WorldWideScience

Sample records for subject unknown aircraft

  1. Prediction of UHPFRC panels thickness subjected to aircraft engine impact

    OpenAIRE

    Thai, Duc-Kien; Kim, Seung-Eock

    2016-01-01

    In the practical design of nuclear building structures subjected to an aircraft crash, the structures are required to prevent scabbing and perforation. NEI 07-13 provided the formulas to predict the minimum reinforced concrete (RC) wall thickness to prevent the local damage caused by aircraft engine impact. However, these formulas may not be suitable for predicting the thickness of the ultra-high performance fiber reinforced concrete (UHPFRC) wall. In this study, the local damage of a UHPFRC ...

  2. Investigation of Tinnitus Characteristics in 36 Patients with Subjective Tinnitus with Unknown Etiology

    Directory of Open Access Journals (Sweden)

    Mahdi Bakhshaee

    2006-06-01

    Full Text Available Background and Aim: Tinnitus represents the perception of sound without an external stimulus. The prevalence of tinnitus ranges from 3% to 30%. In most cases its etiology is unknown. Tinnitus can be classified as pulsatile or nonpulsatile. Nonpulsatile form is the most common form and almost exclusively subjective in nature. There is a range of condition attributed to nonpulsatile high frequency tinnitus (acoustic neuroma, Meniere’s disease, ototoxic agents, and noise exposure, etc. There are many studies about form, site, loudness, and frequency of tinnitus and how it can affect the quality of patient life. Materials and methods: This was a descriptive and analytic study. Thirty-six patients (23 men and 13 women with mean age 53.1 year old with subjective tinnitus evaluated in Pezhvak audiometric clinic in Mashhad.The data consisting of age sex, loudness, frequency form and site of tinnitus. Evaluation of effects of tinnitus on the quality of life and habits was performed with a tinnitus questionnaire (TQ. Results: Tinnitus was unilateral in 64% of cases. The right site was more common. Mean pitch was 7.03 kHz and average loudness was 3.8 dB SPL. SDS was in normal range in all of patients. There was a high frequency sensory neural hearing loss (above the 4 kHz in most of the patients. The greatest score (60.3% of TQ related to intrusiveness aspect. Sleep disorder has the lowest score (39/3%. Global score was 52.4%. Conclusion: Nonpulsatile subjective tinnitus has a broad range of etiology with unknown mechanism in most cases and without any history of underlying disease in a large group of patients. This symptom mostly involves the patients` lifestyle that is intrusiveness aspect in comparison with the other aspects including sleep, hearing and somatic complaints. There is no cure for most patient and more studies are needed in the future.

  3. Trajectory Optimization of Electric Aircraft Subject to Subsystem Thermal Constraints

    Science.gov (United States)

    Falck, Robert D.; Chin, Jeffrey C.; Schnulo, Sydney L.; Burt, Jonathan M.; Gray, Justin S.

    2017-01-01

    Electric aircraft pose a unique design challenge in that they lack a simple way to reject waste heat from the power train. While conventional aircraft reject most of their excess heat in the exhaust stream, for electric aircraft this is not an option. To examine the implications of this challenge on electric aircraft design and performance, we developed a model of the electric subsystems for the NASA X-57 electric testbed aircraft. We then coupled this model with a model of simple 2D aircraft dynamics and used a Legendre-Gauss-Lobatto collocation optimal control approach to find optimal trajectories for the aircraft with and without thermal constraints. The results show that the X-57 heat rejection systems are well designed for maximum-range and maximum-efficiency flight, without the need to deviate from an optimal trajectory. Stressing the thermal constraints by reducing the cooling capacity or requiring faster flight has a minimal impact on performance, as the trajectory optimization technique is able to find flight paths which honor the thermal constraints with relatively minor deviations from the nominal optimal trajectory.

  4. Nuclear containment structure subjected to commercial and fighter aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Sadique, M.R., E-mail: rehan.sadique@gmail.com; Iqbal, M.A., E-mail: iqbalfce@iitr.ernet.in; Bhargava, P., E-mail: bhpdpfce@iitr.ernet.in

    2013-07-15

    Highlights: • Nuclear containment response has been studied against aircraft crash. • Concrete damaged plasticity and Johnson–Cook elasto-viscoplastic models were employed. • Boeing 747-400 and Boeing 767-400 aircrafts caused global failure of containment. • Airbus A320 and Boeing 707-320 aircrafts caused local damage. • Tension damage of concrete was found more prominent compared to compression damage. -- Abstract: The response of a boiling water reactor (BWR) nuclear containment vessel has been studied against commercial and fighter aircraft crash using a nonlinear finite element code ABAQUS. The aircrafts employed were Boeing 747-400, Boeing 767-400, Airbus A-320, Boeing 707-320 and Phantom F4. The containment was modeled as a three-dimensional deformable reinforced concrete structure while the loading of aircraft was assigned using the respective reaction–time curve. The location of strike was considered near the junction of dome and cylinder, and the angle of incidence, normal to the containment surface. The material behavior of the concrete was incorporated using the damaged plasticity model while that of the reinforcement, the Johnson–Cook elasto-viscoplastic model. The containment could not sustain the impact of Boeing 747-400 and Boeing 767-400 aircrafts and suffered rupture of concrete around the impact region leading to global failure. On the other hand, the maximum local deformation at the point of impact was found to be 0.998 m, 0.099 m, 0.092 m, 0.089 m, and 0.074 m against Boeing 747-400, Phantom F4, Boeing 767, Boeing 707-320 and Airbus A-320 aircrafts respectively. The results of the present study were compared with those of the previous analytical and numerical investigations with respect to the maximum deformation and overall behavior of the containment.

  5. Safety assessment of a nuclear power plant building subjected to an aircraft crash

    Energy Technology Data Exchange (ETDEWEB)

    Thai, Duc-Kien; Kim, Seung-Eock, E-mail: sekim@sejong.ac.kr

    2015-11-15

    Highlights: • Numerical analysis of a nuclear auxiliary building under aircraft crash is conducted. • The analysis result of impact force is verified using the Riera function. • The safety assessment is performed with regard to different impact scenarios. • Discussions and conclusions on safety of the nuclear building are presented. - Abstract: This paper presents a safety assessment of a nuclear building subjected to an aircraft crash using numerical analysis. For impact simulation, the reinforced concrete (RC) Primary Auxiliary Building (PAB) of the Korea Standard Nuclear Power Plant (KSNP) is fully modeled and an aircraft model of a Boeing 767-400 is used. The Riera function is used to verify the analysis result of impact force–time history. The IRIS test is used to verify the structural behavior of the RC wall under impact loading. The safety assessment of the building is performed with regard to different impact scenarios. The safety of the nuclear building under aircraft crash, including (1) global structural safety, (2) local structural safety, and (3) vibration safety are evaluated and discussed. The results show that the global and local structural safety of the PAB is ensured in all impact scenarios. However, the vibration safety of the building is not ensured. In accordance, the regulatory guide of United States Nuclear Regulatory Commission (U.S. NRC), shutdown of the nuclear power plant is required.

  6. Aircraft

    Science.gov (United States)

    Hibbs, B.D.; Lissaman, P.B.S.; Morgan, W.R.; Radkey, R.L.

    1998-09-22

    This disclosure provides a solar rechargeable aircraft that is inexpensive to produce, is steerable, and can remain airborne almost indefinitely. The preferred aircraft is a span-loaded flying wing, having no fuselage or rudder. Travelling at relatively slow speeds, and having a two-hundred foot wingspan that mounts photovoltaic cells on most all of the wing`s top surface, the aircraft uses only differential thrust of its eight propellers to turn. Each of five sections of the wing has one or more engines and photovoltaic arrays, and produces its own lift independent of the other sections, to avoid loading them. Five two-sided photovoltaic arrays, in all, are mounted on the wing, and receive photovoltaic energy both incident on top of the wing, and which is incident also from below, through a bottom, transparent surface. The aircraft is capable of a top speed of about ninety miles per hour, which enables the aircraft to attain and can continuously maintain altitudes of up to sixty-five thousand feet. Regenerative fuel cells in the wing store excess electricity for use at night, such that the aircraft can sustain its elevation indefinitely. A main spar of the wing doubles as a pressure vessel that houses hydrogen and oxygen gases for use in the regenerative fuel cell. The aircraft has a wide variety of applications, which include weather monitoring and atmospheric testing, communications, surveillance, and other applications as well. 31 figs.

  7. Safety Analysis of Dual Purpose Metal Cask Subjected to Impulsive Loads due to Aircraft Engine Crash

    Science.gov (United States)

    Shirai, Koji; Namba, Kosuke; Saegusa, Toshiari

    In Japan, the first Interim Storage Facility of spent nuclear fuel away from reactor site is being planned to start its commercial operation around 2010, in use of dual-purpose metal cask in the northern part of Main Japan Island. Business License Examination for safety design approval has started since March, 2007. To demonstrate the more scientific and rational performance of safety regulation activities on each phase for the first license procedure, CREPEI has executed demonstration tests with full scale casks, such as drop tests onto real targets without impact limiters(1) and seismic tests subjected to strong earthquake motions(2). Moreover, it is important to develop the knowledge for the inherent security of metal casks under extreme mechanical-impact conditions, especially for increasing interest since the terrorist attacks from 11th September 2001(3)-(6). This paper presents dynamic mechanical behavior of the metal cask lid closure system caused by direct aircraft engine crash and describes calculated results (especially, leak tightness based on relative dynamic displacements between metallic seals). Firstly, the local penetration damage of the interim storage facility building by a big passenger aircraft engine crash (diameter 2.7m, length 4.3m, weight 4.4ton, impact velocity 90m/s) has been examined. The reduced velocity is calculated by the local damage formula for concrete structure with its thickness of 70cm. The load vs. time function for this reduced velocity (60m/s) is estimated by the impact analysis using Finite Element code LS-DYNA with the full scale engine model onto a hypothetically rigid target. Secondly, as the most critical scenarios for the metal cask, two impact scenarios (horizontal impact hitting the cask and vertical impact onto the lid metallic seal system) are chosen. To consider the geometry of all bolts for two lids, the gasket reaction forces and the inner pressure of the cask cavity, the detailed three dimensional FEM models are

  8. Numerical analysis of nuclear power plant structure subjected to aircraft crash

    National Research Council Canada - National Science Library

    Saberi, Reza; Alinejad, Majid; Mahdavi, Mir Omid; Sepanloo, Kamran

    2017-01-01

    An aircraft crashing into a nuclear containment may induce a series of disasters related to containment capacity, including local penetration and perforation of the containment, intensive vibrations...

  9. Numerical analysis of nuclear power plant structure subjected to aircraft crash

    National Research Council Canada - National Science Library

    Saberi, Reza; Alinejad, Majid; Mahdavi, Mir Omid; Sepanloo, Kamran

    2017-01-01

    ...) has been studied against the direct hit of Airbus A320, Boeing 707-320 and Phantom F4 aircrafts. ABAQUS/explicit finite element code has been used to carry out the three-dimensional numerical simulations...

  10. A Study on External Fire Damage of Structures subjected to Aircraft Impact

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Shup [Hanyang University, Seoul (Korea, Republic of); Hahm, Daegi; Kim, Min Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    A large commercial aircraft consists of various components as fuselage, wings, fuel tank, engine etc. During a collision of the aircraft, the fuel tank with a large amount of jet fuel have a significant effect on the total load of the aircraft as well as causing explosive fire and smoke which affect the safety of the structure and equipment. US Sandia National Laboratories and Finland VTT etc. performed the test and simulation studies to evaluate the dispersion range of the fluid after the crash of liquid filled cylinder missiles. The test condition and results have been referred in this paper. The fluid modeling approach using SPH is applied to evaluate the dispersing range of the fluid, and is compared with the Brown's results. The jet fuel is idealized as particles contained in an aluminum cylinder missile, where those particles can be dispersed to the surrounding area after the missile crashes into a rigid target. The fluid model using the SPH method is briefly verified through comparison with test results, and then the modelling method is applied to a jet fuel model in an aircraft model. The dispersion analysis of jet fuel caused by aircraft impact is performed using an aircraft model for the determination of fire duration and fire affected zone in a nuclear power plant. Finally, the structural integrity of the roof of the structure during a jet fuel fire is evaluated. In this study, the filled jet fuel was modeled by using smooth particle hydrodynamics technique; jet fuel spread area following an aircraft crash was analyzed.

  11. Numerical analysis of nuclear power plant structure subjected to aircraft crash

    Science.gov (United States)

    Saberi, Reza; Alinejad, Majid; Mahdavi, Mir Omid; Sepanloo, Kamran

    2017-12-01

    An aircraft crashing into a nuclear containment may induce a series of disasters related to containment capacity, including local penetration and perforation of the containment, intensive vibrations, and fire ignited after jet fuel leakage. In this study, structural safety of a reinforced concrete containment vessel (RCCV) has been studied against the direct hit of Airbus A320, Boeing 707-320 and Phantom F4 aircrafts. ABAQUS/explicit finite element code has been used to carry out the three-dimensional numerical simulations. The impact locations identified on the nuclear containment structure are mid height of containment, center of the cylindrical portion, junction of dome and cylinder, and over the cylindrical portion close to the foundation level. The loading of the aircraft has been assigned through the corresponding reaction-time response curve. The concrete damaged plasticity model was predicted to simulate the behavior of concrete while the behavior of steel reinforcement was incorporated using elastoplastic material model. Dynamic loading conditions were considered using dynamic increase factor. The mid height of containment and center of cylindrical portion have been found to experience most severe deformation against each aircraft crash. It has also been found that compression damage in concrete is not critical at none of the impact locations.

  12. Numerical analysis of nuclear power plant structure subjected to aircraft crash

    Science.gov (United States)

    Saberi, Reza; Alinejad, Majid; Mahdavi, Mir Omid; Sepanloo, Kamran

    2017-10-01

    An aircraft crashing into a nuclear containment may induce a series of disasters related to containment capacity, including local penetration and perforation of the containment, intensive vibrations, and fire ignited after jet fuel leakage. In this study, structural safety of a reinforced concrete containment vessel (RCCV) has been studied against the direct hit of Airbus A320, Boeing 707-320 and Phantom F4 aircrafts. ABAQUS/explicit finite element code has been used to carry out the three-dimensional numerical simulations. The impact locations identified on the nuclear containment structure are mid height of containment, center of the cylindrical portion, junction of dome and cylinder, and over the cylindrical portion close to the foundation level. The loading of the aircraft has been assigned through the corresponding reaction-time response curve. The concrete damaged plasticity model was predicted to simulate the behavior of concrete while the behavior of steel reinforcement was incorporated using elastoplastic material model. Dynamic loading conditions were considered using dynamic increase factor. The mid height of containment and center of cylindrical portion have been found to experience most severe deformation against each aircraft crash. It has also been found that compression damage in concrete is not critical at none of the impact locations.

  13. Molecular diagnosis of Fragile X syndrome in subjects with intellectual disability of unknown origin: implications of its prevalence in regional Pakistan.

    Directory of Open Access Journals (Sweden)

    Madiha Kanwal

    Full Text Available Fragile-X syndrome (FXS is the most common form of inherited intellectual disability (ID and affects 0.7-3.0% of intellectually compromised population of unknown etiology worldwide. It is mostly caused by repeat expansion mutations in the FMR1 at chromosome Xq27.3. The present study aimed to develop molecular diagnostic tools for a better detection of FXS, to assess implementation of diagnostic protocols in a developing country and to estimate the prevalence of FXS in a cohort of intellectually disabled subjects from Pakistan. From a large pool of individuals with below normal IQ range, 395 subjects with intellectual disability of unknown etiology belonging to different regions of the country were recruited. Conventional-PCR, modified-PCR and Southern blot analysis methods were employed for the detection of CGG repeat polymorphisms in the FMR1 gene. Initial screening with conventional-PCR identified 13 suspected patients. Subsequent investigations through modified PCR and Southern blot analyses confirmed the presence of the FMR1 mutation, suggesting a prevalence of 3.5% and 2.8% (mean 3.3% among the male and female ID patients, respectively. These diagnostic methods were further customized with the in-house conditions to offer robust screening of referral patients/families for diagnostics and genetic counseling. Prescreening and early diagnosis are crucial for designing a prudent strategy for the management of subjects with ID. Outcome of the study recommends health practitioners for implementation of molecular based FXS diagnosis in routine clinical practice to give a better care for patients similar to the ones included in the study.

  14. Dynamic Response Analysis of Storage Cask Lid Structure Subjected to Lateral Impact Load of Aircraft Engine Crash

    Energy Technology Data Exchange (ETDEWEB)

    Almomania, Belal; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of); Lee, Sanghoon [Keimyung Univ., Daegu (Korea, Republic of)

    2015-10-15

    Several numerical methods and tests have been carried out to measure the capability of storage cask to withstand extreme impact loads. Testing methods are often constrained by cost, and difficulty in preparation for several impact conditions with different applied loads, and areas of impact. Instead, analytic method is an acceptable process that can easily apply different impact conditions for the evaluation of cask integrity. The aircraft engine impact is considered as one of the most critical impact accidents on the storage cask that significantly affects onto the lid closure system and may cause a considerable release of radioactive materials. This paper presents a method for evaluating the dynamic responses of one upper metal cask lid closure without impact limiters subjected to lateral impact of an aircraft engine with respect to variation of the impact velocity. An assessment method to predict damage response due to the lateral engine impact onto metal storage cask has been studied by using computer code LS-DYNA. The dynamic behavior of the lid movements was successfully calculated by utilizing a simplified finite element cask model, which showed a good agreement with the previous research. The simulation analyses results showed that no significant plastic deformation for bolts, lid, and the cask body. In this study, the lid opening and sliding displacements are considered as the major factors in initiating the leakage path. This analysis may be useful for evaluating the instantaneous leakage rates in a connection with the sliding and opening displacements between the lid and the flange to ensure that the radiological consequences caused by an aircraft engine crash accident during the storage phase are within the permissible level.

  15. Effect of temperature on composite sandwich structures subjected to low velocity impact. [aircraft construction materials

    Science.gov (United States)

    Sharma, A. V.

    1980-01-01

    The effect of low velocity projectile impact on sandwich-type structural components was investigated. The materials used in the fabrication of the impact surface were graphite-, Kevlar-, and boron-fibers with appropriate epoxy matrices. The testing of the specimens was performed at moderately low- and high-temperatures as well as at room temperature to assess the impact-initiated strength degradation of the laminates. Eleven laminates with different stacking sequences, orientations, and thicknesses were tested. The low energy projectile impact is considered to simulate the damage caused by runway debris, the dropping of the hand tools during servicing, etc., on the secondary aircraft structures fabricated with the composite materials. The results show the preload and the impact energy combinations necessary to cause catastrophic failure in the laminates tested. A set of faired curves indicating the failure thresholds is shown separately for the tension-and compression-loaded laminates. The specific-strengths and -modulii for the various laminates tested are also given.

  16. The effect of exposure duration on the subjective discomfort of aircraft cabin noise.

    Science.gov (United States)

    Huang, Yu; Jiang, Weikang

    2017-01-01

    The time dependency for subjective responses to noise has been a controversial question over many years. For durations of up to 10 min, the discomfort produced by three levels of noise (ie 60, 70 and 80 dBA) was investigated in this experimental study to determine the relation of discomfort to the time duration of noise. The rate of increase in discomfort with increasing duration was 1.5 dB per doubling of exposure duration, whereas it is currently assumed to be 3 dB per doubling of exposure duration. The sound dose level (SDL) was proposed to predict the discomfort caused by noise of long duration. The combination of SDL and vibration dose value (VDV) provided more consistent estimates of the equivalent comfort contours between noise and vibration over durations from 2 to 32 s than the combination of sound exposure level and VDV or that of sound pressure level and r.m.s. acceleration. Practitioner Summary: The discomfort produced by noise of long duration can be well predicted from a new definition of sound dose level, where the discomfort increases at 1.5 dB per doubling of exposure duration.

  17. Subjectivity

    Directory of Open Access Journals (Sweden)

    Jesús Vega Encabo

    2015-11-01

    Full Text Available In this paper, I claim that subjectivity is a way of being that is constituted through a set of practices in which the self is subject to the dangers of fictionalizing and plotting her life and self-image. I examine some ways of becoming subject through narratives and through theatrical performance before others. Through these practices, a real and active subjectivity is revealed, capable of self-knowledge and self-transformation. 

  18. Products of Ozone-initiated Chemistry during 4-hour Exposures of Human Subjects in a Simulated Aircraft Cabin

    DEFF Research Database (Denmark)

    Weschler, Charles J.; Wisthaler, Armin; Tamás, Gyöngyi

    2006-01-01

    Proton-transfer-reaction mass spectrometry (PTR-MS) was used to examine organic compounds in the air of a simulated aircraft cabin under four conditions: low ozone, low air exchange rate; low ozone, high air exchange rate; high ozone, low air exchange rate; high ozone, high air exchange rate...

  19. Attempting to train a digital human model to reproduce human subject reach capabilities in an ejection seat aircraft

    NARCIS (Netherlands)

    Zehner, G.F.; Hudson, J.A.; Oudenhuijzen, A.

    2006-01-01

    From 1997 through 2002, the Air Force Research Lab and TNO Defence, Security and Safety (Business Unit Human Factors) were involved in a series of tests to quantify the accuracy of five Human Modeling Systems (HMSs) in determining accommodation limits of ejection seat aircraft. The results of these

  20. Correlation between subjective assessments of local thermal discomfort and thermal manikin measurements in a simulated aircraft cabin

    DEFF Research Database (Denmark)

    Zukowska, Daria; Strøm-Tejsen, Peter; Jama, Agnieszka

    2005-01-01

    The thermal environment in a 21-seat simulated section of an aircraft cabin installed in a climate chamber was investigated. Using two thermal manikins and fourteen heated cylin-ders to represent passengers, measurements were carried out at cabin temperatures of 20.6°C, 23.3°C and 26.1°C (69°F, 74...

  1. Fever of unknown origin

    NARCIS (Netherlands)

    Mulders-Manders, C.; Simon, A.; Bleeker-Rovers, C.P.

    2015-01-01

    More than 50 years after the first definition of fever of unknown origin (FUO), it still remains a diagnostic challenge. Evaluation starts with the identification of potential diagnostic clues (PDCs), which should guide further investigations. In the absence of PDCs a standardised diagnostic

  2. Development of a Flammability Test Method for Aircraft Blankets

    Science.gov (United States)

    1996-03-01

    Flammability testing of aircraft blankets was conducted in order to develop a fire performance test method and performance criteria for blankets supplied to commercial aircraft operators. Aircraft blankets were subjected to vertical Bunsen burner tes...

  3. Aircraft systems design methodology and dispatch reliability prediction

    OpenAIRE

    Bineid, Mansour

    2005-01-01

    Aircraft despatch reliability was the main subject of this research in the wider content of aircraft reliability. The factors effecting dispatch reliability, aircraft delay, causes of aircraft delays, and aircraft delay costs and magnitudes were examined. Delay cost elements and aircraft delay scenarios were also studied. It concluded that aircraft dispatch reliability is affected by technical and non-technical factors, and that the former are under the designer's control. It showed that ...

  4. Cancer of unknown primary

    DEFF Research Database (Denmark)

    Dyrvig, Anne-Kirstine; Yderstræde, Knud Bonnet; Gerke, Oke

    2017-01-01

    Cancer of unknown primary (CUP) ranges within top 10 cancers in both incidence and mortality. As primary identification is crucial to choosing treatment, guidelines on CUP emphasize the diagnostic strategy. Whether guidelines are complied with, or if they are indeed helpful, is however unclear. We...... to procedures and patient survival. The cohort was investigated in terms of validity of diagnosis through cross-referencing with the Cancer Registry (CR), which served as gold standard for cancer diagnoses and patients' cancer histories.The NPR cohort consisted of 542 patients (275 males, 264 females) of whom...... after 4 years.The validity of a CUP diagnosis in NPR was low when using data from CR as reference. More than half the suspected CUP patients had a previous cancer diagnosis with CUP being the most frequent. Patients were diagnosed in compliance with guidelines indicating high external validity, but less...

  5. [Badminton--unknown sport].

    Science.gov (United States)

    Zekan-Petrinović, Lidija

    2007-01-01

    For a long time, badminton was considered to be only a slow and light game for children, a game that is played outdoors and is structurally undemanding.Today, it is not an unknown and unrecognised sport, especially after it was included into the Olympics Games in 1992. Badminton is one of the oldest sports in the world. It is suitable for all ages (for children and elderly equally), women and men and even handicapped persons. Beginners can start playing badminton matches early because the basics are learned quickly. As a recreational activity, badminton is very popular in Zagreb. In the last 10 years, a number of halls specialized for badminton or offering badminton as one of available sports activities have been opened in Zagreb. At present, there are over 70 professional playgrounds for training of top contestants but also for the citizens who can play recreational badminton.

  6. Designing towards the unknown

    DEFF Research Database (Denmark)

    Wilde, Danielle; Underwood, Jenny

    2018-01-01

    interdisciplinary teams with time and resource constraints need to deliver concrete outcomes on schedule. The Poetic Kinaesthetic Interface project (PKI) engages with this problematic directly. In PKI we use unfolding processes—informed by participatory, speculative and critical design—in emergent actions...... the research potential to far-ranging possibilities. In this article we unpack the motivations driving the PKI project. We present our mixed-methodology, which entangles textile crafts, design interactions and materiality to shape an embodied enquiry. Our research outcomes are procedural and methodological....... PKI brings together diverse human, non-human, known and unknown actors to discover where the emergent assemblages might lead. Our approach is re-invigorating—as it demands re-envisioning of—the design process....

  7. Physics: unknown radiation

    CERN Document Server

    Grenier, E; Liksonov, V I; Tsinoiev, V G

    2002-01-01

    This article reports experiments concerning the study of the electrical explosion of a titanium foil in water. During the electrical discharge a strong luminescence appears, the analysis of spectra shows the presence of new chemical elements and this presence is confirmed by the mass-spectrometry measurements performed on the precipitates found after the discharge. This experiment has been repeated about 200 times and the results are consistent an show an average titanium transmutation rate of 4%. Neither gamma nor neutron radiation have been detected but an unknown radiation, sensitive to magnetic fields, has been detected through tracks left on RF-ZMP fluo-graphical films covered with a 10 mu m-thick emulsion layer. The assumption of a radiation made up of magnetic monopoles is supported by the author. (A.C.)

  8. NEURONAVIGATION - DESTINATION UNKNOWN

    African Journals Online (AJOL)

    1990-03-02

    Mar 2, 1990 ... which would be performed by a robot. There is already pressure to make the use of neuronavigation·devices mandatory, with the implication being that if a device is not used the patient may be subject to undue risk. It may be premature at this stage to suggest that a new technology should be a standard of ...

  9. Development of a Probabilistic Safety Assessment Framework for an Interim Dry Storage Facility Subjected to an Aircraft Crash Using Best-Estimate Structural Analysis

    Directory of Open Access Journals (Sweden)

    Belal Almomani

    2017-03-01

    Full Text Available Using a probabilistic safety assessment, a risk evaluation framework for an aircraft crash into an interim spent fuel storage facility is presented. Damage evaluation of a detailed generic cask model in a simplified building structure under an aircraft impact is discussed through a numerical structural analysis and an analytical fragility assessment. Sequences of the impact scenario are shown in a developed event tree, with uncertainties considered in the impact analysis and failure probabilities calculated. To evaluate the influence of parameters relevant to design safety, risks are estimated for three specification levels of cask and storage facility structures. The proposed assessment procedure includes the determination of the loading parameters, reference impact scenario, structural response analyses of facility walls, cask containment, and fuel assemblies, and a radiological consequence analysis with dose–risk estimation. The risk results for the proposed scenario in this study are expected to be small relative to those of design basis accidents for best-estimated conservative values. The importance of this framework is seen in its flexibility to evaluate the capability of the facility to withstand an aircraft impact and in its ability to anticipate potential realistic risks; the framework also provides insight into epistemic uncertainty in the available data and into the sensitivity of the design parameters for future research.

  10. Aircraft Disinsection

    Science.gov (United States)

    Some countries may require aircraft coming from countries where certain insects or insect-borne diseases are present, such as malaria and Zika virus, to be treated with insecticide. Find out about regulation of pesticides for this treatment.

  11. Amphibious Aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — A brief self composed research article on Amphibious Aircrafts discussing their use, origin and modern day applications along with their advantages and disadvantages...

  12. Imaging an unknown object in an unknown medium

    NARCIS (Netherlands)

    Snieder, R; Wapenaar, C.P.A.

    2016-01-01

    Imaging an unknown object in a medium that is known, such as a medium with constant velocity, is not difficult because one knows exactly where the waves are when they interact with the object. It is much more challenging to image an object in an unknown medium, because in that case one may know the

  13. Provenance of unknown plutonium material.

    Science.gov (United States)

    Nicolaou, G

    2008-10-01

    The determination of the provenance of 'unknown' plutonium material is demonstrated through a simulation study based on an isotopic fingerprinting approach. Plutonium of known provenance was considered as the 'unknown' nuclear material in order to evaluate the potential of the approach and verify its predictive capabilities. Factor analysis was used to compare the Pu isotopic composition of the 'unknown' material with Pu isotopic compositions simulating well known spent fuels from a range of commercial nuclear power stations. The provenance of the 'unknown material' is assigned to the commercial fuel with which exhibits the highest degree of similarity with respect to the Pu composition. The approach appears promising since it accurately predicted the provenance of the one 'unknown' sample considered; nevertheless, the approach is still at the development stage. Important challenging issues related to the simulation uncertainties and its testing on real laboratory samples have to be explored prior to evaluating the potential of the approach.

  14. SIGNAL DETECTION WITH UNKNOWN PARAMETERS

    Directory of Open Access Journals (Sweden)

    Y. A. Sidorkina

    2015-01-01

    Full Text Available The likelihood ratio of the pulse signal with unknown time position while detecting and detecting the signal with unknown frequency, are considered. Is shown that an FFT algorithm should be performed while detecting the signal with unknown frequency, the maximum value of all spectral samples should be found and compared to the detection threshold. Upon detection of a pulse signal with unknown time position a fast convolution algorithm should be performed, the maximum value of all the spectral inverse FFT samples should be found and compared to the detection threshold. The effectiveness of this algorithm is determined by the sampling distribution of the maximum values of random variables distributed according to Rayleigh.

  15. Variation of aircraft noise annoyance

    Science.gov (United States)

    Dempsey, T. K.

    1980-01-01

    Laboratory and field studies were conducted to determine the basis for increased sensitivity of people to noise during aircraft noise studies. This change in sensitivity could be attributed to either a physiological time-of-day effect (i.e., a circadian rhythm) or simply to the total number of aircraft noise events experienced during a laboratory test period. In order to investigate the time-of-day factor, noise sensitivity measures were obtained from subjects at home with cassette tape recorders/headsets over a 24 hour period. The effect of number of aircraft noise events on noise sensitivity was investigated within a laboratory. In these tests, measures of sensitivity to noise were obtained from subjects before and after their exposure to varying numbers of aircraft noise events. The 24 hour data showed no evidence that noise sensitivity is physiologically cyclical. Consequently, these data can not explain annoyance response variation to aircraft noise tests conducted during the daytime. However, the number of aircraft noise events did influence the subject's noise sensitivity. This effect completely accounts for the systematic increase in noise sensitivity during a laboratory test period.

  16. Identification of unknown nuclear material

    Energy Technology Data Exchange (ETDEWEB)

    Nicolaou, G. [University of Thrace, Department of Electrical and Computer Engineering, Laboratory of Nuclear Technology, Kimmerria Campus, 67100 Xanthi (Greece)

    2010-07-01

    Aim: provenance determination of unknown nuclear material: - demonstrated for spent nuclear fuel; - information sought for unknown: fuel type, reactor type where fuel was irradiated, final burnup; Using an isotopic finger-printing method: - U, Pu or Pu isotopics or fission products; - simulations of fuel evolution during irradiation, using ORIGEN; - multivariate statistical tools. Fuel considered: simulated commercial spent fuel for a range of burnups: - PWR UO{sub 2} 3.1% and 3.5% {sup 235}U, - PWR thermal MOX, - BWR UO{sub 2} 3.2% {sup 235}U, - CANDU-N natural U, - CANDU-S UO{sub 2} 3.2% {sup 235}U, - fast Reactor MOX; simulated commercial spent fuel for a range of burnups: - PWR UO{sub 2} 3.1% and 3.5% {sup 235}U, - PWR thermal MOX, - BWR UO{sub 2} 3.2% {sup 235}U, - CANDU-N natural U, - CANDU-S UO{sub 2} 3.2% {sup 235}U, - fast Reactor MOX; 'unknown' spent fuel: - PWR 1: UO{sub 2} 3.1% {sup 235}U (26 GWd/t), - PWR 2: UO{sub 2} 3.1% {sup 235}U (32 GWd/t). Procedures: U, Pu or Pu isotopic compositions or fission products: - isotopic composition of unknown spent fuel, - simulated for commercial spent fuel from a range of nuclear power reactors {yields} comparison of compositions through factor analysis {yields} unknown has the provenance of the commercial spent fuel with which it exhibits the most similar composition. In conclusion: different reactor-fuel types well resolved; fuel and reactor type accurately predicted; burnup predicted to within 5% of declared; different reactor-fuel types. (authors)

  17. Function analysis of unknown genes

    DEFF Research Database (Denmark)

    Rogowska-Wrzesinska, A.

    2002-01-01

      This thesis entitled "Function analysis of unknown genes" presents the use of proteome analysis for the characterisation of yeast (Saccharomyces cerevisiae) genes and their products (proteins especially those of unknown function). This study illustrates that proteome analysis can be used...... be obtained using proteome analysis. Chapter 1 and 2 provide the basic theoretical aspects of proteome analysis, its principles, the main techniques involved and their use in the studies of the molecular biology of yeast cells. Chapter 3 presents the methods and tools involved in proteome analysis and used...... to multiple drug resistance in yeast. It analyses the cellular response to the overexpression of the Pdr5p - an ABC transporter protein that is responsible for resistance of yeast cells to several drugs and chemical compounds. It shows that the overexpression of Pdr5p triggers a strong cell stress response...

  18. Inflammation in Heart Failure: known knowns and unknown unknowns.

    Science.gov (United States)

    Cocco, Giuseppe; Jerie, Paul; Amiet, Philipp; Pandolfi, Stefano

    2017-08-01

    The review deals with inflammation in heart failure (HF). Many data show that systemic inflammation is frequent in HF and implicate that inflammation contributes to damage and dysfunction of the cardiovascular system. Areas Covered: Experimental data have been mainly obtained in acute laboratory animal models. It is questionable whether animals' data can be translated into clinical settings with patients with chronic HF who have concomitant pathologies. The idea of a common inflammatory pathway that characterizes all different forms of clinical HF is unrealistic. It seems realistic that inflammation differs in non-cardiac and cardiac diseases. Research therapeutic options address the use of inhibitors of cytokines, of agents antagonizing oxidative stress, of MMP and of PI3K signaling pathways. Expert Opinion: Considering the many unknowns in our knowledge it is not surprising that early trials aimed to antagonize inflammation in HF have been disappointing. We are far away from having solid therapeutic schedules to use immunomodulation in all subtypes of HF. However, modern trials on HF due to virus infections have proven that immunomodulation is therapeutically effective. We should wisely use the known facts and accept that we have many unknowns. By appropriate selection of the subtypes of HF we may be able to find the appropriate therapy against inflammation in HF.

  19. 10 CFR 70.14 - Foreign military aircraft.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Foreign military aircraft. 70.14 Section 70.14 Energy....14 Foreign military aircraft. The regulations in this part do not apply to persons who carry special nuclear material (other than plutonium) in aircraft of the armed forces of foreign nations subject to 49 U...

  20. 77 FR 22187 - Technical Amendment; Airworthiness Standards-Aircraft Engines

    Science.gov (United States)

    2012-04-13

    ... Federal Aviation Administration 14 CFR Part 33 Technical Amendment; Airworthiness Standards--Aircraft.... SUMMARY: This amendment corrects a number of errors in the airworthiness standards for aircraft engine... additional burden on any person. List of Subjects 14 CFR Part 33 Air transportation, Aircraft, Aviation...

  1. Carcinoma Telangiectaticum of Unknown Primary

    Directory of Open Access Journals (Sweden)

    Demet Çiçek

    2008-07-01

    Full Text Available Carcinoma telangiectaticum is an unusual type of cutaneous metastasis originating from various malignant tumors and characterized by telangiectases. This disorder appears with the spread of malignant cells to the skin via superficial lymphatics. It presents as small pink to purplish pseudovesicles, purpuric papules, plaques and telangiectases. A 58-year-old female patient with extensive internal organ metastasis, the primary of which could not be determined, was consulted for bluish lesion on her abdomen, while she was receiving cisplatinum and etoposide combination chemotherapy and radiotherapy. Histopathologic examination revealed that the superficial lymphatics in dermis were attacked by tumoral cells. Final diagnosis was established by clinical and histopathological findings as carcinoma telangiectaticum due to metastasis of a malignant tumor of unknown origin. Unfortunately our patient succumbed during her chemotherapy.

  2. Striving for the unknown normal

    DEFF Research Database (Denmark)

    Nielsen, Mikka

    the ADHD diagnosis both answers and produces existential questions on what counts as normal behaviour and emotions. The diagnosis helps the diagnosed to identify, accept and handle problems by offering concrete explanations and solutions to diffuse experienced problems. But the diagnostic process......-analysing situation trying to answer: What is ADHD and what is me and my personal features? When are the drugs having the right effect? And since I have never been normal then how would I know what behavioural ideal I am striving for? Moreover, the public questioning of the diagnosis calls the individual...... to constantly claiming recognition of the diagnosis. I end by discussing the moral implications of this striving for the unknown normal and ask if the pathologization of inattentive and hyperactive behaviour is to be addressed as a problematic moral issue or if we have a moral obligation to help people who...

  3. Model of aircraft noise adaptation

    Science.gov (United States)

    Dempsey, T. K.; Coates, G. D.; Cawthorn, J. M.

    1977-01-01

    Development of an aircraft noise adaptation model, which would account for much of the variability in the responses of subjects participating in human response to noise experiments, was studied. A description of the model development is presented. The principal concept of the model, was the determination of an aircraft adaptation level which represents an annoyance calibration for each individual. Results showed a direct correlation between noise level of the stimuli and annoyance reactions. Attitude-personality variables were found to account for varying annoyance judgements.

  4. Aircraft en route noise annoyance

    Science.gov (United States)

    Mccurdy, David A.

    1990-01-01

    Results are reported from a laboratory experiment conducted in order to quantify the annoyance experienced by people on the ground in response to en route noise (ERN) generated by aircraft at cruise conditions. Objectives included the comparison of annoyance responses to ERN with the annoyance responses to takeoff and landing noise; the comparison of the annoyance responses to advanced turboprop aircraft ERN with those of the turbofan ERN; and also the ability of aircraft noise measurement procedures and corrections to predict annoyance to ERN. Tests were conducted at the Langley Acoustics Research Laboratory on 32 human subjects selected at random. Subjects judged the annoyance level of 24 Propfan Test Assessment advanced turboprop ERN stimuli, 18 conventional turbofan ERN stimuli, and 60 conventional turboprop and turbofan takeoff and landing noise stimuli. Analysis of resulting data compared annoyance responses to different aircraft types and operations, examined the ability of current noise measurement and correction procedures to predict annoyance ERN, and calculated optimum duration correction magnitudes for ERN.

  5. Propulsion controlled aircraft computer

    Science.gov (United States)

    Cogan, Bruce R. (Inventor)

    2010-01-01

    A low-cost, easily retrofit Propulsion Controlled Aircraft (PCA) system for use on a wide range of commercial and military aircraft consists of an propulsion controlled aircraft computer that reads in aircraft data including aircraft state, pilot commands and other related data, calculates aircraft throttle position for a given maneuver commanded by the pilot, and then displays both current and calculated throttle position on a cockpit display to show the pilot where to move throttles to achieve the commanded maneuver, or is automatically sent digitally to command the engines directly.

  6. GRAPHICAL MODELS OF THE AIRCRAFT MAINTENANCE PROCESS

    Directory of Open Access Journals (Sweden)

    Stanislav Vladimirovich Daletskiy

    2017-01-01

    Full Text Available The aircraft maintenance is realized by a rapid sequence of maintenance organizational and technical states, its re- search and analysis are carried out by statistical methods. The maintenance process concludes aircraft technical states con- nected with the objective patterns of technical qualities changes of the aircraft as a maintenance object and organizational states which determine the subjective organization and planning process of aircraft using. The objective maintenance pro- cess is realized in Maintenance and Repair System which does not include maintenance organization and planning and is a set of related elements: aircraft, Maintenance and Repair measures, executors and documentation that sets rules of their interaction for maintaining of the aircraft reliability and readiness for flight. The aircraft organizational and technical states are considered, their characteristics and heuristic estimates of connection in knots and arcs of graphs and of aircraft organi- zational states during regular maintenance and at technical state failure are given. It is shown that in real conditions of air- craft maintenance, planned aircraft technical state control and maintenance control through it, is only defined by Mainte- nance and Repair conditions at a given Maintenance and Repair type and form structures, and correspondingly by setting principles of Maintenance and Repair work types to the execution, due to maintenance, by aircraft and all its units mainte- nance and reconstruction strategies. The realization of planned Maintenance and Repair process determines the one of the constant maintenance component. The proposed graphical models allow to reveal quantitative correlations between graph knots to improve maintenance processes by statistical research methods, what reduces manning, timetable and expenses for providing safe civil aviation aircraft maintenance.

  7. Homebuilt aircraft crashes.

    Science.gov (United States)

    Hasselquist, A; Baker, S P

    1999-06-01

    While the number of general aviation crashes has decreased over the 5 yr prior to 1993, the total number of homebuilt aircraft crashes has increased by nearly 25%. Research was undertaken to analyze these crashes and identify causal factors or unique problems associated with homebuilt aircraft. Some 200 National Transportation Safety Board computer records and two-page descriptive briefs were analyzed for homebuilt aircraft crashes during 1993. Using descriptive epidemiology, variables were looked at in detail and comparisons were made with general aviation crashes during the-same year. Despite accounting for only 3% of all hours flown in general aviation certified aircraft for 1993, homebuilt aircraft accounted for 10% of the crashes and experienced a higher fatal crash rate. Crashes due to mechanical failure and crashes on takeoff and climb were more common in homebuilt aircraft as compared with general aviation. Other significant causal factors for homebuilt aircraft crashes included: minimal flight time in type specific aircraft, improper maintenance and improper design or assembly. Greater emphasis needs to be placed on educating homebuilt aircraft owners in the importance of following Federal Aviation Administration guidelines for certification and air worthiness testing. Understanding the aircraft's specifications and design limitations prior to the initial flight and properly maintaining the aircraft should also help to reverse the trend in the number of these crashes and subsequent lives lost. A system for assuring that all home-built aircraft are certified and more accurate reporting of flight hours are needed for accurate tracking of homebuilt aircraft crash rates.

  8. [Energy drinks: an unknown risk].

    Science.gov (United States)

    Petit, Aymeric; Levy, Fanny; Lejoyeux, Michel; Reynaud, Michel; Karila, Laurent

    2012-05-01

    The term "energy drink" designates "any product in the form of a drink or concentrated liquid, which claims to contain a mixture of ingredients having the property to raise the level of energy and vivacity". The main brands, Red Bull, Dark Dog, Rockstar, Burn, and Monster, are present in food stores, sports venues, and bars among other soft drinks and fruit juices. Their introduction into the French market raised many reluctances, because of the presence of taurine, caffeine and glucuronolactone. These components present in high concentrations, could be responsible for adverse effects on health. The association of energy drinks and spirits is widely found among adolescents and adults who justify drinking these mixed drinks by their desire to drink more alcohol while delaying drunkenness. Given the importance of the number of incidents reported among the energy drinks consumers, it seemed appropriate to make a synthesis of available data and to establish causal links between the use of these products and the development of health complications. For a literature review, we selected scientific articles both in English and French published between 2001 and 2011 by consulting the databases Medline, Embase, PsycINFO and Google Scholar. The words used alone or in combination are "energy dinks", "caffeine", "taurine", "toxicity", "dependence". An occasional to a moderate consumption of these drinks seems to present little risk for healthy adults. However, excessive consumption associated with the use of alcohol or drugs in amounts that far exceed the manufacturers recommended amount, could be responsible for negative consequences on health, particularly among subjects with cardiovascular disease.

  9. Unmanned aircraft systems

    Science.gov (United States)

    Unmanned platforms have become increasingly more common in recent years for acquiring remotely sensed data. These aircraft are referred to as Unmanned Airborne Vehicles (UAV), Remotely Piloted Aircraft (RPA), Remotely Piloted Vehicles (RPV), or Unmanned Aircraft Systems (UAS), the official term used...

  10. Unknown Risks: Parental Hesitation about Vaccination.

    Science.gov (United States)

    Blaisdell, Laura L; Gutheil, Caitlin; Hootsmans, Norbert A M; Han, Paul K J

    2016-05-01

    This qualitative study of a select sample of vaccine-hesitant parents (VHPs) explores perceived and constructed personal judgments about the risks and uncertainties associated with vaccines and vaccine-preventable diseases (VPDs) and how these subjective risk judgments influence parents' decisions about childhood vaccination. The study employed semistructured focus group interviews with 42 VHPs to elicit parents' perceptions and thought processes regarding the risks associated with vaccination and nonvaccination, the sources of these perceptions, and their approach to decision making about vaccination for their children. VHPs engage in various reasoning processes and tend to perceive risks of vaccination as greater than the risks of VPDs. At the same time, VHPs engage in other reasoning processes that lead them to perceive ambiguity in information about the harms of vaccination-citing concerns about the missing, conflicting, changing, or otherwise unreliable nature of information. VHPs' refusal of vaccination may reflect their aversion to both the risk and ambiguity they perceive to be associated with vaccination. Mitigating this vaccine hesitancy likely requires reconstructing the risks and ambiguities associated with vaccination-a challenging task that requires providing parents with meaningful evidence-based information on the known risks of vaccination versus VPDs and explicitly acknowledging the risks that remain truly unknown. © The Author(s) 2015.

  11. Experimental and Numerical Investigation of the Dynamic Seat Comfort in Aircrafts

    Science.gov (United States)

    Ciloglu, Hakan

    This research focuses on the dynamic seat comfort in aircrafts specifically during takeoff, landing and cruise through turbulence flight conditions. The experiments are performed using a multi axis shaker table in the Automotive Centre of Excellence (ACE) at the University of Ontario Institute of Technology subjected to sample takeoff, landing and cruise vibration recordings obtained onboard of an actual flight. The input vibrations introduced to the aircraft seats during actual flight conditions and during the experiments in the ACE are compared and it is concluded that the given flight conditions were successfully replicated for the interest of this thesis. The experiments are conducted with two different aircraft seats, economy class and business class. Furthermore, to investigate the importance of seat cushion characteristics in addition to economy and business class seat cushions, three laboratory made cushions were included in the investigation as well. Moreover, the effect of passenger weight is also discussed by conducting the experiments with 1 and 2 identical dummies. It is concluded that static seat properties play a significant role in the comfort perception level as well as flight conditions. Among the three flight condition, landing appeared to be the most uncomfortable case comparing to takeoff and cruise. In addition to experimental work, a numerical study to simulate the flight conditions is undertaken with the initial work of CAD modelling. The simulated responses of the seat is partially matching with experimental results due to unknown parameters of the cushion and the connections of the aircraft seat that cannot be created in the CAD model due to unknown manufacturing processes.

  12. Fatigue tests on big structure assemblies of concorde aircraft

    Science.gov (United States)

    Nguyen, V. P.; Perrais, J. P.

    1972-01-01

    Fatigue tests on structural assemblies of the Concorde supersonic transport aircraft are reported. Two main sections of the aircraft were subjected to pressure, mechanical load, and thermal static tests. The types of fatigue tests conducted and the results obtained are discussed. It was concluded that on a supersonic aircraft whose structural weight is a significant part of the weight analysis, many fatigue and static strength development tests should be made and fatigue and thermal tests of the structures are absolutely necessary.

  13. Dedicated Solutions for Structural Health Monitoring of Aircraft Components

    OpenAIRE

    Pitropakis, Ioannis

    2015-01-01

    Aircraft structures, like any other mechanical structure, are subjected to various external factors that influence their lifetime. Mechanicalnbsp;and the environment are only some of the factors that can degrade the structure of aircraft components. Monitoring of these degradations by regular inspections or automated data recording is vital for the structural health of the critical components of an aircraft. This research proposes a number of dedicated solutions for structural health monitori...

  14. Annoyance caused by aircraft en route noise

    Science.gov (United States)

    Mccurdy, David A.

    1992-01-01

    A laboratory experiment was conducted to quantify the annoyance response of people on the ground to enroute noise generated by aircraft at cruise conditions. The en route noises were ground level recordings of eight advanced turboprop aircraft flyovers and six conventional turbofan flyovers. The eight advanced turboprop enroute noises represented the NASA Propfan Test Assessment aircraft operating at different combinations of altitude, aircraft Mach number, and propeller tip speed. The conventional turbofan en route noises represented six different commercial airliners. The overall durations of the en route noises varied from approximately 40 to 160 sec. In the experiment, 32 subjects judged the annoyance of the en route noises as well as recordings of the takeoff and landing noises of each of 5 conventional turboprop and 5 conventional turbofan aircraft. Each of the noises was presented at three sound pressure levels to the subjects in an anechoic listening room. Analysis of the judgments found small differences in annoyance between three combinations of aircraft type and operation. Current tone and corrections did not significantly improve en route annoyance prediction. The optimum duration-correction magnitude for en route noise was approximately 1 dB per doubling of effective duration.

  15. Aircraft Engine Thrust Estimator Design Based on GSA-LSSVM

    Science.gov (United States)

    Sheng, Hanlin; Zhang, Tianhong

    2017-08-01

    In view of the necessity of highly precise and reliable thrust estimator to achieve direct thrust control of aircraft engine, based on support vector regression (SVR), as well as least square support vector machine (LSSVM) and a new optimization algorithm - gravitational search algorithm (GSA), by performing integrated modelling and parameter optimization, a GSA-LSSVM-based thrust estimator design solution is proposed. The results show that compared to particle swarm optimization (PSO) algorithm, GSA can find unknown optimization parameter better and enables the model developed with better prediction and generalization ability. The model can better predict aircraft engine thrust and thus fulfills the need of direct thrust control of aircraft engine.

  16. 14 CFR 21.128 - Tests: aircraft engines.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tests: aircraft engines. 21.128 Section 21... engines. (a) Each person manufacturing aircraft engines under a type certificate only shall subject each engine (except rocket engines for which the manufacturer must establish a sampling technique) to an...

  17. Sizing Analysis for Aircraft Utilizing Hybrid-Electric Propulsion Systems

    Science.gov (United States)

    2011-03-18

    Lithium-Ion Batteries for Hybrid Electric Vehicles," Mitsubishi Motor Corporation, Japan, Technical Review 15, 2003. [40] Hiroaki et al Yoshida...SIZING ANALYSIS FOR AIRCRAFT UTILIZING HYBRID- ELECTRIC PROPULSION SYSTEMS THESIS Matthew D...of the U.S. Government and is not subject to copyright protection in the United States. AFIT/GAE/ENY/11-M26 SIZING ANALYSIS FOR AIRCRAFT

  18. Controlled unknown quantum operations on hybrid systems

    Science.gov (United States)

    He, Yong; Luo, Ming-Xing

    2016-12-01

    Any unknown unitary operations conditioned on a control system can be deterministically performed if ancillary subspaces are available for the target systems [Zhou X Q, et al. 2011 Nat. Commun. 2 413]. In this paper, we show that previous optical schemes may be extended to general hybrid systems if unknown operations are provided by optical instruments. Moreover, a probabilistic scheme is proposed when the unknown operation may be performed on the subspaces of ancillary high-dimensional systems. Furthermore, the unknown operations conditioned on the multi-control system may be reduced to the case with a control system using additional linear circuit complexity. The new schemes may be more flexible for different systems or hybrid systems. Project supported by the National Natural Science Foundation of China (Grant Nos. 61303039 and 61201253), Chunying Fellowship, and Fundamental Research Funds for the Central Universities, China (Grant No. 2682014CX095).

  19. Fever of unknown origin in rheumatic diseases.

    Science.gov (United States)

    Zenone, Thierry

    2007-12-01

    Noninfectious inflammatory diseases (connective tissue diseases, vasculitis syndromes, granulomatous diseases) emerged as the most frequent cause of fever of unknown origin in western countries. Among these diseases, giant cell arteritis and polymyalgia rheumatica are the most frequent specific diagnosis in the elderly and adult-onset Still's disease the most frequent in younger patients. This article focuses on noninfectious inflammatory diseases as a cause of classic fever of unknown origin (mainly rheumatic diseases, such as vasculitis and connective tissue diseases).

  20. 49 CFR 175.310 - Transportation of flammable liquid fuel; aircraft only means of transportation.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Transportation of flammable liquid fuel; aircraft... Material § 175.310 Transportation of flammable liquid fuel; aircraft only means of transportation. (a) When... racks or slings. (c) Flammable liquid fuels may be carried on a cargo aircraft, subject to the following...

  1. Meet your Aircraft Quiz

    Science.gov (United States)

    1995-01-01

    This quiz is designed to help a pilot meet his or her aircraft. Although no attempt is made to cover in depth all of the information contained in the typical Pilot's Operating Handbook (POH), Owner's Manual (OM), or Aircraft Flight Manual (AFM), the ...

  2. DEVELOPMENT OF AIRCRAFT,

    Science.gov (United States)

    Criteria of effectiveness of aviation; Development of aviation in the period 1918-1939; Main factors of the progress of speed; Cause of changes of main...factors of combat efficiency of aircraft; Equation of state of production of aircraft; Development of aviation 1939-1959; and Development of one-shot winged and ballistic vehicles.

  3. Contextualising aircraft maintenance documentation

    NARCIS (Netherlands)

    Koornneef, H.; Verhagen, W.J.C.; Curran, Ricky

    2017-01-01

    The use of documentation for task support in aircraft line maintenance is still mostly paper-based, which is slow, burdensome and prone to error. This paper provides an overview of the issues associated with the use of paper-based documentation in aircraft line maintenance and describes the

  4. Aircraft operations management manual

    Science.gov (United States)

    1992-01-01

    The NASA aircraft operations program is a multifaceted, highly diverse entity that directly supports the agency mission in aeronautical research and development, space science and applications, space flight, astronaut readiness training, and related activities through research and development, program support, and mission management aircraft operations flights. Users of the program are interagency, inter-government, international, and the business community. This manual provides guidelines to establish policy for the management of NASA aircraft resources, aircraft operations, and related matters. This policy is an integral part of and must be followed when establishing field installation policy and procedures covering the management of NASA aircraft operations. Each operating location will develop appropriate local procedures that conform with the requirements of this handbook. This manual should be used in conjunction with other governing instructions, handbooks, and manuals.

  5. Fast grasping of unknown objects using principal component analysis

    Science.gov (United States)

    Lei, Qujiang; Chen, Guangming; Wisse, Martijn

    2017-09-01

    Fast grasping of unknown objects has crucial impact on the efficiency of robot manipulation especially subjected to unfamiliar environments. In order to accelerate grasping speed of unknown objects, principal component analysis is utilized to direct the grasping process. In particular, a single-view partial point cloud is constructed and grasp candidates are allocated along the principal axis. Force balance optimization is employed to analyze possible graspable areas. The obtained graspable area with the minimal resultant force is the best zone for the final grasping execution. It is shown that an unknown object can be more quickly grasped provided that the component analysis principle axis is determined using single-view partial point cloud. To cope with the grasp uncertainty, robot motion is assisted to obtain a new viewpoint. Virtual exploration and experimental tests are carried out to verify this fast gasping algorithm. Both simulation and experimental tests demonstrated excellent performances based on the results of grasping a series of unknown objects. To minimize the grasping uncertainty, the merits of the robot hardware with two 3D cameras can be utilized to suffice the partial point cloud. As a result of utilizing the robot hardware, the grasping reliance is highly enhanced. Therefore, this research demonstrates practical significance for increasing grasping speed and thus increasing robot efficiency under unpredictable environments.

  6. A memetic algorithm to solve the dynamic multiple runway aircraft landing problem

    Directory of Open Access Journals (Sweden)

    Ghizlane Bencheikh

    2016-01-01

    Full Text Available The aircraft landing problem (ALP consists of scheduling the landing of aircrafts onto the available runways in an airport by assigning to each aircraft a landing time and a specific runway while respecting different operational constraints. This is a complex task for the air traffic controller, especially when the flow of aircrafts entering the radar range is continuous and the number of aircrafts is unknown a priori. In this paper, we study the dynamic version of the ALP when new aircrafts appear over time, which means that the landing of the previous aircrafts should be rescheduled. To solve this problem, we propose a memetic algorithm combining an ant colony algorithm and a local heuristic.

  7. Predicting Visibility of Aircraft

    Science.gov (United States)

    Watson, Andrew; Ramirez, Cesar V.; Salud, Ellen

    2009-01-01

    Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO). In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration. PMID:19462007

  8. Aircraft Engine Emissions Estimator

    Science.gov (United States)

    1985-11-01

    Protection Agency, " Control of Air Pollution From Aircraft and Aircraft Engines," 43 FR 12615, March 24, Vq7. 51 ~~SL% 12. Souza, A.F. F-100 Afterburner...R.G. Technical Support Report-Aircraft Emissions Factors, USEPA Office of Mobile Source Air Pollution Control , Ann Arbor, MI, March 1977. 14. Souza, A.F...STAVILITY CATEGOUY 6 WIND SPELU (METERS/SECOND) 1600 WINU DIRECTION TAILWIN) TEMPERATURa " (F) 38.0O MIXING DEPT" (METLRS) l1.o00

  9. SOLAR AIRCRAFT DESIGN

    OpenAIRE

    Rahmati, Sadegh; GHASED, Amir

    2015-01-01

    Abstract. Generally domain Aircraft uses conventional fuel. These fuel having limited life, high cost and pollutant. Also nowadays price of petrol and other fuels are going to be higher, because of scarcity of those fuels. So there is great demand of use of non-exhaustible unlimited source of energy like solar energy. Solar aircraft is one of the ways to utilize solar energy. Solar aircraft uses solar panel to collect the solar radiation for immediate use but it also store the remaining part ...

  10. Tropospheric sampling with aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Daum, P.H.; Springston, S.R.

    1991-03-01

    Aircraft constitute a unique environment which places stringent requirements on the instruments used to measure the concentrations of atmospheric trace gases and aerosols. Some of these requirements such as minimization of size, weight, and power consumption are general; others are specific to individual techniques. This review presents the basic principles and considerations governing the deployment of trace gas and aerosol instrumentation on an aircraft. An overview of common instruments illustrates these points and provides guidelines for designing and using instruments on aircraft-based measurement programs.

  11. Multidimensional procurement auctions with unknown weights

    DEFF Research Database (Denmark)

    Greve, Thomas

    the principal and the agents leads to unclear reaction strategies. I show that an unknown weight on the principal’s valuation of quality leads to the production of to much quality and to high informational rent. A problem that can be reduced using a revelation mechanism. Having an unknown weight on quality...... gives rise to an analysis of a principal that can not fully commit to the outcome induced by the scoring rule. Therefore, my result apply to contract theory and it’s problems with imperfect commitment....

  12. Protocol for counterfactually transporting an unknown qubit

    Directory of Open Access Journals (Sweden)

    Hatim eSalih

    2016-01-01

    Full Text Available Quantum teleportation circumvents the uncertainty principle using dual channels: a quantum one consisting of previously-shared entanglement, and a classical one, together allowing the disembodied transport of an unknown quantum state over distance. It has recently been shown that a classical bit can be counterfactually communicated between two parties in empty space, Alice and Bob. Here, by using our dual version of the chained quantum Zeno effect to achieve a counterfactual CNOT gate, we propose a protocol for transporting an unknown qubit counterfactually, that is without any physical particles travelling between Alice and Bob—no classical channel and no previously-shared entanglement.

  13. Protocol for counterfactually transporting an unknown qubit

    Science.gov (United States)

    Salih, Hatim

    2015-12-01

    Quantum teleportation circumvents the uncertainty principle using dual channels: a quantum one consisting of previously-shared entanglement, and a classical one, together allowing the disembodied transport of an unknown quantum state over distance. It has recently been shown that a classical bit can be counterfactually communicated between two parties in empty space, “Alice” and “Bob”. Here, by using our “dual” version of the chained quantum Zeno effect to achieve a counterfactual CNOT gate, we propose a protocol for transporting an unknown qubit counterfactually, that is without any physical particles travelling between Alice and Bob—no classical channel and no previously-shared entanglement.

  14. 39 CFR 946.4 - Disposition of property of unknown owners.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Disposition of property of unknown owners. 946.4 Section 946.4 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PROCEDURE RELATING TO THE... § 946.4 Disposition of property of unknown owners. (a) Where no apparent owner of property subject to...

  15. Method for genetic identification of unknown organisms

    Energy Technology Data Exchange (ETDEWEB)

    Colston, Jr., Billy W.; Fitch, Joseph P.; Hindson, Benjamin J.; Carter, Chance J.; Beer, Neil Reginald

    2016-08-23

    A method of rapid, genome and proteome based identification of unknown pathogenic or non-pathogenic organisms in a complex sample. The entire sample is analyzed by creating millions of emulsion encapsulated microdroplets, each containing a single pathogenic or non-pathogenic organism sized particle and appropriate reagents for amplification. Following amplification, the amplified product is analyzed.

  16. Ovine wet carcass syndrome of unknown aetiology

    African Journals Online (AJOL)

    plicating cachexia, inflammatory processes, lymphoedema, cardiac failure, glycogen storage or myxoedema in the pathogenesis of the syndrome. In conclusion, despite intensive investigation the aeti- ology of the wet carcase syndrome remains unknown. At present the possibility of a histamine reaction due to insect bites is ...

  17. Aircraft electromagnetic compatibility

    Science.gov (United States)

    Clarke, Clifton A.; Larsen, William E.

    1987-06-01

    Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.

  18. Aircraft electromagnetic compatibility

    Science.gov (United States)

    Clarke, Clifton A.; Larsen, William E.

    1987-01-01

    Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.

  19. Unmanned Aircraft Systems - Orthoimagery

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS National Unmanned Aircraft Systems (UAS) Project Office utilizes UAS technology for collecting remote sensing data on a local scale. Typical UAS projects...

  20. Depreciation of aircraft

    Science.gov (United States)

    Warner, Edward P

    1922-01-01

    There is a widespread, and quite erroneous, impression to the effect that aircraft are essentially fragile and deteriorate with great rapidity when in service, so that the depreciation charges to be allowed on commercial or private operation are necessarily high.

  1. Aircraft Depainting Technology

    National Research Council Canada - National Science Library

    Kozol, Joseph

    1999-01-01

    ... of aircraft and component stripping at various levels of maintenance. Under this program, the Navy pursued development of non-HAP chemical paint strippers as alternatives for methylene chloride based strippers...

  2. Essentials of aircraft armaments

    CERN Document Server

    Kaushik, Mrinal

    2017-01-01

    This book aims to provide a complete exposure about armaments from their design to launch from the combat aircraft. The book details modern ammunition and their tactical roles in warfare. The proposed book discusses aerodynamics, propulsion, structural as well as navigation, control, and guidance of aircraft armament. It also introduces the various types of ammunition developed by different countries and their changing trends. The book imparts knowledge in the field of design, and development of aircraft armaments to aerospace engineers and covers the role of the United Nations in peacekeeping and disarmament. The book will be very useful to researchers, students, and professionals working in design and manufacturing of aircraft armaments. The book will also serve air force and naval aspirants, and those interested in working on defence research and developments organizations. .

  3. Aircraft Fire Protection Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Navy Aircraft Protection Laboratory provides complete test support for all Navy air vehicle fire protection systems.The facility allows for the simulation of a...

  4. Aircraft Survivability. Summer 2011

    Science.gov (United States)

    2011-01-01

    aircraft in Mombasa, Kenya, in 2002 and a DHL cargo aircraft in Baghdad, Iraq, in 2003, the threat is not limited to military operations, but is of...Government/ Customer Iterate Based on Changes Over the Life of the A/C Describe Performance Requirements Figure 3 Value of Impact Capability Figure 2 FSC... customer describing their performance requirements, identifying probable mission scenarios, prioritizing possible impact conditions, and setting

  5. Aircraft engine noise

    Science.gov (United States)

    Kennepohl, F.

    An overview of the main aircraft engine noise sources is given. Special emphasis is devoted to turbomachinery/rotor noise, which plays an important role in all engine concepts appropriate to regional aircraft, such as turbofans, propellers, or new propfan engine concepts. The noise generating mechanisms, including propagation within the engine, and calculation methods used are described. Noise reduction methods are considered, with emphasis on cutoff design of turbomachines. Some noise features of counter rotating propellers and swept rotor blades are mentioned.

  6. Christian Petzold’s melodramas : From unknown woman to reciprocal unknownness in Phoenix, Wolfsburg, and Barbara

    NARCIS (Netherlands)

    Staat, W.

    2016-01-01

    Stanley Cavell’s theory of film melodrama is used for Christian Petzold’s Phoenix, Wolfsburg, and Barbara. Key for Cavell’s understanding of classical Hollywood melodrama is his notion of the ‘unknown woman.’ Remarkably, Petzold’s more contemporary melodramas feature unknown, i.e. unacknowledged,

  7. Melanoma of unknown origin: a case series.

    LENUS (Irish Health Repository)

    Kelly, J

    2010-12-01

    The natural history of metastatic melanoma involving lymph nodes, in the absence of a known primary site (cutaneous, ocular or mucosal) has, to date, been poorly defined; and the optimal management of this rare subtype of disease is therefore unclear. Melanomas of unknown primary site (MUP) are estimated to comprise between 3.7 and 6% of all melanomas (Anbari et al. in Cancer 79:1861-1821, 1997).

  8. B-52 Launch Aircraft in Flight

    Science.gov (United States)

    2001-01-01

    the development of parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet.

  9. Fever of unknown origin (FUO) revised.

    Science.gov (United States)

    Unger, Manuel; Karanikas, Georgios; Kerschbaumer, Andreas; Winkler, Stefan; Aletaha, Daniel

    2016-11-01

    Fever of unknown origin (FUO) was originally characterised in 1961 by Petersdorf and Beeson as a disease condition of temperature exceeding 38.3 °C on at least three occasions over a period of at least three weeks, with no diagnosis made despite one week of inpatient investigation. However, since underlying diseases are often reported for classical FUO, these presentations may not be considered to be of "unknown origin". Rather, the aetiology of prolonged fever may resolve, or not resolve. The definition of fever with unresolved cause (true FUO) is difficult, as it is a moving target, given the constant advancement of imaging and biomarker analysis. Therefore, the prevalence of fever with unresolved cause (FUO) is unknown.In this review, we report such a case of prolonged fever, which initially has presented as classical FUO, and discuss current literature. Furthermore, we will give an outlook, how a prospective study on FUO will allow to solve outstanding issues like the utility of different diagnostic investigations, and the types and prevalence of various underlying diseases.

  10. Riveted Lap Joints in Aircraft Fuselage Design, Analysis and Properties

    CERN Document Server

    Skorupa, Andrzej

    2012-01-01

    Fatigue of the pressurized fuselages of transport aircraft is a significant problem all builders and users of aircraft have to cope with for reasons associated with assuring a sufficient lifetime and safety, and formulating adequate inspection procedures. These aspects are all addressed in various formal protocols for creating and maintaining airworthiness, including damage tolerance considerations. In most transport aircraft, fatigue occurs in lap joints, sometimes leading to circumstances that threaten safety in critical ways. The problem of fatigue of lap joints has been considerably enlarged by the goal of extending aircraft lifetimes. Fatigue of riveted lap joints between aluminium alloy sheets, typical of the pressurized aircraft fuselage, is the major topic of the present book. The richly illustrated and well-structured chapters treat subjects such as: structural design solutions and loading conditions for fuselage skin joints; relevance of laboratory test results for simple lap joint specimens to rive...

  11. Aircraft and background noise annoyance effects

    Science.gov (United States)

    Willshire, K. F.

    1984-01-01

    To investigate annoyance of multiple noise sources, two experiments were conducted. The first experiment, which used 48 subjects, was designed to establish annoyance-noise level functions for three community noise sources presented individually: jet aircraft flyovers, air conditioner, and traffic. The second experiment, which used 216 subjects, investigated the effects of background noise on aircraft annoyance as a function of noise level and spectrum shape; and the differences between overall, aircraft, and background noise annoyance. In both experiments, rated annoyance was the dependent measure. Results indicate that the slope of the linear relationship between annoyance and noise level for traffic is significantly different from that of flyover and air conditioner noise and that further research was justified to determine the influence of the two background noises on overall, aircraft, and background noise annoyance (e.g., experiment two). In experiment two, total noise exposure, signal-to-noise ratio, and background source type were found to have effects on all three types of annoyance. Thus, both signal-to-noise ratio, and the background source must be considered when trying to determine community response to combined noise sources.

  12. Using Radar Odometry on Small Unmanned Aircraft

    OpenAIRE

    Quist, Eric; Beard, Randy

    2014-01-01

    This paper develops an algorithm to estimate motion using a radar and ground targets. It involves estimating motion using an Extended Kalman Filter (EKF) with an Inertial Measurement Unit (IMU) and a side-looking Synthetic Aperture Radar (SAR) carried on a fixed wing aircraft flying over unknown, flat terrain. The accuracy of the motion estimation is compared to dead reckoning using only the IMU, with truth data being provided by a standard IMU/GPS Kalman filter. Initial results show that over 4....

  13. Identification of Aircraft Hazards

    Energy Technology Data Exchange (ETDEWEB)

    K. Ashley

    2006-12-08

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2005 [DIRS 174235], Section 6.4.1). That determination was conservatively based upon limited knowledge of flight data in the area of concern and upon crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a monitored geologic repository (MGR) at Yucca Mountain, using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987 [DIRS 103124], Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. The intended use of this report is to provide inputs for further screening and analysis of identified aircraft hazards based upon the criteria that apply to Category 1 and Category 2 event sequence analyses as defined in 10 CFR 63.2 [DIRS 176544] (Section 4). The scope of this report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the repository at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (Section 7).

  14. IDENTIFICATION OF AIRCRAFT HAZARDS

    Energy Technology Data Exchange (ETDEWEB)

    K.L. Ashley

    2005-03-23

    Aircraft hazards were determined to be potentially applicable to a repository at Yucca Mountain in the ''Monitored Geological Repository External Events Hazards Screening Analysis'' (BSC 2004, Section 6.4.1). That determination was conservatively based on limited knowledge of flight data in the area of concern and on crash data for aircraft of the type flying near Yucca Mountain. The purpose of this report is to identify specific aircraft hazards that may be applicable to a Monitored Geologic Repository (MGR) at Yucca Mountain using NUREG-0800, ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987, Section 3.5.1.6), as guidance for the inclusion or exclusion of identified aircraft hazards. NUREG-0800 is being used here as a reference because some of the same considerations apply. The intended use of this report is to provide inputs for further screening and analysis of the identified aircraft hazards based on the criteria that apply to Category 1 and 2 event sequence analyses as defined in 10 CFR 63.2 (see Section 4). The scope of this technical report includes the evaluation of military, private, and commercial use of airspace in the 100-mile regional setting of the MGR at Yucca Mountain with the potential for reducing the regional setting to a more manageable size after consideration of applicable screening criteria (see Section 7).

  15. Fever of unknown origin in elderly patients.

    Science.gov (United States)

    Knockaert, D C; Vanneste, L J; Bobbaers, H J

    1993-11-01

    To describe the spectrum of diseases that may give rise to fever of unknown origin in elderly patients and to delineate the diagnostic approach in these patients. Subgroup analysis of a prospectively collected case series followed more than 2 years. General Internal Medicine Service based at University hospital, Leuven, Belgium. Forty-seven consecutive patients, older than 65 years, meeting the classic criteria of fever of unknown origin. The final diagnosis established and the clinical value of diagnostic procedures. Infections, tumors and multisystem diseases (encompassing rheumatic diseases, connective tissue disorders, vasculitis including temporal arteritis, polymyalgia rheumatica, and sarcoidosis) were found in 12 (25%), six (12%) and 15 patients (31%), respectively. Drug-related fever was the cause in three patients (6%), miscellaneous conditions were found in five patients (10%), and six patients (12%) remained undiagnosed. Microbiologic investigations were diagnostic in eight cases (16%), serologic tests yielded one diagnosis, immunologic investigations had a diagnostic value in four cases, standard X-rays yielded a diagnostic contribution in 10 cases, ultrasonography and computed tomography were diagnostic in 11 cases, Gallium scintigraphy had a diagnostic contribution in 17 cases, and biopsies yielded the final diagnosis in 18 cases. Multisystem diseases emerged as the most frequent cause of fever of unknown origin in the elderly, and temporal arteritis was the most frequent specific diagnosis. Infections, particularly tuberculosis, remain an important group. The percentage of tumors was higher in our elderly patients than in the younger ones but still clearly lower than in other recent series of FUO in adults. The number of undiagnosed cases was significantly lower in elderly patients than in younger individuals (P < or = 0.01). The investigation of elderly patients with FUO should encompass routine temporal artery biopsy and extensive search for

  16. To Know The Way To The Unknown

    DEFF Research Database (Denmark)

    Boysen, Mikkel Snorre Wilms

    2017-01-01

    , in various ways, expertise plays an important part in creative processes. However, the case studies also indicate that expertise sometimes leads to an entrenched perspective, in the sense that knowledge and experience may work as a path into the well-known rather than into the unknown. In this article......, these issues are explored with reference to different theoretical approaches to creativity and learning, including actor-network theory, the theory of blind variation and selective retention, and Csikszentmihalyi’s system model. Finally, some educational aspects and implications of this are discussed....

  17. TOURISM PROMOTION FOR UNKNOWN AREAS IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Fotache Lacramioara

    2013-12-01

    Full Text Available The paper is an effort to unknown areas identity affirmation, through collaborative development of advertising mix, with an emphasis on virtual platforms as admissible solution for increasing visibility. Based upon comparative effective analysis of categories of communication particularities, it is suggested a positioning strategic solution, via virtual advertising platform as unique, integrated, complex and very attractive tourism product promotion, fitted for the internal and international tourism circuit. The active promotion of the specified territorial identity will launch a brand with an impact among tourists by using marketing techniques and innovating technical means and prioritizing tourism as a principal vector of local and regional development.

  18. Chronic Traumatic Encephalopathy: Known Causes, Unknown Effects.

    Science.gov (United States)

    Iacono, Diego; Shively, Sharon B; Edlow, Brian L; Perl, Daniel P

    2017-05-01

    Chronic traumatic encephalopathy (CTE) is a neuropathologic diagnosis typically made in human brains with a history of repetitive traumatic brain injury (rTBI). It remains unknown whether CTE occurs exclusively after rTBI, or whether a single TBI (sTBI) can cause CTE. Similarly, it is unclear whether impact (eg, motor vehicle accidents) and non-impact (eg, blasts) types of energy transfer trigger divergent or common pathologies. While it is established that a history of rTBI increases the risk of multiple neurodegenerative diseases (eg, dementia, parkinsonism, and CTE), the possible pathophysiologic and molecular mechanisms underlying these risks have yet to be elucidated. Published by Elsevier Inc.

  19. Life cycle cost analysis of aging aircraft airframe maintenance

    Science.gov (United States)

    Sperry, Kenneth Robert

    Scope and method of study. The purpose of this study was to examine the relationship between an aircraft's age and its annual airframe maintenance costs. Common life cycle costing methodology has previously not recognized the existence of this cost growth potential, and has therefor not determined the magnitude nor significance of this cost element. This study analyzed twenty-five years of DOT Form 41-airframe maintenance cost data for the Boeing 727, 737, 747 and McDonnell Douglas DC9 and DC-10 aircraft. Statistical analysis included regression analysis, Pearson's r, and t-tests to test the null hypothesis. Findings and conclusion. Airframe maintenance cost growth was confirmed to be increasing after an aircraft's age exceeded its designed service objective of approximately twenty-years. Annual airframe maintenance cost growth increases were measured ranging from 3.5% annually for a DC-9, to approximately 9% annually for a DC-10 aircraft. Average measured coefficient of determination between age and airframe maintenance, exceeded .80, confirming a strong relationship between cost: and age. The statistical significance of the difference between airframe costs sampled in 1985, compared to airframe costs sampled in 1998 was confirmed by t-tests performed on each subject aircraft group. Future cost forecasts involving aging aircraft subjects must address cost growth due to aging when attempting to model an aircraft's economic service life.

  20. AIRCRAFT MAINTENANCE HANGAR

    Directory of Open Access Journals (Sweden)

    GEAMBASU Gabriel George

    2017-05-01

    Full Text Available The paper presents the maintenance process that is done on an airplane, at a certain period of time, or after a number of flight hours or cycles and describes the checks performed behind each inspection. The first part of research describes the aircraft maintenance process that has to be done after an updated maintenance manual according with aircraft type, followed by a short introduction about maintenance hangar. The second part of the paper presents a hangar design with a foldable roof and walls, which can be folded or extended, over an airplane when a maintenance process is done, or depending on weather condition.

  1. Composite materials for aircraft structures

    National Research Council Canada - National Science Library

    Baker, A. A; Dutton, Stuart; Kelly, Donald

    2004-01-01

    ... materials for aircraft structures / Alan Baker, Stuart Dutton, and Donald Kelly- 2nd ed. p. cm. - (Education series) Rev. ed. of: Composite materials for aircraft structures / edited by B. C. Hos...

  2. MODELLING OF SOME AIRCRAFT PARAMETERS

    African Journals Online (AJOL)

    . There has, therefore, been a wide range reaction against aircraft noise in particular by community residents living close to the airports. Research has, thus, been mainly on effect of aircraft noise particularly and environmental noise and ...

  3. Variability of annoyance response due to aircraft noise

    Science.gov (United States)

    Dempsey, T. K.; Cawthorn, J. M.

    1979-01-01

    An investigation was conducted to study the variability in the response of subjects participating in noise experiments. This paper presents a description of a model developed to include this variability which incorporates an aircraft-noise adaptation level or an annoyance calibration for each individual. The results indicate that the use of an aircraft-noise adaption level improved prediction accuracy of annoyance responses (and simultaneously reduced response variation).

  4. Annoyance and acceptability judgements of noise produced by three types of aircraft by residents living near JFK Airport

    Science.gov (United States)

    Borsky, P. N.

    1974-01-01

    A random sample of selected communities near JFK Airport were interviewed. Subsamples, with differing feelings of fear of aircraft crashes and different locations of residence were invited to participate in a laboratory experiment. The subjects were exposed to tape recordings of simulated flyovers of aircraft in approach and departure operations at nominal distances from the airport. The subjects judged the extent of noise annoyance and acceptability of the aircraft noises. Results indicate that level of noise is most significant in affecting annoyance judgements. Subjects with feelings of high fear report significantly more annoyance and less acceptability of aircraft noise than subjects with feelings of low fear.

  5. The Aircraft Industry, 2006

    Science.gov (United States)

    2006-01-01

    France Eurocopter , Marseille, France Organization of Economic Cooperation and Development, Paris, France Rolls Royce Aircraft Engines, Civil and...A320/340/380 Production Lines, Blagnac, France BAE Systems plc Corporate Offices, London, United Kingdom Dassault Corporate Headquarters, St. Cloud...Defence Aerospace Divisions, Derby, United Kingdom Societe Nationale d’Etude et de Construction de Moteurs d’Aviation (SNECMA), Evry, France

  6. Robots for Aircraft Maintenance

    Science.gov (United States)

    1993-01-01

    Marshall Space Flight Center charged USBI (now Pratt & Whitney) with the task of developing an advanced stripping system based on hydroblasting to strip paint and thermal protection material from Space Shuttle solid rocket boosters. A robot, mounted on a transportable platform, controls the waterjet angle, water pressure and flow rate. This technology, now known as ARMS, has found commercial applications in the removal of coatings from jet engine components. The system is significantly faster than manual procedures and uses only minimal labor. Because the amount of "substrate" lost is minimal, the life of the component is extended. The need for toxic chemicals is reduced, as is waste disposal and human protection equipment. Users of the ARMS work cell include Delta Air Lines and the Air Force, which later contracted with USBI for development of a Large Aircraft Paint Stripping system (LARPS). LARPS' advantages are similar to ARMS, and it has enormous potential in military and civil aircraft maintenance. The technology may also be adapted to aircraft painting, aircraft inspection techniques and paint stripping of large objects like ships and railcars.

  7. Aircraft to Medicine

    Science.gov (United States)

    1991-01-01

    This video discusses how the technology of computer modeling can improve the design and durability of artificial joints for human joint replacement surgery. Also, ultrasound, originally used to detect structural flaws in aircraft, can also be used to quickly assess the severity of a burn patient's injuries, thus aiding the healing process.

  8. Aircraft adaptive learning control

    Science.gov (United States)

    Lee, P. S. T.; Vanlandingham, H. F.

    1979-01-01

    The optimal control theory of stochastic linear systems is discussed in terms of the advantages of distributed-control systems, and the control of randomly-sampled systems. An optimal solution to longitudinal control is derived and applied to the F-8 DFBW aircraft. A randomly-sampled linear process model with additive process and noise is developed.

  9. The Unknown Component Problem Theory and Applications

    CERN Document Server

    Villa, Tiziano; Brayton, Robert K; Mishchenko, Alan; Petrenko, Alexandre; Sangiovanni-Vincentelli, Alberto

    2012-01-01

    The Problem of the Unknown Component: Theory and Applications addresses the issue of designing a component that, combined with a known part of a system, conforms to an overall specification. The authors tackle this problem by solving abstract equations over a language. The most general solutions are studied when both synchronous and parallel composition operators are used. The abstract equations are specialized to languages associated with important classes of automata used for modeling systems. The book is a blend of theory and practice, which includes a description of a software package with applications to sequential synthesis of finite state machines. Specific topologies interconnecting the components, exact and heuristic techniques, and optimization scenarios are studied. Finally the scope is enlarged to domains like testing, supervisory control, game theory and synthesis for special omega languages. The authors present original results of the authors along with an overview of existing ones.

  10. Adresse inconnue / Address unknown / Suchwiin Bulmyeong

    Directory of Open Access Journals (Sweden)

    Serge Gruzinski

    2005-03-01

    Full Text Available Tous les films asiatiques parlent de métissage, même ceux qui se présentent comme de vastes fresques historiques perdues dans le temps. Les emprunts aux traditions hollywoodiennes et européennes n'ont cessé d'enrichir une cinématographie aussi ancienne que celle du monde occidental. Dans Adresse inconnue (Address unknown le cinéaste coréen Kim Ki-duk explore l'expérience du métissage et le corps du métis à la frontière entre Corée du Nord et Corée du sud. Fils d'un GI américain et noir et d...

  11. Carcinomatous Meningitis from Unknown Primary Carcinoma

    Directory of Open Access Journals (Sweden)

    L. Favier

    2009-10-01

    Full Text Available Carcinomatous meningitis (CM occurs in 3 to 8% of cancer patients. Patients present with a focal symptom, and multifocal signs are often found following neurological examination. The gold standard for diagnosis remains the demonstration of carcinomatous cells in the cerebrospinal fluid on cytopathological examination. Despite the poor prognosis, palliative treatment could improve quality of life and, in some cases, overall survival. We report on a patient who presented with vertigo, tinnitus and left-sided hearing loss followed by progressive diffuse facial nerve paralysis. Lumbar cerebrospinal fluid confirmed the diagnosis of CM. However, no primary tumor was discovered, even after multiple invasive investigations. This is the first reported case in the English-language medical literature of CM resulting from a carcinoma of unknown primary origin.

  12. Information gain when measuring an unknown qubit

    Science.gov (United States)

    Björk, Gunnar

    2018-01-01

    In quantum information the fundamental information-containing system is the qubit. A measurement of a single qubit can at most yield one classical bit. However, a dichotomous measurement of an unknown qubit will yield much less information about the qubit state. We use Bayesian inference to compute how much information one progressively gets by making sucessive, individual measurements on an ensemble of identically prepared qubits. Perhaps surprisingly, even if the measurements are arranged so that each measurement yields one classical bit, that is, the two possible measurement outcomes are a priori equiprobable, it takes almost a handful of measurements before one has gained one bit of information about the gradually concentrated qubit probability density. We also show that by following a strategy that reaps the maximum information per measurement, we are led to a mutually unbiased basis as our measurement bases. This is a pleasing, although not entirely surprising, result.

  13. Education Through Exploration: Evaluating the Unknown

    Science.gov (United States)

    Anbar, A. D.

    2015-12-01

    Mastery of the peculiar and powerful practices of science is increasingly important for the average citizen. With the rise of the Internet, most of human knowledge is at our fingertips. As content becomes a commodity, success and survival aren't about who knows the most, but who is better able to explore the unknown, actively applying and extending knowledge through critical thinking and hypothesis-driven problem-solving. This applies to the economic livelihoods of individuals and to society at large as we grapple with climate change and other science-infused challenges. Unfortunately, science is too often taught as an encyclopedic collection of settled facts to be mastered rather than as a process of exploration that embraces curiosity, inquiry, testing, and communication to reduce uncertainty about the unknown. This problem is exacerbated by the continued prevalence of teacher-centric pedagogy, which promotes learning-from-authority and passive learning. The initial wave of massively open online courses (MOOCs) generally mimic this teaching style in virtual form. It is hypothesized that emerging digital teaching technologies can help address this challenge at Internet scale in "next generation" MOOCs and flipped classroom experiences. Interactive simulations, immersive virtual field trips, gamified elements, rapid adaptive feedback, intelligent tutoring systems, and personalized pathways, should motivate and enhance learning. Through lab-like projects and tutorials, students should be able to construct knowledge from interactive experiences, modeling the authentic practice of science while mastering complex concepts. Freed from lecturing, teaching staff should be available for direct and intense student-teacher interactions. These claims are difficult to evaluate with traditional assessment instruments, but digital technologies provide powerful new ways to evaluate student learning and learn from student behaviors. We will describe ongoing experiences with such

  14. Lightweight sidewalls for aircraft interior noise control

    Science.gov (United States)

    May, D. N.; Plotkin, K. J.; Selden, R. G.; Sharp, B. H.

    1985-01-01

    A theoretical and experimental study was performed to devise lightweight sidewalls for turboprop aircraft. Seven concepts for new sidewalls were analyzed and tested for noise reduction using flat panels of 1.2 m x 1.8 m (4 ft x 6 ft), some of which were aircraft-type constructions and some of which were simpler, easier-to-construct panels to test the functioning of an acoustic principle. Aircraft-application sidewalls were then conceived for each of the seven concepts, and were subjectively evaluated for their ability to meet aircraft nonacoustic design requirements. As a result of the above, the following sidewall concepts were recommended for further investigation: a sidewall in which the interior cavity is vented to ceiling and underfloor areas; sidewalls with wall-mounted resonators, one having a conventional trim panel and one a limp one; and a sidewall with a stiff outer wall and a limp trim panel. These sidewalls appear to promise lower weights than conventional sidewalls adjusted to meet similar acoustic requirements, and further development may prove them to be practical.

  15. Management of neuroendocrine tumors of unknown primary.

    Science.gov (United States)

    Alexandraki, Krystallenia; Angelousi, Anna; Boutzios, Georgios; Kyriakopoulos, Georgios; Rontogianni, Dimitra; Kaltsas, Gregory

    2017-12-04

    Neuroendocrine neoplams (NENs) are mostly relatively indolent malignancies but a significant number have metastatic disease at diagnosis mainly to the liver. Although in the majority of such cases the primary origin of the tumor can be identified, in approximately 11-22% no primary tumor is found and such cases are designated as NENs of unknown primary origin (UPO). This has significant therapeutic implications with respect to potentially resectable hepatic disease and/or application of appropriate medical therapy, either chemotherapeutic agents or targeted treatment, as the response to various treatments varies according to the origin of the primary tumor. This lack of tumor specific orientated treatment may also account for the relatively poorer prognosis of NENs of UPO compared to metastatic NENs with a known primary site. In the majority of cases the primary tumors are located in the small bowel and the lung, but a number may still elude detection. Occasionally the presence of a functional syndrome may direct to the specific tissue of origin but in the majority of cases a number of biochemical, imaging, histopathological and molecular modalities are utilized to help identify the primary origin of the tumor and direct treatment accordingly. Several diagnostic algorithms have recently been developed to help localize an occult primary tumor; however, in a number of cases no lesion is identified even after prolonged follow-up. It is expected that the delineation of the molecular signature of the different NENs may help identify such cases and provide appropriate treatment.

  16. Analysing Trust Transitivity and The Effects of Unknown Dependence

    Directory of Open Access Journals (Sweden)

    Touhid Bhuiyan

    2010-03-01

    Full Text Available Trust can be used to improve online automated recommendation within a given domain. Trust transitivity is used to make it successful. But trust transitivity has different interpretations. Trust and trust transitivity; both are the human mental phenomenon and for this reason, there is no such thing as objective transitivity. Trust transitivity and trust fusion both are important elements in computational trust. This paper analyses the parameter dependence problem in trust transitivity and proposes some definitions considering the effects of base rate. In addition, it also proposes belief functions based on subjective logic to analyse trust transitivity of three specified cases with sensitive and insensitive based rate. Then it presents a quantitative analysis of the effects of unknown dependence problem in an interconnected network environment; such Internet.

  17. Aircraft specific exhaust emissions

    Energy Technology Data Exchange (ETDEWEB)

    Lecht, M.; Deidewig, F.; Doepelheuer, A. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany). Inst. fuer Antriebstechnik

    1997-12-01

    The objective of this work to calculate essential species of aircraft emissions has been approached by a combination of different tasks. First of all engine performance and emission correlation has been modelled taking sea level static measurements from the engine certification process as a reference. At second a flight simulation program has been modified to couple aircraft and engine performance along a flight mission profile. By this for a selected number of aircraft/engine combinations the emissions of NO{sub x}, CO and HC as well as fuel burn for short, medium and long haul flights have been calculated and finally adapted to a specified format of flight distance and altitude increments. Sensitivity studies of the change of emissions along the cruise section showed a 30% decrease of the NO{sub x} emission rate until the end of cruise. Differences of ambient air temperature from ISA conditions will have a substantial impact on NO{sub x}, CO and HC emissions rather than on mission fuel. (orig.) 144 figs., 42 tabs., 497 refs.

  18. Multibeam collection for Blacksod_Bay: Multibeam data collected aboard Aircraft from 2008-06-14 to 2008-06-14, Unknown Port to Unknown Port

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is part of a larger set of data called the Multibeam Bathymetry Database (MBBDB) where other similar data can be found at...

  19. Multibeam collection for Galway_Bay_2008: Multibeam data collected aboard Aircraft from 2008-04-18 to 2008-05-02, Unknown Port to Unknown Port

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is part of a larger set of data called the Multibeam Bathymetry Database (MBBDB) where other similar data can be found at...

  20. Multibeam collection for Lough_Foyle: Multibeam data collected aboard Aircraft from 2008-06-12 to 2008-06-13, Unknown Port to Unknown Port

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is part of a larger set of data called the Multibeam Bathymetry Database (MBBDB) where other similar data can be found at...

  1. Advanced turboprop aircraft flyover noise annoyance

    Science.gov (United States)

    Mccurdy, David A.

    1989-01-01

    Results from recent laboratory experiments in which human subjects were exposed to synthetic sounds simulating the flyover noise emitted by advanced turbofan aircraft engines are briefly summarized. The Aircraft Noise Synthesis System described by McCurdy et al. (1987) is used to simulate the noise from (1) a conventional turboprop engine, (2) a jet engine, (3) a single-rotating turbofan engine, and counterrotating turbofans with (4) equal or (5) unequal numbers of blades on the two rotors. The measured annoyance levels are compared with effective perceived noise levels in a graph. For a given noise level, the annoyance levels for (3) are shown to be slightly lower than those for all the other engine types, especially if the tone/broadband noise ratio is relatively high.

  2. Estimation of symmetrical components and their orthogonal components under unknown frequencies and unknown biases

    Science.gov (United States)

    Chu, Zhaobi; Zhang, Rui; Chen, Bo; Li, Hua

    2017-07-01

    An algorithm to estimate symmetrical components, orthogonal components and amplitudes of each sinusoidal component in three-phase power system signal under unknown frequencies and unknown biases is presented. The algorithm consists of a signal transformation, a biased adaptive orthogonal decomposition (BAOD) and a symmetrical component estimation. The BAOD can be regarded as a combination of a low pass filter and a number of three-phase frequency estimators in parallel. The symmetrical component estimation employs addition and multiplication rather than operations of trigonometry, division and phase shift. The decomposition property and the convergence property were investigated by Lyapunov theorem, integral manifold of slow adaptation and average method. Two design parameters, bandwidth parameter and frequency adaptive gains, give different effects on the convergence property of frequency adaptation and amplitude estimation independently. Simulation results demonstrate the performance of the method.

  3. 19 CFR 122.64 - Other aircraft.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Other aircraft. 122.64 Section 122.64 Customs... AIR COMMERCE REGULATIONS Clearance of Aircraft and Permission To Depart § 122.64 Other aircraft. Clearance or permission to depart shall be requested by the aircraft commander or agent for aircraft covered...

  4. Structural Health Monitoring of Transport Aircraft with Fuzzy Logic Modeling

    Directory of Open Access Journals (Sweden)

    Ray C. Chang

    2013-01-01

    Full Text Available A structural health monitoring method based on the concept of static aeroelasticity is presented in this paper. This paper focuses on the estimation of these aeroelastic effects on older transport aircraft, in particular the structural components that are most affected, in severe atmospheric turbulence. Because the structural flexibility properties are mostly unknown to aircraft operators, only the trend, not the magnitude, of these effects is estimated. For this purpose, one useful concept in static aeroelastic effects for conventional aircraft structures is that under aeroelastic deformation the aerodynamic center should move aft. This concept is applied in the present paper by using the fuzzy-logic aerodynamic models. A twin-jet transport aircraft in severe atmospheric turbulence involving plunging motion is examined. It is found that the pitching moment derivatives in cruise with moderate to severe turbulence in transonic flight indicate some degree of abnormality in the stabilizer (i.e., the horizontal tail. Therefore, the horizontal tail is the most severely affected structural component of the aircraft probably caused by vibration under the dynamic loads induced by turbulence.

  5. 14 CFR 21.6 - Manufacture of new aircraft, aircraft engines, and propellers.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Manufacture of new aircraft, aircraft... Manufacture of new aircraft, aircraft engines, and propellers. (a) Except as specified in paragraphs (b) and (c) of this section, no person may manufacture a new aircraft, aircraft engine, or propeller based on...

  6. Expanding subjectivities

    DEFF Research Database (Denmark)

    Lundgaard Andersen, Linda; Soldz, Stephen

    2012-01-01

    A major theme in recent psychoanalytic thinking concerns the use of therapist subjectivity, especially “countertransference,” in understanding patients. This thinking converges with and expands developments in qualitative research regarding the use of researcher subjectivity as a tool to understa...

  7. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A.G.; Stordal, F.; Knudsen, S. [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  8. Commercial Aircraft Protection

    Energy Technology Data Exchange (ETDEWEB)

    Ehst, David A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-26

    This report summarizes the results of theoretical research performed during 3 years of P371 Project implementation. In results of such research a new scientific conceptual technology of quasi-passive individual infrared protection of heat-generating objects – Spatial Displacement of Thermal Image (SDTI technology) was developed. Theoretical substantiation and description of working processes of civil aircraft individual IR-protection system were conducted. The mathematical models and methodology were presented, there were obtained the analytical dependencies which allow performing theoretical research of the affect of intentionally arranged dynamic field of the artificial thermal interferences with variable contrast onto main parameters of optic-electronic tracking and homing systems.

  9. Aircraft vulnerability analysis by modelling and simulation

    CSIR Research Space (South Africa)

    Willers, CJ

    2014-09-01

    Full Text Available attributable to misuse of the weapon or to missile performance restrictions. This paper analyses some of the factors affecting aircraft vulnerability and demonstrates a structured analysis of the risk and aircraft vulnerability problem. The aircraft...

  10. Advanced energy systems (APU) for large commercial aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Westenberger, A.; Bleil, J.; Arendt, M. [Airbus Deutschland GmbH, Hamburg (Germany)

    2013-06-01

    The intention of using a highly integrated component using on fuel cell technology installed on board of large commercial passenger aircraft for the generation of onboard power for the systems demand during an entire aircraft mission was subject of several studies. The results of these studies have been based on the simulation of the whole system in the context of an aircraft system environment. In front of the work stood the analyses of different fuel cell technologies and the analyses of the aircraft system environment. Today onboard power is provided on ground by an APU and in flight by the main engines. In order to compare fuel cell technology with the today's usual gas turbine operational characteristics have been analysed. A second analysis was devoted to the system demand for typical aircraft categories. The MEA system concept was supposed in all cases. The favourable concept represented an aircraft propelled by conventional engines with starter generator units, providing AC electrical power, covering in total proximately half of the power demand and a component based on fuel cell technology. This component provided electrical DC power, clean potable water, thermal energy at 180 degrees Celsius and nitrogen enriched air for fire suppression and fire extinguishing agent. In opposite of a usual gas turbine based APU, this new unit was operated as the primary power system. (orig.)

  11. ERGONOMIC DESIGN OF AIRCRAFT COCKPIT

    Directory of Open Access Journals (Sweden)

    CÎMPIAN Ionuţ

    2011-06-01

    Full Text Available This paper presents a model for an ergonomic design of an aircraft cockpit with the specification and verification with respect to the new European Aviation Safety Agency (EASA and Federal Aviation Administration (FAA requirements. The goal is to expressing the concepts on which the aircraft cockpit design is based.

  12. ERGONOMIC DESIGN OF AIRCRAFT COCKPIT

    Directory of Open Access Journals (Sweden)

    CÎMPIAN Ionuţ

    2012-09-01

    Full Text Available This paper presents a model for an ergonomic design of an aircraft cockpit with the specification and verification with respect to the new European Aviation Safety Agency (EASA and Federal Aviation Administration (FAA requirements. The goal is to expressing the concepts on which the aircraft cockpit design are based.

  13. Control design for the SISO system with the unknown order and the unknown relative degree.

    Science.gov (United States)

    Zhao, Chunzhe; Li, Donghai

    2014-07-01

    For the uncertain system whose order, relative degree and parameters are unknown in the control design, new research is still in need on the parameter tuning and close-loop stability. During the last 10 years, much progress is made in the application and theory research of the active disturbance rejection control (ADRC) for the uncertain system. In this study, the necessary and sufficient conditions are established for building the ADRC for the minimum-phase system and the open-loop stable system when the plant parameters, orders and relative degrees are unknown, the corresponding ideal dynamics are analyzed, and the theoretical results are verified by the simulations. Considering the wide application and the long history of the PID/PI controller, a method is given to design ADRC quickly based on the existing (generalized or conventional) PID/PI controller. A plenty of simulations are made to illustrate this PID/PI-based design method and the corresponding close-loop performances. The simulation examples include the minimum/nonminimum-phase plants, the stable/integrating plants, the high/low-order plant, and the plants with time delays. Such plants are from a wider scope than the theoretical result, and representative of many kinds of the industrial processes. That leads to a new way to simplify the ADRC design via absorbing the engineering experience in designing the PID/PI controller. © 2013 ISA. Published by ISA. All rights reserved.

  14. Reliability of mechanical trunk responses during known and unknown trunk perturbations

    DEFF Research Database (Denmark)

    Jakobsen, Markus D.; Brandt, Mikkel; Sundstrup, Emil

    2016-01-01

    This study evaluates the between-day reliability of a newly developed trunk perturbation test and compares mechanical response during known and unknown conditions. Mechanical trunk response were measured in seventeen female subjects during unloading and loading perturbations of the abdomen (A: pr...

  15. The Unknown Story: Vocational Education for Adults in Sweden 1918-1968

    Science.gov (United States)

    Nilsson, Anders

    2014-01-01

    Adult education is often defined to emphasise cultural and societal development. This paper proposes that the concept should be more inclusive and that vocational education and training for adults has played a bigger role than is usually recognised. This has not been subject to much research and basic facts are often virtually unknown. In this…

  16. Research advances in liver failure of unknown etiology

    Directory of Open Access Journals (Sweden)

    ZHU Bing

    2015-09-01

    Full Text Available A high proportion of the causes of liver failure remain unknown. This paper reviews the progress in the epidemiology, etiology, treatment, and prognosis of liver failure of unknown etiology. The possible causes of liver failure of unknown etiology may include occult hepatitis B virus infection, herpesvirus infection, transfusion-transmitted virus infection, hepatitis G virus infection, human parvovirus Bl9 infection, autoimmune and hepatitis. Aciclovir can be considered in the empirical treatment for patients with liver failure of unknown etiology. The mortality in patients with liver failure of unknown etiology is high. The research on the etiology and treatments should be strengthened.

  17. Modeling Vibration Intensity of Aircraft Bevel Gears

    Directory of Open Access Journals (Sweden)

    V. V. Golovanov

    2017-01-01

    Full Text Available The subject is the aircraft bevel gears, which are part of the drive systems of gas turbine engines and helicopter transmissions. The article deals with defect specifics of the aircraft conical gears with a circular tooth as compared to the conical gear wheels of general engineering. The finite element method has been used to find by calculation that the main reason for destruction of aircraft bevel gears is a resonant vibration excitation of the gear wheel rim due to its nodal diameter eigenvibrations happened to be within the operating range of the transmission rotation frequencies. A parametric finite element model has been developed. It allows us to investigate the impact of modification parameters of the drive side of gear wheels on the function of the kinematic transmission error at different values of transmitted torque. Using the method of main coordinates, a reduced dynamic model of the bevel gear has been developed to allow simulating the vibration intensity of bevel gears with various parameters of the working profile modification. Within the framework of evaluation test of the dynamic model, amplitude-frequency characteristics have been constructed for the main parameters of transmission oscillations, including vibrational stresses in the teeth space. It is found that modification parameters of the transmission drive side have a significant effect on the vibration intensity of the bevel gears in the entire operating range. The main factor affecting the vibration stress amplitude in the gear wheel is the amplitude of the kinematic error function with the corresponding torque transmitted. The obtained research results can be used when designing the new aircraft drives and modernizing the existing ones. As part of the further development, it is expected to create a technique for recording the damage accumulation in the conical gears, taking into account the typical flight profile of a gas turbine engine or a helicopter.

  18. Runway Detection From Map, Video and Aircraft Navigational Data

    Science.gov (United States)

    2016-03-01

    are corrected using image-processing techniques, such as the Hough transform for linear features. 14. SUBJECT TERMS runway, map, aircraft...video, detection, rotation matrix, Hough transform. 15. NUMBER OF PAGES 87 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18...as the Hough transform for linear features. vi THIS PAGE INTENTIONALLY LEFT BLANK vii TABLE OF CONTENTS I. INTRODUCTION

  19. 77 FR 45480 - Deductions for Entertainment Use of Business Aircraft

    Science.gov (United States)

    2012-08-01

    ... Part 1 [TD 9597] RIN 1545-BF34 Deductions for Entertainment Use of Business Aircraft AGENCY: Internal... Disallowance to Expenses The proposed regulations provide that the disallowance provisions are applied on a pro... applied to total expenses subject to disallowance on a pro rata basis. The final regulations include an...

  20. Trends in aircraft noise annoyance: The role of study and sample characteristics

    NARCIS (Netherlands)

    Kroesen, M.; Molin, E.J.E.; Miedema, H.M.E.; Vos, H.; Janssen, S.A.; Wee, B. van

    2010-01-01

    This study assesses the effects of aircraft noise on residential satisfaction, an important indicator of subjective well-being. A structural equation model is specified that estimates the relationships between objective variables, noise annoyance variables and residential satisfaction. Secondary

  1. Aircraft agility maneuvers

    Science.gov (United States)

    Cliff, Eugene M.; Thompson, Brian G.

    1992-01-01

    A new dynamic model for aircraft motions is presented. This model can be viewed as intermediate between a point-mass model, in which the body attitude angles are control-like, and a rigid-body model, in which the body-attitude angles evolve according to Newton's Laws. Specifically, consideration is given to the case of symmetric flight, and a model is constructed in which the body roll-rate and the body pitch-rate are the controls. In terms of this body-rate model a minimum-time heading change maneuver is formulated. When the bounds on the body-rates are large the results are similar to the point-mass model in that the model can very quickly change the applied forces and produce an acceleration to turn the vehicle. With finite bounds on these rates, the forces change in a smooth way. This leads to a measurable effect of agility.

  2. Commercial aircraft composite technology

    CERN Document Server

    Breuer, Ulf Paul

    2016-01-01

    This book is based on lectures held at the faculty of mechanical engineering at the Technical University of Kaiserslautern. The focus is on the central theme of societies overall aircraft requirements to specific material requirements and highlights the most important advantages and challenges of carbon fiber reinforced plastics (CFRP) compared to conventional materials. As it is fundamental to decide on the right material at the right place early on the main activities and milestones of the development and certification process and the systematic of defining clear requirements are discussed. The process of material qualification - verifying material requirements is explained in detail. All state-of-the-art composite manufacturing technologies are described, including changes and complemented by examples, and their improvement potential for future applications is discussed. Tangible case studies of high lift and wing structures emphasize the specific advantages and challenges of composite technology. Finally,...

  3. Identification of an unknown extraneous contaminant in pharmaceutical product analysis.

    Science.gov (United States)

    Lin, Mingxiang; Li, Min; Rustum, Abu

    2007-12-21

    During the content uniformity test of a drug product (tablet formulation), an unknown peak was observed in the HPLC chromatograms. Upon further investigation, it was determined that the unknown peak was originated from an external source and, therefore, the drug product is free of this unknown peak. The next step was to identify the structure of this unknown peak in order to determine the source of this contaminant species. In this paper, we wish to present the strategy and the results of the experiments that led to the identification of this unknown peak. LC-PDA/UV and LC-MS(n) analyses were conducted to obtain the UV spectrum, molecular weight and MS(n) fragmentation pathways of the unknown peak. The MS analysis revealed certain structural features of the unknown species and a number of model compounds that contain such features were then examined for their UV absorbance profiles in an attempt to establish the functional group connectivity within the unknown species. A careful examination of these results in conjunction with the determination of the high-resolution molecular weight led to a short list of potential candidates for the unknown species, among which the most likely one was 1,3-diphenylguanidine. The identification of the unknown contaminant was confirmed by spiking experiments using the authentic compound. The potential source of this contaminant was also identified as derived from the safety filler of the pipette bulb used to prepare the sample solutions during the drug analysis.

  4. SUBJECT INDEX

    Indian Academy of Sciences (India)

    Subject Index. Variation of surface electric field during geomagnetic disturbed period at Maitri, Antarctica. 1721. Geomorphology. A simple depression-filling method for raster and irregular elevation datasets. 1653. Decision Support System integrated with Geographic. Information System to target restoration actions in water-.

  5. Aircraft Rotor Surface Coating Qualification Testing Aircraft Rotor Surface Coating

    National Research Council Canada - National Science Library

    2006-01-01

    .... The Aviation and Missile Research, Development and Engineering Center "AMRDEC" located at Redstone Arsenal, AL selected the NCDMM to coordinate the initial effort to qualify a new aircraft rotor...

  6. 48 CFR 246.408-71 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Aircraft. 246.408-71... Aircraft. (a) The Federal Aviation Administration (FAA) has certain responsibilities and prerogatives in connection with some commercial aircraft and of aircraft equipment and accessories (Pub. L. 85-726 (72 Stat...

  7. 14 CFR 63.33 - Aircraft ratings.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft ratings. 63.33 Section 63.33... CERTIFICATION: FLIGHT CREWMEMBERS OTHER THAN PILOTS Flight Engineers § 63.33 Aircraft ratings. (a) The aircraft...) Turbopropeller powered; and (3) Turbojet powered. (b) To be eligible for an additional aircraft class rating...

  8. 14 CFR 141.39 - Aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Aircraft. 141.39 Section 141.39 Aeronautics... CERTIFICATED AGENCIES PILOT SCHOOLS Personnel, Aircraft, and Facilities Requirements § 141.39 Aircraft. (a... certificate or provisional pilot school certificate must show that each aircraft used by the school for flight...

  9. 36 CFR 331.14 - Aircraft.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Aircraft. 331.14 Section 331..., KENTUCKY AND INDIANA § 331.14 Aircraft. (a) The operation of aircraft on WCA lands and waters is prohibited... prohibited. (c) The provisions of this section shall not be applicable to aircraft engaged on official...

  10. 40 CFR 87.6 - Aircraft safety.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Aircraft safety. 87.6 Section 87.6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES General Provisions § 87.6 Aircraft safety. The provisions of...

  11. 14 CFR 252.13 - Small aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Small aircraft. 252.13 Section 252.13 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.13 Small aircraft. Air carriers shall prohibit smoking on aircraft...

  12. 36 CFR 327.4 - Aircraft.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Aircraft. 327.4 Section 327.4... Aircraft. (a) This section pertains to all aircraft including, but not limited to, airplanes, seaplanes, helicopters, ultra-light aircraft, motorized hang gliders, hot air balloons, any non-powered flight devices or...

  13. 76 FR 76686 - Notification and Reporting of Aircraft Accidents or Incidents and Overdue Aircraft, and...

    Science.gov (United States)

    2011-12-08

    ... and Reporting of Aircraft Accidents or Incidents and Overdue Aircraft, and Preservation of Aircraft... reporting requirements with regard to aircraft accidents or incidents, found at paragraph (a)(10) of section... final rule entitled, ``Notification and Reporting of Aircraft Accidents or Incidents and Overdue...

  14. VTOL to Transonic Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The cyclogyro, an aircraft propulsion concept with the potential for VTOL to the lower bounds of transonic flight, is conceptually simple but structurally and...

  15. Unmanned Aircraft Systems - Raw Photography

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS National Unmanned Aircraft Systems (UAS) Project Office utilizes UAS technology for collecting remote sensing data on a local scale. Typical UAS projects...

  16. Fire resistant aircraft seat program

    Science.gov (United States)

    Fewell, L. A.

    1979-01-01

    Foams, textiles, and thermoformable plastics were tested to determine which materials were fire retardant, and safe for aircraft passenger seats. Seat components investigated were the decorative fabric cover, slip covers, fire blocking layer, cushion reinforcement, and the cushioning layer.

  17. Quality standard of aircraft maintenance

    Directory of Open Access Journals (Sweden)

    Боузаієнне Меккі бен Салем

    2005-01-01

    Full Text Available  The question of the account of operation conditions of an aeronautical engineering in airlines is considered at formation and a correcting of plans on aircrafts park maintenance.

  18. Aerothermodynamics of aircraft engine components

    National Research Council Canada - National Science Library

    Oates, Gordon C

    1985-01-01

    ....A45A37 1985 ISBN 0-915928-97-3 2. Aircraft gas turbines. 629.134'353 85-13355 Copyright © 1985 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. Printed in the ...

  19. Western Pacific Typhoon Aircraft Fixes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Western Pacific typhoon aircraft reconnaissance data from the years 1946 - 1965 and 1978, excluding 1952, were transcribed from original documents, or copy of...

  20. Lil HAL: digital kneeboard for ejection seat aircraft

    Science.gov (United States)

    Parisi, Vince

    2004-09-01

    In the last few years, airlines, commercial air carriers and the military have begun to introduce electronic tools into the cockpit to replace paper versions of flight publications, flight plans, departure and approach plates, maps, etc. These devices have varied from the common laptop to the smaller pen-tablet type computers. In some instances these devices have been connected to aircraft data buses to collect maintenance data, fault codes and other useful information. None of these devices, however, have been found satisfactory in ejection seat aircraft due to their size, weight, and dynamic characteristics when subjected to the inertial and aerodynamic forces that occur during an ejection. This paper describes an electronic digital kneeboard suitable for use in an ejection seat aircraft. The kneeboard consists of a look at helmet-mounted display, a small streamlined kneeboard input device, a carry-on/carry-off computer and its associated support interfaces.

  1. Optimal nonlinear estimation for aircraft flight control in wind shear

    Science.gov (United States)

    Mulgund, Sandeep S.

    1994-01-01

    The most recent results in an ongoing research effort at Princeton in the area of flight dynamics in wind shear are described. The first undertaking in this project was a trajectory optimization study. The flight path of a medium-haul twin-jet transport aircraft was optimized during microburst encounters on final approach. The assumed goal was to track a reference climb rate during an aborted landing, subject to a minimum airspeed constraint. The results demonstrated that the energy loss through the microburst significantly affected the qualitative nature of the optimal flight path. In microbursts of light to moderate strength, the aircraft was able to track the reference climb rate successfully. In severe microbursts, the minimum airspeed constraint in the optimization forced the aircraft to settle on a climb rate smaller than the target. A tradeoff was forced between the objectives of flight path tracking and stall prevention.

  2. Dryden B-52 Launch Aircraft in Flight over Dryden

    Science.gov (United States)

    1996-01-01

    parachute recovery systems used to recover the space shuttle solid rocket booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.

  3. Aircraft ditching loads simulation tool

    OpenAIRE

    Bonanni, A.; Vandewaeter, L.; Havill, C.; Kanyoo, P.; Taunton, D.J.; Blake, J.I.R.; Cropper, E.; Hancock, S.

    2015-01-01

    The present work presents a novel methodology developed for calculating the steady loads acting on aircraft structures in the event of ditching in water. It represents the preliminary result of Stirling Dynamics as part of a NATEP research project. The overall objective of the project is to expand the capabilities of the Stirling Dynamics proprietary software SD-GLOAD (originally designed for ground and crash loads dynamic simulations) to aircraft ditching simulations. The methodology present...

  4. Real-Time Radar-Based Tracking and State Estimation of Multiple Non-Conformant Aircraft

    Science.gov (United States)

    Cook, Brandon; Arnett, Timothy; Macmann, Owen; Kumar, Manish

    2017-01-01

    In this study, a novel solution for automated tracking of multiple unknown aircraft is proposed. Many current methods use transponders to self-report state information and augment track identification. While conformant aircraft typically report transponder information to alert surrounding aircraft of its state, vehicles may exist in the airspace that are non-compliant and need to be accurately tracked using alternative methods. In this study, a multi-agent tracking solution is presented that solely utilizes primary surveillance radar data to estimate aircraft state information. Main research challenges include state estimation, track management, data association, and establishing persistent track validity. In an effort to realize these challenges, techniques such as Maximum a Posteriori estimation, Kalman filtering, degree of membership data association, and Nearest Neighbor Spanning Tree clustering are implemented for this application.

  5. Optimization in fractional aircraft ownership

    Science.gov (United States)

    Septiani, R. D.; Pasaribu, H. M.; Soewono, E.; Fayalita, R. A.

    2012-05-01

    Fractional Aircraft Ownership is a new concept in flight ownership management system where each individual or corporation may own a fraction of an aircraft. In this system, the owners have privilege to schedule their flight according to their needs. Fractional management companies (FMC) manages all aspects of aircraft operations, including utilization of FMC's aircraft in combination of outsourced aircrafts. This gives the owners the right to enjoy the benefits of private aviations. However, FMC may have complicated business requirements that neither commercial airlines nor charter airlines faces. Here, optimization models are constructed to minimize the number of aircrafts in order to maximize the profit and to minimize the daily operating cost. In this paper, three kinds of demand scenarios are made to represent different flight operations from different types of fractional owners. The problems are formulated as an optimization of profit and a daily operational cost to find the optimum flight assignments satisfying the weekly and daily demand respectively from the owners. Numerical results are obtained by Genetic Algorithm method.

  6. 16 CFR 303.14 - Products containing unknown fibers.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Products containing unknown fibers. 303.14... RULES AND REGULATIONS UNDER THE TEXTILE FIBER PRODUCTS IDENTIFICATION ACT § 303.14 Products containing unknown fibers. (a) Where a textile fiber product is made from miscellaneous scraps, rags, odd lots...

  7. 37 CFR 381.9 - Unknown copyright owners.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Unknown copyright owners. 381.9 Section 381.9 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS... EDUCATIONAL BROADCASTING § 381.9 Unknown copyright owners. If PBS and its stations, NPR and its stations, or...

  8. 37 CFR 253.9 - Unknown copyright owners.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Unknown copyright owners. 253.9 Section 253.9 Patents, Trademarks, and Copyrights COPYRIGHT OFFICE, LIBRARY OF CONGRESS COPYRIGHT... NONCOMMERCIAL EDUCATIONAL BROADCASTING § 253.9 Unknown copyright owners. If PBS and its stations, NPR and its...

  9. 37 CFR 382.7 - Unknown copyright owners.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Unknown copyright owners. 382.7 Section 382.7 Patents, Trademarks, and Copyrights COPYRIGHT ROYALTY BOARD, LIBRARY OF CONGRESS... SATELLITE DIGITAL AUDIO RADIO SERVICES Preexisting Subscription Services § 382.7 Unknown copyright owners...

  10. 37 CFR 260.7 - Unknown copyright owners.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Unknown copyright owners. 260.7 Section 260.7 Patents, Trademarks, and Copyrights COPYRIGHT OFFICE, LIBRARY OF CONGRESS COPYRIGHT... TRANSMISSIONS OF SOUND RECORDINGS AND MAKING OF EPHEMERAL PHONORECORDS § 260.7 Unknown copyright owners. If the...

  11. Aircraft exhaust sulfur emissions

    Energy Technology Data Exchange (ETDEWEB)

    Brown, R.C.; Anderson, M.R.; Miake-Lye, R.C.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics; Sorokin, A.A.; Buriko, Y.I. [Scientific Research Center `Ecolen`, Moscow (Russian Federation)

    1997-12-31

    The extent to which fuel sulfur is converted to SO{sub 3} during combustion and the subsequent turbine flow in supersonic and subsonic aircraft engines is estimated numerically. The analysis is based on: a flamelet model with non-equilibrium sulfur chemistry for the combustor, and a one-dimensional, two-stream model with finite rate chemical kinetics for the turbine. The results indicate that between 2% and 10% of the fuel sulfur is emitted as SO{sub 3}. It is also shown that, for a high fuel sulfur mass loading, conversion in the turbine is limited by the level of atomic oxygen at the combustor exit, leading to higher SO{sub 2} oxidation efficiency at lower fuel sulfur loadings. While SO{sub 2} and SO{sub 3} are the primary oxidation products, the model results further indicate H{sub 2}SO{sub 4} levels on the order of 0.1 ppm for supersonic expansions through a divergent nozzle. This source of fully oxidized S(6) (SO{sub 3} + H{sub 2}SO{sub 4}) exceeds previously calculated S(6) levels due to oxidation of SO{sub 2} by OH in the exhaust plume outside the engine nozzle. (author) 26 refs.

  12. Innovations in Aircraft Design

    Science.gov (United States)

    1997-01-01

    The Boeing 777 carries with it basic and applied research, technology, and aerodynamic knowledge honed at several NASA field centers. Several Langley Research Center innovations instrumental to the development of the aircraft include knowledge of how to reduce engine and other noise for passengers and terminal residents, increased use of lightweight aerospace composite structures for increased fuel efficiency and range, and wind tunnel tests confirming the structural integrity of 777 wing-airframe integration. Test results from Marshall Space Flight Center aimed at improving the performance of the Space Shuttle engines led to improvements in the airplane's new, more efficient jet engines. Finally, fostered by Ames Research Center, the Boeing 777 blankets that protect areas of the plane from high temperatures and fire have a lineage to Advanced Flexible Reusable Surface Insulation used on certain areas of the Space Shuttle. According to Boeing Company estimates, the 777 has captured three-quarters of new orders for airplanes in its class since the program was launched.

  13. Unknown Input Observer Design for Fuzzy Bilinear System: An LMI Approach

    Directory of Open Access Journals (Sweden)

    D. Saoudi

    2012-01-01

    Full Text Available A new method to design a fuzzy bilinear observer (FBO with unknown inputs is developed for a class of nonlinear systems. The nonlinear system is modeled as a fuzzy bilinear model (FBM. This kind of T-S fuzzy model is especially suitable for a nonlinear system with a bilinear term. The proposed fuzzy bilinear observer subject to unknown inputs is developed to ensure the asymptotic convergence of the error dynamic using the Lyapunov method. The proposed design conditions are given in linear matrix inequality (LMI formulation. The paper studies also the problem of fault detection and isolation. An unknown input fuzzy bilinear fault diagnosis observer design is proposed. This work is given for both continuous and discrete cases of fuzzy bilinear models. Illustrative examples are chosen to provide the effectiveness of the given methodology.

  14. Epidemic renal disease of unknown etiology in the Zuni Indians

    Energy Technology Data Exchange (ETDEWEB)

    Hoy, W.E.; Megill, D.M.; Hughson, M.D.

    1987-06-01

    An epidemic of renal disease is occurring among the Zuni Indians in western New Mexico. In 1985, 1.6% of Zunis had clinically recognized renal disease and 1% had renal insufficiency. The incidence of end-stage renal disease (ESRD) in 1984 and 1985 was 14 times the rate for US whites, and three times the rates of other Indians in ESRD network 6. One third of the cases of renal disease and ESRD is due to type 2 diabetes, but the etiology of disease in most of the remainder is unknown. Affected subjects range from early childhood to old age. Early signs are hematuria, mild to moderate proteinuria, normal BP, and low total hemolytic complement, normal or low C3 and C4 levels, in about 40% of the cases. The clinical course varies from benign to rapidly progressive renal failure. Biopsies usually reflect an immune-complex mediated mesangiopathic glomerulonephritis, with IgA, IgG, IgM, and C3 variably present in the mesangium. In some cases, there is a very strong familial pattern suggesting autosomal dominant inheritance or a marked communal exposure effect. This may be a genetic disease educed by the consanguinity in the ethnically homogeneous Zuni population. Mesangiopathic renal disease is common in some Oriental populations, and this phenomenon may reflect the American Indians' Oriental ancestry. This disease may also be due to toxic exposures related to jewelry-making, potting, Zuni water, Zuni salt, or herbal or other products used for medicinal or religious purposes. This epidemic is causing much morbidity and generating huge costs for ESRD treatment. Further study is needed to better understand its etiology.

  15. Ball lightning risk to aircraft

    Science.gov (United States)

    Doe, R.; Keul, A.

    2009-04-01

    Lightning is a rare but regular phenomenon for air traffic. Aircraft are designed to withstand lightning strikes. Research on lightning and aircraft can be called detailed and effective. In the last 57 years, 18 reported lightning aviation disasters with a fatality figure of at least 714 persons occurred. For comparison, the last JACDEC ten-year average fatality figure was 857. The majority encountered lightning in the climb, descent, approach and/or landing phase. Ball lightning, a metastable, rare lightning type, is also seen from and even within aircraft, but former research only reported individual incidents and did not generate a more detailed picture to ascertain whether it constitutes a significant threat to passenger and aircraft safety. Lacking established incident report channels, observations were often only passed on as "air-travel lore". In an effort to change this unsatisfactory condition, the authors have collected a first international dataset of 38 documented ball lightning aircraft incidents from 1938 to 2001 involving 13 reports over Europe, 13 over USA/Canada, and 7 over Russia. 18 (47%) reported ball lightning outside the aircraft, 18 (47%) inside, 2 cases lacked data. 8 objects caused minor damage, 8 major damage (total: 42%), only one a crash. No damage was reported in 18 cases. 3 objects caused minor crew injury. In most cases, ball lightning lasted several seconds. 11 (29%) incidents ended with an explosion of the object. A cloud-aircraft lightning flash was seen in only 9 cases (24%) of the data set. From the detailed accounts of air personnel in the last 70 years, it is evident that ball lightning is rarely, but consistently observed in connection with aircraft and can also occur inside the airframe. Reports often came from multiple professional witnesses and in several cases, damages were investigated by civil or military authorities. Although ball lightning is no main air traffic risk, the authors suggest that incident and accident

  16. Dryden B-52 Launch Aircraft on Edwards AFB Runway

    Science.gov (United States)

    1996-01-01

    booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.

  17. Dryden B-52 Launch Aircraft on Dryden Ramp

    Science.gov (United States)

    1996-01-01

    booster casings. It also supported eight orbiter (space shuttle) drag chute tests in 1990. In addition, the B-52 served as the air launch platform for the first six Pegasus space boosters. During its many years of service, the B-52 has undergone several modifications. The first major modification was made by North American Aviation (now part of Boeing) in support of the X-15 program. This involved creating a launch-panel-operator station for monitoring the status of the test vehicle being carried, cutting a large notch in the right inboard wing flap to accommodate the vertical tail of the X-15 aircraft, and installing a wing pylon that enables the B-52 to carry research vehicles and test articles to be air-launched/dropped. Located on the right wing, between the inboard engine pylon and the fuselage, this wing pylon was subjected to extensive testing prior to its use. For each test vehicle the B-52 carried, minor changes were made to the launch-panel operator's station. Built originally by the Boeing Company, the NASA B-52 is powered by eight Pratt & Whitney J57-19 turbojet engines, each of which produce 12,000 pounds of thrust. The aircraft's normal launch speed has been Mach 0.8 (about 530 miles per hour) and its normal drop altitude has been 40,000 to 45,000 feet. It is 156 feet long and has a wing span of 185 feet. The heaviest load it has carried was the No. 2 X-15 aircraft at 53,100 pounds. Project manager for the aircraft is Roy Bryant.

  18. Aircraft Cabin Environmental Quality Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Gundel, Lara; Kirchstetter, Thomas; Spears, Michael; Sullivan, Douglas

    2010-05-06

    The Indoor Environment Department at Lawrence Berkeley National Laboratory (LBNL) teamed with seven universities to participate in a Federal Aviation Administration (FAA) Center of Excellence (COE) for research on environmental quality in aircraft. This report describes research performed at LBNL on selecting and evaluating sensors for monitoring environmental quality in aircraft cabins, as part of Project 7 of the FAA's COE for Airliner Cabin Environmental Research (ACER)1 effort. This part of Project 7 links to the ozone, pesticide, and incident projects for data collection and monitoring and is a component of a broader research effort on sensors by ACER. Results from UCB and LBNL's concurrent research on ozone (ACER Project 1) are found in Weschler et al., 2007; Bhangar et al. 2008; Coleman et al., 2008 and Strom-Tejsen et al., 2008. LBNL's research on pesticides (ACER Project 2) in airliner cabins is described in Maddalena and McKone (2008). This report focused on the sensors needed for normal contaminants and conditions in aircraft. The results are intended to complement and coordinate with results from other ACER members who concentrated primarily on (a) sensors for chemical and biological pollutants that might be released intentionally in aircraft; (b) integration of sensor systems; and (c) optimal location of sensors within aircraft. The parameters and sensors were selected primarily to satisfy routine monitoring needs for contaminants and conditions that commonly occur in aircraft. However, such sensor systems can also be incorporated into research programs on environmental quality in aircraft cabins.

  19. Eclipse program QF-106 aircraft

    Science.gov (United States)

    1996-01-01

    This photo shows two QF-106 aircraft that were used for the Eclipse project, both parked at the Mojave Airport in Mojave, California. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator -01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  20. Grasping Unknown Objects in an Early Cognitive Vision System

    DEFF Research Database (Denmark)

    Popovic, Mila

    2011-01-01

    Grasping of unknown objects presents an important and challenging part of robot manipulation. The growing area of service robotics depends upon the ability of robots to autonomously grasp and manipulate a wide range of objects in everyday environments. Simple, non task-specific grasps of unknown...... presents a system for robotic grasping of unknown objects us- ing stereo vision. Grasps are defined based on contour and surface information provided by the Early Cognitive Vision System, that organizes visual informa- tion into a biologically motivated hierarchical representation. The contributions...

  1. Adaptive interferometric null testing for unknown freeform optics metrology.

    Science.gov (United States)

    Huang, Lei; Choi, Heejoo; Zhao, Wenchuan; Graves, Logan R; Kim, Dae Wook

    2016-12-01

    We report an adaptive interferometric null testing method for overcoming the dynamic range limitations of conventional null testing approaches during unknown freeform optics metrology or optics manufacturing processes that require not-yet-completed surface measurements to guide the next fabrication process. In the presented adaptive method, a deformable mirror functions as an adaptable null component for an unknown optical surface. The optimal deformable mirror's shape is determined by the stochastic parallel gradient descent algorithm and controlled by a deflectometry system. An adaptive interferometric null testing setup was constructed, and its metrology data successfully demonstrated superb adaptive capability in measuring an unknown surface.

  2. Demographic window to aging in the wild: constructing life tables and estimating survival functions from marked individuals of unknown age

    OpenAIRE

    Müller, Hans-Georg; Wang, Jane-Ling; Carey, James R.; Caswell-Chen, Edward P.; Chen, Carl; Papadopoulos, Nikos; Yao, Fang

    2004-01-01

    We address the problem of establishing a survival schedule for wild populations. A demographic key identity is established, leading to a method whereby age-specific survival and mortality can be deduced from a marked cohort life table established for individuals that are randomly sampled at unknown age and marked, with subsequent recording of time-to-death. This identity permits the construction of life tables from data where the birth date of subjects is unknown. An analogous key identity is...

  3. Objective versus subjective assessment of laparoscopic skill

    NARCIS (Netherlands)

    van Empel, P.J.; van Rijssen, L.B.; Commandeur, J.P.; Verdam, M.G.E.; Huirne, J.A.; Scheele, F.; Bonjer, H.J.; Meijerink, W.J.

    2013-01-01

    Background: The equality of subjective- and objective-assessment methods in laparoscopic surgery are unknown. The aim of this study was to compare a subjective assessment method to an objective assessment method to evaluate laparoscopic skill. Methods: A prospective observational cohort study was

  4. The Unknown Computer Viruses Detection Based on Similarity

    Science.gov (United States)

    Liu, Zhongda; Nakaya, Naoshi; Koui, Yuuji

    New computer viruses are continually being generated and they cause damage all over the world. In general, current anti-virus software detects viruses by matching a pattern based on the signature; thus, unknown viruses without any signature cannot be detected. Although there are some static analysis technologies that do not depend on signatures, virus writers often use code obfuscation techniques, which make it difficult to execute a code analysis. As is generally known, unknown viruses and known viruses share a common feature. In this paper we propose a new static analysis technology that can circumvent code obfuscation to extract the common feature and detect unknown viruses based on similarity. The results of evaluation experiments demonstrated that this technique is able to detect unknown viruses without false positives.

  5. Metastatic cervical carcinoma from an unknown primary: literature review

    National Research Council Canada - National Science Library

    Arrangoiz, Rodrigo; Galloway, Tom J; Papavasiliou, Pavlos; Ridge, John A; Lango, Miriam N

    2014-01-01

    Carcinoma of an unknown primary (CUP) encompasses a heterogeneous group of tumors for which no primary site can be detected following a thorough history, physical examination, and noninvasive and invasive testing...

  6. Using the Wheatstone Bridge to Compute Unknown Resistances.

    Science.gov (United States)

    Schlenker, Richard M.

    This document presents a secondary level physics unit which introduces students to the Wheatstone Bridge, its use in determining the value of unknown resistors, and the effects of wiring resistors in series or in parallel. (SL)

  7. Bone metastases of unknown origin: epidemiology and principles of management

    National Research Council Canada - National Science Library

    Piccioli, Andrea; Maccauro, Giulio; Spinelli, Maria Silvia; Biagini, Roberto; Rossi, Barbara

    2015-01-01

    ... % of patients present with bone metastases of unknown origin, where the site of the primary neoplasm cannot be identified at the time of diagnosis despite a thorough history, physical examination...

  8. Persistent Surveillance of Transient Events with Unknown Statistics

    Science.gov (United States)

    2016-12-18

    stochastic and transient, their exact time of occurrence cannot be known apriori . Hence, the monitoring process requires the robot to visit each location and...unknown apriori . These relaxed assumptions are in contrast to previous problem definitions such as those in [1], [2], [3], where the statistics of...and the canonical problem of prediction with expert advice where the best expert is unknown apriori . An even more profound relationship and similarity

  9. Fast and Automatic Detection and Segmentation of Unknown Objects

    OpenAIRE

    Kootstra, Gert; Bergström, Niklas; Kragic, Danica

    2010-01-01

    This paper focuses on the fast and automatic detection and segmentation of unknown objects in unknown environments. Many existing object detection and segmentation methods assume prior knowledge about the object or human interference. However, an autonomous system operating in the real world will often be confronted with previously unseen objects. To solve this problem, we propose a segmentation approach named Automatic Detection And Segmentation (ADAS). For the detection of objects, we use s...

  10. Stochastic Online Learning in Dynamic Networks under Unknown Models

    Science.gov (United States)

    2016-08-02

    Stochastic Online Learning in Dynamic Networks under Unknown Models This research aims to develop fundamental theories and practical algorithms for...12211 Research Triangle Park, NC 27709-2211 Online learning , multi-armed bandit, dynamic networks REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S... Online Learning in Dynamic Networks under Unknown Models Report Title This research aims to develop fundamental theories and practical algorithms for

  11. Into the Unknown Together. The DOD, NASA, and Early Spaceflight

    Science.gov (United States)

    2005-09-01

    aircraft, all technologically obsolete, when compared to France with 1,400, Germany with 1,000, Russia with 800, and England with 400.74 In the wartime...reentry materials were perfected) and into NASA’s later Mercury, Gemini, and Apollo space capsules . After World War II, the NACA did enough research...the bibliography.) 1. Apollo hardware and its Saturn family of launch vehicles were also used for the three Skylab missions in 1973 and the Apollo Soyuz

  12. Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements

    Directory of Open Access Journals (Sweden)

    A. R. Rodi

    2012-11-01

    Full Text Available A method is described that estimates the error in the static pressure measurement on an aircraft from differential pressure measurements on the hemispherical surface of a Rosemount model 858AJ air velocity probe mounted on a boom ahead of the aircraft. The theoretical predictions for how the pressure should vary over the surface of the hemisphere, involving an unknown sensitivity parameter, leads to a set of equations that can be solved for the unknowns – angle of attack, angle of sideslip, dynamic pressure and the error in static pressure – if the sensitivity factor can be determined. The sensitivity factor was determined on the University of Wyoming King Air research aircraft by comparisons with the error measured with a carefully designed sonde towed on connecting tubing behind the aircraft – a trailing cone – and the result was shown to have a precision of about ±10 Pa over a wide range of conditions, including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, geometric altitude data from a combined Global Navigation Satellite System (GNSS and inertial measurement unit (IMU system are used to estimate acceleration effects on the error, and the algorithm is shown to predict corrections to a precision of better than ±20 Pa under those conditions. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are discussed.

  13. Chinese Unknown Word Recognition for PCFG-LA Parsing

    Directory of Open Access Journals (Sweden)

    Qiuping Huang

    2014-01-01

    Full Text Available This paper investigates the recognition of unknown words in Chinese parsing. Two methods are proposed to handle this problem. One is the modification of a character-based model. We model the emission probability of an unknown word using the first and last characters in the word. It aims to reduce the POS tag ambiguities of unknown words to improve the parsing performance. In addition, a novel method, using graph-based semisupervised learning (SSL, is proposed to improve the syntax parsing of unknown words. Its goal is to discover additional lexical knowledge from a large amount of unlabeled data to help the syntax parsing. The method is mainly to propagate lexical emission probabilities to unknown words by building the similarity graphs over the words of labeled and unlabeled data. The derived distributions are incorporated into the parsing process. The proposed methods are effective in dealing with the unknown words to improve the parsing. Empirical results for Penn Chinese Treebank and TCT Treebank revealed its effectiveness.

  14. Algorithm project weight calculation aircraft

    Directory of Open Access Journals (Sweden)

    Г. В. Абрамова

    2013-07-01

    Full Text Available The paper describes the process of a complex technical object design on the example of the aircraft, using information technology such as CAD/CAM/CAE-systems, presents the basic models of aircraft which are developed in the process of designing and reflect the different aspects of its structure and function. The idea of control parametric model at complex technical object design is entered, which is a set of initial data for the development of design stations and enables the optimal complex technical object control at all stages of design using modern computer technology. The paper discloses a process of weight design, which is associated with all stages of development aircraft and its production. Usage of a scheduling algorithm that allows to organize weight calculations are carried out at various stages of planning and weighing options to optimize the use of available database of formulas and methods of calculation

  15. Aircraft Skin Restoration and Evaluation

    Science.gov (United States)

    Yandouzi, M.; Gaydos, S.; Guo, D.; Ghelichi, R.; Jodoin, B.

    2014-12-01

    The recent development of the cold spray technology has made possible the deposition of low porosity and oxide-free coatings with good adhesion and with almost no change in the microstructure of the coated parts. This focuses on the use of low-pressure cold spray process to repair damaged Al-based aircraft skin, aiming at obtaining dense coatings with strong adhesion to the Al2024-T3 alloy. In order to prove the feasibility of using of the cold spray process as a repair process for aircraft skin, series of characterisation/tests including microstructures, microhardness, adhesion strength, three-point bending, surface finish, fatigue test, and corrosion resistance were performed. The obtained results revealed that the low-pressure cold spray process is a suitable for the repair of aircraft skin.

  16. Aircraft Engine Crankshaft Optimisation

    Directory of Open Access Journals (Sweden)

    Vopařil Jan

    2014-10-01

    Full Text Available This article presents part of the crankshaft development of a two-stroke compression-ignition engine with contra-running pistons where, for invariably specified diameters and pin lengths, the optimal crankshaft shape is searched for. The process of creating several options which are then subjected to critical evaluation followed by the selection mechanism for the final best possible design is described.

  17. Aircraft Survivability. Fall 2011

    Science.gov (United States)

    2011-01-01

    Assembly Styrofoam Guides Figure 1 Example Missile Configuration for Gas-Gun Launch Figure 3 Missile Positioned in the Center of the Static Test Arena A...updated threat models to predict missile penetration and damage to a simple multi- plate array. The multi- plate array will be fabricated and subjected...Flowing to the Instrumentation Shelter at ARL Figure 5 Predictions of Missile Penetration into Multi- Plate Array 9 A ir cr af t S ur vi va bi li ty

  18. Using alternative feedback strategies to improve aircraft inspection performance

    Science.gov (United States)

    Kaewkuekool, Sittichai

    The aircraft inspection and maintenance system consists of several interrelated human and machine components, with visual inspection playing a significant role in ensuring aircraft safety. Training has been identified as one of the most important intervention strategies for enhancing the quality and reliability of aircraft inspection. This process has the potential to be improved using advancements in computer technology, especially virtual reality (VR) technology, which is becoming increasingly more affordable and prevalent. In light of this situation, this study investigated the use of VR technology to support training in the improvement of aircraft inspection performance. An experiment was developed to investigate the use of performance and process feedback in both statistical and graphical forms in two different task environments. In addition, information on defect criticality, defect location, and occurrence of defect was provided to subjects to study the effectiveness of feedforward information on inspection performance. Specifically, the experiment involved the inspection of an aircraft cargo bay using VR technology with eye tracking movement devices and a 6 degree of freedom mouse for pointing and clicking on defects. Results from the feedback training indicated that providing process along with performance feedback improved inspection performance as evidenced in the speed, accuracy and search strategy measures. Similar results were shown for both task environments. However, the addition feedforward information in the heterogeneous task environment yielded ever better inspection performance, and process and performance feedback coupled with feedforward information on defect criticality, defect location, and occurrence of defect yielded the best inspection performance as seen in the speed, accuracy and search strategy measures. The findings of this study indicate that using a combination of training intervention strategies leads to an improvement in

  19. Aircraft noise effects on sleep: Mechanisms, mitigation and research needs

    Directory of Open Access Journals (Sweden)

    Mathias Basner

    2010-01-01

    Full Text Available There is an ample number of laboratory and field studies which provide sufficient evidence that aircraft noise disturbs sleep and, depending on traffic volume and noise levels, may impair behavior and well-being during the day. Although clinical sleep disorders have been shown to be associated with increased risk of cardiovascular diseases, only little is known about the long-term effects of aircraft noise disturbed sleep on health. National and international laws and guidelines try to limit aircraft noise exposure facilitating active and passive noise control to prevent relevant sleep disturbances and its consequences. Adopting the harmonized indicator of the European Union Directive 2002/49/EC, the WHO Night Noise Guideline for Europe (NNG defines four Lnight , outside ranges associated with different risk levels of sleep disturbance and other health effects ( 55 dBA. Although traffic patterns differing in number and noise levels of events that lead to varying degrees of sleep disturbance may result in the same Lnight , simulations of nights with up to 200 aircraft noise events per night nicely corroborate expert opinion guidelines formulated in WHO′s NNG. In the future, large scale field studies on the effects of nocturnal (aircraft noise on sleep are needed. They should involve representative samples of the population including vulnerable groups like children and chronically ill subjects. Optimally, these studies are prospective in nature and examine the long-term consequences of noise-induced sleep disturbances. Furthermore, epidemiological case-control studies on the association of nocturnal (aircraft noise exposure and cardiovascular disease are needed. Despite the existing gaps in knowledge on long-term health effects, sufficient data are available for defining limit values, guidelines and protection concepts, which should be updated with the availability of new data.

  20. Future aircraft networks and schedules

    Science.gov (United States)

    Shu, Yan

    2011-07-01

    Because of the importance of air transportation scheduling, the emergence of small aircraft and the vision of future fuel-efficient aircraft, this thesis has focused on the study of aircraft scheduling and network design involving multiple types of aircraft and flight services. It develops models and solution algorithms for the schedule design problem and analyzes the computational results. First, based on the current development of small aircraft and on-demand flight services, this thesis expands a business model for integrating on-demand flight services with the traditional scheduled flight services. This thesis proposes a three-step approach to the design of aircraft schedules and networks from scratch under the model. In the first step, both a frequency assignment model for scheduled flights that incorporates a passenger path choice model and a frequency assignment model for on-demand flights that incorporates a passenger mode choice model are created. In the second step, a rough fleet assignment model that determines a set of flight legs, each of which is assigned an aircraft type and a rough departure time is constructed. In the third step, a timetable model that determines an exact departure time for each flight leg is developed. Based on the models proposed in the three steps, this thesis creates schedule design instances that involve almost all the major airports and markets in the United States. The instances of the frequency assignment model created in this thesis are large-scale non-convex mixed-integer programming problems, and this dissertation develops an overall network structure and proposes iterative algorithms for solving these instances. The instances of both the rough fleet assignment model and the timetable model created in this thesis are large-scale mixed-integer programming problems, and this dissertation develops subproblem schemes for solving these instances. Based on these solution algorithms, this dissertation also presents

  1. Aircraft Dynamic Modeling in Turbulence

    Science.gov (United States)

    Morelli, Eugene A.; Cunninham, Kevin

    2012-01-01

    A method for accurately identifying aircraft dynamic models in turbulence was developed and demonstrated. The method uses orthogonal optimized multisine excitation inputs and an analytic method for enhancing signal-to-noise ratio for dynamic modeling in turbulence. A turbulence metric was developed to accurately characterize the turbulence level using flight measurements. The modeling technique was demonstrated in simulation, then applied to a subscale twin-engine jet transport aircraft in flight. Comparisons of modeling results obtained in turbulent air to results obtained in smooth air were used to demonstrate the effectiveness of the approach.

  2. Versatile Electric Propulsion Aircraft Testbed Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An all-electric aircraft testbed is proposed to provide a dedicated development environment for the rigorous study and advancement of electrically powered aircraft....

  3. Modular Electric Propulsion Test Bed Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An all electric aircraft test bed is proposed to provide a dedicated development environment for the rigorous study and advancement of electrically powered aircraft....

  4. Military Airlift: The Joint Cargo Aircraft Program

    National Research Council Canada - National Science Library

    Knight, William

    2007-01-01

    Joint Cargo Aircraft (JCA) is a joint acquisition program between the Army and the Air Force designed to procure a commercial off-the-shelf aircraft, capable of meeting Army requirements for "direct support" to maneuver units...

  5. Military Airlift: The Joint Cargo Aircraft Program

    National Research Council Canada - National Science Library

    Hess, Allan

    2008-01-01

    Joint Cargo Aircraft (JCA) is a joint acquisition program between the Army and Air Force intended to procure a commercial off-the-shelf aircraft capable of meeting Army and Air Force requirements for intra-theater airlift...

  6. Statistical estimation of aircraft service conditions

    Directory of Open Access Journals (Sweden)

    Боузаієнне Меккі бен Салем

    2005-03-01

    Full Text Available  The question of an estimation of aircraft service conditions in airlines with use of statistical methods is considered at the analysis of maintenance programs of a aircrafts park to normative requirements.

  7. Musculoskeletal Pain in High-G Aircraft Training Programs: A Survey of Student and Instructor Pilots

    Science.gov (United States)

    2016-06-01

    not addressed early, due to stigmas of reporting and lack of availability of effective therapies, are resulting in chronic long-term disabilities ...symptoms in pilots flying high-G aircraft, impacting mission readiness with concerns for chronic disability . We hypothesized similar prevalence of MS...will result in chronic disabilities . 15. SUBJECT TERMS Musculoskeletal pain, student pilots, instructor pilots, high-G aircraft, OMT, DNIF 16

  8. THE AIRPORT DE-ICING OF AIRCRAFTS

    Directory of Open Access Journals (Sweden)

    Robert KONIECZKA

    2015-03-01

    Full Text Available This article provides a summary of the issues involved in de-icing several kinds of aircrafts before flight. The basic risks of an iced aircraft and the factors that can influence its intensity are stated. It discusses the methods for de-icing and protecting against ice formation on small aircrafts, helicopters, and large aircrafts. It also classifies the fluids and other methods used for these de-icing operations, and explains the characteristics and limitations of their use.

  9. 14 CFR 47.33 - Aircraft not previously registered anywhere.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Aircraft not previously registered anywhere... TRANSPORTATION AIRCRAFT AIRCRAFT REGISTRATION Certificates of Aircraft Registration § 47.33 Aircraft not previously registered anywhere. (a) A person who is the owner of an aircraft that has not been registered...

  10. 14 CFR 91.117 - Aircraft speed.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft speed. 91.117 Section 91.117... AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Flight Rules General § 91.117 Aircraft speed. (a) Unless otherwise authorized by the Administrator, no person may operate an aircraft below 10...

  11. 78 FR 67309 - Earth Stations Aboard Aircraft

    Science.gov (United States)

    2013-11-12

    ... COMMISSION 47 CFR Part 25 Earth Stations Aboard Aircraft AGENCY: Federal Communications Commission. ACTION... collection associated with the Commission's Earth Station Aboard Aircraft, Report and Order (Order), which adopted licensing and service rules for Earth Stations Aboard Aircraft (ESAA) communicating with Fixed...

  12. 48 CFR 908.7102 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Aircraft. 908.7102 Section... REQUIRED SOURCES OF SUPPLIES AND SERVICES Acquisition of Special Items 908.7102 Aircraft. Acquisition of aircraft shall be in accordance with DOE-PMR 41 CFR 109-38.5205. ...

  13. 14 CFR 21.127 - Tests: aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tests: aircraft. 21.127 Section 21.127 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS Production Under Type Certificate Only § 21.127 Tests: aircraft. (a) Each...

  14. 14 CFR 34.6 - Aircraft safety.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Aircraft safety. 34.6 Section 34.6 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES General Provisions § 34.6 Aircraft...

  15. 14 CFR 135.125 - Aircraft security.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Aircraft security. 135.125 Section 135.125... AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Operations § 135.125 Aircraft security. Certificate holders conducting operators conducting operations under this part...

  16. 14 CFR 91.209 - Aircraft lights.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft lights. 91.209 Section 91.209... Requirements § 91.209 Aircraft lights. No person may: (a) During the period from sunset to sunrise (or, in... or the sun is more than 6 degrees below the horizon)— (1) Operate an aircraft unless it has lighted...

  17. 19 CFR 122.37 - Precleared aircraft.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Precleared aircraft. 122.37 Section 122.37 Customs... AIR COMMERCE REGULATIONS Landing Requirements § 122.37 Precleared aircraft. (a) Application. This section applies when aircraft carrying crew, passengers and baggage, or merchandise which has been...

  18. 36 CFR 13.1004 - Aircraft use.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Aircraft use. 13.1004 Section... § 13.1004 Aircraft use. In extraordinary cases where no reasonable alternative exists, local rural residents who permanently reside in the following exempted community(ies) may use aircraft for access to...

  19. 19 CFR 122.42 - Aircraft entry.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Aircraft entry. 122.42 Section 122.42 Customs... AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements for Passengers, Crew Members, and Non-Crew Members Onboard Commercial Aircraft Arriving In, Continuing Within...

  20. 31 CFR 560.528 - Aircraft safety.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Aircraft safety. 560.528 Section 560..., Authorizations and Statements of Licensing Policy § 560.528 Aircraft safety. Specific licenses may be issued on a... the safety of civil aviation and safe operation of U.S.-origin commercial passenger aircraft. ...

  1. 50 CFR 27.34 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Aircraft. 27.34 Section 27.34 Wildlife and... WILDLIFE REFUGE SYSTEM PROHIBITED ACTS Disturbing Violations: With Vehicles § 27.34 Aircraft. The unauthorized operation of aircraft, including sail planes, and hang gliders, at altitudes resulting in...

  2. 47 CFR 32.6113 - Aircraft expense.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Aircraft expense. 32.6113 Section 32.6113... FOR TELECOMMUNICATIONS COMPANIES Instructions for Expense Accounts § 32.6113 Aircraft expense. (a) This account shall include such costs as aircraft fuel, flight crews, mechanics and ground crews...

  3. 43 CFR 423.41 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Aircraft. 423.41 Section 423.41 Public... Aircraft. (a) You must comply with any applicable Federal, State, and local laws, and with any additional... this part 423, with respect to aircraft landings, takeoffs, and operation on or in the proximity of...

  4. 47 CFR 32.2113 - Aircraft.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Aircraft. 32.2113 Section 32.2113... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2113 Aircraft. This account shall include the original cost of aircraft and any associated equipment and furnishings installed...

  5. Impact analysis of composite aircraft structures

    Science.gov (United States)

    Pifko, Allan B.; Kushner, Alan S.

    1993-01-01

    The impact analysis of composite aircraft structures is discussed. Topics discussed include: background remarks on aircraft crashworthiness; comments on modeling strategies for crashworthiness simulation; initial study of simulation of progressive failure of an aircraft component constructed of composite material; and research direction in composite characterization for impact analysis.

  6. Unmanned Cargo Aircraft : From Anywhere to Everywhere

    NARCIS (Netherlands)

    Heerkens, Hans

    2017-01-01

    While unmanned aircraft have been in use for decades, their suitability for transporting cargo is only now slowly being recognised. The first prototypes of unmanned cargo aircraft (UCA) are currently being tested. There are two categories of UCA: short-distance aircraft for delivering packages and

  7. Analyses of Aircraft Responses to Atmospheric Turbulence

    NARCIS (Netherlands)

    Van Staveren, W.H.J.J.

    2003-01-01

    The response of aircraft to stochastic atmospheric turbulence plays an important role in aircraft-design (load calculations), Flight Control System (FCS) design and flight-simulation (handling qualities research and pilot training). In order to simulate these aircraft responses, an accurate

  8. Aircraft height estimation using 2-D radar

    CSIR Research Space (South Africa)

    Hakl, H

    2010-01-01

    Full Text Available A method to infer height information from an aircraft tracked with a single 2-D search radar is presented. The method assumes level flight in the target aircraft and a good estimate of the speed of the aircraft. The method yields good results...

  9. Aircraft Lightning Electromagnetic Environment Measurement

    Science.gov (United States)

    Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.

    2011-01-01

    This paper outlines a NASA project plan for demonstrating a prototype lightning strike measurement system that is suitable for installation onto research aircraft that already operate in thunderstorms. This work builds upon past data from the NASA F106, FAA CV-580, and Transall C-180 flight projects, SAE ARP5412, and the European ILDAS Program. The primary focus is to capture airframe current waveforms during attachment, but may also consider pre and post-attachment current, electric field, and radiated field phenomena. New sensor technologies are being developed for this system, including a fiber-optic Faraday polarization sensor that measures lightning current waveforms from DC to over several Megahertz, and has dynamic range covering hundreds-of-volts to tens-of-thousands-of-volts. A study of the electromagnetic emission spectrum of lightning (including radio wave, microwave, optical, X-Rays and Gamma-Rays), and a compilation of aircraft transfer-function data (including composite aircraft) are included, to aid in the development of other new lightning environment sensors, their placement on-board research aircraft, and triggering of the onboard instrumentation system. The instrumentation system will leverage recent advances in high-speed, high dynamic range, deep memory data acquisition equipment, and fiber-optic interconnect.

  10. Promising Electric Aircraft Drive Systems

    Science.gov (United States)

    Dudley, Michael R.

    2010-01-01

    An overview of electric aircraft propulsion technology performance thresholds for key power system components is presented. A weight comparison of electric drive systems with equivalent total delivered energy is made to help identify component performance requirements, and promising research and development opportunities.

  11. Flight Control of Flexible Aircraft

    Science.gov (United States)

    Nguyen, Nhan T.

    2017-01-01

    This presentation presents an overview of flight control research for flexible high aspect wing aircraft in support of the NASA ARMD Advanced Air Transport Technology (AATT) project. It summarizes multi-objective flight control technology being developed for drag optimization, flutter suppression, and maneuver and gust load alleviation.

  12. Bonded repairs for aircraft fuselages

    OpenAIRE

    Vlot, A.; Verhoeven, S.; Nijssen, P.J.M.

    1998-01-01

    This report will give an overview of the bonded repair work that has been done over the last few years by the Faculty of Aerospace Engineering of Delft University of Technology, in cooperation with the Center for Aircraft Structural Life Extension at the United States Air Force Academy in Colorado Springs.

  13. Bonded repairs for aircraft fuselages

    NARCIS (Netherlands)

    Vlot, A.; Verhoeven, S.; Nijssen, P.J.M.

    1998-01-01

    This report will give an overview of the bonded repair work that has been done over the last few years by the Faculty of Aerospace Engineering of Delft University of Technology, in cooperation with the Center for Aircraft Structural Life Extension at the United States Air Force Academy in Colorado

  14. MATE. Multi Aircraft Training Environment

    DEFF Research Database (Denmark)

    Hauland, G.; Bove, T.; Andersen, Henning Boje

    2002-01-01

    A medium fidelity and low cost training device for pilots, called the Multi Aircraft Training Environment (MATE), is developed to replace other low fidelity stand-alone training devices and integrate them into a flexible environment, primarily aimed attraining pilots in checklist procedures...

  15. Aircraft Fuel Cell Power Systems

    Science.gov (United States)

    Needham, Robert

    2004-01-01

    In recent years, fuel cells have been explored for use in aircraft. While the weight and size of fuel cells allows only the smallest of aircraft to use fuel cells for their primary engines, fuel cells have showed promise for use as auxiliary power units (APUs), which power aircraft accessories and serve as an electrical backup in case of an engine failure. Fuel cell MUS are both more efficient and emit fewer pollutants. However, sea-level fuel cells need modifications to be properly used in aircraft applications. At high altitudes, the ambient air has a much lower pressure than at sea level, which makes it much more difficult to get air into the fuel cell to react and produce electricity. Compressors can be used to pressurize the air, but this leads to added weight, volume, and power usage, all of which are undesirable things. Another problem is that fuel cells require hydrogen to create electricity, and ever since the Hindenburg burst into flames, aircraft carrying large quantities of hydrogen have not been in high demand. However, jet fuel is a hydrocarbon, so it is possible to reform it into hydrogen. Since jet fuel is already used to power conventional APUs, it is very convenient to use this to generate the hydrogen for fuel-cell-based APUs. Fuel cells also tend to get large and heavy when used for applications that require a large amount of power. Reducing the size and weight becomes especially beneficial when it comes to fuel cells for aircraft. My goal this summer is to work on several aspects of Aircraft Fuel Cell Power System project. My first goal is to perform checks on a newly built injector rig designed to test different catalysts to determine the best setup for reforming Jet-A fuel into hydrogen. These checks include testing various thermocouples, transmitters, and transducers, as well making sure that the rig was actually built to the design specifications. These checks will help to ensure that the rig will operate properly and give correct results

  16. Analysis of a Stretched Derivative Aircraft with Open Rotor Propulsion

    Science.gov (United States)

    Berton, Jeffrey J.; Hendricks, Eric S.; Haller, William J.; Guynn, Mark D.

    2015-01-01

    Research into advanced, high-speed civil turboprops received significant attention during the 1970s and 1980s when fuel efficiency was the driving focus of U.S. aeronautical research. But when fuel prices declined sharply there was no longer sufficient motivation to continue maturing the technology. Recent volatility in fuel prices and increasing concern for aviation's environmental impact, however, have renewed interest in unducted, open rotor propulsion and revived research by NASA and a number of engine manufacturers. Recently, NASA and General Electric have teamed to conduct several investigations into the performance and noise of an advanced, single-aisle transport with open rotor propulsion. The results of these initial studies indicate open rotor engines have the potential to provide significant reduction in fuel consumption compared to aircraft using turbofan engines with equivalent core technology. In addition, noise analysis of the concept indicates that an open rotor aircraft in the single-aisle transport class would be able to meet current noise regulations with margin. The behavior of derivative open rotor transports is of interest. Heavier, "stretched" derivative aircraft tend to be noisier than their lighter relatives. Of particular importance to the business case for the concept is how the noise margin changes relative to regulatory limits within a family of similar open rotor aircraft. The subject of this report is a performance and noise assessment of a notional, heavier, stretched derivative airplane equipped with throttle-push variants of NASA's initial open rotor engine design.

  17. Number and mass analysis of particles emitted by aircraft engine

    Directory of Open Access Journals (Sweden)

    Jasiński Remigiusz

    2017-01-01

    Full Text Available Exhaust emissions from aircraft is a complex issue because of the limited possibility of measurements in flight conditions. Most of the studies on this subject were performed on the basis of stationary test. Engine certification data is used to calculate total emissions generated by air transport. However, it doesnt provide any information about the local effects of air traffic. The main threat to local communities is particulate matter emissions, which adversely affects human health. Emissions from air transport affect air quality, particularly in the vicinity of the airports; it also contributes to the greenhouse effect. The article presents the measurement results of the concentration and size distribution of particles emitted during aircraft landing operation. Measurements were carried out during the landings of aircraft at a civilian airport. It was found that a single landing operation causes particle number concentration value increase of several ten-fold in a short period of time. Using aircraft engine certification data, the methodology for determination of the total number of particles emitted during a single landing operation was introduced.

  18. Biomarkers for Ectopic Pregnancy and Pregnancy of Unknown Location

    Science.gov (United States)

    Senapati, Suneeta; Barnhart, Kurt T.

    2013-01-01

    Early pregnancy failure is the most common complication of pregnancy, and 1–2% of all pregnancies will be ectopic. As one of the leading causes of maternal morbidity and mortality, diagnosing ectopic pregnancy and determining the fate of a pregnancy of unknown location are of great clinical concern. Several serum and plasma biomarkers for ectopic pregnancy have been investigated independently and in combination. The following is a review of the state of biomarker discovery and development for ectopic pregnancy and pregnancy of unknown location. PMID:23290746

  19. Fever of unknown origin, giant cell arteritis, and aortic dissection.

    Science.gov (United States)

    Hofheinz, K; Bertz, S; Wacker, J; Schett, G; Manger, B

    2017-02-01

    Giant cell arteritis is one of the most frequent causes of pyrexia of unknown origin after infectious or malignant causes have been ruled out. In this case report we describe a 66-year old female patient, who after five weeks of remitting fever developed a life-threatening, painless severe aortic dissection. The timely use of modern imaging technologies such as magnetic resonance angiography or positron emission computed tomography could in the future be of help to recognize aortic involvement early and to avoid this devastating complication in patients with fever of unknown origin.

  20. Prediction of Primary Tumors in Cancers of Unknown Primary

    DEFF Research Database (Denmark)

    Søndergaard, Dan; Nielsen, Svend; Pedersen, Christian N S

    2017-01-01

    A cancer of unknown primary (CUP) is a metastatic cancer for which standard diagnostic tests fail to identify the location of the primary tumor. CUPs account for 3-5% of cancer cases. Using molecular data to determine the location of the primary tumor in such cases can help doctors make the right...... treatment choice and thus improve the clinical outcome. In this paper, we present a new method for predicting the location of the primary tumor using gene expression data: locating cancers of unknown primary (LoCUP). The method models the data as a mixture of normal and tumor cells and thus allows correct...

  1. Effects of activity interference on annoyance due to aircraft noise

    Science.gov (United States)

    Willshire, K. F.; Powell, C. A.

    1981-01-01

    The effects of aircraft flyover noise on annoyance were compared for face to face conversation, reverie, and television viewing. Eighteen 5 minute sessions, each composed of three flyovers, were presented on each of 2 days to subjects in a simulated living room. Twelve pairs of females and 12 pairs of males were tested, once before and once after work. Flyovers varied in peak noise level from 53 to 83 dB, A weighted. On each day, subjects engaged in 18 sessions, six of conversation, six of television viewing, and six of reverie. The subjects completed subjective ratings of annoyance and acceptability following every session. Annoyance and unacceptability rating scores were significantly higher for the activity of television viewing compared to conversation or reverie. There was no difference between judgments during the latter two activities. No differences were found in the judgments when compared on the basis of "fatigue" (before/after work) or sex of the subject.

  2. Perspectives on Highly Adaptive or Morphing Aircraft

    Science.gov (United States)

    McGowan, Anna-Maria R.; Vicroy, Dan D.; Busan, Ronald C.; Hahn, Andrew S.

    2009-01-01

    The ability to adapt to different flight conditions has been fundamental to aircraft design since the Wright Brothers first flight. Over a hundred years later, unconventional aircraft adaptability, often called aircraft morphing has become a topic of considerable renewed interest. In the past two decades, this interest has been largely fuelled by advancements in multi-functional or smart materials and structures. However, highly adaptive or morphing aircraft is certainly a cross-discipline challenge that stimulates a wide range of design possibilities. This paper will review some of the history of morphing aircraft including recent research programs and discuss some perspectives on this work.

  3. Hydrogen Storage for Aircraft Applications Overview

    Science.gov (United States)

    Colozza, Anthony J.; Kohout, Lisa (Technical Monitor)

    2002-01-01

    Advances in fuel cell technology have brought about their consideration as sources of power for aircraft. This power can be utilized to run aircraft systems or even provide propulsion power. One of the key obstacles to utilizing fuel cells on aircraft is the storage of hydrogen. An overview of the potential methods of hydrogen storage was compiled. This overview identifies various methods of hydrogen storage and points out their advantages and disadvantages relative to aircraft applications. Minimizing weight and volume are the key aspects to storing hydrogen within an aircraft. An analysis was performed to show how changes in certain parameters of a given storage system affect its mass and volume.

  4. Extensive screening for primary tumor is redundant in melanoma of unknown primary

    DEFF Research Database (Denmark)

    Tos, Tina; Klyver, Helle; Drzewiecki, Krzysztof T

    2011-01-01

    primary tumor during the period 1986-2006, 39 (38%) presented primarily with a cutaneous or a subcutaneous metastasis, and 63 (61%) with a lymph node metastasis. One patient presented with a bone metastasis (1%). Eighty-seven patients (84%) were examined by an ophthalmologist. A choroidal melanoma......For decades, patients in our institution with metastastic melanoma of unknown primary have been subjected to extensive examinations in search of the primary tumor. This retrospective study questions the results, and thus the feasibility of these examinations. Of 103 patients diagnosed with unknown...... (89%), revealing no primary tumor. We conclude, that only one possible (but not verified) primary tumor was disclosed by various specialists examinations of 103 patients referred with the diagnosis metastatic melanoma with no primary tumor. Special screenings can thus be considered as redundant. Thus...

  5. Adaptive fuzzy prescribed performance control for MIMO nonlinear systems with unknown control direction and unknown dead-zone inputs.

    Science.gov (United States)

    Shi, Wuxi; Luo, Rui; Li, Baoquan

    2017-01-01

    In this study, an adaptive fuzzy prescribed performance control approach is developed for a class of uncertain multi-input and multi-output (MIMO) nonlinear systems with unknown control direction and unknown dead-zone inputs. The properties of symmetric matrix are exploited to design adaptive fuzzy prescribed performance controller, and a Nussbaum-type function is incorporated in the controller to estimate the unknown control direction. This method has two prominent advantages: it does not require the priori knowledge of control direction and only three parameters need to be updated on-line for this MIMO systems. It is proved that all the signals in the resulting closed-loop system are bounded and that the tracking errors converge to a small residual set with the prescribed performance bounds. The effectiveness of the proposed approach is validated by simulation results. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Aircraft Survivability: An Overview of Aircraft Fire Protection, Spring 2008

    Science.gov (United States)

    2008-01-01

    combination of the two. The detectors are designed to look at a narrow frequency band; however, initial designs were not sophis- ticated enough to...for complete ignition prevention. Experimental Setup This test program was conducted at the Simulated Aircraft Fuel Tank Environ- ment ( SAFTE ) Facility...experi- enced a roll oscillation at a frequency of 0.35 hertz (Hz). Figure 3 shows a liquid phenomenon known as a hydraulic jump (circled region

  7. Detection of unknown occult primary tumors using positron emission tomography

    NARCIS (Netherlands)

    Kole, AC; Nieweg, OE; Pruim, J; Hoekstra, HJ; Roodenburg, JLN; Vaalburg, W; Vermey, A; Schraffordt Koops, H.

    1998-01-01

    BACKGROUND. The potential of positron emission tomography (PET) with F-18-fluoro-2-deoxy-D-glucose (FDG) to detect primary tumors after unsuccessful conventional diagnostic workup was assessed in patients with metastatic disease from an unknown primary tumor. METHODS. Twenty-nine patients with

  8. Prevalence and predictors of unknown HIV status among women ...

    African Journals Online (AJOL)

    Introduction: Knowledge of a person's HIV status during pregnancy is critical for prevention of mother to child transmission of HIV. Objectives: To determine the prevalence and factors associated with unknown HIV status among women delivering in Mulago Hospital. Methods: This was a cross-sectional study of women that ...

  9. Severe scratcher-reaction: an unknown health hazard?

    Directory of Open Access Journals (Sweden)

    Carsten Sauer Mikkelsen

    2015-03-01

    Full Text Available Tattoos are well known to cause skin problems and the number of reported adverse reactions after tattooing has increased. Illegally imported tattoo ink is unrestrained and can contain unknown ingredients and contamination thereby posing a serious health hazard. We present a case illustrating the risk of pronounced phototoxic allergic reaction and other severe complications after using home kit tattoo ink.

  10. RBF neural network based H∞ synchronization for unknown chaotic ...

    Indian Academy of Sciences (India)

    MS received 9 February 2010; accepted 24 May 2010. Abstract. In this paper, we propose a new H∞ synchronization strategy, called a. Radial Basis Function Neural Network H∞ synchronization (RBFNNHS) strategy, for unknown chaotic systems in the presence of external disturbance. In the pro- posed framework, a ...

  11. Bayesian Compressed Sensing with Unknown Measurement Noise Level

    DEFF Research Database (Denmark)

    Hansen, Thomas Lundgaard; Jørgensen, Peter Bjørn; Pedersen, Niels Lovmand

    2013-01-01

    In sparse Bayesian learning (SBL) approximate Bayesian inference is applied to find sparse estimates from observations corrupted by additive noise. Current literature only vaguely considers the case where the noise level is unknown a priori. We show that for most state-of-the-art reconstruction...

  12. Inventory control in case of unknown demand and control parameters

    NARCIS (Netherlands)

    Janssen, E.

    2010-01-01

    This thesis deals with unknown demand and control parameters in inventory control. Inventory control involves decisions on what to order when and in what quantity. These decisions are based on information about the demand. Models are constructed using complete demand information; these models ensure

  13. Designing towards the Unknown: Engaging with Material and Aesthetic Uncertainty

    Directory of Open Access Journals (Sweden)

    Danielle Wilde

    2017-12-01

    Full Text Available New materials with new capabilities demand new ways of approaching design. Destabilising existing methods is crucial to develop new methods. Yet, radical destabilisation—where outcomes remain unknown long enough that new discoveries become possible—is not easy in technology design where complex interdisciplinary teams with time and resource constraints need to deliver concrete outcomes on schedule. The Poetic Kinaesthetic Interface project (PKI engages with this problematic directly. In PKI we use unfolding processes—informed by participatory, speculative and critical design—in emergent actions, to design towards unknown outcomes, using unknown materials. The impossibility of this task is proving as useful as it is disruptive. At its most potent, it is destabilising expectations, aesthetics and processes. Keeping the researchers, collaborators and participants in a state of unknowing, is opening the research potential to far-ranging possibilities. In this article we unpack the motivations driving the PKI project. We present our mixed-methodology, which entangles textile crafts, design interactions and materiality to shape an embodied enquiry. Our research outcomes are procedural and methodological. PKI brings together diverse human, non-human, known and unknown actors to discover where the emergent assemblages might lead. Our approach is re-invigorating—as it demands re-envisioning of—the design process.

  14. A Size Exclusion Chromatography Laboratory with Unknowns for Introductory Students

    Science.gov (United States)

    McIntee, Edward J.; Graham, Kate J.; Colosky, Edward C.; Jakubowski, Henry V.

    2015-01-01

    Size exclusion chromatography is an important technique in the separation of biological and polymeric samples by molecular weight. While a number of laboratory experiments have been published that use this technique for the purification of large molecules, this is the first report of an experiment that focuses on purifying an unknown small…

  15. Editoria: EBOLA: Fear of the unknown | Comoro | Tanzania Journal ...

    African Journals Online (AJOL)

    Tanzania Journal of Health Research. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 2 (2001) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Editoria: EBOLA: Fear of the unknown. C. Comoro, J.

  16. Prevalence and predictors of unknown HIV status among women ...

    African Journals Online (AJOL)

    The labour ward on 5C admits high risk women and re- ferrals from the formal and informal health sector. There are about 2300 deliveries at ward 5C per month. The HIV status of every woman is identified at admission, those with unknown HIV status receive HCT and if positive, are given emergency ARVs for PMTCT.

  17. Anal Cancer debuting as Cancer of Unknown Primary

    DEFF Research Database (Denmark)

    Sveistrup, Joen; Loft, Annika; Engelholm, Svend Aage

    2011-01-01

    Anal cancer usually presents with a visible or palpable tumour. In this case we describe a 54-year old man diagnosed with Cancer of Unknown Primary (CUP) with a single inguinal node as the only finding. Thorough examination failed to identify any primary tumour. The patient was treated with lymph...

  18. Bayesian source term determination with unknown covariance of measurements

    Science.gov (United States)

    Belal, Alkomiet; Tichý, Ondřej; Šmídl, Václav

    2017-04-01

    Determination of a source term of release of a hazardous material into the atmosphere is a very important task for emergency response. We are concerned with the problem of estimation of the source term in the conventional linear inverse problem, y = Mx, where the relationship between the vector of observations y is described using the source-receptor-sensitivity (SRS) matrix M and the unknown source term x. Since the system is typically ill-conditioned, the problem is recast as an optimization problem minR,B(y - Mx)TR-1(y - Mx) + xTB-1x. The first term minimizes the error of the measurements with covariance matrix R, and the second term is a regularization of the source term. There are different types of regularization arising for different choices of matrices R and B, for example, Tikhonov regularization assumes covariance matrix B as the identity matrix multiplied by scalar parameter. In this contribution, we adopt a Bayesian approach to make inference on the unknown source term x as well as unknown R and B. We assume prior on x to be a Gaussian with zero mean and unknown diagonal covariance matrix B. The covariance matrix of the likelihood R is also unknown. We consider two potential choices of the structure of the matrix R. First is the diagonal matrix and the second is a locally correlated structure using information on topology of the measuring network. Since the inference of the model is intractable, iterative variational Bayes algorithm is used for simultaneous estimation of all model parameters. The practical usefulness of our contribution is demonstrated on an application of the resulting algorithm to real data from the European Tracer Experiment (ETEX). This research is supported by EEA/Norwegian Financial Mechanism under project MSMT-28477/2014 Source-Term Determination of Radionuclide Releases by Inverse Atmospheric Dispersion Modelling (STRADI).

  19. CID Aircraft slap-down

    Science.gov (United States)

    1984-01-01

    In this photograph the B-720 is seen during the moments of initial impact. The left wing is digging into the lakebed while the aircraft continues sliding towards wing openers. In 1984 NASA Dryden Flight Research Facility and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID). The test involved crashing a Boeing 720 aircraft with four JT3C-7 engines burning a mixture of standard fuel with an additive, Anti-misting Kerosene (AMK), designed to supress fire. In a typical aircraft crash, fuel spilled from ruptured fuel tanks forms a fine mist that can be ignited by a number of sources at the crash site. In 1984 the NASA Dryden Flight Research Facility (after 1994 a full-fledged Center again) and the Federal Aviation Administration (FAA) teamed-up in a unique flight experiment called the Controlled Impact Demonstration (CID), to test crash a Boeing 720 aircraft using standard fuel with an additive designed to supress fire. The additive, FM-9, a high-molecular-weight long-chain polymer, when blended with Jet-A fuel had demonstrated the capability to inhibit ignition and flame propagation of the released fuel in simulated crash tests. This anti-misting kerosene (AMK) cannot be introduced directly into a gas turbine engine due to several possible problems such as clogging of filters. The AMK must be restored to almost Jet-A before being introduced into the engine for burning. This restoration is called 'degradation' and was accomplished on the B-720 using a device called a 'degrader.' Each of the four Pratt & Whitney JT3C-7 engines had a 'degrader' built and installed by General Electric (GE) to break down and return the AMK to near Jet-A quality. In addition to the AMK research the NASA Langley Research Center was involved in a structural loads measurement experiment, which included having instrumented dummies filling the seats in the passenger compartment. Before the final flight on December 1

  20. The Cognitive Challenges of Flying a Remotely Piloted Aircraft

    Science.gov (United States)

    Hobbs, Alan; Cardoza, Colleen; Null, Cynthia

    2016-01-01

    A large variety of Remotely Piloted Aircraft (RPA) designs are currently in production or in development. These aircraft range from small electric quadcopters that are flown close to the ground within visual range of the operator, to larger systems capable of extended flight in airspace shared with conventional aircraft. Before RPA can operate routinely and safely in civilian airspace, we need to understand the unique human factors associated with these aircraft. The task of flying an RPA in civilian airspace involves challenges common to the operation of other highly-automated systems, but also introduces new considerations for pilot perception, decision-making, and action execution. RPA pilots participated in focus groups where they were asked to recall critical incidents that either presented a threat to safety, or highlighted a case where the pilot contributed to system resilience or mission success. Ninety incidents were gathered from focus-groups. Human factor issues included the impact of reduced sensory cues, traffic separation in the absence of an out-the-window view, control latencies, vigilance during monotonous and ultra-long endurance flights, control station design considerations, transfer of control between control stations, the management of lost link procedures, and decision-making during emergencies. Some of these concerns have received significant attention in the literature, or are analogous to human factors of manned aircraft. The presentation will focus on issues that are poorly understood, and have not yet been the subject of extensive human factors study. Although many of the reported incidents were related to pilot error, the participants also provided examples of the positive contribution that humans make to the operation of highly-automated systems.

  1. Aircraft Derived Data Validation Algorithms

    Science.gov (United States)

    2012-08-06

    required to solve for wind. However, local variations in wind results in unrepresentative estimates when only two samples are used; Therefore, a more...CONCLUSION 37 10. FUTURE WORK 39 REFERENCES 40 A. DATA DEPENDENCY CHART A-1 B. WIND FIELD SAMPLE B-1 C. AIRCRAFT SPECIFIC VALIDATION REPORT (ASVR) SAMPLE ...C-1 D. CROSS TRACK REPORT (XTR) SAMPLE D-1 E. ACRONYM LIST E-1 viii LIST OF ILLUSTRATIONS Figure No. Page 1.1 Register Layouts 2 2.1 ATCRBS

  2. Piloted Aircraft Environment Simulation Techniques

    Science.gov (United States)

    1978-04-01

    model of the KC- 135 tanker aircraft. 1.2 AS INE EIEET DEFINEDI1T AS TNEAllRFORCE APRVED IT AS TESYSTEMS CNINA AS ThECONTRACTRMADE I AS N LOGISTCS ...approach trajectory, he will control speed with pitch attitude, and sink rate with power. More rapid changes can be achieved by reversing the control...thrust reversers (or parachutes) may be of most concern, coupled with runway conditions (water or ice) and crosswinds. Failures and assymetrics will

  3. Aircraft Evaluation Using Stochastic Duels

    Science.gov (United States)

    2017-09-01

    control , structural load factors, and weapon effectiveness are influential in determining the winner in the dogfight. Our model is designed to...models focus on higher resolution applications such as missile control designs. Our aim in this chapter is to provide a review of some of the...occurs. 1. The weapons onboard the aircraft are only missiles, thus excluding the use of guns . This assumption serves to focus on the more

  4. IAR-93 military aircraft monument

    Directory of Open Access Journals (Sweden)

    Radu BISCA

    2011-09-01

    Full Text Available In this presentation, we will concentrate on the vertical support, which is free from all sides. A Finite Element Model (FEM of the IAR-93 aircraft monument has been developed in PATRAN/NASTRAN®, partly from a previous ANSYS® model FEM can be used to investigate potential structural modifications or changes in column monument with realistic component corrections. Model validation should be part of every modern engineering analysis and quality assurance procedure

  5. Impact of Airspace Charges on Transatlantic Aircraft Trajectories

    Science.gov (United States)

    Sridhar, Banavar; Ng, Hok K.; Linke, Florian; Chen, Neil Y.

    2015-01-01

    Aircraft flying over the airspace of different countries are subject to over-flight charges. These charges vary from country to country. Airspace charges, while necessary to support the communication, navigation and surveillance services, may lead to aircraft flying routes longer than wind-optimal routes and produce additional carbon dioxide and other gaseous emissions. This paper develops an optimal route between city pairs by modifying the cost function to include an airspace cost whenever an aircraft flies through a controlled airspace without landing or departing from that airspace. It is assumed that the aircraft will fly the trajectory at a constant cruise altitude and constant speed. The computationally efficient optimal trajectory is derived by solving a non-linear optimal control problem. The operational strategies investigated in this study for minimizing aircraft fuel burn and emissions include flying fuel-optimal routes and flying cost-optimal routes that may completely or partially reduce airspace charges en route. The results in this paper use traffic data for transatlantic flights during July 2012. The mean daily savings in over-flight charges, fuel cost and total operation cost during the period are 17.6 percent, 1.6 percent, and 2.4 percent respectively, along the cost- optimal trajectories. The transatlantic flights can potentially save $600,000 in fuel cost plus $360,000 in over-flight charges daily by flying the cost-optimal trajectories. In addition, the aircraft emissions can be potentially reduced by 2,070 metric tons each day. The airport pairs and airspace regions that have the highest potential impacts due to airspace charges are identified for possible reduction of fuel burn and aircraft emissions for the transatlantic flights. The results in the paper show that the impact of the variation in fuel price on the optimal routes is to reduce the difference between wind-optimal and cost-optimal routes as the fuel price increases. The

  6. METHOD IMPROVEMENT FOR DETERMINING THE TECHNICAL LEVEL OF CIVIL AIRCRAFT

    Directory of Open Access Journals (Sweden)

    2016-01-01

    incorporate features of general aviation aircraft operation. However, according to the authors of this article, this method requires some clarification. This is the subject of this article where the technical level generalized index equation is refinedand with the use of which the technical level of civil long-range aircraft is determined.

  7. Finite Element Analysis of Composite Aircraft Fuselage Frame

    Science.gov (United States)

    Dandekar, Aditya Milind

    Composites have been introduced in aircraft industries, for their stronger, stiffer, and lighter properties than their metal-alloys counterparts. The general purpose of an aircraft is to transport commercial or military payload. Aircraft frames primarily maintains the shape of fuselage and prevent instability of the structure. Fuselage is similar as wing in construction which consist of longitudinal elements (longerons and stringers), transverse elements (frames and bulkheads) and its external skin. The fuselage is subjected to forces such as the wing reactions, landing gear reaction, empennage reaction, inertia forces subjected due to size and weight, internal pressure forces due to high altitude. Frames also ensure fail-safe design against skin crack propagation due to hoops stress. Ideal fuselage frames cross section is often circular ring shape with a frame cap of Z section. They are mainly made up of light alloy commonly used is aluminium alloys such as Al-2024, Al-7010, Al-7050, Al-7175. Aluminium alloys have good strength to density ratios in compression and bending of thin plate. A high strength to weight ratio of composite materials can result in a lighter aircraft structure or better safety factor. This research focuses on analysis of fuselage frame under dynamic load condition with change in material. Composites like carbon fibre reinforced plastics [CFRP] and glass fibre reinforced plastics [GFRP] are compared with traditional aluminium alloy Al-7075. The frame is subjected to impact test by dropping it at a velocity of 30 ft. / secs from a height of 86 inch from its centre of gravity. These parameters are considered in event of failure of landing gear, and an aircraft is subject to belly landing or gear-up landing. The shear flow is calculated due to impact force which acts in radial direction. The frame is analysed under static structural and explicit dynamic load conditions. Geometry is created in ANSYS Design Modeler. Analysis setup is created using

  8. Quantification of advanced turboprop aircraft flyover noise annoyance

    Science.gov (United States)

    Mccurdy, D. A.

    1984-01-01

    A laboratory experiment was conducted to quantify the annoyance to advanced turboprop (propfan) aircraft flyover noise. A computer synthesis system was used to generate 45 realistic, time varying simulations of propeller aircraft flyover noise in which the tonal content was systematically varied to represent the factorial combinations of five fundamental frequencies, three frequency envelope shapes, and three tone-to-broadband noise ratios. In the experiment, 64 subjects judged the annoyance of recordings of the 45 synthesized flyover noises presented at three sound levels in a test facility which simulates the outdoor acoustic environment. Analyses of the judgements showed that frequency envelope shape did not significantly affect annoyance. The interaction of fundamental frequency with tone-to-broadband noise ratio did have a large and complex effect on annoyance. Duration corrected A-weighted sound pressure level with a modified tone correction predicted annoyance better than any other measurement procedure.

  9. Quadrotor Control in the Presence of Unknown Mass Properties

    Science.gov (United States)

    Duivenvoorden, Rikky Ricardo Petrus Rufino

    Quadrotor UAVs are popular due to their mechanical simplicity, as well as their capability to hover and vertically take-off and land. As applications diversify, quadrotors are increasingly required to operate under unknown mass properties, for example as a multirole sensor platform or for package delivery operations. The work presented here consists of the derivation of a generalized quadrotor dynamic model without the typical simplifying assumptions on the first and second moments of mass. The maximum payload capacity of a quadrotor in hover, and the observability of the unknown mass properties are discussed. A brief introduction of L1 adaptive control is provided, and three different L 1 adaptive controllers were designed for the Parrot AR.Drone quadrotor. Their tracking and disturbance rejection performance was compared to the baseline nonlinear controller in experiments. Finally, the results of the combination of L1 adaptive control with iterative learning control are presented, showing high performance trajectory tracking under uncertainty.

  10. Towards high-speed autonomous navigation of unknown environments

    Science.gov (United States)

    Richter, Charles; Roy, Nicholas

    2015-05-01

    In this paper, we summarize recent research enabling high-speed navigation in unknown environments for dynamic robots that perceive the world through onboard sensors. Many existing solutions to this problem guarantee safety by making the conservative assumption that any unknown portion of the map may contain an obstacle, and therefore constrain planned motions to lie entirely within known free space. In this work, we observe that safety constraints may significantly limit performance and that faster navigation is possible if the planner reasons about collision with unobserved obstacles probabilistically. Our overall approach is to use machine learning to approximate the expected costs of collision using the current state of the map and the planned trajectory. Our contribution is to demonstrate fast but safe planning using a learned function to predict future collision probabilities.

  11. Learning Unknown Structure in CRFs via Adaptive Gradient Projection Method

    Directory of Open Access Journals (Sweden)

    Wei Xue

    2016-08-01

    Full Text Available We study the problem of fitting probabilistic graphical models to the given data when the structure is not known. More specifically, we focus on learning unknown structure in conditional random fields, especially learning both the structure and parameters of a conditional random field model simultaneously. To do this, we first formulate the learning problem as a convex minimization problem by adding an l_2-regularization to the node parameters and a group l_1-regularization to the edge parameters, and then a gradient-based projection method is proposed to solve it which combines an adaptive stepsize selection strategy with a nonmonotone line search. Extensive simulation experiments are presented to show the performance of our approach in solving unknown structure learning problems.

  12. Renal disease masquerading as pyrexia of unknown origin

    Directory of Open Access Journals (Sweden)

    D Korivi

    2013-01-01

    Full Text Available Pyrexia of unknown origin is a challenging clinical problem. Infections, malignancies, and connective tissue diseases form the major etiologies for this condition. We report a case of a 57-year-old diabetic male who presented with fever of unknown origin for several months. The course of investigations led to a kidney biopsy which clinched the cause of his fever as well as the underlying diagnosis. The light microscopy findings of expansile storiform fibrosis with a dense inflammatory infiltrate suggested the diagnosis which was confirmed by positive staining of Immunoglobulin G4, the dense lympho-plasmacytic infiltrate and elevated serum IgG4 concentrations. A course of steroids followed by mycophenolate mofetil as maintenance immunosuppression rendered the patient afebrile with improvement of renal function.

  13. Research on LMI based Robust Fault Diagnosis Approach for Civil Aircraft Maintenance System

    Science.gov (United States)

    2016-03-30

    and CHANG Hua 1 1 AVIC Xi’an Flight Automatic Control Research Institute, Xi’an, Shaanxi, China Abstract Safety and reliability are the...The combined H∞/H- observer is derived based on a linear matrix inequality (LMI) approach. The conclusion is that the component or sensor faults of...which will ensure the air safety. Keywords: civil aircraft; H∞/H-; robust unknown input observer; linear matrix inequality (LMI); fault diagnosis

  14. Evaluation of Unknown Tube Well Depth Using Electrical Resistivity Method

    Directory of Open Access Journals (Sweden)

    Zainal Abidin Mohd Hazreek

    2017-01-01

    Full Text Available Electrical resistivity method has increasingly adopted in engineering, environmental, mining and archaeological studies. Systematic and proper studies of unknown civil engineering structure evaluation particularly on tube well depth was rarely being established. Conventionally, camera test or string with weight approach has been used to evaluate unknown tube well depth thus exposed to several restriction due to its expensive and time consuming. Hence, this study focused on evaluation of unknown tube well depth using indirect test with particular reference to electrical resistivity method (ERM.A single spread line of electrical resistivity survey was performed using ABEM SAS 4000 equipment set based on Wenner and Pole-dipole array in line with the tube well position. Electrical resistivity raw data was processed using RES2DINV software producing electrical resistivity tomography (ERT of the subsurface profile studied. Then, electrical resistivity value (ERV obtained from RES2DINV analyses (ERT was extracted and analysed using plotted graph (depth versus ERV specifically at tube well position based on electrical resistivity spread line performed. It was found that both array have shown some good similarity results in term of tube well depth (20 m thus able to verify the result interpreted. Both array have shown some good similarity of ERV representing groundwater (ERV = 10 – 100 Ωm and soil with water (ERV > 100 Ωm at depth of 0 – 20 m and >20 m respectively. All those interpretation have shown good agreement based on verification thru established ERV of earth materials references, geological map and nearest available boreholes data. Hence, this study has shown that the application of ERM was applicable in evaluation of unknown tube well depth which efficient in term of cost, time and environmental sustainable.

  15. Renovation of the Tomb of the Unknown Soldier, Baghdad, Iraq

    Science.gov (United States)

    2010-01-13

    animals, including some of the “ pet ” lions kept by Uday and Qusay Hussein. Also located near the Tomb of the Unknown in the Al Zarwaa Park is an...the following: 4 x 800 amp automatic transfer switches main power boards sub-distribution board for the different facilities main feeder ...repairing the 3-phase diesel generator and installing automatic transfer switches, main power boards, main feeder cables, and interior and exterior

  16. Stability Analysis of Fractional Differential Equations with Unknown Parameters

    OpenAIRE

    Koksal, Mehmet Emir

    2017-01-01

    In this paper, the stability of fractional differential equations (FDEs) with unknown parameters is studied. FDEs bring many advantages to model the physical systems in the nature or man-made systems in the industry. Because this representation has a property between linear differential equations and nonlinear differential equations. Therefore, the designer may use the FDEs to model complex systems instead of nonlinear differential equations which have hard mathematical background. Using the ...

  17. Modal Parameter Identification from Responses of General Unknown Random Inputs

    OpenAIRE

    Ibrahim, S. R.; Asmussen, J. C.; Brincker, Rune

    1995-01-01

    Modal parameter identification from ambient responses due to a general unknown random inputs is investigated. Existing identification techniques which are based on assumptions of white noise and or stationary random inputs are utilized even though the inputs conditions are not satisfied. This is accomplished via adding. In cascade. A force cascade conversion to the structures system under consideration. The input to the force conversion system is white noise and the output of which is the act...

  18. Localized hepatic tuberculosis presenting as fever of unknown origin

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Abreu Ferrari

    Full Text Available Localized hepatic tuberculosis is a rare clinical form of tuberculosis infection; it has signs and symptoms related only to hepatic injury, with minimal or no extrahepatic involvement. It frequently presents as a non-specific syndrome, with systemic manifestations, which can sometimes result in a diagnostic dilemma. A high index of suspicion is required and a definitive diagnosis can be very difficult. We report a case of localized hepatic tuberculosis that presented as fever of unknown origin.

  19. General Unknown Screening by Ion Trap LC/MS/MS

    Science.gov (United States)

    2010-04-01

    are collected at autopsy and sent to CAMI’s Forensic Toxicology Research Laboratory for toxicological analysis of various postmortem fluids and... Forensic Toxicology, General Unknown Screening, LC/MS Document is available to the public through the Defense Technical Information...resulting in an acid/ neutral and a base vial from each specimen. rEsulTs ANd dIsCussION This study established the LOD for 359 forensically

  20. Nonlinear Integral Type Observer Design for State Estimation and Unknown Input Reconstruction

    Directory of Open Access Journals (Sweden)

    Chao-Chung Peng

    2017-01-01

    Full Text Available This paper is concerned with model-based robust observer designs for state observation and its application for unknown input reconstruction. Firstly, a sliding mode observer (SMO, which provides exponential convergence of estimation error, is designed for a class of multivariable perturbed systems. Observer gain matrices subject to specific structures are going to be imposed such that the unknown perturbation will not affect estimate precision during the sliding modes; Secondly, to improve discontinuous control induced in the SMO as well as pursue asymptotic estimate precision, a proportional-integral type observer (PIO is further developed. Both the design procedures of the SMO and PIO algorithms are characterized as feasibility issues of linear matrix inequality (LMI and thus the computations of the control parameters can be efficiently solved. Compared with the SMO, it will be demonstrated that the PIO is capable of achieving better estimation precision as long as the unknown inputs are continuous. Finally, a servo-drive flexible robot arm is selected as an example to demonstrate the applications of the robust observer designs.

  1. Restoring accents in unknown biomedical words: application to the French MeSH thesaurus.

    Science.gov (United States)

    Zweigenbaum, Pierre; Grabar, Natalia

    2002-12-04

    In languages with diacritic marks, such as French, there remain instances of textual or terminological resources that are available in electronic form without diacritic marks, which hinders their use in natural language interfaces. In a specialized domain such as medicine, it is often the case that some words are not found in the available electronic lexicons. The issue of accenting unknown words then arises: it is the theme of this work. We propose two internal methods for accenting unknown words, which both learn on a reference set of accented words the contexts of occurrence of the various accented forms of a given letter. One method is adapted from part-of-speech tagging, the other is based on finite state transducers. We show experimental results for letter e on the French version of the Medical Subject Headings thesaurus. With the best training set, the tagging method obtains a precision-recall breakeven point of 84.2+/-4.4% and the transducer method 83.8+/-4.5% (with a baseline at 64%) for the unknown words that contain this letter. A consensus combination of both increases precision to 92.0+/-3.7% with a recall of 75%. We perform an error analysis and discuss further steps that might help improve over the current performance.

  2. 14 CFR 91.111 - Operating near other aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Operating near other aircraft. 91.111... § 91.111 Operating near other aircraft. (a) No person may operate an aircraft so close to another aircraft as to create a collision hazard. (b) No person may operate an aircraft in formation flight except...

  3. 32 CFR 855.15 - Detaining an aircraft.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Detaining an aircraft. 855.15 Section 855.15 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE AIRCRAFT CIVIL AIRCRAFT USE OF UNITED STATES AIR FORCE AIRFIELDS Civil Aircraft Landing Permits § 855.15 Detaining an aircraft...

  4. 47 CFR 87.191 - Foreign aircraft stations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Foreign aircraft stations. 87.191 Section 87... AVIATION SERVICES Aircraft Stations § 87.191 Foreign aircraft stations. (a) Aircraft of member States of... States airspace only if a license has been issued by the State in which the aircraft is registered and...

  5. Short-term Internet search using makes people rely on search engines when facing unknown issues.

    Science.gov (United States)

    Wang, Yifan; Wu, Lingdan; Luo, Liang; Zhang, Yifen; Dong, Guangheng

    2017-01-01

    The Internet search engines, which have powerful search/sort functions and ease of use features, have become an indispensable tool for many individuals. The current study is to test whether the short-term Internet search training can make people more dependent on it. Thirty-one subjects out of forty subjects completed the search training study which included a pre-test, a six-day's training of Internet search, and a post-test. During the pre- and post- tests, subjects were asked to search online the answers to 40 unusual questions, remember the answers and recall them in the scanner. Un-learned questions were randomly presented at the recalling stage in order to elicited search impulse. Comparing to the pre-test, subjects in the post-test reported higher impulse to use search engines to answer un-learned questions. Consistently, subjects showed higher brain activations in dorsolateral prefrontal cortex and anterior cingulate cortex in the post-test than in the pre-test. In addition, there were significant positive correlations self-reported search impulse and brain responses in the frontal areas. The results suggest that a simple six-day's Internet search training can make people dependent on the search tools when facing unknown issues. People are easily dependent on the Internet search engines.

  6. Short-term Internet search using makes people rely on search engines when facing unknown issues.

    Directory of Open Access Journals (Sweden)

    Yifan Wang

    Full Text Available The Internet search engines, which have powerful search/sort functions and ease of use features, have become an indispensable tool for many individuals. The current study is to test whether the short-term Internet search training can make people more dependent on it. Thirty-one subjects out of forty subjects completed the search training study which included a pre-test, a six-day's training of Internet search, and a post-test. During the pre- and post- tests, subjects were asked to search online the answers to 40 unusual questions, remember the answers and recall them in the scanner. Un-learned questions were randomly presented at the recalling stage in order to elicited search impulse. Comparing to the pre-test, subjects in the post-test reported higher impulse to use search engines to answer un-learned questions. Consistently, subjects showed higher brain activations in dorsolateral prefrontal cortex and anterior cingulate cortex in the post-test than in the pre-test. In addition, there were significant positive correlations self-reported search impulse and brain responses in the frontal areas. The results suggest that a simple six-day's Internet search training can make people dependent on the search tools when facing unknown issues. People are easily dependent on the Internet search engines.

  7. Using virtual reality technology for aircraft visual inspection training: presence and comparison studies.

    Science.gov (United States)

    Vora, Jeenal; Nair, Santosh; Gramopadhye, Anand K; Duchowski, Andrew T; Melloy, Brian J; Kanki, Barbara

    2002-11-01

    The aircraft maintenance industry is a complex system consisting of several interrelated human and machine components. Recognizing this, the Federal Aviation Administration (FAA) has pursued human factors related research. In the maintenance arena the research has focused on the aircraft inspection process and the aircraft inspector. Training has been identified as the primary intervention strategy to improve the quality and reliability of aircraft inspection. If training is to be successful, it is critical that we provide aircraft inspectors with appropriate training tools and environment. In response to this need, the paper outlines the development of a virtual reality (VR) system for aircraft inspection training. VR has generated much excitement but little formal proof that it is useful. However, since VR interfaces are difficult and expensive to build, the computer graphics community needs to be able to predict which applications will benefit from VR. To address this important issue, this research measured the degree of immersion and presence felt by subjects in a virtual environment simulator. Specifically, it conducted two controlled studies using the VR system developed for visual inspection task of an aft-cargo bay at the VR Lab of Clemson University. Beyond assembling the visual inspection virtual environment, a significant goal of this project was to explore subjective presence as it affects task performance. The results of this study indicated that the system scored high on the issues related to the degree of presence felt by the subjects. As a next logical step, this study, then, compared VR to an existing PC-based aircraft inspection simulator. The results showed that the VR system was better and preferred over the PC-based training tool.

  8. Alternate Fuels for Use in Commercial Aircraft

    Science.gov (United States)

    Daggett, David L.; Hendricks, Robert C.; Walther, Rainer; Corporan, Edwin

    2008-01-01

    The engine and aircraft Research and Development (R&D) communities have been investigating alternative fueling in near-term, midterm, and far-term aircraft. A drop in jet fuel replacement, consisting of a kerosene (Jet-A) and synthetic fuel blend, will be possible for use in existing and near-term aircraft. Future midterm aircraft may use a biojet and synthetic fuel blend in ultra-efficient airplane designs. Future far-term engines and aircraft in 50-plus years may be specifically designed to use a low- or zero-carbon fuel. Synthetic jet fuels from coal, natural gas, or other hydrocarbon feedstocks are very similar in performance to conventional jet fuel, yet the additional CO2 produced during the manufacturing needs to be permanently sequestered. Biojet fuels need to be developed specifically for jet aircraft without displacing food production. Envisioned as midterm aircraft fuel, if the performance and cost liabilities can be overcome, biofuel blends with synthetic jet or Jet-A fuels have near-term potential in terms of global climatic concerns. Long-term solutions address dramatic emissions reductions through use of alternate aircraft fuels such as liquid hydrogen or liquid methane. Either of these new aircraft fuels will require an enormous change in infrastructure and thus engine and airplane design. Life-cycle environmental questions need to be addressed.

  9. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose:The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...

  10. 75 FR 51953 - Notification and Reporting of Aircraft Accidents or Incidents and Overdue Aircraft, and...

    Science.gov (United States)

    2010-08-24

    ... notification and reporting of aircraft accidents or incidents by adding a definition of ``unmanned aircraft... Register (FR), is available for inspection and copying in the NTSB's public reading room, located at 490 L... the addition of a new definition of ``unmanned aircraft accident'' to the section of the NTSB's...

  11. 77 FR 1626 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

    Science.gov (United States)

    2012-01-11

    ... Equipped With Rotax Aircraft Engines 912 A Series Engine AGENCY: Federal Aviation Administration (FAA), DOT...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect... Aircraft model Engine model Aeromot-Ind stria AMT-200 912 A2 Mec nico- Metal rgica Ltda. Diamond Aircraft...

  12. COMPARATIVE ANALYSIS OF TRANSPORT AIRCRAFT, BACKROUND FOR SHORT/ MEDIUM COURIER TRANSPORT AIRCRAFT PROCUREMENT

    Directory of Open Access Journals (Sweden)

    Matei POPA

    2010-03-01

    Full Text Available In accordance with Air Force requirements, the comparative analysis of short/medium transport aircraft comes to sustain procurement decision of short/medium transport aircraft. This paper presents, in short, the principles and the results of the comparative analysis for short/medium military transport aircraft.

  13. An Evidence-Based Review Literature About Risk Indicators and Management of Unknown-Origin Xerostomia

    Directory of Open Access Journals (Sweden)

    Farzaneh Agha-hosseini

    2013-01-01

    Full Text Available Objective: This evidence-based article reviews risk indicators and management of unknown-origin xerostomia. Xerostomia and hyposalivation refer to different aspects of dry mouth. Xerostomia is a subjective sensation of dry mouth, whilst hyposalivation is defined as an objective assessment of reduced salivary flow rate. About 30% of the elderly (65 years and older experience xerostomia and hyposalivation. Structural and functional factors, or both may lead to salivary gland dysfunction.Study Selection: The EBM literature search was conducted by using the medical literature database MEDLINE via PubMed and OvidMedline search engines. Results were limited to English language articles (1965 to present including clinical trials (CT, randomized controlled trials (RCT, systematic reviews and review articles. Case control or cohort studies were included for the etiology.Results: Neuropathic etiology such as localized oral alteration of thermal sensations, saliva composition change (for example higher levels of K, Cl, Ca, IgA, amylase, calcium, PTH and cortisol, lower levels of estrogen and progesterone, smaller salivary gland size, and illnesses such as lichen planus, are risk indicators for unknown-origin xerostomia. The management is palliative and preventative. Management of symptoms includes drug administration (systemic secretogogues, saliva substitutes and bile secretion-stimulator, night guard, diet and habit modifications. Other managements may be indicated to treat adverse effects.Conclusion: Neuropathic etiology, saliva composition change, smaller salivary gland size, and illnesses such as oral lichen planus can be suggestive causes for unknown-origin xerostomia. However, longitudinal studies will be important to elucidate the causes of unknown-origin xerostomia.

  14. An Evidence-Based Review Literature About Risk Indicators and Management of Unknown-Origin Xerostomia

    Science.gov (United States)

    Agha-Hosseini, Farzaneh; Moosavi, Mahdieh-Sadat

    2013-01-01

    This evidence-based article reviews risk indicators and management of unknown-origin xerostomia. Xerostomia and hyposalivation refer to different aspects of dry mouth. Xerostomia is a subjective sensation of dry mouth, whilst hyposalivation is defined as an objective assessment of reduced salivary flow rate. About 30% of the elderly (65 years and older) experience xerostomia and hyposalivation. Structural and functional factors, or both may lead to salivary gland dysfunction. The EBM literature search was conducted by using the medical literature database MEDLINE via PubMed and OvidMedline search engines. Results were limited to English language articles (1965 to present) including clinical trials (CT), randomized controlled trials (RCT), systematic reviews and review articles. Case control or cohort studies were included for the etiology. Neuropathic etiology such as localized oral alteration of thermal sensations, saliva composition change (for example higher levels of K, Cl, Ca, IgA, amylase, calcium, PTH and cortisol), lower levels of estrogen and progesterone, smaller salivary gland size, and illnesses such as lichen planus, are risk indicators for unknown-origin xerostomia. The management is palliative and preventative. Management of symptoms includes drug administration (systemic secretogogues, saliva substitutes and bile secretion-stimulator), night guard, diet and habit modifications. Other managements may be indicated to treat adverse effects. Neuropathic etiology, saliva composition change, smaller salivary gland size, and illnesses such as oral lichen planus can be suggestive causes for unknown-origin xerostomia. However, longitudinal studies will be important to elucidate the causes of unknown-origin xerostomia. PMID:25512755

  15. Subjective Evaluations: Discretionary Bonuses and Feedback Credibility

    OpenAIRE

    Fuchs, William

    2013-01-01

    We provide a new rationale for the use of discretionary bonuses. In a setting with unknown match qualities between a worker and a firm and subjective evaluations by the principal, bonuses are useful in order to make the feedback from the firm to the workers credible. This way workers in good matches are less inclined to accept outside offers.

  16. Assessment of Alternative Aircraft Fuels

    Science.gov (United States)

    1984-01-01

    The purpose of this symposium is to provide representatives from industry, government, and academia concerned with the availability and quality of future aviation turbine fuels with recent technical results and a status review of DOD and NASA sponsored fuels research projects. The symposium has included presentations on the potential crude sources, refining methods, and characteristics of future fuels; the effects of changing fuel characteristics on the performance and durability of jet aircraft components and systems; and the prospects for evolving suitable technology to produce and use future fuels.

  17. Technology for aircraft energy efficiency

    Science.gov (United States)

    Klineberg, J. M.

    1977-01-01

    Six technology programs for reducing fuel use in U.S. commercial aviation are discussed. The six NASA programs are divided into three groups: Propulsion - engine component improvement, energy efficient engine, advanced turboprops; Aerodynamics - energy efficient transport, laminar flow control; and Structures - composite primary structures. Schedules, phases, and applications of these programs are considered, and it is suggested that program results will be applied to current transport derivatives in the early 1980s and to all-new aircraft of the late 1980s and early 1990s.

  18. Altus I aircraft on lakebed

    Science.gov (United States)

    1997-01-01

    The remotely-piloted Altus I aircraft climbs away after takeoff from Rogers Dry Lake adjacent to NASA's Dryden Flight Research Center, Edwards, Calif. The short series of test flights sponsored by the Naval Postgraduate School in early August, 1997, were designed to demonstrate the ability of the experimental craft to cruise at altitudes above 40,000 feet for sustained durations. On its final flight Aug. 15, the Altus I reached an altitude of 43,500 feet. The Altus I and its sister ship, the Altus II, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems, Inc. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines. The Altus I incorporates a single-stage turbocharger, while the Altus II, built for NASA's Environmental Research Aircraft and Sensor Technology program, sports a two-stage turbocharger to enable the craft to fly at altitudes above 55,000 feet. The Altus II, the first of the two craft to be completed, made its first flight on May 1, 1996. With its engine augmented by a single-stage turbocharger, the Altus II reached an altitude of 37,000 ft during its first series of development flights at Dryden in Aug., 1996. In Oct. of that year, the Altus II was flown in an Atmospheric Radiation Measurement study for the Department of Energy's Sandia National Laboratory in Oklahoma. During the course of those flights, the Altus II set a single-flight endurance record for remotely-operated aircraft of more than 26 hours. The Altus I, completed in 1997, flew a series of development flights at Dryden that summer. Those test flights culminated with the craft reaching an altitude of 43,500 ft while carrying a simulated 300-lb payload, a record for an unmanned aircraft powered by a piston engine augmented with a single-stage turbocharger. The Altus II sustained an altitudeof 55,000 feet for four hours in 1999. A pilot in a control station on the ground flies the

  19. [The identification of unknown corpses by x-ray comparison].

    Science.gov (United States)

    Riepert, T; Schweden, F; Schild, H; Rittner, C

    1995-03-01

    Between 1987 and 1993, 30 unknown bodies were identified by means of pre- and postmortem radiographs at the Forensic Institute in Mainz. Our experience indicates that radiological identification comprises a useful, rapid and cheap method, at least as valuable as dactyloscopy or odontological comparisons. The ages of available radiographs were up to 25 years; the most suitable regions are the skull (11), pelvis and lumbar spine (6), lower femur and knee (5) and distal leg with the ankle joint (5). In respect of the problem of objectifying the probability of identity, possibilities for solutions are shown.

  20. Anal Cancer debuting as Cancer of Unknown Primary

    DEFF Research Database (Denmark)

    Sveistrup, Joen; Loft, Annika; Engelholm, Svend Aage

    2011-01-01

    Anal cancer usually presents with a visible or palpable tumour. In this case we describe a 54-year old man diagnosed with Cancer of Unknown Primary (CUP) with a single inguinal node as the only finding. Thorough examination failed to identify any primary tumour. The patient was treated with lymph...... node dissection and not until nearly two years after initial diagnosis, was the primary tumour found, and the patient was diagnosed with anal cancer. The patient was treated with chemoradiotherapy and 45 months after initial diagnosis there is still no sign of relapse. This case illustrates, that anal...

  1. Fault tolerant control of wind turbines using unknown input observers

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2012-01-01

    This paper presents a scheme for accommodating faults in the rotor and generator speed sensors in a wind turbine. These measured values are important both for the wind turbine controller as well as the supervisory control of the wind turbine. The scheme is based on unknown input observers, which ...... are also used to detect and isolate these faults. The scheme is tested on a known benchmark for FDI and FTC of wind turbines. Tests on this benchmark model show a clear potential of the proposed scheme....

  2. New entrants and overcapacity: lessons from regional aircraft manufacturing

    NARCIS (Netherlands)

    Steenhuis, H.J.; de Bruijn, E.J.; Heerkens, Johannes M.G.

    2010-01-01

    The commercial aircraft manufacturing industry has been largely dominated by the advanced economies in North America and Western Europe. During recent decades, several emerging economies have invested heavily in the commercial aircraft industry, notably in regional aircraft manufacturing. This paper

  3. Range image registration using a photometric metric under unknown lighting.

    Science.gov (United States)

    Thomas, Diego; Sugimoto, Akihiro

    2013-09-01

    Based on the spherical harmonics representation of image formation, we derive a new photometric metric for evaluating the correctness of a given rigid transformation aligning two overlapping range images captured under unknown, distant, and general illumination. We estimate the surrounding illumination and albedo values of points of the two range images from the point correspondences induced by the input transformation. We then synthesize the color of both range images using albedo values transferred using the point correspondences to compute the photometric reprojection error. This way allows us to accurately register two range images by finding the transformation that minimizes the photometric reprojection error. We also propose a practical method using the proposed photometric metric to register pairs of range images devoid of salient geometric features, captured under unknown lighting. Our method uses a hypothesize-and-test strategy to search for the transformation that minimizes our photometric metric. Transformation candidates are efficiently generated by employing the spherical representation of each range image. Experimental results using both synthetic and real data demonstrate the usefulness of the proposed metric.

  4. Shading-based Surface Detail Recovery under General Unknown Illumination.

    Science.gov (United States)

    Xu, Di; Duan, Qi; Zheng, Jianmin; Zhang, Juyong; Cai, Jianfei; Cham, Tat-Jen

    2017-02-17

    Reconstructing the shape of a 3D object from multi-view images under unknown, general illumination is a fundamental problem in computer vision and high quality reconstruction is usually challenging especially when fine detail is needed and the albedo of the object is non-uniform. This paper introduces vertex overall illumination vectors to model the illumination effect and presents a total variation (TV) based approach for recovering surface details using shading and multi-view stereo (MVS). Behind the approach are the two important observations: (1) the illumination over the surface of an object often appears to be piece wise smooth and (2) the recovery of surface orientation is not sufficient for reconstructing the surface, which was often overlooked previously. Thus we propose to use TV to regularize the overall illumination vectors and use visual hull to constrain partial vertices. The reconstruction is formulated as a constrained TV-minimization problem that simultaneously treats the shape and illumination vectors as unknowns. An augmented Lagrangian method is proposed to quickly solve the TV-minimization problem. As a result, our approach is robust, stable and is able to efficiently recover high quality of surface details even when starting with a coarse model obtained using MVS. These advantages are demonstrated by extensive experiments on the state-of-the-art MVS database, which includes challenging objects with varying albedo.

  5. The random exploration graph for optimal exploration of unknown environments

    Directory of Open Access Journals (Sweden)

    Alfredo Toriz Palacios

    2017-01-01

    Full Text Available The exploration of an unknown environment by a robot system is a well-studied problem in robotics; however, although many of the proposals made in this field represent efficient tools in terms of exploration paradigm, most of them are not efficient for time critical applications since the robot may visit the same place more than once during backtracking. In this way and considering these limitations, this article presents a novel approach called the random exploration graph, which addresses the problem of exploring unknown environments by building a graph structure created incrementally by the random choice of the free frontier in the observation range of the robot. In addition, the random exploration graph algorithm uses a new concept called “frontier control” introduced in this work, used to store nodes left behind in the graph structure that have not been fully explored and that will be used to guide the exploration process in an efficient way, when the algorithm needs to go back to previously visited areas to continue exploration. The frontier control concept next to the versatility of the graph structure used for the exploration process is the main contribution of this work.

  6. Reactive Path Planning Approach for Docking Robots in Unknown Environment

    Directory of Open Access Journals (Sweden)

    Peng Cui

    2017-01-01

    Full Text Available Autonomous robots need to be recharged and exchange information with the host through docking in the long-distance tasks. Therefore, feasible path is required in the docking process to guide the robot and adjust its pose. However, when there are unknown obstacles in the work area, it becomes difficult to determine the feasible path for docking. This paper presents a reactive path planning approach named Dubins-APF (DAPF to solve the path planning problem for docking in unknown environment with obstacles. In this proposed approach the Dubins curves are combined with the designed obstacle avoidance potential field to plan the feasible path. Firstly, an initial path is planned and followed according to the configurations of the robot and the docking station. Then when the followed path is evaluated to be infeasible, the intermediate configuration is calculated as well as the replanned path based on the obstacle avoidance potential field. The robot will be navigated to the docking station with proper pose eventually via the DAPF approach. The proposed DAPF approach is efficient and does not require the prior knowledge about the environment. Simulation results are given to validate the effectiveness and feasibility of the proposed approach.

  7. Three-dimensional cinematography with control object of unknown shape.

    Science.gov (United States)

    Dapena, J; Harman, E A; Miller, J A

    1982-01-01

    A technique for reconstruction of three-dimensional (3D) motion which involves a simple filming procedure but allows the deduction of coordinates in large object volumes was developed. Internal camera parameters are calculated from measurements of the film images of two calibrated crosses while external camera parameters are calculated from the film images of points in a control object of unknown shape but at least one known length. The control object, which includes the volume in which the activity is to take place, is formed by a series of poles placed at unknown locations, each carrying two targets. From the internal and external camera parameters, and from locations of the images of point in the films of the two cameras, 3D coordinates of the point can be calculated. Root mean square errors of the three coordinates of points in a large object volume (5m x 5m x 1.5m) were 15 mm, 13 mm, 13 mm and 6 mm, and relative errors in lengths averaged 0.5%, 0.7% and 0.5%, respectively.

  8. Learned navigation in unknown terrains: A retraction method

    Science.gov (United States)

    Rao, Nageswara S. V.; Stoltzfus, N.; Iyengar, S. Sitharama

    1989-01-01

    The problem of learned navigation of a circular robot R, of radius delta (is greater than or equal to 0), through a terrain whose model is not a-priori known is considered. Two-dimensional finite-sized terrains populated by an unknown (but, finite) number of simple polygonal obstacles are also considered. The number and locations of the vertices of each obstacle are unknown to R. R is equipped with a sensor system that detects all vertices and edges that are visible from its present location. In this context two problems are covered. In the visit problem, the robot is required to visit a sequence of destination points, and in the terrain model acquisition problem, the robot is required to acquire the complete model of the terrain. An algorithmic framework is presented for solving these two problems using a retraction of the freespace onto the Voronoi diagram of the terrain. Algorithms are then presented to solve the visit problem and the terrain model acquisition problem.

  9. Tracking consensus for nonlinear heterogeneous multi-agent systems subject to unknown disturbances via sliding mode control

    Science.gov (United States)

    Zhang, Xiang; Wang, Jin-Huan; Yang, De-Dong; Xu, Yong

    2017-06-01

    Not Available Project supported by the National Natural Science Foundation of China (Grant No. 61203142) and the Natural Science Foundation of Hebei Province, China (Grant Nos. F2014202206 and F2017202009).

  10. Point-Mass Aircraft Trajectory Prediction Using a Hierarchical, Highly-Adaptable Software Design

    Science.gov (United States)

    Karr, David A.; Vivona, Robert A.; Woods, Sharon E.; Wing, David J.

    2017-01-01

    A highly adaptable and extensible method for predicting four-dimensional trajectories of civil aircraft has been developed. This method, Behavior-Based Trajectory Prediction, is based on taxonomic concepts developed for the description and comparison of trajectory prediction software. A hierarchical approach to the "behavioral" layer of a point-mass model of aircraft flight, a clear separation between the "behavioral" and "mathematical" layers of the model, and an abstraction of the methods of integrating differential equations in the "mathematical" layer have been demonstrated to support aircraft models of different types (in particular, turbojet vs. turboprop aircraft) using performance models at different levels of detail and in different formats, and promise to be easily extensible to other aircraft types and sources of data. The resulting trajectories predict location, altitude, lateral and vertical speeds, and fuel consumption along the flight path of the subject aircraft accurately and quickly, accounting for local conditions of wind and outside air temperature. The Behavior-Based Trajectory Prediction concept was implemented in NASA's Traffic Aware Planner (TAP) flight-optimizing cockpit software application.

  11. Multidisciplinary Shape Optimization of a Composite Blended Wing Body Aircraft

    Science.gov (United States)

    Boozer, Charles Maxwell

    A multidisciplinary shape optimization tool coupling aerodynamics, structure, and performance was developed for battery powered aircraft. Utilizing high-fidelity computational fluid dynamics analysis tools and a structural wing weight tool, coupled based on the multidisciplinary feasible optimization architecture; aircraft geometry is modified in the optimization of the aircraft's range or endurance. The developed tool is applied to three geometries: a hybrid blended wing body, delta wing UAS, the ONERA M6 wing, and a modified ONERA M6 wing. First, the optimization problem is presented with the objective function, constraints, and design vector. Next, the tool's architecture and the analysis tools that are utilized are described. Finally, various optimizations are described and their results analyzed for all test subjects. Results show that less computationally expensive inviscid optimizations yield positive performance improvements using planform, airfoil, and three-dimensional degrees of freedom. From the results obtained through a series of optimizations, it is concluded that the newly developed tool is both effective at improving performance and serves as a platform ready to receive additional performance modules, further improving its computational design support potential.

  12. Large-scale design of supersonic aircraft via collaborative optimization

    Science.gov (United States)

    Manning, Valerie Michelle

    The design of supersonic aircraft requires complex analysis in multiple disciplines, posing a challenge for multidisciplinary optimization methods. In this thesis, collaborative optimization, a design architecture developed to solve large-scale multidisciplinary design problems, is applied to the design of supersonic transport concepts. Collaborative optimization, takes advantage of natural disciplinary segmentation to facilitate parallel execution of design tasks. Discipline-specific design optimization proceeds while a coordinating mechanism ensures progress toward an optimum and compatibility between disciplinary designs. Two concepts for supersonic aircraft are investigated: a conventional delta-wing design and a natural laminar flow concept that achieves improved performance by exploiting properties of supersonic flow to delay boundary layer transition. The work involves the development of aerodynamics and structural analyses, and integration within a collaborative optimization framework. Response surface estimation and reduced basis modeling were used to reduce the computational expense of the optimization and to ensure smooth analytic gradients. Both design problems converged successfully. In each problem, the system optimizer minimized aircraft take-off weight with respect to global and disciplinary design variables, subject to aeroelastic and performance constraints. In previous work, the method successfully solved simple and medium fidelity problems. The current work demonstrates collaborative optimization with large-scale designs using industry-standard analyses. The research shows that collaborative optimization is a valuable method for large-scale design, ready for real-world implementation.

  13. Analysis of operational limit of an aircraft: An aeroelastic approach

    Science.gov (United States)

    Hasan, Md. Mehedi; Hassan, M. D. Mehedi; Sarrowar, S. M. Bayazid; Faisal, Kh. Md.; Ahmed, Sheikh Reaz, Dr.

    2017-06-01

    In classical theory of elasticity, external loading acting on the body is independent of deformation of the body. But, in aeroelasticity, aerodynamic forces depend on the attitude of the body relative to the flow. Aircraft's are subjected to a range of static loads resulting from equilibrium or steady flight maneuvers such as coordinated level turn, steady pitch and bank rate, steady and level flight. Interaction of these loads with elastic forces of aircraft structure creates some aeroelastic phenomena. In this paper, we have summarized recent developments in the area of aeroelasticity. A numerical approach has been applied for finding divergence speed, a static aeroelastic phenomena, of a typical aircraft. This paper also involves graphical representations of constraints on load factor and bank angle during different steady flight maneuvers taking flexibility into account and comparing it with the value without flexibility. Effect of wing skin thickness, spar web thickness and position of flexural axis of wing on this divergence speed as well as load factor and bank angle has also been observed using MATLAB.

  14. Noise-Induced Building Vibrations Caused by Concorde and Conventional Aircraft Operations at Dulles and Kennedy International Airports

    Science.gov (United States)

    Mayes, W. H.; Stephens, D. G.; Holmes, H. K.; Lewis, R. B.; Holliday, B. G.; Ward, D. W.; Deloach, R.; Cawthorn, J. M.; Finley, T. D.; Lynch, J. W.

    1978-01-01

    Outdoor and indoor noise levels resulting from aircraft flyovers and certain nonaircraft events were recorded, as were the associated vibration levels in the walls, windows, and floors at building test sites. In addition, limited subjective tests were conducted to examine the human detection and annoyance thresholds for building vibration and rattle caused by aircraft noise. Representative peak levels of aircraft noise-induced building vibrations are reported and comparisons are made with structural damage criteria and with vibration levels induced by common domestic events. In addition, results of a pilot study are reported which indicate the human detection threshold for noise-induced floor vibrations.

  15. Uncertainty quantification in computational fluid dynamics and aircraft engines

    CERN Document Server

    Montomoli, Francesco; D'Ammaro, Antonio; Massini, Michela; Salvadori, Simone

    2015-01-01

    This book introduces novel design techniques developed to increase the safety of aircraft engines. The authors demonstrate how the application of uncertainty methods can overcome problems in the accurate prediction of engine lift, caused by manufacturing error. This in turn ameliorates the difficulty of achieving required safety margins imposed by limits in current design and manufacturing methods. This text shows that even state-of-the-art computational fluid dynamics (CFD) are not able to predict the same performance measured in experiments; CFD methods assume idealised geometries but ideal geometries do not exist, cannot be manufactured and their performance differs from real-world ones. By applying geometrical variations of a few microns, the agreement with experiments improves dramatically, but unfortunately the manufacturing errors in engines or in experiments are unknown. In order to overcome this limitation, uncertainty quantification considers the probability density functions of manufacturing errors...

  16. 14 CFR 121.538 - Aircraft security.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Aircraft security. 121.538 Section 121.538 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS..., FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.538 Aircraft security. Certificate holders...

  17. Bayesian Inference of Aircraft Initial Mass

    NARCIS (Netherlands)

    Sun, J.; Ellerbroek, J.; Hoekstra, J.M.

    2017-01-01

    Aircraft mass is a crucial piece of information for studies on aircraft performance, trajectory prediction, and many other ATM topics. However, it is a common challenge for researchers who have no access to this proprietary information. Previously, several studies have proposed methods to estimates

  18. Cycle Counting Methods of the Aircraft Engine

    Science.gov (United States)

    Fedorchenko, Dmitrii G.; Novikov, Dmitrii K.

    2016-01-01

    The concept of condition-based gas turbine-powered aircraft operation is realized all over the world, which implementation requires knowledge of the end-of-life information related to components of aircraft engines in service. This research proposes an algorithm for estimating the equivalent cyclical running hours. This article provides analysis…

  19. Aircraft of Today. Aerospace Education I.

    Science.gov (United States)

    Savler, D. S.

    This textbook gives a brief idea about the modern aircraft used in defense and for commercial purposes. Aerospace technology in its present form has developed along certain basic principles of aerodynamic forces. Different parts in an airplane have different functions to balance the aircraft in air, provide a thrust, and control the general…

  20. AIRCRAFT SHELTER-DICE THROW Data Report

    Science.gov (United States)

    1977-03-01

    SHELTER-OICE THROW Test Site Layout for 9 AFWL Test Structures 4 AIRCRAFT SHELTER-DICE THROW ANFO Charge Configuration 10 5 Upgraded Aircraft Shelter...approximately 150 meters (500 ft). This shelter is the same as Shelter "$", but with a heavy overlay of concrete. As with Shelter "B", end walls were

  1. Aircraft Manufacturing Occupations. Aviation Careers Series.

    Science.gov (United States)

    Zaharevitz, Walter

    This booklet, one in a series on aviation careers, outlines the variety of careers available in the aircraft manufacturing industry. The first part of the booklet provides general information about careers in the aerospace industry (of which aircraft manufacturing is one part), including the numbers of various types of workers employed in those…

  2. Study on Impedance Characteristics of Aircraft Cables

    Directory of Open Access Journals (Sweden)

    Weilin Li

    2016-01-01

    Full Text Available Voltage decrease and power loss in distribution lines of aircraft electric power system are harmful to the normal operation of electrical equipment and may even threaten the safety of aircraft. This study investigates how the gap distance (the distance between aircraft cables and aircraft skin and voltage frequency (variable frequency power supply will be adopted for next generation aircraft will affect the impedance of aircraft cables. To be more precise, the forming mechanism of cable resistance and inductance is illustrated in detail and their changing trends with frequency and gap distance are analyzed with the help of electromagnetic theoretical analysis. An aircraft cable simulation model is built with Maxwell 2D and the simulation results are consistent with the conclusions drawn from the theoretical analysis. The changing trends of the four core parameters of interest are analyzed: resistance, inductance, reactance, and impedance. The research results can be used as reference for the applications in Variable Speed Variable Frequency (VSVF aircraft electric power system.

  3. A Turbo-Brayton Cryocooler for Aircraft Superconducting Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hybrid turboelectric aircraft with gas turbines driving electric generators connected to electric propulsion motors have the potential to transform the aircraft...

  4. An Instrument to Measure Aircraft Sulfate Particle Emissions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aircraft particle emissions contribute a modest, but growing, portion of the overall particle emissions budget. Characterizing aircraft particle emissions is...

  5. Partially Turboelectric Aircraft Drive Key Performance Parameters

    Science.gov (United States)

    Jansen, Ralph H.; Duffy, Kirsten P.; Brown, Gerald V.

    2017-01-01

    The purpose of this paper is to propose electric drive specific power, electric drive efficiency, and electrical propulsion fraction as the key performance parameters for a partially turboelectric aircraft power system and to investigate their impact on the overall aircraft performance. Breguet range equations for a base conventional turbofan aircraft and a partially turboelectric aircraft are found. The benefits and costs that may result from the partially turboelectric system are enumerated. A break even analysis is conducted to find the minimum allowable electric drive specific power and efficiency, for a given electrical propulsion fraction, that can preserve the range, fuel weight, operating empty weight, and payload weight of the conventional aircraft. Current and future power system performance is compared to the required performance to determine the potential benefit.

  6. Pilot Preferences on Displayed Aircraft Control Variables

    Science.gov (United States)

    Trujillo, Anna C.; Gregory, Irene M.

    2013-01-01

    The experiments described here explored how pilots want available maneuver authority information transmitted and how this information affects pilots before and after an aircraft failure. The aircraft dynamic variables relative to flight performance were narrowed to energy management variables. A survey was conducted to determine what these variables should be. Survey results indicated that bank angle, vertical velocity, and airspeed were the preferred variables. Based on this, two displays were designed to inform the pilot of available maneuver envelope expressed as bank angle, vertical velocity, and airspeed. These displays were used in an experiment involving control surface failures. Results indicate the displayed limitations in bank angle, vertical velocity, and airspeed were helpful to the pilots during aircraft surface failures. However, the additional information did lead to a slight increase in workload, a small decrease in perceived aircraft flying qualities, and no effect on aircraft situation awareness.

  7. Performance and benefits of an advanced technology supersonic cruise aircraft

    Science.gov (United States)

    Fitzsimmons, R. D.

    1976-01-01

    The results of four years research on technology are synthesized in an advanced supersonic cruise aircraft design. Comparisons are presented with the former United States SST and the British-French Concorde, including aerodynamic efficiency, propulsion efficiency, weight efficiency, and community noise. Selected trade study results are presented on the subjects of design cruise Mach number, engine cycle selection, and noise suppression. The critical issue of program timing is addressed and some observations made regarding the impact that timing has on engine selection and minimization of program risk.

  8. PHYLOGENOMICS - GUIDED VALIDATION OF FUNCTION FOR CONSERVED UNKNOWN GENES

    Energy Technology Data Exchange (ETDEWEB)

    V, DE CRECY-LAGARD; D, HANSON A

    2012-01-03

    Identifying functions for all gene products in all sequenced organisms is a central challenge of the post-genomic era. However, at least 30-50% of the proteins encoded by any given genome are of unknown function, or wrongly or vaguely annotated. Many of these 'unknown' proteins are common to prokaryotes and plants. We accordingly set out to predict and experimentally test the functions of such proteins. Our approach to functional prediction is integrative, coupling the extensive post-genomic resources available for plants with comparative genomics based on hundreds of microbial genomes, and functional genomic datasets from model microorganisms. The early phase is computer-assisted; later phases incorporate intellectual input from expert plant and microbial biochemists. The approach thus bridges the gap between automated homology-based annotations and the classical gene discovery efforts of experimentalists, and is much more powerful than purely computational approaches to identifying gene-function associations. Among Arabidopsis genes, we focused on those (2,325 in total) that (i) are unique or belong to families with no more than three members, (ii) are conserved between plants and prokaryotes, and (iii) have unknown or poorly known functions. Computer-assisted selection of promising targets for deeper analysis was based on homology .. independent characteristics associated in the SEED database with the prokaryotic members of each family, specifically gene clustering and phyletic spread, as well as availability of functional genomics data, and publications that could link candidate families to general metabolic areas, or to specific functions. In-depth comparative genomic analysis was then performed for about 500 top candidate families, which connected ~55 of them to general areas of metabolism and led to specific functional predictions for a subset of ~25 more. Twenty predicted functions were experimentally tested in at least one prokaryotic organism

  9. The influence of ozone on self-evaluation of symptoms in a simulated aircraft cabin

    DEFF Research Database (Denmark)

    Strøm-Tejsen, Peter; Weschler, Charles J.; Wargocki, Pawel

    2008-01-01

    Simulated 4-h flights were carried out in a realistic model of a three-row, 21-seat section of an aircraft cabin that was reconstructed inside a climate chamber. Twenty-nine female subjects, age 19-27 years, were split into two groups; each group was exposed to four conditions: two levels of ozone (...

  10. The influence of activities and duration on comfort and discomfort development in time of aircraft passengers

    NARCIS (Netherlands)

    Hiemstra-Van Mastright, S.; Meyenborg, I.; Hoogenhout, M.

    2016-01-01

    BACKGROUND: Discomfort increases when duration of sitting is longer. Aircraft passengers are subjected to prolonged sitting in restricted postures, which can cause discomfort. OBJECTIVE: To examine the relationship between duration of sitting and development of discomfort, as well as the influence

  11. Neck injury criteria and certification procedure for side-facing aircraft seats

    NARCIS (Netherlands)

    Philippens, M.M.G.M.; Forbes, P.A.; Wismans, J.S.H.M.; DeWeese, R.; Moorcroft, D.

    2011-01-01

    This report documents research started in 2002 that identified the potential need for explicit neck injury criteria and tolerances for certification of side-facing seats in aircraft. Laboratory sled tests with full-body postmortem human subjects proved that there is a substantial risk for serious

  12. Cosmic radiation exposure of aircraft crew: compilation of measured and calculated data

    Czech Academy of Sciences Publication Activity Database

    Lindborg, L.; Bartlett, D.; Beck, P.; McAulay, I.; Schnuer, K.; Schraube, H.; Spurný, František

    2004-01-01

    Roč. 110, 1-4 (2004), s. 417-422 ISSN 0144-8420 Grant - others:EC project(XE) FIGM-CT2000-00068 Institutional research plan: CEZ:AV0Z1048901 Keywords : cosmic radiation exposure * aircraft crew * measurement Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.617, year: 2003

  13. Distributed Multisensor Data Fusion under Unknown Correlation and Data Inconsistency

    Directory of Open Access Journals (Sweden)

    Muhammad Abu Bakr

    2017-10-01

    Full Text Available The paradigm of multisensor data fusion has been evolved from a centralized architecture to a decentralized or distributed architecture along with the advancement in sensor and communication technologies. These days, distributed state estimation and data fusion has been widely explored in diverse fields of engineering and control due to its superior performance over the centralized one in terms of flexibility, robustness to failure and cost effectiveness in infrastructure and communication. However, distributed multisensor data fusion is not without technical challenges to overcome: namely, dealing with cross-correlation and inconsistency among state estimates and sensor data. In this paper, we review the key theories and methodologies of distributed multisensor data fusion available to date with a specific focus on handling unknown correlation and data inconsistency. We aim at providing readers with a unifying view out of individual theories and methodologies by presenting a formal analysis of their implications. Finally, several directions of future research are highlighted.

  14. Distributed Multisensor Data Fusion under Unknown Correlation and Data Inconsistency.

    Science.gov (United States)

    Bakr, Muhammad Abu; Lee, Sukhan

    2017-10-27

    The paradigm of multisensor data fusion has been evolved from a centralized architecture to a decentralized or distributed architecture along with the advancement in sensor and communication technologies. These days, distributed state estimation and data fusion has been widely explored in diverse fields of engineering and control due to its superior performance over the centralized one in terms of flexibility, robustness to failure and cost effectiveness in infrastructure and communication. However, distributed multisensor data fusion is not without technical challenges to overcome: namely, dealing with cross-correlation and inconsistency among state estimates and sensor data. In this paper, we review the key theories and methodologies of distributed multisensor data fusion available to date with a specific focus on handling unknown correlation and data inconsistency. We aim at providing readers with a unifying view out of individual theories and methodologies by presenting a formal analysis of their implications. Finally, several directions of future research are highlighted.

  15. An Efficient Algorithm for Direction Finding against Unknown Mutual Coupling

    Directory of Open Access Journals (Sweden)

    Weijiang Wang

    2014-10-01

    Full Text Available In this paper, an algorithm of direction finding is proposed in the presence of unknown mutual coupling. The preliminary direction of arrival (DOA is estimated using the whole array for high resolution. Further refinement can then be conducted by estimating the angularly dependent coefficients (ADCs with the subspace theory. The mutual coupling coefficients are finally determined by solving the least squares problem with all of the ADCs utilized without discarding any. Simulation results show that the proposed method can achieve better performance at a low signal-to-noise ratio (SNR with a small-sized array and is more robust, compared with the similar processes employing the initial DOA estimation and further improvement iteratively.

  16. An efficient algorithm for direction finding against unknown mutual coupling.

    Science.gov (United States)

    Wang, Weijiang; Ren, Shiwei; Ding, Yingtao; Wang, Haoyu

    2014-10-24

    In this paper, an algorithm of direction finding is proposed in the presence of unknown mutual coupling. The preliminary direction of arrival (DOA) is estimated using the whole array for high resolution. Further refinement can then be conducted by estimating the angularly dependent coefficients (ADCs) with the subspace theory. The mutual coupling coefficients are finally determined by solving the least squares problem with all of the ADCs utilized without discarding any. Simulation results show that the proposed method can achieve better performance at a low signal-to-noise ratio (SNR) with a small-sized array and is more robust, compared with the similar processes employing the initial DOA estimation and further improvement iteratively.

  17. Alternate Location Method of a Robot Team in Unknown Environment

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-zhong; LIU Jing-jing

    2008-01-01

    The alternate location method of a robot team is proposed. Three of the robots are kept still as beacon robots, not always the same ones, while the others are regarded as mobile robots. The mobile robots alternatively measure the distance between one of them and three beacon robots with ultrasonic measurement module. The distance data are combined with its dead-reckoning information using iterated extended Kalman filter(IEKF) to realize the optimal estimate of its position. According to the condition the future beacon robots positions should be desired ones, the target function and the nonlinear constrain equations are set up which are used by nonlinear optimization algorithm to estimate the position of the future beacon robots. By alternately changing the robots roles as active beacon, the alternate location in unknown environment can be realized. Process and result of the simulation test are given and the position estimation error is within±10mm, which proves the validity of this method.

  18. Impact of CT in patients with sepsis of unknown origin

    Energy Technology Data Exchange (ETDEWEB)

    Barkhausen, J.; Stoeblen, F.; Mueller, R.D. [University Hospital Essen (Germany). Dept. of Radiology; Dominguez-Fernandez, E. [University Hospital Essen (Germany). Dept. of General Surgery; Henseke, P. [Nycomed-Amersham Arzneimittel GmbH, Muenchen (Germany)

    1999-09-01

    Purpose: To evaluate the diagnostic relevance of CT in patients with sepsis of unknown origin. Material and Methods: Sixty-three consecutive intensive care patients with suspicion of an abscess and negative or inconclusive previous radiological examinations were included. CT was performed using the helical technique. A total of 45 abdominal and 38 chest examinations were evaluated. Results: 5/38 examinations of the chest revealed the source of sepsis (pleural empyema 2, lung abscess 1, mediastinitis 1, retrosternal abscess 1). 7/45 abdominal CT examinations showed the source of sepsis (intraabdominal abscess 2, hepatic abscess 3, intestinal perforation 1, gangrenous colitis 1). Conclusion: CT is useful for the evaluation of patients with fever or sepsis without a known source. Due to the detection of a spetic focus by CT, 19% of the patients in our study could be immediately referred to causal therapy as percutaneous drainage or surgery. (orig.)

  19. Autonomous Underwater Navigation and Optical Mapping in Unknown Natural Environments

    Directory of Open Access Journals (Sweden)

    Juan David Hernández

    2016-07-01

    Full Text Available We present an approach for navigating in unknown environments while, simultaneously, gathering information for inspecting underwater structures using an autonomous underwater vehicle (AUV. To accomplish this, we first use our pipeline for mapping and planning collision-free paths online, which endows an AUV with the capability to autonomously acquire optical data in close proximity. With that information, we then propose a reconstruction pipeline to create a photo-realistic textured 3D model of the inspected area. These 3D models are also of particular interest to other fields of study in marine sciences, since they can serve as base maps for environmental monitoring, thus allowing change detection of biological communities and their environment over time. Finally, we evaluate our approach using the Sparus II, a torpedo-shaped AUV, conducting inspection missions in a challenging, real-world and natural scenario.

  20. Autonomous Underwater Navigation and Optical Mapping in Unknown Natural Environments.

    Science.gov (United States)

    Hernández, Juan David; Istenič, Klemen; Gracias, Nuno; Palomeras, Narcís; Campos, Ricard; Vidal, Eduard; García, Rafael; Carreras, Marc

    2016-07-26

    We present an approach for navigating in unknown environments while, simultaneously, gathering information for inspecting underwater structures using an autonomous underwater vehicle (AUV). To accomplish this, we first use our pipeline for mapping and planning collision-free paths online, which endows an AUV with the capability to autonomously acquire optical data in close proximity. With that information, we then propose a reconstruction pipeline to create a photo-realistic textured 3D model of the inspected area. These 3D models are also of particular interest to other fields of study in marine sciences, since they can serve as base maps for environmental monitoring, thus allowing change detection of biological communities and their environment over time. Finally, we evaluate our approach using the Sparus II, a torpedo-shaped AUV, conducting inspection missions in a challenging, real-world and natural scenario.

  1. An active damper to suppress multiple resonances with unknown frequencies

    DEFF Research Database (Denmark)

    Wang, Xiongfei; Blaabjerg, Frede; Liserre, Marco

    2014-01-01

    The increasing use of power electronics devices tends to aggravate high-frequency harmonics and trigger resonances across a wide frequency range into power systems. This paper presents an active damper to suppress multiple resonances with unknown frequencies. The active damper is realized by a high......-bandwidth power converter that can selectively dampen out the wideband resonances. A cascaded adaptive notch filter structure is proposed to detect the frequencies of resonances, which makes the active damper different from the resistive-active power filter for harmonic resonance suppression. The performance...... of the active damper is validated by implementing it to suppress the resonances in a grid-connected inverter with a long power cable. The results show that the active damper can become a promising approach to stabilizing the future power electronics based power systems....

  2. A Physician’s Nightmare: Fever of Unknown Origin

    Directory of Open Access Journals (Sweden)

    Sana Din

    2016-01-01

    Full Text Available Fever of unknown origin (FUO remains to be a challenge despite advancement in diagnostic technologies and procedures. FUO is considered when fever presents intermittently without an explanation. It has been linked to various etiologies, which makes it difficult to diagnose. We present the case of 18-month-old female with recurrent fever, splenomegaly, abdominal pain, and constipation. The workup for her symptoms revealed wandering spleen. Wandering spleen is a result from excessive laxity or absence of splenic ligaments. The patient underwent splenectomy and was advised to continue on Senna, Miralax, and high fiber diet. Her mother reported that the fever is no longer present and there is marked improvement in her constipation and abdominal pain after splenectomy.

  3. Villitis of unknown aetiology: correlation of recurrence with clinical outcome.

    LENUS (Irish Health Repository)

    Feeley, L

    2010-01-01

    Villitis of unknown aetiology (VUA) is associated with adverse pregnancy outcome. Consequently, an ability to predict recurrence could be clinically relevant. We examined placentas where villitis was diagnosed in a previous pregnancy to establish the risk of recurrence and outcome. A total of 304 cases of VUA were diagnosed in our laboratory over a 4-year period. Subsequently, 19 of this cohort had a second placenta examined histologically. Recurrence and clinical outcome were recorded. Villitis recurred in 7 of 19 cases (37%). There was a high level of adverse pregnancy outcome in this cohort overall, characterised by small for gestational age infants and stillbirth, particularly in cases with high-grade villitis. We identified recurrent villitis more frequently than previously reported. Our findings confirm an association between high-grade villitis and poor outcome. Adequately powered prospective studies are required to determine if enhanced surveillance of subsequent pregnancies is indicated following a diagnosis of villitis.

  4. A Brief Introduction on Mystery, the Unknown, Surprise

    Directory of Open Access Journals (Sweden)

    Sean Scanlan

    2012-03-01

    Full Text Available In this age of globalization, this age of so many ways to know—and so many ways to know things so quickly—it is both satisfying and deeply unnerving to come upon things and events that are really hard to understand, things and events so shocking or strange or mysterious, that they seem Unknown. Perhaps even unknowable. The first note of NANO Issue 2 focuses on an unsolved murder and reveals a mystery that is confounding, creepy, and yet oddly compelling. In “Karr’s Kill Cult: Virtual Cults and Pseudo-Killing in the Digital Age,” Jeremy Biles and Brian Collins explore the edges of where cyber-crime threatens to turn real—and vice versa. In the second note, Jennifer Ballengee compares Oedipus at Colonus with Don DeLillo’s Falling Man.

  5. The Difficulty of Sexing Skeletons from Unknown Populations

    Directory of Open Access Journals (Sweden)

    Ingrid Sierp

    2015-01-01

    Full Text Available Determination of sex from skeletal remains is performed using a number of methods developed by biological anthropology. They must be evaluated for consistency and for their performance in a forensic setting. Twenty skeletons of varied provenance had their sex determined by 15 existing methods of forensic anthropology (7 metric and 8 morphological. The methods were evaluated for their consistency in determination of sex. No single individual was identified as belonging to one sex exclusively. Ambiguous results were obtained by metric methods for fourteen individuals (70% and by morphological methods for only five individuals (25% (Chi-squared = 4.3, df = 1, P<0.05. Methods which use the size of bones as an indicator of sex perform poorly on skeletal remains of individuals of unknown provenance. Methods which combine morphologic and metric techniques, that is, geometric morphometric analysis, may result in greater levels of consistency.

  6. Modal Parameter Identification from Responses of General Unknown Random Inputs

    DEFF Research Database (Denmark)

    Ibrahim, S. R.; Asmussen, J. C.; Brincker, Rune

    1996-01-01

    Modal parameter identification from ambient responses due to a general unknown random inputs is investigated. Existing identification techniques which are based on assumptions of white noise and or stationary random inputs are utilized even though the inputs conditions are not satisfied....... This is accomplished via adding. In cascade. A force cascade conversion to the structures system under consideration. The input to the force conversion system is white noise and the output of which is the actual force(s) applied to the structure. The white noise input(s) and the structures responses are then used...... to identify the compined system. Identification results are then sorted as either structural parameters or input force(s) characteristics....

  7. Angiotropic large cell lymphoma presenting as fever of unknown origin.

    Science.gov (United States)

    Kuvliev, E; Glamour, T; Shekar, R; West, B C

    1999-04-01

    Fever has never before been described as the chief complaint and major finding in angiotropic large cell lymphoma (ALCL). ALCL is a rare and usually fatal intravascular tumor characterized by a widespread proliferation of malignant mononuclear cells within vessels of small caliber, causing their blockage. The majority present as high-grade, B-cell lymphomas with a predilection for the central nervous system and the skin. We report a 61-year-old woman who presented with a fever of unknown origin (FUO) that lasted 9 weeks from onset to death. To our knowledge, this is the first case of ALCL to present solely as a FUO, and the second case of ALCL to be diagnosed by muscle biopsy. We suggest that this rare malignancy (ALCL) be considered in the differential diagnosis of FUO.

  8. Obstacle Avoidance for Unmanned Undersea Vehicle in Unknown Unstructured Environment

    Directory of Open Access Journals (Sweden)

    Zheping Yan

    2013-01-01

    Full Text Available To avoid obstacle in the unknown environment for unmanned undersea vehicle (UUV, an obstacle avoiding system based on improved vector field histogram (VFH is designed. Forward looking sonar is used to detect the environment, and the divisional sonar modal is applied to deal with the measure uncertainty. To adapt to the VFH, rolling occupancy grids are used for the map building, and high accuracy details of local environment are obtained. The threshold is adaptively adjusted by the statistic of obstacles to solve the problem that VFH is sensitive to threshold. To improve the environment adaptability, the hybrid-behaviors strategy is proposed, which selects the optimal avoidance command according to the motion status and environment character. The simulation shows that UUV could avoid the obstacles fast and escape from the U shape obstacles.

  9. Mobile robot navigation in unknown static environments using ANFIS controller

    Directory of Open Access Journals (Sweden)

    Anish Pandey

    2016-09-01

    Full Text Available Navigation and obstacle avoidance are the most important task for any mobile robots. This article presents the Adaptive Neuro-Fuzzy Inference System (ANFIS controller for mobile robot navigation and obstacle avoidance in the unknown static environments. The different sensors such as ultrasonic range finder sensor and sharp infrared range sensor are used to detect the forward obstacles in the environments. The inputs of the ANFIS controller are obstacle distances obtained from the sensors, and the controller output is a robot steering angle. The primary objective of the present work is to use ANFIS controller to guide the mobile robot in the given environments. Computer simulations are conducted through MATLAB software and implemented in real time by using C/C++ language running Arduino microcontroller based mobile robot. Moreover, the successful experimental results on the actual mobile robot demonstrate the effectiveness and efficiency of the proposed controller.

  10. Blind reconstruction of sparse images with unknown point spread function

    Science.gov (United States)

    Herrity, Kyle; Raich, Raviv; Hero, Alfred O., III

    2008-02-01

    We consider the image reconstruction problem when the original image is assumed to be sparse and when partial knowledge of the point spread function (PSF) is available. In particular, we are interested in recovering the magnetization density given magnetic resonance force microscopy (MRFM) data, and we present an iterative alternating minimization algorithm (AM) to solve this problem. A smoothing penalty is introduced on allowable PSFs to improve the reconstruction. Simulations demonstrate its performance in reconstructing both the image and unknown point spread function. In addition, we develop an optimization transfer approach to solving a total variation (TV) blind deconvolution algorithm presented in a paper by Chan and Wong. We compare the performance of the AM algorithm to the blind TV algorithm as well as to a TV based majorization-minimization algorithm developed by Figueiredo et al.

  11. Cancer of unknown primary origin: a case report

    Directory of Open Access Journals (Sweden)

    Elisa De Carlo

    2013-03-01

    Full Text Available Carcinoma of unknown primary origin (CUP accounts for 2-10% of all malignancies. The apparent absence of the primary tumour, the development of early, uncommon systemic metastases and the resistance to therapy and poor prognosis are hallmarks of this heterogeneous clinical entity and are a challenge for physicians. The diagnostic workup of patients with CUP includes a large amount of histopathological examination, as well as the use of imaging techniques that often fail to identify the primary tumour. Therefore, the optimal workup and treatment for these patients remains to be determined. Molecular diagnostic tools, such as DNA microarray analysis, could help in the search for "lost" CUP origin and guide the further treatment approach. We report the case of a 66-year-old man, with mediastinal lymph nodes metastasis of carcinoma and neurological syndrome with diplopia and balance disorders, in which many exams have been performed without finding the primary tumour.

  12. Smooth extrapolation of unknown anatomy via statistical shape models

    Science.gov (United States)

    Grupp, R. B.; Chiang, H.; Otake, Y.; Murphy, R. J.; Gordon, C. R.; Armand, M.; Taylor, R. H.

    2015-03-01

    Several methods to perform extrapolation of unknown anatomy were evaluated. The primary application is to enhance surgical procedures that may use partial medical images or medical images of incomplete anatomy. Le Fort-based, face-jaw-teeth transplant is one such procedure. From CT data of 36 skulls and 21 mandibles separate Statistical Shape Models of the anatomical surfaces were created. Using the Statistical Shape Models, incomplete surfaces were projected to obtain complete surface estimates. The surface estimates exhibit non-zero error in regions where the true surface is known; it is desirable to keep the true surface and seamlessly merge the estimated unknown surface. Existing extrapolation techniques produce non-smooth transitions from the true surface to the estimated surface, resulting in additional error and a less aesthetically pleasing result. The three extrapolation techniques evaluated were: copying and pasting of the surface estimate (non-smooth baseline), a feathering between the patient surface and surface estimate, and an estimate generated via a Thin Plate Spline trained from displacements between the surface estimate and corresponding vertices of the known patient surface. Feathering and Thin Plate Spline approaches both yielded smooth transitions. However, feathering corrupted known vertex values. Leave-one-out analyses were conducted, with 5% to 50% of known anatomy removed from the left-out patient and estimated via the proposed approaches. The Thin Plate Spline approach yielded smaller errors than the other two approaches, with an average vertex error improvement of 1.46 mm and 1.38 mm for the skull and mandible respectively, over the baseline approach.

  13. Twelve previously unknown phage genera are ubiquitous in global oceans.

    Science.gov (United States)

    Holmfeldt, Karin; Solonenko, Natalie; Shah, Manesh; Corrier, Kristen; Riemann, Lasse; Verberkmoes, Nathan C; Sullivan, Matthew B

    2013-07-30

    Viruses are fundamental to ecosystems ranging from oceans to humans, yet our ability to study them is bottlenecked by the lack of ecologically relevant isolates, resulting in "unknowns" dominating culture-independent surveys. Here we present genomes from 31 phages infecting multiple strains of the aquatic bacterium Cellulophaga baltica (Bacteroidetes) to provide data for an underrepresented and environmentally abundant bacterial lineage. Comparative genomics delineated 12 phage groups that (i) each represent a new genus, and (ii) represent one novel and four well-known viral families. This diversity contrasts the few well-studied marine phage systems, but parallels the diversity of phages infecting human-associated bacteria. Although all 12 Cellulophaga phages represent new genera, the podoviruses and icosahedral, nontailed ssDNA phages were exceptional, with genomes up to twice as large as those previously observed for each phage type. Structural novelty was also substantial, requiring experimental phage proteomics to identify 83% of the structural proteins. The presence of uncommon nucleotide metabolism genes in four genera likely underscores the importance of scavenging nutrient-rich molecules as previously seen for phages in marine environments. Metagenomic recruitment analyses suggest that these particular Cellulophaga phages are rare and may represent a first glimpse into the phage side of the rare biosphere. However, these analyses also revealed that these phage genera are widespread, occurring in 94% of 137 investigated metagenomes. Together, this diverse and novel collection of phages identifies a small but ubiquitous fraction of unknown marine viral diversity and provides numerous environmentally relevant phage-host systems for experimental hypothesis testing.

  14. Altamira cave Paleolithic paintings harbor partly unknown bacterial communities.

    Science.gov (United States)

    Schabereiter-Gurtner, Claudia; Saiz-Jimenez, Cesareo; Piñar, Guadalupe; Lubitz, Werner; Rölleke, Sabine

    2002-05-21

    Since it has been reported that microorganisms can affect painting pigments, Paleolithic painting microbiology deserves attention. The present study is the first report on the bacterial colonization of the valuable Paleolithic paintings in the famous Altamira cave (Spain). One sample taken from a painting area in the Polychromes Hall was analyzed culture-independently. This was the first time microbiologists were allowed to take sample material directly from Altamira paintings. Identification methods included PCR amplification of 16S rRNA genes (16S rDNA) and community fingerprinting by denaturing gradient gel electrophoresis (DGGE). The applied approach gave insight into a great bacterial taxonomic diversity, and allowed the detection of unexpected and unknown bacteria with potential effects on the conservation of the painting. Regarding the number of 29 visible DGGE bands in the community fingerprint, the numbers of analyzed clones described about 72% of the phylogenetic diversity present in the sample. Thirty-eight percent of the sequences analyzed were phylogenetically most closely related to cultivated bacteria, while the majority (62%) were most closely related to environmental 16S rDNA clones. Bacteria identified in Altamira were related with sequence similarities between 84.8 and 99.4% to members of the cosmopolitan Proteobacteria (52.3%), to members of the Acidobacterium division (23.8%), Cytophaga/Flexibacter/Bacteroides phylum (9.5%), green non-sulfur bacteria (4.8%), Planctomycetales (4.8%) and Actinobacteria (4.8%). The high number of clones most closely related to environmental 16S rDNA clones showed the broad spectrum of unknown and yet to be cultivated bacteria in Altamira cave.

  15. Do supersonic aircraft avoid contrails?

    Directory of Open Access Journals (Sweden)

    A. Stenke

    2008-02-01

    Full Text Available The impact of a potential future fleet of supersonic aircraft on contrail coverage and contrail radiative forcing is investigated by means of simulations with the general circulation model ECHAM4.L39(DLR including a contrail parameterization. The model simulations consider air traffic inventories of a subsonic fleet and of a combined fleet of sub- and supersonic aircraft for the years 2025 and 2050, respectively. In case of the combined fleet, part of the subsonic fleet is replaced by supersonic aircraft. The combined air traffic scenario reveals a reduction in contrail cover at subsonic cruise levels (10 to 12 km in the northern extratropics, especially over the North Atlantic and North Pacific. At supersonic flight levels (18 to 20 km, contrail formation is mainly restricted to tropical regions. Only in winter is the northern extratropical stratosphere above the 100 hPa level cold enough for the formation of contrails. Total contrail coverage is only marginally affected by the shift in flight altitude. The model simulations indicate a global annual mean contrail cover of 0.372% for the subsonic and 0.366% for the combined fleet in 2050. The simulated contrail radiative forcing is most closely correlated to the total contrail cover, although contrails in the tropical lower stratosphere are found to be optically thinner than contrails in the extratropical upper troposphere. The global annual mean contrail radiative forcing in 2050 (2025 amounts to 24.7 mW m−2 (9.4 mW m−2 for the subsonic fleet and 24.2 mW m−2 (9.3 mW m−2 for the combined fleet. A reduction of the supersonic cruise speed from Mach 2.0 to Mach 1.6 leads to a downward shift in contrail cover, but does not affect global mean total contrail cover and contrail radiative forcing. Hence the partial substitution of subsonic air traffic leads to a shift of contrail occurrence from mid to low latitudes, but the resulting change in

  16. Letters to the editors. On the subject of the technical note ''irradiation of unknown pregnancy: review of 17 cases - N. Chahed, A. Mhiri, A.; Gaiigi, S.; Mtimet, S.'' published in radioprotection 35 (4), 519-527 (in French); Lettre a la redaction. A propos de la note technique ''irradiation d'une grossesse meconnue: revue a court terme de 17 cas - Chahed, N.; Mhiri, A.; Gaigi, S.; Mtimet, S.'' parue dans radioprotection 35(4), 519-527

    Energy Technology Data Exchange (ETDEWEB)

    Cordoliani, Y.S. [Hopital Val de Grace, Service Radiologique, 75 - Paris (France)

    2001-06-01

    The I.C.R.P. gives for a malformation risk after irradiation the threshold dose not before 100 m Grays. The radiological examinations that can occur during an unknown pregnancy are broadly smaller than 100 m Grays. It seems that some pregnancy termination have been recommended for examinations with a radiation dose under this threshold. The author recommends to read the document of the French Society of radiology relative to pregnancy and diagnostic irradiation that summarizes the principal situations and the lines to take in the case of an unknown pregnancy irradiation. (N.C.)

  17. 76 FR 6525 - Airworthiness Directives; Cessna Aircraft Company (Type Certificate Previously Held by Columbia...

    Science.gov (United States)

    2011-02-07

    ... Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing (Previously the Lancair... Aircraft Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing (Previously The... Aircraft Company (type certificate previously held by Columbia Aircraft Manufacturing (previously The...

  18. Aircraft wing structure detail design

    Science.gov (United States)

    Sager, Garrett L.; Roberts, Ron; Mallon, Bob; Alameri, Mohamed; Steinbach, Bill

    1993-01-01

    The provisions of this project call for the design of the structure of the wing and carry-through structure for the Viper primary trainer, which is to be certified as a utility category trainer under FAR part 23. The specific items to be designed in this statement of work were Front Spar, Rear Spar, Aileron Structure, Wing Skin, and Fuselage Carry-through Structure. In the design of these parts, provisions for the fuel system, electrical system, and control routing were required. Also, the total weight of the entire wing planform could not exceed 216 lbs. Since this aircraft is to be used as a primary trainer, and the SOW requires a useful life of 107 cycles, it was decided that all of the principle stresses in the structural members would be kept below 10 ksi. The only drawback to this approach is a weight penalty.

  19. Turboprop aircraft against terrorism: a SWOT analysis of turboprop aircraft in CAS operations

    Science.gov (United States)

    Yavuz, Murat; Akkas, Ali; Aslan, Yavuz

    2012-06-01

    Today, the threat perception is changing. Not only for countries but also for defence organisations like NATO, new threat perception is pointing terrorism. Many countries' air forces become responsible of fighting against terorism or Counter-Insurgency (COIN) Operations. Different from conventional warfare, alternative weapon or weapon systems are required for such operatioins. In counter-terrorism operations modern fighter jets are used as well as helicopters, subsonic jets, Unmanned Aircraft Systems (UAS), turboprop aircraft, baloons and similar platforms. Succes and efficiency of the use of these platforms can be determined by evaluating the conditions, the threats and the area together. Obviously, each platform has advantages and disadvantages for different cases. In this research, examples of turboprop aircraft usage against terrorism and with a more general approach, turboprop aircraft for Close Air Support (CAS) missions from all around the world are reviewed. In this effort, a closer look is taken at the countries using turboprop aircraft in CAS missions while observing the fields these aircraft are used in, type of operations, specifications of the aircraft, cost and the maintenance factors. Thus, an idea about the convenience of using these aircraft in such operations can be obtained. A SWOT analysis of turboprop aircraft in CAS operations is performed. This study shows that turboprop aircraft are suitable to be used in counter-terrorism and COIN operations in low threat environment and is cost benefical compared to jets.

  20. Communication to within a fidelity criterion over unknown networks by reduction to reliable communication problems over unknown networks

    CERN Document Server

    Agarwal, Mukul

    2010-01-01

    Consider a scenerio where various users want to communicate with each other over an unknown network to within a fidelity criterion. Thus, there are various users. Each user has a source that it wants to send to another user to within some distortion level. We abstract this problem as that of universal communication of random sources over networks to within a distortion criterion. We compute ta universally reliably achievable region for a set of networks where networks in the set are defined in terms of end to end distortion that they achieve for transmission of independent signals between various nodes assuming that there is common randomness between sender and corresponding receiver. Using this, we provide results for when communication of independent signals to within particular fidelity criteria is possible in terms of when reliable communication is possible. Using this, we show that when the sources at the various nodes are independent of each other, it is sufficient to consider separation architectures: ...

  1. Residents' annoyance responses to aircraft noise events

    Science.gov (United States)

    Dempsey, T. K.; Stephens, D. G.; Fields, J. M.; Shepherd, K. P.

    1983-01-01

    In a study conducted in the vicinity of Salt Lake City International Airport, community residents reported their annoyance with individual aircraft flyovers during rating sessions conducted in their homes. Annoyance ratings were obtained at different times of the day. Aircraft noise levels were measured, and other characteristics of the aircraft were noted by trained observers. Metrics commonly used for assessing aircraft noise were compared, but none performed significantly better than A-weighted sound pressure level. A significant difference was found between the ratings of commercial jet aircraft and general aviation propeller aircraft, with the latter being judged less annoying. After the effects of noise level were accounted for, no significant differences were found between the ratings of landings and takeoffs. Aircraft noise annoyance reactions are stronger in lowered ambient noise conditions. This is consistent with the theory that reduced nighttime and evening ambient levels could create different reactions at different times of day. After controlling for ambient noise in a multiple regression analysis, no significant differences were found between the ratings of single events obtained during the three time periods: morning, afternoon, and evenings.

  2. Collision avoidance for aircraft in abort landing

    Science.gov (United States)

    Mathwig, Jarret

    We study the collision avoidance between two aircraft flying in the same vertical plane: a host aircraft on a glide path and an intruder aircraft on a horizontal trajectory below that of the host aircraft and heading in the opposite direction. Assuming that the intruder aircraft is uncooperative, the host aircraft executes an optimal abort landing maneuver: it applies maximum thrust setting and maximum angle of attack lifting the flight path over the original path, thereby increasing the timewise minimum distance between the two aircraft and, in this way, avoiding the potential collision. In the presence of weak constraints on the aircraft and/or the environment, the angle of attack must be brought to the maximum value and kept there until the maximin point is reached. On the other hand, in the presence of strong constraints on the aircraft and the environment, desaturation of the angle of attack might have to take place before the maximin point is reached. This thesis includes four parts. In the first part, after an introduction and review of the available literature, we reformulate and solve the one-subarc Chebyshev maximin problem as a two-subarc Bolza-Pontryagin problem in which the avoidance and the recovery maneuvers are treated simultaneously. In the second part, we develop a guidance scheme (gamma guidance) capable of approximating the optimal trajectory in real time. In the third part, we present the algorithms employed to solve the one-subarc and two-subarc problems. In the fourth part, we decompose the two-subarc Bolza-Pontryagin problem into two one-subarc problems: the avoidance problem and the recovery problem, to be solved in sequence; remarkably, for problems where the ratio of total maneuver time to avoidance time is sufficiently large (≥5), this simplified procedure predicts accurately the location of the maximin point as well as the maximin distance.

  3. Kriging with Unknown Variance Components for Regional Ionospheric Reconstruction

    Directory of Open Access Journals (Sweden)

    Ling Huang

    2017-02-01

    Full Text Available Ionospheric delay effect is a critical issue that limits the accuracy of precise Global Navigation Satellite System (GNSS positioning and navigation for single-frequency users, especially in mid- and low-latitude regions where variations in the ionosphere are larger. Kriging spatial interpolation techniques have been recently introduced to model the spatial correlation and variability of ionosphere, which intrinsically assume that the ionosphere field is stochastically stationary but does not take the random observational errors into account. In this paper, by treating the spatial statistical information on ionosphere as prior knowledge and based on Total Electron Content (TEC semivariogram analysis, we use Kriging techniques to spatially interpolate TEC values. By assuming that the stochastic models of both the ionospheric signals and measurement errors are only known up to some unknown factors, we propose a new Kriging spatial interpolation method with unknown variance components for both the signals of ionosphere and TEC measurements. Variance component estimation has been integrated with Kriging to reconstruct regional ionospheric delays. The method has been applied to data from the Crustal Movement Observation Network of China (CMONOC and compared with the ordinary Kriging and polynomial interpolations with spherical cap harmonic functions, polynomial functions and low-degree spherical harmonic functions. The statistics of results indicate that the daily ionospheric variations during the experimental period characterized by the proposed approach have good agreement with the other methods, ranging from 10 to 80 TEC Unit (TECU, 1 TECU = 1 × 1016 electrons/m2 with an overall mean of 28.2 TECU. The proposed method can produce more appropriate estimations whose general TEC level is as smooth as the ordinary Kriging but with a smaller standard deviation around 3 TECU than others. The residual results show that the interpolation precision of the

  4. Aircraft control in wake vortex wind shear

    Science.gov (United States)

    Wold, Gregory R.

    1995-01-01

    In the past, there have been a number of fatal incidents attributable to wake vortex encounters, involving both general aviation and commercial aircraft. In fact, the wake vortex hazard is considered to be the single dominant safety issue determining the aircraft spacing requirements at airports. As the amount of air traffic increases, the number of dangerous encounters is likely only to increase. It is therefore imperative that a means be found to reduce the danger. That is the purpose of this research: to use nonlinear inverse dynamic (NID) control methods in the design of an aircraft control system which can improve the safety margin in a wake vortex encounter.

  5. Aircraft wake vortices in the atmosphere

    Science.gov (United States)

    Gerz, Thomas; Holzäpfel, Frank; Hofbauer, Thomas; Dörnbrack, Andreas; Frech, Michael

    The studies summarized here were motivated by the need to gain information (i) about the impact of aircraft emissions upon the atmosphere and the climate and (ii) about optimized separation distances between aircraft landing at an airport for possibly increasing its capacity. To this end, large-eddy simulations have been performed to learn about the behaviour of vortex wakes shed by cruising aircraft in the free atmosphere and in the atmospheric boundary layer close to the ground. Some results are best illustrated in animated form and may be found under http://www.pa.op.dlr.de/wirbelschleppe/WakeVortex.html.

  6. Computing Linear Mathematical Models Of Aircraft

    Science.gov (United States)

    Duke, Eugene L.; Antoniewicz, Robert F.; Krambeer, Keith D.

    1991-01-01

    Derivation and Definition of Linear Aircraft Model (LINEAR) computer program provides user with powerful, and flexible, standard, documented, and verified software tool for linearization of mathematical models of aerodynamics of aircraft. Intended for use in software tool to drive linear analysis of stability and design of control laws for aircraft. Capable of both extracting such linearized engine effects as net thrust, torque, and gyroscopic effects, and including these effects in linear model of system. Designed to provide easy selection of state, control, and observation variables used in particular model. Also provides flexibility of allowing alternate formulations of both state and observation equations. Written in FORTRAN.

  7. Random neural Q-learning for obstacle avoidance of a mobile robot in unknown environments

    Directory of Open Access Journals (Sweden)

    Jing Yang

    2016-07-01

    Full Text Available The article presents a random neural Q-learning strategy for the obstacle avoidance problem of an autonomous mobile robot in unknown environments. In the proposed strategy, two independent modules, namely, avoidance without considering the target and goal-seeking without considering obstacles, are first trained using the proposed random neural Q-learning algorithm to obtain their best control policies. Then, the two trained modules are combined based on a switching function to realize the obstacle avoidance in unknown environments. For the proposed random neural Q-learning algorithm, a single-hidden layer feedforward network is used to approximate the Q-function to estimate the Q-value. The parameters of the single-hidden layer feedforward network are modified using the recently proposed neural algorithm named the online sequential version of extreme learning machine, where the parameters of the hidden nodes are assigned randomly and the sample data can come one by one. However, different from the original online sequential version of extreme learning machine algorithm, the initial output weights are estimated subjected to quadratic inequality constraint to improve the convergence speed. Finally, the simulation results demonstrate that the proposed random neural Q-learning strategy can successfully solve the obstacle avoidance problem. Also, the higher learning efficiency and better generalization ability are achieved by the proposed random neural Q-learning algorithm compared with the Q-learning based on the back-propagation method.

  8. Effects of Memory Colour on Colour Constancy for Unknown Coloured Objects

    Directory of Open Access Journals (Sweden)

    Jeroen J M Granzier

    2012-04-01

    Full Text Available The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination—colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc within a scene influence colour constancy for unknown coloured objects in the scene. Subjects matched one of four Munsell papers placed in a scene illuminated under either a reddish or a greenish lamp with the Munsell book of colour illuminated by a neutral lamp. The Munsell papers were embedded in four different scenes—one scene containing diagnostically coloured objects, one scene containing incongruent coloured objects, a third scene with geometrical objects of the same colour as the diagnostically coloured objects, and one scene containing non-diagnostically coloured objects (eg, a yellow coffee mug. All objects were placed against a black background. Colour constancy was on average significantly higher for the scene containing the diagnostically coloured objects compared with the other scenes tested. We conclude that the colours of familiar objects help in obtaining colour constancy for unknown objects.

  9. Effects of memory colour on colour constancy for unknown coloured objects.

    Science.gov (United States)

    Granzier, Jeroen J M; Gegenfurtner, Karl R

    2012-01-01

    The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination-colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc) within a scene influence colour constancy for unknown coloured objects in the scene. Subjects matched one of four Munsell papers placed in a scene illuminated under either a reddish or a greenish lamp with the Munsell book of colour illuminated by a neutral lamp. The Munsell papers were embedded in four different scenes-one scene containing diagnostically coloured objects, one scene containing incongruent coloured objects, a third scene with geometrical objects of the same colour as the diagnostically coloured objects, and one scene containing non-diagnostically coloured objects (eg, a yellow coffee mug). All objects were placed against a black background. Colour constancy was on average significantly higher for the scene containing the diagnostically coloured objects compared with the other scenes tested. We conclude that the colours of familiar objects help in obtaining colour constancy for unknown objects.

  10. Effects of memory colour on colour constancy for unknown coloured objects

    Science.gov (United States)

    Granzier, Jeroen J M; Gegenfurtner, Karl R

    2012-01-01

    The perception of an object's colour remains constant despite large variations in the chromaticity of the illumination—colour constancy. Hering suggested that memory colours, the typical colours of objects, could help in estimating the illuminant's colour and therefore be an important factor in establishing colour constancy. Here we test whether the presence of objects with diagnostical colours (fruits, vegetables, etc) within a scene influence colour constancy for unknown coloured objects in the scene. Subjects matched one of four Munsell papers placed in a scene illuminated under either a reddish or a greenish lamp with the Munsell book of colour illuminated by a neutral lamp. The Munsell papers were embedded in four different scenes—one scene containing diagnostically coloured objects, one scene containing incongruent coloured objects, a third scene with geometrical objects of the same colour as the diagnostically coloured objects, and one scene containing non-diagnostically coloured objects (eg, a yellow coffee mug). All objects were placed against a black background. Colour constancy was on average significantly higher for the scene containing the diagnostically coloured objects compared with the other scenes tested. We conclude that the colours of familiar objects help in obtaining colour constancy for unknown objects. PMID:23145282

  11. Sensibility and Subjectivity: Levinas’ Traumatic Subject

    Directory of Open Access Journals (Sweden)

    Rashmika Pandya

    2011-02-01

    Full Text Available The importance of Levinas’ notions of sensibility and subjectivity are evident in the revision of phenomenological method by current phenomenologists such as Jean-Luc Marion and Michel Henry. The criticisms of key tenants of classical phenomenology, intentionality and reduction, are of a particular note. However, there are problems with Levinas’ characterization of subjectivity as essentially sensible. In “Totality and Infinity” and “Otherwise than Being”, Levinas criticizes and recasts a traditional notion of subjectivity, particularly the notion of the subject as the first and foremost rational subject. The subject in Levinas’ works is characterized more by its sensibility and affectedness than by its capacity to reason or affect its world. Levinas ties rationality to economy and suggests an alternative notion of reason that leads to his analysis of the ethical relation as the face-to-face encounter. The ‘origin’ of the social relation is located not in our capacity to know but rather in a sensibility that is diametrically opposed to the reason understood as economy. I argue that the opposition in Levinas’ thought between reason and sensibility is problematic and essentially leads to a self-conflicted subject. In fact, it would seem that violence characterizes the subject’s self-relation and, thus, is also inscribed at the base of the social relation. Rather than overcoming a problematic tendency to dualistic thought in philosophy Levinas merely reverses traditional hierarchies of reason/emotion, subject/object and self/other. 

  12. Territory: An Unknown Quantity in Debates on Territorial Cohesion

    Directory of Open Access Journals (Sweden)

    Andreas Faludi

    2013-08-01

    Full Text Available There are complaints about territorial cohesion being a vague concept, but in relevant debates territory, too, figures as an unknown quantity. Thus, is it the fixed property of any state, region or local administrative unit, or is it a malleable social construct; rather than being filled with bounded territories, does space overall contain a dynamic network with fuzzy internal, as well as external boundaries, with implications for territorial cohesion? After all, if the former were to be true, territorial cohesion would refer to qualities of what is inside bounded territories. If it were to be the latter, then the meaning of territorial cohesion would include qualities of the relations within a complex network of socially constructed, sometimes ephemeral constructs. There are implications for the ways subsidiarity and multi-level governance are invoked in EU discourse where there is a similar failure to question the underlying notion of territory. What is relevant here is the distinction between a ‘territorial’ and ‘relational’ geography. Considered opinion suggests that these alternatives can and, in view of the persistence of the principle of territorial representation, must be reconciled. However, though firmly entrenched, some constitutional theorists question the very principle. The debate is far from conclusive but at least it shows that discussion, even of this apparently fundamental principle is possible.

  13. Physics at 13 TeV: CMS - scanning the unknown

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    CMS is getting ready to use its accurate detector to scan the many ripples of the unknown physics that may lie beyond the Standard Model. Foremost in everyone’s mind is the search for signs of the production of dark matter at a man-made machine.   Interestingly, the observation of dark matter or new weakly interacting particles implies detecting that some energy has escaped, i.e. it’s missing from the upcoming proton collisions at the LHC. This is why measuring and understanding “missing energy” will be a very important step in that direction. “A large amount of missing energy is the signature for many processes of physics beyond the Standard Model. However, it’s not the only interesting signature that we will be able to exploit when the new collision energy is available,” explains Luca Malgeri, CMS Physics Coordinator. Among the interesting things not associated with missing energy are high-mass resonanc...

  14. [Tilt test for the evaluation of syncope of unknown origin].

    Science.gov (United States)

    Muratore, C; Rabinovich, R; Valentino, M; Baranchuk, A; Liprandi, A S

    1997-01-01

    The aim of this study was to evaluate the usefulness of head up tilt testing in patients with syncope of unknown origin. Between January 1994 and September 1995, 93 patients were referred for tilt table assessment due to recurrent syncope of uncertain etiology. There were 42 men (mean age 59 years). Thirty healthy volunteers served as a control group. The specific protocol used involved an initial period of supine rest for 15'. Baseline blood pressure (BP) and heart rate (HR) were recorded. This was followed by a tilt to 80 degrees for 30', BP and HR were measured every minute during the procedure. The test was considered positive when symptoms appeared associated with one of the following responses: systolic BP decreased more than 30 mmHg (vasodepressor), bradicardia or asystolia for up to 3" (cardioinhibitory) or mixed. The tilt test was positive in 31 of 93 patients (33%). Seventeen patients (55%) had a vasodepressor response, 3 patients (9%) a cardioinhibitory response and 11 patients (36%) mixed responses. The clinical manifestations were 62% near syncope, 19% syncope and the other patients presented dypsnea or dizziness. The symptoms disappeared promptly after adopting the supine position. None of the 30 healthy volunteers developed symptoms. We conclude that head up tilt test is a safe and effective method for identifying a neurocardiogenic origin in a syncope of uncertain etiology.

  15. Gravity, strings and particles a journey into the unknown

    CERN Document Server

    Gasperini, Maurizio

    2014-01-01

    New fundamental forces of Nature? New forms of "dark'' energy? Signals from epochs preceding the Big Bang? Is our space-time unique? Only a joint study of the three topics examined in this book – gravity, strings and particles – may provide answers to these questions. Such a study may also provide the key to solving one of the most fascinating mysteries of modern science, namely: Besides time and the three spatial dimensions, how many other dimensions exist in our universe? The book is primarily addressed to readers who do not necessarily have a specific background in physics but are nevertheless interested in discovering the originality and the possible implications of some of the amazing ideas in modern theoretical physics. The emphasis is on conveying ideas rather than explaining formulas, focusing not on what is known but -- mainly -- on what is still unknown. Many parts of the book are devoted to fundamental theoretical models and results which are potentially highly relevant for a deeper understand...

  16. Chronic kidney disease of unknown etiology in Sri Lanka.

    Science.gov (United States)

    Rajapakse, Senaka; Shivanthan, Mitrakrishnan Chrishan; Selvarajah, Mathu

    2016-07-01

    In the last two decades, chronic kidney disease of unknown etiology (CKDu) has emerged as a significant contributor to the burden of chronic kidney disease (CKD) in rural Sri Lanka. It is characterized by the absence of identified causes for CKD. The prevalence of CKDu is 15.1-22.9% in some Sri Lankan districts, and previous research has found an association with farming occupations. A systematic literature review in Pubmed, Embase, Scopus, and Lilacs databases identified 46 eligible peer-reviewed articles and one conference abstract. Geographical mapping indicates a relationship between CKDu and agricultural irrigation water sources. Health mapping studies, human biological studies, and environment-based studies have explored possible causative agents. Most studies focused on likely causative agents related to agricultural practices, geographical distribution based on the prevalence and incidence of CKDu, and contaminants identified in drinking water. Nonetheless, the link between agrochemicals or heavy metals and CKDu remains to be established. No definitive cause for CKDu has been identified. Evidence to date suggests that the disease is related to one or more environmental agents, however pinpointing a definite cause for CKDu is challenging. It is plausible that CKDu is multifactorial. No specific guidelines or recommendations exist for treatment of CKDu, and standard management protocols for CKD apply. Changes in agricultural practices, provision of safe drinking water, and occupational safety precautions are recommended by the World Health Organization.

  17. Adaptive stochastic resonance for unknown and variable input signals.

    Science.gov (United States)

    Krauss, Patrick; Metzner, Claus; Schilling, Achim; Schütz, Christian; Tziridis, Konstantin; Fabry, Ben; Schulze, Holger

    2017-05-26

    All sensors have a threshold, defined by the smallest signal amplitude that can be detected. The detection of sub-threshold signals, however, is possible by using the principle of stochastic resonance, where noise is added to the input signal so that it randomly exceeds the sensor threshold. The choice of an optimal noise level that maximizes the mutual information between sensor input and output, however, requires knowledge of the input signal, which is not available in most practical applications. Here we demonstrate that the autocorrelation of the sensor output alone is sufficient to find this optimal noise level. Furthermore, we demonstrate numerically and analytically the equivalence of the traditional mutual information approach and our autocorrelation approach for a range of model systems. We furthermore show how the level of added noise can be continuously adapted even to highly variable, unknown input signals via a feedback loop. Finally, we present evidence that adaptive stochastic resonance based on the autocorrelation of the sensor output may be a fundamental principle in neuronal systems.

  18. Fever of unknown origin: subacute thyroiditis versus typhoid fever.

    Science.gov (United States)

    Cunha, Burke A; Thermidor, Marjorie; Mohan, Sowjanya; Valsamis, Ageliki S; Johnson, Diane H

    2005-01-01

    Fever of unknown origin (FUO) is not infrequently a diagnostic dilemma for clinicians. Common infectious causes include endocarditis and abscesses in adults, and noninfectious causes include neoplasms and certain collagen vascular diseases, for example, polymyalgia rheumatica, various vasculitides, and juvenile rheumatoid arthritis (adult Still's disease). Subacute thyroiditis is a rare cause of FUO. Among the infectious causes of FUO, typhoid fever is relatively uncommon. We present a case of FUO in a traveler returning from India whose initial complaints were that of left-sided neck pain and angle of the jaw pain, which initially suggested the diagnosis of subacute thyroiditis. After an extensive FUO workup, when typhoid fever is a likely diagnostic possibility, an empiric trial of anti- Salmonella therapy has diagnostic and therapeutic significance. The presence of relative bradycardia, and response to quinolone therapy, was the basis of the clinical diagnosis of typhoid fever as the explanation for this patients FUO. This case illustrates the diagnostic difficulties in assessing patients with FUO with few diagnostic findings.

  19. Fever of unknown origin responding to steroid therapy.

    Science.gov (United States)

    Suzuki, A; Ohosone, Y; Mita, S; Obana, M; Matsuoka, Y; Irimajiri, S

    1997-02-01

    It is not uncommon to find cases of fever of unknown origin (FUO) in which no final diagnosis is made ever after various examinations. We investigated such cases of undiagnosed FUO, with fever persisting for a long periods and responding to steroid therapy. Among 4,596 patients who were hospitalized over 3-year period from September 1991, 25 met Petersdorf's definition of FUO. Among these 25 patient, six cases were steroid-responsive undiagnosed FUO (SR-FUO). Patients with SR-FUO had the following characteristics: marked inflammatory findings and severe illness; without a definite underlying disease being found despite various examinations; no findings which indicated any known diseases such as adult-onset Still's disease, polymyalgia rheumatica, or other collagen diseases; elderly onset, at 58 to 77 years of age (mean age: 67 years); no improvement with antibiotics, antituberculous agents, or antimycotic drugs; significant improvement of symptoms and signs with steroid therapy; and a relatively good prognosis. SR-FUO, which is not caused by any known disease and is highly responsive to steroids, is included among the FUO cases which we have difficulty in diagnosing and treating.

  20. Kidnapping Detection and Recognition in Previous Unknown Environment

    Directory of Open Access Journals (Sweden)

    Yang Tian

    2017-01-01

    Full Text Available An unaware event referred to as kidnapping makes the estimation result of localization incorrect. In a previous unknown environment, incorrect localization result causes incorrect mapping result in Simultaneous Localization and Mapping (SLAM by kidnapping. In this situation, the explored area and unexplored area are divided to make the kidnapping recovery difficult. To provide sufficient information on kidnapping, a framework to judge whether kidnapping has occurred and to identify the type of kidnapping with filter-based SLAM is proposed. The framework is called double kidnapping detection and recognition (DKDR by performing two checks before and after the “update” process with different metrics in real time. To explain one of the principles of DKDR, we describe a property of filter-based SLAM that corrects the mapping result of the environment using the current observations after the “update” process. Two classical filter-based SLAM algorithms, Extend Kalman Filter (EKF SLAM and Particle Filter (PF SLAM, are modified to show that DKDR can be simply and widely applied in existing filter-based SLAM algorithms. Furthermore, a technique to determine the adapted thresholds of metrics in real time without previous data is presented. Both simulated and experimental results demonstrate the validity and accuracy of the proposed method.

  1. Crowdsourcing the unknown: the satellite search for Genghis Khan.

    Directory of Open Access Journals (Sweden)

    A Y M Lin

    Full Text Available Massively parallel collaboration and emergent knowledge generation is described through a large scale survey for archaeological anomalies within ultra-high resolution earth-sensing satellite imagery. Over 10K online volunteers contributed 30K hours (3.4 years, examined 6,000 km², and generated 2.3 million feature categorizations. Motivated by the search for Genghis Khan's tomb, participants were tasked with finding an archaeological enigma that lacks any historical description of its potential visual appearance. Without a pre-existing reference for validation we turn towards consensus, defined by kernel density estimation, to pool human perception for "out of the ordinary" features across a vast landscape. This consensus served as the training mechanism within a self-evolving feedback loop between a participant and the crowd, essential driving a collective reasoning engine for anomaly detection. The resulting map led a National Geographic expedition to confirm 55 archaeological sites across a vast landscape. A increased ground-truthed accuracy was observed in those participants exposed to the peer feedback loop over those whom worked in isolation, suggesting collective reasoning can emerge within networked groups to outperform the aggregate independent ability of individuals to define the unknown.

  2. Ultrastructural mitochondrial alterations in equine myopathies of unknown origin.

    Science.gov (United States)

    Van Driessche, K; Ducatelle, R; Chiers, K; Van Coster, R; van der Kolk, J H; van der Kolk, H

    2015-03-01

    Very few mitochondrial myopathies have been described in horses. To examine the ultrastructure of muscle mitochondria in equine cases of myopathy of unknown origin. Biopsies of vastus lateralis of the Musculus quadriceps femoris were taken predominantly immediately post mortem and processed for transmission electron microscopy. As a result, electron micrographs of 90 horses in total were available for analysis comprising 4 control horses, 16 horses suffering from myopathy and 70 otherwise diseased horses. Following a thorough clinical and laboratory work-up, four out of five patients that did not fit into the usual algorithm to detect known causes of myopathy showed ultrastructural mitochondrial alterations. Small mitochondria with zones with complete disruption of cristae associated with lactic acidemia were detected in a 17-year-old pony mare, extremely long and slender mitochondria with longitudinal cristae in a 5-year-old Quarter horse stallion, a mixture of irregular extremely large mitochondria (measuring 2500 by 800 nm) next to smaller ones in an 8-year-old Hanoverian mare and round mitochondria with only few cristae in a 11-year-old pony gelding. It remains uncertain whether the subsarcolemmal mitochondrial accumulations observed in the fifth patient have any pathological significance. Ultrastructural alterations in mitochondria were detected in at least four horses. To conclude that these are due to mitochondrial dysfuntions, biochemical tests should be performed. The possibility of a mitochondrial myopathy should be included in the differential diagnosis of muscle weakness.

  3. Anaerobic oxidation of methane: progress with an unknown process.

    Science.gov (United States)

    Knittel, Katrin; Boetius, Antje

    2009-01-01

    Methane is the most abundant hydrocarbon in the atmosphere, and it is an important greenhouse gas, which has so far contributed an estimated 20% of postindustrial global warming. A great deal of biogeochemical research has focused on the causes and effects of the variation in global fluxes of methane throughout earth's history, but the underlying microbial processes and their key agents remain poorly understood. This is a disturbing knowledge gap because 85% of the annual global methane production and about 60% of its consumption are based on microbial processes. Only three key functional groups of microorganisms of limited diversity regulate the fluxes of methane on earth, namely the aerobic methanotrophic bacteria, the methanogenic archaea, and their close relatives, the anaerobic methanotrophic archaea (ANME). The ANME represent special lines of descent within the Euryarchaeota and appear to gain energy exclusively from the anaerobic oxidation of methane (AOM), with sulfate as the final electron acceptor according to the net reaction: CH(4) + SO(42-) ---> HCO(3-) + HS(-) + H(2)O. This review summarizes what is known and unknown about AOM on earth and its key catalysts, the ANME clades and their bacterial partners.

  4. Challenges of the Unknown: Clinical Application of Microbial Metagenomics

    Directory of Open Access Journals (Sweden)

    Graham Rose

    2015-01-01

    Full Text Available Availability of fast, high throughput and low cost whole genome sequencing holds great promise within public health microbiology, with applications ranging from outbreak detection and tracking transmission events to understanding the role played by microbial communities in health and disease. Within clinical metagenomics, identifying microorganisms from a complex and host enriched background remains a central computational challenge. As proof of principle, we sequenced two metagenomic samples, a known viral mixture of 25 human pathogens and an unknown complex biological model using benchtop technology. The datasets were then analysed using a bioinformatic pipeline developed around recent fast classification methods. A targeted approach was able to detect 20 of the viruses against a background of host contamination from multiple sources and bacterial contamination. An alternative untargeted identification method was highly correlated with these classifications, and over 1,600 species were identified when applied to the complex biological model, including several species captured at over 50% genome coverage. In summary, this study demonstrates the great potential of applying metagenomics within the clinical laboratory setting and that this can be achieved using infrastructure available to nondedicated sequencing centres.

  5. 8 CFR 234.3 - Aircraft; how considered.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Aircraft; how considered. 234.3 Section 234... PORTS OF ENTRY FOR ALIENS ARRIVING BY CIVIL AIRCRAFT § 234.3 Aircraft; how considered. Except as otherwise specifically provided in the Immigration and Nationality Act and this chapter, aircraft arriving...

  6. 14 CFR 49.11 - FAA Aircraft Registry.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false FAA Aircraft Registry. 49.11 Section 49.11 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT RECORDING OF AIRCRAFT TITLES AND SECURITY DOCUMENTS General § 49.11 FAA Aircraft Registry. To be eligible for recording...

  7. 14 CFR 375.11 - Other foreign civil aircraft.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Other foreign civil aircraft. 375.11... PROCEEDINGS) SPECIAL REGULATIONS NAVIGATION OF FOREIGN CIVIL AIRCRAFT WITHIN THE UNITED STATES Authorization § 375.11 Other foreign civil aircraft. A foreign civil aircraft other than those referred to in § 375.10...

  8. 19 CFR 122.86 - Substitution of aircraft.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Substitution of aircraft. 122.86 Section 122.86... Substitution of aircraft. (a) Application. The residue cargo procedure applies when an airline must substitute aircraft to reach a destination due to weather conditions or operational factors which prevent an aircraft...

  9. 42 CFR 71.44 - Disinsection of aircraft.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Disinsection of aircraft. 71.44 Section 71.44... Disinsection of aircraft. (a) The Director may require disinsection of an aircraft if it has left a foreign area that is infected with insect-borne communicable disease and the aircraft is suspected of harboring...

  10. 14 CFR 65.67 - Aircraft dispatcher certification courses: Personnel.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aircraft dispatcher certification courses... TRANSPORTATION (CONTINUED) AIRMEN CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Aircraft Dispatchers § 65.67 Aircraft dispatcher certification courses: Personnel. (a) Each applicant for an aircraft...

  11. 14 CFR 47.19 - FAA Aircraft Registry.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false FAA Aircraft Registry. 47.19 Section 47.19 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRCRAFT REGISTRATION General § 47.19 FAA Aircraft Registry. Each application, request, notification, or other...

  12. 177 airport acoustics: aircraft ise ibution and modelling of some ...

    African Journals Online (AJOL)

    Keywords :jlircraft noise, aircraft parameters and enoironmenta[ noise climate. 1. Introduction. Since the early 1950s, the number of transportation aircraft has increased tremendously (EPA, 1971). The increase, especially of general aviation aircraft, jet aircraft and helicopters, has had significant impart on our environment, ...

  13. 77 FR 42455 - Airworthiness Directives; Piper Aircraft, Inc. Airplanes

    Science.gov (United States)

    2012-07-19

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Piper Aircraft, Inc... directive (AD) for all Piper Aircraft, Inc. (type certificate previously held by The New Piper Aircraft Inc... receive about this proposed AD. Discussion Three forced landings of Piper Aircraft, Inc. Model PA-18...

  14. Kinematic response of the spine during simulated aircraft ejections.

    Science.gov (United States)

    Damon, Andrew M; Lessley, David J; Salzar, Robert S; Bass, Cameron R; Shen, Francis H; Paskoff, Glenn R; Shender, Barry S

    2010-05-01

    Military aviators are susceptible to spinal injuries during high-speed ejection scenarios. These injuries commonly arise as a result of strains induced by extreme flexion or compression of the spinal column. This study characterizes the vertebral motion of two postmortem human surrogates (PMHS) during a simulated catapult phase of ejection on a horizontal decelerator sled. During testing, the PMHS were restrained supinely to a mock ejection seat and subjected to a horizontal deceleration profile directed along the local z-axis. Two midsized males (175.3 cm, 77.1 kg; 185.4 cm, 72.6 kg) were tested. High-rate motion capture equipment was used to measure the three-dimensional displacement of the head, vertebrae, and pelvis during the ejection event. The two PMHS showed generally similar kinematic motion. Head injury criterion (HIC) results were well below injury threshold levels for both specimens. The specimens both showed compression of the spine, with a reduction in length of 23.9 mm and 45.7 mm. Post-test autopsies revealed fractures in the C5, T1, and L1 vertebrae. This paper provides an analysis of spinal motion during an aircraft ejection.The injuries observed in the test subjects were consistent with those seen in epidemiological studies. Future studies should examine the effects of gender, muscle tensing, out-of-position (of head from neutral position) occupants, and external forces (e.g., windblast) on spinal kinematics during aircraft ejection.

  15. Hearing status among aircraft maintenance personnel in a commercial airline company

    Directory of Open Access Journals (Sweden)

    Greta Smedje

    2011-01-01

    Full Text Available The aim was to study subjective and objective hearing loss in a population of aircraft maintenance workers and identify predictors. A total of 327 aircraft maintenance personnel answered a self-administered work environment questionnaire (response rate 76% and underwent audiometric test. The mean values for the hearing threshold at 3, 4, and 6 kHz for the ear with the most hearing loss were compared with a Swedish population database of persons not occupationally exposed to noise. Equivalent noise exposure during a working day was measured. Relationships between subjective and objective hearing loss and possible predictors (age, years of employment, self-reported exposure to solvents, blood pressure, and psycho-social factors were analyzed by multiple logistic regression. At younger ages (<40 years, aircraft maintenance workers had higher hearing thresholds (1-3 dB compared to the reference group, but such a difference was not found in older employees. Relationships were found between age and objective hearing loss, and between exposure to solvents and reported subjective hearing loss. Equivalent noise exposure during working days were 70-91 dB(A with a maximal noise level of 119 dB(A. Aircraft maintenance workers are exposed to equivalent noise levels above the Swedish occupational standard, including some very high peak exposures. Younger employees have a higher age-matched hearing threshold level compared with a reference group. Thus, there is a need for further preventive measures.

  16. Hearing status among aircraft maintenance personnel in a commercial airline company.

    Science.gov (United States)

    Smedje, Greta; Lunden, Maria; Gärtner, Lotta; Lundgren, Håkan; Lindgren, Torsten

    2011-01-01

    The aim was to study subjective and objective hearing loss in a population of aircraft maintenance workers and identify predictors. A total of 327 aircraft maintenance personnel answered a self-administered work environment questionnaire (response rate 76%) and underwent audiometric test. The mean values for the hearing threshold at 3, 4, and 6 kHz for the ear with the most hearing loss were compared with a Swedish population database of persons not occupationally exposed to noise. Equivalent noise exposure during a working day was measured. Relationships between subjective and objective hearing loss and possible predictors (age, years of employment, self-reported exposure to solvents, blood pressure, and psycho-social factors) were analyzed by multiple logistic regression. At younger ages (<40 years), aircraft maintenance workers had higher hearing thresholds (1-3 dB) compared to the reference group, but such a difference was not found in older employees. Relationships were found between age and objective hearing loss, and between exposure to solvents and reported subjective hearing loss. Equivalent noise exposure during working days were 70-91 dB(A) with a maximal noise level of 119 dB(A). Aircraft maintenance workers are exposed to equivalent noise levels above the Swedish occupational standard, including some very high peak exposures. Younger employees have a higher age-matched hearing threshold level compared with a reference group. Thus, there is a need for further preventive measures.

  17. Impact of Advanced Propeller Technology on Aircraft/Mission Characteristics of Several General Aviation Aircraft

    Science.gov (United States)

    Keiter, I. D.

    1982-01-01

    Studies of several General Aviation aircraft indicated that the application of advanced technologies to General Aviation propellers can reduce fuel consumption in future aircraft by a significant amount. Propeller blade weight reductions achieved through the use of composites, propeller efficiency and noise improvements achieved through the use of advanced concepts and improved propeller analytical design methods result in aircraft with lower operating cost, acquisition cost and gross weight.

  18. Aircraft Test & Evaluation Facility (Hush House)

    Data.gov (United States)

    Federal Laboratory Consortium — The Aircraft Test and Evaluation Facility (ATEF), or Hush House, is a noise-abated ground test sub-facility. The facility's controlled environment provides 24-hour...

  19. Airframe Certification Methods for Unmanned Aircraft

    National Research Council Canada - National Science Library

    Saff, Charles R

    2006-01-01

    The application of conventional structural certification methods to unmanned aircraft can lead to unacceptably long development times and costs that are out of line with the development costs for the airframe...

  20. Aircraft Trajectory Optimization Using Parametric Optimization Theory

    OpenAIRE

    Valenzuela Romero, Alfonso

    2012-01-01

    In this thesis, a study of the optimization of aircraft trajectories using parametric optimization theory is presented. To that end, an approach based on the use of predefined trajectory patterns and parametric optimization is proposed. The trajectory pat

  1. Design of heavy lift cargo aircraft

    Data.gov (United States)

    National Aeronautics and Space Administration — This is the bird of the skies of the future. The heavy lift cargo aircraft which is currently being developed by me has twice the payload capacity of an Antonov...

  2. PLANNING OF TRAINING AIRCRAFT FLIGHT HOURS

    Directory of Open Access Journals (Sweden)

    Visnja Vojvodić Rosenzweig

    2010-12-01

    Full Text Available Maintenance of the training aircraft causes downtime of operations and thereby reduces the operational availability, which is crucial for flight planning in a training organisation. Manual daily planning within the fleet delivers suboptimal results and often causes discontinued flight of several aircraft that have to be maintained at the same time. Optimal maintenance schedule of training aircraft can be obtained by a sliding scale method. This paper presents a mathematical model of the sliding scale formulated by a mixed integer linear problem. Allocation of flight hours is optimised by using AMPL programming language, assuring that a sufficient number of aircraft are always available for training. The model can be used by a flight dispatch department in a training organisation as a basis for optimised planning and reduction of maintenance downtime.

  3. Aircraft Nodal Data Acquisition System (ANDAS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an Aircraft Nodal Data Acquisition System (ANDAS) is proposed. The proposed methodology employs the development of a very thin (135m) hybrid...

  4. Aircraft Nodal Data Acquisition System (ANDAS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an Aircraft Nodal Data Acquisition System (ANDAS) based upon the short haul Zigbee networking standard is proposed. It employs a very thin (135 um)...

  5. Children restraint systems for civil aircraft.

    Science.gov (United States)

    1978-03-01

    Child restraint systems have been developed to provide protection to children involved in automobile crashes. These systems are not yet approved for use in civil aircraft. Six typical systems were exposed to controlled impacts on a test sled to simul...

  6. Child restraint systems for civil aircraft.

    Science.gov (United States)

    1978-03-01

    Child restraint systems have been developed to provide protection to children involved in automobile crashes. These systems are not yet approved for use in civil aircraft. Six typical systems were exposed to controlled impacts on a test sled to simul...

  7. Unmanned Aircraft Systems - Digital Elevation Model

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS National Unmanned Aircraft Systems (UAS) Project Office utilizes UAS technology for collecting remote sensing data on a local scale. Typical UAS projects...

  8. Unmanned Aircraft Systems - Point Cloud Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS National Unmanned Aircraft Systems (UAS) Project Office utilizes UAS technology for collecting remote sensing data on a local scale. Typical UAS projects...

  9. Finite Element Aircraft Simulation of Turbulence

    Science.gov (United States)

    1997-02-01

    A Simulation of Rotor Blade Element Turbulence (SORBET) model has been : developed for realtime aircraft simulation that accommodates stochastic : turbulence and distributed discrete gusts as a function of the terrain. This : model is applicable to c...

  10. Emerging nondestructive inspection methods for aging aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Beattie, A; Dahlke, L; Gieske, J [and others

    1994-01-01

    This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with a discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.

  11. Spring 2008 Industry Study: Aircraft Industry

    National Research Council Canada - National Science Library

    Smith, John; Dedecker, Craig; Doerer, Robert; Dols, Jonathan; Ekwall, Bengt; Heck, Mark; Jungco, Rolando; Koch, David; Lolley, James; Matyi, Kyle; McCaffrey, Terrance; Provost, Carla; Snyder, Daniel; Szucs, Jozsef; Truhn, Harry; Tyler, J. R

    2008-01-01

    .... With the exception of the relatively less mature unmanned aircraft systems sector, significant changes to the number and identity of competing firms are not likely in the next few years, although...

  12. Unmanned aircraft systems for transportation decision support.

    Science.gov (United States)

    2016-11-30

    Our nation relies on accurate geospatial information to map, measure, and monitor transportation infrastructure and the surrounding landscapes. This project focused on the application of Unmanned Aircraft systems (UAS) as a novel tool for improving e...

  13. Unmanned Aircraft Systems Roadmap 2005-2030

    Science.gov (United States)

    2005-01-01

    This document presents the Department of Defense's (DoD) roadmap for developing and employing unmanned aircraft systems over the next 25 years (2005 to 2030). It describes the missions identified by theater warfighters to which systems could be appli...

  14. Thermal Management System for Superconducting Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aircraft powered by hydrogen power plants or gas turbines driving electric generators connected to distributed electric motors for propulsion have the potential to...

  15. Safety of Cargo Aircraft Handling Procedure

    Directory of Open Access Journals (Sweden)

    Daniel Hlavatý

    2017-07-01

    Full Text Available The aim of this paper is to get acquainted with the ways how to improve the safety management system during cargo aircraft handling. The first chapter is dedicated to general information about air cargo transportation. This includes the history or types of cargo aircraft handling, but also the means of handling. The second part is focused on detailed description of cargo aircraft handling, including a description of activities that are performed before and after handling. The following part of this paper covers a theoretical interpretation of safety, safety indicators and legislative provisions related to the safety of cargo aircraft handling. The fourth part of this paper analyzes the fault trees of events which might occur during handling. The factors found by this analysis are compared with safety reports of FedEx. Based on the comparison, there is a proposal on how to improve the safety management in this transportation company.

  16. Modular Electric Propulsion Test Bed Aircraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A hybrid electric aircraft simulation system and test bed is proposed to provide a dedicated development environment for the rigorous study and advancement of hybrid...

  17. AIRCRAFT CONFLICTS RESOLUTION BY COURSE MANEUVERING

    Directory of Open Access Journals (Sweden)

    В. Харченко

    2011-02-01

    Full Text Available Enhancement of requirements for air traffic efficiency at increasing of flights intensity determines the necessity of development of new optimization methods for aircraft conflict resolutions. The statement of problem of optimal conflict resolutions at Cooperative Air Traffic Management was done. The method for optimal aircraft conflict  resolution by course maneuvering has been  developed. The method using dynamic programming provides planning of aircraft conflict-free trajectory with minimum length. The decomposition of conflict resolution process on phases and stages, definition of states, controls and recursive  equations for generation of optimal course control program were done. Computer modeling of aircraft conflict resolution by developed method was done

  18. Known unknowns: indirect energy effects of information and communication technology

    Science.gov (United States)

    Horner, Nathaniel C.; Shehabi, Arman; Azevedo, Inês L.

    2016-10-01

    Background. There has been sustained and growing interest in characterizing the net energy impact of information and communication technology (ICT), which results from indirect effects offsetting (or amplifying) the energy directly consumed by ICT equipment. These indirect effects may be either positive or negative, and there is considerable disagreement as to the direction of this sign as well as the effect magnitude. Literature in this area ranges from studies focused on a single service (such as e-commerce versus traditional retail) to macroeconomic studies attempting to characterize the overall impact of ICT. Methods. We review the literature on the indirect energy effect of ICT found via Google Scholar, our own research, and input from other researchers in the field. The various studies are linked to an effect taxonomy, which is synthesized from several different hierarchies present in the literature. References are further grouped according to ICT service (e.g., e-commerce, telework) and summarized by scope, method, and quantitative and qualitative findings. Review results. Uncertainty persists in understanding the net energy effects of ICT. Results of indirect energy effect studies are highly sensitive to scoping decisions and assumptions made by the analyst. Uncertainty increases as the impact scope broadens, due to complex and interconnected effects. However, there is general agreement that ICT has large energy savings potential, but that the realization of this potential is highly dependent on deployment details and user behavior. Discussion. While the overall net effect of ICT is likely to remain unknown, this review suggests several guidelines for improving research quality in this area, including increased data collection, enhancing traditional modeling studies with sensitivity analysis, greater care in scoping, less confidence in characterizing aggregate impacts, more effort on understanding user behavior, and more contextual integration across the

  19. Treatment of Regional Metastatic Melanoma of Unknown Primary Origin

    Directory of Open Access Journals (Sweden)

    Elke J. A. H. van Beek

    2015-08-01

    Full Text Available (1 Background: The purpose of this retrospective study was to evaluate the recurrence and survival rates of metastatic melanoma of unknown primary origin (MUP, in order to further refine current recommendations for the surgical treatment; (2 Methods: Medical data of all MUP patients registered between 2000 and 2011, were analyzed. Seventy-eight patients were categorized in either lymph node (axilla, groin, head-and neck or subcutaneous MUP. Axillary node MUPs were generally treated with dissections of levels I-III, inguinal node MUPs with combined superficial and deep groin dissections, and head-and-neck node MUPs with neck dissections to various extents, based on lymph drainage patterns. Subcutaneous lesions were excised with 1–2 cm margins. The primary outcome was treatment outcomes in terms of (locoregional recurrence and survival rates; (3 Results: Lymph node MUP recurred regionally in 11% of patients, with an overall recurrence rate of 45%. In contrast, subcutaneous MUP recurred locally in 65% of patients with an overall recurrence rate of 78%. This latter group had a significantly shorter disease-free interval than patients with lymph node MUP (p = 0.000. In the entire study population, 5-year and 10-year overall survival rates were 56% and 47% respectively, with no differences observed between the various subgroups; (4 Conclusion: The relatively low regional recurrence rate after regional lymph node dissection (11% supports its current status as standard surgical treatment for lymph node MUP. Subcutaneous MUP, on the contrary, appears to recur both locally (65% and overall (78% at a significantly higher rate, suggesting a different biological behavior. However, wide local excision remains the best available option for this specific group.

  20. Popular Music in Jia Zhangke’s Unknown Pleasures

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2011-04-01

    Full Text Available With his documentary-style films reflecting upon China’s unprecedented transformation from a state-controlled to a market-driven economy, Jia Zhangke has risen from within the movement of independent Chinese cinema that began to flourish in the late 1990s to become one of the most recognized filmmakers of contemporary China. Born in 1970 and raised in the underdeveloped Shanxi Province, Jia studied film theory at Beijing Film Academy and was first noticed for his controversial “Hometown Trilogy”—'Pickpocket '('Xiao Wu', 1997, 'Platform '('Zhantai', 1999, and 'Unknown Pleasures '('Ren xiao yao', 2002. These three films, shot with handheld video camera on the streets of his hometown province, focus on the reckless changes that China’s aggressive economic growth and globalization have brought to socially marginalized groups. Like other independently made films—films that are produced with capital from outside the state-sponsored avenues and without the approval of film censorship, and that are not allowed to be shown in China’s public theaters—Jia’s first three films reach domestic audiences only through unofficial DVD copies and small-scaled screenings at universities, film bars, and art salons. His limited domestic influence sharply contrasts with the critical acclaim that he receives from international film festival audiences, who are searching for alternative film culture from China after the Fifth Generation directors. By the late 1990s, Jia had become a spokesperson for an ever-increasing group of aspiring Chinese independent filmmakers, particularly through writings and interviews that theorize independent Chinese cinema’s practice.

  1. Identification of unknown waste sites using MIVIS hyperspectral images

    Energy Technology Data Exchange (ETDEWEB)

    Gomarasca, M.A.; Strobelt, S. [National Research Council, Milano (Italy)

    1996-11-01

    This paper presents the results on the individuation of known and unknown (illegal) waste sites using Landsat TM satellite imagery and airborne MIVIS (Multispectral Infrared and Visible Imaging Spectrometer) data for detailed analysis in Italy. Previous results with Landsat TM imagery were partially positive for large waste site identification and negative for small sites. Information acquired by the MIVIS hyperspectral system presents three main characteristics: local scale study, possibility to plan the proper period based on the objectives of the study, high number of spectral bands with high spectral and geometrical resolution. MIVIS airborne shootings were carried out on 7 July 1994 at noon with 4x4 m pixel resolution. The MIVIS 102 bands` sensors can distinguish even objects with similar spectral behavior, thanks to its high spectral resolution. Identification of degraded sites is obtained using traditional spectral and statistical operators (NDVI, Principal Component Analysis, Maximum Likelihood classifier) and innovative combination of filtered band ratios realized to extract specific waste elements (acid slimes or contaminated soils). One of the aims that concerns with this study is the definition of an operative program for the characterization, identification and classification of defined categories of waste disposal sites. The best schedule for the data collection by airborne MIVIS oriented to this target is defined. The planning of the proper flight, based on the waste sites features, is important to optimize this technology. One of the most efficient methods for detecting hidden waste sites is the thermal inertia so two images are necessary: one during low sun load and one with high sun load. The results obtained are operationally useful and winning. This instrument, supported by correct analysis techniques, may offer new interesting prospects in territorial management and environmental monitoring. 5 refs., 5 figs., 1 tab.

  2. Adaptive vison aided integrated navigation for dynamic unknown enviroments

    Science.gov (United States)

    Nematallah, Heba

    In this research, a novel method for visual odometry (VO) and the integration with multi-sensors navigation systems for vehicular platforms is proposed. The proposed method partitions the field of single camera view into regions of interests where each region likely contains different types of visual features. By applying computer vision processing techniques, ambiguous pose estimation is calculated up to a scale factor. The proposed method uses aiding measurements from vehicle's odometer to adaptively resolve the scale factor ambiguity problem in monocular camera systems. Unlike some state-of-art approaches, this work does not depend on offline pre-processing or predefined landmarks or visual maps. In addition, this work addresses unknown uncontrolled environments where moving objects likely exist. Innovative odometer-aided Local Bundle Adjustment (LBA) along with a fuzzy C-mean clustering mechanism is proposed to reject outliers corresponding to moving objects. A Gaussian Mixture approach is also applied to detect visual background regions during stationary periods which enables further rejection of moving objects. Finally, an empirical scoring method is applied to calculate a matching score of the different visual features and to use this score in a Kalman filter as measurement covariance noise to integrate VOestimated pose changes within a larger multi-sensors integrated navigation system. Experimental work was performed with a physical vehicular platform equipped by MEMS inertial sensors, GPS, speed measurements and GPS-enabled camera. The experimental work includes three testing vehicular trajectories in downtown Toronto and the surrounding areas. The experimental work showed significant navigation improvements during long GPS outages where only VO is fused with inertial sensors and the vehicle's speed measurements.

  3. Electrically conductive carbon fibre-reinforced composite for aircraft lightning strike protection

    Science.gov (United States)

    Katunin, Andrzej; Krukiewicz, Katarzyna; Turczyn, Roman; Sul, Przemysław; Bilewicz, Marcin

    2017-05-01

    Aircraft elements, especially elements of exterior fuselage, are subjected to damage caused by lightning strikes. Due to the fact that these elements are manufactured from polymeric composites in modern aircraft, and thus, they cannot conduct electrical charges, the lightning strikes cause burnouts in composite structures. Therefore, the effective lightning strike protection for such structures is highly desired. The solution presented in this paper is based on application of organic conductive fillers in the form of intrinsically conducting polymers and carbon fabric in order to ensure electrical conductivity of whole composite and simultaneously retain superior mechanical properties. The presented studies cover synthesis and manufacturing of the electrically conductive composite as well as its characterization with respect to mechanical and electrical properties. The performed studies indicate that the proposed material can be potentially considered as a constructional material for aircraft industry, which characterizes by good operational properties and low cost of manufacturing with respect to current lightning strike protection materials solutions.

  4. The story of a largely unknown evolution - Germ theory hoax.

    Science.gov (United States)

    Wainwright, Milton; Alharbi, Sulaiman Ali

    2011-10-01

    The Piltdown Man debacle provides us with the most infamous forgery in science. However, another equally intriguing story exists concerning a document by a Bostonian called George Sleeper, which purported to be a pre-Darwin-Wallace anticipation of evolution and an equally convincing account of the germ theory published before Louis Pasteur's famous studies on this subject. The story involves two giants in the world of evolutionary theory, Alfred Russel Wallace and E.B. Poulton. While Wallace was convinced that the Sleeper document was genuine, Poulton's detailed investigations showed that it was a fake and a hoax. Despite this conclusion, doubts still exist about the authenticity of the Sleeper document.

  5. Subjective loudness of "minimized" sonic boom waveforms.

    Science.gov (United States)

    Niedzwiecki, A; Ribner, H S

    1978-12-01

    For very long supersonic aircraft the "midfield" sonic boom signature may not have evolved fully into an N wave at ground level. Thus in current boom minimization techniques the shape of the aircraft may be tailored to optimize this midfield wave form for reduced subjective loudness. The present investigation tests a family of "flat-top" waveforms cited by Darden: all but one have a front shock height (deltapSH) less than the peak amplitude (deltapMAX). For equal subjective loudness, "flat top" vs N wave (peak overpressure deltapN), the peak amplitude of the "flat top" signature was found to be substantially higher than that of the N wave; thus for equal peak amplitude the "flat-top" signature was quieter. The results for equal loudness were well fitted by an emperical law deltapSH + 0.11deltapMAX = deltapN; the equivalence shows how the front shock amplitude (deltapSH) dominates the loudness. All this was found compatible with predictions by the method of Johnson and Robinson.

  6. Conceptual design and optimization methodology for box wing aircraft

    OpenAIRE

    Jemitola, Paul Olugbeji

    2012-01-01

    A conceptual design optimization methodology was developed for a medium range box wing aircraft. A baseline conventional cantilever wing aircraft designed for the same mis- sion and payload was also optimized alongside a baseline box wing aircraft. An empirical formula for the mass estimation of the fore and aft wings of the box wing aircraft was derived by relating conventional cantilever wings to box wing aircraft wings. The results indicate that the fore and aft wings would ...

  7. Methods for Aircraft State and Parameter Identification

    Science.gov (United States)

    1975-05-01

    IFIP Conference on Optimization Techniques. Rome, Italy, May 1973. 3. Mehra, Raman K., and Stepner, David E.: "Maximm Likelihood Identification and...Aircraft. Rept. 1356, Res.. Dept., Cessan Aircraft Co., Key 1957. 10. Stepner, David E., and Mehra, Raman K.: ?Kaximum Likelihood Identification and...the position input signal ass mostly dus to talmtry noise. which mae metly 1 percent of full scale. The eccelerometer signal noias , mialy due to

  8. Aircraft Wake Vortex Deformation in Turbulent Atmosphere

    OpenAIRE

    Hennemann, Ingo; Holzaepfel, Frank

    2007-01-01

    Large-scale distortion of aircraft wake vortices appears to play a crucial role for aircraft safety during approach and landing. Vortex distortion is investigated based on large eddy simulations of wake vortex evolution in a turbulent atmosphere. A vortex identification method is developed that can be adapted to the vortex scales of interest. Based on the identified vortex center tracks, a statistics of vortex curvature radii is established. This statistics constitutes the basis for understan...

  9. Energy-Absorbing Passenger Seat for Aircraft

    Science.gov (United States)

    Eichelberger, C. P.; Alfaro-Bou, E.; Fasanella, E. L.

    1987-01-01

    Development of energy-absorbing passenger seat, designed to minimize injury in commercial-aircraft crash, part of joint FAA/NASA controlledimpact flight test of transport-category commercial aircraft. Modified seat mechanism collapses under heavy load to absorb impact energy and thereby protect passenger. Results of simulation tests indicate probability of passenger survival high. Proposed seat mechanism mitigates passenger injuries by reducing impact forces in crash.

  10. Enabling alternate fuels for commercial aircraft

    OpenAIRE

    Daggett, D.

    2010-01-01

    The following reports on the past four years of work to examine the feasibility, sustainability and economic viability of developing a renewable, greenhouse-gas-neutral, liquid biofuel for commercial aircraft. The sharp increase in environmental concerns, such as global warming, as well as the volatile price fluctuations of fossil fuels, has ignited a search for alternative transportation fuels. However, commercial aircraft can not use present alternative fuels that are designed for ground...

  11. Crashworthiness of composite seats for civil aircraft

    OpenAIRE

    Stephens, V. M.

    1992-01-01

    A study has been conducted into the design of civil aircraft seats which are forward-facing and use the lap-belt method of restraint. Within these terms of reference, the response of the seat restraint occupant system (SROS) to impact loading has been analysed using physical (dynamic testing) and analytical (computer simulation) modelling techniques. With the increasing use of fibre-reinforced polymer composites in aircraft for weight efficiency, and the consequent appearance of composite se...

  12. Aircraft Survivability. Susceptibility Reduction. Fall 2010

    Science.gov (United States)

    2010-01-01

    importance of what we do, and showcased the joint nature of our organization. CDR Fehrle and LT John responded to the scene immediately to begin the...Eye-One Photo SG” spectro-photometer (Gretag Macbeth GRET-0366), which provides 10nm resolution across the 380-730nm spectral range. The paints...Approach The short timelines, prevalence, and portable nature of the aircraft threats described lead us to a change in the paradigm of aircraft

  13. Distributed radar sensors for aircraft detection

    Science.gov (United States)

    Canavan, G. H.

    1991-04-01

    Radars suitable for aircraft detection could be deployed on singlet space-based interceptor (SBI) platforms. They could operate at short ranges and still achieve useful search rates. Powers are modest and insensitive to frequency; the dominant costs are the pulsers and phased-array elements. A fundamental simplification results from mounting the radar on the life jacket rather than the SBI. Many satellites could be processed to derive aircraft trajectories sufficiently accurate for the commitment of fighters or defensive missiles.

  14. Unmanned reconnaissance aircraft, Predator B in flight.

    Science.gov (United States)

    2001-01-01

    Predator B unmanned reconnaissance aircraft, shown here, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. ALTAIR/PREDATOR B -- General Atomics Aeronautical Systems, Inc., is developing the Altair version of its Predator B unmanned reconnaissance aircraft, shown here, under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. NASA plans to use the Altair as a technology demonstrator testbed aircraft to validate a variety of command and control technologies for unmanned aerial vehicles (UAV), as well as demonstrate the capability to perform a variety of Earth science missions. The Altair is designed to carry an 700-lb. payload of scientific instruments and imaging equipment for as long as 32 hours at up to 52,000 feet altitude. Ten-foot extensions have been added to each wing, giving the Altair an overall wingspan of 84 feet with an aspect ratio of 23. It is powered by a 700-hp. rear-mounted TPE-331-10 turboprop engine, driving a three-blade propeller. Altair is scheduled to begin flight tests in the fourth quarter of 2002, and be acquired by NASA following successful completion of those basic airworthiness tests in early 2003 for evaluation of over-the-horizon control, detect, see and avoid and other technologies required to allow UAVs to operate safely with other aircraft in the national airspace.

  15. Smart fastener technology for aging aircraft

    Science.gov (United States)

    Schoess, Jeffrey N.; Paul, Clare A.

    1995-04-01

    Hidden and inaccessible corrosion in aircraft structures is the number 1 logistics problem for the Air Force, with an estimated maintenance cost of greater than one billion dollars per year. The smart aircraft fastener evaluation (SAFE) system is being developed to detect and characterize corrosion factors in hidden locations of aircraft structures. The SAFE concept is a novel `in-situ' measurement approach that measures and autonomously records several environmental factors (i.e., pH, temperature, chloride) associated with corrosion. The SAFE system integrated an electrochemical-based microsensor array directly into the aircraft structure to measure the evidence of active corrosion as an in-situ measurement without reducing aircraft structural integrity. The long term-payoff for the SAFE system will be in predictive maintenance for fixed and rotary wing aircraft structures, industrial tanks, and fugitive emissions applications such as control valves, chemical pipeline vessels, and industrial boilers. Predictive maintenance capability, service and repair will replace the current practice of scheduled maintenance to substantially reduce operational costs.

  16. Nonlinear and Dynamic Aerodynamic Models for Commercial Transport Aircraft with Adverse Weather Effects

    Directory of Open Access Journals (Sweden)

    Ray C. Chang

    2010-01-01

    Full Text Available The flight dynamic equations in mathematics for aircraft response to the adverse weathers, such as wind shear, atmospheric turbulence, and in-flight icing, are nonlinear and unsteady. To effectively analyze the performance degradation and variations in stability of commercial aircraft that encountered these weather hazards, the nonlinear and dynamic (i.e., time dependent aerodynamic models based on flight data would be needed. In the present paper, a numerical modeling method based on a fuzzy-logic algorithm will be presented to estimate the aerodynamic models for a twin-jet transport by using the flight data from the flight data recorder (FDR. The aerodynamic models having the capability to generate continuous stability derivatives, especially for sensitivity study of unknown factors in adverse weather conditions, will be demonstrated in this paper.

  17. Perception of horizontal aircraft separation on a cockpit display of traffic information

    Science.gov (United States)

    Palmer, E. A.; Jago, S. J.; Baty, D. L.; Oconnor, S. L.

    1980-01-01

    The influence of various display symbologies in a cockpit display of traffic information (CDTI) on pilot perception of horizontal aircraft separation is investigated. In a series of nine experiments using different combinations of display symbology, information update rate, display viewing time and encounter geometry, subjects were asked to predict whether an intruder aircraft would pass in front of or behind their own aircraft. It is found that displayed history did not improve task performance, although it was desired by the pilots when no other display of aircraft turn rate was available, and that pilots made fewer errors when they had predictive information. Variations in the rate of updating information from 0.1 to 4 sec and viewing times from 1 to 16 sec are not observed to affect performance. It is concluded that the present task, which may arise in a collision avoidance situation, would require an onboard computer to make a prediction of relative aircraft position and display it on the CDTI.

  18. Charting the Unknown: A Hunt in the Dark

    Science.gov (United States)

    Mohlabeng, Gopolang Mokoka

    Astrophysical and cosmological observations have pointed strongly to the existence of dark matter in the Universe, yet its nature remains elusive. It may be hidden in a vast unknown parameter space in which exhaustively searching for a signal is not feasible. We are, therefore, compelled to consider a robust program based on a wide range of new theoretical ideas and complementary strategies for detection. The aim of this dissertation is to investigate the phenomenology of diverse dark sectors with the objective of understanding and characterizing dark matter. We do so by exploring dark matter phenomenology under three main frameworks of study: (I) the model dependent approach, (II) model independent approach and (III) considering simplified models. In each framework we focus on unexplored and well motivated dark matter scenarios as well as their prospects of detection at current and future experiments. First, we concentrate on the model dependent method where we consider minimal dark matter in the form of mixed fermionic stable states in a gauge extension of the standard model. In particular, we incorporate the fermion mixings governed by gauge invariant interactions with the heavier degrees of freedom. We find that the manner of mixing has an impact on the detectability of the dark matter at experiments. Pursuing this model dependent direction, we explore a space-time extension of the standard model which houses a vector dark matter candidate. We incorporate boundary terms arising from the topology of the model and find that these control the way dark matter may interact with baryonic matter. Next we investigate the model independent approach in which we examine a non-minimal dark sector in the form of boosted dark matter. In this study, we consider an effective field theory involving two stable fermionic states. We probe the sensitivity of this type of dark matter coming from the galactic center and the center of the Sun, and investigate its detection prospects

  19. Information in Repeated Ultimatum Game with Unknown Pie Size

    Directory of Open Access Journals (Sweden)

    Ching Chyi Lee

    2013-01-01

    Full Text Available Within existing literature, it is well known that people’s behavior in ultimatum game experiments cannot be explained by perfect rationality model. There is, however, evidence showing that people are boundedly rational. In this paper, we studied repeated ultimatum game experiments in which the pie size is only known to the proposer (player 1, but the transaction history is made known to both players. We found that subject’s behavior can be very well explained by the history-consistent-rationality model (HCR model of Lee and Ferguson (2010, which suggests that people’s behavior is affected by what they observed in the past. The HCR model is able to yield point predictions whose errors are on average within 5% of the total pie size. The experimental results provide evidence that subjects' behavior is boundedly rational with respect to the transaction history.

  20. Demographic window to aging in the wild: constructing life tables and estimating survival functions from marked individuals of unknown age.

    Science.gov (United States)

    Müller, Hans-Georg; Wang, Jane-Ling; Carey, James R; Caswell-Chen, Edward P; Chen, Carl; Papadopoulos, Nikos; Yao, Fang

    2004-06-01

    Summary We address the problem of establishing a survival schedule for wild populations. A demographic key identity is established, leading to a method whereby age-specific survival and mortality can be deduced from a marked cohort life table established for individuals that are randomly sampled at unknown age and marked, with subsequent recording of time-to-death. This identity permits the construction of life tables from data where the birth date of subjects is unknown. An analogous key identity is established for the continuous case in which the survival schedule of the wild population is related to the density of the survival distribution in the marked cohort. These identities are explored for both life tables and continuous lifetime data. For the continuous case, they are implemented with statistical methods using non-parametric density estimation methods to obtain flexible estimates for the unknown survival distribution of the wild population. The analytical model provided here serves as a starting point to develop more complex models for residual demography, i.e. models for estimating survival of wild populations in which age-at-entry is unknown and using remaining information in randomly encountered individuals. This is a first step towards a broad new concept of 'expressed demographic information content of marked or captured individuals'. Copyright 2004 Blackwell Publishing Ltd.

  1. Modeling Programs Increase Aircraft Design Safety

    Science.gov (United States)

    2012-01-01

    Flutter may sound like a benign word when associated with a flag in a breeze, a butterfly, or seaweed in an ocean current. When used in the context of aerodynamics, however, it describes a highly dangerous, potentially deadly condition. Consider the case of the Lockheed L-188 Electra Turboprop, an airliner that first took to the skies in 1957. Two years later, an Electra plummeted to the ground en route from Houston to Dallas. Within another year, a second Electra crashed. In both cases, all crew and passengers died. Lockheed engineers were at a loss as to why the planes wings were tearing off in midair. For an answer, the company turned to NASA s Transonic Dynamics Tunnel (TDT) at Langley Research Center. At the time, the newly renovated wind tunnel offered engineers the capability of testing aeroelastic qualities in aircraft flying at transonic speeds near or just below the speed of sound. (Aeroelasticity is the interaction between aerodynamic forces and the structural dynamics of an aircraft or other structure.) Through round-the-clock testing in the TDT, NASA and industry researchers discovered the cause: flutter. Flutter occurs when aerodynamic forces acting on a wing cause it to vibrate. As the aircraft moves faster, certain conditions can cause that vibration to multiply and feed off itself, building to greater amplitudes until the flutter causes severe damage or even the destruction of the aircraft. Flutter can impact other structures as well. Famous film footage of the Tacoma Narrows Bridge in Washington in 1940 shows the main span of the bridge collapsing after strong winds generated powerful flutter forces. In the Electra s case, faulty engine mounts allowed a type of flutter known as whirl flutter, generated by the spinning propellers, to transfer to the wings, causing them to vibrate violently enough to tear off. Thanks to the NASA testing, Lockheed was able to correct the Electra s design flaws that led to the flutter conditions and return the

  2. Common factors in the withdrawal of European aircraft manufacturers from the regional aircraft market

    NARCIS (Netherlands)

    Heerkens, Johannes M.G.; de Bruijn, E.J.; Steenhuis, H.J.

    2010-01-01

    We investigate whether there were common causes for the withdrawal from the regional aircraft market of three established manufacturers (BAE Systems, Fokker and Saab), while competitors thrived. We focus on the markets for 50- and 100-seat aircraft. One cause concerning the 50-seat market was the

  3. 76 FR 40219 - Airworthiness Directives; Various Aircraft Equipped With Rotax Aircraft Engines 912 A Series Engine

    Science.gov (United States)

    2011-07-08

    ... Equipped With Rotax Aircraft Engines 912 A Series Engine AGENCY: Federal Aviation Administration (FAA), DOT... action'' under Executive Order 12866; (2) Is not a ``significant rule'' under DOT Regulatory Policies and... stria AMT-200 912 A2. Mec nico- Metal rgica Ltda. Diamond Aircraft Industries... HK 36 R ``SUPER 912 A...

  4. THE FEATURES OF AIRCRAFT FUNCTIONAL SYSTEMS PERFORMANCE MONITORING

    Directory of Open Access Journals (Sweden)

    Stanislav Alexandrovich Krotov

    2017-01-01

    Full Text Available The key steps of aircraft essential parameters and events monitoring during its operation are considered in the arti- cle. Conditions for specific risk monitoring are also presented.The notion of fail-safe feature of aircraft functional systems is analysed, and the necessity of continuous process of safety flight level estimate is shown. The method of quantitative assessment of key events and risks probabilities with the use of modern software is proposed. This method contains 5 basic stages: The monitoring parameters setting - this stage is initial and begins with the consideration of organization safety cul- ture, the main purposes and problems determination, the basic parameters and characteristics forming which are to be monitored. The event monitoring in operation - on this stage continuous process of key events searching and monitoring which are a thing of importance within the framework of the established problems takes place. This process is closely relat- ed to parameters monitoring set on the first stage. The event and risk estimate - this stage begins directly after the event has been discovered. The estimate pro- cess is as long as it is required to identify the event gravity. It also contains the preliminary risk estimate for using in priori- tization of initial expanded estimate and in the working out of plan for activities realization. The working out of plan for activities - on this stage correction data is determined that will make changes to aero- technics working out, operation, maintenance and to staff training directly in linkage to the problem event identified earlier. The activity carrying-out - the realization of actions according to the activity plan. This stage concludes priori- tization, planning and problem carrying-out. The dependence set between the probability of failure situations and the degree of their danger is shown. The key factors which are subject to be estimated while aircraft operating and which aim with

  5. Smart aircraft fastener evaluation (SAFE) system: a condition-based corrosion detection system for aging aircraft

    Science.gov (United States)

    Schoess, Jeffrey N.; Seifert, Greg; Paul, Clare A.

    1996-05-01

    The smart aircraft fastener evaluation (SAFE) system is an advanced structural health monitoring effort to detect and characterize corrosion in hidden and inaccessible locations of aircraft structures. Hidden corrosion is the number one logistics problem for the U.S. Air Force, with an estimated maintenance cost of $700M per year in 1990 dollars. The SAFE system incorporates a solid-state electrochemical microsensor and smart sensor electronics in the body of a Hi-Lok aircraft fastener to process and autonomously report corrosion status to aircraft maintenance personnel. The long-term payoff for using SAFE technology will be in predictive maintenance for aging aircraft and rotorcraft systems, fugitive emissions applications such as control valves, chemical pipeline vessels, and industrial boilers. Predictive maintenance capability, service, and repair will replace the current practice of scheduled maintenance to substantially reduce operational costs. A summary of the SAFE concept, laboratory test results, and future field test plans is presented.

  6. Comparison of advanced turboprop and conventional jet and propeller aircraft flyover noise annoyance: Preliminary results

    Science.gov (United States)

    Mccurdy, D. A.

    1985-01-01

    A laboratory experiment was conducted to compare the flyover noise annoyance of proposed advanced turboprop aircraft with that of conventional turboprop and jet aircraft. The effects of fundamental frequency and tone-to-broadband noise ratio on advanced turboprop annoyance were also examined. A computer synthesis system is used to generate 18 realistic, time varying simulations of propeller aircraft takeoff noise in which the harmonic content is systematically varied to represent the factorial combinations of six fundamental frequencies ranging from 67.5 Hz to 292.5 Hz and three tone-to-broadband noise ratios of 0, 15, and 30 dB. These advanced turboprop simulations along with recordings of five conventional turboprop takeoffs and five conventional jet takeoffs are presented at D-weighted sound pressure levels of 70, 80, and 90 dB to 32 subjects in an anechoic chamber. Analyses of the subjects' annoyance judgments compare the three categories of aircraft and examine the effects of the differences in harmonic content among the advanced turboprop noises. The annoyance prediction ability of various noise measurement procedures and corrections is also examined.

  7. Comparison of advanced turboprop and conventional jet and propeller aircraft flyover noise annoyance - Preliminary results

    Science.gov (United States)

    Mccurdy, D. A.

    1985-01-01

    A laboratory experiment was conducted to compare the flyover noise annoyance of proposed advanced turboprop aircraft with that of conventional turboprop and jet aircraft. The effects of fundamental frequency and tone-to-broadband noise ratio on advanced turboprop annoyance were also examined. A computer synthesis system was used to generate 18 realistic, time varyring simulations of propeller aircraft takeoff noise in which the harmonic content was systematically varied to represent the factorial combinations of six fundamental frequencies ranging from 67.5 Hz to 292.5 Hz and three tone-to-broadband noise ratios of 0, 15, and 30 dB. These advanced turboprop simulations along with recordings of five conventional turboprop takeoffs and five conventional jet takeoffs were presented at D-weighted sound pressure levels of 70, 80, and 90 dB to 32 subjects in an anechoic chamber. Analyses of the subjects' annoyance judgments compare the three categories of aircraft and examine the effects of the differences in harmonic content among the advanced turboprop noises. The annoyance prediction ability of various noise measurement procedures and corrections is also examined.

  8. Shock vibration and damage responses of primary auxiliary buildings from aircraft impact

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Shup [Korea Atomic Energy Research Institute, 1045 Daeduk-daero, Dukjin-dong, Yuseong-gu, Daejeon 305-303 (Korea, Republic of); Department of Civil and Environmental Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Hahm, Daegi [Korea Atomic Energy Research Institute, 1045 Daeduk-daero, Dukjin-dong, Yuseong-gu, Daejeon 305-303 (Korea, Republic of); Park, Taehyo, E-mail: cepark@hanyang.ac.kr [Department of Civil and Environmental Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2016-12-15

    Highlights: • Aircraft impact analyses of PABs were performed using both the force-time history method and missile-target interaction method. • The jet fuel was considered by using the added mass modeling method and SPH method, respectively. • The FRS and the structural integrity of the external wall of the PABs against an aircraft impact were analyzed. - Abstract: Safety assessments on nuclear power plants (NPPs) subjected to an aircraft impact (AI) caused by terrorists are pivotal focuses for amelioration of present. To date, most studies have mainly focused on structure responses and the integrity of the containment building at a nuclear island (NI) subjected to AI. However, the safety assessment of internal equipment and components by shock vibration as well as the structure damage induced by AI are also important. In this study, aircraft impact analyses (AIA) of primary auxiliary buildings (PABs) were carried out using both the force–time history method and the missile–target interaction method. For the AIA, the jet fuel was taken into account by using the added mass modeling method and the smooth particles hydrodynamics (SPH) method, respectively. In addition, the floor response spectra (FRS) and the structural integrity of the external wall of the PAB against an AI were analyzed. Finally, the difference in the FRS at the location of the components on both sides of the bay was analyzed.

  9. Organizational conditions for dealing with the unknown unknown : illustrated by how a Dutch water management authority is preparing for climate change

    NARCIS (Netherlands)

    Termeer, C.J.A.M.; Brink, van den M.A.

    2013-01-01

    The central question of this article is the extent to which organizations, governmental authorities in particular, are able to deal with the unknown unknown. Drawing on Weick’s work on sensemaking, we introduce seven organizational conditions that can facilitate organizations to be reliable under

  10. Organizational Conditions for Dealing with The Unknown Unknown Illustrated by how a Dutch water management authority is preparing for climate change

    NARCIS (Netherlands)

    Termeer, Catrien J. A. M.; van den Brink, Margo A.

    2013-01-01

    The central question of this article is the extent to which organizations, governmental authorities in particular, are able to deal with the unknown unknown. Drawing on Weick's work on sensemaking, we introduce seven organizational conditions that can facilitate organizations to be reliable under

  11. A subjective scheduler for subjective dedicated networks

    Science.gov (United States)

    Suherman; Fakhrizal, Said Reza; Al-Akaidi, Marwan

    2017-09-01

    Multiple access technique is one of important techniques within medium access layer in TCP/IP protocol stack. Each network technology implements the selected access method. Priority can be implemented in those methods to differentiate services. Some internet networks are dedicated for specific purpose. Education browsing or tutorial video accesses are preferred in a library hotspot, while entertainment and sport contents could be subjects of limitation. Current solution may use IP address filter or access list. This paper proposes subjective properties of users or applications are used for priority determination in multiple access techniques. The NS-2 simulator is employed to evaluate the method. A video surveillance network using WiMAX is chosen as the object. Subjective priority is implemented on WiMAX scheduler based on traffic properties. Three different traffic sources from monitoring video: palace, park, and market are evaluated. The proposed subjective scheduler prioritizes palace monitoring video that results better quality, xx dB than the later monitoring spots.

  12. Direct-seismogram inversion for receiver-side structure with unknown source-time functions

    Science.gov (United States)

    Dettmer, J.; Dosso, S. E.; Bodin, T.; Stipcevic, J.; Cummins, P. R.

    2015-12-01

    This work presents direct-seismogram inversion for receiver-side structure which treats the source signal incident from below (the effective source-time function, STF) as a vector of unknown parameters in a Bayesian framework. As a result, direct-seismogram inversion does not require deconvolution by observed seismogram components as typically applied in receiver-function inversion, and avoids the problematic issue of choosing subjective tuning parameters in the deconvolution. This results in more meaningful inversion results and uncertainty estimation (compared to classic receiver function inversion). A rigorous likelihood function is derived for unbiased inversion results and the STF is efficiently inferred by a maximum-likelihood closed form expression that does not require deconvolution by noisy waveforms. Rather, deconvolution is only by predicted impulse responses for the unknown environment. For a given realization of the parameter vector which describes the medium below the station, data predictions are computed as the convolution of the impulse response and the maximum-likelihood source estimate for that medium. Therefore, the assumption of a Gaussian pulse with specified parameters, typical for the prediction of receiver functions, is not required. Directly inverting seismogram components has important consequences for the noise on the data. Since the signal processing does not require filtering and deconvolution, data errors (including measurement and theory errors) appear to be less correlated and more straightforward to model than those for receiver functions. The direct-seismogram inversion is demonstrated for simulated waveforms and applied to teleseismic data recorded for station Hyderabad on the Indian craton.

  13. Can pluralistic approaches based upon unknown languages enhance learner engagement and lead to active social inclusion?

    Science.gov (United States)

    Dahm, Rebecca

    2017-08-01

    One way to foster active social inclusion is to enable students to develop a positive attitude to "foreignness". Creating a situation where mainstream students are less wary of foreign languages and cultures, and where newcomers feel their linguistic background is being valued, provides favourable conditions for the inclusion of these newcomers in the classroom and in society. However, language classrooms in French schools rarely take any previously acquired linguistic knowledge into account, thus unconsciously contributing to the rift between multilingual learners (e.g. 1st- and 2nd-generation immigrant children, refugees, children of parents with different mother tongues) and French learners. Native French learners' first experience of learning another language is usually when English is added as a subject to their curriculum in primary school. In some schools in France, English lessons now include the simulation of multilingual situations, designed in particular for the French "quasi-monolingual" students to lose their fear of unknown languages and "foreignness" in general. But the overall aim is to help both groups of learners become aware of the positive impact of multilingualism on cognitive abilities. However, to achieve long-term effects, this awareness-raising needs to be accompanied by maximum engagement on the part of the students. This article explores an instructional strategy termed Pluralistic Approaches based upon Unknown Languages (PAUL), which was designed to develop learning strategies of quasi-monolingual students in particular and to increase learner engagement more generally. The results of a small-scale PAUL study discussed by the author seem to confirm an increase in learner engagement leading to an enhancement of learning outcomes. Moreover, PAUL seems indeed suitable for helping to prepare the ground for social inclusion.

  14. Risk of cancer of unknown primary after hospitalization for autoimmune diseases.

    Science.gov (United States)

    Hemminki, Kari; Sundquist, Kristina; Sundquist, Jan; Ji, Jianguang

    2015-12-15

    Cancer of unknown primary (CUP) is a heterogeneous syndrome diagnosed at metastatic sites. The etiology is unknown but immune dysfunction may be a contributing factor. Patients with autoimmune diseases were identified from the Swedish Hospital Discharge Register and linked to the Swedish Cancer Registry. Standardized incidence ratios (SIRs) were calculated for subsequent CUP and compared with subjects without autoimmune diseases. A total of 789,681 patients were hospitalized for any of 32 autoimmune diseases during years 1964-2012; 2,658 developed subsequent CUP, giving an overall SIR of 1.27. A total of 16 autoimmune diseases were associated with an increased risk for CUP; polymyositis/dermatomyositis showed the highest SIR of 3.51, followed by primary biliary cirrhosis (1.81) and Addison's disease (1.77). CUP risk is known to be reduced in long-time users of pain-relieving nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin. For patients with ankylosing spondylitis and with some other autoimmune diseases, with assumed chronic medication by NSAIDSs, CUP risks decreased in long-term follow-up. The overall risk of CUP was increased among patients diagnosed with autoimmune diseases, which call for clinical attention and suggest a possible role of immune dysfunction in CUP. The associations with many autoimmune diseases were weak which may imply that autoimmunity may not synergize with CUP-related immune dysfunction. However, long-term NSAID medication probably helped to curtail risks in some autoimmune diseases and CUP risks were generally higher in autoimmune diseases for which NSAIDs are not used and for these CUP appears to be a serious side effect. © 2015 UICC.

  15. Design of workcards for aircraft inspection.

    Science.gov (United States)

    Patel, S; Drury, C G; Lofgren, J

    1994-10-01

    The workcard is the primary document that controls an aircraft inspection task and serves as a major factor influencing inspection performance. The present study develops a methodology for design of workcards, based on the application of human factors knowledge to the analysis of aircraft inspection tasks. A taxonomy for design of usable documentation was developed using four basic categories: information readability, information context, information organization, and physical handling/environmental factors. Within the framework of this taxonomy two extreme representative conditions of aircraft inspection tasks, the A-check and the C-check, were analysed for usability. Issues for workcard redesign were identified within the taxonomy using data from user responses. These were then used to develop alternative design solutions offering improved usability. The increase in usability was measured using inspections of DC-9 aircraft, and proved significant. Not only does this study propose specific design solutions, it also provides a generic methodology that can be followed for design of quality documentation for other aircraft inspection tasks. This methodology is currently being extended for the design of usable information for automated workcards and hypermedia-based documentation.

  16. Probabilistic Fatigue Damage Localization at Unknown Temperatures Using Guided Wave Methods

    Science.gov (United States)

    Hensberry, Kevin

    This research examines the current challenges of using Lamb wave interrogation methods to localize fatigue crack damage in a complex metallic structural component subjected to unknown temperatures. The goal of this work is to improve damage localization results for a structural component interrogated at an unknown temperature, by developing a probabilistic and reference-free framework for estimating Lamb wave velocities and the damage location. The methodology for damage localization at unknown temperatures includes the following key elements: i) a model that can describe the change in Lamb wave velocities with temperature; ii) the extension of an advanced time-frequency based signal processing technique for enhanced time-of-flight feature extraction from a dispersive signal; iii) the development of a Bayesian damage localization framework incorporating data association and sensor fusion. The technique requires no additional transducers to be installed on a structure, and allows for the estimation of both the temperature and the wave velocity in the component. Additionally, the framework of the algorithm allows it to function completely in an unsupervised manner by probabilistically accounting for all measurement origin uncertainty. The novel algorithm was experimentally validated using an aluminum lug joint with a growing fatigue crack. The lug joint was interrogated using piezoelectric transducers at multiple fatigue crack lengths, and at temperatures between 20°C and 80°C. The results showed that the algorithm could accurately predict the temperature and wave speed of the lug joint. The localization results for the fatigue damage were found to correlate well with the true locations at long crack lengths, but loss of accuracy was observed in localizing small cracks due to time-of-flight measurement errors. To validate the algorithm across a wider range of temperatures the electromechanically coupled LISA/SIM model was used to simulate the effects of

  17. File list: ALL.YSt.20.AllAg.Unknown [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.YSt.20.AllAg.Unknown sacCer3 All antigens Yeast strain Unknown SRX695965,SRX695...SRX386340,SRX423150,SRX390617,SRX381288,SRX381305,SRX381248,SRX381298,SRX390619,SRX381289 http://dbarchive.biosciencedbc.jp/kyushu-u/sacCer3/assembled/ALL.YSt.20.AllAg.Unknown.bed ...

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    Full Text Available InP.YSt.20.AllAg.Unknown sacCer3 Input control Yeast strain Unknown SRX423150,SRX39...0617,SRX381248,SRX390619 http://dbarchive.biosciencedbc.jp/kyushu-u/sacCer3/assembled/InP.YSt.20.AllAg.Unknown.bed ...

  19. File list: ALL.YSt.50.AllAg.Unknown [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.YSt.50.AllAg.Unknown sacCer3 All antigens Yeast strain Unknown SRX695965,SRX695...SRX381297,SRX423150,SRX386372,SRX381305,SRX381298,SRX390619,SRX390617 http://dbarchive.biosciencedbc.jp/kyushu-u/sacCer3/assembled/ALL.YSt.50.AllAg.Unknown.bed ...

  20. File list: Oth.YSt.05.AllAg.Unknown [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.YSt.05.AllAg.Unknown sacCer3 TFs and others Yeast strain Unknown SRX105548,SRX6...00,SRX381289,SRX381298 http://dbarchive.biosciencedbc.jp/kyushu-u/sacCer3/assembled/Oth.YSt.05.AllAg.Unknown.bed ...

  1. File list: InP.YSt.05.AllAg.Unknown [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.YSt.05.AllAg.Unknown sacCer3 Input control Yeast strain Unknown SRX423150,SRX38...1248,SRX390619,SRX390617 http://dbarchive.biosciencedbc.jp/kyushu-u/sacCer3/assembled/InP.YSt.05.AllAg.Unknown.bed ...

  2. File list: InP.YSt.50.AllAg.Unknown [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.YSt.50.AllAg.Unknown sacCer3 Input control Yeast strain Unknown SRX423150,SRX39...0619,SRX390617 http://dbarchive.biosciencedbc.jp/kyushu-u/sacCer3/assembled/InP.YSt.50.AllAg.Unknown.bed ...

  3. File list: Oth.YSt.20.AllAg.Unknown [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.YSt.20.AllAg.Unknown sacCer3 TFs and others Yeast strain Unknown SRX695965,SRX6...98,SRX381289 http://dbarchive.biosciencedbc.jp/kyushu-u/sacCer3/assembled/Oth.YSt.20.AllAg.Unknown.bed ...

  4. File list: Oth.YSt.10.AllAg.Unknown [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.YSt.10.AllAg.Unknown sacCer3 TFs and others Yeast strain Unknown SRX695967,SRX6...98,SRX381289,SRX381235 http://dbarchive.biosciencedbc.jp/kyushu-u/sacCer3/assembled/Oth.YSt.10.AllAg.Unknown.bed ...

  5. File list: InP.YSt.10.AllAg.Unknown [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.YSt.10.AllAg.Unknown sacCer3 Input control Yeast strain Unknown SRX423150,SRX38...1248,SRX390617,SRX390619 http://dbarchive.biosciencedbc.jp/kyushu-u/sacCer3/assembled/InP.YSt.10.AllAg.Unknown.bed ...

  6. Automatic control design procedures for restructurable aircraft control

    Science.gov (United States)

    Looze, D. P.; Krolewski, S.; Weiss, J.; Barrett, N.; Eterno, J.

    1985-01-01

    A simple, reliable automatic redesign procedure for restructurable control is discussed. This procedure is based on Linear Quadratic (LQ) design methodologies. It employs a robust control system design for the unfailed aircraft to minimize the effects of failed surfaces and to extend the time available for restructuring the Flight Control System. The procedure uses the LQ design parameters for the unfailed system as a basis for choosing the design parameters of the failed system. This philosophy alloys the engineering trade-offs that were present in the nominal design to the inherited by the restructurable design. In particular, it alloys bandwidth limitations and performance trade-offs to be incorporated in the redesigned system. The procedure also has several other desirable features. It effectively redistributes authority among the available control effectors to maximize the system performance subject to actuator limitations and constraints. It provides a graceful performance degradation as the amount of control authority lessens. When given the parameters of the unfailed aircraft, the automatic redesign procedure reproduces the nominal control system design.

  7. Emergency medical kits on board commercial aircraft: a comparative study.

    Science.gov (United States)

    Sand, Michael; Gambichler, Thilo; Sand, Daniel; Thrandorf, Christina; Altmeyer, Peter; Bechara, Falk G

    2010-11-01

    In cases of critical medical situations on board commercial aircraft, access to emergency medical kits can be lifesaving. Thus, this comparative study investigated acute care medication and equipment supplied in emergency medical kits on board both low-cost carriers and full-service carriers. Thirty-two European airlines (sixteen low-cost carriers and sixteen full-service-carriers) were asked to provide anonymous data on the contents of their emergency medical kits. All emergency medical equipment and medication carried on board were subject to a descriptive analysis with regards to International Civil Aviation Organization (ICAO) standards for emergency medical kits, as well as variation and differences between low-cost carriers and full-service carriers. A total of twelve airlines (seven full-service carriers and five low-cost carriers) participated in this study. None complied with ICAO standards. Emergency medical kits from both full-service carriers and low-cost carriers exhibited a high degree of variability. Two European low-cost carriers were assessed as being insufficiently equipped for a medical emergency requiring acute care. This study demonstrates the high degree of variability in the contents of emergency medical kits. Additionally, some airlines were equipped insufficiently for a critical medical situation on board their aircraft. Frequent checks of national authorities and further evaluation of acute care equipment are required to prepare for potentially life-threatening critical conditions occurring in special environments, such as in airplane during flight. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Aircraft System Design and Integration

    Directory of Open Access Journals (Sweden)

    D. P. Coldbeck

    2000-01-01

    Full Text Available In the 1980's the British aircraft industry changed its approach to the management of projects from a system where a project office would manage a project and rely on a series of specialist departments to support them to a more process oriented method, using systems engineering models, whose most outwardly visible signs were the introduction of multidisciplinary product teams. One of the problems with the old method was that the individual departments often had different priorities and projects would get uneven support. The change in the system was only made possible for complex designs by the electronic distribution of data giving instantaneous access to all involved in the project. In 1997 the Defence and Aerospace Foresight Panel emphasised the need for a system engineering approach if British industry was to remain competitive. The Royal Academy of Engineering recognised that the change in working practices also changed what was required of a chartered engineer and redefined their requirements in 1997 [1]. The result of this is that engineering degree courses are now judged against new criteria with more emphasis placed on the relevance to industry rather than on purely academic content. At the University of Glasgow it was realized that the students ought to be made aware of current working practices and that there ought to be a review to ensure that the degrees give students the skills required by industry. It was decided to produce a one week introduction course in systems engineering for Masters of Engineering (MEng students to be taught by both university lecturers and practitioners from a range of companies in the aerospace industry with the hope of expanding the course into a module. The reaction of the students was favourable in terms of the content but it seems ironic that the main criticism was that there was not enough discussion involving the students. This paper briefly describes the individual teaching modules and discusses the

  9. Review of Idealized Aircraft Wake Vortex Models

    Science.gov (United States)

    Ahmad, Nashat N.; Proctor, Fred H.; Duparcmeur, Fanny M. Limon; Jacob, Don

    2014-01-01

    Properties of three aircraft wake vortex models, Lamb-Oseen, Burnham-Hallock, and Proctor are reviewed. These idealized models are often used to initialize the aircraft wake vortex pair in large eddy simulations and in wake encounter hazard models, as well as to define matched filters for processing lidar observations of aircraft wake vortices. Basic parameters for each vortex model, such as peak tangential velocity and circulation strength as a function of vortex core radius size, are examined. The models are also compared using different vortex characterizations, such as the vorticity magnitude. Results of Euler and large eddy simulations are presented. The application of vortex models in the postprocessing of lidar observations is discussed.

  10. Aircraft Stand Allocation with Associated Resource Scheduling

    DEFF Research Database (Denmark)

    Justesen, Tor Fog; Larsen, Jesper; Lusby, Richard Martin

    An aircraft turn-round refers to the set of processes taking place from when an aircraft parks at its arrival stand until the time it departs from its departure stand. When handling a turn-round, the different processes involved (arrival, disembarkation of passengers, cleaning, etc.) require...... to handle a given set of aircraft turn-rounds. We develop a set packing-based model formulation of the problem which is both flexible in the sense that it can encapsulate any type of resource required during the handling of a turn-round and strong in the sense that conflicts that occur when two or more turn......-rounds simultaneously claim the same resource are handled implicitly. To solve the model, a heuristic based on linear programming is developed. The heuristic iteratively solves a relaxed, restricted version of the problem, adding extra variables at each iteration if needed. The additional variables are identified...

  11. Aircraft induced contrail cirrus over Europe

    Energy Technology Data Exchange (ETDEWEB)

    Mannstein, H.; Schumann, U. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Inst. fuer Physik der Atmosphaere, Oberpfaffenhofen (Germany)

    2005-08-01

    Condensation trails (contrails) and aircraft induced cirrus are nowadays a common feature at the mid latitude skies. Previously the impact of aircraft induced cirrus changes has been roughly estimated from observed decadal trends in cirrus cover but the direct attribution of observed cirrus changes to changes in aviation activity remains uncertain. In this paper the amount of additional cirrus induced from spreading contrails in humid air is estimated from the direct correlation between observed cirrus cover derived with suitable methods from METEOSAT data and aviation flight density reported by EUROCONTROL at high spatial and temporal resolution from June 22 to July 27, 1998 and September 27 to October 21, 2000. The results indicate that the aircraft induced cirrus cover over Europe is about ten times larger than that of linear contrails in the same region. Radiative forcing from the additional cirrus may be more than 10 times higher than that of linear contrails and aviation induced CO{sub 2} increases. (orig.)

  12. Open Vehicle Sketch Pad Aircraft Modeling Strategies

    Science.gov (United States)

    Hahn, Andrew S.

    2013-01-01

    Geometric modeling of aircraft during the Conceptual design phase is very different from that needed for the Preliminary or Detailed design phases. The Conceptual design phase is characterized by the rapid, multi-disciplinary analysis of many design variables by a small engineering team. The designer must walk a line between fidelity and productivity, picking tools and methods with the appropriate balance of characteristics to achieve the goals of the study, while staying within the available resources. Identifying geometric details that are important, and those that are not, is critical to making modeling and methodology choices. This is true for both the low-order analysis methods traditionally used in Conceptual design as well as the highest-order analyses available. This paper will highlight some of Conceptual design's characteristics that drive the designer s choices as well as modeling examples for several aircraft configurations using the open source version of the Vehicle Sketch Pad (Open VSP) aircraft Conceptual design geometry modeler.

  13. Theoretical modeling and computational simulation of robust control for Mars aircraft

    Science.gov (United States)

    Oh, Seyool

    The focus of this dissertation is the development of control system design algorithms for autonomous operation of an aircraft in the Martian atmosphere. This research will show theoretical modeling and computational simulation of robust control and gain scheduling for a prototype Mars aircraft. A few hundred meters above the surface of Mars, the air density is less than 1% of the density of the Earth's atmosphere at sea level. However, at about 33 km (110,000 ft) above the Earth, the air density is similar to that near the surface of Mars. Marsflyer II was designed to investigate these flight regimes: 33 km above the Earth and the actual Mars environment. The fuselage for the preliminary design was cylindrical with a length of 2.59 m (8.49 ft), the wing span was 3.98 m (13.09 ft). The total weight of the demonstrator aircraft was around 4.54 kg (10.02 lb). Aircraft design tools have been developed based on successful aircraft for the Earth`s atmosphere. However, above Mars an airborne robotic explorer would encounter low Reynolds Number flow phenomena combined with high Mach numbers, a region that is unknown for normal Earth aerodynamic applications. These flows are more complex than those occurring at high Reynolds numbers. The performance of airfoils at low Reynolds numbers is poorly understood and generally results in unfavorable aerodynamic characteristics. Design and simulation tools for the low Reynolds number Martian environment could be used to develop Unmanned Aerial Vehicles (UAV). In this study, a robust control method is used to analyze a prototype Mars aircraft. The purpose of this aircraft is to demonstrate stability, control, and performance within a simulated Mars environment. Due to uncertainty regarding the actual Martian environment, flexibility in the operation of the aircraft`s control system is important for successful performance. The stability and control derivatives of Marsflyer II were obtained by using the Advanced Aircraft Analysis (AAA

  14. Eclipse program QF-106 aircraft in flight

    Science.gov (United States)

    1997-01-01

    This photo shows one of the QF-106s used in the Eclipse project in flight. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  15. View of QF-106 aircraft cockpit

    Science.gov (United States)

    1997-01-01

    View of the cockpit and instrument panel of the QF-106 airplane used in the Eclipse project. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wing loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  16. Eclipse program C-141A aircraft

    Science.gov (United States)

    1997-01-01

    This photograph shows the Air Force C-141A that was used in the Eclipse project as a tow vehicle. In 1997 and 1998, the Dryden Flight Research Center at Edwards, California, supported and hosted a Kelly Space & Technology, Inc. project called Eclipse, which sought to demonstrate the feasibility of a reusable tow-launch vehicle concept. The project goal was to successfully tow, inflight, a modified QF-106 delta-wing aircraft with an Air Force C-141A transport aircraft. This would demonstrate the possibility of towing and launching an actual launch vehicle from behind a tow plane. Dryden was the responsible test organization and had flight safety responsibility for the Eclipse project. Dryden provided engineering, instrumentation, simulation, modification, maintenance, range support, and research pilots for the test program. The Air Force Flight Test Center (AFFTC), Edwards, California, supplied the C-141A transport aircraft and crew and configured the aircraft as needed for the tests. The AFFTC also provided the concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator-01) experimental aircraft. Kelly Space & Technology hoped to use the results gleaned from the tow test in developing a series of low-cost, reusable launch vehicles. These tests demonstrated the validity of towing a delta-wing aircraft having high wind loading, validated the tow simulation model, and demonstrated various operational procedures, such as ground processing of in-flight maneuvers and emergency abort scenarios.

  17. Dynamic Leading-Edge Stagnation Point Determination Utilizing an Array of Hot-Film Sensors with Unknown Calibration

    Science.gov (United States)

    Ellsworth, Joel C.

    2017-01-01

    During flight-testing of the National Aeronautics and Space Administration (NASA) Gulfstream III (G-III) airplane (Gulfstream Aerospace Corporation, Savannah, Georgia) SubsoniC Research Aircraft Testbed (SCRAT) between March 2013 and April 2015 it became evident that the sensor array used for stagnation point detection was not functioning as expected. The stagnation point detection system is a self calibrating hot-film array; the calibration was unknown and varied between flights, however, the channel with the lowest power consumption was expected to correspond with the point of least surface shear. While individual channels showed the expected behavior for the hot-film sensors, more often than not the lowest power consumption occurred at a single sensor (despite in-flight maneuvering) in the array located far from the expected stagnation point. An algorithm was developed to process the available system output and determine the stagnation point location. After multiple updates and refinements, the final algorithm was not sensitive to the failure of a single sensor in the array, but adjacent failures beneath the stagnation point crippled the algorithm.

  18. Unmanned aircraft system bridge inspection demonstration project phase II final report.

    Science.gov (United States)

    2017-06-01

    An Unmanned Aircraft System (UAS) is defined by the Federal Aviation Administration (FAA) as an aircraft operated without the possibility of direct human intervention from within the aircraft. Unmanned aircraft are familiarly referred to as drones, a...

  19. 75 FR 66009 - Airworthiness Directives; Cessna Aircraft Company (Type Certificate Previously Held by Columbia...

    Science.gov (United States)

    2010-10-27

    ... Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing (Previously the Lancair... directive (AD): Cessna Aircraft Company (Type Certificate Previously Held by Columbia Aircraft Manufacturing... Company (type certificate previously held by Columbia Aircraft Manufacturing (previously The Lancair...

  20. Improving transient analysis technology for aircraft structures

    Science.gov (United States)

    Melosh, R. J.; Chargin, Mladen

    1989-01-01

    Aircraft dynamic analyses are demanding of computer simulation capabilities. The modeling complexities of semi-monocoque construction, irregular geometry, high-performance materials, and high-accuracy analysis are present. At issue are the safety of the passengers and the integrity of the structure for a wide variety of flight-operating and emergency conditions. The technology which supports engineering of aircraft structures using computer simulation is examined. Available computer support is briefly described and improvement of accuracy and efficiency are recommended. Improved accuracy of simulation will lead to a more economical structure. Improved efficiency will result in lowering development time and expense.

  1. Titanium alloys Russian aircraft and aerospace applications

    CERN Document Server

    Moiseyev, Valentin N

    2005-01-01

    This text offers previously elusive information on state-of-the-art Russian metallurgic technology of titanium alloys. It details their physical, mechanical, and technological properties, as well as treatments and applications in various branches of modern industry, particularly aircraft and aerospace construction. Titanium Alloys: Russian Aircraft and Aerospace Applications addresses all facets of titanium alloys in aerospace and aviation technology, including specific applications, fundamentals, composition, and properties of commercial alloys. It is useful for all students and researchers interested in the investigation and applications of titanium.

  2. Comparison of alternate fuels for aircraft

    Science.gov (United States)

    Witcofski, R. D.

    1979-01-01

    A comparison of candidate alternate fuels for aircraft is presented. The fuels discussed include liquid hydrogen, liquid methane, and synthetic aviation kerosene. Each fuel is evaluated from the standpoint of production, transmission, airport storage and distribution facilities, and use in aircraft. Technology deficient areas for cryogenic fuels, which should be advanced prior to the introduction of the fuels into the aviation industry, are identified, as are the cost and energy penalties associated with not achieving those advances. Environmental emissions and safety aspects of fuel selection are discussed. A detailed description of the various fuel production and liquefaction processes and their efficiencies and economics is given.

  3. A strategic planning methodology for aircraft redesign

    Science.gov (United States)

    Romli, Fairuz Izzuddin

    Due to a progressive market shift to a customer-driven environment, the influence of engineering changes on the product's market success is becoming more prominent. This situation affects many long lead-time product industries including aircraft manufacturing. Derivative development has been the key strategy for many aircraft manufacturers to survive the competitive market and this trend is expected to continue in the future. Within this environment of design adaptation and variation, the main market advantages are often gained by the fastest aircraft manufacturers to develop and produce their range of market offerings without any costly mistakes. This realization creates an emphasis on the efficiency of the redesign process, particularly on the handling of engineering changes. However, most activities involved in the redesign process are supported either inefficiently or not at all by the current design methods and tools, primarily because they have been mostly developed to improve original product development. In view of this, the main goal of this research is to propose an aircraft redesign methodology that will act as a decision-making aid for aircraft designers in the change implementation planning of derivative developments. The proposed method, known as Strategic Planning of Engineering Changes (SPEC), combines the key elements of the product redesign planning and change management processes. Its application is aimed at reducing the redesign risks of derivative aircraft development, improving the detection of possible change effects propagation, increasing the efficiency of the change implementation planning and also reducing the costs and the time delays due to the redesign process. To address these challenges, four research areas have been identified: baseline assessment, change propagation prediction, change impact analysis and change implementation planning. Based on the established requirements for the redesign planning process, several methods and

  4. Rapid prototyping of composite aircraft structures

    Science.gov (United States)

    Bennett, George; Rais-Rohani, Masoud; Hall, Kenneth; Holifield, Walt; Sullivan, Rani; Brown, Scott

    The faculty, staff and students of the Raspet Flight Research Laboratory (RFRL) have developed a rapid prototyping capability in a series of research aircraft and unmanned aircraft development projects. There has been a steady change in the technologies used to accomplish these tasks at the RFRL. The most recent development has been the utilization of computer graphics and a 5-axis gantry robot router to accelerate the design, moldmaking and parts trimming tasks. The composite structure fabrication processes at the RFRL have evolved from wet-lay-up to autoclave curve. Currently, the feasibility of the stitched composite material preform and resin transfer molding process is being explored.

  5. NASA/JPL Aircraft SAR Workshop Proceedings

    Science.gov (United States)

    Donovan, N. (Editor); Evans, D. L. (Editor); Held, D. N. (Editor)

    1985-01-01

    Speaker-supplied summaries of the talks given at the NASA/JPL Aircraft SAR Workshop on February 4 and 5, 1985, are provided. These talks dealt mostly with composite quadpolarization imagery from a geologic or ecologic prespective. An overview and summary of the system characteristics of the L-band synthetic aperture radar (SAR) flown on the NASA CV-990 aircraft are included as supplementary information. Other topics ranging from phase imagery and interferometric techniques classifications of specific areas, and the potentials and limitations of SAR imagery in various applications are discussed.

  6. Response of geese to aircraft disturbances

    Science.gov (United States)

    Ward, David; Stehn, Robert A.; Derksen, Dirk V.

    2000-01-01

    Low-flying aircraft can affect behavior, physiology, and distribution of wildlife (Manci et al., 1988), and over time, may impact a population by reducing survival and reproductive performance. Thus, it is important to identify the particular aspects of overflights that affect animals so that management strategies can be developed to minimize adverse effects.Waterfowl are particularly sensitive to low-flying aircraft (Manci et al., 1988) and respond at all stages of their annual cycle, including breeding (Gollop et al., 1974a; Laing, 1991), molting (Derksen et al., 1979; Mosbech and Glahder, 1991), migration (Jones and Jones, 1966; Belanger and Bedard, 1989), and wintering (Owens, 1977; Kramer et al., 1979; Henry, 1980). Waterfowl response can be quite variable both within and among species (Fleming et al., 1996). For example, response can vary with age, sex, and body condition of individual, habitat type and quality, and previous exposure to aircraft (Dahlgren and Korshgen, 1992). However, the most important factors influencing a response are aircraft type (Davis and Wiseley, 1974; Jensen, 1990), noise (Mosbech and Glahder, 1991; Temple, 1993), and proximity to the birds, as measured in altitude and lateral distance (Derksen et al., 1979; Belanger and Bedard, 1989; Ward et al., 1994). Wildlife managers can reduce impacts on a population by controlling or modifying these factors.In an experimental study conducted at Izembek Lagoon in southwestern Alaska in 1985-1988 (Ward and Stehn, 1989), we conducted planned aircraft overflights with control of aircraft type, noise, altitude, and lateral distance to flocks (hereafter called lateral distance) to measure behavioral response of fall-staging Pacific brant (Branta bernicla nigricans) and Canada geese (B. canadensis taverneri) to fixed- and rotary-wing aircraft. These data were then used to develop predictive models of the relationship between aircraft type, noise, altitude, and lateral distance and the response of

  7. An aircraft Earth station for general aviation

    Science.gov (United States)

    Matyas, R.; Boughton, J.; Lyons, R.; Spenler, S.; Rigley, J.

    While the focus has been international commercial air traffic, an opportunity exists to provide satellite communications to smaller aircraft. For these users equipment cost and weight critically impact the decision to install satellite communications equipment. Less apparent to the operator is the need for a system infrastructure that will be supported both regionally and internationally and that is compatible with the ground segment being installed for commercial aeronautical satellite communications. A system concept is described as well as a low cost terminal that are intended to satisfy the small aircraft market.

  8. Fluid-Structure Interaction in a Fluid-Filled Composite Structure Subjected to Low Velocity Impact

    Science.gov (United States)

    2016-06-01

    this study of impact force, deflection, and strain were measured in a carbon fiber reinforced polymer (CFRP) composite cylinder subjected to low...Sanchez, J. Lopez-Puente, and D. Varas, “On the influence of filling level in CFRP aircraft fuel tank subjected to high velocity impacts,” Composite ...and back sides. The baffle provided the greatest strain reduction at the high fill levels. 14. SUBJECT TERMS glass fiber composite , fluid structure

  9. Conversion of the dual training aircraft (DC into single control advanced training aircraft (SC. Part I

    Directory of Open Access Journals (Sweden)

    Ioan ŞTEFĂNESCU

    2011-03-01

    Full Text Available Converting the DC school jet aircraft into SC advanced training aircraft - and use them forthe combat training of military pilots from the operational units, has become a necessity due to thebudget cuts for Air Force, with direct implications on reducing the number of hours of flight assignedto operating personnel for preparing and training.The purpose of adopting such a program is to reduce the number of flight hours allocated annuallyfor preparing and training in advanced stages of instruction, for every pilot, by more intensive use ofthis type of aircraft, which has the advantage of lower flight hour costs as compared to a supersoniccombat plane.

  10. PRN 96-3: Pesticide Products Used to Disinsect Aircraft

    Science.gov (United States)

    This Notice specifies labeling changes for any pesticide product (insecticide) used for disinsecting aircraft. EPA required these changes based on incident information associated with the use of insecticide spray products occupied aircraft cabins.

  11. A Turbo-Brayton Cryocooler for Aircraft Superconducting Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Hybrid turbo-electric aircraft with gas turbines driving electric generators connected to electric propulsion motors have the potential to transform the aircraft...

  12. Noise transmission loss of aircraft panels using acoustic intensity methods

    Science.gov (United States)

    Mcgary, M. C.

    1982-01-01

    The two-microphone, cross-spectral, acoustic intensity measurement technique was used to determine the acoustic transmission loss of three different aircraft panels. The study was conducted in the transmission loss apparatus in the Langley aircraft noise reduction laboratory.

  13. The contribution of aircraft emissions to the atmospheric sulfur budget

    Energy Technology Data Exchange (ETDEWEB)

    Kjellstroem, E. [Stockholm Univ. (Sweden). Dept. of Meteorology; Feichter, J. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany); Sausen, R.; Hein, R. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

    1998-01-01

    An atmospheric general circulation model including the atmospheric sulfur cycle has been used to investigate the impact of aircraft sulfur emissions on the global sulfur budget of the atmosphere. The relative contribution from aircraft sulfur to the atmospheric sulfate burden is larger than the ratio between aircraft emissions and surface emissions due to the calculated long turn-over time of aircraft sulfate (about 12 days). However, in terms of the sulfate mass balance, aircraft emissions are small, contributing about 1% of the total sulfate mass north of 40 deg C where the aircraft emissions are largest. Despite this small contribution to sulfate mass, the aircraft emissions could potentially significantly enhance the background number concentration of aerosol particles. Based on the model calculations the increased stratospheric background aerosol mass observed during the last decades can not be explained by increased aircraft sulfur emissions 50 refs, 9 figs, 4 tabs

  14. Fault Tolerance, Diagnostics, and Prognostics in Aircraft Flight

    Data.gov (United States)

    National Aeronautics and Space Administration — Abstract In modern fighter aircraft with statically unstable airframe designs, the flight control system is considered flight critical, i.e. the aircraft will...

  15. Practical Voice Recognition for the Aircraft Cockpit Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal responds to the urgent need for improved pilot interfaces in the modern aircraft cockpit. Recent advances in aircraft equipment bring tremendous...

  16. Civil aircraft side-facing seat research summary.

    Science.gov (United States)

    2012-11-01

    The Federal Aviation Administration (FAA) has standards and regulations that are intended to protect aircraft : occupants in the event of a crash. However, side-facing seats were not specifically addressed when aircraft seat : dynamic test standards ...

  17. 77 FR 50954 - Airworthiness Directives; Cessna Aircraft Company

    Science.gov (United States)

    2012-08-23

    ... Directives; Cessna Aircraft Company AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Supplemental... proposed airworthiness directive (AD) for all Cessna Aircraft Company (Cessna) Model 402C airplanes... Company (Cessna) Model 402C airplanes modified by Sierra Industries, Ltd. Supplemental Type Certificate...

  18. Methodology of an Aircraft Accident Response System Assessment

    Directory of Open Access Journals (Sweden)

    Franc Željko Županič

    2012-03-01

    Full Text Available The paper investigates the ability to learn from an aircraft accident as the opportunities for learning diminish with the decline in the accident rate. A safety compromising case is studied as the processes of aircraft accident intervention and recovery can degrade the ability of an aircraft accident investigation process to enhance aviation safety by revealing accident causation. In the case study an assessment of the Slovenian aircraft accident response system was made. For the purpose of evaluating the successfulness of aircraft accident intervention and effectiveness of recovery, a model of aircraft accident response system requirements has been developed. Based on non-conformances identified by the model of requirements, remedial measures are proposed for the enhancement of the aircraft accident response system operation. Criteria for the definition of the transition from accident intervention to recovery are derived from the assessment findings in a manner not to impede the aircraft accident investigation effectiveness and efficiency.

  19. Distributed Data Mining for Aircraft Health Management Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA, DoD, and commercial aircraft operators need to transform vast amounts of aircraft data accumulated in distributed databases into actionable knowledge. We...

  20. 32 CFR 761.14 - Aircraft: Group authorizations.

    Science.gov (United States)

    2010-07-01

    ... authorization: (a) U.S. public aircraft to enter all defense areas. (b) U.S. private aircraft which are under... companies authorized to utilize naval facilities in defense areas for regular commercial activity, to enter...