WorldWideScience

Sample records for schnittbildgefuehrte navigation unter

  1. Comparison of two navigation systems for CT-guided interventions under special consideration of the ergonomic properties of the used systems; Vergleich zweier Navigationshilfen fuer CT-gesteuerte Interventionen unter besonderer Beruecksichtigung der Nutzungseigenschaften der verwendeten Systeme

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, T. [Inst. fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Jena (Germany); Roettger, S. [Klinik fuer Nuklearmedizin, Medizinische Hochschule Hannover (Germany); Bahner-Heyne, E.J.; Kluge, G. [Inst. fuer Psychologie und Arbeitswissenschaft, FG Arbeits-, Ingenieur- und Organisationspsychologie, TU Berlin (Germany)

    2009-06-15

    Purpose: investigation of the influence of CT-based navigation systems on the success of an intervention, assessment of the advantages and disadvantages of the utilized systems, and evaluation of the ergonomic system properties. Materials and method: a simple guiding system PatPos Invent trademark and the computer-based navigation system PinPoint trademark were employed on two CT systems. In order to investigate the influence of the navigation aids on the success of the interventions, 96 prospective, randomized, and standardized punctures were performed on a specifically developed, rigid phantom. 16 examiners punctured 6 targets with 3 degrees of difficulty with the navigation aids. Results: irrespective of the experience of the examiner, both navigation systems guided the target with an equal degree of certainty. PinPoint significantly reduced the length of the examination time (12 - 25 min) as compared to PatPos Invent (20 - 40 min). The expectation conformity and comprehensibility of PatPos Invent were assessed significantly more positively than PinPoint with regard to the general handling of the system. In contrast, the assessment of the usability during preoperative setup favored PinPoint. The type of navigation system has no influence on the precision of the implementation of a puncture procedure. (orig.)

  2. Betoninstandsetzung unter Wasser : Mörtelentwicklung und Applikationstechniken

    OpenAIRE

    Nguyen-Sauerbaum, Lina Phan Anh

    2017-01-01

    Für die Instandsetzung von Betonbauteilen unter Wasser stehen aktuell keine gängigen Verfahren zur Verfügung, die ohne Trockenlegung oder Einschalen des Bauteils auskommen. Diese Arbeit legt die Grundlagen für eine Betoninstandsetzung unter Wasser ohne Einschalen des Bauwerks. Es wurden neue Mörtel entwickelt, die unter Wasser einsetzbar sind und Applikationstechniken untersucht, die eine Applikation unter Wasser mit erfolgreichem Haftverbund erlauben. There are currently no established...

  3. Ausländerfeindlichkeit unter Jugendlichen in Leipzig

    OpenAIRE

    Petermann, Sören; Goldenberg, Olga

    2017-01-01

    In kommunalen Umfragen erhobene Einstellungen gegenüber Ausländern repräsentieren ein Bild gelebter Toleranz. Selten werden Jugendliche zu ihren ausländerbezogenen Einstellungen gefragt und mit altersspezifischen Faktoren in Verbindung gesetzt. Dieser Beitrag bezieht sich auf theoretische Ansätze der Anomietheorie, der Sozialisations- und Deprivationsforschung, um Kompensationsprozesse und Konfliktpotenziale als Wirkungsmechanismen für Ausländerfeindlichkeit unter Leipziger Jugendlichen zu un...

  4. Schlafmedizinische Charakterisierung von Parkinson-Patienten mit Schlafattacken unter dopaminerger Therapie

    OpenAIRE

    Rethfeldt, Mira

    2006-01-01

    1999 wurden erstmals sogenannte Schlafattacken bei Parkinson-Patienten unter der Therapie mit Nonergolin-Dopaminagonisten berichtet. Später zeigten Studien, dass diese Schlafattacken unter jeglicher dopaminerger Therapie auftreten können. Bis heute ist jedoch die Pathophysiologie dieses Phänomens nicht hinreichend geklärt. Es wird diskutiert, ob diese Attacken als paroxysmales Symptom überhaupt bestehen oder nicht vielmehr ...

  5. Ecodesign Navigator

    DEFF Research Database (Denmark)

    Simon, M; Evans, S.; McAloone, Timothy Charles

    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...

  6. Surgical Navigation

    DEFF Research Database (Denmark)

    Azarmehr, Iman; Stokbro, Kasper; Bell, R. Bryan

    2017-01-01

    Purpose: This systematic review investigates the most common indications, treatments, and outcomes of surgical navigation (SN) published from 2010 to 2015. The evolution of SN and its application in oral and maxillofacial surgery have rapidly developed over recent years, and therapeutic indicatio...

  7. Responsibility navigator

    NARCIS (Netherlands)

    Kuhlmann, Stefan; Edler, Jakob; Ordonez Matamoros, Hector Gonzalo; Randles, Sally; Walhout, Bart; Walhout, Bart; Gough, Clair; Lindner, Ralf; Lindner, Ralf; Kuhlmann, Stefan; Randles, Sally; Bedsted, Bjorn; Gorgoni, Guido; Griessler, Erich; Loconto, Allison; Mejlgaard, Niels

    2016-01-01

    Research and innovation activities need to become more responsive to societal challenges and concerns. The Responsibility Navigator, developed in the Res-AGorA project, supports decision-makers to govern such activities towards more conscious responsibility. What is considered “responsible” will

  8. Cislunar navigation

    Science.gov (United States)

    Cesarone, R. J.; Burke, J. D.; Hastrup, R. C.; Lo, M. W.

    2003-01-01

    In the future, navigation and communication in Earth-Moon space and on the Moon will differ from past practice due to evolving technology and new requirements. Here we describe likely requirements, discuss options for meeting them, and advocate steps that can be taken now to begin building the navcom systems needed in coming years for exploring and using the moon.

  9. 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...

  10. Messung der Respirationsverschiebung intraabdominaler Organe am Beispiel der Leber unter maschineller Ventilation

    OpenAIRE

    Olbrich, Bernhard

    2008-01-01

    Ziel dieser Arbeit ist es, die Bewegung intraabominaler Organe am Beispiel der Leber unter den Bedingungen maschineller Beatmung zu quantifizieren. Ein Messverfahren mit Hilfe eines elektromagnetischen Trackingsystems, wurde hierzu im Tierversuch neu entwickelt. Im Anschluss wurden die Messdaten mit Hilfe einer Explorativen Datenanalyse, validiert und ein einfaches Modell entwickelt, das die virtuelle Kompensation der Atemverschiebung ermöglicht. Zusätzlich wird eine praktische Anwendungsmögl...

  11. Die Analyse der Wertschöpfungskette Schweinefleisch unter den Aspekten des Supply Chain Management

    OpenAIRE

    Schönberger, Wolfgang

    2008-01-01

    Inhalt der Arbeit ist die vergleichende Analyse der Wertschöpfungskette Schweinefleisch unter den Aspekten des Supply Chain Management für Bayern sowie für Dänemark als dem weltweit größten Nettoexporteur von Schweinefleisch. Wichtige Wettbewerbsfaktoren und die Strukturen der Wertschöpfungskette werden untersucht. Die Produktionskosten werden nach der Methode der Vollkostenrechnung ermittelt. In Dänemark haben sich auf allen Stufen der Wertschöpfungskette Strukturen entwickelt, die die...

  12. Towards Safe Navigation by Formalizing Navigation Rules

    Directory of Open Access Journals (Sweden)

    Arne Kreutzmann

    2013-06-01

    Full Text Available One crucial aspect of safe navigation is to obey all navigation regulations applicable, in particular the collision regulations issued by the International Maritime Organization (IMO Colregs. Therefore, decision support systems for navigation need to respect Colregs and this feature should be verifiably correct. We tackle compliancy of navigation regulations from a perspective of software verification. One common approach is to use formal logic, but it requires to bridge a wide gap between navigation concepts and simple logic. We introduce a novel domain specification language based on a spatio-temporal logic that allows us to overcome this gap. We are able to capture complex navigation concepts in an easily comprehensible representation that can direcly be utilized by various bridge systems and that allows for software verification.

  13. 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

  14. 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.

  15. Investigation of LPP combustors under elevated pressure conditions; Untersuchungen zu LPP-Flugtriebwerksbrennkammern unter erhoehtem Druck

    Energy Technology Data Exchange (ETDEWEB)

    Fink, R.

    2001-05-01

    The development of new combustor concepts for aero engines to meet future emissions regulations in based on a detailed knowledge of the combustion process and the velocity field. In the presented thesis, non intrusive measurements were performed in a model combustion chamber under almost realistic pressure and temperature conditions. The species OH, NO, unburned hydrocarbons and fuel droplets were detected in 2 dimensions with the Laser Induced Fluorescence (LIF). The velocity field was measured with the Particle Image Velocimetry technique (PIV). [German] Die Weiterentwicklung neuer Brennkammerkonzepte zur Erfuellung zukuenftiger Schadstoffemissionsrichtlinien erfordert genaue Kenntnisse der ablaufenden Verbrennungs- und Stroemungsvorgaenge in der Brennkammer. Bei den in der Arbeit vorgestellten Untersuchungen wurden in einer LPP-Modellbrennkammer unter annaehernd realistischen Eintrittsbedingungen die Spezies OH, NO, unverbrannte Kohlenwasserstoffe sowie noch fluessiger Brennstoff zweidimensional anhand der Laserinduzierten Fluoreszenz (LIF) nachgewiesen. Das Stroemungsfeld wurde mit Hilfe der Particle Image Velocimetry (PIV) gemessen.

  16. A Leapfrog Navigation System

    Science.gov (United States)

    Opshaug, Guttorm Ringstad

    There are times and places where conventional navigation systems, such as the Global Positioning System (GPS), are unavailable due to anything from temporary signal occultations to lack of navigation system infrastructure altogether. The goal of the Leapfrog Navigation System (LNS) is to provide localized positioning services for such cases. The concept behind leapfrog navigation is to advance a group of navigation units teamwise into an area of interest. In a practical 2-D case, leapfrogging assumes known initial positions of at least two currently stationary navigation units. Two or more mobile units can then start to advance into the area of interest. The positions of the mobiles are constantly being calculated based on cross-range distance measurements to the stationary units, as well as cross-ranges among the mobiles themselves. At some point the mobile units stop, and the stationary units are released to move. This second team of units (now mobile) can then overtake the first team (now stationary) and travel even further towards the common goal of the group. Since there always is one stationary team, the position of any unit can be referenced back to the initial positions. Thus, LNS provides absolute positioning. I developed navigation algorithms needed to solve leapfrog positions based on cross-range measurements. I used statistical tools to predict how position errors would grow as a function of navigation unit geometry, cross-range measurement accuracy and previous position errors. Using this knowledge I predicted that a 4-unit Leapfrog Navigation System using 100 m baselines and 200 m leap distances could travel almost 15 km before accumulating absolute position errors of 10 m (1sigma). Finally, I built a prototype leapfrog navigation system using 4 GPS transceiver ranging units. I placed the 4 units in the vertices a 10m x 10m square, and leapfrogged the group 20 meters forwards, and then back again (40 m total travel). Average horizontal RMS position

  17. 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...

  18. Getting Lost Through Navigation

    DEFF Research Database (Denmark)

    Debus, Michael S.

    2017-01-01

    In this presentation, I argued two things. First, that it is navigation that lies at the core of contemporary (3D-) videogames and that its analysis is of utmost importance. Second, that this analysis needs a more rigorous differentiation between specific acts of navigation. Considering the Oxford...... in videogames is a configurational rather than an interpretational one (Eskelinen 2001). Especially in the case of game spaces, navigation appears to be of importance (Wolf 2009; Flynn 2008). Further, it does not only play a crucial role for the games themselves, but also for the experience of the player...

  19. Inertial navigation without accelerometers

    Science.gov (United States)

    Boehm, M.

    The Kennedy-Thorndike (1932) experiment points to the feasibility of fiber-optic inertial velocimeters, to which state-of-the-art technology could furnish substantial sensitivity and accuracy improvements. Velocimeters of this type would obviate the use of both gyros and accelerometers, and allow inertial navigation to be conducted together with vehicle attitude control, through the derivation of rotation rates from the ratios of the three possible velocimeter pairs. An inertial navigator and reference system based on this approach would probably have both fewer components and simpler algorithms, due to the obviation of the first level of integration in classic inertial navigators.

  20. Anforderungen an Marketingkonzepte für Großtraktoren unter Berücksichtigung des Wandels landwirtschaftlicher Rahmenbedingungen

    OpenAIRE

    Thiel, Jörg

    2017-01-01

    Beeinflusst von der Volatilität der Märkte, ergänzt um gesellschaftspolitische wie absatzorientierte Maßnahmen, ist die Landtechnikbranche seit jeher einem permanenten Wandel ausgesetzt. Insbesondere unter dem derzeit im Fokus stehenden Aspekt der Nachhaltigkeit in landwirtschaftlichen Produktionssystemen bedarf es der Gestaltung innovativer Ansätze für effizientere sowie gleichzeitig ressourcenschonende Verfahren. Zusätzlich verstärkt durch die seit geraumer Zeit anhaltend angespannten Situa...

  1. Semiotic resources for navigation

    DEFF Research Database (Denmark)

    Due, Brian Lystgaard; Lange, Simon Bierring

    2018-01-01

    This paper describes two typical semiotic resources blind people use when navigating in urban areas. Everyone makes use of a variety of interpretive semiotic resources and senses when navigating. For sighted individuals, this especially involves sight. Blind people, however, must rely on everything...... else than sight, thereby substituting sight with other modalities and distributing the navigational work to other semiotic resources. Based on a large corpus of fieldwork among blind people in Denmark, undertaking observations, interviews, and video recordings of their naturally occurring practices...... of walking and navigating, this paper shows how two prototypical types of semiotic resources function as helpful cognitive extensions: the guide dog and the white cane. This paper takes its theoretical and methodological perspective from EMCA multimodal interaction analysis....

  2. USACE Navigation Channels 2012

    Data.gov (United States)

    California Natural Resource Agency — This dataset represents both San Francisco and Los Angeles District navigation channel lines. All San Francisco District channel lines were digitized from CAD files...

  3. Visual Guided Navigation

    National Research Council Canada - National Science Library

    Banks, Martin

    1999-01-01

    .... Similarly, the problem of visual navigation is the recovery of an observer's self-motion with respect to the environment from the moving pattern of light reaching the eyes and the complex of extra...

  4. Tinnitus Patient Navigator

    Science.gov (United States)

    ... Cure About Us Initiatives News & Events Professional Resources Tinnitus Patient Navigator Want to get started on the ... unique and may require a different treatment workflow. Tinnitus Health-Care Providers If you, or someone you ...

  5. 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...

  6. Navigating in higher education

    DEFF Research Database (Denmark)

    Thingholm, Hanne Balsby; Reimer, David; Keiding, Tina Bering

    Denne rapport er skrevet på baggrund af spørgeskemaundersøgelsen – Navigating in Higher Education (NiHE) – der rummer besvarelser fra 1410 bachelorstuderende og 283 undervisere fordelt på ni uddannelser fra Aarhus Universitet: Uddannelsesvidenskab, Historie, Nordisk sprog og litteratur, Informati......Denne rapport er skrevet på baggrund af spørgeskemaundersøgelsen – Navigating in Higher Education (NiHE) – der rummer besvarelser fra 1410 bachelorstuderende og 283 undervisere fordelt på ni uddannelser fra Aarhus Universitet: Uddannelsesvidenskab, Historie, Nordisk sprog og litteratur...

  7. Navigating ‘riskscapes’

    DEFF Research Database (Denmark)

    Gee, Stephanie; Skovdal, Morten

    2017-01-01

    This paper draws on interview data to examine how international health care workers navigated risk during the unprecedented Ebola outbreak in West Africa. It identifies the importance of place in risk perception, including how different spatial localities give rise to different feelings of threat...... or safety, some from the construction of physical boundaries, and others mediated through aspects of social relations, such as trust, communication and team dynamics. Referring to these spatial localities as ‘riskscapes’, the paper calls for greater recognition of the role of place in understanding risk...... perception, and how people navigate risk....

  8. Navigating on handheld displays: Dynamic versus Static Keyhole Navigation

    NARCIS (Netherlands)

    Mehra, S.; Werkhoven, P.; Worring, M.

    2006-01-01

    Handheld displays leave little space for the visualization and navigation of spatial layouts representing rich information spaces. The most common navigation method for handheld displays is static peephole navigation: The peephole is static and we move the spatial layout behind it (scrolling). A

  9. Improving Canada's Marine Navigation System through e-Navigation

    Directory of Open Access Journals (Sweden)

    Daniel Breton

    2016-06-01

    The conclusion proposed is that on-going work with key partners and stakeholders can be used as the primary mechanism to identify e-Navigation related innovation and needs, and to prioritize next steps. Moving forward in Canada, implementation of new e-navigation services will continue to be stakeholder driven, and used to drive improvements to Canada's marine navigation system.

  10. Fragmentierungsarten von Nierensteinen unter extrakorporaler Stoßwellenlithotripsie: eine multivariate Analyse

    Directory of Open Access Journals (Sweden)

    Aeberli D

    1999-01-01

    Full Text Available Das primäre Ziel dieser retrospektiven Studie war die Evaluation von routinemäßig anwendbaren Kriterien, welche die Fragmentierung von Nierensteinen unter extrakorporaler Stoßwellenlithotripsie (ESWL voraussagen können. Die Serie umfaßte 202 konsekutive Patienten (121 Männer, 81 Frauen mit einem medianen Alter von 48 Jahren (19-81 Jahre, die an der Urologischen Universitätsklinik Bern mit dem originalen Dornier HM-3 behandelt wurden. Einschlußkriterien waren Einzelsteine von 10-30 mm Größe mit Lage im Nierenbeckenkelchsystem. Die Steine wurden im Abdomen-Leerbild nach ihrer Lage, Größe, Form, Dichte (im Vergleich zur 12. Rippe, Struktur und Oberfläche beurteilt. Weiter wurden Alter, Geschlecht und Body-Mass-Index des Patienten berücksichtigt. Die Desintegration wurde am 1. Tag nach ESWL mittels Abdomen-Leerbild dokumentiert. Zielwert der Analyse war die binäre Variable steinfrei versus Restfragmente, gegen die alle präoperativen Parameter mittels multivariater logistischer Regression getestet wurden. Die Erfolgsrate betrug 95,5 %; 42 Patienten (20,8 % waren steinfrei und 151 Patienten (74,7 % hatten sog. klinisch insignifikante Restfragmente (5 mm oder kleiner. Von den Männern waren 14,9 %, von den Frauen 29,6 % steinfrei (p = 0,01. Alle anderen Parameter erreichten keine statistische Signifikanz, möglicherweise aufgrund zu kleiner Subgruppen (fehlende statistische Macht. Die Desintegrationsrate des HM-3 für Nierensteine ist insgesamt ausgezeichnet, bei Frauen noch besser als bei Männern. Gerade wegen dieser hohen Erfolgsrate wären größere Patientenzahlen notwendig, um eventuelle Unterschiede zwischen den präinterventionellen Parametern definieren zu können.

  11. 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,...

  12. 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...

  13. Navigating ECA-Zones

    DEFF Research Database (Denmark)

    Hansen, Carsten Ørts; Grønsedt, Peter; Hendriksen, Christian

    This report examines the effect that ECA-zone regulation has on the optimal vessel fuel strategies for compliance. The findings of this report are trifold, and this report is coupled with a calculation tool which is released to assist ship-owners in the ECA decision making. The first key insight...... much time their operated vessels navigate the ECA in the future....

  14. "America first": die Außen- und Sicherheitspolitik der USA unter Präsident Trump

    OpenAIRE

    2017-01-01

    "Donald J. Trump ist der 45. Präsident der Vereinigten Staaten - und auch zehn Wochen nach der Wahl hat sich die Aufregung über das Wahlergebnis nicht gelegt. Diesseits des Atlantiks interessiert vor allem eine Frage: Wie wird die amerikanische Außen- und Sicherheitspolitik unter Präsident Trump aussehen? Wird sie von Kontinuität geprägt sein? Oder wird es gravierende Brüche geben? In diesem Report werfen HSFK-Autorinnen und -Autoren Blicke auf Themen, die aus Sicht der Friedens- und Konflikt...

  15. Control algorithms for autonomous robot navigation

    International Nuclear Information System (INIS)

    Jorgensen, C.C.

    1985-01-01

    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

  16. Mobile Robot Navigation

    DEFF Research Database (Denmark)

    Andersen, Jens Christian

    2007-01-01

    the current position to a desired destination. This thesis presents and experimentally validates solutions for road classification, obstacle avoidance and mission execution. The road classification is based on laser scanner measurements and supported at longer ranges by vision. The road classification...... is sufficiently sensitive to separate the road from flat roadsides, and to distinguish asphalt roads from gravelled roads. The vision-based road detection uses a combination of chromaticity and edge detection to outline the traversable part of the road based on a laser scanner classified sample area....... The perception of these two sensors are utilised by a path planner to allow a number of drive modes, and especially the ability to follow road edges are investigated. The navigation mission is controlled by a script language. The navigation script controls route sequencing, junction detection, junction crossing...

  17. 33 CFR 2.36 - Navigable waters of the United States, navigable waters, and territorial waters.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Navigable waters of the United States, navigable waters, and territorial waters. 2.36 Section 2.36 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL JURISDICTION Jurisdictional Terms § 2.36 Navigable waters...

  18. Indoor navigation by image recognition

    Science.gov (United States)

    Choi, Io Teng; Leong, Chi Chong; Hong, Ka Wo; Pun, Chi-Man

    2017-07-01

    With the progress of smartphones hardware, it is simple on smartphone using image recognition technique such as face detection. In addition, indoor navigation system development is much slower than outdoor navigation system. Hence, this research proves a usage of image recognition technique for navigation in indoor environment. In this paper, we introduced an indoor navigation application that uses the indoor environment features to locate user's location and a route calculating algorithm to generate an appropriate path for user. The application is implemented on Android smartphone rather than iPhone. Yet, the application design can also be applied on iOS because the design is implemented without using special features only for Android. We found that digital navigation system provides better and clearer location information than paper map. Also, the indoor environment is ideal for Image recognition processing. Hence, the results motivate us to design an indoor navigation system using image recognition.

  19. 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.

  20. China Satellite Navigation Conference

    CERN Document Server

    Liu, Jingnan; Yang, Yuanxi; Fan, Shiwei; Yu, Wenxian

    2017-01-01

    These proceedings present selected research papers from CSNC2017, held during 23th-25th May in Shanghai, China. The theme of CSNC2017 is Positioning, Connecting All. 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 CSNC2017, 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.

  1. 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

  2. Rigiscan®-Monitoring der Erektion unter audiovisueller sexueller Stimulation ohne/mit Viagra™ bei Patienten mit erektiler Dysfunktion

    Directory of Open Access Journals (Sweden)

    Perabo FGE

    2000-01-01

    Full Text Available Die orale Medikation mit Sildenafil (Viagra™ hat sich zur Therapie der erektilen Dysfunktion etabliert und relativiert die Differentialdiagnose zwischen psychogener und organischer Dysfunktion mit den entsprechenden therapeutischen Konsequenzen. Diesem Problem widmet sich diese Studie zur Prüfung der erektilen Antwort unter RigiScan®-Monitoring ohne/mit 50 mg Viagra™. 64 Patienten (mittleres Alter 48 Jahre mit einer erektilen Dysfunktion arteriogener (n = 10, venöser (n = 7, gemischt neurogen/vaskulärer (n = 15 und psychogener (n = 32 Genese von mehr als 6 Monaten Dauer wurden in die Studie aufgenommen. Alle Patienten wurden eingehend diagnostisch abgeklärt, inklusive Hormonlabor, dynamischer Pharmako-Duplexsonographie und, falls indiziert, mit einer Cavernosometrie/ -graphie. Zur Testung der penilen Rigidität und zur Objektivierung der Erektion wurde das "real-time" RigiScan® verwendet. In zwei konsekutiven Messungen wurden sowohl die direkte erektile Antwort auf visuelle Stimulation als auch die nächtlichen Erektionen abgeleitet und die Meßergebnisse mit den Begleiterkrankungen, "lifestyle"-Faktoren und dem Ergebnis der Pharmako-Duplexsonographie korreliert. Es fand sich keine Korrelation zwischen der Ätiologie der erektilen Dysfunktion in bezug auf organische oder psychogene Genese und dem Alter der Patienten, der Dauer der Erektionsstörung, dem Nikotinabusus, den Blutfetten, den Testosteronwerten, dem klinischen Ergebnis der Pharmakotestung (Erektionsgrad und dem duplexsonographisch gemessenen Fluß der penilen Arterien. Hingegen zeigte sich eine positive Korrelation zwischen Genese der erektilen Dysfunktion (organisch bzw. psychogen und dem RigiScan®-Meßergebnis (r = 0,29. Patienten mit psychogen bedingter Erektionsstörung profitierten am meisten von Viagra™, während Patienten mit vaskulärer Genese oder gemischt neurogener/vaskulärer Genese deutlich schlechter auf Viagra™ ansprachen. Es bestand keine Korrelation

  3. Multitarget Approaches to Robust Navigation

    Data.gov (United States)

    National Aeronautics and Space Administration — The performance, stability, and statistical consistency of a vehicle's navigation algorithm are vitally important to the success and safety of its mission....

  4. Advancements in Optical Navigation Capabilities

    Data.gov (United States)

    National Aeronautics and Space Administration — The Goddard Image Analysis and Navigation Tool (GIANT) is a tool that was developed for the Origins, Spectral Interpretation, Resource Identification,...

  5. 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.

  6. Zu entwicklungstendenzen im satzbau der Deutschen sprache der gegenwart unter besonderer Berücksichtigung der ausrahmung

    Directory of Open Access Journals (Sweden)

    Jasna Makovec

    1983-01-01

    Full Text Available Die vorliegende Arbeit wurde durch das Bestreben motiviert, weitere Ergänzungen zum Phänornen "Ausrahrnung in der modernen deutschen Schriftsprache der Gegenwart" zu leisten. Der Ausgangspunkt dieses "fakultativ" geregelten Bereiches ist die Annahme bzw. die Arbeitshypothese, daß sich linguistische und außerlinguistische Faktoren einander zuordnen lassen. Das bedeutet, daß die Linearität innerhalb des Kornrnunikationspro­ zesses auch einige wichtige kommunikative Funktionen auszuüben hat, und daß die kontextuellen Modifikationen der Stellungsva­ rianten bei gleichern Denotatsbezug unter diesern Blickwinkel untersucht werden müssen, und nicht gleich als stilistische Varianten qualifiziert werden.

  7. Dynamic Transportation Navigation

    Science.gov (United States)

    Meng, Xiaofeng; Chen, Jidong

    Miniaturization of computing devices, and advances in wireless communication and sensor technology are some of the forces that are propagating computing from the stationary desktop to the mobile outdoors. Some important classes of new applications that will be enabled by this revolutionary development include intelligent traffic management, location-based services, tourist services, mobile electronic commerce, and digital battlefield. Some existing application classes that will benefit from the development include transportation and air traffic control, weather forecasting, emergency response, mobile resource management, and mobile workforce. Location management, i.e., the management of transient location information, is an enabling technology for all these applications. In this chapter, we present the applications of moving objects management and their functionalities, in particular, the application of dynamic traffic navigation, which is a challenge due to the highly variable traffic state and the requirement of fast, on-line computations.

  8. Sensory bases of navigation.

    Science.gov (United States)

    Gould, J L

    1998-10-08

    Navigating animals need to know both the bearing of their goal (the 'map' step), and how to determine that direction (the 'compass' step). Compasses are typically arranged in hierarchies, with magnetic backup as a last resort when celestial information is unavailable. Magnetic information is often essential to calibrating celestial cues, though, and repeated recalibration between celestial and magnetic compasses is important in many species. Most magnetic compasses are based on magnetite crystals, but others make use of induction or paramagnetic interactions between short-wavelength light and visual pigments. Though odors may be used in some cases, most if not all long-range maps probably depend on magnetite. Magnetitebased map senses are used to measure only latitude in some species, but provide the distance and direction of the goal in others.

  9. Comprehension of Navigation Directions

    Science.gov (United States)

    Schneider, Vivian I.; Healy, Alice F.

    2000-01-01

    In an experiment simulating communication between air traffic controllers and pilots, subjects were given navigation instructions varying in length telling them to move in a space represented by grids on a computer screen. The subjects followed the instructions by clicking on the grids in the locations specified. Half of the subjects read the instructions, and half heard them. Half of the subjects in each modality condition repeated back the instructions before following them,and half did not. Performance was worse for the visual than for the auditory modality on the longer messages. Repetition of the instructions generally depressed performance, especially with the longer messages, which required more output than did the shorter messages, and especially with the visual modality, in which phonological recoding from the visual input to the spoken output was necessary. These results are explained in terms of the degrading effects of output interference on memory for instructions.

  10. 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...

  11. 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).

  12. Mechanical-biological waste treatment with thermal processing of partial fractions; Mechanisch-biologische Restabfallbehandlung unter Einbindung thermischer Verfahren fuer Teilfraktionen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    Technologies for mechanical-biological treatment of waste in the Land of Hessen were compared including thermal processes like combustion and gasification. The new and more rigid limiting values specified in the Technical Guide for Municipal Waste Treatment (Technische Anleitung Siedlungsabfall - TASI) get a special mention. [Deutsch] Verschiedene Technologien der mechanisch-biologischen Restabfallbehandlung im Raum Hessen wurden unter Einbezug thermischer Verfahren (Verbrennung, Vergasung) miteinander verglichen. Dabei wurden besonders auf die verschaerften Grenzwerte der Technischen Anleitung Siedlungsabfall (TASI) eingegangen. (ABI)

  13. Monitoring Completed Navigation Projects Program

    National Research Council Canada - National Science Library

    Bottin, Jr., Robert R

    2001-01-01

    ... (MCNP) Program. The program was formerly known as the Monitoring Completed Coastal Projects Program, but was modified in the late 1990s to include all navigation projects, inland as well as coastal...

  14. 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...

  15. 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.

  16. Medienpädagogik unter der differenztheoretischen Lupe. Eine Identitätssuche zwischen Disziplin und Profession

    Directory of Open Access Journals (Sweden)

    Franziska Linke

    2017-09-01

    Full Text Available Der Beitrag diskutiert die dem Themenheft zugrundeliegende Fragestellung nach der Konstitution der Medienpädagogik aus einer systemtheoretischen Perspektive. Dabei wird im Anschluss an Stichweh (2013 Ansatz der funktionalen Differenzierung ein Untersuchungsrahmen aufgezeigt, der es ermöglicht, die Medienpädagogik sowohl aus wissenschaftssoziologischer als auch professionssoziologischer Perspektive zu betrachten. Gerade die zentrale Rolle der (digitalen Medien für Lern- und Bildungsprozesse sowie für den Arbeitsmarkt (u. a. KMK 2016 verlangt eine stetige Reflexion professioneller Handlungssysteme der Medienpädagogik, die nicht losgelöst von der Frage nach dem Selbstverständnis der Medienpädagogik als Wissenschaftsdisziplin gelingen kann (u. a. Hugger 2001. Divergierende theoretische Positionierungen der Akteurinnen und Akteure sowie verschiedene Zielvorstellungen zur Medienpädagogik selbst und zu dem, was sie praktisch leisten kann, erschweren ein solches Vorhaben. Die Autorinnen des Beitrags begeben sich daher, unter Berücksichtigung der Differenzierung zwischen Disziplin und Profession, auf die Suche nach möglichen Antworten. Vorgeschlagen wird eine erweiterte Betrachtungsweise, welche die Medienpädagogik als wissenschaftliche Produktionsgemeinschaft beschreibt und dadurch Potenziale eröffnet theoretische und empirische Erkenntnisse von Akteurinnen und Akteuren unterschiedlicher wissenschaftlicher Disziplinen mit Medienzusammenhang zu berücksichtigen. Ferner wird dargelegt, dass ein solcher Beschreibungsansatz neue Forschungsperspektiven auf die professionstheoretische Einordnung praktischer Handlungssysteme der Medienpädagogik eröffnen kann.

  17. Compact autonomous navigation system (CANS)

    Science.gov (United States)

    Hao, Y. C.; Ying, L.; Xiong, K.; Cheng, H. Y.; Qiao, G. D.

    2017-11-01

    Autonomous navigation of Satellite and constellation has series of benefits, such as to reduce operation cost and ground station workload, to avoid the event of crises of war and natural disaster, to increase spacecraft autonomy, and so on. Autonomous navigation satellite is independent of ground station support. Many systems are developed for autonomous navigation of satellite in the past 20 years. Along them American MANS (Microcosm Autonomous Navigation System) [1] of Microcosm Inc. and ERADS [2] [3] (Earth Reference Attitude Determination System) of Honeywell Inc. are well known. The systems anticipate a series of good features of autonomous navigation and aim low cost, integrated structure, low power consumption and compact layout. The ERADS is an integrated small 3-axis attitude sensor system with low cost and small volume. It has the Earth center measurement accuracy higher than the common IR sensor because the detected ultraviolet radiation zone of the atmosphere has a brightness gradient larger than that of the IR zone. But the ERADS is still a complex system because it has to eliminate many problems such as making of the sapphire sphere lens, birefringence effect of sapphire, high precision image transfer optical fiber flattener, ultraviolet intensifier noise, and so on. The marginal sphere FOV of the sphere lens of the ERADS is used to star imaging that may be bring some disadvantages., i.e. , the image energy and attitude measurements accuracy may be reduced due to the tilt image acceptance end of the fiber flattener in the FOV. Besides Japan, Germany and Russia developed visible earth sensor for GEO [4] [5]. Do we have a way to develop a cheaper/easier and more accurate autonomous navigation system that can be used to all LEO spacecraft, especially, to LEO small and micro satellites? To return this problem we provide a new type of the system—CANS (Compact Autonomous Navigation System) [6].

  18. 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) No...

  19. Optimal motion planning using navigation measure

    Science.gov (United States)

    Vaidya, Umesh

    2018-05-01

    We introduce navigation measure as a new tool to solve the motion planning problem in the presence of static obstacles. Existence of navigation measure guarantees collision-free convergence at the final destination set beginning with almost every initial condition with respect to the Lebesgue measure. Navigation measure can be viewed as a dual to the navigation function. While the navigation function has its minimum at the final destination set and peaks at the obstacle set, navigation measure takes the maximum value at the destination set and is zero at the obstacle set. A linear programming formalism is proposed for the construction of navigation measure. Set-oriented numerical methods are utilised to obtain finite dimensional approximation of this navigation measure. Application of the proposed navigation measure-based theoretical and computational framework is demonstrated for a motion planning problem in a complex fluid flow.

  20. 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.

  1. 33 CFR 66.05-100 - Designation of navigable waters as State waters for private aids to navigation.

    Science.gov (United States)

    2010-07-01

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

  2. Surface navigation on Mars with a Navigation Satellite

    Science.gov (United States)

    Vijayaraghavan, A.; Thurman, Sam W.; Kahn, Robert D.; Hastrup, Rolf C.

    Radiometric navigation data from the Deep Space Network (DSN) stations on the earth to transponders and other surface elements such as rovers and landers on Mars, can determine their positions to only within a kilometer in inertial space. The positional error is mostly in the z-component of the surface element parallel to the Martian spin-axis. However, with Doppler and differenced-Doppler data from a Navigation Satellite in orbit around Mars to two or more of such transponders on the planetary surface, their positions can be determined to within 15 meters (or 20 meters for one-way Doppler beacons on Mars) in inertial space. In this case, the transponders (or other vehicles) on Mars need not even be capable of directly communicating to the earth. When the Navigation Satellite data is complemented by radiometric observations from the DSN stations also, directly to the surface elements on Mars, their positions can be determined to within 3 meters in inertial space. The relative positions of such surface elements on Mars (relative to one another) in Mars-fixed coordinates, however, can be determined to within 5 meters from simply range and Doppler data from the DSN stations to the surface elements. These results are obtained from covariance studies assuming X-band data noise levels and data-arcs not exceeding 10 days. They are significant in the planning and deployment of a Mars-based navigation network necessary to support real-time operations during critical phases of manned exploration of Mars.

  3. Kontrastmittelverstärkte Magnet-Resonanz-Urographie unter forcierter Diurese - Stellenwert in der Differentialdiagnostik bei Obstruktionen des oberen Harntraktes

    Directory of Open Access Journals (Sweden)

    Jung P

    2001-01-01

    Full Text Available Die Magnet-Resonanz-Urographie (MRU ist ein relativ neues Verfahren in der Diagnostik des oberen Harntraktes. Das Ziel dieser Studie war der Vergleich der Aussagefähigkeit der MRU unter Gabe von Gadolinium und Furosemid und dem konventionellen Urogramm (IVU in der Diagnostik der Ursache von Obstruktionen im Bereich des Harnleiters. 82 Patienten mit im IVU nachgewiesener Obstruktion des oberen Harntraktes oder urographisch stummer Niere bei sonographisch nachgewiesener Dilatation wurden der MRU zugeführt. Die Bilder beider Untersuchungsmethoden wurden von voneinander unabhängigen Untersuchern befundet. Zwei Urologen befundeten die IVU-Bilder, zwei Radiologen die MRU-Bilder, die Radiologen kannten die IVU-Diagnose nicht. Bei unklarer Diagnose wurden weitere Untersuchungen wie Computertomographie, retrograde Pyelographie oder Ureteroskopie durchgeführt. Die Diagnosen waren: Harnleitersteine bei 72 Patienten, Harnleitertumore bei 8 Patienten und extraureterale Tumore bei 2 Patienten. Eine richtige Diagnose bei den Steinpatienten wurde durch IVU bei 49 von 72 Patienten und durch MRU bei 64 von 72 Patienten gestellt. In dieser Patientengruppe wurden durch die MRU zwei falsche Diagnosen gestellt. Fehlende Kontrastmittelausscheidung war der Hauptgrund für Versagen der IVU. 3 der 8 Patienten mit Harnleitertumoren wurden durch die IVU richtig dignostiziert, bei dreien wurde eine falsche Diagnose gestellt. Durch die MRU konnten in dieser Gruppe 7 von 8 Patienten korrekt diagnostiziert werden, es wurde keine falsche Diagnose erhoben. IVU wird zunächst die Standarduntersuchungstechnik zur Darstellung des oberen Harntraktes bleiben, aber durch diese Studie konnte die Möglichkeit gezeigt werden, die in der MRU in Kombination mit Gadolinium und Furosemid liegt. Die größte Bedeutung dieser Untersuchung liegt in der urographisch stummen Niere, bei Untersuchungen in der Schwangerschaft, bei Kindern und bei Patienten mit Kontrastmittelunverträglichkeit.

  4. 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...

  5. An Integrated Approach to Electronic Navigation

    National Research Council Canada - National Science Library

    Shaw, Peter; Pettus, Bill

    2001-01-01

    While the Global Positioning System (GPS) is and will continue to be an excellent navigation system, it is neither flawless nor is it the only system employed in the navigation of today's seagoing warfighters...

  6. Global Positioning System Navigation Algorithms

    Science.gov (United States)

    1977-05-01

    Historical Remarks on Navigation In Greek mythology , Odysseus sailed safely by the Sirens only to encounter the monsters Scylla and Charybdis...TNED 000 00 1(.7 BIBLIOGRAPHY 1. Pinsent, John. Greek Mythology . Paul Hamlyn, London, 1969. 2. Kline, Morris. Mathematical Thought from Ancient to

  7. 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.

  8. Surgical navigation with QR codes

    Directory of Open Access Journals (Sweden)

    Katanacho Manuel

    2016-09-01

    Full Text Available The presented work is an alternative to established measurement systems in surgical navigation. The system is based on camera based tracking of QR code markers. The application uses a single video camera, integrated in a surgical lamp, that captures the QR markers attached to surgical instruments and to the patient.

  9. Navigation system for interstitial brachytherapy

    International Nuclear Information System (INIS)

    Strassmann, G.; Kolotas, C.; Heyd, R.

    2000-01-01

    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

  10. Treibhausgasemissionen unter Bewässerung und unterschiedlicher Stickstoffdüngungsintensität auf einem Sandboden in Nord-Ost-Deutschland

    OpenAIRE

    Trost, Benjamin

    2015-01-01

    Ziel der Arbeit ist die Gesamtbilanzierung der Treibhausgasemissionen eines Anbausystems unter Bewässerung auf einem Sandboden. Die dazu aufgestellte Treibhausgasbilanz basiert auf langjährigen Datenreihen zu Erträgen und Corg-Vorräten eines Dauerfeldversuchs sowie auf zweijährigen im Feldversuch durchgeführten N2O-Messungen. Die durchgeführten Untersuchungen zum Einfluss der Bewässerung auf die Corg-Vorräte zeigen, dass der Einsatz von mineralischem Stickstoffdünger und Bewässerung auf einem...

  11. 77 FR 42637 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments; Corrections

    Science.gov (United States)

    2012-07-20

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Parts 84 and 115 [Docket No. USCG-2012-0306] RIN 1625-AB86 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments...), the Coast Guard published a final rule entitled ``Navigation and Navigable Waters; Technical...

  12. 32 CFR 644.3 - Navigation Projects.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Navigation Projects. 644.3 Section 644.3 National... HANDBOOK Project Planning Civil Works § 644.3 Navigation Projects. (a) Land to be acquired in fee. All... construction and borrow areas. (3) In navigation-only projects, the right to permanently flood should be...

  13. Theoretical Limits of Lunar Vision Aided Navigation with Inertial Navigation System

    Science.gov (United States)

    2015-03-26

    THEORETICAL LIMITS OF LUNAR VISION AIDED NAVIGATION WITH INERTIAL NAVIGATION SYSTEM THESIS David W. Jones, Capt, USAF AFIT-ENG-MS-15-M-020 DEPARTMENT...Government and is not subject to copyright protection in the United States. AFIT-ENG-MS-15-M-020 THEORETICAL LIMITS OF LUNAR VISION AIDED NAVIGATION WITH...DISTRIBUTION UNLIMITED. AFIT-ENG-MS-15-M-020 THEORETICAL LIMITS OF LUNAR VISION AIDED NAVIGATION WITH INERTIAL NAVIGATION SYSTEM THESIS David W. Jones

  14. Development of field navigation system; Field navigation system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Ibara, S; Minode, M; Nishioka, K [Daihatsu Motor Co. Ltd., Osaka (Japan)

    1995-04-20

    This paper describes the following matters on a field navigation system developed for the purpose of covering a field of several kilometer square. This system consists of a center system and a vehicle system, and the center system comprises a map information computer and a communication data controlling computer; since the accuracy for a vehicle position detected by a GPS is not sufficient, an attempt of increasing the accuracy of vehicle position detection is made by means of a hybrid system; the hybrid system uses a satellite navigation method of differential system in which the error components in the GPS are transmitted from the center, and also uses a self-contained navigation method which performs an auxiliary function when the accuracy in the GPS has dropped; corrected GPS values, emergency messages to all of the vehicles and data of each vehicle position are communicated by wireless transmission in two ways between the center and vehicles; and accommodation of the map data adopted a system that can respond quickly to any change in roads and facilities. 3 refs., 13 figs., 1 tab.

  15. Autonomous Robot Navigation based on Visual Landmarks

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    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 a...... automatically learn and store visual landmarks, and later recognize these landmarks from arbitrary positions and thus estimate robot position and heading.......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...... 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...

  16. 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.

  17. Navigating the Internet of Things

    DEFF Research Database (Denmark)

    Rassia, Stamatina; Steiner, Henriette

    2017-01-01

    Navigating the Internet of Things is an exploration of interconnected objects, functions, and situations in networks created to ease and manage our daily lives. The Internet of Things represents semi-automated interconnections of different objects in a network based on different information...... technologies. Some examples of this are presented here in order to better understand, explain, and discuss the elements that compose the Internet of Things. In this chapter, we provide a theoretical and practical perspective on both the micro- and macro-scales of ‘things’ (objects), small and large (e.......g. computers or interactive maps), that suggest new topographic relationships and challenge our understanding of users’ involvement with a given technology against the semi-automated workings of these systems. We navigate from a philosophical enquiry into the ‘thingness of things’ dating from the 1950s...

  18. Damage characterisation of silicon carbides for applications in gas turbines in complex load conditions; Charakterisierung des Schaedigungsverhaltens von Siliciumcarbiden fuer den Einsatz in Gasturbinen unter komplexen Beanspruchungsbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Nestle, E.

    2000-06-01

    A tensile test facility for simultaneous thermal, mechanical and corrosive loading was developed and constructed for the purpose of characterizing the damage characteristics of ceramic high-temperature materials. Apart from tensile tests for up to 830 h, tests were also carried out on four-point bending test pieces and disk-shaped oxidation test pieces. The experiments were made at 1450 - 1550 C in dry or moist air. The materials investigated were one hot-pressed silicon carbide and two sintered silicon carbides. [German] Um keramische Hochtemperaturwerkstoffe bezueglich ihres Schaedigungsverhaltens charakterisieren zu koennen, wurde im Rahmen der vorliegenden Arbeit eine Zugpruefanlage zur gleichzeitigen Beanspruchung unter thermischen, mechanischen und korrosiven Bedingungen entwickelt und aufgebaut. Neben den in dieser Anlage durchgefuehrten Zugpruefungen mit Versuchszeiten bis zu 830 h wurden begleitende Untersuchungen an Vierpunkt-Biegeproben und scheibenfoermigen Oxidationsproben durchgefuehrt. Die Versuche konzentrierten sich auf den Temperaturbereich 1450-1550 unter trockenen und feuchten Luftatmosphaeren. Bei den untersuchten Werkstoffen handelte es sich um eine heissgepresste und zwei gesinterte Siliciumcarbid-Qualitaeten. (orig.)

  19. Investigations of coal ignition in a short-range flame burner using optical measuring systems; Untersuchungen zur Kohlezuendung am Flachflammenbrenner unter Verwendung optischer Messtechnik

    Energy Technology Data Exchange (ETDEWEB)

    Hackert, G.; Kremer, H.; Wirtz, S. [Bochum Univ. (Germany). Lehrstuhl fuer Energieanlagentechnik

    1999-09-01

    The short-range flame burner and the KOALA reactor of DMT are experimental facilities for realistic simulation of coal conversion processes at high temperatures and pressures in atmospheric conditions. The TOSCA system enable measurements of temperatures, sizes, shapes and velocities of the fuel particles, which serve as a basis for a three-dimensional simulation model of coal combustion. In the future, further parameter studies will deepen the present knowledge of coal dust combustion under pressure and enable optimisation of the numerical models for simulation of industrial-scale systems for coal dust combustion under pressure. [Deutsch] Mit dem Flachflammenbrenner und dem KOALA-Reaktor der DMT stehen Versuchsapparaturen zur Verfuegung, mit deren Hilfe die Kohleumwandlungsprozesse bei hohen Temperaturen unter Druck und unter atmosphaerischen Bedingungen realistisch wiedergegeben werden. Das TOSCA-System erlaubt dabei die Bestimmung von Temperaturen, Groessen, Formen und Geschwindigkeiten der Brennstoffpartikel. Diese Daten liefern die Grundlage fuer die Erstellung eines dreidimensionalen Simulationsmodells zur Modellierung der Kohleverbrennung. In Zukunft werden weitere Parameterstudien das Verstaendnis der Kohlenstaubdruckverbrennung vertiefen und ein Optimierung der numerischen Modelle ermoeglichen, so dass die Simulation grosstechnischer Kohlenstaubdruckverbrennungsanlagen realisiert werden kann. (orig.)

  20. Carbon dioxide digital subtraction angiography using a new gas management system; Digitale Subtraktionsangiographie mit Kohlendioxid unter Verwendung eines neuen Gasdosiersystems

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz-Rode, T.; Alzen, G.; Guenther, R.W. [Klinik fuer Radiologische Diagnostik, Universitaetsklinikum der RWTH Aachen (Germany)

    1997-07-01

    Purpose: The clinical evaluation of digital subtraction angiography with carbon dioxide using a newly developed low-tech CO{sub 2}-dosage- and injection system. Method and patients: The hand-held system (CO{sub 2} angio set) consists of a dosage chamber in connection with a special stopcock to apportion the gas. By optimising injection volume and pressure steady gas flow characteristics are approximated. A safety design prevents unintentional gas injection volume and pressure steady gas flow characteristics are approximated. A safety design prevents unintentional gas injection. CO{sub 2} arteriographies were performed on 185 patients. Main indications were renal insufficiency and a history of adverse reactions to iodinated contrast media. In patients with femoral connula access, catheterless reflux angiography was performed. Results: The injection system provided complete and coherent visualisation of the abdominal aorta, visceral, pelvic, and lower limb arteries via catheter (71 cases) or via femoral cannula using reflux technique (114 cases). Stenoses, occlusions, and collaterals were assessable. Employing the gas reflux over the aortic bifurcation bilateral run-off studies up to the calf trifurcation were performed via unilateral femoral cannula. Use of a dedicated stacking software improved image quality of distal femoral, popliteal and calf arteries. Conclusion: The CO{sub 2} management system allows adequate imaging of the arteries below the diaphragm. Ease and safety of use and low costs are advantageous. (orig.) [Deutsch] Ziel: Die klinische Erprobung der digitalen Subtraktionsangiographie mit Kohlendioxid unter Verwendung eines neuentwickelten, einfachen Gasdosier- und Injektionssystems. Methode und Patienten: Eine Dosierkammer mit einstellbarem Volumen in Verbindung mit einem Spezial-Hahn (CO{sub 2}-Angio-Set) portioniert das Gas. Durch Optimierung von Injektionsvolumen und -druck wurde eine konstante Ausstroemcharakteristik angenaehert. Das System wurde

  1. Navigation in diagnosis and therapy

    International Nuclear Information System (INIS)

    Vannier, Michael W.; Haller, John W.

    1999-01-01

    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

  2. Ein (neuer Blick auf die Konkurrenz unter Frauenforscherinnen A (New Look at Competition Among Women Scholars in Women’s Studies

    Directory of Open Access Journals (Sweden)

    Anina Mischau

    2002-07-01

    Full Text Available Die Solidarität unter Frauenforscherinnen wird bis heute als politisch-ideologisches Postulat der Frauenforschung aufrechterhalten, obwohl im Zuge einer zunehmenden Institutionalisierung und Professionalisierung bei einer gleichzeitig nahezu unveränderten Marginalisierung der Frauenforschung an deutschen Hochschulen eine stärker werdende Konkurrenz auch unter Frauenforscherinnen zu beobachten ist. Sünne Andresen geht der Frage nach den möglichen Ursachen von Konkurrenz unter Frauenforscherinnen in der Hochschule nach. Diese Fragestellung ist in der Frauen- und Geschlechterforschung nicht neu, wenngleich sie bislang eher allgemein auf die Konkurrenz unter Wissenschaftlerinnen bezogen worden ist. Innovativ ist jedoch, dass die Autorin hierfür den subjektwissenschaftlichen Ansatz der Kritischen Psychologie und die Habitus-Feld-Konzeption Bourdieus als theoretischen Bezugsrahmen auswählt und damit deutlich über die vorherrschenden subjektzentrierten oder strukturtheoretischen Erklärungsansätze hinausgeht. Die empirische Basis ihrer Studie sind sechs qualitative Interviews mit Habilitandinnen der geistes- und sozialwissenschaftlichen Fächer, die sich auf die Frauen- und Geschlechterforschung spezialisiert haben. Insgesamt arbeitet die Autorin interessante Aspekte möglicher Ursachen des Konkurrenzverhaltens unter und der Konkurrenzerfahrungen von Frauenforscherinnen heraus. Sie bleibt der Leserin aber mindestens genauso viele Antworten schuldig, wie sie durch die dargestellten „empirischen Ergebnisse" zu geben vermag.Until the present day, solidarity among feminist scholars is upheld as an ideological-political postulate in this particular scholarly community. These views continue to be upheld despite the increasing institutionalisation and professionalisation of research in women’s studies research. These institutional changes result in an increased sense of competition among feminist scholars, while women’s studies continue to

  3. Islands sinking; Land unter

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Joerg-Rainer

    2013-04-15

    The urbanization is a global trend. Today, 22 of the 30megacities, each with more than 10 million inhabitants, are located in developing countries and emerging countries. These megacities consume the most electricity: About two-thirds of the global consumption of electricity and heat are consumed in megacities. At the same time, the prosperity is concentrated in monopolies: In the last 50 years, the per capita income of the urban population has increased by about 150 %. The productivity of urban areas increases. Thus, cities are of central importance to our culture. If global warming is not stopped, climate change hits them with full force.

  4. Ironieentwicklung unter interaktionslinguistischer Perspektive

    OpenAIRE

    Kotthoff, Helga

    2007-01-01

    Der vorliegende Aufsatz gibt Einblick in ein Pilotprojekt zur Entwicklung von Ironie und vergleichbaren Formen der Kommunikation einer Bewertungskluft in Interaktionssituationen mit Schulkindern. Um Ironie zu verstehen, muss man davon ausgehen, dass Äußerungen verschiedene Bedeutungsschichten haben können. Man kann diesem Typus indirekten Sprechens nur Sinn zuordnen, wenn man generelle Haltungen des Sprechers inferieren kann, und diese Haltung dann gleichzeitig zum Ausgangspunkt nimmt, auch s...

  5. Visusminderung unter Silikon

    DEFF Research Database (Denmark)

    Dornonville de la Cour, Morten; Lux, Anja; Heegaard, Steffen

    2010-01-01

    Silicone oil is used as intravitreal tamponading agent in surgery for rhegmatogenous retinal detachment (RRD) cases complicated with proliferative vitreoretinopathy (PVR). Recently, a number of case series have appeared where profound central visual loss has been found in eyes after uncomplicated...... vitrectomy with silicone tamponade for RRD in eyes with seemingly good visual potential. Several reports have demonstrated the migration of silicone oil droplets into the retina and the optic nerve, others the widespread loss of myelinated optic nerve fibres. These reports are reviewed, and it is concluded...... that caution is warranted when silicone oil is used in eyes with good visual potential. Finally the additional danger of central visual loss should be taken into consideration when deciding to use silicone oil or gas as intravitreal tamponade....

  6. Emergency navigation without an infrastructure.

    Science.gov (United States)

    Gelenbe, Erol; Bi, Huibo

    2014-08-18

    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.

  7. 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.

  8. 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...... 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 radical...

  9. Crack initiation and crack growth in high temperature materials under cyclic thermal stresses; Rissinitiierung und Risswachstum in Hochtemperaturwerkstoffen unter zyklisch thermischer Beanspruchung

    Energy Technology Data Exchange (ETDEWEB)

    Gruen, C.

    1996-12-01

    The high temperatures of use in drive units, such as the combustion chamber or the hot gas turbine, for example, usually cause high temperature changes. Great temperature differences occur for short periods in the components, and thermal shock is produced. In this work, theoretical and experimental investigations are introduced on crack initiation and crack growth in high temperature materials under cyclic thermal stresses. The experiments were carried out with the inter-metallic phase Ni{sub 3}Al, the nickel-based alloy Nimonic 80A and the iron-based alloy PM 2000 strengthened by oxide dispersion (ODS). A characteristic crack appearance picture was found for each material, which was examined more closely. The stresses occurring in the sample during one cycle were calculated with the aid of the finite element program ABAQUS, knowing the specific material parameters. Based on the linear-elastic fracture mechanics, stress intensity factors were calculated on the superimposition principle. Using the material data from isothermal crack propagation experiments, the prediction of fatigue crack spread with cyclic thermal stresses is compared with the experimental findings. (orig./AKF) [Deutsch] Die hohen Einsatztemperaturen in Antriebsaggregaten wie z.B. der Brennkammer oder der Heissgasturbine bedingen in der Regel hohe Temperaturwechsel. Dabei treten kurzzeitig grosse Temperaturunterschiede in den Bauteilen auf, ein Thermoschock wird erzeugt. In der vorliegenden Arbeit werden theoretische und experimentelle Untersuchungen zur Rissinitiierung und zum Risswachstum in Hochtemperaturwerkstoffen unter zyklisch thermischer Belastung vorgestellt. Die Experimente wurden mit der intermetallischen Phase Ni{sub 3}Al, der Nickelbasislegierung Nimonic 80A und der oxid-dispersionsverfestigten (ODS) Eisenbasislegierung PM2000 durchgefuehrt. Fuer jeden Werkstoff stellte sich ein charakteristisches Risserscheinungsbild dar, das naeher untersucht wurde. Die in der Probe auftretenden

  10. Robotics_MobileRobot Navigation, Phase I

    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...

  11. Usability Testing of Two Ambulatory EHR Navigators.

    Science.gov (United States)

    Hultman, Gretchen; Marquard, Jenna; Arsoniadis, Elliot; Mink, Pamela; Rizvi, Rubina; Ramer, Tim; Khairat, Saif; Fickau, Keri; Melton, Genevieve B

    2016-01-01

    Despite widespread electronic health record (EHR) adoption, poor EHR system usability continues to be a significant barrier to effective system use for end users. One key to addressing usability problems is to employ user testing and user-centered design. To understand if redesigning an EHR-based navigation tool with clinician input improved user performance and satisfaction. A usability evaluation was conducted to compare two versions of a redesigned ambulatory navigator. Participants completed tasks for five patient cases using the navigators, while employing a think-aloud protocol. The tasks were based on Meaningful Use (MU) requirements. The version of navigator did not affect perceived workload, and time to complete tasks was longer in the redesigned navigator. A relatively small portion of navigator content was used to complete the MU-related tasks, though navigation patterns were highly variable across participants for both navigators. Preferences for EHR navigation structures appeared to be individualized. This study demonstrates the importance of EHR usability assessments to evaluate group and individual performance of different interfaces and preferences for each design.

  12. Applications of navigation for orthognathic surgery.

    Science.gov (United States)

    Bobek, Samuel L

    2014-11-01

    Stereotactic surgical navigation has been used in oral and maxillofacial surgery for orbital reconstruction, reduction of facial fractures, localization of foreign bodies, placement of implants, skull base surgery, tumor removal, temporomandibular joint surgery, and orthognathic surgery. The primary goals in adopting intraoperative navigation into these different surgeries were to define and localize operative anatomy, to localize implant position, and to orient the surgical wound. Navigation can optimize the functional and esthetic outcomes in patients with dentofacial deformities by identifying pertinent anatomic structures, transferring the surgical plan to the patient, and verifying the surgical result. This article discusses the principles of navigation-guided orthognathic surgery. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Airports and Navigation Aids Database System -

    Data.gov (United States)

    Department of Transportation — Airport and Navigation Aids Database System is the repository of aeronautical data related to airports, runways, lighting, NAVAID and their components, obstacles, no...

  14. Youth Mobilisation as Social Navigation

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2010-01-01

     ties and options that arise in such situations. Building on the Guinean Creole term of dubriagem, the article proposes the concept of social navigation as an analytical optic able to shed light on praxis in unstable environments. The concept of social navigation makes it possible to focus on the way we move within changing social environments. It is processuality squared, illuminating motion within motion. The article thus advocates an analysis of praxis that takes its point of departure in a Batesonian and intermorphological understanding of action in order to further our understanding of the acts of youth in conflict....

  15. Off the Beaten tracks: Exploring Three Aspects of Web Navigation

    NARCIS (Netherlands)

    Weinreich, H.; Obendorf, H.; Herder, E.; Mayer, M.; Edmonds, H.; Hawkey, K.; Kellar, M.; Turnbull, D.

    2006-01-01

    This paper presents results of a long-term client-side Web usage study, updating previous studies that range in age from five to ten years. We focus on three aspects of Web navigation: changes in the distribution of navigation actions, speed of navigation and within-page navigation. “Navigation

  16. Dynamic oxygen transfer measurements under operating conditions as a basis for the optimization of ventilation systems; Dynamische Sauerstoffeintragsmessungen unter Betriebsbedingungen als Grundlage zur Optimierung von Belueftungssystemen

    Energy Technology Data Exchange (ETDEWEB)

    Libra, J.A.; Biskup, M.; Wiesmann, U. [Technische Univ. Berlin (Germany). Inst. fuer Verfahrenstechnik; Sahlmann, C.; Gnirss, R. [Berliner Wasserbetriebe, Berlin (Germany)

    1999-07-01

    The largest single energy consumer at sewage treatment plants is the ventilation system of activated sludge tanks. This is why controlling and optimizing ventilation systems is the most appropriate approach to the cutting down of energy costs. The present paper reports on measurements of dynamic oxygen transfer by means of the off-gas method under operating conditions at the Berlin-Ruhleben sewage treatment plant. (orig.) [German] Der groesste Einzelenergieverbraucher auf Klaerwerken ist das Belueftungssystem von Belebungsbecken. Deshalb ist die Kontrolle und Optimierung der Belueftungssysteme der geeignete Weg zur Verringerung der Energiekosten. In diesem Beitrag wird ueber Messungen des dynamischen Sauerstoffeintrags mit der Abluft-Methode unter Betriebsbedingungen im Klaerwerk Berlin-Ruhleben berichtet. (orig.)

  17. Harmonisation of fire testing of conveyor belts for underground applications within the EC; Harmonisierung der brandtechnischen Pruefverfahren von Foerdergurten fuer den Einsatz unter Tage innerhalb der EG

    Energy Technology Data Exchange (ETDEWEB)

    Foit, W. [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Dortmund (Germany). Fachstelle fuer Brand- und Explosionsschutz unter Tage - Versuchsgrube Tremonia

    1998-12-01

    The mining countries of the EC still have different regulations for fire testing of conveyor belts. The test methods will be harmonized for the Common Market, and requirements on conveyor belts will be standardized within the EC. A new EC standard will be drawn up. [Deutsch] Zur Zeit sind in den bergbaubetreibenden Laendern der EG noch unterschiedliche Verfahren zur brandtechnischen Pruefung von Foerdergurten vorgeschrieben. Mit dem Inkrafttreten des Gemeinsamen Marktes und der damit zusammenhaengenden Forderung nach Abbau von Handelshemmnissen sollen diese Pruefverfahren harmonisiert werden. Ziel ist es, die an die Foerdergurte zu stellenden brandtechnischen Anforderungen innerhalb der EG zu vereinheitlichen. Es soll deshalb eine europaeische Norm zur Beurteilung des Brandverhaltens und der Brandausbreitung an Foerdergurten fuer den Kohlenbergbau unter Tage erstellt werden. (orig./MSK)

  18. Vibrotactile in-vehicle navigation system

    NARCIS (Netherlands)

    Erp, J.B.F. van; Veen, H.J. van

    2004-01-01

    A vibrotactile display, consisting ofeight vibrating elements or tactors mounted in a driver's seat, was tested in a driving simulator. Participants drove with visual, tactile and multimodal navigation displays through a built-up area. Workload and the reaction time to navigation messages were

  19. Parsimonious Ways to Use Vision for Navigation

    Directory of Open Access Journals (Sweden)

    Paul Graham

    2012-05-01

    Full Text Available The use of visual information for navigation appears to be a universal strategy for sighted animals, amongst which, one particular group of expert navigators are the ants. The broad interest in studies of ant navigation is in part due to their small brains, thus biomimetic engineers expect to be impressed by elegant control solutions, and psychologists might hope for a description of the minimal cognitive requirements for complex spatial behaviours. In this spirit, we have been taking an interdisciplinary approach to the visual guided navigation of ants in their natural habitat. Behavioural experiments and natural image statistics show that visual navigation need not depend on the remembering or recognition of objects. Further modelling work suggests how simple behavioural routines might enable navigation using familiarity detection rather than explicit recall, and we present a proof of concept that visual navigation using familiarity can be achieved without specifying when or what to learn, nor separating routes into sequences of waypoints. We suggest that our current model represents the only detailed and complete model of insect route guidance to date. What's more, we believe the suggested mechanisms represent useful parsimonious hypotheses for the visually guided navigation in larger-brain animals.

  20. A Semantic Navigation Model for Video Games

    Science.gov (United States)

    van Driel, Leonard; Bidarra, Rafael

    Navigational performance of artificial intelligence (AI) characters in computer games is gaining an increasingly important role in the perception of their behavior. While recent games successfully solve some complex navigation problems, there is little known or documented on the underlying approaches, often resembling a primitive conglomerate of ad-hoc algorithms for specific situations.

  1. Sex differences in navigation strategy and efficiency.

    Science.gov (United States)

    Boone, Alexander P; Gong, Xinyi; Hegarty, Mary

    2018-05-22

    Research on human navigation has indicated that males and females differ in self-reported navigation strategy as well as objective measures of navigation efficiency. In two experiments, we investigated sex differences in navigation strategy and efficiency using an objective measure of strategy, the dual-solution paradigm (DSP; Marchette, Bakker, & Shelton, 2011). Although navigation by shortcuts and learned routes were the primary strategies used in both experiments, as in previous research on the DSP, individuals also utilized route reversals and sometimes found the goal location as a result of wandering. Importantly, sex differences were found in measures of both route selection and navigation efficiency. In particular, males were more likely to take shortcuts and reached their goal location faster than females, while females were more likely to follow learned routes and wander. Self-report measures of strategy were only weakly correlated with objective measures of strategy, casting doubt on their usefulness. This research indicates that the sex difference in navigation efficiency is large, and only partially related to an individual's navigation strategy as measured by the dual-solution paradigm.

  2. Navigator. Volume 45, Number 2, Winter 2009

    Science.gov (United States)

    National Science Education Leadership Association, 2009

    2009-01-01

    The National Science Education Leadership Association (NSELA) was formed in 1959 to meet a need to develop science education leadership for K-16 school systems. "Navigator" is published by NSELA to provide the latest NSELA events. This issue of "Navigator" contains the following reports: (1) A Message from the President: Creating Networks of…

  3. Navigator. Volume 45, Number 3, Spring 2009

    Science.gov (United States)

    National Science Education Leadership Association, 2009

    2009-01-01

    The National Science Education Leadership Association (NSELA) was formed in 1959 to meet a need to develop science education leadership for K-16 school systems. "Navigator" is published by NSELA to provide the latest NSELA events. This issue of "Navigator" includes the following items: (1) A Message from the President (Brenda Wojnowski); (2) NSELA…

  4. Natural Language Navigation Support in Virtual Reality

    NARCIS (Netherlands)

    van Luin, J.; Nijholt, Antinus; op den Akker, Hendrikus J.A.; Giagourta, V.; Strintzis, M.G.

    2001-01-01

    We describe our work on designing a natural language accessible navigation agent for a virtual reality (VR) environment. The agent is part of an agent framework, which means that it can communicate with other agents. Its navigation task consists of guiding the visitors in the environment and to

  5. Risk management model of winter navigation operations

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. - Highlights: •A model to assess and manage the risk of winter navigation operations is proposed. •The risks of oil spills in winter navigation in the Gulf of Finland are analysed. •The model assesses and prioritizes actions to control the risk of the operations. •The model suggests navigational training as the most efficient risk control option.

  6. The Navigation Metaphor in Security Economics

    DEFF Research Database (Denmark)

    Pieters, Wolter; Barendse, Jeroen; Ford, Margaret

    2016-01-01

    The navigation metaphor for cybersecurity merges security architecture models and security economics. By identifying the most efficient routes for gaining access to assets from an attacker's viewpoint, an organization can optimize its defenses along these routes. The well-understood concept of na...... of navigation makes it easier to motivate and explain security investment to a wide audience, encouraging strategic security decisions....

  7. 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…

  8. 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....

  9. Quantum imaging for underwater arctic navigation

    Science.gov (United States)

    Lanzagorta, Marco

    2017-05-01

    The precise navigation of underwater vehicles is a difficult task due to the challenges imposed by the variable oceanic environment. It is particularly difficult if the underwater vehicle is trying to navigate under the Arctic ice shelf. Indeed, in this scenario traditional navigation devices such as GPS, compasses and gyrocompasses are unavailable or unreliable. In addition, the shape and thickness of the ice shelf is variable throughout the year. Current Arctic underwater navigation systems include sonar arrays to detect the proximity to the ice. However, these systems are undesirable in a wartime environment, as the sound gives away the position of the underwater vehicle. In this paper we briefly describe the theoretical design of a quantum imaging system that could allow the safe and stealthy navigation of underwater Arctic vehicles.

  10. Ethical Navigation in Leadership Training

    Directory of Open Access Journals (Sweden)

    Øyvind Kvalnes

    2012-05-01

    Full Text Available Business leaders frequently face dilemmas, circumstances where whatever course of action they choose, something of important value will be offended. How can an organisation prepare its decision makers for such situations? This article presents a pedagogical approach to dilemma training for business leaders and managers. It has evolved through ten years of experience with human resource development, where ethics has been an integral part of programs designed to help individuals to become excellent in their professional roles. The core element in our approach is The Navigation Wheel, a figure used to keep track of relevant decision factors. Feedback from participants indicates that dilemma training has helped them to recognise the ethical dimension of leadership. They respond that the tools and concepts are highly relevant in relation to the challenges that occur in the working environment they return to after leadership training.http://dx.doi.org/10.5324/eip.v6i1.1778

  11. 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.

  12. [Dimitri Steinke: Die Zivilrechtsordnungen des Baltikums unter dem Einfluss ausländischer, insbesondere deutscher Rechtsquellen. (Osnabrücker Schriften zur Rechtsgeschichte, Bd. 16.) V&R unipress. Göttingen 2009. 243 S. ISBN 978-3-89971-573-6] / M

    Index Scriptorium Estoniae

    Luts-Sootak, Marju, 1966-

    2011-01-01

    Arvustus: Dimitri Steinke. Die Zivilrechtsordnungen des Baltikums unter dem Einfluss ausländischer, insbesondere deutscher Rechtsquellen. (Osnabrücker Schriften zur Rechtsgeschichte ; 16). Göttingen, 2009

  13. SLS Model Based Design: A Navigation Perspective

    Science.gov (United States)

    Oliver, T. Emerson; Anzalone, Evan; Park, Thomas; Geohagan, Kevin

    2018-01-01

    The SLS Program has implemented a Model-based Design (MBD) and Model-based Requirements approach for managing component design information and system requirements. This approach differs from previous large-scale design efforts at Marshall Space Flight Center where design documentation alone conveyed information required for vehicle design and analysis and where extensive requirements sets were used to scope and constrain the design. The SLS Navigation Team is responsible for the Program-controlled Design Math Models (DMMs) which describe and represent the performance of the Inertial Navigation System (INS) and the Rate Gyro Assemblies (RGAs) used by Guidance, Navigation, and Controls (GN&C). The SLS Navigation Team is also responsible for navigation algorithms. The navigation algorithms are delivered for implementation on the flight hardware as a DMM. For the SLS Block 1B design, the additional GPS Receiver hardware model is managed as a DMM at the vehicle design level. This paper describes the models, and discusses the processes and methods used to engineer, design, and coordinate engineering trades and performance assessments using SLS practices as applied to the GN&C system, with a particular focus on the navigation components.

  14. 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.

  15. Venous catheterization with ultrasound navigation

    International Nuclear Information System (INIS)

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

    2015-01-01

    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

  16. 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.

  17. Qatari Women Navigating Gendered Space

    Directory of Open Access Journals (Sweden)

    Krystyna Golkowska

    2017-10-01

    Full Text Available ADespite growing interest in the lived experience of Muslim women in Arab countries, there is still a dearth of studies on the Gulf region. This article focuses on Qatar, a Gulf Corporation Council (GCC country, to explore its changing sociocultural landscape and reflect on Qatari women’s agency within the framework of the traditional gendered space model. Applying Grounded Theory methodology to data collected from a variety of scholarly and non-scholarly sources, the author offers a themed overview of factors that facilitate and constrain Qatari women’s mobility. The findings testify to a significant increase in female presence and visibility in the public sphere—specifically in the spaces of education, employment, and sports. They also show that young Qatari women exercise agency through navigating the existing systems rather than question traditional socio-cultural norms. The paper identifies this search for a middle ground between tradition and modernity and its ideological underpinnings as the area of future research that should be led by Qatari women themselves.

  18. Hydrogen diffusion into fatigue cracks of aluminium alloy 6013 in a corrosive environment; Wasserstoffeinlagerung an Ermuedungsrissen der Aluminiumlegierung 6013 unter korrosiver Umgebung

    Energy Technology Data Exchange (ETDEWEB)

    Lenk, Christian Alexander

    2009-08-13

    The author attempted a time-resolved detection of raised hydrogen concentrations in the plastic deformation region of fatigue cracks in an aluminium test piece deformed by cyclic stress in a corrosive environment. Mechanical material parameters like the crack propagation velocity under cyclic stress change dramatically in a corrosive environment. This is assumed to be caused by hydrogen diffusion, but so far there is no method that reliably measures additional hydrogen from the corrosive environment. For this reason, a special analytical configuration was set up which makes use of the thermal desorption method. First, chips with a thickness of about 20 micrometers are sawed out of the test specimen in high-vacuum conditions. The chips fall into a hot melting vessel in a UHV chamber, where the hydrogen contained in the chips is released. The resulting pressure increase is recorded by a mass spectrometer. A hydrogen profile of the test specimen is obtained by assigning the chip position to the signal. For the corrosive medium in which the test specimen is immersed during crack initiation, i.e. NaCl solution, heavy water was used. This makes it possible to distinguish between the hydrogen contained in a piece of technical aluminium alloy (AA6013) and the deuterium diffusing in from the corrosive fluid. The deuterium is found exclusively in the test piece volume in the strongly plastically deformed region surrounding the fatigue crack. (orig.) [German] Das Ziel der vorliegenden Arbeit besteht im ortsaufgeloesten Nachweis einer erhoehten Wasserstoffkonzentration im plastisch deformierten Bereich von Ermuedungsrissen einer unter korrosiver Umgebung zyklisch verformten Aluminiumprobe. Mechanische Materialparameter wie z.B. die Rissausbreitungsgeschwindigkeit unter zyklischer Belastung aendern sich drastisch in korrosiver Umgebung. Als Ursache fuer dieses Verhalten wird eine Eindiffusion von Wasserstoff vermutet, jedoch gibt es bisher keine Messung die den zusaetzlichen

  19. ANALYSIS OF FREE ROUTE AIRSPACE AND PERFORMANCE BASED NAVIGATION IMPLEMENTATION IN THE EUROPEAN AIR NAVIGATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Svetlana Pavlova

    2014-12-01

    Full Text Available European Air Traffic Management system requires continuous improvements as air traffic is increasingday by day. For this purpose it was developed by international organizations Free Route Airspace and PerformanceBased Navigation concepts that allow to offer a required level of safety, capacity, environmental performance alongwith cost-effectiveness. The aim of the article is to provide detailed analysis of Free Route Airspace and PerformanceBased Navigation implementation status within European region including Ukrainian air navigation system.

  20. Real-time precision pedestrian navigation solution using Inertial Navigation System and Global Positioning System

    OpenAIRE

    Yong-Jin Yoon; King Ho Holden Li; Jiahe Steven Lee; Woo-Tae Park

    2015-01-01

    Global Positioning System and Inertial Navigation System can be used to determine position and velocity. A Global Positioning System module is able to accurately determine position without sensor drift, but its usage is limited in heavily urbanized environments and heavy vegetation. While high-cost tactical-grade Inertial Navigation System can determine position accurately, low-cost micro-electro-mechanical system Inertial Navigation System sensors are plagued by significant errors. Global Po...

  1. Smart parking management and navigation system

    KAUST Repository

    Saadeldin, Mohamed

    2017-01-01

    Various examples are provided for smart parking management, which can include navigation. In one example, a system includes a base station controller configured to: receive a wireless signal from a parking controller located at a parking space

  2. Challenges in navigational strategies for flexible endoscopy

    NARCIS (Netherlands)

    van der Stap, N.; van der Heijden, Ferdinand; Broeders, Ivo Adriaan Maria Johannes

    Automating flexible endoscope navigation could lead to an increase in patient safety for endoluminal therapeutic procedures. Additionally, it may decrease the costs of diagnostic flexible endoscope procedures by shortening the learning curve and increasing the efficiency of insertion. Earlier

  3. Fuzzy Logic Controller for Small Satellites Navigation

    National Research Council Canada - National Science Library

    Della Pietra, G; Falzini, S; Colzi, E; Crisconio, M

    2005-01-01

    .... The navigator aims at operating satellites in orbit with a minimum ground support and very good performances, by the adoption of innovative technologies, such as attitude observation GPS, attitude...

  4. From Navigation to Star Hopping: Forgotten Formulae

    Indian Academy of Sciences (India)

    IAS Admin

    Mathematics and wrote a book Navigation and Nautical Astronomy for Sea-men in 1821 with tables ... and arcseconds. The reference ... Roger W Sinnott, an astronomy graduate from Harvard, served on the editorial board of the monthly ...

  5. Comprehension and navigation of networked hypertexts

    NARCIS (Netherlands)

    Blom, Helen; Segers, Eliane; Knoors, Harry; Hermans, Daan; Verhoeven, Ludo

    2018-01-01

    This study aims to investigate secondary school students' reading comprehension and navigation of networked hypertexts with and without a graphic overview compared to linear digital texts. Additionally, it was studied whether prior knowledge, vocabulary, verbal, and visual working memory moderated

  6. 78 FR 68077 - Navigation Safety Advisory Council

    Science.gov (United States)

    2013-11-13

    ... Privacy Act notice regarding our public dockets in the January 17, 2008, issue of the Federal Register (73... commence in calendar year 2014. (4) Navigation Rules Regulatory Project. The Council will receive an update...

  7. 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.

  8. 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.

  9. Onboard Optical Navigation Measurement Processing in GEONS

    Data.gov (United States)

    National Aeronautics and Space Administration — Optical Navigation (OpNav) measurements derived from spacecraft-based images are a powerful data type in the precision orbit determination process.  OpNav...

  10. 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...

  11. 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”.

  12. Unraveling navigational strategies in migratory insects

    OpenAIRE

    Merlin, Christine; Heinze, Stanley; Reppert, Steven M.

    2011-01-01

    Long-distance migration is a strategy some animals use to survive a seasonally changing environment. To reach favorable grounds, migratory animals have evolved sophisticated navigational mechanisms that rely on a map and compasses. In migratory insects, the existence of a map sense (sense of position) remains poorly understood, but recent work has provided new insights into the mechanisms some compasses use for maintaining a constant bearing during long-distance navigation. The best-studied d...

  13. Magnetic navigation and tracking of underwater vehicles

    Digital Repository Service at National Institute of Oceanography (India)

    Teixeira, F.C.; Pascoal, A.M.

    for the navigation of AUVs has been proposed many years ago but the concept still requires practical demonstration. Implementation issues One of the advantages of mag- netic navigation consists in being passive and economical in terms of energy. Magnetic sensors do... like the present one, that require magnetic measurements with very high precision. A typical solution to this problem consists in the placement of magnetic sensors as far away as possible from the sources of noise but this may not be practical...

  14. Navigational Strategies of Migrating Monarch Butterflies

    Science.gov (United States)

    2014-11-10

    AFRL-OSR-VA-TR-2014-0339 NAVIGATIONAL STRATEGIES OF MIGRATING MONARCH BUTTERFLIES Steven Reppert UNIVERSITY OF MASSACHUSETTS Final Report 11/10/2014...Final Progress Statement to (Dr. Patrick Bradshaw) Contract/Grant Title: Navigational Strategies of Migrating Monarch Butterflies Contract...Grant #: FA9550-10-1-0480 Reporting Period: 01-Sept-10 to 31-Aug-14 Overview of accomplishments: Migrating monarch butterflies (Danaus

  15. Clinical applications of virtual navigation bronchial intervention.

    Science.gov (United States)

    Kajiwara, Naohiro; Maehara, Sachio; Maeda, Junichi; Hagiwara, Masaru; Okano, Tetsuya; Kakihana, Masatoshi; Ohira, Tatsuo; Kawate, Norihiko; Ikeda, Norihiko

    2018-01-01

    In patients with bronchial tumors, we frequently consider endoscopic treatment as the first treatment of choice. All computed tomography (CT) must satisfy several conditions necessary to analyze images by Synapse Vincent. To select safer and more precise approaches for patients with bronchial tumors, we determined the indications and efficacy of virtual navigation intervention for the treatment of bronchial tumors. We examined the efficacy of virtual navigation bronchial intervention for the treatment of bronchial tumors located at a variety of sites in the tracheobronchial tree using a high-speed 3-dimensional (3D) image analysis system, Synapse Vincent. Constructed images can be utilized to decide on the simulation and interventional strategy as well as for navigation during interventional manipulation in two cases. Synapse Vincent was used to determine the optimal planning of virtual navigation bronchial intervention. Moreover, this system can detect tumor location and alsodepict surrounding tissues, quickly, accurately, and safely. The feasibility and safety of Synapse Vincent in performing useful preoperative simulation and navigation of surgical procedures can lead to safer, more precise, and less invasion for the patient, and makes it easy to construct an image, depending on the purpose, in 5-10 minutes using Synapse Vincent. Moreover, if the lesion is in the parenchyma or sub-bronchial lumen, it helps to perform simulation with virtual skeletal subtraction to estimate potential lesion movement. By using virtual navigation system for simulation, bronchial intervention was performed with no complications safely and precisely. Preoperative simulation using virtual navigation bronchial intervention reduces the surgeon's stress levels, particularly when highly skilled techniques are needed to operate on lesions. This task, including both preoperative simulation and intraoperative navigation, leads to greater safety and precision. These technological instruments

  16. Shape Perception and Navigation in Blind Adults

    Science.gov (United States)

    Gori, Monica; Cappagli, Giulia; Baud-Bovy, Gabriel; Finocchietti, Sara

    2017-01-01

    Different sensory systems interact to generate a representation of space and to navigate. Vision plays a critical role in the representation of space development. During navigation, vision is integrated with auditory and mobility cues. In blind individuals, visual experience is not available and navigation therefore lacks this important sensory signal. In blind individuals, compensatory mechanisms can be adopted to improve spatial and navigation skills. On the other hand, the limitations of these compensatory mechanisms are not completely clear. Both enhanced and impaired reliance on auditory cues in blind individuals have been reported. Here, we develop a new paradigm to test both auditory perception and navigation skills in blind and sighted individuals and to investigate the effect that visual experience has on the ability to reproduce simple and complex paths. During the navigation task, early blind, late blind and sighted individuals were required first to listen to an audio shape and then to recognize and reproduce it by walking. After each audio shape was presented, a static sound was played and the participants were asked to reach it. Movements were recorded with a motion tracking system. Our results show three main impairments specific to early blind individuals. The first is the tendency to compress the shapes reproduced during navigation. The second is the difficulty to recognize complex audio stimuli, and finally, the third is the difficulty in reproducing the desired shape: early blind participants occasionally reported perceiving a square but they actually reproduced a circle during the navigation task. We discuss these results in terms of compromised spatial reference frames due to lack of visual input during the early period of development. PMID:28144226

  17. Effects of Visual, Auditory, and Tactile Navigation Cues on Navigation Performance, Situation Awareness, and Mental Workload

    National Research Council Canada - National Science Library

    Davis, Bradley M

    2007-01-01

    .... Results from both experiments indicate that augmented visual displays reduced time to complete navigation, maintained situation awareness, and drastically reduced mental workload in comparison...

  18. Predicting the service life of connecting rod and main bearings, taking into account different engine loads. Final report; Lebensdauervorhersage fuer Pleuel- und Hauptlager unter Beruecksichtigung unterschiedlicher Motorlastkollektive. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Berkowitz, B.; Lueneburg, B.; Liu, J.

    1994-12-31

    Connecting rod and main bearings of internal combustion engines are among the most heavily stressed components in modern engines. It was found that these engine components are increasingly reaching the limits of their strength and therefore become the components limiting engine life. However, there is no known process which makes a calculated prediction of the service life of modern connecting rod and main bearings possible, taking into account various engine loads. In this research project, a new concept for the calculated prediction of the service life of non-static highly loaded radial sliding bearings is worked out. The basis is a process of calculation which realistically determines the pressure and gap course in highly loaded sliding bearings. Apart from the viscosity depending on pressure and temperature, the elastic deformations of the system sliding bearing/conn rod are also taken into account. Calculations are done for different operating points for a complete cycle of a four stroke Diesel engine (Daimler-Benz OM 364 LA). The results are compared with the present conventional process of calculation and the effects which occur are discussed. Based on the elasto-hydrodynamic calculation, a method of calculating the service life of non-statically loaded sliding bearings, taking into account various motor loads, is worked out. (orig./HW) [Deutsch] Pleuel- und Hauptlager von Verbrennungskraftmaschinen zaehlen mit zu den spezifisch am hoechsten beanspruchten Bauteilen in modernen Motoren. Es hat sich gezeigt, dass vor allem diese Maschinenelemente zunehmend an die Grenzen ihrer Belastbarkeit stossen und so zum lebensdauerbegrenzenden Bauteil werden. Es ist jedoch kein Verfahren bekannt, das eine rechnerische Lebensdauervorhersage moderner Pleuel- und Hauptlager unter Beruecksichtigung unterschiedlicher Motorlastkollektive ermoeglicht. Im vorliegenden Forschungsvorhaben wird daher ein neuartiges Konzept zur rechnerischen Lebensdauervorhersage von instationaeren

  19. 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

  20. 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.

  1. 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.

  2. E-navigation Services for Non-SOLAS Ships

    Directory of Open Access Journals (Sweden)

    Kwang An

    2016-06-01

    Full Text Available It is clearly understood that the main benefits of e-navigation are improved safety and better protection of the environment through the promotion of standards of navigational system and a reduction in human error. In order to meet the expectations on the benefit of e-navigation, e-navigation services should be more focused on non-SOLAS ships. The purpose of this paper is to present necessary e-navigation services for non-SOLAS ships in order to prevent marine accidents in Korean coastal waters. To meet the objectives of the study, an examination on the present navigation and communication system for non-SOLAS ships was performed. Based on the IMO's e-navigation Strategy Implementation Plan (SIP and Korea's national SIP for e-navigation, future trends for the development and implementation of e-navigation were discussed. Consequently, Electronic Navigational Chart (ENC download and ENC up-date service, ENC streaming service, route support service and communication support service based on Maritime Cloud were presented as essential e-navigation services for non-SOLAS ships. This study will help for the planning and designing of the Korean e-navigation system. It is expected that the further researches on the navigation support systems based on e-navigation will be carried out in order to implement the essential e-navigation services for non-SOLAS ships.

  3. Presentation of the Well Tractor Concept and practical experience in extreme conditions; Vorstellung des Well Tractor Konzepts mit Erfahrungen bei Einsaetzen unter Extrembedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Kater, H.; Preiss, F. [Preussag Wireline- und Messservice, Edemissen (Germany)

    1998-12-31

    So-called extended reach boreholes with horizontal sections of more than 2000 m, short radius drilling, multilaterals and other variations are common enough. Problems occur when this type of borehole needs to be surveyed or modified. The contribution describes the newly developed ``Well Tracotor{sup circledR}`` technology and outlines its potential. (orig.) [Deutsch] Sogenannte Extended Reach Bohrungen mit Horizontalsektionen von mehr als 2.000 Meter Laenge, Short Radius Drilling, Multilaterals und andere Variationen sind bohrtechnisch einwandfrei durchfuehrbar und gehoeren zum gaengigen Repertoire der Bohrfirmen. Grosse Probleme entstehen jedoch wenn dieser Bohrungstyp vermessen, komplettiert oder aufgewaeltigt werden soll. Insbesondere Bohrlochmessfirmen haben es in den letzten ca. 20 Jahren versaeumt Innovationen zwecks oekonomischen Einsatzes ihrer Technologie in diesen Bohrungen bereitzustellen. Die Durchfuehrung von Perforationen und Bohrlochmessungen, das Setzen von Stopfen, Schneiden von Rohren und auch einfachste Slickline-Operationen sind bei einer Bohrlochneigung beginnend bei ca. 60 bis 80 nur unter Anwendung von kosten- und zeitintensiven Verfahren moeglich. Eine guenstige Alternative zu diesen Verfahren bietet der Well Tractor. Diese Technologie ermoeglicht das Einfahren von Geraeten, die ueblicherweise am Kabel oder Draht eingesetzt werden, in Horizontalbohrungen. Im Folgenden werden das technische Konzept, ein Vergleich mit alternativen Verfahren, und verschiedene Referenzen des Well Tracotors {sup trademark} dargestellt. Weiterhin wird auf die Modifikationen eingegangen, die noetig waren, um dieses Geraet den Gegebenheiten in tiefen, heissen Gasbohrungen anzupassen. Abschliessend soll durch einen Ausblick auf zum Teil schon im Feldtest befindliche Weiterentwicklungen das weitere Potential dieser Technologie aufgezeichnet werden. (orig.)

  4. MR-imaging of finger osteoarthritis: Morphology and cartrilage signal intensity before and after treatment with ademetionin; Magnetresonanztomographie der Fingerpolyarthrose: Morphologie und Knorpelsignalverhalten unter Ademetonintherapie

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, H. [Radiologische Klinik, Abt. fuer Roentgendiagnostik und Nuklearmedizin, Univ.-Klinikum Steglitz, FU Berlin (Germany); Stahl, H. [Radiologische Klinik, Univ.-Klinikum Rudolf-Virchow, FU Berlin (Germany); Sieper, J. [Medizinische Klinik und Poliklinik, Univ.-Klinikum Steglitz, FU Berlin (Germany); Wolf, K.J. [Radiologische Klinik, Abt. fuer Roentgendiagnostik und Nuklearmedizin, Univ.-Klinikum Steglitz, FU Berlin (Germany)

    1995-01-01

    This report deals with a prospective study of 21 patients with finger osteoarthritis treated over a period of three months with either Ademetionin (therapy group: 14/21) or without (control group: 7/21). MR-Imaging was carried out before and after treatment using spin-echo and 3D-Flash sequences. Morphological parameters and signal intensity changes of the hyaline cartilage were evaluated. The increase of the cartilage signal intensity was significant in the therapy group, this can be interpreted as an structural improvement. Also a decrease of the cartilage signal intensity with age was found. The morphological parameters showed no significant changes in the therapy and control groups. (orig.) [Deutsch] Im Rahmen einer prospektiven Studie wurden magnetresonanztomographische Untersuchungen bei Patientinnen mit Fingerpolyarthrose vor und nach Ademetionintherapie durchgefuehrt. Es erfolgten zwei Messungen an einer Kontrollgruppe (n=7, keine Ademetionintherapie) und an der Therapiegruppe (n=14) im Abstand von drei Monaten. Zur Anwendung kamen eine Doppel-Spin-Echo-Sequenz sowie eine 3D-Flash-Sequenz. Ausgewertet wurden neben morphologischen Parametern auch der Signalintensitaetsverlauf im Bereich des hyalinen Gelenkknorpels der Interphalangealgelenke. Signifikant war der Knorpelsignalzuwachs unter Ademetionintherapie, dies kann als Zeichen einer strukturellen Befundbesserung interpretiert werden. Ebenfalls signifikant zeigte sich die Abnahme der Knorpelsignalintensitaet mit zunehmendem Lebensalter der Patientinnen. Bei den morphologischen Befundaenderungen konnte kein signifikanter Therapieeffekt festgestellt werden. (orig.)

  5. Self-management by firm, non-elastic adjustable compression wrap device [Translation of Druckmessungen unter Klettverschluss-Kompression - Selbstbehandlung durch feste, unelastische Beinwickelung

    Directory of Open Access Journals (Sweden)

    Giovanni Mosti

    2017-09-01

    Full Text Available Severe forms of chronic venous insufficiency and lymphedema require strong compression-pressure, which exceeds the pressure exerted by medical compression stockings (>40 mmHg. The aim was to investigate if patients are able to apply a Velcro-band compression device (Circaid Juxta Lite™ themselves with sufficient pressure. Thirty-one patients (CEAP C6=23, C5=5, C3=2, mixed ulcer=1 applied Juxta Lite™ on their own legs after a short instruction and were asked to readjust the pressure by their subjective feeling. Sub- bandage pressure was measured after application and 24 h later. In 30 patients without arterial occlusive disease the median sub- bandage pressure values on day 1 and day 2 were 44,5 mmHg (IQR 42-48, and 46 mmHg (IQR 44-48,25 respectively. One patient with an arterialvenous leg ulcer showed pressures of 34 and 36 mmHg. All measured pressure values corresponded to the pursued target range, demonstrating that adequate self application of Velcro bands is feasible and that patents can maintain this pressure by re-adjustment. Source: this paper is an abridged translation of Mosti G, Partsch H. Druckmessungen unter Klettverschluss-Kompression - Selbstbehandlung durch feste, unelastische Beinwickelung. Vasomed 2017;5:212-6.

  6. 78 FR 41304 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments; Correction

    Science.gov (United States)

    2013-07-10

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 105 [Docket No. USCG-2013-0397] RIN 1625-AC06 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments; Correction AGENCY: Coast Guard, DHS. ACTION: Final rule; correction. SUMMARY: The Coast Guard published a final rule...

  7. 75 FR 48564 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector...

    Science.gov (United States)

    2010-08-11

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Parts 3 and 165 [Docket No. USCG-2010-0351] RIN 1625-ZA25 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector Columbia River, WA AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: This rule makes non-substantive...

  8. 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

  9. Integrated navigation method of a marine strapdown inertial navigation system using a star sensor

    International Nuclear Information System (INIS)

    Wang, Qiuying; Diao, Ming; Gao, Wei; Zhu, Minghong; Xiao, Shu

    2015-01-01

    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. (paper)

  10. 75 FR 50884 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector...

    Science.gov (United States)

    2010-08-18

    ... 3 and 165 to reflect changes in Coast Guard internal organizational structure. Sector Portland and... 1625-ZA25 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector... Waters; Technical, Organizational, and Conforming Amendments, Sector Columbia River.'' 2. On page 48564...

  11. 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

  12. 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.

  13. An on-line monitoring system for navigation equipment

    Science.gov (United States)

    Wang, Bo; Yang, Ping; Liu, Jing; Yang, Zhengbo; Liang, Fei

    2017-10-01

    Civil air navigation equipment is the most important infrastructure of Civil Aviation, which is closely related to flight safety. In addition to regular flight inspection, navigation equipment's patrol measuring, maintenance measuring, running measuring under special weather conditions are the important means of ensuring aviation flight safety. According to the safety maintenance requirements of Civil Aviation Air Traffic Control navigation equipment, this paper developed one on-line monitoring system with independent intellectual property rights for navigation equipment, the system breakthroughs the key technologies of measuring navigation equipment on-line including Instrument Landing System (ILS) and VHF Omni-directional Range (VOR), which also meets the requirements of navigation equipment ground measurement set by the ICAO DOC 8071, it provides technical means of the ground on-line measurement for navigation equipment, improves the safety of navigation equipment operation, and reduces the impact of measuring navigation equipment on airport operation.

  14. Benchmark Framework for Mobile Robots Navigation Algorithms

    Directory of Open Access Journals (Sweden)

    Nelson David Muñoz-Ceballos

    2014-01-01

    Full Text Available Despite the wide variety of studies and research on mobile robot systems, performance metrics are not often examined. This makes difficult to establish an objective comparison of achievements. In this paper, the navigation of an autonomous mobile robot is evaluated. Several metrics are described. These metrics, collectively, provide an indication of navigation quality, useful for comparing and analyzing navigation algorithms of mobile robots. This method is suggested as an educational tool, which allows the student to optimize the algorithms quality, relating to important aspectsof science, technology and engineering teaching, as energy consumption, optimization and design.

  15. Wavefront Propagation and Fuzzy Based Autonomous Navigation

    Directory of Open Access Journals (Sweden)

    Adel Al-Jumaily

    2005-06-01

    Full Text Available Path planning and obstacle avoidance are the two major issues in any navigation system. Wavefront propagation algorithm, as a good path planner, can be used to determine an optimal path. Obstacle avoidance can be achieved using possibility theory. Combining these two functions enable a robot to autonomously navigate to its destination. This paper presents the approach and results in implementing an autonomous navigation system for an indoor mobile robot. The system developed is based on a laser sensor used to retrieve data to update a two dimensional world model of therobot environment. Waypoints in the path are incorporated into the obstacle avoidance. Features such as ageing of objects and smooth motion planning are implemented to enhance efficiency and also to cater for dynamic environments.

  16. Cloud Absorption Radiometer Autonomous Navigation System - CANS

    Science.gov (United States)

    Kahle, Duncan; Gatebe, Charles; McCune, Bill; Hellwig, Dustan

    2013-01-01

    CAR (cloud absorption radiometer) acquires spatial reference data from host aircraft navigation systems. This poses various problems during CAR data reduction, including navigation data format, accuracy of position data, accuracy of airframe inertial data, and navigation data rate. Incorporating its own navigation system, which included GPS (Global Positioning System), roll axis inertia and rates, and three axis acceleration, CANS expedites data reduction and increases the accuracy of the CAR end data product. CANS provides a self-contained navigation system for the CAR, using inertial reference and GPS positional information. The intent of the software application was to correct the sensor with respect to aircraft roll in real time based upon inputs from a precision navigation sensor. In addition, the navigation information (including GPS position), attitude data, and sensor position details are all streamed to a remote system for recording and later analysis. CANS comprises a commercially available inertial navigation system with integral GPS capability (Attitude Heading Reference System AHRS) integrated into the CAR support structure and data system. The unit is attached to the bottom of the tripod support structure. The related GPS antenna is located on the P-3 radome immediately above the CAR. The AHRS unit provides a RS-232 data stream containing global position and inertial attitude and velocity data to the CAR, which is recorded concurrently with the CAR data. This independence from aircraft navigation input provides for position and inertial state data that accounts for very small changes in aircraft attitude and position, sensed at the CAR location as opposed to aircraft state sensors typically installed close to the aircraft center of gravity. More accurate positional data enables quicker CAR data reduction with better resolution. The CANS software operates in two modes: initialization/calibration and operational. In the initialization/calibration mode

  17. Mobile Robot Designed with Autonomous Navigation System

    Science.gov (United States)

    An, Feng; Chen, Qiang; Zha, Yanfang; Tao, Wenyin

    2017-10-01

    With the rapid development of robot technology, robots appear more and more in all aspects of life and social production, people also ask more requirements for the robot, one is that robot capable of autonomous navigation, can recognize the road. Take the common household sweeping robot as an example, which could avoid obstacles, clean the ground and automatically find the charging place; Another example is AGV tracking car, which can following the route and reach the destination successfully. This paper introduces a new type of robot navigation scheme: SLAM, which can build the environment map in a totally strange environment, and at the same time, locate its own position, so as to achieve autonomous navigation function.

  18. Navigation of robotic system using cricket motes

    Science.gov (United States)

    Patil, Yogendra J.; Baine, Nicholas A.; Rattan, Kuldip S.

    2011-06-01

    This paper presents a novel algorithm for self-mapping of the cricket motes that can be used for indoor navigation of autonomous robotic systems. The cricket system is a wireless sensor network that can provide indoor localization service to its user via acoustic ranging techniques. The behavior of the ultrasonic transducer on the cricket mote is studied and the regions where satisfactorily distance measurements can be obtained are recorded. Placing the motes in these regions results fine-grain mapping of the cricket motes. Trilateration is used to obtain a rigid coordinate system, but is insufficient if the network is to be used for navigation. A modified SLAM algorithm is applied to overcome the shortcomings of trilateration. Finally, the self-mapped cricket motes can be used for navigation of autonomous robotic systems in an indoor location.

  19. Lucy: Navigating a Jupiter Trojan Tour

    Science.gov (United States)

    Stanbridge, Dale; Williams, Ken; Williams, Bobby; Jackman, Coralie; Weaver, Hal; Berry, Kevin; Sutter, Brian; Englander, Jacob

    2017-01-01

    In January 2017, NASA selected the Lucy mission to explore six Jupiter Trojan asteroids. These six bodies, remnants of the primordial material that formed the outer planets, were captured in the Sun-Jupiter L4 and L5 Lagrangian regions early in the solar system formation. These particular bodies were chosen because of their diverse spectral properties and the chance to observe up close for the first time two orbiting approximately equal mass binaries, Patroclus and Menoetius. KinetX, Inc. is the primary navigation supplier for the Lucy mission. This paper describes preliminary navigation analyses of the approach phase for each Trojan encounter.

  20. BOREAS Level-0 ER-2 Navigation Data

    Science.gov (United States)

    Strub, Richard; Dominguez, Roseanne; Newcomer, Jeffrey A.; Hall, Forrest G. (Editor)

    2000-01-01

    The BOREAS Staff Science effort covered those activities that were BOREAS community-level activities or required uniform data collection procedures across sites and time. These activities included the acquisition, processing, and archiving of aircraft navigation/attitude data to complement the digital image data. The level-0 ER-2 navigation data files contain aircraft attitude and position information acquired during the digital image and photographic data collection missions. Temporally, the data were acquired from April to September 1994. Data were recorded at intervals of 5 seconds. The data are stored in tabular ASCII files.

  1. Navigation: bat orientation using Earth's magnetic field.

    Science.gov (United States)

    Holland, Richard A; Thorup, Kasper; Vonhof, Maarten J; Cochran, William W; Wikelski, Martin

    2006-12-07

    Bats famously orientate at night by echolocation, but this works over only a short range, and little is known about how they navigate over longer distances. Here we show that the homing behaviour of Eptesicus fuscus, known as the big brown bat, can be altered by artificially shifting the Earth's magnetic field, indicating that these bats rely on a magnetic compass to return to their home roost. This finding adds to the impressive array of sensory abilities possessed by this animal for navigation in the dark.

  2. Navigation: Bat orientation using Earth's magnetic field

    DEFF Research Database (Denmark)

    Holland, Richard A.; Thorup, Kasper; Vonhof, Maarten J.

    2006-01-01

    Bats famously orientate at night by echolocation 1 , but this works over only a short range, and little is known about how they navigate over longer distances 2 . Here we show that the homing behaviour of Eptesicus fuscus, known as the big brown bat, can be altered by artificially shifting the Ea...... the Earth's magnetic field, indicating that these bats rely on a magnetic compass to return to their home roost. This finding adds to the impressive array of sensory abilities possessed by this animal for navigation in the dark....

  3. Navigation Problems in Blind-to-Blind Pedestrians Tele-assistance Navigation

    OpenAIRE

    Balata , Jan; Mikovec , Zdenek; Maly , Ivo

    2015-01-01

    International audience; We raise a question whether it is possible to build a large-scale navigation system for blind pedestrians where a blind person navigates another blind person remotely by mobile phone. We have conducted an experiment, in which we observed blind people navigating each other in a city center in 19 sessions. We focused on problems in the navigator’s attempts to direct the traveler to the destination. We observed 96 problems in total, classified them on the basis of the typ...

  4. Deformation behavior and load limits of asphaltic concrete under the conditions of cores in embankment dams; Deformationsverhalten und Belastungsgrenzen des Asphaltbetons unter den Bedingungen von Staudammkerndichtungen

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, U.

    1998-12-31

    Based on the analysis of existing dams with asphaltic diaphragm and investigations in the three-phase-system of asphaltic concrete a recipe for the composition of asphaltic cores is recommended. For the construction, rest and operating period of an embankment dam the load and the reaction of the asphaltic concrete cores as well as the appearing stress and deformations are described. Extensive material testings have been performed and at 41 asphaltic concrete specimens triaxial stress controlled pressure and creeping tests have been carried out. The evaluation of the triaxial tests led to proportions of the main stress and deformation limits as criteria of breaking. Under application of the standard equation for nonlinear viscoelastic element-laws a rheonom element formulation was developed from the experiment data and transformed into its differential form. With this approach the stress and deformation behavior of watertight asphaltic diaphragm can be precalculated for a period up to 10 years. The applicability of this approach, which can be also used within FE-calculations as well, is illustrated in four examples. (orig.) [Deutsch] Nach der Analyse bestehender Staudaemme mit Asphaltbetonkerndichtung und Untersuchungen zum Dreiphasensystem Asphaltbeton wird eine Rezepturempfehlung fuer den Asphaltkerndichtungsbau aufgestellt. Fuer die Bau-, Ruhe- und Betriebsphase eines Staudammes werden die Beanspruchungen und Reaktionen der Asphaltbetonkerndichtung sowie die auftretenden Spannungen und Verformungen beschrieben. Nach umfangreichen Materialpruefungen sind an 41 Asphaltbetonpruefkoerpern triaxiale spannungsgesteuerte Druck-Kriechversuche durchgefuehrt worden. Die Auswertung der Triaxialversuche ergab ein Grenzhauptspannungsverhaeltnis und Deformationsgrenzen als Bruchkriterien. Unter Verwendung der Standarformulierung fuer nichtlineare viskoelastische Stoffgesetze wurde aus den Versuchsdaten ein rheonomer Stoffansatz entwickelt und in seine differentielle Form

  5. Adaptive Landmark-Based Navigation System Using Learning Techniques

    DEFF Research Database (Denmark)

    Zeidan, Bassel; Dasgupta, Sakyasingha; Wörgötter, Florentin

    2014-01-01

    The goal-directed navigational ability of animals is an essential prerequisite for them to survive. They can learn to navigate to a distal goal in a complex environment. During this long-distance navigation, they exploit environmental features, like landmarks, to guide them towards their goal. In...... hexapod robots. As a result, it allows the robots to successfully learn to navigate to distal goals in complex environments.......The goal-directed navigational ability of animals is an essential prerequisite for them to survive. They can learn to navigate to a distal goal in a complex environment. During this long-distance navigation, they exploit environmental features, like landmarks, to guide them towards their goal....... Inspired by this, we develop an adaptive landmark-based navigation system based on sequential reinforcement learning. In addition, correlation-based learning is also integrated into the system to improve learning performance. The proposed system has been applied to simulated simple wheeled and more complex...

  6. GRIP DC-8 NAVIGATION AND HOUSEKEEPING DATA V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP DC-8 Navigation and Housekeeping Data contains aircraft navigational data obtained during the GRIP campaign (15 Aug 2010 - 30 Sep 2010). The major goal was...

  7. GRIP DC-8 NAVIGATION AND HOUSEKEEPING DATA V1

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset contains aircraft navigational data obtained during the GRIP campaign (15 Aug 2010 - 30 Sep 2010). The NASA DC-8 is outfitted with a navigational...

  8. Issues in symbol design for electronic displays of navigation information

    Science.gov (United States)

    2004-10-24

    An increasing number of electronic displays, ranging from small hand-held displays for general aviation to installed displays for air transport, are showing navigation information, such as symbols representing navigational aids. The wide range of dis...

  9. GPM Ground Validation Navigation Data ER-2 OLYMPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation NASA ER-2 Navigation Data OLYMPEX dataset supplies navigation data collected by the NASA ER-2 aircraft for flights that occurred during...

  10. Enabling Autonomous Navigation for Affordable Scooters

    Directory of Open Access Journals (Sweden)

    Kaikai Liu

    2018-06-01

    Full Text Available Despite the technical success of existing assistive technologies, for example, electric wheelchairs and scooters, they are still far from effective enough in helping those in need navigate to their destinations in a hassle-free manner. In this paper, we propose to improve the safety and autonomy of navigation by designing a cutting-edge autonomous scooter, thus allowing people with mobility challenges to ambulate independently and safely in possibly unfamiliar surroundings. We focus on indoor navigation scenarios for the autonomous scooter where the current location, maps, and nearby obstacles are unknown. To achieve semi-LiDAR functionality, we leverage the gyros-based pose data to compensate the laser motion in real time and create synthetic mapping of simple environments with regular shapes and deep hallways. Laser range finders are suitable for long ranges with limited resolution. Stereo vision, on the other hand, provides 3D structural data of nearby complex objects. To achieve simultaneous fine-grained resolution and long range coverage in the mapping of cluttered and complex environments, we dynamically fuse the measurements from the stereo vision camera system, the synthetic laser scanner, and the LiDAR. We propose solutions to self-correct errors in data fusion and create a hybrid map to assist the scooter in achieving collision-free navigation in an indoor environment.

  11. Enabling Autonomous Navigation for Affordable Scooters.

    Science.gov (United States)

    Liu, Kaikai; Mulky, Rajathswaroop

    2018-06-05

    Despite the technical success of existing assistive technologies, for example, electric wheelchairs and scooters, they are still far from effective enough in helping those in need navigate to their destinations in a hassle-free manner. In this paper, we propose to improve the safety and autonomy of navigation by designing a cutting-edge autonomous scooter, thus allowing people with mobility challenges to ambulate independently and safely in possibly unfamiliar surroundings. We focus on indoor navigation scenarios for the autonomous scooter where the current location, maps, and nearby obstacles are unknown. To achieve semi-LiDAR functionality, we leverage the gyros-based pose data to compensate the laser motion in real time and create synthetic mapping of simple environments with regular shapes and deep hallways. Laser range finders are suitable for long ranges with limited resolution. Stereo vision, on the other hand, provides 3D structural data of nearby complex objects. To achieve simultaneous fine-grained resolution and long range coverage in the mapping of cluttered and complex environments, we dynamically fuse the measurements from the stereo vision camera system, the synthetic laser scanner, and the LiDAR. We propose solutions to self-correct errors in data fusion and create a hybrid map to assist the scooter in achieving collision-free navigation in an indoor environment.

  12. Gamifying Navigation in Location-Based Applications

    DEFF Research Database (Denmark)

    Nadarajah, Stephanie Githa; Overgaard, Benjamin Nicholas; Pedersen, Peder Walz

    2017-01-01

    Location-based games entertain players usually by interactions at points of interest (POIs). Navigation between POIs often involve the use of either a physical or digital map, not taking advantage of the opportunity available to engage users in activities between POIs. The paper presents riddle s...

  13. Navigation in musculoskeletal oncology: An overview

    Directory of Open Access Journals (Sweden)

    Guy Vernon Morris

    2018-01-01

    Full Text Available Navigation in surgery has increasingly become more commonplace. The use of this technological advancement has enabled ever more complex and detailed surgery to be performed to the benefit of surgeons and patients alike. This is particularly so when applying the use of navigation within the field of orthopedic oncology. The developments in computer processing power coupled with the improvements in scanning technologies have permitted the incorporation of navigational procedures into day-to-day practice. A comprehensive search of PubMed using the search terms “navigation”, “orthopaedic” and “oncology” yielded 97 results. After filtering for English language papers, excluding spinal surgery and review articles, this resulted in 38 clinical studies and case reports. These were analyzed in detail by the authors (GM and JS and the most relevant papers reviewed. We have sought to provide an overview of the main types of navigation systems currently available within orthopedic oncology and to assess some of the evidence behind its use.

  14. Ohio River Navigation: Past-Present-Future

    Science.gov (United States)

    1979-10-01

    navigation structures had been built: the auxillary 56- by 360-foot lock at dam 41 (Louisville), 1930; Montgomery Locks and Dam, 1936; and Gallipolis...Mile 974.2. This project was approved in 1963, but substantial ’ delay is anticipated ina decision concerning its execu- tion. For this reason a

  15. Mobile Screens: The Visual Regime of Navigation

    NARCIS (Netherlands)

    Verhoeff, N.

    2012-01-01

    In this book on screen media, space, and mobility I compare synchronically, as well as diachronically, diverse and variegated screen media - their technologies and practices – as sites for virtual mobility and navigation. Mobility as a central trope can be found on the multiple levels that are

  16. The "Set Map" Method of Navigation.

    Science.gov (United States)

    Tippett, Julian

    1998-01-01

    Explains the "set map" method of using the baseplate compass to solve walkers' navigational needs as opposed to the 1-2-3 method for taking a bearing. The map, with the compass permanently clipped to it, is rotated to the position in which its features have the same orientation as their counterparts on the ground. Includes directions and…

  17. Neurosurgical robotic arm drilling navigation system.

    Science.gov (United States)

    Lin, Chung-Chih; Lin, Hsin-Cheng; Lee, Wen-Yo; Lee, Shih-Tseng; Wu, Chieh-Tsai

    2017-09-01

    The aim of this work was to develop a neurosurgical robotic arm drilling navigation system that provides assistance throughout the complete bone drilling process. The system comprised neurosurgical robotic arm navigation combining robotic and surgical navigation, 3D medical imaging based surgical planning that could identify lesion location and plan the surgical path on 3D images, and automatic bone drilling control that would stop drilling when the bone was to be drilled-through. Three kinds of experiment were designed. The average positioning error deduced from 3D images of the robotic arm was 0.502 ± 0.069 mm. The correlation between automatically and manually planned paths was 0.975. The average distance error between automatically planned paths and risky zones was 0.279 ± 0.401 mm. The drilling auto-stopping algorithm had 0.00% unstopped cases (26.32% in control group 1) and 70.53% non-drilled-through cases (8.42% and 4.21% in control groups 1 and 2). The system may be useful for neurosurgical robotic arm drilling navigation. Copyright © 2016 John Wiley & Sons, Ltd.

  18. 77 FR 67658 - Navigation Safety Advisory Council

    Science.gov (United States)

    2012-11-13

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard [Docket No. USCG-2012-0212] Navigation Safety Advisory.../en/hotels/florida/embassy-suites-tampa-downtown-convention-center-TPAESES/index.html . For... possible. To facilitate public participation, we are inviting public comment on the issues to be considered...

  19. Orchard navigation using derivative free Kalman filtering

    DEFF Research Database (Denmark)

    Hansen, Søren; Bayramoglu, Enis; Andersen, Jens Christian

    2011-01-01

    This paper describes the use of derivative free filters for mobile robot localization and navigation in an orchard. The localization algorithm fuses odometry and gyro measurements with line features representing the surrounding fruit trees of the orchard. The line features are created on basis of 2...

  20. Cloud-Induced Uncertainty for Visual Navigation

    Science.gov (United States)

    2014-12-26

    can occur due to interference, jamming, or signal blockage in urban canyons. In GPS-denied environments, a GP- S/INS navigation system is forced to rely...physics-based approaches use equations that model fluid flow, thermodynamics, water condensation , and evapora- tion to generate clouds [4]. The drawback

  1. Requirements for e-Navigation Architectures

    Directory of Open Access Journals (Sweden)

    Axel Hahn

    2016-12-01

    Full Text Available Technology is changing the way of navigation. New technologies for communication and navigation can be found on virtually every vessel. System architectures define structure and cooperation of components and subsystems. IMO, IALA, costal authorities, technology provider and many more actually propose new architectures for e-Navigation. This paper looks at other transportation domains and technical as normative requirements for e-Navigation architectures. With the aim of identifying possible synergies in the research, development, certification and standardization, this paper sets out to compare requirements and approaches of these two domains with respect to safety and security aspects. Since from an autonomy perspective, the automotive domain has started earlier and therefore has achieved a higher degree of technical progress, we will start with an overview of the developments in this domain. After that, the paper discusses the requirements on automation and assistance systems in the maritime domain and gives an overview of the developments into this direction within the maritime domain. This then allows us to compare developments in both domains and to derive recommendations for further developments in the maritime domain at the end of this paper.

  2. 'Outsmarting Traffic, Together': Driving as Social Navigation

    Directory of Open Access Journals (Sweden)

    Sam Hind

    2014-04-01

    Full Text Available The automotive world is evolving. Ten years ago Nigel Thrift (2004: 41 made the claim that the experience of driving was slipping into our 'technological unconscious'. Only recently the New York Times suggested that with the rise of automated driving, standalone navigation tools as we know them would cease to exist, instead being 'fully absorbed into the machine' (Fisher, 2013. But in order to bridge the gap between past and future driving worlds, another technological evolution is emerging. This short, critical piece charts the rise of what has been called 'social navigation' in the industry; the development of digital mapping platforms designed to foster automotive sociality. It makes two provisional points. Firstly, that 'ludic' conceptualisations can shed light on the ongoing reconfiguration of drivers, vehicles, roads and technological aids such as touch-screen satellite navigation platforms. And secondly, that as a result of this, there is a coming-into-being of a new kind of driving politics; a 'casual politicking' centred on an engagement with digital interfaces. We explicate both by turning our attention towards Waze; a social navigation application that encourages users to interact with various driving dynamics.

  3. Celestial Navigation on the Surface of Mars

    Science.gov (United States)

    Malay, Benjamin P.

    2001-05-01

    A simple, accurate, and autonomous method of finding position on the surface of Mars currently does not exist. The goal of this project is to develop a celestial navigation process that will fix a position on Mars with 100-meter accuracy. This method requires knowing the position of the stars and planets referenced to the Martian surface with one arcsecond accuracy. This information is contained in an ephemeris known as the Aeronautical Almanac (from Ares, the god of war) . Naval Observatory Vector Astrometry Subroutines (NOVAS) form the basis of the code used to generate the almanac. Planetary position data come the JPL DE405 Planetary Ephemeris. The theoretical accuracy of the almanac is determined mathematically and compared with the Ephemeris for Physical Observations of Mars contained in the Astronautical Almanac. A preliminary design of an autonomous celestial navigation system is presented. Recommendations of how to integrate celestial navigation into NASA=s current Mars exploration program are also discussed. This project is a useful and much-needed first step towards establishing celestial navigation as a practical way to find position on the surface of Mars.

  4. Autonomous Rule Based Robot Navigation In Orchards

    DEFF Research Database (Denmark)

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

    2010-01-01

    Orchard navigation using sensor-based localization and exible mission management facilitates successful missions independent of the Global Positioning System (GPS). This is especially important while driving between tight tree rows where the GPS coverage is poor. This paper suggests localization ...

  5. Navigating Transitions: Challenges for Engineering Students

    Science.gov (United States)

    Moore-Russo, Deborah; Wilsey, Jillian N.; Parthum, Michael J., Sr.; Lewis, Kemper

    2017-01-01

    As college students enter engineering, they face challenges when they navigate across various transitions. These challenges impact whether a student can successfully adapt to the rigorous curricular requirements of an engineering degree and to the norms and expectations that are particular to engineering. This article focuses on the transitions…

  6. Navigable windows of the Northwest Passage

    Science.gov (United States)

    Liu, Xing-he; Ma, Long; Wang, Jia-yue; Wang, Ye; Wang, Li-na

    2017-09-01

    Artic sea ice loss trends support a greater potential for Arctic shipping. The information of sea ice conditions is important for utilizing Arctic passages. Based on the shipping routes given by ;Arctic Marine Shipping Assessment 2009 Report;, the navigable windows of these routes and the constituent legs were calculated by using sea ice concentration product data from 2006 to 2015, by which a comprehensive knowledge of the sea ice condition of the Northwest Passage was achieved. The results showed that Route 4 (Lancaster Sound - Barrow Strait - Prince Regent Inlet and Bellot Strait - Franklin Strait - Larsen Sound - Victoria Strait - Queen Maud Gulf - Dease Strait - Coronation Gulf - Dolphin and Union Strait - Amundsen Gulf) had the best navigable expectation, Route 2 (Parry Channel - M'Clure Strait) had the worst, and the critical legs affecting the navigation of Northwest Passage were Viscount Melville Sound, Franklin Strait, Victoria Strait, Bellot Strait, M'Clure Strait and Prince of Wales Strait. The shortest navigable period of the routes of Northwest Passage was up to 69 days. The methods used and the results of the study can help the selection and evaluation of Arctic commercial routes.

  7. The Navigation Metaphor in Security Economics

    NARCIS (Netherlands)

    Pieters, W.; Barendse, Jeroen; Ford, Margaret; Heath, Claude P R; Probst, Christian W.; Verbij, Ruud

    2016-01-01

    The navigation metaphor for cybersecurity merges security architecture models and security economics. By identifying the most efficient routes for gaining access to assets from an attacker's viewpoint, an organization can optimize its defenses along these routes. The well-understood concept of

  8. The navigation metaphor in security economics

    NARCIS (Netherlands)

    Pieters, Wolter; Barendse, Jeroen; Ford, Margaret; Heath, Claude P.R.; Probst, Christian W.; Verbij, Ruud

    2016-01-01

    The navigation metaphor for cybersecurity merges security architecture models and security economics. By identifying the most efficient routes for gaining access to assets from an attacker's viewpoint, an organization can optimize its defenses along these routes. The well-understood concept of

  9. Spatial navigation by congenitally blind individuals.

    Science.gov (United States)

    Schinazi, Victor R; Thrash, Tyler; Chebat, Daniel-Robert

    2016-01-01

    Spatial navigation in the absence of vision has been investigated from a variety of perspectives and disciplines. These different approaches have progressed our understanding of spatial knowledge acquisition by blind individuals, including their abilities, strategies, and corresponding mental representations. In this review, we propose a framework for investigating differences in spatial knowledge acquisition by blind and sighted people consisting of three longitudinal models (i.e., convergent, cumulative, and persistent). Recent advances in neuroscience and technological devices have provided novel insights into the different neural mechanisms underlying spatial navigation by blind and sighted people and the potential for functional reorganization. Despite these advances, there is still a lack of consensus regarding the extent to which locomotion and wayfinding depend on amodal spatial representations. This challenge largely stems from methodological limitations such as heterogeneity in the blind population and terminological ambiguity related to the concept of cognitive maps. Coupled with an over-reliance on potential technological solutions, the field has diffused into theoretical and applied branches that do not always communicate. Here, we review research on navigation by congenitally blind individuals with an emphasis on behavioral and neuroscientific evidence, as well as the potential of technological assistance. Throughout the article, we emphasize the need to disentangle strategy choice and performance when discussing the navigation abilities of the blind population. For further resources related to this article, please visit the WIREs website. © 2015 The Authors. WIREs Cognitive Science published by Wiley Periodicals, Inc.

  10. Robust Pedestrian Navigation for Challenging Applications

    OpenAIRE

    Gilliéron, PY; Renaudin, V

    2009-01-01

    Presentation of a concept for robust indoor navigation. The concept is based on three key elements: - the use of an absolute geographical reference - the hybridisation of complementary technologies - specific motion models. This concept is illustrated by the means of two applications: the urban displacement of blind people and the indoor guidance of fire-fighters

  11. From translation to navigation of different discourses

    DEFF Research Database (Denmark)

    Livonen, Mirja; Sonnenwald, Diane H.

    1998-01-01

    ' own search experience. Data further suggest that searchers navigate these discourses dynamically and have preferences for certain discourses. Conceptualizing the selection of search terms as a meeting place of different discourses provides new insights into the complex nature of the search term...

  12. Navigating the Bio-Politics of Childhood

    Science.gov (United States)

    Lee, Nick; Motzkau, Johanna

    2011-01-01

    Childhood research has long shared a bio-political terrain with state agencies in which children figure primarily as "human futures". In the 20th century bio-social dualism helped to make that terrain navigable by researchers, but, as life processes increasingly become key sites of bio-political action, bio-social dualism is becoming…

  13. A GPS inspired Terrain Referenced Navigation algorithm

    NARCIS (Netherlands)

    Vaman, D.

    2014-01-01

    Terrain Referenced Navigation (TRN) refers to a form of localization in which measurements of distances to the terrain surface are matched with a digital elevation map allowing a vehicle to estimate its own position within the map. The main goal of this dissertation is to improve TRN performance

  14. Navigated Waterways of Louisiana, Geographic NAD83, LOSCO (1999) [navigated_waterways_LOSCO_1999

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a line dataset of navigated waterways fitting the LOSCO definition: it has been traveled by vessels transporting 10,000 gallons of oil or fuel as determined...

  15. Lunar Navigator - A Miniature, Fully Autonomous, Lunar Navigation, Surveyor, and Range Finder System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcosm will use existing hardware and software from related programs to create a prototype Lunar Navigation Sensor (LNS) early in Phase II, such that most of the...

  16. Vision/INS Integrated Navigation System for Poor Vision Navigation Environments

    Directory of Open Access Journals (Sweden)

    Youngsun Kim

    2016-10-01

    Full Text Available In order to improve the performance of an inertial navigation system, many aiding sensors can be used. Among these aiding sensors, a vision sensor is of particular note due to its benefits in terms of weight, cost, and power consumption. This paper proposes an inertial and vision integrated navigation method for poor vision navigation environments. The proposed method uses focal plane measurements of landmarks in order to provide position, velocity and attitude outputs even when the number of landmarks on the focal plane is not enough for navigation. In order to verify the proposed method, computer simulations and van tests are carried out. The results show that the proposed method gives accurate and reliable position, velocity and attitude outputs when the number of landmarks is insufficient.

  17. Lunar Navigator - A Miniature, Fully Autonomous, Lunar Navigation, Surveyor, and Range Finder System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcosm proposes to design and develop a fully autonomous Lunar Navigator based on our MicroMak miniature star sensor and a gravity gradiometer similar to one on a...

  18. Evaluation of navigation interfaces in virtual environments

    Science.gov (United States)

    Mestre, Daniel R.

    2014-02-01

    When users are immersed in cave-like virtual reality systems, navigational interfaces have to be used when the size of the virtual environment becomes larger than the physical extent of the cave floor. However, using navigation interfaces, physically static users experience self-motion (visually-induced vection). As a consequence, sensorial incoherence between vision (indicating self-motion) and other proprioceptive inputs (indicating immobility) can make them feel dizzy and disoriented. We tested, in two experimental studies, different locomotion interfaces. The objective was twofold: testing spatial learning and cybersickness. In a first experiment, using first-person navigation with a flystick ®, we tested the effect of sensorial aids, a spatialized sound or guiding arrows on the ground, attracting the user toward the goal of the navigation task. Results revealed that sensorial aids tended to impact negatively spatial learning. Moreover, subjects reported significant levels of cybersickness. In a second experiment, we tested whether such negative effects could be due to poorly controlled rotational motion during simulated self-motion. Subjects used a gamepad, in which rotational and translational displacements were independently controlled by two joysticks. Furthermore, we tested first- versus third-person navigation. No significant difference was observed between these two conditions. Overall, cybersickness tended to be lower, as compared to experiment 1, but the difference was not significant. Future research should evaluate further the hypothesis of the role of passively perceived optical flow in cybersickness, but manipulating the virtual environment'sperrot structure. It also seems that video-gaming experience might be involved in the user's sensitivity to cybersickness.

  19. Biologically inspired autonomous agent navigation using an integrated polarization analyzing CMOS image sensor

    NARCIS (Netherlands)

    Sarkaer, M.; San Segundo Bello, D.; Van Hoof, C.; Theuwissen, A.

    2010-01-01

    The navigational strategies of insects using skylight polarization are interesting for applications in autonomous agent navigation because they rely on very little information for navigation. A polarization navigation sensor using the Stokes parameters to determine the orientation is presented. The

  20. Municipal climate protection as a measure for sustainable energy supply under the conditions of globalization and liberalization? An empirical investigation considering the municipal actors and public utility companies; Kommunaler Klimaschutz als Instrument einer nachhaltigen Energieversorgung unter den Bedingungen von Globalisierung und Liberalisierung? Eine empirische Untersuchung unter besonderer Beruecksichtigung der Akteure Kommune und Stadtwerke

    Energy Technology Data Exchange (ETDEWEB)

    Bielitza-Mimjaehner, Ralf

    2007-03-01

    With the background of the threatening global warming that requires a reduction of greenhouse gas emission by 20 % until 2010 und by 80% until 2050 in Germany, t is reasonable to consider local or municipal climate protection activities. A climate protection politics ''from the bottom'' is not only contributing to a real greenhouse gas reduction, but also triggering the stagnant international climate politics and enhances the sustainable development on a local level. Due to this fact amongst others the Enquete commission of the German Bundestag ''sustainable energy supply under the conditions of globalization and liberalization'' identifies the municipal climate protection activities as important part within the mix of measures that will allow the initiation of an alteration of the actual energy system toward a sustainable energy supply in the long-run. The consequences of globalization and liberalization on the municipal level have not yet been discussed or considered by the Enquete commission. This thesis analyses the conditions induced by the globalization and liberalization on the municipal climate protection activities as constituent of a sustainable energy supply. The project is focusing on the municipal actors and the public utility companies as central point of the considerations. [German] Vor dem Hintergrund einer drohenden globalen Erwaermung, die eine Reduktion der klimawirksamen Treibhausgase bundesweit um 20 % bis 2010 und um 80 % bis 2050 noetig macht, sind Klimaschutzaktivitaeten auf einer lokalen oder kommunalen Ebene in mehreren Dimensionen sinnvoll. Den tatsaechlichen, bezifferbaren Reduktionen von CO2, die hier geleistet werden, gesellt sich ein ''vorbildhafter'' Druck auf eine stockende internationale Klimapolitik hinzu, ebenso leistet die ''Klimaschutzpolitik von unten'' einer nachhaltigen Entwicklung der lokalen Ebene durch Lerneffekte Vorschub. Unter anderem aus

  1. 22 CFR 401.25 - Government brief regarding navigable waters.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Government brief regarding navigable waters. 401... PROCEDURE Applications § 401.25 Government brief regarding navigable waters. When in the opinion of the Commission it is desirable that a decision should be rendered which affects navigable waters in a manner or...

  2. Gray and White Matter Correlates of Navigational Ability in Humans

    NARCIS (Netherlands)

    Wegman, J.B.T.; Fonteijn, H.M.; Ekert, J. van; Tyborowska, A.B.; Jansen, C.; Janzen, G.

    2014-01-01

    Humans differ widely in their navigational abilities. Studies have shown that self-reports on navigational abilities are good predictors of performance on navigation tasks in real and virtual environments. The caudate nucleus and medial temporal lobe regions have been suggested to subserve different

  3. PRIVATE GRAPHS – ACCESS RIGHTS ON GRAPHS FOR SEAMLESS NAVIGATION

    Directory of Open Access Journals (Sweden)

    W. Dorner

    2016-06-01

    Full Text Available After the success of GNSS (Global Navigational Satellite Systems and navigation services for public streets, indoor seems to be the next big development in navigational services, relying on RTLS – Real Time Locating Services (e.g. WIFI and allowing seamless navigation. In contrast to navigation and routing services on public streets, seamless navigation will cause an additional challenge: how to make routing data accessible to defined users or restrict access rights for defined areas or only to parts of the graph to a defined user group? The paper will present case studies and data from literature, where seamless and especially indoor navigation solutions are presented (hospitals, industrial complexes, building sites, but the problem of restricted access rights was only touched from a real world, but not a technical perspective. The analysis of case studies will show, that the objective of navigation and the different target groups for navigation solutions will demand well defined access rights and require solutions, how to make only parts of a graph to a user or application available to solve a navigational task. The paper will therefore introduce the concept of private graphs, which is defined as a graph for navigational purposes covering the street, road or floor network of an area behind a public street and suggest different approaches how to make graph data for navigational purposes available considering access rights and data protection, privacy and security issues as well.

  4. 76 FR 27337 - Houston/Galveston Navigation Safety Advisory Committee

    Science.gov (United States)

    2011-05-11

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2010-1116] Houston/Galveston Navigation Safety...: The Houston/Galveston Navigation Safety Advisory Committee postponed its originally scheduled February... Houston Ship Channel, and various other navigation safety matters in the Galveston Bay area. The meeting...

  5. Benefits of multisensory presentation on perception, memory and navigation

    NARCIS (Netherlands)

    Philippi, T.G.|info:eu-repo/dai/nl/313711577

    2012-01-01

    Navigation is the process of planning and following routes to travel from the current location to a target location. In comparison with real world navigation, we have considerable difficulty with navigation in virtual environments. An important cause is that less information is presented in a

  6. 76 FR 58105 - Regulated Navigation Area; Saugus River, Lynn, MA

    Science.gov (United States)

    2011-09-20

    ... final rule. SUMMARY: The Coast Guard is establishing a Regulated Navigation Area (RNA) on the navigable... INFORMATION: Regulatory Information The Coast Guard is issuing this temporary rule without prior notice and... Pipeline bridge poses to the navigational channel necessitates that all mariners comply with this RNA...

  7. Time and Motion Study of a Community Patient Navigator

    Directory of Open Access Journals (Sweden)

    Sara S. Phillips

    2014-04-01

    Full Text Available Research on patient navigation has focused on validating the utility of navigators by defining their roles and analyzing their effects on patient outcomes, patient satisfaction, and cost effectiveness. Patient navigators are increasingly used outside the research context, and their roles without research responsibilities may look very different. This pilot study captured the activities of a community patient navigator for uninsured women with a positive screening test for breast cancer, using a time and motion approach over a period of three days. We followed the actions of this navigator minute by minute to assess the relative ratios of actions performed and to identify areas for time efficiency improvement to increase direct time with patients. This novel approach depicts the duties of a community patient navigator no longer fettered by navigation logs, research team meetings, surveys, and the consent process. We found that the community patient navigator was able to spend more time with patients in the clinical context relative to performing paperwork or logging communication with patients as a result of her lack of research responsibilities. By illuminating how community patient navigation functions as separate from the research setting, our results will inform future hiring and training of community patient navigators, system design and operations for improving the efficiency and efficacy of navigators, and our understanding of what community patient navigators do in the absence of research responsibilities.

  8. Navigating oceans and cultures: Polynesian and European navigation systems in the late eighteenth century

    Science.gov (United States)

    Walker, M.

    2012-05-01

    Significant differences in the rotation of the celestial dome between the tropical and temperate zones did not stop the peoples of either the tropical Pacific or temperate Europe from using geocentric astronomy to guide exploration of the oceans. Although the differences in the night sky contributed to differences between the Pacific Island and European systems for navigation at sea, the two navigation systems exhibit substantial similarities. Both systems define positions on the surface of the Earth using two coordinates that vary at right angles to each other and use stars, and to a lesser extent the sun, to determine directions. This essay explores similarities and differences in the use of geocentric astronomy for navigation at sea by the peoples of Polynesia and Europe in the late eighteenth century. Captain Cook's orders to discover the unknown southern continent after observing the transit of Venus combined with differences in language and culture to obscure the deeper similarities between the navigation systems used by Cook and the Polynesians. Although it was a further 200 years before anthropologists studied Pacific navigation, collaborations in voyaging with communities in Oceania demonstrated the effectiveness of Pacific navigation systems, revived interest in traditional voyaging in island communities around the Pacific, and potentially open the way for further collaborations in other areas.

  9. SLS Navigation Model-Based Design Approach

    Science.gov (United States)

    Oliver, T. Emerson; Anzalone, Evan; Geohagan, Kevin; Bernard, Bill; Park, Thomas

    2018-01-01

    The SLS Program chose to implement a Model-based Design and Model-based Requirements approach for managing component design information and system requirements. This approach differs from previous large-scale design efforts at Marshall Space Flight Center where design documentation alone conveyed information required for vehicle design and analysis and where extensive requirements sets were used to scope and constrain the design. The SLS Navigation Team has been responsible for the Program-controlled Design Math Models (DMMs) which describe and represent the performance of the Inertial Navigation System (INS) and the Rate Gyro Assemblies (RGAs) used by Guidance, Navigation, and Controls (GN&C). The SLS Navigation Team is also responsible for the navigation algorithms. The navigation algorithms are delivered for implementation on the flight hardware as a DMM. For the SLS Block 1-B design, the additional GPS Receiver hardware is managed as a DMM at the vehicle design level. This paper provides a discussion of the processes and methods used to engineer, design, and coordinate engineering trades and performance assessments using SLS practices as applied to the GN&C system, with a particular focus on the Navigation components. These include composing system requirements, requirements verification, model development, model verification and validation, and modeling and analysis approaches. The Model-based Design and Requirements approach does not reduce the effort associated with the design process versus previous processes used at Marshall Space Flight Center. Instead, the approach takes advantage of overlap between the requirements development and management process, and the design and analysis process by efficiently combining the control (i.e. the requirement) and the design mechanisms. The design mechanism is the representation of the component behavior and performance in design and analysis tools. The focus in the early design process shifts from the development and

  10. 14 CFR 121.349 - Communication and navigation equipment for operations under VFR over routes not navigated by...

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Communication and navigation equipment for... § 121.349 Communication and navigation equipment for operations under VFR over routes not navigated by... receiver providing visual and aural signals; and (iii) One ILS receiver; and (3) Any RNAV system used to...

  11. 33 CFR 209.170 - Violations of laws protecting navigable waters.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Violations of laws protecting navigable waters. 209.170 Section 209.170 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF... navigable waters. (a) [Reserved] (b) Injuries to Government works. Section 14 of the River and Harbor Act of...

  12. 33 CFR 64.16 - Duration of marking on sunken vessels in navigable waters.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Duration of marking on sunken vessels in navigable waters. 64.16 Section 64.16 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... Sunken Vessels and Other Obstructions § 64.16 Duration of marking on sunken vessels in navigable waters...

  13. 33 CFR 117.458 - Inner Harbor Navigation Canal, New Orleans.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Inner Harbor Navigation Canal, New Orleans. 117.458 Section 117.458 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Harbor Navigation Canal, New Orleans. (a) The draws of the SR 46 (St. Claude Avenue) bridge, mile 0.5...

  14. 33 CFR 207.600 - Rochester (Charlotte) Harbor, N.Y.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Rochester (Charlotte) Harbor, N.Y.; use, administration, and navigation. 207.600 Section 207.600 Navigation and Navigable Waters CORPS OF... (Charlotte) Harbor, N.Y.; use, administration, and navigation. (a)-(b) [Reserved] (c) No vessel shall moor or...

  15. 33 CFR 207.580 - Buffalo Harbor, N.Y.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Buffalo Harbor, N.Y.; use, administration, and navigation. 207.580 Section 207.580 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.580 Buffalo Harbor, N.Y.; use...

  16. Optical surgical navigation system causes pulse oximeter malfunction.

    Science.gov (United States)

    Satoh, Masaaki; Hara, Tetsuhito; Tamai, Kenji; Shiba, Juntaro; Hotta, Kunihisa; Takeuchi, Mamoru; Watanabe, Eiju

    2015-01-01

    An optical surgical navigation system is used as a navigator to facilitate surgical approaches, and pulse oximeters provide valuable information for anesthetic management. However, saw-tooth waves on the monitor of a pulse oximeter and the inability of the pulse oximeter to accurately record the saturation of a percutaneous artery were observed when a surgeon started an optical navigation system. The current case is thought to be the first report of this navigation system interfering with pulse oximetry. The causes of pulse jamming and how to manage an optical navigation system are discussed.

  17. Low Cost Integrated Navigation System for Unmanned Vessel

    Directory of Open Access Journals (Sweden)

    Yang Changsong

    2017-11-01

    Full Text Available Large errors of low-cost MEMS inertial measurement unit (MIMU lead to huge navigation errors, even wrong navigation information. An integrated navigation system for unmanned vessel is proposed. It consists of a low-cost MIMU and Doppler velocity sonar (DVS. This paper presents an integrated navigation method, to improve the performance of navigation system. The integrated navigation system is tested using simulation and semi-physical simulation experiments, whose results show that attitude, velocity and position accuracy has improved awfully, giving exactly accurate navigation results. By means of the combination of low-cost MIMU and DVS, the proposed system is able to overcome fast drift problems of the low cost IMU.

  18. Design of all-weather celestial navigation system

    Science.gov (United States)

    Sun, Hongchi; Mu, Rongjun; Du, Huajun; Wu, Peng

    2018-03-01

    In order to realize autonomous navigation in the atmosphere, an all-weather celestial navigation system is designed. The research of celestial navigation system include discrimination method of comentropy and the adaptive navigation algorithm based on the P value. The discrimination method of comentropy is studied to realize the independent switching of two celestial navigation modes, starlight and radio. Finally, an adaptive filtering algorithm based on P value is proposed, which can greatly improve the disturbance rejection capability of the system. The experimental results show that the accuracy of the three axis attitude is better than 10″, and it can work all weather. In perturbation environment, the position accuracy of the integrated navigation system can be increased 20% comparing with the traditional method. It basically meets the requirements of the all-weather celestial navigation system, and it has the ability of stability, reliability, high accuracy and strong anti-interference.

  19. Testing Two Tools for Multimodal Navigation

    Directory of Open Access Journals (Sweden)

    Mats Liljedahl

    2012-01-01

    Full Text Available The latest smartphones with GPS, electronic compasses, directional audio, touch screens, and so forth, hold a potential for location-based services that are easier to use and that let users focus on their activities and the environment around them. Rather than interpreting maps, users can search for information by pointing in a direction and database queries can be created from GPS location and compass data. Users can also get guidance to locations through point and sweep gestures, spatial sound, and simple graphics. This paper describes two studies testing two applications with multimodal user interfaces for navigation and information retrieval. The applications allow users to search for information and get navigation support using combinations of point and sweep gestures, nonspeech audio, graphics, and text. Tests show that users appreciated both applications for their ease of use and for allowing users to interact directly with the surrounding environment.

  20. Visual Navigation of Complex Information Spaces

    Directory of Open Access Journals (Sweden)

    Sarah North

    1995-11-01

    Full Text Available The authors lay the foundation for the introduction of visual navigation aid to assist computer users in direct manipulation of the complex information spaces. By exploring present research on scientific data visualisation and creating a case for improved information visualisation tools, they introduce the design of an improved information visualisation interface utilizing dynamic slider, called Visual-X, incorporating icons with bindable attributes (glyphs. Exploring the improvement that these data visualisations, make to a computing environment, the authors conduct an experiment to compare the performance of subjects who use traditional interfaces and Visual-X. Methodology is presented and conclusions reveal that the use of Visual-X appears to be a promising approach in providing users with a navigation tool that does not overload their cognitive processes.

  1. Unraveling navigational strategies in migratory insects.

    Science.gov (United States)

    Merlin, Christine; Heinze, Stanley; Reppert, Steven M

    2012-04-01

    Long-distance migration is a strategy some animals use to survive a seasonally changing environment. To reach favorable grounds, migratory animals have evolved sophisticated navigational mechanisms that rely on a map and compasses. In migratory insects, the existence of a map sense (sense of position) remains poorly understood, but recent work has provided new insights into the mechanisms some compasses use for maintaining a constant bearing during long-distance navigation. The best-studied directional strategy relies on a time-compensated sun compass, used by diurnal insects, for which neural circuits have begun to be delineated. Yet, a growing body of evidence suggests that migratory insects may also rely on other compasses that use night sky cues or the Earth's magnetic field. Those mechanisms are ripe for exploration. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Automatic document navigation for digital content remastering

    Science.gov (United States)

    Lin, Xiaofan; Simske, Steven J.

    2003-12-01

    This paper presents a novel method of automatically adding navigation capabilities to re-mastered electronic books. We first analyze the need for a generic and robust system to automatically construct navigation links into re-mastered books. We then introduce the core algorithm based on text matching for building the links. The proposed method utilizes the tree-structured dictionary and directional graph of the table of contents to efficiently conduct the text matching. Information fusion further increases the robustness of the algorithm. The experimental results on the MIT Press digital library project are discussed and the key functional features of the system are illustrated. We have also investigated how the quality of the OCR engine affects the linking algorithm. In addition, the analogy between this work and Web link mining has been pointed out.

  3. Effects of age on navigation strategy.

    Science.gov (United States)

    Rodgers, M Kirk; Sindone, Joseph A; Moffat, Scott D

    2012-01-01

    Age differences in navigation strategies have been demonstrated in animals, with aged animals more likely to prefer an egocentric (route) strategy and younger animals more likely to prefer an allocentric (place) strategy. Using a novel virtual Y-maze strategy assessment (vYSA), the present study demonstrated substantial age differences in strategy preference in humans. Older adults overwhelmingly preferred an egocentric strategy, while younger adults were equally distributed between egocentric and allocentric preference. A preference for allocentric strategy on the Y-maze strategy assessment was found to benefit performance on an independent assessment (virtual Morris water task) only in younger adults. These results establish baseline age differences in spatial strategies and suggest this may impact performance on other spatial navigation assessments. The results are interpreted within the framework of age differences in hippocampal structure and function. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Navigation simulator for the Space Tug vehicle

    Science.gov (United States)

    Colburn, B. K.; Boland, J. S., III; Peters, E. G.

    1977-01-01

    A general simulation program (GSP) for state estimation of a nonlinear space vehicle flight navigation system is developed and used as a basis for evaluating the performance of a Space Tug navigation system. An explanation of the iterative guidance mode (IGM) guidance law, derivation of the dynamics, coordinate frames and state estimation routines are given in order to clarify the assumptions and approximations made. A number of simulation and analytical studies are used to demonstrate the operation of the Tug system. Included in the simulation studies are (1) initial offset vector parameter study; (2) propagation time vs accuracy; (3) measurement noise parametric study and (4) reduction in computational burden of an on-board implementable scheme. From the results of these studies, conclusions and recommendations concerning future areas of practical and theoretical work are presented.

  5. Internet-Based Indoor Navigation Services

    OpenAIRE

    Zeinalipour-Yazti, Demetrios; Laoudias, Christos; Georgiou, Kyriakos

    2017-01-01

    Smartphone advances are leading to a class of Internet-based Indoor Navigation services. IIN services rely on geolocation databases that store indoor models, comprising floor maps and points of interest, along with wireless, light, and magnetic signals for localizing users. Developing IIN services creates new information management challenges - such as crowdsourcing indoor models, acquiring and fusing big data velocity signals, localization algorithms, and custodians' location privacy. Here, ...

  6. Towards automated visual flexible endoscope navigation.

    Science.gov (United States)

    van der Stap, Nanda; van der Heijden, Ferdinand; Broeders, Ivo A M J

    2013-10-01

    The design of flexible endoscopes has not changed significantly in the past 50 years. A trend is observed towards a wider application of flexible endoscopes with an increasing role in complex intraluminal therapeutic procedures. The nonintuitive and nonergonomical steering mechanism now forms a barrier in the extension of flexible endoscope applications. Automating the navigation of endoscopes could be a solution for this problem. This paper summarizes the current state of the art in image-based navigation algorithms. The objectives are to find the most promising navigation system(s) to date and to indicate fields for further research. A systematic literature search was performed using three general search terms in two medical-technological literature databases. Papers were included according to the inclusion criteria. A total of 135 papers were analyzed. Ultimately, 26 were included. Navigation often is based on visual information, which means steering the endoscope using the images that the endoscope produces. Two main techniques are described: lumen centralization and visual odometry. Although the research results are promising, no successful, commercially available automated flexible endoscopy system exists to date. Automated systems that employ conventional flexible endoscopes show the most promising prospects in terms of cost and applicability. To produce such a system, the research focus should lie on finding low-cost mechatronics and technologically robust steering algorithms. Additional functionality and increased efficiency can be obtained through software development. The first priority is to find real-time, robust steering algorithms. These algorithms need to handle bubbles, motion blur, and other image artifacts without disrupting the steering process.

  7. Spatial navigation by congenitally blind individuals

    OpenAIRE

    Schinazi, Victor R.; Thrash, Tyler; Chebat, Daniel?Robert

    2015-01-01

    Spatial navigation in the absence of vision has been investigated from a variety of perspectives and disciplines. These different approaches have progressed our understanding of spatial knowledge acquisition by blind individuals, including their abilities, strategies, and corresponding mental representations. In this review, we propose a framework for investigating differences in spatial knowledge acquisition by blind and sighted people consisting of three longitudinal models (i.e., convergen...

  8. Solar-based navigation for robotic explorers

    Science.gov (United States)

    Shillcutt, Kimberly Jo

    2000-12-01

    This thesis introduces the application of solar position and shadowing information to robotic exploration. Power is a critical resource for robots with remote, long-term missions, so this research focuses on the power generation capabilities of robotic explorers during navigational tasks, in addition to power consumption. Solar power is primarily considered, with the possibility of wind power also contemplated. Information about the environment, including the solar ephemeris, terrain features, time of day, and surface location, is incorporated into a planning structure, allowing robots to accurately predict shadowing and thus potential costs and gains during navigational tasks. By evaluating its potential to generate and expend power, a robot can extend its lifetime and accomplishments. The primary tasks studied are coverage patterns, with a variety of plans developed for this research. The use of sun, terrain and temporal information also enables new capabilities of identifying and following sun-synchronous and sun-seeking paths. Digital elevation maps are combined with an ephemeris algorithm to calculate the altitude and azimuth of the sun from surface locations, and to identify and map shadows. Solar navigation path simulators use this information to perform searches through two-dimensional space, while considering temporal changes. Step by step simulations of coverage patterns also incorporate time in addition to location. Evaluations of solar and wind power generation, power consumption, area coverage, area overlap, and time are generated for sets of coverage patterns, with on-board environmental information linked to the simulations. This research is implemented on the Nomad robot for the Robotic Antarctic Meteorite Search. Simulators have been developed for coverage pattern tests, as well as for sun-synchronous and sun-seeking path searches. Results of field work and simulations are reported and analyzed, with demonstrated improvements in efficiency

  9. Celestial Navigation in the USA, Fiji, and Tunisia

    Science.gov (United States)

    Holbrook, Jarita C.

    2015-05-01

    Today there are many coastal communities that are home to navigators who use stars for position finding at night; I was, however, unaware of this fact when I began researching celestial navigation practices in 1997. My project focused on three communities: the Moce Islanders of Fiji, the Kerkennah Islanders in Tunisia, and the U.S. Navy officers and students at the United States Naval Academy, Annapolis, Maryland. My goal was to answer the question of why people continue to navigate by the stars, but also to understand the role of technology in their navigation practices. Using anthropology techniques of ethnography including participant observation, formal and informal interviews, audio and videotaping, I gathered data over five years at the three communities. I began by learning the details of how they use the stars for navigation. Next, I learned about who did the navigation and where they learned to navigate. I gathered opinions on various navigation aids and instruments, and opinions about the future of using the stars for navigation. I listened to the stories that they told about navigating. In the United States I worked in English, in Fiji, in Fijian and English, and in Tunisia, French and English. For the formal interviews I worked with translators. The navigators use stars for navigating today but the future of their techniques is not certain. Though practiced today, these celestial navigation traditions have undergone and continue to undergo changes. New navigational technologies are part of the stimulation for change, thus 'a meeting of different worlds' is symbolized by peoples encounters with these technologies.

  10. New approaches for the reliability-oriented structural optimization considering time-variant aspects; Neue Ansaetze fuer die zuverlaessigkeitsorientierte Strukturoptimierung unter Beachtung zeitvarianter Aspekte

    Energy Technology Data Exchange (ETDEWEB)

    Kuschel, N.

    2000-07-01

    The optimization of structures with respect to cost, weight or performance is a well-known application of the nonlinear optimization. However reliability-based structural optimization has been subject of only very few studies. The approaches suggested up to now have been unsatisfactory regarding general possibility of application or easy handling by user. The objective of this thesis is the development of general approaches to solve both optimization problems, the minimization of cost with respect to constraint reliabilty and the maximization of reliability under cost constraint. The extented approach of an one-level-method will be introduced in detail for the time-invariant problems. Here, the reliability of the sturcture will be analysed in the framework of the First-Order-Reliability-Method (FORM). The use of time-variant reliability analysis is necessary for a realistic modelling of many practical problems. Therefore several generalizations of the new approaches will be derived for the time-variant reliability-based structural optimization. Some important properties of the optimization problems are proved. In addition some interesting extensions of the one-level-method, for example the cost optimization of structural series systems and the cost optimization in the frame of the Second-Order-Reliabiity-Method (SORM), are presented in the thesis. (orig.) [German] Die Optimierung von Tragwerken im Hinblick auf die Kosten, das Gewicht oder die Gestalt ist eine sehr bekannte Anwendung der nichtlinearen Optimierung. Die zuverlaessigkeitsorientierte Strukturoptimierung wurde dagegen weit seltener untersucht. Die bisher vorgeschlagenen Ansaetze koennen bezueglich ihrer allgemeinen Verwendbarkeit oder ihrer nutzerfreundlichen Handhabung nicht befriedigen. Das Ziel der vorliegenden Arbeit ist nun die Entwicklung allgemeiner Ansaetze zur Loesung der beiden Optimierungsprobleme, einer Kostenminimierung unter Zuverlaessigkeitsrestriktionen und einer

  11. Numerically efficient simulation of multi-vaporator air conditioners in highly dynamic boundary conditions; Numerisch effiziente Simulation von Mehrverdampfer-Klimaanlagen unter hochdynamischen Randbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, Christian; Kaiser, Christian [TLK-Thermo GmbH, Braunschweig (Germany); Tegethoff, Wilhelm; Koehler, Juergen [TU Braunschweig (Germany). Inst. fuer Thermodynamik

    2011-07-01

    In the development of physically based models for dynamic simulations of cycle processes, a good equilibrium must be chosen between the degree of detailing and the speed of calculation. Dynamic modelling of mult-evaporator air conditioners is a special challenge as the interaction of several heat transfer fluides at one pressure level may result in numerically challenging effects like reflux. The contribution goes into the simulation of the heat transfer fluids in such systems in highly dynamic boundary conditions, e.g. after shutoff of the compressor. There are different modelling methods, e.g. finite volume, moving boundary, or finite element analysis. The methods are presented and evaluated. For the 1-D finite volume method, various established simplification strategies are presented that may enhance numerical efficiency. It is also shown that the equation system will not always be solvable with these strategies, and an approach to ensure solvability is presented. The new approach is illustrated by the example of a multi-evaporator bus air conditioner. [German] Bei der Erstellung von physikalisch basierten Modellen fuer die dynamische Simulation von Kreisprozessen muss ein gutes Gleichgewicht zwischen Detaillierungsgrad und Rechengeschwindigkeit gewaehlt werden: Das Modell muss die Realitaet hinreichend genau abbilden, im Gegenzug jedoch auch innerhalb eines angemessenen Zeitraums Ergebnisse liefern sowie in allen Betriebszustaenden loesbar sein. Die dynamische Modellierung von Mehrverdampfer-Klimaanlagen stellt im Vergleich zu einfachen Kreisprozessen eine besondere Herausforderung dar, da in diesen Systemen die Interaktion mehrerer Waermeuebertrager auf einem Druckniveau zu numerisch herausfordernden Effekten wie z. B. Rueckstroemung fuehren kann. Dieser Beitrag beschaeftigt sich mit der Simulation der Waermeuebertrager in diesen Systemen unter hochdynamischen Randbedingungen wie z. B. einer Abschaltung des Verdichters. Zur Modellierung der Waermeuebertrager

  12. Alkali release and sorption during combustion and gasification of coal under pressure; Freisetzung und Einbindung von Alkalien bei der Verbrennung und Vergasung von Kohle unter Druck

    Energy Technology Data Exchange (ETDEWEB)

    Steffin, C.R.; Wanzl, W.; Heek, K.H. van [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany). Geschaeftsbereich FuelTec - Kokerei- und Brennstofftechnik

    1999-09-01

    Investigations and model calculations have shown that water-soluble alkaline substances (in German coal, mostly NaCl) are released by a desorption process rather than a purely physical evaporation process. Sorption takes place in the presence of reactive oxygen species (H{sub 2}O or O{sub 2}), but only the reaction with water vapour is applicable to technical processes. Soorption is preferred to desorption at low temperatures both kinetically and thermodynamically. Metakaolin has a high alkali sorption capacity and potential depending significantly on the chemical properties of the clay mineral. With increasing basicity, the sorption potential decreases drastically, which has a significant effect in terms of fuel selection and mode of operation of the process of coal dust combustion under pressure. A fuel with low alkali emissions would be a coal grade with a small fraction of water-soluble alkalis and a high fraction of acid clay minerals. Intensive scrubbing in a wet chemical treatment stage may serve to reduce the water-soluble alkalis. [Deutsch] Die Untersuchungen und Modellrechnungen haben gezeigt, dass die Freisetzung der wasserloeslichen Alkalien, was in deutschen Steinkohlen hauptsaechlich NaCl ist, ein Desorptionsmechanismus zugrunde liegt und die Vorstellung eines rein physikalischen Verdampfungsprozesses verworfen werden muss. Die Einbindung der Alkalien findet unter Teilnahme reaktiver Sauerstoffspezies (H{sub 2}O oder O{sub 2}) statt, wobei aber nur die Reaktion mit Wasserdampf auch auf technische Prozesse uebertragbar ist. Die Einbindung ist gegenueber der Desorption bei niedrigen Temperaturen kinetisch und thermodynamisch bevorzugt. Metakaolin besitzt eine hohe Kapazitaet und ein hohes Potential zur Einbindung von Alkalien, wobei die Faehigkeit zur Einbindung ganz entscheidend von den chemischen Eigenschaften des Tonminerals abhaengig ist. Mit steigender Basizitaet nimmt das Einbindungspotential der Mineralsubstanz drastisch ab. Das hat auch

  13. Prefrontal-hippocampal interactions for spatial navigation.

    Science.gov (United States)

    Ito, Hiroshi T

    2018-04-01

    Animals have the ability to navigate to a desired location by making use of information about environmental landmarks and their own movements. While decades of neuroscience research have identified neurons in the hippocampus and parahippocampal structures that represent an animal's position in space, it is still largely unclear how an animal can choose the next movement direction to reach a desired goal. As the goal destination is typically located somewhere outside of the range of sensory perception, the animal is required to rely on the internal metric of space to estimate the direction and distance of the destination to plan a next action. Therefore, the hippocampal spatial map should interact with action-planning systems in other cortical regions. In accordance with this idea, several recent studies have indicated the importance of functional interactions between the hippocampus and the prefrontal cortex for goal-directed navigation. In this paper, I will review these studies and discuss how an animal can estimate its future positions correspond to a next movement. Investigation of the navigation problem may further provide general insights into internal models of the brain for action planning. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

  14. Laboratory experiments in mobile robot navigation

    International Nuclear Information System (INIS)

    Kar, Asim; Pal, Prabir K.

    1997-01-01

    Mobile robots have potential applications in remote surveillance and operation in hazardous areas. To be effective, they must have the ability to navigate on their own to desired locations. Several experimental navigational runs of a mobile robot developed have been conducted. The robot has three wheels of which the front wheel is steered and the hind wheels are driven. The robot is equipped with an ultrasonic range sensor, which is turned around to get range data in all directions. The range data is fed to the input of a neural net, whose output steers the robot towards the goal. The robot is powered by batteries (12V 10Ah). It has an onboard stepper motor controller for driving the wheels and the ultrasonic setup. It also has an onboard computer which runs the navigation program NAV. This program sends the range data and configuration parameters to the operator''s console program OCP, running on a stationary PC, through radio communication on a serial line. Through OCP, an operator can monitor the progress of the robot from a distant control room and intervene if necessary. In this paper the control modules of the mobile robot, its ways of operation and also results of some of the experimental runs recorded are reported. It is seen that the trained net guides the mobile robot through gaps of 1m and above to its destination with about 84% success measured over a small sample of 38 runs

  15. Geomagnetic storm effects on GPS based navigation

    Directory of Open Access Journals (Sweden)

    P. V. S. Rama Rao

    2009-05-01

    Full Text Available The energetic events on the sun, solar wind and subsequent effects on the Earth's geomagnetic field and upper atmosphere (ionosphere comprise space weather. Modern navigation systems that use radio-wave signals, reflecting from or propagating through the ionosphere as a means of determining range or distance, are vulnerable to a variety of effects that can degrade the performance of the navigational systems. In particular, the Global Positioning System (GPS that uses a constellation of earth orbiting satellites are affected due to the space weather phenomena.

    Studies made during two successive geomagnetic storms that occurred during the period from 8 to 12 November 2004, have clearly revealed the adverse affects on the GPS range delay as inferred from the Total Electron Content (TEC measurements made from a chain of seven dual frequency GPS receivers installed in the Indian sector. Significant increases in TEC at the Equatorial Ionization anomaly crest region are observed, resulting in increased range delay during the periods of the storm activity. Further, the storm time rapid changes occurring in TEC resulted in a number of phase slips in the GPS signal compared to those on quiet days. These phase slips often result in the loss of lock of the GPS receivers, similar to those that occur during strong(>10 dB L-band scintillation events, adversely affecting the GPS based navigation.

  16. Velocity navigator for motion compensated thermometry.

    Science.gov (United States)

    Maier, Florian; Krafft, Axel J; Yung, Joshua P; Stafford, R Jason; Elliott, Andrew; Dillmann, Rüdiger; Semmler, Wolfhard; Bock, Michael

    2012-02-01

    Proton resonance frequency shift thermometry is sensitive to breathing motion that leads to incorrect phase differences. In this work, a novel velocity-sensitive navigator technique for triggering MR thermometry image acquisition is presented. A segmented echo planar imaging pulse sequence was modified for velocity-triggered temperature mapping. Trigger events were generated when the estimated velocity value was less than 0.2 cm/s during the slowdown phase in parallel to the velocity-encoding direction. To remove remaining high-frequency spikes from pulsation in real time, a Kalman filter was applied to the velocity navigator data. A phantom experiment with heating and an initial volunteer experiment without heating were performed to show the applicability of this technique. Additionally, a breath-hold experiment was conducted for comparison. A temperature rise of ΔT = +37.3°C was seen in the phantom experiment, and a root mean square error (RMSE) outside the heated region of 2.3°C could be obtained for periodic motion. In the volunteer experiment, a RMSE of 2.7°C/2.9°C (triggered vs. breath hold) was measured. A novel velocity navigator with Kalman filter postprocessing in real time significantly improves the temperature accuracy over non-triggered acquisitions and suggests being comparable to a breath-held acquisition. The proposed technique might be clinically applied for monitoring of thermal ablations in abdominal organs.

  17. Investigations on radionuclide release and on the corrosion behaviour of spent fuels from research reactors under disposal conditions. Final report; Untersuchungen zur Radionuklidfreisetzung und zum Korrosionsverhalten von bestrahltem Kernbrennstoff aus Forschungsreaktoren unter Endlagerbeedingungen. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Bruecher, H.; Curtius, H.; Fachinger, J.; Kaiser, G.; Mazeina, L.; Nau, K.

    2003-12-01

    From the present report 'Untersuchungen zur Radionuklidfreisetzung und zum Korrosionsverhalten von bestrahltem Kernbrennstoff aus Forschungsreaktoren unter Endlagerbedingungen' with the code number FKZ 9108 carried out in the time periode 01.06.1998 till 30.11.2001 the following results can be withdrawn: U/Al-RR-fuel elements corroded slowly in granite water (Grimsel-West) at 90 C under anaerobic conditions. For a complete dissolution of the fuel element a time period of 10{sup 3} years is assumed according to present conservative results. In salt brines, especially in magnesium chloride rich brines the corrosion rate is high. Addition of GGG40 (basic material of the fuel element container with iron as main element) had an acceleration effect. A complete dissolution of the fuel is achieved within a couple of months. Under aerobic and under anaerobic conditions the bulk of released radionuclides were fixed by the corrosion products formed (secondary phases). The actinides were mobilised by variation of the ionic strength of the leaching solution. This process can be explained by phase conversion reactions within the secondary phases. Secondary phases formed by corrosion of a non-irradiated U/Al-RR-fuel element, were analysed and hydrotalcites were identified as phase components. This result justifies the assumption, that hydrotalcites are components of the corrosion products from irradiated fuels. To clarify the questions which bindings exist between radionuclides and secondary phases, sorption experiments were performed. The sorption experiments were performed in salt brines and in granite water using repository relevant radionuclides and minerals which are considered to represent thermodynamic final components of the secondary phases. Pu sorbed as cationic species quantitatively and the binding is covalent. In granite water the same behaviour was found for Am. (orig.) [German] Aus dem vorliegenden Bericht 'Untersuchungen zur Radionuklidfreisetzung

  18. Assimilation of carbon and transport of assimilates in coniferous trees under the influence of airborne pollutants. Photosynthesis rate and assimilate distribution in young fir trees (Picea abies [L.]Karst.) under controlled exposure to ozone. Final report; Assimilation von Kohlenstoff und der Assimilattransport in Coniferen unter dem Einfluss von Luftschadstoffen. Photosyntheseleistung und Assimilatverteilung in jungen Fichten (Picea abies [L.]Karst.) unter kontrollierter Ozon-Exposition. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Willenbrink, J.; Schatten, T.

    1992-12-31

    In this project, effects of long-term, low-level ozone exposure on CO{sub 2}fixation and assimilate partitioning in 4-years spruces old were studied. 1. In October, ozone exposure resulted in a 40% decrease of photosynthesis. Chlorophyll content was not altered. Depression of net photosynthesis by ozone exposure fluctuates. At least partly, this depression of net photosynthesis might reflect an increase of respiration. After 6 weeks of ozone exposure, both stomatal conductivity and transpiration seemed to be lowered. However, internal [CO{sub 2}] and water use efficiency were not significantly altered. 2. Compared with the control, needles of ozone-exposed plants exhibited a shift of the {sup 14}C-ratio of {beta}-carotene/xanthophylls which effect faded away with the season (October). 3. In August and October, translocation of {sup 14}C-assimilates from the {sup 14}C-fed source leaves seems to be impeded by ozone exposure. 4. No O{sub 3}-related differences were found for the lipophilic as well as for the fractions of organic or amino acids. For the sink tissues (twig, stem, root), less label was found in non-starch residue in August (main growth season), in O{sub 3}-exposed plants. 5. Starch and sugar content of cortex, cambium, xylem, and of the root follow annual cycles. Under ozon exposure, levels of {sup 14}C-starch and {sup 14}C-sucrose are lowered whereas in the needles, build-up of {sup 14}C-starch was detected. 6. Obviously, long-term low-level ozone affects allocation of assimilates. Secondary effects on chloroplasts by the treatment cannot be excluded. (orig./UWA) [Deutsch] Unter Labor- bzw. Gewaechshausbedingungen wurde der Einfluss einer kontrollierten Ozonexposition auf die Photosyntheseleistung und die Assimilatverteilung in 4-jaehrigen Fichten untersucht. 1. Unter Ozon-Exposition wird die Netto-Photosyntheserate in den jungen Nadeln zum Herbst hin reduziert, waehrend der Chlorophyllgehalt unbeeinflusst bleibt. Die Photosyntheserate der jungen Nadeln

  19. Multi-Flight-Phase GPS Navigation Filter Applications to Terrestrial Vehicle Navigation and Positioning

    Science.gov (United States)

    Park, Young W.; Montez, Moises N.

    1994-01-01

    A candidate onboard space navigation filter demonstrated excellent performance (less than 8 meter level RMS semi-major axis accuracy) in performing orbit determination of a low-Earth orbit Explorer satellite using single-frequency real GPS data. This performance is significantly better than predicted by other simulation studies using dual-frequency GPS data. The study results revealed the significance of two new modeling approaches evaluated in the work. One approach introduces a single-frequency ionospheric correction through pseudo-range and phase range averaging implementation. The other approach demonstrates a precise axis-dependent characterization of dynamic sample space uncertainty to compute a more accurate Kalman filter gain. Additionally, this navigation filter demonstrates a flexibility to accommodate both perturbational dynamic and observational biases required for multi-flight phase and inhomogeneous application environments. This paper reviews the potential application of these methods and the filter structure to terrestrial vehicle and positioning applications. Both the single-frequency ionospheric correction method and the axis-dependent state noise modeling approach offer valuable contributions in cost and accuracy improvements for terrestrial GPS receivers. With a modular design approach to either 'plug-in' or 'unplug' various force models, this multi-flight phase navigation filter design structure also provides a versatile GPS navigation software engine for both atmospheric and exo-atmospheric navigation or positioning use, thereby streamlining the flight phase or application-dependent software requirements. Thus, a standardized GPS navigation software engine that can reduce the development and maintenance cost of commercial GPS receivers is now possible.

  20. Intelligent personal navigator supported by knowledge-based systems for estimating dead reckoning navigation parameters

    Science.gov (United States)

    Moafipoor, Shahram

    Personal navigators (PN) have been studied for about a decade in different fields and applications, such as safety and rescue operations, security and emergency services, and police and military applications. The common goal of all these applications is to provide precise and reliable position, velocity, and heading information of each individual in various environments. In the PN system developed in this dissertation, the underlying assumption is that the system does not require pre-existing infrastructure to enable pedestrian navigation. To facilitate this capability, a multisensor system concept, based on the Global Positioning System (GPS), inertial navigation, barometer, magnetometer, and a human pedometry model has been developed. An important aspect of this design is to use the human body as navigation sensor to facilitate Dead Reckoning (DR) navigation in GPS-challenged environments. The system is designed predominantly for outdoor environments, where occasional loss of GPS lock may happen; however, testing and performance demonstration have been extended to indoor environments. DR navigation is based on a relative-measurement approach, with the key idea of integrating the incremental motion information in the form of step direction (SD) and step length (SL) over time. The foundation of the intelligent navigation system concept proposed here rests in exploiting the human locomotion pattern, as well as change of locomotion in varying environments. In this context, the term intelligent navigation represents the transition from the conventional point-to-point DR to dynamic navigation using the knowledge about the mechanism of the moving person. This approach increasingly relies on integrating knowledge-based systems (KBS) and artificial intelligence (AI) methodologies, including artificial neural networks (ANN) and fuzzy logic (FL). In addition, a general framework of the quality control for the real-time validation of the DR processing is proposed, based on a

  1. Piles, tabs and overlaps in navigation among documents

    DEFF Research Database (Denmark)

    Jakobsen, Mikkel Rønne; Hornbæk, Kasper

    2010-01-01

    Navigation among documents is a frequent, but ill supported activity. Overlapping or tabbed documents are widespread, but they offer limited visibility of their content. We explore variations on navigation support: arranging documents with tabs, as overlapping windows, and in piles. In an experim......Navigation among documents is a frequent, but ill supported activity. Overlapping or tabbed documents are widespread, but they offer limited visibility of their content. We explore variations on navigation support: arranging documents with tabs, as overlapping windows, and in piles....... In an experiment we compared 11 participants’ navigation with these variations and found strong task effects. Overall, overlapping windows were preferred and their structured layout worked well with some tasks. Surprisingly, tabbed documents were efficient in tasks requiring simply finding a document. Piled...... on document navigation and its support by piling....

  2. Cancer Patient Navigator Tasks across the Cancer Care Continuum

    Science.gov (United States)

    Braun, Kathryn L.; Kagawa-Singer, Marjorie; Holden, Alan E. C.; Burhansstipanov, Linda; Tran, Jacqueline H.; Seals, Brenda F.; Corbie-Smith, Giselle; Tsark, JoAnn U.; Harjo, Lisa; Foo, Mary Anne; Ramirez, Amelie G.

    2011-01-01

    Cancer patient navigation (PN) programs have been shown to increase access to and utilization of cancer care for poor and underserved individuals. Despite mounting evidence of its value, cancer patient navigation is not universally understood or provided. We describe five PN programs and the range of tasks their navigators provide across the cancer care continuum (education and outreach, screening, diagnosis and staging, treatment, survivorship, and end-of-life). Tasks are organized by their potential to make cancer services understandable, available, accessible, affordable, appropriate, and accountable. Although navigators perform similar tasks across the five programs, their specific approaches reflect differences in community culture, context, program setting, and funding. Task lists can inform the development of programs, job descriptions, training, and evaluation. They also may be useful in the move to certify navigators and establish mechanisms for reimbursement for navigation services. PMID:22423178

  3. A fuzzy logic based navigation for mobile robot

    International Nuclear Information System (INIS)

    Adel Ali S Al-Jumaily; Shamsudin M Amin; Mohamed Khalil

    1998-01-01

    The main issue of intelligent robot is how to reach its goal safely in real time when it moves in unknown environment. The navigational planning is becoming the central issue in development of real-time autonomous mobile robots. Behaviour based robots have been successful in reacting with dynamic environment but still there are some complexity and challenging problems. Fuzzy based behaviours present as powerful method to solve the real time reactive navigation problems in unknown environment. We shall classify the navigation generation methods, five some characteristics of these methods, explain why fuzzy logic is suitable for the navigation of mobile robot and automated guided vehicle, and describe a reactive navigation that is flexible to react through their behaviours to the change of the environment. Some simulation results will be presented to show the navigation of the robot. (Author)

  4. [Cost analysis for navigation in knee endoprosthetics].

    Science.gov (United States)

    Cerha, O; Kirschner, S; Günther, K-P; Lützner, J

    2009-12-01

    Total knee arthroplasty (TKA) is one of the most frequent procedures in orthopaedic surgery. The outcome depends on a range of factors including alignment of the leg and the positioning of the implant in addition to patient-associated factors. Computer-assisted navigation systems can improve the restoration of a neutral leg alignment. This procedure has been established especially in Europe and North America. The additional expenses are not reimbursed in the German DRG system (Diagnosis Related Groups). In the present study a cost analysis of computer-assisted TKA compared to the conventional technique was performed. The acquisition expenses of various navigation systems (5 and 10 year depreciation), annual costs for maintenance and software updates as well as the accompanying costs per operation (consumables, additional operating time) were considered. The additional operating time was determined on the basis of a meta-analysis according to the current literature. Situations with 25, 50, 100, 200 and 500 computer-assisted TKAs per year were simulated. The amount of the incremental costs of the computer-assisted TKA depends mainly on the annual volume and the additional operating time. A relevant decrease of the incremental costs was detected between 50 and 100 procedures per year. In a model with 100 computer-assisted TKAs per year an additional operating time of 14 mins and a 10 year depreciation of the investment costs, the incremental expenses amount to 300-395 depending on the navigation system. Computer-assisted TKA is associated with additional costs. From an economical point of view an amount of more than 50 procedures per year appears to be favourable. The cost-effectiveness could be estimated if long-term results will show a reduction of revisions or a better clinical outcome.

  5. Surgical navigation in urology: European perspective.

    Science.gov (United States)

    Rassweiler, Jens; Rassweiler, Marie-Claire; Müller, Michael; Kenngott, Hannes; Meinzer, Hans-Peter; Teber, Dogu

    2014-01-01

    Use of virtual reality to navigate open and endoscopic surgery has significantly evolved during the last decade. Current status of seven most interesting projects inside the European Association of Urology section of uro-technology is summarized with review of literature. Marker-based endoscopic tracking during laparoscopic radical prostatectomy using high-definition technology reduces positive margins. Marker-based endoscopic tracking during laparoscopic partial nephrectomy by mechanical overlay of three-dimensional-segmented virtual anatomy is helpful during planning of trocar placement and dissection of renal hilum. Marker-based, iPAD-assisted puncture of renal collecting system shows more benefit for trainees with reduction of radiation exposure. Three-dimensional laser-assisted puncture of renal collecting system using Uro-Dyna-CT realized in an ex-vivo model enables minimal radiation time. Electromagnetic tracking for puncture of renal collecting system using a sensor at the tip of ureteral catheter worked in an in-vivo model of porcine ureter and kidney. Attitude tracking for ultrasound-guided puncture of renal tumours by accelerometer reduces the puncture error from 4.7 to 1.8 mm. Feasibility of electromagnetic and optical tracking with the da Vinci telemanipulator was shown in vitro as well as using in-vivo model of oesophagectomy. Target registration error was 11.2 mm because of soft-tissue deformation. Intraoperative navigation is helpful during percutaneous puncture collecting system and biopsy of renal tumour using various tracking techniques. Early clinical studies demonstrate advantages of marker-based navigation during laparoscopic radical prostatectomy and partial nephrectomy. Combination of different tracking techniques may further improve this interesting addition to video-assisted surgery.

  6. Models for map building and navigation

    International Nuclear Information System (INIS)

    Penna, M.A.; Jian Wu

    1993-01-01

    In this paper the authors present several models for solving map building and navigation problems. These models are motivated by biological processes, and presented in the context of artificial neural networks. Since the nodes, weights, and threshold functions of the models all have physical meanings, they can easily predict network topologies and avoid traditional trial-and-error training. On one hand, this makes their models useful in constructing solutions to engineering problems (problems such as those that occur in robotics, for example). On the other hand, this might also contribute to the ability of their models to explain some biological processes, few of which are completely understood at this time

  7. Strategies for navigating the healthcare credit market.

    Science.gov (United States)

    Wareham, T L

    2001-04-01

    Not-for-profit healthcare organizations are experiencing a tightened credit market due to financial stresses on the healthcare industry such as declining payments, effects of the Balanced Budget Act of 1997, and the shift to outpatient care. In the future, healthcare organizations wanting to access the capital market will be expected to preserve cash as an "insurance policy," offer greater security and stricter covenants, and report financial information on a quarterly basis. To meet these requirements and navigate today's tighter credit market, healthcare financial managers will need to focus on the organization's most reliably profitable areas of business, link strategic and financial issues, and carefully monitor the balance sheet.

  8. Image matching navigation based on fuzzy information

    Institute of Scientific and Technical Information of China (English)

    田玉龙; 吴伟仁; 田金文; 柳健

    2003-01-01

    In conventional image matching methods, the image matching process is mostly based on image statistic information. One aspect neglected by all these methods is that there is much fuzzy information contained in these images. A new fuzzy matching algorithm based on fuzzy similarity for navigation is presented in this paper. Because the fuzzy theory is of the ability of making good description of the fuzzy information contained in images, the image matching method based on fuzzy similarity would look forward to producing good performance results. Experimental results using matching algorithm based on fuzzy information also demonstrate its reliability and practicability.

  9. Fiber optic gyroscopes for vehicle navigation systems

    Science.gov (United States)

    Kumagai, Tatsuya; Soekawa, Hirokazu; Yuhara, Toshiya; Kajioka, Hiroshi; Oho, Shigeru; Sonobe, Hisao

    1994-03-01

    Fiber optic gyroscopes (FOGs) have been developed for vehicle navigation systems and are used in Toyota Motor Corporation models Mark II, Chaser and Cresta in Japan. Use of FOGs in these systems requires high reliability under a wide range of conditions, especially in a temperature range between -40 and 85 degree(s)C. In addition, a high cost-performance ratio is needed. We have developed optical and electrical systems that are inexpensive and can perform well. They are ready to be mass-produced. FOGs have already been installed in luxury automobiles, and will soon be included in more basic vehicles. We have developed more inexpensive FOGs for this purpose.

  10. Navigating in Higher Education (NiHE)

    DEFF Research Database (Denmark)

    Thingholm, Hanne Balsby

    and students experience during their teaching and studying. The purpose of the survey is to explore differences and similarities in how teachers and students navigate in higher education. The study will provide data for qualifying teaching by developing a Meta- cognitive Oriented Learning Environment (MOLE......). MOLE is characterized by teaching High Order Thinking and thereby achieving Deep Understanding (HOT-DUG). Qualifying education in this way results in deeper understanding for the students regarding not only what to study but also why and how to study, the teachers become more explicit about objectives...

  11. Development of A Plant Navigation System

    International Nuclear Information System (INIS)

    Furuta, Tomihiko; Nakagawa, Tsuneo; Kubota, Ryuji; Ikeda, Kouji

    1998-01-01

    A 'Plant Navigation System (PNS)' is under development to assist nuclear power plant (NPP) operators by automatically displaying the plant situation and plant operational procedures on a CRT screen when abnormalities occur. The operation procedures given in a symptom-oriented manual are expressed in a tree - type flowchart (modified PAD). The optimum operation procedure for an NPP is selected automatically using built-in diagnostic logics based on the current status of the NPP. Concerning the plant situation, the PNS displays important information only on the current status of the NPP. A prototype PNS system is being constructed. (authors)

  12. ROBERT autonomous navigation robot with artificial vision

    International Nuclear Information System (INIS)

    Cipollini, A.; Meo, G.B.; Nanni, V.; Rossi, L.; Taraglio, S.; Ferjancic, C.

    1993-01-01

    This work, a joint research between ENEA (the Italian National Agency for Energy, New Technologies and the Environment) and DIGlTAL, presents the layout of the ROBERT project, ROBot with Environmental Recognizing Tools, under development in ENEA laboratories. This project aims at the development of an autonomous mobile vehicle able to navigate in a known indoor environment through the use of artificial vision. The general architecture of the robot is shown together with the data and control flow among the various subsystems. Also the inner structure of the latter complete with the functionalities are given in detail

  13. Navigation and history of science: Scurvy

    Directory of Open Access Journals (Sweden)

    Ignacio Jáuregui-Lobera

    2017-09-01

    Full Text Available The history of scurvy might be summarized in terms of mystery, death, tenacity and finally success. In this history three very important people deserve special mention, two of them were doctors, the other one was a famous navigator: Lind, Blane and Cook. The first one had the glory of having been the author of the first clinical trial, as we understand it nowadays, with all the criticisms that could be done at present. However, the joint effort of these three men led to the solution of something, which seemed to be an irresolvable mystery.

  14. OSIRIX: open source multimodality image navigation software

    Science.gov (United States)

    Rosset, Antoine; Pysher, Lance; Spadola, Luca; Ratib, Osman

    2005-04-01

    The goal of our project is to develop a completely new software platform that will allow users to efficiently and conveniently navigate through large sets of multidimensional data without the need of high-end expensive hardware or software. We also elected to develop our system on new open source software libraries allowing other institutions and developers to contribute to this project. OsiriX is a free and open-source imaging software designed manipulate and visualize large sets of medical images: http://homepage.mac.com/rossetantoine/osirix/

  15. Error Analysis of Inertial Navigation Systems Using Test Algorithms

    OpenAIRE

    Vaispacher, Tomáš; Bréda, Róbert; Adamčík, František

    2015-01-01

    Content of this contribution is an issue of inertial sensors errors, specification of inertial measurement units and generating of test signals for Inertial Navigation System (INS). Given the different levels of navigation tasks, part of this contribution is comparison of the actual types of Inertial Measurement Units. Considering this comparison, there is proposed the way of solving inertial sensors errors and their modelling for low – cost inertial navigation applications. The last part is ...

  16. Acoustic Communications and Navigation for Mobile Under-Ice Sensors

    Science.gov (United States)

    2017-02-04

    contact below the ice. 15. SUBJECT TERMS Arctic Ocean , Undersea Workstations & Vehicles, Signal Processing, Navigation , Underwater Acoustics 16...Partan, Peter Koski, and Sandipa Singh, "Long Range Acoustic Communications and Navigation in the Arctic", Proc. IEEE/MTS Oceans Conf., Washington, DC...Oct. 2015. Freitag, L., P. Koski, A. Morozov, S. Singh, J. Partan, "Acoustic Communications and Navigation Under Arctic Ice", OCEANS , 2012

  17. Ballistic Aspects of Feasibility for Prospective Satellite Navigation Technologies

    Directory of Open Access Journals (Sweden)

    L. N. Lysenko

    2015-01-01

    Full Text Available When modeling the operating processes of ballistics and navigation support it is expedient to make decomposition of the general problem of coordinate-time and navigation support into the typical options of its engineering implementation.As the satellite navigation technologies the paper considers inter-satellite measurement and autonomous navigation mode of differential correction. It also assesses the possibility of their application to improve the accuracy of navigation determinations.Technologies using inter-satellite measurement tools such as GLONASS / GPS equipment, equipment of inter-satellite radio link, astro-optical space based devices are an independent class of navigation technologies.However, each of these options has both advantages and disadvantages that affect the eva luation of the appropriateness and feasibility of their use.The paper separately considers the problem of increasing survivability of space systems and conservation of ground control complex due to introduction of requirements to ensure the independent functioning of spacecraft and application of technologies of ballistics and navigation support, supposing to involve minimum means of automated ground control complex for these purposes.Currently, there is a completely developed theory of autonomous navigation based on astronomical positional gauges, which are used as onboard optical sensors of orientation and stabilization systems.To date, the differential navigation mode is, virtually, the only approach that can allow the olution of tasks in terms of increased accuracy, but with some restrictions.The implementation of differential mode of treatment is carried out through the creation of differential subsystems of the satellite navigation systems. These subsystems are usually divided into wide-range, regional and local ones.Analysis of ballistic aspects to implement discussed navigation technologies allowed us to identify constraints for improving accuracy to define

  18. THE ROLE OF NAVIGATIONAL AIDS IN FLIGHT SAFETY MANAGEMENT WITHIN ICAO GLOBAL AIR NAVIGATION PLAN

    Directory of Open Access Journals (Sweden)

    Vadim V. Vurobyov

    2017-01-01

    Full Text Available The development of the global civil aviation is provided on the basis of the ICAO Communication and Surveillance/Air Traffic Management Concept, which has determined the basic strategy for further commercial flight management effectiveness improvement. On the basis of this concept a Global Air Navigation Plan has been developed by ICAO recently. The core strategies of CNS/ATM concept were specified and combined into so-called blocks. Thus the term Global Aviation System block upgrade has been introduced. At the same time, GANP states that the introduction of new procedures and flight management systems will inevitably affect flight safety. Accordingly, there is a task of flight safety management level maintaining, or even increasing within the Global Air Navigation Plan implementation. Various air navigational aids play a significant role in the process as they are directly associated with the new systems and structures introduction.This breeds the new global challenge of flight safety management level change assessment during the introduction of new procedures and systems connected with the use of both navigational aids and instruments. Some aspects of this problem solution are covered in the article.

  19. Navigation Operations with Prototype Components of an Automated Real-Time Spacecraft Navigation System

    Science.gov (United States)

    Cangahuala, L.; Drain, T. R.

    1999-01-01

    At present, ground navigation support for interplanetary spacecraft requires human intervention for data pre-processing, filtering, and post-processing activities; these actions must be repeated each time a new batch of data is collected by the ground data system.

  20. Fault-tolerant Sensor Fusion for Marine Navigation

    DEFF Research Database (Denmark)

    Blanke, Mogens

    2006-01-01

    Reliability of navigation data are critical for steering and manoeuvring control, and in particular so at high speed or in critical phases of a mission. Should faults occur, faulty instruments need be autonomously isolated and faulty information discarded. This paper designs a navigation solution...... where essential navigation information is provided even with multiple faults in instrumentation. The paper proposes a provable correct implementation through auto-generated state-event logics in a supervisory part of the algorithms. Test results from naval vessels document the performance and shows...... events where the fault-tolerant sensor fusion provided uninterrupted navigation data despite temporal instrument defects...

  1. Fault-tolerant and Diagnostic Methods for Navigation

    DEFF Research Database (Denmark)

    Blanke, Mogens

    2003-01-01

    to diagnose faults and autonomously provide valid navigation data, disregarding any faulty sensor data and use sensor fusion to obtain a best estimate for users. This paper discusses how diagnostic and fault-tolerant methods are applicable in marine systems. An example chosen is sensor fusion for navigation......Precise and reliable navigation is crucial, and for reasons of safety, essential navigation instruments are often duplicated. Hardware redundancy is mostly used to manually switch between instruments should faults occur. In contrast, diagnostic methods are available that can use analytic redundancy...

  2. 75 FR 6215 - Houston/Galveston Navigation Safety Advisory Committee

    Science.gov (United States)

    2010-02-08

    ... groups will meet in Houston, Texas to discuss waterway improvements, aids to navigation, area projects...; (b) Dredging subcommittee report; (c) Technology subcommittee report; (d) Waterways Optimization...

  3. Expected Navigation Flight Performance for the Magnetospheric Multiscale (MMS) Mission

    Science.gov (United States)

    Olson, Corwin; Wright, Cinnamon; Long, Anne

    2012-01-01

    The Magnetospheric Multiscale (MMS) mission consists of four formation-flying spacecraft placed in highly eccentric elliptical orbits about the Earth. The primary scientific mission objective is to study magnetic reconnection within the Earth s magnetosphere. The baseline navigation concept is the independent estimation of each spacecraft state using GPS pseudorange measurements (referenced to an onboard Ultra Stable Oscillator) and accelerometer measurements during maneuvers. State estimation for the MMS spacecraft is performed onboard each vehicle using the Goddard Enhanced Onboard Navigation System, which is embedded in the Navigator GPS receiver. This paper describes the latest efforts to characterize expected navigation flight performance using upgraded simulation models derived from recent analyses.

  4. Visual navigation using edge curve matching for pinpoint planetary landing

    Science.gov (United States)

    Cui, Pingyuan; Gao, Xizhen; Zhu, Shengying; Shao, Wei

    2018-05-01

    Pinpoint landing is challenging for future Mars and asteroid exploration missions. Vision-based navigation scheme based on feature detection and matching is practical and can achieve the required precision. However, existing algorithms are computationally prohibitive and utilize poor-performance measurements, which pose great challenges for the application of visual navigation. This paper proposes an innovative visual navigation scheme using crater edge curves during descent and landing phase. In the algorithm, the edge curves of the craters tracked from two sequential images are utilized to determine the relative attitude and position of the lander through a normalized method. Then, considering error accumulation of relative navigation, a method is developed. That is to integrate the crater-based relative navigation method with crater-based absolute navigation method that identifies craters using a georeferenced database for continuous estimation of absolute states. In addition, expressions of the relative state estimate bias are derived. Novel necessary and sufficient observability criteria based on error analysis are provided to improve the navigation performance, which hold true for similar navigation systems. Simulation results demonstrate the effectiveness and high accuracy of the proposed navigation method.

  5. Navigating Institutions and Institutional Leadership to Address Sexual Violence

    Science.gov (United States)

    Sisneros, Kathy; Rivera, Monica

    2018-01-01

    Using an institutional example, this chapter offers strategies to effectively navigate institutional culture, processes, and structures to engage the entire campus community in addressing sexual violence.

  6. Radiology in managed care environment: Opportunities for cost savings in an HMO; Radiologie unter Managed-Care-Bedingungen. Einsparpotenziale aus der Sicht einer Krankenversicherung in den USA

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, C. [Universitaet Kiel (Germany). Klinik fuer Allgemeine Chirurgie und Thoraxchirurgie; Mohr, A. [University of California, San Francisco (United States). Dept. of Radiology; Universitaet Kiel (Germany). Klinik fuer Radiologische Diagnostik; Moeller, J. [Universitaet Bielefeld (Germany). Fakultaet fuer Gesundheitswissenschaften; Levin-Scherz, J. [Tufts Healthplan, Boston (United States); Heller, M. [Universitaet Kiel (Germany). Klinik fuer Radiologische Diagnostik

    2003-09-01

    : Darstellung des Einsparungspotenzials, welches einer effizienten Nutzung von Radiologieleistungen in einer Health-Maintenance-Organisation (HMO) innewohnt, und der zur Realisierung verwendeten Managed-Care-Techniken. Material und Methoden: Im Rahmen eines Projektes zur Kostenreduktion an einer HMO in den USA wurden die Ursachen fuer gestiegene Ausgaben im Bereich Radiologie (''Radiology-Utilisation-Line'') untersucht. Durch umfassende Datenanalysen, Ueberpruefungen der Kodierlogik, Interviews mit Angestellten sowie kritische Beleuchtung der Vertragsbeziehungen zu Leistungserbringern konnte das Einsparpotenzial beziffert werden. Saemtliche Daten wurden in Microsoft Excel {sup trademark} dokumentiert und unter Verwendung von SPSS 8.0 (Statistical Package for the Social Sciences) fuer Windows {sup trademark} mithilfe nicht-parametrischer Tests ausgewertet. Ergebnisse: Hauptursache war eine verstaerkte Verordnung von Radiologieleistungen pro versichertem Patienten, wobei die Kosten pro Untersuchung annaehernd gleich blieben. Ein wesentlicher Kostenhebel lag in der Verbesserung des elektronischen Abrechnungssystems, welches fuer eine Ueberbezahlung von Leistungen verantwortlich war. Die Gestaltung der vertraglichen Risikovereinbarungen zwischen Versicherer und Leistungserbringer sowie die Qualitaet der Managementstrukturen innerhalb der radiologischen Einrichtungen hatten einen signifikanten Einfluss auf deren Wirtschaftlichkeit. Ferner konnte nachgewiesen werden, dass Aerzte mit eigenen Roentgenanlagen bis zu 4-5-mal mehr Untersuchungen veranlassen als Aerzte ohne eigene Roentgenausstattung und so einen erheblichen Kostentreiber darstellen. (orig.)

  7. Receptor imaging of schizophrenic patients under treatment with typical and atypical neuroleptics; Nuklearmedizinische Rezeptordiagnostik bei schizophrenen Patienten unter Therapie mit typischen und atypischen Neuroleptika

    Energy Technology Data Exchange (ETDEWEB)

    Dresel, S.; Tatsch, K. [Klinik und Poliklinik fuer Nuklearmedizin der Ludwig-Maximilians-Univ. Muenchen (Germany); Meisenzahl, E. [Psychiatrische Klinik der Ludwig-Maximilians-Univ. Muenchen (Germany); Scherer, J. [Bezirkskrankenhaus Haar (Germany)

    2002-09-01

    -motorische Nebenwirkungen hervorzurufen. Die Besetzung postsynaptischer Dopamin-D2-Rezeptoren wird als ein wesentlicher Aspekt der antipsychotischen Wirksamkeit der Neuroleptika angesehen. Diese koennen nuklearmedizinisch durch [I-123]IBZM-SPECT dargestellt werden. Fuer das typische Neuroleptikum Haloperidol wurde eine dosisabhaengige, exponentielle Besetzung der Dopamin-D2-Rezeptoren nachgewiesen. Ab einem Schwellenwert des spezifischen Bindungsindex von 0,4 (Norm: >0,95) zeigten mit einer Ausnahme alle untersuchten Patienten extrapyramidal-motorische Nebenwirkungen. Auch unter Therapie mit dem atypischen Neuroleptikum Clozapin ergab sich eine exponentielle Dosis-Wirkungsbeziehung mit jedoch einem deutlich flacheren Kurvenverlauf im Vergleich zu Haloperidol. Extrapyramidalmotorische Nebenwirkungen traten bei diesen Patienten nicht auf. Neuere, als atypisch eingestufte Neuroleptika wie Risperidon und Olanzapin zeigten ebenfalls eine exponenzielle Dosis-Wirkungsbeziehung, wobei deren Kurvenverlaeufe zwischen denen von Haloperidol und Clozapin lagen. Extrapyramidal-motorische Nebenwirkungen traten bei den letzteren Neuroleptika seltener als bei Haloperidol, bei Olanzapin nur bei einem Patienten in unserem eigenen Patientengut auf. Das pharmakologische Profil atypischer Neuroleptika zeichnet sich neben der Bindung an die postsynaptischen Dopamin-D2-Rezeptoren auch durch Bindung an Rezeptoren diverser anderer Neurotransmittersysteme, insbesondere des serotonergen Systems, aus. Somit ist wahrscheinlich, dass die niedrigere Inzidenz fuer extrapyramidal-motorische Nebenwirkungen bei atypischen Neuroleptika durch (orig.)

  8. Navigating the fifth dimension: new concepts in interactive multimodality and multidimensional image navigation

    Science.gov (United States)

    Ratib, Osman; Rosset, Antoine; Dahlbom, Magnus; Czernin, Johannes

    2005-04-01

    Display and interpretation of multi dimensional data obtained from the combination of 3D data acquired from different modalities (such as PET-CT) require complex software tools allowing the user to navigate and modify the different image parameters. With faster scanners it is now possible to acquire dynamic images of a beating heart or the transit of a contrast agent adding a fifth dimension to the data. We developed a DICOM-compliant software for real time navigation in very large sets of 5 dimensional data based on an intuitive multidimensional jog-wheel widely used by the video-editing industry. The software, provided under open source licensing, allows interactive, single-handed, navigation through 3D images while adjusting blending of image modalities, image contrast and intensity and the rate of cine display of dynamic images. In this study we focused our effort on the user interface and means for interactively navigating in these large data sets while easily and rapidly changing multiple parameters such as image position, contrast, intensity, blending of colors, magnification etc. Conventional mouse-driven user interface requiring the user to manipulate cursors and sliders on the screen are too cumbersome and slow. We evaluated several hardware devices and identified a category of multipurpose jogwheel device that is used in the video-editing industry that is particularly suitable for rapidly navigating in five dimensions while adjusting several display parameters interactively. The application of this tool will be demonstrated in cardiac PET-CT imaging and functional cardiac MRI studies.

  9. Structure and navigation for electronic publishing

    Science.gov (United States)

    Tillinghast, John; Beretta, Giordano B.

    1998-01-01

    The sudden explosion of the World Wide Web as a new publication medium has given a dramatic boost to the electronic publishing industry, which previously was a limited market centered around CD-ROMs and on-line databases. While the phenomenon has parallels to the advent of the tabloid press in the middle of last century, the electronic nature of the medium brings with it the typical characteristic of 4th wave media, namely the acceleration in its propagation speed and the volume of information. Consequently, e-publications are even flatter than print media; Shakespeare's Romeo and Juliet share the same computer screen with a home-made plagiarized copy of Deep Throat. The most touted tool for locating useful information on the World Wide Web is the search engine. However, due to the medium's flatness, sought information is drowned in a sea of useless information. A better solution is to build tools that allow authors to structure information so that it can easily be navigated. We experimented with the use of ontologies as a tool to formulate structures for information about a specific topic, so that related concepts are placed in adjacent locations and can easily be navigated using simple and ergonomic user models. We describe our effort in building a World Wide Web based photo album that is shared among a small network of people.

  10. Tactile object exploration using cursor navigation sensors

    DEFF Research Database (Denmark)

    Kraft, Dirk; Bierbaum, Alexander; Kjaergaard, Morten

    2009-01-01

    In robotic applications tactile sensor systems serve the purpose of localizing a contact point and measuring contact forces. We have investigated the applicability of a sensorial device commonly used in cursor navigation technology for tactile sensing in robotics. We show the potential of this se......In robotic applications tactile sensor systems serve the purpose of localizing a contact point and measuring contact forces. We have investigated the applicability of a sensorial device commonly used in cursor navigation technology for tactile sensing in robotics. We show the potential...... of this sensor for active haptic exploration. More specifically, we present experiments and results which demonstrate the extraction of relevant object properties such as local shape, weight and elasticity using this technology. Besides its low price due to mass production and its modularity, an interesting...... aspect of this sensor is that beside a localization of contact points and measurement of the contact normal force also shear forces can be measured. This is relevant for many applications such as surface normal estimation and weight measurements. Scalable tactile sensor arrays have been developed...

  11. Navigating actions through the rodent parietal cortex

    Directory of Open Access Journals (Sweden)

    Jonathan R. Whitlock

    2014-05-01

    Full Text Available The posterior parietal cortex (PPC participates in a manifold of cognitive functions, including visual attention, working memory, spatial processing and movement planning. Given the vast interconnectivity of PPC with sensory and motor areas, it is not surprising that neuronal recordings show that PPC often encodes mixtures of spatial information as well as the movements required to reach a goal. Recent work sought to discern the relative strength of spatial versus motor signaling in PPC by recording single unit activity in PPC of freely behaving rats during selective changes in either the spatial layout of the local environment or in the pattern of locomotor behaviors executed during navigational tasks. The results revealed unequivocally a predominant sensitivity of PPC neurons to locomotor action structure, with subsets of cells even encoding upcoming movements more than 1 second in advance. In light of these and other recent findings in the field, I propose that one of the key contributions of PPC to navigation is the synthesis of goal-directed behavioral sequences, and that the rodent PPC may serve as an apt system to investigate cellular mechanisms for spatial motor planning as traditionally studied in humans and monkeys.

  12. 33 CFR 150.705 - What are the requirements for maintaining and inspecting aids to navigation?

    Science.gov (United States)

    2010-07-01

    ... maintaining and inspecting aids to navigation? 150.705 Section 150.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: OPERATIONS Aids to Navigation § 150.705 What are the requirements for maintaining and inspecting aids to navigation? (a) All...

  13. A simultaneous navigation and radiation evasion algorithm (SNARE)

    Energy Technology Data Exchange (ETDEWEB)

    Khasawneh, Mohammed A., E-mail: mkha@ieee.org [Department of Electrical Engineering, Jordan University of Science and Technology, Irbid 221 10 (Jordan); Jaradat, Mohammad A., E-mail: majaradat@just.edu.jo [Department of Mechanical Engineering, Jordan University of Science and Technology, Irbid 221 10 (Jordan); Al-Shboul, Zeina Aman M., E-mail: xeinaaman@gmail.com [Department of Electrical Engineering, Jordan University of Science and Technology, Irbid 221 10 (Jordan)

    2013-12-15

    Highlights: • A new navigation algorithm for radiation evasion around nuclear facilities. • An optimization criteria minimized under algorithm operation. • A man-borne device guiding the occupational worker towards paths that warrant least radiation × time products. • Benefits of using localized navigation as opposed to global navigation schemas. • A path discrimination function for finding the navigational paths exhibiting the least amounts of radiation. - Abstract: In this paper, we address the issue of localization as pertains to indoor navigation under radiation contaminated environments. In this context, navigation, in the absence of any GPS signals, is guided by the location of the sensors that make up the entire wireless sensor network in a given locality within a nuclear facility. It, also, draws on the radiation levels as measured by the sensors around a given locale. Here, localization is inherently embedded into the algorithm presented in (Khasawneh et al., 2011a, 2011b) which was designed to provide navigational guidance to optimize any of two criteria: “Radiation Evasion” and “Nearest Exit”. As such, the algorithm can either be applied to setting a navigational “lowest” radiation exposure path from an initial point A to some other point B; a case typical of occupational workers performing maintenance operations around the facility; or providing a radiation-safe passage from point A to the nearest exit. Algorithm's navigational performance is tested under statistical reference, wherein for a given number of runs (trials) algorithm performance is evaluated as a function of the number of steps of look-ahead it uses to acquire navigational information, and is compared against the performance of the renowned Dijkstra global navigation algorithm. This is done with reference to the amount of (radiation × time) product and that of the time needed to reach an exit point, under the two optimization criteria. To evaluate algorithm

  14. A simultaneous navigation and radiation evasion algorithm (SNARE)

    International Nuclear Information System (INIS)

    Khasawneh, Mohammed A.; Jaradat, Mohammad A.; Al-Shboul, Zeina Aman M.

    2013-01-01

    Highlights: • A new navigation algorithm for radiation evasion around nuclear facilities. • An optimization criteria minimized under algorithm operation. • A man-borne device guiding the occupational worker towards paths that warrant least radiation × time products. • Benefits of using localized navigation as opposed to global navigation schemas. • A path discrimination function for finding the navigational paths exhibiting the least amounts of radiation. - Abstract: In this paper, we address the issue of localization as pertains to indoor navigation under radiation contaminated environments. In this context, navigation, in the absence of any GPS signals, is guided by the location of the sensors that make up the entire wireless sensor network in a given locality within a nuclear facility. It, also, draws on the radiation levels as measured by the sensors around a given locale. Here, localization is inherently embedded into the algorithm presented in (Khasawneh et al., 2011a, 2011b) which was designed to provide navigational guidance to optimize any of two criteria: “Radiation Evasion” and “Nearest Exit”. As such, the algorithm can either be applied to setting a navigational “lowest” radiation exposure path from an initial point A to some other point B; a case typical of occupational workers performing maintenance operations around the facility; or providing a radiation-safe passage from point A to the nearest exit. Algorithm's navigational performance is tested under statistical reference, wherein for a given number of runs (trials) algorithm performance is evaluated as a function of the number of steps of look-ahead it uses to acquire navigational information, and is compared against the performance of the renowned Dijkstra global navigation algorithm. This is done with reference to the amount of (radiation × time) product and that of the time needed to reach an exit point, under the two optimization criteria. To evaluate algorithm

  15. Percolation experiments to determine fluid-matrix interaction (with particular regard to pretreatment of the drill core); Kerndurchstroemungsversuche zur Ermittlung von Fluid-Matrix-Wechselwirkungen (unter besonderer Beruecksichtigung der Kernvorbehandlung)

    Energy Technology Data Exchange (ETDEWEB)

    Martin, M; Seibt, A [TU Bergakademie Freiberg (Germany). Inst. fuer Bohrtechnik und Fluidbergbau; Hoth, P [GeoForschungsZentrum Potsdam (Germany)

    1997-12-01

    The injection of fluids into sandstone reservoirs leads to interactions between these waters, the reservoir rocks, and the formation fluids. Estimations about possible permeability reducing processes caused by these interactions are therefore of great importance for the exploitation of sandstone aquifers as geothermal reservoirs. Percolation experiments under in situ conditions with core samples from North German geothermal boreholes were done in order to investigate these fluid-rock interactions. (orig./AKF) [Deutsch] Die Injektion von Fluiden in Aquiferspeicher fuehrt zu Wechselwirkungen zwischen dem Speichergestein, den Formationsfluiden und den injizierten Loesungen. Fuer die Bewirtschaftung der Speicher sind insbesondere Kenntnisse ueber moegliche Permeabilitaetsreduzierungen durch diese Wechselwirkungen von Bedeutung. Mit Hilfe von Kern-Durchstroemungsexperimenten, durchgefuehrt unter lagerstaettenaehnlichen Bedingungen mit Original- bzw. modifizierten Fluiden, wurde daher das Durchstroemungsverhalten von unterschiedlich ausgebildeten Reservoirsandsteinen aus norddeutschen Geothermiebohrungen untersucht. (orig./AKF)

  16. Finding Home: Landmark Ambiguity in Human Navigation

    Directory of Open Access Journals (Sweden)

    Simon Jetzschke

    2017-07-01

    Full Text Available Memories of places often include landmark cues, i.e., information provided by the spatial arrangement of distinct objects with respect to the target location. To study how humans combine landmark information for navigation, we conducted two experiments: To this end, participants were either provided with auditory landmarks while walking in a large sports hall or with visual landmarks while walking on a virtual-reality treadmill setup. We found that participants cannot reliably locate their home position due to ambiguities in the spatial arrangement when only one or two uniform landmarks provide cues with respect to the target. With three visual landmarks that look alike, the task is solved without ambiguity, while audio landmarks need to play three unique sounds for a similar performance. This reduction in ambiguity through integration of landmark information from 1, 2, and 3 landmarks is well modeled using a probabilistic approach based on maximum likelihood estimation. Unlike any deterministic model of human navigation (based e.g., on distance or angle information, this probabilistic model predicted both the precision and accuracy of the human homing performance. To further examine how landmark cues are integrated we introduced systematic conflicts in the visual landmark configuration between training of the home position and tests of the homing performance. The participants integrated the spatial information from each landmark near-optimally to reduce spatial variability. When the conflict becomes big, this integration breaks down and precision is sacrificed for accuracy. That is, participants return again closer to the home position, because they start ignoring the deviant third landmark. Relying on two instead of three landmarks, however, goes along with responses that are scattered over a larger area, thus leading to higher variability. To model the breakdown of integration with increasing conflict, the probabilistic model based on a

  17. Orion Absolute Navigation System Progress and Challenges

    Science.gov (United States)

    Holt, Greg N.; D'Souza, Christopher

    2011-01-01

    The Orion spacecraft is being designed as NASA's next-generation exploration vehicle for crewed missions beyond Low-Earth Orbit. The navigation system for the Orion spacecraft is being designed in a Multi-Organizational Design Environment (MODE) team including contractor and NASA personnel. The system uses an Extended Kalman Filter to process measurements and determine the state. The design of the navigation system has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a timely and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudorange and deltarange, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an Agee-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are modeled as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, scale factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, pad alignment, cold start are discussed as are

  18. Vision enhanced navigation for unmanned systems

    Science.gov (United States)

    Wampler, Brandon Loy

    A vision based simultaneous localization and mapping (SLAM) algorithm is evaluated for use on unmanned systems. SLAM is a technique used by a vehicle to build a map of an environment while concurrently keeping track of its location within the map, without a priori knowledge. The work in this thesis is focused on using SLAM as a navigation solution when global positioning system (GPS) service is degraded or temporarily unavailable. Previous work on unmanned systems that lead up to the determination that a better navigation solution than GPS alone is first presented. This previous work includes control of unmanned systems, simulation, and unmanned vehicle hardware testing. The proposed SLAM algorithm follows the work originally developed by Davidson et al. in which they dub their algorithm MonoSLAM [1--4]. A new approach using the Pyramidal Lucas-Kanade feature tracking algorithm from Intel's OpenCV (open computer vision) library is presented as a means of keeping correct landmark correspondences as the vehicle moves through the scene. Though this landmark tracking method is unusable for long term SLAM due to its inability to recognize revisited landmarks, as opposed to the Scale Invariant Feature Transform (SIFT) and Speeded Up Robust Features (SURF), its computational efficiency makes it a good candidate for short term navigation between GPS position updates. Additional sensor information is then considered by fusing INS and GPS information into the SLAM filter. The SLAM system, in its vision only and vision/IMU form, is tested on a table top, in an open room, and finally in an outdoor environment. For the outdoor environment, a form of the slam algorithm that fuses vision, IMU, and GPS information is tested. The proposed SLAM algorithm, and its several forms, are implemented in C++ using an Extended Kalman Filter (EKF). Experiments utilizing a live video feed from a webcam are performed. The different forms of the filter are compared and conclusions are made on

  19. Representing User Navigation in XML Retrieval with Structural Summaries

    DEFF Research Database (Denmark)

    Ali, M. S.; Consens, Mariano P.; Larsen, Birger

    This poster presents a novel way to represent user navigation in XML retrieval using collection statistics from XML summaries. Currently, developing user navigation models in XML retrieval is costly and the models are specific to collected user assessments. We address this problem by proposing...

  20. Navigating across Cultures: Narrative Constructions of Lived Experience

    Science.gov (United States)

    Pufall-Jones, Elizabeth; Mistry, Jayanthi

    2010-01-01

    In this study, we investigated how individuals from diverse backgrounds learn to navigate the many worlds in which they live and explore how variations in life experiences are associated with aspects of navigating across cultures. We conducted the study using a phenomenological approach based on retrospective personal narratives from 19 young…

  1. Environmental layout complexity affects neural activity during navigation in humans.

    Science.gov (United States)

    Slone, Edward; Burles, Ford; Iaria, Giuseppe

    2016-05-01

    Navigating large-scale surroundings is a fundamental ability. In humans, it is commonly assumed that navigational performance is affected by individual differences, such as age, sex, and cognitive strategies adopted for orientation. We recently showed that the layout of the environment itself also influences how well people are able to find their way within it, yet it remains unclear whether differences in environmental complexity are associated with changes in brain activity during navigation. We used functional magnetic resonance imaging to investigate how the brain responds to a change in environmental complexity by asking participants to perform a navigation task in two large-scale virtual environments that differed solely in interconnection density, a measure of complexity defined as the average number of directional choices at decision points. The results showed that navigation in the simpler, less interconnected environment was faster and more accurate relative to the complex environment, and such performance was associated with increased activity in a number of brain areas (i.e. precuneus, retrosplenial cortex, and hippocampus) known to be involved in mental imagery, navigation, and memory. These findings provide novel evidence that environmental complexity not only affects navigational behaviour, but also modulates activity in brain regions that are important for successful orientation and navigation. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  2. The impact of navigation systems on traffic safety

    NARCIS (Netherlands)

    Rooijen, T. van; Vonk, T.

    2007-01-01

    This paper studies the impact of navigation systems on traffic safety in the Netherlands. This study consists of four analyses: a literature survey, a database analysis, a user survey and an instrumented vehicle study. The results of the four sections show that navigation systems have a positive

  3. The impact of navigation systems on traffic safety

    NARCIS (Netherlands)

    Rooijen, T. van; Vonk, T.

    2008-01-01

    This paper studies the impact of navigation systems on traffic safety in the Netherlands. This study consists of four analyses: a literature survey, a database analysis, a user survey and an instrumented vehicle study. The results of the four sections show that navigation systems have a positive

  4. A Qualitative Approach to Mobile Robot Navigation Using RFID

    International Nuclear Information System (INIS)

    Hossain, M; Rashid, M M; Bhuiyan, M M I; Ahmed, S; Akhtaruzzaman, M

    2013-01-01

    Radio Frequency Identification (RFID) system allows automatic identification of items with RFID tags using radio-waves. As the RFID tag has its unique identification number, it is also possible to detect a specific region where the RFID tag lies in. Recently it is widely been used in mobile robot navigation, localization, and mapping both in indoor and outdoor environment. This paper represents a navigation strategy for autonomous mobile robot using passive RFID system. Conventional approaches, such as landmark or dead-reckoning with excessive number of sensors, have complexities in establishing the navigation and localization process. The proposed method satisfies less complexity in navigation strategy as well as estimation of not only the position but also the orientation of the autonomous robot. In this research, polar coordinate system is adopted on the navigation surface where RFID tags are places in a grid with constant displacements. This paper also presents the performance comparisons among various grid architectures through simulation to establish a better solution of the navigation system. In addition, some stationary obstacles are introduced in the navigation environment to satisfy the viability of the navigation process of the autonomous mobile robot

  5. Collective navigation of complex networks: Participatory greedy routing.

    Science.gov (United States)

    Kleineberg, Kaj-Kolja; Helbing, Dirk

    2017-06-06

    Many networks are used to transfer information or goods, in other words, they are navigated. The larger the network, the more difficult it is to navigate efficiently. Indeed, information routing in the Internet faces serious scalability problems due to its rapid growth, recently accelerated by the rise of the Internet of Things. Large networks like the Internet can be navigated efficiently if nodes, or agents, actively forward information based on hidden maps underlying these systems. However, in reality most agents will deny to forward messages, which has a cost, and navigation is impossible. Can we design appropriate incentives that lead to participation and global navigability? Here, we present an evolutionary game where agents share the value generated by successful delivery of information or goods. We show that global navigability can emerge, but its complete breakdown is possible as well. Furthermore, we show that the system tends to self-organize into local clusters of agents who participate in the navigation. This organizational principle can be exploited to favor the emergence of global navigability in the system.

  6. GNSS-based receiver autonomous integrity monitoring for aircraft navigation

    NARCIS (Netherlands)

    Imparato, D.

    2016-01-01

    Nowadays, GNSS-based navigation is moving more and more to critical applications. Global Navigation Satellite Systems (GNSS), which in the past used to be represented by the American GPS and the Russian GLONASS are now growing in number and performance. The European systemGalileo and the Chinese

  7. Remarks on the observability of single beacon underwater navigation

    DEFF Research Database (Denmark)

    Jouffroy, Jerome; Ross, Andrew

    This paper contributes a simple and intuitive result in the analysis of underwater navigation using a single ranging beacon. This analysis should help with the design of small and lightweight underwater vehicles by reducing the amount of instrumentation required for accurate navigation. The concept...

  8. Distributed Cognition in Ship Navigation and Prevention of Collision

    DEFF Research Database (Denmark)

    Koester, Thomas; Hyll, Nikolaj; Stage, Jan

    2009-01-01

    In this paper we investigate how technology can help the navigator to a better performance. We use three examples based on observations onboard three ships to show, how technology can support the work of the navigator and thereby enhance the performance. Our analysis is based on the paradigm...

  9. Comparative advantage between traditional and smart navigation systems

    Science.gov (United States)

    Shin, Jeongkyu; Kim, Pan-Jun; Kim, Seunghwan

    2013-03-01

    The smart navigation system that refers to real-time traffic data is believed to be superior to traditional navigation systems. To verify this belief, we created an agent-based traffic model and examined the effect of changing market share of the traditional shortest-travel-time algorithm based navigation and the smart navigation system. We tested our model on the grid and actual metropolitan road network structures. The result reveals that the traditional navigation system have better performance than the smart one as the market share of the smart navigation system exceeds a critical value, which is contrary to conventional expectation. We suggest that the superiority inversion between agent groups is strongly related to the traffic weight function form, and is general. We also found that the relationship of market share, traffic flow density and travel time is determined by the combination of congestion avoidance behavior of the smartly navigated agents and the inefficiency of shortest-travel-time based navigated agents. Our results can be interpreted with the minority game and extended to the diverse topics of opinion dynamics. This work was supported by the Original Technology Research Program for Brain Science through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology(No. 2010-0018847).

  10. Information content in reflected global navigation satellite system signals

    DEFF Research Database (Denmark)

    Høeg, Per; Carlstrom, Anders

    2011-01-01

    The direct signals from satellites in global satellite navigation satellites systems (GNSS) as, GPS, GLONASS and GALILEO, constitute the primary source for positioning, navigation and timing from space. But also the reflected GNSS signals contain an important information content of signal travel...

  11. Towards support for collaborative navigation in complex indoor environments

    NARCIS (Netherlands)

    Bouwer, A.; Nack, F.; Evers, V.

    2011-01-01

    In this paper we present first results of an observation study on indoor navigation behaviour of visitors at a large public fair. As an outcome we present a number of requirements for mobile indoor navigation systems that support collaborative destination and path finding tasks.

  12. 75 FR 51473 - Houston/Galveston Navigation Safety Advisory Committee

    Science.gov (United States)

    2010-08-20

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard [Docket No. USCG-2010-0656] Houston/Galveston... Houston/Galveston Navigation Safety Advisory Committee (HOGANSAC) and its working groups will meet in Houston, Texas, to discuss waterway improvements, aids to navigation, area projects impacting safety on...

  13. 75 FR 23793 - Houston/Galveston Navigation Safety Advisory Committee

    Science.gov (United States)

    2010-05-04

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard [Docket No. USCG-2010-0032] Houston/Galveston... Houston/Galveston Navigation Safety Advisory Committee (``HOGANSAC'' or ``the Committee'') and its working groups will meet in Houston, Texas to discuss waterway improvements, aids to navigation, area projects...

  14. 14 CFR 125.203 - Communication and navigation equipment.

    Science.gov (United States)

    2010-01-01

    ... within the degree of accuracy required for ATC; (ii) One marker beacon receiver providing visual and... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Communication and navigation equipment. 125... Equipment Requirements § 125.203 Communication and navigation equipment. (a) Communication equipment—general...

  15. A navigational evaluation model for content management systems

    International Nuclear Information System (INIS)

    Gilani, S.; Majeed, A.

    2016-01-01

    Web applications are widely used world-wide, however it is important that the navigation of these websites is effective, to enhance usability. Navigation is not limited to links between pages, it is also how we complete a task. Navigational structure presented as hypertext is one of the most important component of the Web application besides content and presentation. The main objective of this paper is to explore the navigational structure of various open source Content Management Systems from the developer's perspective. For this purpose three CMS are chosen which are WordPress, Joomla, and Drupal. Objective of the research is to identify the important navigational aspects present in these CMSs. Moreover, a comparative study of these CMSs in terms of navigational support is required. For this purpose an industrial survey is conducted based on our proposed navigational evaluation model. The results shows that there exist correlation between the identified factors and these CMSs provide helpful and effective navigational support to their users. (author)

  16. Navigation in space by X-ray pulsars

    CERN Document Server

    Emadzadeh, Amir Abbas

    2011-01-01

    This book covers modeling of X-ray pulsar signals and explains how X-ray pulsar signals can be used to solve the relative navigation problem. It formulates the problem, proposes a recursive solution and analyzes different aspects of the navigation system.

  17. Ultrasound-Aided Pedestrian Dead Reckoning for Indoor Navigation

    NARCIS (Netherlands)

    Fischer, C.; Kavitha Muthukrishnan, K.; Hazas, M.; Gellersen, H.

    2008-01-01

    Ad hoc solutions for tracking and providing navigation support to emergency response teams is an important and safety-critical challenge. We propose a navigation system based on a combination of foot-mounted inertial sensors and ultrasound beacons. We evaluate experimentally the performance of our

  18. 33 CFR 164.78 - Navigation under way: Towing vessels.

    Science.gov (United States)

    2010-07-01

    ...) Evaluates the danger of each closing visual or radar contact; (5) Knows and applies the variation and... type of correction; (6) Knows the speed and direction of the current, and the set, drift, and tidal... vessels. 164.78 Section 164.78 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND...

  19. Examining care navigation: librarian participation in a teambased approach?

    Directory of Open Access Journals (Sweden)

    A. Tyler Nix, MSLS

    2016-11-01

    Full Text Available Objective: This study investigated responsibilities, skill sets, degrees, and certifications required of health care navigators in order to identify areas of potential overlap with health sciences librarianship. Method: The authors conducted a content analysis of health care navigator position announcements and developed and assigned forty-eight category terms to represent the sample’s responsibilities and skill sets. Results: Coordination of patient care and a bachelor’s degree were the most common responsibility and degree requirements, respectively. Results also suggest that managing and providing health information resources is an area of overlap between health care navigators and health sciences librarians, and that librarians are well suited to serve on navigation teams. Conclusion: Such overlap may provide an avenue for collaboration between navigators and health sciences librarians.

  20. Autonomous Vehicles Navigation with Visual Target Tracking: Technical Approaches

    Directory of Open Access Journals (Sweden)

    Zhen Jia

    2008-12-01

    Full Text Available This paper surveys the developments of last 10 years in the area of vision based target tracking for autonomous vehicles navigation. First, the motivations and applications of using vision based target tracking for autonomous vehicles navigation are presented in the introduction section. It can be concluded that it is very necessary to develop robust visual target tracking based navigation algorithms for the broad applications of autonomous vehicles. Then this paper reviews the recent techniques in three different categories: vision based target tracking for the applications of land, underwater and aerial vehicles navigation. Next, the increasing trends of using data fusion for visual target tracking based autonomous vehicles navigation are discussed. Through data fusion the tracking performance is improved and becomes more robust. Based on the review, the remaining research challenges are summarized and future research directions are investigated.

  1. A Discussion on e-Navigation and Implementation in Turkey

    Directory of Open Access Journals (Sweden)

    Y.V. Aydogdu

    2014-03-01

    Full Text Available Electronic navigation, which has great important for ship management, has taken a step with technological improvements. In the result of these enhancements, new systems appeared as well as existing systems and these systems began to be integrated each other or used data of obtaining from the others like that AIS, Radar, ECDIS etc. All these and likely future systems have been put together under the roof of enhanced navigation (e-navigation is defined by organizations such as International Maritime Organization (IMO, International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA, General Lighthouse Authority (GLA etc. Especially IALA guidelines serve as model future applications in Turkish waterways. In this study aim to redefine e-navigation concept based on maritime safety awareness, maritime service portfolio (MSC 85/26 and discuss possible applications.

  2. 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.

  3. Mapping the 2017 Eclipse: Education, Navigation, Inspiration

    Science.gov (United States)

    Zeiler, M.

    2015-12-01

    Eclipse maps are a unique vessel of knowledge. At a glance, they communicate the essential knowledge of where and when to successfully view a total eclipse of the sun. An eclipse map also provides detailed knowledge of eclipse circumstances superimposed on the highway system for optimal navigation, especially in the event that weather forces relocation. Eclipse maps are also a vital planning tool for solar physicists and astrophotographers capturing high-resolution imagery of the solar corona. Michael Zeiler will speak to the role of eclipse maps in educating the American public and inspiring people to make the effort to reach the path of totality for the sight of a lifetime. Michael will review the role of eclipse maps in astronomical research and discuss a project under development, the 2017 Eclipse Atlas for smartphones, tablets, and desktop computers.

  4. Enhanced Subsea Acoustically Aided Inertial Navigation

    DEFF Research Database (Denmark)

    Jørgensen, Martin Juhl

    time is expensive so lots of effort is put into cutting down on time spent on all tasks. Accuracy demanding tasks such as subsea construction and surveying are subject to strict quality control requirements taking up a lot of time. Offshore equipment is rugged and sturdy as the environmental conditions...... are harsh, likewise should the use of it be simple and robust to ensure that it actually works. The contributions of this thesis are all focused on enhancing accuracy and time efficiency while bearing operational reliability and complexity strongly in mind. The basis of inertial navigation, the inertial...... at desired survey points; the other uses a mapping sensor such as subsea lidar to simply map the area in question. Both approaches are shown to work in practice. Generating high resolution maps, as the latter approach, is how the author anticipates all subsea surveys will be conducted in the near future....

  5. Infrasound and the avian navigational map.

    Science.gov (United States)

    Hagstrum, J T

    2000-04-01

    Birds can navigate accurately over hundreds to thousands of kilometres, and this ability of homing pigeons is the basis for a worldwide sport. Compass senses orient avian flight, but how birds determine their location in order to select the correct homeward bearing (map sense) remains a mystery. Also mysterious are rare disruptions of pigeon races in which most birds are substantially delayed and large numbers are lost. Here, it is shown that in four recent pigeon races in Europe and the northeastern USA the birds encountered infrasonic (low-frequency acoustic) shock waves from the Concorde supersonic transport. An acoustic avian map is proposed that consists of infrasonic cues radiated from steep-sided topographic features; the source of these signals is microseisms continuously generated by interfering oceanic waves. Atmospheric processes affecting these infrasonic map cues can explain perplexing experimental results from pigeon releases.

  6. Independent Navigation System for a Surgical Colonoscope

    Directory of Open Access Journals (Sweden)

    Lilia A. Ochoa-Luna

    2013-08-01

    Full Text Available This paper provides a novel algorithm to attain the independent navigation of a colonoscopy surgical endoscope. First, it introduces a brief description of this issue through the scientist advance for medical robotics. It then makes a quickly count of the existent methods and at the end it provides the basis in order to propose a new alternative solution with help from vision-guidance. That means that images will be processed and interpreted with the purpose of maintaining the endoscope always at the intestine center. All this considered will help us to reduce colonoscopy surgeries consequences and the most important advantage of this new method proposed is that surgeons will accomplish their work easier and more efficiently.

  7. Camera Based Navigation System with Augmented Reality

    Directory of Open Access Journals (Sweden)

    M. Marcu

    2012-06-01

    Full Text Available Nowadays smart mobile devices have enough processing power, memory, storage and always connected wireless communication bandwidth that makes them available for any type of application. Augmented reality (AR proposes a new type of applications that tries to enhance the real world by superimposing or combining virtual objects or computer generated information with it. In this paper we present a camera based navigation system with augmented reality integration. The proposed system aims to the following: the user points the camera of the smartphone towards a point of interest, like a building or any other place, and the application searches for relevant information about that specific place and superimposes the data over the video feed on the display. When the user moves the camera away, changing its orientation, the data changes as well, in real-time, with the proper information about the place that is now in the camera view.

  8. Smart parking management and navigation system

    KAUST Repository

    Saadeldin, Mohamed

    2017-11-09

    Various examples are provided for smart parking management, which can include navigation. In one example, a system includes a base station controller configured to: receive a wireless signal from a parking controller located at a parking space; determine a received signal strength indicator (RSSI) from the wireless signal; and identify a presence of a vehicle located at the parking space based at least in part on the RSSI. In another example, a method includes receiving a wireless signals from a base station controller and a parking controller located at a parking space; determining RSSIs from the wireless signals; and determining a location of the mobile computing device in a parking facility based at least in part on the RSSIs. In another example, a RSSI can be received, a parking occupancy can be determined using the RSSI, and an electronic record can be updated based on the parking occupancy.

  9. Navigating cross-media news use

    DEFF Research Database (Denmark)

    Swart, Joëlle; Peters, Chris; Broersma, Marcel

    2017-01-01

    distinctive cross-media repertoires, and what makes these compositions meaningful. This article analyzes the value of different platforms, genres and practices in everyday life by mapping patterns of cross-media news use. Combining Q methodology with think-aloud protocols and day-in-the-life-interviews, five...... distinct news media repertoires are identified: 1) regionally-oriented 2) background-oriented 3) digital 4) laid-back and 5) nationally-oriented news use. Our findings indicate that users do not always use what they prefer, nor do they prefer what they use. Moreover, the boundaries they draw between news......The current news media landscape is characterized by an abundance of digital outlets and increased opportunities for users to navigate news themselves. Yet, it is still unclear how people negotiate this fluctuating environment to decide which news media to select or ignore, how they assemble...

  10. Development of a new automotive navigation system; Shingata navigation system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sone, M; Nakano, H; Nakayama, O; Tanemura, E; Yoshitsugu, N; Watanabe, M [Nissan Motor Co. Ltd., Tokyo (Japan)

    1996-01-31

    An automotive navigation system was outlined. Features of this system are described below: map display called `Bird View` extending up to the horizon was commercialized; accuracy of determining the vehicle`s present position was realized using new algorithm; and automatic route selection was adopted. Human machine interface of this system also was completely reviewed. `Bird View` was realized by reading plane map data out from CD-ROM and converting them onto the coordinate on the virtual screen in front of the view point. Automatic selection which depends mostly on self-contained navigation adopts the certain way in comparison of the computation position in GPS. To assume vehicle advancing direction, employed were optical fiber gyroscope, geomagnetic sensor, and Karman filter making a good use of advantages of GPS, for the improvement of accuracy. For the automatic distance correction, a function of correcting pulse-distance conversion coefficient was employed, and the free maintenance was realized. 5 figs.

  11. 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...

  12. Orion Absolute Navigation System Progress and Challenge

    Science.gov (United States)

    Holt, Greg N.; D'Souza, Christopher

    2012-01-01

    The absolute navigation design of NASA's Orion vehicle is described. It has undergone several iterations and modifications since its inception, and continues as a work-in-progress. This paper seeks to benchmark the current state of the design and some of the rationale and analysis behind it. There are specific challenges to address when preparing a timely and effective design for the Exploration Flight Test (EFT-1), while still looking ahead and providing software extensibility for future exploration missions. The primary onboard measurements in a Near-Earth or Mid-Earth environment consist of GPS pseudo-range and delta-range, but for future explorations missions the use of star-tracker and optical navigation sources need to be considered. Discussions are presented for state size and composition, processing techniques, and consider states. A presentation is given for the processing technique using the computationally stable and robust UDU formulation with an Agee-Turner Rank-One update. This allows for computational savings when dealing with many parameters which are modeled as slowly varying Gauss-Markov processes. Preliminary analysis shows up to a 50% reduction in computation versus a more traditional formulation. Several state elements are discussed and evaluated, including position, velocity, attitude, clock bias/drift, and GPS measurement biases in addition to bias, scale factor, misalignment, and non-orthogonalities of the accelerometers and gyroscopes. Another consideration is the initialization of the EKF in various scenarios. Scenarios such as single-event upset, ground command, and cold start are discussed as are strategies for whole and partial state updates as well as covariance considerations. Strategies are given for dealing with latent measurements and high-rate propagation using multi-rate architecture. The details of the rate groups and the data ow between the elements is discussed and evaluated.

  13. Magnetic navigation in a coronary phantom: experimental results.

    Science.gov (United States)

    García-García, Héctor M; Tsuchida, Keiichi; Meulenbrug, Hans; Ong, Andrew T L; Van der Giessen, Willem J; Serruys, Patrick W

    2005-11-01

    The objective was to investigate the efficacy of a magnetic navigation system (MNS) in a coronary phantom. The number of coronary interventional procedures performed is steadily increasing with the availability of new devices to treat more complex lesions. Vessel tortuosity remains an important limiting factor in percutaneous coronary intervention. The MNS can orient the tip of magnetized wire. The coronary phantom is a representation of the coronary tree. Two operators using both a magnetic wire and a standard wire, measured the procedural time (PT), the fluoroscopic time (FT) and the radiation exposure/area product (DAP) required to navigate through to fourteen segments. Ten wire advancements were performed per segment. In all but two segments, the PT was significantly longer using magnetic navigation than using manual navigation. The median FT in the left main artery (LMA) - first septal segment was 7 seconds vs. 18 seconds, with magnetic and manual navigation respectively, (p=0.05); in the LMA - obtuse marginal segment the median FT was 15 seconds with magnetic navigation vs. 29.5 seconds with manual navigation, (p=0.01); in the segment from proximal right coronary artery (RCA1) to the acute marginal branch, the median FT was 8 seconds with magnetic vs. 11 seconds with manual navigation, (p=0.05); and in the RCA1 -posterior descending segment the median FT was 9.5 seconds with magnetic vs. 15 seconds with manual navigation, (p=0.006). The MNS facilitates wire access to distal segments in a coronary phantom, with a reduction in FT and radiation exposure using magnetic navigation in tortuous segments.

  14. Design Issues for MEMS-Based Pedestrian Inertial Navigation Systems

    Directory of Open Access Journals (Sweden)

    P. S. Marinushkin

    2015-01-01

    Full Text Available The paper describes design issues for MEMS-based pedestrian inertial navigation systems. By now the algorithms to estimate navigation parameters for strap-down inertial navigation systems on the basis of plural observations have been already well developed. At the same time mathematical and software processing of information in the case of pedestrian inertial navigation systems has its specificity, due to the peculiarities of their functioning and exploitation. Therefore, there is an urgent task to enhance existing fusion algorithms for use in pedestrian navigation systems. For this purpose the article analyzes the characteristics of the hardware composition and configuration of existing systems of this class. The paper shows advantages of various technical solutions. Relying on their main features it justifies a choice of the navigation system architecture and hardware composition enabling improvement of the estimation accuracy of user position as compared to the systems using only inertial sensors. The next point concerns the development of algorithms for complex processing of heterogeneous information. To increase an accuracy of the free running pedestrian inertial navigation system we propose an adaptive algorithm for joint processing of heterogeneous information based on the fusion of inertial info rmation with magnetometer measurements using EKF approach. Modeling of the algorithm was carried out using a specially developed functional prototype of pedestrian inertial navigation system, implemented as a hardware/software complex in Matlab environment. The functional prototype tests of the developed system demonstrated an improvement of the navigation parameters estimation compared to the systems based on inertial sensors only. It enables to draw a conclusion that the synthesized algorithm provides satisfactory accuracy for calculating the trajectory of motion even when using low-grade inertial MEMS sensors. The developed algorithm can be

  15. Integrated INS/GPS Navigation from a Popular Perspective

    Science.gov (United States)

    Omerbashich, Mensur

    2002-01-01

    Inertial navigation, blended with other navigation aids, Global Positioning System (GPS) in particular, has gained significance due to enhanced navigation and inertial reference performance and dissimilarity for fault tolerance and anti-jamming. Relatively new concepts based upon using Differential GPS (DGPS) blended with Inertial (and visual) Navigation Sensors (INS) offer the possibility of low cost, autonomous aircraft landing. The FAA has decided to implement the system in a sophisticated form as a new standard navigation tool during this decade. There have been a number of new inertial sensor concepts in the recent past that emphasize increased accuracy of INS/GPS versus INS and reliability of navigation, as well as lower size and weight, and higher power, fault tolerance, and long life. The principles of GPS are not discussed; rather the attention is directed towards general concepts and comparative advantages. A short introduction to the problems faced in kinematics is presented. The intention is to relate the basic principles of kinematics to probably the most used navigation method in the future-INS/GPS. An example of the airborne INS is presented, with emphasis on how it works. The discussion of the error types and sources in navigation, and of the role of filters in optimal estimation of the errors then follows. The main question this paper is trying to answer is 'What are the benefits of the integration of INS and GPS and how is this, navigation concept of the future achieved in reality?' The main goal is to communicate the idea about what stands behind a modern navigation method.

  16. Modern Estimation Techniques and Optimal Maneuver Targeting for Autonomous Optical Navigation around Small Bodies

    Data.gov (United States)

    National Aeronautics and Space Administration — Autonomous Optical Navigation (AON) allows for significant advances in spacecraft navigation accuracy around small bodies located far from Earth, such as asteroids...

  17. Performance Evaluation and Requirements Assessment for Gravity Gradient Referenced Navigation

    Directory of Open Access Journals (Sweden)

    Jisun Lee

    2015-07-01

    Full Text Available In this study, simulation tests for gravity gradient referenced navigation (GGRN are conducted to verify the effects of various factors such as database (DB and sensor errors, flight altitude, DB resolution, initial errors, and measurement update rates on the navigation performance. Based on the simulation results, requirements for GGRN are established for position determination with certain target accuracies. It is found that DB and sensor errors and flight altitude have strong effects on the navigation performance. In particular, a DB and sensor with accuracies of 0.1 E and 0.01 E, respectively, are required to determine the position more accurately than or at a level similar to the navigation performance of terrain referenced navigation (TRN. In most cases, the horizontal position error of GGRN is less than 100 m. However, the navigation performance of GGRN is similar to or worse than that of a pure inertial navigation system when the DB and sensor errors are 3 E or 5 E each and the flight altitude is 3000 m. Considering that the accuracy of currently available gradiometers is about 3 E or 5 E, GGRN does not show much advantage over TRN at present. However, GGRN is expected to exhibit much better performance in the near future when accurate DBs and gravity gradiometer are available.

  18. GPS surveying method applied to terminal area navigation flight experiments

    Energy Technology Data Exchange (ETDEWEB)

    Murata, M; Shingu, H; Satsushima, K; Tsuji, T; Ishikawa, K; Miyazawa, Y; Uchida, T [National Aerospace Laboratory, Tokyo (Japan)

    1993-03-01

    With an objective of evaluating accuracy of new landing and navigation systems such as microwave landing guidance system and global positioning satellite (GPS) system, flight experiments are being carried out using experimental aircraft. This aircraft mounts a GPS and evaluates its accuracy by comparing the standard orbits spotted by a Kalman filter from the laser tracing data on the aircraft with the navigation results. The GPS outputs position and speed information from an earth-centered-earth-fixed system called the World Geodetic System, 1984 (WGS84). However, in order to compare the navigation results with output from a reference orbit sensor or other navigation sensor, it is necessary to structure a high-precision reference coordinates system based on the WGS84. A method that applies the GPS phase interference measurement for this problem was proposed, and used actually in analyzing a flight experiment data. As referred to a case of the method having been applied to evaluating an independent navigation accuracy, the method was verified sufficiently effective and reliable not only in navigation method analysis, but also in the aspect of navigational operations. 12 refs., 10 figs., 5 tabs.

  19. Electrophysiological correlates of mental navigation in blind and sighted people.

    Science.gov (United States)

    Kober, Silvia Erika; Wood, Guilherme; Kampl, Christiane; Neuper, Christa; Ischebeck, Anja

    2014-10-15

    The aim of the present study was to investigate functional reorganization of the occipital cortex for a mental navigation task in blind people. Eight completely blind adults and eight sighted matched controls performed a mental navigation task, in which they mentally imagined to walk along familiar routes of their hometown during a multi-channel EEG measurement. A motor imagery task was used as control condition. Furthermore, electrophysiological activation patterns during a resting measurement with open and closed eyes were compared between blind and sighted participants. During the resting measurement with open eyes, no differences in EEG power were observed between groups, whereas sighted participants showed higher alpha (8-12Hz) activity at occipital sites compared to blind participants during an eyes-closed resting condition. During the mental navigation task, blind participants showed a stronger event-related desynchronization in the alpha band over the visual cortex compared to sighted controls indicating a stronger activation in this brain region in the blind. Furthermore, groups showed differences in functional brain connectivity between fronto-central and parietal-occipital brain networks during mental navigation indicating stronger visuo-spatial processing in sighted than in blind people during mental navigation. Differences in electrophysiological parameters between groups were specific for mental navigation since no group differences were observed during motor imagery. These results indicate that in the absence of vision the visual cortex takes over other functions such as spatial navigation. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. 33 CFR 66.05-10 - State waters for private aids to navigation; designations; revisions, and revocations.

    Science.gov (United States)

    2010-07-01

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

  1. 33 CFR 165.T09-1080 - Safety Zone and Regulated Navigation Area, Chicago Sanitary and Ship Canal, Romeoville, IL.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety Zone and Regulated Navigation Area, Chicago Sanitary and Ship Canal, Romeoville, IL. 165.T09-1080 Section 165.T09-1080 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED...

  2. 33 CFR 162.260 - Channel leading to San Juan Harbor, P.R.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Channel leading to San Juan Harbor, P.R.; use, administration, and navigation. 162.260 Section 162.260 Navigation and Navigable... WATERWAYS NAVIGATION REGULATIONS § 162.260 Channel leading to San Juan Harbor, P.R.; use, administration...

  3. The River Danube: An Examination of Navigation on the River

    Science.gov (United States)

    Cooper, R. W.

    One of the definitions of Navigation that gets little attention in this Institute is (Oxford English Dictionary), and which our French friends call La Navigation. I have always found this subject fascinating, and have previously navigated the Rivers Mekong, Irrawaddy, Hooghly, Indus, Shatt-al-Arab, Savannah and RhMainKanal (RMDK) and the River Danube, a distance of approximately 4000 km. This voyage has only recently become possible with the opening of the connecting RMDK at the end of 1992, but has been made little use of because of the civil war in the former Yugoslavia.

  4. Autonomous GPS/INS navigation experiment for Space Transfer Vehicle

    Science.gov (United States)

    Upadhyay, Triveni N.; Cotterill, Stephen; Deaton, A. W.

    1993-01-01

    An experiment to validate the concept of developing an autonomous integrated spacecraft navigation system using on board Global Positioning System (GPS) and Inertial Navigation System (INS) measurements is described. The feasibility of integrating GPS measurements with INS measurements to provide a total improvement in spacecraft navigation performance, i.e. improvement in position, velocity and attitude information, was previously demonstrated. An important aspect of this research is the automatic real time reconfiguration capability of the system designed to respond to changes in a spacecraft mission under the control of an expert system.

  5. Survey of computer vision technology for UVA navigation

    Science.gov (United States)

    Xie, Bo; Fan, Xiang; Li, Sijian

    2017-11-01

    Navigation based on computer version technology, which has the characteristics of strong independence, high precision and is not susceptible to electrical interference, has attracted more and more attention in the filed of UAV navigation research. Early navigation project based on computer version technology mainly applied to autonomous ground robot. In recent years, the visual navigation system is widely applied to unmanned machine, deep space detector and underwater robot. That further stimulate the research of integrated navigation algorithm based on computer version technology. In China, with many types of UAV development and two lunar exploration, the three phase of the project started, there has been significant progress in the study of visual navigation. The paper expounds the development of navigation based on computer version technology in the filed of UAV navigation research and draw a conclusion that visual navigation is mainly applied to three aspects as follows.(1) Acquisition of UAV navigation parameters. The parameters, including UAV attitude, position and velocity information could be got according to the relationship between the images from sensors and carrier's attitude, the relationship between instant matching images and the reference images and the relationship between carrier's velocity and characteristics of sequential images.(2) Autonomous obstacle avoidance. There are many ways to achieve obstacle avoidance in UAV navigation. The methods based on computer version technology ,including feature matching, template matching, image frames and so on, are mainly introduced. (3) The target tracking, positioning. Using the obtained images, UAV position is calculated by using optical flow method, MeanShift algorithm, CamShift algorithm, Kalman filtering and particle filter algotithm. The paper expounds three kinds of mainstream visual system. (1) High speed visual system. It uses parallel structure, with which image detection and processing are

  6. Songlines and navigation in Wardaman and other Australian Aboriginal cultures

    Science.gov (United States)

    Norris, Ray P.; Harney, Bill Yidumdum

    2014-07-01

    We discuss the songlines and navigation of the Wardaman people, and place them in context by comparing them with corresponding practices in other Aboriginal Australian language groups, using previously-unpublished information and also information drawn from the literature. Songlines are effectively oral maps of the landscape, enabling the transmission of oral navigational skills in cultures that do not have a written language. In many cases, songlines on the Earth are mirrored by songlines in the sky, enabling the sky to be used as a navigational tool, both by using it as a compass and by using it as a mnemonic.

  7. Determining navigability of terrain using point cloud data.

    Science.gov (United States)

    Cockrell, Stephanie; Lee, Gregory; Newman, Wyatt

    2013-06-01

    This paper presents an algorithm to identify features of the navigation surface in front of a wheeled robot. Recent advances in mobile robotics have brought about the development of smart wheelchairs to assist disabled people, allowing them to be more independent. These robots have a human occupant and operate in real environments where they must be able to detect hazards like holes, stairs, or obstacles. Furthermore, to ensure safe navigation, wheelchairs often need to locate and navigate on ramps. The algorithm is implemented on data from a Kinect and can effectively identify these features, increasing occupant safety and allowing for a smoother ride.

  8. Minimally Invasive Spinal Surgery with Intraoperative Image-Guided Navigation

    Directory of Open Access Journals (Sweden)

    Terrence T. Kim

    2016-01-01

    Full Text Available We present our perioperative minimally invasive spine surgery technique using intraoperative computed tomography image-guided navigation for the treatment of various lumbar spine pathologies. We present an illustrative case of a patient undergoing minimally invasive percutaneous posterior spinal fusion assisted by the O-arm system with navigation. We discuss the literature and the advantages of the technique over fluoroscopic imaging methods: lower occupational radiation exposure for operative room personnel, reduced need for postoperative imaging, and decreased revision rates. Most importantly, we demonstrate that use of intraoperative cone beam CT image-guided navigation has been reported to increase accuracy.

  9. The Programmer's Guide to iSeries Navigator

    CERN Document Server

    Touhy, Paul

    2012-01-01

    iSeries Navigator is a favorite tool of operators and administrators-who use it with great success-but many programmers have missed the great programming tools that is provides! This book introduces you to iSeries Navigator along with all the powerful tools and interfaces that will expand your programming horizons. As iSeries applications continue to move toward a graphical user interface (GUI), so does the development environment. Programs such as CODE and WDSC may fill the need for the programming environment, but iSeries Navigator fills the programmer's need for general system access as wel

  10. Sensor fusion for mobile robot navigation

    International Nuclear Information System (INIS)

    Kam, M.; Zhu, X.; Kalata, P.

    1997-01-01

    The authors review techniques for sensor fusion in robot navigation, emphasizing algorithms for self-location. These find use when the sensor suite of a mobile robot comprises several different sensors, some complementary and some redundant. Integrating the sensor readings, the robot seeks to accomplish tasks such as constructing a map of its environment, locating itself in that map, and recognizing objects that should be avoided or sought. The review describes integration techniques in two categories: low-level fusion is used for direct integration of sensory data, resulting in parameter and state estimates; high-level fusion is used for indirect integration of sensory data in hierarchical architectures, through command arbitration and integration of control signals suggested by different modules. The review provides an arsenal of tools for addressing this (rather ill-posed) problem in machine intelligence, including Kalman filtering, rule-based techniques, behavior based algorithms and approaches that borrow from information theory, Dempster-Shafer reasoning, fuzzy logic and neural networks. It points to several further-research needs, including: robustness of decision rules; simultaneous consideration of self-location, motion planning, motion control and vehicle dynamics; the effect of sensor placement and attention focusing on sensor fusion; and adaptation of techniques from biological sensor fusion

  11. Navigating Negative Conversations in Climate Change

    Science.gov (United States)

    Mandia, S. A.; Abraham, J. P.; Dash, J. W.; Ashley, M. C.

    2012-12-01

    Politically charged public discussions of climate change often lead to polarization as a direct result of many societal, economic, religious and other factors which form opinions. For instance, the general public views climate change as a political discussion rather than a scientific matter. Additionally, many media sources such as websites and mainstream venues and persons have served to promote the "controversy". Scientists who engage in a public discourse of climate change often encounter politically charged environments and audiences. Traditional presentations of the science without attention paid to political, social, or economic matters are likely to worsen the existing divide. An international organization, the Climate Science Rapid Response Team (CSRRT) suggests a strategy that can be used to navigate potentially troublesome situations with divided audiences. This approach can be used during live lecture presentations, and radio, print, or television interviews. The strategy involves identifying alternative motivations for taking action on climate change. The alternative motivations are tailored to the audience and can range from national defense, economic prosperity, religious motivation, patriotism, energy independence, or hunting/fishing reasons. Similar messaging modification can be used to faithfully and accurately convey the importance of taking action on climate change but present the motivations in a way that will be received by the audience.

  12. Categorizing words through semantic memory navigation

    Science.gov (United States)

    Borge-Holthoefer, J.; Arenas, A.

    2010-03-01

    Semantic memory is the cognitive system devoted to storage and retrieval of conceptual knowledge. Empirical data indicate that semantic memory is organized in a network structure. Everyday experience shows that word search and retrieval processes provide fluent and coherent speech, i.e. are efficient. This implies either that semantic memory encodes, besides thousands of words, different kind of links for different relationships (introducing greater complexity and storage costs), or that the structure evolves facilitating the differentiation between long-lasting semantic relations from incidental, phenomenological ones. Assuming the latter possibility, we explore a mechanism to disentangle the underlying semantic backbone which comprises conceptual structure (extraction of categorical relations between pairs of words), from the rest of information present in the structure. To this end, we first present and characterize an empirical data set modeled as a network, then we simulate a stochastic cognitive navigation on this topology. We schematize this latter process as uncorrelated random walks from node to node, which converge to a feature vectors network. By doing so we both introduce a novel mechanism for information retrieval, and point at the problem of category formation in close connection to linguistic and non-linguistic experience.

  13. Sources of Error in Satellite Navigation Positioning

    Directory of Open Access Journals (Sweden)

    Jacek Januszewski

    2017-09-01

    Full Text Available An uninterrupted information about the user’s position can be obtained generally from satellite navigation system (SNS. At the time of this writing (January 2017 currently two global SNSs, GPS and GLONASS, are fully operational, two next, also global, Galileo and BeiDou are under construction. In each SNS the accuracy of the user’s position is affected by the three main factors: accuracy of each satellite position, accuracy of pseudorange measurement and satellite geometry. The user’s position error is a function of both the pseudorange error called UERE (User Equivalent Range Error and user/satellite geometry expressed by right Dilution Of Precision (DOP coefficient. This error is decomposed into two types of errors: the signal in space ranging error called URE (User Range Error and the user equipment error UEE. The detailed analyses of URE, UEE, UERE and DOP coefficients, and the changes of DOP coefficients in different days are presented in this paper.

  14. Navigation of the autonomous vehicle reverse movement

    Science.gov (United States)

    Rachkov, M.; Petukhov, S.

    2018-02-01

    The paper presents a mathematical formulation of the vehicle reverse motion along a multi-link polygonal trajectory consisting of rectilinear segments interconnected by nodal points. Relevance of the problem is caused by the need to solve a number of tasks: to save the vehicle in the event of а communication break by returning along the trajectory already passed, to avoid a turn on the ground in constrained obstacles or dangerous conditions, or a partial return stroke for the subsequent bypass of the obstacle and continuation of the forward movement. The method of navigation with direct movement assumes that the reverse path is elaborated by using landmarks. To measure landmarks on board, a block of cameras is placed on a vehicle controlled by the operator through the radio channel. Errors in estimating deviation from the nominal trajectory of motion are determined using the multidimensional correlation analysis apparatus based on the dynamics of a lateral deviation error and a vehicle speed error. The result of the experiment showed a relatively high accuracy in determining the state vector that provides the vehicle reverse motion relative to the reference trajectory with a practically acceptable error while returning to the start point.

  15. Navigating climate communication in Trump's America

    Science.gov (United States)

    Myhre, S. E.

    2017-12-01

    The rise of anti-evidence, climate-dismissive hate speech from the United States Presidency changes the landscape of decisions and public actions for scientists. Indeed, it is a challenging and necessary time to communicate in public as a scientist. The professional paradigm of science communication, which emphasizes storytelling, narrative, and personality, is an insufficient toolkit for navigating these political, ideological, and dysfunctional spaces. When basic scientific evidence is distorted through a partisan lens, scientific communication will be viewed as political speech. This is a problem, because information and data are critical tools for governance. What is more, tribalism, nationalism, misogyny, and racism have been emboldened in our culture, and these views can be coupled with climate-dismissive public voices. It is naïve for institutions, in this political moment, to expect scholars participating in public communication and engagement to simply "keep it to the science". In truth, that apolitical middle ground does not exist - it is a fabrication meant to devalue consensus climate science and to devalue the voices of women, people of color, and other marginalized scientists. Who are we to not advocate for the lives and futures of our families, colleagues, and communities? We need to look directly at the misfit between our public scientific communication and the vacuum of leadership and integrity exhibited at the very top of the US political system. Scientists have a vital culture role, and we must choose wholehearted public engagement and climate leadership during this challenging time.

  16. MR-imaging of the breast at 0.5 Tesla: menstrual-cycle dependency of parenchymal contrast enhancement in healthy volunteers with oral contraceptive use?; MR-Mammographie bei 0,5 Tesla: Menstruationszyklusabhaengigkeit der Kontrastmittelanreicherung unter hormoneller Kontrazeption?

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzen, J.; Welger, J.; Krupski, G.; Adam, G. [Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Universitaetsklinikum Hamburg-Eppendorf (Germany); Lisboa, B.W. [Klinik und Poliklinik fuer Frauenheilkunde und Geburtshilfe, Universitaetsklinikum Hamburg-Eppendorf (Germany)

    2003-04-01

    Introduction: To evaluate changes of contrast medium enhancement of the breast parenchyma due to menstrual cycle in healthy volunteers with oral contraceptive use in MR-imaging of the breast. Material and Methods: 15 healthy volunteers (age: 22 - 36, mean 28,2) without breast disease were examined two times during one menstrual cycle (days 7 - 14 and days 21 - 2). Two volunteers were examined only in the second part of the cycle (days 21 - 2). All volunteers used oral contraceptives for more than 6 month continuously. Examinations were performed with a 0,5 T magnet (dynamic 3D-gradient echo protocol with subtraction postprocessing). We evaluated the number of enhancing foci and the parenchymal contrast medium enhancement during the different phases of the cycle by region of interest. Results: Only a total of two enhancing foci were found in 2 of 17 volunteers. Time/signal intensity diagrams in these both cases were not suspicious (< 80% initial signal increase after of contrast medium injection, no wash-out phenomenon) and sonography of the breast in these two cases was inconspicuous. Contrast medium enhancement of breast parenchyma in cycle days 7 - 14 (mean enhancement: 0.12 - 0.26, minutes 1 - 9 p.i.) was not significantly different (p = 0.2209; Wilcoxon signed rank test) from cycle days 21 - 2 (mean: 0.13 - 0.32). Conclusion: Menstrual cycle dependency of parenchymal contrast medium enhancement seems to be of minor relevance for premenopausal women with use of oral contraceptives. (orig.) [German] Fragestellung: Untersuchung der Kontrastmittelaufnahme des Brustparenchyms in Abhaengigkeit vom Menstruationszyklus bei gesunden Probandinnen unter oraler Kontrazeption. Material und Methode: Bei 15 gesunden Probandinnen ohne Brusterkrankung in der Anamnese wurde eine MR-Mammographie zweimal waehrend eines Menstruationszyklus durchgefuehrt (Zyklustag: 7 - 14 und 21 - 2). Bei zwei weiteren Probandinnen erfolgte die MR-Mammographie nur in der zweiten Zyklushaelfte

  17. Next-Generation Navigational Infrastructure and the ATLAS Event Store

    CERN Document Server

    van Gemmeren, P; The ATLAS collaboration; Nowak, M

    2014-01-01

    The ATLAS event store employs a persistence framework with extensive navigational capabilities. These include real-time back navigation to upstream processing stages, externalizable data object references, navigation from any data object to any other both within a single file and across files, and more. The 2013-2014 shutdown of the Large Hadron Collider provides an opportunity to enhance this infrastructure in several ways that both extend these capabilities and allow the collaboration to better exploit emerging computing platforms. Enhancements include redesign with efficient file merging in mind, content-based indices in optimized reference types, and support for forward references. The latter provide the potential to construct valid references to data before those data are written, a capability that is useful in a variety of multithreading, multiprocessing, distributed processing, and deferred processing scenarios. This paper describes the architecture and design of the next generation of ATLAS navigation...

  18. Next-Generation Navigational Infrastructure and the ATLAS Event Store

    CERN Document Server

    van Gemmeren, P; The ATLAS collaboration; Nowak, M

    2013-01-01

    The ATLAS event store employs a persistence framework with extensive navigational capabilities. These include real-time back navigation to upstream processing stages, externalizable data object references, navigation from any data object to any other both within a single file and across files, and more. The 2013-2014 shutdown of the Large Hadron Collider provides an opportunity to enhance this infrastructure in several ways that both extend these capabilities and allow the collaboration to better exploit emerging computing platforms. Enhancements include redesign with efficient file merging in mind, content-based indices in optimized reference types, and support for forward references. The latter provide the potential to construct valid references to data before those data are written, a capability that is useful in a variety of multithreading, multiprocessing, distributed processing, and deferred processing scenarios. This paper describes the architecture and design of the next generation of ATLAS navigation...

  19. IMPLEMENTATION OF INTERTIAL NAVIGATION SYSTEM MODEL DURING AIRCRAFT TESTING

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available The flight subset control is required during the aviation equipment test flights. In order to achieve this objective the complex consisting of strap down inertial navigation system (SINS and user equipment of satellite navigation systems (SNS can be used. Such combination needs to be used for error correction in positioning which is accumulated in SINS with time. This article shows the research results of the inertial navigation system (INS model. The results of the position- ing error calculation for various INS classes are given. Each of the examined INS has a different accumulated error for the same time lag. The methods of combining information of INS and SRNS are covered. The results obtained can be applied for upgrading the aircraft flight and navigation complexes. In particular, they can allow to continuously determine speed, coordinates, angular situation and repositioning rate of change of axes of the instrument frame.

  20. Pilot stereotypes for navigation symbols on electronic displays

    Science.gov (United States)

    2006-09-20

    There is currently no common symbology standard for the : electronic display of navigation information. The wide : range of display technologies and the different functions : these displays support make it difficult to design symbols : that are easil...

  1. Topological mapping and navigation in indoor environment with invisible barcode

    International Nuclear Information System (INIS)

    Huh, Jin Wook; Chung, Woong Sik; Chung, Wan Kyun

    2006-01-01

    This paper addresses the localization and navigation problem using invisible two dimensional barcodes on the floor. Compared with other methods using natural/artificial landmark, the proposed localization method has great advantages in cost and appearance, since the location of the robot is perfectly known using the barcode information after the mapping is finished. We also propose a navigation algorithm which uses the topological structure. For the topological information, we define nodes and edges which are suitable for indoor navigation, especially for large area having multiple rooms, many walls and many static obstacles. The proposed algorithm also has an advantage that errors occurred in each node are mutually independent and can be compensated exactly after some navigation using barcode. Simulation and experimental results were performed to verify the algorithm in the barcode environment, and the result showed an excellent performance. After mapping, it is also possible to solve the kidnapped case and generate paths using topological information

  2. Fusion of Inertial Navigation and Imagery Data, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovations of the Fusion of Inertial Navigation and Imagery Data are the application of the concept to the dynamic entry-interface through near-landing phases,...

  3. Forgetting Bad Behavior: Memory Management for Case-Based Navigation

    National Research Council Canada - National Science Library

    Kira, Zsolt; Arkin, Ronald C

    2006-01-01

    ...) system applied to autonomous robot navigation. This extends previous work that involved a CBR architecture that indexes cases by the spatio-temporal characteristics of the sensor data, and outputs or selects parameters of behaviors in a behavior...

  4. A Low-Cost, High-Precision Navigator, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Toyon Research Corporation proposes to develop and demonstrate a prototype low-cost precision navigation system using commercial-grade gyroscopes and accelerometers....

  5. Next-generation navigational infrastructure and the ATLAS event store

    International Nuclear Information System (INIS)

    Gemmeren, P van; Malon, D; Nowak, M

    2014-01-01

    The ATLAS event store employs a persistence framework with extensive navigational capabilities. These include real-time back navigation to upstream processing stages, externalizable data object references, navigation from any data object to any other both within a single file and across files, and more. The 2013-2014 shutdown of the Large Hadron Collider provides an opportunity to enhance this infrastructure in several ways that both extend these capabilities and allow the collaboration to better exploit emerging computing platforms. Enhancements include redesign with efficient file merging in mind, content-based indices in optimized reference types, and support for forward references. The latter provide the potential to construct valid references to data before those data are written, a capability that is useful in a variety of multithreading, multiprocessing, distributed processing, and deferred processing scenarios. This paper describes the architecture and design of the next generation of ATLAS navigational infrastructure.

  6. Navigating the National Qualifications Framework (NQF): The role of ...

    African Journals Online (AJOL)

    Navigating the National Qualifications Framework (NQF): The role of career guidance. ... opportunities (including, but not confined to, those within higher education). ... It argues that the time is ripe for a high-level national career development ...

  7. DARPA looks beyond GPS for positioning, navigating, and timing

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, David

    2014-10-01

    Cold-atom interferometry, microelectromechanical systems, signals of opportunity, and atomic clocks are some of the technologies the defense agency is pursuing to provide precise navigation when GPS is unavailable.

  8. Mapping, Navigation, and Learning for Off-Road Traversal

    DEFF Research Database (Denmark)

    Konolige, Kurt; Agrawal, Motilal; Blas, Morten Rufus

    2009-01-01

    The challenge in the DARPA Learning Applied to Ground Robots (LAGR) project is to autonomously navigate a small robot using stereo vision as the main sensor. During this project, we demonstrated a complete autonomous system for off-road navigation in unstructured environments, using stereo vision......, online terrain traversability learning, visual odometry, map registration, planning, and control. At the end of 3 years, the system we developed outperformed all nine other teams in final blind tests over previously unseen terrain.......The challenge in the DARPA Learning Applied to Ground Robots (LAGR) project is to autonomously navigate a small robot using stereo vision as the main sensor. During this project, we demonstrated a complete autonomous system for off-road navigation in unstructured environments, using stereo vision...

  9. Improved artificial bee colony algorithm based gravity matching navigation method.

    Science.gov (United States)

    Gao, Wei; Zhao, Bo; Zhou, Guang Tao; Wang, Qiu Ying; Yu, Chun Yang

    2014-07-18

    Gravity matching navigation algorithm is one of the key technologies for gravity aided inertial navigation systems. With the development of intelligent algorithms, the powerful search ability of the Artificial Bee Colony (ABC) algorithm makes it possible to be applied to the gravity matching navigation field. However, existing search mechanisms of basic ABC algorithms cannot meet the need for high accuracy in gravity aided navigation. Firstly, proper modifications are proposed to improve the performance of the basic ABC algorithm. Secondly, a new search mechanism is presented in this paper which is based on an improved ABC algorithm using external speed information. At last, modified Hausdorff distance is introduced to screen the possible matching results. Both simulations and ocean experiments verify the feasibility of the method, and results show that the matching rate of the method is high enough to obtain a precise matching position.

  10. IceBridge GPS L0 Raw Satellite Navigation Data

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge GPS L0 Raw Satellite Navigation Data (IPUTG0) data set contains GPS readings, including latitude, longitude, track, ground speed, off distance,...

  11. Human Performance Assessments when Using Augmented Reality for Navigation

    National Research Council Canada - National Science Library

    Goldiez, Brian F; Saptoka, Nabin; Aedunuthula, Prashanth

    2006-01-01

    Human performance executing search and rescue type of navigation is one area that can benefit from augmented reality technology when the proper computer generated information is added to a real scene...

  12. METHODOLOGY FOR ANALYSIS OF DECISION MAKING IN AIR NAVIGATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Volodymyr Kharchenko

    2011-03-01

    Full Text Available Abstract. In the research of Air Navigation System as a complex socio-technical system the methodologyof analysis of human-operator's decision-making has been developed. The significance of individualpsychologicalfactors as well as the impact of socio-psychological factors on the professional activities of ahuman-operator during the flight situation development from normal to catastrophic were analyzed. On thebasis of the reflexive theory of bipolar choice the expected risks of decision-making by the Air NavigationSystem's operator influenced by external environment, previous experience and intentions were identified.The methods for analysis of decision-making by the human-operator of Air Navigation System usingstochastic networks have been developed.Keywords: Air Navigation System, bipolar choice, human operator, decision-making, expected risk, individualpsychologicalfactors, methodology of analysis, reflexive model, socio-psychological factors, stochastic network.

  13. Model Basis for the Navigation Aid Analysis Tool

    National Research Council Canada - National Science Library

    Morris, Peter

    1999-01-01

    ...), a self-contained software product that computes the probability of being in a given system state, most commonly, the incident state, for a user-constructed scenario of surface marine navigation...

  14. Navigation Study, Colorado Locks, Colorado River, Matagorda, Texas

    National Research Council Canada - National Science Library

    McCollum, Randy

    2000-01-01

    A 1:70 physical navigation model was built to replicate the Matagorda Locks, approximately one mile of the GIWW east of the locks, approximately one-half mile of the Colorado River north of the GIWW...

  15. 78 FR 19277 - Navigation Safety Advisory Council; Meeting

    Science.gov (United States)

    2013-03-29

    ... regarding multiple risk assessments for U.S. ports and waterways. If you have been adversely affected by the... measures; marine information; diving safety; and aids to navigation systems. This notice corrects the...

  16. Mars Atmospheric Entry Integrated Navigation with Partial Intermittent Measurements

    Directory of Open Access Journals (Sweden)

    Tai-shan Lou

    2017-01-01

    Full Text Available Signal degradation suffered by the vehicle is a combination brownout and blackout during Mars atmospheric entry. The communications brownout means that signal fades and blackout means that the signal is lost completely. The communications brownout and blackout periods are analyzed and predicted with an altitude and velocity profiles. In the brownout period, the range measurements between the vehicle and the orbiters are modeled as intermittent measurements with the radio signal arrival probabilities, which are distributed as a Rayleigh distribution of the electron number density around the entry vehicle. A new integrated navigation strategy during the Mars atmospheric entry phase is proposed to consider the probabilities of the radio measurements in the communications brownout and blackout periods under the IMU/beacon scenario based on the information filter with intermittent measurements. Numerical navigation simulations are designed to show the performance of the proposed navigation strategy under the integrated navigation scenario.

  17. NAMMA LANGLEY AEROSOL RESEARCH GROUP EXPERIMENT NAVIGATION DATA V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA Langley Aerosol Research Group Experiment Navigation Data is the DC-8 NAV data (ICATS) extracted into columns with time correction. These data files were...

  18. Autonomous Navigation in GNSS-Denied Environments, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Aurora proposes to transition UMD methods for insect-inspired, lightweight vision- and optical sensor-based navigation methods for a combined air-ground system that...

  19. Deep Space Navigation and Timing Architecture and Simulation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcosm will develop a deep space navigation and timing architecture and associated simulation, incorporating state-of-the art radiometric, x-ray pulsar, and laser...

  20. Bio-robots automatic navigation with electrical reward stimulation.

    Science.gov (United States)

    Sun, Chao; Zhang, Xinlu; Zheng, Nenggan; Chen, Weidong; Zheng, Xiaoxiang

    2012-01-01

    Bio-robots that controlled by outer stimulation through brain computer interface (BCI) suffer from the dependence on realtime guidance of human operators. Current automatic navigation methods for bio-robots focus on the controlling rules to force animals to obey man-made commands, with animals' intelligence ignored. This paper proposes a new method to realize the automatic navigation for bio-robots with electrical micro-stimulation as real-time rewards. Due to the reward-seeking instinct and trial-and-error capability, bio-robot can be steered to keep walking along the right route with rewards and correct its direction spontaneously when rewards are deprived. In navigation experiments, rat-robots learn the controlling methods in short time. The results show that our method simplifies the controlling logic and realizes the automatic navigation for rat-robots successfully. Our work might have significant implication for the further development of bio-robots with hybrid intelligence.

  1. X-ray Pulsar Navigation Algorithms and Testbed for SEXTANT

    Science.gov (United States)

    Winternitz, Luke M. B.; Hasouneh, Monther A.; Mitchell, Jason W.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven; hide

    2015-01-01

    The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) is a NASA funded technologydemonstration. SEXTANT will, for the first time, demonstrate real-time, on-board X-ray Pulsar-based Navigation (XNAV), a significant milestone in the quest to establish a GPS-like navigation capability available throughout our Solar System and beyond. This paper describes the basic design of the SEXTANT system with a focus on core models and algorithms, and the design and continued development of the GSFC X-ray Navigation Laboratory Testbed (GXLT) with its dynamic pulsar emulation capability. We also present early results from GXLT modeling of the combined NICER X-ray timing instrument hardware and SEXTANT flight software algorithms.

  2. 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...

  3. Addressing the Influence of Space Weather on Airline Navigation

    Science.gov (United States)

    Sparks, Lawrence

    2012-01-01

    The advent of satellite-based augmentation systems has made it possible to navigate aircraft safely using radio signals emitted by global navigation satellite systems (GNSS) such as the Global Positioning System. As a signal propagates through the earth's ionosphere, it suffers delay that is proportional to the total electron content encountered along the raypath. Since the magnitude of this total electron content is strongly influenced by space weather, the safety and reliability of GNSS for airline navigation requires continual monitoring of the state of the ionosphere and calibration of ionospheric delay. This paper examines the impact of space weather on GNSS-based navigation and provides an overview of how the Wide Area Augmentation System protects its users from positioning error due to ionospheric disturbances

  4. GNSS global navigation satellite systems : GPS, GLONASS, Galileo, and more

    CERN Document Server

    Hofmann-Wellenhof, Bernhard; Wasle, Elmar

    2008-01-01

    This book is an extension to the acclaimed scientific bestseller "GPS - Theory and Practice". It covers Global Navigation Satellite Systems (GNSS) and includes the Russian GLONASS, the European system Galileo, and additional systems.

  5. Multi-focal Vision and Gaze Control Improve Navigation Performance

    Directory of Open Access Journals (Sweden)

    Kolja Kuehnlenz

    2008-11-01

    Full Text Available Multi-focal vision systems comprise cameras with various fields of view and measurement accuracies. This article presents a multi-focal approach to localization and mapping of mobile robots with active vision. An implementation of the novel concept is done considering a humanoid robot navigation scenario where the robot is visually guided through a structured environment with several landmarks. Various embodiments of multi-focal vision systems are investigated and the impact on navigation performance is evaluated in comparison to a conventional mono-focal stereo set-up. The comparative studies clearly show the benefits of multi-focal vision for mobile robot navigation: flexibility to assign the different available sensors optimally in each situation, enhancement of the visible field, higher localization accuracy, and, thus, better task performance, i.e. path following behavior of the mobile robot. It is shown that multi-focal vision may strongly improve navigation performance.

  6. Aircraft navigation and surveillance analysis for a spherical earth

    Science.gov (United States)

    2014-10-01

    This memorandum addresses a fundamental function in surveillance and navigation analysis : quantifying the geometry of two or more locations relative to each other and to a spherical earth. Here, geometry refers to: (a) points (idealized lo...

  7. Plenoptic Imager for Automated Surface Navigation, Phase I

    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...

  8. Low computation vision-based navigation for a Martian rover

    Science.gov (United States)

    Gavin, Andrew S.; Brooks, Rodney A.

    1994-01-01

    Construction and design details of the Mobot Vision System, a small, self-contained, mobile vision system, are presented. This system uses the view from the top of a small, roving, robotic vehicle to supply data that is processed in real-time to safely navigate the surface of Mars. A simple, low-computation algorithm for constructing a 3-D navigational map of the Martian environment to be used by the rover is discussed.

  9. Computer Navigation-aided Resection of Sacral Chordomas

    Directory of Open Access Journals (Sweden)

    Yong-Kun Yang

    2016-01-01

    Full Text Available Background: Resection of sacral chordomas is challenging. The anatomy is complex, and there are often no bony landmarks to guide the resection. Achieving adequate surgical margins is, therefore, difficult, and the recurrence rate is high. Use of computer navigation may allow optimal preoperative planning and improve precision in tumor resection. The purpose of this study was to evaluate the safety and feasibility of computer navigation-aided resection of sacral chordomas. Methods: Between 2007 and 2013, a total of 26 patients with sacral chordoma underwent computer navigation-aided surgery were included and followed for a minimum of 18 months. There were 21 primary cases and 5 recurrent cases, with a mean age of 55.8 years old (range: 35-84 years old. Tumors were located above the level of the S3 neural foramen in 23 patients and below the level of the S3 neural foramen in 3 patients. Three-dimensional images were reconstructed with a computed tomography-based navigation system combined with the magnetic resonance images using the navigation software. Tumors were resected via a posterior approach assisted by the computer navigation. Mean follow-up was 38.6 months (range: 18-84 months. Results: Mean operative time was 307 min. Mean intraoperative blood loss was 3065 ml. For computer navigation, the mean registration deviation during surgery was 1.7 mm. There were 18 wide resections, 4 marginal resections, and 4 intralesional resections. All patients were alive at the final follow-up, with 2 (7.7% exhibiting tumor recurrence. The other 24 patients were tumor-free. The mean Musculoskeletal Tumor Society Score was 27.3 (range: 19-30. Conclusions: Computer-assisted navigation can be safely applied to the resection of the sacral chordomas, allowing execution of preoperative plans, and achieving good oncological outcomes. Nevertheless, this needs to be accomplished by surgeons with adequate experience and skill.

  10. Modeling 3D Objects for Navigation Purposes Using Laser Scanning

    Directory of Open Access Journals (Sweden)

    Cezary Specht

    2016-07-01

    Full Text Available The paper discusses the creation of 3d models and their applications in navigation. It contains a review of available methods and geometric data sources, focusing mostly on terrestrial laser scanning. It presents detailed description, from field survey to numerical elaboration, how to construct accurate model of a typical few storey building as a hypothetical reference in complex building navigation. Hence, the paper presents fields where 3d models are being used and their potential new applications.

  11. Iconic memory-based omnidirectional route panorama navigation.

    Science.gov (United States)

    Yagi, Yasushi; Imai, Kousuke; Tsuji, Kentaro; Yachida, Masahiko

    2005-01-01

    A route navigation method for a mobile robot with an omnidirectional image sensor is described. The route is memorized from a series of consecutive omnidirectional images of the horizon when the robot moves to its goal. While the robot is navigating to the goal point, input is matched against the memorized spatio-temporal route pattern by using dual active contour models and the exact robot position and orientation is estimated from the converged shape of the active contour models.

  12. Interaction of HPP Regulation Operation and Navigation at Water Structures

    OpenAIRE

    Možiešik, Ľudovít; Cabadaj, Roman; Čepcová, Zuzana

    2009-01-01

    Significant impact on navigation operation by hydropower plant (HPP) operation is mostly in diversion channels of hydropower plants, when these channels are used for navigation as well. It is caused by sudden changes in flow rate of hydropower plants, which is connected to providing of support services for electric power system. The objective of the research is to determine limits of acceptable hydropower plant operation or propose precautions which enable harmonization of opposing interests ...

  13. 33 CFR 165.1402 - Apra Outer Harbor, Guam-regulated navigation area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Apra Outer Harbor, Guam-regulated....1402 Apra Outer Harbor, Guam—regulated navigation area. (a) The following is a regulated navigation area—The waters of the Pacific Ocean and Apra Outer Harbor enclosed by a line beginning at latitude 13...

  14. 19 CFR 4.66b - Pollution of coastal and navigable waters.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Pollution of coastal and navigable waters. 4.66b... coastal and navigable waters. (a) If any Customs officer has reason to believe that any refuse matter is being or has been deposited in navigable waters or any tributary of any navigable waters in violation of...

  15. Lost in Virtual Space: Studies in Human and Ideal Spatial Navigation

    Science.gov (United States)

    Stankiewicz, Brian J.; Legge, Gordon E.; Mansfield, J. Stephen; Schlicht, Erik J.

    2006-01-01

    The authors describe 3 human spatial navigation experiments that investigate how limitations of perception, memory, uncertainty, and decision strategy affect human spatial navigation performance. To better understand the effect of these variables on human navigation performance, the authors developed an ideal-navigator model for indoor navigation…

  16. 33 CFR 207.50 - Hudson River Lock at Troy, N.Y.; navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Hudson River Lock at Troy, N.Y..., DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.50 Hudson River Lock at Troy, N.Y.; navigation. (a...) [Reserved] (n) Trespass on U.S. property. Trespass on U.S. property, or willful injury to the banks, masonry...

  17. 75 FR 76943 - Regulated Navigation Area; Hudson River South of the Troy Locks, NY

    Science.gov (United States)

    2010-12-10

    ...-AA11 Regulated Navigation Area; Hudson River South of the Troy Locks, NY AGENCY: Coast Guard, DHS... Navigation Area (RNA) on the navigable waters of the Hudson River in New York, south of the Troy Locks. This... within the waters of the Hudson River south of the Troy Locks when ice is a threat to navigation. DATES...

  18. 33 CFR 165.1171 - Copper Canyon, Lake Havasu, Colorado River-Regulated Navigation Area.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Copper Canyon, Lake Havasu... Guard District § 165.1171 Copper Canyon, Lake Havasu, Colorado River—Regulated Navigation Area. (a) Location. The following is a regulated navigation area: (1) In the water area of Copper Canyon, Lake Havasu...

  19. Implementation of a vector-based tracking loop receiver in a pseudolite navigation system.

    Science.gov (United States)

    So, Hyoungmin; Lee, Taikjin; Jeon, Sanghoon; Kim, Chongwon; Kee, Changdon; Kim, Taehee; Lee, Sanguk

    2010-01-01

    We propose a vector tracking loop (VTL) algorithm for an asynchronous pseudolite navigation system. It was implemented in a software receiver and experiments in an indoor navigation system were conducted. Test results show that the VTL successfully tracks signals against the near-far problem, one of the major limitations in pseudolite navigation systems, and could improve positioning availability by extending pseudolite navigation coverage.

  20. The value of magnetic resonance imaging (MRI) in the treatment planning of vertebral metastasis considering economic aspects. A cost benefit-analysis; Die Wertigkeit der Magnetresonanztomographie (MRT) unter oekonomischen Aspekten bei der Bestrahlungsplanung von Wirbelkoerpermetastasen. Eine Kosten-Nutzen-Analyse

    Energy Technology Data Exchange (ETDEWEB)

    Prott, F.J.; Schlehuber, E.; Scharding, B.J.; Rinast, E. [Strahlentherapie Wiesbaden, St.-Josefs-Hospital (Germany); Micke, O. [Klinik und Poliklinik fuer Strahlentherapie - Radioonkologie, Universitaetsklinikum Muenster (Germany)

    2002-05-01

    Is magnetic resonance imaging (MRI) based target volume definition for treatment planning of vertebral metastasis effective under economic considerations.From 1994 to 1999, a total of 137 patients with bone metastases affecting the vertebral column underwent MRI of the cercival, thoracic, or lumbar spine for the treatment planning of palliative radiation therapy. The following radiation treatment consisted in a irradiation of the affected vertebral region up to a total dose of 30-40 Gy.The cost calculation for radiotherapy and magnetic resonance tomography was done using the common tariff model (EBM) of the German Health Insurances.In 73% of patients (101 patients), magnetic resonance imaging resulted in marked corrections of the irradiation fields which would have resulted in the necessity of treatment for recurrence in the case of treatment planning without MRI.Consequently, the higher cost of MRI of 345.00 DEM (176,40 EUR) lead to a saving of 497.00 DEM (254,11 EUR) compared to a recurrence treatment of 10 fractions and of 1,428.00 DEM (730,12 EUR) compared to 20 fractions. The transport expenses for the second treatment could be saved as well.Even under economic considerations MRI is effective. (orig.) [German] Ist eine MRT-gestuetzte Zielvolumendefinition bei der Strahlentherapie von Knochenmetastasen ein sinnvolles Vorgehen unter oekonomischen Gesichtspunkten?1994-1999 wurde bei 137 Patienten mit einem ossaer metastasierenden Tumor und Befall der Wirbelsaeule eine Magnetresonanztomographie (MRT) zur Planung einer palliativen Radiatio durchgefuehrt. Die nachfolgende Strahlentherapie bestand aus einer Radiatio des betroffenen Wirbelkoerperabschnitts bis zu einer Gesamtherddosis von 30-40 Gy. Fuer die Berechnung der Kosten wurde der einheitliche Bewertungsmassstab der Deutschen Krankenkassen zugrunde gelegt.Aufgrund der MRT-Untersuchungen wurde bei 73% der Patienten eine Veraenderung des Bestrahlungsfeldes vorgenommen, die im Falle einer nicht MRT

  1. Eye tracking, strategies, and sex differences in virtual navigation.

    Science.gov (United States)

    Andersen, Nicolas E; Dahmani, Louisa; Konishi, Kyoko; Bohbot, Véronique D

    2012-01-01

    Reports of sex differences in wayfinding have typically used paradigms sensitive to the female advantage (navigation by landmarks) or sensitive to the male advantage (navigation by cardinal directions, Euclidian coordinates, environmental geometry, and absolute distances). The current virtual navigation paradigm allowed both men and women an equal advantage. We studied sex differences by systematically varying the number of landmarks. Eye tracking was used to quantify sex differences in landmark utilisation as participants solved an eight-arm radial maze task within different virtual environments. To solve the task, participants were required to remember the locations of target objects within environments containing 0, 2, 4, 6, or 8 landmarks. We found that, as the number of landmarks available in the environment increases, the proportion of time men and women spend looking at landmarks and the number of landmarks they use to find their way increases. Eye tracking confirmed that women rely more on landmarks to navigate, although landmark fixations were also associated with an increase in task completion time. Sex differences in navigational behaviour occurred only in environments devoid of landmarks and disappeared in environments containing multiple landmarks. Moreover, women showed sustained landmark-oriented gaze, while men's decreased over time. Finally, we found that men and women use spatial and response strategies to the same extent. Together, these results shed new light on the discrepancy in landmark utilisation between men and women and help explain the differences in navigational behaviour previously reported. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Model-base visual navigation of a mobile robot

    International Nuclear Information System (INIS)

    Roening, J.

    1992-08-01

    The thesis considers the problems of visual guidance of a mobile robot. A visual navigation system is formalized consisting of four basic components: world modelling, navigation sensing, navigation and action. According to this formalization an experimental system is designed and realized enabling real-world navigation experiments. A priori knowledge of the world is used for global path finding, aiding scene analysis and providing feedback information to the close the control loop between planned and actual movements. Two world models were developed. The first approach was a map-based model especially designed for low-level description of indoor environments. The other was a higher level and more symbolic representation of the surroundings utilizing the spatial graph concept. Two passive vision approaches were developed to extract navigation information. With passive three- camera stereovision a sparse depth map of the scene was produced. Another approach employed a fish-eye lens to map the entire scene of the surroundings without camera scanning. The local path planning of the system is supported by three-dimensional scene interpreter providing a partial understanding of scene contents. The interpreter consists of data-driven low-level stages and a model-driven high-level stage. Experiments were carried out in a simulator and test vehicle constructed in the laboratory. The test vehicle successfully navigated indoors

  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. Image processing and applications based on visualizing navigation service

    Science.gov (United States)

    Hwang, Chyi-Wen

    2015-07-01

    When facing the "overabundant" of semantic web information, in this paper, the researcher proposes the hierarchical classification and visualizing RIA (Rich Internet Application) navigation system: Concept Map (CM) + Semantic Structure (SS) + the Knowledge on Demand (KOD) service. The aim of the Multimedia processing and empirical applications testing, was to investigating the utility and usability of this visualizing navigation strategy in web communication design, into whether it enables the user to retrieve and construct their personal knowledge or not. Furthermore, based on the segment markets theory in the Marketing model, to propose a User Interface (UI) classification strategy and formulate a set of hypermedia design principles for further UI strategy and e-learning resources in semantic web communication. These research findings: (1) Irrespective of whether the simple declarative knowledge or the complex declarative knowledge model is used, the "CM + SS + KOD navigation system" has a better cognition effect than the "Non CM + SS + KOD navigation system". However, for the" No web design experience user", the navigation system does not have an obvious cognition effect. (2) The essential of classification in semantic web communication design: Different groups of user have a diversity of preference needs and different cognitive styles in the CM + SS + KOD navigation system.

  5. Growing Homophilic Networks Are Natural Navigable Small Worlds.

    Science.gov (United States)

    Malkov, Yury A; Ponomarenko, Alexander

    2016-01-01

    Navigability, an ability to find a logarithmically short path between elements using only local information, is one of the most fascinating properties of real-life networks. However, the exact mechanism responsible for the formation of navigation properties remained unknown. We show that navigability can be achieved by using only two ingredients present in the majority of networks: network growth and local homophily, giving a persuasive answer how the navigation appears in real-life networks. A very simple algorithm produces hierarchical self-similar optimally wired navigable small world networks with exponential degree distribution by using only local information. Adding preferential attachment produces a scale-free network which has shorter greedy paths, but worse (power law) scaling of the information extraction locality (algorithmic complexity of a search). Introducing saturation of the preferential attachment leads to truncated scale-free degree distribution that offers a good tradeoff between these parameters and can be useful for practical applications. Several features of the model are observed in real-life networks, in particular in the brain neural networks, supporting the earlier suggestions that they are navigable.

  6. Growing Homophilic Networks Are Natural Navigable Small Worlds.

    Directory of Open Access Journals (Sweden)

    Yury A Malkov

    Full Text Available Navigability, an ability to find a logarithmically short path between elements using only local information, is one of the most fascinating properties of real-life networks. However, the exact mechanism responsible for the formation of navigation properties remained unknown. We show that navigability can be achieved by using only two ingredients present in the majority of networks: network growth and local homophily, giving a persuasive answer how the navigation appears in real-life networks. A very simple algorithm produces hierarchical self-similar optimally wired navigable small world networks with exponential degree distribution by using only local information. Adding preferential attachment produces a scale-free network which has shorter greedy paths, but worse (power law scaling of the information extraction locality (algorithmic complexity of a search. Introducing saturation of the preferential attachment leads to truncated scale-free degree distribution that offers a good tradeoff between these parameters and can be useful for practical applications. Several features of the model are observed in real-life networks, in particular in the brain neural networks, supporting the earlier suggestions that they are navigable.

  7. 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.

  8. Image-based path planning for automated virtual colonoscopy navigation

    Science.gov (United States)

    Hong, Wei

    2008-03-01

    Virtual colonoscopy (VC) is a noninvasive method for colonic polyp screening, by reconstructing three-dimensional models of the colon using computerized tomography (CT). In virtual colonoscopy fly-through navigation, it is crucial to generate an optimal camera path for efficient clinical examination. In conventional methods, the centerline of the colon lumen is usually used as the camera path. In order to extract colon centerline, some time consuming pre-processing algorithms must be performed before the fly-through navigation, such as colon segmentation, distance transformation, or topological thinning. In this paper, we present an efficient image-based path planning algorithm for automated virtual colonoscopy fly-through navigation without the requirement of any pre-processing. Our algorithm only needs the physician to provide a seed point as the starting camera position using 2D axial CT images. A wide angle fisheye camera model is used to generate a depth image from the current camera position. Two types of navigational landmarks, safe regions and target regions are extracted from the depth images. Camera position and its corresponding view direction are then determined using these landmarks. The experimental results show that the generated paths are accurate and increase the user comfort during the fly-through navigation. Moreover, because of the efficiency of our path planning algorithm and rendering algorithm, our VC fly-through navigation system can still guarantee 30 FPS.

  9. 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.

  10. Comparing two types of navigational interfaces for Virtual Reality.

    Science.gov (United States)

    Teixeira, Luís; Vilar, Elisângela; Duarte, Emília; Rebelo, Francisco; da Silva, Fernando Moreira

    2012-01-01

    Previous studies suggest significant differences between navigating virtual environments in a life-like walking manner (i.e., using treadmills or walk-in-place techniques) and virtual navigation (i.e., flying while really standing). The latter option, which usually involves hand-centric devices (e.g., joysticks), is the most common in Virtual Reality-based studies, mostly due to low costs, less space and technology demands. However, recently, new interaction devices, originally conceived for videogames have become available offering interesting potentialities for research. This study aimed to explore the potentialities of the Nintendo Wii Balance Board as a navigation interface in a Virtual Environment presented in an immersive Virtual Reality system. Comparing participants' performance while engaged in a simulated emergency egress allows determining the adequacy of such alternative navigation interface on the basis of empirical results. Forty university students participated in this study. Results show that participants were more efficient when performing navigation tasks using the Joystick than with the Balance Board. However there were no significantly differences in the behavioral compliance with exit signs. Therefore, this study suggests that, at least for tasks similar to the studied, the Balance Board have good potentiality to be used as a navigation interface for Virtual Reality systems.

  11. Satellite Imagery Assisted Road-Based Visual Navigation System

    Science.gov (United States)

    Volkova, A.; Gibbens, P. W.

    2016-06-01

    There is a growing demand for unmanned aerial systems as autonomous surveillance, exploration and remote sensing solutions. Among the key concerns for robust operation of these systems is the need to reliably navigate the environment without reliance on global navigation satellite system (GNSS). This is of particular concern in Defence circles, but is also a major safety issue for commercial operations. In these circumstances, the aircraft needs to navigate relying only on information from on-board passive sensors such as digital cameras. An autonomous feature-based visual system presented in this work offers a novel integral approach to the modelling and registration of visual features that responds to the specific needs of the navigation system. It detects visual features from Google Earth* build a feature database. The same algorithm then detects features in an on-board cameras video stream. On one level this serves to localise the vehicle relative to the environment using Simultaneous Localisation and Mapping (SLAM). On a second level it correlates them with the database to localise the vehicle with respect to the inertial frame. The performance of the presented visual navigation system was compared using the satellite imagery from different years. Based on comparison results, an analysis of the effects of seasonal, structural and qualitative changes of the imagery source on the performance of the navigation algorithm is presented. * The algorithm is independent of the source of satellite imagery and another provider can be used

  12. Space Launch Systems Block 1B Preliminary Navigation System Design

    Science.gov (United States)

    Oliver, T. Emerson; Park, Thomas; Anzalone, Evan; Smith, Austin; Strickland, Dennis; Patrick, Sean

    2018-01-01

    NASA is currently building the Space Launch Systems (SLS) Block 1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. In parallel, NASA is also designing the Block 1B launch vehicle. The Block 1B vehicle is an evolution of the Block 1 vehicle and extends the capability of the NASA launch vehicle. This evolution replaces the Interim Cryogenic Propulsive Stage (ICPS) with the Exploration Upper Stage (EUS). As the vehicle evolves to provide greater lift capability, increased robustness for manned missions, and the capability to execute more demanding missions so must the SLS Integrated Navigation System evolved to support those missions. This paper describes the preliminary navigation systems design for the SLS Block 1B vehicle. The evolution of the navigation hard-ware and algorithms from an inertial-only navigation system for Block 1 ascent flight to a tightly coupled GPS-aided inertial navigation system for Block 1B is described. The Block 1 GN&C system has been designed to meet a LEO insertion target with a specified accuracy. The Block 1B vehicle navigation system is de-signed to support the Block 1 LEO target accuracy as well as trans-lunar or trans-planetary injection accuracy. Additionally, the Block 1B vehicle is designed to support human exploration and thus is designed to minimize the probability of Loss of Crew (LOC) through high-quality inertial instruments and robust algorithm design, including Fault Detection, Isolation, and Recovery (FDIR) logic.

  13. Navigation through unknown and dynamic open spaces using topological notions

    Science.gov (United States)

    Miguel-Tomé, Sergio

    2018-04-01

    Until now, most algorithms used for navigation have had the purpose of directing system towards one point in space. However, humans communicate tasks by specifying spatial relations among elements or places. In addition, the environments in which humans develop their activities are extremely dynamic. The only option that allows for successful navigation in dynamic and unknown environments is making real-time decisions. Therefore, robots capable of collaborating closely with human beings must be able to make decisions based on the local information registered by the sensors and interpret and express spatial relations. Furthermore, when one person is asked to perform a task in an environment, this task is communicated given a category of goals so the person does not need to be supervised. Thus, two problems appear when one wants to create multifunctional robots: how to navigate in dynamic and unknown environments using spatial relations and how to accomplish this without supervision. In this article, a new architecture to address the two cited problems is presented, called the topological qualitative navigation architecture. In previous works, a qualitative heuristic called the heuristic of topological qualitative semantics (HTQS) has been developed to establish and identify spatial relations. However, that heuristic only allows for establishing one spatial relation with a specific object. In contrast, navigation requires a temporal sequence of goals with different objects. The new architecture attains continuous generation of goals and resolves them using HTQS. Thus, the new architecture achieves autonomous navigation in dynamic or unknown open environments.

  14. Geographos asteroid flyby and autonomous navigation study

    Energy Technology Data Exchange (ETDEWEB)

    Ng, L.C.; Pines, D.J. [Lawrence Livermore National Lab., CA (United States); Patz, B.J.; Perron, D.C. [Coleman Research Corp., Orlando, FL (United States)

    1993-02-22

    Deep Space Program Science Experiment (DSPSE), also known as Clementine, is a collection of science experiments conducted in near-earth with the goal of demonstrating Strategic Defense Initiative Office (SDIO) developed technologies. The 785 lb (fully fueled) spacecraft will be launched into low Earth orbit in February 1994 together with a Star 37 solid kick motor and interstage. After orbit circulation using Clementine`s 110 lb Delta-V thruster, the Star 37 will execute a trans-lunar injection burn that will send the spacecraft toward lunar obit. The 110-lb will then be used in a sequence of burns to insert Clementine into a trimmed, polar orbit around the moon. After a two month moon mapping mission, Clementine will execute burns to leave lunar orbit, sling-shot around Earth, and flyby the moon on a 9.4 million km journey toward the asteroid Geographos. After about three months in transit, Clementine will attempt a flyby with a closest point of approach of 100 km from the asteroid on August 31, 1994. During its approach to Geographos, Clementine will be tracked by the Deep Space Network (DSN) and receive guidance updates. The last update and correction burn will occur about one day out of the flyby. Multiple experiments will be performed at key events during the mission that utilize Clementine`s SDIO-derived resources, including its Star Trackers, UV/Vis camera, infrared sensors (NWIR and LWIR), and high resolution laser radar (HIRes/LIDAR). In addition to the evaluation of SDIO algorithms and sensors, high resolution imagery will be obtained while the spacecraft is in Earth orbit, lunar obit and during the Geographos flyby. This paper describes the results of a study on the precision guidance, navigation, and intercept strategy for the flyby mission.

  15. Cassini-Huygens maneuver automation for navigation

    Science.gov (United States)

    Goodson, Troy; Attiyah, Amy; Buffington, Brent; Hahn, Yungsun; Pojman, Joan; Stavert, Bob; Strange, Nathan; Stumpf, Paul; Wagner, Sean; Wolff, Peter; hide

    2006-01-01

    Many times during the Cassini-Huygens mission to Saturn, propulsive maneuvers must be spaced so closely together that there isn't enough time or workforce to execute the maneuver-related software manually, one subsystem at a time. Automation is required. Automating the maneuver design process has involved close cooperation between teams. We present the contribution from the Navigation system. In scope, this includes trajectory propagation and search, generation of ephemerides, general tasks such as email notification and file transfer, and presentation materials. The software has been used to help understand maneuver optimization results, Huygens probe delivery statistics, and Saturn ring-plane crossing geometry. The Maneuver Automation Software (MAS), developed for the Cassini-Huygens program enables frequent maneuvers by handling mundane tasks such as creation of deliverable files, file delivery, generation and transmission of email announcements, generation of presentation material and other supporting documentation. By hand, these tasks took up hours, if not days, of work for each maneuver. Automated, these tasks may be completed in under an hour. During the cruise trajectory the spacing of maneuvers was such that development of a maneuver design could span about a month, involving several other processes in addition to that described, above. Often, about the last five days of this process covered the generation of a final design using an updated orbit-determination estimate. To support the tour trajectory, the orbit determination data cut-off of five days before the maneuver needed to be reduced to approximately one day and the whole maneuver development process needed to be reduced to less than a week..

  16. Interactive navigation-guided ophthalmic plastic surgery: navigation enabling of telescopes and their use in endoscopic lacrimal surgeries

    Directory of Open Access Journals (Sweden)

    Ali MJ

    2016-11-01

    Full Text Available Mohammad Javed Ali,1 Swati Singh,1 Milind N Naik,1 Swathi Kaliki,2 Tarjani Vivek Dave1 1The Institute of Dacryology, 2The Operation Eyesight Universal Institute for Eye Cancer, L.V. Prasad Eye Institute, Hyderabad, India Purpose: The aims of this study were to report the preliminary experience of using telescopes, which were enabled for navigation guidance, and their utility in complex endoscopic lacrimal surgeries. Methods: Navigation enabling of the telescope was achieved by using the AxiEM™ malleable neuronavigation shunt stylet. Image-guided dacryolocalization was performed in five patients using the intraoperative image-guided StealthStation™ system in the electromagnetic mode. The “look ahead” protocol software was used to assist the surgeon in assessing the intraoperative geometric location of the endoscope and what lies ahead in real time. All patients underwent navigation-guided powered endoscopic dacryocystorhinostomy. The utility of uninterrupted navigation guidance throughout the surgery with the endoscope as the navigating tool was noted. Results: Intraoperative geometric localization of the lacrimal sac and the nasolacrimal duct could be easily deciphered. Constant orientation of the lacrimal drainage system and the peri-lacrimal anatomy was possible without the need for repeated point localizations throughout the surgery. The “look ahead” features could accurately alert the surgeon of anatomical structures that exists at 5, 10 and 15 mm in front of the endoscope. Good securing of the shunt stylet with the telescope was found to be essential for constant and accurate navigation. Conclusion: Navigation-enabled endoscopes provide the surgeon with the advantage of sustained stereotactic anatomical awareness at all times during the surgery. Keywords: telescope, endoscope, image guidance, navigation, lacrimal surgery, powered endoscopic DCR

  17. Ground-Based Global Navigation Satellite System GLONASS (GLObal NAvigation Satellite System) Combined Broadcast Ephemeris Data (daily files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) GLONASS Combined Broadcast Ephemeris Data (daily files of all distinct navigation...

  18. Letting in-vehicle navigation lead the way: Older drivers' perceptions of and ability to follow a GPS navigation system.

    Science.gov (United States)

    Stinchcombe, Arne; Gagnon, Sylvain; Kateb, Matthew; Curtis, Meredith; Porter, Michelle M; Polgar, Jan; Bédard, Michel

    2017-09-01

    In-vehicle navigation systems have the potential to simplify the driving task by reducing the drivers' need to engage in wayfinding, especially in unfamiliar environments. This study sought to characterize older drivers' overall assessment of using in-vehicle GPS technology as part of a research study and to explore whether the use of this technology has an impact on participants' driving behaviour. Forty-seven older drivers completed an on-road evaluation where directions were provided by an in-vehicle GPS navigation system and their behaviour was recorded using video technology. They later completed a questionnaire to assess their perception of the navigation system. After the study, participants were grouped based on whether they were able to accurately follow the instructions provided by the navigation system. The results indicated that most drivers were satisfied with the navigation technology and found the directions it provided to be clear. There were no statistically significant differences in the number of on-road errors committed by drivers who did not follow the directions from the navigation system in comparison to drivers who did follow the directions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Powertrain definitions for Opel's brand sound considering the vehicle portfolio; Gestaltung des Powertrains fuer den Opel-Brand-Sound unter Beruecksichtigung der unterschiedlichen Positionierung der Fahrzeugpalette

    Energy Technology Data Exchange (ETDEWEB)

    Bernhard, U.; Herrmann, G.; Schmidt, G.O. [Adam Opel AG, Ruesselsheim (Germany)

    2002-07-01

    The change of value orientation in Western Europe lead to an increase of emotions buying a car. In addition to classic factors like design, today the carmakers use elements of emotion like brand sound to inspire the customers. On the one hand the job of the acoustic engineers is to meet the acoustic expectations depending on driving conditions. On the other hand there are to develop both combining elements over the whole portfolio and elements which allow a defined position of a carline-powertrain combination in the market. (orig.) [German] Im Zuge der Wandlung der westlichen Gesellschaften spielen Emotionen beim Kauf eines Automobils eine immer staerkere Rolle. Zur Unterstuetzung klassischer Mittel wie dem Design werden heute weitere emotionalisierende Elemente zur Begeisterung der Kunden eingesetzt, unter anderem auch das Klangbild eines Fahrzeugs. Dabei liegt die Aufgabe einerseits darin, der unterschiedlichen Erwartungshaltung in Abhaengigkeit vom Fahrzustand des Fahrzeugs gerecht zu werden. Andererseits die Gestaltung des Klangbildes so durchzufuehren, dass innerhalb des Portfolios sowohl verbindende Elemente als markentypisch zu finden sind als auch der Marktpositionierung gerecht werdende Elemente der einzelnen Fahrzeugtypen zu generieren. (orig.)

  20. Comparison calculation/experiment on the load case ``shutdown of TH high pressure pumps under consideration of fluid structure interaction``; Vergleich Rechnung/Messung zum Lastfall ``Abschaltung der TH-Hochdruckpumpen unter Beruecksichtigung der Fluid-Struktur-Wechselwirkung``

    Energy Technology Data Exchange (ETDEWEB)

    Erath, W.; Nowotny, B.; Maetz, J. [KED, Rodenbach (Germany)

    1998-11-01

    Measurements of an experiment in a pipe system with pump shutdown and valve closing have been performed in the nuclear power plant KRB II. Comparative calculations of fluid and structure including interaction show an excellent agreement with the measured results. Theory and implementation of the fluid/structure interaction and the results of the comparison are described. It turns out that the consideration of the fluid/structure interaction is mostly a significant increase of the effective structural damping. (orig.) [Deutsch] Es wurden Messungen am nuklearen Nachkuehlsystem des Kernkraftwerks Gundremmingen (KRB II) bei einem Versuche mit Pumpenabschalten und Ventilschliessen durchgefuehrt. Vergleichsrechnungen der Fluid-Strukturdynamik unter echter Beruecksichtigung der Wechselwirkung ergaben eine ausgezeichnete Uebereinstimmung der Rechnung mit den Messungen. Es werden Theorie und Implementierung der Koppelung der Fluid- und Struktur-Berechnungen sowie die Vergleiche von Messung und Rechnung beschrieben. Es ergibt sich, dass die Beruecksichtigung der Wechselwirkung notwendig ist zur genaueren Berechnung von `weichen` Rohrleitungsystemen. Eine wichtige Folge der Wechselwirkung ist meist eine deutliche Erhoehung der effektiven Strukturdaempfung. (orig.)

  1. Optimisation of a truck diesel engine with a view to environmental pollution. Interstate research project. Final report; Optimierung eines mit Rapsoelmethylester betriebenen Nutzfahrzeug-Dieselmotors unter besonderer Beruecksichtigung der Umweltvertraeglichkeit. Laenderuebergreifendes Verbundforschungsvorhaben. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hattingen, U.; Adt, H.U. [Kaiserslautern Univ. (Germany). Arbeitsgruppe Verbrennungskraftmaschinen; Sauer, B.; Ruhl, C.; Huber, M. [Kaiserslautern Univ. (Germany). Lehrstuhl fuer Maschinenelemente und Getriebetechnik; Regitz, M.; Weber, B. [Kaiserslautern Univ. (Germany). Lehrstuhl fuer Organische Chemie; Bereswill, S. [Motoren-Werke Mannheim AG (Germany); Luther, R.; Acker, I. [Fuchs Mineraloelwerke GmbH, Eschweiler (Germany)

    1999-05-01

    Detailed rheological analyses of lubricants are carried out with a view to the temperature dependence of the viscosity functions. Two sliding bearings of similar design but made of different materials were tested on a test bench after lubrication with an oil of the SAE grade 10W-40 diluted with increasing concentrations of rapeseed oil methyl ester. The results were analyzed and compared with the bearings characteristics calculated according to DIN 31652. The measurements were found to be in good agreement with calculated values. [German] Im Rahmen dieses Projektes wurden zunaechst detaillierte rheologische Untersuchungen der Schmierstoffeigenschaften unter Beruecksichtigung der Schmieroelverduennung mit RME und DK vorgenommen und die Temperaturabhaengigkeit der jeweiligen Viskositaetsfunktion ermittelt. Auf einem geeigneten Gleitlagerpruefstand wurden zwei bezueglich der Motorenhauptlager geometrisch aehnliche Lager unterschiedlichen Werkstoffes untersucht. Die Schmierung erfolgte dabei mit einem Motorenoel der SAE-Klasse 10W-40, welches zuvor jeweils mit einem im Verlauf der Versuchsreihe ansteigenden Anteil an Rapsoelmethylester verduennt wurde. Die Messergebnisse wurden ausgewertet und den nach DIN 31652 berechneten Lagerkennzahlen gegenuebergestellt. Danach ergeben sich fuer die gemessenen Lagerkenngroessen qualitativ aehnliche Abhaengigkeiten von der Schmieroelverduennung wie berechnet. (orig.)

  2. Gender differences in navigational memory: pilots vs. nonpilots.

    Science.gov (United States)

    Verde, Paola; Piccardi, Laura; Bianchini, Filippo; Guariglia, Cecilia; Carrozzo, Paolo; Morgagni, Fabio; Boccia, Maddalena; Di Fiore, Giacomo; Tomao, Enrico

    2015-02-01

    The coding of space as near and far is not only determined by arm-reaching distance, but is also dependent on how the brain represents the extension of the body space. Recent reports suggest that the dissociation between reaching and navigational space is not limited to perception and action but also involves memory systems. It has been reported that gender differences emerged only in adverse learning conditions that required strong spatial ability. In this study we investigated navigational versus reaching memory in air force pilots and a control group without flight experience. We took into account temporal duration (working memory and long-term memory) and focused on working memory, which is considered critical in the gender differences literature. We found no gender effects or flight hour effects in pilots but observed gender effects in working memory (but not in learning and delayed recall) in the nonpilot population (Women's mean = 5.33; SD= 0.90; Men's mean = 5.54; SD= 0.90). We also observed a difference between pilots and nonpilots in the maintenance of on-line reaching information: pilots (mean = 5.85; SD=0.76) were more efficient than nonpilots (mean = 5.21; SD=0.83) and managed this type of information similarly to that concerning navigational space. In the navigational learning phase they also showed better navigational memory (mean = 137.83; SD=5.81) than nonpilots (mean = 126.96; SD=15.81) and were significantly more proficient than the latter group. There is no gender difference in a population of pilots in terms of navigational abilities, while it emerges in a control group without flight experience. We found also that pilots performed better than nonpilots. This study suggests that once selected, male and female pilots do not differ from each other in visuo-spatial abilities and spatial navigation.

  3. National Positioning, Navigation, and Timing Architecture Study

    Science.gov (United States)

    van Dyke, K.; Vicario, J.; Hothem, L.

    2007-12-01

    The purpose of the National Positioning, Navigation and Timing (PNT) Architecture effort is to help guide future PNT system-of-systems investment and implementation decisions. The Assistant Secretary of Defense for Networks and Information Integration and the Under Secretary of Transportation for Policy sponsored a National PNT Architecture study to provide more effective and efficient PNT capabilities focused on the 2025 timeframe and an evolutionary path for government provided systems and services. U.S. Space-Based PNT Policy states that the U.S. must continue to improve and maintain GPS, augmentations to GPS, and back-up capabilities to meet growing national, homeland, and economic security needs. PNT touches almost every aspect of people´s lives today. PNT is essential for Defense and Civilian applications ranging from the Department of Defense´s Joint network centric and precision operations to the transportation and telecommunications sectors, improving efficiency, increasing safety, and being more productive. Absence of an approved PNT architecture results in uncoordinated research efforts, lack of clear developmental paths, potentially wasteful procurements and inefficient deployment of PNT resources. The national PNT architecture effort evaluated alternative future mixes of global (space and non space-based) and regional PNT solutions, PNT augmentations, and autonomous PNT capabilities to address priorities identified in the DoD PNT Joint Capabilities Document (JCD) and civil equivalents. The path to achieving the Should-Be architecture is described by the National PNT Architecture's Guiding Principles, representing an overarching Vision of the US' role in PNT, an architectural Strategy to fulfill that Vision, and four Vectors which support the Strategy. The National PNT Architecture effort has developed nineteen recommendations. Five foundational recommendations are tied directly to the Strategy while the remaining fourteen individually support one of

  4. AUTOMATIC RECOGNITION OF INDOOR NAVIGATION ELEMENTS FROM KINECT POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    L. Zeng

    2017-09-01

    Full Text Available This paper realizes automatically the navigating elements defined by indoorGML data standard – door, stairway and wall. The data used is indoor 3D point cloud collected by Kinect v2 launched in 2011 through the means of ORB-SLAM. By contrast, it is cheaper and more convenient than lidar, but the point clouds also have the problem of noise, registration error and large data volume. Hence, we adopt a shape descriptor – histogram of distances between two randomly chosen points, proposed by Osada and merges with other descriptor – in conjunction with random forest classifier to recognize the navigation elements (door, stairway and wall from Kinect point clouds. This research acquires navigation elements and their 3-d location information from each single data frame through segmentation of point clouds, boundary extraction, feature calculation and classification. Finally, this paper utilizes the acquired navigation elements and their information to generate the state data of the indoor navigation module automatically. The experimental results demonstrate a high recognition accuracy of the proposed method.

  5. Automatic Recognition of Indoor Navigation Elements from Kinect Point Clouds

    Science.gov (United States)

    Zeng, L.; Kang, Z.

    2017-09-01

    This paper realizes automatically the navigating elements defined by indoorGML data standard - door, stairway and wall. The data used is indoor 3D point cloud collected by Kinect v2 launched in 2011 through the means of ORB-SLAM. By contrast, it is cheaper and more convenient than lidar, but the point clouds also have the problem of noise, registration error and large data volume. Hence, we adopt a shape descriptor - histogram of distances between two randomly chosen points, proposed by Osada and merges with other descriptor - in conjunction with random forest classifier to recognize the navigation elements (door, stairway and wall) from Kinect point clouds. This research acquires navigation elements and their 3-d location information from each single data frame through segmentation of point clouds, boundary extraction, feature calculation and classification. Finally, this paper utilizes the acquired navigation elements and their information to generate the state data of the indoor navigation module automatically. The experimental results demonstrate a high recognition accuracy of the proposed method.

  6. Advanced Navigation Aids System based on Augmented Reality

    Directory of Open Access Journals (Sweden)

    Jaeyong OH

    2016-12-01

    Full Text Available Many maritime accidents have been caused by human-error including such things as inadequate watch keeping and/or mistakes in ship handling. Also, new navigational equipment has been developed using Information Technology (IT technology to provide various kinds of information for safe navigation. Despite these efforts, the reduction of maritime accidents has not occurred to the degree expected because, navigational equipment provides too much information, and this information is not well organized, such that users feel it to be complicated rather than helpful. In this point of view, the method of representation of navigational information is more important than the quantity of that information and research is required on the representation of information to make that information more easily understood and to allow decisions to be made correctly and promptly. In this paper, we adopt Augmented Reality (AR technologies for the representation of information. AR is a 3D computer graphics technology that blends virtual reality and the real world. Recently, this technology has been widely applied in our daily lives because it can provide information more effectively to users. Therefore, we propose a new concept, a navigational system based on AR technology; we review experimental results from a ship-handling simulator and from an open sea test to verify the efficiency of the proposed system.

  7. Comparison of three filters in asteroid-based autonomous navigation

    International Nuclear Information System (INIS)

    Cui Wen; Zhu Kai-Jian

    2014-01-01

    At present, optical autonomous navigation has become a key technology in deep space exploration programs. Recent studies focus on the problem of orbit determination using autonomous navigation, and the choice of filter is one of the main issues. To prepare for a possible exploration mission to Mars, the primary emphasis of this paper is to evaluate the capability of three filters, the extended Kalman filter (EKF), unscented Kalman filter (UKF) and weighted least-squares (WLS) algorithm, which have different initial states during the cruise phase. One initial state is assumed to have high accuracy with the support of ground tracking when autonomous navigation is operating; for the other state, errors are set to be large without this support. In addition, the method of selecting asteroids that can be used for navigation from known lists of asteroids to form a sequence is also presented in this study. The simulation results show that WLS and UKF should be the first choice for optical autonomous navigation during the cruise phase to Mars

  8. Evaluation of a Hospital-Based Pneumonia Nurse Navigator Program.

    Science.gov (United States)

    Seldon, Lisa E; McDonough, Kelly; Turner, Barbara; Simmons, Leigh Ann

    2016-12-01

    The aim of this study is to evaluate the effectiveness of a hospital-based pneumonia nurse navigator program. This study used a retrospective, formative evaluation. Data of patients admitted from January 2012 through December 2014 to a large community hospital with a primary or secondary diagnosis of pneumonia, excluding aspiration pneumonia, were used. Data included patient demographics, diagnoses, insurance coverage, core measures, average length of stay (ALOS), disposition, readmission rate, financial outcomes, and patient barriers to care were collected. Descriptive statistics and parametric testing were used to analyze data. Core measure performance was sustained at the 90th percentile 2 years after the implementation of the navigator program. The ALOS did not decrease to established benchmarks; however, the SD for ALOS decreased by nearly half after implementation of the navigator program, suggesting the program decreased the number and length of extended stays. Charges per case decreased by 21% from 2012 to 2014. Variable costs decreased by 4% over a 2-year period, which increased net profit per case by 5%. Average readmission payments increased by 8% from 2012 to 2014, and the net revenue per case increased by 8.3%. The pneumonia nurse navigator program may improve core measures, reduce ALOS, and increase net revenue. Future evaluations are necessary to substantiate these findings and optimize the cost and quality performance of navigator programs.

  9. Awake craniotomy using electromagnetic navigation technology without rigid pin fixation.

    Science.gov (United States)

    Morsy, Ahmed A; Ng, Wai Hoe

    2015-11-01

    We report our institutional experience using an electromagnetic navigation system, without rigid head fixation, for awake craniotomy patients. The StealthStation® S7 AxiEM™ navigation system (Medtronic, Inc.) was used for this technique. Detailed preoperative clinical and neuropsychological evaluations, patient education and contrast-enhanced MRI (thickness 1.5mm) were performed for each patient. The AxiEM Mobile Emitter was typically placed in a holder, which was mounted to the operating room table, and a non-invasive patient tracker was used as the patient reference device. A monitored conscious sedation technique was used in all awake craniotomy patients, and the AxiEM Navigation Pointer was used for navigation during the procedure. This offers the same accuracy as optical navigation, but without head pin fixation or interference with intraoperative neurophysiological techniques and surgical instruments. The application of the electromagnetic neuronavigation technology without rigid head fixation during an awake craniotomy is accurate, and offers superior patient comfort. It is recommended as an effective adjunctive technique for the conduct of awake surgery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Absolute Navigation Information Estimation for Micro Planetary Rovers

    Directory of Open Access Journals (Sweden)

    Muhammad Ilyas

    2016-03-01

    Full Text Available This paper provides algorithms to estimate absolute navigation information, e.g., absolute attitude and position, by using low power, weight and volume Microelectromechanical Systems-type (MEMS sensors that are suitable for micro planetary rovers. Planetary rovers appear to be easily navigable robots due to their extreme slow speed and rotation but, unfortunately, the sensor suites available for terrestrial robots are not always available for planetary rover navigation. This makes them difficult to navigate in a completely unexplored, harsh and complex environment. Whereas the relative attitude and position can be tracked in a similar way as for ground robots, absolute navigation information, unlike in terrestrial applications, is difficult to obtain for a remote celestial body, such as Mars or the Moon. In this paper, an algorithm called the EASI algorithm (Estimation of Attitude using Sun sensor and Inclinometer is presented to estimate the absolute attitude using a MEMS-type sun sensor and inclinometer, only. Moreover, the output of the EASI algorithm is fused with MEMS gyros to produce more accurate and reliable attitude estimates. An absolute position estimation algorithm has also been presented based on these on-board sensors. Experimental results demonstrate the viability of the proposed algorithms and the sensor suite for low-cost and low-weight micro planetary rovers.

  11. Aging specifically impairs switching to an allocentric navigational strategy.

    Science.gov (United States)

    Harris, Mathew A; Wiener, Jan M; Wolbers, Thomas

    2012-01-01

    Navigation abilities decline with age, partly due to deficits in numerous component processes. Impaired switching between these various processes (i.e., switching navigational strategies) is also likely to contribute to age-related navigational impairments. We tested young and old participants on a virtual plus maze task (VPM), expecting older participants to exhibit a specific strategy switching deficit, despite unimpaired learning of allocentric (place) and egocentric (response) strategies following reversals within each strategy. Our initial results suggested that older participants performed worse during place trial blocks but not response trial blocks, as well as in trial blocks following a strategy switch but not those following a reversal. However, we then separated trial blocks by both strategy and change type, revealing that these initial results were due to a more specific deficit in switching to the place strategy. Place reversals and switches to response, as well as response reversals, were unaffected. We argue that this specific "switch-to-place" deficit could account for apparent impairments in both navigational strategy switching and allocentric processing and contributes more generally to age-related decline in navigation.

  12. Unified Simulation and Analysis Framework for Deep Space Navigation Design

    Science.gov (United States)

    Anzalone, Evan; Chuang, Jason; Olsen, Carrie

    2013-01-01

    As the technology that enables advanced deep space autonomous navigation continues to develop and the requirements for such capability continues to grow, there is a clear need for a modular expandable simulation framework. This tool's purpose is to address multiple measurement and information sources in order to capture system capability. This is needed to analyze the capability of competing navigation systems as well as to develop system requirements, in order to determine its effect on the sizing of the integrated vehicle. The development for such a framework is built upon Model-Based Systems Engineering techniques to capture the architecture of the navigation system and possible state measurements and observations to feed into the simulation implementation structure. These models also allow a common environment for the capture of an increasingly complex operational architecture, involving multiple spacecraft, ground stations, and communication networks. In order to address these architectural developments, a framework of agent-based modules is implemented to capture the independent operations of individual spacecraft as well as the network interactions amongst spacecraft. This paper describes the development of this framework, and the modeling processes used to capture a deep space navigation system. Additionally, a sample implementation describing a concept of network-based navigation utilizing digitally transmitted data packets is described in detail. This developed package shows the capability of the modeling framework, including its modularity, analysis capabilities, and its unification back to the overall system requirements and definition.

  13. PROBLEMS OF SEA-GOING NAVIGATION IN KERCI STRAIT

    Directory of Open Access Journals (Sweden)

    M. ŞTEFAN

    2011-03-01

    Full Text Available Kerch Strait was the main passage between the Azov Sea and the Black Sea.The passage of ships through the strait is hampered by several physical and geographical factors: emerged and submerged morphology, the climatic and hydrological parameters. As a result of the extremely low depths of the strait, for the safety of navigation, authorities have been forced to dredge a canal for passage of the vessels with a medium draft, to make a properly hydrographical develop¬ment of the fairway and of the shores, and to establish a favorable anchoring area etc. Ice, which occurs in winter, makes the navigation very difficult, which takes place in convoys, preceded by ice breakers. Fog, frequent in the transitional seasons, hampered navigation; many accidents happened because of this inconvenience. Most accidents due to weather conditions (fog, wind are specific to smaller vessels, sea-river type, which are sailing in the area and which, due to their construction, are not able to deal with exceptional weather conditions at sea. The existence of surface currents, with the dominant direction north-south, from the Sea of Azov to the Black Sea, affects navigation only around the heads where cau¬ses circular currents. In this case are affected only pleasure boats and low powered vessel. With all these impediments to navigation, the Kerch Strait is an important waterway, especially for the countries bordering the Sea of Azov: Ukraine and the Russian Federation, and also for the countries from the Black Sea basin.

  14. Neural-network-based depth computation for blind navigation

    Science.gov (United States)

    Wong, Farrah; Nagarajan, Ramachandran R.; Yaacob, Sazali

    2004-12-01

    A research undertaken to help blind people to navigate autonomously or with minimum assistance is termed as "Blind Navigation". In this research, an aid that could help blind people in their navigation is proposed. Distance serves as an important clue during our navigation. A stereovision navigation aid implemented with two digital video cameras that are spaced apart and fixed on a headgear to obtain the distance information is presented. In this paper, a neural network methodology is used to obtain the required parameters of the camera which is known as camera calibration. These parameters are not known but obtained by adjusting the weights in the network. The inputs to the network consist of the matching features in the stereo pair images. A back propagation network with 16-input neurons, 3 hidden neurons and 1 output neuron, which gives depth, is created. The distance information is incorporated into the final processed image as four gray levels such as white, light gray, dark gray and black. Preliminary results have shown that the percentage errors fall below 10%. It is envisaged that the distance provided by neural network shall enable blind individuals to go near and pick up an object of interest.

  15. INDOOR POSITIONING AND NAVIGATION BASED ON CONTROL SPHERECAL PANORAMIC IMAGES

    Directory of Open Access Journals (Sweden)

    T.-C. Huang

    2016-06-01

    Full Text Available Continuous indoor and outdoor positioning and navigation is the goal to achieve in the field of mobile mapping technology. However, accuracy of positioning and navigation will be largely degraded in indoor or occluded areas, due to receiving weak or less GNSS signals. Targeting the need of high accuracy indoor and outdoor positioning and navigation for mobile mapping applications, the objective of this study is to develop a novel method of indoor positioning and navigation with the use of spherical panoramic image (SPI. Two steps are planned in the technology roadmap. First, establishing a control SPI database that contains a good number of well-distributed control SPIs pre-acquired in the target space. A control SPI means an SPI with known exterior orientation parameters, which can be solved with a network bundle adjustment of SPIs. Having a control SPI database, the target space will be ready to provide the service of positioning and navigation. Secondly, the position and orientation of a newly taken SPI can be solved by using overlapped SPIs searched from the control SPI database. The method of matching SPIs and finding conjugate image features will be developed and tested. Two experiments will be planned and conducted in this paper to test the feasibility and validate the test results of the proposed methods. Analysis of appropriate number and distribution of needed control SPIs will also be included in the experiments with respect to different test cases.

  16. Effect of electromagnetic navigated ventriculoperitoneal shunt placement on failure rates.

    Science.gov (United States)

    Jung, Nayoung; Kim, Dongwon

    2013-03-01

    To evaluate the effect of electromagnetic (EM) navigation system on ventriculoperitoneal (VP) shunt failure rate through comparing the result of standard shunt placement. All patients undergoing VP shunt from October 2007 to September 2010 were included in this retrospective study. The first group received shunt surgery using EM navigation. The second group had catheters inserted using manual method with anatomical landmark. The relationship between proximal catheter position and shunt revision rate was evaluated using postoperative computed tomography by a 3-point scale. 1) Grade I; optimal position free-floating in cerebrospinal fluid, 2) Grade II; touching choroid or ventricular wall, 3) Grade III; tip within parenchyma. A total of 72 patients were participated, 27 with EM navigated shunts and 45 with standard shunts. Grade I was found in 25 patients from group 1 and 32 patients from group 2. Only 2 patients without use of navigation belonged to grade III. Proximal obstruction took place 7% in grade I, 15% in grade II and 100% in grade III. Shunt revision occurred in 11% of group 1 and 31% of group 2. Compared in terms of proximal catheter position, there was growing trend of revision rate according to increase of grade on each group. Although infection rate was similar between both groups, the result had no statistical meaning (p=0.905, chi-square test). The use of EM navigation in routine shunt surgery can eliminate poor shunt placement resulting in a dramatic reduction in failure rates.

  17. Structured Kernel Subspace Learning for Autonomous Robot Navigation.

    Science.gov (United States)

    Kim, Eunwoo; Choi, Sungjoon; Oh, Songhwai

    2018-02-14

    This paper considers two important problems for autonomous robot navigation in a dynamic environment, where the goal is to predict pedestrian motion and control a robot with the prediction for safe navigation. While there are several methods for predicting the motion of a pedestrian and controlling a robot to avoid incoming pedestrians, it is still difficult to safely navigate in a dynamic environment due to challenges, such as the varying quality and complexity of training data with unwanted noises. This paper addresses these challenges simultaneously by proposing a robust kernel subspace learning algorithm based on the recent advances in nuclear-norm and l 1 -norm minimization. We model the motion of a pedestrian and the robot controller using Gaussian processes. The proposed method efficiently approximates a kernel matrix used in Gaussian process regression by learning low-rank structured matrix (with symmetric positive semi-definiteness) to find an orthogonal basis, which eliminates the effects of erroneous and inconsistent data. Based on structured kernel subspace learning, we propose a robust motion model and motion controller for safe navigation in dynamic environments. We evaluate the proposed robust kernel learning in various tasks, including regression, motion prediction, and motion control problems, and demonstrate that the proposed learning-based systems are robust against outliers and outperform existing regression and navigation methods.

  18. Spatial and temporal aspects of navigation in two neurological patients.

    Science.gov (United States)

    van der Ham, Ineke J M; van Zandvoort, Martine J E; Meilinger, Tobias; Bosch, Sander E; Kant, Neeltje; Postma, Albert

    2010-07-14

    We present two cases (A.C. and W.J.) with navigation problems resulting from parieto-occipital right hemisphere damage. For both the cases, performance on the neuropsychological tests did not indicate specific impairments in spatial processing, despite severe subjective complaints of spatial disorientation. Various aspects of navigation were tested in a new virtual reality task, the Virtual Tübingen task. A double dissociation between spatial and temporal deficits was found; A.C. was impaired in route ordering, a temporal test, whereas W.J. was impaired in scene recognition and route continuation, which are spatial in nature. These findings offer important insights in the functional and neural architecture of navigation.

  19. Collaborative filtering to improve navigation of large radiology knowledge resources.

    Science.gov (United States)

    Kahn, Charles E

    2005-06-01

    Collaborative filtering is a knowledge-discovery technique that can help guide readers to items of potential interest based on the experience of prior users. This study sought to determine the impact of collaborative filtering on navigation of a large, Web-based radiology knowledge resource. Collaborative filtering was applied to a collection of 1,168 radiology hypertext documents available via the Internet. An item-based collaborative filtering algorithm identified each document's six most closely related documents based on 248,304 page views in an 18-day period. Documents were amended to include links to their related documents, and use was analyzed over the next 5 days. The mean number of documents viewed per visit increased from 1.57 to 1.74 (P Collaborative filtering can increase a radiology information resource's utilization and can improve its usefulness and ease of navigation. The technique holds promise for improving navigation of large Internet-based radiology knowledge resources.

  20. Radio/FADS/IMU integrated navigation for Mars entry

    Science.gov (United States)

    Jiang, Xiuqiang; Li, Shuang; Huang, Xiangyu

    2018-03-01

    Supposing future orbiting and landing collaborative exploration mission as the potential project background, this paper addresses the issue of Mars entry integrated navigation using radio beacon, flush air data sensing system (FADS), and inertial measurement unit (IMU). The range and Doppler information sensed from an orbiting radio beacon, the dynamic pressure and heating data sensed from flush air data sensing system, and acceleration and attitude angular rate outputs from an inertial measurement unit are integrated in an unscented Kalman filter to perform state estimation and suppress the system and measurement noise. Computer simulations show that the proposed integrated navigation scheme can enhance the navigation accuracy, which enables precise entry guidance for the given Mars orbiting and landing collaborative exploration mission.

  1. A goggle navigation system for cancer resection surgery

    Science.gov (United States)

    Xu, Junbin; Shao, Pengfei; Yue, Ting; Zhang, Shiwu; Ding, Houzhu; Wang, Jinkun; Xu, Ronald

    2014-02-01

    We describe a portable fluorescence goggle navigation system for cancer margin assessment during oncologic surgeries. The system consists of a computer, a head mount display (HMD) device, a near infrared (NIR) CCD camera, a miniature CMOS camera, and a 780 nm laser diode excitation light source. The fluorescence and the background images of the surgical scene are acquired by the CCD camera and the CMOS camera respectively, co-registered, and displayed on the HMD device in real-time. The spatial resolution and the co-registration deviation of the goggle navigation system are evaluated quantitatively. The technical feasibility of the proposed goggle system is tested in an ex vivo tumor model. Our experiments demonstrate the feasibility of using a goggle navigation system for intraoperative margin detection and surgical guidance.

  2. Navigation in head and neck oncological surgery: an emerging concept.

    Science.gov (United States)

    Gangloff, P; Mastronicola, R; Cortese, S; Phulpin, B; Sergeant, C; Guillemin, F; Eluecque, H; Perrot, C; Dolivet, G

    2011-01-01

    Navigation surgery, initially applied in rhinology, neurosurgery and orthopaedic cases, has been developed over the last twenty years. Surgery based on computed tomography data has become increasingly important in the head and neck region. The technique for hardware fusion between RMI and computed tomography is also becoming more useful. We use such device since 2006 in head and neck carcinologic situation. Navigation allows control of the resection in order to avoid and protect the precise anatomical structures (vessels and nerves). It also guides biopsy and radiofrequency. Therefore, quality of life is much more increased and morbidity is decreased for these patients who undergo major and mutilating head and neck surgery. Here we report the results of 33 navigation procedures performed for 31 patients in our institution.

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

    DEFF Research Database (Denmark)

    Kulvicius, Tomas; Tamosiunaite, Minija; Ainge, James

    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......-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...

  4. The Judicial Regime of Danube Navigation between 1856- 1919

    Directory of Open Access Journals (Sweden)

    Constantin Tănase

    2015-08-01

    Full Text Available The basics of the judicial regime of Danube navigation, in the moern sens of the term, were inserted in the Peace Treaty in Paris, March 30, 1856, concluded at the end of Crimeea War. This judicial act of international law ended a situation in the area of the large European river where the rules were imposed by the big empires of Austria, Turkey and Russia, according to their interests. The rights and interests of the riverains such as the Romanian states, Serbia, Bulgari etc. were ignored and brutally violated. Until 1919, the European Danube Commission, institution created by the Paris Treaty, has contributed to the modernization of the lower Danube and development of navigation in this sector. This paper aims at clarifying to a certain extent the circumstances of the regulation of navigation during the reference period of time in this naval sector.

  5. Educator or Counselor? Navigating Uncertain Boundaries in the Clinical Environment.

    Science.gov (United States)

    Lane, Annette M; Corcoran, Lynn

    2016-04-01

    Nurse educators in the clinical environment experience great rewards and challenges in their work with undergraduate students. However, closely working with students can lead to the challenge of intervening with those who are emotionally distressed. How do nurse educators navigate the precarious and subtle territory between educating and counseling? This article briefly reviews how boundaries are explored in nursing. Two case studies are presented to demonstrate how nurse educators can determine when their support and education begins to move into the counseling role. Finally, future directions for nurse educators are suggested. Little research exists that examines how nurse educators navigate the boundaries between educator and counselor roles with students in clinical settings. Navigating between the educator and counselor roles with students experiencing emotional distress in clinical settings can be challenging for nurse educators. Copyright 2016, SLACK Incorporated.

  6. An Indoor Navigation System for the Visually Impaired

    Directory of Open Access Journals (Sweden)

    Luis A. Guerrero

    2012-06-01

    Full Text Available Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they involve an important deployment effort or use artifacts that are not natural for blind users. This paper presents an indoor navigation system that was designed taking into consideration usability as the quality requirement to be maximized. This solution enables one to identify the position of a person and calculates the velocity and direction of his movements. Using this information, the system determines the user’s trajectory, locates possible obstacles in that route, and offers navigation information to the user. The solution has been evaluated using two experimental scenarios. Although the results are still not enough to provide strong conclusions, they indicate that the system is suitable to guide visually impaired people through an unknown built environment.

  7. An indoor navigation system for the visually impaired.

    Science.gov (United States)

    Guerrero, Luis A; Vasquez, Francisco; Ochoa, Sergio F

    2012-01-01

    Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they involve an important deployment effort or use artifacts that are not natural for blind users. This paper presents an indoor navigation system that was designed taking into consideration usability as the quality requirement to be maximized. This solution enables one to identify the position of a person and calculates the velocity and direction of his movements. Using this information, the system determines the user's trajectory, locates possible obstacles in that route, and offers navigation information to the user. The solution has been evaluated using two experimental scenarios. Although the results are still not enough to provide strong conclusions, they indicate that the system is suitable to guide visually impaired people through an unknown built environment.

  8. 3D Reconfigurable MPSoC for Unmanned Spacecraft Navigation

    Science.gov (United States)

    Dekoulis, George

    2016-07-01

    This paper describes the design of a new lightweight spacecraft navigation system for unmanned space missions. The system addresses the demands for more efficient autonomous navigation in the near-Earth environment or deep space. The proposed instrumentation is directly suitable for unmanned systems operation and testing of new airborne prototypes for remote sensing applications. The system features a new sensor technology and significant improvements over existing solutions. Fluxgate type sensors have been traditionally used in unmanned defense systems such as target drones, guided missiles, rockets and satellites, however, the guidance sensors' configurations exhibit lower specifications than the presented solution. The current implementation is based on a recently developed material in a reengineered optimum sensor configuration for unprecedented low-power consumption. The new sensor's performance characteristics qualify it for spacecraft navigation applications. A major advantage of the system is the efficiency in redundancy reduction achieved in terms of both hardware and software requirements.

  9. Navigation studies based on the ubiquitous positioning technologies

    Science.gov (United States)

    Ye, Lei; Mi, Weijie; Wang, Defeng

    2007-11-01

    This paper summarized the nowadays positioning technologies, such as absolute positioning methods and relative positioning methods, indoor positioning and outdoor positioning, active positioning and passive positioning. Global Navigation Satellite System (GNSS) technologies were introduced as the omnipresent out-door positioning technologies, including GPS, GLONASS, Galileo and BD-1/2. After analysis of the shortcomings of GNSS, indoor positioning technologies were discussed and compared, including A-GPS, Cellular network, Infrared, Electromagnetism, Computer Vision Cognition, Embedded Pressure Sensor, Ultrasonic, RFID (Radio Frequency IDentification), Bluetooth, WLAN etc.. Then the concept and characteristics of Ubiquitous Positioning was proposed. After the ubiquitous positioning technologies contrast and selection followed by system engineering methodology, a navigation system model based on Incorporate Indoor-Outdoor Positioning Solution was proposed. And this model was simulated in the Galileo Demonstration for World Expo Shanghai project. In the conclusion, the prospects of ubiquitous positioning based navigation were shown, especially to satisfy the public location information acquiring requirement.

  10. Navigation strategies for multiple autonomous mobile robots moving in formation

    Science.gov (United States)

    Wang, P. K. C.

    1991-01-01

    The problem of deriving navigation strategies for a fleet of autonomous mobile robots moving in formation is considered. Here, each robot is represented by a particle with a spherical effective spatial domain and a specified cone of visibility. The global motion of each robot in the world space is described by the equations of motion of the robot's center of mass. First, methods for formation generation are discussed. Then, simple navigation strategies for robots moving in formation are derived. A sufficient condition for the stability of a desired formation pattern for a fleet of robots each equipped with the navigation strategy based on nearest neighbor tracking is developed. The dynamic behavior of robot fleets consisting of three or more robots moving in formation in a plane is studied by means of computer simulation.

  11. Systems and Methods for Determining Inertial Navigation System Faults

    Science.gov (United States)

    Bharadwaj, Raj Mohan (Inventor); Bageshwar, Vibhor L. (Inventor); Kim, Kyusung (Inventor)

    2017-01-01

    An inertial navigation system (INS) includes a primary inertial navigation system (INS) unit configured to receive accelerometer measurements from an accelerometer and angular velocity measurements from a gyroscope. The primary INS unit is further configured to receive global navigation satellite system (GNSS) signals from a GNSS sensor and to determine a first set of kinematic state vectors based on the accelerometer measurements, the angular velocity measurements, and the GNSS signals. The INS further includes a secondary INS unit configured to receive the accelerometer measurements and the angular velocity measurements and to determine a second set of kinematic state vectors of the vehicle based on the accelerometer measurements and the angular velocity measurements. A health management system is configured to compare the first set of kinematic state vectors and the second set of kinematic state vectors to determine faults associated with the accelerometer or the gyroscope based on the comparison.

  12. Distributed Ship Navigation Control System Based on Dual Network

    Science.gov (United States)

    Yao, Ying; Lv, Wu

    2017-10-01

    Navigation system is very important for ship’s normal running. There are a lot of devices and sensors in the navigation system to guarantee ship’s regular work. In the past, these devices and sensors were usually connected via CAN bus for high performance and reliability. However, as the development of related devices and sensors, the navigation system also needs the ability of high information throughput and remote data sharing. To meet these new requirements, we propose the communication method based on dual network which contains CAN bus and industrial Ethernet. Also, we import multiple distributed control terminals with cooperative strategy based on the idea of synchronizing the status by multicasting UDP message contained operation timestamp to make the system more efficient and reliable.

  13. A full 3D-navigation system in a suitcase.

    Science.gov (United States)

    Freysinger, W; Truppe, M J; Gunkel, A R; Thumfart, W F

    2001-01-01

    To reduce the impact of contemporary 3D-navigation systems on the environment of typical otorhinolaryngologic operating rooms, we demonstrate that a transfer of navigation software to modern high-power notebook computers is feasible and results in a practicable way to provide positional information to a surgeon intraoperatively. The ARTMA Virtual Patient System has been implemented on a Macintosh PowerBook G3 and, in connection with the Polhemus FASTRAK digitizer, provides intraoperative positional information during endoscopic endonasal surgery. Satisfactory intraoperative navigation has been realized in two- and three-dimensional medical image data sets (i.e., X-ray, ultrasound images, CT, and MR) and live video. This proof-of-concept study demonstrates that acceptable ergonomics and excellent performance of the system can be achieved with contemporary high-end notebook computers. Copyright 2001 Wiley-Liss, Inc.

  14. Oral and maxillofacial surgery with computer-assisted navigation system.

    Science.gov (United States)

    Kawachi, Homare; Kawachi, Yasuyuki; Ikeda, Chihaya; Takagi, Ryo; Katakura, Akira; Shibahara, Takahiko

    2010-01-01

    Intraoperative computer-assisted navigation has gained acceptance in maxillofacial surgery with applications in an increasing number of indications. We adapted a commercially available wireless passive marker system which allows calibration and tracking of virtually every instrument in maxillofacial surgery. Virtual computer-generated anatomical structures are displayed intraoperatively in a semi-immersive head-up display. Continuous observation of the operating field facilitated by computer assistance enables surgical navigation in accordance with the physician's preoperative plans. This case report documents the potential for augmented visualization concepts in surgical resection of tumors in the oral and maxillofacial region. We report a case of T3N2bM0 carcinoma of the maxillary gingival which was surgically resected with the assistance of the Stryker Navigation Cart System. This system was found to be useful in assisting preoperative planning and intraoperative monitoring.

  15. MONTE: the next generation of mission design and navigation software

    Science.gov (United States)

    Evans, Scott; Taber, William; Drain, Theodore; Smith, Jonathon; Wu, Hsi-Cheng; Guevara, Michelle; Sunseri, Richard; Evans, James

    2018-03-01

    The Mission analysis, Operations and Navigation Toolkit Environment (MONTE) (Sunseri et al. in NASA Tech Briefs 36(9), 2012) is an astrodynamic toolkit produced by the Mission Design and Navigation Software Group at the Jet Propulsion Laboratory. It provides a single integrated environment for all phases of deep space and Earth orbiting missions. Capabilities include: trajectory optimization and analysis, operational orbit determination, flight path control, and 2D/3D visualization. MONTE is presented to the user as an importable Python language module. This allows a simple but powerful user interface via CLUI or script. In addition, the Python interface allows MONTE to be used seamlessly with other canonical scientific programming tools such as SciPy, NumPy, and Matplotlib. MONTE is the prime operational orbit determination software for all JPL navigated missions.

  16. Absolute Navigation Performance of the Orion Exploration Fight Test 1

    Science.gov (United States)

    Zanetti, Renato; Holt, Greg; Gay, Robert; D'Souza, Christopher; Sud, Jastesh

    2016-01-01

    Launched in December 2014 atop a Delta IV Heavy from the Kennedy Space Center, the Orion vehicle's Exploration Flight Test-1 (EFT-1) successfully completed the objective to stress the system by placing the un-crewed vehicle on a high-energy parabolic trajectory replicating conditions similar to those that would be experienced when returning from an asteroid or a lunar mission. Unique challenges associated with designing the navigation system for EFT-1 are presented with an emphasis on how redundancy and robustness influenced the architecture. Two Inertial Measurement Units (IMUs), one GPS receiver and three barometric altimeters (BALTs) comprise the navigation sensor suite. The sensor data is multiplexed using conventional integration techniques and the state estimate is refined by the GPS pseudorange and deltarange measurements in an Extended Kalman Filter (EKF) that employs UDU factorization. The performance of the navigation system during flight is presented to substantiate the design.

  17. Organizations And Services In The System Of International Aviation Navigation

    Directory of Open Access Journals (Sweden)

    Alexander I. Travnikov

    2015-03-01

    Full Text Available In the present article author reveals the order of creation, structure, aims and objectives of national and international intergovernmental aeronautical organizations, governing procedure for flight operations and providing direct air traffic control over sovereign territory and abroad. In this article, author notes that in the world there are three main organizational and legal forms of air traffic control systems to ensure coordination between civil and military air navigation services (agencies. In the Russian Federation, author notes that air navigation services on behalf of the State are made by the State Corporation for Air Traffic Management that has the legal status of the commercial organization - the Federal State Unitary Enterprise. Author analyzes the work of the Organization for the Civil Air Navigation Services (CANSO, the International Federation of Air Traffic Controllers (IFATCA. During the study author also concludes that in the past decade, there is the steady trend of transferring functions of air navigation from the State to commercial organizations (joint stock companies and limited liability companies, which are financed from the funds received as payment for air traffic services. The responsibility for the improper maintenance of international air navigation, of course, is borne by the State. Author notes that regional and international intergovernmental aeronautical organizations operate in respect of all aircraft (public, civil, experimental, i.e., perform general air navigation, unlike ICAO, which takes standards and recommended practices, rules and procedures for safety and air traffic services only to civil aircraft, that does not ensure the creation of a regulatory framework for the global unification of aeronautical processes.

  18. Navigation and Robotics in Spinal Surgery: Where Are We Now?

    Science.gov (United States)

    Overley, Samuel C; Cho, Samuel K; Mehta, Ankit I; Arnold, Paul M

    2017-03-01

    Spine surgery has experienced much technological innovation over the past several decades. The field has seen advancements in operative techniques, implants and biologics, and equipment such as computer-assisted navigation and surgical robotics. With the arrival of real-time image guidance and navigation capabilities along with the computing ability to process and reconstruct these data into an interactive three-dimensional spinal "map", so too have the applications of surgical robotic technology. While spinal robotics and navigation represent promising potential for improving modern spinal surgery, it remains paramount to demonstrate its superiority as compared to traditional techniques prior to assimilation of its use amongst surgeons.The applications for intraoperative navigation and image-guided robotics have expanded to surgical resection of spinal column and intradural tumors, revision procedures on arthrodesed spines, and deformity cases with distorted anatomy. Additionally, these platforms may mitigate much of the harmful radiation exposure in minimally invasive surgery to which the patient, surgeon, and ancillary operating room staff are subjected.Spine surgery relies upon meticulous fine motor skills to manipulate neural elements and a steady hand while doing so, often exploiting small working corridors utilizing exposures that minimize collateral damage. Additionally, the procedures may be long and arduous, predisposing the surgeon to both mental and physical fatigue. In light of these characteristics, spine surgery may actually be an ideal candidate for the integration of navigation and robotic-assisted procedures.With this paper, we aim to critically evaluate the current literature and explore the options available for intraoperative navigation and robotic-assisted spine surgery. Copyright © 2016 by the Congress of Neurological Surgeons.

  19. Current Role of Computer Navigation in Total Knee Arthroplasty.

    Science.gov (United States)

    Jones, Christopher W; Jerabek, Seth A

    2018-01-31

    Computer-assisted surgical (CAS) navigation has been developed with the aim of improving the accuracy and precision of total knee arthroplasty (TKA) component positioning and therefore overall limb alignment. The historical goal of knee arthroplasty has been to restore the mechanical alignment of the lower limb by aligning the femoral and tibial components perpendicular to the mechanical axis of the femur and tibia. Despite over 4 decades of TKA component development and nearly 2 decades of interest in CAS, the fundamental question remains; does the alignment goal and/or the method of achieving that goal affect the outcome of the TKA in terms of patient-reported outcome measures and/or overall survivorship? The quest for reliable and reproducible achievement of the intraoperative alignment goal has been the primary motivator for the introduction, development, and refinement of CAS navigation. Numerous proprietary systems now exist, and rapid technological advancements in computer processing power are stimulating further development of robotic surgical systems. Three categories of CAS can be defined: image-based large-console navigation; imageless large-console navigation, and more recently, accelerometer-based handheld navigation systems have been developed. A review of the current literature demonstrates that there are enough well-designed studies to conclude that both large-console CAS and handheld navigation systems improve the accuracy and precision of component alignment in TKA. However, missing from the evidence base, other than the subgroup analysis provided by the Australian Orthopaedic Association National Joint Replacement Registry, are any conclusive demonstrations of a clinical superiority in terms of improved patient-reported outcome measures and/or decreased cumulative revision rates in the long term. Few authors would argue that accuracy of alignment is a goal to ignore; therefore, in the absence of clinical evidence, many of the arguments against

  20. THE DEVELOPMENT OF NAVIGATION SYSTEMS IN CIVIL AVIATION

    Directory of Open Access Journals (Sweden)

    Anastasiya Sergeyevna Stepanenko

    2017-01-01

    Full Text Available The article describes the history of navigation systems formation, such as "Cicada" system, which at that time could compete with the US "Transit", European, Chinese Beidou navigation system and the Japanese Quasi-Zenit.The detailed information about improving the American GPS system, launched in 1978 and working till now is provided. The characteristics of GPS-III counterpart "Transit", which became the platform for creating such modern globalnavigation systems as GLONASS and GPS. The process of implementation of the GLONASS system in civil aviation, itssegments, functions and features are considered. The stages of GLONASS satellite system orbital grouping formation are analyzed. The author draws the analogy with the American GPS system, the GALILEO system, which has a number of additional advantages, are given. The author remarks the features of the European counterpart of the GALILEO global nav- igation system. One of the goals of this system is to provide a high-precision positioning system, which Europe can rely on regardless of the Russian GLONASS system, the US - GPS and the Chinese Beidou. GALILEO offers a unique global search and rescue function called SAR, with an important feedback function. The peculiarities of Chinese scientists’ navi- gation system, the Beidou satellite system, and the Japanese global Quasi-Zenith Satellite System are described.Global navigation systems development tendencies are considered. The author dwells upon the path to world satel- lite systems globalization, a good example of which is the trend towards GLONASS and Beidou unification. Most attention was paid to the latest development of Russian scientists’ autonomous navigation system SINS 2015, which is a strap-down inertial navigation system and allows you to navigate the aircraft without being connected to a global satellite system. The ways of navigation systems further development in Russia are determined. The two naturally opposite directions are

  1. Practical indoor mobile robot navigation using hybrid maps

    DEFF Research Database (Denmark)

    Özkil, Ali Gürcan; Fan, Zhun; Xiao, Jizhong

    2011-01-01

    This paper presents a practical navigation scheme for indoor mobile robots using hybrid maps. The method makes use of metric maps for local navigation and a topological map for global path planning. Metric maps are generated as 2D occupancy grids by a range sensor to represent local information...... about partial areas. The global topological map is used to indicate the connectivity of the 'places-of-interests' in the environment and the interconnectivity of the local maps. Visual tags on the ceiling to be detected by the robot provide valuable information and contribute to reliable localization...... robot and evaluated in a hospital environment....

  2. Data Analysis Techniques for a Lunar Surface Navigation System Testbed

    Science.gov (United States)

    Chelmins, David; Sands, O. Scott; Swank, Aaron

    2011-01-01

    NASA is interested in finding new methods of surface navigation to allow astronauts to navigate on the lunar surface. In support of the Vision for Space Exploration, the NASA Glenn Research Center developed the Lunar Extra-Vehicular Activity Crewmember Location Determination System and performed testing at the Desert Research and Technology Studies event in 2009. A significant amount of sensor data was recorded during nine tests performed with six test subjects. This paper provides the procedure, formulas, and techniques for data analysis, as well as commentary on applications.

  3. The Ship Movement Trajectory Prediction Algorithm Using Navigational Data Fusion.

    Science.gov (United States)

    Borkowski, Piotr

    2017-06-20

    It is essential for the marine navigator conducting maneuvers of his ship at sea to know future positions of himself and target ships in a specific time span to effectively solve collision situations. This article presents an algorithm of ship movement trajectory prediction, which, through data fusion, takes into account measurements of the ship's current position from a number of doubled autonomous devices. This increases the reliability and accuracy of prediction. The algorithm has been implemented in NAVDEC, a navigation decision support system and practically used on board ships.

  4. Adaptive Human aware Navigation based on Motion Pattern Analysis

    DEFF Research Database (Denmark)

    Tranberg, Søren; Svenstrup, Mikael; Andersen, Hans Jørgen

    2009-01-01

    Respecting people’s social spaces is an important prerequisite for acceptable and natural robot navigation in human environments. In this paper, we describe an adaptive system for mobile robot navigation based on estimates of whether a person seeks to interact with the robot or not. The estimates...... are based on run-time motion pattern analysis compared to stored experience in a database. Using a potential field centered around the person, the robot positions itself at the most appropriate place relative to the person and the interaction status. The system is validated through qualitative tests...

  5. Street navigation using visual information on mobile phones

    DEFF Research Database (Denmark)

    Nguyen, Phuong Giang; Andersen, Hans Jørgen; Høilund, Carsten

    2010-01-01

    Applications with street navigation have been recently introduced on mobile phone devices. A major part of existing systems use integrated GPS as input for indicating the location. However, these systems often fail or make abrupt shifts in urban environment due to occlusion of satellites....... Furthermore, they only give the position of a person and not the object of his attention, which is just as important for localization based services. In this paper we introduce a system using mobile phones built-in cameras for navigation and localization using visual information in accordance with the way we...

  6. Mobile Augmented Reality enhances indoor navigation for wheelchair users

    Directory of Open Access Journals (Sweden)

    Luciene Chagas de Oliveira

    Full Text Available Introduction: Individuals with mobility impairments associated with lower limb disabilities often face enormous challenges to participate in routine activities and to move around various environments. For many, the use of wheelchairs is paramount to provide mobility and social inclusion. Nevertheless, they still face a number of challenges to properly function in our society. Among the many difficulties, one in particular stands out: navigating in complex internal environments (indoors. The main objective of this work is to propose an architecture based on Mobile Augmented Reality to support the development of indoor navigation systems dedicated to wheelchair users, that is also capable of recording CAD drawings of the buildings and dealing with accessibility issues for that population. Methods Overall, five main functional requirements are proposed: the ability to allow for indoor navigation by means of Mobile Augmented Reality techniques; the capacity to register and configure building CAD drawings and the position of fiducial markers, points of interest and obstacles to be avoided by the wheelchair user; the capacity to find the best route for wheelchair indoor navigation, taking stairs and other obstacles into account; allow for the visualization of virtual directional arrows in the smartphone displays; and incorporate touch or voice commands to interact with the application. The architecture is proposed as a combination of four layers: User interface; Control; Service; and Infrastructure. A proof-of-concept application was developed and tests were performed with disable volunteers operating manual and electric wheelchairs. Results The application was implemented in Java for the Android operational system. A local database was used to store the test building CAD drawings and the position of fiducial markers and points of interest. The Android Augmented Reality library was used to implement Augmented Reality and the Blender open source

  7. INS integrated motion analysis for autonomous vehicle navigation

    Science.gov (United States)

    Roberts, Barry; Bazakos, Mike

    1991-01-01

    The use of inertial navigation system (INS) measurements to enhance the quality and robustness of motion analysis techniques used for obstacle detection is discussed with particular reference to autonomous vehicle navigation. The approach to obstacle detection used here employs motion analysis of imagery generated by a passive sensor. Motion analysis of imagery obtained during vehicle travel is used to generate range measurements to points within the field of view of the sensor, which can then be used to provide obstacle detection. Results obtained with an INS integrated motion analysis approach are reviewed.

  8. The Ship Movement Trajectory Prediction Algorithm Using Navigational Data Fusion

    Directory of Open Access Journals (Sweden)

    Piotr Borkowski

    2017-06-01

    Full Text Available It is essential for the marine navigator conducting maneuvers of his ship at sea to know future positions of himself and target ships in a specific time span to effectively solve collision situations. This article presents an algorithm of ship movement trajectory prediction, which, through data fusion, takes into account measurements of the ship’s current position from a number of doubled autonomous devices. This increases the reliability and accuracy of prediction. The algorithm has been implemented in NAVDEC, a navigation decision support system and practically used on board ships.

  9. Navigation GPS/GLONASS in the Arctic and aurora

    Directory of Open Access Journals (Sweden)

    Chernouss S. A.

    2016-12-01

    Full Text Available The correspondence of the time-spatial distribution of the radiances of the aurora oval and time-spatial changes in the parameters of the navigation satellites' signal has been shown. For this aim the experimental data on the regional and local heterogeneities of the Total Electron Content (or TEC and the data on the signal delays in the polar ionosphere have been analyzed. Using the data concerning aurora as the indicator of disturbances in the work of the GPS/GLONASS systems can give the opportunity to increase considerably the accuracy of positioning in the Arctic with the help of satellite navigation systems (SNS.

  10. A System for Fast Navigation of Autonomous Vehicles

    Science.gov (United States)

    1991-09-01

    AD-A243 523 4, jj A System for Fast Navigation of Autonomous Vehicles Sanjiv Singh, Dai Feng, Paul Keller, Gary Shaffer, Wen Fan Shi, Dong Hun Shin...FUNDING NUMBERS A System for Fast Navigation of Autonomous Vehicles 6. AUTHOR(S) S. Singh, D. Feng, P. Keller, G. Shaffer, W.F. Shi, D.H. Shin, J. West...common in the control of autonomous vehicles to establish the necessary kinematic models but to ignore an explicit representation of the vehicle dynamics

  11. Validation of Navigation Ultrasound for Clavicular Length Measurement

    DEFF Research Database (Denmark)

    Høj, Anders Thorsmark; Villa, Chiara; Christensen, Ole M.

    2017-01-01

    interval): approximately ± 7.5 mm, Pearson's correlation R: 0.948-0.974). Navigation ultrasound can measure clavicular length with an intra-rater reliability matching that of 3-D rendered computed tomography scans and with high validity. Its use could spread to other fields requiring accurate...... of 52.5 (range: 21-78 y) were included. Navigation ultrasound exhibited high reliability (intra-class correlation coefficient: 0.942-0.997, standard error of the mean: 0.7-2.9 mm, minimal detectable change: 2.3-8.1 mm) and validity (measurement error: 1.3%-1.8%, limits of agreement (95% confidence...

  12. INFORMATION AS AN ELEMENT OF THE NAVIGATION DECISIONMAKING PROCESS

    Directory of Open Access Journals (Sweden)

    Andrzej BANACHOWICZ

    2016-09-01

    Full Text Available The operation of vehicles (watercraft, aircraft, land-based, spacecraft, unmanned requires the use of navigation systems for their control. These systems can be characterized by varying degrees of complexity and technological advancement. However, each system has sources of information about the state (position of the navigating object, state of the environment in which the object is moving and the task to be accomplished. These components are integrated by the decision-maker (human or automated, who/which makes and implements decisions adjusted to current conditions

  13. Box jellyfish use terrestrial visual cues for navigation

    DEFF Research Database (Denmark)

    Garm, Anders; Oskarsson, Magnus; Nilsson, Dan-Eric

    2011-01-01

    been a puzzle why they need such a complex set of eyes. Here we report that medusae of the box jellyfish Tripedalia cystophora are capable of visually guided navigation in mangrove swamps using terrestrial structures seen through the water surface. They detect the mangrove canopy by an eye type...... that is specialized to peer up through the water surface and that is suspended such that it is constantly looking straight up, irrespective of the orientation of the jellyfish. The visual information is used to navigate to the preferred habitat at the edge of mangrove lagoons....

  14. Navigating a Maze with Balance Board and Wiimote

    Science.gov (United States)

    Fikkert, Wim; Hoeijmakers, Niek; van der Vet, Paul; Nijholt, Anton

    Input from the lower body in human-computer interfaces can be beneficial, enjoyable and even entertaining when users are expected to perform tasks simultaneously. Users can navigate a virtual (game) world or even an (empirical) dataset while having their hands free to issue commands. We compared the Wii Balance Board to a hand-held Wiimote for navigating a maze and found that users completed this task slower with the Balance Board. However, the Balance Board was considered more intuitive, easy to learn and ‘much fun’.

  15. Deep sea AUV navigation using multiple acoustic beacons

    Science.gov (United States)

    Ji, Da-xiong; Song, Wei; Zhao, Hong-yu; Liu, Jian

    2016-04-01

    Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles (AUVs). To estimate the vehicle position, we present an algorithm using an extended Kalman filter (EKF) to integrate dead-reckoning position with acoustic ranges from multiple beacons pre-deployed in the operating environment. Owing to high latency, variable sound speed multipath transmissions and unreliability in acoustic measurements, outlier recognition techniques are proposed as well. The navigation algorithm has been tested by the recorded data of deep sea AUV during field operations in a variety of environments. Our results show the improved performance over prior techniques based on position computation.

  16. Paediatric patient navigation models of care in Canada: An environmental scan.

    Science.gov (United States)

    Luke, Alison; Doucet, Shelley; Azar, Rima

    2018-05-01

    (1) To provide other organizations with useful information when implementing paediatric navigation programs and (2) to inform the implementation of a navigation care centre in New Brunswick for children with complex health conditions. This environmental scan consisted of a literature review of published and grey literature for paediatric patient navigation programs across Canada. Additional programs were found following discussions with program coordinators and navigators. Interviews were conducted with key staff from each program and included questions related to patient condition; target population and location; method delivery; navigator background; and navigator roles. Data analysis included analysis of interviews and identification of common themes across the different programs. We interviewed staff from 19 paediatric navigation programs across Canada. Programs varied across a number of different themes, including: condition and disease type, program location (e.g., hospital or clinic), navigator background (e.g., registered nurse or peer/lay navigator) and method of delivery (e.g., phone or face-to-face). Overall, navigator roles are similar across all programs, including advocacy, education, support and assistance in accessing resources from both within and outside the health care system. This scan offers a road map of Canadian paediatric navigation programs. Knowledge learned from this scan will inform stakeholders who are either involved in the delivery of paediatric patient navigation programs or planning to implement such a program. Specifically, our scan informed the development of a navigation centre for children with complex health conditions in New Brunswick.

  17. A navigator-based rigid body motion correction for magnetic resonance imaging

    International Nuclear Information System (INIS)

    Ullisch, Marcus Goerge

    2012-01-01

    A novel three-dimensional navigator k-space trajectory for rigid body motion detection for Magnetic Resonance Imaging (MRI) - the Lissajous navigator - was developed and quantitatively compared to the existing spherical navigator trajectory [1]. The spherical navigator cannot sample the complete spherical surface due to slew rate limitations of the scanner hardware. By utilizing a two dimensional Lissajous figure which is projected onto the spherical surface, the Lissajous navigator overcomes this limitation. The complete sampling of the sphere consequently leads to rotation estimates with higher and more isotropic accuracy. Simulations and phantom measurements were performed for both navigators. Both simulations and measurements show a significantly higher overall accuracy of the Lissajous navigator and a higher isotropy of the rotation estimates. Measured under identical conditions with identical postprocessing, the measured mean absolute error of the rotation estimates for the Lissajous navigator was 38% lower (0.3 ) than for the spherical navigator (0.5 ). The maximum error of the Lissajous navigator was reduced by 48% relative to the spherical navigator. The Lissajous navigator delivers higher accuracy of rotation estimation and a higher degree of isotropy than the spherical navigator with no evident drawbacks; these are two decisive advantages, especially for high-resolution anatomical imaging.

  18. An Effective Terrain Aided Navigation for Low-Cost Autonomous Underwater Vehicles.

    Science.gov (United States)

    Zhou, Ling; Cheng, Xianghong; Zhu, Yixian; Dai, Chenxi; Fu, Jinbo

    2017-03-25

    Terrain-aided navigation is a potentially powerful solution for obtaining submerged position fixes for autonomous underwater vehicles. The application of terrain-aided navigation with high-accuracy inertial navigation systems has demonstrated meter-level navigation accuracy in sea trials. However, available sensors may be limited depending on the type of the mission. Such limitations, especially for low-grade navigation sensors, not only degrade the accuracy of traditional navigation systems, but further impact the ability to successfully employ terrain-aided navigation. To address this problem, a tightly-coupled navigation is presented to successfully estimate the critical sensor errors by incorporating raw sensor data directly into an augmented navigation system. Furthermore, three-dimensional distance errors are calculated, providing measurement updates through the particle filter for absolute and bounded position error. The development of the terrain aided navigation system is elaborated for a vehicle equipped with a non-inertial-grade strapdown inertial navigation system, a 4-beam Doppler Velocity Log range sensor and a sonar altimeter. Using experimental data for navigation performance evaluation in areas with different terrain characteristics, the experiment results further show that the proposed method can be successfully applied to the low-cost AUVs and significantly improves navigation performance.

  19. A navigator-based rigid body motion correction for magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ullisch, Marcus Goerge

    2012-01-24

    A novel three-dimensional navigator k-space trajectory for rigid body motion detection for Magnetic Resonance Imaging (MRI) - the Lissajous navigator - was developed and quantitatively compared to the existing spherical navigator trajectory [1]. The spherical navigator cannot sample the complete spherical surface due to slew rate limitations of the scanner hardware. By utilizing a two dimensional Lissajous figure which is projected onto the spherical surface, the Lissajous navigator overcomes this limitation. The complete sampling of the sphere consequently leads to rotation estimates with higher and more isotropic accuracy. Simulations and phantom measurements were performed for both navigators. Both simulations and measurements show a significantly higher overall accuracy of the Lissajous navigator and a higher isotropy of the rotation estimates. Measured under identical conditions with identical postprocessing, the measured mean absolute error of the rotation estimates for the Lissajous navigator was 38% lower (0.3 ) than for the spherical navigator (0.5 ). The maximum error of the Lissajous navigator was reduced by 48% relative to the spherical navigator. The Lissajous navigator delivers higher accuracy of rotation estimation and a higher degree of isotropy than the spherical navigator with no evident drawbacks; these are two decisive advantages, especially for high-resolution anatomical imaging.

  20. Cross-sectoral modeling and optimization of a future German energy system, taking energy efficiency measures into account in the building sector; Sektoruebergreifende Modellierung und Optimierung eines zukuenftigen deutschen Energiesystems unter Beruecksichtigung von Energieeffizienzmassnahmen im Gebaeudesektor

    Energy Technology Data Exchange (ETDEWEB)

    Palzer, Andreas

    2016-07-01

    With the aim of reducing greenhouse gas emissions, comprehensive climate protection measures have already been adopted both nationally and internationally. This raises the question of how economically and ecologically useful system infrastructure looks, which at the same time ensures the supply reliability of all consumers. The regenerative energy model (REMod) presented in this book has been developed to provide answers. The sectors electricity, heat, transport and industry are considered for the first time simultaneous in an energy system model. In particular, in order to satisfy the criterion of reliability of supply, the model calculates the energy flows in hourly resolution for the period from today (2015) to 2050. The system is optimized with regard to minimum overall costs and under the boundary condition that a maximum set quantity of permitted greenhouse gas emissions is not exceed. On the example of Germany (REMod-D), the results show that, in particular, the interaction of the sectors can lead to strong differences in the design of the system infrastructure. [German] Mit dem Ziel den Ausstoss der Treibhausgase zu reduzieren, wurden bereits national wie international umfangreiche Klimaschutzmassnahmen verabschiedet. Hieraus ergibt sich die Frage wie eine oekonomisch und oekologisch sinnvolle Systeminfrastruktur aussieht, die gleichzeitig die Versorgungssicherheit aller Verbraucher gewaehrleistet. Das in diesem Buch vorgestellte Regenerative Energien Modell (REMod) wurde entwickelt um hierauf Antworten zu liefern. Beruecksichtigt werden erstmalig in einem Energiesystemmodell die Sektoren Strom, Waerme, Verkehr und Industrie gleichzeitig. Insbesondere um dem Kriterium der Versorgungssicherheit gerecht zu werden, berechnet das Modell die Energiefluesse in stuendlicher Aufloesung fuer den Zeitraum von heute (2015) bis 2050. Optimiert wird das System hinsichtlich minimaler Gesamtkosten und unter der Randbedingung, dass eine maximal vorgegebene Menge erlaubter

  1. Marginal flow in compressor cascades. Influence of gap, cascade geometry, loads and inflow boundary layer. Final report; Randstroemung in Verdichtergittern. Untersuchung der Randstroemung in Verdichtergittern unter dem Einfluss von Spalt, Gittergeometrie, Gitterbelastung und Zustroemgrenzschicht. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, J

    1996-07-01

    der Abstroemwinkelverteilung zusammengestellt und mit den Messungen verglichen. Dabei ergab sich eine grosse Streubreite der Korrelationen, die auf eine unterschiedliche Bewertung der Spaltweite und der aerodynamischen Belastung zurueckzufuehren ist. Die haeufig anzutreffende Trennung in einen reinen Spaltverlust und einen von der Spaltstroemung unbeeinflussten Sekundaerverlust erscheint physikalisch nicht sinnvoll. Unter Beruecksichtigung der experimentellen Ergebnisse wurden verbesserte Spaltverlust- und Abstroemwinkelkorrelationen erarbeitet. (orig.)

  2. A laser-based study of kerosine evaporation and -mixing for lean prevaporized combustion at elevated pressure; Lasermesstechnische Untersuchung der Kerosinverdampfung und -mischung fuer die magere Vormischverbrennung unter erhoehtem Druck

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, M.

    1999-05-01

    The evaporation and mixing of a kerosine spray in the turbulent airstream of a prevaporizer is investigated at conditions prevailing in the combustion chamber of gas turbines. An experiment is described that allows to study an evaporating fuel spray downstream a prefilming airblast atomizer with Phase-Doppler anemometry, laser-induced fluorescence and an infrared light absorption technique. At an air pressure of 9 bars, an air temperature of 750 K, a mean air velocity of 120 m/s and a fuel flow rate of 1 g/s the kerosine spray evaporates completely without autoignition. At this operating condition the parameters air pressure, air temperature and air turbulence are varied. The influence of these parametric variations on the dropsize distribution, the evaporation rate and the concentration profiles of liquid and evaporated fuel is presented and discussed. (orig.) [German] Die Verdampfung und Vermischung eines Kerosinsprays in der turbulenten Luftstroemung eines Vorverdampfers wird unter Bedingungen untersucht, die in Brennkammern fuer Gasturbinen vorherrschen. Ein Experiment wird vorgestellt, welches es erlaubt, ein verdampfendes Kraftstoffspray stromab eines ebenen Luftstromzerstaeubers mit Filmleger mittels der Phasen-Doppler-Anemometrie, Laser-induzierter Fluoreszenz und einer Infrarotabsorptionsmesstechnik zu untersuchen. Bei einem Luftdruck von 9 bar, einer Vorwaermetemperatur der Luft von 750 K, einer mittleren Luftgeschwindigkeit von 120 m/s und einem Kraftstoffmassenstrom von 1 g/s verdampft das Kerosinspray vollstaendig, ohne die Selbstzuendungszeit zu erreichen. Bei dieser Betriebsbedingung werden die Parameter Luftdruck, Lufttemperatur und Turbulenzgrad variiert. Der Einfluss dieser Parameter auf das Tropfengroessenspektrum, den Verdampfungsgrad und die Konzentrationsprofile des fluessigen sowie des verdampften Kraftstoffs wird dargestellt und diskutiert. (orig.)

  3. Materials model for describing the austenite-martensite phase transformation considering transformation-induced plasticity; Ein Materialmodell zur Beschreibung der Austenit-Martensit Phasentransformation unter Beruecksichtigung der transformationsinduzierten Plastizitaet

    Energy Technology Data Exchange (ETDEWEB)

    Oberste-Brandenburg, C.

    1999-06-01

    In this thesis, a model to describe the austenite martensite transformation was developed. The transformation induced plasticity (TRIP) was taken into consideration. The model can be used to design complex structures. A local examination of the energy and entropy balance at the phase boundary serves as the starting point for the identification of the thermodynamical driving force and the thermodynamic flow. For both, a tensorial description is necessary for a general nonhydrostatically stressed solid. In the second part, a material law for the description of TRIP-Steels was developed based on the values derived in the first part. The different mechanical behavior of the phases, especially the differing yield stresses, was taken into account. The model developed was implemented into the finite element program MARC. Simulations of the material and the structural behavior were performed. The experimentally observed strong dependence of the transformation kinetics on the yield stress of the austenite and the dependence of the orientation of the martensite inclusion on the stress state could be verified. (orig.) [German] Im Rahmen dieser Arbeit wurde ein Materialmodell zur Beschreibung der Austenit-Martensit Phasenumwandlung unter Beruecksichtigung der transformationsinduzierten Plastizitaet (TRIP) entwickelt. Das Modell ist zur Berechnung ausgedehnter Strukturen einsetzbar. Eine lokale Betrachtung der Energie- und Entropiebilanz an der Phasengrenze bildet den Ausgangspunkt zur Identifikation der thermodynamischen Kraft und des thermodynamischen Flusses bei Beschreibung der Transformationskinetik. Fuer beide Groessen muss fuer den allgemein nichthydrostatischen Spannungszustand eine tensorielle Beschreibung verwendet werden. Im zweiten Teil der Arbeit bilden diese Groessen die Basis zur Entwicklung eines Stoffgesetzes zur Beschreibung des TRIP-Phaenomens. Es wird das unterschiedliche mechanische Verhalten der Phasen, insbesondere die stark unterschiedlichen

  4. GPM GROUND VALIDATION NASA ER-2 NAVIGATION DATA MC3E V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation NASA ER-2 Navigation Data MC3E dataset contains information recorded by an on board navigation recorder (NavRec). In addition to typical...

  5. Aids to Navigation for US waters, including territories, as of April 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 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,...

  6. 78 FR 20581 - Patient Protection and Affordable Care Act; Exchange Functions: Standards for Navigators and Non...

    Science.gov (United States)

    2013-04-05

    ... rule, in order to mitigate conflicts of interest, there are three types of information that Navigators... require disclosure of two other types of indirect financial conflicts of interest. Navigators and their... stop loss insurance or subsidiaries of such [[Page 20588

  7. Autonomous Unmanned Merchant Vessel and its Contribution towards the e-Navigation Implementation: The MUNIN Perspective

    Directory of Open Access Journals (Sweden)

    Hans-Christoph Burmeister

    2014-12-01

    Full Text Available While IMO's e-Navigation project's scope is to enhance safety of navigation by improved ship-to-shore-cooperation, the EU's FP7 project MUNIN's aim is to develop a concept for an autonomous dry bulk carrier, that is at least as safe as a manned vessel. As e-Navigation has a strong focus on improving the human element in shipping and MUNIN tends towards an unmanned bridge, a common baseline might look quite contradictory at first, but they share the need to ensure and enhance the safety of navigation. After an introduction into e-Navigation and the MUNIN project, this paper will demonstrate with two examples, how MUNIN's results address identified e-Navigation's gaps and addresses e-Navigation's user needs. Thus, MUNIN contributes to the development and implementation of the prioritized e-Navigation solutions.

  8. Application of γ ray to field investigation of float mud in ocean outfalls and navigation channels

    International Nuclear Information System (INIS)

    Yi Ruiji; Ding Yuanguo; Cheng Hesen

    2007-01-01

    The γ ray gauge is used to investigate the density and distribution of float mud in navigation channel area on site. The results provide important prototype information for effectively using navigable depth and studying rules of back silting. (authors)

  9. The effect of experienced individuals on navigation by king penguin chick pairs

    NARCIS (Netherlands)

    Nesterova, A.P.; Flack, A.; van Loon, E.E.; Bonadonna, F.; Biro, D.

    2015-01-01

    Group members' individual experience can have important influences when navigating collectively. However, how exactly they structure group travel performance is still not fully understood. This study investigated how navigation and leadership dynamics are affected by the presence of an experienced

  10. Optimal Geometric Deployment of a Ground Based Pseudolite Navigation System to Track a Landing Aircraft

    National Research Council Canada - National Science Library

    Crawford, Matthew P

    2006-01-01

    With much of the military and civilian communities becoming dependent on GPS technology to navigate it has become imperative that the navigation systems be tested in situations in which GPS does not work...

  11. Effects of Drawdown and Structures on Bed-Load Transport in Pool 8 Navigation Channel

    National Research Council Canada - National Science Library

    Abraham, David; Hendrickson, Jon

    2003-01-01

    ... of a pool drawdown and structures on bed-load transport in the Pool 8 navigation channel. Work was conducted as part of the Monitoring of Completed Navigation Projects (MCNP) program. BACKGROUND...

  12. The Creation of Differential Correction Systems and the Systems of Global Navigation Satellite System Monitoring

    National Research Council Canada - National Science Library

    Polishchuk, G. M; Kozlov, V. I; Urlichich, Y. M; Dvorkin, V. V; Gvozdev, V. V

    2002-01-01

    ... for the Russian Federation and a system of global navigation satellite system monitoring. These projects are some of the basic ones in the Federal program "Global Navigation System," aimed at maintenance and development of the GLONASS system...

  13. 75 FR 22674 - Airborne Area Navigation Equipment Using Loran-C Inputs

    Science.gov (United States)

    2010-04-29

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Airborne Area Navigation Equipment Using Loran-C Inputs AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of cancellation... the cancellation of Technical Standard Order (TSO) C-60, Airborne Area Navigation Equipment Using...

  14. 75 FR 42819 - Airborne Area Navigation Equipment Using Loran-C Inputs

    Science.gov (United States)

    2010-07-22

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Airborne Area Navigation Equipment Using Loran-C Inputs AGENCY: Federal Aviation Administration (FAA), DOT ACTION: Notice of cancellation... the cancellation of Technical Standard Order (TSO) C-60, Airborne Area Navigation Equipment Using...

  15. Ground-Based Global Navigation Satellite System Combined Broadcast Ephemeris Data (daily files) from NASA CDDIS

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset consists of ground-based Global Navigation Satellite System (GNSS) Combined Broadcast Ephemeris Data (daily files of all distinct navigation messages...

  16. Metrics for evaluating patient navigation during cancer diagnosis and treatment: crafting a policy-relevant research agenda for patient navigation in cancer care.

    Science.gov (United States)

    Guadagnolo, B Ashleigh; Dohan, Daniel; Raich, Peter

    2011-08-01

    Racial and ethnic minorities as well as other vulnerable populations experience disparate cancer-related health outcomes. Patient navigation is an emerging health care delivery innovation that offers promise in improving quality of cancer care delivery to these patients who experience unique health-access barriers. Metrics are needed to evaluate whether patient navigation can improve quality of care delivery, health outcomes, and overall value in health care during diagnosis and treatment of cancer. Information regarding the current state of the science examining patient navigation interventions was gathered via search of the published scientific literature. A focus group of providers, patient navigators, and health-policy experts was convened as part of the Patient Navigation Leadership Summit sponsored by the American Cancer Society. Key metrics were identified for assessing the efficacy of patient navigation in cancer diagnosis and treatment. Patient navigation data exist for all stages of cancer care; however, the literature is more robust for its implementation during prevention, screening, and early diagnostic workup of cancer. Relatively fewer data are reported for outcomes and efficacy of patient navigation during cancer treatment. Metrics are proposed for a policy-relevant research agenda to evaluate the efficacy of patient navigation in cancer diagnosis and treatment. Patient navigation is understudied with respect to its use in cancer diagnosis and treatment. Core metrics are defined to evaluate its efficacy in improving outcomes and mitigating health-access barriers. Copyright © 2011 American Cancer Society.

  17. Risk-based asset management of a navigation network

    NARCIS (Netherlands)

    Toorn, A. van der; Wiel, W. van der; Rooij, M. de; Janssen, H.; Kiljan, D.J.

    2013-01-01

    In the Netherlands the State Public Works is responsible for the main waterway network, where locks are mostly the decisive bottlenecks in the navigation corridors. In the last decade the State Public Works has changed from a technical oriented maintenance organization mainly focussed at the

  18. Facilitating Navigation in Quality Manuals by Providing Bookmarks or Similar

    International Nuclear Information System (INIS)

    Shaharum bin Ramli

    2012-01-01

    Nuclear Malaysia level quality manuals need to be shared with all divisions. A manual is usually distributed in the form of an electronic document that contains all procedures. Navigation from one heading or procedure to another should be facilitated by providing bookmarks or similar. This paper shows how to do it for Microsoft Word and PDF documents. (author)

  19. 46 CFR 111.75-17 - Navigation lights.

    Science.gov (United States)

    2010-10-01

    ... of these navigation lights. Each light source must be connected to a separate fused branch circuit. The panel must have a fused feeder disconnect switch, and the fuses must have at least twice the..., two-lamp type, have each lamp connected to its branch circuit conductors either by an individual...

  20. Image-based navigation for a robotized flexible endoscope

    NARCIS (Netherlands)

    van der Stap, N.; Slump, Cornelis H.; Broeders, Ivo Adriaan Maria Johannes; van der Heijden, Ferdinand; Luo, Xiongbiao; Reichl, Tobias; Mirota, Daniel; Soper, Timothy

    2014-01-01

    Robotizing flexible endoscopy enables image-based control of endoscopes. Especially during high-throughput procedures, such as a colonoscopy, navigation support algorithms could improve procedure turnaround and ergonomics for the endoscopist. In this study, we have developed and implemented a

  1. Bioactivity-guided mapping and navigation of chemical space

    NARCIS (Netherlands)

    Renner, S.; Otterlo, van W.A.L.; Seoane, M.D.; Möcklinghoff, S.; Hofmann, B.; Wetzel, S.; Schuffenhauer, A.; Ertl, P.; Oprea, T.I.; Steinhilber, D.; Brunsveld, L.; Rauh, D.; Waldmann, H.

    2009-01-01

    The structure- and chemistry-based hierarchical organization of library scaffolds in tree-like arrangements provides a valid, intuitive means to map and navigate chemical space. We demonstrate that scaffold trees built using bioactivity as the key selection criterion for structural simplification

  2. Navigating Instructional Dialectics: Empirical Exploration of Paradox in Teaching

    Science.gov (United States)

    Thompson, Blair; Rudick, C. Kyle; Kerssen-Griep, Jeff; Golsan, Kathryn

    2018-01-01

    Navigating contradiction represents an integral part of the teaching process. While educational literature has discussed the paradoxes that teachers experience in the classroom, minimal empirical research has analyzed the strategies teachers employ to address these paradoxes. Using relational dialectics as a theoretical framework for understanding…

  3. An Analysis of Video Navigation Behavior for Web Leisure

    Directory of Open Access Journals (Sweden)

    Ying-Han Chang

    2012-12-01

    Full Text Available People nowadays put much emphasis on leisure activities, and web video has gradually become one of the main sources for popular leisure. This article introduces the related concepts of leisure and navigation behavior as well as some recent research topics. Moreover, using YouTube as an experimental setting, the authors invited some experienced web video users and conducted an empirical study on their navigating the web videos for leisure purpose. The study used questionnaires, navigation logs, diaries, and interviews to collect data. Major results show: the subjects watched a variety of video content on the web either from traditional media or user-generated video; these videos can meet their leisure needs of both the broad and personal interests; during the navigation process, each subject quite focuses on video leisure, and is willingly to explore unknown videos; however, within a limited amount of time for leisure, a balance between leisure and rest becomes an issue of achieving real relaxation, which is worth of further attention. [Article content in Chinese

  4. Lost after stroke: Theory, assessment, and rehabilitation of navigation impairment

    NARCIS (Netherlands)

    Claessen, M.H.G.

    2017-01-01

    The general objective of this thesis was to better understand the navigation problems that nearly a third of stroke patients are faced with. Insight into these types of problems is currently very limited in this patient group. I adopted four approaches to address this main objective, corresponding

  5. A Behaviour-Based Architecture for Mapless Navigation Using Vision

    Directory of Open Access Journals (Sweden)

    Mehmet Serdar Guzel

    2012-04-01

    Full Text Available Autonomous robots operating in an unknown and uncertain environment must be able to cope with dynamic changes to that environment. For a mobile robot in a cluttered environment to navigate successfully to a goal while avoiding obstacles is a challenging problem. This paper presents a new behaviour-based architecture design for mapless navigation. The architecture is composed of several modules and each module generates behaviours. A novel method, inspired from a visual homing strategy, is adapted to a monocular vision-based system to overcome goal-based navigation problems. A neural network-based obstacle avoidance strategy is designed using a 2-D scanning laser. To evaluate the performance of the proposed architecture, the system has been tested using Microsoft Robotics Studio (MRS, which is a very powerful 3D simulation environment. In addition, real experiments to guide a Pioneer 3-DX mobile robot, equipped with a pan-tilt-zoom camera in a cluttered environment are presented. The analysis of the results allows us to validate the proposed behaviour-based navigation strategy.

  6. True navigation and magnetic maps in spiny lobsters.

    Science.gov (United States)

    Boles, Larry C; Lohmann, Kenneth J

    2003-01-02

    Animals are capable of true navigation if, after displacement to a location where they have never been, they can determine their position relative to a goal without relying on familiar surroundings, cues that emanate from the destination, or information collected during the outward journey. So far, only a few animals, all vertebrates, have been shown to possess true navigation. Those few invertebrates that have been carefully studied return to target areas using path integration, landmark recognition, compass orientation and other mechanisms that cannot compensate for displacements into unfamiliar territory. Here we report, however, that the spiny lobster Panulirus argus oriented reliably towards a capture site when displaced 12-37 km to unfamiliar locations, even when deprived of all known orientation cues en route. Little is known about how lobsters and other animals determine position during true navigation. To test the hypothesis that lobsters derive positional information from the Earth's magnetic field, lobsters were exposed to fields replicating those that exist at specific locations in their environment. Lobsters tested in a field north of the capture site oriented themselves southwards, whereas those tested in a field south of the capture site oriented themselves northwards. These results imply that true navigation in spiny lobsters, and perhaps in other animals, is based on a magnetic map sense.

  7. Emergency operation procedure navigation to avoid commission errors

    International Nuclear Information System (INIS)

    Gofuku, Akio; Ito, Koji

    2004-01-01

    New types of operation control system equipped with a large screen and CRT-based operation panels have been installed in newly constructed nuclear power plants. The operators can share important information of plant conditions by the large screen. The operation control system can know the operations by operators through the computers connected to the operation panels. The software switches placed in the CRT-based operation panels have a problem such that operators may make an error to manipulate an irrelevant software switch with their current operation. This study develops an operation procedure navigation technique to avoid this kind of commission errors. The system lies between CRT-based operation panels and plant control systems and checks an operation by operators if it follows the operation procedure of operation manuals. When the operation is a right one, the operation is executed as if the operation command is directly transmitted to control systems. If the operation does not follow the operation procedure, the system warns the commission error to operators. This paper describes the operation navigation technique, format of base operation model, and a proto-type operation navigation system for a three loop pressurized water reactor plant. The validity of the proto-type system is demonstrated by the operation procedure navigation for a steam generator tube rupture accident. (author)

  8. Electromagnetic navigation diagnostic bronchoscopy for small peripheral lung lesions.

    Science.gov (United States)

    Makris, D; Scherpereel, A; Leroy, S; Bouchindhomme, B; Faivre, J-B; Remy, J; Ramon, P; Marquette, C-H

    2007-06-01

    The present study prospectively evaluated the diagnostic yield and safety of electromagnetic navigation-guided bronchoscopy biopsy, for small peripheral lung lesions in patients where standard techniques were nondiagnostic. The study was conducted in a tertiary medical centre on 40 consecutive patients considered unsuitable for straightforward surgery or computed tomography (CT)-guided transthoracic needle aspiration biopsy, due to comorbidities. The lung lesion diameter was mean+/-sem 23.5+/-1.5 mm and the depth from the visceral-costal pleura was 14.9+/-2 mm. Navigation was facilitated by an electromagnetic tracking system which could detect a position sensor incorporated into a flexible catheter advanced through a bronchoscope. Information obtained during bronchoscopy was superimposed on previously acquired CT data. Divergence between CT data and data obtained during bronchoscopy was calculated by the system's software as a measure of navigational accuracy. All but one of the target lesions was reached and the overall diagnostic yield was 62.5% (25-40). Diagnostic yield was significantly affected by CT-to-body divergence; yield was 77.2% when estimated divergence was drainage was required in one case. Electromagnetic navigation-guided bronchoscopy has the potential to improve the diagnostic yield of transbronchial biopsies without additional fluoroscopic guidance, and may be useful in the early diagnosis of lung cancer, particularly in nonoperable patients.

  9. Longitudinal navigation log data on a large web domain

    NARCIS (Netherlands)

    Verberne, S.; Arends, B.; Kraaij, W.; Vries, A. de

    2016-01-01

    We have collected the access logs for our university's web domain over a time span of 4.5 years. We now release the pre-processed data of a 3-month period for research into user navigation behavior. We preprocessed the data so that only successful GET requests of web pages by non-bot users are kept.

  10. 4D Dynamic Required Navigation Performance Final Report

    Science.gov (United States)

    Finkelsztein, Daniel M.; Sturdy, James L.; Alaverdi, Omeed; Hochwarth, Joachim K.

    2011-01-01

    New advanced four dimensional trajectory (4DT) procedures under consideration for the Next Generation Air Transportation System (NextGen) require an aircraft to precisely navigate relative to a moving reference such as another aircraft. Examples are Self-Separation for enroute operations and Interval Management for in-trail and merging operations. The current construct of Required Navigation Performance (RNP), defined for fixed-reference-frame navigation, is not sufficiently specified to be applicable to defining performance levels of such air-to-air procedures. An extension of RNP to air-to-air navigation would enable these advanced procedures to be implemented with a specified level of performance. The objective of this research effort was to propose new 4D Dynamic RNP constructs that account for the dynamic spatial and temporal nature of Interval Management and Self-Separation, develop mathematical models of the Dynamic RNP constructs, "Required Self-Separation Performance" and "Required Interval Management Performance," and to analyze the performance characteristics of these air-to-air procedures using the newly developed models. This final report summarizes the activities led by Raytheon, in collaboration with GE Aviation and SAIC, and presents the results from this research effort to expand the RNP concept to a dynamic 4D frame of reference.

  11. Research notes : solar powered navigational lighting system demonstration project.

    Science.gov (United States)

    2011-04-01

    ODOT will be installing a solar powered navigational lighting system on the AstoriaMegler Bridge as part of a pilot project approved by the Federal Highways Administration (FHWA). The coastal bridge is the connection across the Columbia River on U.S....

  12. Improving navigability on the Kromme River Estuary: A choice ...

    African Journals Online (AJOL)

    Navigation of estuaries is a vitally important aspect of boating recreation in South Africa and elsewhere. This paper uses a choice experiment to estimate recreation values of the Kromme River Estuary, a popular estuary along South Africa's east coast. This valuation methodology allows for the identification of preferred ...

  13. Agents for navigating virtual reality E-commerce environments

    NARCIS (Netherlands)

    Nijholt, Anton; van Dijk, Betsy; Sebaaly, Milad Fares

    2001-01-01

    We report about work in progress on capabilities of navigation agents in virtual environments. These agents may help a user to explore the environment: where to go, where to buy, where to find, etc. The agents may make suggestions based on a user profile, earlier visits and earlier given advice and

  14. Complementary terrain/single beacon-based AUV navigation

    Digital Repository Service at National Institute of Oceanography (India)

    Maurya, P.; Curado, T.F.; António, P.

    is not sufficiently "rich" in terms of topographic features. The key contribution of this paper is a formal analysis of the benefits of using complementary filtering, in opposition to TAN navigation only. To this effect, we exploit key tools of estimation theory...

  15. Feasibility of remote magnetic navigation for epicardial ablation

    NARCIS (Netherlands)

    P. Abraham; L.D. Abkenari; E.C.H. Peters; T. Szili-Torok (Tamas)

    2013-01-01

    textabstractPercutaneous epicardial mapping and ablation is an emerging method to treat ventricular tachycardias (VT), premature ventricular complexes (PVC), and accessory pathways. The use of a remote magnetic navigation system (MNS) could enhance precision and maintain safety. This multiple case

  16. FSA of the Navigational Safety in Baltic West

    DEFF Research Database (Denmark)

    Friis-Hansen, Peter; Ravn, Erik Sonne; Hartmann, J.P.

    2004-01-01

    This paper is the result of a pilot study carried out in the spring of 2004 by the Technical University of Denmark, The Royal Danish Administration of Navigation and Hydrography's and the Danish Maritime Authority. The objective of the pilot study was to illustrate a procedure that allowed a risk...

  17. Enriching location-based games with navigational game activities

    DEFF Research Database (Denmark)

    Nadarajah, Stephanie Githa; Overgaard, Benjamin Nicholas; Pedersen, Peder Walz

    2016-01-01

    Mobile location-based games are experiences that entertain its players by requiring interactions mainly at points of interest (POIs). Navigation between POIs often involve the use of either a physical or digital map, not taking advantage of the opportunity available to engage users in activities...

  18. True navigation in migrating gulls requires intact olfactory nerves

    DEFF Research Database (Denmark)

    Wikelski, Martin; Arriero, Elena; Gagliardo, Anna

    2015-01-01

    debated. In this experiment we subjected adult lesser black-backed gulls migrating from their Finnish/Russian breeding grounds (from >60°N) to Africa (to ... of the trigeminal nerve sectioned oriented towards their population-specific migratory corridor. Thus, air-borne olfactory information seems to be important for migrating gulls to navigate successfully in some circumstances....

  19. Neonicotinoids interfere with specific components of navigation in honeybees.

    Directory of Open Access Journals (Sweden)

    Johannes Fischer

    Full Text Available Three neonicotinoids, imidacloprid, clothianidin and thiacloprid, agonists of the nicotinic acetylcholine receptor in the central brain of insects, were applied at non-lethal doses in order to test their effects on honeybee navigation. A catch-and-release experimental design was applied in which feeder trained bees were caught when arriving at the feeder, treated with one of the neonicotinoids, and released 1.5 hours later at a remote site. The flight paths of individual bees were tracked with harmonic radar. The initial flight phase controlled by the recently acquired navigation memory (vector memory was less compromised than the second phase that leads the animal back to the hive (homing flight. The rate of successful return was significantly lower in treated bees, the probability of a correct turn at a salient landscape structure was reduced, and less directed flights during homing flights were performed. Since the homing phase in catch-and-release experiments documents the ability of a foraging honeybee to activate a remote memory acquired during its exploratory orientation flights, we conclude that non-lethal doses of the three neonicotinoids tested either block the retrieval of exploratory navigation memory or alter this form of navigation memory. These findings are discussed in the context of the application of neonicotinoids in plant protection.

  20. Neonicotinoids Interfere with Specific Components of Navigation in Honeybees

    Science.gov (United States)

    Fischer, Johannes; Müller, Teresa; Spatz, Anne-Kathrin; Greggers, Uwe; Grünewald, Bernd; Menzel, Randolf

    2014-01-01

    Three neonicotinoids, imidacloprid, clothianidin and thiacloprid, agonists of the nicotinic acetylcholine receptor in the central brain of insects, were applied at non-lethal doses in order to test their effects on honeybee navigation. A catch-and-release experimental design was applied in which feeder trained bees were caught when arriving at the feeder, treated with one of the neonicotinoids, and released 1.5 hours later at a remote site. The flight paths of individual bees were tracked with harmonic radar. The initial flight phase controlled by the recently acquired navigation memory (vector memory) was less compromised than the second phase that leads the animal back to the hive (homing flight). The rate of successful return was significantly lower in treated bees, the probability of a correct turn at a salient landscape structure was reduced, and less directed flights during homing flights were performed. Since the homing phase in catch-and-release experiments documents the ability of a foraging honeybee to activate a remote memory acquired during its exploratory orientation flights, we conclude that non-lethal doses of the three neonicotinoids tested either block the retrieval of exploratory navigation memory or alter this form of navigation memory. These findings are discussed in the context of the application of neonicotinoids in plant protection. PMID:24646521