WorldWideScience

Sample records for clearances navigation

  1. Structural stability and navigable clearance of anti collision device of Wanzhou Yangtze River Highway Bridge%万州长江公路大桥防撞装置结构稳定性及通航净空尺度

    Institute of Scientific and Technical Information of China (English)

    林江; 母德伟; 余葵; 刘洋; 李俊

    2013-01-01

    In order to study its navigation adaptability, the structural stability and navigation clearance of an anti-collision device of the Wanzhou Yangtze River Highway Bridge were analyzed by means of the finite element software ABAQUS and a physical model. The calculated and experimental results show that the anti-collision belt maintains the structural integrity after being hit by a ship, and the ship can pass through the bridge safely without rubbing the bridge arch. Thus, the anti-collision device of the Wanzhou Yangtze River Highway Bridge can meet the security requirements of the ship and the bridge, as well as its own, and it can provide effective protection for the reservoir bridges.%  为了研究万州长江公路大桥防撞装置的通航适应性,分别采用有限元软件ABAQUS、物理模型试验等方法对该装置的结构稳定性及通航净空进行了分析。模型计算和试验结果表明,船舶撞击防撞带后,防撞带保持了较好的完整性,船舶也未出现擦刮大桥拱圈和自身翻覆现象,满足桥、船和防撞设施“三不坏冶原则,防撞装置对大桥能进行有效地防撞保护。

  2. 33 CFR 222.3 - Clearances for power and communication lines over reservoirs.

    Science.gov (United States)

    2010-07-01

    ... be provided when relocating existing or constructing new power and communication lines over waters of... section). (e) Required clearances. Minimum vertical clearances for power and communication lines over... communication lines over reservoirs. 222.3 Section 222.3 Navigation and Navigable Waters CORPS OF...

  3. Security Clearance Tracking System

    Data.gov (United States)

    National Archives and Records Administration — SCTS supports the adjudication process of private background investigations and clearances for potential employees, contractors, interns and student workers.

  4. Generic Clearance Values

    International Nuclear Information System (INIS)

    This paper analyzes the Generic Clearance Values established for natural and artificial radionuclides with the objective of evaluating their degree of conservatism in views of adopting them into the regulatory body. Generic clearance values for natural radionuclides have been chosen by experts judgments as the optimum boundary between, on the one hand, the ubiquitous unmodified soil concentrations and, on the other hand, activity concentrations in ores, mineral sands, industrial residues and wastes. For artificial radionuclides the clearance levels have been derived from the scenarios postulated in the document Safety Reports Series 44 of the IAEA considering quantitative exemption criteria. A set of 8 scenarios were postulated covering external, ingestion and inhalation exposure pathways. For each radionuclide, the generic clearance level was derived as the more restrictive value obtained from the scenarios, that is the lowest ratio between the applicable individual dose and the dose per unit activity concentration (Bq/g). The individual dose was calculated by a formula depending on each scenario and pathway, with different parameters, such as exposure time, dosimetric factors, dilution factor, density of the material, geometric factors, etc. It was concluded that the basis and parameters used for the derivation of the generic clearance levels are quite conservative and therefore its the adoption in Argentina has been recommended. It is expected that their implementation will contribute to optimize the regulatory management system. (authors)

  5. Ecodesign Navigator

    DEFF Research Database (Denmark)

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

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

  6. Mucociliary clearance in chronic sinusitis

    OpenAIRE

    Birdi, Surinder Mohan; Singh, Sunder; Singh, Ajit

    1998-01-01

    Mucociliary clearance is an important defence mechanism of upper and lower respiratory tracts. Any disturbance in the mechanism leads to stagnation of secretions and secondary infection with prolonged mucociliary clearance time. The present study was undertaken to establish normal mucociliary clearance time in our region and to evaluate its diagnostic and prognostic potential in chronic sinusitis of variable duration with and without obstructive diseases.

  7. Site clearance working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The Gulf of Mexico and Louisiana continue to be areas with a high level of facility removal, and the pace of removal is projected to increase. Regulations were promulgated for the Gulf of Mexico and Louisiana requiring that abandoned sites be cleared of debris that could interfere with fishing and shrimping activities. The site clearance regulations also required verification that the sites were clear. Additionally, government programs were established to compensate fishermen for losses associated with snagging their equipment on oil and gas related objects that remained on the water bottoms in areas other than active producing sites and sites that had been verified as clear of obstructions and snags. The oil and gas industry funds the compensation programs. This paper reviews the regulations and evolving operating practices in the Gulf of Mexico and Louisiana where site clearance and fisherman`s gear compensation regulations have been in place for a number of years. Although regulations and guidelines may be in place elsewhere in the world, this paper focuses on the Gulf of Mexico and Louisiana. Workshop participants are encouraged to bring up international issues during the course of the workshop. Additionally, this paper raises questions and focuses on issues that are of concern to the various Gulf of Mexico and Louisiana water surface and water bottom stakeholders. This paper does not have answers to the questions or issues. During the workshop participants will debate the questions and issues in an attempt to develop consensus opinions and/or make suggestions that can be provided to the appropriate organizations, both private and government, for possible future research or policy adjustments. Site clearance and facility removal are different activities. Facility removal deals with removal of the structures used to produce oil and gas including platforms, wells, casing, piles, pipelines, well protection structures, etc.

  8. 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...

  9. Robotic Mounted Detection System: robotics for route clearance

    Science.gov (United States)

    Hutchison, John; Klager, Gene; McCoy, Edward; Fite, David; Frederick, Brian

    2010-04-01

    Robotic Mounted Detection System (RMDS) is a government program to enable robotic control of a Husky route clearance vehicle with a mine detection sensor payload. The goal is for the operator to control the Husky and mine detection sensor from another vehicle. This program will provide the user with standard tele-operation control of the vehicle as well as semi-autonomous modes including cruise control, precision waypoint navigation with operator error correction and a visual mode allowing the operator to enter waypoints in the current video feed. The use of autonomy will be tailored to give the operator maximum control of the robotic vehicle's path while minimizing the effort required to maintain the desired route. Autonomous alterations of the path would conflict with the goal of route clearance, so waypoint navigation will allow the operator to supply offsets to counteract location errors. While following a waypoint path, the Husky will be capable of controlling its speed to maintain an operator specified distance from the control vehicle. Obstacle avoidance will be limited to protecting the mine detection sensor, leaving any decision to leave the path up to the operator. Video will be the primary navigational sensor feed to the operator, who will use an augmented steering wheel controller and computer display to control the Husky. A LADAR system will be used to detect obstacles that could damage the mine sensor and to maintain the optimal sensor orientation while the vehicle is moving. Practical issues and lessons learned during integration will be presented.

  10. Universal navigation on smartphones

    CERN Document Server

    Karimi, Hassan A

    2011-01-01

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

  11. 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.

  12. Lithium clearance in chronic nephropathy

    DEFF Research Database (Denmark)

    Kamper, A L; Holstein-Rathlou, N H; Leyssac, P P;

    1989-01-01

    1. Lithium clearance measurements were made in 72 patients with chronic nephropathy of different aetiology and moderate to severely reduced renal function. 2. Lithium clearance was strictly correlated with glomerular filtration rate, and there was no suggestion of distal tubular reabsorption of...... lithium or influence of osmotic diuresis. 3. Fractional reabsorption of lithium was reduced in most patients with glomerular filtration rates below 25 ml/min. 4. Calculated fractional distal reabsorption of sodium was reduced in most patients with glomerular filtration rates below 50 ml/min. 5. Lithium...... lithium clearance may be a measure of the delivery of sodium and water from the renal proximal tubule. With this assumption it was found that adjustment of the sodium excretion in chronic nephropathy initially takes place in the distal parts of the nephron (loop of Henle, distal tubule and collecting duct...

  13. Lactate clearance in cardiorespiratory emergency

    Directory of Open Access Journals (Sweden)

    Serena Greco

    2007-08-01

    Full Text Available Early goal directed therapy has been found to improve prognosis in septic patients, if the therapeutic goal is achieved within the first six hours. The aim of our study is to demonstrate that in patients with acute cardiorespiratory failure, rapid (within 2 hours lactate clearance can help define patients’ prognosis. 67 consecutive patients, admitted to our 16-bed Emergency Medicine ward for acute cardiorespiratory failure (age 75,9 ± 9,8 (APACHE II score 19,0 ± 4,1, were included in the study. Blood lactate concentration was read at admission and after 2, 6 and 24 hours. We evaluated mortality at seven days and the use of orotracheal intubation (patients with negative outcome vs. discharge or transfer to a non-emergency ward with subsequent discharge (patients with negative outcome. Lactate concentration at admission was 4,6 ± 2,5 mmol/l; lactate clearance (% at 2 hours was 40,4 ± 32,1 in patients with a positive outcome and –8,3 ± 5,0 in patients with a negative outcome (p < 0,05. Lactate clearance at 2 hours < 25% is correlated to a negative outcome with an 84,2% sensitivity and a 79,2% specificity. The positive predictive value was 61,5% and the negative predictive value was 92,2%. Systematic lactate clearance monitoring can be used in cases of acute cardiorespiratory insufficiency to identify patients with a high risk of negative outcome. In our study, low clearance at two hours was associated with an increase in mortality and/or the need for orotracheal intubation. Conversely, a clearance at two hours of > 25% in most cases confirms the therapeutic strategy undertaken. Serial evaluation of blood lactate concentration may therefore be useful in guiding treatment strategies.

  14. Noninvasive clearance of airway secretions.

    Science.gov (United States)

    Hardy, K A; Anderson, B D

    1996-06-01

    Airway clearance techniques are indicated for specific diseases that have known clearance abnormalities (Table 2). Murray and others have commented that such techniques are required only for patients with a daily sputum production of greater than 30 mL. The authors have observed that patients with diseases known to cause clearance abnormalities can have sputum clearance with some techniques, such as positive expiratory pressure, autogenic drainage, and active cycle of breathing techniques, when PDPV has not been effective. Hasani et al has shown that use of the forced exhalatory technique in patients with nonproductive cough still resulted in movement of secretions proximally from all regions of the lung in patients with airway obstruction. It is therefore reasonable to consider airway clearance techniques for any patient who has a disease known to alter mucous clearance, including CF, dyskinetic cilia syndromes, and bronchiectasis from any cause. Patients with atelectasis from mucous plugs and hypersecretory states, such as asthma and chronic bronchitis, patients with pain secondary to surgical procedures, and patients with neuromuscular disease, weak cough, and abnormal patency of the airway may also benefit from the application of airway clearance techniques. Infants and children up to 3 years of age with airway clearance problems need to be treated with PDPV. Manual percussion with hands alone or a flexible face mask or cup and small mechanical vibrator/percussors, such as the ultrasonic devices, can be used. The intrapulmonary percussive ventilator shows growing promise in this area. The high-frequency oscillator is not supplied with vests of appropriate sizes for tiny babies and has not been studied in this group. Young patients with neuromuscular disease may require assisted ventilation and airway oscillations can be applied. CPAP alone has been shown to improve achievable flow rates that will increase air-liquid interactions for patients with these diseases

  15. 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...

  16. 49 CFR 192.325 - Underground clearance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Underground clearance. 192.325 Section 192.325... Lines and Mains § 192.325 Underground clearance. (a) Each transmission line must be installed with at least 12 inches (305 millimeters) of clearance from any other underground structure not associated...

  17. 30 CFR 18.24 - Electrical clearances.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electrical clearances. 18.24 Section 18.24... APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.24 Electrical clearances. Minimum clearances between uninsulated electrical...

  18. 14 CFR 25.925 - Propeller clearance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller clearance. 25.925 Section 25.925 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.925 Propeller clearance. Unless smaller clearances are substantiated,...

  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. Research on Web Navigations

    Directory of Open Access Journals (Sweden)

    Qian Zhongsheng

    2011-10-01

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

  1. Navigating the Internet.

    OpenAIRE

    Powsner, S M; Roderer, N K

    1994-01-01

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

  2. 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.

  3. Navigation Using Inertial Sensors

    OpenAIRE

    Groves, P. D.

    2015-01-01

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

  4. Mobile Robot Navigation

    DEFF Research Database (Denmark)

    Andersen, Jens Christian

    2007-01-01

    . The research is now progressing towards autonomous robots which will be able to assist us in our daily life. One of the enabling technologies is navigation, and navigation is the subject of this thesis. Navigation of an autonomous robot is concerned with the ability of the robot to direct itself from....... The perception of these two sensors are utilised by a path planner to allow a number of drive modes, and especially the ability to follow road edges are investigated. The navigation mission is controlled by a script language. The navigation script controls route sequencing, junction detection, junction crossing......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...

  5. Navigation lights color study

    Science.gov (United States)

    Barbosa, Jose G.; Alberg, Matthew T.

    2015-05-01

    The chromaticity of navigation lights are defined by areas on the International Commission on Illumination (CIE) 1931 chromaticity diagram. The corner coordinates for these areas are specified in the International Regulations for Prevention of Collisions at Sea, 1972 (72 COLREGS). The navigation light's color of white, red, green, and yellow are bounded by these areas. The chromaticity values specified by the COLREGS for navigation lights were intended for the human visual system (HVS). The HVS can determine the colors of these lights easily under various conditions. For digital color camera imaging systems the colors of these lights are dependent on the camera's color spectral sensitivity, settings, and color correction. At night the color of these lights are used to quickly determine the relative course of vessels. If these lights are incorrectly identified or there is a delay in identifying them this could be a potential safety of ship concern. Vessels that use camera imaging systems exclusively for sight, at night, need to detect, identify, and discriminate navigation lights for navigation and collision avoidance. The introduction of light emitting diode (LED) lights and lights with different spectral signatures have the potential to be imaged very differently with an RGB color filter array (CFA) color camera than with the human eye. It has been found that some green navigation lights' images appear blue verse green. This has an impact on vessels that use camera imaging systems exclusively for navigation. This paper will characterize color cameras ability to properly reproducing navigation lights' color and survey a set of navigation light to determine if they conform to the COLREGS.

  6. The attack navigator

    DEFF Research Database (Denmark)

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

    2016-01-01

    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......-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....

  7. 19 CFR 122.77 - Clearance certificate.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Clearance certificate. 122.77 Section 122.77 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Documents Required for Clearance and Permission To Depart;...

  8. 14 CFR 23.925 - Propeller clearance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller clearance. 23.925 Section 23.925 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant General § 23.925 Propeller clearance. Unless...

  9. 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...

  10. 19 CFR 4.66b - Pollution of coastal and navigable waters.

    Science.gov (United States)

    2010-04-01

    ... shorelines, or into or upon the waters of the contiguous zone in violation of the Federal Water Pollution... 19 Customs Duties 1 2010-04-01 2010-04-01 false Pollution of coastal and navigable waters. 4.66b...; DEPARTMENT OF THE TREASURY VESSELS IN FOREIGN AND DOMESTIC TRADES Foreign Clearances § 4.66b Pollution...

  11. SKIN KINETICS AND DERMAL CLEARANCE

    Directory of Open Access Journals (Sweden)

    Prakash Shashi

    2012-08-01

    Full Text Available Availability of several therapeutic and cosmetic formulations for topical application has made the research on skin kinetics as a topic of current interest. Topical formulations are typically meant for local effect although there is always a chance that the low molecular weight chemicals are easily transported across the skin layer and make it available in the systemic circulation. Thus there is a major concern about the transport of chemical moieties following the topical application of cosmetics and therapeutic formulations and the real time measurement of the molecules in the skin layer has become obligatory. It is well known that the properties of both drug and the excipients have identical role in determining the skin permeability of chemical moieties. In the last decade several investigations have been carried out in this filed using several in vitro and in vivo models. This review provides a brief account on the basics of skin kinetics, parameters assessed, various techniques and methods adapted in skin kinetic studies. Moreover, we have also discussed about the micro-environment inside the skin layer and the possible mechanism of drug depot formation, skin metabolism and clearance of molecules from the skin layers.

  12. Nucleotide-mediated airway clearance.

    Science.gov (United States)

    Schmid, Andreas; Clunes, Lucy A; Salathe, Mathias; Verdugo, Pedro; Dietl, Paul; Davis, C William; Tarran, Robert

    2011-01-01

    A thin layer of airway surface liquid (ASL) lines the entire surface of the lung and is the first point of contact between the lung and the environment. Surfactants contained within this layer are secreted in the alveolar region and are required to maintain a low surface tension and to prevent alveolar collapse. Mucins are secreted into the ASL throughout the respiratory tract and serve to intercept inhaled pathogens, allergens and toxins. Their removal by mucociliary clearance (MCC) is facilitated by cilia beating and hydration of the ASL by active ion transport. Throughout the lung, secretion, ion transport and cilia beating are under purinergic control. Pulmonary epithelia release ATP into the ASL which acts in an autocrine fashion on P2Y(2) (ATP) receptors. The enzymatic network describes in Chap. 2 then mounts a secondary wave of signaling by surface conversion of ATP into adenosine (ADO), which induces A(2B) (ADO) receptor-mediated responses. This chapter offers a comprehensive description of MCC and the extensive ramifications of the purinergic signaling network on pulmonary surfaces. PMID:21560046

  13. 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

  14. 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,...

  15. Deposition of aerosols and bronchial clearance measurements

    International Nuclear Information System (INIS)

    A special inhalative device is described for reproducible deposition patterns of radioactive aerosols to measure mucociliary and tussive clearance and to evaluate the effect of drugs on the bronchial tree is described. Additive actions on mucus transport exist between β2-agonists and theophylline, but not incombination with inhalative quarternary ammonium compounds (ipatropium and oxitropium bromide). Mucolytics are generally less effective on mucociliary clearance than β2-agonists and theophylline, positive, negative and nonresponders are ofter seen due to the different viscoelastic properties of the mucus. Mucus transport is more than mucociliary clearance. Two-phase gas/liquid movement and coughing are also important transport mechanisms for bronchial mucus. Therefore, bronchodilators enhance mucus transport by increasing airway patency, which increases total and regional air flow and improves cough clearance. (orig.)

  16. Plasma Creatinine Clearance in the Dog

    Science.gov (United States)

    Frazier, Loy W.

    1977-01-01

    Lists materials and methods for an experiment that demonstrates the concept of glomerular filtration rate (GFR) using anesthesized dogs. In the dog, GFR is equivalent to the renal plasma clearance of exogenous creatinine. (CS)

  17. 48 CFR 801.602-76 - Business clearance review.

    Science.gov (United States)

    2010-10-01

    ... obtain a business clearance review prior to award of any contract, task or delivery order, or blanket... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Business clearance review... Authority, and Responsibilities 801.602-76 Business clearance review. (a) A business clearance review is...

  18. Lower metabolic clearance of tizanidine in Japanese subjects.

    Science.gov (United States)

    Momo, Kenji; Homma, Masato; Kohda, Yukinao

    2013-12-01

    Our aim was to determine whether metabolic clearance, renal clearance, or both elimination pathways contribute to ethnic differences in tizanidine clearance, which is ~ 2-fold higher in Caucasians than in Asians. The pharmacokinetic parameters of tizanidine in 9 healthy male Japanese subjects were compared with those of Caucasians in previous studies. Metabolic clearance of tizanidine was lower in Japanese than in Caucasian subjects (5.9 vs. 8.1 - 10.9 l/h/kg), although renal clearances were similar (0.040 vs. 0.047 - 0.055 l/h/kg). The results suggest that ethnic differences in tizanidine clearance are due to differences in metabolic clearance.

  19. 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...

  20. 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,...

  1. Mobile Robot Navigation

    OpenAIRE

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

    2007-01-01

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

  2. Navigational Query Languages

    OpenAIRE

    Surinx, Dimitri

    2013-01-01

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

  3. 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.

  4. Navigating stories in films

    OpenAIRE

    Salway, Andrew; Xu, Yan

    2005-01-01

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

  5. 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”.

  6. Navigation in virtual environments

    Science.gov (United States)

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

    1996-06-01

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

  7. 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.

  8. Pharmacologic agents for mucus clearance in bronchiectasis.

    Science.gov (United States)

    Nair, Girish B; Ilowite, Jonathan S

    2012-06-01

    There are no approved pharmacologic agents to enhance mucus clearance in non-cystic fibrosis (CF) bronchiectasis. Evidence supports the use of hyperosmolar agents in CF, and studies with inhaled mannitol and hypertonic saline are ongoing in bronchiectasis. N-acetylcysteine may act more as an antioxidant than a mucolytic in other lung diseases. Dornase α is beneficial to patients with CF, but is not useful in patients with non-CF bronchiectasis. Mucokinetic agents such as β-agonists have the potential to improve mucociliary clearance in normals and many disease states, but have not been adequately studied in patients with bronchiectasis.

  9. Pharmacologic agents for mucus clearance in bronchiectasis.

    Science.gov (United States)

    Nair, Girish B; Ilowite, Jonathan S

    2012-06-01

    There are no approved pharmacologic agents to enhance mucus clearance in non-cystic fibrosis (CF) bronchiectasis. Evidence supports the use of hyperosmolar agents in CF, and studies with inhaled mannitol and hypertonic saline are ongoing in bronchiectasis. N-acetylcysteine may act more as an antioxidant than a mucolytic in other lung diseases. Dornase α is beneficial to patients with CF, but is not useful in patients with non-CF bronchiectasis. Mucokinetic agents such as β-agonists have the potential to improve mucociliary clearance in normals and many disease states, but have not been adequately studied in patients with bronchiectasis. PMID:22640851

  10. 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... ADMINISTRATIVE PROCEDURE § 209.325 Navigation lights, aids to navigation, navigation charts, and related data... procedure to be used by all Corps of Engineers installations and activities in connection with aids...

  11. Clinical evaluation of amylase-creatinine clearance ratio and amylase isoenzyme clearance in chronic renal failure.

    Science.gov (United States)

    Maeda, M; Otsuki, M; Okano, K; Yamasaki, T; Baba, S

    1981-01-01

    Amylase-creatinine clearance ratio (ACCR) and amylase isoenzyme clearance were determined simultaneously in patients with chronic renal failure. ACCR in patients with compensated renal failure (3.5 +/- 0.4%) was not significantly different from normals (2.6 +/- 0.2%), while that in patients with non-compensated renal failure (6.7 +/- 0.4%) was significantly higher than that in normals. Clearance ratio of pancreatic isoamylase (Amylase-1) relative to creatinine clearance (CAmy . 1/Ccr) in patients with both compensated (5.9 +/- 1.0%) and non-compensated (6.8 +/- 0.4%) renal failure was as high as that in patients with acute pancreatitis (6.6 +/- 0.5%). On the other hand, clearance ratio of salivary isoamylase (Amylase-3) relative to creatinine clearance (CAmy . 3/CCr) in patients with compensated renal failure (1.5 +/- 0.3%) was almost the same as that in normals (2.1 +/- 0.1%), while that in patients with non-compensated renal failure was 5.9 +/- 0.7%, which was significantly higher than that in normals. The present study revealed that elevated ACCR in patients with severely impaired renal function was due to the increase of the clearance ratio for both pancreatic and salivary amylase. These facts suggested that glomerular permeability and tubular reabsorption for pancreatic and salivary amylase might play an important role on ACCR in patients with severely impaired renal function.

  12. Clinical evaluation of amylase-creatinine clearance ratio and amylase isoenzyme clearance in chronic renal failure.

    Science.gov (United States)

    Maeda, M; Otsuki, M; Okano, K; Yamasaki, T; Baba, S

    1981-01-01

    Amylase-creatinine clearance ratio (ACCR) and amylase isoenzyme clearance were determined simultaneously in patients with chronic renal failure. ACCR in patients with compensated renal failure (3.5 +/- 0.4%) was not significantly different from normals (2.6 +/- 0.2%), while that in patients with non-compensated renal failure (6.7 +/- 0.4%) was significantly higher than that in normals. Clearance ratio of pancreatic isoamylase (Amylase-1) relative to creatinine clearance (CAmy . 1/Ccr) in patients with both compensated (5.9 +/- 1.0%) and non-compensated (6.8 +/- 0.4%) renal failure was as high as that in patients with acute pancreatitis (6.6 +/- 0.5%). On the other hand, clearance ratio of salivary isoamylase (Amylase-3) relative to creatinine clearance (CAmy . 3/CCr) in patients with compensated renal failure (1.5 +/- 0.3%) was almost the same as that in normals (2.1 +/- 0.1%), while that in patients with non-compensated renal failure was 5.9 +/- 0.7%, which was significantly higher than that in normals. The present study revealed that elevated ACCR in patients with severely impaired renal function was due to the increase of the clearance ratio for both pancreatic and salivary amylase. These facts suggested that glomerular permeability and tubular reabsorption for pancreatic and salivary amylase might play an important role on ACCR in patients with severely impaired renal function. PMID:6167484

  13. 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.

  14. Control algorithms for autonomous robot navigation

    International Nuclear Information System (INIS)

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

  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. Uptake and clearance of uranium by misgurnus

    International Nuclear Information System (INIS)

    The author studied the bioconcentration and clearance of uranium in misgurnus and determined bioconcentration factors (BCF) as well as uptake and depuration rate constants. The test was performed under semi-static conditions. The depuration of uranium was best described by a two-compartment first order kinetic model

  17. 32 CFR 154.16 - Security clearance.

    Science.gov (United States)

    2010-07-01

    ... requirements for clearance—(1) Top Secret. (i) Final Clearance: (A) BI. (B) Established billet per § 154.13(e... initiated (D) Favorable review of local personnel, base/military police, medical, and other security records...) Provisions of paragraph § 154.14(e) (1) and (2) have been met regarding civilian personnel. (2) Secret....

  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. Navigating Hypermasculine Terrains

    DEFF Research Database (Denmark)

    Henriksen, Ann-Karina Eske

    2015-01-01

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

  1. Dynamics modeling and simulation of mechanism with joint clearance

    Institute of Scientific and Technical Information of China (English)

    BAI Zheng-feng; TIAN Hao; ZHAO Yang

    2010-01-01

    The existence of clearance in the joints of mechanisms system is inevitable.The movements of the real mechanism are deftection from the ideal mechanism due to the clearances and the motion accuracv is decreased.The effects of the hinge clearance on the crank and rocker mechanism system are studied.The svstem dynamics equation with clearance is presented.The contact dynamics model is established using the nonlinear equivalent spring-damp model and the friction effect is considered by using Coulomb friction model.Then the models are incorporated into ADAMS,and based on the model,large numbers numeric simulations are made.The regularity of contact forces in clearance are studied in detail.And the effects of clearance size.clearance friction on the mechanism dynamics characteristic are analyzed.The simulation resuhs Can predict the effects of clearance on the mechanism dynamics characteristic preferably.

  2. 19 CFR 122.26 - Entry and clearance.

    Science.gov (United States)

    2010-04-01

    ... AIR COMMERCE REGULATIONS Private Aircraft § 122.26 Entry and clearance. Private aircraft, as defined... information as set forth in § 122.22(c), and grants electronic clearance via electronic mail or telephone....

  3. 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.

  4. 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

  5. Diminished creatinine clearance in anorexia nervosa: reversal with weight gain.

    OpenAIRE

    Boag, F.; Weerakoon, J; Ginsburg, J; Havard, C W; Dandona, P

    1985-01-01

    To assess whether patients with anorexia nervosa have abnormalities in creatinine clearance, we measured plasma creatinine concentration, urinary creatinine excretion, and creatinine clearance in 10 patients with anorexia nervosa before and during treatment. Urinary creatinine excretion and creatinine clearance were diminished in all patients. Nine patients had significant decreases in their plasma creatinine and creatinine clearance was increased even when corrected for body weight and body ...

  6. Wear analysis of revolute joints with clearance in multibody systems

    Science.gov (United States)

    Bai, ZhengFeng; Zhao, Yang; Wang, XingGui

    2013-08-01

    In this work, the prediction of wear for revolute joint with clearance in multibody systems is investigated using a computational methodology. The contact model in clearance joint is established using a new hybrid nonlinear contact force model and the friction effect is considered by using a modified Coulomb friction model. The dynamics model of multibody system with clearance is established using dynamic segmentation modeling method and the computational process for wear analysis of clearance joint in multibody systems is presented. The main computational process for wear analysis of clearance joint includes two steps, which are dynamics analysis and wear analysis. The dynamics simulation of multibody system with revolute clearance joint is carried out and the contact forces are drawn and used to calculate the wear amount of revolute clearance joint based on the Archard's wear model. Finally, a four-bar multibody mechanical system with revolute clearance joint is used as numerical example application to perform the simulation and show the dynamics responses and wear characteristics of multibody systems with revolute clearance joint. The main results of this work indicate that the contact between the joint elements is wider and more frequent in some specific regions and the wear phenomenon is not regular around the joint surface, which causes the clearance size increase non-regularly after clearance joint wear. This work presents an effective method to predict wear of revolute joint with clearance in multibody systems.

  7. 10 CFR 706.31 - Clearance of conciliators and arbitrators.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Clearance of conciliators and arbitrators. 706.31 Section... RELATIONS Contract Negotiation and Administration § 706.31 Clearance of conciliators and arbitrators. Conciliators and arbitrators who are regularly assigned to DOE cases may be processed for “Q” clearance at...

  8. Guangzhou Customs Guide to Clearance of Import/Export Goods

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Management of the Enterprises Granted for Convenient and Quick Customs Clearance 1.What is the enterprise granted for convenient and quick customs clearance? Customs General Administration and the Ministry of Foreign Trade and Economic Cooperation jointly issued policy measures to facilitate customs clearance in 2001 to further support the development of hightech industries.The enterprise .

  9. 14 CFR 1260.63 - Customs clearance and visas.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Customs clearance and visas. 1260.63 Section 1260.63 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GRANTS AND COOPERATIVE AGREEMENTS General Special Conditions § 1260.63 Customs clearance and visas. Customs Clearance and Visas...

  10. 14 CFR 27.661 - Rotor blade clearance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor blade clearance. 27.661 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure...

  11. 14 CFR 29.661 - Rotor blade clearance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor blade clearance. 29.661 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.661 Rotor blade clearance. There must be enough clearance between the rotor blades and other parts of the structure...

  12. 32 CFR 644.517 - Clearance of Army lands.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Clearance of Army lands. 644.517 Section 644.517 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL... and Improvements § 644.517 Clearance of Army lands. The responsibility for performing clearance...

  13. Glial K(+) Clearance and Cell Swelling

    DEFF Research Database (Denmark)

    Macaulay, Nanna; Zeuthen, Thomas

    2012-01-01

    An important feature of neuronal signalling is the increased concentration of K(+) in the extracellular space. The K(+) concentration is restored to its original basal level primarily by uptake into nearby glial cells. The molecular mechanisms by which K(+) is transferred from the extracellular...... space into the glial cell are debated. Although spatial buffer currents may occur, their quantitative contribution to K(+) clearance is uncertain. The concept of spatial buffering of K(+) precludes intracellular K(+) accumulation and is therefore (i) difficult to reconcile with the K(+) accumulation...... repeatedly observed in glial cells during K(+) clearance and (ii) incompatible with K(+)-dependent glial cell swelling. K(+) uptake into non-voltage clamped cultured glial cells is carried out by the Na(+)/K(+)-ATPase and the Na(+)/K(+)/Cl(-) cotransporter in combination. In brain slices and intact optic...

  14. ADSORBENTS USED IN THE CLEARANCE OF ENDOTOXIN

    Institute of Scientific and Technical Information of China (English)

    YU Mei; LIU Tao; Hou Guanghui; YUAN Zhi

    2003-01-01

    A series of modified poly (methyl methacrylate, PMMA) resins were prepared and compared their adsorption abilities to endotoxin. The results showed that adsorbents, which were grafted with tertiary amine and long spacing arms, had the best adsorption capacities and good blood compatibility, It is hopeful to be used as adsorbent in hemoperfusion for clinical clearance of endotoxin. The influence of original concentration of endotoxin on adsorption and the adsorption mechanism were also investigated.

  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. Airway Clearance Devices for Cystic Fibrosis

    Science.gov (United States)

    2009-01-01

    Executive Summary Objective The purpose of this evidence-based analysis is to examine the safety and efficacy of airway clearance devices (ACDs) for cystic fibrosis and attempt to differentiate between devices, where possible, on grounds of clinical efficacy, quality of life, safety and/or patient preference. Background Cystic fibrosis (CF) is a common, inherited, life-limiting disease that affects multiple systems of the human body. Respiratory dysfunction is the primary complication and leading cause of death due to CF. CF causes abnormal mucus secretion in the airways, leading to airway obstruction and mucus plugging, which in turn can lead to bacterial infection and further mucous production. Over time, this almost cyclical process contributes to severe airway damage and loss of respiratory function. Removal of airway secretions, termed airway clearance, is thus an integral component of the management of CF. A variety of methods are available for airway clearance, some requiring mechanical devices, others physical manipulation of the body (e.g. physiotherapy). Conventional chest physiotherapy (CCPT), through the assistance of a caregiver, is the current standard of care for achieving airway clearance, particularly in young patients up to the ages of six or seven. CF patients are, however, living much longer now than in decades past. The median age of survival in Canada has risen to 37.0 years for the period of 1998-2002 (5-year window), up from 22.8 years for the 5-year window ending in 1977. The prevalence has also risen accordingly, last recorded as 3,453 in Canada in 2002, up from 1,630 in 1977. With individuals living longer, there is a greater need for independent methods of airway clearance. Airway Clearance Devices There are at least three classes of airway clearance devices: positive expiratory pressure devices (PEP), airway oscillating devices (AOD; either handheld or stationary) and high frequency chest compression (HFCC)/mechanical percussion (MP

  17. [Ratio of amylase clearance and creatinine clearance in the diagnosis of acute pancreatitis].

    Science.gov (United States)

    Haffter, D; Reichlin, B; Gyr, K

    1981-05-30

    In 21 healthy volunteers the ratio of amylase clearance and creatinine clearance (Cam/Ccr) was determined in urine collected at admission, after a 1-hour collection period and after a 2-hour collection period. The normal values were 1.8 +/- 1.6%, 1.9 +/- 2% and 2.0 +/- 1.7% respectively. They were comparable with those published by others. The reproducibility of the method was acceptable (r = 0.62). When compared with serum amylase determinations, Cam/Ccr showed neither better sensitivity in 19 patients suffering an acute episode of proven pancreatitis, nor better specificity in 19 patients with acute abdomen but no evidence of pancreatitis.

  18. 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.

  19. 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...

  20. Navigation/Prop Software Suite

    Science.gov (United States)

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

    2012-01-01

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

  1. Clearance and release from control - An international perspective

    International Nuclear Information System (INIS)

    This paper tries to give an overview of the clearance, or release from regulatory control, on an international scale, including some of those countries where clearance has become or is about to become vital for D and D. The emphasis lies on the impact of clearance, and in particular of differences between clearance levels of various countries, on D and D. Relevance of clearance for D and D of nuclear installations Clearance is an essential part of waste management (or more general, material management) in nuclear installations, and in particular during the decommissioning phase where waste streams continues to arise. Of course, the relevance of clearance in a particular country depends on a number of factors, like: availability of a final repository and its price; prevailing decommissioning strategy; number of nuclear installations reaching decommissioning phase. This small selection of reasons why clearance may be of varying importance for different countries may already suffice to illustrate why up to now clearance has been developed and implemented in quite different ways. If one thinks of additional reasons that may influence clearance, like politics, the public opinion, availability of funds etc., the situation becomes even more complex. It is, however safe to draw the conclusion that countries with a certain number of nuclear installations which have been or will soon be shut down or which are already in the decommissioning phase will need to implement provisions for clearance. This has indeed been the case with countries like the UK, Germany, the USA, Sweden, and a number of others. It is not essential for clearance levels to be exactly equal between various countries. They may differ as long as the difference is not too large, e.g. the values fall into the same order of magnitude. This is the reason why for example Germany has no problems with clearance levels which differ from the EU recommendation RP 122 partially adopted in a number of EU countries

  2. 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...

  3. Amylase creatinine clearance ratio after biliary surgery.

    Science.gov (United States)

    Donaldson, L A; McIntosh, W; Joffe, S N

    1977-01-01

    The amylase creatinine clearance ratio (ACCR) is considered to be a more sensitive index of acute pancreatitis than the serum amylase level. Serial ACCR estimations were undertaken in 25 patients undergoing an elective cholecystectomy. Using accepted criteria, 28% of these patients developed, in the postoperative period, biochemical evidence of pancreatic gland damage, although the serum amylase level remained normal. This raised ACCR was particularly noted in patients who had undergone an exploration of the common bile duct. The ACCR would appear to be a more sensitive index of pancreatic gland disruption secondary to biliary surgery than the serum amylase level.

  4. Amylase creatinine clearance ratio after biliary surgery.

    Science.gov (United States)

    Donaldson, L A; McIntosh, W; Joffe, S N

    1977-01-01

    The amylase creatinine clearance ratio (ACCR) is considered to be a more sensitive index of acute pancreatitis than the serum amylase level. Serial ACCR estimations were undertaken in 25 patients undergoing an elective cholecystectomy. Using accepted criteria, 28% of these patients developed, in the postoperative period, biochemical evidence of pancreatic gland damage, although the serum amylase level remained normal. This raised ACCR was particularly noted in patients who had undergone an exploration of the common bile duct. The ACCR would appear to be a more sensitive index of pancreatic gland disruption secondary to biliary surgery than the serum amylase level. PMID:402305

  5. Navigating "Assisted Dying".

    Science.gov (United States)

    Schipper, Harvey

    2016-02-01

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

  6. 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...

  7. 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...

  8. Study of blade clearance effects on centrifugal pumps

    Science.gov (United States)

    Hoshide, R. K.; Nielson, C. E.

    1972-01-01

    A program of analysis, design, fabrication, and testing has been conducted to develop and experimentally verify analytical models to predict the effects of impeller blade clearance on centrifugal pumps. The effect of tip clearance on pump efficiency, and the relationship between the head coefficient and torque loss with tip clearance was established. Analysis were performed to determine the cost variation in design, manufacture, and test that would occur between unshrouded and shrouded impellers. An impeller, representative of typical rocket engine impellers, was modified by removing its front shroud to permit variation of its blade clearances. It was tested in water with special instrumentation to provide measurements of blade surface pressures during operation. Pump performance data were obtained from tests at various impeller tip clearances. Blade pressure data were obtained at the nominal tip clearance. Comparisons of predicted and measured data are given.

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

    Science.gov (United States)

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

    2015-07-01

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

  10. Allometric scaling for predicting human clearance of bisphenol A

    Energy Technology Data Exchange (ETDEWEB)

    Collet, Séverine H., E-mail: s.collet@envt.fr; Picard-Hagen, Nicole, E-mail: n.hagen-picard@envt.fr; Lacroix, Marlène Z., E-mail: m.lacroix@envt.fr; Puel, Sylvie, E-mail: s.puel@envt.fr; Viguié, Catherine, E-mail: c.viguie@envt.fr; Bousquet-Melou, Alain, E-mail: a.bousquet-Melou@envt.fr; Toutain, Pierre-Louis, E-mail: pltoutain@wanadoo.fr; Gayrard, Véronique, E-mail: v.gayrard@envt.fr

    2015-05-01

    The investigation of interspecies differences in bisphenol A (BPA) pharmacokinetics (PK) may be useful for translating findings from animal studies to humans, identifying major processes involved in BPA clearance mechanisms, and predicting BPA PK parameters in man. For the first time, a large range of species in terms of body weight, from 0.02 kg (mice) to 495 kg (horses) was used to predict BPA clearance in man by an allometric approach. BPA PK was evaluated after intravenous administration of BPA in horses, sheep, pigs, dogs, rats and mice. A non-compartmental analysis was used to estimate plasma clearance and steady state volume of distribution and predict BPA PK parameters in humans from allometric scaling. In all the species investigated, BPA plasma clearance was high and of the same order of magnitude as their respective hepatic blood flow. By an allometric scaling, the human clearance was estimated to be 1.79 L/min (equivalent to 25.6 mL/kg.min) with a 95% prediction interval of 0.36 to 8.83 L/min. Our results support the hypothesis that there are highly efficient and hepatic mechanisms of BPA clearance in man. - Highlights: • Allometric scaling was used to predict BPA pharmacokinetic parameters in humans. • In all species, BPA plasma clearance approached hepatic blood flow. • Human BPA clearance was estimated to be 1.79 L/min.

  11. Clearance systems in the brain-implications for Alzheimer disease.

    Science.gov (United States)

    Tarasoff-Conway, Jenna M; Carare, Roxana O; Osorio, Ricardo S; Glodzik, Lidia; Butler, Tracy; Fieremans, Els; Axel, Leon; Rusinek, Henry; Nicholson, Charles; Zlokovic, Berislav V; Frangione, Blas; Blennow, Kaj; Ménard, Joël; Zetterberg, Henrik; Wisniewski, Thomas; de Leon, Mony J

    2015-08-01

    Accumulation of toxic protein aggregates-amyloid-β (Aβ) plaques and hyperphosphorylated tau tangles-is the pathological hallmark of Alzheimer disease (AD). Aβ accumulation has been hypothesized to result from an imbalance between Aβ production and clearance; indeed, Aβ clearance seems to be impaired in both early and late forms of AD. To develop efficient strategies to slow down or halt AD, it is critical to understand how Aβ is cleared from the brain. Extracellular Aβ deposits can be removed from the brain by various clearance systems, most importantly, transport across the blood-brain barrier. Findings from the past few years suggest that astroglial-mediated interstitial fluid (ISF) bulk flow, known as the glymphatic system, might contribute to a larger portion of extracellular Aβ (eAβ) clearance than previously thought. The meningeal lymphatic vessels, discovered in 2015, might provide another clearance route. Because these clearance systems act together to drive eAβ from the brain, any alteration to their function could contribute to AD. An understanding of Aβ clearance might provide strategies to reduce excess Aβ deposits and delay, or even prevent, disease onset. In this Review, we describe the clearance systems of the brain as they relate to proteins implicated in AD pathology, with the main focus on Aβ. PMID:26195256

  12. Do dialysate conductivity measurements provide conductivity clearance or ionic dialysance?

    Science.gov (United States)

    Petitclerc, T

    2006-11-01

    Dialysate conductivity measurements allow on-line estimation of urea clearance during hemodialysis session. Conductivity measurements provide a value of 'conductivity clearance' for some authors, but a value of 'ionic dialysance' for others. This paper aims at explaining which term should be the more appropriate. Clearance is a parameter defined for measuring the power of a mechanism, which aims at 'clearing' a solution by depurating some solutes. In hemodialysis, clearance measures the efficacy of patient's depuration. In contrast, dialysance measures the capability of transferring solutes between blood and dialysate. The conventional definition of dialysance, requiring the absence of convective transfer, should be generalized to the case of the usual presence of ultrafiltration during the hemodialysis session. For a solute (as urea) absent from the dialysate delivered to the dialyzer inlet, the clearance is equal to its dialysance. In order to avoid a dramatic fall in ionic concentrations during hemodialysis treatment, the clearance of ions is reduced by adding these ions in the dialysate and becomes lower than their dialysance. Conductivity measurements provide a value of electrolytes dialysance. Thus the term of 'ionic dialysance' is more appropriate than the term of 'conductivity clearance'. Nevertheless ionic dialysance represents a good estimation of urea clearance.

  13. Radioaerosol delivery and clearance in patients with respiratory failure

    International Nuclear Information System (INIS)

    A technique for radioaerosol delivery to patients requiring mechanical ventilation is described. Ventilation images and pulmonary radioaerosol clearance rates were successfully obtained in 35 patients regardless of ventilator type or level of positive end-expiratory pressure (PEEP). Those patients with noncardiogenic pulmonary edema (NPE) had significantly increased clearance rates relative to those patients in whom NPE was not present

  14. 48 CFR 32.502-2 - Contract finance office clearance.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Contract finance office clearance. 32.502-2 Section 32.502-2 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION... finance office clearance. The contracting officer shall obtain the approval of the contract finance...

  15. 48 CFR 1432.502-2 - Contract finance office clearance.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract finance office clearance. 1432.502-2 Section 1432.502-2 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... finance office clearance. The CO shall obtain approval of the bureau finance office prior to...

  16. 48 CFR 832.502-2 - Contract finance office clearance.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Contract finance office clearance. 832.502-2 Section 832.502-2 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS... finance office clearance. Contracting officers must obtain approval from the DSPE before taking...

  17. 32 CFR 644.522 - Clearance of military scrap.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Clearance of military scrap. 644.522 Section 644... Excess Land and Improvements § 644.522 Clearance of military scrap. Military scrap can contain or be... determining whether scrap metal will be removed should be the safety of persons coming on the land in...

  18. 14 CFR 29.411 - Ground clearance: tail rotor guard.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 29.411... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to contact the landing surface during a normal landing. (b) If a tail rotor guard is required to...

  19. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 27.411... System Loads § 27.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to contact the landing surface during a normal landing. (b) If a tail rotor guard is required to...

  20. Benefits of Improved HP Turbine Active Clearance Control

    Science.gov (United States)

    Ruiz, Rafael; Albers, Bob; Sak, Wojciech; Seitzer, Ken; Steinetz, Bruce M.

    2007-01-01

    As part of the NASA Propulsion 21 program, GE Aircraft Engines was contracted to develop an improved high pressure turbine(HPT) active clearance control (ACC) system. The system is envisioned to minimize blade tip clearances to improve HPT efficiency throughout the engine operation range simultaneously reducing fuel consumption and emissions.

  1. Allometric scaling for predicting human clearance of bisphenol A

    International Nuclear Information System (INIS)

    The investigation of interspecies differences in bisphenol A (BPA) pharmacokinetics (PK) may be useful for translating findings from animal studies to humans, identifying major processes involved in BPA clearance mechanisms, and predicting BPA PK parameters in man. For the first time, a large range of species in terms of body weight, from 0.02 kg (mice) to 495 kg (horses) was used to predict BPA clearance in man by an allometric approach. BPA PK was evaluated after intravenous administration of BPA in horses, sheep, pigs, dogs, rats and mice. A non-compartmental analysis was used to estimate plasma clearance and steady state volume of distribution and predict BPA PK parameters in humans from allometric scaling. In all the species investigated, BPA plasma clearance was high and of the same order of magnitude as their respective hepatic blood flow. By an allometric scaling, the human clearance was estimated to be 1.79 L/min (equivalent to 25.6 mL/kg.min) with a 95% prediction interval of 0.36 to 8.83 L/min. Our results support the hypothesis that there are highly efficient and hepatic mechanisms of BPA clearance in man. - Highlights: • Allometric scaling was used to predict BPA pharmacokinetic parameters in humans. • In all species, BPA plasma clearance approached hepatic blood flow. • Human BPA clearance was estimated to be 1.79 L/min

  2. Study of global operational needs for mine clearance equipment

    Science.gov (United States)

    Blagden, Paddy M.

    2003-09-01

    The Geneva International Centre for Humanitarian Demining studied the needs of landmine clearance groups for equipment to carry out specific functions of mine clearance. This was done on a global level, and useful results were obtained, which will provide the basis for further analysis.

  3. GPS Navigation and Tracking Device

    Directory of Open Access Journals (Sweden)

    Yahya Salameh Khraisat

    2011-10-01

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

  4. Predicting clearance in humans from in vitro data.

    Science.gov (United States)

    Obach, R Scott

    2011-01-01

    The use of in vitro metabolism in scaling to predict human clearance of new chemical entities has become a commonplace activity in the research and development of new drugs. The measurement of in vitro lability in human liver microsomes, a rich source of drug metabolizing cytochrome P450 enzymes, has become a high throughput screen in many research organizations which is a testament to its usefulness in drug design. In this chapter, the methods used to scale in vitro clearance data to predict in vivo clearance are described. Importantly, the numerous assumptions that are required in order to use in vitro data in this manner are laid out. These include assumptions regarding the scaling process as well as technical aspects of the generation of the in vitro data. Finally, some other drug clearance processes that have been emerging as important are described with regard to ongoing research efforts to develop clearance prediction methods.

  5. 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.

  6. Surgical navigation in oral implantology.

    Science.gov (United States)

    Miller, Robert J; Bier, Jurgen

    2006-03-01

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

  7. Analysis of conservativity analysis for clearance levels. Final report

    International Nuclear Information System (INIS)

    When deriving clearance levels for material from nuclear installations it is necessary to proceed with a certain degree of conservativity. This can, however, differ between various sets of clearance levels leading to inconsistencies between clearance pathways. The aim of the work therefore is to compare levels of conservativity for the following two sets of clearance levels: clearance levels for disposal as conventional waste and for metallic materials for recycling/reuse. A method was developed to quantify the degree of conservativity and make it comparable. The actual and future situation for disposal of (conventional) wastes in Germany was analysed. In addition, the masses, nuclide vectors, geographical distribution etc. for slightly radioactive material being cleared for conventional disposal was analysed and modelled and the resulting dose distributions were calculated. The values for the clearance levels were taken from the 1995 recommendation by the German Commission on Radiation Protection (SSK). By using realistic scenarios, the exposure was calculated for the personnel on the landfills and for persons of the general public being exposed via groundwater pathways. It could be shown that the trivial dose range will not be exceeded even if the masses of cleared material per landfill site exceed 100 Mg/a. Because of the types and distribution of nuclear installations in Germany and because of the nuclide vectors it is therefore not necessary to limit the masses per landfill sites. Clearance levels that are determined by the exposure pathways external exposure to and the inhalation of dust by the landfill personnel show a similar level of conservativity as those for metal scrap. This means that the clearance levels for gamma emitting nuclides are not overly restrictive. Although radiologically justified, raising the clearance levels would not lead to an increase of the material quantities because other nuclides of the respective nuclide vectors are limiting. In

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

    OpenAIRE

    I. V. Tykhonov

    2010-01-01

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

  9. Nuclear regulation. NRC's security clearance program can be strengthened

    International Nuclear Information System (INIS)

    Because of the national security implications of its programs, the Nuclear Regulatory Commission (NRC) investigates the background of its employees and consultants as well as others to ensure that they are reliable and trustworthy. If the investigation indicates that an employee will not endanger national security, NRC grants a security clearance that allows access to classified information, material, and facilities. NRC also requires periodic checks for some clearance holders to ensure their continued clearance eligibility. The Chairman, Subcommittee on Environment, Energy, and Natural Resources, House Committee on Government Operations, asked GAO to review NRC's personnel security clearance program and assess the procedures that NRC uses to ensure that those who operate nuclear power plants do not pose a threat to the public. The Atomic Energy Act of 1954 requires NRC to conduct background investigations of its employees and consultants as well as others who have access to classified information, material, or facilities. To do this, NRC established a personnel security clearance program. Under NRC policies, a security clearance is granted after the Office of Personnel Management (OPM) or the Federal Bureau of Investigation checks the background of those applying for an NRC clearance. NRC also periodically reassesses the integrity of those holding the highest level clearance. NRC employees, consultants, contractors, and licensees as well as other federal employees hold approximately 10,600 NRC clearances. NRC does not grant clearances to commercial nuclear utility employees unless they require access to classified information or special nuclear material. However, the utilities have voluntarily established screening programs to ensure that their employees do not pose a threat to nuclear plants. NRC faces a dilemma when it hires new employees. Although its policy calls for new hires to be cleared before they start work, the security clearance process takes so long

  10. 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.

  11. Autonomous navigation for artificial satellites

    Science.gov (United States)

    Desai, P. S.

    1975-01-01

    An autonomous navigation system is considered that provides a satellite with sufficient numbers and types of sensors, as well as computational hardware and software, to enable it to track itself. Considered are attitude type sensors, meteorological cameras and scanners, one way Doppler, and image correlator.

  12. Effects of drugs on mucus clearance.

    Science.gov (United States)

    Houtmeyers, E; Gosselink, R; Gayan-Ramirez, G; Decramer, M

    1999-08-01

    Mucociliary clearance (MCC), the process in which airway mucus together with substances trapped within are moved out of the lungs, is an important defence mechanism of the human body. Drugs may alter this process, such that it is necessary to know the effect of the drugs on MCC. Indeed, agents stimulating MCC may be used therapeutically in respiratory medicine, especially in patients suspected of having an impairment of their mucociliary transport system. In contrast, caution should be taken with drugs depressing MCC as an undesired side-effect, independently of their therapeutic indication. Since cough clearance (CC) serves as a back-up system when MCC fails, the influence of drugs must be examined not only on MCC but also on CC. Ultimately, the clinical repercussions of alterations in mucus transport induced by drug administration must be studied. Tertiary ammonium compounds (anticholinergics), aspirin, anaesthetic agents and benzodiazepines have been shown to be capable of depressing the mucociliary transport system. Cholinergics, methylxanthines, sodium cromoglycate, hypertonic saline, saline as well as water aerosol have been shown to increase MCC. Adrenergic antagonists, guaifenesin, S-carboxymethylcysteine, sodium 2-mercapto-ethane sulphonate and frusemide have been reported not to alter the mucociliary transport significantly. Amiloride, uridine 5'-triphosphate (UTP), quaternary ammonium compounds (anticholinergics), adrenergic agonists, corticosteroids, recombinant human deoxyribonuclease (rhDNase), N-acetylcysteine, bromhexine and ambroxol have been reported either not to change or to augment MCC. Indirect data suggest that surfactant as well as antibiotics may improve the mucociliary transport system. As for the influence of drugs on CC, amiloride and rhDNase have been demonstrated to increase the effectiveness of cough. A trend towards an improved CC was noted after treatment with adrenergic agonists. The anticholinergic agent ipratropium bromide, which

  13. Analysis of viral clearance unit operations for monoclonal antibodies.

    Science.gov (United States)

    Miesegaes, George; Lute, Scott; Brorson, Kurt

    2010-06-01

    Demonstration of viral clearance is a critical step in assuring the safety of biotechnology products. We generated a viral clearance database that contains product information, unit operation process parameters, and viral clearance data from monoclonal antibody and antibody-related regulatory submissions to FDA. Here we present a broad overview of the database and resulting analyses. We report that the diversity of model viruses tested expands as products transition to late-phase. We also present averages and ranges of viral clearance results by Protein A and ion exchange chromatography steps, low pH chemical inactivation, and virus filtration, focusing on retro- and parvoviruses. For most unit operations, an average log reduction value (LRV, a measure of clearance power) for retrovirus of >4 log(10) were measured. Cases where clearance data fell outside of the anticipated range (i.e., outliers) were rationally explained. Lastly, a historical analysis did not find evidence of any improvement trend in viral clearance over time. The data collectively suggest that many unit operations in general can reliably clear viruses.

  14. Integrated Turbine Tip Clearance and Gas Turbine Engine Simulation

    Science.gov (United States)

    Chapman, Jeffryes W.; Kratz, Jonathan; Guo, Ten-Huei; Litt, Jonathan

    2016-01-01

    Gas turbine compressor and turbine blade tip clearance (i.e., the radial distance between the blade tip of an axial compressor or turbine and the containment structure) is a major contributing factor to gas path sealing, and can significantly affect engine efficiency and operational temperature. This paper details the creation of a generic but realistic high pressure turbine tip clearance model that may be used to facilitate active tip clearance control system research. This model uses a first principles approach to approximate thermal and mechanical deformations of the turbine system, taking into account the rotor, shroud, and blade tip components. Validation of the tip clearance model shows that the results are realistic and reflect values found in literature. In addition, this model has been integrated with a gas turbine engine simulation, creating a platform to explore engine performance as tip clearance is adjusted. Results from the integrated model explore the effects of tip clearance on engine operation and highlight advantages of tip clearance management.

  15. 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)...

  16. NUMERICAL SIMULATION OF TIP-CLEARANCE FLOW IN CASCADE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The tip-clearance flow in a cascade was numerically simulated by solving the RANS equations of incompressible fluids. The computational model was based upon the artificial compressibility formulation proposed by Chorin. The Baldwin-Lomax turbulence model was used to make the governing equations closed. For the specific structure of tip-clearance flow, a multi-block grid structure was adopted to facilitate numerical computations. The comparison of numerical results with experimental data indicates that the present method is capable of simulating tip-clearance flows with satisfactory accuracy.

  17. Clearance from the anterior chamber of RBCs from human diabetics

    International Nuclear Information System (INIS)

    Erythrocytes from diabetic patients manifest decreased deformability and increased adherence. These abnormal membrane properties may diminish the ability of erythrocytes (RBCs) from diabetics to undergo deformation in passage through the trabecular meshwork. Using sodium chromate Cr 51-labeled RBCs from type I diabetic patients with proliferative retinopathy and normal control subjects, we studied RBC clearance from the rabbit anterior chamber. The mean time for 50% clearance (T50) of RBCs from diabetics (76 hours) was significantly longer than that for RBCs from normal subjects (19.5 hours). In this model, RBCs from diabetics have a slower clearance from the anterior chamber than do RBCs from normal subjects

  18. 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...

  19. 33 CFR 66.05-100 - Designation of navigable waters as State waters for private aids to navigation.

    Science.gov (United States)

    2010-07-01

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

  20. Novel Environmental Features for Robust Multisensor Navigation

    OpenAIRE

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

    2013-01-01

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

  1. 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...

  2. 32 CFR 644.3 - Navigation Projects.

    Science.gov (United States)

    2010-07-01

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

  3. The compliance contact model of cylindrical joints with clearances

    Institute of Scientific and Technical Information of China (English)

    Caishan Liu; Ke Zhang; Lei Yang; Keren Wang

    2005-01-01

    This paper is concerned with the determination of the normal force-displacement (NFD) relation for the contact problem of cylindrical joints with clearance. A simple formulation for this contact problem is developed by modeling the pin as a rigid wedge and the elastic plate as a simple Winkler elastic foundation. The numerical results show that the normal displacement relation based on Hertz theory is only valid for the case of large clearance with a small normal load, and the NFD relation based on Persson theory is only effective in the case of very small clearance. The proposed approximate model in this paper gives better results than Hertz theory and Persson theory in a large range of clearances as seen from the comparison with the results of FEM.

  4. Design Optimization of Ground Clearance of Domestic Cars

    Directory of Open Access Journals (Sweden)

    Debojyoti Mitra

    2010-07-01

    Full Text Available Drag and lift forces plays a vital role in the performance and stability of vehicles. Less drag means less fuel consumption and hence less vehicular pollution. Also, lower lift force means higher chance of adhesion of the car body with the ground causing less overturning of the vehicle, which improves the vehicle performance. Both drag and lift forces can be manipulated by varying the ground clearance of the cars. The present study concentrates on studying the effect of ground clearance on these aerodynamic forces experimentally. Wind tunnel studies with a notch-back car model revealed increase in drag and decrease in lift with increase in ground clearance. Therefore, optimization is required for designing the best ground clearance and a preferable value of the same is thus obtained.

  5. 49 CFR 229.71 - Clearance above top of rail.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Suspension System § 229.71 Clearance above top of rail. No part or appliance of a locomotive except the wheels,...

  6. Enhancement of the amylase-creatinine clearance ratio in pregnancy.

    Science.gov (United States)

    Naeije, R; Neuray, F; Van Melsen, A; Delcourt, A

    1979-01-01

    The renal clearance of amylase, expressed as a proportion of simultaneous creatinine clearance (Cam/-Ccr), was determined in 131 women in various stages of pregnancy. No abnormal serum levels of amylase were found. A moderate but significant increase in Cam/Ccr occurred during the last 15 weeks of pregnancy. Possible causes for this change were investigated in smaller groups of subjects. No increase in rapidly cleared isoamylase could be detected. No modification in renal tubular handling of protein could be evidenced, as assessed by measurements of the renal clearance of beta 2 microglobulin, expressed as a proportion of simultaneous creatinine clearance. An incrased glomerular permeability to amylase probably accounts for elevated Cam/Ccr in pregnancy.

  7. IFNL4 affects clearance of hepatitis C virus

    Science.gov (United States)

    Scientists have discovered a new human interferon gene, Interferon Lambda 4 (IFNL4), that affects clearance of the hepatitis C virus. They also identified an inherited genetic variant within IFNL4 that predicts how people respond to treatment for hepatit

  8. 06421 Abstracts Collection -- Robot Navigation

    OpenAIRE

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

    2007-01-01

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

  9. Orientation and navigation in birds

    OpenAIRE

    Bouwman, H.

    1998-01-01

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

  10. 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...

  11. Interplanetary spacecraft navigation using pulsars

    OpenAIRE

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

    2013-01-01

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

  12. 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.

  13. 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.

  14. The optimal clearance design of micro-punching die

    Directory of Open Access Journals (Sweden)

    K.S. Lee

    2008-07-01

    Full Text Available Purpose: The purpose of this research paper is focused on the optimal clearance design of micro-punching die by abductive network and SA method.Design/methodology/approach: The punching data (input and wear size (output were collected for a training database. In order to select proper clearance to evaluate the wear of die, the abductive network was used to establish an efficient relationship between input parameters and output result. This can help to predict wear size under any degree of clearance and hence to replace worn punches and dies at the right time. A simulated annealing (SA optimization algorithm with a performance index is then applied to the neural network for searching the optimal clearance parameters, and obtains rather satisfactory result as compared with the corresponding experiment verification.Findings: This study aims to identify the relationship between clearance and service life of micro punches using the Neural Network, and to find relational data involving the service life of punches and punching parameters in non-metal blanking processes. The result can be used to estimate optimal clearance between punch and die for industrial applications.Research limitations/implications: In this study, the practical punching processes with different punching conditions were carried out for a set of training data. A trained model exhibited a relationship between service life and clearance of micro punch and die through an abductive network system. The predicted value of wear by abductive network is very close to the actual experimental value, with an error of less than 8%. This result satisfies the required standard for IC factory production.Originality/value: A good clearance design not only increases the quality of product manufactured, but also reduces product’s burr. As a result, the wear of punches and dies can be greatly reduced and the life expectancy of punching dies increased.

  15. Fluid damping clearance in a control valve of injector

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jianming; ZHANG Weigang; YANG Bing; WANG Yawei

    2007-01-01

    A force model of a control valve of injector is set up, and the changes of the fluid damping clearance are investigated on the basis of the results of the computational fluid dynamics (CFD) and the experiments of control valve of injector. Results indicate that a damping clearance of 0.02-0.03 mm between the poppet and the valve guide is the most sufficient to dampen any excessive control valve poppet bouncing.

  16. Navigation in diagnosis and therapy

    International Nuclear Information System (INIS)

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

  17. 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.

  18. Experimental study on fluid flow in arciform clearance

    Institute of Scientific and Technical Information of China (English)

    邵俊鹏; 汤卉; 贾慧娟

    2002-01-01

    The system damping and dynamic characteristics can be further improved by properly increasing thedamping coefficient ξh. For a special hydraulic damping structure, an arciform damping clearance often used inFCS, a mathematical model has been established for fluid flow using the theory of laminar flow in the clearanceof parallel plates. Analytical calculations are made for fluid flow in the arciform clearance and relational expres-sion is deduced for flow rate along the arciform cleaance height, pressure difference, maximum arciform clear-ance height, the flow rate for the fluid flow in arciform clearance as well, and its simplified formula is obtainedby using the theory of hydrodynamics and the curve - fitting method. This paper consists of two sections: the firstsection focuses on the theoretical analysis by using the simplified mathematical model and the second sectionmainly describes experimental analysis. The simplified formula is corrected with experimental results by consid-erig various boundary conditions of the damping clearance. Experimental results show that this study of arciformdamping clearance is reliable and practical.

  19. Model of mucociliary clearance in cystic fibrosis lungs.

    Science.gov (United States)

    Kurbatova, P; Bessonov, N; Volpert, V; Tiddens, H A W M; Cornu, C; Nony, P; Caudri, D

    2015-05-01

    Mucus clearance is a primary innate defense mechanism in the human airways. Cystic fibrosis (CF) is a genetic disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein. CF is characterized by dehydration of airway surface liquid and impaired mucociliary clearance. As a result, microorganisms are not efficiently removed from the airways, and patients experience chronic pulmonary infections and inflammation. We propose a new physiologically based mathematical model of muco-ciliary transport consisting of the two major components of the mucociliary clearance system: (i) periciliary liquid layer (PCL) and (ii) mucus layer. We study mucus clearance under normal conditions and in CF patients. Restoring impaired clearance of airway secretions in one of the major goals of therapy in patients with CF. We consider the action of the aerosolized and inhaled medication dornase alfa, which reduces the viscosity of cystic fibrosis mucus, by selectively cleaving the long DNA strands it contains. The results of the model simulations stress the potential relevance of the location of the drug deposition in the central or peripheral airways. Mucus clearance was increased in case the drug was primarily deposited peripherally, i.e. in the small airways. PMID:25746843

  20. Cooperative navigation and localization for multiple UUVs

    Science.gov (United States)

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

    2009-09-01

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

  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. 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.

  3. Youth Mobilisation as Social Navigation

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2010-01-01

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

  4. 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...

  5. 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.

  6. PNP: mining of profile navigational patterns

    Science.gov (United States)

    Li, Hua-Fu; Shan, Man-Kwan

    2002-03-01

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

  7. Radioactive Aerosols in the Clinical Study of Pulmonary Clearance

    International Nuclear Information System (INIS)

    The study of pulmonary clearance mechanisms has acquired particular importance owing to the growing pollution of the environment and to the increasing incidence and seriousness of cases of pneumoconiosis. Such research is particularly important in radiopathology because of the frequent occurrence of respiratory radioactive contamination. The authors' aim is to tackle this problem and in particular to study long-term clearance mechanisms. Before starting this work, however, they propose to determine the contamination parameters as accurately as possible. For this purpose they plan to study respiratory function in normal subjects by administering labelled aerosols with well-defined physico-chemical characteristics; the first stage of the investigation is then to observe the kinetics of fixation and clearance in the short term. They describe the installations used for this voluntary contamination which must provide a means of producing the aerosols and administering them in controlled amounts and must also ensure efficient protection of the operators against irradiation arid contamination. The choice of the aerosols is also discussed: this is governed mainly by the nature of the vectors, the particle size and the physical characteristics of the tracers. Finally, the authors outline the detection and measuring techniques which they are using to study contamination kinetics, evaluate contamination burdens and follow the short-term clearance. These data constitute a preliminary basis for the study of long-term clearance. (author)

  8. Optic flow and autonomous navigation.

    Science.gov (United States)

    Campani, M; Giachetti, A; Torre, V

    1995-01-01

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

  9. Intelligent navigation and multivehicle coordination

    Science.gov (United States)

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

    1999-07-01

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

  10. 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.

  11. Indoor inertial waypoint navigation for the blind.

    Science.gov (United States)

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

    2013-01-01

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

  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. 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......The use of landmarks for robot navigation is a popular alternative to having a geometrical model of the environment through which to navigate and monitor self-localization. If the landmarks are defined as special visual structures already in the environment then we have the possibility of fully...... 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...

  14. 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.

  15. 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.

  16. 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.

  17. [Laser navigation guided cleft lip repair].

    Science.gov (United States)

    Bing, Shi

    2016-06-01

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

  18. Konzeption und Implementierung eines Quellcode-Navigators

    OpenAIRE

    Lu, Leiqin

    2004-01-01

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

  19. 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.

  20. Memory consolidation of landmarks in good navigators.

    Science.gov (United States)

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

    2008-01-01

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

  1. Progress with volunteer studies of nasal deposition and clearance

    International Nuclear Information System (INIS)

    Inhalation is the main route of intake of radioactive material for workers, and can be an important pathway for members of the public following accidental releases of radioactivity to the environment. Much of the inhaled radioactivity initially deposits in the nose, typically over 40% for particles of aerodynamic diameter (dae) greater than 2 μm. However, there is remarkably little information on the clearance from the human nose of particles deposited during inhalation and, until now, none on the clearance of the significant fraction of material that remains in the nasal passage for more than 12 hours. NRPB is conducting a volunteer study to determine the effects of particle size and breathing pattern on particle deposition in, and clearance from, the human nasal passage. This article summarises results obtained to date. (author)

  2. Improving mucociliary clearance in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Bhowmik, Angshu; Chahal, Kamaljeet; Austin, Gillian; Chakravorty, Indranil

    2009-04-01

    Patients with COPD usually experience mucus hypersecretion as a result of airway inflammation and response to noxious stimuli. These in turn lead to worsening airway resistance, impaired airflow, increased work of breathing, dyspnoea and exercise intolerance. Mucus hypersecretion may also lead to increased exacerbations and poor health related quality of life (HRQL). Institution based pulmonary rehabilitation programs incorporating airway clearance techniques have been shown to improve HRQL, reduce dyspnoea and improve exercise tolerance but are often difficult to provide due to restricted accessibility and resource implications. This review examines the current evidence base and best clinical practice in the area of airway clearance. Mechanical devices such as the flutter valves, positive end expiratory pressure and high frequency chest wall oscillation (HFCWO) may be able to provide the benefits of improved airway clearance in the patient's home potentially with reduced demands on healthcare resources.

  3. Pharmacometabonomic Prediction of Busulfan Clearance in Hematopoetic Cell Transplant Recipients.

    Science.gov (United States)

    Navarro, Sandi L; Randolph, Timothy W; Shireman, Laura M; Raftery, Daniel; McCune, Jeannine S

    2016-08-01

    Intravenous (IV) busulfan doses are often personalized to a concentration at steady state (Css) using the patient's clearance, which is estimated with therapeutic drug monitoring. We sought to identify biomarkers of IV busulfan clearance using a targeted pharmacometabonomics approach. A total of 200 metabolites were quantitated in 106 plasma samples, each obtained before IV busulfan administration in hematopoietic cell transplant (HCT) recipients. Both univariate linear regression with false discovery rate (FDR) and pathway enrichment analyses using the Global test were performed. In the univariate analysis, glycine, N-acetylglycine, 2-hydroxyisovaleric acid, creatine, serine, and tyrosine were statistically significantly associated with IV busulfan clearance at P 0.1. Glycine is a component of glutathione, which is conjugated with busulfan via glutathione transferase enzymes. These results demonstrate the potential utility of pharmacometabonomics to inform IV busulfan dosing. Future studies are required to validate these findings. PMID:27350098

  4. Bromosulphophthalein clearance rates in sheep with pyrrolizidine liver damage.

    Science.gov (United States)

    Lanigan, G W; Peterson, J E

    1979-05-01

    Sheep fed a ration containing 50% of dried Heliotropium europaeum showed a marked decline in bromosulphophthalein (BSP) fractional clearance rate during the first 3 months feeding. Thereafter, the response of individual animals varied widely on a time basis, although 3 groups could be identified. In the terminal stages, mean clearance rates were below 20% of initial values, with some sheep showing a decline in excess of 90%. Loss of liver functional capacity was generally much greater than indicated by the degree of damage revealed by histopathology. Thus, a suitably modified test could have considerable prognostic value in the field. In this investigation, all sheep with clearance rates below 0.15 died when exposed to a further period of H. europaeum feeding. PMID:475677

  5. Periodic response of multi-disk rotors with bearing clearances

    Science.gov (United States)

    Kim, Y. B.; Noah, S. T.; Choi, Y. S.

    1991-02-01

    The forced steady state response of a multi-disk rotor system involving a clearance at one of the bearings is determined by using a harmonic balance approach. The impedance method is applied to each of the harmonic steady state components in order to reduce the system to its displacement at the non-linear bearing support. The results reveal the interrelated roles of the bearing clearance, mass eccentricity and side force in producing dangerous subharmonics. The significant effects of the strong non-linearity of a bearing clearance are studied as related to the various system parameters. The results show that the approach developed in this study is computationally superior to numerical integration methods in analyzing multi-disk rotor systems with strong non-linearity.

  6. APPLICATION OF DSM IN OBSTACLE CLEARANCE SURVEYING OF AERODROME

    Directory of Open Access Journals (Sweden)

    X. Qiao

    2016-06-01

    Full Text Available Compared to the wide use of digital elevation model (DEM, digital surface model (DSM receives less attention because that it is composed by not only terrain surface, but also vegetations and man-made objects which are usually regarded as useless information. Nevertheless, these objects are useful for the identification of obstacles around an aerodrome. The primary objective of the study was to determine the applicability of DSM in obstacle clearance surveying of aerodrome. According to the requirements of obstacle clearance surveying at QT airport, aerial and satellite imagery were used to generate DSM, by means of photogrammetry, which was spatially analyzed with the hypothetical 3D obstacle limitation surfaces (OLS to identify the potential obstacles. Field surveying was then carried out to retrieve the accurate horizontal position and height of the obstacles. The results proved that the application of DSM could make considerable improvement in the efficiency of obstacle clearance surveying of aerodrome.

  7. 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...

  8. 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...

  9. Navigation and Ancillary Information Facility's SPICE

    Data.gov (United States)

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

  10. 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.

  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. Effect of Internal Clearance on Load Distribution and Life of Radially Loaded Ball and Roller Bearings

    Science.gov (United States)

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2012-01-01

    The effect of internal clearance on radially loaded deepgroove ball and cylindrical roller bearing load distribution and fatigue life was determined for four clearance groups defined in the bearing standards. The analysis was extended to negative clearance (interference) conditions to produce a curve of life factor versus internal clearance. Rolling-element loads can be optimized and bearing life maximized for a small negative operating clearance. Life declines gradually with positive clearance and rapidly with increasing negative clearance. Relationships were found between bearing life and internal clearance as a function of ball or roller diameter, adjusted for load. Results are presented as life factors for radially loaded bearings independent of bearing size or applied load. In addition, a modified Stribeck Equation is presented that relates the maximum rolling-element load to internal bearing clearance.

  13. Mucociliary clearance, airway inflammation and nasal symptoms in urban motorcyclists

    Directory of Open Access Journals (Sweden)

    Tereza C.S. Brant

    2014-01-01

    Full Text Available OBJECTIVES: There is evidence that outdoor workers exposed to high levels of air pollution exhibit airway inflammation and increased airway symptoms. We hypothesized that these workers would experience increased airway symptoms and decreased nasal mucociliary clearance associated with their exposure to air pollution. METHODS: In total, 25 non-smoking commercial motorcyclists, aged 18-44 years, were included in this study. These drivers work 8-12 hours per day, 5 days per week, driving on urban streets. Nasal mucociliary clearance was measured by the saccharine transit test; airway acidification was measured by assessing the pH of exhaled breath condensate; and airway symptoms were measured by the Sino-nasal Outcome Test-20 questionnaire. To assess personal air pollution exposure, the subjects used a passive-diffusion nitrogen dioxide (NO2 concentration-monitoring system during the 14 days before each assessment. The associations between NO2 and the airway outcomes were analyzed using the Mann-Whitney test and the Chi-Square test. Clinicaltrials.gov: NCT01976039. RESULTS: Compared with clearance in healthy adult males, mucociliary clearance was decreased in 32% of the motorcyclists. Additionally, 64% of the motorcyclists had airway acidification and 92% experienced airway symptoms. The median personal NO2 exposure level was 75 mg/m3 for these subjects and a significant association was observed between NO2 and impaired mucociliary clearance (p = 0.036. CONCLUSION: Non-smoking commercial motorcyclists exhibit increased airway symptoms and airway acidification as well as decreased nasal mucociliary clearance, all of which are significantly associated with the amount of exposure to air pollution.

  14. Effect of oral N-acetylcysteine on mucus clearance.

    Science.gov (United States)

    Millar, A B; Pavia, D; Agnew, J E; Lopez-Vidriero, M T; Lauque, D; Clarke, S W

    1985-07-01

    Oral N-acetylcysteine has been advocated as a mucolytic agent for use in chronic bronchitis. We have investigated the effects of regular use of this drug at a dose of 200 mg thrice daily for 4 weeks in nine patients with chronic bronchitis on lung function, lung mucociliary clearance and sputum viscosity in a controlled, double-blind, crossover study. No significant differences were found in lung function, mucociliary clearance curves or sputum viscosity following treatment with N-acetylcysteine compared to control or placebo measurements.

  15. The influence of body posture on lithium clearance

    DEFF Research Database (Denmark)

    Kamper, A L; Strandgaard, S; Holstein-Rathlou, N H;

    1988-01-01

    fall in the sitting position, and fell significantly to 26 +/- 5 ml/min (p less than 0.025) in walking subjects. Absolute proximal tubular reabsorption rate of fluid correspondingly rose from 83 +/- 16 to 92 +/- 15 ml/min (p less than 0.005) and sodium clearance fell from 1.52 +/- 0.81 to 1.00 +/- 0...... during moderate physical activity. Hence, when renal tubular function is studied with the lithium clearance method, standardization of posture and physical activity is important. In such studies physical activity such as walking should particularly be avoided....

  16. Derivation methods for clearance levels applied to reactors

    Energy Technology Data Exchange (ETDEWEB)

    Okoshi, Minoru; Seki, Takeo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-12-01

    In order to support the discussion by the Nuclear Safety Commission, JAERI derived the unconditional clearance levels for concrete and metal arising from the operation and dismantling of nuclear reactors. The clearance levels of 20 radionuclides were derived from 10 {mu}Sv/y of individual doses by deterministic approach. In this approach, calculation models were established to assess individual doses resulting from 73 exposure pathways related to disposal and recycle/reuse, and realistic parameter values were selected considering Japanese natural and social conditions. The appropriateness of selected parameter values was confirmed by stochastic analyses. (author)

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

    OpenAIRE

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

    2014-01-01

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

  18. 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

  19. 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.

  20. US Satellite Navigation Program Status

    Science.gov (United States)

    McCullough, Carl

    This, and the following paper, were first presented during the European GNSS98 Symposium held at the Centre de Congrès Pierre Baudis, Toulouse, France, from 20 to 23 October 1998; however, both authors have provided updated scripts for use in this Volume of the Journal.This paper provides an update of the development and implementation of the United States of America Federal Aviation Administration (FAA) Wide Area Augmentation System (WAAS) and Local Area Augmentation Systems (LAAS). It also addresses FAA efforts to implement these satellite navigation technologies into the US National Airspace System (NAS), as well as interoperability efforts concerning Satellite Based Augmentation Systems (SBAS) between the FAA and other worldwide Civil Aviation Authorities.

  1. 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.

  2. 轴承游隙计算分析%Analysis and calculation of bearing clearance

    Institute of Scientific and Technical Information of China (English)

    郭玉朋

    2014-01-01

    This paper analyzes the original common bearing clearance, installation clearance,clearance work,what used to solve bearing in C0,C3 clearance clearance work group size,select the project for future reference bearing clearance.%本文通过分析常用轴承的原始游隙,安装游隙,工作游隙,来求解一下常用轴承在C0,C3游隙组中的工作游隙的大小,作为以后项目选取轴承游隙的参考。

  3. 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.

  4. 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.

  5. 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…

  6. 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

  7. 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

  8. 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

  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. 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…

  11. Mucociliary and cough clearance as a biomarker for therapeutic development

    DEFF Research Database (Denmark)

    Bennett, William D; Daviskas, Evangelia; Hasani, Amir;

    2010-01-01

    A workshop/symposium on “Mucociliary and Cough Clearance (MCC/CC) as a Biomarker for Therapeutic Development” was held on October 21–22, 2008, in Research Triangle Park, NC, to discuss the methods for measurement of MCC/CC and how they may be optimized for assessing new therapies designed...

  12. Highly fluorescent resorcinarene cavitand nanocapsules with efficient renal clearance

    Science.gov (United States)

    Mahadevan, Kalpana; Patthipati, Venkata Suresh; Han, Sangbum; Swanson, R. James; Whelan, Eoin C.; Osgood, Christopher; Balasubramanian, Ramjee

    2016-08-01

    Nanomaterial based imaging approaches hold substantial promise in addressing current diagnostic and therapeutic challenges. One of the key requirements for the successful clinical translation of nanomaterials is their complete clearance from the body within a reasonable time period preferably via the renal filtration route. This article describes the synthesis of highly fluorescent, water soluble, resorcinarene cavitand nanocapsules and demonstrates their effective renal clearance in mice. The synthesis and functionalization of nanocapsules was accomplished in a one-pot operation via thiol-ene reactions without involving self-assembly, sacrificial templates or emulsions. Water soluble resorcinarene cavitand nanocapsules obtained by this approach were covalently functionalized with Alexa Fluor 750. Highly fluorescent nanocapsules with hydrodynamic diameters of 122 nm and 68 nm and extinction coefficients of 1.3 × 109 M-1 cm-1 and 1.5 × 108 M-1 cm-1 respectively were prepared by varying the reaction conditions. The in vivo biodistribution and clearance of these nanocapsules in mice followed by whole-body fluorescence imaging showed that they were both cleared renally within a few hours. Given the inherent encapsulation capabilities of nanocapsules, the renal clearance demonstrated in this work opens up new opportunities for their theranostic applications especially for targeting and treating the urinary tract.

  13. Decreased renal clearance of digoxin in chronic congestive heart failure.

    Science.gov (United States)

    Naafs, M A; van der Hoek, C; van Duin, S; Koorevaar, G; Schopman, W; Silberbusch, J

    1985-01-01

    Renal digoxin clearance was compared in patients suffering from atrial fibrillation with well preserved cardiac function (n = 9; salt intake +/- 170 mmol daily) and patients with chronic congestive heart failure (n = 10; salt intake 50 mmol daily and maintenance treatment with diuretics). There was no difference between the groups concerning digoxin dosage, creatinine clearance, diuresis or sodium excretion in the urine. Digoxin clearance in chronic heart failure proved to be significantly lower than in atrial fibrillation (48 +/- 21 vs 71 +/- 36 ml X min-1, p less than 0.05), and Cdig/Ccreat was similarly reduced at 0.73 +/- 0.15 compared to 1.09 +/- 0.27 (p less than 0.005). Steady state serum digoxin concentration was significantly higher in patients with congestive heart failure (1.44 +/- 0.47 vs 0.87 +/- 0.33 micrograms X 1(-1), p less than 0.01). Chronic congestive heart failure is a state with reduced digoxin clearance by the kidney, which could lead to digoxin intoxication not explicable by overdose, reduced renal function or the effect of interacting drugs. PMID:4007028

  14. In Vivo Renal Clearance, Biodistribution, Toxicity of Gold nanoclusters

    CERN Document Server

    Zhang, Xiao-Dong; Shen, Xiu; Liu, Pei-Xun; Fan, Fei-Yue; Fan, Sai-Jun; 10.1016/j.biomaterials.2012.03.020

    2012-01-01

    Gold nanoparticles have shown great prospective in cancer diagnosis and therapy, but they can not be metabolized and prefer to accumulate in liver and spleen due to their large size. The gold nanoclusters with small size can penetrate kidney tissue and have promise to decrease in vivo toxicity by renal clearance. In this work, we explore the in vivo renal clearance, biodistribution, and toxicity responses of the BSA- and GSH-protected gold nanoclusters for 24 hours and 28 days. The BSA-protected gold nanoclusters have low-efficient renal clearance and only 1% of gold can be cleared, but the GSH-protected gold nanoclusters have high-efficient renal clearance and 36 % of gold can be cleared after 24 hours. The biodistribution further reveals that 94% of gold can be metabolized for the GSH-protected nanoclusters, but only less than 5% of gold can be metabolized for the BSA-protected nanoclusters after 28 days. Both of the GSH- and BSA-protected gold nanoclusters cause acute infection, inflammation, and kidney fu...

  15. Early clearance of Mycobacterium tuberculosis: a new frontier in prevention

    NARCIS (Netherlands)

    Verrall, A.J.; Netea, M.G.; Alisjahbana, B.; Hill, P.C.; Crevel, R. van

    2014-01-01

    Early clearance (EC) is the successful eradication of inhaled Mycobacterium tuberculosis before an adaptive immune response develops. Evidence for EC comes from case contact studies that consistently show that a proportion of heavily exposed individuals do not develop M. tuberculosis infection. Furt

  16. 46 CFR 61.20-23 - Tailshaft clearance; bearing weardown.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Tailshaft clearance; bearing weardown. 61.20-23 Section...; bearing weardown. (a) Water lubricated bearings, other than rubber, must be rebushed as follows: (1) Where the propelling machinery is located amidship, the after stern tube bearing must be rebushed when it...

  17. Spontaneous Clearance of Hepatitis C after Liver and Renal Transplantation

    Directory of Open Access Journals (Sweden)

    CH Dale

    2009-01-01

    Full Text Available Spontaneous clearance of hepatitis C virus (HCV is rare in immunocompromised patients, such as those who have undergone organ transplantation. It has been recognized that patients receiving liver transplantation for HCV-related disease have decreased graft and patient survival compared with those transplanted for other etiologies. There is a growing trend toward treating HCV recurrence aggressively after liver transplantation. For other organ transplant recipients with concurrent HCV, treatment is not often an option, given the high rates of graft rejection and loss secondary to interferon and its immunomodulatory effects. Although spontaneous clearance of HCV has been reported in recipients of solitary liver and renal transplants, a common factor arising in these cases has been previous exposure to interferon. To date, no reports of spontaneous clearance of HCV RNA have been reported in a multiorgan transplant recipient. A case of spontaneous clearance of HCV RNA in an immunocompromised patient, within five months of simultaneous liver and kidney retransplantation is described. Importantly, this patient had no previous exposure to interferon.

  18. Mucociliary clearance, airway inflammation and nasal symptoms in urban motorcyclists

    OpenAIRE

    Brant, Tereza C S; Yoshida, Carolina T; Tomas de S. Carvalho; Nicola, Marina L; Jocimar. A. Martins; Lays M. Braga; Regiani C. de Oliveira; Vilma Leyton; Carmen S. de André; Saldiva, Paulo H. N.; Rubin, Bruce K.; Naomi K. Nakagawa

    2014-01-01

    OBJECTIVES: There is evidence that outdoor workers exposed to high levels of air pollution exhibit airway inflammation and increased airway symptoms. We hypothesized that these workers would experience increased airway symptoms and decreased nasal mucociliary clearance associated with their exposure to air pollution. METHODS:...

  19. Influence of clearance model on numerical simulation of centrifugal pump

    Science.gov (United States)

    Wang, Z.; Gao, B.; Yang, L.; Du, W. Q.

    2016-05-01

    Computing models are always simplified to save the computing resources and time. Particularly, the clearance that between impeller and pump casing is always ignored. But the completer model is, the more precise result of numerical simulation is in theory. This paper study the influence of clearance model on numerical simulation of centrifugal pump. We present such influence via comparing performance, flow characteristic and pressure pulsation of two cases that the one of two cases is the model pump with clearance and the other is not. And the results show that the head decreases and power increases so that efficiency decreases after computing with front and back cavities. Then no-leakage model would improve absolute velocity magnitude in order to reach the rated flow rate. Finally, more disturbance induced by front cavity flow and wear-ring flow would change the pressure pulsation of impeller and volute. The performance of clearance flow is important for the whole pump in performance, flow characteristic, pressure pulsation and other respects.

  20. 19 CFR 4.61 - Requirements for clearance.

    Science.gov (United States)

    2010-04-01

    ... either on the Customs Form 1300 or by approved electronic means. Customs port directors may permit the.... Customs may take local resources into consideration in allowing clearance to be transacted on board... thereto by any means of communication that is satisfactory to the local Customs port director, and...

  1. Modifications of lung clearance mechanisms by acute influenza A infection

    International Nuclear Information System (INIS)

    Four volunteers with naturally acquired, culture-proved influenza A infection inhaled a radiolabeled aerosol to permit investigation of lung mucociliary clearance mechanisms during and after symptomatic illness. Mucus transport in the trachea was undetectable when monitored with an external multidetector probe within 48 hours of the onset of the illness, but was found at a normal velocity by 1 week in three of the four subjects. In two volunteers who coughed 23 to 48 times during the 4.5-hour observation period, whole lung clearance was as fast within the first 48 hours of illness as during health 3 months later in spite of the absence of measurable tracheal mucus transport. Conversely, in spite of the return 1 week later of mucus transport at velocities expected in the trachea, whole lung clearance for the 4.5-hour period was slowed in two volunteers who coughed less than once an hour. The data offer evidence that cough is important in maintaining lung clearance for at least several days after symptomatic influenza A infection when other mechanisms that depend on ciliary function are severely deficient

  2. Effect of lindane on the clearance rate of Daphnia magna

    NARCIS (Netherlands)

    Hartgers, E.M.; Heugens, E.W.; Deneer, J.W.

    1999-01-01

    The impact of the insecticide lindane (%-hexachlorocyclohexane) on the clearance rate (CR) of Daphnia magna was investigated using artificial beads. CR (24-h EC50: 65 7g Lm1) was found to be a more sensitive endpoint than acute lethality for D. magna (48-h LC50: 516 7g Lm1). The onset of the effect

  3. 75 FR 52798 - State-07, Cryptographic Clearance Records

    Science.gov (United States)

    2010-08-27

    ...: Unclassified. SYSTEM LOCATION: Department of State, 301 4th St., SW., Room 750 Washington, DC 20547. CATEGORIES... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE State-07, Cryptographic Clearance Records Summary: Notice is hereby given that the Department of State proposes to...

  4. CLEARANCE OF INDOMETHACIN OCCURS PREDOMINANTLY BY RENAL GLUCURONIDATION

    NARCIS (Netherlands)

    MOOLENAAR, F; CRANCRINUS, S; VISSER, J; DEZEEUW, D; MEIJER, DKF

    1992-01-01

    In this report we describe the conditions of collection, storage and handling of urine samples, collected after oral dosing with indometacin in man, in order to maintain the integrity of the labile glucuronide formed. We found that the body clearance occurs predominantly by renal metabolism, due to

  5. 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

  6. 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.

  7. Risk management model of winter navigation operations.

    Science.gov (United States)

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

    2016-07-15

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

  8. Metabolism of nanomaterials in vivo: blood circulation and organ clearance.

    Science.gov (United States)

    Wang, Bing; He, Xiao; Zhang, Zhiyong; Zhao, Yuliang; Feng, Weiyue

    2013-03-19

    Before researchers apply nanomaterials (NMs) in biomedicine, they need to understand the blood circulation and clearance profile of these materials in vivo. These qualities determine the balance between nanomaterial-induced activity and unwanted toxicity. NMs have heterogeneous characteristics: they combine the bulk properties of solids with the mobility of molecules, and their highly active contact interfaces exhibit diverse functionalities. Any new and unexpected circulation features and clearance patterns are of great concern in toxicological studies and pharmaceutical screens. A number of studies have reported that NMs can enter the bloodstream directly during their application or indirectly via inhalation, ingestion, and dermal exposure. Due to the small size of NMs, the blood can then transport them throughout the circulation and to many organs where they can be stored. In this Account, we discuss the blood circulation and organ clearance patterns of NMs in the lung, liver, and kidney. The circulation of NMs in bloodstream is critical for delivery of inhalable NMs to extrapulmonary organs, the delivery of injectable NMs, the dynamics of tissue redistribution, and the overall targeting of drug carriers to specific cells and organs. The lung, liver, and kidney are the major distribution sites and target organs for NMs exposure, and the clearance patterns of NMs in these organs are critical for understanding the in vivo fate of NMs. Current studies suggest that multiple factors control the circulation and organ clearance of NMs. The size, shape, surface charge, surface functional groups, and aspect ratio of NMs as well as tissue microstructures strongly influence the circulation of NMs in bloodstream, their site-specific extravasation, and their clearance profiles within organs. Therefore structure design and surface modification can improve biocompatibility, regulate the in vivo metabolism, and reduce the toxicity of NMs. The biophysicochemical interactions

  9. 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.

  10. 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.

  11. 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

  12. 77 FR 19673 - Proposed Collection; Comment Request; Generic Clearance To Conduct Voluntary Customer/Partner...

    Science.gov (United States)

    2012-04-02

    ... HUMAN SERVICES National Institutes of Health Proposed Collection; Comment Request; Generic Clearance To... and Budget (OMB) for review and approval. Proposed Collection: Title: Generic Clearance to Conduct... strategy in ] accomplishing reinvention goals is the ability to periodically receive input and...

  13. A comparison of analytic procedures for measurement of fractional dextran clearances

    NARCIS (Netherlands)

    Hemmelder, MH; de Jong, PE; de Zeeuw, D

    1998-01-01

    Fractional dextran clearances have been extensively used to study glomerular size selectivity. We report on an analysis of different laboratory procedures involved in measuring fractional dextran clearances. The deproteinization of plasma samples by 20% trichloroacetic acid (TCA) revealed a protein

  14. 19 CFR 122.66 - Clearance or permission to depart denied.

    Science.gov (United States)

    2010-04-01

    ...; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Clearance of Aircraft and Permission To Depart § 122.66 Clearance or permission to depart denied. If advance electronic air cargo information is not received...

  15. Consumer Response to Seasonal Clearance Sales: Experimental Analysis of Consumer Personality Traits in Self Service Stores

    OpenAIRE

    Rajagopal, MR

    2006-01-01

    Consumer responses to clearance sales, both in terms of consumer satisfaction with the decision process and in terms of subsequent store choice behavior, are explored in the paper through four controlled experiments conducted involving clearance sales in a consumer choice and decision satisfaction context. The results suggest that consumer response to clearance sales is driven to a large extent by two factors: the effect of a clearance sale on the available options of goods and the degree of ...

  16. Venous catheterization with ultrasound navigation

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-17

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

  17. Inertial sensors for smartphones navigation.

    Science.gov (United States)

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

    2015-01-01

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

  18. 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...

  19. 77 FR 66794 - Proposed Information Collection; Comment Request; Generic Clearance for Master Address File (MAF...

    Science.gov (United States)

    2012-11-07

    ... of each activity conducted. The generic clearance enables OMB to review our overall strategy for MTdb... Census Bureau Proposed Information Collection; Comment Request; Generic Clearance for Master Address File... ). SUPPLEMENTARY INFORMATION: I. Abstract The Census Bureau presently operates a generic clearance...

  20. 48 CFR 245.7101-4 - DD Form 1640, Request for Plant Clearance.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false DD Form 1640, Request for Plant Clearance. 245.7101-4 Section 245.7101-4 Federal Acquisition Regulations System DEFENSE... Forms 245.7101-4 DD Form 1640, Request for Plant Clearance. Use to request plant clearance assistance...

  1. Whole body and regional clearances of noradrenaline and adrenaline in man

    DEFF Research Database (Denmark)

    Christensen, N J; Galbo, H; Gjerris, A;

    1984-01-01

    we found no correlation between clearance values based on venous and arterial sampling. In other experiments we measured the influence of physical exercise in young healthy subjects on the clearance rate of plasma adrenaline (A). The clearance of A, which at rest averaged 1.9 l/min tended to increase...

  2. 77 FR 28625 - Comment Request for Information Collection for the Agricultural and Food Processing Clearance...

    Science.gov (United States)

    2012-05-15

    ... Food Processing Clearance Order, ETA Form 790, Extension With Revisions, and the Agricultural and Food... employers must use the Agricultural and Food Processing Clearance Order, ETA Form 790, to list the job... Agricultural and Food Processing Clearance Memorandum, ETA Form 795, is used by SWAs to extend job...

  3. The Principle and Application of Maser Navigation

    OpenAIRE

    Dong, Jiang

    2008-01-01

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

  4. Navigated minimally invasive unicompartmental knee arthroplasty.

    Science.gov (United States)

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

    2006-10-01

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

  5. 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.

  6. Navigational Use of Cassini Delta V Telemetry

    Science.gov (United States)

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

    2008-01-01

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

  7. The relationship between the renal clearance of creatinine and the apparent renal clearance of beta-2-microglobulin in patients with normal and impaired kidney function.

    Science.gov (United States)

    Vree, T B; Guelen, P J; Jongman-Nix, B; Walenkamp, G H

    1981-07-18

    The renal clearances of creatinine and beta 2-microglobulin of patients with either normal or impaired kidney function were measured. The renal clearance of beta 2-microglobulin depends on the urinary pH and must be considered as an apparent renal clearance because after tubular reabsorption the compound is metabolized in the kidney. Impaired kidney function reduces the percentage of tubular reabsorption of beta 2-microglobulin. PMID:6166414

  8. Nanoparticle clearance from the airways : development and testing of a new in vitro model to investigate mucociliary clearance of aerosol particles

    OpenAIRE

    Henning, Andreas Michael

    2008-01-01

    The current challenge in pulmonary drug delivery is to overcome and to control drug clearance from the lung. Here, the interaction with the mucociliary lung clearance plays a key role for any drug formulation technology. By today many open questions on mucociliary clearance (MC) have to be answered but suffer from limited experimental options. Considering these facts, the central part of this work was to develop a new in vitro test model to investigate the complex mechanism of MC more detaile...

  9. Vision assisted aircraft lateral navigation

    Science.gov (United States)

    Mohideen, Mohamed Ibrahim; Ramegowda, Dinesh; Seiler, Peter

    2013-05-01

    Surface operation is currently one of the least technologically equipped phases of aircraft operation. The increased air traffic congestion necessitates more aircraft operations in degraded weather and at night. The traditional surface procedures worked well in most cases as airport surfaces have not been congested and airport layouts were less complex. Despite the best efforts of FAA and other safety agencies, runway incursions continue to occur frequently due to incorrect surface operation. Several studies conducted by FAA suggest that pilot induced error contributes significantly to runway incursions. Further, the report attributes pilot's lack of situational awareness - local (e.g., minimizing lateral deviation), global (e.g., traffic in the vicinity) and route (e.g., distance to next turn) - to the problem. An Enhanced Vision System (EVS) is one concept that is being considered to resolve these issues. These systems use on-board sensors to provide situational awareness under poor visibility conditions. In this paper, we propose the use of an Image processing based system to estimate the aircraft position and orientation relative to taxiway markings to use as lateral guidance aid. We estimate aircraft yaw angle and lateral offset from slope of the taxiway centerline and horizontal position of vanishing line. Unlike automotive applications, several cues such as aircraft maneuvers along assigned route with minimal deviations, clear ground markings, even taxiway surface, limited aircraft speed are available and enable us to implement significant algorithm optimizations. We present experimental results to show high precision navigation accuracy with sensitivity analysis with respect to camera mount, optics, and image processing error.

  10. Numerical analysis of bump foil bearings without nominal radial clearance

    Institute of Scientific and Technical Information of China (English)

    LIU Zhan-sheng; XU Huai-jin; ZHANG Guang-hui

    2008-01-01

    Bump foil bearings without nominal radial clearance were analyzed. An air film thickness model and a bearing theoretical analytical model were developed accounting for air compressibility and foil deformation. To analyze hydrodynamic characteristics of bump foil beatings with different operating eccentricities, the air film thickness equation and Reynolds equation were coupled through pressure and solved by Newton-Raphson Method(NRM) and Finite Difference Method (FDM). The characteristics of an bump foil bearing model were dis-cussed including load carrying capacity, film thickness and pressure distributions. The results of simulation show that bump foil beating without nominal radial clearance can provide better stability and greater load capaci-ty. This numerical analytical method also reveals a good convergence in numerical calculation.

  11. Apoptotic cell clearance: basic biology and therapeutic potential.

    Science.gov (United States)

    Poon, Ivan K H; Lucas, Christopher D; Rossi, Adriano G; Ravichandran, Kodi S

    2014-03-01

    The prompt removal of apoptotic cells by phagocytes is important for maintaining tissue homeostasis. The molecular and cellular events that underpin apoptotic cell recognition and uptake, and the subsequent biological responses, are increasingly better defined. The detection and disposal of apoptotic cells generally promote an anti-inflammatory response at the tissue level, as well as immunological tolerance. Consequently, defects in apoptotic cell clearance have been linked with various inflammatory diseases and autoimmunity. Conversely, under certain conditions, such as the killing of tumour cells by specific cell-death inducers, the recognition of apoptotic tumour cells can promote an immunogenic response and antitumour immunity. Here, we review the current understanding of the complex process of apoptotic cell clearance in physiology and pathology, and discuss how this knowledge could be harnessed for new therapeutic strategies.

  12. [Amylase-creatinine clearance ratios in burned patients (author's transl)].

    Science.gov (United States)

    Minaire, Y; Marichy, J; Forichon, J; Motin, J

    1978-09-01

    The amylase/creatinine clearance ratio (ACCR) has been examined every 3 days, in 34 burned patients during the 20 days following the accident. This ratio was often abnormal since it was found increased at least on one occasion, in 75% of these patients, to be compared with 23 and 13% for amylase in serum and urine respectively. In another group of 9 burned patients, the ACCR was monitored for time-period between 10 to 52 days. It was observed that a high frequency in increased ACCR was associated with a fatal outcome. Finally simultaneous measurements of ACCR and of the beta2 microglobulin/creatinine clearance ratio (MCCR) showed that increased ACCR were statistically associated with increased MCCR suggesting a decreased renal tubular reabsorption of low molecular weight proteins in these burned patients.

  13. [Amylase-creatinine clearance ratios in burned patients (author's transl)].

    Science.gov (United States)

    Minaire, Y; Marichy, J; Forichon, J; Motin, J

    1978-09-01

    The amylase/creatinine clearance ratio (ACCR) has been examined every 3 days, in 34 burned patients during the 20 days following the accident. This ratio was often abnormal since it was found increased at least on one occasion, in 75% of these patients, to be compared with 23 and 13% for amylase in serum and urine respectively. In another group of 9 burned patients, the ACCR was monitored for time-period between 10 to 52 days. It was observed that a high frequency in increased ACCR was associated with a fatal outcome. Finally simultaneous measurements of ACCR and of the beta2 microglobulin/creatinine clearance ratio (MCCR) showed that increased ACCR were statistically associated with increased MCCR suggesting a decreased renal tubular reabsorption of low molecular weight proteins in these burned patients. PMID:360162

  14. 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.

  15. Mars Rover Local Navigation And Hazard Avoidance

    Science.gov (United States)

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

    1989-03-01

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

  16. Analysis of Ares 1 Ascent Navigation Options

    Science.gov (United States)

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

    2008-01-01

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

  17. Observability analysis of Mars entry integrated navigation

    Science.gov (United States)

    Wang, Liansheng; Xia, Yuanqing

    2015-09-01

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

  18. 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...

  19. 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.

  20. 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.

  1. 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...

  2. Guangzhou Customs Guide to "Local Declaration & Port Clearance"

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Ⅰ.Characteristic of the supervision mode of "Local Declaration & Port Clearance" This new mode means that the consignor,consignee or agent (hereafter referred to as "declarant") could choose any competent customs under the jurisdiction of Guangzhou Customs to make declaration and go through the formalities of document-checking and duty-paying,and then finish the cargo-examination and cargo-release at the customs office of entry or exit.

  3. Surface code—biophysical signals for apoptotic cell clearance

    Science.gov (United States)

    Biermann, Mona; Maueröder, Christian; Brauner, Jan M.; Chaurio, Ricardo; Janko, Christina; Herrmann, Martin; Muñoz, Luis E.

    2013-12-01

    Apoptotic cell death and the clearance of dying cells play an important and physiological role in embryonic development and normal tissue turnover. In contrast to necrosis, apoptosis proceeds in an anti-inflammatory manner. It is orchestrated by the timed release and/or exposure of so-called ‘find-me’, ‘eat me’ and ‘tolerate me’ signals. Mononuclear phagocytes are attracted by various ‘find-me’ signals, including proteins, nucleotides, and phospholipids released by the dying cell, whereas the involvement of granulocytes is prevented via ‘stay away’ signals. The exposure of anionic phospholipids like phosphatidylserine (PS) by apoptotic cells on the outer leaflet of the plasma membrane is one of the main ‘eat me’ signals. PS is recognized by a number of innate receptors as well as by soluble bridging molecules on the surface of phagocytes. Importantly, phagocytes are able to discriminate between viable and apoptotic cells both exposing PS. Due to cytoskeleton remodeling PS has a higher lateral mobility on the surfaces of apoptotic cells thereby promoting receptor clustering on the phagocyte. PS not only plays an important role in the engulfment process, but also acts as ‘tolerate me’ signal inducing the release of anti-inflammatory cytokines by phagocytes. An efficient and fast clearance of apoptotic cells is required to prevent secondary necrosis and leakage of intracellular danger signals into the surrounding tissue. Failure or prolongation of the clearance process leads to the release of intracellular antigens into the periphery provoking inflammation and development of systemic inflammatory autoimmune disease like systemic lupus erythematosus. Here we review the current findings concerning apoptosis-inducing pathways, important players of apoptotic cell recognition and clearance as well as the role of membrane remodeling in the engulfment of apoptotic cells by phagocytes.

  4. Surface code—biophysical signals for apoptotic cell clearance

    International Nuclear Information System (INIS)

    Apoptotic cell death and the clearance of dying cells play an important and physiological role in embryonic development and normal tissue turnover. In contrast to necrosis, apoptosis proceeds in an anti-inflammatory manner. It is orchestrated by the timed release and/or exposure of so-called ‘find-me’, ‘eat me’ and ‘tolerate me’ signals. Mononuclear phagocytes are attracted by various ‘find-me’ signals, including proteins, nucleotides, and phospholipids released by the dying cell, whereas the involvement of granulocytes is prevented via ‘stay away’ signals. The exposure of anionic phospholipids like phosphatidylserine (PS) by apoptotic cells on the outer leaflet of the plasma membrane is one of the main ‘eat me’ signals. PS is recognized by a number of innate receptors as well as by soluble bridging molecules on the surface of phagocytes. Importantly, phagocytes are able to discriminate between viable and apoptotic cells both exposing PS. Due to cytoskeleton remodeling PS has a higher lateral mobility on the surfaces of apoptotic cells thereby promoting receptor clustering on the phagocyte. PS not only plays an important role in the engulfment process, but also acts as ‘tolerate me’ signal inducing the release of anti-inflammatory cytokines by phagocytes. An efficient and fast clearance of apoptotic cells is required to prevent secondary necrosis and leakage of intracellular danger signals into the surrounding tissue. Failure or prolongation of the clearance process leads to the release of intracellular antigens into the periphery provoking inflammation and development of systemic inflammatory autoimmune disease like systemic lupus erythematosus. Here we review the current findings concerning apoptosis-inducing pathways, important players of apoptotic cell recognition and clearance as well as the role of membrane remodeling in the engulfment of apoptotic cells by phagocytes. (paper)

  5. Mathematical modeling and analysis of insulin clearance in vivo

    OpenAIRE

    Koschorreck, Markus; Gilles, Ernst Dieter

    2008-01-01

    Background Analyzing the dynamics of insulin concentration in the blood is necessary for a comprehensive understanding of the effects of insulin in vivo. Insulin removal from the blood has been addressed in many studies. The results are highly variable with respect to insulin clearance and the relative contributions of hepatic and renal insulin degradation. Results We present a dynamic mathematical model of insulin concentration in the blood and of insulin receptor activation in hepatocytes. ...

  6. Mathematical modeling and analysis of insulin clearance in vivo

    OpenAIRE

    Koschorreck, M.; Gilles, E. D.

    2008-01-01

    Background: Analyzing the dynamics of insulin concentration in the blood is necessary for a comprehensive understanding of the effects of insulin in vivo. Insulin removal from the blood has been addressed in many studies. The results are highly variable with respect to insulin clearance and the relative contributions of hepatic and renal insulin degradation. Results: We present a dynamic mathematical model of insulin concentration in the blood and of insulin receptor acti...

  7. Mathematical modeling and analysis of insulin clearance in vivo

    OpenAIRE

    Koschorreck, M.; Gilles, E.

    2008-01-01

    Background: Analyzing the dynamics of insulin concentration in the blood is necessary for a comprehensive understanding of the effects of insulin in vivo. Insulin removal from the blood has been addressed in many studies. The results are highly variable with respect to insulin clearance and the relative contributions of hepatic and renal insulin degradation. Results: We present a dynamic mathematical model of insulin concentration in the blood and of insulin receptor activation in hepatocytes...

  8. Lung Clearance Index bei erwachsenen Patienten mit Mukoviszidose

    OpenAIRE

    Rückel, Helena Sophie

    2011-01-01

    Die Spirometrie mit Bestimmung des forcierten exspiratorischen Volumens in einer Sekunde gilt derzeit als Gold-Standard bei der Beurteilung der Lungenfunktion von Patienten mit Cystischer Fibrose. Da die spirometrische Untersuchung eine aktive Mitarbeit des Patienten erfordert, kann sie jedoch erst etwa ab dem fünften Lebensjahr durchgeführt werden. Im Gegensatz dazu kann der Lung Clearance Index (LCI), der aus Gasdilutionsuntersuchungen abgeleitet wird, in jedem Alter, d.h. auch im Säugl...

  9. Respiratory Protection Program medical clearance for respirator use

    Science.gov (United States)

    1993-01-01

    Background on occupational exposure to various inhalents is discussed including on-site hazard control measures, procedures, physiological effects, and interpretation of results for the medical clearance of employee for use of personal respiratory protection devices. The purpose of the Respiratory Protection Program at LeRC is outlined, and the specifics of the Medical Surveillance Program for Respiratory Protection at LeRC are discussed.

  10. Apoptotic clearance in rabbits with experimental pulmonary emphysema

    OpenAIRE

    Žunić-Božinovski Snežana; Žunić Svetlana; Mladenović-Đorđević Aleksandra; Ruždijić Sabera; Kanazir Selma

    2011-01-01

    In order to better understand pathogenesis of pulmonary emphysema, the model of experimentally induced pulmonary emphysema in Chinchilla rabbits was used for the estimation of apoptotic clearance of pulmonary tissue. Bronchoalveolar lavage was performed in three groups of animals: experimental group-E on hypercholesterolemic diet (4% edible oil solution of crystalline cholesterol), control group-C1 on standard diet for that animal species and animals on oil...

  11. Early clearance of pneumococci from the lungs of decomplemented rats.

    OpenAIRE

    Rehm, S R; Coonrod, J D

    1982-01-01

    Pneumococcal types which exhibited varying degrees of interaction with the complement system in vitro wee aerosolized into normal and decomplemented rats, and the rate of killing of pneumococci was monitored by serial cultures of whole lung homogenates. The clearance of pneumococci from the alveoli did not correlate with the ability of the pneumococci to be opsonized by complement in vitro. Similarly, rats depleted of complement in the serum and the bronchoalveolar lavage fluid maintained the...

  12. Mine clearance industry: background, geography, funding, analysis and future projections

    OpenAIRE

    Donmez, Erkan

    2007-01-01

    MBA Professional Report Approved for public release; distribution is unlimited Contrary to common belief, the problems caused by landmines or other counter mobility devices have been threatening the lives of human beings for thousands of years. However, the actual efforts to remove the buried mines are a comparatively new issue. The mine clearance industry has been growing steadily, mostly because of increasing demand from the mine-afflicted countries, NGOs, international organizati...

  13. Highly Catalytic Nanodots with Renal Clearance for Radiation Protection

    OpenAIRE

    Zhang, Xiao-Dong; Zhang, Jinxuan; Wang, Junying; Yang, Jiang; Chen, Jie; Shen, Xiu; Deng, Jiao; Deng, Dehui; Long, Wei; Sun, Yuan-Ming; Liu, Changlong; Li, Meixian

    2016-01-01

    Ionizing radiation (gamma and x-ray) is widely used in industry and medicine, but it can also pose a significant hazardous effect on health and induce cancer, physical deformity and even death, due to DNA damages and invasion of free radicals. There is therefore an urgent unmet demand in designing highly efficient radioprotectants with synergetic integration of effective renal clearance and low toxicity. In this study, we designed ultrasmall (sub-5 nm) highly catalytically active and cysteine...

  14. Inertial Navigation and Mapping for Autonomous Vehicles

    OpenAIRE

    Skoglund, Martin

    2014-01-01

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

  15. Electromagnetic tracking and steering for catheter navigation

    OpenAIRE

    O'Donoghue, Kilian

    2014-01-01

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

  16. Sensory mechanisms of animal orientation and navigation

    OpenAIRE

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

    2014-01-01

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

  17. Mobility and Navigation among the Yucatec Maya

    OpenAIRE

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

    2015-01-01

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

  18. VOR area navigation - Techniques and results

    Science.gov (United States)

    Ragsdale, W. A.

    1982-01-01

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

  19. Magnetic navigation and tracking of underwater vehicles

    Digital Repository Service at National Institute of Oceanography (India)

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

    applications. Keywords: Navigation; tracking; magnetic methods; inverse problems; particle filters. 1. INTRODUCTION AND MAIN CONTRIBUTION OF THE PAPER The execution of long-range and long-term missions by robotic underwater vehicles in a fully autonomous mode... vehicles the capacity of executing long-range missions with minimum human intervention. Among the novel methods proposed, the terrain aided navigation (TAN) and the Simultaneous localization and mapping (SLAM) approaches have great potential...

  20. 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”.

  1. Visual navigation for an autonomous mobile vehicle

    OpenAIRE

    Peterson, Kevin Robert

    1992-01-01

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

  2. 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)

  3. Neurobiologically inspired mobile robot navigation and planning

    OpenAIRE

    Mathias Quoy

    2007-01-01

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

  4. Neurobiologically Inspired Mobile Robot Navigation and Planning

    OpenAIRE

    Cuperlier, Nicolas; Quoy, Mathias; Gaussier, Philippe

    2007-01-01

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

  5. Interactive learning of visual topological navigation

    OpenAIRE

    Filliat, David

    2008-01-01

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

  6. 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

  7. Effectiveness and Ergonomics of Integrated Navigation System

    OpenAIRE

    Vidan, Pero; Stanivuk, Tatjana; Bielić, Toni

    2012-01-01

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

  8. Comparison of Two Alternate Methods for Tracking Toe Clearance

    Science.gov (United States)

    Miller, Christopher A.; Feiveson, Alan H.; Bloomberg, Jacob J.

    2007-01-01

    Analyses of toe clearance during the swing phase of locomotion has often been utilized in determining a subject s propensity to trip while either walking or stepping over an obstacle. In the literature, toe clearance has been studied using a marker on the superior aspect of the second toe (rtoe), a marker on the lateral aspect of the fifth metatarsal head (mth5), or a virtual marker positioned at the anterior tip of the toe (vtoe). The purpose of this study was to compute toe clearance and associated parameters using a fifth metatarsal marker and a virtual toe marker, and compare the results with those of the standard toe marker. Subjects walked on a motorized treadmill at five different speeds while performing a visual acuity task at two separate target distances (ten 60-second trials). The minimum vertical height (TCl) was determined for each stride, along with its point of occurence in the gait cycle, and the angles of the foot and ankle at that time. A regression analysis was performed on the vtoe and mth5 results versus rtoe individually. For all TCl parameters, the mth5 marker did not correlate well with rtoe; the vtoe marker showed better agreement. Most importantly, the mth5 marker predicted a later occurence of TCl than rtoe and vtoe - thereby missing the most dangerous point in swing phase for a trip. From this analysis, the vtoe marker proved to be a better analog to rtoe than mth5, especially for determining a subject s propensity to trip.

  9. Effect of Guide Vane Clearance Gap on Francis Turbine Performance

    Directory of Open Access Journals (Sweden)

    Ravi Koirala

    2016-04-01

    Full Text Available Francis turbine guide vanes have pivoted support with external control mechanism, for conversion of pressure to kinetic energy and to direct them to runner vanes. This movement along the support is dependent on variation of load and flow (operating conditions. Small clearance gaps between facing plates and the upper and lower guide vane tips are available to aid this movement, through which leakage flow occurs. This secondary flow disturbs the main flow stream, resulting performance loss. Additionally, these increased horseshoe vortex, in presence of sand, when crosses through the gaps, both the surfaces are eroded. This causes further serious effect on performance and structural property by increasing gaps. This paper discusses the observation of the severity in hydropower plants and effect of clearance gaps on general performance of the Francis turbine through computational methods. It also relates the primary result with the empirical relation for leakage flow prediction. Additionally, a possible method to computationally estimate thickness depletion has also been presented. With increasing clearance gap, leakage increases, which lowers energy conversion and turbine efficiency along with larger secondary vortex.

  10. Dysregulation of Nutrient Sensing and CLEARance in Presenilin Deficiency

    Directory of Open Access Journals (Sweden)

    Kavya Reddy

    2016-03-01

    Full Text Available Attenuated auto-lysosomal system has been associated with Alzheimer disease (AD, yet all underlying molecular mechanisms leading to this impairment are unknown. We show that the amino acid sensing of mechanistic target of rapamycin complex 1 (mTORC1 is dysregulated in cells deficient in presenilin, a protein associated with AD. In these cells, mTORC1 is constitutively tethered to lysosomal membranes, unresponsive to starvation, and inhibitory to TFEB-mediated clearance due to a reduction in Sestrin2 expression. Normalization of Sestrin2 levels through overexpression or elevation of nuclear calcium rescued mTORC1 tethering and initiated clearance. While CLEAR network attenuation in vivo results in buildup of amyloid, phospho-Tau, and neurodegeneration, presenilin-knockout fibroblasts and iPSC-derived AD human neurons fail to effectively initiate autophagy. These results propose an altered mechanism for nutrient sensing in presenilin deficiency and underline an importance of clearance pathways in the onset of AD.

  11. RENAL CLEARANCE AND URINARY EXCRETION OF CIPROFLOXACIN IN GOATS

    Directory of Open Access Journals (Sweden)

    Z. IQBAL, I. JAVED, B. ASLAM, F. MUHAMMAD AND I. U. JAN

    2007-10-01

    Full Text Available The renal clearance and urinary excretion of ciprofloxacin were investigated in eight healthy female goats. In each animal, ciprofloxacin was administered intramuscularly at the rate of 5 mg/kg body weight. Following drug administration, blood and urine samples were collected at different time intervals and analyzed for ciprofloxacin and creatinine. High performance liquid chromatography (HPLC was used to determine the drug concentration in the plasma and urine. The value of diuresis after single administration of ciprofloxacin was 0.073 ± 0.014 ml/min/kg. Mean (± SE values for renal clearance of creatinine and ciprofloxacin were 1.870 ± 0.385 and 0.982 ± 0.166 ml/min/kg, respectively. The ratio between the renal clearance of ciprofloxacin and that of creatinine remained less than one, which was indicative of back diffusion. The mean (± SE value for the cumulative percent of ciprofloxacin dose excreted at 10 hours following its intramuscular administration was 13.03 ± 2.07. Based on these results, it was evident that besides glomerular filtration, renal handling of drug involved back diffusion also. It was concluded that in local goats glomerular filtration rate (GFR was lower than that reported for their foreign counterparts.

  12. Smoking produced mucus and clearance of particulates in the lung

    International Nuclear Information System (INIS)

    Some studies of miners have shown a lesser relative lung-cancer risk for smokers than for nonsmokers. For example, experiments by Cross and associates with dogs have shown an apparent protective effect of cigarette smoke against radon-daughter and dust exposure. One reason for these changes may be the thickened mucus layer in the tracheobronchial region of smokers. Physiological changes in the lung due to smoking may decrease the effects of radioactive particles in cancers in the bronchial region by apparently promoting faster clearance, in that region, of radioactive particles and by decreasing the radiation dose through reduced penetration to the sensitive basal epithelial cells. Because of the short half-life of radon daughters, even if there is possible tobacco-related delay of particle clearance from the alveolar region it cannot affect radon clearance. Therefore, the possible mitigating effect of tobacco on radon-produced cancer appears to be limited to the tracheobronchial region. It would be of value to a number of occupations if the same changes in the lungs due to smoking could be produced in exposed workers in the absence of cigarette-smoking. Beta-carotene and vitamin A, which affect maintenance and secretion of the mucosal lining, appear to thicken mucus, thereby providing protection against radon-induced lung cancers that is similar to smoking-related changes in the lung

  13. Respirable industrial fibres: deposition, clearance and dissolution in animal models.

    Science.gov (United States)

    Jones, A D

    1993-04-01

    This paper examines the available experimental and theoretical results describing deposition and clearance of mineral fibres inhaled by animals and humans in order to define the limits which these mechanisms impose on the relevance of animal experiments in the assessment of potential human health risks. Direct experimental data for deposition of spherical particles are extended by examination of the physical processes and by some limited experimental data for fibres. This shows that alveolar deposition efficiency (in rat and in man) is sufficiently similar for particles and fibres with aerodynamic diameters less that 5 microns for rats to be a relevant model for airborne dusts in this size range. Inter-species differences in mechanical clearance are substantial, with clearance being faster in the rat than in man, and this is a factor which should be considered in interpreting animal toxicity studies. The durability of fibres in the biochemical conditions of the lung may be more important over the longer lifespan of humans. PMID:8317856

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

    OpenAIRE

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

    2014-01-01

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

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

    OpenAIRE

    Steven, Ruediger.

    1996-01-01

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

  16. The Mathematics of Navigating the Solar System

    Science.gov (United States)

    Hintz, Gerald

    2000-01-01

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

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. Numerical investigation of tip clearance effects on the performance of ducted propeller

    Directory of Open Access Journals (Sweden)

    Yongle Ding

    2015-09-01

    Full Text Available Tip clearance loss is a limitation of the improvement of turbomachine performance. Previous studies show the Tip clearance loss is generated by the leakage flow through the tip clearance, and is roughly linearly proportional to the gap size. This study investigates the tip clearance effects on the performance of ducted propeller. The investigation was carried out by solving the Navier-Stokes equations with the commercial Computational Fluid Dynamic (CFD code CFX14.5. These simulations were carried out to determine the underlying mechanisms of the tip clearance effects. The calculations were performed at three different chosen advance ratios. Simulation results showed that the tip loss slope was not linearly at high advance due to the reversed pressure at the leading edge. Three type of vortical structures were observed in the tip clearance at different clearance size.

  4. 33 CFR 245.20 - Determination of hazard to navigation.

    Science.gov (United States)

    2010-07-01

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

  5. 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...

  6. 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.

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

    International Nuclear Information System (INIS)

    This paper presents an integrated navigation method of the strapdown inertial navigation system (SINS) using a star sensor. According to the principle of SINS, its own navigation information contains an error that increases with time. Hence, the inertial attitude matrix from the star sensor is introduced as the reference information to correct the SINS increases error. For the integrated navigation method, the vehicle’s attitude can be obtained in two ways: one is calculated from SINS; the other, which we have called star sensor attitude, is obtained as the product between the SINS position and the inertial attitude matrix from the star sensor. Therefore, the SINS position error is introduced in the star sensor attitude error. Based on the characteristics of star sensor attitude error and the mathematical derivation, the SINS navigation errors can be obtained by the coupling calculation between the SINS attitude and the star sensor attitude. Unlike several current techniques, the navigation process of this method is non-radiating and invulnerable to jamming. The effectiveness of this approach was demonstrated by simulation and experimental study. The results show that this integrated navigation method can estimate the attitude error and the position error of SINS. Therefore, the SINS navigation accuracy is improved. (paper)

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  9. 75 FR 50884 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector...

    Science.gov (United States)

    2010-08-18

    ... INFORMATION: In FR doc 2010-19754 appearing on page 48564 in the issue of Wednesday, August 11, 2010, the..., Organizational, and Conforming Amendments, Sector Columbia River; Correction AGENCY: Coast Guard, DHS. ACTION... read ``Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments,...

  10. 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...

  11. 76 FR 31831 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments

    Science.gov (United States)

    2011-06-02

    ... Conforming Amendments AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: This rule makes non-substantive... conforming amendments and technical corrections to Coast Guard navigation and navigable water regulations.... 553(b)(B) as this rule consists only of corrections and editorial, organizational, and...

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

    Science.gov (United States)

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

    2015-11-01

    This paper presents an integrated navigation method of the strapdown inertial navigation system (SINS) using a star sensor. According to the principle of SINS, its own navigation information contains an error that increases with time. Hence, the inertial attitude matrix from the star sensor is introduced as the reference information to correct the SINS increases error. For the integrated navigation method, the vehicle’s attitude can be obtained in two ways: one is calculated from SINS; the other, which we have called star sensor attitude, is obtained as the product between the SINS position and the inertial attitude matrix from the star sensor. Therefore, the SINS position error is introduced in the star sensor attitude error. Based on the characteristics of star sensor attitude error and the mathematical derivation, the SINS navigation errors can be obtained by the coupling calculation between the SINS attitude and the star sensor attitude. Unlike several current techniques, the navigation process of this method is non-radiating and invulnerable to jamming. The effectiveness of this approach was demonstrated by simulation and experimental study. The results show that this integrated navigation method can estimate the attitude error and the position error of SINS. Therefore, the SINS navigation accuracy is improved.

  13. 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.

  14. Indoor navigation using Bluetooth Low Energy (BLE) beacons

    OpenAIRE

    Herrera Vargas, Milan

    2016-01-01

    The popularity of indoor navigation has significantly increased during the last decade. Nowadays, many studies aim to develop new indoor navigation systems and improve the accuracy of the already existing ones. Unfortunately, no definitive method for indoor navigation has been approved yet, which is why this type of systems are not as accessible as those used for outdoor navigation. The purpose of this thesis is to introduce the concept of indoor navigation and demonstrate how common elec...

  15. Evaluation of Navigational Aspects of Moodle

    Directory of Open Access Journals (Sweden)

    Raheela Arshad

    2016-03-01

    Full Text Available Learning Management System (LMS is an effective platform for communication and collaboration among teachers and students to enhance learning. These LMSs are now widely used in both conventional and virtual and distance learning paradigms. These LMSs have various limitations as identified in the existing literature, including poor learning content, use of appropriate technology and usability issues. Poor usability leads to the distraction of users. Literature covers many aspects of usability evaluation of LMS. However, there is less focus on navigational issues. Poor navigational can lead to disorientation and cognitive overload of the users of any Web application. For this reason, we have proposed a navigational evaluation framework to evaluate the navigational structure of the LMS. We have applied this framework to evaluate the navigational structure of Moodle. We conducted a survey among students and teachers of two leading universities in Pakistan, where Moodle is in use. This work summarizes the survey results and proposes guidelines to improve the usability of Moodle based on the feedback received from its users.

  16. 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.

  17. SOIL QUALITY CHANGES FOLLOWING FOREST CLEARANCE IN BENGKULU, SUMATRA

    Directory of Open Access Journals (Sweden)

    I.P. HANDAYANI

    2004-01-01

    Full Text Available Intense destruction and degradation of tropical forests is recognized as one of the environmental threats and tragedies. These have increased the need to assess the effects of subsequent land-use following forest extraction on soil quality. Therefore, the objective of this study is to evaluate the impacts of land-use type on soil quality properties in Bengkulu Province, Sumatra. Soil samples were collected from adjacent sites including natural secondary forest, bare land, cultivated land and grassland. The results show that land-use following forest clearance lowered saturated hydraulic conductivity (85%, porosity (10.50%, soil water content at field capacity (34%,C organic (27%, N total (26%, inorganic N (37%, soil microbial biomass C (32%, mineralizable C (22%, and particulate organic matter (50%, but slightly increased water soluble organic C. Specific respiration activi ty rates increased about 14% in cultivated soils compared to natural forest soils, indicating greater C turnover per labile C pool in the form of soil microbial biomass, thus decreased biologically active soil organic matter. Forest conversion tends to reduce the C,ffg/Crer for all deforested sites. All of deforested areas relatively have infertile soil, with the worst case found in cultivated field. The C^g/Crd of cultivated field s was about 24% less than that of remnant fo rest (1.07. Grassland apparently mainta ins only slightly higher soil C levels than the bare land. On average, degradation index of so il following forest clearance was 35% with the highest deterioration occurred in the bare land (38%. Fallowing the fields by naturally growth of Imperata cylindrica for about 15 yr in abandoned land after 3-5 years of cultivation did not improve the soil quality. Moreover, forest clearance has an impact on soil quality as resulted in the loss of a physically protected organic matter and reduction in some labile C pools, thus declined biological activity at disturbed

  18. Upregulation of Phagocytic Clearance of Apoptotic Cells by Autoimmune Regulator

    Institute of Scientific and Technical Information of China (English)

    石亮; 胡丽华; 李一荣

    2010-01-01

    To investigate the effect of autoimmune regulator(AIRE) on phagocytic clearance of apoptotic cells,a recombinant expression vector containing full-length human AIRE cDNA was transfected into 16HBE cells.After incubation with transfected 16HBE cells,engulfment of apoptotic HL-60 cells induced by camptothecin was detected by myeloperoxidase(MPO) staining.The change in the expression of Rac 1 in transfected 16HBE cells was determined by RT-PCR and Western blotting.The results showed that the phagocytosis perce...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Foot mounted inertial system for pedestrian navigation

    International Nuclear Information System (INIS)

    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

  6. 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.

  7. 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 < 0.01) in computer 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 < 0.01] in computer 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 < 0.01) in computer 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 < 0.01) in computer navigation group than that in the other group. The intraoperative blood loss was fewer (WMD = -167.49, 95 % CI: -266.39- -68.58, P < 0.01) in computer 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

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  9. Range Filtering For Navigation By Satellite

    Science.gov (United States)

    Paielli, Russell

    1989-01-01

    Less processing and storage of data needed. Mathematical basis developed for Kalman filtering of sequential measurements of range from single-channel receiver in Global Positioning System (GPS) to each of several navigation satellites. Range filtering involves separate applications of kinematic Kalman tracking filter to measurements of signal from each satellite in use. State vector consists of pseudorange and time derivatives. Main advantages: simplification of tuning and decreases in required amounts of storage and processing of data for navigation in ships, airplanes, and ground vehicles.

  10. Quartz angular rate sensor for automotive navigation

    Energy Technology Data Exchange (ETDEWEB)

    Nozoe, Toshiyuki; Ichinose, Toshihiko; Kawasaki, Syusaku; Hatanaka, Masakazu; Kuroda, Keisuke [Matsushita Electronic Components Co. Ltd. (Japan); Yamamoto, Kohji; Ogata, Motoki; Takeno, Shoichi [Fukui Matsushita Electric Co. Ltd. (Japan); Ishihara, Minoru; Ishii, Tadashi; Umeki, Mitoshi [Nihonn Denpa Kogyo Co. Ltd. (Japan)

    1999-07-01

    Many of the recent automotive navigation systems are introducing an angular rate sensor that detect vehicle yaw in their system due to the advantage of higher accuracy, in addition to a conventional GPS (Global Positioning System) and vehicle speed signals. Though there are a couple of other methods to get a vehicle direction information, the angular rate sensor is the most suitable device as a gyro in accuracy and reliability point of view. Matsushita developed a new compact angular rate sensor using quartz crystal for automotive navigation systems. The sensor's operation is based upon Coriolis force imposed on a vibrating quartz tuning fork. (orig.)

  11. 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.

  12. 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.

  13. Clearance of 99mTc-DTPA and experimentally increased alveolar surfactant content

    International Nuclear Information System (INIS)

    The authors measured clearance of 99mTc-labeled diethylenetriamine pentaacetic acid (99mTc-DTPA) in rabbits with experimentally increased alveolar surfactant content. In one group of animals, surfactant production was increased by treatment with ambroxol, and another group of animals was treated with tracheal instillation of natural surfactant. A group of untreated control animals and animals treated with instillation of saline were also studied. Clearance was measured during standard conditions of mechanical ventilation and during ventilation with large tidal volumes. In ambroxol- and surfactant-treated groups, clearance rate was reduced compared with untreated control animals. In contrast, clearance rate increased after saline instillation. The differences were observed at both modes of ventilation. The findings indicate that the pulmonary surfactant system is a rate-limiting factor for the clearance of 99mTc-DTPA and that the volume dependence of clearance is not explained by stretching of the alveolar wall only. 28 refs., 2 figs., 1 tab

  14. Understanding of the Interaction between Clearance Leakage Flow and Main Passage Flow in a VGT Turbine

    Directory of Open Access Journals (Sweden)

    Ben Zhao

    2015-02-01

    Full Text Available The clearance flow between the nozzle and endwall in a variable geometry turbine (VGT has been numerically investigated to understand the clearance effect on the VGT performance and internal flow. It was found that the flow rate through turbine increases but the turbine efficiency decreases with height of clearance. Detailed flow field analyses indicated that most of the efficiency loss resulting from the leakage flow occurs at the upstream of the rotor area, that is, in the nozzle endwall clearance and between the nozzle vanes. There are two main mechanisms associated with this efficiency loss. One is due to the formation of the local vortex flow structure between the clearance flow and the main flow. The other is due to the impact of the clearance flow on the main flow after the nozzle throat. This impact reduces the span of shockwave with increased shockwave magnitude by changing the trajectory of the main flow.

  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. Bio-inspired polarized skylight navigation: a review

    Science.gov (United States)

    Zhang, Xi; Wan, Yongqin; Li, Lijing

    2015-12-01

    The idea of using skylight polarization in navigation is learned from animals such as desert ants and honeybees. Various research groups have been working on the development of novel navigation systems inspired by polarized skylight. The research of background in polarized skylight navigation is introduced, and basic principle of the insects navigation is expatiated. Then, the research progress status at home and abroad in skylight polarization pattern, three bio-inspired polarized skylight navigation sensors and polarized skylight navigation are reviewed. Finally, the research focuses in the field of polarized skylight navigation are analyzed. At the same time, the trend of development and prospect in the future are predicted. It is believed that the review is helpful to people understand polarized skylight navigation and polarized skylight navigation sensors.

  17. LRP1 in Brain Vascular Smooth Muscle Cells Mediates Local Clearance of Alzheimer's Amyloid-β

    OpenAIRE

    Kanekiyo, Takahisa; Liu, Chia-Chen; Shinohara, Mitsuru; Li, Jie; Bu, Guojun

    2012-01-01

    Impaired clearance of amyloid-β (Aβ) is a major pathogenic event for Alzheimer’s disease (AD). Aβ depositions in brain parenchyma as senile plaques and along cerebrovasculature as cerebral amyloid angiopathy (CAA) are hallmarks of AD. A major pathway that mediates brain Aβ clearance is the cerebrovascular system where Aβ is eliminated through the blood-brain barrier (BBB) and/or degraded by cerebrovascular cells along the interstitial fluid drainage pathway. An Aβ clearance receptor, the low-...

  18. The screening value of the amylase-creatinine clearance ratio in acute pancreatitis.

    Science.gov (United States)

    Van Hee, R; Hubens, A

    1979-01-01

    The screening value of the amylase creatinine clearance ratio in acute pancreatitis is studied. A series of 28 patients with pancreatic disease is compared with 80 controls and 82 patients with other intra-abdominal disease. The greatest specificity of the amylase creatinine clearance ratio value is reached at the 3.5 level. The amylase creatinine clearance ratio value proves to be of interest, not only in the diagnosis of acute pancreatitis but also in differentiating mild and heavy forms of pancreatitis.

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

    Science.gov (United States)

    Wegman, Joost; Janzen, Gabriele

    2011-12-01

    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 locations (nondecision points) during simple object recognition. This study aimed at unraveling how this neural marking of objects relevant for navigation is established during learning and postlearning rest. Twenty-four participants were scanned using fMRI while they were viewing a route through a virtual environment. Eye movements were measured, and brain responses were time-locked to viewing each object. The PHG showed increased responses to decision point objects compared with nondecision point objects during route learning. We compared functional connectivity between the PHG and the rest of the brain in a resting state scan postlearning with such a scan prelearning. Results show that functional connectivity between the PHG and the hippocampus is positively related to participants' self-reported navigational ability. On the other hand, connectivity with the caudate nucleus correlated negatively with navigational ability. These results are in line with a distinction between egocentric and allocentric spatial representations in the caudate nucleus and the hippocampus, respectively. Our results thus suggest a relation between navigational ability and a neural preference for a specific type of spatial representation. Together, these results show that the PHG is immediately involved in the encoding of navigationally relevant object information. Furthermore, they provide insight into the neural correlates of individual differences in spatial ability. PMID:21671733

  20. Two-phase deep-lung clearance in man

    International Nuclear Information System (INIS)

    For toxicological as well as physiological considerations, it is important to determine whether the long-term clearance of particles from the lungs of man takes place in more than one temporal subphase. Although long-term retention can be characterized with a single exponential, the existence of two distinct components would significantly alter estimates of overall residence times and hence potential effects of inhaled particulates. Physiological interpretations of the mechanisms of long-term particle clearance depend on the identification and quantification of such temporal subphases. A highly sensitive whole-body counter was used to measure the long-term retention of inhaled particles in man. After inhalation of 85Sr, lung retention was monitored in eight volunteers for periods ranging from 197 to 399 days. Their pulmonary-function values fell within normal limits, and they reported no symptoms of lung disease. Four of the individuals had never smoked, and four had not smoked for a minimum of 5 years. Single exponential representation half-times for the long-term retention were comparable between the two groups and were combined to give a mean half-time of 197 +- 32 days

  1. Reduction in slow intercompartmental clearance of urea during dialysis

    Energy Technology Data Exchange (ETDEWEB)

    Bowsher, D.J.; Krejcie, T.C.; Avram, M.J.; Chow, M.J.; Del Greco, F.; Atkinson, A.J. Jr.

    1985-04-01

    The kinetics of urea and inulin were analyzed in five anesthetized dogs during sequential 2-hour periods before, during, and after hemodialysis. The distribution of both compounds after simultaneous intravenous injection was characterized by three-compartment models, and the total volumes of urea (0.66 +/- 0.05 L/kg) and inulin (0.19 +/- 0.01 L/kg) distribution were similar to expected values for total body water and extravascular space, respectively. Intercompartmental clearances calculated before dialysis were used to estimate blood flows to the fast and slow equilibrating compartments. In agreement with previous results, the sum of these flows was similar to cardiac output, averaging 101% of cardiac output measured before dialysis (range 72% to 135%). Dialysis was accompanied by reductions in the slow intercompartmental clearances of urea (81%) and inulin (47%), which reflected a 90% attenuation in blood flow supplying the slow equilibrating compartments. This was estimated to result in a 10% average reduction in the efficiency with which urea was removed by dialysis (range 2.0% to 16.4%). Mean arterial pressure fell by less than 5% during dialysis, but total peripheral resistance increased by 47% and cardiac output fell by 35%. In the postdialysis period, total peripheral resistance and cardiac output returned toward predialysis values, but blood flow to the slow equilibrating peripheral compartment was still reduced by 80%. These changes parallel activation of the renin-angiotensin system, but further studies are required to establish causality.

  2. Radionuclide quantification of oropharyngeal clearance with and without pharyngitis

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, P.S.; Siegel, J.A.; Maurer, A.H.; Schachtel, B.P.; Malmud, L.S.

    1984-01-01

    The purpose of this study was to evaluate a new radionuclide method for quantifying oropharyngeal clearance (C) in 10 otherwise normal patients with and without pharyngitis (PH). Patients with objective evidence of PH initially swallowed 10 ml of water mixed with 1 mCi Tc-99m sulfur colloid and then performed a dry swallow each 15 seconds. This was repeated 1-4 weeks later when there was no evidence of pharyngitis (NP). Images were acquired using a high sensitivity collimator for 0.1 sec/image for 30 sec and 15 sec/image for an additional 270 sec. Time activity curves generated from a region of interest over the oropharynx were fit to a biexponential function, C = Ae/sup -k/1/sup t/ + Be/sup -k/2/sup t/; where A and B are the percent of activity clearing with fast and slow components, k/sub 1/, and k/sub 2/, respectively, with half times 0.693/k/sub l,2/. The T1/2 for the slow component was reproducible for PH and NP. The fast component was slightly prolonged with PH, but not to statistical significance (p>.2). The authors conclude that a biexponential model of clearance may be used to quantify oropharyngeal function, for patients with normal and abnormal swallowing.

  3. The amylase creatinine clearance ratio in acute pancreatitis.

    Science.gov (United States)

    Murray, W R; Mackay, C

    1977-03-01

    One hundred and twenty-two patients have been studied in order to evaluate the usefulness of the amylase creatinine clearance ratio (ACCR) as a simple diagnostic test for acute pancreatitis. Sixteen out of 17 patients with acute pancreatitis had significant elevations in ACCR; in only 10 of these 17 cases was the serum amylase greater than 1200iu/l. The mean ACCR was within the normal range in control patients, in patients with chronic gastro-intestinal disease and in patients with acute abdominal conditions excluding pancreatitis; however, the mean serum amylase was significantly greater in patients with acute abdominal conditions than in the control group (P less than 0-05). The ACCR remained significantly elevated in patients with acute pancreatitis for longer than either serum or urine amylase values. The findings of the study suggest that the amylase creatinine clearance ratio is a simple yet reliable diagnostic test which could be used when screening patients suspected of having acute pancreatitis.

  4. 123I-IMP clearance of the lung in pneumoconiosis

    International Nuclear Information System (INIS)

    We studied 123I-IMP lung clearance on 10 cases of pneumoconiosis and compared it with the data of 5 non-smoking young adults. After the venous injection of 111 MBq of 123I-IMP we collected the lung dynamic data using 1 frame/10 sec for 10 minutes and 1 frame/min for following 40 minutes. The time activity curve after the injection of 123I-IMP was obtained as follows: C(t)=A1e-k1t+A2e-k2t (k1, k2: slopes of the exponential component at the early and delayed phase). The 123I-IMP clearance was delayed in the patients group especially on the early phase and the k1 was lower than that of the normal group. Our results indicate that the pulmonary blood flow of the patients with pneumoconiosis decreased because of the advanced fibrotic change. This dynamic analysis may prove useful for the evaluation of the pneumoconiosis objectively and quantitatively. (author)

  5. The amylase creatinine clearance ratio in acute pancreatitis.

    Science.gov (United States)

    Murray, W R; Mackay, C

    1977-03-01

    One hundred and twenty-two patients have been studied in order to evaluate the usefulness of the amylase creatinine clearance ratio (ACCR) as a simple diagnostic test for acute pancreatitis. Sixteen out of 17 patients with acute pancreatitis had significant elevations in ACCR; in only 10 of these 17 cases was the serum amylase greater than 1200iu/l. The mean ACCR was within the normal range in control patients, in patients with chronic gastro-intestinal disease and in patients with acute abdominal conditions excluding pancreatitis; however, the mean serum amylase was significantly greater in patients with acute abdominal conditions than in the control group (P less than 0-05). The ACCR remained significantly elevated in patients with acute pancreatitis for longer than either serum or urine amylase values. The findings of the study suggest that the amylase creatinine clearance ratio is a simple yet reliable diagnostic test which could be used when screening patients suspected of having acute pancreatitis. PMID:890263

  6. Beta 2-Microglobulin clearance as measured by radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Woo, J.; Floyd, M.; Longley, M.A.; Cannon, D.C.

    1980-07-01

    We describe a radioimmunoassay for beta 2-microglobulin (beta 2 mu) in serum and urine. We incubated aliquots of diluted samples at room temperature for 1 h with /sup 125/I-labeled beta 2 mu and a rabbit antiserum monospecific for human beta 2 mu, and separated the phases by the double-antibody technique. The logit-log transformed dose-response curve was linear in the range 2 to 64 ng, equivalent to 0.5 to 16 mg/L of serum and 0.5 to 320 mg/L of urine. Assay sensitivity was 2.4 ng of beta 2 mu. Validation studies included tests of precision, accuracy, antibody specificity, and parallelism of the dose-response curves for standard and unknown. In a study of 25 normal individuals, serum and urine beta 2 mu ranged from 1.1 to 2.3 mg/L and 40 to 360 micrograms/24 h; the clearance of beta 2 mu was 8 to 130 microL/min. In 21 renal allograft recipients tested one to five weeks after transplantation, serum and urine beta 2 mu ranged from 3.9 to 15.6 mg/L and 7.2 to 611 mg/24 h; beta 2 mu clearance was 0.60 to 33.3 mL/min. Values for both serum and urine correlated well with severity of allograft rejection.

  7. Renal clearance of pancreatic and salivary amylase relative to creatinine in patients with chronic renal insufficiency.

    Science.gov (United States)

    Keogh, J B; McGeeney, K F; Drury, M I; Counihan, T B; O'Donnell, M D

    1978-12-01

    Pancreatic and salivary amylase/creatinine clearance ratios in patients with various degrees of renal impairment were compared with those obtained for control subjects. In chronic renal insufficiency (mean GFR 30 ml/min +/- 15 SD; n = 13) the clearance ratios for pancreatic (mean 3.5 +/- 1.85 SD) and salivary (mean 2.3 +/- 1.3 SD) amylase were significantly higher (P less than 0.05) than those in controls. Corresponding control values (n = 26) were 2.64 +/- 0.86 (pancreatic) and 1.64 +/- 0.95 (salivary). Three patients showed values above the normal limit. In the diabetic group (mean GFR 41 ml/min +/- 22 SD; n = 10) salivary amylase/creatinine clearance ratios (mean 2.36 +/- 1.55 SD) were significantly higher than in controls (P less than 0.05). Three patients showed raised values. Pancreatic amylase clearance was raised in only one of these patients. Three patients with terminal disease (mean GFR 10 ml/min) showed markedly raised (two- to threefold) clearance ratios for both salivary and pancreatic amylase. Of a total of 26 patients, eight had increased total amylase/creatinine clearance ratios. Pancreatic amylase/creatinine clearance was increased in seven patients, while nine patients showed raised salivary amylase/creatinine ratios. Patients with raised clearance ratios did not have clinical evidence of pancreatitis. We suggest that, in the presence of impaired renal function, a high amylase/creatinine clearance ratio need not be indicative of pancreatic disease.

  8. Clearance of glucose and sucrose from the saliva of human subjects.

    Science.gov (United States)

    Sreebny, L M; Chatterjee, R; Kleinberg, I

    1985-01-01

    The ability of 20 healthy people to clear test solutions of sucrose (0.73 M) and glucose (1.4 M) from the mouth was examined. Both sugars were cleared within 20 min in a two-step manner. Rapid clearance occurred between 0 and 6 min; much slower clearance occurred thereafter. It took 7.2 min with glucose and 6.3 min with sucrose for the saliva-sugar concentration to fall to 1 mg/ml. Salivary flow, stimulated during sugar exposure, decreased in a two-step pattern similar to sugar clearance. Evidently, clearance was dependent on the rate of flow of saliva which took about 1 h to return to its resting flow level. Comparison of the pattern of sugar clearance to the Stephan curve (the rapid pH fall followed by a slow pH rise seen after rinsing with sugar solutions) indicated that the pH-fall phase of the curve occurs during the initial period of rapid sugar clearance and salivary flow, and the pH-rise phase occurs during the subsequent period of slower clearance and slow saliva flow. Comparison with the data of Swenander-Lanke (1957) [Acta odont. scand. 15, 3-156], indicated that the clearance of sugar solutions also reflects the clearance of sugar-containing solid foods from the mouth. PMID:3857898

  9. Gamma-variate plasma clearance versus urinary plasma clearance of (51) Cr-EDTA in patients with cirrhosis with and without fluid retention

    DEFF Research Database (Denmark)

    Fuglsang, Stefan; Henriksen, Ulrik L; Hansen, Hanne B;

    2016-01-01

    In patients with fluid retention, the plasma clearance of (51) Cr-EDTA (Clexp obtained by multiexponential fit) may overestimate the glomerular filtration rate (GFR). The present study was undertaken to compare a gamma-variate plasma clearance (Clgv) with the urinary plasma clearance of (51) Cr...... the injected dose relative to the plasma concentration-time area, obtained by a gamma-variate iterative fit. Clexp and Clu were determined by standard technique. In patients without fluid retention, Clgv , Clexp and Clu were closely similar. The difference between Clgv and Clu (Clgv - Clu = ΔCl) was mean -0...

  10. 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. PMID:26227680

  11. 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

  12. Navigating cross-media news use

    DEFF Research Database (Denmark)

    Swart, Joëlle; Peters, Chris; Broersma, Marcel

    2016-01-01

    The current news media landscape is characterized by an abundance of digital outlets and increased opportunities for users to navigate news themselves. Yet, it is still unclear how people negotiate this fluctuating environment to decide which news media to select or ignore, how they assemble...

  13. Thinking Style, Browsing Primes and Hypermedia Navigation

    Science.gov (United States)

    Fiorina, Lorenzo; Antonietti, Alessandro; Colombo, Barbara; Bartolomeo, Annella

    2007-01-01

    There is a common assumption that hypermedia navigation is influenced by a learner's style of thinking, so people who are inclined to apply sequential and analytical strategies (left-thinkers) are thought to browse hypermedia in a linear way, whereas those who prefer holistic and intuitive strategies (right-thinkers) tend towards non-linear paths.…

  14. Autonomous Rule Based Robot Navigation In Orchards

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  15. '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.   

  16. 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 less useful…

  17. 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...

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 46 CFR 120.420 - Navigation lights.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Navigation lights. 120.420 Section 120.420 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS ELECTRICAL INSTALLATION...

  3. Tactile object exploration using cursor navigation sensors

    DEFF Research Database (Denmark)

    Kraft, Dirk; Bierbaum, Alexander; Kjaergaard, Morten;

    2009-01-01

    In robotic applications tactile sensor systems serve the purpose of localizing a contact point and measuring contact forces. We have investigated the applicability of a sensorial device commonly used in cursor navigation technology for tactile sensing in robotics. We show the potential of this se...

  4. Spatial Navigation in Preclinical Alzheimer's Disease.

    Science.gov (United States)

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

    2016-02-01

    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. 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.

  6. 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

  7. 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

  8. Indoor Autonomous Airship Control and Navigation System

    OpenAIRE

    Fedorenko Roman; Krukhmalev Victor

    2016-01-01

    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.

  9. 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.

  10. 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

  11. 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 ...

  12. Evaluation of navigation interfaces in virtual environments

    Science.gov (United States)

    Mestre, Daniel R.

    2014-02-01

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

  13. Bronchoscintigraphy and pulmonary clearance of {sup 99{sup m}}Tc-albumin colloid in study of mucociliary clearance

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, Jann

    1998-12-31

    A radioaerosol based method for measuring MC was introduced. It included an inhalation protocol that resulted in a predominant deposition of radioaerosol in the central bronchi and two simple procedures of evaluation: 1) a visual semi-quantitative bronchoscintigraphic analysis, and 2) a quantitative analysis of the retention of the radioactivity at different points after the inhalation. The results showed that bronchoscintigraphy was a simple technique that may be used to visualize a stimulation of mucociliary transport in the central airways of individuals that do not suffer from too much mucus hypersecretion. Comparison of the MC between individuals, however, should preferably be performed by the method of quantitative analysis of the radioactivity disappearance. A change of MC was found to be one of the first detectable effects on lung function of tobacco smoking. It could be effectively detected by measurement of radioaerosol clearance both by bronchoscintigraphy and simple quantification of the MC. The MC may be either acutely enhanced, reduced or not changed by smoking. Long-term smoking impairs MC. The enhancement of MC by {beta}{sub 2}-agonists was very limited in most patients with CF. In the hope of increasing mucus transport in patients with CF, these are treated with various chest physiotherapy techniques. The radioaerosol based method of measurement of MC could assess mucus clearance by chest physiotherapy and cough. (au) 141 refs.

  14. 33 CFR 66.01-50 - Protection of private aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Protection of private aids to... 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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.

  19. 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...

  20. Clearance of beta-2-microglobulin and middle molecules in haemodiafiltration.

    Science.gov (United States)

    Tattersall, James

    2007-01-01

    Middle molecules, consisting mostly of peptides and small proteins with molecular weight the range of 500-60,000 Da, accumulate in renal failure and contribute to the uraemic toxic state. Beta2-microglobulin (beta2-MG) with a molecular weight of 11,000 is considered representative of these middle molecules. These solutes are not well cleared by low-flux dialysis. High-flux dialysis will clear middle molecules, partly by internal filtration. This convective component of high-flux dialysis can be enhanced in a predictable way by haemodiafiltration (HDF). The convective and diffusive clearance rates of any middle molecule across any haemodiafilter can be predicted from known or measurable factors such as its sieving coefficient, bound fraction and molecular weight. The removal of middle molecules is also influenced by factors within the patient. Beta2-MG is distributed within the extracellular fluid. During HDF, beta2-MG must transfer into the intravascular compartment across the capillary walls. This transcapillary transfer at a rate of approximately 100 ml/min slows beta2-MG removal from the body. Continuing transfer after the end of a treatment session results in a significant rebound of beta2-MG levels. This intercompartment transfer and its effect on beta2-MG clearance and concentration can be predicted by a 2-compartment model. By extrapolation, the behaviour of other middle molecules can be predicted. The 2-compartment model, which takes non-dialytic beta2-MG clearance at a rate of 3 ml/min and beta2-MG generation at a rate of 0.1 mg/min into account, can predict the effect of any HDF schedule on beta2-MG levels. Low-flux dialysis results in a beta2-MG level of around 40 mg/l. Three times weekly, 4-hour HDF can reduce beta2-MG levels to around 20 mg/l. Long (nocturnal) HDF can reduce beta2-MG levels to around 10 mg/l, compared to physiological levels of less than 5 mg/l.

  1. Shape memory alloy adaptive control of gas turbine engine compressor blade tip clearance

    Science.gov (United States)

    Schetky, Lawrence M.; Steinetz, Bruce M.

    1998-06-01

    The ambient air ingested through the inlet of a gas turbine is first compressed by an axial compressor followed by further compression in a centrifugal compressor and then fed into the combustion chamber where ignition and expansion take place to produce the engine thrust. The axial compressor typically has five or more stages which consist of revolving blades and stators and the overall performance of the turbine is strongly affected by the compressor efficiency. When the turbine is turned on, to accommodate the rapid initial increase in the compressor blade length due to centrifugal force, the cold turbine has a built in clearance between the turbine blade tip and the casing. As the turbine reached its operating temperature there is a further increase in the blade length due to thermal expansion and, at the same time, the diameter of the casing increases. The net result is that when these various components have reached their equilibrium temperatures, the initial cold build clearance is reduced, but there remains a residual clearance. The magnitude of this clearance has a direct effect on the compressor efficiency and can be stated as: Δη/Δ CLR equals 0.5 where η is efficiency and CLR is the tip clearance. The concept of adaptive tip clearance control is based on the ability of a shape memory alloy ring to shrink to a predetermined diameter when heated to the temperature of a particular stage, and thus reducing the tip clearance. The ring is fabricated from a CuAlNi shape memory alloy and is mounted in the casing so as to be coaxial with the rotating blades of the particular stage. When cold, the ring dimensions are such as to provide the required cold build clearance, but when at operating temperature the reduced diameter creates a very small tip clearance. The clearance provided by this concept is much smaller than the clearance normally obtained for a turbine of the size being studied.

  2. Zasnova mobilne multimodalne komunikacijske naprave - osebni navigator: The design of mobile multimodal communication device - personal navigator:

    OpenAIRE

    Horvat, Bogomir; Horvat, Boštjan; Kačič, Zdravko; Kotnik, Bojan; Kramberger, Iztok; Rotovnik, Tomaž

    2001-01-01

    In today's world there are increasing demands for products that would enable a palette of services and would be portable, light, small and ergonomically designed. Their handling, however, should be as simple as possible, e.g. voice driven. Demands like that have brought about an integration of different technologies. The concept of the device which we describe in this article is called personal navigator. Personal navigator presents a multimodal communication device. It enables the user visua...

  3. Science Benefits of Onboard Spacecraft Navigation

    Science.gov (United States)

    Cangahuala, Al; Bhaskaran, Shyam; Owen, Bill

    2012-01-01

    Primitive bodies (asteroids and comets), which have remained relatively unaltered since their formation, are important targets for scientific missions that seek to understand the evolution of the solar system. Often the first step is to fly by these bodies with robotic spacecraft. The key to maximizing data returns from these flybys is to determine the spacecraft trajectory relative to the target body-in short, navigate the spacecraft- with sufficient accuracy so that the target is guaranteed to be in the instruments' field of view. The most powerful navigation data in these scenarios are images taken by the spacecraft of the target against a known star field (onboard astrometry). Traditionally, the relative trajectory of the spacecraft must be estimated hours to days in advance using images collected by the spacecraft. This is because of (1)!the long round-trip light times between the spacecraft and the Earth and (2)!the time needed to downlink and process navigation data on the ground, make decisions based on the result, and build and uplink instrument pointing sequences from the results. The light time and processing time compromise navigation accuracy considerably, because there is not enough time to use more accurate data collected closer to the target-such data are more accurate because the angular capability of the onboard astrometry is essentially constant as the distance to the target decreases, resulting in better "plane-of- sky" knowledge of the target. Excellent examples of these timing limitations are high-speed comet encounters. Comets are difficult to observe up close; their orbits often limit scientists to brief, rapid flybys, and their coma further restricts viewers from seeing the nucleus in any detail, unless they can view the nucleus at close range. Comet nuclei details are typically discernable for much shorter durations than the roundtrip light time to Earth, so robotic spacecraft must be able to perform onboard navigation. This onboard

  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. Effects of active navigation on object recognition in virtual environments.

    Science.gov (United States)

    Hahm, Jinsun; Lee, Kanghee; Lim, Seung-Lark; Kim, Sei-Young; Kim, Hyun-Taek; Lee, Jang-Han

    2007-04-01

    We investigated the importance and efficiency of active and passive exploration on the recognition of objects in a variety of virtual environments (VEs). In this study, 54 participants were randomly allocated into one of active and passive navigation conditions. Active navigation was performed by allowing participants to self-pace and control their own navigation, but passive navigation was conducted by forced navigation. After navigating VEs, participants were asked to recognize the objects that had been in the VEs. Active navigation condition had a significantly higher percentage of hit responses (t (52) = 4.000, p object recognition than the passive condition. These results suggest that active navigation plays an important role in spatial cognition as well as providing an explanation for the efficiency of learning in a 3D-based program. PMID:17474852

  6. Adaptive Landmark-Based Navigation System Using Learning Techniques

    DEFF Research Database (Denmark)

    Zeidan, Bassel; Dasgupta, Sakyasingha; Wörgötter, Florentin;

    2014-01-01

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

  7. NRPB volunteer study: deposition and clearance of inhaled particles

    International Nuclear Information System (INIS)

    At the Board Meeting of the National Radiological Protection Board held on 15 February 1996, approval was given for an experimental study of the deposition and clearance of inhaled particles in the human nasal passage. This is the latest in a series of volunteer biokinetic studies that have been conducted at NRPB since its formation. This article explains the purpose of the study, how ethical approval was obtained, how the study will be performed, what volunteers will be asked to do, and what doses they will receive. Doses will of course be carefully controlled, and will be well below the annual limits set for such experiments. The success of the study is of course crucially dependent on recruitment of a sufficient number of volunteers. The aim of this article is to provide information to anyone who might be interested in volunteering. (UK)

  8. Effect of lindane on the clearance rate of daphnia magna

    Science.gov (United States)

    Hartgers; Heugens; Deneer

    1999-05-01

    The impact of the insecticide lindane (gamma-hexachlorocyclohexane) on the clearance rate (CR) of Daphnia magna was investigated using artificial beads. CR (24-h EC50: 65 &mgr;g L-1) was found to be a more sensitive endpoint than acute lethality for D. magna (48-h LC50: 516 &mgr;g L-1). The onset of the effect was rapid; after 2 h of exposure to approximately 241 &mgr;g L-1 of lindane a significant decrease in CR was observed. Daphnids recovered rapidly after transfer to clean water; after 24 h of exposure to approximately 250 &mgr;g L-1 lindane, transfer into clean water resulted in recovery to 80% of control levels within 2 h and complete recovery within 24 h. PMID:10227859

  9. Biodistribution and clearance of instilled carbon nanotubes in rat lung

    Directory of Open Access Journals (Sweden)

    Rogerieux Françoise

    2008-12-01

    Full Text Available Abstract Background Constituted only by carbon atoms, CNT are hydrophobic and hardly detectable in biological tissues. These properties make biokinetics and toxicology studies more complex. Methods We propose here a method to investigate the biopersistence of CNT in organism, based on detection of nickel, a metal present in the MWCNT we investigated. Results and conclusion Our results in rats that received MWCNT by intratracheal instillation, reveal that MWCNT can be eliminated and do not significantly cross the pulmonary barrier but are still present in lungs 6 months after a unique instillation. MWCNT structure was also showed to be chemically modified and cleaved in the lung. These results provide the first data of CNT biopersistence and clearance at 6 months after respiratory administration.

  10. Dynamic analysis for planar beam with clearance joint

    Science.gov (United States)

    Yao, XiaoGuang; Guo, XiaoSong; Feng, YongBao; Yu, ChuanQiang; Ma, Changlin

    2015-03-01

    An analytical model was presented in this study to describe the dynamic characteristics of a planar rotation beam with clearance joint. The spherical contact model was introduced to calculate the collision forces for the planar revolute joint. Unlike previous research, to acquire an accurate and convergent solution, the second-order coupling term of the beam axial deformation is taken into account. Then, the flexible beam was divided into discrete elements via the finite element method. The dynamic equations of the model were deduced via the Hamilton's principle. Further, the dynamic responses were obtained and analyzed in the non-inertial and inertial coordinates. To prove the validity of the presented methodology, a virtual prototype model with identical conditions was created in ADAMS. A numerical example was simultaneously calculated by the two different approaches. Comparison of the results shows that the two approaches match quite well. Finally, some valuable conclusions describing the inner-joint collision process are extracted and summarized.

  11. Restoration of an endodontically treated premolar with limited interocclusal clearance

    Directory of Open Access Journals (Sweden)

    Sandya K Kini

    2013-01-01

    Full Text Available Endodontically treated teeth with the loss of coronal tooth structure when left untreated for a long period may cause supraeruption, drifting, tipping, and rotation of adjacent and opposing teeth. This may be challenging to the clinician, when fabricating a crown because of inadequate interocclusal space. This case report describes a simple technique to restore an endodontically treated maxillary first premolar with the loss of coronal tooth structure and lack of interocclusal space. The maxillary first premolar had a single root canal and was endodontically treated. The lower premolar had supraerupted reducing the interocclusal space. A minimally invasive and esthetic technique was used to restore the tooth with limited interocclusal clearance. The tooth was restored with a Richmond crown, which had the morphology of a canine instead of a premolar. Thus, the tooth was salvaged by changing the morphology of the crown and the desired functional and esthetic results were obtained.

  12. Clinical use of amylase clearance and isoamylase measurements.

    Science.gov (United States)

    Levitt, M D

    1979-07-01

    Isoamylase determinations and measurements of the ratio of the renal clearance of amylase relative to creatinine (CAm/CCr) were employed in an attempt to improve the diagnostic accuracy of the standard amylase measurement. An elevated CAm/CCr reflects defective proximal tubular reabsorption of amylase which occurs in virtually all patients with clear-cut acute pancreatitis. However, other conditions that apparently are associated with acute defective tubular function, such as burns and diabetic acidosis, may cause an elevated ratio. Thus, elevations of CAm/CCr cannot be considered to be specific for acute pancreatitis. Pancreatic isoamylase represents, on the average, about 33% of the normal serum amylase activity, whereas about 66% is salivary-type isoamylase. Isoamylase measurements are useful in determining whether an elevated value for serum amylase activity is of pancreatic origin. However, this measurement is not useful for determining whether patients with normal serum amylase activity have pancreatitis.

  13. Esophageal clearance scintigraphy in, diabetic patients; A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Karayalcin, B.; Karayalcin, U.; Aburano, Tamio; Nakajima, Kenichi; Hisada, Kinichi; Morise, Toshio; Okada, Toshihide; Takeda, Ryoyu (Kanazawa Univ. (Japan). School of Medicine)

    1992-05-01

    The aim of this preliminary study was to evaluate the predictive value of esophageal clearance scintigraphy (ECS) in the diagnosis of esophageal autonomic neuropathy in diabetic patients without any esophageal symptoms. A single swallon ECS was performed in 12 diabetic patients and 15 normal volunteers, and esophageal transit time (ETT) and esophageal (Es) T 1/2 values were calculated. ETT and Es 1/2 were found to be significantly prolonged in the diabetic group (p<0.01 and p<0.05, respectively). In this preliminary study, our results strongly suggest that ECS may be an important noninvasive diagnostic tool in the evaluation of diabetic patients with asymptomatic esophageal autonomic neuropathy. (author).

  14. Estimate of clearance levels for metal materials contaminated with uranium

    International Nuclear Information System (INIS)

    Clearance levels for the solid materials contaminated with uranium were estimated based on deterministic dose calculation approach for metal reuse scenario. The activity concentrations for major radionuclides, U-234, U-235 and U-238, were calculated to be 1.5Bq/g, 1.4Bq/g and 1.8Bq/g, respectively. In order to confirm the validity of the calculated concentrations, the authors estimated the uncertainties on scenario description after metal recycling and on parameter values used in the deterministic calculation. The validity of the calculated activity concentrations by the deterministic approach was confirmed from the results of both the analysis for an additional scenario on the landfill disposal of residue of slag after metal recycling and the Monte Carlo-based analysis for parameter uncertainties. (author)

  15. Container scanning to reduce time of customs clearance process

    Directory of Open Access Journals (Sweden)

    Yuri da Cunha Ferreira,

    2015-12-01

    Full Text Available One way to increase customs clearance efficiency and to assure supply chain security is the use of non-intrusive inspection equipment, such as scanners. In Brazil, scanners are new, but their use at port terminals is growing rapidly. Considering the possibility of Brazilian Customs requesting 100% scanning of loads, this study aims to assess the operational impacts of this possible request at a specific port terminal. This is the originality of this research. To do so, this study uses applied simulation methods in a case study. Results show that for the current scenario, scanners do not appear to be an operational bottleneck at this port, but the scanning capacity will be exceeded with the planned port expansion. Hence, scheduling rules for single machines were applied to optimize scanning performance. These heuristics provided good performance, suggesting that scanners can provide benefits to priority cargo handling, and could eventually increase the performance of port terminals throughout the country.

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

    OpenAIRE

    Huang, Tsung-Che; Tseng, Yi-Hsing

    2016-01-01

    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 sph...

  17. Renal Clearance: Using an Interactive Activity to Visualize a Tricky Concept

    Science.gov (United States)

    Hull, Kerry

    2016-01-01

    Renal clearance, the volume of blood cleared of a substance in a particular time period, is commonly recognized as one of the most difficult concepts in physiology. This difficulty may in part reflect the quantitative nature of renal clearance since many life sciences majors perceive that mathematics is irrelevant to their discipline. Students may…

  18. Development of a modular virus clearance package for anion exchange chromatography operated in weak partitioning mode.

    Science.gov (United States)

    Iskra, Timothy; Sacramo, Ashley; Gallo, Chris; Godavarti, Ranga; Chen, Shuang; Lute, Scott; Brorson, Kurt

    2015-01-01

    Anion exchange chromatography (AEX) operated under weak partitioning mode has been proven to be a powerful polishing step as well as a robust viral clearance step in Pfizer's monoclonal antibody (mAb) platform purification process. A multivariate design of experiment (DoE) study was conducted to understand the impact of operating parameters and feedstream impurity levels on viral clearance by weak partitioning mode AEX. Bacteriophage was used initially as a surrogate for neutral and acidic isoelectric point mammalian viruses (e.g., retrovirus and parvovirus). Five different mAbs were used in the evaluation of process parameters such as load challenge (both product and impurities), load pH, load conductivity, and contact time (bed height and flow-rate). The operating ranges obtained from phage clearance studies and Pfizer's historical data were used to define an appropriate operating range for a subsequent clearance study with model retrovirus and parvovirus. Both phage and virus clearance evaluations included feedstreams containing different levels of impurities such as high molecular mass species (HMMS), host cell proteins (HCPs), and host cell DNA. For all the conditions tested, over 5 log10 of clearance for both retrovirus and parvovirus was achieved. The results demonstrated that weak partitioning mode AEX chromatography is a robust step for viral clearance and has the potential to be included as part of the modular viral clearance approach.

  19. 49 CFR 236.73 - Open-wire transmission line; clearance to other circuits.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Open-wire transmission line; clearance to other... line; clearance to other circuits. Open-wire transmission line operating at voltage of 750 volts or... THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS,...

  20. Low serum hyaluronic acid levels associated with spontaneous HBsAg clearance

    NARCIS (Netherlands)

    Harkisoen, S.; Arends, J. E.; van den Hoek, A.; van Erpecum, K. J.; Boland, G. J.; Hoepelman, A. I. M.

    2015-01-01

    Purpose The pathophysiological underlying mechanism of spontaneous HBsAg clearance in hepatitis B virus (HBV) infected patients is largely unknown. However, serum hyaluronic acid (sHA) plays a role in liver fibrosis progression and reversely could serve as a potential biomarker for HBsAg clearance.

  1. Relationship of end-expiratory pressure, lung volume, and /sup 99m/Tc-DTPA clearance

    International Nuclear Information System (INIS)

    We investigated the dose-response effect of positive end-expiratory pressure (PEEP) and increased lung volume on the pulmonary clearance rate of aerosolized technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA). Clearance of lung radioactivity was expressed as percent decrease per minute. Base-line clearance was measured while anesthetized sheep (n = 20) were ventilated with 0 cmH2O end-expiratory pressure. Clearance was remeasured during ventilation at 2.5, 5, 10, 15, or 20 cmH2O PEEP. Further studies showed stepwise increases in functional residual capacity (FRC) (P less than 0.05) measured at 0, 2.5, 5, 10, 15, and 20 cmH2O PEEP. At 2.5 cmH2O PEEP, the clearance rate was not different from that at base line (P less than 0.05), although FRC was increased from base line. Clearance rate increased progressively with increasing PEEP at 5, 10, and 15 cmH2O (P less than 0.05). Between 15 and 20 cmH2O PEEP, clearance rate was again unchanged, despite an increase in FRC. The pulmonary clearance of aerosolized /sup 99m/Tc-DTPA shows a sigmoidal response to increasing FRC and PEEP, having both threshold and maximal effects. This relationship is most consistent with the hypothesis that alveolar epithelial permeability is increased by lung inflation

  2. Influence of Renal Failure on Intestinal Clearance of Ciprofloxacin in Rats

    OpenAIRE

    Dautrey, Sophie; Rabbaa, Lydia; Laouari, Denise; Lacour, Bernard; Carbon, Claude; Farinotti, Robert

    1999-01-01

    Following intravenous doses, ciprofloxacin pharmacokinetics in control and nephrectomized rats were studied. There were no differences between control and nephrectomized rats for area under the concentration-time curve in plasma or biliary clearance. The intestinal clearance of ciprofloxacin was increased in nephrectomized rats. Intestinal elimination seems to compensate partially for the decrease in urinary excretion of ciprofloxacin in nephrectomized rats.

  3. Factors Associated with Spontaneous Clearance of Hepatitis C Virus in Chinese Population

    Directory of Open Access Journals (Sweden)

    Fei Kong

    2014-01-01

    Full Text Available Hepatitis C virus (HCV infections spontaneously clear in approximately 15–45% of infected individuals. Factors which influence spontaneous HCV clearance remain to be identified. The purpose of the present study was to identify variables associated with spontaneous HCV clearance in a referred population of Chinese patients. The prevalence of host, viral, and environmental factors known to influence the outcome of HCV infections was compared in 92 HCV spontaneous clearance subjects and 318 HCV persistent infection subjects. Univariate and multivariate analyses were performed to identify those factors associated with spontaneous HCV clearance. In univariate analysis, female gender, a history of icteric hepatitis, serologic evidence of concurrent HBV infection, and rs12979860 CC genotype were positively associated with spontaneous HCV clearance, while alcohol consumption was negatively associated with clearance. In multivariate analysis, female gender, a history of icteric hepatitis, concurrent HBV infection, and rs12979860 CC genotype remained independent variables associated with spontaneous HCV clearance. Spontaneous HCV clearance is more likely to occur in females, subjects with a history of icteric hepatitis, HBV coinfections, and those with the rs12979860 CC genotype.

  4. Effect of prior immobilization on muscular glucose clearance in resting and running rats

    International Nuclear Information System (INIS)

    In vitro studies have shown that prior disuse impairs the glucose clearance of red skeletal muscle because of a developed insensitivity to insulin. We studied whether an impaired glucose clearance is present in vivo in 42-h immobilized muscles of resting rats and, furthermore, whether the exercise-induced increase in glucose clearance of red muscles is affected by prior immobilization. The 2-[3H]deoxy-D-glucose (2DG) bolus injection method was used to determine glucose clearance of individual muscles. At rest, glucose clearance was markedly impaired in rats with previously immobilized red muscles compared with nonimmobilized control rats. During running, glucose clearance did not differ between muscles in previously immobilized and control rats. Insulin levels were always similar in the two groups and decreased during exercise. Intracellular nonphosphorylated 2DG was present in tissues with high glucose clearances. In conclusion, 42 h of immobilization markedly impairs glucose clearance of resting red muscle fibers in vivo. Apparently, physical inactivity in particular affects steps involved in insulin-mediated action that are not part of contraction-induced glucose uptake and metabolism. Presence of intracellular 2DG shows that separate determination of phosphorylated 2DG is necessary for accurate estimates of glucose metabolism and that accumulation of phosphorylated 2DG does not accurately reflect glucose transport

  5. Tube to U-bend support bar in-situ clearance measurement

    International Nuclear Information System (INIS)

    Most recirculating nuclear steam generators throughout the world have some type of flat bar U-bend restraint or anti-vibration bar for the purpose of positioning the long flexible U-bend tubes in their respective planes. These support bars minimize tube response to flow induced vibration forces and mitigate fretting of tubes due to those forces. Steam generators from all sources have experienced some degree of fretting, usually on a relatively small number of tubes. Flow induced vibration response and fretting are influenced by a large number of parameters including the flow velocity, density, the tube diameter and stiffness, the tube and bar material combination and also the magnitude and consistency of the tube to bar clearances. Over the years the nominal tube to bar support clearances have been systematically reduced. Nevertheless some fretting has still persisted. In pursuing the problem, the expectation is that the situation will be avoided by further reducing nominal clearance. On the other hand, there is little data in hand as to the actual local clearances or the distribution of clearances within a U-bend array. Therefore, it is not possible to ascertain from field data what clearance conditions are necessary for fretting to exist; or more importantly what clearance conditions are necessary to avoid fretting. This paper describes the development for eddy current inspection techniques for in-situ measurement of tube to U-bend support bar clearance. (author)

  6. Active generalized predictive control of turbine tip clearance for aero-engines

    Institute of Scientific and Technical Information of China (English)

    Peng Kai; Fan Ding; Yang Fan; Fu Qiang; Li Yong

    2013-01-01

    Active control of turbine blade tip clearance continues to be a concern in design and con-trol of gas turbines. Ever increasing demands for improved efficiency and higher operating temper-atures require more stringent tolerances on turbine tip clearance. In this paper, a turbine tip clearance control apparatus and a model of turbine tip clearance are proposed;an implicit active generalized predictive control (GPC), with auto-regressive (AR) error modification and fuzzy adjustment on control horizon, is presented, as well as a quantitative analysis method of robust per-turbation radius of the system. The active clearance control (ACC) of aero-engine turbine tip clear-ance is evaluated in a lapse-rate take-off transient, along with the comparative and quantitative analysis of the stability and robustness of the active tip clearance control system. The results show that the resultant active tip clearance control system with the improved GPC has favorable steady-state and dynamic performance and benefits of increased efficiency, reduced specific fuel consump-tion, and additional service life.

  7. Effect of adrenergic stimulation on clearance from small ciliated airways in healthy subjects.

    Science.gov (United States)

    Svartengren, K; Philipson, K; Svartengren, M; Camner, P

    1998-01-01

    Mucociliary transport is an important clearance mechanism of larger airways, but in the smallest ciliated airways (bronchioles) it may be less effective. The present study aimed at investigating whether clearance from the bronchioles in subjects with healthy airways was stimulated by an adrenergic agonist (terbutaline sulphate). Tracheobronchial clearance was studied twice in 10 healthy subjects after inhalation of 6-micron (aerodynamic diameter) monodisperse Teflon particles labeled with 111In. At one exposure, oral treatment with terbutaline sulphate, known to stimulate clearance in large airways, began immediately after inhalation of the particles. The other exposure was a control measurement. The particles were inhaled at an extremely slow flow, 0.05 L/s, which gave deposition mainly in the small ciliated airways (bronchioles). Lung retention was measured at 0, 24, 48, and 72 h. Clearance was significant every 24 h for both exposures (p terbutaline sulphate, the subjects' pulse rates tended to be higher, but clearance rates did not increase. We found, as expected, no significant correlation between lung retention and lung function in either exposure. This study shows that an adrenergic agonist does not significantly influence overall clearance from the bronchiolar region in healthy subjects. This suggests that mucociliary transport does not significantly contribute to clearance from the smallest ciliated airways. Other mechanisms may be more important for the transportation of mucus from these airways. PMID:9555573

  8. Effect of prior immobilization on muscular glucose clearance in resting and running rats

    DEFF Research Database (Denmark)

    Vissing, J; Ohkuwa, T; Ploug, Thorkil;

    1988-01-01

    In vitro studies have shown that prior disuse impairs the glucose clearance of red skeletal muscle because of a developed insensitivity to insulin. We studied whether an impaired glucose clearance is present in vivo in 42-h immobilized muscles of resting rats and, furthermore, whether the exercis...

  9. 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... Provisions § 64.31 Determination of hazard to navigation. In determining whether an obstruction is a hazard... vessel incidents involving the obstruction; and (k) Whether the obstruction is defined as a hazard...

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

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  11. 14 CFR 121.305 - Flight and navigational equipment.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight and navigational equipment. 121.305... Flight and navigational equipment. No person may operate an airplane unless it is equipped with the following flight and navigational instruments and equipment: (a) An airspeed indicating system with...

  12. Time and Motion Study of a Community Patient Navigator

    Directory of Open Access Journals (Sweden)

    Sara S. Phillips

    2014-04-01

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

  13. Fault-tolerant Sensor Fusion for Marine Navigation

    DEFF Research Database (Denmark)

    Blanke, Mogens

    2006-01-01

    Reliability of navigation data are critical for steering and manoeuvring control, and in particular so at high speed or in critical phases of a mission. Should faults occur, faulty instruments need be autonomously isolated and faulty information discarded. This paper designs a navigation solution...... events where the fault-tolerant sensor fusion provided uninterrupted navigation data despite temporal instrument defects...

  14. Field-based validation of a tactile navigation device

    NARCIS (Netherlands)

    Elliott, L.R.; Erp, J. van; Redden, E.S.; Duistermaat, M.

    2010-01-01

    In this paper, we present three field-based evaluations of a tactile land navigation system. In Experiment 1, we transition from a laboratory setting to rugged terrain used to train US Army soldier land navigation. Navigation in this challenging terrain requires careful attention to one's surroundin

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

    NARCIS (Netherlands)

    Philippi, T.G.

    2012-01-01

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

  16. 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.

  17. 47 CFR 22.365 - Antenna structures; air navigation safety.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Antenna structures; air navigation safety. 22... Antenna structures; air navigation safety. Licensees that own their antenna structures must not allow these antenna structures to become a hazard to air navigation. In general, antenna structure owners...

  18. Regional alterations in long bone produced by internal fixation devices. Part I. 85Sr clearance

    International Nuclear Information System (INIS)

    We examined the effect of rigid plate application on the radiostrontium clearance of the intact canine femur at 6 months. We examined each of the component surgical steps. We calculated the clearance both for the whole bone and for each of the five transverse sections of the whole bone. Screw application, but not drilling, increased the clearance in the segment about the screw holes. Plate application produced an increase in the segment beneath the plate as well as around the screws and in the whole bone. These changes are accomplished not only by an absolute increase in clearance to the middle three segments, but by a relative diminution in clearance by the most proximal and distal segments. The histomorphometric changes in long bones following rigid plating may be accompanied by regional increases in bone blood flow

  19. Vest Chest Physiotherapy Airway Clearance is Associated with Nitric Oxide Metabolism

    Directory of Open Access Journals (Sweden)

    Joseph H. Sisson

    2013-01-01

    Full Text Available Background. Vest chest physiotherapy (VCPT enhances airway clearance in cystic fibrosis (CF by an unknown mechanism. Because cilia are sensitive to nitric oxide (NO, we hypothesized that VCPT enhances clearance by changing NO metabolism. Methods. Both normal subjects and stable CF subjects had pre- and post-VCPT airway clearance assessed using nasal saccharin transit time (NSTT followed by a collection of exhaled breath condensate (EBC analyzed for NO metabolites (. Results. VCPT shorted NSTT by 35% in normal and stable CF subjects with no difference observed between the groups. EBC concentrations decreased 68% in control subjects after VCPT (before = 115 ± 32 μM versus after = 37 ± 17 μM; . CF subjects had a trend toward lower EBC . Conclusion. We found an association between VCPT-stimulated clearance and exhaled levels in human subjects. We speculate that VCPT stimulates clearance via increased NO metabolism.

  20. Study on leakage flow characteristics of radial inflow turbines at rotor tip clearance

    Institute of Scientific and Technical Information of China (English)

    DENG QingHua; NIU JiuFang; FENG ZhenPing

    2008-01-01

    Tip clearance leakage flow in a radial inflow turbine rotor for microturbines under the stage environment is investigated using a three-dimensional viscous flow simulation. The results indicate that the scraping flow caused by relative motion between casing and rotor tip, and the pressure difference between pressure side and suction side at rotor tip, play important roles in tip clearance leakage flow. The more the rotor tip speed increases and tip clearance height decreases, the more the scraping effect acta. Though the leakage velocity of tip clearance at midsection and exducer regions changes less when the rotor rotational speed is changing, the distance between passage vortex and rotor suction side varies in evidence. Main leakage flow rate of tip clearance takes place at region of exducer tip and some seal configurations will be quite effective for cutting leakage flow if these configurations are arranged over midsection and exducer of the radial inflow rotor.

  1. Study on leakage flow characteristics of radial inflow turbines at rotor tip clearance

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Tip clearance leakage flow in a radial inflow turbine rotor for microturbines under the stage environment is investigated using a three-dimensional viscous flow simulation. The results indicate that the scraping flow caused by relative motion between casing and rotor tip, and the pressure difference between pressure side and suction side at rotor tip, play important roles in tip clearance leakage flow. The more the rotor tip speed increases and tip clearance height decreases, the more the scraping effect acts. Though the leakage velocity of tip clearance at midsection and exducer regions changes less when the rotor rotational speed is changing, the distance between passage vortex and rotor suction side varies in evidence. Main leakage flow rate of tip clearance takes place at region of exducer tip and some seal configurations will be quite effective for cutting leakage flow if these configurations are arranged over midsection and exducer of the radial inflow rotor.

  2. Testing Two Tools for Multimodal Navigation

    Directory of Open Access Journals (Sweden)

    Mats Liljedahl

    2012-01-01

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

  3. Autonomous rough terrain navigation - Lessons learned

    Science.gov (United States)

    Miller, David P.

    1991-01-01

    Because of light-time delays, a planetary rover located on Mars or beyond will probably need to be able to navigate autonomously, in order to do significant exploration. Recent work at JPL has explored several different autonomous navigation strategies. This work includes highly deliberative methods that require large amounts of computation and internal storage but yield very planful behavior to more reactive systems that require less resources but whose behavior is more difficult to model. This paper briefly presents these methods, the results from experiments both in simulation and in the field, and some conclusions on the value of different approaches, and their possible impact on the structure of the robot and the mission architecture.

  4. Content-based navigation within virtual museums

    Directory of Open Access Journals (Sweden)

    Anestis Koutsoudis

    2012-05-01

    Full Text Available The ongoing evolution of the Internet has enabled web applications that use real time three-dimensional (3D graphics and virtual environments. Moreover, in recent years, cultural technology has also flourished notably. Virtual museums represent one significant application that combines culture with modern technologies and the internet, requiring an interdisciplinary approach aiming both at dissemination and education. We present our approach to enhance virtual museums by incorporating content-based retrieval that refers to 3D objects. In this context, a virtual visitor is able to navigate within the museum, examine the exhibited artifacts and perform queries-by-example in order to locate the position of related artifacts. The retrieval mechanism responds to the visitor’s queries by indicating similar artifacts, which are ranked according to their similarity scores. This way, the visitor is able to navigate within a virtual museum not only by means of a virtual walkthrough but also by means of the context

  5. Energy Navigation: Simulation Evaluation and Benefit Analysis

    Science.gov (United States)

    Williams, David H.; Oseguera-Lohr, Rosa M.; Lewis, Elliot T.

    2011-01-01

    This paper presents results from two simulation studies investigating the use of advanced flight-deck-based energy navigation (ENAV) and conventional transport-category vertical navigation (VNAV) for conducting a descent through a busy terminal area, using Continuous Descent Arrival (CDA) procedures. This research was part of the Low Noise Flight Procedures (LNFP) element within the Quiet Aircraft Technology (QAT) Project, and the subsequent Airspace Super Density Operations (ASDO) research focus area of the Airspace Project. A piloted simulation study addressed development of flight guidance, and supporting pilot and Air Traffic Control (ATC) procedures for high density terminal operations. The procedures and charts were designed to be easy to understand, and to make it easy for the crew to make changes via the Flight Management Computer Control-Display Unit (FMC-CDU) to accommodate changes from ATC.

  6. Navigational mechanisms of migrating monarch butterflies.

    Science.gov (United States)

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

    2010-09-01

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

  7. Reactive navigational controller for autonomous mobile robots

    Science.gov (United States)

    Hawkins, Scott

    1993-12-01

    Autonomous mobile robots must respond to external challenges and threats in real time. One way to satisfy this requirement is to use a fast low level intelligence to react to local environment changes. A fast reactive controller has been implemented which performs the task of real time local navigation by integrating primitive elements of perception, planning, and control. Competing achievement and constraint behaviors are used to allow abstract qualitative specification of navigation goals. An interface is provided to allow a higher level deliberative intelligence with a more global perspective to set local goals for the reactive controller. The reactive controller's simplistic strategies may not always succeed, so a means to monitor and redirect the reactive controller is provided.

  8. Automatic document navigation for digital content remastering

    Science.gov (United States)

    Lin, Xiaofan; Simske, Steven J.

    2003-12-01

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

  9. Design of Evolvable Hardware for Robotic Navigation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents an integrated on-line learning system toevolve programmabl e logic array (PLA) controllers for navigating an autonomous robot in a two-dime n sional environment. The integrated on-line learning system consists of two lear n ing modules: one is the module of reinforcement learning based on temporal-diff e rence learning based on genetic algorithms, and the other is the module of evolu tionary learning based on genetic algorithms. The control rules extracted from t he module of reinforcement learning can be used as input to the module of evolut ionary learning, and quickly implemented by the PLA through on-line evolution. T he on-line evolution has shown promise as a method of learning systems in compl e x environment. The evolved PLA controllers can successfully navigate the robot t o a target in the two-dimensional environment while avoiding collisions with ra ndomly positioned obstacles.

  10. Development of autonomous grasping and navigating robot

    Science.gov (United States)

    Kudoh, Hiroyuki; Fujimoto, Keisuke; Nakayama, Yasuichi

    2015-01-01

    The ability to find and grasp target items in an unknown environment is important for working robots. We developed an autonomous navigating and grasping robot. The operations are locating a requested item, moving to where the item is placed, finding the item on a shelf or table, and picking the item up from the shelf or the table. To achieve these operations, we designed the robot with three functions: an autonomous navigating function that generates a map and a route in an unknown environment, an item position recognizing function, and a grasping function. We tested this robot in an unknown environment. It achieved a series of operations: moving to a destination, recognizing the positions of items on a shelf, picking up an item, placing it on a cart with its hand, and returning to the starting location. The results of this experiment show the applicability of reducing the workforce with robots.

  11. Robot navigation system using intrinsic evolvable hardware

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Recently there has been great interest in the idea that evolvable system based on the principle of ar tifcial intelligence can be used to continuously and autonomously adapt the behaviour of physically embedded systems such as autonomous mobile robots and intelligent home devices. Meanwhile, we have seen the introduc tion of evolvable hardware(EHW): new integrated electronic circuits that are able to continuously evolve to a dapt the chages in the environment implemented by evolutionary algorithms such as genetic algorithm(GA)and reinforcement learning. This paper concentrates on developing a robotic navigation system whose basic behav iours are obstacle avoidance and light source navigation. The results demonstrate that the intrinsic evolvable hardware system is able to create the stable robotiiuc behaviours as required in the real world instead of the tra ditional hardware systems.

  12. Pedestrian navigation using the sense of touch

    OpenAIRE

    Jacob, Ricky; Winstanley, Adam; Togher, Naomi; Roche, Richard; Mooney, Peter

    2012-01-01

    Haptics is a feedback technology that takes advantage of the human sense of touch by applying forces, vibrations, and/or motions to a haptic-enabled user device such as a mobile phone. Historically, human–computer interaction has been visual, data, or images on a screen. Haptic feedback can be an important modality in Mobile Location-Based Services like – knowledge discovery, pedestrian navigation and notification systems. In this paper we describe a methodology for the implementa...

  13. Visual SLAM for Autonomous Navigation of MAVs

    OpenAIRE

    Yang, Shaowu

    2014-01-01

    This thesis focuses on developing onboard visual simultaneous localization and mapping (SLAM) systems to enable autonomous navigation of micro aerial vehicles (MAVs), which is still a challenging topic considering the limited payload and computational capability that an MAV normally has. In MAV applications, the visual SLAM systems are required to be very efficient, especially when other visual tasks have to be done in parallel. Furthermore, robustness in pose tracking is highly desired in or...

  14. Sensor Fusion Navigation for Sounding Rocket Applications

    OpenAIRE

    Nilsson, Mattias; Vinkvist, Rikard

    2008-01-01

    One of Saab Space’s products is the S19 guidance system for sounding rockets.Today this system is based on an inertial navigation system that blindly calculatesthe position of the rocket by integrating sensor readings with unknown bias. Thepurpose of this thesis is to integrate a Global Positioning System (GPS) receiverinto the guidance system to increase precision and robustness. There are mainlytwo problems involved in this integration. One is to integrate the GPS with sensorfusion into the...

  15. Particle Filters for Positioning, Navigation and Tracking

    OpenAIRE

    Gustafsson, Fredrik; Gunnarsson, Fredrik; Bergman, Niclas; Forssell, Urban; Jansson, Jonas; Karlsson, Rickard; Nordlund, Per-Johan

    2001-01-01

    A framework for positioning, navigation and tracking problems using particle filters (sequential Monte Carlo methods) is developed. It consists of a class of motion models and a general non-linear measurement equation in position. A general algorithm is presented, which is parsimonious with the particle dimension. It is based on marginalization, enabling a Kalman filter to estimate all position derivatives, and the particle filter becomes low-dimensional. This is of utmost importance for high...

  16. Interior Design and Navigation in Virtual Reality

    OpenAIRE

    Tingvall, Jesper

    2015-01-01

    This thesis examined how virtual reality could be used in interior design. The thesis was limited to virtual reality experienced using a head mounted display. The Method was to integrate virtual reality into an existing interior design software called CET Designer. After investigating the available commercial virtual reality hardware and software Oculus SDK and OpenVR was chosen. Unity 3D was used as a prototyping tool for experimenting with different interaction and navigation methods. An use...

  17. Reactive Robot Navigation Utilizing Nonlinear Control

    OpenAIRE

    Lei Ting; Macnab, Chris J.B.; Sebastian Magierowski

    2014-01-01

    In this paper, we propose a computationally efficient heuristic solution to choosing a path around obstacles in the face of limited sensor information. Specifically, we propose a navigation algorithm for a mobile robot that reaches a measured target position while avoiding obstacles, making decisions in real-time (without stopping) and relying strictly on information obtained from limited and noisy robot-mounted sensors to determine the location and severity of obstacles. The solution utilize...

  18. Biologically Inspired Vision for Indoor Robot Navigation

    OpenAIRE

    Saleiro, Mário; Tersic, K.; Lobato, D.; Rodrigues, J. M. F.; du Buf, J. M. H.

    2014-01-01

    Ultrasonic, infrared, laser and other sensors are being applied in robotics. Although combinations of these have allowed robots to navigate, they are only suited for specific scenarios, depending on their limitations. Recent advances in computer vision are turning cameras into useful low-cost sensors that can operate in most types of environments. Cameras enable robots to detect obstacles, recognize objects, obtain visual odometry, detect and recognize people and gestures, a...

  19. Navigational Mechanisms of Migrating Monarch Butterflies

    OpenAIRE

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

    2010-01-01

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

  20. Navigation, perception et apprentissage pour la robotique

    OpenAIRE

    Filliat, David

    2011-01-01

    We conducted research mainly in the areas of navigation, perception and learning for mobile robots. These studies, oriented toward a cognitive approach to robotics have the overall goal of allowing robots to adapt to their environment, providing ba- sic primitives such as open space, position, or the presence of objects necessary to choose actions. A large part of this work is inspired by capabilities found in nature, but without trying to reproduce exactly the biological systems inner functi...

  1. Distributed parallel computing using navigational programming

    OpenAIRE

    Pan, Lei; Lai, M. K.; Noguchi, K; Huseynov, J J; L. F. Bic; Dillencourt, M B

    2004-01-01

    Message Passing ( MP) and Distributed Shared Memory (DSM) are the two most common approaches to distributed parallel computing. MP is difficult to use, whereas DSM is not scalable. Performance scalability and ease of programming can be achieved at the same time by using navigational programming (NavP). This approach combines the advantages of MP and DSM, and it balances convenience and flexibility. Similar to MP, NavP suggests to its programmers the principle of pivot-computes and hence is ef...

  2. The meteoroids hazard for space navigation

    CERN Document Server

    Foschini, L

    1998-01-01

    Thanks to post-flight analyses of several artificial satellites carried out during last years, the meteoroids hazard for space navigation and in-orbit satellites permanence is now clear. Even if catastrophic impact is a rare event, high meteoroids fluxes can erode and weaken the satellite or space station main structures. However, the main danger seems to be the impact-generated plasma, which can produce electromagnetic interferences, disturbing the on-board electronics.

  3. Outdoor autonomous navigation using monocular vision

    OpenAIRE

    Royer, Eric; Bom, Jonathan; Dhome, Michel; Thuilot, Benoît; Lhuillier, Maxime; Marmoiton, Francois

    2005-01-01

    International audience; In this paper, a complete system for outdoor robot navigation is presented. It uses only monocular vision. The robot is first guided on a path by a human. During this learning step, the robot records a video sequence. From this sequence, a three dimensional map of the trajectory and the environment is built. When this map has been computed, the robot is able to follow the same trajectory by itself. Experimental results carried out with an urban electric vehicle are sho...

  4. Simultaneous Navigation and Synthetic Aperture Radar Focusing

    OpenAIRE

    Sjanic, Zoran; Gustafsson, Fredrik

    2015-01-01

    Synthetic aperture radar (SAR) equipment is a radar imaging system that can be used to create high-resolution images of a scene by utilizing the movement of a flying platform. Knowledge of the platforms trajectory is essential to get good and focused images. An emerging application field is real-time SAR imaging using small and cheap platforms where estimation errors in navigation systems imply unfocused images. This contribution investigates a joint estimation of the trajectory and SAR image...

  5. Factors contributing to delay in parasite clearance in uncomplicated falciparum malaria in children

    Directory of Open Access Journals (Sweden)

    Sijuade Abayomi

    2010-02-01

    Full Text Available Abstract Background Drug resistance in Plasmodium falciparum is common in many endemic and other settings but there is no clear recommendation on when to change therapy when there is delay in parasite clearance after initiation of therapy in African children. Methods The factors contributing to delay in parasite clearance, defined as a clearance time > 2 d, in falciparum malaria were characterized in 2,752 prospectively studied children treated with anti-malarial drugs between 1996 and 2008. Results 1,237 of 2,752 children (45% had delay in parasite clearance. Overall 211 children (17% with delay in clearance subsequently failed therapy and they constituted 72% of those who had drug failure, i.e., 211 of 291 children. The following were independent risk factors for delay in parasite clearance at enrolment: age less than or equal to 2 years (Adjusted odds ratio [AOR] = 2.13, 95% confidence interval [CI]1.44-3.15, P 50,000/ul (AOR = 2.21, 95% CI = 1.77-2.75, P 20000/μl a day after treatment began, were independent risk factors for delay in clearance. Non-artemisinin monotherapies were associated with delay in clearance and treatment failures, and in those treated with chloroquine or amodiaquine, with pfmdr 1/pfcrt mutants. Delay in clearance significantly increased gametocyte carriage (P Conclusion Delay in parasite clearance is multifactorial, is related to drug resistance and treatment failure in uncomplicated malaria and has implications for malaria control efforts in sub-Saharan Africa.

  6. Geomagnetic storm effects on GPS based navigation

    Directory of Open Access Journals (Sweden)

    P. V. S. Rama Rao

    2009-05-01

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

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

  7. Cues indicating location in pigeon navigation.

    Science.gov (United States)

    Beason, Robert C; Wiltschko, Wolfgang

    2015-10-01

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

  8. Navigation in Orthognathic Surgery: 3D Accuracy.

    Science.gov (United States)

    Badiali, Giovanni; Roncari, Andrea; Bianchi, Alberto; Taddei, Fulvia; Marchetti, Claudio; Schileo, Enrico

    2015-10-01

    This article aims to determine the absolute accuracy of maxillary repositioning during orthognathic surgery according to simulation-guided navigation, that is, the combination of navigation and three-dimensional (3D) virtual surgery. We retrospectively studied 15 patients treated for asymmetric dentofacial deformities at the Oral and Maxillofacial Surgery Unit of the S.Orsola-Malpighi University Hospital in Bologna, Italy, from January 2010 to January 2012. Patients were scanned with a cone-beam computed tomography before and after surgery. The virtual surgical simulation was realized with a dedicated software and loaded on a navigation system to improve intraoperative reproducibility of the preoperative planning. We analyzed the outcome following two protocols: (1) planning versus postoperative 3D surface analysis; (2) planning versus postoperative point-based analysis. For 3D surface comparison, the mean Hausdorff distance was measured, and median among cases was 0.99 mm. Median reproducibility orthognathic surgery, if compared with the surgical computer-designed project realized with a dedicated software, particularly for the vertical dimension, which is the most challenging to manage.

  9. Multimodal cognitive interface for robot navigation.

    Science.gov (United States)

    Elmogy, Mohammed; Habel, Christopher; Zhang, Jianwei

    2011-02-01

    To build effective interactions between humans and robots, they should have common ground of understanding that creates realistic expectations and forms the basis communications. An emerging approach to doing this is to create cognitive models of human reasoning and behavior selection. We have developed a robot navigation system that uses both spatial language and graphical representation to describe route-based navigation tasks for a mobile robot. Our proposed route instruction language (RIL) is intended as a semi-formal language for instructing the robot to execute a route in an indoor environment. We implemented an instruction interpreter to process the route description and generate its equivalent symbolic and topological map representations. A topological map is generated to describe relationships among features of the environment in a more abstract form without any absolute reference system to treat the ambiguity which can occur when the robot cannot recognize the current landmark. The symbolic and topological map representations are supplied to other system components as an initial path estimation to guide the robot while it plans its navigation task. We conducted some experiments to evaluate the routes which are written by using the RIL instructions.

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

    Science.gov (United States)

    2010-01-01

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

  11. Cancer Patient Navigation Case Studies in Hawai‘i: The Complimentary Role of Clinical and Community Navigators

    OpenAIRE

    Domingo, Jermy B; Davis, Elise L; Allison, Amanda L; Braun, Kathryn L.

    2011-01-01

    This article describes the activities performed by cancer patient navigators in community-based and hospital settings. The case study demonstrates the depth and breadth of navigation activities and illustrates how hospital-based and community-based navigators work together to help individuals access cancer care and complete cancer treatment.

  12. Indoor inertial navigation application for smartphones with Android

    Science.gov (United States)

    Kamiński, Ł.; Tarapata, G.

    2015-09-01

    Inertial navigation is widely used by the military, in logistics and sailing. In mobile devices, inertial sensors are mostly used as a support for GPS and Wi-Fi-based navigation systems. Inertial-based navigation might prove useful on mobile devices running Android OS. At present, in spite of the accelerometer sensor's precision having been greatly improved, as well as the devices' computing power continuously rising, inertial navigation's precision still suffers. For smartphones, the key solution seems to be the usage of sensor fusion and signal smart filtering, both discussed in this paper. The paper also describes implementation of inertial navigation in Android devices, their analysis as well as test results.

  13. An integrated GPS/DR navigation system for AUV

    Institute of Scientific and Technical Information of China (English)

    PANG Yong-jie; SUN Yu-shan; GAN Yong; WAN Lei

    2006-01-01

    GPS/Dead-reckoning navigation system for autonomous underwater vehicle (AUV) is introduced, which includes navigation overall architecture, hardware and software structure.Dead-reckoning theory is presented in details. And the strong tracking Kalman filter and Singer model are applied to handle the imprecise navigation mode, which can improve the navigation system's precision and reliability. Finally, the sea experiments which include autonomous search mission in an unknown area and long distance motion are conducted to demonstrate the reliability and feasibility of the navigation system.

  14. Principles of X-ray Navigation

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, John Eric; /SLAC

    2006-03-17

    X-ray navigation is a new concept in satellite navigation in which orientation, position and time are measured by observing stellar emissions in x-ray wavelengths. X-ray navigation offers the opportunity for a single instrument to be used to measure these parameters autonomously. Furthermore, this concept is not limited to missions in close proximity to the earth. X-ray navigation can be used on a variety of missions from satellites in low earth orbit to spacecraft on interplanetary missions. In 1997 the Unconventional Stellar Aspect Experiment (USA) will be launched as part of the Advanced Research and Global Observation Satellite (ARGOS). USA will provide the first platform for real-time experimentation in the field of x-ray navigation and also serves as an excellent case study for the design and manufacturing of space qualified systems in small, autonomous groups. Current techniques for determining the orientation of a satellite rely on observations of the earth, sun and stars in infrared, visible or ultraviolet wavelengths. It is possible to use x-ray imaging devices to provide arcsecond level measurement of attitude based on star patterns in the x-ray sky. This technique is explored with a simple simulation. Collimated x-ray detectors can be used on spinning satellites to provide a cheap and reliable measure of orientation. This is demonstrated using observations of the Crab Pulsar taken by the high Energy Astronomy Observatory (HEAO-1) in 1977. A single instrument concept is shown to be effective, but dependent on an a priori estimate of the guide star intensity and thus susceptible to errors in that estimate. A star scanner based on a differential measurement from two x-ray detectors eliminates the need for an a priori estimate of the guide star intensity. A first order model and a second order model of the two star scanner concepts are considered. Many of the stars that emit in the x-ray regime are also x-ray pulsars with frequency stability approaching a

  15. 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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  17. Reference frames in learning from maps and navigation.

    Science.gov (United States)

    Meilinger, Tobias; Frankenstein, Julia; Watanabe, Katsumi; Bülthoff, Heinrich H; Hölscher, Christoph

    2015-11-01

    In everyday life, navigators often consult a map before they navigate to a destination (e.g., a hotel, a room, etc.). However, not much is known about how humans gain spatial knowledge from seeing a map and direct navigation together. In the present experiments, participants learned a simple multiple corridor space either from a map only, only from walking through the virtual environment, first from the map and then from navigation, or first from navigation and then from the map. Afterwards, they conducted a pointing task from multiple body orientations to infer the underlying reference frames. We constructed the learning experiences in a way such that map-only learning and navigation-only learning triggered spatial memory organized along different reference frame orientations. When learning from maps before and during navigation, participants employed a map- rather than a navigation-based reference frame in the subsequent pointing task. Consequently, maps caused the employment of a map-oriented reference frame found in memory for highly familiar urban environments ruling out explanations from environmental structure or north preference. When learning from navigation first and then from the map, the pattern of results reversed and participants employed a navigation-based reference frame. The priority of learning order suggests that despite considerable difference between map and navigation learning participants did not use the more salient or in general more useful information, but relied on the reference frame established first. PMID:25416007

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

    Science.gov (United States)

    Holbrook, Jarita C.

    2015-05-01

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

  19. Can toe-ground footwear margin alter swing-foot ground clearance?

    Science.gov (United States)

    Nagano, Hanatsu; Sparrow, W A; Begg, Rezaul K

    2015-07-01

    Falls are an important healthcare concern in the older population and tripping is the primary cause. Greater swing foot-ground clearance is functional for tripping prevention. Trips frequently occur due to the lowest part of the shoe contacting the walking surface. Shoe design effects on swing foot-ground clearance are, therefore, important considerations. When a shoe is placed on a flat surface, there usually is small vertical margin (VM) between the walking surface and the minimum toe point (MTP). The current study examined the effects of VM on swing foot-ground clearance at a critical gait cycle event, minimum foot clearance (MFC). 3D coordinates of the swing foot (i.e. MTP and heel) were obtained during the swing phase. MTP represented the swing foot-ground clearance and various MTPs were modelled based on a range of VMs. The sagittal orientation of the toe and heel relative to the walking surface was also considered to evaluate effects of VM and swing foot angle on foot-ground clearance. Greater VM increased the swing foot-ground clearance. At MFC, for example, 0.09 cm increase was estimated for every 0.1cm VM. Foot angle throughout the swing phase was typically -30° and 70°. Increasing swing ankle dorsiflexion can maximise VM, which is effective for tripping prevention. Further research will be needed to determine the maximum thresholds of VM to be safely incorporated into a shoe.

  20. Effect of clearance on cartilage tribology in hip hemi-arthroplasty.

    Science.gov (United States)

    Lizhang, Jia; Taylor, Simon D; Jin, Zhongmin; Fisher, John; Williams, Sophie

    2013-12-01

    Hemi-arthroplasty of the hip (an artificial femoral head articulating against the natural acetabulum) is used to treat fractured necks of femur; however, there is evidence that articulation causes erosion of the cartilage, resulting in pain for the patient. Parameters that may influence this cartilage erosion include head material and roughness, clearance between the head and acetabulum and activity levels of the patient. This study has assessed the effect of clearance of hemi-arthroplasty articulations on the contact stress, friction and cartilage deformation in an in vitro tribological simulation of the hemi-arthroplasty joint that applied dynamic loads and motion. It has been demonstrated that peak contact stress increased from 5.6 to 10.6 MPa as radial clearance increased from small (1.8 mm). In all samples, friction factor increased with time and was significantly less with extra-large clearances compared to small (<0.6 mm), medium (0.6-1.2 mm) and large (1.2-1.8 mm) clearances. The cartilage deformation observed was significantly greater in acetabulum samples paired to give small or extra-large clearances compared to those with medium or large clearances.

  1. Numerical Investigation of Pressure Fluctuation Characteristics in a Centrifugal Pump with Variable Axial Clearance

    Directory of Open Access Journals (Sweden)

    Lei Cao

    2016-01-01

    Full Text Available Clearance flows in the sidewall gaps of centrifugal pumps are unsteady as well as main flows in the volute casing and impeller, which may cause vibration and noise, and the corresponding pressure fluctuations are related to the axial clearance size. In this paper, unsteady numerical simulations were conducted to predict the unsteady flows within the entire flow passage of a centrifugal pump operating in the design condition. Pressure fluctuation characteristics in the volute casing, impeller, and sidewall gaps were investigated with three axial clearance sizes. Results show that an axial clearance variation affects the pressure fluctuation characteristics in each flow domain by different degree. The greatest pressure fluctuation occurs at the blade pressure surface and is almost not influenced by the axial clearance variation which has a certainly effect on the pressure fluctuation characteristics around the tongue. The maximum pressure fluctuation amplitude in the sidewall gaps is larger than that in the volute casing, and different spectrum characteristics show up in the three models due to the interaction between the clearance flow and the main flow as well as the rotor-stator interaction. Therefore, clearance flow should be taken into consideration in the hydraulic design of centrifugal pumps.

  2. Modelling of Outer and Inner Film Oil Pressure for Floating Ring Bearing Clearance in Turbochargers

    Science.gov (United States)

    Zhang, Hao; Shi, Zhanqun; Gu, Fengshou; Ball, Andrew

    2011-07-01

    Floating ring bearing is widely used in turbochargers to undertake the extreme condition of high rotating speed and high operating temperature. It is also the most concerned by the designers and users alike due to its high failure rate and high maintenance cost. Any little clearance change may result in oil leakage, which in turn cause blue smoke or black smoke according to leakage types. However, there is no condition monitoring of this bearing because it is almost impossible to measure the clearance especially the inner clearance, in which the inner oil film directly bears the high speed rotation. In stead of measuring clearance directly, this paper has proposed a method that uses film pressure as a measure to monitor the bearing clearance and its variation. A non-linear mathematical model is developed by using Reynolds equations with non-linear oil film pressure. A full description of the outer and inner film is provided along both axial and radial directions. A numerical simulation is immediately carried out. Variable clearance changes are investigated using the mathematical model. Results show the relationship between clearance and film pressure.

  3. Effect of glucagon infusion on the renal clearance of amylase relative to creatinine.

    Science.gov (United States)

    Tedesco, F J; Davila, E; Gardner, L B

    1978-10-01

    Recent data seem to support a tubular defect as the mechanism of the elevated renal clearance of amylase relative to creatinine in acute pancreatitis. Glucagon has been proposed by some to be an important factor in this phenomenon. To examine the role of glucagon as this "tubular dysfunction factor", we investigated the effect of intravenously infused glucagon on the fractional excretion of amylase and the tubular handling of a low molecular weight protein, beta2 microglobulin, in normal, healthy volunteers. At glucagon levels far in excess of those seen in pancreatitis, the clearance ratio of beta2 microglobulin relative to creatinine increased, whereas the clearance ratio of amylase relative to creatinine did not increase above the normal range. The dissociation between beta2 microglobulin clearance and amylase clearance allows one to question the theory that tubular dysfunction is the mechanism of the elevated renal clearance of amylase relative to creatinine in acute pancreatitis. Glucagon does not appear to be the sole factor responsible for the elevation of renal clearance of amylase relative to creatinine in acute pancreatitis.

  4. 33 CFR 207.580 - Buffalo Harbor, N.Y.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

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

  5. 33 CFR 149.505 - What are the general requirements for aids to navigation?

    Science.gov (United States)

    2010-07-01

    ... for aids to navigation? 149.505 Section 149.505 Navigation and Navigable Waters COAST GUARD... EQUIPMENT Aids to Navigation General § 149.505 What are the general requirements for aids to navigation? The following requirements apply to navigation aids under this subpart: (a) Section 66.01-5 of this chapter,...

  6. 33 CFR 165.726 - Regulated Navigation Areas; Miami River, Miami, Florida.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Regulated Navigation Areas; Miami River, Miami, Florida. 165.726 Section 165.726 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 165.726 Regulated Navigation Areas; Miami River, Miami, Florida. (a) Location. The following...

  7. Clinical application of plasma clearance of iohexol on feline patients.

    Science.gov (United States)

    Miyamoto, K

    2001-09-01

    Glomerular filtration rate (GFR) was estimated by plasma clearance of iohexol (PCio) in 52 conscious cats presented for a variety of reasons to Angel Animal Hospital over a 2-year period. Cats were divided into four groups according to their clinical conditions and reasons for measuring PCio. The median PCio (ml/min/kg) was 3.68 in normal cats (NM), 2.39 in cats with suspected renal disease (SP), 1.35 in cats referred to confirm renal dysfunction (RD), and 0.84 in cats with apparent clinical signs of renal failure (RF). There was a significant difference between the results for each group. The respective medians of blood urea nitrogen (BUN) and plasma creatinine concentration (Pcr) (mg/dl) were 15 and 1.40 in NM cats, 21 and 1.71 in SP cats, 30 and 2.20 in RD cats, and 48 and 3.30 in RF cats. The reference values of BUN and Pcr were 21 +/- 7 mg/dl and 1.5 +/- 0.4 mg/dl (mean +/- SD). Diminished renal function could not be detected in SP cats by either BUN or Pcr, while a marked decrease of GFR was demonstrated before BUN and Pcr increased, indicating the insensitivity of BUN and Pcr in detecting renal dysfunction in cats. PCio can be performed non-invasively in conscious cats, which improves the veterinarian's ability to detect early stages of chronic renal disease. PMID:11876631

  8. A Microwave Blade Tip Clearance Sensor for Propulsion Health Monitoring

    Science.gov (United States)

    Woike, Mark R.; Abdul-Aziz, Ali; Bencic, Timothy J.

    2010-01-01

    Microwave sensor technology is being investigated by the NASA Glenn Research Center as a means of making non-contact structural health measurements in the hot sections of gas turbine engines. This type of sensor technology is beneficial in that it is accurate, it has the ability to operate at extremely high temperatures, and is unaffected by contaminants that are present in turbine engines. It is specifically being targeted for use in the High Pressure Turbine (HPT) and High Pressure Compressor (HPC) sections to monitor the structural health of the rotating components. It is intended to use blade tip clearance to monitor blade growth and wear and blade tip timing to monitor blade vibration and deflection. The use of microwave sensors for this application is an emerging concept. Techniques on their use and calibration needed to be developed. As a means of better understanding the issues associated with the microwave sensors, a series of experiments have been conducted to evaluate their performance for aero engine applications. This paper presents the results of these experiments.

  9. Environmental studies and clearance compliance of Kudankulam Atomic Power Project

    International Nuclear Information System (INIS)

    Full text: Nuclear industry has played a leading role in evolving proper and effective environmental management impact from development practices right form inception thus minimizing the environmental impact from developmental activities of man. In the engineering design of nuclear power plant, safety is further enhanced considerably by providing double back-upped engineered safety systems. Besides the engineered safety, the other factors considered for ensuring environmental impact minimization are siting criteria, conservative rad-waste management, effluent treatment, application of stringent environmental protection standards for limiting waste discharges, an elaborate environmental surveillance program and an on site and off site emergency preparedness plan. Recently, nuclear power industry has taken a drive to develop and implement Environmental Management System (EMS) to all its operating stations in line with ISO-14001 standards. For Kudankulam atomic power project, a number of studies specifically for environmental protection are carried out to meet the requirements of Russian Federation, new guidelines of Ministry of environment and Forests (MOEF) and Atomic Energy Regulatory Board (AERB). In the present paper an attempt has been made to present the environmental management plan and clearance compliance status of the project

  10. Rate of clearance of intrathecal iopamidol in the dog.

    Science.gov (United States)

    Wilcox, J; Evill, C A; Sage, M R

    1986-01-01

    The incidence of post-myelographic side-effects has been significantly reduced since the advent of the new generation of water-soluble, non-ionic, contrast media (CM). One of these CM, iopamidol, has recently been released for clinical intrathecal use in Australia. Clinical evaluations have shown iopamidol to give excellent diagnostic results. However, many adverse side-effects have been cited in the literature. Reactions to iopamidol following myelography are thought to be due to the lack of a physiologic barrier between the extracellular fluid of the brain parenchyma and the CSF, thereby allowing CM to penetrate the brain parenchyma tissue, following subarachnoid injection. This study investigates the rate of clearance of intrathecal iopamidol from the brain in dogs by performing coronal CT scans at intervals over a 48 h, post-injection period. Analysis of similar regions of interest (ROI) for each time period indicate that iopamidol can be detected in canine brains for at least 48 h following intrathecal injection (P less than 0.05). Furthermore, the disappearance of iopamidol from the brain parenchyma is approximately logarithmic in form, with a half-life of approximately 22 h.

  11. Interspecies comparison of lung clearance using monodisperse terbium oxide particles

    International Nuclear Information System (INIS)

    Preliminary results are reported of measurements on human subjects, monkeys, dogs and rats following inhalation of 1.0 μm monodisperse 160Tb-labelled terbium oxide particles. Lung retention at 6 months ranged from about 0.1 of the initial alveolar deposit (IAD) in man, monkey and dog to 0.03 in rats. Most of 160Tb cleared from the lungs was dissolved and absorbed by blood and accumulated at systemic sites, with skeleton, and to a lesser extent liver, being shown as the principal organs of accumulation in the animal species. Neglecting fast particle clearance into faeces during the first days after inhalation, 160Tb was mainly excreted and accumulated in the urine (0.1 IAD). The results from this study, with metabolic data obtained from intravenously injected terbium, will be used with recently developed biokinetic models to derive the kinetics of absorption from the lungs to blood of these particles and the particle transport to the GI tract for each species. The biokinetics of each of the animal species will be compared with those determined for the human. (author)

  12. The amylase-creatinine clearance ratio following cardiopulmonary bypass.

    Science.gov (United States)

    Murray, W R; Mittra, S; Mittra, D; Roberts, L B; Taylor, K M

    1981-08-01

    The incidence of unexplained pancreatitis in patients dying after cardiac operations has been recorded as 16%, with evidence to implicate ischemia in the pathogenesis of the pancreatitis. Increased amylase--to--creatinine clearance ratios (ACCR), suggesting pancreatic dysfunction, have been reported in patients following nonpulsatile cardiopulmonary bypass (CPB). Pulsatile CPB is increasingly recognized to be a more physiological form of perfusion, particularly with respect to capillary blood flow. In this study the ACCR has been determined before, during, and after cardiac operations performed with both nonpulsatile and pulsatile CPB. Twenty patients undergoing elective cardiac operations were studied. Ten patients had nonpulsatile CPB (nonpulsatile group) and 10 had pulsatile CPB (pulsatile group). The two groups were comparable as regards perioperative variables and perfusion parameters. In both groups the ACCR was estimated preoperatively, on three occasions during the operation, and daily on the first 5 postoperative days. A significant elevation in ACCR was observed in nine of 10 patients in the nonpulsatile group but in only one of 10 patients in the pulsatile group (p less than 0.001). The significant improvement of ACCR stability following pulsatile CPB may indicate that this form of perfusion will reduce the risk of pancreatitis following cardiac operations performed with CPB.

  13. The amylase-creatinine clearance ratio following cardiopulmonary bypass.

    Science.gov (United States)

    Murray, W R; Mittra, S; Mittra, D; Roberts, L B; Taylor, K M

    1981-08-01

    The incidence of unexplained pancreatitis in patients dying after cardiac operations has been recorded as 16%, with evidence to implicate ischemia in the pathogenesis of the pancreatitis. Increased amylase--to--creatinine clearance ratios (ACCR), suggesting pancreatic dysfunction, have been reported in patients following nonpulsatile cardiopulmonary bypass (CPB). Pulsatile CPB is increasingly recognized to be a more physiological form of perfusion, particularly with respect to capillary blood flow. In this study the ACCR has been determined before, during, and after cardiac operations performed with both nonpulsatile and pulsatile CPB. Twenty patients undergoing elective cardiac operations were studied. Ten patients had nonpulsatile CPB (nonpulsatile group) and 10 had pulsatile CPB (pulsatile group). The two groups were comparable as regards perioperative variables and perfusion parameters. In both groups the ACCR was estimated preoperatively, on three occasions during the operation, and daily on the first 5 postoperative days. A significant elevation in ACCR was observed in nine of 10 patients in the nonpulsatile group but in only one of 10 patients in the pulsatile group (p less than 0.001). The significant improvement of ACCR stability following pulsatile CPB may indicate that this form of perfusion will reduce the risk of pancreatitis following cardiac operations performed with CPB. PMID:6166815

  14. Highly Catalytic Nanodots with Renal Clearance for Radiation Protection

    CERN Document Server

    Zhang, Xiao-Dong; Wang, Junying; Yang, Jiang; Chen, Jie; Shen, Xiu; Deng, Jiao; Deng, Dehui; Long, Wei; Sun, Yuan-Ming; Liu, Changlong; Li, Meixian

    2016-01-01

    Ionizing radiation (gamma and x-ray) is widely used in industry and medicine, but it can also pose a significant hazardous effect on health and induce cancer, physical deformity and even death, due to DNA damages and invasion of free radicals. There is therefore an urgent unmet demand in designing highly efficient radioprotectants with synergetic integration of effective renal clearance and low toxicity. In this study, we designed ultrasmall (sub-5 nm) highly catalytically active and cysteine-protected MoS2 dots as radioprotectants and investigated their application in protection against ionizing radiation. In vivo preclinical studies showed that the surviving fraction of MoS2-treated mice can appreciably increase to up to 79 % when they were exposed to high-energy ionizing radiation. Furthermore, MoS2 dots can contribute in cleaning up the accumulated free radicals within the body, repairing DNA damages and recovering all vital chemical and biochemical indicators, suggesting their unique role as free radical...

  15. The kidneys play an important role in the clearance of rFVIIa in rats

    DEFF Research Database (Denmark)

    Vestergaard, Bill; Appa, Rupa S.; Lykkesfeldt, Jens;

    2014-01-01

    INTRODUCTION: Previous distribution and histological studies have indicated that the kidneys and renal proximal tubular cells play a role in clearance of rFVIIa. However, the relative importance of the kidneys in clearance of rFVIIa has not previously been addressed. The objective of the present...... study was to evaluate the importance of the kidneys in the clearance process of rFVIIa after iv administration to rats using a nephrectomy model. MATERIALS AND METHODS: A nephrectomized rat model was established and validated using inulin, a compound primarily cleared by the kidneys, as a test substance...

  16. Pressure losses and flow field distortion induced by tip clearance of centrifugal and axial compressors

    Science.gov (United States)

    Senoo, Yasutoshi

    1987-03-01

    The flow field near the tip of compressor rotor blades is distorted by leakage through the tip clearance and the performance of the compressor is deteriorated. The literature regarding the tip clearance of compressor blades consists of computational fluid mechanics and experimental studies on the flow field and the pressure loss. Empirical equations expressing the pressure loss and the efficiency drop are varied. They relate to the lift coefficient in different ways, depending upon the ways of understanding the mechanics of pressure losses. These methods are examined and compared. Also, a brief discussion is made on the optimum value of the tip clearance.

  17. Limitation of amylase creatinine clearance ratio as a diagnostic test for postoperative pancreatitis.

    Science.gov (United States)

    Wapnick, S; Evans, M I; Hadas, N; Grosberg, S J

    1980-05-01

    The mean +/- S.E.M. ratio of amylase to creatinine clearance significantly increased at 24 hours after operations on the stomach and gallbladder but not after operations at sites remote from the abdominal cavity. Clinically, the elevated amylase to creatinine clearance ratio was not accompanied by pancreatitis. In dogs, surgical handling of the pancreas alone caused a significant increase in this measurement. The amylase to creatinine clearance ratio is not likely to be helpful in predicting the rare, but serious, postoperative complication of pancreatitis.

  18. Pressure loss due to the tip clearance of impellar blades in centrifugal and axial blowers

    Science.gov (United States)

    Senoo, Y.

    Equations to evaluate pressure loss based on the tip clearance of impeller blades (pressure loss induced by the leakage flow through the clearance, and pressure loss for supporting fluid against the pressure gradient in the thin annular clearance space between the shroud and the impeller) are derived. The predicted pressure losses are compared with experimental data for two types of centrifugal impellers. The equations are simplified for axial impellers as a special case, and the predicted efficiency-drop is compared with the experimental data for seven cases. Good agreement is demonstrated.

  19. Inhaled adrenergics and anticholinergics in obstructive lung disease: do they enhance mucociliary clearance?

    Science.gov (United States)

    Restrepo, Ruben D

    2007-09-01

    Pulmonary mucociliary clearance is an essential defense mechanism against bacteria and particulate matter. Mucociliary dysfunction is an important feature of obstructive lung diseases such as chronic obstructive pulmonary disease, asthma, cystic fibrosis, and bronchiectasis. This dysfunction in airway clearance is associated with accelerated loss of lung function in patients with obstructive lung disease. The involvement of the cholinergic and adrenergic neural pathways in the pathophysiology of mucus hypersecretion suggests the potential therapeutic role of bronchodilators as mucoactive agents. Although anticholinergics and adrenergic agonist bronchodilators have been routinely used, alone or in combination, to enhance mucociliary clearance in patients with obstructive lung disease, the existing evidence does not consistently show clinical effectiveness.

  20. Another point of view on proportional navigation

    Directory of Open Access Journals (Sweden)

    E. Duflos

    1998-01-01

    Full Text Available Proportional navigation is one of the most popular and one of the most used of the guidance laws. But the way it is studied is always the same: the acceleration needed to reach a known target is derived or analyzed. This way of studying guidance laws is called “the direct problem” by the authors. On the contrary, the problem considered here is to find, from the knowledge of a part of the trajectory of a maneuvering object, the target of this object. The authors call this way of studying guidance laws “the inverse problem”.

  1. Optimum Route Selection for Vehicle Navigation

    Directory of Open Access Journals (Sweden)

    Dalip

    2016-02-01

    Full Text Available The objective of Optimum Route Selection for Vehicle Navigation System (ORSVNS article is to develop a system, which provides information about real time alternate routes to the drivers and also helps in selecting the optimal route among all the alternate routes from an origin to destination. Two types of query systems, special and general, are designed for drivers. Here, the criterion for route selection is introduced using primary and secondary road attributes. The presented methodology helps the drivers in better decision making to choose optimal route using fuzzy logic. For experimental results ORSVNS is tested over 220 km portion of Haryana state in India.

  2. Image matching navigation based on fuzzy information

    Institute of Scientific and Technical Information of China (English)

    田玉龙; 吴伟仁; 田金文; 柳健

    2003-01-01

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

  3. Navigation, immersion og interaktion i videoinstallationen

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2008-01-01

    Artiklen diskuterer, hvilken rolle videoinstallationen har spillet i de seneste årtiers radikale receptionsæstetiske omstillinger inden for samtidskunsten i almindelighed og installationskunsten i særdeleshed. I fokus for diskussionen står beskuerens krop og spørgsmålet om på hvilke måder videoin...... receptionsformer lige fra genrens undfangelse i 1960’erne. I forlængelse heraf påvises det, at videoinstallationer kan invitere til en vifte af forskellige receptionsformer, hvoraf artiklen særligt koncentrerer sig om at redegøre for tre: navigation, immersion og interaktion....

  4. Predictive Navigation by Understanding Human Motion Patterns

    Directory of Open Access Journals (Sweden)

    Shu-Yun Chung

    2011-03-01

    Full Text Available To make robots coexist and share the environments with humans, robots should understand the behaviors or the intentions of humans and further predict their motions. In this paper, an A*-based predictive motion planner is represented for navigation tasks. A generalized pedestrian motion model is proposed and trained by the statistical learning method. To deal with the uncertainty, a localization, tracking and prediction framework is also introduced. The corresponding recursive Bayesian formula represented as DBNs (Dynamic Bayesian Networks is derived for real time operation. Finally, the simulations and experiments are shown to validate the idea of this paper.

  5. Fiber optic gyroscopes for vehicle navigation systems

    Science.gov (United States)

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

    1994-03-01

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

  6. Sensor Fusion for Autonomous Mobile Robot Navigation

    DEFF Research Database (Denmark)

    Plascencia, Alfredo

    Multi-sensor data fusion is a broad area of constant research which is applied to a wide variety of fields such as the field of mobile robots. Mobile robots are complex systems where the design and implementation of sensor fusion is a complex task. But research applications are explored constantly.......  The main objective of a multi-sensor system is to improve the capabilities of a single sensor when translating different sensory inputs into the construction of a map that can be used for navigation. In this context, it is important to find novel solutions based on the state of the art of this field...

  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. Road vehicle navigation through virtual world simulation

    OpenAIRE

    Yung, NHC; Ye, C; Fong, FP

    1997-01-01

    In this paper, an integrated virtual world simulator for road vehicles and networks is presented. The structure of the simulator is modular and object-oriented, where the virtual world is hierarchically constructed. It supports 2D/3D real-time graphic rendering of objects which can be visualized on multiple X-windows, and a direct `plug-and-play' of algorithms written in C/C++. The simulator provides a test bed for automated driving, driving assistance, collision avoidance and navigation stra...

  9. Fault tolerant highly reliable inertial navigation system

    Science.gov (United States)

    Jeerage, Mahesh; Boettcher, Kevin

    This paper describes a development of failure detection and isolation (FDI) strategies for highly reliable inertial navigation systems. FDI strategies are developed based on the generalized likelihood ratio test (GLRT). A relationship between detection threshold and false alarm rate is developed in terms of the sensor parameters. A new method for correct isolation of failed sensors is presented. Evaluation of FDI performance parameters, such as false alarm rate, wrong isolation probability, and correct isolation probability, are presented. Finally a fault recovery scheme capable of correcting false isolation of good sensors is presented.

  10. Capsules with external navigation and triggered release.

    Science.gov (United States)

    Shchukin, Dmitry G; Shchukina, Elena

    2014-10-01

    Encapsulation is an important technology for pharmaceutical industry, food production, et cetera. Its current level of development requires capsule functionalization. One of the interesting ideas to provide new functionality to the microcapsule and nanocapsule is layer-by-layer deposition of functional species. This technique provides step-by-step adsorption of various species (polyelectrolytes, nanoparticles, proteins) when the layer growth is controlled by electrostatic, hydrogen bonding, hydrophobic forces and forming multilayer shells with nanometer precision. This review article introduces recent achievements of layer-by-layer technique attaining external navigation ability and release properties the capsule shell.

  11. Sulfadoxine-pyrimethamine monotherapy in Tanzanian children gives rapid parasite clearance but slow fever clearance that is improved by chloroquine in combination therapy

    DEFF Research Database (Denmark)

    Tarimo, D S; Minjas, J N; Bygbjerg, I C

    2002-01-01

    paracetamol (PCM) (n=38) in children with uncomplicated malaria. Over 72 h, there were eight (20.5%) treatment failures in the CQ group but none in the other groups. Although not significant (P > 0.1), irrespective of resistance CQ alone had a shorter median survival time to fever clearance than SP alone (54......Following widespread chloroquine (CQ) resistance, sulfadoxine plus pyrimethamine (SP) is now the first line antimalarial drug in a number of African countries including Tanzania. Unlike CQ, SP has no antipyretic effects, a feature that might delay fever clearance, and by acting on late stage...... vs. 60 h). SP plus CQ had a highly significantly shorter median survival time to fever clearance than SP alone (48 vs. 60 h) (P

  12. Short-range navigation: does it contribute to understanding navigation over longer distances?

    Science.gov (United States)

    Collett

    1996-01-01

    A major reason for analysing short-range navigation is that it is relatively easy to record on video tape the details of an animal's behaviour over an area of about a square metre. Frequently, the orientation of the animal's body is revealed in addition to its trajectory through space. This is particularly useful in the study of insect navigation, the subject of the four contributions to this section. An insect's eyes are fixed in its head, and there are often no significant head movements during flight. Consequently, reasonable assumptions can be made about where the insect looks while it navigates and how the image of its surroundings moves over its retina. All four contributions depend to a large degree upon being able to freeze behaviour on video tape and to infer what the animal sees. To what extent do the conclusions using the abundant information that can be collected in this way extrapolate to navigation on a larger scale? Clearly, the coded information that instructs the monarch butterfly on its migrations from wide areas of North America to northern Michoacan in Mexico contains elements unique to long-distance travel. But there may be many similarities in the mechanisms available to an orchid bee as it travels over its 20 km foraging route from orchid to orchid and a wasp negotiating the last few metres through a complex environment to reach its nest.

  13. Navigational Support in Lifelong Learning: Enhancing Effectiveness through Indirect Social Navigation

    Science.gov (United States)

    Janssen, Jose; van den Berg, Bert; Tattersall, Colin; Hummel, Hans; Koper, Rob

    2007-01-01

    Efficient and effective lifelong learning requires that learners can make well informed choices from a vast amount of learning opportunities. This article proposes to support learners by drawing on principles of self-organization and indirect social navigation; by analysing choices made by learners who went before and feeding this information back…

  14. Navigating mazes in a virtual environment

    Science.gov (United States)

    Browse, Roger A.; Skillicorn, David B.; Middleman, Darren

    2003-06-01

    In this research we are concerned with computer interfaces with which subjects navigate through maze simulations which are essentially buildings, with corridors and intersections, such as frequently encountered in computer games and simulations. We wish to determine if virtual reality interfaces introduce a performance enhancement that might be expected for display configurations which mimic natural perceptual experiences. We have experimented primarily with two display conditions for presentation of and navigation through the mazes. Subjects either view the maze on a desktop computer monitor, turning and moving within the maze with the mouse in a way that is similar to the configurations used in most first-person role playing computer games, or they viewed the maze from a standing position with a head-mounted display, being free to direct the view of the maze through body and head movements, and using the depression of a mouse button to effect movement in the direction that they were facing. Head-tracking was required for this latter condition. As expected there are striking individual differences in subjects" abilities to learn to traverse the mazes. Across a variety of maze configuration parameters which significantly do influence performance, the results indicate that the virtual reality enhancements have no effect subjects' ability to learn the mazes, either as route knowledge or as cognitive maps.

  15. Navigating actions through the rodent parietal cortex

    Directory of Open Access Journals (Sweden)

    Jonathan R. Whitlock

    2014-05-01

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

  16. Basal ganglia contributions to adaptive navigation.

    Science.gov (United States)

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

    2009-04-12

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

  17. The European Satellite Navigation System Galileo

    Institute of Scientific and Technical Information of China (English)

    G.W. Hein; T. Pany

    2003-01-01

    This paper starts with a brief discussion of the Galileo project status and with a description of the present Galileo architecture (space segment, ground segment, user segment). It focuses on explaining special features compared to the American GPS system. The presentation of the user segment comprises a discussion of the actual Galileo signal structure. The Galileo carrier frequency, modulation scheme and data rate of all 10 navigation signals are described as well as parameters of the search and rescue service. The navigation signals are used to realize three types of open services, the safety of life service, two types of commercial services and the public regulated service. The signal performance in terms of the pseudorange code error due to thermal noise and multipath is discussed as well as interference to and from other radionavigation services broadcasting in the E5 and E6 frequency band. The interoperability and compatibility of Galileo and GPS is realized by a properly chosen signal structures in E5a/L5 and E2-L1-E1 and compatible geodetic and time reference frames. Some new results on reciprocal GPS/Galileo signal degradation due to signal overlay are presented as well as basic requirements on the Galileo code sequences.

  18. Olfaction, navigation, and the origin of isocortex.

    Science.gov (United States)

    Aboitiz, Francisco; Montiel, Juan F

    2015-01-01

    There are remarkable similarities between the brains of mammals and birds in terms of microcircuit architecture, despite obvious differences in gross morphology and development. While in reptiles and birds the most expanding component (the dorsal ventricular ridge) displays an overall nuclear shape and derives from the lateral and ventral pallium, in mammals a dorsal pallial, six-layered isocortex shows the most remarkable elaboration. Regardless of discussions about possible homologies between mammalian and avian brains, a main question remains in explaining the emergence of the mammalian isocortex, because it represents a unique phenotype across amniotes. In this article, we propose that the origin of the isocortex was driven by behavioral adaptations involving olfactory driven goal-directed and navigating behaviors. These adaptations were linked with increasing sensory development, which provided selective pressure for the expansion of the dorsal pallium. The latter appeared as an interface in olfactory-hippocampal networks, contributing somatosensory information for navigating behavior. Sensory input from other modalities like vision and audition were subsequently recruited into this expanding region, contributing to multimodal associative networks.

  19. Navigation system for neurosurgery with PC platform.

    Science.gov (United States)

    Akatsuka, Y; Shibasaki, T; Saito, A; Kosaka, A; Matsuzaki, H; Asano, T; Furuhashi, Y

    2000-01-01

    This paper presents a navigation system for a surgical microscope and an endoscope which can be used for neurosurgery. In this system, a wireframe model of a target tumor and other significant anatomical landmarks are superimposed in real-time onto live video images taken from the microscope and the endoscope. The wireframe model is generated from a CT/MRI slice images. Overlaid images are simultaneously displayed in the same monitor using the picture-in-picture function so that the surgeon can concentrate on the single monitor during the surgery. The system measures the position and orientation of the patient using specially designed non-contact sensing devices mounted on the microscope and the endoscope. Based on this real-time measurement, the system displays other useful information about the navigation as well as the rendered wireframe. The accuracy of registration between the wireframe model and the actual live view is less than 2 mm. We tested this system in actual surgery several times, and verified its performance and effectiveness.

  20. Olfaction, navigation, and the origin of isocortex

    Science.gov (United States)

    Aboitiz, Francisco; Montiel, Juan F.

    2015-01-01

    There are remarkable similarities between the brains of mammals and birds in terms of microcircuit architecture, despite obvious differences in gross morphology and development. While in reptiles and birds the most expanding component (the dorsal ventricular ridge) displays an overall nuclear shape and derives from the lateral and ventral pallium, in mammals a dorsal pallial, six-layered isocortex shows the most remarkable elaboration. Regardless of discussions about possible homologies between mammalian and avian brains, a main question remains in explaining the emergence of the mammalian isocortex, because it represents a unique phenotype across amniotes. In this article, we propose that the origin of the isocortex was driven by behavioral adaptations involving olfactory driven goal-directed and navigating behaviors. These adaptations were linked with increasing sensory development, which provided selective pressure for the expansion of the dorsal pallium. The latter appeared as an interface in olfactory-hippocampal networks, contributing somatosensory information for navigating behavior. Sensory input from other modalities like vision and audition were subsequently recruited into this expanding region, contributing to multimodal associative networks. PMID:26578863

  1. Total plasma clearance versus urinary plasma clearance of (51)Cr-EDTA in patients with cirrhosis with and without fluid retention

    DEFF Research Database (Denmark)

    Henriksen, Ulrik Lütken; Hansen, Hanne B; Ring-Larsen, Helmer;

    2015-01-01

    Abstract Background and aim. In patients with fluid retention, the total plasma clearance of (51)Cr-EDTA (ClP) may overestimate the glomerular filtration rate (GFR). The present study was therefore undertaken in order to compare ClP with the urinary plasma clearance of (51)Cr-EDTA (ClU) in patients...... with cirrhosis with and without fluid retention. Material and methods. A total of 136 patients with cirrhosis (24 without fluid retention, 112 with ascites) received a quantitative intravenous injection of (51)Cr-EDTA followed by plasma and quantitative urinary samples for 5 hours. ClP was determined from...

  2. Replication and clearance of respiratory syncytial virus - Apoptosis is an important pathway of virus clearance after experimental infection with bovine respiratory syncytial virus

    DEFF Research Database (Denmark)

    Viuff, B.; Tjørnehøj, Kirsten; Larsen, Lars Erik;

    2002-01-01

    and clearance in a natural target animal. Replication of BRSV was demonstrated in the luminal part of the respiratory epithelial cells and replication in the upper respiratory tract preceded the replication in the lower respiratory tract. Virus excreted to the lumen of the respiratory tract was cleared...... by neutrophils whereas apoptosis was an important way of clearance of BRSV-infected epithelial cells. Neighboring cells, which probably were epithelial cells, phagocytized the BRSV-infected apoptotic cells. The number of both CD4+ and CD8+ T cells increased during the course of infection, but the T cells were...

  3. Esophageal Acid Clearance Is Faster in Patients with Barrett's Esophagus Than in Healthy Controls During Random Swallowing

    DEFF Research Database (Denmark)

    Lottrup, Christian; Krarup, Anne Petas Swane; Gregersen, Hans;

    2016-01-01

    Background/Aims: Impaired esophageal acid clearance may be a contributing factor in the pathogenesis of Barrett's esophagus. However, few studies have measured acid clearance as such in these patients. In this explorative, cross-sectional study, we aimed to compare esophageal acid clearance...... and swallowing rate in patients with Barrett's esophagus to that in healthy controls. Methods: A total of 26 patients with histology-confirmed Barrett's esophagus and 12 healthy controls underwent (1) upper endoscopy, (2) an acid clearance test using a pH-impedance probe under controlled conditions including...... clearance test were not correlated (all P > 0.3). Conclusions: More frequent swallowing and thus faster acid clearance in Barrett's esophagus may constitute a protective reflex due to impaired mucosal integrity and possibly acid hypersensitivity. Despite these reinforced mechanisms, acid clearance ability...

  4. Traffic Incident Clearance Time and Arrival Time Prediction Based on Hazard Models

    Directory of Open Access Journals (Sweden)

    Yang beibei Ji

    2014-01-01

    Full Text Available Accurate prediction of incident duration is not only important information of Traffic Incident Management System, but also an effective input for travel time prediction. In this paper, the hazard based prediction models are developed for both incident clearance time and arrival time. The data are obtained from the Queensland Department of Transport and Main Roads’ STREAMS Incident Management System (SIMS for one year ending in November 2010. The best fitting distributions are drawn for both clearance and arrival time for 3 types of incident: crash, stationary vehicle, and hazard. The results show that Gamma, Log-logistic, and Weibull are the best fit for crash, stationary vehicle, and hazard incident, respectively. The obvious impact factors are given for crash clearance time and arrival time. The quantitative influences for crash and hazard incident are presented for both clearance and arrival. The model accuracy is analyzed at the end.

  5. NONLINEAR STABILITY OF BALANCED ROTOR DUE TO EFFECT OF BALL BEARING INTERNAL CLEARANCE

    Institute of Scientific and Technical Information of China (English)

    BAI Chang-qing; XU Qing-yu; ZHANG Xiao-long

    2006-01-01

    Stability and dynamic characteristics of a ball bearing-rotor system are investigated under the effect of the clearance in the ball bearing. Different clearance values are assumed to calculate the nonlinear stability of periodic solution with the aid of the Floquet theory. Bifurcation and chaos behavior are analyzed with variation of the clearance and rotational speed. It is found that there are three routes to unstable periodic solution.The period-doubling bifurcation and the secondary Hopf bifurcation are two usual routes to instability. The third route is the boundary crisis, a chaotic attractor occurs suddenly as the speed passes through its critical value. At last, the instable ranges for different internal clearance values are described. It is useful to investigate the stability property of ball bearing rotor system.

  6. Dynamics Research of rigid-flexible model of crank-rocker mechanism with Multi Clearance

    Directory of Open Access Journals (Sweden)

    Bo Shao Jun

    2016-01-01

    Full Text Available This paper takes the crank-rocker mechanism as the research object, purposed for the simulation of the motion pair with clearance utilizing the contact force model and the coulomb friction model, we build the virtual prototype of four-bar mechanism with clearance joints in the ADAMS. The article mainly contrasts the influence dynamics characteristics towards the mechanism multi-joint clearance between the rigid rocker and the flexible rocker. Considering the jointed arm’s flexibility, the four, five and six order modal of the rocker, generated by ANSYS as a neutral document, were imported into ADAMS for simulation. The result shows that Mechanism with four joint clearance increased the impact on the speed and the acceleration appeared greater fluctuation, the flexible rod has a buffer effect to the contact-impact forces, and the dynamic characteristics of fluctuations are improved.

  7. Intra-operative colloid administration increases the clearance of a post-operative fluid load

    DEFF Research Database (Denmark)

    Borup, Tine; Hahn, Robert; Holte, K;

    2009-01-01

    BACKGROUND: It is unknown whether an intra-operative colloid infusion alters the dynamics of a crystalloid load administered post-operatively. METHODS: Ten patients received 12.5 ml/kg of Ringer's lactate over 30 min 1-3 days before and 4 h after laparoscopic cholecystectomy, during which 10 ml....../kg of a colloid solution, hydroxyethylstarch (HES 130/0.4), was infused. The total body clearance of the pre- and post-operative test infusions was taken as the ratio between the urinary excretion and the Hb-derived dilution of venous plasma over 150 min. The plasma clearance of the infused fluid was calculated...... using volume kinetics based on the plasma dilution alone. The pre-operative plasma clearance was compared with the post-operative plasma clearance and patients served as their own control. RESULTS: The urinary excretion averaged 350 ml for the pre-operative infusion and 612 ml post-operatively, which...

  8. NUMERICAL SIMULATIONS FOR THE CASE OF RIGID ROTATING KINEMATIC COUPLING WITH BIG CLEARANCE

    Directory of Open Access Journals (Sweden)

    Jan-Cristian GRIGORE

    2010-10-01

    Full Text Available In this paper an algorithm based on [1] [2] are numerical simulations, achieving generalized coordinates of motion, positions, speeds of a rigid rotating kinematic coupling with big clearance in joint, case without friction

  9. 14 CFR 91.123 - Compliance with ATC clearances and instructions.

    Science.gov (United States)

    2010-01-01

    ... obtained, an emergency exists, or the deviation is in response to a traffic alert and collision avoidance... avoidance system resolution advisory, deviates from an ATC clearance or instruction shall notify ATC of...

  10. 78 FR 23627 - Agency Information Collection Activities: Requests for Comments; Clearance of Renewed Approval of...

    Science.gov (United States)

    2013-04-19

    ... aircraft and administer the leasing of the aircraft among the owners. DATES: Written comments should be... Collection Clearance Officer, IT Enterprises Business Services Division, AES-200. BILLING CODE 4910-13-P...

  11. Tramadol and o-desmethyl tramadol clearance maturation and disposition in humans

    DEFF Research Database (Denmark)

    Allegaert, Karel; Holford, Nick; Anderson, Brian J;

    2015-01-01

    BACKGROUND AND OBJECTIVES: We aimed to study the impact of size, maturation and cytochrome P450 2D6 (CYP2D6) genotype activity score as predictors of intravenous tramadol disposition. METHODS: Tramadol and O-desmethyl tramadol (M1) observations in 295 human subjects (postmenstrual age 25 weeks...... to 84.8 years, weight 0.5-186 kg) were pooled. A population pharmacokinetic analysis was performed using a two-compartment model for tramadol and two additional M1 compartments. Covariate analysis included weight, age, sex, disease characteristics (healthy subject or patient) and CYP2D6 genotype...... activity. A sigmoid maturation model was used to describe age-related changes in tramadol clearance (CLPO), M1 formation clearance (CLPM) and M1 elimination clearance (CLMO). A phenotype-based mixture model was used to identify CLPM polymorphism. RESULTS: Differences in clearances were largely accounted...

  12. 77 FR 30318 - Agency Information Collection Activities: 30-Day Notice of Intention To Request Clearance of...

    Science.gov (United States)

    2012-05-22

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF THE INTERIOR National Park Service Agency Information Collection Activities: 30-Day Notice of Intention To Request Clearance of Collection of Information; Opportunity for Public Comment AGENCY: National Park...

  13. 77 FR 50157 - Agency Information Collection Activities: 30-Day Notice of Intention To Request Clearance of...

    Science.gov (United States)

    2012-08-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR National Park Service Agency Information Collection Activities: 30-Day Notice of Intention To Request Clearance of Collection of Information; Opportunity for Public Comment AGENCY: National Park...

  14. Sensitivity of the amylase-creatinine clearance ratio in acute pancreatitis.

    Science.gov (United States)

    Farrar, W H; Calkins, G

    1978-06-01

    An elevated amylase-creatinine clearance ratio has been established as being highly specific for the diagnosis of acute pancreatitis. In the present study, the sensitivity of this test was compared to that of the serum amylase and the one-hour urinary amylase test in 29 patients with acute pancreatitis. Abnormal elevations of the amylase-creatinine clearance ratio were found less frequently than abnormal elevations of the serum and one-hour urinary amylases. Moreover, abnormal elevations of the amylase-creatinine clearance ratio showed less deviation from normal and values returned to normal sooner than those of the serum and one-hour urinary amylases. When compared to the serum amylase and the one-hour urinary amylase tests, the amylase-creatinine clearance ratio is a relatively insensitive test in patients with acute pancreatitis.

  15. Amylase-creatinine clearance ratios and serum amylase isoenzymes in moderate renal insufficiency.

    Science.gov (United States)

    Banks, P A; Sidi, S; Gelman, M L; Lee, K H; Warshaw, A L

    1979-12-01

    Both the amylase-creatinine clearance ratio (normal 1.55%) and proportion of pancreatic isoamylase in serum (normal 41.0%) increase in acute pancreatitis, and are therefore useful measurements to support that diagnosis. Whether renal insufficiency interferes with the accuracy and specificity of these tests has been debated. Our study indicates that even moderate renal insufficiency (creatinine clearance 30.5 ml/minute) raises the amylase-creatinine clearance ratio (3.23%) close enough to values characteristic of acute pancreatitis (4.41%) to cause potential diagnostic confusion. The fraction of pancreatic isoamylase in serum is also increased (69.9%), but not to the levels of acute pancreatitis (91.0%). We therefore caution against the use of the amylase-creatinine clearance ratio for the diagnosis of acute pancreatitis in patients with moderate renal insufficiency.

  16. Optical Method for Real-Time Turbine Blade Tip Clearance Measurement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Monitoring and controlling blade tip clearance of high pressure turbines are important for maintaining the integrity of the engine during its operating points and...

  17. Proficiency testing criteria for clearance level in solid waste gamma measurement in Taiwan.

    Science.gov (United States)

    Chen, Chun-Liang; Wang, Jeng-Jong; Chiu, Huang-Sheng

    2013-11-01

    To guarantee the measurement quality for clearance level in solid waste material, the Institute of Nuclear Energy Research (INER) established the criteria for proficiency testing of clearance level measurement. INER and the Taiwan Accreditation Foundation (TAF) organized the Technique Committee Meeting twice to discuss these criteria in 2011. The participating laboratories must completely conform to the ISO/IEC 17025, and they also must meet the requirements of the criteria. According to the criteria, the participating laboratories analyzed the minimum detectable amount (MDA) and that should be less than 20% of the clearance level (AMDA) given in the Atomic Energy Council's (AEC) "Regulations on Clearance Level for Radioactive Waste Management". The testing results should conform to the deviation and traceability requirements. PMID:23591296

  18. Radial Clearance Control and Internal Leakage Analysis of a Tri-Proportion Controller

    Institute of Scientific and Technical Information of China (English)

    LI Dai-jin; ZHANG Yu-wen; TANG Hao; DANG Jian-jun; LUO Kai

    2009-01-01

    The tri-propellant thermal propulsion system is one of the hottest subjects in the.field of underwater vehicles recently. To improve efficiency of underwater vehicles, a method of radial clearance control of the tri-proportion has been proposed. Based on analyzing the factors which influence the pressure decrease and leakage of the tri-proportion controller, a method is used for precision analysis and proportion adjustment by using the median optimizing theory. Analysis results show that accuracy of the proportion controller is dependent on all the leakage, while the leakage is decided by radial clearance and pressure; the leakage can be controlled effectively and the accuracy of the proportion can be improved with the radial clearance control method. The method of accuracy analysis and clearance control has value on the design of various hydraulic motors.

  19. Using radioaerosols to monitor physiotherapy-enhanced mucus clearance at different levels of the bronchial tree

    Energy Technology Data Exchange (ETDEWEB)

    Hasani, A.; Pavia, D.; Clarke, S.W.; Agnew, J.E. (Royal Free Hospital, London (United Kingdom))

    1993-01-01

    Patients with airways obstruction often find it difficult to clear excess lung secretions. Frequent coughing can clear the larger airways but may itself further damage the airways ciliated epithelium. Various physiotherapy regimes have been proposed yet objective evidence of their efficacy is sparse. Deposited aerosol particles - with an appropriate label for gamma imaging - can track clearance from different lung regions. Published reports have however tended to be equivocal in respect of clearance from the more distal conducting airways. Questions also arise as to coordination of transport rates at different levels of the bronchial tree. We therefore sought to re-assess requirements for effective analysis of physiotherapy-enhanced clearance to yield data on both peripheral and central airways clearance. (author).

  20. Increased hepatic insulin clearance after Roux-en-Y gastric bypass

    DEFF Research Database (Denmark)

    Bojsen-Møller, Kirstine N; Dirksen, Carsten; Jørgensen, Nils B;

    2013-01-01

    Context:Roux-en-Y gastric bypass (RYGB) improves glucose tolerance and ameliorates fasting hyperinsulinemia within days after surgery. Improvements in hepatic insulin sensitivity and insulin clearance could contribute importantly to these effects.Objective:The objective of the investigation...