degree of divergence (DOD) parameter. The proposed FACKF algorithm shows promising accuracy improvement as compared to the extended Kalman filter (EKF), unscented Kalman filter (UKF), and CKF approaches. PMID:27472336

  20. Reference frames in virtual spatial navigation are viewpoint dependent

    Directory of Open Access Journals (Sweden)

    Ágoston eTörök

    2014-09-01

    Full Text Available Spatial navigation in the mammalian brain relies on a cognitive map of the environment. Such cognitive maps enable us, for example, to take the optimal route from a given location to a known target. The formation of these maps is naturally influenced by our perception of the environment, meaning it is dependent on factors such as our viewpoint and choice of reference frame. Yet, it is unknown how these factors influence the construction of cognitive maps. Here, we evaluated how various combinations of viewpoints and reference frames affect subjects’ performance when they navigated in a bounded virtual environment without landmarks. We measured both their path length and time efficiency and found that (i ground perspective was associated with egocentric frame of reference, (ii aerial perspective was associated with allocentric frame of reference, (iii there was no appreciable performance difference between first and third person egocentric viewing positions and (iv while none of these effects were dependent on gender, males tended to perform better in general. Our study provides evidence that there are inherent associations between visual perspectives and cognitive reference frames. This result has implications about the mechanisms of path integration in the human brain and may also inspire designs of virtual reality applications. Lastly, we demonstrated the effective use of a tablet PC and spatial navigation tasks for studying spatial and cognitive aspects of human memory.

  1. GPS/MEMS IMU/Microprocessor Board for Navigation

    Science.gov (United States)

    Gender, Thomas K.; Chow, James; Ott, William E.

    2009-01-01

    A miniaturized instrumentation package comprising a (1) Global Positioning System (GPS) receiver, (2) an inertial measurement unit (IMU) consisting largely of surface-micromachined sensors of the microelectromechanical systems (MEMS) type, and (3) a microprocessor, all residing on a single circuit board, is part of the navigation system of a compact robotic spacecraft intended to be released from a larger spacecraft [e.g., the International Space Station (ISS)] for exterior visual inspection of the larger spacecraft. Variants of the package may also be useful in terrestrial collision-detection and -avoidance applications. The navigation solution obtained by integrating the IMU outputs is fed back to a correlator in the GPS receiver to aid in tracking GPS signals. The raw GPS and IMU data are blended in a Kalman filter to obtain an optimal navigation solution, which can be supplemented by range and velocity data obtained by use of (l) a stereoscopic pair of electronic cameras aboard the robotic spacecraft and/or (2) a laser dynamic range imager aboard the ISS. The novelty of the package lies mostly in those aspects of the design of the MEMS IMU that pertain to controlling mechanical resonances and stabilizing scale factors and biases.

  2. A clinical study of navigation accuracy during surgery

    International Nuclear Information System (INIS)

    It is essential to implement image-guided surgery or neuronavigation technologies that can be applied during functional surgery to localize targets accurately in the surgical field. Various navigation systems have been developed, such as the optical system and mechanical-arm-based system, to localize targets in the operative field. However, either the reference system, in optical systems, or the arm joint, in mechanical-arm-based systems, can sometimes interfere with surgical maneuvers. Therefore, we used the magnetic-force-based Computed Assisted Neurosurgery system (CANS system, Shimadzu, Co. Ltd., Kyoto, Japan) for neuronavigation. The purpose of this study was to evaluate the accuracy of the CANS navigation system. Ten patients with medically refractory epilepsy underwent implantation of subdural electrode grids to detect the epilepsy focus, and then lobectomy or multiple subpial transection was performed after informed consent was obtained. The male/female ratio was 6:4 and the mean age was 30.7 years. The CANS navigator system consists mainly of a magnetic source, a localizer probe with magnetic sensor, a three-dimensional locating measuring instrument (digitizer), an image scanner, and a personal computer. To determine the localization accuracy, the probe was moved on the subdural electrode grid which typically consists of 64 or 16 platinum-iridium electrode contacts (3 mm in the diameter) embedded in a Silastic sheet. The array of electrodes was 8 x 8 cm or 2 x 8 cm and the center-to-center inter-electrode distance was 10 mm. We evaluated the inter-electrode distances and spatial relationships among the electrodes to quantitate the precision of the probe tip localization and assumed the nasion origin reference system to assess the distribution of target coordinates. The measurement errors of each component derived from different planes for the same targets were evaluated in ten patients. The error in X-dimension ranged from 0.38 mm to 7.8 mm, the error in Y

  3. 46 CFR 61.20-3 - Main and auxiliary machinery and associated equipment, including fluid control systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Main and auxiliary machinery and associated equipment... SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND INSPECTIONS Periodic Tests of Machinery and Equipment § 61.20-3 Main and auxiliary machinery and associated equipment, including fluid control...

  4. Acylation, Diastereoselective Alkylation, and Cleavage of an Oxazolidinone Chiral Auxiliary: A Multistep Asymmetric Synthesis Experiment for Advanced Undergraduates

    Science.gov (United States)

    Smith, Thomas E.; Richardson, David P.; Truran, George A.; Belecki, Katherine; Onishi, Megumi

    2008-01-01

    An introduction to the concepts and experimental techniques of diastereoselective synthesis using a chiral auxiliary is described. The 4-benzyl-2-oxazolidinone chiral auxiliary developed by Evans is acylated with propionic anhydride under mild conditions using DMAP as an acyl transfer catalyst. Deprotonation with NaN(TMS)[subscript 2] at -78…

  5. Research on Auxiliary Staff's Work in Universities and the Vocational Quality Promotion%高校教辅人员工作现状及职业素质提升路径研究

    Institute of Scientific and Technical Information of China (English)

    郭翠婷

    2013-01-01

      高校教辅人员普遍存在工作任务繁琐复杂、精神压力过大、人员流动频繁的现状。加强高校教辅人员的专业化和职业化建设是改变教辅人员工作现状的重要路径,为此,应通过提升思想境界、准确定位角色;增强竞争意识、完善职业规划;健全科研机制,挖掘科研能力等方面来提升高校教辅人员的职业素质。%The auxiliary staff plays an increasingly important role in universities , yet surveys show that the difficult task and heavy responsibility resulted in their great mental stress and frequent flow of persons . Strengthening the construction of specialization and professionalization of auxiliary staff in the University is the important way to change the status of auxiliary staff . For this purpose , it should be done by promoting the ideological awareness , increasing competition , improving career planning ;perfecting scientific research mechanism , developing research capacity to enhance the auxiliary staff's professional quality in universities .

  6. 33 CFR 245.20 - Determination of hazard to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Determination of hazard to..., DEPARTMENT OF DEFENSE REMOVAL OF WRECKS AND OTHER OBSTRUCTIONS § 245.20 Determination of hazard to navigation... Coast Guard district to jointly determine whether the obstruction poses a hazard to navigation....

  7. Cognitive Costs of Navigation Aids in Hypermedia Learning

    Science.gov (United States)

    Waniek, Jacqueline; Ewald, Karolin

    2008-01-01

    This study examines the cognitive costs of navigation aids in a hypermedia learning task. In a 2(navigable vs. non-navigable) x 2(map vs. content list) experimental design cognitive requirements were measured by users' eye movement data. Additionally, data from users' navigation operations, knowledge acquisition, and subjective evaluation of the…

  8. Computer determination of event maps with application to auxiliary supply systems

    International Nuclear Information System (INIS)

    A method of evaluating the reliability of sequential operations in systems containing standby and alternate supply facilities is presented. The method is based upon the use of a digital computer for automatic development of event maps. The technique is illustrated by application to a nuclear power plant auxiliary supply system. (author)

  9. An auxiliary equation technique and exact solutions for a nonlinear Klein-Gordon equation

    International Nuclear Information System (INIS)

    A mathematical technique based on an auxiliary equation and the symbolic computation system Matlab is developed to construct the exact travelling wave solutions to a nonlinear Klein-Gordon equation. Some new solutions including the Jacobi elliptic function solutions, the degenerated soliton-like solutions and the triangle function solutions to the equation are obtained.

  10. Application of the Method of Auxiliary Sources for the Analysis of Electromagnetic Scattering by Impedance Spheres

    DEFF Research Database (Denmark)

    Karamehmedovic, Mirza; Breinbjerg, Olav

    2002-01-01

    The Method of Auxiliary Sources (MAS) is applied to 3D scattering problems involving spherical impedance scatterers. The MAS results are compared with the reference spherical wave expansion (SWE) solution. It is demonstrated that good agreement is achieved between the MAS and SWE results....

  11. Dynamic Response during the Online Compensation of Misalignment Based on Auxiliary Electromagnetic Support

    Institute of Scientific and Technical Information of China (English)

    LI Hui-min; LI Yan; HE Yong

    2008-01-01

    A new support structure,named auxiliary electromagnetic support,is introduced to adjust the position of rotor shaft online.The auxiliary electromagnetic support consists of sliding bearing,iron core,radial spring,pedestal and electroraagnet that could adjust the rotor position.In a rotor system adopting two auxiliary electromagnetic supports,the online compensation of misalignment was achieved without stopping work.Using the proposed auxiliary electromagnetic support,the analytical solution of dynamic response was obtained by analyzing a simulated single-degree-of-freedom(SDOF)system.And the dynamic response of the multi-degrees-of-freedom(MDOF)system in the experiment is acquired using Newmark variable step-size integration method.Further the new design is tested in a symmetrical single-disk rotor-bearing system.With both the theory analysis and the experimental results,some conclusions are obtained about the relationship between the vibration and the system damping which are related to system stability.

  12. Equivalence Between Different Auxiliary Field Formulations of ${\\cal N}=1$ Supergravity Coupled to Matter

    CERN Document Server

    Aoki, Shuntaro

    2016-01-01

    We reconsider the relation between three supergravity formalisms with different sets of auxiliary fields, known as the old-, new-, and non-minimal supergravity. Although it has been known that the old minimal formulation is the broadest class, we find that, with an unphysical $U(1)$ gauge symmetry and a compensating superfield, all of them become completely equivalent.

  13. Natural convection in an asymmetrically heated vertical channel with an adiabatic auxiliary plate

    International Nuclear Information System (INIS)

    The effect of an auxiliary plate on natural convection in an asymmetrically heated channel is studied numerically in laminar regime. The computational procedure is made by solving the unsteady two dimensional Navier-Stokes and energy equations. This nonlinear system is integrated by a finite volume approach and then solved in time using the projection method, allowing the decoupling pressure from velocity. More than hundred simulations are performed to determine the best positions of the auxiliary plate that enhance the induced mass flow and the heat transfer rate for modified Rayleigh numbers ranging from Ram = 102 to Ram = 105. Contour maps are plotted and then used to precise the enhancement rates of the mass flow and the heat transfer for any position of the auxiliary plate in the channel. The numerical results (velocity, pressure and temperature fields) provide detailed information about the evolution of the flow structure according to the geometry considered in this study. In addition, they permit to explain why the mass flow rate and Nusselt number are enhanced for certain positions of the auxiliary plate and are on the contrary deteriorated for others. (authors)

  14. Auxiliary Women Workers in the Legal Sector: Traversing Subjectivities and "Self" to Learn through Work

    Science.gov (United States)

    Cavanagh, Jillian Maria

    2012-01-01

    This study is about female auxiliary workers in the Australian legal sector. The purpose is to explore the impact of subjectivities on women workers and how they negotiate their positionality to participate in meaningful work and learning. The study is grounded in theories of identity and socio-cultural perspectives of subjectivity, agentic action…

  15. Performance of turbine auxiliaries and service systems at Rajasthan Atomic Power Station

    International Nuclear Information System (INIS)

    Performance of the turbine auxiliaries and service systems at the Rajasthan Atomic Power Station, India are described. Some of the specific problems encountered in connection with the feed water, turbine governing and common services like compressed air, chilled water, water treatment and chlorination systems are outlined. (K.B.)

  16. Kindergarten Mathematics with "Pepe the Rabbit": How Kindergartners Use Auxiliary Means to Solve Problems

    Science.gov (United States)

    Skoumpourdi, Chrysanthi

    2010-01-01

    The aim of this paper is to investigate the role that auxiliary means (manipulatives such as cubes and representations such as number line) play for kindergartners in working out mathematical tasks. Our assumption was that manipulatives such as cubes would be used by kindergartners easily and successfully whereas the number line would be used by…

  17. A study on the decay heat removal capability of a reactor vessel auxiliary cooling system

    International Nuclear Information System (INIS)

    A reactor vessel auxiliary cooling system (RVACS) is a potential candidate as a fully passive decay heat removal system for small FBRs. In this study the heat transfer performance of a collector with fins is discussed through experiment and the evaluation method is proposed for the heat removal capability of the system. (author)

  18. From Root Infinitive to Finite Sentence : The acquisition of verbal inflections and auxiliaries

    NARCIS (Netherlands)

    Blom, W.B.T.

    2003-01-01

    Across languages, children in the earliest stages of syntactic development tend to omit overt markings of finiteness, such as verbal inflections and auxiliaries: when children use a verb, they use an infinitival form (e.g. Dutch) or a bare stem (e.g. English). From Root Infinitive to Finite Sentence

  19. Analysis of Circularly Polarized Hemispheroidal Dielectric Resonator Antenna Phased Arrays Using the Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2007-01-01

    The method of auxiliary sources is employed to model and analyze probe-fed hemispheroidal dielectric resonator antennas and arrays. Circularly polarized antenna elements of different designs are analyzed, and impedance bandwidths of up to 14.7% are achieved. Selected element designs are...

  20. Application of the method of auxiliary sources in optical diffraction microscopy

    DEFF Research Database (Denmark)

    Karamehmedovic, Mirza; Sørensen, Mads Peter; Hansen, Poul-Erik;

    2010-01-01

    The Method of Auxiliary Sources is used for characterisation of grating defects. Grating profiles are characterised by best fit matching of a library of diffraction efficiencies with numerical simulated diffraction efficiencies with defects. It is shown that the presented method can solve...

  1. Computation of auxiliary functions in molecular integral up to arbitrary accuracy: Pt. 2

    International Nuclear Information System (INIS)

    With regard to evaluation of auxiliary function Iμ (x) up to arbitrary accuracy, it is required that the forward recurrence scheme of the function can be used as far as possible. Applying a new inequality, the authors have set up a criterion which can accurately decide whether the requirement can be met

  2. Harbingers of Artin's Reciprocity Law. I. The Continuing Story of Auxiliary Primes

    CERN Document Server

    Lemmermeyer, Franz

    2011-01-01

    In this article we present the history of auxiliary primes used in proofs of reciprocity laws from the quadratic to Artin's reciprocity law. We also show that the gap in Legendre's proof can be closed with a simple application of Gauss's genus theory.

  3. Estimation of finite population mean using known correlation coefficient between auxiliary characters

    OpenAIRE

    Singh, Housila P.; R. Tailor

    2013-01-01

    This paper proposes a modified ratio-cum-product estimator of finite population mean of the study variate Y using known correlation coefficient between two auxiliary characters X1 and X2. An almost unbiased ratio-cum-product estimator has also been obtained by using Jackknife technique envisaged by Quenouille (1956). The merits of the proposed estimator are examined through a numerical illustration.

  4. Auxiliary BE Production by African American English-Speaking Children with and without Specific Language Impairment

    Science.gov (United States)

    Garrity, April W.; Oetting, Janna B.

    2010-01-01

    Purpose: To examine 3 forms ("am," "is," "are") of auxiliary BE production by African American English (AAE)-speaking children with and without specific language impairment (SLI). Method: Thirty AAE speakers participated: 10 six-year-olds with SLI, 10 age-matched controls, and 10 language-matched controls. BE production was examined through…

  5. Radiation effects on natural convection in a vertical channel with an auxiliary plate

    International Nuclear Information System (INIS)

    In this experimental study the effects of unheated auxiliary plate positions along the centerline of a vertical channel on combined natural convective in air and radiative heat transfer are investigated. The vertical channel is symmetrically heated and a uniform heat flux along the principal walls of the channel is assumed. Comparisons between experimental data carried out from different positions of the auxiliary plate and two surfaces emissivity values are given in terms of heated wall temperatures and radiative heat transfer. Average Nusselt numbers by means of experimental data are evaluated. Results are given for different thermal and geometrical dimensionless parameters. Results show that the lowest maximum channel wall temperatures are attained for the auxiliary plate placed at the channel exit for high channel Rayleigh numbers and heat flux values. Correlations for average Nusselt numbers, global average Nusselt numbers and dimensionless maximum wall temperatures in terms of channel Rayleigh numbers and auxiliary plate-to-channel height ratio, h/L, are evaluated in the ranges: 20 < Ra'< 1.5 x 105, 22 < Ra'* < 1.7 x 105 and 0 ≤ h/L ≤ 0.5 for inlet and outlet positions and walls emissivity equal to 0.9. The proposed correlations are in good agreement with correlation for simple channel. (authors)

  6. Asymmetric synthesis of 3-butylphthalide using isomannide and isosorbide as chiral auxiliaries

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new approach for asymmetric syntheses of (S) and (R)-3-n-butylphthalide (NBP) is presented. The diastereoselective addition of dibutylzinic to aromatic aldehyde 10 or 11 generated from isomannide- or isosorbide-derived chiral auxiliary afforded S-NBP or R-NBP in high optical yields.

  7. Exact solutions of some coupled nonlinear diffusion-reaction equations using auxiliary equation method

    Indian Academy of Sciences (India)

    Ranjit Kumar

    2012-09-01

    Travelling and solitary wave solutions of certain coupled nonlinear diffusion-reaction equations have been constructed using the auxiliary equation method. These equations arise in a variety of contexts not only in biological, chemical and physical sciences but also in ecological and social sciences.

  8. Low-cost auxiliary system for broadband NMR on strongly magnetic systems

    DEFF Research Database (Denmark)

    Nevald, Rolf; Hansen, Poul Erik

    1978-01-01

    A low cost auxiliary system consisting of He cryostat, superconducting magnet, and sample holder assembly with field probe has been constructed. The system meets the requirements of NMR on strongly paramagnetic or ordered magnetic materials, which are accurate temperature settings over a wide range...

  9. Soft switching DC/DC converter using controlled output rectifier with auxiliary circuit

    OpenAIRE

    Dudrik, Jaroslav; BODOR Marcel; TRIP Daniel Nistor

    2010-01-01

    Auxiliary circuit for DC/DC converter withcontrolled output rectifier is presented in this paper.Soft switching for power switches of the inverter isachieved by using controlled output rectifier and softswitching of the controlled rectifier by using losslessauxiliary circuit. The principle of converter operationis explained and analyzed and experimental results onthe laboratory model are presented.

  10. 33 CFR 66.01-50 - Protection of private aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Protection of private aids to navigation. 66.01-50 Section 66.01-50 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State §...

  11. Speech Recognition Technology Applied to Intelligent Mobile Navigation System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The capability of human-computer interaction reflects the intelligent degree of mobile navigation system.The navigation data and functions of mobile navigation system are divided into system commands and non-system commands in this paper.And then a group of speech commands are Abstracted.This paper applies speech recognition technology to intelligent mobile navigation system to process speech commands and does some deep research on the integration of speech recognition technology with mobile navigation system.The navigation operation can be performed by speech commands,which makes human-computer interaction easy during navigation.Speech command interface of navigation system is implemented by Dutty ++ Software,which is based on speech recognition system -Via Voice of IBM.Through navigation experiments,navigation can be done almost without keyboard,which proved that human-computer interaction is very convenient by speech commands and the reliability is also higher.

  12. Intelligent navigation to improve obstetrical sonography.

    Science.gov (United States)

    Yeo, Lami; Romero, Roberto

    2016-04-01

    'Manual navigation' by the operator is the standard method used to obtain information from two-dimensional and volumetric sonography. Two-dimensional sonography is highly operator dependent and requires extensive training and expertise to assess fetal anatomy properly. Most of the sonographic examination time is devoted to acquisition of images, while 'retrieval' and display of diagnostic planes occurs rapidly (essentially instantaneously). In contrast, volumetric sonography has a rapid acquisition phase, but the retrieval and display of relevant diagnostic planes is often time-consuming, tedious and challenging. We propose the term 'intelligent navigation' to refer to a new method of interrogation of a volume dataset whereby identification and selection of key anatomical landmarks allow the system to: 1) generate a geometrical reconstruction of the organ of interest; and 2) automatically navigate, find, extract and display specific diagnostic planes. This is accomplished using operator-independent algorithms that are both predictable and adaptive. Virtual Intelligent Sonographer Assistance (VIS-Assistance®) is a tool that allows operator-independent sonographic navigation and exploration of the surrounding structures in previously identified diagnostic planes. The advantage of intelligent (over manual) navigation in volumetric sonography is the short time required for both acquisition and retrieval and display of diagnostic planes. Intelligent navigation technology automatically realigns the volume, and reorients and standardizes the anatomical position, so that the fetus and the diagnostic planes are consistently displayed in the same manner each time, regardless of the fetal position or the initial orientation. Automatic labeling of anatomical structures, subject orientation and each of the diagnostic planes is also possible. Intelligent navigation technology can operate on conventional computers, and is not dependent on specific ultrasound platforms or on the

  13. Integrated navigation method of a marine strapdown inertial navigation system using a star sensor

    International Nuclear Information System (INIS)

    This paper presents an integrated navigation method of the strapdown inertial navigation system (SINS) using a star sensor. According to the principle of SINS, its own navigation information contains an error that increases with time. Hence, the inertial attitude matrix from the star sensor is introduced as the reference information to correct the SINS increases error. For the integrated navigation method, the vehicle’s attitude can be obtained in two ways: one is calculated from SINS; the other, which we have called star sensor attitude, is obtained as the product between the SINS position and the inertial attitude matrix from the star sensor. Therefore, the SINS position error is introduced in the star sensor attitude error. Based on the characteristics of star sensor attitude error and the mathematical derivation, the SINS navigation errors can be obtained by the coupling calculation between the SINS attitude and the star sensor attitude. Unlike several current techniques, the navigation process of this method is non-radiating and invulnerable to jamming. The effectiveness of this approach was demonstrated by simulation and experimental study. The results show that this integrated navigation method can estimate the attitude error and the position error of SINS. Therefore, the SINS navigation accuracy is improved. (paper)

  14. Peculiarities of future air navigation system based on inertial navigation systems/global positioning system

    OpenAIRE

    Sineglazov, V. M.; National Aviation University,; Zakharin, F. M.; National Aviation University

    2014-01-01

    Using an inertial navigation system and Global Positioning System together is preferable to using any of them separately. Derived benefits depend on the level of combining information. Inertial navigation systems/Global Positioning System integration architectures are defined as separate, loosely and tightly coupled, deeply integrated configurations.

  15. Does Navigation Always Predict Performance? Effects of Navigation on Digital Reading Are Moderated by Comprehension Skills

    Science.gov (United States)

    Naumann, Johannes; Salmerón, Ladislao

    2016-01-01

    This study investigated interactive effects of navigation and offline comprehension skill on digital reading performance. As indicators of navigation, relevant page selection and irrelevant page selection were considered. In 533 Spanish high school students aged 11-17 positive effects of offline comprehension skill and relevant page selection on…

  16. Target relative navigation results from hardware-in-the-loop tests using the sinplex navigation system

    NARCIS (Netherlands)

    Steffes, S.; Dumke, M.; Heise, D.; Sagliano, M.; Samaan, M.; Theil, S.; Boslooper, E.C.; Oosterling, J.A.J.; Schulte, J.; Skaborn, D.; Söderholm, S.; Conticello, S.; Esposito, M.; Yanson, Y.; Monna, B.; Stelwagen, F.; Visee, R.

    2014-01-01

    The goal of the SINPLEX project is to develop an innovative solution to significantly reduce the mass of the navigation subsystem for exploration missions which include landing and/or rendezvous and capture phases. The system mass is reduced while still maintaining good navigation performance as com

  17. Integrated navigation method of a marine strapdown inertial navigation system using a star sensor

    Science.gov (United States)

    Wang, Qiuying; Diao, Ming; Gao, Wei; Zhu, Minghong; Xiao, Shu

    2015-11-01

    This paper presents an integrated navigation method of the strapdown inertial navigation system (SINS) using a star sensor. According to the principle of SINS, its own navigation information contains an error that increases with time. Hence, the inertial attitude matrix from the star sensor is introduced as the reference information to correct the SINS increases error. For the integrated navigation method, the vehicle’s attitude can be obtained in two ways: one is calculated from SINS; the other, which we have called star sensor attitude, is obtained as the product between the SINS position and the inertial attitude matrix from the star sensor. Therefore, the SINS position error is introduced in the star sensor attitude error. Based on the characteristics of star sensor attitude error and the mathematical derivation, the SINS navigation errors can be obtained by the coupling calculation between the SINS attitude and the star sensor attitude. Unlike several current techniques, the navigation process of this method is non-radiating and invulnerable to jamming. The effectiveness of this approach was demonstrated by simulation and experimental study. The results show that this integrated navigation method can estimate the attitude error and the position error of SINS. Therefore, the SINS navigation accuracy is improved.

  18. ASCERTAINMENT OF ELECTRIC-SUPPLY SCHEMES RELIABILITY FOR THE ATOMIC POWER PLANT AUXILIARIES

    Directory of Open Access Journals (Sweden)

    A. L. Starzhinskij

    2015-01-01

    Full Text Available The paper completes ascertainment of electrical-supply scheme reliability for the auxiliaries of a nuclear power plant. Thereat the author considers the system behavior during the block normal operation, carrying out current maintenance, and capital repairs in combination with initiating events. The initiating events for reactors include complete blackout, i.e. the loss of outside power supply (normal and reserve; emergency switching one of the working turbogenerators; momentary dumping the normal rating to the level of auxiliaries with seating the cutout valve of one turbo-generator. The combination of any initiating event with the repairing mode in case of one of the system elements failure should not lead to blackout occurrence of more than one system of the reliable power supply. This requirement rests content with the help of the reliable power supply system self-dependence (electrical and functional and the emergency power-supply operational autonomy (diesel generator and accumulator batteries.The reliability indicators of the power supply system for the nuclear power plant auxiliaries are the conditional probabilities of conjoined blackout of one, two, and three sections of the reliable power supply conditional upon an initiating event emerging and the blackout of one, two, and three reliable power-supply sections under the normal operational mode. Furthermore, they also are the blackout periodicity of one and conjointly two, three, and four sections of normal operation under the block normal operational mode. It is established that the blackout of one bus section of normal operation and one section of reliable power-supply system of the auxiliaries that does not lead to complete blackout of the plant auxiliaries may occur once in three years. The probability of simultaneous power failure of two or three normal-operation sections and of two reliable power-supply sections during the power plant service life is unlikely.

  19. Navigation Architecture for a Space Mobile Network

    Science.gov (United States)

    Valdez, Jennifer E.; Ashman, Benjamin; Gramling, Cheryl; Heckler, Gregory W.; Carpenter, Russell

    2016-01-01

    The Tracking and Data Relay Satellite System (TDRSS) Augmentation Service for Satellites (TASS) is a proposed beacon service to provide a global, space based GPS augmentation service based on the NASA Global Differential GPS (GDGPS) System. The TASS signal will be tied to the GPS time system and usable as an additional ranging and Doppler radiometric source. Additionally, it will provide data vital to autonomous navigation in the near Earth regime, including space weather information, TDRS ephemerides, Earth Orientation Parameters (EOP), and forward commanding capability. TASS benefits include enhancing situational awareness, enabling increased autonomy, and providing near real-time command access for user platforms. As NASA Headquarters' Space Communication and Navigation Office (SCaN) begins to move away from a centralized network architecture and towards a Space Mobile Network (SMN) that allows for user initiated services, autonomous navigation will be a key part of such a system. This paper explores how a TASS beacon service enables the Space Mobile Networking paradigm, what a typical user platform would require, and provides an in-depth analysis of several navigation scenarios and operations concepts. This paper provides an overview of the TASS beacon and its role within the SMN and user community. Supporting navigation analysis is presented for two user mission scenarios: an Earth observing spacecraft in low earth orbit (LEO), and a highly elliptical spacecraft in a lunar resonance orbit. These diverse flight scenarios indicate the breadth of applicability of the TASS beacon for upcoming users within the current network architecture and in the SMN.

  20. Fuzzy Behavior Modulation with Threshold Activation for Autonomous Vehicle Navigation

    Science.gov (United States)

    Tunstel, Edward

    2000-01-01

    This paper describes fuzzy logic techniques used in a hierarchical behavior-based architecture for robot navigation. An architectural feature for threshold activation of fuzzy-behaviors is emphasized, which is potentially useful for tuning navigation performance in real world applications. The target application is autonomous local navigation of a small planetary rover. Threshold activation of low-level navigation behaviors is the primary focus. A preliminary assessment of its impact on local navigation performance is provided based on computer simulations.