WorldWideScience

Sample records for pre navigation group

  1. Local Navigation for Unmanned Group Vehicles

    Science.gov (United States)

    2005-12-01

    processing power may allow the development of one all- encompassing navigation algorithm, but more likely, autonomous systems will switch between algorithms... planifier précisément les séquences des mouvements du robot. La portée des résultats : L’évitement des obstacles à deux dimensions est plus ou moins un...and interacts with the terrain. This process is much more difficult for robotic vehicles. In addition to the limitations of sensing equipment, it has

  2. Navigating Pre-, In-, and Post-Fieldwork: Elements for Consideration

    Science.gov (United States)

    Lamoureux, Sylvie A.

    2011-01-01

    In this article, the author reflects on the transitions she has navigated since 2005 and offers insight into elements of research relationships. As she guides and accompanies a new generation of qualitative researchers planning and experiencing their fieldwork, the need for writing that addresses the complexities of "the intersubjectivity of the…

  3. Design and Flight Performance of the Orion Pre-Launch Navigation System

    Science.gov (United States)

    Zanetti, Renato

    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 test the prelaunch and entry components of the system. Orion's pre-launch absolute navigation design is presented, together with its EFT-1 performance.

  4. Psychoanalytic multifamily groups with pre-adolescents

    Directory of Open Access Journals (Sweden)

    Simone Bruschetta

    2014-09-01

    Full Text Available This paper presents two variations of the classic group device (GPMF developed by García Badaracco (1989, 2000, in order to adapt to the prevention and early care. In particular, the two variations of multi- family setting, which will be described below, are addressed to children aged 9-10 and 13-14 years, attending junior-high schools, and belonging to those types of families mentioned in the scientific literature as families with multiple-problems or those social groups marginalized and at risk such as children with severe distress at school.Keywords: Multifamiliar psychoanalysis, Serious mental illness, Pre-adolescently age, Therapeutic community, Junior-high school, Severe socio-familiar distress.

  5. Social networks improve leaderless group navigation by facilitating long-distance communication

    Directory of Open Access Journals (Sweden)

    Nikolai W. F. BODE, A. Jamie WOOD, Daniel W. FRANKS

    2012-04-01

    Full Text Available Group navigation is of great importance for many animals, such as migrating flocks of birds or shoals of fish. One theory states that group membership can improve navigational accuracy compared to limited or less accurate individual navigational ability in groups without leaders (“Many-wrongs principle”. Here, we simulate leaderless group navigation that includes social connections as preferential interactions between individuals. Our results suggest that underlying social networks can reduce navigational errors of groups and increase group cohesion. We use network summary statistics, in particular network motifs, to study which characteristics of networks lead to these improvements. It is networks in which preferences between individuals are not clustered, but spread evenly across the group that are advantageous in group navigation by effectively enhancing long-distance information exchange within groups. We suggest that our work predicts a base-line for the type of social structure we might expect to find in group-living animals that navigate without leaders [Current Zoology 58 (2: 329-341, 2012].

  6. Social networks improve leaderless group navigation by facilitating long-distance communication

    Institute of Scientific and Technical Information of China (English)

    Nikolai W.F.BODE; A.Jamie WOOD; Daniel W.FRANKS

    2012-01-01

    Group navigation is of great importance for many animals,such as migrating flocks of birds or shoals of fish.One theory states that group membership can improve navigational accuracy compared to limited or less accurate individual navigational ability in groups without leaders ("Many-wrongs principle").Here,we simulate leaderless group navigation that includes social connectious as preferential interactions between individuals.Our results suggest that underlying social networks can reduce navigational errors of groups and increase group cohesion.We use network summary statistics,in particular network motifs,to study which characteristics of networks lead to these improvements.It is networks in which preferences between individuals are not clustered,but spread evenly across the group that are advantageous in group navigation by effectively enhancing long-distance information exchange within groups.We suggest that our work predicts a base-line for the type of social structure we might expect to find in group-living animals that navigate without leaders [Current Zoology 58 (2):329-341,2012].

  7. Pre-Flare Dynamics of Sunspot Groups

    CERN Document Server

    Korsos, M B; Ludmany, A

    2014-01-01

    Several papers provide evidences that the most probable sites of flare onset are the regions of high horizontal magnetic field gradients in solar active regions. Besides the localization of flare producing areas the present work intends to reveal the characteristic temporal variations in these regions prior to flares. This study uses sunspot data instead of magnetograms, it follows the behaviour of a suitable defined proxy measure representing the horizontal magnetic field gradient. The source of the data is the SDD (SOHO/MDI-Debrecen Data) sunspot catalogue. The most promising pre-flare signatures are the following properties of the gradient variation: i) steep increase, ii) high maximum, iii) significant fluctuation and iv) a gradual decrease between the maximum and the flare onset which can be related to the "pull mode" of the current layer. These properties may yield a tool for the assessment of flare probability and intensity within the next 8-10 hours.

  8. Pre-flare dynamics of sunspot groups

    Energy Technology Data Exchange (ETDEWEB)

    Korsós, M. B.; Baranyi, T.; Ludmány, A., E-mail: korsos.marianna@csfk.mta.hu, E-mail: baranyi.tunde@csfk.mta.hu, E-mail: ludmany.andras@csfk.mta.hu [Heliophysical Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, 4010 Debrecen, P.O. Box 30 (Hungary)

    2014-07-10

    Several papers provide evidence that the most probable sites of flare onset are the regions of high horizontal magnetic field gradients in solar active regions. Besides the localization of flare-producing areas, this work intends to reveal the characteristic temporal variations in these regions prior to flares. This study uses sunspot data instead of magnetograms and follows the behavior of a suitable defined proxy measure representing the horizontal magnetic field gradient. The source of the data is the SDD (SOHO/MDI-Debrecen Data) sunspot catalog. The most promising pre-flare signatures are the following properties of gradient variation: (1) steep increase, (2) high maximum, (3) significant fluctuation, and (4) a gradual decrease between the maximum and the flare onset that can be related to the 'pull mode' of the current layer. These properties may yield a tool for the assessment of flare probability and intensity within the following 8-10 hr.

  9. Encounter detection to improve navigation in a group of unattended vehicles

    Science.gov (United States)

    Ruizenaar, M. G. A.

    2014-10-01

    Research was conducted on groups of unattended vehicles performing some collaborative tasks. Navigation of these vehicles and more specifically, knowing each other's position, is mandatory. In densely built environments, forests, etc., GPS is not always available or accurate. Using information about encounters between the vehicles may significantly improve position information. Detecting encounters can be done very easily with low cost sensors. TNO developed and patented an innovative technology that uses information on encounters to improve the position information. The first promising results show that information on encounters can be used in standard integrated INS/GNSS navigation systems to aid the navigation solution. To increase the number of encounters, a group of unattended vehicles may deliberately try to encounter each other if their navigation solution becomes less certain during GNSS outages.

  10. Navigable rivers facilitated the spread and recurrence of plague in pre-industrial Europe

    Science.gov (United States)

    Pak Hong, Y. R.

    2016-12-01

    nfectious diseases have become a rising challenge to mankind in a globalizing world. Yet, little is known about the inland transmission of infectious diseases in history. In this study, we based on the spatio-temporal information of 5559 plague (Yersinia pestis) outbreaks in Europe and its neighboring regions in AD1347-1760 to statistically examine the connection between navigable rivers and plague outbreak. Our results showed that 95.5% of plague happened within 10km proximity of navigable rivers. Besides, the count of plague outbreak was positively correlated with the width of river and negatively correlated with the distance between city and river. This association remained robust in different regression model specifications. An increase of 100m in the width of river and a shortening of 1km distance between city and river resulted in 9 and 0.96 more plague outbreaks in our study period, respectively. We suggested that trade and transportation brought by river was an important medium for the spread and recurrence of plague in pre-industrial Europe.

  11. Encounter Detection to Improve Navigation in a Group of Unattended Vehicles

    NARCIS (Netherlands)

    Ruizenaar, M.G.A.

    2014-01-01

    Research was conducted on groups of unattended vehicles performing some collaborative tasks. Navigation of these vehicles and more specifically, knowing each other's position, is mandatory. In densely built environments, forests, etc., GPS is not always available or accurate. Using information about

  12. An Efficient Cluster Based Web Object Filters From Web Pre-Fetching And Web Caching On Web User Navigation

    Directory of Open Access Journals (Sweden)

    A. K. Santra

    2012-05-01

    Full Text Available The World Wide Web is a distributed internet system, which provides dynamic and interactive services includes on line tutoring, video/audio conferencing, e-commerce, and etc., which generated heavy demand on network resources and web servers. It increase over the past few year at a very rapidly rate, due to which the amount of traffic over the internet is increasing. As a result, the network performance has now become very slow. Web Pre-fetching and Caching is one of the effective solutions to reduce the web access latency and improve the quality of service. The existing model presented a Cluster based pre-fetching scheme identified clusters of correlated Web pages based on users access patterns. Web Pre-fetching and Caching cause significant improvements on the performance of Web infrastructure. In this paper, we present an efficient Cluster based Web Object Filters from Web Pre-fetching and Web caching scheme to evaluate the web user navigation patterns and user references of product search. Clustering of web page objects obtained from pre-fetched and web cached contents. User Navigation is evaluated from the web cluster objects with similarity retrieval in subsequent user sessions. Web Object Filters are built with the interpretation of the cluster web pages related to the unique users by discarding redundant pages. Ranking is done on users web page product preferences at multiple sessions of each individual user. The performance is measured in terms of Objective function, Number of clusters and cluster accuracy.

  13. A Computerized Navigation Support for Maneuvering Clustered Ship Groups in Close Proximity

    Directory of Open Access Journals (Sweden)

    Akira Kawaguchi

    2005-06-01

    Full Text Available The aim of this research is to investigate navigation behaviors and effects of interferences of multiple ocean-going vessels that share the same sailing course like a transport convoy. Detecting and evading other clusters in close proximity is one of the most important tasks in navigation as contacting these will potentially cause serious risks to the ship. Focus of this paper is to investigate computational capabilities added to the so-called ship cluster behavior model of our previous work. Enhancement is made to predict a risky situation and to guide for multiple ship clusters, enabling them to move safely and avoid contact with each other. Such improvement is critical, especially when the traffic becomes congested with a number of clustered ship groups moving to distinctive directions. Foundations for and preliminary experimental results of this study are discussed.

  14. Development of Navigation Schemes for Grouped Mobile Robots Leading to Biomimetic Applications

    Directory of Open Access Journals (Sweden)

    Ming-Hsin Chen

    2012-03-01

    Full Text Available Biomimetic autonomous group manipulation of mobile robots has great potential in artificial intelligence, smart life, and automation related applications. In addition, it is also possible to use it as a tool for exploring the behavior of biological group motion in groups such as geese and fish. In order to fulfill these goals, fundamental capabilities of identification, navigation, and communication between robots must be established. In this work, key schemes are proposed for carrying out subsequent navigation tasks. By integrating omni-wheel mobile robots with X-Bee communication protocols, Arduino controls, IR range finders, and CMOS cameras, as well as with wiimote multi-zone localization, tasks such as obstacle and collision avoidance, object following, autonomous movement, and the indoor localization of group robots are implemented as the first step toward the autonomous control of group robots for subsequent biomimetic and smart life applications. With the resolution of these key issues, more realistic scenarios can be designed to achieve real group robot applications for indoor service in the future.

  15. PreGarside monoids and groups, parabolicity, amalgamation, and FC property

    CERN Document Server

    Godelle, Eddy

    2012-01-01

    We define the notion of preGarside group slightly lightening the definition of Garside group so that all Artin-Tits groups are preGarside groups. This paper intends to give a first basic study on these groups. Firstly, we introduce the notion of parabolic subgroup, we prove that any preGarside group has a (partial) complemented presentation, and we characterize the parbolic subgroups in terms of these presentations. Afterwards we prove that the amalgamated product of two preGarside groups along a common parabolic subgroup is again a preGarside group. This enables us to define the family of preGarside groups of FC type as the smallest family of preGarside groups that contains the Garside groups and that is closed by amalgamation along parabolic subgroups. Finally, we make an algebraic and combinatorial study on FC type preGarside groups and their parabolic subgroups.

  16. Architecture de contrôle / commande sûre et flexible pour la navigation en formation d'un groupe de véhicules

    OpenAIRE

    Vilca Ventura, José Miguel

    2015-01-01

    Beyond the interest of robotics laboratories for the development of dedicated strategies for single vehicle navigation, several laboratories around the world are more and more involved in the general challenging field of cooperative multi-robot navigation. In this context, this work deals with the navigation in formation of a group of Unmanned Ground Vehicles (UGVs) dedicated to structured environments. The complexity of this Multi-Robot System (MRS) does not permit the direct use of neither ...

  17. Flexible Pre-Majors: Final Report of the Flexible Pre-Majors Working Group

    Science.gov (United States)

    FitzGibbon, John; Orum, Jennifer

    2011-01-01

    This report provides advice for program areas contemplating the development of a Flexible Pre-Major (FPM) in their discipline. The FPM is another means of aiding student transfer in a system that expects and encourages significant student mobility. The FPM addresses a problematic area for academic students: that of completing the lower level major…

  18. A Pre-Gaia Census of Nearby Stellar Groups

    CERN Document Server

    Mamajek, Eric E

    2015-01-01

    The nearest, youngest groups of stars to the Sun provide important samples of age-dated stars for studying circumstellar disk evolution, imaged exoplanets, and brown dwarfs. I briefly comment on the status of the known stellar groups within 100 pc: $\\beta$ Pic, AB Dor, UMa, Car-Near, Tuc-Hor and $\\beta$ Tuc nucleus, Hyades, Col, TW Hya, Car, Coma Ber, 32 Ori, $\\eta$ Cha, and $\\chi^1$ For. I also discuss some poorly characterized groups and "non-groups." Grades for 2015 of Pass, Satisfactory, or Fail are assigned to the groups for the purposes of age-dating stars and brown dwarfs. I speculate that Tuc-Hor could have provided a supernova ~60 pc away ~2.2 Myr ago which showered the Earth with traces of 60Fe-bearing dust.

  19. Developing an Educational Technology Group for Pre-Service Teachers

    Science.gov (United States)

    Wilson, Jay

    2012-01-01

    The College of Education Technology Group is a pilot program that supports teacher candidates in developing an understanding of the integration of technology. By engaging teacher candidates with local schools the program is enhancing technology-based learning in the classroom for high school students, especially those from First Nations and other…

  20. Behavior of pre-stress group anchors--Theory approach and model

    Institute of Scientific and Technical Information of China (English)

    HE Siming; WANG Chenghua; QIAO Jianping

    2003-01-01

    First of all the pre-stress group anchor ropes are resolved into two sub-systems: the stable rock stand lateral resistance load and inner bonding section stand lateral resistance load and pre-stress load. Then, discretization of every sub-system was carried on and it is assumed that different micro-sections possess uniform distribution side resistance. On the basis of Mindlin stress solution, stress overlay principle, modified layered-summation method as well as the load transfer method, we study the anchor group effect and present a theory model which calculates the anchor group effect and establishes the relevant iterate standard.

  1. Pre-Service Teachers' Questions about the Profession during Mentoring Group Conversations

    Science.gov (United States)

    Eriksson, Anita

    2017-01-01

    The use of mentoring group conversations as a tool to support pre-service teachers' professional development has become more common. However, there is still a lack of research that shows how conversations are used to develop knowledge. The present paper is based on ethnographical observations of mentoring group conversations, and describes how…

  2. Grouped to Achieve: Are There Benefits to Assigning Students to Heterogeneous Cooperative Learning Groups Based on Pre-Test Scores?

    Science.gov (United States)

    Werth, Arman Karl

    Cooperative learning has been one of the most widely used instructional practices around the world since the early 1980's. Small learning groups have been in existence since the beginning of the human race. These groups have grown in their variance and complexity overtime. Classrooms are getting more diverse every year and instructors need a way to take advantage of this diversity to improve learning. The purpose of this study was to see if heterogeneous cooperative learning groups based on student achievement can be used as a differentiated instructional strategy to increase students' ability to demonstrate knowledge of science concepts and ability to do engineering design. This study includes two different groups made up of two different middle school science classrooms of 25-30 students. These students were given an engineering design problem to solve within cooperative learning groups. One class was put into heterogeneous cooperative learning groups based on student's pre-test scores. The other class was grouped based on random assignment. The study measured the difference between each class's pre-post gains, student's responses to a group interaction form and interview questions addressing their perceptions of the makeup of their groups. The findings of the study were that there was no significant difference between learning gains for the treatment and comparison groups. There was a significant difference between the treatment and comparison groups in student perceptions of their group's ability to stay on task and manage their time efficiently. Both the comparison and treatment groups had a positive perception of the composition of their cooperative learning groups.

  3. Emergent group level navigation: an agent-based evaluation of movement patterns in a folivorous primate.

    Science.gov (United States)

    Bonnell, Tyler R; Campennì, Marco; Chapman, Colin A; Gogarten, Jan F; Reyna-Hurtado, Rafael A; Teichroeb, Julie A; Wasserman, Michael D; Sengupta, Raja

    2013-01-01

    The foraging activity of many organisms reveal strategic movement patterns, showing efficient use of spatially distributed resources. The underlying mechanisms behind these movement patterns, such as the use of spatial memory, are topics of considerable debate. To augment existing evidence of spatial memory use in primates, we generated movement patterns from simulated primate agents with simple sensory and behavioral capabilities. We developed agents representing various hypotheses of memory use, and compared the movement patterns of simulated groups to those of an observed group of red colobus monkeys (Procolobus rufomitratus), testing for: the effects of memory type (Euclidian or landmark based), amount of memory retention, and the effects of social rules in making foraging choices at the scale of the group (independent or leader led). Our results indicate that red colobus movement patterns fit best with simulated groups that have landmark based memory and a follow the leader foraging strategy. Comparisons between simulated agents revealed that social rules had the greatest impact on a group's step length, whereas the type of memory had the highest impact on a group's path tortuosity and cohesion. Using simulation studies as experimental trials to test theories of spatial memory use allows the development of insight into the behavioral mechanisms behind animal movement, developing case-specific results, as well as general results informing how changes to perception and behavior influence movement patterns.

  4. Emergent group level navigation: an agent-based evaluation of movement patterns in a folivorous primate.

    Directory of Open Access Journals (Sweden)

    Tyler R Bonnell

    Full Text Available The foraging activity of many organisms reveal strategic movement patterns, showing efficient use of spatially distributed resources. The underlying mechanisms behind these movement patterns, such as the use of spatial memory, are topics of considerable debate. To augment existing evidence of spatial memory use in primates, we generated movement patterns from simulated primate agents with simple sensory and behavioral capabilities. We developed agents representing various hypotheses of memory use, and compared the movement patterns of simulated groups to those of an observed group of red colobus monkeys (Procolobus rufomitratus, testing for: the effects of memory type (Euclidian or landmark based, amount of memory retention, and the effects of social rules in making foraging choices at the scale of the group (independent or leader led. Our results indicate that red colobus movement patterns fit best with simulated groups that have landmark based memory and a follow the leader foraging strategy. Comparisons between simulated agents revealed that social rules had the greatest impact on a group's step length, whereas the type of memory had the highest impact on a group's path tortuosity and cohesion. Using simulation studies as experimental trials to test theories of spatial memory use allows the development of insight into the behavioral mechanisms behind animal movement, developing case-specific results, as well as general results informing how changes to perception and behavior influence movement patterns.

  5. Polycomb group proteins: navigators of lineage pathways led astray in cancer

    DEFF Research Database (Denmark)

    Bracken, Adrian P; Helin, Kristian

    2009-01-01

    The Polycomb group (PcG) proteins are transcriptional repressors that regulate lineage choices during development and differentiation. Recent studies have advanced our understanding of how the PcG proteins regulate cell fate decisions and how their deregulation potentially contributes to cancer. ...

  6. The effect of group play therapy on social-emotional skills in pre-school children.

    Science.gov (United States)

    Chinekesh, Ahdieh; Kamalian, Mehrnoush; Eltemasi, Masoumeh; Chinekesh, Shirin; Alavi, Manijeh

    2013-12-24

    Childhood is important and critical period in human life. The foundation of ego is shaped in childhood. Play therapy is one of the successful strategies to help children with inner conflicts problems. This method of psychotherapy is base on the normal learning processes of children, provides solutions to relieve feelings of stress, and expands self-expression. Group play therapy can enhance the self-awareness, self- regulation, social communication, empathy and adoptability in children. Present study investigated the effects of play therapy on relational and emotional skills of pre-school children. For this purpose, the total numbers of 372 pre-school children were randomly selected, and divided into two equal groups (case and control). In next step, the BUSSE-SR methodology was used for evaluation and comparison of self-awareness, self-regulation, social interaction, empathy, adoptability, and control groups. Pre-test were performed for both groups and case group was involved in-group play therapy. According to the results of post-test, correlation of variables between case-control groups was examined by multivariate analysis of covariance. Frequency of boys and girls in our sample were 51.3 and 48.7 percent, respectively. The mean age of children was 5.1±0.6 year. According to the results of present study, play therapy significantly enhanced the social-emotional skills (Pskills and communicate with others.

  7. Creative Strategies to Foster Pre-Service School Counselor Group Leader Self-Efficacy

    Science.gov (United States)

    Springer, Sarah I.; Schimmel, Christine J.

    2016-01-01

    Counselor education programs accredited by the Council for Accreditation of Counseling and Related Educational Programs are charged with the important task of providing pre-service school counselors with didactic information and experiential opportunities that prepare students for the realities of group work in the school setting. It is important…

  8. Effects of Cooperative Group Work Activities on Pre-School Children's Pattern Recognition Skills

    Science.gov (United States)

    Tarim, Kamuran

    2015-01-01

    The aim of this research is twofold; to investigate the effects of cooperative group-based work activities on children's pattern recognition skills in pre-school and to examine the teachers' opinions about the implementation process. In line with this objective, for the study, 57 children (25 girls and 32 boys) were chosen from two private schools…

  9. Creative Strategies to Foster Pre-Service School Counselor Group Leader Self-Efficacy

    Science.gov (United States)

    Springer, Sarah I.; Schimmel, Christine J.

    2016-01-01

    Counselor education programs accredited by the Council for Accreditation of Counseling and Related Educational Programs are charged with the important task of providing pre-service school counselors with didactic information and experiential opportunities that prepare students for the realities of group work in the school setting. It is important…

  10. Pre-Session Satiation as a Treatment for Stereotypy During Group Activities.

    Science.gov (United States)

    Rispoli, Mandy; Camargo, Síglia Hoher; Neely, Leslie; Gerow, Stephanie; Lang, Russell; Goodwyn, Fara; Ninci, Jennifer

    2014-05-01

    Individuals with developmental disabilities may engage in automatically reinforced behaviors that may interfere with learning opportunities. Manipulation of motivating operations has been shown to reduce automatically maintained behavior in some individuals. Considering behavioral indicators of satiation may assist in identifying the point at which an abolishing operation has begun to effect behavior. The purpose of this study was to evaluate the effects of pre-session satiation of automatic reinforcement on subsequent levels of stereotypy and activity engagement during group activities for three males ages 5 to 13 years with developmental disabilities. Following functional analyses with analogue conditions, an alternating treatment design compared a pre-session access to stereotypy condition with a no-pre-session access condition prior to group activity sessions. Results indicated that pre-session satiation of the putative reinforcer produced by stereotypy was effective in decreasing stereotypy and increasing activity engagement during subsequent group activities for all participants. These findings add to the literature supporting the effectiveness of abolishing operations to decrease automatically maintained stereotypy.

  11. A novel interplanetary optical navigation algorithm based on Earth-Moon group photos by Chang'e-5T1 probe

    Science.gov (United States)

    Bu, Yanlong; Zhang, Qiang; Ding, Chibiao; Tang, Geshi; Wang, Hang; Qiu, Rujin; Liang, Libo; Yin, Hejun

    2017-02-01

    This paper presents an interplanetary optical navigation algorithm based on two spherical celestial bodies. The remarkable characteristic of the method is that key navigation parameters can be estimated depending entirely on known sizes and ephemerides of two celestial bodies, especially positioning is realized through a single image and does not rely on traditional terrestrial radio tracking any more. Actual Earth-Moon group photos captured by China's Chang'e-5T1 probe were used to verify the effectiveness of the algorithm. From 430,000 km away from the Earth, the camera pointing accuracy reaches 0.01° (one sigma) and the inertial positioning error is less than 200 km, respectively; meanwhile, the cost of the ground control and human resources are greatly reduced. The algorithm is flexible, easy to implement, and can provide reference to interplanetary autonomous navigation in the solar system.

  12. The influence of pre-Slavic ethnic groups on the hydronymy of present-day Slovakia

    Directory of Open Access Journals (Sweden)

    Jaromír Krško

    2015-12-01

    Full Text Available In this paper, we focus on the influence of pre-Slavic ethnic groups on the hydronymy of present-day Slovakia. The migration of entire ethnic groups – especially after the dissolution of the Roman Empire – led to contact between native and incoming people. Ethnic contact also affected languages of these ethnic groups, as mutual influencing and borrowing of vocabulary occurred. Incoming ethnic groups had to find their way around in the new surroundings as well as identify and distinguish important landmarks, mainly hills, mountains and streams. We can approach the issue of pre-Slavic hydronyms from two points of view: one, by analyzing the names preserved from the time period before the arrival of Slavs in the territory of Slovakia, and two, by analyzing the names whose origin some authors consider to be pre-Slavic. The oldest name of a river from the Slovak region comes from the time period before the arrival of the Slavs. It was recorded by the Roman emperor Marcus Aurelius in years 166–180 AD as Granoua. It is a record of the river Hron at which Roman legions fought against the Germanic tribes of the Marcomanni and Quadi. Several historians and linguists believe that besides the rivers Dunaj, Morava and Tisa, other names of big rivers date from before the arrival of Slavs in the central Europe. In the paper, we analyse the names Dunaj, Morava, Váh, Hron, Tisa, Nitra and Hornád.

  13. Research on US navy carrier vehicle and group navigation system%美国海军航母及编队导航系统分析

    Institute of Scientific and Technical Information of China (English)

    宿勇; 郭隆华

    2012-01-01

    This paper researchs on US navy carrier vehicle and group navigation system's core-navigation sensor system interface ( NAVSSI) , consist of system configuration and main functions, analyzes US navy carrier vehicle and group navigation system's information security issues and total information flow, which consist of data input, data inspect, data process and data distribute. Finally, summarize US navy carrier vehicle and group navigation system's characteristic.%重点研究美国航母及编队导航系统的核心——导航传感器系统接口(NAVSSI)的系统构成及主要功能,分析美国航母及编队导航系统从数据输入、数据检查、数据处理到数据分发的整个信息流程及信息安全问题,并总结美国航母及编队导航系统的特点.

  14. Modeling the production of intergalactic light in the pre-collapse phase of galaxy groups

    OpenAIRE

    Solanes, Jose M.; Darriba, Laura; Collaboration, for the IDILICO

    2012-01-01

    This paper reports one recent result from a set of pre-virialized galaxy group simulations that are being used in an investigation of measurement techniques for the quantity of intragroup light (IGL). We present evidence that the binding energy of the stellar material stripped from the galaxies is essentially uncorrelated with the local mass density. This suggests that IGL detection methods based on the distribution of luminosity perform poorly in detecting the unbound stars.

  15. Electrophysiology of Intuition: Pre-stimulus Responses in Group and Individual Participants Using a Roulette Paradigm.

    Science.gov (United States)

    McCraty, Rollin; Atkinson, Mike

    2014-03-01

    This study used electrophysiological measures of pre-stimulus effects that can occur prior to an unknown future event as an indicator of nonlocal intuition. Intuition in this context is considered as a process by which information normally outside the range of conscious awareness is detected at the cellular level by the heart, the brain, and the autonomic nervous system. This study extends the findings of previous experiments demonstrating that aspects of our physiology can respond to an emotionally engaging stimulus before it is actually experienced. The study evaluated a revised version of a roulette protocol, which included two pre-stimulus segments and included an analysis of the individual participant's data over eight separate trials in addition to a group-level analysis. We also assessed the potential effects of the moon phase on the pre-stimulus response outcomes and participant winning and amount won ratios. Data were collected under controlled laboratory conditions from 13 participants in 8 separate sessions using a modified version of a gambling paradigm protocol based on roulette. Half of the experimental sessions were conducted during the full moon phase and half during the new moon phase. Within each trial a total of three segments of physiological data were assessed. There were two separate pre-stimulus periods, pre-bet (4 sec) and postbet (12 sec), and a post-result period (6 sec). Participants were told that they were participating in a gambling experiment and were given an initial starting kitty and told they could keep any winnings over the course of 26 trials for each of the eight sessions. The physiological measures included the electrocardiogram (ECG), from which cardiac inter-beat-intervals (heart rate variability, HRV) were derived, and skin conductance. Before the participants participated in the first session, they completed the Cognitive Styles Index questionnaire, which assesses analytical vs intuitive styles. Overall, the results

  16. Navigating the Paradoxes of Neoliberalism: Quiet Subversion in Mentored Service-Learning for the Pre-Health Humanities.

    Science.gov (United States)

    Fletcher, Erica Hua; Piemonte, Nicole M

    2017-06-29

    In describing the foundations of our pedagogical approaches to service-learning, we seek to go beyond the navel-gazing-at times, paralyzing-paradoxes of neoliberal forces, which can do "good" for students and their communities, yet which also call students into further calculative frameworks for understanding the "value" of pre-health humanities education and social engagement. We discuss methods to create quiet forms of subversion that call for a moral imagination in extending an ethics of care to students as well as to the communities with which they engage. While we recognize the partiality and limitations of our attempts, framing mentored service-learning in unexpected ways can help students and practitioners to understand their role within broader social, historical, cultural, and emotional contexts and encourage them to act intentionally toward the communities they seek to serve in response to this new self-knowledge. To that end, we outline an academically rigorous service-learning intervention at one of our universities.

  17. Radioguided surgery and the GOSTT concept: From pre-operative image and intraoperative navigation to image-assisted excision.

    Science.gov (United States)

    Bowles, H; Sánchez, N; Tapias, A; Paredes, P; Campos, F; Bluemel, C; Valdés Olmos, R A; Vidal-Sicart, S

    Radio-guided surgery has been developed for application in those disease scheduled for surgical management, particularly in areas of complex anatomy. This is based on the use of pre-operative scintigraphic planar, tomographic and fused SPECT/CT images, and the possibility of 3D reconstruction for the subsequent intraoperative locating of active lesions using handheld devices (detection probes, gamma cameras, etc.). New tracers and technologies have also been incorporated into these surgical procedures. The combination of visual and acoustic signals during the intraoperative procedure has become possible with new portable imaging modalities. In daily practice, the images offered by these techniques and devices combine perioperative nuclear medicine imaging with the superior resolution of additional optical guidance in the operating room. In many ways they provide real-time images, allowing accurate guidance during surgery, a reduction in the time required for tissue location and an anatomical environment for surgical recognition. All these approaches have been included in the concept known as (radio) Guided intraOperative Scintigraphic Tumour Targeting (GOSTT). This article offers a general view of different nuclear medicine and allied technologies used for several GOSTT procedures, and illustrates the crossing of technological frontiers in radio-guided surgery. Copyright © 2016 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  18. Design, Development and Pre-Flight Testing of the Communications, Navigation, and Networking Reconfigurable Testbed (Connect) to Investigate Software Defined Radio Architecture on the International Space Station

    Science.gov (United States)

    Over, Ann P.; Barrett, Michael J.; Reinhart, Richard C.; Free, James M.; Cikanek, Harry A., III

    2011-01-01

    The Communication Navigation and Networking Reconfigurable Testbed (CoNNeCT) is a NASA-sponsored mission, which will investigate the usage of Software Defined Radios (SDRs) as a multi-function communication system for space missions. A softwaredefined radio system is a communication system in which typical components of the system (e.g., modulators) are incorporated into software. The software-defined capability allows flexibility and experimentation in different modulation, coding and other parameters to understand their effects on performance. This flexibility builds inherent redundancy and flexibility into the system for improved operational efficiency, real-time changes to space missions and enhanced reliability/redundancy. The CoNNeCT Project is a collaboration between industrial radio providers and NASA. The industrial radio providers are providing the SDRs and NASA is designing, building and testing the entire flight system. The flight system will be integrated on the Express Logistics Carrier (ELC) on the International Space Station (ISS) after launch on the H-IIB Transfer Vehicle in 2012. This paper provides an overview of the technology research objectives, payload description, design challenges and pre-flight testing results.

  19. Freudenthal Duality in Gravity: from Groups of Type E7 to Pre-Homogeneous Spaces

    CERN Document Server

    Marrani, Alessio

    2015-01-01

    Freudenthal duality can be defined as an anti-involutive, non-linear map acting on symplectic spaces. It was introduced in four-dimensional Maxwell-Einstein theories coupled to a non-linear sigma model of scalar fields. In this short review, I will consider its relation to the U-duality Lie groups of type E7 in extended supergravity theories, and comment on the relation between the Hessian of the black hole entropy and the pseudo-Euclidean, rigid special (pseudo)Kaehler metric of the pre-homogeneous spaces associated to the U-orbits.

  20. Software support: Pre-empting the quick question. [User's support group at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Loebel, L.

    1987-09-01

    High energy physicists, researchers and graduate students, from universities all around the world come to Fermi National Accelerator Laboratory to do their experiments. They use our computer facilities to perform all phases of their data-analysis and presentation. We have a large turnover of users and a rather small support group, in a multi-vendor environment. We strive to make our users self-sufficient through the use of well-publicized maintenance procedures, documentation systems, and product support standards. By these pre-emptive measures we attempt to have quick answers at hand for the truly quick questions, leaving us time for the interesting problems.

  1. AUTOMATIC NAVIGATION.

    Science.gov (United States)

    NAVIGATION, REPORTS), (*CONTROL SYSTEMS, *INFORMATION THEORY), ABSTRACTS, OPTIMIZATION, DYNAMIC PROGRAMMING, GAME THEORY, NONLINEAR SYSTEMS, CORRELATION TECHNIQUES, FOURIER ANALYSIS, INTEGRAL TRANSFORMS, DEMODULATION, NAVIGATION CHARTS, PATTERN RECOGNITION, DISTRIBUTION THEORY , TIME SHARING, GRAPHICS, DIGITAL COMPUTERS, FEEDBACK, STABILITY

  2. Trace element analysis of teeth from pre-Columbian population groups in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Solis, C.; Oliver, A.; Andrade, E.; Macias, R. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Mexico (Mexico); Mansilla, J. [Departamento de Antropologia Fisica, Instituto Nacional de Antropologia e Historia, Mexico (Mexico); Chavez-Lomeli, M.E.

    1999-07-01

    Human teeth from pre-Columbian and recent population groups have been analyzed by PIXE. Ancient teeth corresponding to children and adults were obtained from archaeological burials located in five geographic areas of Mexico. Inter-specific and inter-site differences in the trace element contents of enamel were compared in order to get some insight into differences in diet, environmental conditions, teeth health, disease state and post mortem alteration among the co-occurring populations. For permanent teeth from adults, small variations in trace element levels were found depending on the collection site or tooth health, but for deciduous teeth from children, the concentration of elements such as Mn, Fe and Sr varied considerably. In this work, the possible sources of variation are discussed. (author)

  3. Lecturers' experiences of facilitating guided group reflection with pre-registration BSc Nursing students.

    Science.gov (United States)

    Mc Carthy, Jane; Cassidy, Irene; Tuohy, Dympna

    2013-01-01

    The development of reflective practitioners is integral to undergraduate nursing degree programmes. This study reports on lecturers' experiences of facilitating guided group reflection with pre-registration BSc Nursing students.The research purposively sampled lecturers (n=7) working in a department of nursing and midwifery at a third level institute in Ireland, all of whom were registered nurses. Using a qualitative research approach, data was collected through audio-taped semi-structured individual interviews. The data were thematically analysed using guidelines developed by Braun and Clarke (2006). Tripartite researcher discussion and further analysis of these initial individual analyses led to consensus regarding the three themes arising from the study. These were: Being a facilitator; Facilitating reflective learning and Creating structure. The discussion centred on: having knowledge and experience to effectively facilitate guided group reflection; the influence of the facilitator's personal philosophy on reflection and adult learning on group facilitation; and finally concerns regarding professional responsibility in response to students' reflective practice accounts.

  4. Examining the Impact of Novel Pre-activity Tasks on Macroskills: The Case of Group Discussion on Writing Ability

    Directory of Open Access Journals (Sweden)

    Hooshang Khoshsima

    2016-02-01

    Full Text Available The main concern of most researchers in the field of second and foreign language teaching is lessening the problems and eliminating the hinders on the way of learning a language. Writing is considered as one of the most challenging and complicated tasks for learners to perform particularly when they have to write in a second or foreign language. Numerous studies were done on the importance of the pre-writing stage and activities which are directly and indirectly related to the theme of the writing. Accordingly, the main aim of this study was to examine the effects of group discussion as a pre- activity task on writing ability. To this aim, 27 Iranian EFL learners, who were at the same level –intermediate- studying at Shokuh and Safir Institutes, Birjand, Iran were chosen randomly. Two groups- one control and one experimental group- were studied. In control group the conventional method was used in teaching writing, while in experimental group, group discussion pre-activity task was administered. After 16 sessions, the obtained data of the pretests and posttests was analyzed by SPSS software. According to the results, researcher strongly concluded that group discussion has no significant effect on writing ability of Iranian intermediate learners. This study can help teachers and syllabus designers in choosing and applying an effective pre-activity task. Keywords: writing ability, pre-activity task, group discussion, EFL learners

  5. Robot-Assisted Navigation versus Computer-Assisted Navigation in Primary Total Knee Arthroplasty: Efficiency and Accuracy.

    Science.gov (United States)

    Clark, Tanner C; Schmidt, Frank H

    2013-01-01

    Background. Since the introduction of robot-assisted navigation in primary total knee arthroplasty (TKA), there has been little research conducted examining the efficiency and accuracy of the system compared to computer-assisted navigation systems. Objective. To compare the efficiency and accuracy of Praxim robot-assisted navigation (RAN) and Stryker computer-assisted navigation (CAN) in primary TKA. Methods. This was a retrospective study consisting of 52 patients who underwent primary TKA utilizing RAN and 29 patients utilizing CAN. The primary outcome measure was navigation time. Secondary outcome measures included intraoperative final mechanical axis alignment, intraoperative robot-assisted bone cut accuracy, tourniquet time, and hospitalization length. Results. RAN navigation times were, on average, 9.0 minutes shorter compared to CAN after adjustment. The average absolute intraoperative malalignment was 0.5° less in the RAN procedures compared to the CAN procedures after adjustment. Patients in the RAN group tended to be discharged 0.6 days earlier compared to patients in the CAN group after adjustment. Conclusions. Among patients undergoing TKA, there was decreased navigation time, decreased final malalignment, and decreased hospitalization length associated with the use of RAN when compared to CAN independent of age, BMI, and pre-replacement alignment.

  6. An excellent navigation system and experience in craniomaxillofacial navigation surgery: a double-center study.

    Science.gov (United States)

    Dai, Jiewen; Wu, Jinyang; Wang, Xudong; Yang, Xudong; Wu, Yunong; Xu, Bing; Shi, Jun; Yu, Hongbo; Cai, Min; Zhang, Wenbin; Zhang, Lei; Sun, Hao; Shen, Guofang; Zhang, Shilei

    2016-06-16

    Numerous problems regarding craniomaxillofacial navigation surgery are not well understood. In this study, we performed a double-center clinical study to quantitatively evaluate the characteristics of our navigation system and experience in craniomaxillofacial navigation surgery. Fifty-six patients with craniomaxillofacial disease were included and randomly divided into experimental (using our AccuNavi-A system) and control (using Strker system) groups to compare the surgical effects. The results revealed that the average pre-operative planning time was 32.32 mins vs 29.74 mins between the experimental and control group, respectively (p > 0.05). The average operative time was 295.61 mins vs 233.56 mins (p > 0.05). The point registration orientation accuracy was 0.83 mm vs 0.92 mm. The maximal average preoperative navigation orientation accuracy was 1.03 mm vs 1.17 mm. The maximal average persistent navigation orientation accuracy was 1.15 mm vs 0.09 mm. The maximal average navigation orientation accuracy after registration recovery was 1.15 mm vs 1.39 mm between the experimental and control group. All patients healed, and their function and profile improved. These findings demonstrate that although surgeons should consider the patients' time and monetary costs, our qualified navigation surgery system and experience could offer an accurate guide during a variety of craniomaxillofacial surgeries.

  7. Immediate stress reduction effects of yoga during pregnancy: One group pre-post test.

    Science.gov (United States)

    Kusaka, Momoko; Matsuzaki, Masayo; Shiraishi, Mie; Haruna, Megumi

    2016-10-01

    Excessive stress during pregnancy may cause mental disorders in pregnant women and inhibit fetal growth. Yoga may alleviate stress during pregnancy. To verify the immediate effects of yoga on stress response during pregnancy. One group pre-post test was conducted at a hospital in Japan. We recruited 60 healthy primiparas without complications and asked them to attend yoga classes twice a month and to practice yoga at their homes using DVD 3 times a week from 20 gestational weeks until childbirth. Salivary cortisol and alpha-amylase concentration were measured before and after yoga classes at time 1 (27-32 gestational weeks) and time 2 (34-37 gestational weeks). Subjective mood was assessed using the profile of mood states. Saliva values and mood scores before and after each yoga class were compared using paired t-test and Wilcoxon rank-sum test, respectively. We analyzed 44 and 35 women at time 1 and time 2, respectively. The mean salivary cortisol concentration declined significantly after each yoga class [time 1: 0.36-0.26μg/dL (pstress reduction effects of yoga during pregnancy. Copyright © 2016 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  8. Single Group, Pre- and Post-Test Research Designs: Some Methodological Concerns

    Science.gov (United States)

    Marsden, Emma; Torgerson, Carole J.

    2012-01-01

    This article provides two illustrations of some of the factors that can influence findings from pre- and post-test research designs in evaluation studies, including regression to the mean (RTM), maturation, history and test effects. The first illustration involves a re-analysis of data from a study by Marsden (2004), in which pre-test scores are…

  9. Update Your Status: Exploring Pre-Service Teacher Identities in an Online Discussion Group

    Science.gov (United States)

    Lu, Yolanda; Curwood, Jen Scott

    2015-01-01

    A substantial body of research indicates that a teacher's identity is an essential aspect of their professional practice. As this body of research grows, researchers have increasingly sought to investigate the nature of pre-service teacher identities. This paper reports on a study that examined identities in the context of a pre-service cohort's…

  10. Update Your Status: Exploring Pre-Service Teacher Identities in an Online Discussion Group

    Science.gov (United States)

    Lu, Yolanda; Curwood, Jen Scott

    2015-01-01

    A substantial body of research indicates that a teacher's identity is an essential aspect of their professional practice. As this body of research grows, researchers have increasingly sought to investigate the nature of pre-service teacher identities. This paper reports on a study that examined identities in the context of a pre-service cohort's…

  11. Single Group, Pre- and Post-Test Research Designs: Some Methodological Concerns

    Science.gov (United States)

    Marsden, Emma; Torgerson, Carole J.

    2012-01-01

    This article provides two illustrations of some of the factors that can influence findings from pre- and post-test research designs in evaluation studies, including regression to the mean (RTM), maturation, history and test effects. The first illustration involves a re-analysis of data from a study by Marsden (2004), in which pre-test scores are…

  12. The association between retrospective outcome evaluations and pre-post-treatment changes in psychodynamic group-psychotherapy

    DEFF Research Database (Denmark)

    Jensen, Hans Henrik; Mortensen, Erik Lykke; Lotz, Martin

    2008-01-01

    In the present study of 203 patients in psychodynamic group psychotherapy, we explore associations between patient and therapist global retrospective outcome evaluations (ROE), and pre-post-treatment changes on the Symptom Check List 90 Revised (SCL-90-R) and non-symptomatic focus of therapy. The...

  13. Surgical neuro navigator guided by preoperative magnetic resonance images, based on a magnetic position sensor;Neuronavegador cirurgico guiado por imagens de ressonancia magnetica pre-operatoria, baseado num transdutor de posicao magnetico

    Energy Technology Data Exchange (ETDEWEB)

    Perini, Ana Paula; Siqueira, Rogerio Bulha; Carneiro, Antonio Adilton Oliveira, E-mail: adilton@ffclrp.usp.b [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica; Oliveira, Lucas Ferrari de [Universidade Federal de Pelotas (UFPel), RS (Brazil). Dept. de Informatica; Machado, Helio Rubens [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Dept. de Neurocirurgia

    2009-08-15

    Image guided neurosurgery enables the neurosurgeon to navigate inside the patient's brain using pre-operative images as a guide and a tracking system, during a surgery. Following a calibration procedure, three-dimensional position and orientation of surgical instruments may be transmitted to computer. The spatial information is used to access a region of interest, in the pre-operative images, displaying them to the neurosurgeon during the surgical procedure. However, when a craniotomy is involved and the lesion is removed, movements of brain tissue can be a significant source of error in these conventional navigation systems. The architecture implemented in this work intends the development of a system to surgical planning and orientation guided by ultrasound image. For surgical orientation, the software developed allows the extraction of slices from the volume of the magnetic resonance images (MRI) with orientation supplied by a magnetic position sensor (Polhemus{sup R}). The slices extracted with this software are important because they show the cerebral area that the neurosurgeon is observing during the surgery, and besides they can be correlated with the intra-operative ultrasound images to detect and to correct the deformation of brain tissue during the surgery. Also, a tool for per-operative navigation was developed, providing three orthogonal planes through the image volume. In the methodology used for the software implementation, the Python{sup tm} programming language and the Visualization Toolkit (VTK) graphics library were used. The program to extract slices of the MRI volume allowed the application of transformations in the volume, using coordinates supplied by the position sensor. (author)

  14. The perceived benefits of belonging to an extra curricular group within a pre-registration nursing course.

    Science.gov (United States)

    Gerrard, Sabina; Billington, John

    2014-05-01

    This study describes a qualitative research design that focuses on nursing students who were aligned to different extra-curricular groups (a student representative committee, a Nurses' Day Committee and a magazine editorial team) within the School of Health. The study explores the nursing students' experiences and perceptions of belonging to an extra-curricular group within a pre-registration nursing course. Data were collected using focus groups. The findings of this study suggest that students who are members of extra-curricular groups perceive group membership to have many positive benefits. The findings were grouped into three main themes namely: employability, retention and personal gain. The findings suggest that students are clearly aware of their career development and expressed how group membership meant they were able to develop skills around employability. Students highlighted that they gained support and built lasting relationships through the groups which supported and reassured them which it was felt enabled them to progress successfully through the course. These themes reinforce the value of having established groups within a pre-registration curriculum.

  15. Reflection in Action: Using Inquiry Groups to Explore Critical Digital Literacy with Pre-Service Teachers

    Science.gov (United States)

    Lohnes Watulak, Sarah

    2016-01-01

    The challenge of preparing teachers and their eventual students to be successful, full participants in today's digital society is one that faces all teacher preparation programs. However, in the United States our current system of technology instruction in pre-service education focuses primarily on functional technology skills, and critical and…

  16. Reflection in Action: Using Inquiry Groups to Explore Critical Digital Literacy with Pre-Service Teachers

    Science.gov (United States)

    Lohnes Watulak, Sarah

    2016-01-01

    The challenge of preparing teachers and their eventual students to be successful, full participants in today's digital society is one that faces all teacher preparation programs. However, in the United States our current system of technology instruction in pre-service education focuses primarily on functional technology skills, and critical and…

  17. 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...

  18. From the Dress-Up Corner to the Senior Prom: Navigating Gender and Sexuality Diversity in PreK-12 Schools

    Science.gov (United States)

    Bryan, Jennifer

    2012-01-01

    Very few PreK-12 teachers are adequately trained to address the gender identity and sexual identity of their students in a developmentally-appropriate and pedagogically-sound manner. Yet responsible adults--parents, educators, pre-service teachers, coaches, religious instructors, camp administrators and school counselors--must help children…

  19. Effects of Tagcloud-Anchored Group Discussions on Pre-Service Teachers' Collaborative Knowledge Construction

    Science.gov (United States)

    Lin, Shu-Yuan; Xie, Ying

    2017-01-01

    Group discussions are critical for students constructing new understanding and knowledge in both classroom and distance education. Tagclouds can provide an intuitive overview about the group's collective knowledge and could potentially be used as an anchor for group discussions. The effect of using tagclouds as anchors for group discussions was…

  20. Identity Politics, Justice and the Schooling of Muslim Girls: Navigating the Tensions between Multiculturalism, Group Rights and Feminism

    Science.gov (United States)

    Keddie, Amanda

    2014-01-01

    This article focuses on the concerns expressed by three female Muslim educators who are support staff at an English comprehensive school. Consistent with the debates associated with multiculturalism, group rights and feminism, the article illuminates spaces of gender constraint and possibility within the discourses shaping these women's lives and…

  1. Identity Politics, Justice and the Schooling of Muslim Girls: Navigating the Tensions between Multiculturalism, Group Rights and Feminism

    Science.gov (United States)

    Keddie, Amanda

    2014-01-01

    This article focuses on the concerns expressed by three female Muslim educators who are support staff at an English comprehensive school. Consistent with the debates associated with multiculturalism, group rights and feminism, the article illuminates spaces of gender constraint and possibility within the discourses shaping these women's lives…

  2. Identity Politics, Justice and the Schooling of Muslim Girls: Navigating the Tensions between Multiculturalism, Group Rights and Feminism

    Science.gov (United States)

    Keddie, Amanda

    2014-01-01

    This article focuses on the concerns expressed by three female Muslim educators who are support staff at an English comprehensive school. Consistent with the debates associated with multiculturalism, group rights and feminism, the article illuminates spaces of gender constraint and possibility within the discourses shaping these women's lives and…

  3. Treatment of children with early pre-B and pre-B acute lymphocytic leukemia with antimetabolite-based intensification regimens: a Pediatric Oncology Group Study.

    Science.gov (United States)

    Harris, M B; Shuster, J J; Pullen, J; Borowitz, M J; Carroll, A J; Behm, F G; Camitta, B; Land, V J

    2000-09-01

    Between May 1987 and January 1991, 1354 patients, 1-21 years old, with standard or poor prognosis B-lineage acute lymphocytic leukemia were treated on the Pediatric Oncology Group Study 8602. One thousand three hundred and twenty-three patients entered remission and 1051 patients were randomized on day 43 to an intensification regimen containing L-asparaginase and intermediate-dose methotrexate (regimen B) or cytarabine and intermediate dose methotrexate (regimen C). After completion of intensification at week 25, all patients received the same maintenance therapy until 3 years from diagnosis. Overall 5-year continuous complete remission (CCR) for regimen B was 72+/-2% (s.e.) and for regimen C, 73+/-2% (P = 0.72 by log-rank analysis). Significant differences between treatments for CCR, testicular, CNS relapses overall or with regard to phenotype (pre-B vs early pre-B), gender, or race were not detected. During intensification, regimen C had significantly more bacterial infections (P = 0.05) and days spent in the hospital (P intensification phase of therapy in children with B-lineage acute lymphocytic leukemia.

  4. Influence of pre-Mississippian paleogeology on Carboniferous Lisburne Group, Arctic National Wildlife Refuge, northeastern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Watts, K.F.; Carlson, R.; Imm, T.; Gruzlovic, P.; Hanks, C.

    1988-01-01

    The Carboniferous Lisburne Group of northern Alaska formed an extensive carbonate platform, which was later deformed as part of the Brooks Range fold and thrust belt. In the northeast, the Lisburne Group is parautochthonous and analogous to that at Prudhoe Bay. The Lisburne's paleogeography and facies relationships pertain to assessment of the petroleum potential of the Arctic National Wildlife Refuge (ANWR). The Franklinian paleogeology, unconformably underlying the Ellesmerial sequence, has influenced sedimentation patterns in the Lisburne Group. The transgressive Endicott Group (Kekiktuk conglomerate and Kayak Shale) and Lisburne Group thin northward over Franklinian basement highs. In the Sadlerochit Mountains, the Katakturuk Dolomite formed a paleotopographic high over which the Endicott Group pinched out and the Lisburne Group thinned. Shallow-marine oolitic grainstone developed in the cyclic Pennsylvanian Wahoo Limestone. To the south in the Shublik Mountains, a repeated sequence of Katakturuk Dolomite and the Nanook Limestone were lower, so the Endicott Group lapped over the area and was later overlain by comparable Lisburne Group rocks. In the Fourth Range, the Lisburne Group is thicker and limestones also occur in the upper Endicott Group. Oolitic grainstone in the Wahoo Limestone is rare, and broad ooid shoals apparently pinched out into deeper water carbonates on a southward sloping carbonate ramp.

  5. Influence of pre-Mississippian paleogeology on Carboniferous Lisburne Group, Arctic National Wildlife refuge, northeastern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Watts, K.F.; Carlson, R.; Imm, T.; Gruzlovic, P.; Hanks, C.

    1988-02-01

    The Carboniferous Lisburne Group of northern Alaska formed an extensive carbonate platform, which was later deformed as part of the Brooks Range fold and thrust belt. In the northeast, the Lisburne Group is parautochthonous and analogous to that at Prudhoe Bay. The Lisburne's paleogeography and facies relationships pertain to assessment of the petroleum potential of the Arctic National Wildlife Refuge (ANWR). The Franklinian paleogeology, unconformably underlying the Ellesmerian sequence, has influenced sedimentation patterns in the Lisburne Group. The transgressive Endicott Group (Kekiktuk Conglomerate and Kayak, Shale) and Lisburne Group thin northward over Franklinian basement highs. In the Sadlerochit Mountains, the Katakturuk Dolomite formed a paleotopographic high over which the Endicott Group inched out and the Lisburne Group thinned. Shallow-marine oolitic grainstone developed in the cyclic Pennsylvanian Wahoo Limestone.

  6. Comparison of postoperative pain relief by intercostal block between pre-rib harvest and post-rib harvest groups.

    Science.gov (United States)

    Bashir, Muhammad Mustehsan; Shahzad, Muhammad Ateeq; Yousaf, Muhammad Nadeem; Khan, Bilal Ahmad; Khan, Farid Ahmad

    2014-01-01

    To compare intercostal nerve block before and after rib harvest in terms of mean postoperative pain score and mean postoperative tramadol usage. Randomized controlled trial. Department of Plastic Surgery, Mayo Hospital, KEMU, Lahore, from January 2011 to July 2012. Patients (n = 120) of either gender with ASA class-I and II requiring autogenous costal cartilage graft were inducted. Patients having history of local anaesthetic hypersensitivity and age 60 years were excluded. Subjects were randomly assigned to pre-rib harvest (group-1) and post-rib harvest (group-2). Local anaesthetic mixture was prepared by adding 10 milliliters 2% lidocaine to 10 milliliters 0.5% bupivacaine to obtain a total 20 ml solution. Group-1 received local anaesthetic infiltration along the proposed incision lines and intercostals block before the rib harvest. Group-2 received the infiltration and block after rib harvest. Postoperative consumption of tramadol and pain scores were measured at 6 and 12 hours postoperatively using VAS. Mean age was 31.43 ± 10.78 years. The mean pain scores at 6 hours postoperatively were 1.033 ± 0.609 and 2.4667 ± 0.812 in pre-rib harvest and post-rib harvest groups respectively (p Intercostal block administered before rib harvest as preemptive strategy result in decreased postoperative pain scores and narcotic use.

  7. The Use of Pre-Group Instruction to Improve Student Collaboration

    Science.gov (United States)

    Snyder, Lisa Gueldenzoph

    2010-01-01

    The emphasis on the importance of collaborative skill is evident at nearly all levels of education. In higher education, teamwork and group skills are critical elements in a business student's training. To be successful in the business world, students must be able to work well in teams. Group work can be a successful learning experience if…

  8. The Use of Pre-Group Instruction to Improve Student Collaboration

    Science.gov (United States)

    Snyder, Lisa Gueldenzoph

    2010-01-01

    The emphasis on the importance of collaborative skill is evident at nearly all levels of education. In higher education, teamwork and group skills are critical elements in a business student's training. To be successful in the business world, students must be able to work well in teams. Group work can be a successful learning experience if…

  9. PlantPAN: Plant promoter analysis navigator, for identifying combinatorial cis-regulatory elements with distance constraint in plant gene groups

    Directory of Open Access Journals (Sweden)

    Huang Hsien-Da

    2008-11-01

    Full Text Available Abstract Background The elucidation of transcriptional regulation in plant genes is important area of research for plant scientists, following the mapping of various plant genomes, such as A. thaliana, O. sativa and Z. mays. A variety of bioinformatic servers or databases of plant promoters have been established, although most have been focused only on annotating transcription factor binding sites in a single gene and have neglected some important regulatory elements (tandem repeats and CpG/CpNpG islands in promoter regions. Additionally, the combinatorial interaction of transcription factors (TFs is important in regulating the gene group that is associated with the same expression pattern. Therefore, a tool for detecting the co-regulation of transcription factors in a group of gene promoters is required. Results This study develops a database-assisted system, PlantPAN (Plant Promoter Analysis Navigator, for recognizing combinatorial cis-regulatory elements with a distance constraint in sets of plant genes. The system collects the plant transcription factor binding profiles from PLACE, TRANSFAC (public release 7.0, AGRIS, and JASPER databases and allows users to input a group of gene IDs or promoter sequences, enabling the co-occurrence of combinatorial transcription factor binding sites (TFBSs within a defined distance (20 bp to 200 bp to be identified. Furthermore, the new resource enables other regulatory features in a plant promoter, such as CpG/CpNpG islands and tandem repeats, to be displayed. The regulatory elements in the conserved regions of the promoters across homologous genes are detected and presented. Conclusion In addition to providing a user-friendly input/output interface, PlantPAN has numerous advantages in the analysis of a plant promoter. Several case studies have established the effectiveness of PlantPAN. This novel analytical resource is now freely available at http://PlantPAN.mbc.nctu.edu.tw.

  10. Experiences and Comfort with Culturally Diverse Groups in Undergraduate Pre-Nursing Students.

    Science.gov (United States)

    Eliason, Michele J.; Raheim, Salome

    2000-01-01

    A survey of 196 white students in prenursing found they had little discomfort with diverse racial/ethnic groups. They would have considerable difficulty working with lesbian, gay, or bisexual clients or patients with AIDS. Reasons for discomfort included lack of knowledge, skill, or exposure; disapproval of sexual orientation; and sympathy, pity,…

  11. Non-rigid alignment of pre-operative MRI, fMRI, and DT-MRI with intra-operative MRI for enhanced visualization and navigation in image-guided neurosurgery.

    Science.gov (United States)

    Archip, Neculai; Clatz, Olivier; Whalen, Stephen; Kacher, Dan; Fedorov, Andriy; Kot, Andriy; Chrisochoides, Nikos; Jolesz, Ferenc; Golby, Alexandra; Black, Peter M; Warfield, Simon K

    2007-04-01

    The usefulness of neurosurgical navigation with current visualizations is seriously compromised by brain shift, which inevitably occurs during the course of the operation, significantly degrading the precise alignment between the pre-operative MR data and the intra-operative shape of the brain. Our objectives were (i) to evaluate the feasibility of non-rigid registration that compensates for the brain deformations within the time constraints imposed by neurosurgery, and (ii) to create augmented reality visualizations of critical structural and functional brain regions during neurosurgery using pre-operatively acquired fMRI and DT-MRI. Eleven consecutive patients with supratentorial gliomas were included in our study. All underwent surgery at our intra-operative MR imaging-guided therapy facility and have tumors in eloquent brain areas (e.g. precentral gyrus and cortico-spinal tract). Functional MRI and DT-MRI, together with MPRAGE and T2w structural MRI were acquired at 3 T prior to surgery. SPGR and T2w images were acquired with a 0.5 T magnet during each procedure. Quantitative assessment of the alignment accuracy was carried out and compared with current state-of-the-art systems based only on rigid registration. Alignment between pre-operative and intra-operative datasets was successfully carried out during surgery for all patients. Overall, the mean residual displacement remaining after non-rigid registration was 1.82 mm. There is a statistically significant improvement in alignment accuracy utilizing our non-rigid registration in comparison to the currently used technology (paugmented reality visualization to aid the surgeon.

  12. [The model of Human Caring: results of a pre- and post-intervention study with a control group].

    Science.gov (United States)

    Brunetti, Piercarlo; Pellegrini, Walter; Masera, Giuliana; Berchialla, Paola; Dal Molin, Alberto

    2015-01-01

    The "Human Caring" model is a philosophy of care based on individual centrality and which, although developed within nursing discipline, could be used by all professionals who take care of individuals. Nurses who work within the field of Mental Health, is subjected to a considerable emotional burden and it is believed that the introduction of this model can have a positive impact. To evaluate the effects of the introduction of the model Human Caring in the Department of Mental Health Asl Cuneo 1, in order to improve health care professionals' well-being and patients' perception with respect to care and assistance. A pre and post intervention design approach with control group where variables were measured before (T0) and after (T1) the implementation of the model of care Human Caring. 80 health care professionals and 125 clients were observed. Results show a non statistically significant difference between the pre and post test both for health care professionals and clients. Human Caring model does not seem to have a positive impact in the short term. However, it is arguably a protective action for health care professionals that further studies should deeply explore with longer period of follow-up.

  13. Situated navigational working memory: the role of positive mood.

    Science.gov (United States)

    Palmiero, Massimiliano; Nori, Raffaella; Rogolino, Carmelo; D'Amico, Simonetta; Piccardi, Laura

    2015-09-01

    The perspective of situated cognition assumes that cognition is not separated from the context. In the present study, the issue if visuospatial memory and navigational working memory are situated was explored by manipulating participants' mood (positive, negative and neutral) while performing two different tasks. College students were randomly assigned to the group of positive, negative or neutral music. Participants filled out the positive and negative affect schedule (PANAS) before and after carrying out the Corsi Test and the Walking Corsi Test. Both tasks were performed forward and backward. Music was played throughout the memory tasks. Firstly, comparing pre-mood induction PANAS scores to post-mood induction PANAS scores, results showed that only positive affects were manipulated: After mood induction, the Positive Music Group produced higher scores, whereas the Negative Music Group produced lower scores than before mood induction; the Neutral Music Group produced no effect. Secondly, the Positive Music Group produced higher scores than Negative and Neutral Music Groups both at the Corsi Test and at the Walking Corsi Test. These results show that situational contexts that induce a specific mood can affect visuospatial memory and navigational working memory, and open to the idea that positive emotions may play a crucial role in enhancing navigational strategies.

  14. 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...

  15. Flippin' Fluid Mechanics - Quasi-experimental Pre-test and Post-test Comparison Using Two Groups

    Science.gov (United States)

    Webster, D. R.; Majerich, D. M.; Luo, J.

    2014-11-01

    A flipped classroom approach has been implemented in an undergraduate fluid mechanics course. Students watch short on-line videos before class, participate in active in-class problem solving (in dyads), and complete individualized on-line quizzes weekly. In-class activities are designed to achieve a trifecta of: 1. developing problem solving skills, 2. learning subject content, and 3. developing inquiry skills. The instructor and assistants provide critical ``just-in-time tutoring'' during the in-class problem solving sessions. Comparisons are made with a simultaneous section offered in a traditional mode by a different instructor. Regression analysis was used to control for differences among students and to quantify the effect of the flipped fluid mechanics course. The dependent variable was the students' combined final examination and post-concept inventory scores and the independent variables were pre-concept inventory score, gender, major, course section, and (incoming) GPA. The R-square equaled 0.45 indicating that the included variables explain 45% of the variation in the dependent variable. The regression results indicated that if the student took the flipped fluid mechanics course, the dependent variable (i.e., combined final exam and post-concept inventory scores) was raised by 7.25 points. Interestingly, the comparison group reported significantly more often that their course emphasized memorization than did the flipped classroom group.

  16. OAST Space Theme Workshop. Volume 3: Working group summary. 1: Navigation, guidance, control (E-1) A. Statement. B. Technology needs (form 1). C. Priority assessment (form 2)

    Science.gov (United States)

    1976-01-01

    The six themes identified by the Workshop have many common navigation guidance and control needs. All the earth orbit themes have a strong requirement for attitude, figure and stabilization control of large space structures, a requirement not currently being supported. All but the space transportation theme have need for precision pointing of spacecraft and instruments. In addition all the themes have requirements for increasing autonomous operations for such activities as spacecraft and experiment operations, onboard mission modification, rendezvous and docking, spacecraft assembly and maintenance, navigation and guidance, and self-checkout, test and repair. Major new efforts are required to conceptualize new approaches to large space antennas and arrays that are lightweight, readily deployable, and capable of precise attitude and figure control. Conventional approaches offer little hope of meeting these requirements. Functions that can benefit from increasing automation or autonomous operations are listed.

  17. Prevalence of Human Papillomavirus (HPV in upper respiratory tract mucosa in a group of pre-school children

    Directory of Open Access Journals (Sweden)

    Jaroslaw Szydłowski

    2014-11-01

    Full Text Available [b]introduction[/b]. Human Papillomavirus (HPV is a group of DNA viruses which is an etiological factor of many benign and malignant diseases of the upper respiratory tract mucosa, female genital tract and the skin. HPV infection is considered a sexually-transmitted infection, but can also be transmitted by non-sexual routes, including perinatal vertical transmission, physical contact, iatrogenic infection and autoinoculation. Recurrent Respiratory Papillomatosis (RRP in children is connected with HPV infection transmitted vertically from mother to child during the passage of the foetus through an infected birth canal. [b]objective. [/b]The aim of this study was to establish the level of Human Papillomaviruses carrier state in upper respiratory tract mucosa in healthy pre-school children, and to identify potential risk factors for HPV infection. [b]materials and method[/b]. After obtaining consent from their parents, 97 pre-school children were examined – 51 girls and 46 boys between the ages of 3 – 5 years; average age – 4 years and 5 months. 68 children were urban dwellers and 29 came from a rural environment. A questionnaire with detailed history was taken including parents’ and child`s personal data, as well as perinatal risk factors in pregnancy. Socio-demographic information was also obtained, including the standard of living, and chosen environmental factors. Routine ENT examination was performed. Exfoliated oral squamous cells were collected from swabs and analysed for the presence of DNA papillomaviruses by polymerase chain reaction. [b]results.[/b] The presence of HPV in the respiratory tract in children was detected in 19.6% cases. ‘High oncogenic potential’ HPVs, such as HPV-16 and HPV-18, were not observed in squamous cell mucosa of the respiratory tract in the children. No significant differences were observed between the HPV carrier state in urban and rural inhabitants.

  18. Computer navigation versus fluoroscopy-guided navigation for thoracic pedicle screw placement: a meta-analysis.

    Science.gov (United States)

    Meng, Xiao-Tong; Guan, Xiao-Fei; Zhang, Hai-Long; He, Shi-Sheng

    2016-07-01

    Although application of intraoperative computer navigation technique had been integrated into placement of pedicle screws (PSs) in thoracic fusion for years, its security and practicability remain controversial. The aim of this study is to evaluate the accuracy, the operative time consumption, the amount of intraoperative blood loss, time of pedicle insertion and the incidence of complications of thoracic pedicle screw placement in patients with thoracic diseases such as scoliosis and kyphosis. Pubmed, Web of Knowledge, and Google scholar were searched to identify comparative studies of thoracic pedicle screw placement between intraoperative computer navigation and fluoroscopy-guided navigation. Outcomes of malposition rate, operative time consumption, insertion time, intraoperative blood loss, and the incidence of complications are evaluated. Fourteen articles including 1723 patients and 9019 PSs were identified matching inclusion criteria. The malposition rate was lower (RR: 0.33, 95 % CI: 0.28-0.38, P navigation group than that in fluoroscopy-guided navigation group; the operative time was significantly longer [weighted mean difference (WMD) = 23.66, 95 % CI: 14.74-32.57, P navigation group than that in fluoroscopy-guided navigation group. The time of insertion was shorter (WMD = -1.88, 95 % CI: -2.25- -1.52, P navigation group than that in fluoroscopy-guided navigation group. The incidence of complications was lower (RR = 0. 23, 95 % CI: 0.12-0.46, P navigation group than that in the other group. The intraoperative blood loss was fewer (WMD = -167.49, 95 % CI: -266.39- -68.58, P navigation group than that in the other. In conclusion, the meta-analysis of thoracic pedicle screw placement studies clearly demonstrated lower malposition rate, less intraoperative blood loss, and fewer complications when using computer navigation. This result provides strong evidence that computer technology could be safer and more reliable than

  19. Speech Recognition Technology Applied to Intelligent Mobile Navigation System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The capability of human-computer interaction reflects the intelligent degree of mobile navigation system.The navigation data and functions of mobile navigation system are divided into system commands and non-system commands in this paper.And then a group of speech commands are Abstracted.This paper applies speech recognition technology to intelligent mobile navigation system to process speech commands and does some deep research on the integration of speech recognition technology with mobile navigation system.The navigation operation can be performed by speech commands,which makes human-computer interaction easy during navigation.Speech command interface of navigation system is implemented by Dutty ++ Software,which is based on speech recognition system -Via Voice of IBM.Through navigation experiments,navigation can be done almost without keyboard,which proved that human-computer interaction is very convenient by speech commands and the reliability is also higher.

  20. The Effectiveness of the Constant Time Delay Procedure in Teaching Pre-School Academic Skills to Children with Developmental Disabilities in a Small Group Teaching Arrangement

    Science.gov (United States)

    Aldemir, Ozgul; Gursel, Oguz

    2014-01-01

    Children with developmental disabilities are trained using different teaching arrangements. One of these arrangements is called small-group teaching. It has been ascertained that a small-group teaching arrangement is more effective than a one-to-one teaching arrangement. In that sense, teaching academic skills to pre-school children in small-group…

  1. Spatial navigation in young versus older adults

    Directory of Open Access Journals (Sweden)

    Ivana eGazova

    2013-12-01

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

  2. Adenoid and tonsil surgeries in children: How relevant is pre-operative blood grouping and cross-matching?

    Directory of Open Access Journals (Sweden)

    Lucky Onotai

    2013-01-01

    Full Text Available Background: As a part of pre-operative evaluation, several otolaryngologists group and cross-match blood routinely for children undergoing adenoid and tonsil surgeries. This practice has generated several debates either in support or against this practice. The aim of this study is to critically evaluate the incidence of post-tonsillectomy (with or without adenoidectomy bleeding and blood transfusions in otherwise healthy children with adenoid/tonsil pathologies conducted in the University of Port Harcourt Teaching Hospital (UPTH. Patients and Methods: A descriptive retrospective study of children who underwent adenoid and tonsil surgeries in the Department of Ear, Nose and Throat (ENT surgery of UPTH from January 2003 to December 2012. Children with family history of bleeding disorders and derangement of clotting profile as well as different co-morbidity like sickle cell disease were excluded from this study. The patients′ data were retrieved from the registers of ENT out-patient clinics, theatre registers and patients case notes. Demographic data, indications for surgery, preoperative investigations, complications and management outcomes were recorded and analyzed. Results: Out of 145 children that had adenoid and tonsil surgeries; only 100 met the criteria for this study. The study subjects included 65 males and 35 females (male: female ratio 1.9:1 belonging to 0-16 years age group (mean age: 3.46 ± 2.82 years. The age group of 3-5 years had the highest (n = 40, 40% number of surgeries. Adenotonsillectomy was the commonest (n = 85, 85% surgery performed on patients who had obstructive sleep apnea (OSA. The commonest (n = 6, 6% complication was haemorrhage, and only few (n = 3, 3% patients had blood transfusion. However, mortality was recorded in some (n = 3, 3% patients. Conclusion: This study confirms that the incidence of post adenoidectomy/tonsillectomy bleeding in otherwise healthy children is low and rarely requires blood transfusion

  3. Apollo Onboard Navigation Techniques

    Science.gov (United States)

    Interbartolo, Michael

    2009-01-01

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

  4. Inertial Navigation Sensors

    Science.gov (United States)

    2010-03-01

    Capteurs de navigation a faible cout et technologie d’integration) RTO-EN-SET-116(2010) 14. ABSTRACT For many navigation applications , improved...ABSTRACT For many navigation applications , improved accuracy/performance is not necessarily the most important issue, but meeting performance at...reduced cost and size is. In particular, small navigation sensor size allows the introduction of guidance, navigation, and control into applications

  5. Controlled Cohort Study of Serum Gonadal and Adrenocortical Steroid Levels in Males Prior to Onset of Rheumatoid Arthritis (pre-RA: A Comparison to pre-RA Females and Sex Differences among the Study Groups

    Directory of Open Access Journals (Sweden)

    Alfonse T. Masi

    2013-01-01

    Full Text Available Serum testosterone levels are generally reported to be lower in male rheumatoid arthritis (RA patients, but it is not determined if a deficiency may occur before clinical onset of disease (pre-RA. Lower testosterone levels were recently reported in males many years before RA onset but were predictive only of rheumatoid factor (RF—negative disease. A preceding prospective study did not reveal androgenic-anabolic hormone association with risk of RA in men or women. This cohort study of males analyzed baseline serum levels of gonadal and adrenocortical steroids, luteinizing hormone, and prolactin in 18 pre-RA versus 72 matched non-RA control (CN subjects. Findings in males were compared to those in female pre-RA and CN subjects in the same cohort, and sex differences were analyzed. Steroidal and hormonal levels, including total testosterone, were similar between male study groups. In females, mean (±SE serum androstenedione (nmol/L was slightly (P=0.048 lower in 36 pre-RA (6.7 ± 0.36 than 144 CN (7.6 ± 0.22. With the exception of 3 partial correlations of hormonal variables observed to differ between pre-RA versus CN subjects, the patterns were similar overall. However, partial correlations of hormonal variables differed frequently by sex, both within and between study groups.

  6. Choosing Content and Methods: Focus Group Interviews with Faculty Teachers in Norwegian Pre-Service Subject Teacher Education in Design, Art, and Crafts

    Science.gov (United States)

    Gulliksen, Marte S.; Hjardemaal, Finn R.

    2016-01-01

    The study is aimed at generating knowledge on how faculty teachers reflect and justify their choice of subject content logic in teacher education, exemplified by a concurrent pre-service Subject Teacher Education in design, art, and crafts. Focus-group interviews generated data. Three topics were discussed: too many choices, different logics, and…

  7. The group I-like ribozyme DiGIR1 mediates alternative processing of pre-rRNA transcripts in Didymium iridis

    DEFF Research Database (Denmark)

    Vader, Anna; Johansen, Steinar; Nielsen, Henrik

    2002-01-01

    During starvation induced encystment, cells of the myxomycete Didymium iridis accumulate a 7.5-kb RNA that is the result of alternative processing of pre-rRNA. The 5' end corresponds to an internal processing site cleaved by the group I-like ribozyme DiGIR1, located within the twin-ribozyme intron...

  8. Optical Navigation System Project

    Data.gov (United States)

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

  9. Optical Navigation System Project

    Data.gov (United States)

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

  10. Impact of Structured Group Activities on Pre-Service Teachers' Beliefs about Classroom Motivation: An Exploratory Study

    Science.gov (United States)

    Mansfield, Caroline F.; Volet, Simone E.

    2014-01-01

    Pre-service teachers' beliefs about classroom motivation, and how these beliefs may be developed during initial teacher preparation, is a relatively new aspect of enquiry in the fields of motivation and teacher education. An empirical study, grounded in a social constructivist perspective, was designed to examine the impact of providing…

  11. Teacher Efficacy of Pre-Service Teachers in Taiwan: The Influence of Classroom Teaching and Group Discussions

    Science.gov (United States)

    Liaw, En-Chong

    2009-01-01

    The greatest benefit of teacher preparation programs is field-related training where pre-service teachers contextualize the learned knowledge and theories with tasks and students during training. This preliminary study is based on the collaboration between a teacher training program and an elementary school to investigate the effect that exposure…

  12. Guided Group Reflections of First-Year Pre-Service Teachers: Moving beyond the Rhetoric of "Go and Reflect"

    Science.gov (United States)

    Beylefeld, Adri; le Roux, Adré

    2015-01-01

    In South Africa, pre-service teachers enter education programmes with diverse preunderstandings of the teaching profession. For some, their experiences are often naively divorced from a genuine understanding of how present-day education perpetuates patterns of poverty and privilege. Responding to the pedagogical challenge of framing problems of…

  13. Surgical Navigation

    DEFF Research Database (Denmark)

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

    2017-01-01

    were identified in the field of traumatology. Treatment of complex orbital fractures was considerably improved by the use of SN compared with traditionally treated control groups. Conclusions: SN seems to be a very promising addition to the surgical toolkit. Planning details of the surgical procedure...... in a 3-dimensional virtual environment and execution with real-time guidance can significantly improve precision. Among factors to be considered are the financial investments necessary and the learning curve....

  14. Exploring changes found in lab reports of pre-service science teachers by adapting a group questioning strategy with using the science writing heuristic template

    Directory of Open Access Journals (Sweden)

    Myeong-Kyeong Shin

    2012-12-01

    Full Text Available Pre-service elementary teachers' view on how scientific practice works could be shown in their lab reports especially which were designed to write their testing questions, methods, claims and evidences. For better practice of scientific inquiry for the pre-service teachers, Science Writing Heuristic was used as a teaching method. Only adopting worksheet of SWH and following the steps may lead students to the proper experience of scientific inquiry, which might be hardly expected. The stage of making their own testable questions is essential and critical for the scientific practice as well. This study presumed that a group questioning strategy at this stage would be effective for better scientific inquiry. The purpose of this study is to demonstrate changes of scientific practices after adapting group questioning strategy in terms of scientific reasoning and consistency among elements of scientific practices including questions, methods, claims, and evidences based on pre-service teachers' lab reports on elementary level science activities. During the science teaching methods course for pre-service elementary science teachers, the activity of various subjects in elementary science textbooks were implemented. In this study, two classes were observed and participants' writings were collected; one used science writing form without and the other with group questioning strategy. During participants' practices with the form, participants were asked to write what they were curious about, what they did and was their evidences, and what they claimed through the activity. There were found to be more interactions among participants and more relevant and testable questions asked in a class with group questioning strategies. It was implicated that participant pre-service teachers acted similar with children in terms of scientific practices as well. Further it was discussed whether scientific practice in school science truly include testing students' own

  15. LEO AUTONOMOUS NAVIGATION BASED ON IMAGE MOTION

    Institute of Scientific and Technical Information of China (English)

    DUANFang; LIUJian-ye; YUFeng

    2005-01-01

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

  16. Pre-operative digital design for osteotomy and intra-operative navigation for treatment of secondary thoracolumbar kyphosis following surgery of thoracolumbar fracture%术前数字化截骨设计及术中导航辅助技术矫正胸腰段骨折术后继发角状后凸畸形

    Institute of Scientific and Technical Information of China (English)

    樊勇; 吴子祥; 杨红军; 漆伟; 雷伟; 裴彦军; 裴国献; 桑宏勋

    2015-01-01

    Objective To evaluate the efficacy of pre-operative digital design for osteotomy and intra-operative navigation for treatment of secondary thoracolumbar kyphosis following surgery of thoracolumbar fracture.Methods Thirty-four patients with secondary thoracolumbar kyphosis following surgery of thoracolumbar fracture were treated with pedicle subtraction osteotomy (PSO) from January 2008 to April 2013.They were 18 men and 16 women,from 17 to 44 years of age (average,26.5 years).Of them,11 received traditional posterior osteotomy (unassisted group) and 23 received preoperative design with Mimics software and intraoperative navigation (assisted group).The 2 groups were compared in terms of operation time,blood loss,local deformity correction rate,cobb angle,visual analogue scale (VAS),and Oswestry disability index (ODI).Results The assisted group bad significantly shorter operation time,less blood loss and a higher deformity correction rate than the unassisted group (P < 0.05).All patients were followed up for a mean duration of 38 months (from 6 to 51 months).In all patients,the preoperative cobb angle,VAS and ODI scores were significantly improved at postoperation and the last follow-up (P < 0.05).At the last follow-up,the cobb angle,VAS and ODI scores in the assisted group were significantly better than in the unassisted group (P < 0.05).In all the patients,rigid fusion of the spinal vertebrae fixated was achieved,no implant failure occurred,the secondary thoracolumbar kyphosis was obviously corrected,and back pain disappeared.Conclusion The pre-operative digital design for osteotomy and intra-operative navigation improve the safety of PSO,therapeutic outcomes and local deformity correction for treatment of secondaU thoracolumbar kyphosis following surgery of thoracolumbar fracture.%目的 探讨联合应用术前数字化截骨设计和术中导航技术辅助矫正胸腰段骨折术后继发角状后凸畸形的有效性. 方法 2008年1至201 3年4月对34

  17. A comparison of different pre-lysis methods and extraction kits for recovery of Streptococcus agalacticae (Lancefield group B Streptococcus) DNA from whole blood.

    Science.gov (United States)

    Burke, Rachael M; McKenna, James P; Cox, Ciara; Coyle, Peter V; Shields, Michael D; Fairley, Derek J

    2016-10-01

    Sub-optimal recovery of bacterial DNA from whole blood samples can limit the sensitivity of molecular assays to detect pathogenic bacteria. We compared 3 different pre-lysis protocols (none, mechanical pre-lysis and achromopeptidase pre-lysis) and 5 commercially available DNA extraction platforms for direct detection of Group B Streptococcus (GBS) in spiked whole blood samples, without enrichment culture. DNA was extracted using the QIAamp Blood Mini kit (Qiagen), UCP Pathogen Mini kit (Qiagen), QuickGene DNA Whole Blood kit S (Fuji), Speed Xtract Nucleic Acid Kit 200 (Qiagen) and MagNA Pure Compact Nucleic Acid Isolation Kit I (Roche Diagnostics Corp). Mechanical pre-lysis increased yields of bacterial genomic DNA by 51.3 fold (95% confidence interval; 31.6-85.1, pextraction methods. Including a pre-lysis step can improve the limits of detection of GBS using PCR or other molecular methods without need for culture. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Pre-Mission Communication And Awareness Stratgies For Positive Group Functioning And Development: Analysis Of A Crew At The Mars Desert Research Station (MDRS) In Utah, USA

    Science.gov (United States)

    Allner, Matthew; Bishop, Sheryl; Gushin, Vadim; McKay, Chris; Rygalov, Vadim; Allner, Matthew

    Introduction: Psychosocial group functioning has become an increased international focus of many space faring nations due to the recent shift in focus of colonizing the Moon and then preparing to travel to Mars and beyond. Purpose: This study investigates the effects of pre-mission communication and awareness strategies for positive group functioning in extreme environments as well as suggestive countermeasures to maintain positive group dynamic development in isolated and confined extreme (ICE) environments. The study is supported by both preand intra-mission management efforts, which included crewmember assessments at various mission phases (pre-, intra-, and end-mission). Methods: A six person heterogeneous American crew conducted a Mars simulation mission at the Mars Society's Mars Desert Research Station in Utah, USA in 2006 as part of a new NASA training program called Spaceward Bound. Participants were administered assessments of personality, personal and group identity/functioning, subjective stress, coping, and subjective motivation. All participants were also provided information (pre-mission) regarding past research and tendencies of group functioning, stressors, cognitive functioning, and mission mistakes from a mission phase analysis approach, to see if this would be a factor in positive group dynamic development. Results: Data collected and obtained by both assessment and journaling methods were both consistent and indicative of positive personalities desirable of expedition crews. Assessment data further indicated positive group cohesion and group interactions, along with supportive and strong leadership, all which led to positive personal and group experiences for crewmembers. Crewmembers all displayed low levels of competition while still reporting high motivation and satisfaction for the group dynamic development and the mission objectives that were completed. Journals kept by the crew psychologist indicated that crewmembers all felt that the pre

  19. 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

  20. How do students navigate and learn from nonlinear science texts: Can metanavigation support promote science learning?

    Science.gov (United States)

    Stylianou, Agni

    2003-06-01

    Digital texts which are based on hypertext and hypermedia technologies are now being used to support science learning. Hypertext offers certain opportunities for learning as well as difficulties that challenge readers to become metacognitively aware of their navigation decisions in order to trade both meaning and structure while reading. The goal of this study was to investigate whether supporting sixth grade students to monitor and regulate their navigation behavior while reading from hypertext would lead to better navigation and learning. Metanavigation support in the form of prompts was provided to groups of students who used a hypertext system called CoMPASS to complete a design challenge. The metanavigation prompts aimed at encouraging students to understand the affordances of the navigational aids in CoMPASS and use them to guide their navigation. The study was conducted in a real classroom setting during the implementation of CoMPASS in sixth grade science classes. Multiple sources of group and individual data were collected and analyzed. Measures included student's individual performance in a pre-science knowledge test, the Metacognitive Awareness of Reading Strategies Inventory (MARSI), a reading comprehension test and a concept map test. Process measures included log file information that captured group navigation paths during the use of CoMPASS. The results suggested that providing metanavigation support enabled the groups to make coherent transitions among the text units. Findings also revealed that reading comprehension, presence of metanavigation support and prior domain knowledge significantly predicted students' individual understanding of science. Implications for hypertext design and literacy research fields are discussed.

  1. Space Shuttle navigation validation

    Science.gov (United States)

    Ragsdale, A.

    The validation of the guidance, navigation, and control system of the Space Shuttle is explained. The functions of the ascent, on-board, and entry mission phases software of the navigation system are described. The common facility testing, which evaluates the simulations to be used in the navigation validation, is examined. The standard preflight analysis of the operational modes of the navigation software and the post-flight navigation analysis are explained. The conversion of the data into a useful reference frame and the use of orbit parameters in the analysis of the data are discussed. Upon entry the data received are converted to flags, ratios, and residuals in order to evaluate performance and detect errors. Various programs developed to support navigation validation are explained. A number of events that occurred with the Space Shuttle's navigation system are described.

  2. A navigation system for the visually impaired using colored navigation lines and RFID tags.

    Science.gov (United States)

    Seto, First Tatsuya

    2009-01-01

    In this paper, we describe about a developed navigation system that supports the independent walking of the visually impaired in the indoor space. Our developed instrument consists of a navigation system and a map information system. These systems are installed on a white cane. Our navigation system can follow a colored navigation line that is set on the floor. In this system, a color sensor installed on the tip of a white cane senses the colored navigation line, and the system informs the visually impaired that he/she is walking along the navigation line by vibration. The color recognition system is controlled by a one-chip microprocessor and this system can discriminate 6 colored navigation lines. RFID tags and a receiver for these tags are used in the map information system. The RFID tags and the RFID tag receiver are also installed on a white cane. The receiver receives tag information and notifies map information to the user by mp3 formatted pre-recorded voice. Three normal subjects who were blindfolded with an eye mask were tested with this system. All of them were able to walk along the navigation line. The performance of the map information system was good. Therefore, our system will be extremely valuable in supporting the activities of the visually impaired.

  3. 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.

  4. EVOLUTION IN THE H I GAS CONTENT OF GALAXY GROUPS: PRE-PROCESSING AND MASS ASSEMBLY IN THE CURRENT EPOCH

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Kelley M. [Astrophysics, Cosmology and Gravity Centre (ACGC), Department of Astronomy, University of Cape Town, Rondebosch 7701 (South Africa); Wilcots, Eric M., E-mail: hess@ast.uct.ac.za, E-mail: ewilcots@astro.wisc.edu [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2013-11-01

    We present an analysis of the neutral hydrogen (H I) content and distribution of galaxies in groups as a function of their parent dark matter halo mass. The Arecibo Legacy Fast ALFA survey α.40 data release allows us, for the first time, to study the H I properties of over 740 galaxy groups in the volume of sky common to the Sloan Digital Sky Survey (SDSS) and ALFALFA surveys. We assigned ALFALFA H I detections a group membership based on an existing magnitude/volume-limited SDSS Data Release 7 group/cluster catalog. Additionally, we assigned group ''proximity' membership to H I detected objects whose optical counterpart falls below the limiting optical magnitude—thereby not contributing substantially to the estimate of the group stellar mass, but significantly to the total group H I mass. We find that only 25% of the H I detected galaxies reside in groups or clusters, in contrast to approximately half of all optically detected galaxies. Further, we plot the relative positions of optical and H I detections in groups as a function of parent dark matter halo mass to reveal strong evidence that H I is being processed in galaxies as a result of the group environment: as optical membership increases, groups become increasingly deficient of H I rich galaxies at their center and the H I distribution of galaxies in the most massive groups starts to resemble the distribution observed in comparatively more extreme cluster environments. We find that the lowest H I mass objects lose their gas first as they are processed in the group environment, and it is evident that the infall of gas rich objects is important to the continuing growth of large scale structure at the present epoch, replenishing the neutral gas supply of groups. Finally, we compare our results to those of cosmological simulations and find that current models cannot simultaneously predict the H I selected halo occupation distribution for both low and high mass halos.

  5. 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.

  6. Private Graphs - Access Rights on Graphs for Seamless Navigation

    Science.gov (United States)

    Dorner, W.; Hau, F.; Pagany, R.

    2016-06-01

    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.

  7. Evolution in the H I Gas Content of Galaxy Groups: Pre-Processing and Mass Assembly in the Current Epoch

    CERN Document Server

    Hess, Kelley M

    2013-01-01

    We present an analysis of the neutral hydrogen (HI) content and distribution of galaxies in groups as a function of their parent dark matter halo mass. The Arecibo Legacy Fast ALFA survey alpha.40 data release allows us, for the first time, to study the HI properties of over 740 galaxy groups in the volume of sky common to the SDSS and ALFALFA surveys. We assigned ALFALFA HI detections a group membership based on an existing magnitude/volume-limited SDSS DR7 group/cluster catalog. Additionally, we assigned group "proximity" membership to HI detected objects whose optical counterpart falls below the limiting optical magnitude--thereby not contributing substantially to the estimate of the group stellar mass, but significantly to the total group HI mass. We find that only 25% of the HI detected galaxies reside in groups or clusters, in contrast to approximately half of all optically detected galaxies. Further, we plot the relative positions of optical and HI detections in groups as a function of parent dark matt...

  8. Image Based Indoor Navigation

    OpenAIRE

    Noreikis, Marius

    2014-01-01

    Over the last years researchers proposed numerous indoor localisation and navigation systems. However, solutions that use WiFi or Radio Frequency Identification require infrastructure to be deployed in the navigation area and infrastructureless techniques, e.g. the ones based on mobile cell ID or dead reckoning suffer from large accuracy errors. In this Thesis, we present a novel approach of infrastructure-less indoor navigation system based on computer vision Structure from Motion techniques...

  9. Screening of patients for cochlear implant through a questionnaire online. GroupProfile of patients pre-and peri lingual not summoned

    Directory of Open Access Journals (Sweden)

    Leal, Aquiles Figueiredo

    2010-06-01

    Full Text Available Introduction: Facilitating access to specialized centers and properly screen patients seeking cochlear implants are critical steps for proper rehabilitation. Objective: To describe the group of patients pre-and peri-lingual is not called for in a service evaluation of cochlear implants. Method: A retrospective study analyzed 401 questionnaires of patients pre-and peri-lingual Web site registered in the Central Brazilian cochlear implant. For the failure to call these patients were used as criteria applied some variables: age, use of hearing aids, speech therapy, duration of deafness, type of progression of hearing loss and type of communication used by the patient. Results: The group of patients with pre-and peri-lingual deafness accounted for 34% of total questionnaires completed during the period. The distribution by age found that 54% of patients were over 17 years, 30% between 9 and 17 years, and remaining less than 9 years. The duration of deafness was higher than 20 years in 50% of patients, between 10 and 20 years by 32% between 5 and 10 years in 9% and between 0 and 5 years in 9%. Regarding the performance of voice rehabilitation 58% of patients had performed and 42% did not. Regarding the mode of communication 49% had global communication, 18% LIBRAS, 6% oral communication, 26% no communication. Conclusion: Advanced age, duration of deafness high, so mostly no oral communication and lack of voice rehabilitation were crucial to the failure to call these patients.

  10. 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.

  11. Innovation processes navigated by women groups in the Malian shea sector: How targeting of international niche markets results in fragmentation and obstructs coordination

    NARCIS (Netherlands)

    Sidibe, A.; Vellema, S.; Dembele, M.M.; Traore, K.; Kuyper, T.W.

    2012-01-01

    The incorporation of women and their associations into international markets and value chains is proposed increasingly as a development pathway in Sub-Saharan Africa. The underlying assumption is that exclusion of individual women from groups specialized in supplying a single international niche mar

  12. Group psychotherapy for eating disorders: A randomized clinical trial and a pre-treatment moderator and mediator analyses

    DEFF Research Database (Denmark)

    Davidsen, Annika Helgadóttir

    disorders in group therapy. We conducted a randomized clinical trial and included 159 adult participants, 156 females and 3 males, diagnosed with bulimia nervosa, binge eating disorder, or eating disorder not otherwise specified according to DSM-IV. Eighty participants were allocated to the experimental...

  13. Association of genetic polymorphism of pre-microRNA-146a rs2910164 and serum high-mobility group box 1 with febrile seizures in Egyptian children.

    Science.gov (United States)

    Issac, Marianne Samir Makboul; Girgis, Marian; Haroun, Mervat; Shalaby, Amal

    2015-03-01

    Interaction between immune-inflammatory process and genetic factors might be implicated in the pathogenesis of febrile seizures. Pre-microRNA (miR)-146a rs2910164 polymorphism is postulated to modulate expression of miR-146a whose anti-inflammatory role involves regulation of high-mobility group box 1. Our aim is to examine whether rs2910164 polymorphism influences serum high-mobility group box 1 levels and whether an association exists between both and febrile seizures. The study included 136 children, divided into 4 groups. Real-time polymerase chain reaction was used for detection of rs2910164 polymorphism and high-mobility group box 1 was measured using enzyme-linked immunosorbent assay. High-mobility group box 1 levels were higher in febrile seizure patients compared to the other groups. Rs2910164 polymorphism was not associated with increased risk of febrile seizures. Rs2910164 polymorphism might be accompanied by an upregulation of the proinflammatory process as it might be associated with an increase in high-mobility group box 1 and leukocytic count. © The Author(s) 2014.

  14. Indicators of speed and explosive strength in the pre-season of annual macrocycle of young male and female weightlifters of the different groups of weight categories

    Directory of Open Access Journals (Sweden)

    Lutovinov Iu.A.

    2012-12-01

    Full Text Available Here is the indicators of speed and explosive strength in the pre-season of annual macrocycle of young male and female weightlifters of the different groups of weight categories who are training for the Championship of Ukraine. 40 young male and 12 female sportsman has taken part in investigation. Age of sportsman is 15 years old. The correlation of height indicator of standing high-jump (Abalakov jump and body weight indicator of sportsman weightlifters was analyzed. The interconnection of indicators of body weight and length of sportsman weightlifters alongside with the indicators of spring, speed as well as speed and power abilities of the different groups of weight categories was given. It was analyzed that the indicators of standing high-jump (Abalakov jump, standing long-jump and 30-meter sprint of sportsman are tend to grow by 11.5 %, 3.9 % and 2.7%, respectively, in the pre-season with an increase of weight category groups. The comparison of indicators of spring, speed as well as speed and power abilities of sportsman weightlifters was estimated.

  15. Working group reports: evaluation of the evidence to support practice guidelines for nutritional care of preterm infants-the Pre-B Project.

    Science.gov (United States)

    Raiten, Daniel J; Steiber, Alison L; Carlson, Susan E; Griffin, Ian; Anderson, Diane; Hay, William W; Robins, Sandra; Neu, Josef; Georgieff, Michael K; Groh-Wargo, Sharon; Fenton, Tanis R

    2016-02-01

    The "Evaluation of the Evidence to Support Practice Guidelines for the Nutritional Care of Preterm Infants: The Pre-B Project" is the first phase in a process to present the current state of knowledge and to support the development of evidence-informed guidance for the nutritional care of preterm and high-risk newborn infants. The future systematic reviews that will ultimately provide the underpinning for guideline development will be conducted by the Academy of Nutrition and Dietetics' Evidence Analysis Library (EAL). To accomplish the objectives of this first phase, the Pre-B Project organizers established 4 working groups (WGs) to address the following themes: 1) nutrient specifications for preterm infants, 2) clinical and practical issues in enteral feeding of preterm infants, 3) gastrointestinal and surgical issues, and 4) current standards of infant feeding. Each WG was asked to 1) develop a series of topics relevant to their respective themes, 2) identify questions for which there is sufficient evidence to support a systematic review process conducted by the EAL, and 3) develop a research agenda to address priority gaps in our understanding of the role of nutrition in health and development of preterm/neonatal intensive care unit infants. This article is a summary of the reports from the 4 Pre-B WGs.

  16. Major differences in oral health knowledge and behavior in a group of Iranian pre-university students: a cross-sectional study.

    Science.gov (United States)

    Neamatollahi, Hossain; Ebrahimi, Masoumeh; Talebi, Maryam; Ardabili, Mana H; Kondori, Keiwan

    2011-06-01

    To establish efficient methods for self-prevention of oral diseases, assessment of dental health behavior and knowledge in various social classes is necessary. The main purpose of this study was to determine the major differences in oral health knowledge and behavior in a group of Iranian pre-university students. In this cross-sectional study, 591 pre-university students from different regions of Mashhad, Iran were randomly selected to complete a questionnaire consisting of two parts including dental health behavior and knowledge. Scores were recorded and statistical analyses performed to determine the correlation between dental health behavior and knowledge. Data was analyzed with Student's t-test, one-way analysis of variance and Pearson correlation. The mean score of dental health knowledge was significantly lower than the dental health behavior (2.95 ± 0.02 vs. 3.31 ± 0.05, P difference was observed with gender, birth location and major subject of study. The dental health behavior of Iranian pre-university students was inadequate and their dental health knowledge was at a lower level compared to their behavior. Experimental science students had better oral health behavior compared to other students.

  17. Prevalence of Human Papillomavirus (HPV) in upper respiratory tract mucosa in a group of pre-school children

    OpenAIRE

    Jaroslaw Szydłowski; Katarzyna Jonczyk-Potoczna; Beata Pucher; Beata Buraczyńska-Andrzejewska; Magdalena Prauzińska; Jagoda Kolasińska-Lipńska; Hanna Krauss; Jacek Piątek; Wioletta Żukiewicz-Sobczak

    2014-01-01

    [b]introduction[/b]. Human Papillomavirus (HPV) is a group of DNA viruses which is an etiological factor of many benign and malignant diseases of the upper respiratory tract mucosa, female genital tract and the skin. HPV infection is considered a sexually-transmitted infection, but can also be transmitted by non-sexual routes, including perinatal vertical transmission, physical contact, iatrogenic infection and autoinoculation. Recurrent Respiratory Papillomatosis (RRP) in children is connect...

  18. An exploration of computer-simulated evolution and small group discussion on pre-service science teachers' perceptions of evolutionary concepts

    Science.gov (United States)

    MacDonald, Ronald Douglas

    The primary goal of this study was to explore how the use of a computer simulation of basic evolutionary processes, in combination with small-group discussions, affected Intermediate/Senior pre-service science teachers' perspectives of basic evolutionary concepts. Qualitative and quantitative methods were used in a case study approach with 19 pre-service Intermediate/Senior science teachers at an Ontario university. Several sub-goals were explored. The first sub-goal was to assess Intermediate/Senior pre-service science teachers' current conceptions of evolution. The results indicated that approximately two-thirds of the participants had a poor understanding of basic evolutionary concepts, with only 2 of the 19 participants demonstrating a strong comprehension. These results were found to be very similar to comparable samples of subjects from other research. The second sub-goal was to explore the relationships among Intermediate/Senior pre-service science teachers' understanding of contemporary evolutionary concepts, their perspectives of the nature of science, and their intentions to teach evolutionary concepts in the classroom. Participants' knowledge of evolutionary concepts was found to be associated strongly with their intentions to teach evolution by natural selection (r = .42). However, knowledge of evolutionary concepts was not found to be associated with any particular science epistemology perspective. The third sub-goal was to analyze and to interpret the small-group discussions as members interacted with the simulation. The simulation was found to be highly engaging and a very effective method of encouraging participants to speculate, question, discuss and learn about important evolutionary concepts. Analyses of the discussions revealed that the simulation evoked a wide array of correct conceptions as well as misconceptions. The fourth sub-goal was to assess the extent to which creating a lesson plan on the topic of natural selection could affect

  19. 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...

  20. Prognostic Correlations between ABO Blood Group and Pre-Treatment Plasma Epstein-Barr Virus DNA in Patients with Nasopharyngeal Carcinoma Receiving Intensity-Modulated Radiotherapy.

    Science.gov (United States)

    Peng, Hao; Chen, Lei; Li, Wen-Fei; Zhang, Yuan; Liu, Li-Zhi; Tian, Li; Lin, Ai-Hua; Sun, Ying; Ma, Jun

    2016-01-01

    The objective of this study is to assess the prognostic value of ABO blood group in nasopharyngeal carcinoma (NPC) treated by intensity-modulated radiotherapy (IMRT). We retrospectively reviewed the data on 1397 patients with non-metastatic, newly diagnosed NPC treated using IMRT. Patient survival between different ABO blood groups were compared using log-rank test. Cox hazards model was adopted to establish independent prognostic factors. In our study, the distribution of the A, B, AB and O blood groups was 26.6% (372/1397), 26.2% (366/1397), 5.2% (73/1397) and 42.0% (586/1397), respectively. The cut-off value of pre-treatment Epstein-Barr virus (EBV) DNA based on disease-free survival (DFS) was 1355 copies/ml (area under curve [AUC], 0.649; sensitivity, 0.76; specificity, 0.496) for the whole cohort. Estimated four-year DFS, overall survival (OS), distant metastasis-free survival (DMFS) and locoregional relapse-free survival (LRRFS) rates were 81.7%, 89.2%, 89.4% and 92.3% for blood group A; 82.1%, 89.3%, 89.0% and 92.0% for group B; 83.3%, 88.1%, 86.2% and 95.5% for group AB, 80.9%, 90.7%, 88.4% and 90.2% for group O (P > 0.05 for all rates). Multivariate analysis revealed ABO blood group was not an independent prognostic factor for DFS, OS, DMFS or LRRFS (P > 0.05 for all rates) after adjusting for plasma EBV DNA in either the whole cohort or subgroup analysis by gender. The prognostic value of ABO blood group may be limited for patients with NPC in the era of IMRT, and no substantial correlation between ABO blood group and plasma EBV DNA was observed.

  1. Evaluating effectiveness of small group information literacy instruction for Undergraduate Medical Education students using a pre- and post-survey study design.

    Science.gov (United States)

    McClurg, Caitlin; Powelson, Susan; Lang, Eddy; Aghajafari, Fariba; Edworthy, Steven

    2015-06-01

    The Undergraduate Medical Education (UME) programme at the University of Calgary is a three-year programme with a strong emphasis on small group learning. The purpose of our study was to determine whether librarian led small group information literacy instruction, closely integrated with course content and faculty participation, but without a hands on component, was an effective means to convey EBM literacy skills. Five 15-minute EBM information literacy sessions were delivered by three librarians to 12 practicing physician led small groups of 15 students. Students were asked to complete an online survey before and after the sessions. Data analysis was performed through simple descriptive statistics. A total of 144 of 160 students responded to the pre-survey, and 112 students answered the post-survey. Instruction in a small group environment without a mandatory hands on component had a positive impact on student's evidence-based information literacy skills. Students were more likely to consult a librarian and had increased confidence in their abilities to search and find relevant information. Our study demonstrates that student engagement and faculty involvement are effective tools for delivering information literacy skills when working with students in a small group setting outside of a computer classroom. © 2015 Health Libraries Group.

  2. Indoor waypoint navigation via magnetic anomalies.

    Science.gov (United States)

    Riehle, Timothy H; Anderson, Shane M; Lichter, Patrick A; Condon, John P; Sheikh, Suneel I; Hedin, Daniel S

    2011-01-01

    A wide assortment of technologies have been proposed to construct indoor navigation services for the blind and vision impaired. Proximity-based systems and multilateration systems have been successfully demonstrated and employed. Despite the technical success of these technologies, broad adoption has been limited due to their significant infrastructure and maintenance costs. An alternative approach utilizing the indoor magnetic signatures inherent to steel-frame buildings solves the infrastructure cost problem; in effect the existing building is the location system infrastructure. Although magnetic indoor navigation does not require the installation of dedicated hardware, the dedication of resources to produce precise survey maps of magnetic anomalies represents a further barrier to adoption. In the present work an alternative leader-follower form of waypoint-navigation system has been developed that works without surveyed magnetic maps of a site. Instead the wayfarer's magnetometer readings are compared to a pre-recorded magnetic "leader" trace containing magnetic data collected along a route and annotated with waypoint information. The goal of the navigation system is to correlate the follower's magnetometer data with the leader's to trigger audio cues at precise points along the route, thus providing location-based guidance to the user. The system should also provide early indications of off-route conditions. As part of the research effort a smartphone based application was created to record and annotate leader traces with audio and numeric data at waypoints of interest, and algorithms were developed to determine (1) when the follower reaches a waypoint and (2) when the follower goes off-route. A navigation system utilizing this technology would enable a low-cost indoor navigation system capable of replaying audio annotations at precise locations along pre-recorded routes.

  3. The relationship between osteoporosis and body composition in pre- and postmenopausal women from different ethnic groups in China.

    Science.gov (United States)

    Mo, Dan; Hsieh, Peishan; Yu, Hongrong; Zhou, Lining; Gong, Jichun; Xu, Lin; Liu, Peng; Chen, Gang; Chen, Zhao; Deng, Qiongying

    2017-06-01

    To investigate the ethnic differences in osteoporosis (OP) and body composition (BC) and their relationship in the Maonan, Mulam, Hmong, and Yao minorities in China. A total of 860 Maonan, Mulam, Hmong, and Yao women were included in this cross-sectional study. Demographic, health history, and lifestyle information was collected using questionnaires. BC was measured through bioelectrical impedance analysis, and bone mineral density (BMD) was assessed via calcaneal quantitative ultrasound. Compared with premenopausal women, postmenopausal women exhibited a lower fat-free mass (FFM), muscle mass (MM), limb muscle mass, and T-score but a higher waist-to-hip ratio and prevalence of OP in each minority (p women displayed the highest body mass index, fat mass, percentage of body fat, visceral fat, and subcutaneous fat contents, while Yao women presented the highest T-scores and lowest prevalence of OP among the four minorities (p  1). In addition, our results revealed that FFM and MM exhibited exactly the same weak positive relationship with the T-score (r = 0.081, p relationship between BC and the T-score existed in the four minorities studied here. BC and OP prevalence varied by menopausal status and ethnic group, and ethnic-specific relationships between BC and BMD were present in the four minorities. More research is needed to further investigate the ethnic differences in BC, OP, and risk factors for lower BMD to develop targeted prevention strategies to reduce the burden of OP across different ethnic groups in China.

  4. Self-assembly and sensing-group graft of pre-modified CNTs on resonant micro-cantilevers for specific detection of volatile organic compound vapors

    Science.gov (United States)

    Xu, Pengcheng; Li, Xinxin; Yu, Haitao; Liu, Min; Li, Jungang

    2010-11-01

    This paper reports MWCNT (multi-wall carbon nano-tube)-modified resonant micro-cantilever chemical sensors for detection of trinitrotoluene (TNT) vapor. The MWCNTs are pre-modified and then area-selectively self-assembled at the free-end gold pad of a micro-cantilever, in which a resonance-exciting heater and a signal-readout piezoresistive Wheatstone bridge are integrated. Featuring a high specific surface area, the MWCNTs are further functionalized with TNT-sensitive groups by grafting onto the sidewalls of the MWCNTs. To lower the non-specific absorption of water and other small organic molecules, the SiO2 surface of the micro-cantilever was also pre-treated for hydrophobicity and oleophobicity by self-assembling a monolayer of heptadecafluorodecyltrimethoxysilane. The results of our sensing experiments have shown a capability to rapidly detect ppb-level TNT vapor, and a high specificity of the functionalized groups to TNT molecules. The experiment has also confirmed a good long-term stability in detecting sensitivity.

  5. 78 FR 68861 - Certain Navigation Products, Including GPS Devices, Navigation and Display Systems, Radar Systems...

    Science.gov (United States)

    2013-11-15

    ... COMMISSION Certain Navigation Products, Including GPS Devices, Navigation and Display Systems, Radar Systems... the United States after importation of certain navigation products, including GPS devices, navigation... products, including GPS devices, navigation and display systems, radar systems, navigational aids,...

  6. Pre-consultation educational group intervention to improve shared decision-making in postmastectomy breast reconstruction: study protocol for a pilot randomized controlled trial

    Science.gov (United States)

    2013-01-01

    Background The Pre-Consultation Educational Group Intervention pilot study seeks to assess the feasibility and inform the optimal design for a definitive randomized controlled trial that aims to improve the quality of decision-making in postmastectomy breast reconstruction patients. Methods/design This is a mixed-methods pilot feasibility randomized controlled trial that will follow a single-center, 1:1 allocation, two-arm parallel group superiority design. Setting: The University Health Network, a tertiary care cancer center in Toronto, Canada. Participants: Adult women referred to one of three plastic and reconstructive surgeons for delayed breast reconstruction or prophylactic mastectomy with immediate breast reconstruction. Intervention: We designed a multi-disciplinary educational group workshop that incorporates the key components of shared decision-making, decision-support, and psychosocial support for cancer survivors prior to the initial surgical consult. The intervention consists of didactic lectures by a plastic surgeon and nurse specialist on breast reconstruction choices, pre- and postoperative care; a value-clarification exercise led by a social worker; and discussions with a breast reconstruction patient. Control: Usual care includes access to an informational booklet, website, and patient volunteer if desired. Outcomes: Expected pilot outcomes include feasibility, recruitment, and retention targets. Acceptability of intervention and full trial outcomes will be established through qualitative interviews. Trial outcomes will include decision-quality measures, patient-reported outcomes, and service outcomes, and the treatment effect estimate and variability will be used to inform the sample size calculation for a full trial. Discussion Our pilot study seeks to identify the (1) feasibility, acceptability, and design of a definitive RCT and (2) the optimal content and delivery of our proposed educational group intervention. Thirty patients have been

  7. Algorithms for vehicle navigation

    OpenAIRE

    Storandt, Sabine

    2012-01-01

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

  8. Mobile Robot Navigation

    DEFF Research Database (Denmark)

    Andersen, Jens Christian

    2007-01-01

    Abstract Robots will soon take part in everyone’s daily life. In industrial production this has been the case for many years, but up to now the use of mobile robots has been limited to a few and isolated applications like lawn mowing, surveillance, agricultural production and military applications....... The research is now progressing towards autonomous robots which will be able to assist us in our daily life. One of the enabling technologies is navigation, and navigation is the subject of this thesis. Navigation of an autonomous robot is concerned with the ability of the robot to direct itself from...

  9. Identifying clinical learning needs using structured group feedback: first year evaluation of pre-registration nursing and midwifery degree programmes.

    Science.gov (United States)

    Frazer, Kate; Connolly, Michael; Naughton, Corina; Kow, Veronica

    2014-07-01

    Facilitating and supporting clinical learning for student nurses and midwives are essential within their practice environments. Clinical placements provide unique opportunities in preparation for future roles. Understanding the experiences of first year student nurses and midwives following clinical exposures and examining the clinical facilitators and barriers can assist in maintaining and developing clinical supports. The study used a structured group feedback approach with a convenience sample of 223 first year nursing and midwifery students in one Irish university in April 2011 to ascertain feedback on the clinical aspects of their degree programme. Approximately 200 students participated in the process. Two key clinical issues were identified by students: facilitating clinical learning and learning experiences and needs. Positive learning environments, supportive staff and increased opportunities for reflection were important issues for first year students. The role of supportive mentoring staff in clinical practice is essential to enhance student learning. Students value reflection in practice and require more opportunities to engage during placements. More collaborative approaches are required to ensure evolving and adapting practice environments can accommodate student learning. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Community to clinic navigation to improve diabetes outcomes

    Directory of Open Access Journals (Sweden)

    Nancy E. Schoenberg

    2017-03-01

    Full Text Available Rural residents experience rates of Type 2 Diabetes Mellitus (T2DM that are considerably higher than their urban or suburban counterparts. Two primary modifiable factors, self-management and formal clinical management, have potential to greatly improve diabetes outcomes. “Community to Clinic Navigation to Improve Diabetes Outcomes,” is the first known randomized clinical trial pilot study to test a hybrid model of diabetes self-management education plus clinical navigation among rural residents with T2DM. Forty-one adults with T2DM were recruited from two federally qualified health centers in rural Appalachia from November 2014–January 2015. Community health workers provided navigation, including helping participants understand and implement a diabetes self-management program through six group sessions and, if needed, providing assistance in obtaining clinic visits (contacting providers' offices for appointments, making reminder calls, and facilitating transportation and dependent care. Pre and post-test data were collected on T2DM self-management, physical measures, demographics, psychosocial factors, and feasibility (cost, retention, and satisfaction. Although lacking statistical significance, some outcomes indicate trends in positive directions, including diet, foot care, glucose monitoring, and physical health, including decreased HbA1c and triglyceride levels. Process evaluations revealed high levels of satisfaction and feasibility. Due to the limited intervention dose, modest program expenditures (~$29,950, and a severely affected population most of whom had never received diabetes education, outcomes were not as robust as anticipated. Given high rates of satisfaction and retention, this culturally appropriate small group intervention holds promise for hard to reach rural populations. Modifications should include expanded recruitment venues, sample size, intervention dosage and longer term assessment.

  11. USACE Navigation Channels 2012

    Data.gov (United States)

    California Department of Resources — This dataset represents both San Francisco and Los Angeles District navigation channel lines. All San Francisco District channel lines were digitized from CAD files...

  12. Improving sexual health for HIV patients by providing a combination of integrated public health and hospital care services; a one-group pre- and post test intervention comparison

    Directory of Open Access Journals (Sweden)

    Dukers-Muijrers Nicole HTM

    2012-12-01

    Full Text Available Abstract Background Hospital HIV care and public sexual health care (a Sexual Health Care Centre services were integrated to provide sexual health counselling and sexually transmitted infections (STIs testing and treatment (sexual health care to larger numbers of HIV patients. Services, need and usage were assessed using a patient perspective, which is a key factor for the success of service integration. Methods The study design was a one-group pre-test and post-test comparison of 447 HIV-infected heterosexual individuals and men who have sex with men (MSM attending a hospital-based HIV centre serving the southern region of the Netherlands. The intervention offered comprehensive sexual health care using an integrated care approach. The main outcomes were intervention uptake, patients’ pre-test care needs (n=254, and quality rating. Results Pre intervention, 43% of the patients wanted to discuss sexual health (51% MSM; 30% heterosexuals. Of these patients, 12% to 35% reported regular coverage, and up to 25% never discussed sexual health topics at their HIV care visits. Of the patients, 24% used our intervention. Usage was higher among patients who previously expressed a need to discuss sexual health. Most patients who used the integrated services were new users of public health services. STIs were detected in 13% of MSM and in none of the heterosexuals. The quality of care was rated good. Conclusions The HIV patients in our study generally considered sexual health important, but the regular counselling and testing at the HIV care visit was insufficient. The integration of public health and hospital services benefited both care sectors and their patients by addressing sexual health questions, detecting STIs, and conducting partner notification. Successful sexual health care uptake requires increased awareness among patients about their care options as well as a cultural shift among care providers.

  13. Coastal Navigation Portfolio Management

    Science.gov (United States)

    2015-02-19

    the entire navigation portfolio of projects , both inland and coastal. The Coastal Structures Management , Analysis, and Ranking Tool (CSMART) is a...FEB 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Coastal Navigatoin Portfolio Management 5a. CONTRACT...CIRP.aspx Coastal Inlets Research Program Coastal Navigation Portfolio Management The Coastal Navigatoin Portfolio Management work unit

  14. Kilohoku Ho`okele Wa`a--- Na `Ohana Hoku `Eha (The Astronomy of the Hawaiian Navigators--- The Four Star Families)

    Science.gov (United States)

    Slater, Stephanie; Slater, Timothy F.; Baybayan, Kalepa C.

    2016-01-01

    This paper documents the complete modern Hawaiian navigational full-sky. Over eight years of field notes, observations, and interviews with cultural leaders, historians, and ho`okele wa`a (navigators) were used to construct and validate Kilohoku Ho`okele Wa`a, the Astronomy of the Hawaiian Navigators. In contrast to the various historical sky maps designed by different practitioners and local groups in pre-colonial times, this sky-map depicts the four whole-sky constellations used by present day wayfinders. Designed by a loosely bound group of cultural leaders and navigators as a tool to use in modern non-instrumental navigation, Kilohoku Ho`okele Wa`a is a pragmatic fusion of ancient Hawaiian tradition, traditions of greater Polynesia, and modern-day Indigenous cultural forces. Like a very small number of cultures who use the sky for non-instrumental navigation, the ho`okele wa`a conceive of each season's visible sky as a whole image, using a single constellation that stretches from the northern to the southern horizon as a tool that facilitates direction finding in skies that are often very cloudy, and that chunks the sky into sections that decrease the cognitive load placed on the navigator. Moving through the seasons, beginning in Winter, Na `Ohana Hoku `Eha (The Four Star Families) are Kekaomakali`I (The Bailer), Kaiwikuamo`o (The Backbone), Manaiakalani (The Fishhook), and Kalupekawelo (The Kite). The whole-sky character of each of the four "star families," combines with that star family's mo`olelo (purposeful story) to further facilitate navigation, employing the emotional component of moral and familial associations to enhance memorization and to provide wayfinders with encouragement on their long journeys.

  15. Intervención psicomotriz en el área personal/social de un grupo de educación preescolar/ Psychomotor intervention on social/personal area of a group of children of pre-school education

    National Research Council Canada - National Science Library

    Rocío Rubio Ponce; David Arnoldo García Fernández; Natanael Cervantes Hernández

    2011-01-01

      In the present study there are realized the analysis of a group of children of the third degree of pre-school education, as for the possible improvement in their personal / social area that includes...

  16. 33 CFR 209.325 - Navigation lights, aids to navigation, navigation charts, and related data policy, practices and...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Navigation lights, aids to navigation, navigation charts, and related data policy, practices and procedure. 209.325 Section 209.325 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF...

  17. The sex specificity of navigational strategies in Alzheimer disease.

    Science.gov (United States)

    Cushman, Laura A; Duffy, Charles J

    2007-01-01

    Alzheimer disease (AD) is associated with navigational impairments that limit functional independence. We have now examined the role of cognitive and perceptual mechanisms in the navigational impairment of AD to test the hypothesis that men and women with AD may focus on different navigational cues. We conducted navigational, neuropsychologic, and psychophysical testing in men and women from 3 groups: older normal controls, patients with mild cognitive impairment, and patients with AD. Men and women showed parallel declines in navigational capacities from the older normal control, to the mild cognitive impairment, to the AD groups with men and women making similar numbers of errors but different types of errors. There were small sex differences in neuropsychologic and psychophysical performance but large sex differences in how those measures related to navigational capacity: men showed strong links between visual motion processing and navigation. Women showed strong links between verbal capacities and navigation. The findings of these cross-sectional comparisons suggest that there may be sex differences in the progressive navigational decline of AD: men and women who are impaired to the same degree may suffer somewhat different patterns of decline with men relying more on visuospatial processing and women relying more on verbal mediation.

  18. Beginnings of Satellite Navigation

    Directory of Open Access Journals (Sweden)

    Miljenko Solarić

    2008-05-01

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

  19. Synthesis and Validation of Vision Based Spacecraft Navigation

    DEFF Research Database (Denmark)

    Massaro, Alessandro Salvatore

    at the NASA Ames Research Center's Intelligent Robotics Group (ARCIRG) resulted in the successful implementation of an infrastructure-free global localization algorithm for surface robotic navigation. The algorithm is now integrated with other rover navigation routines developed by IRG. Finally, collaboration...

  20. Navigating Distributed Services

    DEFF Research Database (Denmark)

    Beute, Berco

    2002-01-01

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

  1. 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...

  2. Navigational Planning in Orienteering

    Science.gov (United States)

    Murakoshi, Shin

    Navigation is a human activity with the aim being to arrive at a predetermined destination. In order to find the way to the destination, the use of current input from the actual environment while travelling is needed as well as stored and organized knowledge of the local geography. Although the knowledge requirement has been studied extensively in the form of cognitive maps or other spatial representation, few studies deal with how the knowledge is used together with the input from the actual environment while navigating.

  3. Effects of video-feedback on the communication, clinical competence and motivational interviewing skills of practice nurses: a pre-test posttest control group study.

    Science.gov (United States)

    Noordman, Janneke; van der Weijden, Trudy; van Dulmen, Sandra

    2014-10-01

    To examine the effects of individual video-feedback on the generic communication skills, clinical competence (i.e. adherence to practice guidelines) and motivational interviewing skills of experienced practice nurses working in primary care. Continuing professional education may be necessary to refresh and reflect on the communication and motivational interviewing skills of experienced primary care practice nurses. A video-feedback method was designed to improve these skills. Pre-test/posttest control group design. Seventeen Dutch practice nurses and 325 patients participated between June 2010-June 2011. Nurse-patient consultations were videotaped at two moments (T0 and T1), with an interval of 3-6 months. The videotaped consultations were rated using two protocols: the Maastrichtse Anamnese en Advies Scorelijst met globale items (MAAS-global) and the Behaviour Change Counselling Index. Before the recordings, nurses were allocated to a control or video-feedback group. Nurses allocated to the video-feedback group received video-feedback between T0 and T1. Data were analysed using multilevel linear or logistic regression. Nurses who received video-feedback appeared to pay significantly more attention to patients' request for help, their physical examination and gave significantly more understandable information. With respect to motivational interviewing, nurses who received video-feedback appeared to pay more attention to 'agenda setting and permission seeking' during their consultations. Video-feedback is a potentially effective method to improve practice nurses' generic communication skills. Although a single video-feedback session does not seem sufficient to increase all motivational interviewing skills, significant improvement in some specific skills was found. Nurses' clinical competences were not altered after feedback due to already high standards. © 2014 John Wiley & Sons Ltd.

  4. 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.

  5. 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...

  6. 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,...

  7. Navigating Hypermasculine Terrains

    DEFF Research Database (Denmark)

    Henriksen, Ann-Karina Eske

    2015-01-01

    The study addresses how young women navigate urban terrains that are characterized by high levels of interpersonal aggression and crime. It is argued that young women apply a range of gendered tactics to establish safety and social mastery, and that these are framed by the limits and possibilitie...

  8. Personal Navigation System

    Science.gov (United States)

    2005-10-31

    GPS Satellite Simulator PC I B us PC I B us Embedded C language software TMS320VC33 DSP • Sensor I/O • Navigation Equations • Deep Integration...Simulator Test Display Simulation Controller 22 Figure 12. PNS Prototype Software System Integration Environment Embedded C language

  9. The attack navigator

    DEFF Research Database (Denmark)

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

    2016-01-01

    -technical system, the attack navigator identifies routes to an attacker goal. Specific attacker properties such as skill or resources can be included through attacker profiles. This enables defenders to explore attack scenarios and the effectiveness of defense alternatives under different threat conditions....

  10. 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...

  11. Crew-Aided Autonomous Navigation

    Science.gov (United States)

    Holt, Greg N.

    2015-01-01

    A sextant provides manual capability to perform star/planet-limb sightings and offers a cheap, simple, robust backup navigation source for exploration missions independent from the ground. Sextant sightings from spacecraft were first exercised in Gemini and flew as the lost-communication backup for all Apollo missions. This study characterized error sources of navigation-grade sextants for feasibility of taking star and planetary limb sightings from inside a spacecraft. A series of similar studies was performed in the early/mid-1960s in preparation for Apollo missions. This study modernized and updated those findings in addition to showing feasibility using Linear Covariance analysis techniques. The human eyeball is a remarkable piece of optical equipment and provides many advantages over camera-based systems, including dynamic range and detail resolution. This technique utilizes those advantages and provides important autonomy to the crew in the event of lost communication with the ground. It can also provide confidence and verification of low-TRL automated onboard systems. The technique is extremely flexible and is not dependent on any particular vehicle type. The investigation involved procuring navigation-grade sextants and characterizing their performance under a variety of conditions encountered in exploration missions. The JSC optical sensor lab and Orion mockup were the primary testing locations. For the accuracy assessment, a group of test subjects took sextant readings on calibrated targets while instrument/operator precision was measured. The study demonstrated repeatability of star/planet-limb sightings with bias and standard deviation around 10 arcseconds, then used high-fidelity simulations to verify those accuracy levels met the needs for targeting mid-course maneuvers in preparation for Earth reen.

  12. From translation to navigation of different discourses

    DEFF Research Database (Denmark)

    Livonen, Mirja; Sonnenwald, Diane H.

    1998-01-01

    We propose a model of the search term selection process based on our empirical study of professional searchers during the pre-online stage of the search process. The model characterizes the selection of search terms as the navigation of different discourses. Discourse refers to the ways of talking...... and thinking about a certain topic; there often exists multiple, diverse discourses on the same topic. When selecting search terms, searchers appear to navigate a variety of discourses, i.e., they view the topic of a client's search request from the perspective of multiple discourse communities, and evaluate...... and synthesize differences and similarities among those discourses when selecting search terms. Six discourses emerged as sources of search terms in our study. These discourses are controlled vocabularies, documents and the domain, the practice of indexing, clients' search requests, databases, and the searchers...

  13. Consensus definition of sarcopenia, cachexia and pre-cachexia: joint document elaborated by Special Interest Groups (SIG) "cachexia-anorexia in chronic wasting diseases" and "nutrition in geriatrics".

    Science.gov (United States)

    Muscaritoli, M; Anker, S D; Argilés, J; Aversa, Z; Bauer, J M; Biolo, G; Boirie, Y; Bosaeus, I; Cederholm, T; Costelli, P; Fearon, K C; Laviano, A; Maggio, M; Rossi Fanelli, F; Schneider, S M; Schols, A; Sieber, C C

    2010-04-01

    Chronic diseases as well as aging are frequently associated with deterioration of nutritional status, loss muscle mass and function (i.e. sarcopenia), impaired quality of life and increased risk for morbidity and mortality. Although simple and effective tools for the accurate screening, diagnosis and treatment of malnutrition have been developed during the recent years, its prevalence still remains disappointingly high and its impact on morbidity, mortality and quality of life clinically significant. Based on these premises, the Special Interest Group (SIG) on cachexia-anorexia in chronic wasting diseases was created within ESPEN with the aim of developing and spreading the knowledge on the basic and clinical aspects of cachexia and anorexia as well as of increasing the awareness of cachexia among health professionals and care givers. The definition, the assessment and the staging of cachexia, were identified as a priority by the SIG. This consensus paper reports the definition of cachexia, pre-cachexia and sarcopenia as well as the criteria for the differentiation between cachexia and other conditions associated with sarcopenia, which have been developed in cooperation with the ESPEN SIG on nutrition in geriatrics. Copyright 2009 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  14. Choice of food and food traditions in pre-war Bosnia-Herzegovina: focus group interviews with immigrant women in Sweden.

    Science.gov (United States)

    Jonsson, Inger M; Wallin, Anne-Marie; Hallberg, Lillemor R-M; Gustafsson, Inga-Britt

    2002-08-01

    Immigrants in Sweden have on average poorer health than native Swedes, including the risk of nutritional problems. In Sweden's multicultural society there is a need for increased knowledge about eating habits in public health work within health and education. A survey of refugees from Bosnia-Herzegovina living in Sweden was undertaken to describe the choice of food and food traditions in pre-war Bosnia. The purpose was to introduce the subject of food, health and migration into public health work and develop culture-adapted food and health advice. Focus-group interviews were undertaken with a total of 20 women refugees from Bosnia-Herzegovina. Qualitative data analysis identified a large consumption of bread as a staple food with meat, vegetables, milk, cheese, legumes, egg and fish as additions. Self-sufficiency was noted with milk souring, jam making and the production of sweet fruit drinks. Home made cheese and drying or smoking of meat were common methods of food storage. In child rearing, breast-feeding for 6-8 months was most common. Home made breast milk replacements were made from semolina, rice and 'petit biscuits'. Several important factors need to be taken into account when giving culturally adapted food and health advice to Bosnian families, such as encouraging bread, vegetable and legume consumption and giving advice on substituting sweet fruit drinks for natural fruit. One should be conscious of how religious beliefs as well as socio-cultural, historical, ecological, economical and psychological influences may guide food choices.

  15. Control algorithms for autonomous robot navigation

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, C.C.

    1985-09-20

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

  16. 33 CFR 401.53 - Obstructing navigation.

    Science.gov (United States)

    2010-07-01

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

  17. Exploring Attitudes towards Computer Use among Pre-Service Teachers from Singapore and the UK: A Multi-Group Invariance Test of the Technology Acceptance Model (TAM)

    Science.gov (United States)

    Teo, Timothy; Noyes, Jan

    2010-01-01

    Purpose: This paper aims to compare the pre-service teachers from Singapore and the UK on their self-reported attitude towards computer use (ATCU) by employing the technology acceptance model (TAM) as the research framework. Design/methodology/approach: In total, 395 pre-service teachers completed a survey questionnaire measuring their responses…

  18. Navigation-guided oral and maxillofacial surgery (reconstructive and plastic, orthognathic, oncology)

    Institute of Scientific and Technical Information of China (English)

    Shen GF; Zhang SL; Wang CT

    2008-01-01

    @@ Purpose: Advance in the field of compeer assisted surgery enables the surgical procedures to be less invasive and more accurate for the support of diagnosis imaging, pre-operative simulation and intraoperative navigation.

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

    Science.gov (United States)

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

    2016-04-01

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

  20. 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......, Informationsteknologi, Biologi, Fysik, Medicin, Odontologi og Folkesundhedsvidenskab. NiHE undersøgelsen er gennemført i efteråret 2015 og vinter 2016, og den har til formål at generere data til almen undervisningsudvikling og rummer derfor både faglige, sociale og personlige perspektiver på undervisning....

  1. GPS computer navigators to shorten EMS response and transport times.

    Science.gov (United States)

    Ota, F S; Muramatsu, R S; Yoshida, B H; Yamamoto, L G

    2001-05-01

    GPS (global positioning satellite system to determine one's position on earth) units have become inexpensive and compact. The purpose of this study is to assess the effectiveness of a GPS enhanced computer street map navigator to improve the ability of EMS drivers in an urban setting to locate their destination and shorten response times. For part I, residential addresses in the city were randomly selected from a telephone directory. Two driver/navigator teams were assigned to drive to the address adhering to speed limits. One team used a standard street map, whereas the other team used a GPS computer navigator. The travel time and distance of the runs were compared. For part II, the computer GPS navigator was placed on an ambulance to supplement their normal methods of navigation to find the address requesting EMS. After the run was completed, EMS providers were interviewed to determine their opinion of whether the GPS navigator was helpful. For part I the results showed that in the 29 initial test runs, comparing the GPS team versus the standard map team, the mean distances traveled were 8.7 versus 9.0 kilometers (not significant) and the mean travel times were 13.5 versus 14.6 minutes (P=.02), respectively. The GPS team arrived faster in 72% runs. For part II the results showed that most EMS providers surveyed noted that the GPS computer navigator enhanced their ability to find the destination and all EMS providers acknowledged that it would enhance their ability to find a destination in an area in which they were unfamiliar. These results suggest that a portable GPS computer navigator system is helpful and can enhance the ability of prehospital care providers to locate their destination. Because these units are accurate and inexpensive, GPS computer navigators may be a valuable tool in reducing pre-hospital transport times.

  2. Artificial Pheromone System Using RFID for Navigation of Autonomous Robots

    Institute of Scientific and Technical Information of China (English)

    Herianto; Toshiki Sakakibara; Daisuke Kurabayashi

    2007-01-01

    Navigation system based on the animal behavior has received a growing attention in the past few years. The navigation systems using artificial pheromone are still few so far. For this reason, this paper presents our research that aim to implement autonomous navigation with artificial pheromone system. By introducing artificial pheromone system composed of data carriers and autonomous robots, the robotic system creates a potential field to navigate their group. We have developed a pheromone density model to realize the function of pheromones with the help of data carriers. We intend to show the effectiveness of the proposed system by performing simulations and realization using modified mobile robot. The pheromone potential field system can be used for navigation of autonomous robots.

  3. 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.

  4. Spatial Navigation in Preclinical Alzheimer's Disease

    Science.gov (United States)

    Allison, Samantha L.; Fagan, Anne M.; Morris, John C.; Head, Denise

    2016-01-01

    Although several previous studies have demonstrated navigational deficits in early-stage symptomatic Alzheimer's disease (AD), navigational abilities in preclinical AD have not been examined. The present investigation examined the effects of preclinical AD and early-stage symptomatic AD on spatial navigation performance. Performance on tasks of wayfinding and route learning in a virtual reality environment were examined. Comparisons were made across the following three groups: Clinically normal without preclinical AD (n = 42), clinically normal with preclinical AD (n = 13), and early-stage symptomatic AD (n = 16) groups. Preclinical AD was defined based on cerebrospinal fluid Aβ42 levels below 500 pg/ml. Preclinical AD was associated with deficits in the use of a wayfinding strategy, but not a route learning strategy. Moreover, post-hoc analyses indicated that wayfinding performance had moderate sensitivity and specificity. Results also confirmed early-stage symptomatic AD-related deficits in the use of both wayfinding and route learning strategies. The results of this study suggest that aspects of spatial navigation may be particularly sensitive at detecting the earliest cognitive deficits of AD. PMID:26967209

  5. Waves at Navigation Structures

    Science.gov (United States)

    2014-10-27

    ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same as Report (SAR) 18. NUMBER OF PAGES 2 19a. NAME...upgrades the Coastal Modeling System’s ( CMS ) wave model CMS -Wave, a phase-averaged spectral wave model, and BOUSS-2D, a Boussinesq-type nonlinear wave...provided by this work unit address these critical needs of the Corps’ navigation mission. Description Issue Addressed CMS -Wave application at Braddock

  6. Invisible Navigation (or Impossible?).

    OpenAIRE

    Özcan, Oğuzhan; O'Neil, Mary Lou

    2013-01-01

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

  7. Self-navigating robot

    Science.gov (United States)

    Thompson, A. M.

    1978-01-01

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

  8. Body image and quality of life in patients with and without body contouring surgery following bariatric surgery: a comparison of pre- and post-surgery groups

    Science.gov (United States)

    de Zwaan, Martina; Georgiadou, Ekaterini; Stroh, Christine E.; Teufel, Martin; Köhler, Hinrich; Tengler, Maxi; Müller, Astrid

    2014-01-01

    Background: Massive weight loss (MWL) following bariatric surgery frequently results in an excess of overstretched skin causing physical discomfort and negatively affecting quality of life, self-esteem, body image, and physical functioning. Methods: In this cross-sectional study 3 groups were compared: (1) patients prior to bariatric surgery (n = 79), (2) patients after bariatric surgery who had not undergone body contouring surgery (BCS) (n = 252), and (3) patients after bariatric surgery who underwent subsequent BCS (n = 62). All participants completed self-report questionnaires assessing body image (Multidimensional Body-Self Relations Questionnaire, MBSRQ), quality of life (IWQOL-Lite), symptoms of depression (PHQ-9), and anxiety (GAD-7). Results: Overall, 62 patients (19.2%) reported having undergone a total of 90 BCS procedures. The most common were abdominoplasties (88.7%), thigh lifts (24.2%), and breast lifts (16.1%). Post-bariatric surgery patients differed significantly in most variables from pre-bariatric surgery patients. Although there were fewer differences between patients with and without BCS, patients after BCS reported better appearance evaluation (AE), body area satisfaction (BAS), and physical functioning, even after controlling for excess weight loss and time since surgery. No differences were found for symptoms of depression and anxiety, and most other quality of life and body image domains. Discussion: Our results support the results of longitudinal studies demonstrating significant improvements in different aspects of body image, quality of life, and general psychopathology after bariatric surgery. Also, we found better AE and physical functioning in patients after BCS following bariatric surgery compared to patients with MWL after bariatric surgery who did not undergo BCS. Overall, there appears to be an effect of BCS on certain aspects of body image and quality of life but not on psychological aspects on the whole. PMID:25477839

  9. Body image and quality of life in patients with and without body contouring surgery following bariatric surgery: a comparison of pre- and post-surgery groups

    Directory of Open Access Journals (Sweden)

    Martina eDe Zwaan

    2014-11-01

    Full Text Available Background: Massive weight loss (MWL following bariatric surgery frequently results in an excess of overstretched skin causing physical discomfort and negatively affecting quality of life, self-esteem, body image and physical functioning.Methods: In this cross-sectional study 3 groups were compared: 1 patients prior to bariatric surgery (n=79, 2 patients after bariatric surgery who had not undergone BCS (n=252, and 3 patients after bariatric surgery who underwent subsequent body contouring surgery (BCS (n=62. All participants completed self-report questionnaires assessing body image (MBSRQ, quality of life (IWQOL-Lite, symptoms of depression (PHQ-9 and anxiety (GAD-7.Results: Overall, 62 patients (19.2% reported having undergone a total of 90 BCS procedures. The most common were abdominoplasties (88.7%, thigh lifts (24.2%, and breast lifts (16.1%. Post-bariatric surgery patients differed significantly in most variables from pre-bariatric surgery patients; however, there were fewer differences between patients with and without BCS. Patients after BCS reported better appearance evaluation, body area satisfaction, and physical functioning, even after controlling for excess weight loss and time since surgery. No differences were found for symptoms of depression and anxiety, and most other quality of life and body image domains. Discussion: Our results support the results of longitudinal studies demonstrating significant improvements in different aspects of body image, quality of life, and general psychopathology after bariatric surgery. Also, we found better appearance evaluation and physical functioning in patients after BCS following bariatric surgery compared to patients with MWL after bariatric surgery who did not undergo BCS. Overall, there appears to be an effect of BCS on certain aspects of body image and quality of life but not on psychological aspects on the whole.

  10. Multisensor robot navigation system

    Science.gov (United States)

    Persa, Stelian; Jonker, Pieter P.

    2002-02-01

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

  11. Navigating Language Barriers: A Systematic Review of Patient Navigators' Impact on Cancer Screening for Limited English Proficient Patients.

    Science.gov (United States)

    Genoff, Margaux C; Zaballa, Alexandra; Gany, Francesca; Gonzalez, Javier; Ramirez, Julia; Jewell, Sarah T; Diamond, Lisa C

    2016-04-01

    To systematically review the literature on the impact of patient navigators on cancer screening for limited English proficient (LEP) patients. Electronic databases (PubMed, PsycINFO via OVID, Web of Science, Cochrane, EMBASE, and Scopus) through 8 May 2015. Articles in this review had: (1) a study population of LEP patients eligible for breast, cervical or colorectal cancer screenings, (2) a patient navigator intervention to provide services prior to or during cancer screening, (3) a comparison of the patient navigator intervention to either a control group or another intervention, and (4) language-specific outcomes related to the patient navigator intervention. We assessed the quality of the articles using the Downs and Black Scale. Fifteen studies met the inclusion criteria and evaluated the screening rates for breast, colorectal, and cervical cancer in 15 language populations. Fourteen studies resulted in improved screening rates for LEP patients between 7 and 60%. There was great variability in the patient navigation interventions evaluated. Training received by navigators was not reported in nine of the studies and no studies assessed the language skills of the patient navigators in English or the target language. This study is limited by the variability in study designs and limited reporting on patient navigator interventions, which reduces the ability to draw conclusions on the full effect of patient navigators. Overall, we found evidence that navigators improved screening rates for breast, cervical and colorectal cancer screening for LEP patients. Future studies should systematically collect data on the training curricula for navigators and assess their English and non-English language skills in order to identify ways to reduce disparities for LEP patients.

  12. 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).

  13. Assessment of the accuracy of infrared and electromagnetic navigation using an industrial robot: Which factors are influencing the accuracy of navigation?

    Science.gov (United States)

    Liodakis, Emmanouil; Chu, Kongfai; Westphal, Ralf; Krettek, Christian; Citak, Musa; Gosling, Thomas; Kenawey, Mohamed

    2011-10-01

    Our objectives were to detect factors that influence the accuracy of surgical navigation (magnitude of deformity, plane of deformity, position of the navigation bases) and compare the accuracy of infrared with electromagnetic navigation. Human cadaveric femora were used. A robot connected with a computer moved one of the bony fragments in a desired direction. The bases of the infrared navigation (BrainLab) and the receivers of the electromagnetic device (Fastrak-Pohlemus) were attached to the proximal and distal parts of the bone. For the first part of the study, deformities were classified in eight groups (e.g., 0 to 5(°)). For the second part, the bases were initially placed near the osteotomy and then far away. The mean absolute differences between both navigation system measurements and the robotic angles were significantly affected by the magnitude of angulation with better accuracy for smaller angulations (p navigation was significantly better in the frontal and sagittal plane. Changing the position of the navigation bases near and far away from the deformity apex had no significant effect on the accuracy of infrared navigation; however, it influenced the accuracy of electromagnetic navigation in the frontal plane (p navigation systems for corrections of small angulation-deformities in the frontal or sagittal plane provides the most accurate results, irrespectively from the positioning of the navigation bases.

  14. Effects of cervical mobilization and exercise on pain, movement and function in subjects with temporomandibular disorders: a single group pre-post test

    Science.gov (United States)

    CALIXTRE, Letícia Bojikian; GRÜNINGER, Bruno Leonardo da Silva; HAIK, Melina Nevoeiro; ALBURQUERQUE-SENDÍN, Francisco; OLIVEIRA, Ana Beatriz

    2016-01-01

    ABSTRACT Objective To investigate the effect of a rehabilitation program based on cervical mobilization and exercise on clinical signs and mandibular function in subjects with temporomandibular disorder (TMD). Material and Methods: Single-group pre-post test, with baseline comparison. Subjects Twelve women (22.08±2.23 years) with myofascial pain and mixed TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders. Outcome measures Subjects were evaluated three times: twice before (baseline phase) and once after intervention. Self-reported pain, jaw function [according to the Mandibular Functional Impairment Questionnaire (MFIQ)], pain-free maximum mouth opening (MMO), and pressure pain thresholds (PPTs) of both masseter and temporalis muscles were obtained. Baseline and post-intervention differences were investigated, and effect size was estimated through Cohen’s d coefficient. Results Jaw function improved 7 points on the scale after the intervention (P=0.019), and self-reported pain was significantly reduced (P=0.009). Pain-free MMO varied from 32.3±8.8 mm to 38±8.8 mm and showed significant improvement (P=0.017) with moderate effect size when compared to the baseline phase. PPT also increased with moderate effect size, and subjects had the baseline values changed from 1.23±0.2 kg/cm2 to 1.4±0.2 kg/cm2 in the left masseter (P=0.03), from 1.31±0.28 kg/cm2 to 1.51±0.2 kg/cm2 in the right masseter (P>0.05), from 1.32±0.2 kg/cm2 to 1.46±0.2 kg/cm2 in the left temporalis (P=0.047), and from 1.4±0.2 kg/cm2 to 1.67±0.3 kg/cm2 in the right temporalis (P=0.06). Conclusions The protocol caused significant changes in pain-free MMO, self-reported pain, and functionality of the stomatognathic system in subjects with myofascial TMD, regardless of joint involvement. Even though these differences are statistically significant, their clinical relevance is still questionable. PMID:27383698

  15. Effects of cervical mobilization and exercise on pain, movement and function in subjects with temporomandibular disorders: a single group pre-post test

    Directory of Open Access Journals (Sweden)

    Letícia Bojikian CALIXTRE

    Full Text Available ABSTRACT Objective To investigate the effect of a rehabilitation program based on cervical mobilization and exercise on clinical signs and mandibular function in subjects with temporomandibular disorder (TMD. Material and Methods: Single-group pre-post test, with baseline comparison. Subjects Twelve women (22.08±2.23 years with myofascial pain and mixed TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders. Outcome measures Subjects were evaluated three times: twice before (baseline phase and once after intervention. Self-reported pain, jaw function [according to the Mandibular Functional Impairment Questionnaire (MFIQ], pain-free maximum mouth opening (MMO, and pressure pain thresholds (PPTs of both masseter and temporalis muscles were obtained. Baseline and post-intervention differences were investigated, and effect size was estimated through Cohen’s d coefficient. Results Jaw function improved 7 points on the scale after the intervention (P=0.019, and self-reported pain was significantly reduced (P=0.009. Pain-free MMO varied from 32.3±8.8 mm to 38±8.8 mm and showed significant improvement (P=0.017 with moderate effect size when compared to the baseline phase. PPT also increased with moderate effect size, and subjects had the baseline values changed from 1.23±0.2 kg/cm2 to 1.4±0.2 kg/cm2 in the left masseter (P=0.03, from 1.31±0.28 kg/cm2 to 1.51±0.2 kg/cm2 in the right masseter (P>0.05, from 1.32±0.2 kg/cm2 to 1.46±0.2 kg/cm2 in the left temporalis (P=0.047, and from 1.4±0.2 kg/cm2 to 1.67±0.3 kg/cm2 in the right temporalis (P=0.06. Conclusions The protocol caused significant changes in pain-free MMO, self-reported pain, and functionality of the stomatognathic system in subjects with myofascial TMD, regardless of joint involvement. Even though these differences are statistically significant, their clinical relevance is still questionable.

  16. Effects of cervical mobilization and exercise on pain, movement and function in subjects with temporomandibular disorders: a single group pre-post test.

    Science.gov (United States)

    Calixtre, Letícia Bojikian; Grüninger, Bruno Leonardo da Silva; Haik, Melina Nevoeiro; Alburquerque-Sendín, Francisco; Oliveira, Ana Beatriz

    2016-01-01

    To investigate the effect of a rehabilitation program based on cervical mobilization and exercise on clinical signs and mandibular function in subjects with temporomandibular disorder (TMD). Single-group pre-post test, with baseline comparison. Twelve women (22.08±2.23 years) with myofascial pain and mixed TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders. Subjects were evaluated three times: twice before (baseline phase) and once after intervention. Self-reported pain, jaw function [according to the Mandibular Functional Impairment Questionnaire (MFIQ)], pain-free maximum mouth opening (MMO), and pressure pain thresholds (PPTs) of both masseter and temporalis muscles were obtained. Baseline and post-intervention differences were investigated, and effect size was estimated through Cohen's d coefficient. Jaw function improved 7 points on the scale after the intervention (P=0.019), and self-reported pain was significantly reduced (P=0.009). Pain-free MMO varied from 32.3±8.8 mm to 38±8.8 mm and showed significant improvement (P=0.017) with moderate effect size when compared to the baseline phase. PPT also increased with moderate effect size, and subjects had the baseline values changed from 1.23±0.2 kg/cm2 to 1.4±0.2 kg/cm2 in the left masseter (P=0.03), from 1.31±0.28 kg/cm2 to 1.51±0.2 kg/cm2 in the right masseter (P>0.05), from 1.32±0.2 kg/cm2 to 1.46±0.2 kg/cm2 in the left temporalis (P=0.047), and from 1.4±0.2 kg/cm2 to 1.67±0.3 kg/cm2 in the right temporalis (P=0.06). The protocol caused significant changes in pain-free MMO, self-reported pain, and functionality of the stomatognathic system in subjects with myofascial TMD, regardless of joint involvement. Even though these differences are statistically significant, their clinical relevance is still questionable.

  17. Navigating ECA-Zones

    DEFF Research Database (Denmark)

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

    is the substantial impact of the current and future oil price on the optimal compliance strategies ship-owners choose when complying with the new air emission requirements for vessels. The oil price determines the attractiveness of investing in asset modification for compliance, given the capital investment required......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....

  18. 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

  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. Songlines and Navigation in Wardaman and other Australian Aboriginal Cultures

    CERN Document Server

    Norris, Ray P

    2014-01-01

    We discuss the songlines and navigation of the Wardaman people, and place them in context by comparing them with corresponding practices in other Australian Aboriginal 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

  2. Navigation Performance of Global Navigation Satellite Systems in the Space Service Volume

    Science.gov (United States)

    Force, Dale A.

    2013-01-01

    GPS has been used for spacecraft navigation for many years center dot In support of this, the US has committed that future GPS satellites will continue to provide signals in the Space Service Volume center dot NASA is working with international agencies to obtain similar commitments from other providers center dot In support of this effort, I simulated multi-constellation navigation in the Space Service Volume In this presentation, I extend the work to examine the navigational benefits and drawbacks of the new constellations center dot A major benefit is the reduced geometric dilution of precision (GDOP). I show that there is a substantial reduction in GDOP by using all of the GNSS constellations center dot The increased number of GNSS satellites broadcasting does produce mutual interference, raising the noise floor. A near/far signal problem can also occur where a nearby satellite drowns out satellites that are far away. - In these simulations, no major effect was observed Typically, the use of multi-constellation GNSS navigation improves GDOP by a factor of two or more over GPS alone center dot In addition, at the higher altitudes, four satellite solutions can be obtained much more often center dot This show the value of having commitments to provide signals in the Space Service Volume Besides a commitment to provide a minimum signal in the Space Service Volume, detailed signal gain information is useful for mission planning center dot Knowledge of group and phase delay over the pattern would also reduce the navigational uncertainty

  3. Deep Sea AUV Navigation Using Multiple Acoustic Beacons

    Institute of Scientific and Technical Information of China (English)

    冀大雄; 宋伟; 赵宏宇; 刘健

    2016-01-01

    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.

  4. 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.

  5. Collective strategy for obstacle navigation during cooperative transport by ants.

    Science.gov (United States)

    McCreery, Helen F; Dix, Zachary A; Breed, Michael D; Nagpal, Radhika

    2016-11-01

    Group cohesion and consensus have primarily been studied in the context of discrete decisions, but some group tasks require making serial decisions that build on one another. We examine such collective problem solving by studying obstacle navigation during cooperative transport in ants. In cooperative transport, ants work together to move a large object back to their nest. We blocked cooperative transport groups of Paratrechina longicornis with obstacles of varying complexity, analyzing groups' trajectories to infer what kind of strategy the ants employed. Simple strategies require little information, but more challenging, robust strategies succeed with a wider range of obstacles. We found that transport groups use a stochastic strategy that leads to efficient navigation around simple obstacles, and still succeeds at difficult obstacles. While groups navigating obstacles preferentially move directly toward the nest, they change their behavior over time; the longer the ants are obstructed, the more likely they are to move away from the nest. This increases the chance of finding a path around the obstacle. Groups rapidly changed directions and rarely stalled during navigation, indicating that these ants maintain consensus even when the nest direction is blocked. Although some decisions were aided by the arrival of new ants, at many key points, direction changes were initiated within the group, with no apparent external cause. This ant species is highly effective at navigating complex environments, and implements a flexible strategy that works for both simple and more complex obstacles. © 2016. Published by The Company of Biologists Ltd.

  6. Exploring Pre-Service Science Teacher Methods and Strategies for the Driving Questions in Research Inquiry: From Consulting an Instructor to Group Discussion

    Science.gov (United States)

    Aydin, Miraç

    2016-01-01

    An important stage in any research inquiry is the development of research questions that need to be answered. The strategies to develop research questions should be defined and described, but few studies have considered this process in greater detail. This study explores pre-service science teachers' research questions and the strategies they can…

  7. Explaining the Intention to Use Technology among Pre-Service Teachers: A Multi-Group Analysis of the Unified Theory of Acceptance and Use of Technology

    Science.gov (United States)

    Teo, Timothy; Noyes, Jan

    2014-01-01

    Pre-service teachers' self-reported intentions to use information technology were studied. Two hundred and sixty-four participants completed a survey questionnaire measuring their responses to four constructs (performance expectancy, effort expectancy, social influence and facilitating conditions) derived from the Unified Theory of Acceptance and…

  8. 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.

  9. Underwater Navigation using Pseudolite

    Directory of Open Access Journals (Sweden)

    Krishneshwar Tiwary

    2011-07-01

    Full Text Available Using pseudolite or pseudo satellite, a proven technology for ground and space applications for the augmentation of GPS, is proposed for underwater navigation. Global positioning systems (GPS like positioning for underwater system, needs minimum of four pseudolite-ranging signals for pseudo-range and accumulated delta range measurements. Using four such measurements and using the models of underwater attenuation and delays, the navigation solution can be found. However, for application where the one-way ranging does not give good accuracy, alternative algorithms based upon the bi-directional and self-difference ranging is proposed using selfcalibrated pseudolite array algorithm. The hardware configuration is proposed for pseudolite transceiver for making the self-calibrated array. The pseudolite array, fixed or moored under the sea, can give position fixing similar to GPS for underwater applications.Defence Science Journal, 2011, 61(4, pp.331-336, DOI:http://dx.doi.org/10.14429/dsj.61.1087

  10. 33 CFR 207.185 - Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and navigation. 207.185 Section 207.185 Navigation and... § 207.185 Taylors Bayou, Tex., Beaumont Navigation District Lock; use, administration, and...

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

    Science.gov (United States)

    Codling, Edward A; Bode, Nikolai W F

    2016-04-07

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

  12. 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

  13. Introductory Course on Satellite Navigation

    Science.gov (United States)

    Giger, Kaspar; Knogl, J. Sebastian

    2012-01-01

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

  14. SU-F-P-42: “To Navigate, Or Not to Navigate: HDR BT in Recurrent Spine Lesions”

    Energy Technology Data Exchange (ETDEWEB)

    Voros, L; Cohen, G; Zaider, M; Yamada, Y [Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2016-06-15

    Purpose: We compare the accuracy of HDR catheter placement for paraspinal lesions using O-arm CBCT imaging combined with StealthStation navigation and traditional fluoroscopically guided catheter placement. Methods: CT and MRI scans were acquired pre-treatment to outline the lesions and design treatment plans (pre-plans) to meet dosimetric constrains. The pre-planned catheter trajectories were transferred into the StealthStation Navigation system prior to the surgery. The StealthStation is an infra red (IR) optical navigation system used for guidance of surgical instruments. An intraoperative CBCT scan (O-arm) was acquired with reference IR optical fiducials anchored onto the patient and registered with the preplan image study to guide surgical instruments in relation to the patients’ anatomy and to place the brachytherapy catheters along the pre-planned trajectories. The final treatment plan was generated based on a 2nd intraoperative CBCT scan reflecting achieved implant geometry. The 2nd CBCT was later registered with the initial CT scan to compare the preplanned dwell positions with actual dwell positions (catheter placements). Similar workflow was used in placement of 8 catheters (1 patient) without navigation, but under fluoroscopy guidance in an interventional radiology suite. Results: A total of 18 catheters (3 patients) were placed using navigation assisted surgery. Average displacement of 0.66 cm (STD=0.37cm) was observed between the pre-plan source positions and actual source positions in the 3 dimensional space. This translates into an average 0.38 cm positioning error in one direction including registration errors, digitization errors, and the surgeons ability to follow the planned trajectory. In comparison, average displacement of non-navigated catheters was 0.50 cm (STD=0.22cm). Conclusion: Spinal lesion HDR brachytherapy planning is a difficult task. Catheter placement has a direct impact on target coverage and dose to critical structures. While

  15. Autonomous Spacecraft Navigation With Pulsars

    CERN Document Server

    Becker, Werner; Jessner, Axel

    2013-01-01

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

  16. 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...

  17. 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.

  18. Precision Navigation Using Pre-Georegistered Map Data

    Science.gov (United States)

    2009-09-10

    satellite point of view. Generally, the results were best for this case except in heading. This is possibly a product of near- singular solutions , or...to the results achieved by SIFT. It appears that it is slightly more vulnerable to near- singular solutions than is SIFT. The dotted lines represent the...that had the most problems with near- singular solutions . The dotted lines are the ensemble standard deviation, and the solid lines represent the

  19. 33 CFR 66.10-15 - Aids to navigation.

    Science.gov (United States)

    2010-07-01

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

  20. 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).

  1. 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.

  2. Indoor Positioning and Navigation Based on Control Spherecal Panoramic Images

    Science.gov (United States)

    Huang, Tsung-Che; Tseng, Yi-Hsing

    2016-06-01

    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.

  3. Navigable networks as Nash equilibria of navigation games

    Science.gov (United States)

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

    2015-07-01

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

  4. A greedy-navigator approach to navigable city plans

    CERN Document Server

    Lee, Sang Hoon

    2012-01-01

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

  5. Navigation in Augmented Reality, Navigation i Augmented Reality

    OpenAIRE

    Bernelind, Sarah

    2015-01-01

    The concept of augmented reality has existed since the 60’s. In this thesis it has been investigated if navigation using a mobile device would benefit, from a usability perspective, if the navigational data were presented using augmented reality instead of a standardized map. The usability principles from which the applications were evaluated are learnability, user satisfaction, efficiency and effectivity. An AR prototype was developed and tested against a standard map, in the form of Google ...

  6. Analysis of group cohesion levels and pre-competitive psychological stress in volleyball athletes.. http://dx.doi.org/10.5007/1980-0037.2012v14n6p704

    Directory of Open Access Journals (Sweden)

    Guilherme Moraes Balbim

    2012-11-01

    Full Text Available This descriptive study was designed to analyze the level of group cohesion and pre-competitive psychological stress of adult volleyball athletes. The subjects consisted of 155 male and female athletes from the state of Parana who played in the JAPS/ 1st division (A, and 2nd division (B. The assessment instruments used were the Group Environment Questionnaire (GEQ and the Volleyball Psychic Stress Test (V-PST. For data analysis, the following tools were used: Cronbach’s alpha, Kolmogorov-Smirnov, Mann-Whitney, one-way Anova, and Tukey’s post hoc (p<0.05. The results revealed that athletes of division A were more negatively influenced by stress factors than the athletes of division B; in terms of individual attraction to the social group (p=0.014 and tasks (p=0016 athletes of division B had higher levels of group cohesion than athletes from division A; athletes with low social cohesion were negatively impacted by factors of "inappropriate physical conditioning" and "excessive nervousness;" athletes with low levels of cohesion for the task were negatively influenced by the factors of "Pressure from other people to win" and positively by the factor "Behavior of the fans in the game outside." It was concluded that group cohesion is demonstrated to be an intervening factor in pre-competitive stress thereby demonstrating that the higher the dispute level, the higher the negative influence of stress.

  7. Geomagnetic Navigation in Sea Turtles

    Science.gov (United States)

    Lohmann, K.; Putman, N.; Lohmann, C.

    2011-12-01

    Young loggerhead sea turtles (Caretta caretta) from eastern Florida undertake a transoceanic migration in which they gradually circle the north Atlantic Ocean before returning to the North American coast. Newly hatched turtles (hatchlings) begin the migration with a 'magnetic map' in which regional magnetic fields function as navigational markers and elicit changes in swimming direction at crucial geographic boundaries. In laboratory experiments, young turtles that had never before been in the ocean were exposed to fields like those that exist at various, widely separated locations along their transoceanic migratory route. Turtles responded by swimming in directions that would, in each case, help them remain within the North Atlantic gyre currents and advance along the migratory pathway. The results demonstrate that turtles can derive both longitudinal and latitudinal information from the Earth's field, and provide strong evidence that hatchling loggerheads inherit a remarkably elaborate set of responses that function in guiding them along their open-sea migratory route. For young sea turtles, couplings of oriented swimming to regional magnetic fields appear to provide the fundamental building blocks from which natural selection can sculpt a sequence of responses capable of guiding first-time ocean migrants along complex migratory routes. The results imply that hatchlings from different populations in different parts of the world are likely to have magnetic navigational responses uniquely suited for the migratory routes that each group follows. Thus, from a conservation perspective, turtles from different populations are not interchangeable. From an evolutionary perspective, the responses are not incompatible with either secular variation or magnetic polarity reversals. As Earth's field gradually changes, strong selective pressure presumably acts to maintain an approximate match between the responses of hatchlings and the fields that exist at critical points along

  8. Exploring maps with greedy navigators

    CERN Document Server

    Lee, Sang Hoon

    2011-01-01

    During the last decade of network researches focusing on structural and dynamical properties of networks, the role of network users has been more or less underestimated from the bird's eye view of global perspective. In this era of GPS-equipped smartphones, however, user's ability to access local geometric information and find efficient pathways on networks plays a crucial role, rather than the globally optimal pathways. We present a simple greedy spatial navigation strategy as a probe to explore spatial networks. These greedy navigators use directional information in every move they take, without being trapped in a dead end based on their memory about previous routes. We suggest that the centralities measures have to be modified to incorporate the navigators' behavior, and present the intriguing effect of navigators' greediness where removing some edges may actually enhance the routing efficiency, which is reminiscent of Braess's paradox caused by the chasm between user and global optimum. In addition, using...

  9. Radio Navigation Waveform Experiment Project

    Data.gov (United States)

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

  10. 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...

  11. LITERATURE FORENSICS: NAVIGATING THROUGH ...

    Science.gov (United States)

    Intimidation and bewilderment are but two feelings scientists often confront when facing the ever- expanding universe of the published scientific literature. With the birth of any hypothesis, all fantasies of a one-way freeway for a scientific endeavor evaporate when the journey abruptly confronts a forked-road dilemma. One direction (what is known and what was known) leads back in time. A twisted, rutted, convoluted course, it can reveal how, and from where, pioneers from other, unrelated journeys arrived at the same juncture; but it can make for a punishing and, at first thought, boring ride. The other (what is unknown or pretends to be the unknown) quickly recedes into what at least appears to be the unexplored horizon - and its seductive siren can easily win our attention. Proper navigation of this juncture of old vs. new, past vs. future, dull vs. exciting, known vs. unknown is critical in avoiding a morass of ill fates, including reinventions duplication, and attendant ridicule or censure by our colleagues for failing to build upon or acknowledge what those before us have done. Following the siren of exploration without investigating where others have traveled is fraught with risks - the worst being when the fork's two branches loop back on one another, revealing that they are one continuum. What had seemed to be uncharted territory is unveiled as a Mobius path towards the fool's gold of rediscovery. Much like the disoriented spelunker seeking a

  12. Preanalytical quality improvement. In pursuit of harmony, on behalf of European Federation for Clinical Chemistry and Laboratory Medicine (EFLM) Working group for Preanalytical Phase (WG-PRE).

    Science.gov (United States)

    Lippi, Giuseppe; Banfi, Giuseppe; Church, Stephen; Cornes, Michael; De Carli, Gabriella; Grankvist, Kjell; Kristensen, Gunn B; Ibarz, Mercedes; Panteghini, Mauro; Plebani, Mario; Nybo, Mads; Smellie, Stuart; Zaninotto, Martina; Simundic, Ana-Maria

    2015-02-01

    Laboratory diagnostics develop through different phases that span from test ordering (pre-preanalytical phase), collection of diagnostic specimens (preanalytical phase), sample analysis (analytical phase), results reporting (postanalytical phase) and interpretation (post-postanalytical phase). Although laboratory medicine seems less vulnerable than other clinical and diagnostic areas, the chance of errors is not negligible and may adversely impact on quality of testing and patient safety. This article, which continues a biennial tradition of collective papers on preanalytical quality improvement, is aimed to provide further contributions for pursuing quality and harmony in the preanalytical phase, and is a synopsis of lectures of the third European Federation of Clinical Chemistry and Laboratory Medicine (EFLM)-Becton Dickinson (BD) European Conference on Preanalytical Phase meeting entitled 'Preanalytical quality improvement. In pursuit of harmony' (Porto, 20-21 March 2015). The leading topics that will be discussed include unnecessary laboratory testing, management of test request, implementation of the European Union (EU) Directive on needlestick injury prevention, harmonization of fasting requirements for blood sampling, influence of physical activity and medical contrast media on in vitro diagnostic testing, recent evidence about the possible lack of necessity of the order of draw, the best practice for monitoring conditions of time and temperature during sample transportation, along with description of problems emerging from inappropriate sample centrifugation. In the final part, the article includes recent updates about preanalytical quality indicators, the feasibility of an External Quality Assessment Scheme (EQAS) for the preanalytical phase, the results of the 2nd EFLM WG-PRE survey, as well as specific notions about the evidence-based quality management of the preanalytical phase.

  13. The impact of patient navigation on the delivery of diagnostic breast cancer care in the National Patient Navigation Research Program: a prospective meta-analysis.

    Science.gov (United States)

    Battaglia, Tracy A; Darnell, Julie S; Ko, Naomi; Snyder, Fred; Paskett, Electra D; Wells, Kristen J; Whitley, Elizabeth M; Griggs, Jennifer J; Karnad, Anand; Young, Heather; Warren-Mears, Victoria; Simon, Melissa A; Calhoun, Elizabeth

    2016-08-01

    Patient navigation is emerging as a standard in breast cancer care delivery, yet multi-site data on the impact of navigation at reducing delays along the continuum of care are lacking. The purpose of this study was to determine the effect of navigation on reaching diagnostic resolution at specific time points after an abnormal breast cancer screening test among a national sample. A prospective meta-analysis estimated the adjusted odds of achieving timely diagnostic resolution at 60, 180, and 365 days. Exploratory analyses were conducted on the pooled sample to identify which groups had the most benefit from navigation. Clinics from six medical centers serving vulnerable populations participated in the Patient Navigation Research Program. Women with an abnormal breast cancer screening test between 2007 and 2009 were included and received the patient navigation intervention or usual care. Patient navigators worked with patients and their care providers to address patient-specific barriers to care to prevent delays in diagnosis. A total of 4675 participants included predominantly racial/ethnic minorities (74 %) with public insurance (40 %) or no insurance (31 %). At 60 days and 180 days, there was no statistically significant effect of navigation on achieving timely diagnostic care, but a benefit of navigation was seen at 365 days (aOR 2.12, CI 1.36-3.29). We found an equal benefit of navigation across all groups, regardless of race/ethnicity, language, insurance status, and type of screening abnormality. Patient navigation resulted in more timely diagnostic resolution at 365 days among a diverse group of minority, low-income women with breast cancer screening abnormalities. Trial registrations clinicaltrials.gov Identifiers: NCT00613275, NCT00496678, NCT00375024, NCT01569672.

  14. Effects of gamma radiation on banana 'nanica' (Musa sp., group AAA) irradiated in pre climacteric phase; Efeitos da radicao gama em banana 'nanica' (Musa sp., grupo AAA) irradiada na fase pre-climaterica

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Simone Faria [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindutria de Alimentos e Nutricao; Dionisio, Ana Paula [Universidade Estadual de Campinas (FEA/UNICAMP), SP (Brazil). Faculdade de Engenharia de Alimentos. Dept. de Ciencia de Alimentos; Walder, Julio Marcos Melges [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Radioentomologia e Irradiacao de Alimentos

    2007-07-15

    The present work verified the effect of gamma radiation on physical and chemical parameters of banana 'nanica', analyzing possible alterations on the period of conservation and the possibility of commercial irradiation aiming the exportation. The results had demonstrated that the radiations had not produced effect on pH and total acidity. However, the bananas of the 'control group' and those that had received 0,75 kGy, had presented greater maturation degree and, radiated with 0,30 kGy, had presented greater firmness. In accordance with the results of the organoleptic analysis, can be perceived that the bananas most mature, especially of the 'control group', had had greater acceptance. The bananas of treatments 0,30 and 0,60 kGy had had minors notes for presenting minor maturation stadium. Knowing that the irradiation in adequate dose and fruits of good quality brings benefits to the storage and the process of exportation, we conclude that the dose most appropriate for the control of the maturation of the 'nanica' banana is 0,30 kGy. (author)

  15. From translation to navigation of different discourses

    DEFF Research Database (Denmark)

    Livonen, Mirja; Sonnenwald, Diane H.

    1998-01-01

    We propose a model of the search term selection process based on our empirical study of professional searchers during the pre-online stage of the search process. The model characterizes the selection of search terms as the navigation of different discourses. Discourse refers to the ways of talking...... and synthesize differences and similarities among those discourses when selecting search terms. Six discourses emerged as sources of search terms in our study. These discourses are controlled vocabularies, documents and the domain, the practice of indexing, clients' search requests, databases, and the searchers...... selection process. It emphasizes the multiplicity and complexity of sources of search terms, the dynamic nature of the search term selection process, and the complex analysis and synthesis of differences and similarities among sources of search terms. It suggests that searchers may need to understand...

  16. 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.

  17. Navigation and Control of a Vehicle to the Parking Place Using Ins

    Directory of Open Access Journals (Sweden)

    Rastislav PIRNÍK

    2015-11-01

    Full Text Available This article discusses possibility of usage of the inertial navigation system for an autonomous navigation of a vehicle to the parking place inside intelligent parking house. Our research has shown that inertial navigation is suitable only for heading and attitude estimation. In order to achieve reliable and precise position estimation the additional odometer sensor is required. Article also describes control algorithm which can be used for steering control of the car according to pre-set waypoints. Waypoints have to be placed with respect to the dimensions and overall maneuverability of the vehicle.

  18. Computer-assisted navigation systems for insertion of cannulated screws in femoral neck fractures: a comparison of bi-planar robot navigation with optoelectronic navigation in a Synbone hip model trial

    Institute of Scientific and Technical Information of China (English)

    WANG Jun-qiang; ZHAO Chun-peng; SU Yong-gang; ZHOU Li; HU Lei; WANG Tian-miao; WANG Man-yi

    2011-01-01

    Background Computer-assisted procedures have recently been introduced for navigated femoral neck screw placement.Currently there is little information available regarding accuracy and efficiency of the different navigated procedures.The aim of this study was to compare two fluoroscopic navigation tracking technologies,a novel bi-planar robot navigation and standardized optoelectronic navigation,versus standard freehand fluoroscopic insertion in a Synbone hip model.Methods Eighteen fixed Synbone hip models were divided into 3 groups.C-arm navigated cannulated screws (AO-ASIF,diameter 7.3 mm) were inserted using freehand targeting (control group).A novel bi-planar robot system (TINAV,GD2000) and an optoelectronic system (Stryker OTS Navigation System) were used for the navigated procedures (robot group and optoelectronic group).Accuracy was measured using radiographic evaluation including the measurement of screw parallelism and decentralization,and joint penetration.To evaluate the efficiency,the number of guidewire passes,operative time and fluoroscopic images taken were noted.Results The two computer-assisted systems provided significantly improved accuracy compared to the freehand technique.Each of the parameters,including guidewire passes and number of fluoroscopy images,was significantly lower when using the computer-assisted systems than for freehand-unguided insertion (P <0.05),but operative time was significantly shorter when using freehand-unguided insertion than for the computer-assisted systems (P <0.05).Accuracy,operative time and number of fluoroscopy images taken were similar among the two navigated groups (P >0.05),but guidewire passes in the robot group were significantly less than in the optoelectronic group (P <0.05).Conclusions Both bi-planar robot navigation and optoelectronic navigation were similarly accurate and have the potential to improve accuracy and reduce radiation for freehand fluoroscopic targeting for insertion of cannulated

  19. Simulation-based camera navigation training in laparoscopy-a randomized trial

    DEFF Research Database (Denmark)

    Nilsson, Cecilia; Sørensen, Jette Led; Konge, Lars

    2017-01-01

    patient safety. The objectives of this trial were to examine how to train laparoscopic camera navigation and to explore the transfer of skills to the operating room. MATERIALS AND METHODS: A randomized, single-center superiority trial with three groups: The first group practiced simulation-based camera...... navigation tasks (camera group), the second group practiced performing a simulation-based cholecystectomy (procedure group), and the third group received no training (control group). Participants were surgical novices without prior laparoscopic experience. The primary outcome was assessment of camera.......033), had a higher score. CONCLUSIONS: Simulation-based training improves the technical skills required for camera navigation, regardless of practicing camera navigation or the procedure itself. Transfer to the clinical setting could, however, not be demonstrated. The control group demonstrated higher...

  20. Differentiation in Data Analysis & Probability, PreK-Grade 2: A Content Companion for Ongoing Assessment, Grouping Students, Targeting Instruction, and Adjusting Levels of Cognitive Demand

    Science.gov (United States)

    Taylor-Cox, Jennifer

    2008-01-01

    This book applies the author's easy but effective differentiation strategies to the data analysis and probability content standard. Taking the foundational elements of differentiation in this book, it helps you: (1) assess students' math abilities quickly and efficiently; (2) group children by need; (3) target instruction to meet every student's…

  1. Pre-existing dwarfs, tidal knots and a tidal dwarf galaxy: an unbiased HI study of the gas-rich interacting galaxy group NGC 3166/9

    CERN Document Server

    Lee-Waddell, Karen; Haynes, Martha P; Stierwalt, Sabrina; Chengalur, Jayaram; Chandra, Poonam; Giovanelli, Riccardo

    2012-01-01

    We present Arecibo Legacy Fast ALFA (ALFALFA) and follow-up Giant Metrewave Radio Telescope (GMRT) HI observations of the gas-rich interacting group NGC 3166/9. The sensitive ALFALFA data provide a complete census of HI-bearing systems in the group while the high-resolution GMRT data elucidate their origin, enabling one of the first unbiased physical studies of gas-rich dwarf companions and the subsequent identification of second generation, tidal dwarf galaxies in a nearby group. The ALFALFA maps reveal an extended HI envelope around the NGC 3166/9 group core, which we mosaic at higher resolution using six GMRT pointings spanning ~1 square degree. A thorough search of the GMRT datacube reveals eight low-mass objects with gas masses ranging from 4x10^7 to 3x10^8 M_sol and total dynamical masses up to 1.4x10^9 M_sol. A comparison of the HI fluxes measured from the GMRT data to those measured in the ALFALFA data suggests that a significant fraction (~60%) of the HI is smoothly distributed on scales greater than...

  2. Differentiation in Data Analysis & Probability, PreK-Grade 2: A Content Companion for Ongoing Assessment, Grouping Students, Targeting Instruction, and Adjusting Levels of Cognitive Demand

    Science.gov (United States)

    Taylor-Cox, Jennifer

    2008-01-01

    This book applies the author's easy but effective differentiation strategies to the data analysis and probability content standard. Taking the foundational elements of differentiation in this book, it helps you: (1) assess students' math abilities quickly and efficiently; (2) group children by need; (3) target instruction to meet every student's…

  3. 33 CFR 100.45 - Establishment of aids to navigation.

    Science.gov (United States)

    2010-07-01

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

  4. 33 CFR 67.35-10 - Private aids to navigation.

    Science.gov (United States)

    2010-07-01

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

  5. 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)...

  6. Navigation improves accuracy of rotational alignment in total knee arthroplasty.

    Science.gov (United States)

    Stöckl, Bernd; Nogler, Michael; Rosiek, Rafal; Fischer, Martin; Krismer, Martin; Kessler, Oliver

    2004-09-01

    Successful total knee arthroplasty is dependent on the correct alignment of implanted prostheses. Major clinical problems can be related to poor femoral component positioning, including sagittal plane and rotational malalignment. A prospective randomized study was designed to test whether an optical navigation system for total knee arthroplasty achieved greater implantation precision than a nonnavigated technique. The primary variable was rotation of the femoral component in the transverse plane, measured from postoperative radiographs and computed tomography images. Sixty-four patients were included in the study. All patients received the Duracon total knee prosthesis. The patients were randomly divided into two groups: Group C patients had conventional total knee arthroplasty without navigation; Group N patients had total knee arthroplasty using a computer-assisted knee navigation system. Analysis showed that patients in Group N had significantly better rotational alignment and flexion angle of the femoral component than patients in Group C. In addition, superior postoperative alignment of the mechanical axis, posterior tibial slope, and rotational alignment was achieved for patients in Group N. The use of a navigation system provides improved alignment accuracy, and can help to avoid femoral malrotation and errors in axial alignment.

  7. A relativistic and autonomous navigation satellite system

    CERN Document Server

    Delva, Pacôme; Kostić, Uros; Carloni, Sante

    2011-01-01

    A relativistic positioning system has been proposed by Bartolom\\'e Coll in 2002. Since then, several group developed this topic with different approaches. I will present a work done in collaboration with Ljubljana University and the ESA Advanced Concepts Team. We developed a concept, Autonomous Basis of Coordinates, in order to take advantage of the full autonomy of a satellite constellation for navigation and positioning, by means of satellite inter-links. I will present the advantages of this new paradigm and a number of potential application for reference systems, geophysics and relativistic gravitation.

  8. The Key of the Maze: The role of mental imagery and cognitive flexibility in navigational planning.

    Science.gov (United States)

    Bocchi, Alessia; Carrieri, Marika; Lancia, Stefania; Quaresima, Valentina; Piccardi, Laura

    2017-06-09

    Spatial navigation planning ability relies on both mental imagery and cognitive flexibility. Considering the importance of planning ability in everyday life, several neuropsychological tests are used in clinical practice for its assessment, although some of these are not aimed at assessing the strategies of navigational planning. The Porteus Maze Test (PMT) and the Key Search Task (KST) require to plan a strategy in a maze and in an imagined space, respectively. To the best of our knowledge, although these two tests share some features, the relationship between them has never been explored. The purpose of the present study was to investigate, for the first time, the relationship between the PMT and the KST performances in 38 healthy subjects in order to understand the implications of this association for the assessment of spatial navigation ability. Subjects were subdivided in bad or good navigation planners on the basis of the their KST score. The results of the study have revealed a significant difference (t=2.35; p=0.03) in the number of errors made at the PMT by bad navigational planners (0.78±0.28) and good navigational planners (0.10±0.06). The first group (bad navigational planners) made more errors at the PMT than the good navigational planners (who made less errors at the PMT). This provides evidence of the possibility to use the KST and the PMT in a combined way as a new tool for the assessment of spatial navigational planning ability. Furthermore, this finding highlights the importance of mental imagery and cognitive flexibility in spatial navigation, suggesting that these functions could be the link between a good planning ability and a successful spatial navigation. In conclusion, this study suggests that an efficient navigation would not be possible without a good navigational planning ability. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Longitudinal analysis of VP7 gene of group A human rotavirus G2P[4] strains circulating in the pre-vaccine era in Sapporo, Japan from 1991 to 2011.

    Science.gov (United States)

    Tatsumi, Masatoshi; Nagaoka, Yoshinobu; Tsugawa, Takeshi; Yoto, Yuko; Hori, Tsukasa; Tsutsumi, Hiroyuki

    2014-09-01

    Sequence analysis of the VP7 gene in 23 group A human rotavirus G2P[4] strains obtained during 1991-2011, that is, the pre-vaccine era, in Sapporo, Japan showed considerable genetic diversity, mainly in variable regions. Recent G2P[4] epidemic strains were located in sublineage IVa with a distinctive substitution of D96N. This study provides background data on the genetic variability of G2P[4] rotavirus-VP7 gene prior to the widespread use of rotavirus vaccines in Japan.

  10. Global navigation satellite systems, inertial navigation, and integration

    CERN Document Server

    Grewal, Mohinder S; Bartone, Chris G

    2013-01-01

    An updated guide to GNSS, and INS, and solutions to real-world GNSS/INS problems with Kalman filtering Written by recognized authorities in the field, this third edition of a landmark work provides engineers, computer scientists, and others with a working familiarity of the theory and contemporary applications of Global Navigation Satellite Systems (GNSS), Inertial Navigational Systems, and Kalman filters. Throughout, the focus is on solving real-world problems, with an emphasis on the effective use of state-of-the-art integration techniques for those systems, especially the application of Kal

  11. 33 CFR 207.275 - McClellan-Kerr Arkansas River navigation system: use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false McClellan-Kerr Arkansas River navigation system: use, administration, and navigation. 207.275 Section 207.275 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS §...

  12. 33 CFR 165.122 - Regulated Navigation Area: Navigable waters within Narragansett Bay and the Providence River...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Regulated Navigation Area... SAFETY REGULATED NAVIGATION AREAS AND LIMITED ACCESS AREAS Specific Regulated Navigation Areas and Limited Access Areas First Coast Guard District § 165.122 Regulated Navigation Area: Navigable waters...

  13. Comparison of nonnavigated and 3-dimensional image-based computer navigated balloon kyphoplasty.

    Science.gov (United States)

    Sembrano, Jonathan N; Yson, Sharon C; Polly, David W; Ledonio, Charles Gerald T; Nuckley, David J; Santos, Edward R G

    2015-01-01

    Balloon kyphoplasty is a common treatment for osteoporotic and pathologic compression fractures. Advantages include minimal tissue disruption, quick recovery, pain relief, and in some cases prevention of progressive sagittal deformity. The benefit of image-based navigation in kyphoplasty has not been established. The goal of this study was to determine whether there is a difference between fluoroscopy-guided balloon kyphoplasty and 3-dimensional image-based navigation in terms of needle malposition rate, cement leakage rate, and radiation exposure time. The authors compared navigated and nonnavigated needle placement in 30 balloon kyphoplasty procedures (47 levels). Intraoperative 3-dimensional image-based navigation was used for needle placement in 21 cases (36 levels); conventional 2-dimensional fluoroscopy was used in the other 9 cases (11 levels). The 2 groups were compared for rates of needle malposition and cement leakage as well as radiation exposure time. Three of 11 (27%) nonnavigated cases were complicated by a malpositioned needle, and 2 of these had to be repositioned. The navigated group had a significantly lower malposition rate (1 of 36; 3%; P=.04). The overall rate of cement leakage was also similar in both groups (P=.29). Radiation exposure time was similar in both groups (navigated, 98 s/level; nonnavigated, 125 s/level; P=.10). Navigated kyphoplasty procedures did not differ significantly from nonnavigated procedures except in terms of needle malposition rate, where navigation may have decreased the need for needle repositioning.

  14. Søgning og navigation

    DEFF Research Database (Denmark)

    Grauballe, Henning; Strunck, Kirsten Marie

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

  15. Behavioral Mapless Navigation Using Rings

    Science.gov (United States)

    Monroe, Randall P.; Miller, Samuel A.; Bradley, Arthur T.

    2012-01-01

    This paper presents work on the development and implementation of a novel approach to robotic navigation. In this system, map-building and localization for obstacle avoidance are discarded in favor of moment-by-moment behavioral processing of the sonar sensor data. To accomplish this, we developed a network of behaviors that communicate through the passing of rings, data structures that are similar in form to the sonar data itself and express the decisions of each behavior. Through the use of these rings, behaviors can moderate each other, conflicting impulses can be mediated, and designers can easily connect modules to create complex emergent navigational techniques. We discuss the development of a number of these modules and their successful use as a navigation system in the Trinity omnidirectional robot.

  16. Navigation in endoscopic soft tissue surgery: perspectives and limitations.

    Science.gov (United States)

    Baumhauer, Matthias; Feuerstein, Marco; Meinzer, Hans-Peter; Rassweiler, J

    2008-04-01

    Despite rapid developments in the research areas of medical imaging, medical image processing, and robotics, the use of computer assistance in surgical routine is still limited to diagnostics, surgical planning, and interventions on mostly rigid structures. In order to establish a computer-aided workflow from diagnosis to surgical treatment and follow-up, several proposals for computer-assisted soft tissue interventions have been made in recent years. By means of different pre- and intraoperative information sources, such as surgical planning, intraoperative imaging, and tracking devices, surgical navigation systems aim to support surgeons in localizing anatomical targets, observing critical structures, and sparing healthy tissue. Current research in particular addresses the problem of organ shift and tissue deformation, and obstacles in communication between navigation system and surgeon. In this paper, we review computer-assisted navigation systems for soft tissue surgery. We concentrate on approaches that can be applied in endoscopic thoracic and abdominal surgery, because endoscopic surgery has special needs for image guidance due to limitations in perception. Furthermore, this paper informs the reader about new trends and technologies in the area of computer-assisted surgery. Finally, a balancing of the key challenges and possible benefits of endoscopic navigation refines the perspectives of this increasingly important discipline of computer-aided medical procedures.

  17. Submarine navigation based on gravity gradient-terrain matching

    Science.gov (United States)

    Xiong, Ling; Ma, Jie; Zhang, Li; Tian, Jin-Wen; Liu, Jian

    2007-11-01

    Based on the geophysics technology, a gravity gradient-terrain matching submarine navigation approach is proposed in this paper. The submarine's current position obtained by matching the measured gravity gradient data to the prepared gravity gradient reference map is used to correct the inertial navigation system's accumulated error. Although the precision gradiometer is in use, there is no world-wide gravity gradient map. The ocean's gravity gradient data is even scarce. Therefore, a gravity gradient matching navigation system directly utilizing the gravity gradient reference map can't be realized. With the sensitivity of gravity gradient to terrain, the gravity gradient reference map can be computed from the local terrain elevation data and the preparing approach of the gravity gradient map is proposed in detail in the paper. Since the seabed terrain elevation map, especially highly accurate offing terrain elevation map has been pre-surveyed, the location can be actualized through matching the real-time measured gravity gradient data to the prepared gravity gradient reference map. Simulations show that the submarine navigation approach on gravity gradient-terrain matching is feasible and can be put into practice.

  18. Twelve Group I introns in the same pre-rRNA transcript of the myxomycete Fuligo septica: RNA processing and evolution.

    Science.gov (United States)

    Lundblad, Eirik W; Einvik, Christer; Rønning, Sissel; Haugli, Kari; Johansen, Steinar

    2004-07-01

    The ribosomal DNA region of the myxomycete Fuligo septica was investigated and found to contain 12 group I introns (four in the small subunit and eight in the large subunit ribosomal RNAs). We have performed molecular and phylogenetic analyses to provide insight into intron structure and function, intron-host biology, and intron origin and evolution. The introns vary in size from 398 to 943 nt, all lacking detectable open reading frames. Secondary structure models revealed considerable structural diversity, but all, except one (subclass IB), represent the common group IC1 intron subclass. In vitro splicing analysis revealed that 10 of the 12 introns were able to self-splice as naked RNA, but all 12 introns were able to splice out from the precursor rRNA in vivo as evaluated by reverse transcription PCR analysis on total F. septica RNA. Furthermore, RNA processing analyses in vitro and in vivo showed that 10 of 12 introns perform hydrolytic cleavage at the 3' splice site, as well as intron circularization. Full-length intron RNA circles were detected in vivo. The order of splicing was analyzed by a reverse transcription PCR approach on cellular RNA, but no strict order of intron excision could be detected. Phylogenetic analysis indicated that most Fuligo introns were distantly related to each other and were independently gained in ribosomal DNA during evolution.

  19. Observability of Inertial Navigation System

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

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

  20. Navigation of total knee arthroplasty: rotation of components and clinical results in a prospectively randomized study

    Directory of Open Access Journals (Sweden)

    Efe Turgay

    2011-01-01

    Full Text Available Abstract Background Navigation was introduced into total knee arthroplasty (TKA to improve accuracy of component position, function and survival of implants. This study was designed to assess the outcome of navigated TKA in comparison with conventional implantation with the focus on rotational component position and clinical mid-term results. Methods In a prospectively randomized single-blinded approach, 90 patients with primary gonarthrosis were assigned to three different groups. Thirty patients each were assigned to NexGen LPS without and with navigation (groups 1 and 2, and 30 patients to navigation with the Stryker Scorpio PS (group 3. The navigation system used was the imageless Stryker KneeTrac, version 1.0. Clinical outcome was assessed by a blinded observer applying the Knee Society Score (KSS and a visual analogue scale (VAS for pain. CT scans and radiographs were conducted prior to and 12 weeks after index surgery. Results Seventy-nine patients were available for clinical evaluation at 3 ± 0.4 years follow-up. Four implants had to be revised for early loosening or infection (4.4%. Four patients had died and three patients were not able to follow the invitation for clinical assessment. Functional results in the KSS were significantly lower after navigated TKA. Operation time and incisions with navigation were significantly longer. Significantly less radiological outliers with navigation were found for coronal alignment of the femur, only. Conclusion In this series, no beneficial effect for navigation in TKA could be shown assessing clinical data, as functional results in the presented series seemed to be lower after first generation navigated TKA. The clinical mid- to long-term value of navigation remains to be evaluated in larger patient series or meta-analyses at longer follow-up. Trial registration number DRKS 00000430

  1. 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

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

    Science.gov (United States)

    Monz, M; Küfer, K H; Bortfeld, T R; Thieke, C

    2008-02-21

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

  3. Generating navigation models from existing building data

    NARCIS (Netherlands)

    Liu, L.; Zlatanova, S.

    2013-01-01

    Research on indoor navigation models mainly focuses on geometric and logical models .The models are enriched with specific semantic information which supports localisation, navigation and guidance. Geometric models provide information about the structural (physical) distribution of spaces in a build

  4. Improved navigation for image-guided bronchoscopy

    Science.gov (United States)

    Khare, Rahul; Yu, Kun-Chang; Higgins, William E.

    2009-02-01

    Past work has shown that guidance systems help improve both the navigation through airways and final biopsy of regions of interest via bronchoscopy. We have previously proposed an image-based bronchoscopic guidance system. The system, however, has three issues that arise during navigation: 1) sudden disorienting changes can occur in endoluminal views; 2) more feedback could be afforded during navigation; and 3) the system's graphical user interface (GUI) lacks a convenient interface for smooth navigation between bifurcations. In order to alleviate these issues, we present an improved navigation system. The improvements offer the following: 1) an enhanced visual presentation; 2) smooth navigation; 3) an interface for handling registration errors; and 4) improved bifurcation-point identification. The improved navigation system thus provides significant ergonomic and navigational advantages over the previous system.

  5. 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...

  6. 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...

  7. Generating navigation models from existing building data

    NARCIS (Netherlands)

    Liu, L.; Zlatanova, S.

    2013-01-01

    Research on indoor navigation models mainly focuses on geometric and logical models .The models are enriched with specific semantic information which supports localisation, navigation and guidance. Geometric models provide information about the structural (physical) distribution of spaces in a

  8. Using ontologies to model human navigation behavior in information networks: A study based on Wikipedia.

    Science.gov (United States)

    Lamprecht, Daniel; Strohmaier, Markus; Helic, Denis; Nyulas, Csongor; Tudorache, Tania; Noy, Natalya F; Musen, Mark A

    The need to examine the behavior of different user groups is a fundamental requirement when building information systems. In this paper, we present Ontology-based Decentralized Search (OBDS), a novel method to model the navigation behavior of users equipped with different types of background knowledge. Ontology-based Decentralized Search combines decentralized search, an established method for navigation in social networks, and ontologies to model navigation behavior in information networks. The method uses ontologies as an explicit representation of background knowledge to inform the navigation process and guide it towards navigation targets. By using different ontologies, users equipped with different types of background knowledge can be represented. We demonstrate our method using four biomedical ontologies and their associated Wikipedia articles. We compare our simulation results with base line approaches and with results obtained from a user study. We find that our method produces click paths that have properties similar to those originating from human navigators. The results suggest that our method can be used to model human navigation behavior in systems that are based on information networks, such as Wikipedia. This paper makes the following contributions: (i) To the best of our knowledge, this is the first work to demonstrate the utility of ontologies in modeling human navigation and (ii) it yields new insights and understanding about the mechanisms of human navigation in information networks.

  9. Navigation Issues in the South China Sea

    OpenAIRE

    2005-01-01

    The South China Sea is one of the most important sea lanes with numerous competing sovereignty disputes. The freedom of navigation in this region is critical to all major trading States in the world. After an introduction to the navigational regimes of UNCLOS, this article describes the whole navigation situation in this region, by separately introducing the navigation issues in the territorial sea, straits, archipelagic waters and the Spratly area. Meanwhile, since the legal status of the ma...

  10. Mobile Robot Navigation Support in Living Environments

    Science.gov (United States)

    Armbrust, Christopher; Koch, Jan; Stocker, Ulf; Berns, Karsten

    Navigation and application functionality of mobile robots rely on their collision-avoiding capabilities, also known as local navigation. We present the mobile robot ARTOS (Autonomous Robot for Transport and Service) that is particularly designed to operate in living environments and therefore faces the problem of fuzzy and unstructured obstacles. The local navigation architecture is motivated regarding decisions on sensor hardware setup as well as the software layers that support and influence navigation control.

  11. Celestial navigation in a nutshell

    CERN Document Server

    Schlereth, Hewitt

    2000-01-01

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

  12. Designing automated handheld navigation support

    NARCIS (Netherlands)

    Uluca, D.; Streefkerk, J.W.; Sciacchitano, B.; McCrickard, D.S.

    2008-01-01

    Map usage on handheld devices suffers from limited screen size and the minimal attention that users can dedicate to them in mobile situations. This work examines effects of automating navigation features like zooming and panning as well as other features such as rotation, path finding and artifact r

  13. Safety effects of navigation systems.

    NARCIS (Netherlands)

    2009-01-01

    Increasing numbers of drivers are using navigation systems in their cars. The advantages to the user are obvious: you can get to your destination via the fastest and shortest route. This reduces stress and exposure to other traffic. However, there are also some (unintended) negative effects. For exa

  14. 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.

  15. Averaging VMAT treatment plans for multi-criteria navigation

    CERN Document Server

    Craft, David; Unkelbach, Jan

    2013-01-01

    The main approach to smooth Pareto surface navigation for radiation therapy multi-criteria treatment planning involves taking real-time averages of pre-computed treatment plans. In fluence-based treatment planning, fluence maps themselves can be averaged, which leads to the dose distributions being averaged due to the linear relationship between fluence and dose. This works for fluence-based photon plans and proton spot scanning plans. In this technical note, we show that two or more sliding window volumetric modulated arc therapy (VMAT) plans can be combined by averaging leaf positions in a certain way, and we demonstrate that the resulting dose distribution for the averaged plan is approximately the average of the dose distributions of the original plans. This leads to the ability to do Pareto surface navigation, i.e. interactive multi-criteria exploration of VMAT plan dosimetric tradeoffs.

  16. 19 CFR 4.98 - Navigation fees.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Navigation fees. 4.98 Section 4.98 Customs Duties... VESSELS IN FOREIGN AND DOMESTIC TRADES General § 4.98 Navigation fees. (a)(1) The Customs Service shall... revised schedule of navigation fees for the following services: Fee No. and description of services...

  17. Lunar roving vehicle navigation system performance review

    Science.gov (United States)

    Smith, E. C.; Mastin, W. C.

    1973-01-01

    The design and operation of the lunar roving vehicle (LRV) navigation system are briefly described. The basis for the premission LRV navigation error analysis is explained and an example included. The real time mission support operations philosophy is presented. The LRV navigation system operation and accuracy during the lunar missions are evaluated.

  18. Simulation Platform for Vision Aided Inertial Navigation

    Science.gov (United States)

    2014-09-18

    canyons, indoors or underground. It is also possible for a GPS signal to be jammed. This weakness motivates the development of alternate navigation ...Johnson, E. N., Magree, D., Wu, A., & Shein, A. (2013). "GPS‐Denied Indoor and Outdoor Monocular Vision Aided Navigation and Control of Unmanned...SIMULATION PLATFORM FOR VISION AIDED INERTIAL NAVIGATION THESIS SEPTEMBER 2014 Jason Gek

  19. Pre-Osteoarthritis

    Science.gov (United States)

    Brittberg, Mats; Eriksson, Karl; Jurvelin, Jukka S.; Lindahl, Anders; Marlovits, Stefan; Möller, Per; Richardson, James B.; Steinwachs, Matthias; Zenobi-Wong, Marcy

    2015-01-01

    Objective An attempt to define pre-osteoarthritis (OA) versus early OA and definitive osteoarthritis. Methods A group of specialists in the field of cartilage science and treatment was formed to consider the nature of OA onset and its possible diagnosis. Results Late-stage OA, necessitating total joint replacement, is the end stage of a biological process, with many previous earlier stages. Early-stage OA has been defined and involves structural changes identified by arthroscopy or radiography. The group argued that before the “early-stage OA” there must exist a stage where cellular processes, due to the presence of risk factors, have kicked into action but have not yet resulted in structural changes. The group suggested that this stage could be called “pre-osteoarthritis” (pre-OA). Conclusions The group suggests that defining points of initiation for OA in the knee could be defined, for example, by traumatic episodes or surgical meniscectomy. Such events may set in motion metabolic processes that could be diagnosed by modern MRI protocols or arthroscopy including probing techniques before structural changes of early OA have developed. Preventive measures should preferably be applied at this pre-OA stage in order to stop the projected OA “epidemic.” PMID:26175861

  20. Restructuring the navigational field: individual predisposition towards field independence predicts preferred navigational strategy.

    Science.gov (United States)

    Boccia, Maddalena; Piccardi, Laura; D'Alessandro, Adele; Nori, Raffaella; Guariglia, Cecilia

    2017-06-01

    To successfully navigate within an environment, individuals have to organize the spatial information in terms of salient landmarks, paths and general layout of the navigational environment. They may differ in the strategy they adopt to orientate themselves, with some individuals preferring to use salient landmarks (landmark spatial style, L-SS), others preferring to plan routes or paths through an egocentric strategy in which landmarks are connected with each other (route spatial style, R-SS) and others still create a global map-like configuration of the environment regardless of their own position in the environment (survey spatial style, S-SS). Here, we assessed whether Field independence (FI), that is the extent to which the individual perceives part of a field as discrete from the surrounding field rather than embedded in the field, predicted the individual's spatial style. We assessed the individual's spatial style using the spatial cognitive style test (SCST) and measured FI using the group embedded figure test (GEFT). We found that FI predicted general spatial ability, with a higher level of FI being associated with better performances on the SCST. Also, Field-independent individuals showed a marked preference for an S-SS. These results suggest that a higher level of FI is associated with better performance on higher level spatial tasks (i.e. R-SS and S-SS) that is tasks requiring individuals to restructure the "navigational field" according to the navigational goal. The results also suggest that a higher level of FI makes individuals more prone to use a global and complex map-like representation of the environment.

  1. A novel monocular visual navigation method for cotton-picking robot based on horizontal spline segmentation

    Science.gov (United States)

    Xu, ShengYong; Wu, JuanJuan; Zhu, Li; Li, WeiHao; Wang, YiTian; Wang, Na

    2015-12-01

    Visual navigation is a fundamental technique of intelligent cotton-picking robot. There are many components and cover in the cotton field, which make difficulties of furrow recognition and trajectory extraction. In this paper, a new field navigation path extraction method is presented. Firstly, the color image in RGB color space is pre-processed by the OTSU threshold algorithm and noise filtering. Secondly, the binary image is divided into numerous horizontally spline areas. In each area connected regions of neighboring images' vertical center line are calculated by the Two-Pass algorithm. The center points of the connected regions are candidate points for navigation path. Thirdly, a series of navigation points are determined iteratively on the principle of the nearest distance between two candidate points in neighboring splines. Finally, the navigation path equation is fitted by the navigation points using the least squares method. Experiments prove that this method is accurate and effective. It is suitable for visual navigation in the complex environment of cotton field in different phases.

  2. Inattentional blindness increased with augmented reality surgical navigation.

    Science.gov (United States)

    Dixon, Benjamin J; Daly, Michael J; Chan, Harley H L; Vescan, Allan; Witterick, Ian J; Irish, Jonathan C

    2014-01-01

    Augmented reality (AR) surgical navigation systems, designed to increase accuracy and efficiency, have been shown to negatively impact on attention. We wished to assess the effect "head-up" AR displays have on attention, efficiency, and accuracy, while performing a surgical task, compared with the same information being presented on a submonitor (SM). Fifty experienced otolaryngology surgeons (n = 42) and senior otolaryngology trainees (n = 8) performed an endoscopic surgical navigation exercise on a predissected cadaveric model. Computed tomography-generated anatomic contours were fused with the endoscopic image to provide an AR view. Subjects were randomized to perform the task with a standard endoscopic monitor with the AR navigation displayed on an SM or with AR as a single display. Accuracy, task completion time, and the recognition of unexpected findings (a foreign body and a critical complication) were recorded. Recognition of the foreign body was significantly better in the SM group (15/25 [60%]) compared with the AR alone group (8/25 [32%]; p = 0.02). There was no significant difference in task completion time (p = 0.83) or accuracy (p = 0.78) between the two groups. Providing identical surgical navigation on a SM, rather than on a single head-up display, reduced the level of inattentional blindness as measured by detection of unexpected findings. These gains were achieved without any measurable impact on efficiency or accuracy. AR displays may distract the user and we caution injudicious adoption of this technology for medical procedures.

  3. 33 CFR 401.97 - Closing procedures and ice navigation.

    Science.gov (United States)

    2010-07-01

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

  4. 33 CFR 207.306 - Missouri River; administration and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Missouri River; administration and navigation. 207.306 Section 207.306 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.306 Missouri River;...

  5. 33 CFR 64.31 - Determination of hazard to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Determination of hazard to navigation. 64.31 Section 64.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION MARKING OF STRUCTURES, SUNKEN VESSELS AND OTHER OBSTRUCTIONS...

  6. 33 CFR 162.240 - Tongass Narrows, Alaska; navigation.

    Science.gov (United States)

    2010-07-01

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

  7. 33 CFR 117.455 - Houma Navigation Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Houma Navigation Canal. 117.455 Section 117.455 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.455 Houma Navigation Canal. The draw of SR 661 (Houma Nav Canal) bridge,...

  8. Pulsar/CNS integrated navigation based on federated UKF

    Institute of Scientific and Technical Information of China (English)

    Jin Liu; Jie Ma; Jinwen Tian

    2010-01-01

    In order to improve the autonomous navigation capability of satellite,a pulsar/CNS(celestial navigation system)integrated navigation method based on federated unscented Kalman filter(UKF)is proposed.The celestial navigation is a mature and stable navigation method.However,its position determination performance is not satisfied due to the low accuracy of horizon sensor.Single pulsar navigation is a new navigation method,which can provide highly accurate range measurements.The major drawback of single pulsar navigation is that the system is completely unobservabie.As two methods are complementary to each other,the federated UKF is used here for fusing the navigation data from single pulsar navigation and CNS.Compared to the traditional celestial navigation method and single pulsar navigation,the integrated navigation method can provide better navigation performance.The simulation results demonstrate the feasibility and effectiveness of the navigation method.

  9. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

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

  10. Computer navigation results in less severe flexion contracture following total knee arthroplasty.

    Science.gov (United States)

    Bin Abd Razak, Hamid Rahmatullah; Yeo Jin, Seng; Chong Chi, Hwei

    2014-12-01

    We compared postoperative flexion contracture in navigated total knee arthroplasty (TKA) versus conventional TKA. Two groups (Group 1: conventional, Group 2: navigated) of 235 consecutive patients matched for age and gender were retrospectively compared. Range of motion, mechanical axes, Knee Society Scores, Oxford Knee Scores and Short Form-36® (SF-36) scores were collected prospectively and compared preoperatively and at 2years following TKA. At 2years, patients who underwent navigated TKA averaged significantly lesser flexion contracture of 1 degree compared to 6 degrees in patients who underwent conventional TKA. There were a significantly larger proportion of outliers in the conventional group. Computer navigation results in less severe flexion contracture and less frequent flexion contracture of more than 5 degrees as compared to conventional techniques. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. A Direct Comparison of Real-World and Virtual Navigation Performance in Chronic Stroke Patients

    NARCIS (Netherlands)

    Claessen, Michiel H G; Visser-Meily, Johanna M A; de Rooij, Nicolien K; Postma, Albert; van der Ham, Ineke J M

    2015-01-01

    OBJECTIVES: An increasing number of studies have presented evidence that various patient groups with acquired brain injury suffer from navigation problems in daily life. This skill is, however, scarcely addressed in current clinical neuropsychological practice and suitable diagnostic instruments are

  12. Indoor Pedestrian Navigation Using Foot-Mounted IMU and Portable Ultrasound Range Sensors

    NARCIS (Netherlands)

    Girard, G.; Cote, S.; Zlatanova, S.; Barette, Y.; St-Pierre, J.; Van Oosterom, P.J.M.

    2011-01-01

    Many solutions have been proposed for indoor pedestrian navigation. Some rely on pre-installed sensor networks, which offer good accuracy but are limited to areas that have been prepared for that purpose, thus requiring an expensive and possibly time-consuming process. Such methods are therefore ina

  13. Indoor Pedestrian Navigation Using Foot-Mounted IMU and Portable Ultrasound Range Sensors

    NARCIS (Netherlands)

    Girard, G.; Cote, S.; Zlatanova, S.; Barette, Y.; St-Pierre, J.; Van Oosterom, P.J.M.

    2011-01-01

    Many solutions have been proposed for indoor pedestrian navigation. Some rely on pre-installed sensor networks, which offer good accuracy but are limited to areas that have been prepared for that purpose, thus requiring an expensive and possibly time-consuming process. Such methods are therefore

  14. 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...

  15. Autonomous Guidance, Navigation and Control

    Science.gov (United States)

    Bordano, A. J.; Mcswain, G. G.; Fernandes, S. T.

    1991-01-01

    The NASA Autonomous Guidance, Navigation and Control (GN&C) Bridging program is reviewed to demonstrate the program plan and GN&C systems for the Space Shuttle. The ascent CN&C system is described in terms of elements such as the general-purpose digital computers, sensors for the navigation subsystem, the guidance-system software, and the flight-control subsystem. Balloon-based and lidar wind soundings are used for operations assessment on the day of launch, and the guidance software is based on dedicated units for atmospheric powered flight, vacuum powered flight, and abort-specific situations. Optimization of the flight trajectories is discussed, and flight-control responses are illustrated for wavelengths of 500-6000 m. Alternate sensors are used for load relief, and adaptive GN&C systems based on alternate gain synthesis are used for systems failures.

  16. A navigation system for the visually impaired an intelligent white cane.

    Science.gov (United States)

    Fukasawa, A Jin; Magatani, Kazusihge

    2012-01-01

    In this paper, we describe about a developed navigation system that supports the independent walking of the visually impaired in the indoor space. Our developed instrument consists of a navigation system and a map information system. These systems are installed on a white cane. Our navigation system can follow a colored navigation line that is set on the floor. In this system, a color sensor installed on the tip of a white cane, this sensor senses a color of navigation line and the system informs the visually impaired that he/she is walking along the navigation line by vibration. This color recognition system is controlled by a one-chip microprocessor. RFID tags and a receiver for these tags are used in the map information system. RFID tags are set on the colored navigation line. An antenna for RFID tags and a tag receiver are also installed on a white cane. The receiver receives the area information as a tag-number and notifies map information to the user by mp3 formatted pre-recorded voice. And now, we developed the direction identification technique. Using this technique, we can detect a user's walking direction. A triaxiality acceleration sensor is used in this system. Three normal subjects who were blindfolded with an eye mask were tested with our developed navigation system. All of them were able to walk along the navigation line perfectly. We think that the performance of the system is good. Therefore, our system will be extremely valuable in supporting the activities of the visually impaired.

  17. Orientation in birds. Olfactory navigation.

    Science.gov (United States)

    Papi, F

    1991-01-01

    Research work on the olfactory navigation of birds, which has only recently attracted attention, has shown that many wild species rely on an osmotactic mechanism to find food sources, even at a considerable distance. The homing pigeon, the only bird to have been thoroughly investigated with respect to olfactory navigation, has been found to rely on local odours for homeward orientation, and to integrate olfactory cues perceived during passive transportation with those picked up at the release site. It is possible to design experiments in which birds are given false olfactory information, and predictions about the effects of this can be made and tested. Pigeons are able to home from unfamiliar sites because they acquire an olfactory map extending beyond the area they have flown over. The olfactory map is built up by associating wind-borne odours with the direction from which they come; this was shown by experiments which aimed to prevent, limit or alter this association. One aim of the research work has been to test whether pigeons flying over unfamiliar areas also rely or can learn to rely on non-olfactory cues, depending on their local availability, and/or on the methods of rearing and training applied to them. Various evaluations have been made of the results; the most recent experiments, however, confirm that pigeons do derive directional information from atmospheric odours. A neurobiological approach is also in progress; its results show that some telencephalic areas are involved in orientation and olfactory navigation. The lack of any knowledge about the distribution and chemical nature of the odorants which allow pigeons to navigate hinders progress in this area of research.

  18. Orientation and navigation in birds

    Directory of Open Access Journals (Sweden)

    H. Bouwman

    1998-07-01

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

  19. 06421 Executive Summary -- Robot Navigation

    OpenAIRE

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

    2007-01-01

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

  20. CT navigated lateral interbody fusion.

    Science.gov (United States)

    Drazin, Doniel; Liu, John C; Acosta, Frank L

    2013-10-01

    Lateral interbody fusion techniques are heavily reliant on fluoroscopy for retractor docking and graft placement, which expose both the patient and surgeon to high doses of radiation. Use of image-guided technologies with CT-based images, however, can eliminate this radiation exposure for the surgeon. We describe the surgical technique of performing lateral lumbar interbody fusion using CT navigation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Celestial Navigation for the Novice

    Science.gov (United States)

    Sadler, Philip M.

    2011-01-01

    What kinds of astronomical lab activities can introductory astronomy students carry out easily in daytime? The most impressive is the determination of their latitude and longitude from observations of the sun. The "shooting of a noon sight” and its "reduction to a position” is a technique still practiced by navigators in this age of GPS. Indeed, the U.S. Coast Guard exams for ocean-going licenses and include celestial navigation. These techniques continue to be used by the military and by private sailors as a backup to electronic navigation systems. We present a method to establish one's latitude and longitude to better than 30 miles from measurements of the sun's altitude that is easily within the capability non-science majors. This is a practical application of astronomy in use the world over. The streamlined method used is based on an easy-to-build protractor and string quadrant. Participants will leave with all materials to conduct this activity in their own classroom.

  2. 3D surgical planning and navigation for CMF surgery

    Science.gov (United States)

    Chapuis, Jonas; Rudolph, Tobias; Borgesson, Blake; De Momi, Elena; Pappas, Ion P.; Hallermann, Wok; Schramm, Alexander; Caversaccio, Marco

    2004-05-01

    In this paper we describe a system for corrective and reconstructive CMF surgery that allows planning of bone segment relocations in 3D and transfer of the goal positions into an intra-operative navigation module, which provides guidance to realize the planned movement. In addition, the pre-operative planning module offers functions of mirroring and allows insertion of distraction devices. We present three clinical cases of CMF surgical procedures planned a posteriori with our application: bimaxillary realignment, involving subcondylar osteotomy of the mandible and LeFort I osteotomy, secondary orbital reconstruction and mandibular reconstruction.

  3. Differences in navigation performance and postpartal striatal volume associated with pregnancy in humans.

    Science.gov (United States)

    Lisofsky, Nina; Wiener, Jan; de Condappa, Olivier; Gallinat, Jürgen; Lindenberger, Ulman; Kühn, Simone

    2016-10-01

    Pregnancy is accompanied by prolonged exposure to high estrogen levels. Animal studies have shown that estrogen influences navigation strategies and, hence, affects navigation performance. High estrogen levels are related to increased use of hippocampal-based allocentric strategies and decreased use of striatal-based egocentric strategies. In humans, associations between hormonal shifts and navigation strategies are less well studied. This study compared 30 peripartal women (mean age 28years) to an age-matched control group on allocentric versus egocentric navigation performance (measured in the last month of pregnancy) and gray matter volume (measured within two months after delivery). None of the women had a previous pregnancy before study participation. Relative to controls, pregnant women performed less well in the egocentric condition of the navigation task, but not the allocentric condition. A whole-brain group comparison revealed smaller left striatal volume (putamen) in the peripartal women. Across the two groups, left striatal volume was associated with superior egocentric over allocentric performance. Limited by the cross-sectional study design, the findings are a first indication that human pregnancy might be accompanied by structural brain changes in navigation-related neural systems and concomitant changes in navigation strategy.

  4. Age and active navigation effects on episodic memory: A virtual reality study.

    Science.gov (United States)

    Sauzéon, Hélène; N'Kaoua, Bernard; Arvind Pala, Prashant; Taillade, Mathieu; Guitton, Pascal

    2016-02-01

    We investigated the navigation-related age effects on learning, proactive interference semantic clustering, recognition hits, and false recognitions in a naturalistic situation using a virtual apartment-based task. We also examined the neuropsychological correlates (executive functioning [EF] and episodic memory) of navigation-related age effects on memory. Younger and older adults either actively navigated or passively followed the computer-guided tour of an apartment. The results indicated that active navigation increased recognition hits compared with passive navigation, but it did not influence other memory measures (learning, proactive interference, and semantic clustering) to a similar extent in either age group. Furthermore, active navigation helped to reduce false recognitions in younger adults but increased those made by older adults. This differential effect of active navigation for younger and older adults was accounted for by EF score. Like for the subject-performed task effects, the effects from the navigation manipulation were well accounted for by item-specific/relational processing distinction, and they were also consistent with a source monitoring deficit in older adults. © 2015 The British Psychological Society.

  5. Adaptive learning systems: Supporting navigation with customized suggestions

    Directory of Open Access Journals (Sweden)

    Sibel Somyürek

    2014-01-01

    Full Text Available The aim of this study was to share the results from an experimental research which investigate the effects of link annotations in an educational hypermedia on students’ navigation. This study was conducted through a post-test only control group design with 67 undergraduate students. The voluntary research participants were randomly assigned into the experimental and control group. The required data were collected through an academic achievement test, the Motivated Strategies for Learning Questionnaire, the Non-Linear Media Disorientation Assessment Tool, a questionnaire about users’ opinions and user logs. The findings showed that the perceived disorientation scores and revisitation rates were significantly lower for the learners who studied in the adaptive environment than those in the non-adaptive environment. It was observed that students’ non-sequential navigation in experimental group increased significantly and they followed the system's advices. 

  6. Fluoroscopy-based navigation system in spine surgery

    CERN Document Server

    Merloz, Philippe; Vouaillat, Hervé; Vasile, Christian; Tonetti, Jérôme; Eid, Ahmad; Plaweski, Stéphane

    2007-01-01

    The variability in width, height, and spatial orientation of a spinal pedicle makes pedicle screw insertion a delicate operation. The aim of the current paper is to describe a computer-assisted surgical navigation system based on fluoroscopic X-ray image calibration and three-dimensional optical localizers in order to reduce radiation exposure while increasing accuracy and reliability of the surgical procedure for pedicle screw insertion. Instrumentation using transpedicular screw fixation was performed: in a first group, a conventional surgical procedure was carried out with 26 patients (138 screws); in a second group, a navigated surgical procedure (virtual fluoroscopy) was performed with 26 patients (140 screws). Evaluation of screw placement in every case was done by using plain X-rays and post-operative computer tomography scan. A 5 per cent cortex penetration (7 of 140 pedicle screws) occurred for the computer-assisted group. A 13 per cent penetration (18 of 138 pedicle screws) occurred for the non comp...

  7. Navigation of Pedicle Screws in the Thoracic Spine with a New Electromagnetic Navigation System: A Human Cadaver Study

    Directory of Open Access Journals (Sweden)

    Patrick Hahn

    2015-01-01

    Full Text Available Introduction. Posterior stabilization of the spine is a standard procedure in spinal surgery. In addition to the standard techniques, several new techniques have been developed. The objective of this cadaveric study was to examine the accuracy of a new electromagnetic navigation system for instrumentation of pedicle screws in the spine. Material and Method. Forty-eight pedicle screws were inserted in the thoracic spine of human cadavers using EMF navigation and instruments developed especially for electromagnetic navigation. The screw position was assessed postoperatively by a CT scan. Results. The screws were classified into 3 groups: grade 1 = ideal position; grade 2 = cortical penetration <2 mm; grade 3 = cortical penetration ≥2 mm. The initial evaluation of the system showed satisfied positioning for the thoracic spine; 37 of 48 screws (77.1%, 95% confidence interval [62.7%, 88%] were classified as group 1 or 2. Discussion. The screw placement was satisfactory. The initial results show that there is room for improvement with some changes needed. The ease of use and short setup times should be pointed out. Instrumentation is achieved without restricting the operator’s mobility during navigation. Conclusion. The results indicate a good placement technique for pedicle screws. Big advantages are the easy handling of the system.

  8. Navigation Operations for the Magnetospheric Multiscale Mission

    Science.gov (United States)

    Long, Anne; Farahmand, Mitra; Carpenter, Russell

    2015-01-01

    The Magnetospheric Multiscale (MMS) mission employs four identical spinning spacecraft flying in highly elliptical Earth orbits. These spacecraft will fly in a series of tetrahedral formations with separations of less than 10 km. MMS navigation operations use onboard navigation to satisfy the mission definitive orbit and time determination requirements and in addition to minimize operations cost and complexity. The onboard navigation subsystem consists of the Navigator GPS receiver with Goddard Enhanced Onboard Navigation System (GEONS) software, and an Ultra-Stable Oscillator. The four MMS spacecraft are operated from a single Mission Operations Center, which includes a Flight Dynamics Operations Area (FDOA) that supports MMS navigation operations, as well as maneuver planning, conjunction assessment and attitude ground operations. The System Manager component of the FDOA automates routine operations processes. The GEONS Ground Support System component of the FDOA provides the tools needed to support MMS navigation operations. This paper provides an overview of the MMS mission and associated navigation requirements and constraints and discusses MMS navigation operations and the associated MMS ground system components built to support navigation-related operations.

  9. GPS Auto-Navigation Design for Unmanned Air Vehicles

    Science.gov (United States)

    Nilsson, Caroline C. A.; Heinzen, Stearns N.; Hall, Charles E., Jr.; Chokani, Ndaona

    2003-01-01

    A GPS auto-navigation system is designed for Unmanned Air Vehicles. The objective is to enable the air vehicle to be used as a test-bed for novel flow control concepts. The navigation system uses pre-programmed GPS waypoints. The actual GPS position, heading, and velocity are collected by the flight computer, a PC104 system running in Real-Time Linux, and compared with the desired waypoint. The navigator then determines the necessity of a heading correction and outputs the correction in the form of a commanded bank angle, for a level coordinated turn, to the controller system. This controller system consists of 5 controller! (pitch rate PID, yaw damper, bank angle PID, velocity hold, and altitude hold) designed for a closed loop non-linear aircraft model with linear aerodynamic coefficients. The ability and accuracy of using GPS data, is validated by a GPS flight. The autopilots are also validated in flight. The autopilot unit flight validations show that the designed autopilots function as designed. The aircraft model, generated on Matlab SIMULINK is also enhanced by the flight data to accurately represent the actual aircraft.

  10. A projective surgical navigation system for cancer resection

    Science.gov (United States)

    Gan, Qi; Shao, Pengfei; Wang, Dong; Ye, Jian; Zhang, Zeshu; Wang, Xinrui; Xu, Ronald

    2016-03-01

    Near infrared (NIR) fluorescence imaging technique can provide precise and real-time information about tumor location during a cancer resection surgery. However, many intraoperative fluorescence imaging systems are based on wearable devices or stand-alone displays, leading to distraction of the surgeons and suboptimal outcome. To overcome these limitations, we design a projective fluorescence imaging system for surgical navigation. The system consists of a LED excitation light source, a monochromatic CCD camera, a host computer, a mini projector and a CMOS camera. A software program is written by C++ to call OpenCV functions for calibrating and correcting fluorescence images captured by the CCD camera upon excitation illumination of the LED source. The images are projected back to the surgical field by the mini projector. Imaging performance of this projective navigation system is characterized in a tumor simulating phantom. Image-guided surgical resection is demonstrated in an ex-vivo chicken tissue model. In all the experiments, the projected images by the projector match well with the locations of fluorescence emission. Our experimental results indicate that the proposed projective navigation system can be a powerful tool for pre-operative surgical planning, intraoperative surgical guidance, and postoperative assessment of surgical outcome. We have integrated the optoelectronic elements into a compact and miniaturized system in preparation for further clinical validation.

  11. Simulation-based camera navigation training in laparoscopy-a randomized trial

    DEFF Research Database (Denmark)

    Nilsson, Cecilia; Sorensen, Jette Led; Konge, Lars

    2016-01-01

    BACKGROUND: Inexperienced operating assistants are often tasked with the important role of handling camera navigation during laparoscopic surgery. Incorrect handling can lead to poor visualization, increased operating time, and frustration for the operating surgeon-all of which can compromise...... patient safety. The objectives of this trial were to examine how to train laparoscopic camera navigation and to explore the transfer of skills to the operating room. MATERIALS AND METHODS: A randomized, single-center superiority trial with three groups: The first group practiced simulation-based camera...... navigation tasks (camera group), the second group practiced performing a simulation-based cholecystectomy (procedure group), and the third group received no training (control group). Participants were surgical novices without prior laparoscopic experience. The primary outcome was assessment of camera...

  12. INS/CNS/GNSS integrated navigation technology

    CERN Document Server

    Quan, Wei; Gong, Xiaolin; Fang, Jiancheng

    2015-01-01

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

  13. Quantum Navigation and Ranking in Complex Networks

    Science.gov (United States)

    Sánchez-Burillo, Eduardo; Duch, Jordi; Gómez-Gardeñes, Jesús; Zueco, David

    2012-08-01

    Complex networks are formal frameworks capturing the interdependencies between the elements of large systems and databases. This formalism allows to use network navigation methods to rank the importance that each constituent has on the global organization of the system. A key example is Pagerank navigation which is at the core of the most used search engine of the World Wide Web. Inspired in this classical algorithm, we define a quantum navigation method providing a unique ranking of the elements of a network. We analyze the convergence of quantum navigation to the stationary rank of networks and show that quantumness decreases the number of navigation steps before convergence. In addition, we show that quantum navigation allows to solve degeneracies found in classical ranks. By implementing the quantum algorithm in real networks, we confirm these improvements and show that quantum coherence unveils new hierarchical features about the global organization of complex systems.

  14. Spatial Database Modeling for Indoor Navigation Systems

    Science.gov (United States)

    Gotlib, Dariusz; Gnat, Miłosz

    2013-12-01

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

  15. Fusion of Onboard Sensors for Better Navigation

    Directory of Open Access Journals (Sweden)

    Ravi Shankar

    2013-03-01

    Full Text Available This paper presents simulation results of navigation sensors such as integrated navigation system (INS, global navigation satellite system (GNSS and TACAN sensors onboard an aircraft to find the navigation solutions. Mathematical models for INS, GNSS (GPS satellite trajectories, GPS receiver and TACAN characteristics are simulated in Matlab. The INS simulation generates the output for position, velocity and attitude based on aerosond dynamic model. The GPS constellation is generated based on the YUMA almanac data. The GPS dilution of precession (DOP parameters are calculated and the best combination of four satellites (minimum PDOP is used for calculating the user position and velocity. The INS, GNSS, and TACAN solutions are integrated through loosely coupled extended Kalman filter for calculating the optimum navigation solution. The work is starting stone for providing aircraft based augmentation system for required navigation performance in terms of availability, accuracy, continuity and integrity.

  16. Indoor inertial waypoint navigation for the blind.

    Science.gov (United States)

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

    2013-01-01

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

  17. Reliable dynamic in-vehicle navigation

    OpenAIRE

    Kaparias, I.

    2008-01-01

    Having started off from luxury makes and models, in-vehicle navigation systems are now gradually spreading through the entire vehicle fleet, as drivers appreciate their usefulness. Increasingly sophisticated systems are being developed, having much more advanced functions than simple driving directions. This thesis presents a new approach for in-vehicle navigation, in which travel time reliability is incorporated in the route finding component of the navigation system. Based on historical tra...

  18. Vector database for vehicle road navigation

    OpenAIRE

    Kenda, Lian

    2007-01-01

    Vehicle navigation devices use vector cartographic view, which is designed as a vector database. Database creation begins by setting up a landscape model which includes all the graphical and descriptive data required for accurate vehicle navigation. This paper presents the creation of a database part called StreetConnect, which is used for road navigation. Data obtained using distinct specifications have been transformed into the format compatible with Garmin GPS devices. Data have been obtai...

  19. Research on integrated navigation method for AUV

    Institute of Scientific and Technical Information of China (English)

    GUO Zhen; SUN Feng

    2005-01-01

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

  20. Global navigation satellite systems and their applications

    CERN Document Server

    Madry, Scott

    2015-01-01

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

  1. 75 FR 39632 - Regulated Navigation Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey...

    Science.gov (United States)

    2010-07-12

    ..., Inner Harbor Navigation Canal, Harvey Canal, Algiers Canal, New Orleans, LA; Correction ACTION: Interim... Navigation Canal, Harvey Canal, Algiers Canal, New Orleans, LA into the Code of Federal Regulations....

  2. Neural encoding of objects relevant for navigation and resting state correlations with navigational ability

    NARCIS (Netherlands)

    Wegman, J.B.T.; Janzen, G.

    2011-01-01

    Objects along a route can help us to successfully navigate through our surroundings. Previous neuroimaging research has shown that the parahippocampal gyrus (PHG) distinguishes between objects that were previously encountered at navigationally relevant locations (decision points) and irrelevant loca

  3. Melatonin improves spatial navigation memory in male diabetic rats

    Directory of Open Access Journals (Sweden)

    Farrin Babaei-Balderlou

    2012-09-01

    Full Text Available The aim of the present study was to evaluate the effect of melatonin as an antioxidant on spatial navigation memory in male diabetic rats. Thirty-two male white Wistar rats weighing 200 ± 20 g were divided into four groups, randomly: control, melatonin, diabetic and melatonin-treated diabetic. Experimental diabetes was induced by intraperitoneal injection of 50 mg kg-1 streptozotocin. Melatonin was injected (10 mg kg-1 day-1, ip for 2 weeks after 21 days of diabetes induction. At the end of administration period, the spatial navigation memory of rats was evaluated by cross-arm maze. In this study lipid peroxidation levels, glutathione-peroxidase and catalase activities were measured in hippocampus. Diabetes caused to significant decrease in alternation percent in the cross-arm maze, as a spatial memory index, compared to the control group (p < 0.05, whereas administration of melatonin prevented the spatial memory deficit in diabetic rats. Also melatonin injection significantly increased the spatial memory in intact animals compared to the control group (p < 0.05. Assessment of hippocampus homogenates indicated an increase in lipid peroxidation levels and a decrease in GSH-Px and CAT activities in the diabetic group compared to the control animals, while melatonin administration ameliorated these indices in diabetic rats. In conclusion, diabetes induction leads to debilitation of spatial navigation memory in rats, and the melatonin treatment improves the memory presumably through the reduction of oxidative stress in hippocampus of diabetic rats.

  4. 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.

  5. Youth Mobilisation as Social Navigation

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2010-01-01

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

  6. 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.

  7. Hybrid Guidance System for Relative Navigation Project

    Data.gov (United States)

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

  8. Ground Vehicle Navigation Using Magnetic Field Variation

    Science.gov (United States)

    Shockley, Jeremiah A.

    The Earth's magnetic field has been the bedrock of navigation for centuries. The latest research highlights the uniqueness of magnetic field measurements based on position due to large scale variations as well as localized perturbations. These observable changes in the Earth's magnetic field as a function of position provide distinct information which can be used for navigation. This dissertation describes ground vehicle navigation exploiting variation in Earth's magnetic field using a self-contained navigation system consisting of only a magnetometer and magnetic field maps. In order to achieve navigation, effective calibration enables repeatable magnetic field measurements from different vehicles and facilitates mapping of the observable magnetic field as a function of position. A new modified ellipsoid calibration technique for strapdown magnetometers in large vehicles is described, as well as analysis of position measurement generation comparing a multitude of measurement compositions using existing and newly developed likelihood techniques. Finally, navigation solutions are presented using both a position measurement and direct incorporation of the magnetometer measurements via a particle filter to demonstrate road navigation in three different environments. Emphatically, the results affirm that navigation using magnetic field variation in ground vehicles is viable and achieves adequate performance for road level navigation.

  9. Limitations of navigation through Nubaria canal, Egypt.

    Science.gov (United States)

    Samuel, Magdy G

    2014-03-01

    Alexandria port is the main Egyptian port at the Mediterranean Sea. It is connected to the Nile River through Nubaria canal, which is a main irrigation canal. The canal was designed to irrigate eight hundred thousand acres of agricultural lands, along its course which extends 100 km. The canal has three barrages and four locks to control the flow and allow light navigation by some small barges. Recently, it was decided to improve the locks located on the canal. More than 40 million US$ was invested in these projects. This decision was taken to allow larger barges and increase the transported capacity through the canal. On the other hand, navigation through canals and restricted shallow waterways is affected by several parameters related to both the channel and the vessel. Navigation lane width as well as vessel speed and maneuverability are affected by both the channel and vessel dimensions. Moreover, vessel dimensions and speed will affect the canal stability. In Egypt, there are no guide rules for navigation through narrow and shallow canals such Nubaria. This situation threatens the canal stability and safety of navigation through it. This paper discussed the characteristics of Nubaria canal and the guide rules for navigation in shallow restricted water ways. Dimensions limitation for barges navigating through Nubaria canal is presented. New safe operation rules for navigation in Nubaria canal are also presented. Moreover, the implication of navigation through locks on canal discharge is estimated.

  10. Limitations of navigation through Nubaria canal, Egypt

    Directory of Open Access Journals (Sweden)

    Magdy G. Samuel

    2014-03-01

    Full Text Available Alexandria port is the main Egyptian port at the Mediterranean Sea. It is connected to the Nile River through Nubaria canal, which is a main irrigation canal. The canal was designed to irrigate eight hundred thousand acres of agricultural lands, along its course which extends 100 km. The canal has three barrages and four locks to control the flow and allow light navigation by some small barges. Recently, it was decided to improve the locks located on the canal. More than 40 million US$ was invested in these projects. This decision was taken to allow larger barges and increase the transported capacity through the canal. On the other hand, navigation through canals and restricted shallow waterways is affected by several parameters related to both the channel and the vessel. Navigation lane width as well as vessel speed and maneuverability are affected by both the channel and vessel dimensions. Moreover, vessel dimensions and speed will affect the canal stability. In Egypt, there are no guide rules for navigation through narrow and shallow canals such Nubaria. This situation threatens the canal stability and safety of navigation through it. This paper discussed the characteristics of Nubaria canal and the guide rules for navigation in shallow restricted water ways. Dimensions limitation for barges navigating through Nubaria canal is presented. New safe operation rules for navigation in Nubaria canal are also presented. Moreover, the implication of navigation through locks on canal discharge is estimated.

  11. Robotics_MobileRobot Navigation Project

    Data.gov (United States)

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

  12. 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...

  13. Lunar Autonomous Automatic Surface Navigation System Project

    Data.gov (United States)

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

  14. 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.

  15. Precision optical navigation guidance system

    Science.gov (United States)

    Starodubov, D.; McCormick, K.; Nolan, P.; Johnson, D.; Dellosa, M.; Volfson, L.; Fallahpour, A.; Willner, A.

    2016-05-01

    We present the new precision optical navigation guidance system approach that provides continuous, high quality range and bearing data to fixed wing aircraft during landing approach to an aircraft carrier. The system uses infrared optical communications to measure range between ship and aircraft with accuracy and precision better than 1 meter at ranges more than 7.5 km. The innovative receiver design measures bearing from aircraft to ship with accuracy and precision better than 0.5 mRad. The system provides real-time range and bearing updates to multiple aircraft at rates up to several kHz, and duplex data transmission between ship and aircraft.

  16. The N456 Navigator System

    Science.gov (United States)

    2009-01-01

    system, the N456 timing functions are not used or affected. – 4 – 5. PRV Mode This is a common navigation method for the Jason/ Medea system. In...this mode, a trigger is sent down the tether, where it is causes an interrogation pulse from Medea . Boards dedicated to Medea and Jason both time the... Medea uses PING_BOARD=2 # MODE_CYCLE = the name of a ping cycle definition # IS_TIMED = 0 if pings occur at the commanded instant

  17. Fuzzy sets and autonomous navigation

    Science.gov (United States)

    Lea, Robert N.

    1987-01-01

    The use of fuzzy sets in modeling the human expert for certain Space Shuttle navigation problems is discussed with particular reference to onboard and ground console data monitoring tasks traditionally performed by astronauts and engineers. Specific problems include determining the quality of sensor data and of the filter state. The results obtained in this study indicate that fuzzy sets can be successfully used in modeling human reaction to rules in decision-making processes. They can also be used within software systems where guidelines have traditionally been used to set strict tolerances.

  18. Interplanetary spacecraft navigation using pulsars

    CERN Document Server

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

    2013-01-01

    We demonstrate how observations of pulsars can be used to help navigate a spacecraft travelling in the solar system. We make use of archival observations of millisecond pulsars from the Parkes radio telescope in order to demonstrate the effectiveness of the method and highlight issues, such as pulsar spin irregularities, which need to be accounted for. We show that observations of four millisecond pulsars every seven days using a realistic X-ray telescope on the spacecraft throughout a journey from Earth to Mars can lead to position determinations better than approx. 20km and velocity measurements with a precision of approx. 0.1m/s.

  19. 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...

  20. Chemical compass for bird navigation

    DEFF Research Database (Denmark)

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

    2014-01-01

    Migratory birds travel spectacular distances each year, navigating and orienting by a variety of means, most of which are poorly understood. Among them is a remarkable ability to perceive the intensity and direction of the Earth's magnetic field. Biologically credible mechanisms for the detection...... 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...

  1. Less outliers in pinless navigation compared with conventional surgery in total knee arthroplasty.

    Science.gov (United States)

    Chen, Jerry Yongqiang; Chin, Pak Lin; Tay, Darren Keng Jin; Chia, Shi-Lu; Lo, Ngai Nung; Yeo, Seng Jin

    2014-08-01

    The aim of this study was to investigate the effectiveness of a new pinless navigation system (BrainLAB(®) VectorVision(®) Knee 2.5 Navigation System) as an intra-operative alignment check in total knee arthroplasty using conventional cutting jigs. 200 patients who underwent total knee arthroplasty using conventional technique or pinless navigation by a senior surgeon were included in the study and prospectively followed up. Intra-operative readings from the pinless navigation system were recorded, and post-operative long limb radiographic films were taken. The accepted values for normal alignment were 180 ± 3° for Hip-Knee-Ankle Angle and 90 ± 3° for Coronal Femoral-Component Angle or Coronal Tibia-Component Angle. There was no difference in the duration of surgery. The mean Coronal Femoral-Component Angle was 89.8 ± 2.0° and 91.3 ± 2.3° in the pinless navigation and conventional group, respectively (p outliers was 10 % in the pinless navigation group compared to 26 % in the conventional group (p = 0.005). For Coronal Femoral-Component Angle and Coronal Tibia-Component Angle, the proportion of outliers was 7 and 4 %, respectively, in the pinless navigation group, compared to 22 and 19 % in the conventional group (p = 0.004 and p = 0.001, respectively). The measurements of Coronal Femoral-Component Angle and Coronal Tibia-Component Angle on post-operative radiographic films were similar to intra-operative readings. This study showed that pinless navigation is an effective tool for reducing the proportion of outliers, without significantly increasing the duration of surgery. The authors recommend its use in total knee arthroplasty using conventional cutting jigs.

  2. 33 CFR 245.20 - Determination of hazard to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Determination of hazard to navigation. 245.20 Section 245.20 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE REMOVAL OF WRECKS AND OTHER OBSTRUCTIONS § 245.20 Determination of hazard to...

  3. 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 acti

  4. Quantum control of isomerization by robust navigation in the energy spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Murgida, G. E., E-mail: murgida@tandar.cnea.gov.ar [Centro Atómico Constituyentes, GIyA, CNEA, San Martín, and Consejo Nacional de Investigaciones Científicas y Técnicas, C1033AAJ Buenos Aires (Argentina); Arranz, F. J., E-mail: fj.arranz@upm.es [Grupo de Sistemas Complejos, Universidad Politécnica de Madrid, 28040 Madrid (Spain); Borondo, F., E-mail: f.borondo@uam.es [Departamento de Química, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Instituto de Ciencias Matemáticas (ICMAT), Cantoblanco, 28049 Madrid (Spain)

    2015-12-07

    In this paper, we present a detailed study on the application of the quantum control technique of navigation in the energy spectrum to chemical isomerization processes, namely, CN–Li⇆ Li–CN. This technique is based on the controlled time variation of a Hamiltonian parameter, an external uniform electric field in our case. The main result of our work establishes that the navigation involved in the method is robust, in the sense that quite sizable deviations from a pre-established control parameter time profile can be introduced and still get good final results. This is specially relevant thinking of a experimental implementation of the method.

  5. Opus-H: a new navigational and targeting observation device

    Science.gov (United States)

    van der Merwe, J.; Fritze, J.; Muenzberg, M.

    2008-04-01

    Current and future land warriors operate in a group or autonomously. The necessity to observe and locate targets during day, night and all weather conditions inspire developments of small, but complex handheld devices, which are able to fulfill these tasks. Observation in daylight can be achieved by means of a visual telescope with high resolution. For night operation a thermal imager is required. Navigation tasks can be fulfilled with a digital magnetic compass and a GPS receiver. For measuring ranges to targets an eye-safe laser rangefinder is necessary. OPUS H, the newest member of the ZEISS family of handheld navigational and targeting devices, combines all these functions in a light-weight instrument and analyses all data to provide first hand information about potential targets to the soldier and his group with sufficient accuracy for combat decisions.

  6. Design and Development of the WVU Advanced Technology Satellite for Optical Navigation

    Science.gov (United States)

    Straub, Miranda

    In order to meet the demands of future space missions, it is beneficial for spacecraft to have the capability to support autonomous navigation. This is true for both crewed and uncrewed vehicles. For crewed vehicles, autonomous navigation would allow the crew to safely navigate home in the event of a communication system failure. For uncrewed missions, autonomous navigation reduces the demand on ground-based infrastructure and could allow for more flexible operation. One promising technique for achieving these goals is through optical navigation. To this end, the present work considers how camera images of the Earth's surface could enable autonomous navigation of a satellite in low Earth orbit. Specifically, this study will investigate the use of coastlines and other natural land-water boundaries for navigation. Observed coastlines can be matched to a pre-existing coastline database in order to determine the location of the spacecraft. This paper examines how such measurements may be processed in an on-board extended Kalman filter (EKF) to provide completely autonomous estimates of the spacecraft state throughout the duration of the mission. In addition, future work includes implementing this work on a CubeSat mission within the WVU Applied Space Exploration Lab (ASEL). The mission titled WVU Advanced Technology Satellite for Optical Navigation (WATSON) will provide students with an opportunity to experience the life cycle of a spacecraft from design through operation while hopefully meeting the primary and secondary goals defined for mission success. The spacecraft design process, although simplified by CubeSat standards, will be discussed in this thesis as well as the current results of laboratory testing with the CubeSat model in the ASEL.

  7. Remote Visualization and Navigation of 3d Models of Archeological Sites

    Science.gov (United States)

    Callieri, M.; Dellepiane, M.; Scopigno, R.

    2015-02-01

    The remote visualization and navigation of 3D data directly inside the web browser is becoming a viable option, due to the recent efforts in standardizing the components for 3D rendering on the web platform. Nevertheless, handling complex models may be a challenge, especially when a more generic solution is needed to handle different cases. In particular, archeological and architectural models are usually hard to handle, since their navigation can be managed in several ways, and a completely free navigation may be misleading and not realistic. In this paper we present a solution for the remote navigation of these dataset in a WebGL component. The navigation has two possible modes: the "bird's eye" mode, where the user is able to see the model from above, and the "first person" mode, where the user can move inside the structure. The two modalities are linked by a point of interest, that helps the user to control the navigation in an intuitive fashion. Since the terrain may not be flat, and the architecture may be complex, it's necessary to handle these issues, possibly without implementing complex mesh-based collision mechanisms. Hence, a complete navigation is obtained by storing the height and collision information in an image, which provides a very simple source of data. Moreover, the same image-based approach can be used to store additional information that could enhance the navigation experience. The method has been tested in two complex test cases, showing that a simple yet powerful interaction can be obtained with limited pre-processing of data.

  8. Visual information, sparse decomposition, and transmission for multi- UAV visual navigation

    Science.gov (United States)

    Liu, Hui; Dai, Qionghai

    2012-06-01

    In recent years, visual navigation of unmanned aerial vehicles (UAVs) has been an active area of research. There is a large amount of visual information to be processed and transmitted with real-time requirements for the flight scenes change rapidly. However, it has already become one of the major factors that block the cooperative communication in multi-UAV visual navigation. The traditional video image orthogonal decomposition methods can not be well adapted to the multi-UAV visual navigation system, because with the compression ratio increases, there is a sharp decline in video image quality. This paper proposes a novel visual information sparse decomposition and transmission (VSDT) framework for multi-UAV visual navigation. In the framework, aiming at the visual information characteristics, firstly we pre-process the video images by introducing a multi-scale visual information acquisition mechanism. Then a fast video image sparse decomposition is made for transmission. It can greatly reduce the original video information amount, while the quality of visual information needed for navigation is guaranteed. Finally, based on data correlations and feature matching, a real-time transmission scheme is designed to make the receiver UAV can quickly reconstruct the flight scene information for navigation. The simulated results are presented and discussed. The main advantage of this framework lies in the ability to reduce the visual information transmission amount while ensuring the quality of visual information needed for navigation and solve the cooperative communication problems such as information lag, data conjunction and match error often encountered in multi-UAV visual navigation environment.

  9. 76 FR 31831 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments

    Science.gov (United States)

    2011-06-02

    ... conforming amendments and technical corrections to Coast Guard navigation and navigable water regulations... that erroneously omitted the words ``within a''. The correction to the section is not substantive and..., Waterways. 33 CFR Part 107 Harbors, Facilities, Marine safety, Maritime security, Navigation (water...

  10. Navigated focal laser photocoagulation for central serous chorioretinopathy

    Directory of Open Access Journals (Sweden)

    Chhablani J

    2014-08-01

    Full Text Available Jay Chhablani,1 Padmaja Kumari Rani,1 Annie Mathai,1 Subhadra Jalali,1 Igor Kozak2 1Srimati Kanuri Santhamma Vitreo-Retina Service, L V Prasad Eye Institute, Hyderabad, India; 2Division of Vitreoretinal Diseases and Surgery, King Khaled Eye Specialist Hospital, Riyadh, Kingdom of Saudi Arabia Background and objective: To assess the efficacy of navigated laser (Navilas® treatment for central serous chorioretinopathy.Materials and methods: Prospective study included 16 eyes of 15 subjects with nonresolving central serous chorioretinopathy. Fluorescein-angiography guided Navilas® treatment was performed. Pre- and posttreatment best-corrected visual acuity, pre- and posttreatment central macular thickness, number of leaks on fluorescein angiography, and various treatment parameters were analyzed. Pain experience was evaluated using the visual analog pain scale.Results: Sixteen eyes from 15 subjects (mean age 42.2±9.9 years were analyzed. Mean duration of symptoms was 11.45±6.6 months. Average number of leaks per eye was 2.8 and one laser spot per leak was performed. There was complete resolution of subretinal fluid in 15 out of 16 eyes at 2 months. Average visual analog pain scale score was 0.63±1.41. Conclusion: Navilas® without a contact lens achieved resolution of subretinal fluid with a single laser spot for each single leak and minimum iatrogenic damage. Keywords: navigated laser, Navilas®

  11. A flexible navigation mechanism for complex data models

    Directory of Open Access Journals (Sweden)

    Oleg Burlaca

    2010-07-01

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

  12. Optic flow and autonomous navigation.

    Science.gov (United States)

    Campani, M; Giachetti, A; Torre, V

    1995-01-01

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

  13. Compliance of blood sampling procedures with the CLSI H3-A6 guidelines: An observational study by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) working group for the preanalytical phase (WG-PRE).

    Science.gov (United States)

    Simundic, Ana-Maria; Church, Stephen; Cornes, Michael P; Grankvist, Kjell; Lippi, Giuseppe; Nybo, Mads; Nikolac, Nora; van Dongen-Lases, Edmee; Eker, Pinar; Kovalevskaya, Svjetlana; Kristensen, Gunn B B; Sprongl, Ludek; Sumarac, Zorica

    2015-08-01

    An observational study was conducted in 12 European countries by the European Federation of Clinical Chemistry and Laboratory Medicine Working Group for the Preanalytical Phase (EFLM WG-PRE) to assess the level of compliance with the CLSI H3-A6 guidelines. A structured checklist including 29 items was created to assess the compliance of European phlebotomy procedures with the CLSI H3-A6 guideline. A risk occurrence chart of individual phlebotomy steps was created from the observed error frequency and severity of harm of each guideline key issue. The severity of errors occurring during phlebotomy was graded using the risk occurrence chart. Twelve European countries participated with a median of 33 (18-36) audits per country, and a total of 336 audits. The median error rate for the total phlebotomy procedure was 26.9 % (10.6-43.8), indicating a low overall compliance with the recommended CLSI guideline. Patient identification and test tube labelling were identified as the key guideline issues with the highest combination of probability and potential risk of harm. Administrative staff did not adhere to patient identification procedures during phlebotomy, whereas physicians did not adhere to test tube labelling policy. The level of compliance of phlebotomy procedures with the CLSI H3-A6 guidelines in 12 European countries was found to be unacceptably low. The most critical steps in need of immediate attention in the investigated countries are patient identification and tube labelling.

  14. Fat and muscle mass in different groups of pre-pubertal and pubertal rural children. Cross-cultural comparisons between Sahelian (rural Senegal) and Amazonian (Beni River, Bolivia) children.

    Science.gov (United States)

    Benefice, Eric; Luna Monrroy, Selma J; Lopez Rodriguez, Ronald W; Ndiaye, Gnagna

    2011-07-01

    An increase in fat accretion is essential for triggering the puberty spurt. Hence, nutritional constraints may influence puberty timing. To measure changes in fat and muscle mass in children living in natural environments but with different nutritional exposures. Cross-comparisons of children from rural Senegal and lowland (Amazonian) Bolivia were carried out. Anthropometric measurements of stature, weight, four subcutaneous skin-folds (triceps, biceps, subscapular, supra-iliac) and arm circumference were made. Children were divided into two age groups (5-9.9-year-olds or 'pre pubescents' (n = 381) and 10-15-year-olds or 'pubescents' (n = 692)). Senegalese girls menstruated later than Bolivian girls and Senegalese boys also matured later than Bolivian boys. Bolivian children displayed more fat and muscle before puberty and during puberty than the Senegalese. They also had more fat deposited on the trunk. There were substantial differences in living conditions and nutritional patterns between both locations. In Senegal, nutritional stress is likely to appear early during in utero life and to persist throughout the growth period, including puberty. This leads to a deficit in fat accretion before and during puberty that is associated with a considerable delay in puberty occurrence. In Bolivia, such stress is far less severe. Variability in puberty should be analysed taking into account these differences.

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

    Science.gov (United States)

    Huang, Yufeng; Liu, Yi; Liu, Jianguo

    2015-04-01

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

  16. On credibility improvements for automotive navigation systems

    NARCIS (Netherlands)

    Schaub, Florian; Hipp, Markus; Kargl, Frank; Weber, Michael

    2012-01-01

    Automotive navigation systems are becoming ubiquitous as driver assistance systems. Vendors continuously aim to enhance route guidance by adding new features to their systems. However, we found in an analysis of current navigation systems that many share interaction weaknesses, which can damage the

  17. Understanding the Social Navigation User Experience

    Science.gov (United States)

    Goecks, Jeremy

    2009-01-01

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

  18. 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.

  19. Blavigator: a navigation aid for blind persons

    OpenAIRE

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

    2012-01-01

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

  20. 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 measu

  1. Traffic safety effects of navigation systems

    NARCIS (Netherlands)

    Feenstra, P.J.; Hogema, J.H.; Vonk, T.

    2007-01-01

    Abstract— To investigate effects of navigation systems on traffic safety, a literature search, a damages database analysis, a user survey and an instrumented car study were conducted. This paper presents the instrumented car study to investigate the effects of a navigation system on driving behavior

  2. Waypoint navigation with a vibrotactile waist belt

    NARCIS (Netherlands)

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

    2005-01-01

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

  3. Disputing Viking navigation by polarized skylight.

    Science.gov (United States)

    Roslund, C; Beckman, C

    1994-07-20

    The widely held notion that the Vikings utilized polarization of skylight on overcast days for navigational purposes is demonstrated to have no scientific basis. The use of polarized skylight for navigation under partly cloudfree skies should be treated with caution and skepticism.

  4. Ground Vehicle Navigation Using Magnetic Field Variation

    Science.gov (United States)

    2012-09-13

    using three-axis magnetic field measurements for navigation. While Storms innovative work exposed the ability to navigate using three-axis magnetometer...level of difficulty, Ascher et al. combine a magnetometer with a pair of inertial measurement units, a barometer , and a laser for precise indoor

  5. The Navigational Power of Web Browsers

    NARCIS (Netherlands)

    Bielecki, M.; Hidders, J.; Paredaens, J.; Spielmann, M.; Tyszkiewicz, J.; Van den Bussche, J.

    2010-01-01

    We investigate the computational capabilities of Web browsers, when equipped with a standard finite automaton. We observe that Web browsers are Turingcomplete. We introduce the notion of a navigational problem, and investigate the complexity of solving Web queries and navigational problems by Web br

  6. Validation of principles for tactile navigation displays

    NARCIS (Netherlands)

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

    2006-01-01

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

  7. 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

  8. 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…

  9. 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....

  10. 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 navigation makes it easier to motivate and explain security investment to a wide audience, encouraging strategic security decisions....

  11. 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 navig

  12. 磁导航系统遥控导管消融治疗右心室流出道室性心动过速/室性早搏%Remote radiofrequency catheter ablation of right ventricular outflow tract ventricular tachycardia/pre-mature ventricular complexes using the magnetic navigation system combined with non-contact map-ping system

    Institute of Scientific and Technical Information of China (English)

    翟立上; 顾凯; 陈明龙; 曹克将; 杨兵; 孙建辉; 徐东杰; 张凤祥; 居维竹; 陈红武; 郦明芳; 杨刚

    2014-01-01

    Objective To evaluate the safety and efficacy of remote radiofrequency catheter ablation of right ventricular outflow tract ventricular tachycardia/premature ventricular complexes ( RVOT-VT/PVCs ) using the magnetic navigation system combined with the non-contact mapping system. Methods Totally 16 pa-tients with RVOT-VT/PVCs [12 women and 4 men,mean aged (44±15) years] were enrolled. The original site of arrhythmias was determined by non-contact activation mapping and conventional pace mapping. Ablation was performed using HeliosⅡmagnetic temperature-controled catheter manipulated by NiobeⅡmagnetic navi-gation system. If failed with magnetic system,the procedure would be transferred to manually controlled session. Results Among 10 of 16 subjects,documented RVOT-VT/PVCs were successfully abolished by remote abla-tion controlled by magnetic navigation system. In the other 6 patients,RVOT VT/PVCs were eliminated by man-ually controlled catheter ablation. The total procedure time was (190±42) min,and the mean ablation time was (240±33) s,and the average times of energy application were 3. 9±1. 6. The total X-ray exposure time was (4. 8±2. 6) min,which including (3. 2±2. 0) min for operators,and (1. 6±1. 0) min for remote ablation,respec-tively. No other complications were observed except one patient developed postoperative arteriovenous fistula. Conclusion Magnetic navigation system combined with non-contact mapping system was safe and effective for remote radiofrequency catheter ablation of RVOT-VT/PVCs. It may potentially reduce X-ray exposure time for both patients and operators.%目的:探讨应用磁导航遥控导管消融治疗右心室流出道起源的室性心动过速/室性早搏( RVOT-VT/PVCs)的安全性和有效性。方法2008年11月至2009年11月,在南京医科大学第一附属医院心血管内科行体表心电图检查,诊断为RVOT-VT/PVCs的患者共16例[女12例,男4例,平均年龄(44±15)岁],结合应用非接触标测系

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

    Directory of Open Access Journals (Sweden)

    Yong-Jin Yoon

    2015-03-01

    Full Text Available 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 Positioning System is coupled with Inertial Navigation System to correct the errors, while Inertial Navigation System itself can be used to provide navigation solution during a Global Positioning System outage. Data from Global Positioning System and Inertial Navigation System can be integrated by extensive Kalman filtering, using loosely coupled integration architecture to provide navigation solutions. In this study, real-time low-cost loosely coupled micro-electro-mechanical system Inertial Navigation System/Global Positioning System sensors have been used for pedestrian navigation. Trial runs of Global Positioning System outages have been conducted to determine the accuracy of the system described. The micro-electro-mechanical system Inertial Navigation System/Global Positioning System can successfully project a trajectory during a Global Positioning System outage and produces a root mean square error of 9.35 m in latitude direction and 10.8 m in longitude direction. This technology is very suitable for visually impaired pedestrians.

  14. Sex differences in virtual navigation influenced by scale and navigation experience.

    Science.gov (United States)

    Padilla, Lace M; Creem-Regehr, Sarah H; Stefanucci, Jeanine K; Cashdan, Elizabeth A

    2017-04-01

    The Morris water maze is a spatial abilities test adapted from the animal spatial cognition literature and has been studied in the context of sex differences in humans. This is because its standard design, which manipulates proximal (close) and distal (far) cues, applies to human navigation. However, virtual Morris water mazes test navigation skills on a scale that is vastly smaller than natural human navigation. Many researchers have argued that navigating in large and small scales is fundamentally different, and small-scale navigation might not simulate natural human navigation. Other work has suggested that navigation experience could influence spatial skills. To address the question of how individual differences influence navigational abilities in differently scaled environments, we employed both a large- (146.4 m in diameter) and a traditional- (36.6 m in diameter) scaled virtual Morris water maze along with a novel measure of navigation experience (lifetime mobility). We found sex differences on the small maze in the distal cue condition only, but in both cue-conditions on the large maze. Also, individual differences in navigation experience modulated navigation performance on the virtual water maze, showing that higher mobility was related to better performance with proximal cues for only females on the small maze, but for both males and females on the large maze.

  15. EL DESEMPEÑO SENSORIAL DE UN GRUPO DE PRE-ESCOLARES Y ESCOLARES CON DIFICULTADES EN LAS ACTIVIDADES COTIDIANAS Evaluation of sensory modulation in a children group of preschool and school age with deficits in daily activities

    Directory of Open Access Journals (Sweden)

    Rubio G María Helena

    2010-12-01

    , in correctly appreciating their abilities, and in taking responsibilities for their actions. Traditionally, assessment and intervention with these children has focused on the disability management. The ICF recognizes the individuality and the barriers and facilitators stemming from environmental and personal factors. Objectives. Compare the evaluation of children group with sensory integration deficit from the point of view of disability and CIF evaluation on daily activities deficits. Materials and Methods. The study was exploratory and descriptive, six pre-school and twenty-two students who attended SERH between September 2008 and March 2009. We compared and coded the score for each element of the sensory profile Based upon these; we evaluated bodily functioning and participation in daily activities. Results. The results demonstrate compatibility between the functions and participation activities and sections of sensory processing, but not, in relation to the factors for the specificity of the test. Characterization of sensory processing conditions is feasible with the combined use of references. Conclusion. This study shows that sensory stimulation can have a positive impact in development and performance of daily activities in disabled children. There is increasing need to provide appropriate treatment alternatives through proper professional and family education.

  16. Autonomous Robot Navigation based on Visual Landmarks

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    autonomous navigation and self-localization using automatically selected landmarks. The thesis investigates autonomous robot navigation and proposes a new method which benefits from the potential of the visual sensor to provide accuracy and reliability to the navigation process while relying on naturally...... available environment features (natural landmarks). The goal is also to integrate techniques and algorithms (also related to other research field) in the same navigation system, in order to improve localization performance and system autonomy. The proposed localization strategy is based on a continuous...... update of the estimated robot position while the robot is moving. In order to make the system autonomous, both acquisition and observation of landmarks have to be carried out automatically. The thesis consequently proposes a method for learning and navigation of a working environment and it explores...

  17. Autonomous Deep-Space Optical Navigation Project

    Science.gov (United States)

    D'Souza, Christopher

    2014-01-01

    This project will advance the Autonomous Deep-space navigation capability applied to Autonomous Rendezvous and Docking (AR&D) Guidance, Navigation and Control (GNC) system by testing it on hardware, particularly in a flight processor, with a goal of limited testing in the Integrated Power, Avionics and Software (IPAS) with the ARCM (Asteroid Retrieval Crewed Mission) DRO (Distant Retrograde Orbit) Autonomous Rendezvous and Docking (AR&D) scenario. The technology, which will be harnessed, is called 'optical flow', also known as 'visual odometry'. It is being matured in the automotive and SLAM (Simultaneous Localization and Mapping) applications but has yet to be applied to spacecraft navigation. In light of the tremendous potential of this technique, we believe that NASA needs to design a optical navigation architecture that will use this technique. It is flexible enough to be applicable to navigating around planetary bodies, such as asteroids.

  18. Navigation in spatial networks: A survey

    Science.gov (United States)

    Huang, Wei; Chen, Shengyong; Wang, Wanliang

    2014-01-01

    The study on the navigation process in spatial networks has attracted much attention in recent years due to the universal applications in real communication networks. This article surveys recent advances of the navigation problem in spatial networks. Due to the ability to overcome scaling limitations in utilizing geometric information for designing navigation algorithms in spatial networks, we summarize here several important navigation algorithms based on geometric information on both homogeneous and heterogeneous spatial networks. Due to the geometric distance employed, the cost associated with the lengths of additional long-range connections is also taken into account in this survey. Therefore, some contributions reporting how the distribution of long-range links’ lengths affects the average navigation time are summarized. We also briefly discuss two other related processes, i.e. the random walk process and the transportation process. Finally, a few open discussions are included at the end of this survey.

  19. Beacons for supporting lunar landing navigation

    Science.gov (United States)

    Theil, Stephan; Bora, Leonardo

    2017-03-01

    Current and future planetary exploration missions involve a landing on the target celestial body. Almost all of these landing missions are currently relying on a combination of inertial and optical sensor measurements to determine the current flight state with respect to the target body and the desired landing site. As soon as an infrastructure at the landing site exists, the requirements as well as conditions change for vehicles landing close to this existing infrastructure. This paper investigates the options for ground-based infrastructure supporting the onboard navigation system and analyzes the impact on the achievable navigation accuracy. For that purpose, the paper starts with an existing navigation architecture based on optical navigation and extends it with measurements to support navigation with ground infrastructure. A scenario of lunar landing is simulated and the provided functions of the ground infrastructure as well as the location with respect to the landing site are evaluated. The results are analyzed and discussed.

  20. 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.

  1. Enhancing Navigation on Wikipedia with Social Tags

    CERN Document Server

    Zubiaga, Arkaitz

    2012-01-01

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

  2. 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

  3. 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.

  4. Autonomous navigation system and method

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Processing Images of Craters for Spacecraft Navigation

    Science.gov (United States)

    Cheng, Yang; Johnson, Andrew E.; Matthies, Larry H.

    2009-01-01

    A crater-detection algorithm has been conceived to enable automation of what, heretofore, have been manual processes for utilizing images of craters on a celestial body as landmarks for navigating a spacecraft flying near or landing on that body. The images are acquired by an electronic camera aboard the spacecraft, then digitized, then processed by the algorithm, which consists mainly of the following steps: 1. Edges in an image detected and placed in a database. 2. Crater rim edges are selected from the edge database. 3. Edges that belong to the same crater are grouped together. 4. An ellipse is fitted to each group of crater edges. 5. Ellipses are refined directly in the image domain to reduce errors introduced in the detection of edges and fitting of ellipses. 6. The quality of each detected crater is evaluated. It is planned to utilize this algorithm as the basis of a computer program for automated, real-time, onboard processing of crater-image data. Experimental studies have led to the conclusion that this algorithm is capable of a detection rate >93 percent, a false-alarm rate <5 percent, a geometric error <0.5 pixel, and a position error <0.3 pixel.

  6. Intraoperative computed tomography with integrated navigation system in spinal stabilizations.

    Science.gov (United States)

    Zausinger, Stefan; Scheder, Ben; Uhl, Eberhard; Heigl, Thomas; Morhard, Dominik; Tonn, Joerg-Christian

    2009-12-15

    STUDY DESIGN.: A prospective interventional case-series study plus a retrospective analysis of historical patients for comparison of data. OBJECTIVE.: To evaluate workflow, feasibility, and clinical outcome of navigated stabilization procedures with data acquisition by intraoperative computed tomography. SUMMARY OF BACKGROUND DATA.: Routine fluoroscopy to assess pedicle screw placement is not consistently reliable. Our hypothesis was that image-guided spinal navigation using an intraoperative CT-scanner can improve the safety and precision of spinal stabilization surgery. METHODS.: CT data of 94 patients (thoracolumbar [n = 66], C1/2 [n = 12], cervicothoracic instability [n = 16]) were acquired after positioning the patient in the final surgical position. A sliding gantry 40-slice CT was used for image acquisition. Data were imported to a frameless infrared-based neuronavigation workstation. Intraoperative CT was obtained to assess the accuracy of instrumentation and, if necessary, the extent of decompression. All patients were clinically evaluated by Odom-criteria after surgery and after 3 months. RESULTS.: Computed accuracy of the navigation system reached /=2 mm without persistent neurologic or vascular damage in 20/414 screws (4.8%) leading to immediate correction of 10 screws (2.4%). Control-iCT changed the course of surgery in 8 cases (8.5% of all patients). The overall revision rate was 8.5% (4 wound revisions, 2 CSF fistulas, and 2 epidural hematomas). There was no reoperation due to implant malposition. According to Odom-criteria all patients experienced a clinical improvement. A retrospective analysis of 182 patients with navigated thoracolumbar transpedicular stabilizations in the preiCT era revealed an overall revision rate of 10.4% with 4.4% of patients requiring screw revision. CONCLUSION.: Intraoperative CT in combination with neuronavigation provides high accuracy of screw placement and thus safety for patients undergoing spinal stabilization

  7. Multi-rover navigation on the lunar surface

    Science.gov (United States)

    Dabrowski, Borys; Banaszkiewicz, Marek

    2008-07-01

    The paper presents a method of determination an accurate position of a target (rover, immobile sensor, astronaut) on surface of the Moon or other celestial body devoid of navigation infrastructure (like Global Positioning System), by using a group of self-calibrating rovers, which serves as mobile reference points. The rovers are equipped with low-precision clocks synchronized by external broadcasting signal, to measure the moments of receiving radio signals sent by localized target. Based on the registered times, distances between transmitter and receivers installed on beacons are calculated. Each rover determines and corrects its own absolute position and orientation by using odometry navigation and measurements of relative distances and angles to other mobile reference points. Accuracy of navigation has been improved by the use of a calibration algorithm based on the extended Kalman filter, which uses internal encoder readings as inputs and relative measurements of distances and orientations between beacons as feedback information. The key idea in obtaining reliable values of absolute position and orientation of beacons is to first calibrate one of the rovers, using the remaining ones as reference points and then allow the whole group to move together and calibrate all the rovers in-motion. We consider a number of cases, in which basic modeling parameters such as terrain roughness, formation size and shape as well as availability of distance and angle measurements are varied.

  8. Reliable Alignment in Total Knee Arthroplasty by the Use of an iPod-Based Navigation System

    Directory of Open Access Journals (Sweden)

    Paola Koenen

    2016-01-01

    Full Text Available Axial alignment is one of the main objectives in total knee arthroplasty (TKA. Computer-assisted surgery (CAS is more accurate regarding limb alignment reconstruction compared to the conventional technique. The aim of this study was to analyse the precision of the innovative navigation system DASH® by Brainlab and to evaluate the reliability of intraoperatively acquired data. A retrospective analysis of 40 patients was performed, who underwent CAS TKA using the iPod-based navigation system DASH. Pre- and postoperative axial alignment were measured on standardized radiographs by two independent observers. These data were compared with the navigation data. Furthermore, interobserver reliability was measured. The duration of surgery was monitored. The mean difference between the preoperative mechanical axis by X-ray and the first intraoperatively measured limb axis by the navigation system was 2.4°. The postoperative X-rays showed a mean difference of 1.3° compared to the final navigation measurement. According to radiographic measurements, 88% of arthroplasties had a postoperative limb axis within ±3°. The mean additional time needed for navigation was 5 minutes. We could prove very good precision for the DASH system, which is comparable to established navigation devices with only negligible expenditure of time compared to conventional TKA.

  9. Reliable Alignment in Total Knee Arthroplasty by the Use of an iPod-Based Navigation System.

    Science.gov (United States)

    Koenen, Paola; Schneider, Marco M; Fröhlich, Matthias; Driessen, Arne; Bouillon, Bertil; Bäthis, Holger

    2016-01-01

    Axial alignment is one of the main objectives in total knee arthroplasty (TKA). Computer-assisted surgery (CAS) is more accurate regarding limb alignment reconstruction compared to the conventional technique. The aim of this study was to analyse the precision of the innovative navigation system DASH® by Brainlab and to evaluate the reliability of intraoperatively acquired data. A retrospective analysis of 40 patients was performed, who underwent CAS TKA using the iPod-based navigation system DASH. Pre- and postoperative axial alignment were measured on standardized radiographs by two independent observers. These data were compared with the navigation data. Furthermore, interobserver reliability was measured. The duration of surgery was monitored. The mean difference between the preoperative mechanical axis by X-ray and the first intraoperatively measured limb axis by the navigation system was 2.4°. The postoperative X-rays showed a mean difference of 1.3° compared to the final navigation measurement. According to radiographic measurements, 88% of arthroplasties had a postoperative limb axis within ±3°. The mean additional time needed for navigation was 5 minutes. We could prove very good precision for the DASH system, which is comparable to established navigation devices with only negligible expenditure of time compared to conventional TKA.

  10. HIV感染高危人群暴露前预防用药临床试验依从性分析%Pre-exposure prophylaxis for HIV high-risk groups: an analysis of clinical compliance

    Institute of Scientific and Technical Information of China (English)

    高菲菲; 黄文祥; 黄爱龙; 钟晓妮; 彭斌; 张燕; 梁浩; 邹云峰; 戴江红; 刘倩萍; 宋本莉

    2012-01-01

    To investigate the factors influencing the compliance of pre-exposure prophylaxis (PrEP) amonghigh-risk groups of human immunodeficiency virus (HIV). Methods A total of 352 subjects were selected into the cohort by non-probability sampling, including 153 men who have sex with men (MSM) , 36 female sex workers (FSMs) , and 163 fixed sex partners(PARs) of HIV carriers. Each subject was randomly given a medication regimen of either once daily or twice a week. The pre-exposure prophylaxis compliance was evaluated by observing the maintenance of the cohort and medication omission every 4 weeks from week 0 to week 28. Cochran-Mantel-Haenszel (CMH) test was employed to conduct univariate analysis and logistic regression was adopted for multiple variable analysis. Results It was found that 76. 70% (270/352) of the subjects finished the 28-week-observation in this PrEP clinical trial among high-risk groups of HIV. The medication omission rate fluctuated around 35% during the follow-up, with the total compliance score being 82. 12 + 27. 48 and the median score being 95. 24. Logistic regression suggested that the monthly income, presence of worries or difficulties during the trials, need for medical service, and the way of follow-up were the factors influencing the maintenance of cohort. The marital status, medication method, presence of worries or difficulties during the trial, and presence of adverse effect were the influencing factors of medication omission. The population type, number of sex partners, taking of other drugs at the same time, need of medical service during the trial, and way of follow-up were the factors impacting the overall compliance score. Conclusion The compliance of the present PrEP clinical trials among high-risk groups of HIV is high, and it has multiple influencing factors. Compliance management should be reinforced among MSM and FSW populations with greater motility. The cohort management model of follow-up by fixed specialists should be continued

  11. Pulsar Navigation in the Solar System

    CERN Document Server

    Dong, Jiang

    2008-01-01

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

  12. DYNAMIC LAYOUT ADJUSTMENT AND NAVIGATION FOR ENTERPRISE GIS BASED ON OBJECT MARK RECOGNITION

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper a new method is developed to make a dynamic layout adjustment and navigation for enterprise Geographic Information System(GIS) based on object mark recognition. The extraction of object mark images is based on some morphological structural patterns, which are described by morphological structural points, contour property, and other geometrical data in a binary image of enterprise geographic information map. Some pre-processing methods, contour smooth following, linearization and extraction patterns of structural points, are introduced. If any special object is selected to make a decision in a GIS map, the all information around it will be obtained. That is, we need to investigate similar object enterprises around selected region to analyse whether it is necessary for establishing the object enterprise at that place. To further navigate GIS map, we need to move from one region to another. Each time a region is formed and displayed based on the user′ s focus. If a focus point of a map is selected, in terms of extracted object mark image, a dynamic layout and navigation diagram is constructed. When the user changes the focus (i.e. click a node in the navigation mode), a new sub-diagram is formed by dropping old nodes and adding new nodes. The prototype system provides effective interfaces that support GIS image navigation, detailed local image/map viewing, and enterprise information browsing.

  13. Testing the Preliminary X-33 Navigation System

    Science.gov (United States)

    Lomas, James J.; Mitchell, Daniel W.; Freestone, Todd M.; Lee, Charles; Lessman, Craig; Foster, Lee D. (Technical Monitor)

    2001-01-01

    The X-33 Reusable Launch Vehicle (RLV) must meet the demanding requirements of landing autonomously on a narrow landing strip following a flight that reaches an altitude of up to 200,000 feet and a speed in excess of Mach 9 with significant in-flight energy bleed-off maneuvers. To execute this flight regimen a highly reliable avionics system has been designed that includes three LN-100G Inertial Navigation System/Global Positioning System (INS/GPS) units as the primary navigation system for the X-33. NASA's Marshall Space Flight Center (MSFC) tested an INS/GPS system in real-time simulations to determine the ability of this navigation suite to meet the in flight and autonomous landing requirements of the X-33 RLV. A total of sixty-one open loop tests were performed to characterize the navigation accuracy of the LN-100G. Twenty-seven closed-loop tests were also performed to evaluate the performance of the X-33 Guidance, Navigation and Control (GN&C) algorithms with the real navigation hardware. These closed-loop tests were also designed to expose any integration or operational issues with the real-time X-33 vehicle simulation. Dynamic road tests of the INS/GPS were conducted by Litton to assess the performance of differential and nondifferential INS/GPS hybrid navigation solutions. The results of the simulations and road testing demonstrate that this novel solution is capable of meeting the demanding requirements of take-off, in-flight navigation, and autonomous landing of the X-33 RLV. This paper describes the test environment developed to stimulate the LN-100G and discusses the results of this test effort. This paper also presents recommendations for a navigation system suitable to an operational RLV system.

  14. Inner Harbor Navigation Canal Basin Velocity Analysis

    Science.gov (United States)

    2014-10-01

    ER D C/ CH L TR -1 4- 12 Inner Harbor Navigation Canal Basin Velocity Analysis Co as ta l a nd H yd ra ul ic s La bo ra to ry...library at http://acwc.sdp.sirsi.net/client/default. ERDC/CHL TR-14-12 October 2014 Inner Harbor Navigation Canal Basin Velocity Analysis...system of levees, gates, and drainage structures in the Inner Harbor Navigation Canal (IHNC) basin and the greater New Orleans, Louisiana, area. Two

  15. Bio-Inspired, Odor-Based Navigation

    Science.gov (United States)

    2006-03-01

    Bio -Inspired, Odor-Based Navigation THESIS Maynard John Porter III, Captain, USAF AFIT/GE/ENG/06-48 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR...States Government. AFIT/GE/ENG/06-48 Bio -Inspired, Odor-Based Navigation THESIS Presented to the Faculty Department of Electrical and Computer...APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT/GE/ENG/06-48 Bio -Inspired, Odor-Based Navigation Maynard John Porter III, B.S.E.E. Captain

  16. Enhancing Navigation Skills through Audio Gaming.

    Science.gov (United States)

    Sánchez, Jaime; Sáenz, Mauricio; Pascual-Leone, Alvaro; Merabet, Lotfi

    2010-01-01

    We present the design, development and initial cognitive evaluation of an Audio-based Environment Simulator (AbES). This software allows a blind user to navigate through a virtual representation of a real space for the purposes of training orientation and mobility skills. Our findings indicate that users feel satisfied and self-confident when interacting with the audio-based interface, and the embedded sounds allow them to correctly orient themselves and navigate within the virtual world. Furthermore, users are able to transfer spatial information acquired through virtual interactions into real world navigation and problem solving tasks.

  17. 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.

  18. Pre-emptive perception.

    Science.gov (United States)

    Bodis-Wollner, Ivan

    2008-01-01

    How can an action to a target be selected without yet knowing what it is? Pre-emptive perception (PEP) is a framework which orders neuronal mechanisms in association with voluntary actions before an action is started and until it is completed. It is assumed that PEP serves the purpose of perception, but a conscious, perceptual identification of the goal is not obligatorily completed during the time period of PEP itself. The concept of PEP is that the brain pre-emptively optimizes an action plan to maximize eventual perception, even before being sure what the goal is. Experimental studies of voluntary saccadic eye movements are considered as prototypic activity within the framework of PEP. The core concept of pre-emption is that a particular saccade is selected while a large number of other possible actions are deselected. Pre-emptive computations include mechanisms associated with internal context and reward. Neurophysiological studies which show anatomically and functionally separate cortical and some subcortical neuronal groups in computing saccades are summarized. There is a potential relationship of PEP as a neurobiological framework and some philosophical concepts. Terms for processes between planning and action, such as intention, anticipation, and attention, are often incongruent in everyday language and in epistemology. It is proposed here that a scrutiny of these terms can be rigorously approached by temporal subdivision of PEP and conversely, clear definitions of these terms can lead to organized experimental designs of cognitive neurobiology. The temporal subdivision of PEP allows a critique of The Will in the definition of Schopenhauer and distinguishes it from the 'free will'.

  19. 14 CFR 63.61 - Flight navigator courses.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Flight navigator courses. 63.61 Section 63...) AIRMEN CERTIFICATION: FLIGHT CREWMEMBERS OTHER THAN PILOTS Flight Navigators § 63.61 Flight navigator courses. An applicant for approval of a flight navigator course must submit a letter to the...

  20. 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...

  1. 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.

  2. 78 FR 68077 - Navigation Safety Advisory Council

    Science.gov (United States)

    2013-11-13

    ... Study (ACPARS). The Council will receive an update on the ACPARS undertaken to accommodate offshore wind..., and those expected to commence in calendar year 2014. (4) Navigation Rules Regulatory Project....

  3. Autonomous Robot Navigation based on Visual Landmarks

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    autonomous navigation and self-localization using automatically selected landmarks. The thesis investigates autonomous robot navigation and proposes a new method which benefits from the potential of the visual sensor to provide accuracy and reliability to the navigation process while relying on naturally...... update of the estimated robot position while the robot is moving. In order to make the system autonomous, both acquisition and observation of landmarks have to be carried out automatically. The thesis consequently proposes a method for learning and navigation of a working environment and it explores...... of the proposed method is based on a system with a simple setup. The novelty and potentiality, are in combining algorithms for panoramic view-synthesis, attention selection, stereo reconstruction, triangulation, optimal triplet selection, and image-based rendering. Experiments demonstrate that the system can...

  4. 5th China Satellite Navigation Conference

    CERN Document Server

    Jiao, Wenhai; Wu, Haitao; Lu, Mingquan

    2014-01-01

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

  5. Plenoptic Imager for Automated Surface Navigation Project

    Data.gov (United States)

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

  6. 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.

  7. Indoor magnetic navigation for the blind.

    Science.gov (United States)

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

    2012-01-01

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

  8. Inertial sensors for smartphones navigation.

    Science.gov (United States)

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

    2015-01-01

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

  9. Venous catheterization with ultrasound navigation

    Science.gov (United States)

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

    2015-11-01

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

  10. 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.

  11. Seamless Navigation Using Various Sensors: AN Overview of the Seamless Navigation Campaign

    Science.gov (United States)

    Nakagawa, M.; Yamada, Y.; Namie, H.; Ebinuma, T.; Kubo, N.; Kawaguchi, T.; Yoshida, M.; Yasuda, A.

    2012-07-01

    Seamless positioning techniques in indoor and outdoor environments are necessary for obtaining sensor locations. However, no definitive indoor-outdoor navigation system simultaneously provides high accuracy, high availability and low installation cost. Furthermore, crowded indoor-outdoor navigation systems consisting of multiple techniques will destructively interfere with each other, but an exclusive navigation environment will have difficulty providing stable location services for users. This anticipated issue needs to be investigated with experimental data and simulation results. However, experiments that are deliberately overcrowded with disparate location systems are rare. Therefore, the initial focus in our research was the construction of a test environment for indoor-outdoor seamless navigation experiments. Based on "Standards and Recommended Practices" (SARPs), we focused on accuracy, availability, continuity and integrity to verify the effects of seamless navigation under a combination of as many disparate systems and sensors as possible. We then conducted data acquisition and data analysis in seamless navigation through four integrated experiments. Based on the results of our experiments, we summarize some observations about seamless navigation using multiple navigation systems, and offer examples of the representative issues in our research. We also suggest some directions in indoor-outdoor navigation environment construction for seamless positioning using disparate systems and sensors.

  12. BiopSee® – transperineal stereotactic navigated prostate biopsy

    Directory of Open Access Journals (Sweden)

    Dimos Baltas

    2011-07-01

    Full Text Available In the recent years, prostate cancer was the most commonly diagnosed cancer in men. Currently secure diagnosis confirmation is done by a transrectal biopsy and following histopathological examination. Conventional transrectal biopsy success rates are rather low with ca. 30% detection upon the first and ca 20% after re-biopsy. The paper presents a novel system for stereotactic navigated prostate biopsy. The approach results into higher accuracy, reproducibility and unrestricted and effective access to all prostate regions. Custom designed ultrasound, new template design and integrated 2-axes stepper allows superior 2D and 3D prostate imaging quality and precise needle navigation. DICOM functionality and image fusion enable to import pre-operative datasets (e.g. multiparametric MRI, targets etc. and overlay all available radiological information into the biopsy planning and guiding procedure. The biopsy needle insertion itself is performed under augmented reality ultrasound guidance. Each procedure step is automatically documented in order to provide quality assurance and permit data re-usage for the further treatment. First clinical results indicates success rates of ca. 70% by first biopsies by our approach.

  13. 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

  14. 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”.

  15. Navigation System for Reusable Launch Vehicle

    OpenAIRE

    Schlotterer, Markus

    2008-01-01

    PHOENIX is a downscaled experimental vehicle to demonstrate automatic landing capabilities of future Reusable Launch Vehicles (RLVs). PHOENIX has flown in May 2004 at NEAT (North European Aerospace Test range) in Vidsel, Sweden. As the shape of the vehicle has been designed for re-entry, the dynamics are very high and almost unstable. This requires a fast and precise GNC system. This paper describes the navigation system and the navigation filter of PHOENIX. The system is introduced and the h...

  16. Navigation and Control of an Autonomous Vehicle

    OpenAIRE

    Schworer, Ian Josef

    2005-01-01

    The navigation and control of an autonomous vehicle is a highly complex task. Making a vehicle intelligent and able to operate â unmannedâ requires extensive theoretical as well as practical knowledge. An autonomous vehicle must be able to make decisions and respond to situations completely on its own. Navigation and control serves as the major limitation of the overall performance, accuracy and robustness of an autonomous vehicle. This thesis will address this problem and propose a uni...

  17. Visual navigation for an autonomous mobile vehicle

    OpenAIRE

    Peterson, Kevin Robert

    1992-01-01

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

  18. An integrated platform for inertial navigation systems

    Science.gov (United States)

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

    2015-02-01

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

  19. 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

  20. Navigation in Curved Space-Time

    CERN Document Server

    Bahder, T B

    2001-01-01

    A covariant and invariant theory of navigation in curved space-time with respect to electromagnetic beacons is written in terms of J. L. Synge's two-point invariant world function. Explicit equations are given for navigation in space-time in the vicinity of the Earth in Schwarzschild coordinates and in rotating coordinates. The restricted problem of determining an observer's coordinate time when their spatial position is known is also considered.

  1. Precise laser gyroscope for autonomous inertial navigation

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-31

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

  2. Navigation domain representation for interactive multiview imaging.

    Science.gov (United States)

    Maugey, Thomas; Daribo, Ismael; Cheung, Gene; Frossard, Pascal

    2013-09-01

    Enabling users to interactively navigate through different viewpoints of a static scene is a new interesting functionality in 3D streaming systems. While it opens exciting perspectives toward rich multimedia applications, it requires the design of novel representations and coding techniques to solve the new challenges imposed by the interactive navigation. In particular, the encoder must prepare a priori a compressed media stream that is flexible enough to enable the free selection of multiview navigation paths by different streaming media clients. Interactivity clearly brings new design constraints: the encoder is unaware of the exact decoding process, while the decoder has to reconstruct information from incomplete subsets of data since the server generally cannot transmit images for all possible viewpoints due to resource constrains. In this paper, we propose a novel multiview data representation that permits us to satisfy bandwidth and storage constraints in an interactive multiview streaming system. In particular, we partition the multiview navigation domain into segments, each of which is described by a reference image (color and depth data) and some auxiliary information. The auxiliary information enables the client to recreate any viewpoint in the navigation segment via view synthesis. The decoder is then able to navigate freely in the segment without further data request to the server; it requests additional data only when it moves to a different segment. We discuss the benefits of this novel representation in interactive navigation systems and further propose a method to optimize the partitioning of the navigation domain into independent segments, under bandwidth and storage constraints. Experimental results confirm the potential of the proposed representation; namely, our system leads to similar compression performance as classical inter-view coding, while it provides the high level of flexibility that is required for interactive streaming. Because of

  3. 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.

  4. Stereotaxy, navigation and the temporal concatenation.

    Science.gov (United States)

    Apuzzo, M L; Chen, J C

    1999-01-01

    Nautical and cerebral navigation share similar elements of functional need and similar developmental pathways. The need for orientation necessitates the development of appropriate concepts, and such concepts are dependent on technology for practical realization. Occasionally, a concept precedes technology in time and requires periods of delay for appropriate development. A temporal concatenation exists where time allows the additive as need, concept and technology ultimately provide an endpoint of elegant solution. Nautical navigation has proceeded through periods of dead reckoning and celestial navigation to satellite orientation with associated refinements of instrumentation and charts for guidance. Cerebral navigation has progressed from craniometric orientation and burr hole mounted guidance systems to simple rectolinear and arc-centered devices based on radiographs to guidance by complex anatomical and functional maps provided as an amalgam of modern imaging modes. These maps are now augmented by complex frame and frameless systems which allow not only precise orientation, but also point and volumetric action. These complex technical modalities required and developed in part from elements of maritime navigation that have been translated to cerebral navigation in a temporal concatenation.

  5. Global navigation system with RFID tags

    Science.gov (United States)

    Tsukiyama, Toshifumi

    2002-02-01

    A new navigation system is described for a mobile robot moving around in man-made environments such as hallways in a building. The system is based on a commercial three-wheel mobile platform with the addition of a Linux-based laptop computer, a Radio Frequency Identification (RDID) tag sensor and a vision system. At critical junctions such as the intersection of two passages the navigation system must identify the robot's location on a given map. We propose a method using RFID tags as landmarks. Each RFID tag has a unique ID number corresponding to its location on the map. The navigation system can decide the next movement (left-turn, right-turn and so on) toward a given goal based on this number. The navigation system also can automatically follow walls using the vision system. Since the equipment setup is very simple and the navigation system is easily combined with general mobile robot systems, our proposed technique would be useful for real-world robotic applications such as intelligent navigation for motorized wheelchairs.

  6. 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

  7. Sensor fusion for improved indoor navigation

    Science.gov (United States)

    Emilsson, Erika; Rydell, Joakim

    2012-09-01

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

  8. Unmanned vehicle mobility: Limits of autonomous navigation

    Science.gov (United States)

    McCormac, A. W.; Hanna, D. M.; McFee, J.

    Considerable research is being conducted on the development of unmanned vehicles for military and civilian applications, particularly for hostile environments. It is desirable to produce a vehicle which can select its own route, not requiring remote navigation, but then it would be required to sense its surroundings. Although imaging systems and modern computers make this possible, the extreme data processing demands usually make it impractical. It is suggested that an inverse relationship exists between vehicle mobility and the complexity of the autonomous navigation system required for an unmanned vehicle. An overview of vehicle navigation is presented which shows the degree to which navigation is affected by increasing inherent mobility. If the inherent mobility of a vehicle is greatly enhanced, the scene image processing requirements and navigational computations are greatly simplified. This means the vehicle path selection and speed and steering adjustments may be made more quickly, resulting in higher vehicle speeds whenever possible. Combined with reduced deviation from the intended path, this would greatly increase the speed of the vehicle from one given point to another, suggesting that high speed autonomous navigation may be feasible.

  9. Forty years of olfactory navigation in birds.

    Science.gov (United States)

    Gagliardo, Anna

    2013-06-15

    Forty years ago, Papi and colleagues discovered that anosmic pigeons cannot find their way home when released at unfamiliar locations. They explained this phenomenon by developing the olfactory navigation hypothesis: pigeons at the home loft learn the odours carried by the winds in association with wind direction; once at the release site, they determine the direction of displacement on the basis of the odours perceived locally and orient homeward. In addition to the old classical experiments, new GPS tracking data and observations on the activation of the olfactory system in displaced pigeons have provided further evidence for the specific role of olfactory cues in pigeon navigation. Although it is not known which odours the birds might rely on for navigation, it has been shown that volatile organic compounds in the atmosphere are distributed as fairly stable gradients to allow environmental odour-based navigation. The investigation of the potential role of olfactory cues for navigation in wild birds is still at an early stage; however, the evidence collected so far suggests that olfactory navigation might be a widespread mechanism in avian species.

  10. Fusion of Onboard Sensors for Better Navigation

    Directory of Open Access Journals (Sweden)

    Ravi Shankar

    2013-03-01

    Full Text Available This paper presents simulation results of navigation sensors such as integrated navigation system (INS, global navigation satellite system (GNSS and TACAN sensors onboard an aircraft to find the navigation solutions. Mathematical models for INS, GNSS (GPS satellite trajectories, GPS receiver and TACAN characteristics are simulated in Matlab. The INS simulation generates the output for position, velocity and attitude based on aerosond dynamic model. The GPS constellation is generated based on the YUMA almanac data. The GPS dilution of precession (DOP parameters are calculated and the best combination of four satellites (minimum PDOP is used for calculating the user position and velocity. The INS, GNSS, and TACAN solutions are integrated through loosely coupled extended Kalman filter for calculating the optimum navigation solution. The work is starting stone for providing aircraft based augmentation system for required navigation performance in terms of availability, accuracy, continuity and integrity.Defence Science Journal, 2013, 63(2, pp.145-152, DOI:http://dx.doi.org/10.14429/dsj.63.4256

  11. NFC internal: an indoor navigation system.

    Science.gov (United States)

    Ozdenizci, Busra; Coskun, Vedat; Ok, Kerem

    2015-03-27

    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.

  12. Advanced Navigation System for Aircraft Applications

    Directory of Open Access Journals (Sweden)

    G. Satheesh Reddy

    2013-03-01

    Full Text Available Various forms of navigation are present in today’s world, leading from satellite based navigation to several archaic forms of navigation like star gazing. Now, lots of technologies are available to achieve this but with certain limitations. For example, FOG based navigation provides accuracy with in 0.10-100 range which is not sufficient for various military applications. Therefore, there is a need to design a system which will have better accuracy and thus requires development of ring laser gyro-based inertial systems. This paper concentrates on the aided navigation system based on ring laser gyro of 0.01 deg/hr class and GPS - GLONASS to further enhance the capability of system in terms of accuracy. The usage of such systems not only provides accurate results momentarily but it also persists for longer duration with the aid of GPS - GLONASS for applications like aircraft, ship and long range missiles. The system provides accuracy of the level of 1 Nm/hr in pure navigation and 30 m with the aid of GPS - GLONASS. Apart from this, the availability of gyro-compass and baro-inertial algorithms further enhances the system capabilities and made them self dependent to the major extent.Defence Science Journal, 2013, 63(2, pp.131-137, DOI:http://dx.doi.org/10.14429/dsj.63.4254

  13. Patient navigation improves cancer diagnostic resolution: an individually randomized clinical trial in an underserved population.

    Science.gov (United States)

    Raich, Peter C; Whitley, Elizabeth M; Thorland, William; Valverde, Patricia; Fairclough, Diane

    2012-10-01

    Barriers to timely resolution of abnormal cancer screening tests add to cancer health disparities among low-income, uninsured, and minority populations. We conducted a randomized trial to evaluate the impact of lay patient navigators on time to resolution and completion of follow-up testing among patients with abnormal screening tests in a medically underserved patient population. Denver Health, the safety-net health care system serving Denver, is one of 10 performance sites participating in the Patient Navigation Research Program. Of 993 eligible subjects with abnormal screening tests randomized to navigation and no-navigation (control) arms and analyzed, 628 had abnormal breast screens (66 abnormal clinical breast examinations, 304 BIRADS 0, 200 BIRADS 3, 58 BIRADS 4 or 5) whereas 235 had abnormal colorectal and 130 had abnormal prostate screens. Time to resolution was significantly shorter in the navigated group (stratified log rank test, P BIRADS 3 (P = 0.0003) and BIRADS 0 (P = 0.09), but not BIRADS 4/5 or abnormal breast examinations. Navigation shortened the time for both colorectal (P = 0.0017) and prostate screening resolution (P = 0.06). Participant demographics included 72% minority, 49% with annual household income less than $10,000, and 36% uninsured. Patient navigation positively impacts time to resolution of abnormal screening tests for breast, colorectal, and prostate cancers in a medically underserved population. By shortening the time to and increasing the proportion of patients with diagnostic resolution patient navigation could reduce disparities in stage at diagnosis and improve cancer outcomes. 2012 AACR

  14. 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.

  15. Pre-Test Assessment

    Science.gov (United States)

    Berry, Thomas

    2008-01-01

    Pre-tests are a non-graded assessment tool used to determine pre-existing subject knowledge. Typically pre-tests are administered prior to a course to determine knowledge baseline, but here they are used to test students prior to topical material coverage throughout the course. While counterintuitive, the pre-tests cover material the student is…

  16. Changes in the pattern of service utilisation and health problems of women, men and various age groups following a destructive disaster : a matched cohort study with a pre-disaster assessment

    NARCIS (Netherlands)

    Soeteman, R.J.H.; Yzermans, C.J.; Spreeuwenberg, P.; Lagro-Janssen, A.L.M.; Bosch, W.J.H.M. van den; Zee, J. van der

    2008-01-01

    OBJECTIVES: Female gender and young age are known risk factors for psychological morbidity after a disaster, but this conclusion is based on studies without a pre-disaster assessment. The aim of this study in family practice was to investigate if these supposed risk factors would still occur in a

  17. Changes in the pattern of service utilisation and health problems of women, men and various age groups following a destructive disaster: a matched cohort study with a pre-disaster assessment.

    NARCIS (Netherlands)

    Soeteman, R.J.H.; Yzermans, C.J.; Spreeuwenberg, P.; Lagro-Janssen, T.L.M.; Bosch, W.J.H.M. van den; Zee, J. van der

    2008-01-01

    ABSTRACT: Objectives: Female gender and young age are known risk factors for psychological morbidity after a disaster, but this conclusion is based on studies without a pre-disaster assessment. The aim of this study in family practice was to investigate if these supposed risk factors would still

  18. Changes in the pattern of service utilisation and health problems of women, men and various age groups following a destructive disaster: A matched cohort study with a pre-disaster assessment

    NARCIS (Netherlands)

    Soeteman, R.J.H.; Yzermans, C.J.; Spreeuwenberg, P.; Lagro-Janssen, A.L.M.; Bosch, W.J.H.M. van den; Zee, J. van der

    2008-01-01

    Objectives: Female gender and young age are known risk factors for psychological morbidity after a disaster, but this conclusion is based on studies without a pre-disaster assessment. The aim of this study in family practice was to investigate if these supposed risk factors would still occur in a

  19. 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.

  20. Proximity and physical navigation in collaborative work with a multi-touch wall-display

    DEFF Research Database (Denmark)

    Jakobsen, Mikkel Rønne; Hornbæk, Kasper

    2012-01-01

    Multi-touch, wall-sized displays afford new forms of collaboration. Yet, most data on collaboration with multi-touch displays come from tabletop settings, where users often sit and where space is a limited resource. We study how two-person groups navigate in relation to a 2.8m!1.2m multi......-touch display with 24.8 megapixels and to each other when solving a sensemaking task on a document collection. The results show that users physically navigate to shift fluently among different parts of the display and between parallel and joint group work....

  1. Peer Navigators and Integrated Care to Address Ethnic Health Disparities of People with Serious Mental Illness

    Science.gov (United States)

    Corrigan, Patrick W.; Pickett, Susan; Batia, Karen; Michaels, Patrick J.

    2017-01-01

    People of color with serious mental illnesses experience high rates of morbidity and mortality. Patient navigators, developed for cancer care, may help this group benefit from integrated care. This review examined patient navigators’ key ingredients for cancer care for relevance to patients of color for application of peer services to psychiatric goals. Among cancer patients, navigators lead to greater treatment engagement and improved health outcomes for ethnic minority groups. Research also suggests peers can improve integrated care by providing effective psychiatric services to individuals with mental illness. Ongoing research examines peer navigators’ impact on integrated care for patients of color. PMID:25144699

  2. Accuracy of neuro-navigated cranial screw placement using optical surface imaging (Conference Presentation)

    Science.gov (United States)

    Jakubovic, Raphael; Gupta, Shuarya; Guha, Daipayan; Mainprize, Todd; Yang, Victor X. D.

    2017-02-01

    Cranial neurosurgical procedures are especially delicate considering that the surgeon must localize the subsurface anatomy with limited exposure and without the ability to see beyond the surface of the surgical field. Surgical accuracy is imperative as even minor surgical errors can cause major neurological deficits. Traditionally surgical precision was highly dependent on surgical skill. However, the introduction of intraoperative surgical navigation has shifted the paradigm to become the current standard of care for cranial neurosurgery. Intra-operative image guided navigation systems are currently used to allow the surgeon to visualize the three-dimensional subsurface anatomy using pre-acquired computed tomography (CT) or magnetic resonance (MR) images. The patient anatomy is fused to the pre-acquired images using various registration techniques and surgical tools are typically localized using optical tracking methods. Although these techniques positively impact complication rates, surgical accuracy is limited by the accuracy of the navigation system and as such quantification of surgical error is required. While many different measures of registration accuracy have been presented true navigation accuracy can only be quantified post-operatively by comparing a ground truth landmark to the intra-operative visualization. In this study we quantified the accuracy of cranial neurosurgical procedures using a novel optical surface imaging navigation system to visualize the three-dimensional anatomy of the surface anatomy. A tracked probe was placed on the screws of cranial fixation plates during surgery and the reported position of the centre of the screw was compared to the co-ordinates of the post-operative CT or MR images, thus quantifying cranial neurosurgical error.

  3. Surgical accuracy in high tibial osteotomy: coronal equivalence of computer navigation and gap measurement.

    Science.gov (United States)

    Schröter, S; Ihle, C; Elson, D W; Döbele, S; Stöckle, U; Ateschrang, A

    2016-11-01

    Medial opening wedge high tibial osteotomy (MOW HTO) is now a successful operation with a range of indications, requiring an individualised approach to the choice of intended correction. This manuscript introduces the concept of surgical accuracy as the absolute deviation of the achieved correction from the intended correction, where small values represent greater accuracy. Surgical accuracy is compared in a randomised controlled trial (RCT) between gap measurement and computer navigation groups. This was a prospective RCT conducted over 3 years of 120 consecutive patients with varus malalignment and medial compartment osteoarthritis, who underwent MOW HTO. All procedures were planned with digital software. Patients were randomly assigned into gap measurement or computer navigation groups. Coronal plane alignment was judged using the mechanical tibiofemoral angle (mTFA), before and after surgery. Absolute (positive) values were calculated for surgical accuracy in each individual case. There was no significant difference in the mean intended correction between groups. The achieved mTFA revealed a small under-correction in both groups. This was attributed to a failure to account for saw blade thickness (gap measurement) and over-compensation for weight bearing (computer navigation). Surgical accuracy was 1.7° ± 1.2° (gap measurement) compared to 2.1° ± 1.4° (computer navigation) without statistical significance. The difference in tibial slope increases of 2.7° ± 3.9° (gap measurement) and 2.1° ± 3.9° (computer navigation) had statistical significance (P osteotomy for individual cases. This work is clinically relevant because coronal surgical accuracy was not superior in either group. Therefore, the increased expense and surgical time associated with navigated MOW HTO is not supported, because meticulously conducted gap measurement yields equivalent surgical accuracy. I.

  4. 75 FR 50884 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector...

    Science.gov (United States)

    2010-08-18

    ... rule revises 33 CFR parts 3 and 165 to reflect changes in Coast Guard internal organizational structure..., Organizational, and Conforming Amendments, Sector Columbia River; Correction AGENCY: Coast Guard, DHS. ACTION... read ``Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector...

  5. Research on the airborne SINS/CNS integrated navigation system assisted by BD navigation system

    Science.gov (United States)

    Xie, Mei-lin; Yang, Xiao-xu; Han, Jun-feng; Wei, Yu; Yue, Peng; Deng, Xiao-guo; Huang, Wei

    2016-01-01

    When the star navigation system working during the day, the strong sky background radiation lead to a result that the detect target light is too weak, in the field of view, because of the limitation on the number of the navigation star, usually choose the single star navigation work mode. In order to improve the reliability of the airborne SINS/CNS integrated navigation system, meet the demand of the long-endurance and high precision navigation, use the tight combination way, single star patrol algorithm to get the position and attitude. There exists filtering divergence problem because of the model error and the system measurement noise is uncertain, put forward a new fuzzy adaptive kalman filtering algorithm. Adjust the size of measurement noise to prevent the filter divergence; the positioning accuracy of integrated navigation system can be improved through BeiDou satellite. Without the information of BeiDou satellite, based on the level of the virtual reference, the navigation precision of integrated navigation system can be ensured over a period of time.

  6. 77 FR 42637 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments; Corrections

    Science.gov (United States)

    2012-07-20

    ... Register of Thursday, June 21, 2012 (77 FR 37305). The regulations related to technical, organizational and... 21, 2012 (77 FR 37305), the Coast Guard published a final rule entitled ``Navigation and Navigable..., Organizational, and Conforming Amendments; Corrections AGENCY: Coast Guard, DHS. ACTION: Correcting...

  7. Target relative navigation results from hardware-in-the-loop tests using the sinplex navigation system

    NARCIS (Netherlands)

    Steffes, S.; Dumke, M.; Heise, D.; Sagliano, M.; Samaan, M.; Theil, S.; Boslooper, E.C.; Oosterling, J.A.J.; Schulte, J.; Skaborn, D.; Söderholm, S.; Conticello, S.; Esposito, M.; Yanson, Y.; Monna, B.; Stelwagen, F.; Visee, R.

    2014-01-01

    The goal of the SINPLEX project is to develop an innovative solution to significantly reduce the mass of the navigation subsystem for exploration missions which include landing and/or rendezvous and capture phases. The system mass is reduced while still maintaining good navigation performance as com

  8. Does Navigation Always Predict Performance? Effects of Navigation on Digital Reading Are Moderated by Comprehension Skills

    Science.gov (United States)

    Naumann, Johannes; Salmerón, Ladislao

    2016-01-01

    This study investigated interactive effects of navigation and offline comprehension skill on digital reading performance. As indicators of navigation, relevant page selection and irrelevant page selection were considered. In 533 Spanish high school students aged 11-17 positive effects of offline comprehension skill and relevant page selection on…

  9. Target relative navigation results from hardware-in-the-loop tests using the sinplex navigation system

    NARCIS (Netherlands)

    Steffes, S.; Dumke, M.; Heise, D.; Sagliano, M.; Samaan, M.; Theil, S.; Boslooper, E.C.; Oosterling, J.A.J.; Schulte, J.; Skaborn, D.; Söderholm, S.; Conticello, S.; Esposito, M.; Yanson, Y.; Monna, B.; Stelwagen, F.; Visee, R.

    2014-01-01

    The goal of the SINPLEX project is to develop an innovative solution to significantly reduce the mass of the navigation subsystem for exploration missions which include landing and/or rendezvous and capture phases. The system mass is reduced while still maintaining good navigation performance as com

  10. 78 FR 34293 - Regulated Navigation Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, New Orleans...

    Science.gov (United States)

    2013-06-07

    ... Navigation Canal (IHNC), the Harvey Canal, and the Algiers Canal. This action is necessary for the flood... Supplemental Notice of Proposed Rulemaking CPRA Coastal Protection Restoration Authority HSDRRS Hurricane Storm... Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey Canal, Algiers Canal, New Orleans, LA'' in the...

  11. 75 FR 32275 - Regulated Navigation Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey...

    Science.gov (United States)

    2010-06-08

    ...), Harvey Canal, and Algiers Canal during severe hurricane conditions. Vessels will not be permitted to stay... Harbor Navigation Canal, Harvey Canal, and Algiers Canal during severe hurricane conditions. Those..., Inner Harbor Navigation Canal, Harvey Canal, Algiers Canal, New Orleans, LA AGENCY: Coast Guard, DHS...

  12. 33 CFR 66.05-35 - Private aids to navigation other than State owned.

    Science.gov (United States)

    2010-07-01

    ... HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-35 Private... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Private aids to navigation other... States, shall establish, erect or maintain in State waters for private aids to navigation any aid...

  13. 33 CFR 66.01-50 - Protection of private aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State § 66.01-50 Protection of private aids to navigation. Private aids to navigation lawfully maintained under... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Protection of private aids...

  14. 33 CFR 66.05-25 - Change and modification of State aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... aids to navigation. 66.05-25 Section 66.05-25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-25 Change and modification of State aids to navigation. Wherever a State Administrator determines...

  15. Global navigation satellite system; Jisedai kokoho senjo system

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, S.; Suga, S. [Toshiba Corp., Tokyo (Japan)

    2000-05-01

    The safety of civil aviation relies on ground navigation aids. In areas where there are no ground aids and on oceanic air routes, aircraft must depend on their own navigation system. The predicted increase in civil aviation traffic in the near future will make it difficult for current navigation aids to support navigation in all phases of flights. To avoid this problem, the International Civil Aviation Organization (ICAO) is directing the establishment of standards for the global navigation satellite system (GNSS). GNSS employs navigation satellites, such as those of the global positioning system (GPS), to provide navigation capability throughout the world. In Japan, the Electronic Navigation Research Institute, the Ministry of Transport, and the Japan civil Aviation Promotion Foundation are carrying out research on this navigation system. Toshiba has been providing experimental equipment for this research. (author)

  16. 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

  17. 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.

  18. A New Electromagnetic Navigation System for Pedicle Screws Placement: A Human Cadaver Study at the Lumbar Spine.

    Directory of Open Access Journals (Sweden)

    Patrick Hahn

    Full Text Available Technical developments for improving the safety and accuracy of pedicle screw placement play an increasingly important role in spine surgery. In addition to the standard techniques of free-hand placement and fluoroscopic navigation, the rate of complications is reduced by 3D fluoroscopy, cone-beam CT, intraoperative CT/MRI, and various other navigation techniques. Another important aspect that should be emphasized is the reduction of intraoperative radiation exposure for personnel and patient. The aim of this study was to investigate the accuracy of a new navigation system for the spine based on an electromagnetic field.Twenty pedicle screws were placed in the lumbar spine of human cadavers using EMF navigation. Navigation was based on data from a preoperative thin-slice CT scan. The cadavers were positioned on a special field generator and the system was matched using a patient tracker on the spinous process. Navigation was conducted using especially developed instruments that can be tracked in the electromagnetic field. Another thin-slice CT scan was made postoperatively to assess the result. The evaluation included the position of the screws in the direction of trajectory and any injury to the surrounding cortical bone. The results were classified in 5 groups: grade 1: ideal screw position in the center of the pedicle with no cortical bone injury; grade 2: acceptable screw position, cortical bone injury with cortical penetration ≤ 2 mm; grade 3: cortical bone injury with cortical penetration 2,1-4 mm, grad 4: cortical bone injury with cortical penetration 4,1-6 mm, grade 5: cortical bone injury with cortical penetration >6 mm.The initial evaluation of the system showed good accuracy for the lumbar spine (65% grade 1, 20% grade 2, 15% grade 3, 0% grade 4, 0% grade 5. A comparison of the initial results with other navigation techniques in literature (CT navigation, 2D fluoroscopic navigation shows that the accuracy of this system is

  19. Navigated macular laser decreases retreatment rate for diabetic macular edema: a comparison with conventional macular laser

    Directory of Open Access Journals (Sweden)

    Neubauer AS

    2013-01-01

    Full Text Available Aljoscha S Neubauer,1,* Julian Langer,1,* Raffael Liegl,1 Christos Haritoglou,1 Armin Wolf,1 Igor Kozak,2 Florian Seidensticker,1 Michael Ulbig,1 William R Freeman,2 Anselm Kampik,1 Marcus Kernt,1 1Ludwig-Maximilians University, Department of Ophthalmology, Munich, Germany; 2Jacobs Retina Center, University of California San Diego, La Jolla, CA, USA*These authors contributed equally to this workBackground: The purpose of this study was to evaluate and compare clinical outcomes and retreatment rates using navigated macular laser versus conventional laser for the treatment of diabetic macular edema (DME.Methods: In this prospective, interventional pilot study, 46 eyes from 46 consecutive patients with DME were allocated to receive macular laser photocoagulation using navigated laser. Best corrected visual acuity and retreatment rate were evaluated for up to 12 months after treatment. The control group was drawn based on chart review of 119 patients treated by conventional laser at the same institutions during the same time period. Propensity score matching was performed with Stata, based on the nearest-neighbor method.Results: Propensity score matching for age, gender, baseline visual acuity, and number of laser spots yielded 28 matched patients for the control group. Visual acuity after navigated macular laser improved from a mean 0.48 ± 0.37 logMAR by a mean +2.9 letters after 3 months, while the control group showed a mean −4.0 letters (P = 0.03. After 6 months, navigated laser maintained a mean visual gain of +3.3 letters, and the conventional laser group showed a slower mean increase to +1.9 letters versus baseline. Using Kaplan-Meier analysis, the laser retreatment rate showed separation of the survival curves after 2 months, with fewer retreatments in the navigated group than in the conventional laser group during the first 8 months (18% versus 31%, respectively, P = 0.02.Conclusion: The short-term results of this pilot study suggest

  20. 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...... summary navigation models which describe user navigation in terms of XML summaries. We develop our proposal using assessments collected in the interactive track at INEX 2006. Our preliminary results suggest that summary navigation models can represent user navigation in a way that is e ective...

  1. A New Feature Points Reconstruction Method in Spacecraft Vision Navigation

    Directory of Open Access Journals (Sweden)

    Bing Hua

    2015-01-01

    Full Text Available The important applications of monocular vision navigation in aerospace are spacecraft ground calibration tests and spacecraft relative navigation. Regardless of the attitude calibration for ground turntable or the relative navigation between two spacecraft, it usually requires four noncollinear feature points to achieve attitude estimation. In this paper, a vision navigation system based on the least feature points is designed to deal with fault or unidentifiable feature points. An iterative algorithm based on the feature point reconstruction is proposed for the system. Simulation results show that the attitude calculation of the designed vision navigation system could converge quickly, which improves the robustness of the vision navigation of spacecraft.

  2. Mobile Navigation for Sport’s Pilots

    Directory of Open Access Journals (Sweden)

    Dušan Fister

    2013-06-01

    Full Text Available Today, global object-positioning is accomplished very precisely by GPS satellite technology. Access to this information is provided globally by widespread mobile devices with integrated GPS receivers from everywhere also from airplane. This paper presents a mobile device using GPS receiver to be used by mobile navigation for sports pilots. In fact, the mobile navigation is a mobile application running on Android. Thus, the current position of the airplane is indicated on the GoogleMaps and compared with the planned direction of the flight by the pilot. In addition, this mobile application could also serve flight instructors when tracking student pilots by first independent flights. The proposed solution has shown in practice to be the cheapest substitute for expensive professional navigation devices.

  3. Active-imaging-based underwater navigation

    Science.gov (United States)

    Monnin, David; Schmitt, Gwenaël.; Fischer, Colin; Laurenzis, Martin; Christnacher, Frank

    2015-10-01

    Global navigation satellite systems (GNSS) are widely used for the localization and the navigation of unmanned and remotely operated vehicles (ROV). In contrast to ground or aerial vehicles, GNSS cannot be employed for autonomous underwater vehicles (AUV) without the use of a communication link to the water surface, since satellite signals cannot be received underwater. However, underwater autonomous navigation is still possible using self-localization methods which determines the relative location of an AUV with respect to a reference location using inertial measurement units (IMU), depth sensors and even sometimes radar or sonar imaging. As an alternative or a complementary solution to common underwater reckoning techniques, we present the first results of a feasibility study of an active-imaging-based localization method which uses a range-gated active-imaging system and can yield radiometric and odometric information even in turbid water.

  4. Airborne gravimetry, altimetry, and GPS navigation errors

    Science.gov (United States)

    Colombo, Oscar L.

    1992-01-01

    Proper interpretation of airborne gravimetry and altimetry requires good knowledge of aircraft trajectory. Recent advances in precise navigation with differential GPS have made it possible to measure gravity from the air with accuracies of a few milligals, and to obtain altimeter profiles of terrain or sea surface correct to one decimeter. These developments are opening otherwise inaccessible regions to detailed geophysical mapping. Navigation with GPS presents some problems that grow worse with increasing distance from a fixed receiver: the effect of errors in tropospheric refraction correction, GPS ephemerides, and the coordinates of the fixed receivers. Ionospheric refraction and orbit error complicate ambiguity resolution. Optimal navigation should treat all error sources as unknowns, together with the instantaneous vehicle position. To do so, fast and reliable numerical techniques are needed: efficient and stable Kalman filter-smoother algorithms, together with data compression and, sometimes, the use of simplified dynamics.

  5. 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

  6. Foot mounted inertial system for pedestrian navigation

    Science.gov (United States)

    Godha, S.; Lachapelle, G.

    2008-07-01

    This paper discusses algorithmic concepts, design and testing of a system based on a low-cost MEMS-based inertial measurement unit (IMU) and high-sensitivity global positioning system (HSGPS) receivers for seamless personal navigation in a GPS signal degraded environment. The system developed here is mounted on a pedestrian shoe/foot and uses measurements based on the dynamics experienced by the inertial sensors on the user's foot. The IMU measurements are processed through a conventional inertial navigation system (INS) algorithm and are then integrated with HSGPS receiver measurements and dynamics derived constraint measurements using a tightly coupled integration strategy. The ability of INS to bridge the navigation solution is evaluated through field tests conducted indoors and in severely signal degraded forest environments. The specific focus is on evaluating system performance under challenging GPS conditions.

  7. Web Navigation Sequences Automation in Modern Websites

    Science.gov (United States)

    Montoto, Paula; Pan, Alberto; Raposo, Juan; Bellas, Fernando; López, Javier

    Most today’s web sources are designed to be used by humans, but they do not provide suitable interfaces for software programs. That is why a growing interest has arisen in so-called web automation applications that are widely used for different purposes such as B2B integration, automated testing of web applications or technology and business watch. Previous proposals assume models for generating and reproducing navigation sequences that are not able to correctly deal with new websites using technologies such as AJAX: on one hand existing systems only allow recording simple navigation actions and, on the other hand, they are unable to detect the end of the effects caused by an user action. In this paper, we propose a set of new techniques to record and execute web navigation sequences able to deal with all the complexity existing in AJAX-based web sites. We also present an exhaustive evaluation of the proposed techniques that shows very promising results.

  8. 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.

  9. 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.

  10. Website Optimization through Mining User Navigational Pattern

    CERN Document Server

    Biswal, Biswajit

    2008-01-01

    With the World Wide Web's ubiquity increase and the rapid development of various online businesses, the complexity of web sites grow. The analysis of web user's navigational pattern within a web site can provide useful information for server performance enhancements, restructuring a website and direct marketing in e-commerce etc. In this paper, an algorithm is proposed for mining such navigation patterns. The key insight is that users access information of interest and follow a certain path while navigating a web site. If they don't find it, they would backtrack and choose among the alternate paths till they reach the destination. The point they backtrack is the Intermediate Reference Location. Identifying such Intermediate locations and destinations out of the pattern will be the main endeavor in the rest of this report.

  11. Rotational and translational laxity after computer-navigated single- and double-bundle anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Hofbauer, M; Valentin, P; Kdolsky, R; Ostermann, R C; Graf, A; Figl, M; Aldrian, S

    2010-09-01

    Based on biomechanical cadaver studies, anatomic double-bundle reconstruction of the anterior cruciate ligament (ACL) was introduced to achieve better stability in the knee, particularly in respect of rotatory loads. Previously, the success of ACL reconstruction was believed to be mainly dependent on correct positioning of the graft, irrespective of the number of reconstructed bundles for which computer-assisted surgery was developed to avoid malpositioning of the tunnel. The aim of the present study is to compare rotational and translational stability after computer-navigated standard single-bundle, and anatomic double-bundle ACL reconstruction. The authors investigated 55 consecutive patients who had undergone the single-bundle or double-bundle ACL reconstruction procedure with the use of autogenous hamstring tendon grafts and EndoButton fixation, and the patients had been followed for a minimum period of 24 months. Intraoperative, anteroposterior and rotational laxity was measured with the computer navigation system, and compared between groups. Both surgical procedures significantly reduced anteroposterior displacement (AP) and internal rotation (IR) of the tibia compared to the pre-operative ACL-deficient knee (P ACL reconstruction, which is a highly accurate method of graft placement, could be useful for inexperienced surgeons to avoid malposition. Whether double-bundle ACL reconstruction, which was associated with improved rotational laxity and significantly better IKDC and Lysholm scores compared to the standard single-bundle ACL reconstruction procedure, provide an influence in terms of avoiding osteoarthritis or meniscus degeneration, long-term results of at least 5 years are needed.

  12. Indoor Pedestrian Navigation Using Foot-Mounted IMU and Portable Ultrasound Range Sensors

    Directory of Open Access Journals (Sweden)

    Stéphane Côté

    2011-08-01

    Full Text Available Many solutions have been proposed for indoor pedestrian navigation. Some rely on pre-installed sensor networks, which offer good accuracy but are limited to areas that have been prepared for that purpose, thus requiring an expensive and possibly time-consuming process. Such methods are therefore inappropriate for navigation in emergency situations since the power supply may be disturbed. Other types of solutions track the user without requiring a prepared environment. However, they may have low accuracy. Offline tracking has been proposed to increase accuracy, however this prevents users from knowing their position in real time. This paper describes a real time indoor navigation system that does not require prepared building environments and provides tracking accuracy superior to previously described tracking methods. The system uses a combination of four techniques: foot-mounted IMU (Inertial Motion Unit, ultrasonic ranging, particle filtering and model-based navigation. The very purpose of the project is to combine these four well-known techniques in a novel way to provide better indoor tracking results for pedestrians.

  13. Indoor pedestrian navigation using foot-mounted IMU and portable ultrasound range sensors.

    Science.gov (United States)

    Girard, Gabriel; Côté, Stéphane; Zlatanova, Sisi; Barette, Yannick; St-Pierre, Johanne; van Oosterom, Peter

    2011-01-01

    Many solutions have been proposed for indoor pedestrian navigation. Some rely on pre-installed sensor networks, which offer good accuracy but are limited to areas that have been prepared for that purpose, thus requiring an expensive and possibly time-consuming process. Such methods are therefore inappropriate for navigation in emergency situations since the power supply may be disturbed. Other types of solutions track the user without requiring a prepared environment. However, they may have low accuracy. Offline tracking has been proposed to increase accuracy, however this prevents users from knowing their position in real time. This paper describes a real time indoor navigation system that does not require prepared building environments and provides tracking accuracy superior to previously described tracking methods. The system uses a combination of four techniques: foot-mounted IMU (Inertial Motion Unit), ultrasonic ranging, particle filtering and model-based navigation. The very purpose of the project is to combine these four well-known techniques in a novel way to provide better indoor tracking results for pedestrians.

  14. High accuracy GNSS based navigation in GEO

    Science.gov (United States)

    Capuano, Vincenzo; Shehaj, Endrit; Blunt, Paul; Botteron, Cyril; Farine, Pierre-André

    2017-07-01

    Although significant improvements in efficiency and performance of communication satellites have been achieved in the past decades, it is expected that the demand for new platforms in Geostationary Orbit (GEO) and for the On-Orbit Servicing (OOS) on the existing ones will continue to rise. Indeed, the GEO orbit is used for many applications including direct broadcast as well as communications. At the same time, Global Navigation Satellites System (GNSS), originally designed for land, maritime and air applications, has been successfully used as navigation system in Low Earth Orbit (LEO) and its further utilization for navigation of geosynchronous satellites becomes a viable alternative offering many advantages over present ground based methods. Following our previous studies of GNSS signal characteristics in Medium Earth Orbit (MEO), GEO and beyond, in this research we specifically investigate the processing of different GNSS signals, with the goal to determine the best navigation performance they can provide in a GEO mission. Firstly, a detailed selection among different GNSS signals and different combinations of them is discussed, taking into consideration the L1 and L5 frequency bands, and the GPS and Galileo constellations. Then, the implementation of an Orbital Filter is summarized, which adaptively fuses the GN1SS observations with an accurate orbital forces model. Finally, simulation tests of the navigation performance achievable by processing the selected combination of GNSS signals are carried out. The results obtained show an achievable positioning accuracy of less than one meter. In addition, hardware-in-the-loop tests are presented using a COTS receiver connected to our GNSS Spirent simulator, in order to collect real-time hardware-in-the-loop observations and process them by the proposed navigation module.

  15. Retrosplenial Cortical Neurons Encode Navigational Cues, Trajectories and Reward Locations During Goal Directed Navigation.

    Science.gov (United States)

    Vedder, Lindsey C; Miller, Adam M P; Harrison, Marc B; Smith, David M

    2016-07-29

    The retrosplenial cortex (RSC) plays an important role in memory and spatial navigation. It shares functional similarities with the hippocampus, including the presence of place fields and lesion-induced impairments in spatial navigation, and the RSC is an important source of visual-spatial input to the hippocampus. Recently, the RSC has been the target of intense scrutiny among investigators of human memory and navigation. fMRI and lesion data suggest an RSC role in the ability to use landmarks to navigate to goal locations. However, no direct neurophysiological evidence of encoding navigational cues has been reported so the specific RSC contribution to spatial cognition has been uncertain. To examine this, we trained rats on a T-maze task in which the reward location was explicitly cued by a flashing light and we recorded RSC neurons as the rats learned. We found that RSC neurons rapidly encoded the light cue. Additionally, RSC neurons encoded the reward and its location, and they showed distinct firing patterns along the left and right trajectories to the goal. These responses may provide key information for goal-directed navigation, and the loss of these signals may underlie navigational impairments in subjects with RSC damage.

  16. Diffusive chaos in navigation satellites orbits

    CERN Document Server

    Daquin, J; Tsiganis, K

    2016-01-01

    The navigation satellite constellations in medium-Earth orbit exist in a background of third-body secular resonances stemming from the perturbing gravitational effects of the Moon and the Sun. The resulting chaotic motions, emanating from the overlapping of neighboring resonant harmonics, induce especially strong perturbations on the orbital eccentricity, which can be transported to large values, thereby increasing the collision risk to the constellations and possibly leading to a proliferation of space debris. We show here that this transport is of a diffusive nature and we present representative diffusion maps that are useful in obtaining a global comprehension of the dynamical structure of the navigation satellite orbits.

  17. 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.

  18. Navigation and control of an autonomous vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Simon, A.; Soehnitz, I.; Becker, J.C.; Schumacher, W. [Technical Univ. Braunschweig (Germany). Inst. of Control Engineering

    2000-07-01

    This paper describes the fusion of sensor data for the navigation of an autonomous vehicle as well as two lateral control concepts to track the vehicle along a desired path. The fusion of navigation data is based on information provided by multiple object-detecting sensors. The object data is fused to increase the accuracy and to obtain the vehicle's state from the relative movement w.r.t. the objects. The presented lateral control methods are an LQG/H{sub 2}-design and an input-output linearizing algorithm. These control schemes were both implemented on a test vehicle. (orig.)

  19. Evolutionary strategy for achieving autonomous navigation

    Science.gov (United States)

    Gage, Douglas W.

    1999-01-01

    An approach is presented for the evolutionary development of supervised autonomous navigation capabilities for small 'backpackable' ground robots, in the context of a DARPA- sponsored program to provide robotic support to small units of dismounted warfighters. This development approach relies on the implementation of a baseline visual serving navigation capability, including tools to support operator oversight and override, which is then enhanced with semantically referenced commands and a mission scripting structure. As current and future machine perception techniques are able to automatically designate visual serving goal points, this approach should provide a natural evolutionary pathway to higher levels of autonomous operation and reduced requirements for operator intervention.

  20. 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 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....

  1. Counterstories of College Persistence by Undocumented Mexicana Students: Navigating Race, Class, Gender, and Legal Status

    Science.gov (United States)

    Munoz, Susana Maria; Maldonado, Marta Maria

    2012-01-01

    This paper draws from four sets of four in-depth interviews and one subsequent focus group to examine how undocumented Mexicana students navigate identities and the meanings of race, gender, class, and legal status. We mobilize a critical race theory framework to center and explore the content of students' counterstories. While majoritarian…

  2. Navigating across Academic Contexts: Campo and Angolan Students in a Brazilian University

    Science.gov (United States)

    Castanheira, Maria Lucia; Street, Brian V.; Carvalho, Gilcinei Teodoro

    2015-01-01

    This paper draws on the Academic Literacies approach to examine tutor/student relations in the production of academic texts. We address issues associated with learning to write in such contexts, through exploring the perspectives of two groups of non-traditional students as they reflect on their experiences in navigating educational contexts in a…

  3. Creating design guidelines for a navigational aid for mild demented pedestrians

    NARCIS (Netherlands)

    Hagethorn, F.N.; Kröse, B.J.A.; de Greef, P.; Helmer, M.E.

    2008-01-01

    In this paper we describe our project in which we study design options for a GPS-based navigation aid for elderly with beginning dementia. In a user centered approach we first studied problems of the target group. Results were used in the design of a WoZ prototype. The method proved to work very

  4. LiAISON: Linked, Autonomous Interplanetary Satellite Orbit Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new navigation technique known as LiAISON (Linked Autonomous Interplanetary Satellite Orbit Navigation) may be used to propel the benefits of GPS to new orbits,...

  5. Wireless Cortical Brain-Machine Interface for Whole-Body Navigation in Primates

    Science.gov (United States)

    Rajangam, Sankaranarayani; Tseng, Po-He; Yin, Allen; Lehew, Gary; Schwarz, David; Lebedev, Mikhail A.; Nicolelis, Miguel A. L.

    2016-03-01

    Several groups have developed brain-machine-interfaces (BMIs) that allow primates to use cortical activity to control artificial limbs. Yet, it remains unknown whether cortical ensembles could represent the kinematics of whole-body navigation and be used to operate a BMI that moves a wheelchair continuously in space. Here we show that rhesus monkeys can learn to navigate a robotic wheelchair, using their cortical activity as the main control signal. Two monkeys were chronically implanted with multichannel microelectrode arrays that allowed wireless recordings from ensembles of premotor and sensorimotor cortical neurons. Initially, while monkeys remained seated in the robotic wheelchair, passive navigation was employed to train a linear decoder to extract 2D wheelchair kinematics from cortical activity. Next, monkeys employed the wireless BMI to translate their cortical activity into the robotic wheelchair’s translational and rotational velocities. Over time, monkeys improved their ability to navigate the wheelchair toward the location of a grape reward. The navigation was enacted by populations of cortical neurons tuned to whole-body displacement. During practice with the apparatus, we also noticed the presence of a cortical representation of the distance to reward location. These results demonstrate that intracranial BMIs could restore whole-body mobility to severely paralyzed patients in the future.

  6. Pediatric lumbar pedicle screw placement using navigation templates: A cadaveric study

    Directory of Open Access Journals (Sweden)

    Xing Wang

    2017-01-01

    Full Text Available Background: Pedicle screw technique is commonly used treatment of adult spinal trauma, tumor, degeneration. The application of pedicle screws is very challenging in children because children have a fast growing spine and spinal pedicle morphology of children and adult has large difference. 3 D reconstruction individual navigation templates improve the success rate of pediatric pedicle screw system. This study is aimed to provide a precise method for lumbar spine pedicle screw placement in children using computer-aided design and rapid prototyping technology. Materials and Methods: Computed tomography (CT scans of cadaver specimens of 4 children were obtained, and the raw data were reconstructed using three-dimensional reconstruction software. Pedicle screws were placed using the conventional method or by using individually designed navigation templates based on the principles of reverse engineering and rapid prototyping technology. Results: We evaluated the accuracy of the pedicle screws placed using the two methods by CT scan. Ten navigation templates were designed for placement of 20 lumbar pedicle screws in the navigation group, and CT scan confirmed that all the screws were placed accurately in the corresponding pedicle. Conversely, of the 20 lumbar pedicle screws placed using the conventional method, 3 screws perforated the pedicle. The findings showed that lumbar pedicle screw placement was successful using navigation templates in children. Conclusions: This technique is simple, easy to master, and allows personalized screw placement, thus providing a new and feasible method for lumbar pedicle screw placement in children.

  7. Bio-Inspired Polarized Skylight-Based Navigation Sensors: A Review

    Directory of Open Access Journals (Sweden)

    S. Zaleha M. Diah

    2012-10-01

    Full Text Available Animal senses cover a broad range of signal types and signal bandwidths and have inspired various sensors and bioinstrumentation devices for biological and medical applications. Insects, such as desert ants and honeybees, for example, utilize polarized skylight pattern-based information in their navigation activities. They reliably return to their nests and hives from places many kilometers away. The insect navigation system involves the dorsal rim area in their compound eyes and the corresponding polarization sensitive neurons in the brain. The dorsal rim area is equipped with photoreceptors, which have orthogonally arranged small hair-like structures termed microvilli. These are the specialized sensors for the detection of polarized skylight patterns (e-vector orientation. Various research groups have been working on the development of novel navigation systems inspired by polarized skylight-based navigation in animals. Their major contributions are critically reviewed. One focus of current research activities is on imitating the integration path mechanism in desert ants. The potential for simple, high performance miniaturized bioinstrumentation that can assist people in navigation will be explored.

  8. 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.

  9. Houston-Galveston Navigation Channel Shoaling Study

    Science.gov (United States)

    2014-12-01

    Inflows BUFFALO OYSTER CEDAR DICKINSON CLEAR_CRK CHOCOLATE LIVE_OAK ERDC/CHL TR-14-14 70 Wind Wind data used in the 1990 and 2000 efforts were...m) 5 Speed(avg, m/s) 5.71 Vessel Ocean Crescent; Carol Brent; Eagle Dewall; Martin Navigator; Industrial Century Type General cargo; NA; NA

  10. Indoor Autonomous Airship Control and Navigation System

    Directory of Open Access Journals (Sweden)

    Fedorenko Roman

    2016-01-01

    Full Text Available The paper presents an automatic control system for autonomous airship. The system is designed to organize autonomous flight of the mini-airship performing flight mission defined from ground control station. Structure, hardware and software implementation of indoor autonomous airship and its navigation and control system as well as experiment results are described.

  11. 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 inves

  12. '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.   

  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 thr

  14. Cameras Improve Navigation for Pilots, Drivers

    Science.gov (United States)

    2012-01-01

    Advanced Scientific Concepts Inc. (ASC), of Santa Barbara, California, received SBIR awards and other funding from the Jet Propulsion Laboratory, Johnson Space Center, and Langley Research Center to develop and refine its 3D flash LIDAR technologies for space applications. Today, ASC's NASA-derived technology is sold to assist with collision avoidance, navigation, and object tracking.

  15. The safety potential of navigation systems.

    NARCIS (Netherlands)

    Oei, H.-l.

    2002-01-01

    This study deals with the possible negative and positive effects of navigation systems on road safety. The literature shows that the human factors side is open for improvement: the design of the menu, possibility of manual programming during driving and shifting the attention of the driver from the

  16. Tactual Strip Maps as Navigational Aids.

    Science.gov (United States)

    Golledge, R. G.

    1991-01-01

    This article reviews the history and use of tactual maps by blind and visually impaired travelers. It discusses textual patterns, symbols, and graphics; differences between conventional geographic-cartographic maps and strip maps used as navigational aids; and current advances, including disposable, quick-to-produce, and easy-to-update strip maps.…

  17. Spatial abstraction for autonomous robot navigation.

    Science.gov (United States)

    Epstein, Susan L; Aroor, Anoop; Evanusa, Matthew; Sklar, Elizabeth I; Parsons, Simon

    2015-09-01

    Optimal navigation for a simulated robot relies on a detailed map and explicit path planning, an approach problematic for real-world robots that are subject to noise and error. This paper reports on autonomous robots that rely on local spatial perception, learning, and commonsense rationales instead. Despite realistic actuator error, learned spatial abstractions form a model that supports effective travel.

  18. 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...

  19. Underground navigation and localisation using RFID tags

    CSIR Research Space (South Africa)

    James, S

    2012-10-01

    Full Text Available One of the major issues in the field of mobile robotics is localisation and navigation in an unknown environment. These tasks become even more challenging in an underground environment where no GPS signals or stationary landmark towers are available...

  20. What We Can Learn from Navigation Exercises.

    Science.gov (United States)

    Covell, Geoff

    1992-01-01

    Navigation exercises in the outdoors involve interactive team skills; individual assessment of self-confidence, competence, and esteem; and leadership skills. Learning goals include planning, managing a team, handling information, allocating individual objectives, making decisions, and attending to accuracy. Provides facilitators with instructions…

  1. Navigation system for a smart wheelchair

    Institute of Scientific and Technical Information of China (English)

    BONCI Andrea; LONGHI Sauro; MONTERI(U) Andrea; VACCARINI Massimo

    2005-01-01

    Recent results on the development of a navigation system for a smart wheelchair are presented in this paper. In order to reduce the development cost, a modular solution is designed by using commercial and low cost devices. The functionalities of the tracking control system are described. Experimental results of the proposed assistive system are also presented and discussed.

  2. 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

  3. A multimodal interaction system for navigation

    NARCIS (Netherlands)

    Hofs, Dennis; Akker, op den Rieks; Nijholt, Anton; Hondorp, Hendri; Kruijff-Korbayova, I.; Kosny, C.

    2003-01-01

    To help users find their way in a virtual theatre we developed a navigation agent. In natural language dialogue the agent assists users looking for the location of an object or room, and it shows routes between locations. The speech-based dialogue system allows users to ask questions such as “Where

  4. Apparatus and method of navigating an instrument

    NARCIS (Netherlands)

    Bakker, N.H.; Den Heeten, G.J.

    2004-01-01

    An apparatus to be used with navigating an instrument in a vascular tree of a patient, comprises a patient's examination table, a C-arm, mounted to which is an X-ray source and an image recorder for registering first X-ray images of the patient, obtained by the use of the X-ray source, and a process

  5. Multimedia for mobile environment: image enhanced navigation

    Science.gov (United States)

    Gautam, Shantanu; Sarkis, Gabi; Tjandranegara, Edwin; Zelkowitz, Evan; Lu, Yung-Hsiang; Delp, Edward J.

    2006-01-01

    As mobile systems (such as laptops and mobile telephones) continue growing, navigation assistance and location-based services are becoming increasingly important. Existing technology allow mobile users to access Internet services (e.g. email and web surfing), simple multimedia services (e.g. music and video clips), and make telephone calls. However, the potential of advanced multimedia services has not been fully developed, especially multimedia for navigation or location based services. At Purdue University, we are developing an image database, known as LAID, in which every image is annotated with its location, compass heading, acquisition time, and weather conditions. LAID can be used to study several types of navigation problems: A mobile user can take an image and transmit the image to the LAID sever. The server compares the image with the images stored in the database to determine where the user is located. We refer to this as the "forward" navigation problem. The second type of problem is to provide a "virtual tour on demand". A user inputs a starting and an ending addresses and LAID retrieves the images along a route that connects the two addresses. This is a generalization of route planning. Our database currently contains over 20000 images and covers approximately 25% of the city of West Lafayette, Indiana.

  6. Magnetic Navigation in Percutaneous Cardiac Intervention

    NARCIS (Netherlands)

    M.S. Patterson (Mark)

    2010-01-01

    textabstractMagnetic navigation is the use of a magnetic fi eld to re-orientate a magnetically-enabled wire or device. The fi eld is directed by external magnets that are moved by a computercontrolled system. This technology could improve percutaneous coronary interventional procedures as it

  7. Autonomous system for cross-country navigation

    Science.gov (United States)

    Stentz, Anthony; Brumitt, Barry L.; Coulter, R. C.; Kelly, Alonzo

    1993-05-01

    Autonomous cross-country navigation is essential for outdoor robots moving about in unstructured environments. Most existing systems use range sensors to determine the shape of the terrain, plan a trajectory that avoids obstacles, and then drive the trajectory. Performance has been limited by the range and accuracy of sensors, insufficient vehicle-terrain interaction models, and the availability of high-speed computers. As these elements improve, higher- speed navigation on rougher terrain becomes possible. We have developed a software system for autonomous navigation that provides for greater capability. The perception system supports a large braking distance by fusing multiple range images to build a map of the terrain in front of the vehicle. The system identifies range shadows and interpolates undersamples regions to account for rough terrain effects. The motion planner reduces computational complexity by investigating a minimum number of trajectories. Speeds along the trajectory are set to provide for dynamic stability. The entire system was tested in simulation, and a subset of the capability was demonstrated on a real vehicle. Results to date include a continuous 5.1 kilometer run across moderate terrain with obstacles. This paper begins with the applications, prior work, limitations, and current paradigms for autonomous cross-country navigation, and then describes our contribution to the area.

  8. 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 thr

  9. Enhanced Subsea Acoustically Aided Inertial Navigation

    DEFF Research Database (Denmark)

    Jørgensen, Martin Juhl

    This thesis deals with enhancing state-of-the-art underwater acoustic–inertial navigation systems that are necessary for deep water robotic operations. Throughout the project intelligent and simple operational solutions to complex real-world problems was emphasized. Offshore hydrocarbon, oil...

  10. 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...

  11. Navigation services of the Mars Network

    Science.gov (United States)

    Ely, T. A.; Guinn, J.; Quintanilla, E.

    2003-01-01

    The Mars Network provides proximity based communications and navigation services to support Mars exploration. The network will be comprised of science orbiters with a MN relay transceiver, and potentially, dedicated telecommunication orbiters. The common MN transceiver, called Electra, is currently in deployment, and is being designed for both communications and radiometric tracking.

  12. Return Velocity and Drawdown in Navigable Waterways

    Science.gov (United States)

    1996-08-01

    I2) DRIGHT -((2 * ARIGHT) /BRIGHT) -(ONAX /2) BRRAT =BRIGHT * RAT DLRAT -DLEFT * RAT I)RRAT -DRIGHT * RAT MNAT - DRAX * RAT SELECT CASE DMRAT CASE IS...M., and Chen, Y. H. (1988). "Physical impacts of navigation on the Upper Mississippi River Systems," U.S. Army Engineer District, St. Louis , St. Louis

  13. 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…

  14. Non-Navigable Streams and Wetlands

    Science.gov (United States)

    In 2006, the US Supreme Court addressed jurisdiction of non-navigable waters and adjacent wetlands (NSW) under the Clean Water Act (CWA). The Rapanos decision resulted in two criteria for determining CWA jurisdiction of NSWs: their hydrological permanence and whether they have ...

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

    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. Wayfinding and Navigation for People with Disabilities Using Social Navigation Networks

    Directory of Open Access Journals (Sweden)

    Hassan A. Karimi

    2014-10-01

    Full Text Available To achieve safe and independent mobility, people usually depend on published information, prior experience, the knowledge of others, and/or technology to navigate unfamiliar outdoor and indoor environments. Today, due to advances in various technologies, wayfinding and navigation systems and services are commonplace and are accessible on desktop, laptop, and mobile devices. However, despite their popularity and widespread use, current wayfinding and navigation solutions often fail to address the needs of people with disabilities (PWDs. We argue that these shortcomings are primarily due to the ubiquity of the compute-centric approach adopted in these systems and services, where they do not benefit from the experience-centric approach. We propose that following a hybrid approach of combining experience-centric and compute-centric methods will overcome the shortcomings of current wayfinding and navigation solutions for PWDs.

  18. Lunar Navigator - A Miniature, Fully Autonomous, Lunar Navigation, Surveyor, and Range Finder System Project

    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...

  19. 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...

  20. Geometric Calibration of the Orion Optical Navigation Camera using Star Field Images

    Science.gov (United States)

    Christian, John A.; Benhacine, Lylia; Hikes, Jacob; D'Souza, Christopher

    2016-12-01

    The Orion Multi Purpose Crew Vehicle will be capable of autonomously navigating in cislunar space using images of the Earth and Moon. Optical navigation systems, such as the one proposed for Orion, require the ability to precisely relate the observed location of an object in a 2D digital image with the true corresponding line-of-sight direction in the camera's sensor frame. This relationship is governed by the camera's geometric calibration parameters — typically described by a set of five intrinsic parameters and five lens distortion parameters. While pre-flight estimations of these parameters will exist, environmental conditions often necessitate on-orbit recalibration. This calibration will be performed for Orion using an ensemble of star field images. This manuscript provides a detailed treatment of the theory and mathematics that will form the foundation of Orion's on-orbit camera calibration. Numerical results and examples are also presented.