Science.gov

Sample records for robust flight scheduling

  1. Robust Aircraft Squadron Scheduling in the Face of Absenteeism

    DTIC Science & Technology

    2008-03-01

    manually preparing robust schedules, resistant to changes on paper without any computer help. They try to manually preserve the balance between...But flight schedulers are still assigned to prepare a feasible flight schedule on paper . Schedulers desire to prepare a weekly robust schedule by...the mean of a scheduling model. The desire is for a robust schedule from paper to a computer, thus preparing a robust model will help the

  2. Robust stochastic mine production scheduling

    NASA Astrophysics Data System (ADS)

    Kumral, Mustafa

    2010-06-01

    The production scheduling of open pit mines aims to determine the extraction sequence of blocks such that the net present value (NPV) of a mining project is maximized under capacity and access constraints. This sequencing has significant effect on the profitability of the mining venture. However, given that the values of coefficients in the optimization procedure are obtained in a medium of sparse data and unknown future events, implementations based on deterministic models may lead to destructive consequences to the company. In this article, a robust stochastic optimization (RSO) approach is used to deal with mine production scheduling in a manner such that the solution is insensitive to changes in input data. The approach seeks a trade off between optimality and feasibility. The model is demonstrated on a case study. The findings showed that the approach can be used in mine production scheduling problems efficiently.

  3. Methodologies for building robust schedules

    NASA Technical Reports Server (NTRS)

    Dean, John H.

    1992-01-01

    COMPASS is the name of a Computer Aided Scheduling System designed and built for NASA. COMPASS can be used to develop schedule of activities based upon the temporal relationships of the activities and their resource requirements. COMPASS uses this information, and guided by the user, develops precise start and stop times for the activities. In actual practice however, it is impossible to know with complete certainty what the actual durations of the scheduled activities will really be. The best that one can hope for is knowledge of the probability distribution for the durations. This paper investigates methodologies for using a scheduling tool like COMPASS that is based upon definite values for the resource requirements, while building schedules that remain valid in the face of the schedule execution perturbations. Representations for the schedules developed by these methodologies are presented, along with a discussion of the algorithm that could be used by a computer onboard a spacecraft to efficiently monitor and execute these schedules.

  4. Robust flight control of rotorcraft

    NASA Astrophysics Data System (ADS)

    Pechner, Adam Daniel

    With recent design improvement in fixed wing aircraft, there has been a considerable interest in the design of robust flight control systems to compensate for the inherent instability necessary to achieve desired performance. Such systems are designed for maximum available retention of stability and performance in the presence of significant vehicle damage or system failure. The rotorcraft industry has shown similar interest in adopting these reconfigurable flight control schemes specifically because of their ability to reject disturbance inputs and provide a significant amount of robustness for all but the most catastrophic of situations. The research summarized herein focuses on the extension of the pseudo-sliding mode control design procedure interpreted in the frequency domain. Application of the technique is employed and simulated on two well known helicopters, a simplified model of a hovering Sikorsky S-61 and the military's Black Hawk UH-60A also produced by Sikorsky. The Sikorsky helicopter model details are readily available and was chosen because it can be limited to pitch and roll motion reducing the number of degrees of freedom and yet contains two degrees of freedom, which is the minimum requirement in proving the validity of the pseudo-sliding control technique. The full order model of a hovering Black Hawk system was included both as a comparison to the S-61 helicopter design system and as a means to demonstrate the scaleability and effectiveness of the control technique on sophisticated systems where design robustness is of critical concern.

  5. Advances in robust flight design

    NASA Technical Reports Server (NTRS)

    Wong, Kelvin K.; Dhand, Sanjeev K.

    1991-01-01

    Current launch vehicle trajectory design philosophies, generally based on maximizing payload capability, result in an expensive and time-consuming iteration in trajectory design for each mission. However, for a launch system that is not performance-driven, a flight design that is robust to variations in missions and provides single-engine-out capability can be highly cost-effective. This philosophy has led to the development of two flight design concepts to reduce recurring costs: standard trajectories and command multiplier steering. Preliminary analyses of these two concepts had proven the feasibility and showed encouraging results in applications to an Advanced Launch System vehicle. Recent progress has demonstrated the effective and efficient integration of the two concepts with minimal payload penalty.

  6. 14 CFR 91.1029 - Flight scheduling and locating requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Flight scheduling and locating requirements... Ownership Operations Program Management § 91.1029 Flight scheduling and locating requirements. (a) Each... established for locating each flight, for which a flight plan is not filed, that— (1) Provide the...

  7. Low Bandwidth Robust Controllers for Flight

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel J.; Chou, Hwei-Lan

    1993-01-01

    Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.

  8. Low bandwidth robust controllers for flight

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel J.; Chou, Hwei-Lan

    1993-01-01

    Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.

  9. 14 CFR 91.1029 - Flight scheduling and locating requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Flight scheduling and locating requirements. 91.1029 Section 91.1029 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Ownership Operations Program Management § 91.1029 Flight scheduling and locating requirements. (a) Each...

  10. Optimizing Flight Schedules by an Automated Decision Support System

    DTIC Science & Technology

    2014-03-01

    As a result of this, constructing the solution model in a language which is easy to enhance is critical. VBA is a powerful language for easy and quick...Flight Schedule Model ...............................................................................................45 Manual Assignments by...Scheduling Model .............................................................................62 Contribution of scheduling model to air force(s

  11. Methods for in-flight robustness evaluation

    NASA Technical Reports Server (NTRS)

    Brenner, Marty; Paduano, James D.; Feron, Eric

    1995-01-01

    The goal of this program was to combine modern control concepts with new identification techniques to develop a comprehensive package for estimation of 'robust flutter boundaries' based on experimental data. The goal was to use flight data, combined with a fundamental physical understanding of flutter dynamics, to generate a prediction of flutter speed and an estimate of the accuracy of the prediction. This report is organized as follows: the specific contributions of this project will be listed first. Then, the problem under study will be stated and the general approach will be outlined. Third, the specific system under study (F- 18 SRA) will be described and a preliminary data analysis will be performed. Then, the various steps of the flutter boundary determination will be outlined and applied to tile F-18 SRA data and others.

  12. On the robustness of update schedules in Boolean networks.

    PubMed

    Aracena, J; Goles, E; Moreira, A; Salinas, L

    2009-07-01

    Deterministic Boolean networks have been used as models of gene regulation and other biological networks. One key element in these models is the update schedule, which indicates the order in which states are to be updated. We study the robustness of the dynamical behavior of a Boolean network with respect to different update schedules (synchronous, block-sequential, sequential), which can provide modelers with a better understanding of the consequences of changes in this aspect of the model. For a given Boolean network, we define equivalence classes of update schedules with the same dynamical behavior, introducing a labeled graph which helps to understand the dependence of the dynamics with respect to the update, and to identify interactions whose timing may be crucial for the presence of a particular attractor of the system. Several other results on the robustness of update schedules and of dynamical cycles with respect to update schedules are presented. Finally, we prove that our equivalence classes generalize those found in sequential dynamical systems.

  13. Robust optimisation-based microgrid scheduling with islanding constraints

    DOE PAGES

    Liu, Guodong; Starke, Michael; Xiao, Bailu; ...

    2017-02-17

    This paper proposes a robust optimization based optimal scheduling model for microgrid operation considering constraints of islanding capability. Our objective is to minimize the total operation cost, including generation cost and spinning reserve cost of local resources as well as purchasing cost of energy from the main grid. In order to ensure the resiliency of a microgrid and improve the reliability of the local electricity supply, the microgrid is required to maintain enough spinning reserve (both up and down) to meet local demand and accommodate local renewable generation when the supply of power from the main grid is interrupted suddenly,more » i.e., microgrid transitions from grid-connected into islanded mode. Prevailing operational uncertainties in renewable energy resources and load are considered and captured using a robust optimization method. With proper robust level, the solution of the proposed scheduling model ensures successful islanding of the microgrid with minimum load curtailment and guarantees robustness against all possible realizations of the modeled operational uncertainties. Numerical simulations on a microgrid consisting of a wind turbine, a PV panel, a fuel cell, a micro-turbine, a diesel generator and a battery demonstrate the effectiveness of the proposed scheduling model.« less

  14. Optimization of Daily Flight Training Schedules

    DTIC Science & Technology

    2014-03-01

    ENS RL 1 2nd Lt GR 1 ENS YY 1 ENS DH 1 ENS FL 1 LTJG UM 1 LTJG PK ENS HG ENS CC 1 1 19 Table 10. Sample completed events The advanced strike...model uses one “ macro ” CQ event to schedule every CQ eligible student for multiple CQ events throughout the entire CQ training phase. This modeling

  15. Robust and reconfigurable flight control system design

    NASA Astrophysics Data System (ADS)

    Siwakosit, Wichai

    2001-07-01

    A reconfigurable flight control system is a control system which can automatically adapt itself to maintain the performance of a damaged aircraft to be as close as possible to that of the normal or undamaged one. This research focuses mainly on Multi-Input, Multi-Output (MIMO) reconfigurable flight control for an aircraft with damaged actuator(s) which may greatly affect the performance and control of the aircraft, and also pose a challenging flight control problem. The foundation of the control system is a baseline controller and an adaptive module which constitutes a reconfigurable part. The baseline controller ensures that the aircraft has acceptable performance and handling qualities throughout the flight envelope. The combination of a Quantitative Feedback Theory (QFT) Pre-Design Technique (PDT) and a Reduced-order, Linear, Dynamic Inversion (RLDI) control strategy yields a flight control system with good tracking performance and handling qualities with no Pilot Induced Oscillation (PIO) tendencies throughout the designated set of flight conditions. In addition, the system is highly immune to large uncertainties in the aircraft dynamics. The modified filtered-ɛ adaptive algorithm is developed and utilized in the adaptive module of the system. This adaptive algorithm performs well with MIMO system with the added advantage of not having to pre-identify the dynamics of the damaged aircraft, provided that the conditions of reconfigurability are met. An example of the proposed control system with the NASA F-18 HARV vehicle model and a damaged actuator demonstrates the effectiveness of the concept.

  16. Optimization models for flight test scheduling

    NASA Astrophysics Data System (ADS)

    Holian, Derreck

    with restriction removal is based on heuristic approaches to support the reality of flight test in both solution space and computational time. Exact methods for yielding an optimized solution will be discussed however they are not directly applicable to the flight test problem and therefore have not been included in the system.

  17. Robust Control Design for Flight Control

    DTIC Science & Technology

    1989-07-01

    to achieve desired performance over the full flight envelope when linear feedback is employed. Exact linearization methods [48] provide means for...designing nonlinear feedback laws which satisfy these requirements. However, exact linearization is not always compatible with control authority...specific situations. The most promising approaches appear to be those associated with methods of exact linearization . This procedure is based on some

  18. Low bandwidth robust controllers for flight

    NASA Technical Reports Server (NTRS)

    Biezad, Daniel J.; Chou, Hwei-Lan

    1992-01-01

    During the final reporting period (Jun. - Dec. 1992), analyses of the longitudinal and lateral flying qualities were made for propulsive-only flight control (POFC) of a Boeing 720 aircraft model. Performance resulting from compensators developed using Quantitative Feedback Theory (QFT) is documented and analyzed. This report is a first draft of a thesis to be presented by graduate student Hwei-Lan Chou. The final thesis will be presented to NASA when it is completed later this year. The latest landing metrics related to bandwidth criteria and based on the Neal-Smith approach to flying qualities prediction were used in developing performance criteria for the controllers. The compensator designs were tested on the NASA simulator and exhibited adequate performance for piloted flight. There was no significant impact of QFT on performance of the propulsive-only flight controllers in either the longitudinal or lateral modes of flight. This was attributed to the physical limits of thrust available and the engine rate of response, both of whiih severely limited the available bandwidth of the closed-loop system.

  19. Robust Flutter Margin Analysis that Incorporates Flight Data

    NASA Technical Reports Server (NTRS)

    Lind, Rick; Brenner, Martin J.

    1998-01-01

    An approach for computing worst-case flutter margins has been formulated in a robust stability framework. Uncertainty operators are included with a linear model to describe modeling errors and flight variations. The structured singular value, mu, computes a stability margin that directly accounts for these uncertainties. This approach introduces a new method of computing flutter margins and an associated new parameter for describing these margins. The mu margins are robust margins that indicate worst-case stability estimates with respect to the defined uncertainty. Worst-case flutter margins are computed for the F/A-18 Systems Research Aircraft using uncertainty sets generated by flight data analysis. The robust margins demonstrate flight conditions for flutter may lie closer to the flight envelope than previously estimated by p-k analysis.

  20. Robust Gain-Scheduled Fault Tolerant Control for a Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Gregory, Irene

    2007-01-01

    This paper presents an application of robust gain-scheduled control concepts using a linear parameter-varying (LPV) control synthesis method to design fault tolerant controllers for a civil transport aircraft. To apply the robust LPV control synthesis method, the nonlinear dynamics must be represented by an LPV model, which is developed using the function substitution method over the entire flight envelope. The developed LPV model associated with the aerodynamic coefficient uncertainties represents nonlinear dynamics including those outside the equilibrium manifold. Passive and active fault tolerant controllers (FTC) are designed for the longitudinal dynamics of the Boeing 747-100/200 aircraft in the presence of elevator failure. Both FTC laws are evaluated in the full nonlinear aircraft simulation in the presence of the elevator fault and the results are compared to show pros and cons of each control law.

  1. Individual differences in strategic flight management and scheduling

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher D.; Raby, Mireille

    1991-01-01

    A group of 30 instrument-rated pilots was made to fly simulator approaches to three airports under conditions of low, medium, and high workload conditions. An analysis is presently conducted of the difference in discrete task scheduling between the group of 10 highest and 10 lowest performing pilots in the sample; this categorization was based on the mean of various flight-profile measures. The two groups were found to differ from each other only in terms of the time when specific events were conducted, and of the optimality of scheduling for certain high-priority tasks. These results are assessed in view of the relative independence of task-management skills from aircraft-control skills.

  2. Individual differences in strategic flight management and scheduling

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher D.; Raby, Mireille

    1991-01-01

    A group of 30 instrument-rated pilots was made to fly simulator approaches to three airports under conditions of low, medium, and high workload conditions. An analysis is presently conducted of the difference in discrete task scheduling between the group of 10 highest and 10 lowest performing pilots in the sample; this categorization was based on the mean of various flight-profile measures. The two groups were found to differ from each other only in terms of the time when specific events were conducted, and of the optimality of scheduling for certain high-priority tasks. These results are assessed in view of the relative independence of task-management skills from aircraft-control skills.

  3. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service... to the International Air Services Transit Agreement in transit across the United States may not...

  4. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service... to the International Air Services Transit Agreement in transit across the United States may not...

  5. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service... to the International Air Services Transit Agreement in transit across the United States may not...

  6. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service... to the International Air Services Transit Agreement in transit across the United States may not...

  7. 14 CFR 375.50 - Transit flights; scheduled international air service operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Transit flights; scheduled international... WITHIN THE UNITED STATES Transit Flights § 375.50 Transit flights; scheduled international air service... to the International Air Services Transit Agreement in transit across the United States may not...

  8. Robust, Decoupled, Flight Control Design with Rate Saturating Actuators

    NASA Technical Reports Server (NTRS)

    Snell, S. A.; Hess, R. A.

    1997-01-01

    Techniques for the design of control systems for manually controlled, high-performance aircraft must provide the following: (1) multi-input, multi-output (MIMO) solutions, (2) acceptable handling qualities including no tendencies for pilot-induced oscillations, (3) a tractable approach for compensator design, (4) performance and stability robustness in the presence of significant plant uncertainty, and (5) performance and stability robustness in the presence actuator saturation (particularly rate saturation). A design technique built upon Quantitative Feedback Theory is offered as a candidate methodology which can provide flight control systems meeting these requirements, and do so over a considerable part of the flight envelope. An example utilizing a simplified model of a supermaneuverable fighter aircraft demonstrates the proposed design methodology.

  9. Multi-Agent Flight Simulation with Robust Situation Generation

    NASA Technical Reports Server (NTRS)

    Johnson, Eric N.; Hansman, R. John, Jr.

    1994-01-01

    A robust situation generation architecture has been developed that generates multi-agent situations for human subjects. An implementation of this architecture was developed to support flight simulation tests of air transport cockpit systems. This system maneuvers pseudo-aircraft relative to the human subject's aircraft, generating specific situations for the subject to respond to. These pseudo-aircraft maneuver within reasonable performance constraints, interact in a realistic manner, and make pre-recorded voice radio communications. Use of this system minimizes the need for human experimenters to control the pseudo-agents and provides consistent interactions between the subject and the pseudo-agents. The achieved robustness of this system to typical variations in the subject's flight path was explored. It was found to successfully generate specific situations within the performance limitations of the subject-aircraft, pseudo-aircraft, and the script used.

  10. Robust flight design for an advanced launch system vehicle

    NASA Technical Reports Server (NTRS)

    Dhand, Sanjeev K.; Wong, Kelvin K.

    1991-01-01

    Current launch vehicle trajectory design philosophies are generally based on maximizing payload capability. This approach results in an expensive trajectory design process for each mission. Two concepts of robust flight design have been developed to significantly reduce this cost: Standardized Trajectories and Command Multiplier Steering (CMS). These concepts were analyzed for an Advanced Launch System (ALS) vehicle, although their applicability is not restricted to any particular vehicle. Preliminary analysis has demonstrated the feasibility of these concepts at minimal loss in payload capability.

  11. Preliminary assessment of the robustness of dynamic inversion based flight control laws

    NASA Technical Reports Server (NTRS)

    Snell, S. A.

    1992-01-01

    Dynamic-inversion-based flight control laws present an attractive alternative to conventional gain-scheduled designs for high angle-of-attack maneuvering, where nonlinearities dominate the dynamics. Dynamic inversion is easily applied to the aircraft dynamics requiring a knowledge of the nonlinear equations of motion alone, rather than an extensive set of linearizations. However, the robustness properties of the dynamic inversion are questionable especially when considering the uncertainties involved with the aerodynamic database during post-stall flight. This paper presents a simple analysis and some preliminary results of simulations with a perturbed database. It is shown that incorporating integrators into the control loops helps to improve the performance in the presence of these perturbations.

  12. Mars Science Laboratory Flight Software Boot Robustness Testing Project Report

    NASA Technical Reports Server (NTRS)

    Roth, Brian

    2011-01-01

    On the surface of Mars, the Mars Science Laboratory will boot up its flight computers every morning, having charged the batteries through the night. This boot process is complicated, critical, and affected by numerous hardware states that can be difficult to test. The hardware test beds do not facilitate testing a long duration of back-to-back unmanned automated tests, and although the software simulation has provided the necessary functionality and fidelity for this boot testing, there has not been support for the full flexibility necessary for this task. Therefore to perform this testing a framework has been build around the software simulation that supports running automated tests loading a variety of starting configurations for software and hardware states. This implementation has been tested against the nominal cases to validate the methodology, and support for configuring off-nominal cases is ongoing. The implication of this testing is that the introduction of input configurations that have yet proved difficult to test may reveal boot scenarios worth higher fidelity investigation, and in other cases increase confidence in the robustness of the flight software boot process.

  13. Robust Aerial Object Tracking in High Dynamic Flight Maneuvers

    NASA Astrophysics Data System (ADS)

    Nussberger, A.; Grabner, H.; van Gool, L.

    2015-08-01

    Integrating drones into the civil airspace is one of the biggest challenges for civil aviation, responsible authorities and involved com- panies around the world in the upcoming years. For a full integration into non-segregated airspace such a system has to provide the capability to automatically detect and avoid other airspace users. Electro-optical cameras have proven to be an adequate sensor to detect all types of aerial objects, especially for smaller ones such as gliders or paragliders. Robust detection and tracking of approaching traffic on a potential collision course is the key component for a successful avoidance maneuver. In this paper we focus on the aerial object tracking during dynamic flight maneuvers of the own-ship where accurate attitude information corresponding to the camera images is essential. Because the 'detect and avoid' functionality typically extends existing autopilot systems the received attitude measurements have unknown delays and dynamics. We present an efficient method to calculate the angular rates from a multi camera rig which we fuse with the delayed attitude measurements. This allows for estimating accurate absolute attitude angles for every camera frame. The proposed method is further integrated into an aerial object tracking framework. A detailed evaluation of the pipeline on real collision encounter scenarios shows that the multi camera rig based attitude estimation enables the correct tracking of approaching traffic during dynamic flight, at which the tracking framework previously failed.

  14. Mars Science Laboratory Flight Software Boot Robustness Testing Project Report

    NASA Technical Reports Server (NTRS)

    Roth, Brian

    2011-01-01

    On the surface of Mars, the Mars Science Laboratory will boot up its flight computers every morning, having charged the batteries through the night. This boot process is complicated, critical, and affected by numerous hardware states that can be difficult to test. The hardware test beds do not facilitate testing a long duration of back-to-back unmanned automated tests, and although the software simulation has provided the necessary functionality and fidelity for this boot testing, there has not been support for the full flexibility necessary for this task. Therefore to perform this testing a framework has been build around the software simulation that supports running automated tests loading a variety of starting configurations for software and hardware states. This implementation has been tested against the nominal cases to validate the methodology, and support for configuring off-nominal cases is ongoing. The implication of this testing is that the introduction of input configurations that have yet proved difficult to test may reveal boot scenarios worth higher fidelity investigation, and in other cases increase confidence in the robustness of the flight software boot process.

  15. 14 CFR 135.265 - Flight time limitations and rest requirements: Scheduled operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Flight time limitations and rest requirements: Scheduled operations. 135.265 Section 135.265 Aeronautics and Space FEDERAL AVIATION... PERSONS ON BOARD SUCH AIRCRAFT Crewmember Flight Time and Duty Period Limitations and Rest Requirements...

  16. 14 CFR 135.265 - Flight time limitations and rest requirements: Scheduled operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Flight time limitations and rest requirements: Scheduled operations. 135.265 Section 135.265 Aeronautics and Space FEDERAL AVIATION... PERSONS ON BOARD SUCH AIRCRAFT Crewmember Flight Time and Duty Period Limitations and Rest Requirements...

  17. 14 CFR 135.265 - Flight time limitations and rest requirements: Scheduled operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Flight time limitations and rest requirements: Scheduled operations. 135.265 Section 135.265 Aeronautics and Space FEDERAL AVIATION... PERSONS ON BOARD SUCH AIRCRAFT Crewmember Flight Time and Duty Period Limitations and Rest Requirements...

  18. 14 CFR 135.265 - Flight time limitations and rest requirements: Scheduled operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations and rest requirements: Scheduled operations. 135.265 Section 135.265 Aeronautics and Space FEDERAL AVIATION... PERSONS ON BOARD SUCH AIRCRAFT Crewmember Flight Time and Duty Period Limitations and Rest Requirements...

  19. 14 CFR 135.265 - Flight time limitations and rest requirements: Scheduled operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Flight time limitations and rest requirements: Scheduled operations. 135.265 Section 135.265 Aeronautics and Space FEDERAL AVIATION... PERSONS ON BOARD SUCH AIRCRAFT Crewmember Flight Time and Duty Period Limitations and Rest Requirements...

  20. Analysis of Navy Flight Scheduling Methods Using FlyAwake

    DTIC Science & Technology

    2009-09-01

    THIS PAGE INTENTIONALLY LEFT BLANK xvii EXECUTIVE SUMMARY Naval Aviation has established strict scheduling guidelines aimed at mitigating aircrew...contributor to mishaps in Naval Aviation . Naval Aviation has published instructions that establish specific guidelines for crew day and crew rest...aircrew rest and work cycles. These terms are known within the aviation community as crew rest and crew day, respectively. The guidelines in both

  1. Robust gain-scheduling for smart-structures in parallel robots

    NASA Astrophysics Data System (ADS)

    Algermissen, Stephan; Rose, Michael; Keimer, Ralf; Sinapius, Michael

    2009-03-01

    In the past years parallel robots demonstrated their capability in applications with high-dynamic trajectories. Smart-structures offer the potential to further increase the productivity of parallel robots by reducing disturbing vibrations caused by high dynamic loads effectively. To investigate parallel robots and their applications, including suitable control concepts for smart-structures, the Collaborative Research Center 562 was founded by the German Research Council (DFG). The latest prototype within this research center is called Triglide. It is a four degree of freedom (DOF) robot with three translational and one rotational DOF. It realizes an acceleration of 10 g* at the effector. In the structure of the robot six active rods and a tri-axial accelerometer are integrated to control effector vibrations in three translational DOF. The main challenge of this control application is the position dependent vibration behavior. A single robust controller is not able to gain satisfying performance within the entire workspace. Therefore a strategy for describing the vibration behavior by linearization at several operating points is developed. Behavior in-between is approximated by a linear approach. On a trajectory robust controllers in all operating points are smoothly switched by robust gain-scheduling. The scheduling parameters are fast varying and though a suitable stability proof is defined, based on Small-Gain approach. Several transformations enhance the results from Small-Gain Theorem and reduce the usual conservatism. Experimental data is used to show the improvements made.

  2. LMI-based robust flight control of an aircraft subject to CG variation

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Yub; Hong, Sung Kyung; Park, Sungsu

    2010-05-01

    This article presents a simple and effective design method for the single robust flight controller of a highly manoeuvring aircraft subject to centre of gravity (CG) variation in flight. This methodology is based on an linear matrix inequality (LMI) regional pole-placement design framework for the polytopic models for the CG variation ranges. The application of this method for a design of stability/control augmentation system for the longitudinal flight control system of a high-performance aircraft is shown. Simulation results show that the proposed LMI-based regional pole-placement design methodology robustly yields consistent performances with adequate Level 1 flying qualities over the entire CG variation range.

  3. Real-Time Robust Adaptive Modeling and Scheduling for an Electronic Commerce Server

    NASA Astrophysics Data System (ADS)

    Du, Bing; Ruan, Chun

    With the increasing importance and pervasiveness of Internet services, it is becoming a challenge for the proliferation of electronic commerce services to provide performance guarantees under extreme overload. This paper describes a real-time optimization modeling and scheduling approach for performance guarantee of electronic commerce servers. We show that an electronic commerce server may be simulated as a multi-tank system. A robust adaptive server model is subject to unknown additive load disturbances and uncertain model matching. Overload control techniques are based on adaptive admission control to achieve timing guarantees. We evaluate the performance of the model using a complex simulation that is subjected to varying model parameters and massive overload.

  4. Robust intelligent flight control for hypersonic vehicles. Ph.D. Thesis - Massachusetts Inst. of Technology

    NASA Technical Reports Server (NTRS)

    Chamitoff, Gregory Errol

    1992-01-01

    Intelligent optimization methods are applied to the problem of real-time flight control for a class of airbreathing hypersonic vehicles (AHSV). The extreme flight conditions that will be encountered by single-stage-to-orbit vehicles, such as the National Aerospace Plane, present a tremendous challenge to the entire spectrum of aerospace technologies. Flight control for these vehicles is particularly difficult due to the combination of nonlinear dynamics, complex constraints, and parametric uncertainty. An approach that utilizes all available a priori and in-flight information to perform robust, real time, short-term trajectory planning is presented.

  5. Wake Cycle Robustness of the Mars Science Laboratory Flight Software

    NASA Technical Reports Server (NTRS)

    Whitehill, Robert

    2011-01-01

    The Mars Science Laboratory (MSL) is a spacecraft being developed by the Jet Propulsion Laboratory (JPL) for the purpose of in-situ exploration on the surface of Mars. The objective of MSL is to explore and quantitatively assess a local region on the Martian surface as a habitat for microbial life, past or present. This objective will be accomplished through the assessment of the biological potential of at least one target environment, the characterization of the geology and geochemistry of the landing region, an investigation of the planetary process relevant to past habitability, and a characterization of surface radiation. For this purpose, MSL incorporates a total of ten scientific instruments for which functions are to include, among others, atmospheric and descent imaging, chemical composition analysis, and radiation measurement. The Flight Software (FSW) system is responsible for all mission phases, including launch, cruise, entry-descent-landing, and surface operation of the rover. Because of the essential nature of flight software to project success, each of the software modules is undergoing extensive testing to identify and correct errors.

  6. Wake Cycle Robustness of the Mars Science Laboratory Flight Software

    NASA Technical Reports Server (NTRS)

    Whitehill, Robert

    2011-01-01

    The Mars Science Laboratory (MSL) is a spacecraft being developed by the Jet Propulsion Laboratory (JPL) for the purpose of in-situ exploration on the surface of Mars. The objective of MSL is to explore and quantitatively assess a local region on the Martian surface as a habitat for microbial life, past or present. This objective will be accomplished through the assessment of the biological potential of at least one target environment, the characterization of the geology and geochemistry of the landing region, an investigation of the planetary process relevant to past habitability, and a characterization of surface radiation. For this purpose, MSL incorporates a total of ten scientific instruments for which functions are to include, among others, atmospheric and descent imaging, chemical composition analysis, and radiation measurement. The Flight Software (FSW) system is responsible for all mission phases, including launch, cruise, entry-descent-landing, and surface operation of the rover. Because of the essential nature of flight software to project success, each of the software modules is undergoing extensive testing to identify and correct errors.

  7. A wavelet neural network based on genetic algorithm and its application to gain scheduling flight control

    NASA Astrophysics Data System (ADS)

    Sun, Xun; Zhang, Weiguo; Yin, Wei; Li, Aijun

    2006-11-01

    As enlarging of the flight envelop, the aerodynamic derivative of the airplane varies enormous. The gain scheduling method is usually used to deal with it. But the workload is enormously and the stability is difficulty to be assured. To solve the above problem, a large envelope wavelet neural network gain scheduling flight control law design method based on genetic algorithm is presented in this paper. Wavelet has good time accuracy in high frequency-domain and the good frequency accuracy in low frequency-domain. Neural network has the self-learning character. In this method, wavelet function instead of Sigmoid function as the excitation function. So the two merits are merged and the high nonlinear function approximation capability could be achieved. In order to obtain higher accuracy and faster speed, genetic algorithm is used to optimize the parameters of the wavelet neural network. This method is used in design the large envelope gain scheduling flight control law. This simulation results show that good control capability could be achieved in large envelope and the system is still stable when modeling error is 20%. In the situation of 20% modeling error, the maximum overshoot is only 12m and it is 35% of the maximum overshoot using normal method.

  8. Reconfigurable Flight Control Design using a Robust Servo LQR and Radial Basis Function Neural Networks

    NASA Technical Reports Server (NTRS)

    Burken, John J.

    2005-01-01

    This viewgraph presentation reviews the use of a Robust Servo Linear Quadratic Regulator (LQR) and a Radial Basis Function (RBF) Neural Network in reconfigurable flight control designs in adaptation to a aircraft part failure. The method uses a robust LQR servomechanism design with model Reference adaptive control, and RBF neural networks. During the failure the LQR servomechanism behaved well, and using the neural networks improved the tracking.

  9. Utilizing Traveler Demand Modeling to Predict Future Commercial Flight Schedules in the NAS

    NASA Technical Reports Server (NTRS)

    Viken, Jeff; Dollyhigh, Samuel; Smith, Jeremy; Trani, Antonio; Baik, Hojong; Hinze, Nicholas; Ashiabor, Senanu

    2006-01-01

    The current work incorporates the Transportation Systems Analysis Model (TSAM) to predict the future demand for airline travel. TSAM is a multi-mode, national model that predicts the demand for all long distance travel at a county level based upon population and demographics. The model conducts a mode choice analysis to compute the demand for commercial airline travel based upon the traveler s purpose of the trip, value of time, cost and time of the trip,. The county demand for airline travel is then aggregated (or distributed) to the airport level, and the enplanement demand at commercial airports is modeled. With the growth in flight demand, and utilizing current airline flight schedules, the Fratar algorithm is used to develop future flight schedules in the NAS. The projected flights can then be flown through air transportation simulators to quantify the ability of the NAS to meet future demand. A major strength of the TSAM analysis is that scenario planning can be conducted to quantify capacity requirements at individual airports, based upon different future scenarios. Different demographic scenarios can be analyzed to model the demand sensitivity to them. Also, it is fairly well know, but not well modeled at the airport level, that the demand for travel is highly dependent on the cost of travel, or the fare yield of the airline industry. The FAA projects the fare yield (in constant year dollars) to keep decreasing into the future. The magnitude and/or direction of these projections can be suspect in light of the general lack of airline profits and the large rises in airline fuel cost. Also, changes in travel time and convenience have an influence on the demand for air travel, especially for business travel. Future planners cannot easily conduct sensitivity studies of future demand with the FAA TAF data, nor with the Boeing or Airbus projections. In TSAM many factors can be parameterized and various demand sensitivities can be predicted for future travel. These

  10. Flying Schedule-Matching Descents to Explore Flight Crews' Perceptions of Their Load and Task Feasibility

    NASA Technical Reports Server (NTRS)

    Martin, Lynne Hazel; Sharma, Shivanjli; Lozito, Sharon; Kaneshige, John; Hayashi, Miwa; Dulchinos, Victoria

    2012-01-01

    Multiple studies have investigated the development and use of ground-based (controller) tools to manage and schedule traffic in future terminal airspace. No studies have investigated the impacts that such tools (and concepts) could have on the flight-deck. To begin to redress the balance, an exploratory study investigated the procedures and actions of ten Boeing-747-400 crews as they flew eight continuous descent approaches in the Los Angeles terminal airspace, with the descents being controlled using speed alone. Although the study was exploratory in nature, four variables were manipulated: speed changes, route constraints, clearance phraseology, and winds. Despite flying the same scenarios with the same events and timing, there was at least a 50 second difference in the time it took crews to fly the approaches. This variation is the product of a number of factors but highlights potential difficulties for scheduling tools that would have to accommodate this amount of natural variation in descent times. The primary focus of this paper is the potential impact of ground scheduling tools on the flight crews performance and procedures. Crews reported "moderate to low" workload, on average; however, short periods of intense and high workload were observed. The non-flying pilot often reported a higher level of workload than the flying-pilot, which may be due to their increased interaction with the Flight Management Computer, when using the aircraft automation to assist with managing the descent clearances. It is concluded that ground-side tools and automation may have a larger impact on the current-day flight-deck than was assumed and that studies investigating this impact should continue in parallel with controller support tool development.

  11. Robust Flight Path Determination for Mars Precision Landing Using Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Bayard, David S.; Kohen, Hamid

    1997-01-01

    This paper documents the application of genetic algorithms (GAs) to the problem of robust flight path determination for Mars precision landing. The robust flight path problem is defined here as the determination of the flight path which delivers a low-lift open-loop controlled vehicle to its desired final landing location while minimizing the effect of perturbations due to uncertainty in the atmospheric model and entry conditions. The genetic algorithm was capable of finding solutions which reduced the landing error from 111 km RMS radial (open-loop optimal) to 43 km RMS radial (optimized with respect to perturbations) using 200 hours of computation on an Ultra-SPARC workstation. Further reduction in the landing error is possible by going to closed-loop control which can utilize the GA optimized paths as nominal trajectories for linearization.

  12. Robust, Radiation Tolerant Command and Data Handling and Power System Electronics from NASA Goddard Space Flight Center

    NASA Technical Reports Server (NTRS)

    Nguyen, Hanson C.; Fraction, James; Ortiz-Acosta, Melyane; Dakermanji, George; Kercheval, Bradford P.; Hernandez-Pellerano, Amri; Kim, David S.; Jung, David S.; Meyer, Steven E.; Mallik, Udayan; hide

    2016-01-01

    The Goddard Modular Smallsat Architecture (GMSA) is developed at NASA Goddard Space Flight Center (GSFC) to address future reliability along with minimizing cost and schedule challenges for NASA Cubesat and Smallsat missions.

  13. Optimal search patterns in honeybee orientation flights are robust against emerging infectious diseases

    PubMed Central

    Wolf, Stephan; Nicholls, Elizabeth; Reynolds, Andrew M.; Wells, Patricia; Lim, Ka S.; Paxton, Robert J.; Osborne, Juliet L.

    2016-01-01

    Lévy flights are scale-free (fractal) search patterns found in a wide range of animals. They can be an advantageous strategy promoting high encounter rates with rare cues that may indicate prey items, mating partners or navigational landmarks. The robustness of this behavioural strategy to ubiquitous threats to animal performance, such as pathogens, remains poorly understood. Using honeybees radar-tracked during their orientation flights in a novel landscape, we assess for the first time how two emerging infectious diseases (Nosema sp. and the Varroa-associated Deformed wing virus (DWV)) affect bees’ behavioural performance and search strategy. Nosema infection, unlike DWV, affected the spatial scale of orientation flights, causing significantly shorter and more compact flights. However, in stark contrast to disease-dependent temporal fractals, we find the same prevalence of optimal Lévy flight characteristics (μ ≈ 2) in both healthy and infected bees. We discuss the ecological and evolutionary implications of these surprising insights, arguing that Lévy search patterns are an emergent property of fundamental characteristics of neuronal and sensory components of the decision-making process, making them robust against diverse physiological effects of pathogen infection and possibly other stressors. PMID:27615605

  14. Flight control application of new stability robustness bounds for linear uncertain systems

    NASA Technical Reports Server (NTRS)

    Yedavalli, Rama K.

    1993-01-01

    This paper addresses the issue of obtaining bounds on the real parameter perturbations of a linear state-space model for robust stability. Based on Kronecker algebra, new, easily computable sufficient bounds are derived that are much less conservative than the existing bounds since the technique is meant for only real parameter perturbations (in contrast to specializing complex variation case to real parameter case). The proposed theory is illustrated with application to several flight control examples.

  15. Flight control application of new stability robustness bounds for linear uncertain systems

    NASA Technical Reports Server (NTRS)

    Yedavalli, Rama K.

    1993-01-01

    This paper addresses the issue of obtaining bounds on the real parameter perturbations of a linear state-space model for robust stability. Based on Kronecker algebra, new, easily computable sufficient bounds are derived that are much less conservative than the existing bounds since the technique is meant for only real parameter perturbations (in contrast to specializing complex variation case to real parameter case). The proposed theory is illustrated with application to several flight control examples.

  16. Calculation of Flight Deck Interval Management Assigned Spacing Goals Subject to Multiple Scheduling Constraints

    NASA Technical Reports Server (NTRS)

    Robinson, John E.

    2014-01-01

    The Federal Aviation Administration's Next Generation Air Transportation System will combine advanced air traffic management technologies, performance-based procedures, and state-of-the-art avionics to maintain efficient operations throughout the entire arrival phase of flight. Flight deck Interval Management (FIM) operations are expected to use sophisticated airborne spacing capabilities to meet precise in-trail spacing from top-of-descent to touchdown. Recent human-in-the-loop simulations by the National Aeronautics and Space Administration have found that selection of the assigned spacing goal using the runway schedule can lead to premature interruptions of the FIM operation during periods of high traffic demand. This study compares three methods for calculating the assigned spacing goal for a FIM operation that is also subject to time-based metering constraints. The particular paradigms investigated include: one based upon the desired runway spacing interval, one based upon the desired meter fix spacing interval, and a composite method that combines both intervals. These three paradigms are evaluated for the primary arrival procedures to Phoenix Sky Harbor International Airport using the entire set of Rapid Update Cycle wind forecasts from 2011. For typical meter fix and runway spacing intervals, the runway- and meter fix-based paradigms exhibit moderate FIM interruption rates due to their inability to consider multiple metering constraints. The addition of larger separation buffers decreases the FIM interruption rate but also significantly reduces the achievable runway throughput. The composite paradigm causes no FIM interruptions, and maintains higher runway throughput more often than the other paradigms. A key implication of the results with respect to time-based metering is that FIM operations using a single assigned spacing goal will not allow reduction of the arrival schedule's excess spacing buffer. Alternative solutions for conducting the FIM operation

  17. Multivariable flight control synthesis and literal robustness analysis for an aeroelastic vehicle

    NASA Technical Reports Server (NTRS)

    Schmidt, David K.; Newman, Brett

    1990-01-01

    An integrated flight/aeroelastic control law is developed analytically for a hypothetical large supersonic transport aircraft in which the first aeroelastic mode frequency of the fuselage (6 rad/sec) is near the short-period mode (2 rad/sec). The approach employed is based on a linear-quadratic-regulator (LQR) formulation (yielding model-following state-feedback gains), followed by asymptotic loop-transfer recovery of LQR robustness (to produce an output-feedback control law). The derivation is outlined, and numerical results comparing the performance and multivariate stability robustness of the present controller with those of a classical controller are presented in graphs. The two controllers are shown to have similar characteristics, even with respect to the sources of limitations on robustness.

  18. Robust nonlinear dynamic inversion flight control design using structured singular value synthesis based on genetic algorithm

    NASA Astrophysics Data System (ADS)

    Ying, Sibin; Ai, Jianliang; Luo, Changhang; Wang, Peng

    2006-11-01

    Non-linear Dynamic Inversion (NDI) is a technique for control law design, which is based on the feedback linearization and achieving desired dynamic response characteristics. NDI requires an ideal and precise model, however, there must be some errors due to the modeling error or actuator faults, therefore the control law designed by NDI has less robustness. Combining with structured singular value μ synthesis method, the system's robustness can be improved notably. The designed controller, which uses the structured singular value μ synthesis method, has high dimensions, and the dimensions must be reduced when we calculate it. This paper presents a new method for the design of robust flight control, which uses structured singular value μ synthesis based on genetic algorithm. The designed controller, which uses this method, can reduce the dimensions obviously compared with the normal method of structured singular value synthesis, so it is easier for application. The presented method is applied to robustness controller design of some super maneuverable fighter. The simulation results show that the dynamic inversion control law achieves a high level of performance in post-stall maneuver condition, and the whole control system has perfect robustness and anti-disturbance ability.

  19. Axial flow effects on robustness of vortical structures about actively deflected wings in flapping flight

    NASA Astrophysics Data System (ADS)

    Medina, Albert; Kweon, Jihoon; Choi, Haecheon; Eldredge, Jeff D.

    2012-11-01

    Flapping wing flight has garnered much attention in the past decade driven by our desire to understand capabilities observed in nature and to develop agile small-scale aerial vehicles. Nature has demonstrated the breadth of maneuverability achievable by flapping wing flight. However, despite recent advances the role of wing flexibility remains poorly understood. In an effort to develop a deeper understanding of wing deflection effects and to explore novel approaches to increasing leading-edge vortex robustness, this three-dimensional computational study explores the aerodynamics of low aspect ratio plates, in hovering kinematics, with isolated flexion lines undergoing prescribed deflection. Major flexion lines, recognized as the primary avenue for deflection in biological fliers, are isolated here in two distinct configurations, resulting in deflection about the wing root and the wing tip, respectively. Of interest is the interaction between axial flow along the span and the vortical structures about the wing. It is proposed that the modes of deflection explored may provide a means of axial flow control for favorably promoting LEV robustness over a broad range of flapping conditions, and provide insight into the nature of flexibility in flapping wing flight. National Science Foundation, National Research Foundation of Korea.

  20. Flight-Deck Strategies and Outcomes When Flying Schedule-Matching Descents

    NASA Technical Reports Server (NTRS)

    Kaneshige, John T.; Sharma, Shivanjli; Martin Lynne; Lozito, Sandra; Dulchinos, Victoria

    2013-01-01

    Recent studies at NASA Ames Research Center have investigated the development and use of ground-based (air traffic controller) tools to manage and schedule air traffic in future terminal airspace. An exploratory study was undertaken to investigate the impacts that such tools (and concepts) could have on the flight-deck. Ten Boeing 747-400 crews flew eight optimized profile descents in the Los Angeles terminal airspace, while receiving scripted current day and futuristic speed clearances, to ascertain their ability to fly schedulematching descents without prior training. Although the study was exploratory in nature, four variables were manipulated: route constraints, winds, speed changes, and clearance phraseology. Despite flying the same scenarios with the same events and timing, there were significant differences in the time it took crews to fly the approaches. This variation is the product of a number of factors but highlights potential difficulties for scheduling tools that would have to accommodate this amount of natural variation in descent times. The focus of this paper is the examination of the crews' aircraft management strategies and outcomes. This includes potentially problematic human-automation interaction issues that may negatively impact arrival times, speed and altitude constraint compliance, and energy management efficiency.

  1. An Analysis of Robust Workforce Scheduling Models for a Nurse Rostering Problem

    DTIC Science & Technology

    2007-03-01

    12 Moz and Pato ...problem and the nurse rerostering problem. The nurse rostering problem has received much attention in the staff scheduling literature (Moz and Pato , 2007...Most recently, Moz and Pato (2007) developed constructive heuristics and genetic algorithms to re-roster a schedule following a disruption. Their use

  2. A robust rotorcraft flight control system design methodology utilizing quantitative feedback theory

    NASA Technical Reports Server (NTRS)

    Gorder, Peter James

    1993-01-01

    Rotorcraft flight control systems present design challenges which often exceed those associated with fixed-wing aircraft. First, large variations in the response characteristics of the rotorcraft result from the wide range of airspeeds of typical operation (hover to over 100 kts). Second, the assumption of vehicle rigidity often employed in the design of fixed-wing flight control systems is rarely justified in rotorcraft where rotor degrees of freedom can have a significant impact on the system performance and stability. This research was intended to develop a methodology for the design of robust rotorcraft flight control systems. Quantitative Feedback Theory (QFT) was chosen as the basis for the investigation. Quantitative Feedback Theory is a technique which accounts for variability in the dynamic response of the controlled element in the design robust control systems. It was developed to address a Multiple-Input Single-Output (MISO) design problem, and utilizes two degrees of freedom to satisfy the design criteria. Two techniques were examined for extending the QFT MISO technique to the design of a Multiple-Input-Multiple-Output (MIMO) flight control system (FCS) for a UH-60 Black Hawk Helicopter. In the first, a set of MISO systems, mathematically equivalent to the MIMO system, was determined. QFT was applied to each member of the set simultaneously. In the second, the same set of equivalent MISO systems were analyzed sequentially, with closed loop response information from each loop utilized in subsequent MISO designs. The results of each technique were compared, and the advantages of the second, termed Sequential Loop Closure, were clearly evident.

  3. A Robust Digital Flight Control System for an Unmanned Research Vehicle Using Discrete Quantitative Feedback Theory

    DTIC Science & Technology

    1991-12-01

    distribution unlimited 91-18995 IIMIEHEIII 1IlII 9 1 12 24 0 2 4 REPO T DO UME TATIN PA E 1 Form ApprovedIREPO T D CUMETATON P GE0MB No. 0704-0188...Master’s Thesis 4 . TITLE AND SUBTITLE 15. FUNDING NUMBERS A ROBUST DIGITAL FLIGHT CONTROL SYSTEM FOR AN UNMANNED RESEARCH VEHICLE USING DISCRETE...1-2 1.4 Assumptions .. .. .. .. .. .. ... .. ... ..... 1- 4 1.5 Scope................................ 1-5 1.6 Standards

  4. LQG/LTR Design of a Robust Flight Controller for the STOL F-15.

    DTIC Science & Technology

    1985-12-01

    BUREAU OF STANDARDSI 963-A IA ’uOF LQG/LTR DESIGN OF ROBSTFLIGHT CONTROLLERFOR THE STOL F-15 THESIS Gregory L. Gross Captain, USAF DT IC ~E.ECTEM...fpuic~ rt~t, ftrbuo 8:6 2 1.2 AFIT/GAE/ENG/85D-1 S LQG/LTR DESIGN OF A ROBUST FLIGHT CONTROLLER FOR THE STOL F-15 THESIS Gregory L. Gross Captain, USAF...FOR THE STOL F-I5 THESIS Presented to the Faculty of the School of Engineering of the Air Force Institute of Technology Air University in Partial

  5. Flight control design using a blend of modern nonlinear adaptive and robust techniques

    NASA Astrophysics Data System (ADS)

    Yang, Xiaolong

    In this dissertation, the modern control techniques of feedback linearization, mu synthesis, and neural network based adaptation are used to design novel control laws for two specific applications: F/A-18 flight control and reusable launch vehicle (an X-33 derivative) entry guidance. For both applications, the performance of the controllers is assessed. As a part of a NASA Dryden program to develop and flight test experimental controllers for an F/A-18 aircraft, a novel method of combining mu synthesis and feedback linearization is developed to design longitudinal and lateral-directional controllers. First of all, the open-loop and closed-loop dynamics of F/A-18 are investigated. The production F/A-18 controller as well as the control distribution mechanism are studied. The open-loop and closed-loop handling qualities of the F/A-18 are evaluated using low order transfer functions. Based on this information, a blend of robust mu synthesis and feedback linearization is used to design controllers for a low dynamic pressure envelope of flight conditions. For both the longitudinal and the lateral-directional axes, a robust linear controller is designed for a trim point in the center of the envelope. Then by including terms to cancel kinematic nonlinearities and variations in the aerodynamic forces and moments over the flight envelope, a complete nonlinear controller is developed. In addition, to compensate for the model uncertainty, linearization error and variations between operating points, neural network based adaptation is added to the designed longitudinal controller. The nonlinear simulations, robustness and handling qualities analysis indicate that the performance is similar to or better than that for the production F/A-18 controllers. When the dynamic pressure is very low, the performance of both the experimental and the production flight controllers is degraded, but Level I handling qualities are still achieved. A new generation of Reusable Launch Vehicles

  6. Robust stability analysis and dynamic gain-scheduled controller design for point time-delay systems with parametrical uncertainties

    NASA Astrophysics Data System (ADS)

    De la Sen, M.

    2008-08-01

    This paper discusses linear fractional representations (LFR) of parameter-dependent nonlinear systems with real-rational nonlinearities and point-delayed dynamics. Sufficient conditions for robust global asymptotic stability independent of the delays and the existence of a robust stabilizing gain-scheduled dynamic controller are investigated via linear matrix inequalities. Such inequalities are obtained from the values of the time-derivatives of appropriate Lyapunov functions at all the vertices of the polytope which contains the parametrized uncertainties. The synthesized stabilizing controller consists of an interpolation being performed with the stabilizing controllers at the set of vertices of a certain polytope where the nonlinear-rational parametrization belongs to. Some extensions are also given concerning robust global asymptotic stability dependent of the delays. Numerical examples corroborate the usefulness of the proposed formalism and its applicability to practical related problems.

  7. Deterministic schedules for robust and reproducible non-uniform sampling in multidimensional NMR.

    PubMed

    Eddy, Matthew T; Ruben, David; Griffin, Robert G; Herzfeld, Judith

    2012-01-01

    We show that a simple, general, and easily reproducible method for generating non-uniform sampling (NUS) schedules preserves the benefits of random sampling, including inherently reduced sampling artifacts, while removing the pitfalls associated with choosing an arbitrary seed. Sampling schedules are generated from a discrete cumulative distribution function (CDF) that closely fits the continuous CDF of the desired probability density function. We compare random and deterministic sampling using a Gaussian probability density function applied to 2D HSQC spectra. Data are processed using the previously published method of Spectroscopy by Integration of Frequency and Time domain data (SIFT). NUS spectra from deterministic sampling schedules were found to be at least as good as those from random schedules at the SIFT critical sampling density, and significantly better at half that sampling density. The method can be applied to any probability density function and generalized to greater than two dimensions. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. On-Line Mu Method for Robust Flutter Prediction in Expanding a Safe Flight Envelope for an Aircraft Model Under Flight Test

    NASA Technical Reports Server (NTRS)

    Lind, Richard C. (Inventor); Brenner, Martin J.

    2001-01-01

    A structured singular value (mu) analysis method of computing flutter margins has robust stability of a linear aeroelastic model with uncertainty operators (Delta). Flight data is used to update the uncertainty operators to accurately account for errors in the computed model and the observed range of aircraft dynamics of the aircraft under test caused by time-varying aircraft parameters, nonlinearities, and flight anomalies, such as test nonrepeatability. This mu-based approach computes predict flutter margins that are worst case with respect to the modeling uncertainty for use in determining when the aircraft is approaching a flutter condition and defining an expanded safe flight envelope for the aircraft that is accepted with more confidence than traditional methods that do not update the analysis algorithm with flight data by introducing mu as a flutter margin parameter that presents several advantages over tracking damping trends as a measure of a tendency to instability from available flight data.

  9. Two Reconfigurable Flight-Control Design Methods: Robust Servomechanism and Control Allocation

    NASA Technical Reports Server (NTRS)

    Burken, John J.; Lu, Ping; Wu, Zheng-Lu; Bahm, Cathy

    2001-01-01

    Two methods for control system reconfiguration have been investigated. The first method is a robust servomechanism control approach (optimal tracking problem) that is a generalization of the classical proportional-plus-integral control to multiple input-multiple output systems. The second method is a control-allocation approach based on a quadratic programming formulation. A globally convergent fixed-point iteration algorithm has been developed to make onboard implementation of this method feasible. These methods have been applied to reconfigurable entry flight control design for the X-33 vehicle. Examples presented demonstrate simultaneous tracking of angle-of-attack and roll angle commands during failures of the fight body flap actuator. Although simulations demonstrate success of the first method in most cases, the control-allocation method appears to provide uniformly better performance in all cases.

  10. Aerodynamics and Mechanics of Robust Flight in Bats: Animal Flight and Physical Model Experiments for Flapping MAV Applications

    DTIC Science & Technology

    During the past three years, we have begun pioneering investigations of the basis of the aerodynamically and mechanically highlyrobust flight ofbats...Our interdisciplinary approach integrates quantitative study of animals executing naturalistic flight behaviors with detailedexplorations thatemploy...foundational contributions to understanding the mechanistic basis for important aspects of bat flight , particularly inertialmaneuvering

  11. Robust In-Flight Sensor Fault Diagnostics for Aircraft Engine Based on Sliding Mode Observers

    PubMed Central

    Chang, Xiaodong; Huang, Jinquan; Lu, Feng

    2017-01-01

    For a sensor fault diagnostic system of aircraft engines, the health performance degradation is an inevitable interference that cannot be neglected. To address this issue, this paper investigates an integrated on-line sensor fault diagnostic scheme for a commercial aircraft engine based on a sliding mode observer (SMO). In this approach, one sliding mode observer is designed for engine health performance tracking, and another for sensor fault reconstruction. Both observers are employed in in-flight applications. The results of the former SMO are analyzed for post-flight updating the baseline model of the latter. This idea is practical and feasible since the updating process does not require the algorithm to be regulated or redesigned, so that ground-based intervention is avoided, and the update process is implemented in an economical and efficient way. With this setup, the robustness of the proposed scheme to the health degradation is much enhanced and the latter SMO is able to fulfill sensor fault reconstruction over the course of the engine life. The proposed sensor fault diagnostic system is applied to a nonlinear simulation of a commercial aircraft engine, and its effectiveness is evaluated in several fault scenarios. PMID:28398255

  12. Robust In-Flight Sensor Fault Diagnostics for Aircraft Engine Based on Sliding Mode Observers.

    PubMed

    Chang, Xiaodong; Huang, Jinquan; Lu, Feng

    2017-04-11

    For a sensor fault diagnostic system of aircraft engines, the health performance degradation is an inevitable interference that cannot be neglected. To address this issue, this paper investigates an integrated on-line sensor fault diagnostic scheme for a commercial aircraft engine based on a sliding mode observer (SMO). In this approach, one sliding mode observer is designed for engine health performance tracking, and another for sensor fault reconstruction. Both observers are employed in in-flight applications. The results of the former SMO are analyzed for post-flight updating the baseline model of the latter. This idea is practical and feasible since the updating process does not require the algorithm to be regulated or redesigned, so that ground-based intervention is avoided, and the update process is implemented in an economical and efficient way. With this setup, the robustness of the proposed scheme to the health degradation is much enhanced and the latter SMO is able to fulfill sensor fault reconstruction over the course of the engine life. The proposed sensor fault diagnostic system is applied to a nonlinear simulation of a commercial aircraft engine, and its effectiveness is evaluated in several fault scenarios.

  13. Flight Schedule and the Circadian Clock Influence on Sleep Loss During Overnight Cargo Operations

    NASA Technical Reports Server (NTRS)

    Gander, Philippa H.; Gregory, Kevin B.; Rosekind, Mark R.; Shafto, Michael G. (Technical Monitor)

    1995-01-01

    Thirty-four flight crew members were monitored before, during, and after two 8-day overnight cargo duty patterns which involved multiple flights at night crossing no more than one time zone per 24 h. Rectal temperature, heart rate, and wrist activity were recorded every 2 min. Sleep quantity and quality, and nap timing, were noted in a logbook. To reduce the masking effects of physical activity on temperature, 0.28 C was added to each subject's raw temperature data whenever he reported being asleep. For both masked and unmasked data, daily temperature minima were estimated from the multiple complex demodulated waveform. The temperature minima did not show a progressive adaptation to night duty, which was interrupted by a night off after 5 nights on one trip pattern and after 3 nights on the other. On duty days, the average temperature minimum delayed by about 3 h, occurring near the end of the duty period. Daytime sleep episodes averaged 2.9 h shorter than nighttime sleep episodes, and were rated as lighter, less restorative, and poorer overall. Fifty-three percent of subjects slept more than once per 24 h while they were on night duty, compared to 17% when able to sleep at night. The total sleep per 24 h on duty days averaged 1.2 h less than pretrip. Twenty-nine percent of subjects lost more than 2 h of sleep per 24 h across the 8-day duty patterns. After night duty, subjects awoke around 1400 local time, even when they had slept 2-3 h less than a normal nocturnal sleep episode. Consequently, the duration of morning sleep episodes was correlated with the off-duty time (multiple r(sup 2)=0.44, F=37.23, p less than 0.0001). Anecdotally, crew members complained of being unable to sleep longer and not feeling well-rested. These wakeups were clustered 6 h after the temperature minimum, which suggests that they may have been a response to the circadian wakeup signal. Daytime layovers in which crew members were able to sleep again in the evening ended later (0200

  14. Robustness

    NASA Technical Reports Server (NTRS)

    Ryan, R.

    1993-01-01

    Robustness is a buzz word common to all newly proposed space systems design as well as many new commercial products. The image that one conjures up when the word appears is a 'Paul Bunyon' (lumberjack design), strong and hearty; healthy with margins in all aspects of the design. In actuality, robustness is much broader in scope than margins, including such factors as simplicity, redundancy, desensitization to parameter variations, control of parameter variations (environments flucation), and operational approaches. These must be traded with concepts, materials, and fabrication approaches against the criteria of performance, cost, and reliability. This includes manufacturing, assembly, processing, checkout, and operations. The design engineer or project chief is faced with finding ways and means to inculcate robustness into an operational design. First, however, be sure he understands the definition and goals of robustness. This paper will deal with these issues as well as the need for the requirement for robustness.

  15. Crash Rates of Scheduled Commuter and Air Carrier Flights Before and After a Regulatory Change

    PubMed Central

    Baker, Susan P.; Groff, Loren; Haaland, Wren; Qiang, Yandong; Rebok, George W.; Li, Guohua

    2010-01-01

    Introduction In 1997, in an effort to reduce the crash rate of scheduled commuter flights, the FAA required aircraft with 10–30 passenger seats to operate under stricter rules. Training and other requirements of 14 CFR Part 121 rules were applied to these midsize commuters, which previously had operated under the less strict Part 135 rules. Published crash rates obscured changes related to aircraft size. This research was undertaken to determine whether the rule change affected crash rates of aircraft with 10–30 passenger seats. Method We determined the number of passenger seats on each Part 135 or Part 121 aircraft that crashed between 1983 and 2007. For aircraft with < 10, 10–30, and > 30 seats, we estimated the numbers of departures and crash rates, adjusting for changes in total departures and numbers of in-service aircraft. Results The Part 135 crash rate tripled in 1997 when commuters with 10–30 seats were excluded, reflecting the administrative change. However, the crash rate of aircraft with 10–30 passenger seats began to decline 4 yr before the rule change; thereafter, their rate was lower than for larger aircraft. The fleet size of aircraft with 10–30 passenger seats increased from 1983 to 1997, then declined as they were replaced with larger aircraft in response to the rule change. Discussion No effect of the rule change on crash rates of 10–30-seat aircraft was apparent. The decline in their crash rates began before the rule change and may have been related to the 1992 requirement for ground proximity warning devices. PMID:19378909

  16. Robustness Analysis and Reliable Flight Regime Estimation of an Integrated Resilent Control System for a Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Belcastro, Christine

    2008-01-01

    Formal robustness analysis of aircraft control upset prevention and recovery systems could play an important role in their validation and ultimate certification. As a part of the validation process, this paper describes an analysis method for determining a reliable flight regime in the flight envelope within which an integrated resilent control system can achieve the desired performance of tracking command signals and detecting additive faults in the presence of parameter uncertainty and unmodeled dynamics. To calculate a reliable flight regime, a structured singular value analysis method is applied to analyze the closed-loop system over the entire flight envelope. To use the structured singular value analysis method, a linear fractional transform (LFT) model of a transport aircraft longitudinal dynamics is developed over the flight envelope by using a preliminary LFT modeling software tool developed at the NASA Langley Research Center, which utilizes a matrix-based computational approach. The developed LFT model can capture original nonlinear dynamics over the flight envelope with the ! block which contains key varying parameters: angle of attack and velocity, and real parameter uncertainty: aerodynamic coefficient uncertainty and moment of inertia uncertainty. Using the developed LFT model and a formal robustness analysis method, a reliable flight regime is calculated for a transport aircraft closed-loop system.

  17. Constraint based scheduling for the Goddard Space Flight Center distributed Active Archive Center's data archive and distribution system

    NASA Technical Reports Server (NTRS)

    Short, Nick, Jr.; Bedet, Jean-Jacques; Bodden, Lee; Boddy, Mark; White, Jim; Beane, John

    1994-01-01

    The Goddard Space Flight Center (GSFC) Distributed Active Archive Center (DAAC) has been operational since October 1, 1993. Its mission is to support the Earth Observing System (EOS) by providing rapid access to EOS data and analysis products, and to test Earth Observing System Data and Information System (EOSDIS) design concepts. One of the challenges is to ensure quick and easy retrieval of any data archived within the DAAC's Data Archive and Distributed System (DADS). Over the 15-year life of EOS project, an estimated several Petabytes (10(exp 15)) of data will be permanently stored. Accessing that amount of information is a formidable task that will require innovative approaches. As a precursor of the full EOS system, the GSFC DAAC with a few Terabits of storage, has implemented a prototype of a constraint-based task and resource scheduler to improve the performance of the DADS. This Honeywell Task and Resource Scheduler (HTRS), developed by Honeywell Technology Center in cooperation the Information Science and Technology Branch/935, the Code X Operations Technology Program, and the GSFC DAAC, makes better use of limited resources, prevents backlog of data, provides information about resources bottlenecks and performance characteristics. The prototype which is developed concurrently with the GSFC Version 0 (V0) DADS, models DADS activities such as ingestion and distribution with priority, precedence, resource requirements (disk and network bandwidth) and temporal constraints. HTRS supports schedule updates, insertions, and retrieval of task information via an Application Program Interface (API). The prototype has demonstrated with a few examples, the substantial advantages of using HTRS over scheduling algorithms such as a First In First Out (FIFO) queue. The kernel scheduling engine for HTRS, called Kronos, has been successfully applied to several other domains such as space shuttle mission scheduling, demand flow manufacturing, and avionics communications

  18. Robust design of a 2-DOF GMV controller: a direct self-tuning and fuzzy scheduling approach.

    PubMed

    Silveira, Antonio S; Rodríguez, Jaime E N; Coelho, Antonio A R

    2012-01-01

    This paper presents a study on self-tuning control strategies with generalized minimum variance control in a fixed two degree of freedom structure-or simply GMV2DOF-within two adaptive perspectives. One, from the process model point of view, using a recursive least squares estimator algorithm for direct self-tuning design, and another, using a Mamdani fuzzy GMV2DOF parameters scheduling technique based on analytical and physical interpretations from robustness analysis of the system. Both strategies are assessed by simulation and real plants experimentation environments composed of a damped pendulum and an under development wind tunnel from the Department of Automation and Systems of the Federal University of Santa Catarina.

  19. Nicotine maintains robust self-administration in rats on a limited-access schedule.

    PubMed

    Corrigall, W A; Coen, K M

    1989-01-01

    Intravenous nicotine maintained substantial responding on the drug-reinforced lever with a limited-access, fixed-ratio 5 schedule of self-administration. Responding demonstrated the expected pharmacological sensitivity; it was dose-dependently reduced by pre-session treatment with either nicotine or mecamylamine but not with hexamethonium. In addition, responding was dependent on the size of the unit dose, with maximum values occurring at 0.01 and 0.03 mg/kg/infusion. Self-administration behavior decreased at doses both above and below these, and extinction followed the substitution of saline for nicotine. Total session drug intake increased with unit dose up to a maximal value of approximately 0.5 mg/kg at 0.03 mg/kg/infusion, but did not increase further at the 0.06 mg/kg/infusion dose. A decrease in the time-out duration at the dose of 0.03 mg/kg/infusion also did not change the total session intake of nicotine. It is suggested that nicotine intake is controlled both by the total amount of drug obtained and by the magnitude of the unit dose. These results demonstrate that intravenous nicotine can maintain substantial self-administration behavior in rodents.

  20. Robust gain-scheduling energy-to-peak control of vehicle lateral dynamics stabilisation

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Zhang, Xinjie; Wang, Junmin

    2014-03-01

    In this paper, we investigate the vehicle lateral dynamics stabilisation problem to enhance vehicle handling by considering time-varying longitudinal velocity. The longitudinal velocity is described by a polytope with finite vertices and a novel technique is proposed to reduce the number of vertices. Since the tyre dynamics is nonlinear, the cornering stiffness is represented via the norm-bounded uncertainty. Concerning the time-varying velocity and the nonlinear tyre model, a linear parameter-varying vehicle model is obtained. As the velocity and the states are measurable, a gain-scheduling state-feedback controller is introduced. In the lateral control, the sideslip angle is required to be as small as possible and the yaw rate is constrained to a certain level. Thus, the control objective is to minimise the sideslip angle while the yaw rate is under a prescribed level or constrain both the sideslip angle and the yaw rate to prescribed levels. To consider the transient response of the closed-loop system, the ?-stability is also employed in the energy-to-peak control. The optimal controller can be obtained by solving a set of linear matrix inequalities. A nonlinear vehicle model is utilised to illustrate the design procedure and the effectiveness of the proposed design method. Finally, simulations and comparisons are carried out to show the significant advantage of the designed controller. Compared to the open-loop system, the closed-loop system with the designed controller can achieve much smaller sideslip angle and the yaw rate is closer to the desired yaw rate from a reference model. Therefore, the vehicle safety and the handling are both improved in our simulation cases.

  1. Nonlinear robust control of hypersonic aircrafts with interactions between flight dynamics and propulsion systems.

    PubMed

    Li, Zhaoying; Zhou, Wenjie; Liu, Hao

    2016-09-01

    This paper addresses the nonlinear robust tracking controller design problem for hypersonic vehicles. This problem is challenging due to strong coupling between the aerodynamics and the propulsion system, and the uncertainties involved in the vehicle dynamics including parametric uncertainties, unmodeled model uncertainties, and external disturbances. By utilizing the feedback linearization technique, a linear tracking error system is established with prescribed references. For the linear model, a robust controller is proposed based on the signal compensation theory to guarantee that the tracking error dynamics is robustly stable. Numerical simulation results are given to show the advantages of the proposed nonlinear robust control method, compared to the robust loop-shaping control approach. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Aircraft motion and passenger comfort data from scheduled commercial airline flights

    NASA Technical Reports Server (NTRS)

    Gruesbeck, M. G.; Sullivan, D. F.

    1976-01-01

    Data concerning the ride quality of aircraft taken on board commercial airline flights was presented. Five types of data are included: (1) root mean square (RMS) values of linear acceleration, angular acceleration or angular velocities, along with passenger subjective evaluations, (2) power spectra for the motion in each of six degrees of freedom, (3) scattergrams showing the probability density of the rms accelerations in the vertical and transverse directions, (4) probability distributions of the motion, and (5) on board noise levels during takeoff, climb, cruise, and descent.

  3. Robust reliable sampled-data control for switched systems with application to flight control

    NASA Astrophysics Data System (ADS)

    Sakthivel, R.; Joby, Maya; Shi, P.; Mathiyalagan, K.

    2016-11-01

    This paper addresses the robust reliable stabilisation problem for a class of uncertain switched systems with random delays and norm bounded uncertainties. The main aim of this paper is to obtain the reliable robust sampled-data control design which involves random time delay with an appropriate gain control matrix for achieving the robust exponential stabilisation for uncertain switched system against actuator failures. In particular, the involved delays are assumed to be randomly time-varying which obeys certain mutually uncorrelated Bernoulli distributed white noise sequences. By constructing an appropriate Lyapunov-Krasovskii functional (LKF) and employing an average-dwell time approach, a new set of criteria is derived for ensuring the robust exponential stability of the closed-loop switched system. More precisely, the Schur complement and Jensen's integral inequality are used in derivation of stabilisation criteria. By considering the relationship among the random time-varying delay and its lower and upper bounds, a new set of sufficient condition is established for the existence of reliable robust sampled-data control in terms of solution to linear matrix inequalities (LMIs). Finally, an illustrative example based on the F-18 aircraft model is provided to show the effectiveness of the proposed design procedures.

  4. Flight Demonstration Results of a Two-Way Robust Acquisition of Data (2-RAD) System

    DTIC Science & Technology

    2004-01-01

    Ground (YPG), Arizona, for their contributions in component selection, software programming, and support of the flight demonstration. Charles ...consultation of Ed Bukowski of DSI about battery power and recharging is greatly appreciated. John Condon of ARL is thanked for his consultation on the

  5. Control design for robust stability in linear regulators: Application to aerospace flight control

    NASA Technical Reports Server (NTRS)

    Yedavalli, R. K.

    1986-01-01

    Time domain stability robustness analysis and design for linear multivariable uncertain systems with bounded uncertainties is the central theme of the research. After reviewing the recently developed upper bounds on the linear elemental (structured), time varying perturbation of an asymptotically stable linear time invariant regulator, it is shown that it is possible to further improve these bounds by employing state transformations. Then introducing a quantitative measure called the stability robustness index, a state feedback conrol design algorithm is presented for a general linear regulator problem and then specialized to the case of modal systems as well as matched systems. The extension of the algorithm to stochastic systems with Kalman filter as the state estimator is presented. Finally an algorithm for robust dynamic compensator design is presented using Parameter Optimization (PO) procedure. Applications in a aircraft control and flexible structure control are presented along with a comparison with other existing methods.

  6. A Robust H ∞ Controller for an UAV Flight Control System

    PubMed Central

    López, J.

    2015-01-01

    The objective of this paper is the implementation and validation of a robust H ∞ controller for an UAV to track all types of manoeuvres in the presence of noisy environment. A robust inner-outer loop strategy is implemented. To design the H ∞ robust controller in the inner loop, H ∞ control methodology is used. The two controllers that conform the outer loop are designed using the H ∞ Loop Shaping technique. The reference vector used in the control architecture formed by vertical velocity, true airspeed, and heading angle, suggests a nontraditional way to pilot the aircraft. The simulation results show that the proposed control scheme works well despite the presence of noise and uncertainties, so the control system satisfies the requirements. PMID:26221622

  7. A Robust H ∞ Controller for an UAV Flight Control System.

    PubMed

    López, J; Dormido, R; Dormido, S; Gómez, J P

    2015-01-01

    The objective of this paper is the implementation and validation of a robust H ∞ controller for an UAV to track all types of manoeuvres in the presence of noisy environment. A robust inner-outer loop strategy is implemented. To design the H ∞ robust controller in the inner loop, H ∞ control methodology is used. The two controllers that conform the outer loop are designed using the H ∞ Loop Shaping technique. The reference vector used in the control architecture formed by vertical velocity, true airspeed, and heading angle, suggests a nontraditional way to pilot the aircraft. The simulation results show that the proposed control scheme works well despite the presence of noise and uncertainties, so the control system satisfies the requirements.

  8. Designing for Damage: Robust Flight Control Design using Sliding Mode Techniques

    NASA Technical Reports Server (NTRS)

    Vetter, T. K.; Wells, S. R.; Hess, Ronald A.; Bacon, Barton (Technical Monitor); Davidson, John (Technical Monitor)

    2002-01-01

    A brief review of sliding model control is undertaken, with particular emphasis upon the effects of neglected parasitic dynamics. Sliding model control design is interpreted in the frequency domain. The inclusion of asymptotic observers and control 'hedging' is shown to reduce the effects of neglected parasitic dynamics. An investigation into the application of observer-based sliding mode control to the robust longitudinal control of a highly unstable is described. The sliding mode controller is shown to exhibit stability and performance robustness superior to that of a classical loop-shaped design when significant changes in vehicle and actuator dynamics are employed to model airframe damage.

  9. Robust Adaptive Flight Control Design of Air-breathing Hypersonic Vehicles

    DTIC Science & Technology

    2016-12-07

    control of an air-breathing hypersonic vehicle in the cruise phase of flight. The first type of controller uses dynamic inversion and the second one is...both controllers is enhanced by augmenting them with a fast disturbance observer. The controller is derived using dynamic inversion technique, by...the controller using dynamic inversion , which is very difficult to achieve in the case of air-breathing hypersonic vehicle. Hence, constrained neuro

  10. Centripetal Acceleration Reaction: An Effective and Robust Mechanism for Flapping Flight in Insects.

    PubMed

    Zhang, Chao; Hedrick, Tyson L; Mittal, Rajat

    2015-01-01

    Despite intense study by physicists and biologists, we do not fully understand the unsteady aerodynamics that relate insect wing morphology and kinematics to lift generation. Here, we formulate a force partitioning method (FPM) and implement it within a computational fluid dynamic model to provide an unambiguous and physically insightful division of aerodynamic force into components associated with wing kinematics, vorticity, and viscosity. Application of the FPM to hawkmoth and fruit fly flight shows that the leading-edge vortex is the dominant mechanism for lift generation for both these insects and contributes between 72-85% of the net lift. However, there is another, previously unidentified mechanism, the centripetal acceleration reaction, which generates up to 17% of the net lift. The centripetal acceleration reaction is similar to the classical inviscid added-mass in that it depends only on the kinematics (i.e. accelerations) of the body, but is different in that it requires the satisfaction of the no-slip condition, and a combination of tangential motion and rotation of the wing surface. Furthermore, the classical added-mass force is identically zero for cyclic motion but this is not true of the centripetal acceleration reaction. Furthermore, unlike the lift due to vorticity, centripetal acceleration reaction lift is insensitive to Reynolds number and to environmental flow perturbations, making it an important contributor to insect flight stability and miniaturization. This force mechanism also has broad implications for flow-induced deformation and vibration, underwater locomotion and flows involving bubbles and droplets.

  11. Centripetal Acceleration Reaction: An Effective and Robust Mechanism for Flapping Flight in Insects

    PubMed Central

    Zhang, Chao; Hedrick, Tyson L.; Mittal, Rajat

    2015-01-01

    Despite intense study by physicists and biologists, we do not fully understand the unsteady aerodynamics that relate insect wing morphology and kinematics to lift generation. Here, we formulate a force partitioning method (FPM) and implement it within a computational fluid dynamic model to provide an unambiguous and physically insightful division of aerodynamic force into components associated with wing kinematics, vorticity, and viscosity. Application of the FPM to hawkmoth and fruit fly flight shows that the leading-edge vortex is the dominant mechanism for lift generation for both these insects and contributes between 72–85% of the net lift. However, there is another, previously unidentified mechanism, the centripetal acceleration reaction, which generates up to 17% of the net lift. The centripetal acceleration reaction is similar to the classical inviscid added-mass in that it depends only on the kinematics (i.e. accelerations) of the body, but is different in that it requires the satisfaction of the no-slip condition, and a combination of tangential motion and rotation of the wing surface. Furthermore, the classical added-mass force is identically zero for cyclic motion but this is not true of the centripetal acceleration reaction. Furthermore, unlike the lift due to vorticity, centripetal acceleration reaction lift is insensitive to Reynolds number and to environmental flow perturbations, making it an important contributor to insect flight stability and miniaturization. This force mechanism also has broad implications for flow-induced deformation and vibration, underwater locomotion and flows involving bubbles and droplets. PMID:26252016

  12. Advanced nonlinear control: Robustness and stability with applications to aircraft flight control systems

    NASA Astrophysics Data System (ADS)

    Frye, Michael Takaichi

    This dissertation examines the problem of global decentralized control by output feedback for large-scale uncertain nonlinear systems whose subsystems are interconnected not only by their outputs but also by their unmeasurable states. Several innovative techniques will be developed to create decentralized output feedback controllers rendering the closed-loop systems globally asymptotically stable. This is accomplished by extending an output feedback domination design that requires only limited information about the nonlinear system. We will apply our design to lower, upper, and non-triangular nonlinear systems. A time-varying output feedback controller is also constructed for use with large-scale systems that have unknown parameters. Furthermore, a mixed large-scale system consisting of both lower and upper triangular systems is shown to be stabilizable by employing a combined high and low gain domination technique. The significance of our results is that we do not need to have prior information about the nonlinearities of the system. In addition, a new design technique was developed using homogeneous system theory, which allows for the design of nonsmooth controllers and observers to stabilize a class of feedforward system with uncontrollable and unobservable linearization. An example of a large-scale system is a group of autonomous airships performing the function of a temporary mobile cell phone network. An airship mobile cell phone network is a novel solution to the problem of maintaining communication during the advent of extensive damage to the communication infrastructure; be it from a flood, earthquake, hurricane, or terrorist attack. A first principle force-based dynamic model for the Tri-Turbofan Airship was developed and will be discussed in detail. The mathematical model was based on actual flight test data that has been collected at the Gait Analysis and Innovative Technologies Laboratory. This model was developed to research autonomous airship

  13. A Multi-Verse Optimizer with Levy Flights for Numerical Optimization and Its Application in Test Scheduling for Network-on-Chip.

    PubMed

    Hu, Cong; Li, Zhi; Zhou, Tian; Zhu, Aijun; Xu, Chuanpei

    2016-01-01

    We propose a new meta-heuristic algorithm named Levy flights multi-verse optimizer (LFMVO), which incorporates Levy flights into multi-verse optimizer (MVO) algorithm to solve numerical and engineering optimization problems. The Original MVO easily falls into stagnation when wormholes stochastically re-span a number of universes (solutions) around the best universe achieved over the course of iterations. Since Levy flights are superior in exploring unknown, large-scale search space, they are integrated into the previous best universe to force MVO out of stagnation. We test this method on three sets of 23 well-known benchmark test functions and an NP complete problem of test scheduling for Network-on-Chip (NoC). Experimental results prove that the proposed LFMVO is more competitive than its peers in both the quality of the resulting solutions and convergence speed.

  14. A Multi-Verse Optimizer with Levy Flights for Numerical Optimization and Its Application in Test Scheduling for Network-on-Chip

    PubMed Central

    Hu, Cong; Li, Zhi; Zhou, Tian; Zhu, Aijun; Xu, Chuanpei

    2016-01-01

    We propose a new meta-heuristic algorithm named Levy flights multi-verse optimizer (LFMVO), which incorporates Levy flights into multi-verse optimizer (MVO) algorithm to solve numerical and engineering optimization problems. The Original MVO easily falls into stagnation when wormholes stochastically re-span a number of universes (solutions) around the best universe achieved over the course of iterations. Since Levy flights are superior in exploring unknown, large-scale search space, they are integrated into the previous best universe to force MVO out of stagnation. We test this method on three sets of 23 well-known benchmark test functions and an NP complete problem of test scheduling for Network-on-Chip (NoC). Experimental results prove that the proposed LFMVO is more competitive than its peers in both the quality of the resulting solutions and convergence speed. PMID:27926946

  15. Initial Investigations of Controller Tools and Procedures for Schedule-Based Arrival Operations with Mixed Flight-Deck Interval Management Equipage

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.; Cabrall, Christopher; Kupfer, Michael; Omar, Faisal G.; Prevot, Thomas

    2012-01-01

    NASA?s Air Traffic Management Demonstration-1 (ATD-1) is a multi-year effort to demonstrate high-throughput, fuel-efficient arrivals at a major U.S. airport using NASA-developed scheduling automation, controller decision-support tools, and ADS-B-enabled Flight-Deck Interval Management (FIM) avionics. First-year accomplishments include the development of a concept of operations for managing scheduled arrivals flying Optimized Profile Descents with equipped aircraft conducting FIM operations, and the integration of laboratory prototypes of the core ATD-1 technologies. Following each integration phase, a human-in-the-loop simulation was conducted to evaluate and refine controller tools, procedures, and clearance phraseology. From a ground-side perspective, the results indicate the concept is viable and the operations are safe and acceptable. Additional training is required for smooth operations that yield notable benefits, particularly in the areas of FIM operations and clearance phraseology.

  16. Robust Flight Controllers.

    DTIC Science & Technology

    1983-12-01

    linear stochastic differential equation k(t) - F(t) x(t) + B(t) u(t) + G(t) w(t) (2-1) where w(t) is a white Gaussian noise with statistics , 4- E{w(t)1...t) + PHTR- 1 [z(t) - H(t)] (2-12a).. P(t) - FP(t) + P(t)FT + GQGT - P(t) HTR HP(t) (2-12b) These differential equations are solved forward in time...that they do not exceed physical limits or design specifications. The assumed linear differential equation describing the continuous- time truth model

  17. Statistical Survey of Icing Data Measured on Scheduled Airline Flights over the United States and Canada from November 1951 to June 1952

    NASA Technical Reports Server (NTRS)

    Perkins, Porter J

    1955-01-01

    A statistical survey and a preliminary analysis are made of icing data collected from scheduled flights over the United States and Canada from November 1951 to June 1952 by airline aircraft equipped with NACA pressure-type icing-rate meters. This interim report presents information obtained from a continuing program sponsored by the NACA with the cooperation of the airlines. An analysis of over 600 icing encounters logged by three airlines operating in the United States, one operating in Canada and one operating up the coast to Alaska, is presented. The icing conditions encountered provided relative frequencies of many icing-cloud variables, such as horizontal extent, vertical thickness, temperatures, icing rate, liquid-water content, and total ice accumulation. Liquid-water contents were higher than data from earlier research flights in layer-type clouds but slightly lower than previous data from cumulus clouds. Broken-cloud conditions, indicated by intermittent icing, accounted for nearly one-half of all the icing encounters. About 90 percent of the encounters did not exceed a distance of 120 miles, and continuous icing did not exceed 50 miles for 90 percent of the unbroken conditions. Icing cloud thicknesses measured during climbs and descents were less than 4500 feet for 90 percent of the vertical cloud traverses.

  18. Design and implementation of robust decentralized control laws for the ACES structure at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Collins, Emmanuel G., Jr.; Phillips, Douglas J.; Hyland, David C.

    1990-01-01

    Many large space system concepts will require active vibration control to satisfy critical performance requirements such as line-of-sight accuracy. In order for these concepts to become operational it is imperative that the benefits of active vibration control be practically demonstrated in ground based experiments. The results of the experiment successfully demonstrate active vibration control for a flexible structure. The testbed is the Active Control Technique Evaluation for Spacecraft (ACES) structure at NASA Marshall Space Flight Center. The ACES structure is dynamically traceable to future space systems and especially allows the study of line-of-sight control issues.

  19. Flexible Scheduling.

    ERIC Educational Resources Information Center

    Davis, Harold S.; Bechard, Joseph E.

    A flexible schedule allows teachers to change group size, group composition, and class length according to the purpose of the lesson. This pamphlet presents various "master" schedules for flexible scheduling: (1) Simple block schedules, (2) back-to-back schedules, (3) interdisciplinary schedules, (4) school-wide block schedules, (5) open-lab…

  20. Robust Hurwitz Stability and Performance Analysis of H-Infinity Controlled Forward-Velocity Dynamics of UAVs in Close Formation Flight Using Bounded Phase Conditions in a Kharitonov Framework

    NASA Astrophysics Data System (ADS)

    Johnson, Y.; Dasgupta, S.

    2014-07-01

    Multiple unmanned aerial vehicle (UAV) control in formation flight is comparatively a new research area in the field of aerospace engineering. In the proposed work, robust control techniques are implemented to maintain a fixed relative distance in horizontal and vertical direction with uniform pitch orientation in an uncertain leader-follower pattern of close formation flight platform. The forward velocity dynamics is of focal interest in this paper. H-infinity controllers are designed for leader control and its tracking. The robustness of the H-infinity controller is validated with Kharitonov related bounded phase conditions by forming interval polynomials.

  1. Development of a Robust, High Current, Low Power Field Emission Electron Gun for a Spaceflight Reflectron Time-of-Flight Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Southard, Adrian E.; Getty, Stephanie A.; Feng, Steven; Glavin, Daniel P.; Auciello, Orlando; Sumant, Anirudha

    2012-01-01

    Carbon materials, including carbon nanotubes (CNTs) and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD), have been of considerable interest for field emission applications for over a decade. In particular, robust field emission materials are compelling for space applications due to the low power consumption and potential for miniaturization. A reflectron time-of-flight mass spectrometer (TOF-MS) under development for in situ measurements on the Moon and other Solar System bodies uses a field emitter to generate ions from gaseous samples, using electron ionization. For these unusual environments, robustness, reliability, and long life are of paramount importance, and to this end, we have explored the field emission properties and lifetime of carbon nanotubes and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) thin films, the latter developed and patented by Argonne National Laboratory. We will present recent investigations of N-UNCD as a robust field emitter, revealing that this material offers stable performance in high vacuum for up to 1000 hours with threshold voltage for emission of about 3-4 V/lJm and current densities in the range of tens of microA. Optimizing the mass resolution and sensitivity of such a mass spectrometer has also been enabled by a parallel effort to scale up a CNT emitter to an array measuring 2 mm x 40 mm. Through simulation and experiment of the new extended format emitter, we have determined that focusing the electron beam is limited due to the angular spread of the emitted electrons. This dispersion effect can be reduced through modification of the electron gun geometry, but this reduces the current reaching the ionization region. By increasing the transmission efficiency of the electron beam to the anode, we have increased the anode current by two orders of magnitude to realize a corresponding enhancement in instrument sensitivity, at a moderate cost to mass resolution. We will report recent experimental and

  2. 14 CFR 291.45 - BTS Schedule T-100, U.S. Air Carrier Traffic and Capacity Data by Nonstop Segment and On-Flight...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... combination of scheduled and nonscheduled operations with passenger, all-cargo, and military services are...-Cargo. L Nonscheduled Civilian Passenger/Cargo/ P Nonscheduled Civilian Cargo. N Nonscheduled Military Passenger/Cargo. R Nonscheduled Military Cargo. (2) Scheduled services include traffic and capacity...

  3. 14 CFR 291.45 - BTS Schedule T-100, U.S. Air Carrier Traffic and Capacity Data by Nonstop Segment and On-Flight...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... combination of scheduled and nonscheduled operations with passenger, all-cargo, and military services are...-Cargo. L Nonscheduled Civilian Passenger/Cargo/ P Nonscheduled Civilian Cargo. N Nonscheduled Military Passenger/Cargo. R Nonscheduled Military Cargo. (2) Scheduled services include traffic and capacity...

  4. Robust multivariable turbofan engine control: A case study

    SciTech Connect

    Nordgren, R.E.; Nwokah, O.D.I.; Gastineau, Z.; Adibhatla, S.; Grewal, G.S.

    1994-12-31

    The application of robust controller design techniques to aircraft turbofan engine control problems has a long and intensive history. These applications have revealed many of the strengths and weaknesses of the many solution techniques. Quantitative Nyquist Array, are applied to the GE16 aircraft turbofan engine control problem for the purpose of designing a full flight envelope controller capable of meeting robust performance specifications. Performance and implementation issues of the two controllers are explored and compared to a control law based upon gain scheduling.

  5. A Genetic Algorithm Tool (splicer) for Complex Scheduling Problems and the Space Station Freedom Resupply Problem

    NASA Technical Reports Server (NTRS)

    Wang, Lui; Valenzuela-Rendon, Manuel

    1993-01-01

    The Space Station Freedom will require the supply of items in a regular fashion. A schedule for the delivery of these items is not easy to design due to the large span of time involved and the possibility of cancellations and changes in shuttle flights. This paper presents the basic concepts of a genetic algorithm model, and also presents the results of an effort to apply genetic algorithms to the design of propellant resupply schedules. As part of this effort, a simple simulator and an encoding by which a genetic algorithm can find near optimal schedules have been developed. Additionally, this paper proposes ways in which robust schedules, i.e., schedules that can tolerate small changes, can be found using genetic algorithms.

  6. 14 CFR 291.45 - BTS Schedule T-100, U.S. Air Carrier Traffic and Capacity Data by Nonstop Segment and On-Flight...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... date S M Origin airport code S M Destination airport code S M Service class code S M Aircraft type code...' Accounting and Reporting Directives. (6) Origin, Destination airport code(s). These codes represent the.... The total number of revenue passengers enplaned at the origin point of a flight, boarding the flight...

  7. 14 CFR 291.45 - BTS Schedule T-100, U.S. Air Carrier Traffic and Capacity Data by Nonstop Segment and On-Flight...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... date S M Origin airport code S M Destination airport code S M Service class code S M Aircraft type code...' Accounting and Reporting Directives. (6) Origin, Destination airport code(s). These codes represent the.... The total number of revenue passengers enplaned at the origin point of a flight, boarding the flight...

  8. Linear-parameter-varying gain-scheduled control of aerospace systems

    NASA Astrophysics Data System (ADS)

    Barker, Jeffrey Michael

    The dynamics of many aerospace systems vary significantly as a function of flight condition. Robust control provides methods of guaranteeing performance and stability goals across flight conditions. In mu-syntthesis, changes to the dynamical system are primarily treated as uncertainty. This method has been successfully applied to many control problems, and here is applied to flutter control. More recently, two techniques for generating robust gain-scheduled controller have been developed. Linear fractional transformation (LFT) gain-scheduled control is an extension of mu-synthesis in which the plant and controller are explicit functions of parameters measurable in real-time. This LFT gain-scheduled control technique is applied to the Benchmark Active Control Technology (BACT) wing, and compared with mu-synthesis control. Linear parameter-varying (LPV) gain-scheduled control is an extension of Hinfinity control to parameter varying systems. LPV gain-scheduled control directly incorporates bounds on the rate of change of the scheduling parameters, and often reduces conservatism inherent in LFT gain-scheduled control. Gain-scheduled LPV control of the BACT wing compares very favorably with the LFT controller. Gain-scheduled LPV controllers are generated for the lateral-directional and longitudinal axes of the Innovative Control Effectors (ICE) aircraft and implemented in nonlinear simulations and real-time piloted nonlinear simulations. Cooper-Harper and pilot-induced oscillation ratings were obtained for an initial design, a reference aircraft and a redesign. Piloted simulation results for the initial LPV gain-scheduled control of the ICE aircraft are compared with results for a conventional fighter aircraft in discrete pitch and roll angle tracking tasks. The results for the redesigned controller are significantly better than both the previous LPV controller and the conventional aircraft.

  9. NASA Schedule Management Handbook

    NASA Technical Reports Server (NTRS)

    2011-01-01

    The purpose of schedule management is to provide the framework for time-phasing, resource planning, coordination, and communicating the necessary tasks within a work effort. The intent is to improve schedule management by providing recommended concepts, processes, and techniques used within the Agency and private industry. The intended function of this handbook is two-fold: first, to provide guidance for meeting the scheduling requirements contained in NPR 7120.5, NASA Space Flight Program and Project Management Requirements, NPR 7120.7, NASA Information Technology and Institutional Infrastructure Program and Project Requirements, NPR 7120.8, NASA Research and Technology Program and Project Management Requirements, and NPD 1000.5, Policy for NASA Acquisition. The second function is to describe the schedule management approach and the recommended best practices for carrying out this project control function. With regards to the above project management requirements documents, it should be noted that those space flight projects previously established and approved under the guidance of prior versions of NPR 7120.5 will continue to comply with those requirements until project completion has been achieved. This handbook will be updated as needed, to enhance efficient and effective schedule management across the Agency. It is acknowledged that most, if not all, external organizations participating in NASA programs/projects will have their own internal schedule management documents. Issues that arise from conflicting schedule guidance will be resolved on a case by case basis as contracts and partnering relationships are established. It is also acknowledged and understood that all projects are not the same and may require different levels of schedule visibility, scrutiny and control. Project type, value, and complexity are factors that typically dictate which schedule management practices should be employed.

  10. Future aircraft networks and schedules

    NASA Astrophysics Data System (ADS)

    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

  11. Completable scheduling: An integrated approach to planning and scheduling

    NASA Technical Reports Server (NTRS)

    Gervasio, Melinda T.; Dejong, Gerald F.

    1992-01-01

    The planning problem has traditionally been treated separately from the scheduling problem. However, as more realistic domains are tackled, it becomes evident that the problem of deciding on an ordered set of tasks to achieve a set of goals cannot be treated independently of the problem of actually allocating resources to the tasks. Doing so would result in losing the robustness and flexibility needed to deal with imperfectly modeled domains. Completable scheduling is an approach which integrates the two problems by allowing an a priori planning module to defer particular planning decisions, and consequently the associated scheduling decisions, until execution time. This allows a completable scheduling system to maximize plan flexibility by allowing runtime information to be taken into consideration when making planning and scheduling decision. Furthermore, through the criteria of achievability placed on deferred decision, a completable scheduling system is able to retain much of the goal-directedness and guarantees of achievement afforded by a priori planning. The completable scheduling approach is further enhanced by the use of contingent explanation-based learning, which enables a completable scheduling system to learn general completable plans from example and improve its performance through experience. Initial experimental results show that completable scheduling outperforms classical scheduling as well as pure reactive scheduling in a simple scheduling domain.

  12. Cost Estimation and Control for Flight Systems

    NASA Technical Reports Server (NTRS)

    Hammond, Walter E.; Vanhook, Michael E. (Technical Monitor)

    2002-01-01

    Good program management practices, cost analysis, cost estimation, and cost control for aerospace flight systems are interrelated and depend upon each other. The best cost control process cannot overcome poor design or poor systems trades that lead to the wrong approach. The project needs robust Technical, Schedule, Cost, Risk, and Cost Risk practices before it can incorporate adequate Cost Control. Cost analysis both precedes and follows cost estimation -- the two are closely coupled with each other and with Risk analysis. Parametric cost estimating relationships and computerized models are most often used. NASA has learned some valuable lessons in controlling cost problems, and recommends use of a summary Project Manager's checklist as shown here.

  13. Cost Estimation and Control for Flight Systems

    NASA Technical Reports Server (NTRS)

    Hammond, Walter E.; Vanhook, Michael E. (Technical Monitor)

    2002-01-01

    Good program management practices, cost analysis, cost estimation, and cost control for aerospace flight systems are interrelated and depend upon each other. The best cost control process cannot overcome poor design or poor systems trades that lead to the wrong approach. The project needs robust Technical, Schedule, Cost, Risk, and Cost Risk practices before it can incorporate adequate Cost Control. Cost analysis both precedes and follows cost estimation -- the two are closely coupled with each other and with Risk analysis. Parametric cost estimating relationships and computerized models are most often used. NASA has learned some valuable lessons in controlling cost problems, and recommends use of a summary Project Manager's checklist as shown here.

  14. Analysis of gain scheduled control for nonlinear plants

    NASA Technical Reports Server (NTRS)

    Shamma, Jeff S.; Athans, Michael

    1990-01-01

    Gain scheduling has proven to be a successful design methodology in many engineering applications. In the absence of a sound theoretical analysis, these designs come with no guarantees of the robustness, performance, or even nominal stability of the overall gain-scheduled design. An analysis is presented for two types of nonlinear gain-scheduled control systems: (1) scheduling on a reference trajectory and (2) scheduling on the plant output. Conditions which guarantee stability, robustness, and performance properties of the global gain schedule designs are given. These conditions confirm and formalize popular notions regarding gain-scheduled designs, such as that the scheduling variable should vary slowly and capture the plant's nonlinearities.

  15. The comparison of predictive scheduling algorithms for different sizes of job shop scheduling problems

    NASA Astrophysics Data System (ADS)

    Paprocka, I.; Kempa, W. M.; Grabowik, C.; Kalinowski, K.; Krenczyk, D.

    2016-08-01

    In the paper a survey of predictive and reactive scheduling methods is done in order to evaluate how the ability of prediction of reliability characteristics influences over robustness criteria. The most important reliability characteristics are: Mean Time to Failure, Mean Time of Repair. Survey analysis is done for a job shop scheduling problem. The paper answers the question: what method generates robust schedules in the case of a bottleneck failure occurrence before, at the beginning of planned maintenance actions or after planned maintenance actions? Efficiency of predictive schedules is evaluated using criteria: makespan, total tardiness, flow time, idle time. Efficiency of reactive schedules is evaluated using: solution robustness criterion and quality robustness criterion. This paper is the continuation of the research conducted in the paper [1], where the survey of predictive and reactive scheduling methods is done only for small size scheduling problems.

  16. Adaptive and Robust Resource Allocation and Scheduling

    DTIC Science & Technology

    2010-05-03

    HOK nvjrnocn OT. vvunr. uim l NUMDUI /. rtni-unminiu UHUHNUA I IUN NMivttis) HNU Muuneosicoi Brown University Office of Research...telecommunication technologies which enables entreprises and organizations to track their operations in real-time us- ing technologies such as GPS...RFIDs, sensors, and high- performance networks. The ubiquity of telecommunication technologies led to a paradigm shift in business processes

  17. Automated Platform Management System Scheduling

    NASA Technical Reports Server (NTRS)

    Hull, Larry G.

    1990-01-01

    The Platform Management System was established to coordinate the operation of platform systems and instruments. The management functions are split between ground and space components. Since platforms are to be out of contact with the ground more than the manned base, the on-board functions are required to be more autonomous than those of the manned base. Under this concept, automated replanning and rescheduling, including on-board real-time schedule maintenance and schedule repair, are required to effectively and efficiently meet Space Station Freedom mission goals. In a FY88 study, we developed several promising alternatives for automated platform planning and scheduling. We recommended both a specific alternative and a phased approach to automated platform resource scheduling. Our recommended alternative was based upon use of exactly the same scheduling engine in both ground and space components of the platform management system. Our phased approach recommendation was based upon evolutionary development of the platform. In the past year, we developed platform scheduler requirements and implemented a rapid prototype of a baseline platform scheduler. Presently we are rehosting this platform scheduler rapid prototype and integrating the scheduler prototype into two Goddard Space Flight Center testbeds, as the ground scheduler in the Scheduling Concepts, Architectures, and Networks Testbed and as the on-board scheduler in the Platform Management System Testbed. Using these testbeds, we will investigate rescheduling issues, evaluate operational performance and enhance the platform scheduler prototype to demonstrate our evolutionary approach to automated platform scheduling. The work described in this paper was performed prior to Space Station Freedom rephasing, transfer of platform responsibility to Code E, and other recently discussed changes. We neither speculate on these changes nor attempt to predict the impact of the final decisions. As a consequence some of our

  18. Scheduling Supercomputers.

    DTIC Science & Technology

    1983-02-01

    no task is scheduled with overlap. Let numpi be the total number of preemptions and idle slots of size at most to that are introduced. We see that if...no usable block remains on Qm-*, then numpi < m-k. Otherwise, numpi ! m-k-1. If j>n when this procedure terminates, then all tasks have been scheduled

  19. Composite Scheduling

    ERIC Educational Resources Information Center

    Childers, Gary L.; Ireland, Rebecca Weeks

    2005-01-01

    In education, there is no one best way to do anything. There are compelling reasons why some courses should be taught in longer segments of time, which the block schedule provides. There are also compelling reasons why some classes should be taught in shorter segments. At Watauga High School in Boone, North Carolina, an alternative schedule that…

  20. KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Charles Camarda arrives at KSC aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment,to the Space Station, and the external stowage platform.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Charles Camarda arrives at KSC aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment,to the Space Station, and the external stowage platform.

  1. KENNEDY SPACE CENTER, FLA. - STS-114 Commander Eileen Collins talks with workers in the Orbiter Processing Facility. She and other crew members are at KSC to become familiar with Shuttle and mission equipment. The mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Commander Eileen Collins talks with workers in the Orbiter Processing Facility. She and other crew members are at KSC to become familiar with Shuttle and mission equipment. The mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

  2. KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Stephen Robinson arrives at KSC aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Stephen Robinson arrives at KSC aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

  3. KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Soichi Noguchi arrives at KSC aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Soichi Noguchi arrives at KSC aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

  4. Scheduling game

    SciTech Connect

    Kleck, W

    1982-04-01

    Structuring a schedule - whether by Critical Path Method (CPM) or Precedence Charting System (PCS) - involves estimating the duration of one or more activities and arranging them in the most logical sequence. Given the start date, the completion date is relatively simple to determine. What is then so complicated about the process. It is complicated by the people involved - the people who make the schedules and the people who attempt to follow them. Schedules are an essential part of project management and construction contract administration. Much of the material available pertains to the mechanics of schedules, the types of logic networks, the ways that data can be generated and presented. This paper sheds light on other facets of the subject - the statistical and philosophical fundamentals involved in scheduling.

  5. SO - SCHEDULE ORGANIZER COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer SO, Schedule Tracker, ST (COSMIC Program MSC-21526), and Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term). Schedule Report Generator provides a simple method for generating periodic schedule reports. SO contains the following primary menu that is displayed at the beginning of the program. The menu provides options: to write input files to an output distribution file, to change a schedule title field and/or distribution list field, to browse through the schedule and input names file for requested schedule numbers, to create an input names file and a schedule titles file, and to delete input schedule titles and associated names. SO provides a choice of two input files. One file holds twenty-five groups of up to twenty-five names for each group. The other file holds twenty-five records, each of which may hold a task schedule title. SO creates three output files. One holds the formatted list of schedule titles for printout. Another file holds the formatted distribution list for printout; there is one for each input names file schedule group. The third output file holds the last schedule title deleted by

  6. SO - SCHEDULE ORGANIZER COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer SO, Schedule Tracker, ST (COSMIC Program MSC-21526), and Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term). Schedule Report Generator provides a simple method for generating periodic schedule reports. SO contains the following primary menu that is displayed at the beginning of the program. The menu provides options: to write input files to an output distribution file, to change a schedule title field and/or distribution list field, to browse through the schedule and input names file for requested schedule numbers, to create an input names file and a schedule titles file, and to delete input schedule titles and associated names. SO provides a choice of two input files. One file holds twenty-five groups of up to twenty-five names for each group. The other file holds twenty-five records, each of which may hold a task schedule title. SO creates three output files. One holds the formatted list of schedule titles for printout. Another file holds the formatted distribution list for printout; there is one for each input names file schedule group. The third output file holds the last schedule title deleted by

  7. System/360 Computer Assisted Network Scheduling (CANS) System

    NASA Technical Reports Server (NTRS)

    Brewer, A. C.

    1972-01-01

    Computer assisted scheduling techniques that produce conflict-free and efficient schedules have been developed and implemented to meet needs of the Manned Space Flight Network. CANS system provides effective management of resources in complex scheduling environment. System is automated resource scheduling, controlling, planning, information storage and retrieval tool.

  8. 14 CFR 399.81 - Unrealistic or deceptive scheduling.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Unrealistic or deceptive scheduling. 399.81... Unrealistic or deceptive scheduling. (a) The unrealistic scheduling of flights by any air carrier providing scheduled passenger air transportation is an unfair or deceptive practice and an unfair method...

  9. 14 CFR 399.81 - Unrealistic or deceptive scheduling.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Unrealistic or deceptive scheduling. 399.81... Unrealistic or deceptive scheduling. (a) The unrealistic scheduling of flights by any air carrier providing scheduled passenger air transportation is an unfair or deceptive practice and an unfair method...

  10. 14 CFR 399.81 - Unrealistic or deceptive scheduling.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Unrealistic or deceptive scheduling. 399.81... Unrealistic or deceptive scheduling. (a) The unrealistic scheduling of flights by any air carrier providing scheduled passenger air transportation is an unfair or deceptive practice and an unfair method...

  11. 14 CFR 399.81 - Unrealistic or deceptive scheduling.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Unrealistic or deceptive scheduling. 399.81... Unrealistic or deceptive scheduling. (a) The unrealistic scheduling of flights by any air carrier providing scheduled passenger air transportation is an unfair or deceptive practice and an unfair method...

  12. 14 CFR 399.81 - Unrealistic or deceptive scheduling.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Unrealistic or deceptive scheduling. 399.81... Unrealistic or deceptive scheduling. (a) It is the policy of the Board to consider unrealistic scheduling of flights by any air carrier providing scheduled passenger air transportation to be an unfair or...

  13. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1991-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocations for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its applications to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  14. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1991-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  15. Constraint-based scheduling

    NASA Technical Reports Server (NTRS)

    Zweben, Monte

    1993-01-01

    The GERRY scheduling system developed by NASA Ames with assistance from the Lockheed Space Operations Company, and the Lockheed Artificial Intelligence Center, uses a method called constraint-based iterative repair. Using this technique, one encodes both hard rules and preference criteria into data structures called constraints. GERRY repeatedly attempts to improve schedules by seeking repairs for violated constraints. The system provides a general scheduling framework which is being tested on two NASA applications. The larger of the two is the Space Shuttle Ground Processing problem which entails the scheduling of all the inspection, repair, and maintenance tasks required to prepare the orbiter for flight. The other application involves power allocation for the NASA Ames wind tunnels. Here the system will be used to schedule wind tunnel tests with the goal of minimizing power costs. In this paper, we describe the GERRY system and its application to the Space Shuttle problem. We also speculate as to how the system would be used for manufacturing, transportation, and military problems.

  16. Applications of Eigenstructure Assignment to Design of Robust MIMO (Multi Input Multi Output) Decoupling Controllers and to Reconfiguration Algorithms for Damaged Flight Control Systems.

    DTIC Science & Technology

    1986-12-01

    0 * NAVAL POSTGRADUATE SCHOOL 00 Monterey, California A DTIC ELECTE MAY 1 4 9871 c~z( D THESIS APPLICATIONS OF EIGENSTRUCTURE ASSIGNMENT TO DESIGN OF... Thesis Advisor D.J. Collins Approved for public release; distribution iE unlimited. 87 U DISCLAIMER NOTICE THIS DOCUMENT IS BEST QUALITY PRACTICABLE. THE...reconfiguring damaged digital flight controllers is then p resented. The thesis concludes with reconfigy red solution demonstrations as applied to the

  17. Development of An Intelligent Flight Propulsion Control System

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Rysdyk, R. T.; Leonhardt, B. K.

    1999-01-01

    The initial design and demonstration of an Intelligent Flight Propulsion and Control System (IFPCS) is documented. The design is based on the implementation of a nonlinear adaptive flight control architecture. This initial design of the IFPCS enhances flight safety by using propulsion sources to provide redundancy in flight control. The IFPCS enhances the conventional gain scheduled approach in significant ways: (1) The IFPCS provides a back up flight control system that results in consistent responses over a wide range of unanticipated failures. (2) The IFPCS is applicable to a variety of aircraft models without redesign and,(3) significantly reduces the laborious research and design necessary in a gain scheduled approach. The control augmentation is detailed within an approximate Input-Output Linearization setting. The availability of propulsion only provides two control inputs, symmetric and differential thrust. Earlier Propulsion Control Augmentation (PCA) work performed by NASA provided for a trajectory controller with pilot command input of glidepath and heading. This work is aimed at demonstrating the flexibility of the IFPCS in providing consistency in flying qualities under a variety of failure scenarios. This report documents the initial design phase where propulsion only is used. Results confirm that the engine dynamics and associated hard nonlineaaities result in poor handling qualities at best. However, as demonstrated in simulation, the IFPCS is capable of results similar to the gain scheduled designs of the NASA PCA work. The IFPCS design uses crude estimates of aircraft behaviour. The adaptive control architecture demonstrates robust stability and provides robust performance. In this work, robust stability means that all states, errors, and adaptive parameters remain bounded under a wide class of uncertainties and input and output disturbances. Robust performance is measured in the quality of the tracking. The results demonstrate the flexibility of

  18. Mission scheduling

    NASA Technical Reports Server (NTRS)

    Gaspin, Christine

    1989-01-01

    How a neural network can work, compared to a hybrid system based on an operations research and artificial intelligence approach, is investigated through a mission scheduling problem. The characteristic features of each system are discussed.

  19. ST - SCHEDULE TRACKER COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST, and Schedule Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term). Schedule Report Generator provides a simple method for generating periodic schedule reports. ST and SRG use the same data base file as input. The common data base file has a maximum number of 400 entries. The time span of all three programs is nineteen months. Both of these maximum numbers can be modified by the user. ST requires the VMS Operating System on DEC VAX and was written in PL/1 and DEC Command Language (DCL). The program requires a memory of 233KB. ST can be purchased separately or in a package (COSMIC Program COS-10021) containing SO, ST, and SRG. ST was developed in 1985.

  20. ST - SCHEDULE TRACKER COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST, and Schedule Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term). Schedule Report Generator provides a simple method for generating periodic schedule reports. ST and SRG use the same data base file as input. The common data base file has a maximum number of 400 entries. The time span of all three programs is nineteen months. Both of these maximum numbers can be modified by the user. ST requires the VMS Operating System on DEC VAX and was written in PL/1 and DEC Command Language (DCL). The program requires a memory of 233KB. ST can be purchased separately or in a package (COSMIC Program COS-10021) containing SO, ST, and SRG. ST was developed in 1985.

  1. Gain scheduling of aircraft pitch attitude and control of discrete, affine, linear parametrically varying systems

    NASA Astrophysics Data System (ADS)

    Lin, Zhe

    This research is motivated by gain scheduling, a technique which has been successfully applied to many nonlinear control problems. In flight controls, the wide variations in the characteristics of the aircraft dynamics throughout the flight envelope make gain scheduling a particularly suitable design strategy. This research consists of two parts: (1) aircraft pitch attitude scheduling scheme designs, and (2) control of a class of linear parametrically varying (LPV) systems. In the first part, the classical gain scheduling technique and the single quadratic Lyapunov function (SQLF) based LPV technique are investigated. In the classical gain scheduling design, the Hinfinity mixed sensitivity GS/T method is chosen for local linear time invariant (LTI) designs to provide robustness to unmodeled dynamics and parametric uncertainties. Following a model reduction procedure that exploits the optimal controller structure, LTI controllers designed at the selected equilibrium points are reduced to second order controllers and realized in a feedback path configuration. Such controllers are shown to retain the superior robust performance at each flight condition, while having a low order that is amenable to scheduling. A gain-scheduling law is developed and simulation results verify that the closed-loop performance specifications are met. In the LPV design, the mixed sensitivity S/KS/T design setup is used. An approximation to the original LPV controller using the linear fractional transformation (LFT) representation is constructed. Our design exhibits potential applications of the LPV technique to commercial aircraft gain scheduling designs. In the second part, we consider a class of discrete, affine, linear parametrically varying (DALPV) systems. For this type of systems, the parameters are assumed to vary in a polytope and the state space matrices are assumed to depend affinely on the varying parameters. A sufficient condition is derived to analyze the stability and the

  2. Scheduling and SVTs: Rx for Efficiency

    DTIC Science & Technology

    2013-12-01

    to follow in scheduling. In July 2012, the Office of Performance Assessments and An X-47B Unmanned Combat Air System ( UCAS ) demonstrator flies...47B Unmanned Combat Air System ( UCAS ) demonstrator completes an arrested landing on the flight deck of the aircraft carrier USS George H.W. Bush...depends in part on the quality of its schedule. A well-formulated schedule can help Unmanned Combat Air System ( UCAS ) demonstrator launches from the

  3. A planning language for activity scheduling

    NASA Technical Reports Server (NTRS)

    Zoch, David R.; Lavallee, David; Weinstein, Stuart; Tong, G. Michael

    1991-01-01

    Mission planning and scheduling of spacecraft operations are becoming more complex at NASA. Described here are a mission planning process; a robust, flexible planning language for spacecraft and payload operations; and a software scheduling system that generates schedules based on planning language inputs. The mission planning process often involves many people and organizations. Consequently, a planning language is needed to facilitate communication, to provide a standard interface, and to represent flexible requirements. The software scheduling system interprets the planning language and uses the resource, time duration, constraint, and alternative plan flexibilities to resolve scheduling conflicts.

  4. Scheduling algorithms

    NASA Astrophysics Data System (ADS)

    Wolfe, William J.; Wood, David; Sorensen, Stephen E.

    1996-12-01

    This paper discusses automated scheduling as it applies to complex domains such as factories, transportation, and communications systems. The window-constrained-packing problem is introduced as an ideal model of the scheduling trade offs. Specific algorithms are compared in terms of simplicity, speed, and accuracy. In particular, dispatch, look-ahead, and genetic algorithms are statistically compared on randomly generated job sets. The conclusion is that dispatch methods are fast and fairly accurate; while modern algorithms, such as genetic and simulate annealing, have excessive run times, and are too complex to be practical.

  5. Anchorage Arrival Scheduling Under Off-Nominal Weather Conditions

    NASA Technical Reports Server (NTRS)

    Grabbe, Shon; Chan, William N.; Mukherjee, Avijit

    2012-01-01

    Weather can cause flight diversions, passenger delays, additional fuel consumption and schedule disruptions at any high volume airport. The impacts are particularly acute at the Ted Stevens Anchorage International Airport in Anchorage, Alaska due to its importance as a major international portal. To minimize the impacts due to weather, a multi-stage scheduling process is employed that is iteratively executed, as updated aircraft demand and/or airport capacity data become available. The strategic scheduling algorithm assigns speed adjustments for flights that originate outside of Anchorage Center to achieve the proper demand and capacity balance. Similarly, an internal departure-scheduling algorithm assigns ground holds for pre-departure flights that originate from within Anchorage Center. Tactical flight controls in the form of airborne holding are employed to reactively account for system uncertainties. Real-world scenarios that were derived from the January 16, 2012 Anchorage visibility observations and the January 12, 2012 Anchorage arrival schedule were used to test the initial implementation of the scheduling algorithm in fast-time simulation experiments. Although over 90% of the flights in the scenarios arrived at Anchorage without requiring any delay, pre-departure scheduling was the dominant form of control for Anchorage arrivals. Additionally, tactical scheduling was used extensively in conjunction with the pre-departure scheduling to reactively compensate for uncertainties in the arrival demand. For long-haul flights, the strategic scheduling algorithm performed best when the scheduling horizon was greater than 1,000 nmi. With these long scheduling horizons, it was possible to absorb between ten and 12 minutes of delay through speed control alone. Unfortunately, the use of tactical scheduling, which resulted in airborne holding, was found to increase as the strategic scheduling horizon increased because of the additional uncertainty in the arrival times

  6. Decentralized aircraft landing scheduling at single runway non-controlled airports

    NASA Astrophysics Data System (ADS)

    Ding, Yuanyuan

    at single runway non-controlled airports can be achieved. It is shown from the flight simulations that reasonable performance of decentralized aircraft landing scheduling is achieved with successful integration of publisher/subscriber communication scheme and aircraft landing scheduling model. The extension from the non-controlled airport application to controlled airport case is expected with suitable amendment, where the reliance on centralized air traffic management can be reduced gradually in favor of a decentralized management to provide more airspace capacity, flight flexibility, and increase operation robustness.

  7. 14 CFR 1214.109 - Scheduling.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Scheduling. 1214.109 Section 1214.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT General Provisions Regarding Space Shuttle Flights of Payloads for Non-U.S. Government, Reimbursable Customers § 1214.109...

  8. 14 CFR § 1214.109 - Scheduling.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Scheduling. § 1214.109 Section § 1214.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT General Provisions Regarding Space Shuttle Flights of Payloads for Non-U.S. Government, Reimbursable Customers § 1214.109...

  9. 14 CFR 1214.109 - Scheduling.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Scheduling. 1214.109 Section 1214.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT General Provisions Regarding Space Shuttle Flights of Payloads for Non-U.S. Government, Reimbursable Customers § 1214.109...

  10. 14 CFR 1214.109 - Scheduling.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Scheduling. 1214.109 Section 1214.109 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT General Provisions Regarding Space Shuttle Flights of Payloads for Non-U.S. Government, Reimbursable Customers § 1214.109...

  11. Prescribed Travel Schedules for Fatigue Management

    NASA Technical Reports Server (NTRS)

    Whitmire, Alexandra; Johnston, Smith; Lockley, Steven

    2011-01-01

    The NASA Fatigue Management Team is developing recommendations for managing fatigue during travel and for shift work operations, as Clinical Practice Guidelines for the Management of Circadian Desynchrony in ISS Operations. The Guidelines provide the International Space Station (ISS ) flight surgeons and other operational clinicians with evidence-based recommendations for mitigating fatigue and other factors related to sleep loss and circadian desynchronization. As much international travel is involved both before and after flight, the guidelines provide recommendations for: pre-flight training, in-flight operations, and post-flight rehabilitation. The objective of is to standardize the process by which care is provided to crewmembers, ground controllers, and other support personnel such as trainers, when overseas travel or schedule shifting is required. Proper scheduling of countermeasures - light, darkness, melatonin, diet, exercise, and medications - is the cornerstone for facilitating circadian adaptation, improving sleep, enhancing alertness, and optimizing performance. The Guidelines provide, among other things, prescribed travel schedules that outline the specific implementation of these mitigation strategies. Each travel schedule offers evidence based protocols for properly using the NASA identified countermeasures for fatigue. This presentation will describe the travel implementation schedules and how these can be used to alleviate the effects of jet lag and/or schedule shifts.

  12. 14 CFR 323.16 - Listings in schedule publications.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Listings in schedule publications. 323.16... schedule publications. Each air carrier filing a notice under § 323.3 (a)(2), (a)(4), (a)(5), or (c) shall continue to list the affected flights in all generally-distributed schedule publications in which...

  13. 14 CFR 323.16 - Listings in schedule publications.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Listings in schedule publications. 323.16... schedule publications. Each air carrier filing a notice under § 323.3 (a)(2), (a)(4), (a)(5), or (c) shall continue to list the affected flights in all generally-distributed schedule publications in which...

  14. Synthese et validation d'un systeme de commandes de vol robuste et autosequence

    NASA Astrophysics Data System (ADS)

    Lhachemi, Hugo

    Flight control system development remains a very challenging issue due to architectural complexity, stringent performance requirements, and strict certification processes. Such control systems must ensure the global stability and the required performance within the whole flight envelope, even in the presence of modeling errors, parametric uncertainties, environmental fluctuations, and disturbances. As the dynamic behavior of an aircraft is highly nonlinear and varies significantly with the fight condition, controller parameters must be adequately adjusted based on the operating point. Among the viable solutions for this purpose, one can find gain-scheduling control, which is one of the most well-known techniques widely adopted in aerospace industry. In addition, it is of practical interest from an industrial point of view to leverage the legacy accumulated in the past by imposing a priori the controller structure based on classical ight control system architectures. The present research project aims at developing a procedure for the design and the validation of robust gain-scheduled ight control systems with a fixed structure. This problem is located at the junction of three topics in control, namely synthesis of fixed-structure control systems, robust control, and LPV systems control in the gain-scheduling framework. In the first phase of this research project, a nonlinear dynamic model of an aircraft that explicitly takes into account mass and center of gravity (CG) position is established. This model is linearized around a trim condition in cruise ight. A numerical model of the F-16 Fighting Falcon is then derived and the impact of mass and CG position variations on the aircraft dynamics is analyzed. In the second phase, a method for the design of a robust and self-scheduled controller with a predefined architecture is proposed. Based on the multi-model synthesis capability of structured Hinfinity methods, robustness and gain-scheduling issues are both cast into

  15. Altering Flight Schedules for Increased Fuel Efficiency

    DTIC Science & Technology

    2015-06-19

    7 Air Force Aviation Operations Energy Plan... Aviation Operations Energy Plan Pillars (Air Force, 2010) .............. 9 Figure 4. Aviation Operations Energy Utilization (Air Force, 2010...USAF) is the largest user of aviation fuel in the Department of Defense (DoD), and air mobility operations consume the greatest amount. Rising

  16. An Aid for Flight Squadron Scheduling

    DTIC Science & Technology

    1990-03-01

    Organization Report Numbedsl 5 Monitoring Organization Report Numberfsl 6a Name of Performing Organization Naval Postaraduate School 6b Office...3033AP. in 7£ 5 (I L THESIS DISCLAIMER The reader is cautioned that computer programs developed in this research may not have been exercised for all...Readiness 7 3. Pilots S 4. A Pilot’s Tour S 5 . Syllabus 8 a. Second Pilot Syllabus 10 b. Aircraft Commander Syllabus 10 6. Day and Night

  17. Computational Cognition and Robust Decision Making

    DTIC Science & Technology

    2013-03-06

    processes underlying human performance in complex problem solving tasks; 2. Achieving robust and seamless symbiosis between humans and systems in...prediction, planning, scheduling, and decision making. Challenges and Strategy: • Seek computational principles for optimal symbiosis of mixed human

  18. Mission Planning and Scheduling System for NASA's Lunar Reconnaissance Mission

    NASA Technical Reports Server (NTRS)

    Garcia, Gonzalo; Barnoy, Assaf; Beech, Theresa; Saylor, Rick; Cosgrove, Sager; Ritter, Sheila

    2009-01-01

    In the framework of NASA's return to the Moon efforts, the Lunar Reconnaissance Orbiter (LRO) is the first step. It is an unmanned mission to create a comprehensive atlas of the Moon's features and resources necessary to design and build a lunar outpost. LRO is scheduled for launch in April, 2009. LRO carries a payload comprised of six instruments and one technology demonstration. In addition to its scientific mission LRO will use new technologies, systems and flight operations concepts to reduce risk and increase productivity of future missions. As part of the effort to achieve robust and efficient operations, the LRO Mission Operations Team (MOT) will use its Mission Planning System (MPS) to manage the operational activities of the mission during the Lunar Orbit Insertion (LOI) and operational phases of the mission. The MPS, based on GMV's flexplan tool and developed for NASA with Honeywell Technology Solutions (prime contractor), will receive activity and slew maneuver requests from multiple science operations centers (SOC), as well as from the spacecraft engineers. flexplan will apply scheduling rules to all the requests received and will generate conflict free command schedules in the form of daily stored command loads for the orbiter and a set of daily pass scripts that help automate nominal real-time operations.

  19. Mission Planning and Scheduling System for NASA's Lunar Reconnaissance Mission

    NASA Technical Reports Server (NTRS)

    Garcia, Gonzalo; Barnoy, Assaf; Beech, Theresa; Saylor, Rick; Cosgrove, Jennifer Sager; Ritter, Sheila

    2009-01-01

    In the framework of NASA's return to the Moon efforts, the Lunar Reconnaissance Orbiter (LRO) is the first step. It is an unmanned mission to create a comprehensive atlas of the Moon's features and resources necessary to design and build a lunar outpost. LRO is scheduled for launch in April, 2009. LRO carries a payload comprised of six instruments and one technology demonstration. In addition to its scientific mission LRO will use new technologies, systems and flight operations concepts to reduce risk and increase productivity of future missions. As part of the effort to achieve robust and efficient operations, the LRO Mission Operations Team (MOT) will use its Mission Planning System (MPS) to manage the operational activities of the mission during the Lunar Orbit Insertion (LOI) and operational phases of the mission. The MPS, based on GMV's flexplan tool and developed for NASA with Honeywell Technology Solutions (prime contractor), will receive activity and slew maneuver requests from multiple science operations centers (SOC), as well as from the spacecraft engineers. flexplan will apply scheduling rules to all the requests received and will generate conflict free command schedules in the form of daily stored command loads for the orbiter and a set of daily pass scripts that help automate nominal real-time operations.

  20. ASTER Scheduling Prioritization Function

    NASA Technical Reports Server (NTRS)

    Cohen, Ron

    1996-01-01

    ASTER schedules are generated by an automated scheduling system. This scheduler will generate psuedo-optimal schedules based on a priority scheme. This priority scheme is controlled by the Science Team.

  1. Advanced flight control system study

    NASA Technical Reports Server (NTRS)

    Mcgough, J.; Moses, K.; Klafin, J. F.

    1982-01-01

    The architecture, requirements, and system elements of an ultrareliable, advanced flight control system are described. The basic criteria are functional reliability of 10 to the minus 10 power/hour of flight and only 6 month scheduled maintenance. A distributed system architecture is described, including a multiplexed communication system, reliable bus controller, the use of skewed sensor arrays, and actuator interfaces. Test bed and flight evaluation program are proposed.

  2. Real-time analysis of aromatics in combustion engine exhaust by resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS): a robust tool for chassis dynamometer testing.

    PubMed

    Adam, T W; Clairotte, M; Streibel, T; Elsasser, M; Pommeres, A; Manfredi, U; Carriero, M; Martini, G; Sklorz, M; Krasenbrink, A; Astorga, C; Zimmermann, R

    2012-07-01

    Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS) is a robust method for real-time analysis of monocyclic and polycyclic aromatic hydrocarbons in complex emissions. A mobile system has been developed which enables direct analysis on site. In this paper, we utilize a multicomponent calibration scheme based on the analytes' photo-ionisation cross-sections relative to a calibrated species. This allows semi-quantification of a great number of components by only calibrating one compound of choice, here toluene. The cross-sections were determined by injecting nebulised solutions of aromatic compounds into the TOF-MS ion source with the help of a HPLC pump. Then, REMPI-TOF-MS was implemented at various chassis dynamometers and test cells and the exhaust of the following vehicles and engines investigated: a compression ignition light-duty (LD) passenger car, a compression ignition LD van, two spark ignition LD passenger cars, 2 two-stroke mopeds, and a two-stroke engine of a string gas trimmer. The quantitative time profiles of benzene are shown. The results indicate that two-stroke engines are a significant source for toxic and cancerogenic compounds. Air pollution and health effects caused by gardening equipment might still be underestimated.

  3. 14 CFR 121.541 - Operations schedules: Domestic and flag operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Operations schedules: Domestic and flag... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.541 Operations schedules: Domestic and flag operations. In establishing flight operations schedules, each...

  4. 14 CFR 121.541 - Operations schedules: Domestic and flag operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Operations schedules: Domestic and flag... OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS Flight Operations § 121.541 Operations schedules: Domestic and flag operations. In establishing flight operations schedules, each...

  5. Mission Operations Planning and Scheduling System (MOPSS)

    NASA Technical Reports Server (NTRS)

    Wood, Terri; Hempel, Paul

    2011-01-01

    MOPSS is a generic framework that can be configured on the fly to support a wide range of planning and scheduling applications. It is currently used to support seven missions at Goddard Space Flight Center (GSFC) in roles that include science planning, mission planning, and real-time control. Prior to MOPSS, each spacecraft project built its own planning and scheduling capability to plan satellite activities and communications and to create the commands to be uplinked to the spacecraft. This approach required creating a data repository for storing planning and scheduling information, building user interfaces to display data, generating needed scheduling algorithms, and implementing customized external interfaces. Complex scheduling problems that involved reacting to multiple variable situations were analyzed manually. Operators then used the results to add commands to the schedule. Each architecture was unique to specific satellite requirements. MOPSS is an expert system that automates mission operations and frees the flight operations team to concentrate on critical activities. It is easily reconfigured by the flight operations team as the mission evolves. The heart of the system is a custom object-oriented data layer mapped onto an Oracle relational database. The combination of these two technologies allows a user or system engineer to capture any type of scheduling or planning data in the system's generic data storage via a GUI.

  6. National remote computational flight research facility

    NASA Technical Reports Server (NTRS)

    Rediess, Herman A.

    1989-01-01

    The extension of the NASA Ames-Dryden remotely augmented vehicle (RAV) facility to accommodate flight testing of a hypersonic aircraft utilizing the continental United States as a test range is investigated. The development and demonstration of an automated flight test management system (ATMS) that uses expert system technology for flight test planning, scheduling, and execution is documented.

  7. Unsupervised, Robust Estimation-based Clustering for Multispectral Images

    NASA Technical Reports Server (NTRS)

    Netanyahu, Nathan S.

    1997-01-01

    To prepare for the challenge of handling the archiving and querying of terabyte-sized scientific spatial databases, the NASA Goddard Space Flight Center's Applied Information Sciences Branch (AISB, Code 935) developed a number of characterization algorithms that rely on supervised clustering techniques. The research reported upon here has been aimed at continuing the evolution of some of these supervised techniques, namely the neural network and decision tree-based classifiers, plus extending the approach to incorporating unsupervised clustering algorithms, such as those based on robust estimation (RE) techniques. The algorithms developed under this task should be suited for use by the Intelligent Information Fusion System (IIFS) metadata extraction modules, and as such these algorithms must be fast, robust, and anytime in nature. Finally, so that the planner/schedule module of the IlFS can oversee the use and execution of these algorithms, all information required by the planner/scheduler must be provided to the IIFS development team to ensure the timely integration of these algorithms into the overall system.

  8. Fuzzy scheduled RTDA controller design.

    PubMed

    Srinivasan, K; Anbarasan, K

    2013-03-01

    In this paper, the design and development of fuzzy scheduled robustness, tracking, disturbance rejection and overall aggressiveness (RTDA) controller design for non-linear processes are discussed. pH process is highly non-linear and the design of good controller for this process is always a challenging one due to large gain variation. Fuzzy scheduled RTDA controller design based on normalized integral square error (N_ISE) performance criteria for pH neutralization process is developed. The applicability of the proposed controller is tested for other different non-linear processes like type I diabetic process and conical tank process. The servo and regulatory performance of fuzzy scheduled RTDA controller design is compared with well-tuned internal model control (IMC) and dynamic matrix control (DMC)-based control schemes. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

  9. Intelligent flight control systems

    NASA Technical Reports Server (NTRS)

    Stengel, Robert F.

    1993-01-01

    The capabilities of flight control systems can be enhanced by designing them to emulate functions of natural intelligence. Intelligent control functions fall in three categories. Declarative actions involve decision-making, providing models for system monitoring, goal planning, and system/scenario identification. Procedural actions concern skilled behavior and have parallels in guidance, navigation, and adaptation. Reflexive actions are spontaneous, inner-loop responses for control and estimation. Intelligent flight control systems learn knowledge of the aircraft and its mission and adapt to changes in the flight environment. Cognitive models form an efficient basis for integrating 'outer-loop/inner-loop' control functions and for developing robust parallel-processing algorithms.

  10. Flight Planning in the Cloud

    NASA Technical Reports Server (NTRS)

    Flores, Sarah L.; Chapman, Bruce D.; Tung, Waye W.; Zheng, Yang

    2011-01-01

    This new interface will enable Principal Investigators (PIs), as well as UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar) members to do their own flight planning and time estimation without having to request flight lines through the science coordinator. It uses an all-in-one Google Maps interface, a JPL hosted database, and PI flight requirements to design an airborne flight plan. The application will enable users to see their own flight plan being constructed interactively through a map interface, and then the flight planning software will generate all the files necessary for the flight. Afterward, the UAVSAR team can then complete the flight request, including calendaring and supplying requisite flight request files in the expected format for processing by NASA s airborne science program. Some of the main features of the interface include drawing flight lines on the map, nudging them, adding them to the current flight plan, and reordering them. The user can also search and select takeoff, landing, and intermediate airports. As the flight plan is constructed, all of its components are constantly being saved to the database, and the estimated flight times are updated. Another feature is the ability to import flight lines from previously saved flight plans. One of the main motivations was to make this Web application as simple and intuitive as possible, while also being dynamic and robust. This Web application can easily be extended to support other airborne instruments.

  11. A novel approach to rapidly explore analytical markers for quality control of Radix Salviae Miltiorrhizae extract granules by robust principal component analysis with ultra-high performance liquid chromatography-ultraviolet-quadrupole time-of-flight mass spectrometry.

    PubMed

    Song, Jing-Zheng; Li, Song-Lin; Zhou, Yan; Qiao, Chun-Feng; Chen, Shi-Lin; Xu, Hong-Xi

    2010-11-02

    In a well-controlled experiment, outliers discriminated by robust principal component analysis (RPCA) represent contents in samples which are of particular quality distinguishable from the rest of the others, therefore chemical constituents in a natural product causing discrimination between outliers and the majority of samples could be considered as analytical markers for quality control. Based on this strategy, a novel approach for rapidly exploring characteristic analytical markers was proposed for the quality control of extract granules of Radix Salviae Miltiorrhizae (EGRSM). In this study, large sizes of samples were analyzed via high-throughput ultra-high performance liquid chromatography-ultraviolet-quadrupole time-of-flight mass spectrometry (UHPLC-UV-Q-Tof MS). RPCA was first performed on the three groups of samples: RSM (the raw material), the in-house prepared aqueous extract of Radix Salviae Miltiorrhizae (AERSM) and commercial product of EGRSM, to determine the variation of specific constituents between raw material and the final products as well as the effect of manufacturing process on the overall quality. Then RPCA was performed on the commercial products of EGRSM to explore the applicability of identified characteristic markers for the quality control of EGRSM. Candidate markers were extracted by RPCA, and their molecular formulae were determined by high resolution electrospray ionization-mass spectrometric (ESI-MS) analysis. The suitability of identified markers was then evaluated by determining the relationship between quantities of the identified markers with their antioxidant activities biologically, and further confirmed in a variety of samples. In conclusion, the combination of RPCA with UHPLC-UV-Q-Tof MS is a reliable means to identify chemical markers for evaluating quality of herbal medicines.

  12. Avco Lycoming emission and flight test results

    NASA Technical Reports Server (NTRS)

    Duke, L. C.

    1976-01-01

    The Avco Lycoming flight test program for reduced emissions was conducted to determine and document the lean fuel schedule limits for current production aircraft based on flight safety. Based on analysis of the emissions profile, Avco Lycoming proposed to evaluate the effect of leaner schedules in the idle/taxi, climb, and approach modes. These modes were selected as areas where it was felt that possible improvements could be made with the greatest improvement in cyclic emissions reduction. The fuel systems to produce these leaner stepped fuel schedules were tailored specifically for the flight test.

  13. Guaranteed properties of gain scheduled control for linear parameter-varying plants

    NASA Technical Reports Server (NTRS)

    Shamma, Jeff S.; Athans, Michael

    1991-01-01

    Gain scheduling has proven to be a successful design methodology in many engineering applications. However, in the absence of a sound theoretical analysis, these designs come with no guarantees on the robustness, performance, or even nominal stability of the overall gain scheduled design. This paper presents such an analysis for one type of gain scheduled system, namely, a linear parameter-varying plant scheduling on its exogenous parameters. Conditions are given which guarantee that the stability, robustness, and performance properties of the fixed operating point designs carry over to the global gain scheduled design. These conditions confirm and formalize popular notions regarding gain scheduled design, such as the scheduling variable should 'vary slowly'.

  14. DSIF station schedules

    NASA Technical Reports Server (NTRS)

    Flarity, L. D.; Hanson, R. J.; Thom, E. H.

    1971-01-01

    System manages Deep Space Instrumentation Facilities /DSIF/ equipment construction and modification planning. Versatile program applies to such tasks as employee time and task schedules, pay schedules, operations schedules, and plant and equipment procurement, construction, modification or service.

  15. The Hybrid Schedule: Scheduling to the Curriculum.

    ERIC Educational Resources Information Center

    Boarman, Gerald L.; Kirkpatrick, Barbara S.

    1995-01-01

    A series of experiments with single and double mod scheduling at a large suburban Maryland high school has led to a highly flexible schedule that meets teachers' and students' needs. This schedule allows courses to be offered in the most suitable format, creates more time for students and teachers, streamlines hallway traffic, and fosters a team…

  16. Sickness absence and flight type exposure in flight crew members.

    PubMed

    van Drongelen, A; van der Beek, A J; Penders, G B S; Hlobil, H; Smid, T; Boot, C R L

    2015-01-01

    Shift work research has shown that the relationship between exposure to irregular working times and sickness absence may differ between working populations. Not much is known about the prevalence of sickness absence in flight crews or about the relationship between exposure to different flight schedules and sickness absence in this population. To examine the association between cumulative exposure to different flight types and sickness absence in flight crew members. The study population consisted of flight crew members from a 5 year historic cohort. Flight schedule and sickness absence data were obtained from company records. The association between the cumulative exposure to different flight types and sickness absence episodes of >7 days was determined using univariate and multivariate logistic regression analyses. Adjusted models were obtained by adding potential confounders. Previous sickness absence was added to compose the fully adjusted models. The records of 8228 employees were analysed. The fully adjusted univariate analyses showed that the numbers of medium-haul flights and flights with time zone crossings were associated with an increase in the odds for sickness absence. The fully adjusted multivariate analyses showed no significant associations between flight types and sickness absence. Cumulative exposure to flight types was not independently associated with sickness absence in flight crew members when previous sickness absence was taken into account. Because sickness absence in the past can predict future absence, preventive strategies targeted at flight crew members with a history of high sickness absence may be effective. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Departure Queue Prediction for Strategic and Tactical Surface Scheduler Integration

    NASA Technical Reports Server (NTRS)

    Zelinski, Shannon; Windhorst, Robert

    2016-01-01

    A departure metering concept to be demonstrated at Charlotte Douglas International Airport (CLT) will integrate strategic and tactical surface scheduling components to enable the respective collaborative decision making and improved efficiency benefits these two methods of scheduling provide. This study analyzes the effect of tactical scheduling on strategic scheduler predictability. Strategic queue predictions and target gate pushback times to achieve a desired queue length are compared between fast time simulations of CLT surface operations with and without tactical scheduling. The use of variable departure rates as a strategic scheduler input was shown to substantially improve queue predictions over static departure rates. With target queue length calibration, the strategic scheduler can be tuned to produce average delays within one minute of the tactical scheduler. However, root mean square differences between strategic and tactical delays were between 12 and 15 minutes due to the different methods the strategic and tactical schedulers use to predict takeoff times and generate gate pushback clearances. This demonstrates how difficult it is for the strategic scheduler to predict tactical scheduler assigned gate delays on an individual flight basis as the tactical scheduler adjusts departure sequence to accommodate arrival interactions. Strategic/tactical scheduler compatibility may be improved by providing more arrival information to the strategic scheduler and stabilizing tactical scheduler changes to runway sequence in response to arrivals.

  18. Iterative refinement scheduling

    NASA Technical Reports Server (NTRS)

    Biefeld, Eric

    1992-01-01

    We present a heuristics-based approach to deep space mission scheduling which is modeled on the approach used by expert human schedulers in producing schedules for planetary encounters. New chronological evaluation techniques are used to focus the search by using information gained during the scheduling process to locate, classify, and resolve regions of conflict. Our approach is based on the assumption that during the construction of a schedule there exist several disjunct temporal regions where the demand for one resource type or a single temporal constraint dominates (bottleneck regions). If the scheduler can identify these regions and classify them based on their dominant constraint, then the scheduler can select the scheduling heuristic.

  19. 14 CFR 121.525 - Flight time limitations: Pilots serving in more than one kind of flight crew.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... more than one kind of flight crew. 121.525 Section 121.525 Aeronautics and Space FEDERAL AVIATION... of flight crew. (a) This section applies to each pilot assigned during any 30 consecutive days to more than one type of flight crew. (b) The flight time limitations for a pilot who is scheduled...

  20. Scheduler's assistant: a tool for intelligent scheduling

    NASA Astrophysics Data System (ADS)

    Griffin, Neal L.

    1991-03-01

    The objective of this project was to use expert system technology to aid in the scheduling activities performed at the White Sands Missile Range (WSMR). The WSMR range scheduling problem presents a complex interactive environment. A human factors approach was undertaken, in that, the goal was to implement a system which mimics current WSMR scheduling procedures. The results of this project have produced a prototypic scheduling tool, called Scheduler's Assistant (SA), to aid WSMR range schedulers to generate a daily schedule. The system provides resource conflict detection and resolution advice through a series of cooperating expert systems. Immediate advantages of the system are increased safety, insurance of proper schedule execution and improved speed for turnaround time of sudden schedule changes. Additional benefits of SA include: expandability as future operations grow, allows for rapid redeployment for changing resources, promotes efficient management of WSMR resources, provides a formal representation of knowledge such that years of range personnel experience is preserved and enables the flexibility of a scheduling aid as opposed to a rigid methodology. Prior development efforts by Perceptics have produced a sophisticated expert system development tool, called Knowledge Shaper, which was used to implement all of the expert systems. The development of SA included a library of routines (the SA toolbox) to permit the manipulation of internal data tables and define a data transfer protocol to and from the SA environment. The combination of Knowledge Shaper and the SA toolbox provide a powerful set of design tools for the development of future scheduling applications.

  1. 78 FR 61446 - Schedule of Charges Outside the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Schedule of Charges Outside the United States AGENCY: Federal Aviation... for services of FAA Flight Standards Aviation Safety Inspectors outside the United States....

  2. 75 FR 65401 - Schedule of Charges Outside the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Schedule of Charges Outside the United States AGENCY: Federal Aviation... for services of FAA Flight Standards Aviation Safety Inspectors outside the United States....

  3. 77 FR 60005 - Schedule of Charges Outside the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Schedule of Charges Outside the United States AGENCY: Federal Aviation... of charges for services of FAA Flight Standards Aviation Safety Inspectors outside the United...

  4. Aircraft nonlinear optimal control using fuzzy gain scheduling

    NASA Astrophysics Data System (ADS)

    Nusyirwan, I. F.; Kung, Z. Y.

    2016-10-01

    Fuzzy gain scheduling is a common solution for nonlinear flight control. The highly nonlinear region of flight dynamics is determined throughout the examination of eigenvalues and the irregular pattern of root locus plots that show the nonlinear characteristic. By using the optimal control for command tracking, the pitch rate stability augmented system is constructed and the longitudinal flight control system is established. The outputs of optimal control for 21 linear systems are fed into the fuzzy gain scheduler. This research explores the capability in using both optimal control and fuzzy gain scheduling to improve the efficiency in finding the optimal control gains and to achieve Level 1 flying qualities. The numerical simulation work is carried out to determine the effectiveness and performance of the entire flight control system. The simulation results show that the fuzzy gain scheduling technique is able to perform in real time to find near optimal control law in various flying conditions.

  5. KENNEDY SPACE CENTER, FLA. - This bird's-eye view of a high bay in the Orbiter Processing Facility (OPF) shows Space Shuttle Atlantis surrounded by the standard platforms and equipment required to process a Space Shuttle orbiter for flight. The high bay is 197 feet (60 meters) long, 150 feet (46 meters) wide, 95 feet (29 meters) high, and encompasses a 29,000-square-foot (2,694-meter) area. Platforms, a main access bridge, and two rolling bridges with trucks provide access to various parts of the orbiter. The next mission scheduled for Atlantis is STS-114, a utilization and logistics flight to the International Space Station.

    NASA Image and Video Library

    2003-09-03

    KENNEDY SPACE CENTER, FLA. - This bird's-eye view of a high bay in the Orbiter Processing Facility (OPF) shows Space Shuttle Atlantis surrounded by the standard platforms and equipment required to process a Space Shuttle orbiter for flight. The high bay is 197 feet (60 meters) long, 150 feet (46 meters) wide, 95 feet (29 meters) high, and encompasses a 29,000-square-foot (2,694-meter) area. Platforms, a main access bridge, and two rolling bridges with trucks provide access to various parts of the orbiter. The next mission scheduled for Atlantis is STS-114, a utilization and logistics flight to the International Space Station.

  6. Robust Nanoparticles

    DTIC Science & Technology

    2015-01-21

    advanced the chemis1:Iy of ftmctional nanopruiicles and used these patiicles in advanced materials assembly for the fabrication of nanopatiicle...polymer ligands, and the robustness resulting fi:om ligand cross-linking post- assembly . The project developed a facile evaporative assembly method...used these particles in advanced materials assembly for the fabrication of nanoparticle-based mesostructures. These hybrid materials possess extremely

  7. A manpower scheduling heuristic for aircraft maintenance application

    NASA Astrophysics Data System (ADS)

    Sze, San-Nah; Sze, Jeeu-Fong; Chiew, Kang-Leng

    2012-09-01

    This research studies a manpower scheduling for aircraft maintenance, focusing on in-flight food loading operation. A group of loading teams with flexible shifts is required to deliver and upload packaged meals from the ground kitchen to aircrafts in multiple trips. All aircrafts must be served within predefined time windows. The scheduling process takes into account of various constraints such as meal break allocation, multi-trip traveling and food exposure time limit. Considering the aircrafts movement and predefined maximum working hours for each loading team, the main objective of this study is to form an efficient roster by assigning a minimum number of loading teams to the aircrafts. We proposed an insertion based heuristic to generate the solutions in a short period of time for large instances. This proposed algorithm is implemented in various stages for constructing trips due to the presence of numerous constraints. The robustness and efficiency of the algorithm is demonstrated in computational results. The results show that the insertion heuristic more efficiently outperforms the company's current practice.

  8. Flight Simulation.

    DTIC Science & Technology

    1986-09-01

    lefthand corner of the flight envelope relatively unexplored. This is precisely the flight regime where asymmetric thrust is most critical, however, due...seven data flights were conducted in the late spring of 1979. Seven right-seat subjects (all Caispan employees ) with differing flight experience were

  9. Application of stochastic robustness to aircraft control systems

    NASA Technical Reports Server (NTRS)

    Ryan, Laura E.

    1990-01-01

    Guaranteeing robustness has long been an important design objective of control system analysis. Stochastic robustness is a simple numerical procedure that can be used to measure and gain insight into robustness properties associated with linear control systems. In the realm of aircraft control systems, problems such as the effects of flight condition perturbations and model-order uncertainties on robustness are easily and effectively analyzed using stochastic robustness. The concept of stochastic robustness is reviewed and examples are presented demonstrating its use in flight control system analysis.

  10. Future Air Traffic Growth and Schedule Model User's Guide

    NASA Technical Reports Server (NTRS)

    Kimmel, William M. (Technical Monitor); Smith, Jeremy C.; Dollyhigh, Samuel M.

    2004-01-01

    The Future Air Traffic Growth and Schedule Model was developed as an implementation of the Fratar algorithm to project future traffic flow between airports in a system and of then scheduling the additional flights to reflect current passenger time-of-travel preferences. The methodology produces an unconstrained future schedule from a current (or baseline) schedule and the airport operations growth rates. As an example of the use of the model, future schedules are projected for 2010 and 2022 for all flights arriving at, departing from, or flying between all continental United States airports that had commercial scheduled service for May 17, 2002. Inter-continental US traffic and airports are included and the traffic is also grown with the Fratar methodology to account for their arrivals and departures to the continental US airports. Input data sets derived from the Official Airline Guide (OAG) data and FAA Terminal Area Forecast (TAF) are included in the examples of the computer code execution.

  11. Future Air Traffic Growth and Schedule Model, Supplement

    NASA Technical Reports Server (NTRS)

    Kimmel, William M. (Technical Monitor); Smith, Jeremy C.; Dollyhigh, Samuel M.

    2004-01-01

    The Future Air Traffic Growth and Schedule Model was developed as an implementation of the Fratar algorithm to project future traffic flow between airports in a system and of then scheduling the additional flights to reflect current passenger time-of-travel preferences. The methodology produces an unconstrained future schedule from a current (or baseline) schedule and the airport operations growth rates. As an example of the use of the model, future schedules are projected for 2010 and 2022 for all flights arriving at, departing from, or flying between all continental United States airports that had commercial scheduled service for May 17, 2002. Inter-continental US traffic and airports are included and the traffic is also grown with the Fratar methodology to account for their arrivals and departures to the continental US airports. Input data sets derived from the Official Airline Guide (OAG) data and FAA Terminal Area Forecast (TAF) are included in the examples of the computer code execution.

  12. Protocols for distributive scheduling

    NASA Technical Reports Server (NTRS)

    Richards, Stephen F.; Fox, Barry

    1993-01-01

    The increasing complexity of space operations and the inclusion of interorganizational and international groups in the planning and control of space missions lead to requirements for greater communication, coordination, and cooperation among mission schedulers. These schedulers must jointly allocate scarce shared resources among the various operational and mission oriented activities while adhering to all constraints. This scheduling environment is complicated by such factors as the presence of varying perspectives and conflicting objectives among the schedulers, the need for different schedulers to work in parallel, and limited communication among schedulers. Smooth interaction among schedulers requires the use of protocols that govern such issues as resource sharing, authority to update the schedule, and communication of updates. This paper addresses the development and characteristics of such protocols and their use in a distributed scheduling environment that incorporates computer-aided scheduling tools. An example problem is drawn from the domain of space shuttle mission planning.

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

    NASA Astrophysics Data System (ADS)

    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. SO/ST/SRG - SCHEDULING PROGRAMS

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST (COSMIC Program MSC-21526), and Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Organizer contains a primary menu that is displayed at the beginning of the program. The menu provides options as follows: to write input files to an output distribution file, to change a schedule title field and/or distribution list field, to browse through the schedule and input names file for requested schedule numbers, to create an input names file and a schedule titles file, and to delete input schedule titles and associated names. SO provides a choice of two input files. One file holds 25 groups of up to 25 names for each group. The other file holds 25 records. Each 60-character-long record holds a task schedule title or it is a blank entry. SO creates three output files. One holds the formatted list of schedule titles for printout. Another file holds the formatted distribution list for printout. There is one for each input names file schedule group. The third output file holds the schedule title of the last schedule title file deleted by the user. Schedule Tracker provides an effective method for tracking tasks that are "past due" and/or "near term". ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term

  15. SO/ST/SRG - SCHEDULING PROGRAMS

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST (COSMIC Program MSC-21526), and Report Generator, SRG (COSMIC Program MSC-21527), are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Organizer contains a primary menu that is displayed at the beginning of the program. The menu provides options as follows: to write input files to an output distribution file, to change a schedule title field and/or distribution list field, to browse through the schedule and input names file for requested schedule numbers, to create an input names file and a schedule titles file, and to delete input schedule titles and associated names. SO provides a choice of two input files. One file holds 25 groups of up to 25 names for each group. The other file holds 25 records. Each 60-character-long record holds a task schedule title or it is a blank entry. SO creates three output files. One holds the formatted list of schedule titles for printout. Another file holds the formatted distribution list for printout. There is one for each input names file schedule group. The third output file holds the schedule title of the last schedule title file deleted by the user. Schedule Tracker provides an effective method for tracking tasks that are "past due" and/or "near term". ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are scheduled for recent completion (near term

  16. Aspects of job scheduling

    NASA Technical Reports Server (NTRS)

    Phillips, K.

    1976-01-01

    A mathematical model for job scheduling in a specified context is presented. The model uses both linear programming and combinatorial methods. While designed with a view toward optimization of scheduling of facility and plant operations at the Deep Space Communications Complex, the context is sufficiently general to be widely applicable. The general scheduling problem including options for scheduling objectives is discussed and fundamental parameters identified. Mathematical algorithms for partitioning problems germane to scheduling are presented.

  17. Aspects of job scheduling

    NASA Technical Reports Server (NTRS)

    Phillips, K.

    1976-01-01

    A mathematical model for job scheduling in a specified context is presented. The model uses both linear programming and combinatorial methods. While designed with a view toward optimization of scheduling of facility and plant operations at the Deep Space Communications Complex, the context is sufficiently general to be widely applicable. The general scheduling problem including options for scheduling objectives is discussed and fundamental parameters identified. Mathematical algorithms for partitioning problems germane to scheduling are presented.

  18. X-37 Flight Demonstrator

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The photograph depicts the X-37 neutral buoyancy simulator mockup at Dryden Flight Research Center. The X-37 experimental launch vehicle is roughly 27.5 feet (8.3 meters) long and 15 feet (4.5 meters) in wingspan. Its experiment bay is 7 feet (2.1 meters) long and 4 feet (1.2 meters) in diameter. Designed to operate in both the orbital and reentry phases of flight, the X-37 will increase both safety and reliabiltiy, while reducing launch costs from $10,000 per pound to $1000 per pound. Managed by Marshall Space Flight Center and built by the boeing Company, the X-37 is scheduled to fly two orbital missions in 2002/2003 to test the reusable launch vehicle technologies.

  19. Visually Exploring Transportation Schedules.

    PubMed

    Palomo, Cesar; Guo, Zhan; Silva, Cláudio T; Freire, Juliana

    2016-01-01

    Public transportation schedules are designed by agencies to optimize service quality under multiple constraints. However, real service usually deviates from the plan. Therefore, transportation analysts need to identify, compare and explain both eventual and systemic performance issues that must be addressed so that better timetables can be created. The purely statistical tools commonly used by analysts pose many difficulties due to the large number of attributes at trip- and station-level for planned and real service. Also challenging is the need for models at multiple scales to search for patterns at different times and stations, since analysts do not know exactly where or when relevant patterns might emerge and need to compute statistical summaries for multiple attributes at different granularities. To aid in this analysis, we worked in close collaboration with a transportation expert to design TR-EX, a visual exploration tool developed to identify, inspect and compare spatio-temporal patterns for planned and real transportation service. TR-EX combines two new visual encodings inspired by Marey's Train Schedule: Trips Explorer for trip-level analysis of frequency, deviation and speed; and Stops Explorer for station-level study of delay, wait time, reliability and performance deficiencies such as bunching. To tackle overplotting and to provide a robust representation for a large numbers of trips and stops at multiple scales, the system supports variable kernel bandwidths to achieve the level of detail required by users for different tasks. We justify our design decisions based on specific analysis needs of transportation analysts. We provide anecdotal evidence of the efficacy of TR-EX through a series of case studies that explore NYC subway service, which illustrate how TR-EX can be used to confirm hypotheses and derive new insights through visual exploration.

  20. KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Soichi Noguchi is happy to be back at KSC after arriving aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Soichi Noguchi is happy to be back at KSC after arriving aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

  1. KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, STS-114 Mission Specialist Stephen Robinson (right) learns about the Japanese Experiment Module (JEM) from Louise Kleba (left), with United Space Alliance at KSC, and Jennifer Goldsmith (center), with USA at Johnson Space Center. Crew members are at KSC becoming familiar with Shuttle and mission equipment. The mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, STS-114 Mission Specialist Stephen Robinson (right) learns about the Japanese Experiment Module (JEM) from Louise Kleba (left), with United Space Alliance at KSC, and Jennifer Goldsmith (center), with USA at Johnson Space Center. Crew members are at KSC becoming familiar with Shuttle and mission equipment. The mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

  2. KENNEDY SPACE CENTER, FLA. - - In the Space Station Processing Facility, STS-114 Mission Specialist Stephen Robinson (left) learns about the Japanese Experiment Module (JEM) from Jennifer Goldsmith (center), with United Space Alliance at Johnson Space Center, and Louise Kleba (right), with USA at KSC. Crew members are at KSC to become familiar with Shuttle and mission equipment. The mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - - In the Space Station Processing Facility, STS-114 Mission Specialist Stephen Robinson (left) learns about the Japanese Experiment Module (JEM) from Jennifer Goldsmith (center), with United Space Alliance at Johnson Space Center, and Louise Kleba (right), with USA at KSC. Crew members are at KSC to become familiar with Shuttle and mission equipment. The mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

  3. KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Soichi Noguchi, who is with the Japanese Aerospace and Exploration Agency, looks at the inside of the Japanese Experiment Module (JEM) in the Space Station Processing Facility. He and other crew members are at KSC becoming familiar with Shuttle and mission equipment. The mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Soichi Noguchi, who is with the Japanese Aerospace and Exploration Agency, looks at the inside of the Japanese Experiment Module (JEM) in the Space Station Processing Facility. He and other crew members are at KSC becoming familiar with Shuttle and mission equipment. The mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

  4. KENNEDY SPACE CENTER, FLA. - STS-114 Mission Commander Eileen Collins is pleased to be back at KSC after arriving aboard a T-38 jet aircraft. She and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver to the Space Station the external stowage platform and the Multi-Purpose Logistics Module with supplies and equipment.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Mission Commander Eileen Collins is pleased to be back at KSC after arriving aboard a T-38 jet aircraft. She and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver to the Space Station the external stowage platform and the Multi-Purpose Logistics Module with supplies and equipment.

  5. KENNEDY SPACE CENTER, FLA. - STS-114 Pilot Jim Kelly is pleased to be back at KSC after arriving aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Pilot Jim Kelly is pleased to be back at KSC after arriving aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

  6. KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Wendy Lawrence is pleased to be back at KSC after arriving aboard a T-38 jet aircraft. She and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Wendy Lawrence is pleased to be back at KSC after arriving aboard a T-38 jet aircraft. She and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver the Multi-Purpose Logistics Module carrying supplies and equipment to the Space Station and the external stowage platform.

  7. KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Andrew Thomas is pleased to be back at KSC after arriving aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver to the Space Station the external stowage platform and the Multi-Purpose Logistics Module with supplies and equipment.

    NASA Image and Video Library

    2004-03-05

    KENNEDY SPACE CENTER, FLA. - STS-114 Mission Specialist Andrew Thomas is pleased to be back at KSC after arriving aboard a T-38 jet aircraft. He and other crew members are at the Center for familiarization activities with equipment. The mission is Logistics Flight 1, scheduled to deliver to the Space Station the external stowage platform and the Multi-Purpose Logistics Module with supplies and equipment.

  8. Automated Long - Term Scheduling for the SOFIA Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Civeit, Thomas

    2013-01-01

    The NASA Stratospheric Observatory for Infrared Astronomy (SOFIA) is a joint US/German project to develop and operate a gyro-stabilized 2.5-meter telescope in a Boeing 747SP. SOFIA's first science observations were made in December 2010. During 2011, SOFIA accomplished 30 flights in the "Early Science" program as well as a deployment to Germany. The new observing period, known as Cycle 1, is scheduled to begin in 2012. It includes 46 science flights grouped in four multi-week observing campaigns spread through a 13-month span. Automation of the flight scheduling process offers a major challenge to the SOFIA mission operations. First because it is needed to mitigate its relatively high cost per unit observing time compared to space-borne missions. Second because automated scheduling techniques available for ground-based and space-based telescopes are inappropriate for an airborne observatory. Although serious attempts have been made in the past to solve part of the problem, until recently mission operations staff was still manually scheduling flights. We present in this paper a new automated solution for generating SOFIA long-term schedules that will be used in operations from the Cycle 1 observing period. We describe the constraints that should be satisfied to solve the SOFIA scheduling problem in the context of real operations. We establish key formulas required to efficiently calculate the aircraft course over ground when evaluating flight schedules. We describe the foundations of the SOFIA long-term scheduler, the constraint representation, and the random search based algorithm that generates observation and instrument schedules. Finally, we report on how the new long-term scheduler has been used in operations to date.

  9. X-29 flight research program

    NASA Technical Reports Server (NTRS)

    Putnam, T. W.

    1983-01-01

    The X-29A aircraft is the first manned, experimental high-performance aircraft to be fabricated and flown in many years. The approach for expanding the X-29 flight envelope and collecting research data is described including the methods for monitoring wing divergence, flutter, and aeroservoelastic coupling of the aerodynamic forces with the structure and the flight-control system. Examples of the type of flight data to be acquired are presented along with types of aircraft maneuvers that will be flown. A brief description of the program management structure is also presented and the program schedule is discussed.

  10. Mars Airplane Valles Marineris Terrain Flight

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This is a computer simulation showing a proposed configuration of the Langley Mars Airplane on a flyover of the Valles Marineris system on the planet Mars. The actual flight is scheduled for Dec. 17, 2003, timed to mark the 100th anniversary of the Wright brothers' historic powered flight at Kitty Hawk, N.C.

  11. 75 FR 22519 - Airworthiness Directives; Honeywell International Inc., Primus EPIC and Primus APEX Flight...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-29

    ... its scheduled flight path, and result in possible collision with other aircraft or terrain. DATES... transport airplanes: Chip Adam, Flight Test Pilot, Flight Test Branch, ANM-160L, FAA, Los Angeles Aircraft... during flight. Because of our requirement to promote safe flight of civil aircraft and thus the...

  12. Dedicated heterogeneous node scheduling including backfill scheduling

    DOEpatents

    Wood, Robert R.; Eckert, Philip D.; Hommes, Gregg

    2006-07-25

    A method and system for job backfill scheduling dedicated heterogeneous nodes in a multi-node computing environment. Heterogeneous nodes are grouped into homogeneous node sub-pools. For each sub-pool, a free node schedule (FNS) is created so that the number of to chart the free nodes over time. For each prioritized job, using the FNS of sub-pools having nodes useable by a particular job, to determine the earliest time range (ETR) capable of running the job. Once determined for a particular job, scheduling the job to run in that ETR. If the ETR determined for a lower priority job (LPJ) has a start time earlier than a higher priority job (HPJ), then the LPJ is scheduled in that ETR if it would not disturb the anticipated start times of any HPJ previously scheduled for a future time. Thus, efficient utilization and throughput of such computing environments may be increased by utilizing resources otherwise remaining idle.

  13. Interference Cognizant Network Scheduling

    NASA Technical Reports Server (NTRS)

    Varadarajan, Srivatsan (Inventor); Hall, Brendan (Inventor); Smithgall, William Todd (Inventor); Bonk, Ted (Inventor); DeLay, Benjamin F. (Inventor)

    2017-01-01

    Systems and methods for interference cognizant network scheduling are provided. In certain embodiments, a method of scheduling communications in a network comprises identifying a bin of a global timeline for scheduling an unscheduled virtual link, wherein a bin is a segment of the timeline; identifying a pre-scheduled virtual link in the bin; and determining if the pre-scheduled and unscheduled virtual links share a port. In certain embodiments, if the unscheduled and pre-scheduled virtual links don't share a port, scheduling transmission of the unscheduled virtual link to overlap with the scheduled transmission of the pre-scheduled virtual link; and if the unscheduled and pre-scheduled virtual links share a port: determining a start time delay for the unscheduled virtual link based on the port; and scheduling transmission of the unscheduled virtual link in the bin based on the start time delay to overlap part of the scheduled transmission of the pre-scheduled virtual link.

  14. SRG - SCHEDULE REPORT GENERATOR COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST (COSMIC Program MSC-21526), and Schedule Report Generator, SRG, are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are schedule for recent completion (near term). Schedule Reports Generator provides a simple method for generating periodic schedule reports. SRG enables an engineering manager to monitor tasks assigned to staff members on a weekly basis. SRG sorts three types of reports using one or more data fields as sort keys. One type is sorted using the calendar year as the primary key and the end date as the secondary key. Another type is sorted by flight number. A third type of report, Waterfall plots, is also generated by SRG using the end date as the sorting key. SRG requires as input a single file or two concatenated files with up to 400 single line entries. The user constructs the input file by using the LSE editor VAX utility prior to the execution of the program. The user is able to modify the current functional description text lines just displayed. ST and SRG use the same data base file as input. The common data base file has a maximum number of 400 entries. The time span of all three programs is nineteen months. Both of these maximum

  15. SRG - SCHEDULE REPORT GENERATOR COMPUTER PROGRAM

    NASA Technical Reports Server (NTRS)

    Collazo, F. F.

    1994-01-01

    The Schedule Organizer, SO (COSMIC Program MSC-21525), Schedule Tracker, ST (COSMIC Program MSC-21526), and Schedule Report Generator, SRG, are programs that manipulate data base files in ways that are advantageous to scheduling applications. Originally designed for the Space Shuttle flight schedule, the program can be easily modified for other scheduling situations. Schedule Organizer provides a simple method for generating distribution lists. These distribution lists contain readers' names for each task schedule defined by the input files. Schedule Tracker provides an effective method for tracking tasks that are 'past due' and/or 'near term'. ST generates reports for each responsible staff member with one or more assigned tasks that fall within the two listed categories. This enables an engineering manager to monitor tasks assigned to staff by running ST on a weekly basis. ST only lists tasks on reports that have become past due or are schedule for recent completion (near term). Schedule Reports Generator provides a simple method for generating periodic schedule reports. SRG enables an engineering manager to monitor tasks assigned to staff members on a weekly basis. SRG sorts three types of reports using one or more data fields as sort keys. One type is sorted using the calendar year as the primary key and the end date as the secondary key. Another type is sorted by flight number. A third type of report, Waterfall plots, is also generated by SRG using the end date as the sorting key. SRG requires as input a single file or two concatenated files with up to 400 single line entries. The user constructs the input file by using the LSE editor VAX utility prior to the execution of the program. The user is able to modify the current functional description text lines just displayed. ST and SRG use the same data base file as input. The common data base file has a maximum number of 400 entries. The time span of all three programs is nineteen months. Both of these maximum

  16. Applications of Payload Directed Flight

    NASA Technical Reports Server (NTRS)

    Ippolito, Corey; Fladeland, Matthew M.; Yeh, Yoo Hsiu

    2009-01-01

    Next generation aviation flight control concepts require autonomous and intelligent control system architectures that close control loops directly around payload sensors in manner more integrated and cohesive that in traditional autopilot designs. Research into payload directed flight control at NASA Ames Research Center is investigating new and novel architectures that can satisfy the requirements for next generation control and automation concepts for aviation. Tighter integration between sensor and machine requires definition of specific sensor-directed control modes to tie the sensor data directly into a vehicle control structures throughout the entire control architecture, from low-level stability- and control loops, to higher level mission planning and scheduling reasoning systems. Payload directed flight systems can thus provide guidance, navigation, and control for vehicle platforms hosting a suite of onboard payload sensors. This paper outlines related research into the field of payload directed flight; and outlines requirements and operating concepts for payload directed flight systems based on identified needs from the scientific literature.'

  17. Integrated flight/propulsion control design for a STOVL aircraft using H-infinity control design techniques

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Ouzts, Peter J.

    1991-01-01

    Results are presented from an application of H-infinity control design methodology to a centralized integrated flight propulsion control (IFPC) system design for a supersonic Short Takeoff and Vertical Landing (STOVL) fighter aircraft in transition flight. The emphasis is on formulating the H-infinity control design problem such that the resulting controller provides robustness to modeling uncertainties and model parameter variations with flight condition. Experience gained from a preliminary H-infinity based IFPC design study performed earlier is used as the basis to formulate the robust H-infinity control design problem and improve upon the previous design. Detailed evaluation results are presented for a reduced order controller obtained from the improved H-infinity control design showing that the control design meets the specified nominal performance objectives as well as provides stability robustness for variations in plant system dynamics with changes in aircraft trim speed within the transition flight envelope. A controller scheduling technique which accounts for changes in plant control effectiveness with variation in trim conditions is developed and off design model performance results are presented.

  18. ATD-2 Surface Scheduling and Metering Concept

    NASA Technical Reports Server (NTRS)

    Coppenbarger, Richard A.; Jung, Yoon Chul; Capps, Richard Alan; Engelland, Shawn A.

    2017-01-01

    This presentation describes the concept of ATD-2 tactical surface scheduling and metering. The concept is composed of several elements, including data exchange and integration; surface modeling; surface scheduling; and surface metering. The presentation explains each of the elements. Surface metering is implemented to balance demand and capacity• When surface metering is on, target times from surface scheduler areconverted to advisories for throttling demand• Through the scheduling process, flights with CTOTs will not get addedmetering delay (avoids potential for ‘double delay’)• Carriers can designate certain flights as exempt from metering holds• Demand throttle in Phase 1 at CLT is through advisories sent to rampcontrollers for pushback instructions to the flight deck– Push now– Hold for an advised period of time (in minutes)• Principles of surface metering can be more generally applied to otherairports in the NAS to throttle demand via spot-release times (TMATs Strong focus on optimal use of airport resources• Flexibility enables stakeholders to vary the amount of delay theywould like transferred to gate• Addresses practical aspects of executing surface metering in aturbulent real world environment• Algorithms designed for both short term demand/capacityimbalances (banks) or sustained metering situations• Leverage automation to enable surface metering capability withoutrequiring additional positions• Represents first step in Tactical/Strategic fusion• Provides longer look-ahead calculations to enable analysis ofstrategic surface metering potential usage

  19. Distributed scheduling with COMPASS

    NASA Technical Reports Server (NTRS)

    Rufat-Latre, Jorge; Culbert, Chris

    1991-01-01

    COMPASS (COMPuter Aided Scheduling System) is a sophisticated, interactive scheduling tool used within NASA. Like most existing tools, however, COMPASS is a single-user application. There is a large class of scheduling problems which may be better solved by allowing several people at various locations to build separate schedules with shared resources. DISCORS (DIStributed COmputer Resource Scheduling) is a set of services which support a distributed version of COMPASS. This architecture naturally accommodates the integration of user-defined resource models without modifying COMPASS. DISCORS services include the ability to establish and manage communications, to code messages in efficient formats, to provide fault detection and recovery, and to configure schedulers across a network. In its present form, DISCORS effectively supports distributed COMPASS, but fails to run fast and to guarantee efficient schedules. Further enhancements may allow several users to simultaneously and interactively work together to create complex schedules while COMPASS detects and coordinates the resolution of conflicting requests.

  20. Class Schedules Need Class.

    ERIC Educational Resources Information Center

    Monfette, Ronald J.

    1986-01-01

    Argues that college publications, including class schedules, must be accurate, timely, and easy to read and follow. Describes Schoolcraft College's unified format approach to publications marketing. Offers suggestions on the design, format, and distribution of class schedules. (DMM)

  1. Immunization Schedules for Adults

    MedlinePlus

    ... ACIP Vaccination Recommendations Why Immunize? Vaccines: The Basics Immunization Schedules for Adults in Easy-to-read Formats ... previous immunizations. View or Print a Schedule Recommended Immunizations for Adults (19 Years and Older) by Age ...

  2. Instant Childhood Immunization Schedule

    MedlinePlus

    ... Recommendations Why Immunize? Vaccines: The Basics Instant Childhood Immunization Schedule Recommend on Facebook Tweet Share Compartir Get ... date. See Disclaimer for additional details. Based on Immunization Schedule for Children 0 through 6 Years of ...

  3. School Construction Scheduling.

    ERIC Educational Resources Information Center

    Delaney, J. B.

    1983-01-01

    Explains that favorable market and working conditions influence the scheduling of school construction projects. Facility planners, architects, and contractors are advised to develop a realistic time schedule for the entire project. (MLF)

  4. Projecting Future Scheduled Airline Demand, Schedules and NGATS Benefits Using TSAM

    NASA Technical Reports Server (NTRS)

    Dollyhigh, Samuel; Smith, Jeremy; Viken, Jeff; Trani, Antonio; Baik, Hojong; Hinze, Nickolas; Ashiabor, Senanu

    2006-01-01

    The Transportation Systems Analysis Model (TSAM) developed by Virginia Tech s Air Transportation Systems Lab and NASA Langley can provide detailed analysis of the effects on the demand for air travel of a full range of NASA and FAA aviation projects. TSAM has been used to project the passenger demand for very light jet (VLJ) air taxi service, scheduled airline demand growth and future schedules, Next Generation Air Transportation System (NGATS) benefits, and future passenger revenues for the Airport and Airway Trust Fund. TSAM can project the resulting demand when new vehicles and/or technology is inserted into the long distance (100 or more miles one-way) transportation system, as well as, changes in demand as a result of fare yield increases or decreases, airport transit times, scheduled flight times, ticket taxes, reductions or increases in flight delays, and so on. TSAM models all long distance travel in the contiguous U.S. and determines the mode choice of the traveler based on detailed trip costs, travel time, schedule frequency, purpose of the trip (business or non-business), and household income level of the traveler. Demand is modeled at the county level, with an airport choice module providing up to three airports as part of the mode choice. Future enplanements at airports can be projected for different scenarios. A Fratar algorithm and a schedule generator are applied to generate future flight schedules. This paper presents the application of TSAM to modeling future scheduled air passenger demand and resulting airline schedules, the impact of NGATS goals and objectives on passenger demand, along with projections for passenger fee receipts for several scenarios for the FAA Airport and Airway Trust Fund.

  5. Schedule Risk Assessment

    NASA Technical Reports Server (NTRS)

    Smith, Greg

    2003-01-01

    Schedule Risk Assessment needs to determine the probability of finishing on or before a given point in time. Task in a schedule should reflect the "most likely" duration for each task. IN reality, each task is different and has a varying degree of probability of finishing within or after the duration specified. Schedule risk assessment attempt to quantify these probabilities by assigning values to each task. Bridges the gap between CPM scheduling and the project's need to know the likelihood of "when".

  6. Reinforcement learning in scheduling

    NASA Technical Reports Server (NTRS)

    Dietterich, Tom G.; Ok, Dokyeong; Zhang, Wei; Tadepalli, Prasad

    1994-01-01

    The goal of this research is to apply reinforcement learning methods to real-world problems like scheduling. In this preliminary paper, we show that learning to solve scheduling problems such as the Space Shuttle Payload Processing and the Automatic Guided Vehicle (AGV) scheduling can be usefully studied in the reinforcement learning framework. We discuss some of the special challenges posed by the scheduling domain to these methods and propose some possible solutions we plan to implement.

  7. Web Publishing Schedule

    EPA Pesticide Factsheets

    Section 207(f)(2) of the E-Gov Act requires federal agencies to develop an inventory and establish a schedule of information to be published on their Web sites, make those schedules available for public comment. To post the schedules on the web site.

  8. Analysis of Issues for Project Scheduling by Multiple, Dispersed Schedulers (distributed Scheduling) and Requirements for Manual Protocols and Computer-based Support

    NASA Technical Reports Server (NTRS)

    Richards, Stephen F.

    1991-01-01

    Although computerized operations have significant gains realized in many areas, one area, scheduling, has enjoyed few benefits from automation. The traditional methods of industrial engineering and operations research have not proven robust enough to handle the complexities associated with the scheduling of realistic problems. To address this need, NASA has developed the computer-aided scheduling system (COMPASS), a sophisticated, interactive scheduling tool that is in wide-spread use within NASA and the contractor community. Therefore, COMPASS provides no explicit support for the large class of problems in which several people, perhaps at various locations, build separate schedules that share a common pool of resources. This research examines the issue of distributing scheduling, as applied to application domains characterized by the partial ordering of tasks, limited resources, and time restrictions. The focus of this research is on identifying issues related to distributed scheduling, locating applicable problem domains within NASA, and suggesting areas for ongoing research. The issues that this research identifies are goals, rescheduling requirements, database support, the need for communication and coordination among individual schedulers, the potential for expert system support for scheduling, and the possibility of integrating artificially intelligent schedulers into a network of human schedulers.

  9. DSN Scheduling Engine

    NASA Technical Reports Server (NTRS)

    Clement, Bradley; Johnston, Mark; Wax, Allan; Chouinard, Caroline

    2008-01-01

    The DSN (Deep Space Network) Scheduling Engine targets all space missions that use DSN services. It allows clients to issue scheduling, conflict identification, conflict resolution, and status requests in XML over a Java Message Service interface. The scheduling requests may include new requirements that represent a set of tracks to be scheduled under some constraints. This program uses a heuristic local search to schedule a variety of schedule requirements, and is being infused into the Service Scheduling Assembly, a mixed-initiative scheduling application. The engine resolves conflicting schedules of resource allocation according to a range of existing and possible requirement specifications, including optional antennas; start of track and track duration ranges; periodic tracks; locks on track start, duration, and allocated antenna; MSPA (multiple spacecraft per aperture); arraying/VLBI (very long baseline interferometry)/delta DOR (differential one-way ranging); continuous tracks; segmented tracks; gap-to-track ratio; and override or block-out of requirements. The scheduling models now include conflict identification for SOA(start of activity), BOT (beginning of track), RFI (radio frequency interference), and equipment constraints. This software will search through all possible allocations while providing a best-effort solution at any time. The engine reschedules to accommodate individual emergency tracks in 0.2 second, and emergency antenna downtime in 0.2 second. The software handles doubling of one mission's track requests over one week (to 42 total) in 2.7 seconds. Further tests will be performed in the context of actual schedules.

  10. NASA scheduling technologies

    NASA Technical Reports Server (NTRS)

    Adair, Jerry R.

    1994-01-01

    This paper is a consolidated report on ten major planning and scheduling systems that have been developed by the National Aeronautics and Space Administration (NASA). A description of each system, its components, and how it could be potentially used in private industry is provided in this paper. The planning and scheduling technology represented by the systems ranges from activity based scheduling employing artificial intelligence (AI) techniques to constraint based, iterative repair scheduling. The space related application domains in which the systems have been deployed vary from Space Shuttle monitoring during launch countdown to long term Hubble Space Telescope (HST) scheduling. This paper also describes any correlation that may exist between the work done on different planning and scheduling systems. Finally, this paper documents the lessons learned from the work and research performed in planning and scheduling technology and describes the areas where future work will be conducted.

  11. Supersonic Flight Dynamics Test 1 - Post-Flight Assessment of Simulation Performance

    NASA Technical Reports Server (NTRS)

    Dutta, Soumyo; Bowes, Angela L.; Striepe, Scott A.; Davis, Jody L.; Queen, Eric M.; Blood, Eric M.; Ivanov, Mark C.

    2015-01-01

    NASA's Low Density Supersonic Decelerator (LDSD) project conducted its first Supersonic Flight Dynamics Test (SFDT-1) on June 28, 2014. Program to Optimize Simulated Trajectories II (POST2) was one of the flight dynamics codes used to simulate and predict the flight performance and Monte Carlo analysis was used to characterize the potential flight conditions experienced by the test vehicle. This paper compares the simulation predictions with the reconstructed trajectory of SFDT-1. Additionally, off-nominal conditions seen during flight are modeled in post-flight simulations to find the primary contributors that reconcile the simulation with flight data. The results of these analyses are beneficial for the pre-flight simulation and targeting of the follow-on SFDT flights currently scheduled for summer 2015.

  12. Application of an integrated flight/propulsion control design methodology to a STOVL aircraft

    NASA Technical Reports Server (NTRS)

    Garg, Sanjay; Mattern, Duane L.

    1991-01-01

    The application of an emerging Integrated Flight/Propulsion Control design methodology to a STOVL aircraft in transition flight is reported. The methodology steps consist of: (1) design of a centralized feedback controller to provide command tracking and stability and performance robustness considering the fully integrated airframe/propulsion model as one high-order system; (2) partition of the centralized controller into a decentralized, hierarchical form compatible with implementation requirements; and (3) design of command shaping prefilters from pilot control effectors to commanded variables to provide the overall desired response to pilot inputs. Intermediate design results using this methodology are presented, the complete point control design with the propulsion system operating schedule and limit protection logic included is evaluated for sample pilot control inputs, and the response is compared with that of an 'ideal response model' derived from Level I handling qualities requirements.

  13. Orion Exploration Flight Test-l (EFT -1) Absolute Navigation Design

    NASA Technical Reports Server (NTRS)

    Sud, Jastesh; Gay, Robert; Holt, Greg; Zanetti, Renato

    2014-01-01

    Scheduled to launch in September 2014 atop a Delta IV Heavy from the Kennedy Space Center, the Orion Multi-Purpose-Crew-Vehicle (MPCV's) maiden flight dubbed "Exploration Flight Test -1" (EFT-1) intends to stress the system by placing the uncrewed vehicle on a high-energy parabolic trajectory replicating conditions similar to those that would be experienced when returning from an asteroid or a lunar mission. Unique challenges associated with designing the navigation system for EFT-1 are presented in the narrative with an emphasis on how redundancy and robustness influenced the architecture. Two Inertial Measurement Units (IMUs), one GPS receiver and three barometric altimeters (BALTs) comprise the navigation sensor suite. The sensor data is multiplexed using conventional integration techniques and the state estimate is refined by the GPS pseudorange and deltarange measurements in an Extended Kalman Filter (EKF) that employs the UDUT decomposition approach. The design is substantiated by simulation results to show the expected performance.

  14. Simulation of Flight Operations and Pilot Duties in LANTIRN Fighter Squadrons Using Simkit

    DTIC Science & Technology

    2008-06-01

    Supervisor of Flight RSU Runway Supervisory Unit BFO Base Flight Operations BWOC Base War Operations Center MCR MANTIRN Combat Readiness LCR...DutySchedulerSOF class schedules pilots for this duty based on flight schedule. Another pilot has to be in the Runway Supervisory Unit ( RSU ) located near...Parameters tDuty = max duty duration tRST = return to squadron time State Variables K = number A/C in use currentRSU = RSU officer at present time

  15. Mixed-Integer Formulations for Constellation Scheduling

    NASA Astrophysics Data System (ADS)

    Valicka, C.; Hart, W.; Rintoul, M.

    Remote sensing systems have expanded the set of capabilities available for and critical to national security. Cooperating, high-fidelity sensing systems and growing mission applications have exponentially increased the set of potential schedules. A definitive lack of advanced tools places an increased burden on operators, as planning and scheduling remain largely manual tasks. This is particularly true in time-critical planning activities where operators aim to accomplish a large number of missions through optimal utilization of single or multiple sensor systems. Automated scheduling through identification and comparison of alternative schedules remains a challenging problem applicable across all remote sensing systems. Previous approaches focused on a subset of sensor missions and do not consider ad-hoc tasking. We have begun development of a robust framework that leverages the Pyomo optimization modeling language for the design of a tool to assist sensor operators planning under the constraints of multiple concurrent missions and uncertainty. Our scheduling models have been formulated to address the stochastic nature of ad-hoc tasks inserted under a variety of scenarios. Operator experience is being leveraged to select appropriate model objectives. Successful development of the framework will include iterative development of high-fidelity mission models that consider and expose various schedule performance metrics. Creating this tool will aid time-critical scheduling by increasing planning efficiency, clarifying the value of alternative modalities uniquely provided by multi-sensor systems, and by presenting both sets of organized information to operators. Such a tool will help operators more quickly and fully utilize sensing systems, a high interest objective within the current remote sensing operations community. Preliminary results for mixed-integer programming formulations of a sensor scheduling problem will be presented. Assumptions regarding sensor geometry

  16. Schedule-Organizer Computer Program

    NASA Technical Reports Server (NTRS)

    Collazo, Fernando F.

    1990-01-01

    Schedule Organizer provides simple method for generating distribution lists. Contains readers' names for each task schedule defined by input files. Schedule Organizer (SO), Schedule Tracker (ST) (COSMIC program MSC-21526), and Schedule Report Generator (SRG) (COSMIC program MSC-21527) computer programs manipulating data-base files in ways advantageous in scheduling. Written in PL/1 and DEC Command Language (DCL).

  17. SOFIA's Choice: Automating the Scheduling of Airborne Observations

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Norvig, Peter (Technical Monitor)

    1999-01-01

    This paper describes the problem of scheduling observations for an airborne telescope. Given a set of prioritized observations to choose from, and a wide range of complex constraints governing legitimate choices and orderings, how can we efficiently and effectively create a valid flight plan which supports high priority observations? This problem is quite different from scheduling problems which are routinely solved automatically in industry. For instance, the problem requires making choices which lead to other choices later, and contains many interacting complex constraints over both discrete and continuous variables. Furthermore, new types of constraints may be added as the fundamental problem changes. As a result of these features, this problem cannot be solved by traditional scheduling techniques. The problem resembles other problems in NASA and industry, from observation scheduling for rovers and other science instruments to vehicle routing. The remainder of the paper is organized as follows. In 2 we describe the observatory in order to provide some background. In 3 we describe the problem of scheduling a single flight. In 4 we compare flight planning and other scheduling problems and argue that traditional techniques are not sufficient to solve this problem. We also mention similar complex scheduling problems which may benefit from efforts to solve this problem. In 5 we describe an approach for solving this problem based on research into a similar problem, that of scheduling observations for a space-borne probe. In 6 we discuss extensions of the flight planning problem as well as other problems which are similar to flight planning. In 7 we conclude and discuss future work.

  18. Cost and schedule analytical techniques development

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This contract provided technical services and products to the Marshall Space Flight Center's Engineering Cost Office (PP03) and the Program Plans and Requirements Office (PP02) for the period of 3 Aug. 1991 - 30 Nov. 1994. Accomplishments summarized cover the REDSTAR data base, NASCOM hard copy data base, NASCOM automated data base, NASCOM cost model, complexity generators, program planning, schedules, NASA computer connectivity, other analytical techniques, and special project support.

  19. Building Secure and Reliable Networks Through Robust Resource Scheduling

    DTIC Science & Technology

    2005-07-01

    processor is either a single processor, a symmetric multiprocessor ( SMP ), or a complex/hybrid 8 PCI BUS Pentium III Motherboard Filtering Bridge plus...but these tickets should not exceed OutTktRate t/s. S0 S1 S2 S3 S4 S5 S6 10Mb/s 10Mb/s 10Mb/s 2Mb/s 1Mb/s 1000t/s 500t/s 1000t/s 900t/s 300t/s 1Mb/s...at which tickets are consumed does not exceed OutTktRate t/s. To ensure the source 47 S0 S1 S2 S3 S4 S5S6 10Mb/s 10Mb/s 10Mb/s 1000t/s 500t/s 1000t/s

  20. Integrated resource scheduling in a distributed scheduling environment

    NASA Technical Reports Server (NTRS)

    Zoch, David; Hall, Gardiner

    1988-01-01

    The Space Station era presents a highly-complex multi-mission planning and scheduling environment exercised over a highly distributed system. In order to automate the scheduling process, customers require a mechanism for communicating their scheduling requirements to NASA. A request language that a remotely-located customer can use to specify his scheduling requirements to a NASA scheduler, thus automating the customer-scheduler interface, is described. This notation, Flexible Envelope-Request Notation (FERN), allows the user to completely specify his scheduling requirements such as resource usage, temporal constraints, and scheduling preferences and options. The FERN also contains mechanisms for representing schedule and resource availability information, which are used in the inter-scheduler inconsistency resolution process. Additionally, a scheduler is described that can accept these requests, process them, generate schedules, and return schedule and resource availability information to the requester. The Request-Oriented Scheduling Engine (ROSE) was designed to function either as an independent scheduler or as a scheduling element in a network of schedulers. When used in a network of schedulers, each ROSE communicates schedule and resource usage information to other schedulers via the FERN notation, enabling inconsistencies to be resolved between schedulers. Individual ROSE schedules are created by viewing the problem as a constraint satisfaction problem with a heuristically guided search strategy.

  1. Integrated resource scheduling in a distributed scheduling environment

    NASA Technical Reports Server (NTRS)

    Zoch, David; Hall, Gardiner

    1988-01-01

    The Space Station era presents a highly-complex multi-mission planning and scheduling environment exercised over a highly distributed system. In order to automate the scheduling process, customers require a mechanism for communicating their scheduling requirements to NASA. A request language that a remotely-located customer can use to specify his scheduling requirements to a NASA scheduler, thus automating the customer-scheduler interface, is described. This notation, Flexible Envelope-Request Notation (FERN), allows the user to completely specify his scheduling requirements such as resource usage, temporal constraints, and scheduling preferences and options. The FERN also contains mechanisms for representing schedule and resource availability information, which are used in the inter-scheduler inconsistency resolution process. Additionally, a scheduler is described that can accept these requests, process them, generate schedules, and return schedule and resource availability information to the requester. The Request-Oriented Scheduling Engine (ROSE) was designed to function either as an independent scheduler or as a scheduling element in a network of schedulers. When used in a network of schedulers, each ROSE communicates schedule and resource usage information to other schedulers via the FERN notation, enabling inconsistencies to be resolved between schedulers. Individual ROSE schedules are created by viewing the problem as a constraint satisfaction problem with a heuristically guided search strategy.

  2. Automated telescope scheduling

    NASA Astrophysics Data System (ADS)

    Johnston, Mark D.

    1988-08-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  3. Automated telescope scheduling

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.

    1988-01-01

    With the ever increasing level of automation of astronomical telescopes the benefits and feasibility of automated planning and scheduling are becoming more apparent. Improved efficiency and increased overall telescope utilization are the most obvious goals. Automated scheduling at some level has been done for several satellite observatories, but the requirements on these systems were much less stringent than on modern ground or satellite observatories. The scheduling problem is particularly acute for Hubble Space Telescope: virtually all observations must be planned in excruciating detail weeks to months in advance. Space Telescope Science Institute has recently made significant progress on the scheduling problem by exploiting state-of-the-art artificial intelligence software technology. What is especially interesting is that this effort has already yielded software that is well suited to scheduling groundbased telescopes, including the problem of optimizing the coordinated scheduling of more than one telescope.

  4. SOFIA'S Challenge: Scheduling Airborne Astronomy Observations

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy

    2005-01-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is NASA's next generation airborne astronomical observatory, and will commence operations in 2005. The facility consists of a 747-SP modified to accommodate a 2.5 meter telescope. SOFIA is expected to fly an average of 140 science flights per year over its 20 year lifetime. Depending on the nature of the instrument used during flight, 5-15 observations per flight are expected. The SOFIA telescope is mounted aft of the wings on the port side of the aircraft and is articulated through a range of 20deg to 60deg of elevation. The telescope has minimal lateral flexibility; thus, the aircraft must turn constantly to maintain the telescope's focus on an object during observations. A significant problem in future SOFIA operations is that of scheduling flights in support of observations. Investigators are expected to propose small numbers of observations, and many observations must be grouped together to make up single flights. Flight planning for the previous generation airborne observatory, the Kuiper Airborne Observatory (KAO), was done by hand; planners had to choose takeoff time, observations to perform, and decide on setup-actions (called "dead-legs") to position the aircraft prior to observing. This task frequently required between 6-8 hours to plan one flight The scope of the flight planning problem for supporting GI observations with the anticipated flight rate for SOFIA makes the manual approach for flight planning daunting. In response, we have designed an Automated Flight Planner (AFP) that accepts as input a set of requested observations, designated flight days, weather predictions and fuel limitations, and searches automatically for high-quality flight plans that satisfy all relevant aircraft and astronomer specified constraints. The AFP can generate one candidate flight plan in 5-10 minutes, of computation time, a feat beyond the capabilities of human flight planners. The rate at which the AFP can

  5. SOFIA'S Challenge: Scheduling Airborne Astronomy Observations

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy

    2005-01-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is NASA's next generation airborne astronomical observatory, and will commence operations in 2005. The facility consists of a 747-SP modified to accommodate a 2.5 meter telescope. SOFIA is expected to fly an average of 140 science flights per year over its 20 year lifetime. Depending on the nature of the instrument used during flight, 5-15 observations per flight are expected. The SOFIA telescope is mounted aft of the wings on the port side of the aircraft and is articulated through a range of 20deg to 60deg of elevation. The telescope has minimal lateral flexibility; thus, the aircraft must turn constantly to maintain the telescope's focus on an object during observations. A significant problem in future SOFIA operations is that of scheduling flights in support of observations. Investigators are expected to propose small numbers of observations, and many observations must be grouped together to make up single flights. Flight planning for the previous generation airborne observatory, the Kuiper Airborne Observatory (KAO), was done by hand; planners had to choose takeoff time, observations to perform, and decide on setup-actions (called "dead-legs") to position the aircraft prior to observing. This task frequently required between 6-8 hours to plan one flight The scope of the flight planning problem for supporting GI observations with the anticipated flight rate for SOFIA makes the manual approach for flight planning daunting. In response, we have designed an Automated Flight Planner (AFP) that accepts as input a set of requested observations, designated flight days, weather predictions and fuel limitations, and searches automatically for high-quality flight plans that satisfy all relevant aircraft and astronomer specified constraints. The AFP can generate one candidate flight plan in 5-10 minutes, of computation time, a feat beyond the capabilities of human flight planners. The rate at which the AFP can

  6. Optimal outpatient appointment scheduling.

    PubMed

    Kaandorp, Guido C; Koole, Ger

    2007-09-01

    In this paper optimal outpatient appointment scheduling is studied. A local search procedure is derived that converges to the optimal schedule with a weighted average of expected waiting times of patients, idle time of the doctor and tardiness (lateness) as objective. No-shows are allowed to happen. For certain combinations of parameters the well-known Bailey-Welch rule is found to be the optimal appointment schedule.

  7. Operational VGOS Scheduling

    NASA Astrophysics Data System (ADS)

    Searle, Anthony; Petrachenko, Bill

    2016-12-01

    The VLBI Global Observing System (VGOS) has been designed to take advantage of advances in data recording speeds and storage capacity, allowing for smaller and faster antennas, wider bandwidths, and shorter observation durations. Here, schedules for a ``realistic" VGOS network, frequency sequences, and expanded source lists are presented using a new source-based scheduling algorithm. The VGOS aim for continuous observations presents new operational challenges. As the source-based strategy is independent of the observing network, there are operational advantages which allow for more flexible scheduling of continuous VLBI observations. Using VieVS, simulations of several schedules are presented and compared with previous VGOS studies.

  8. 14 CFR 121.523 - Flight time limitations: Crew of three or more pilots and additional airmen as required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Crew of three or... OPERATIONS Flight Time Limitations: Supplemental Operations § 121.523 Flight time limitations: Crew of three... operations may schedule an airman for flight deck duty as a flight engineer, or navigator in a crew of...

  9. A neural based intelligent flight control system for the NASA F-15 flight research aircraft

    NASA Technical Reports Server (NTRS)

    Urnes, James M.; Hoy, Stephen E.; Ladage, Robert N.; Stewart, James

    1993-01-01

    A flight control concept that can identify aircraft stability properties and continually optimize the aircraft flying qualities has been developed by McDonnell Aircraft Company under a contract with the NASA-Dryden Flight Research Facility. This flight concept, termed the Intelligent Flight Control System, utilizes Neural Network technology to identify the host aircraft stability and control properties during flight, and use this information to design on-line the control system feedback gains to provide continuous optimum flight response. This self-repairing capability can provide high performance flight maneuvering response throughout large flight envelopes, such as needed for the National Aerospace Plane. Moreover, achieving this response early in the vehicle's development schedule will save cost.

  10. An Improved Ant Algorithm for Grid Task Scheduling Strategy

    NASA Astrophysics Data System (ADS)

    Wei, Laizhi; Zhang, Xiaobin; Li, Yun; Li, Yujie

    Task scheduling is an important factor that directly influences the performance and efficiency of the system. Grid resources are usually distributed in different geographic locations, belonging to different organizations and resources' properties are vastly different, in order to complete efficiently, intelligently task scheduling, the choice of scheduling strategy is essential. This paper proposes an improved ant algorithm for grid task scheduling strategy, by introducing a new type pheromone and a new node redistribution selection rule. On the one hand, the algorithm can track performances of resources and tag it. On the other hand, add algorithm to deal with task scheduling unsuccessful situations that improve the algorithm's robustness and the successful probability of task allocation and reduce unnecessary overhead of system, shortening the total time to complete tasks. The data obtained from simulation experiment shows that use this algorithm to resolve schedule problem better than traditional ant algorithm.

  11. Enabling a New Planning and Scheduling Paradigm

    NASA Technical Reports Server (NTRS)

    Jaap, John; Davis, Elizabeth

    2004-01-01

    The Flight Projects Directorate at NASA's Marshall Space Flight Center is developing a new planning and scheduling environment and a new scheduling algorithm to enable a paradigm shift in planning and scheduling concepts. Over the past 33 years Marshall has developed and evolved a paradigm for generating payload timelines for Skylab, Spacelab, various other Shuttle payloads, and the International Space Station. The current paradigm starts by collecting the requirements, called "tasks models," from the scientists and technologists for the tasks that they want to be done. Because of shortcomings in the current modeling schema, some requirements are entered as notes. Next a cadre with knowledge of vehicle and hardware modifies these models to encompass and be compatible with the hardware model; again, notes are added when the modeling schema does not provide a better way to represent the requirements. Finally, another cadre further modifies the models to be compatible with the scheduling engine. This last cadre also submits the models to the scheduling engine or builds the timeline manually to accommodate requirements that are expressed in notes. A future paradigm would provide a scheduling engine that accepts separate science models and hardware models. The modeling schema would have the capability to represent all the requirements without resorting to notes. Furthermore, the scheduling engine would not require that the models be modified to account for the capabilities (limitations) of the scheduling engine. The enabling technology under development at Marshall has three major components. (1) A new modeling schema allows expressing all the requirements of the tasks without resorting to notes or awkward contrivances. The chosen modeling schema is both maximally expressive and easy to use. It utilizes graphics methods to show hierarchies of task constraints and networks of temporal relationships. (2) A new scheduling algorithm automatically schedules the models

  12. Enabling a New Planning and Scheduling Paradigm

    NASA Technical Reports Server (NTRS)

    Jaap, John; Davis, Elizabeth

    2004-01-01

    The Flight Projects Directorate at NASA's Marshall Space Flight Center is developing a new planning and scheduling environment and a new scheduling algorithm to enable a paradigm shift in planning and scheduling concepts. Over the past 33 years Marshall has developed and evolved a paradigm for generating payload timelines for Skylab, Spacelab, various other Shuttle payloads, and the International Space Station. The current paradigm starts by collecting the requirements, called "tasks models," from the scientists and technologists for the tasks that they want to be done. Because of shortcomings in the current modeling schema, some requirements are entered as notes. Next a cadre with knowledge of vehicle and hardware modifies these models to encompass and be compatible with the hardware model; again, notes are added when the modeling schema does not provide a better way to represent the requirements. Finally, another cadre further modifies the models to be compatible with the scheduling engine. This last cadre also submits the models to the scheduling engine or builds the timeline manually to accommodate requirements that are expressed in notes. A future paradigm would provide a scheduling engine that accepts separate science models and hardware models. The modeling schema would have the capability to represent all the requirements without resorting to notes. Furthermore, the scheduling engine would not require that the models be modified to account for the capabilities (limitations) of the scheduling engine. The enabling technology under development at Marshall has three major components. (1) A new modeling schema allows expressing all the requirements of the tasks without resorting to notes or awkward contrivances. The chosen modeling schema is both maximally expressive and easy to use. It utilizes graphics methods to show hierarchies of task constraints and networks of temporal relationships. (2) A new scheduling algorithm automatically schedules the models

  13. Identification and robust control of linear parameter-varying systems

    NASA Astrophysics Data System (ADS)

    Lee, Lawton Hubert

    This dissertation deals with linear parameter-varying (LPV) systems: linear dynamic systems that depend on time-varying parameters. These systems appear in gain scheduling problems, and much recent research has been devoted to their prospective usefulness for systematic gain scheduling. We primarily focus on robust control of uncertain LPV systems and identification of LPV systems that are modelable as linear-fractional transformations (LFTs). Using parameter-dependent quadratic Lyapunov functions, linear matrix inequalities (LMIs), and scaled small-gain arguments, we define notions of stability and induced-{cal L}sb2 performance for uncertain LPV systems whose parameters and rates of parameter variation satisfy given bounds. The performance criterion involves integral quadratic constraints and implies naturally parameter-dependent induced-{cal L}sb2 norm bounds. We formulate and solve an {cal H}sb{infty}-like control problem for an LPV plant with measurable parameters and an "Output/State Feedback" structure: the feedback outputs include some noiselessly measured states. Necessary and sufficient solvability conditions reduce to LMIs that can be solved approximately using finite-dimensional convex programming. Reduced-order LPV controllers are constructed from the LMI solutions. A D-K iteration-like procedure provides robustness to structured, time-varying, parametric uncertainty. The design method is applied to a motivating example: flight control for the F-16 VISTA throughout its subsonic flight envelope. Parameter-dependent weights and {cal H}sb{infty} design principles describe the performance objectives. Closed-loop responses exhibited by nonlinear simulations indicate satisfactory flying qualities. Identification of linear-fractional LPV systems is treated using maximum-likelihood parameter estimation. Computing the gradient and Hessian of a maximum-likelihood cost function reduces to simulating one LPV filter per identified parameter. We use nonlinear

  14. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media are briefed on the upcoming Orion flight test by Ron Fortson, United Launch Alliance director of Mission Management. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  15. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media are briefed on the upcoming Orion flight test by Bryan Austin, Lockheed Martin mission manager. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  16. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media listen as NASA and contractor officials plans for the upcoming Orion flight test. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  17. STS-74 Flight Day 2

    NASA Technical Reports Server (NTRS)

    1995-01-01

    On the second day of the STS-74 mission, the flight crew, Cmdr. Kenneth Cameron, Pilot James Halsell, and Mission Specialists William McArthur, Jerry Ross, and Chris Hadfield, were awakened to music from the play 'The Nutcracker'. The astronauts hosted an in-orbit interview with Canadian reporters and journalists from Toronto, answering general questions about living in space and space flight, and explaining the delicate maneuvers that the shuttle will have to perform for the Mir docking procedures scheduled for the next day. Due to the awkward angle that the shuttle will use to approach the Mir, the docking procedure will be done in an almost blind state.

  18. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media are briefed on the upcoming Orion flight test by Mark Geyer, NASA Orion Program manager. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  19. Scheduling: Seven Period Day

    ERIC Educational Resources Information Center

    Williamson, Ronald

    2010-01-01

    Driven by stable or declining financial resources many school districts are considering the costs and benefits of a seven-period day. While there is limited evidence that any particular scheduling model has a greater impact on student learning than any other, it is clear that the school schedule is a tool that can significantly impact teacher…

  20. Alternative Work Schedules: Definitions

    ERIC Educational Resources Information Center

    Journal of the College and University Personnel Association, 1977

    1977-01-01

    The term "alternative work schedules" encompasses any variation of the requirement that all permanent employees in an organization or one shift of employees adhere to the same five-day, seven-to-eight-hour schedule. This article defines staggered hours, flexible working hours (flexitour and gliding time), compressed work week, the task system, and…

  1. The probability of small schedule values and preference for random-interval schedules.

    PubMed

    Soreth, Michelle Ennis; Hineline, Philip N

    2009-01-01

    Preference for working on variable schedules and temporal discrimination were simultaneously examined in two experiments using a discrete-trial, concurrent-chains arrangement with fixed interval (FI) and random interval (RI) terminal links. The random schedule was generated by first sampling a probability distribution after the programmed delay to reinforcement on the FI schedule had elapsed, and thus the RI never produced a component schedule value shorter than the FI and maintained a rate of reinforcement half that of the FI. Despite these features, the FI was not strongly preferred. The probability of obtaining the smallest programmed delay to reinforcement on the RI schedule was manipulated in Experiment 1, and the interaction of this probability and initial link length was examined in Experiment 2. As the probability of obtaining small values in the RI increased, preference for the schedule increased while the discriminated time of reinforcer availability in the terminal link decreased. Both of these effects were attenuated by lengthening the initial links. The results support the view that in addition to the delay to reinforcement, the probability of obtaining a short delay is an important choice-affecting variable that likely contributes to the robust preferences for variable, as opposed to fixed, schedules of reinforcement.

  2. Accelerated immunotherapy schedules.

    PubMed

    Calabria, Christopher W

    2013-08-01

    Rush and cluster immunotherapy schedules are accelerated immunotherapy build-up schedules. A cluster immunotherapy schedule involves the patient receiving several allergen injections (generally 2-4) sequentially in a single day of treatment on nonconsecutive days. The maintenance dose is generally reached in 4-8 weeks. In rush immunotherapy protocols, higher doses are administered at 15- to 60-min intervals over a 1- to 3-day period until the maintenance dose is achieved. This review will serve as an update for accelerated immunotherapy schedules. The review will include recent investigations demonstrating the safety of cluster schedules in atopic dermatitis, pediatric patients, and inhalant allergen mixtures and an accelerated protocol utilizing an infusion pump for allergen delivery. There has also been further elucidation on the immunological changes which occur during accelerated immunotherapy. Finally, new studies analyzing systemic reaction risk factors are discussed.

  3. DSN Resource Scheduling

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Baldwin, John

    2007-01-01

    TIGRAS is client-side software, which provides tracking-station equipment planning, allocation, and scheduling services to the DSMS (Deep Space Mission System). TIGRAS provides functions for schedulers to coordinate the DSN (Deep Space Network) antenna usage time and to resolve the resource usage conflicts among tracking passes, antenna calibrations, maintenance, and system testing activities. TIGRAS provides a fully integrated multi-pane graphical user interface for all scheduling operations. This is a great improvement over the legacy VAX VMS command line user interface. TIGRAS has the capability to handle all DSN resource scheduling aspects from long-range to real time. TIGRAS assists NASA mission operations for DSN tracking of station equipment resource request processes from long-range load forecasts (ten years or longer), to midrange, short-range, and real-time (less than one week) emergency tracking plan changes. TIGRAS can be operated by NASA mission operations worldwide to make schedule requests for the DSN station equipment.

  4. Schedule Analysis Software Saves Time for Project Planners

    NASA Technical Reports Server (NTRS)

    2015-01-01

    Since the early 2000s, a resource management team at Marshall Space Flight Center has developed and improved the Schedule Test and Assessment Tool, a software add-on capable of analyzing, summarizing, and finding logic gaps in project schedules. Companies like Lanham, Maryland-based Vantage Systems Inc. use the tool to manage NASA projects, but it has also been released for free to more than 200 US companies, agencies, and other entities.

  5. Flight Planning

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Seagull Technology, Inc., Sunnyvale, CA, produced a computer program under a Langley Research Center Small Business Innovation Research (SBIR) grant called STAFPLAN (Seagull Technology Advanced Flight Plan) that plans optimal trajectory routes for small to medium sized airlines to minimize direct operating costs while complying with various airline operating constraints. STAFPLAN incorporates four input databases, weather, route data, aircraft performance, and flight-specific information (times, payload, crew, fuel cost) to provide the correct amount of fuel optimal cruise altitude, climb and descent points, optimal cruise speed, and flight path.

  6. Applications of robust control theory - Educational implications

    NASA Technical Reports Server (NTRS)

    Dorato, P.; Yedavalli, R. K.

    1992-01-01

    A survey is made of applications of robust control theory to problems of flight control, control of flexible space structures, and engine control which have appeared in recent conferences and journals. An analysis is made of which theoretical techniques are most commonly used and what implications this has for graduate and undergraduate education in aerospace engineering.

  7. Power Extension Package (PEP) system definition extension, orbital service module systems analysis study. Volume 11: PEP, cost, schedules, and work breakdown structure dictionary

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Cost scheduling and funding data are presented for the reference design of the power extension package. Major schedule milestones are correlated with current Spacelab flight dates. Funding distributions provide for minimum expenditure during the first year of the project.

  8. Deployment Optimization for Embedded Flight Avionics Systems

    DTIC Science & Technology

    2011-11-01

    architecture containing many computing nodes. At the individual node level, ARINC 653 -compliant time and space partitioning separates the soft...Efficiently In real - time systems , such as the embedded flight avionics case study from Section 4, either fixed priority scheduling algo- rithms, such as...Marchok. Responsive, deterministic IEEE 802.5 token ring scheduling. Real - Time Systems , 1(2):133–158, 1989. 3. L. Lehoczky, J.P. snf Sha and J. Strosnider

  9. A format for the interchange of scheduling models

    NASA Technical Reports Server (NTRS)

    Jaap, John P.; Davis, Elizabeth K.

    1994-01-01

    In recent years a variety of space-activity schedulers have been developed within the aerospace community. Space-activity schedulers are characterized by their need to handle large numbers of activities which are time-window constrained and make high demands on many scarce resources, but are minimally constrained by predecessor/successor requirements or critical paths. Two needs to exchange data between these schedulers have materialized. First, there is significant interest in comparing and evaluating the different scheduling engines to ensure that the best technology is applied to each scheduling endeavor. Second, there is a developing requirement to divide a single scheduling task among different sites, each using a different scheduler. In fact, the scheduling task for International Space Station Alpha (ISSA) will be distributed among NASA centers and among the international partners. The format used to interchange scheduling data for ISSA will likely use a growth version of the format discussed in this paper. The model interchange format (or MIF, pronounced as one syllable) discussed in this paper is a robust solution to the need to interchange scheduling requirements for space activities. It is highly extensible, human-readable, and can be generated or edited with common text editors. It also serves well the need to support a 'benchmark' data case which can be delivered on any computer platform.

  10. Understanding Flight

    SciTech Connect

    Anderson, David

    2001-01-31

    Through the years the explanation of flight has become mired in misconceptions that have become dogma. Wolfgang Langewiesche, the author of 'Stick and Rudder' (1944) got it right when he wrote: 'Forget Bernoulli's Theorem'. A wing develops lift by diverting (from above) a lot of air. This is the same way that a propeller produces thrust and a helicopter produces lift. Newton's three laws and a phenomenon called the Coanda effect explain most of it. With an understanding of the real physics of flight, many things become clear. Inverted flight, symmetric wings, and the flight of insects are obvious. It is easy to understand the power curve, high-speed stalls, and the effect of load and altitude on the power requirements for lift. The contribution of wing aspect ratio on the efficiency of a wing, and the true explanation of ground effect will also be discussed.

  11. Robust Crossfeed Design for Hovering Rotorcraft

    NASA Technical Reports Server (NTRS)

    Catapang, David R.

    1993-01-01

    Control law design for rotorcraft fly-by-wire systems normally attempts to decouple angular responses using fixed-gain crossfeeds. This approach can lead to poor decoupling over the frequency range of pilot inputs and increase the load on the feedback loops. In order to improve the decoupling performance, dynamic crossfeeds may be adopted. Moreover, because of the large changes that occur in rotorcraft dynamics due to small changes about the nominal design condition, especially for near-hovering flight, the crossfeed design must be 'robust'. A new low-order matching method is presented here to design robust crossfeed compensators for multi-input, multi-output (MIMO) systems. The technique identifies degrees-of-freedom that can be decoupled using crossfeeds, given an anticipated set of parameter variations for the range of flight conditions of concern. Cross-coupling is then reduced for degrees-of-freedom that can use crossfeed compensation by minimizing off-axis response magnitude average and variance. Results are presented for the analysis of pitch, roll, yaw and heave coupling of the UH-60 Black Hawk helicopter in near-hovering flight. Robust crossfeeds are designed that show significant improvement in decoupling performance and robustness over nominal, single design point, compensators. The design method and results are presented in an easily used graphical format that lends significant physical insight to the design procedure. This plant pre-compensation technique is an appropriate preliminary step to the design of robust feedback control laws for rotorcraft.

  12. Columbia's first flight shakes down space transportation system

    NASA Technical Reports Server (NTRS)

    Garrett, D.; Young, D.; White, T.

    1981-01-01

    The first space shuttle mission is described. Topics include launch preparations, flight profile, trajectory, and landing operations. The spaceflight tracking and data network is discussed and the photography and television schedules are included.

  13. Effective Schedule and Cost Management as a Product Development Lead

    NASA Technical Reports Server (NTRS)

    Simmons, Cynthia

    2015-01-01

    The presentation will be given at the 26th Annual Thermal Fluids Analysis Workshop (TFAWS 2015) hosted by the Goddard SpaceFlight Center (GSFC) Thermal Engineering Branch (Code 545). This course provides best practices, helpful tools and lessons learned for staying on plan and day-to-day management of Subsystem flight development after getting Project approval for your Subsystem schedule and budget baseline.

  14. Operational aspects of a spacecraft planning/scheduling expert system

    NASA Technical Reports Server (NTRS)

    Mclean, David R.; Littlefield, Ronald G.; Beyer, David S.

    1987-01-01

    Various operational aspects of the Earth Radiation Budget Satellite (ERBS) Tracking and Data Relay Satellite System (TDRSS) are described. The ERBS-TDRSS Contract Planning System is an expert system which has been used operationally since June 1987 by the ERBS Flight Operations Team (FOT) at Goddard Space Flight Center to build weekly schedules of requests for service from the TDRSS. The basic operation of the system and significant enhancements and changes are discussed.

  15. [Decision rules to schedule patient appointments].

    PubMed

    Sepúlveda R, Juan Pedro; Berroeta M, Cristián

    2012-07-01

    Outpatient scheduling has a significant impact on the perceived quality of service by the users and the efficient use of resources in the health system. There are mathematical methods that assist in solving this problem, but are seldom applied. To propose decision rules that are based on the own conditions of each institution and indicate which appointment system is the most suitable for the decision makers. Through computer simulation, the effect of a wide range of decision and environmental factors over the appointment systems performance was assessed, in order to determine how these factors affect them. Considering performance indicators associated to the patient's satisfaction and resources utilization, scheduling shorter length patients (e.g. check-up patients) in the beginning of the working day resulted to be in the efficient solutions frontier, as well as scheduling patients in one person blocks (shifting to multiple patient blocks only if resources utilization indicators are prioritized). Performance indicators are more sensitive to the sequence used to schedule different length patients, rather than the number of patients scheduled per block. Moreover, decision rules based on the institution priorities are proposed, which are quite robust to environmental factors.

  16. Computerizing the Reference Desk Schedule.

    ERIC Educational Resources Information Center

    deHaas, Pat

    1983-01-01

    Discussion of the scheduling procedures of librarians' hours at the reference desk at the Rutherford Humanities and Social Sciences Library, University of Alberta, highlights services provided, the preference table system, and manual scheduling versus computer scheduling. (EJS)

  17. Aeroservoelastic Uncertainty Model Identification from Flight Data

    NASA Technical Reports Server (NTRS)

    Brenner, Martin J.

    2001-01-01

    Uncertainty modeling is a critical element in the estimation of robust stability margins for stability boundary prediction and robust flight control system development. There has been a serious deficiency to date in aeroservoelastic data analysis with attention to uncertainty modeling. Uncertainty can be estimated from flight data using both parametric and nonparametric identification techniques. The model validation problem addressed in this paper is to identify aeroservoelastic models with associated uncertainty structures from a limited amount of controlled excitation inputs over an extensive flight envelope. The challenge to this problem is to update analytical models from flight data estimates while also deriving non-conservative uncertainty descriptions consistent with the flight data. Multisine control surface command inputs and control system feedbacks are used as signals in a wavelet-based modal parameter estimation procedure for model updates. Transfer function estimates are incorporated in a robust minimax estimation scheme to get input-output parameters and error bounds consistent with the data and model structure. Uncertainty estimates derived from the data in this manner provide an appropriate and relevant representation for model development and robust stability analysis. This model-plus-uncertainty identification procedure is applied to aeroservoelastic flight data from the NASA Dryden Flight Research Center F-18 Systems Research Aircraft.

  18. Job shop scheduling problem with late work criterion

    NASA Astrophysics Data System (ADS)

    Piroozfard, Hamed; Wong, Kuan Yew

    2015-05-01

    Scheduling is considered as a key task in many industries, such as project based scheduling, crew scheduling, flight scheduling, machine scheduling, etc. In the machine scheduling area, the job shop scheduling problems are considered to be important and highly complex, in which they are characterized as NP-hard. The job shop scheduling problems with late work criterion and non-preemptive jobs are addressed in this paper. Late work criterion is a fairly new objective function. It is a qualitative measure and concerns with late parts of the jobs, unlike classical objective functions that are quantitative measures. In this work, simulated annealing was presented to solve the scheduling problem. In addition, operation based representation was used to encode the solution, and a neighbourhood search structure was employed to search for the new solutions. The case studies are Lawrence instances that were taken from the Operations Research Library. Computational results of this probabilistic meta-heuristic algorithm were compared with a conventional genetic algorithm, and a conclusion was made based on the algorithm and problem.

  19. Characterization of Tactical Departure Scheduling in the National Airspace System

    NASA Technical Reports Server (NTRS)

    Capps, Alan; Engelland, Shawn A.

    2011-01-01

    This paper discusses and analyzes current day utilization and performance of the tactical departure scheduling process in the National Airspace System (NAS) to understand the benefits in improving this process. The analysis used operational air traffic data from over 1,082,000 flights during the month of January, 2011. Specific metrics included the frequency of tactical departure scheduling, site specific variances in the technology's utilization, departure time prediction compliance used in the tactical scheduling process and the performance with which the current system can predict the airborne slot that aircraft are being scheduled into from the airport surface. Operational data analysis described in this paper indicates significant room for improvement exists in the current system primarily in the area of reduced departure time prediction uncertainty. Results indicate that a significant number of tactically scheduled aircraft did not meet their scheduled departure slot due to departure time uncertainty. In addition to missed slots, the operational data analysis identified increased controller workload associated with tactical departures which were subject to traffic management manual re-scheduling or controller swaps. An analysis of achievable levels of departure time prediction accuracy as obtained by a new integrated surface and tactical scheduling tool is provided to assess the benefit it may provide as a solution to the identified shortfalls. A list of NAS facilities which are likely to receive the greatest benefit from the integrated surface and tactical scheduling technology are provided.

  20. Registration Review Schedules

    EPA Pesticide Factsheets

    This schedule indicates plans for completion of risk assessments, proposed interim decisions and interim decisions for pesticides in the Registration Review program, EPA reviews all registered pesticides at least every 15 years as required by FIFRA.

  1. Childhood Vaccine Schedule

    MedlinePlus

    ... Navigation Bar Home Current Issue Past Issues Childhood Vaccine Schedule Past Issues / Spring 2008 Table of Contents ... please turn Javascript on. When to Vaccinate What Vaccine Why Birth (or any age if not previously ...

  2. Distributed network scheduling

    NASA Technical Reports Server (NTRS)

    Clement, Bradley J.; Schaffer, Steven R.

    2004-01-01

    Distributed Network Scheduling is the scheduling of future communications of a network by nodes in the network. This report details software for doing this onboard spacecraft in a remote network. While prior work on distributed scheduling has been applied to remote spacecraft networks, the software reported here focuses on modeling communication activities in greater detail and including quality of service constraints. Our main results are based on a Mars network of spacecraft and include identifying a maximum opportunity of improving traverse exploration rate a factor of three; a simulation showing reduction in one-way delivery times from a rover to Earth from as much as 5 to 1.5 hours; simulated response to unexpected events averaging under an hour onboard; and ground schedule generation ranging from seconds to 50 minutes for 15 to 100 communication goals.

  3. Initial Hardware Development Schedule

    NASA Technical Reports Server (NTRS)

    Culpepper, William X.

    1991-01-01

    The hardware development schedule for the Common Lunar Lander's (CLLs) tracking system is presented. Among the topics covered are the following: historical perspective, solution options, industry contacts, and the rationale for selection.

  4. Pushing schedule derivation method

    SciTech Connect

    Henriquez, B.

    1996-12-31

    The development of a Pushing Schedule Derivation Method has allowed the company to sustain the maximum production rate at CSH`s Coke Oven Battery, in spite of having single set oven machinery with a high failure index as well as a heat top tendency. The stated method provides for scheduled downtime of up to two hours for machinery maintenance purposes, periods of empty ovens for decarbonization and production loss recovery capability, while observing lower limits and uniformity of coking time.

  5. Cibola flight experiment satellite

    NASA Astrophysics Data System (ADS)

    Davies, P.; Liddle, Doug; Paffett, John; Sweeting, Martin; Curiel, A.; Sun, Wei; Eves, Stuart

    2004-11-01

    In order to achieve an "economy of scale" with respect to payload capacity the major trend in telecommunications satellites is for larger and larger platforms. With these large platforms the level of integration between platform and payload is increasing leading to longer delivery schedules. The typical lifecycle for procurement of these large telecommunications satellites is now 3-6 years depending on the level of non-recurring engineering needed. Surrey Satellite Technology Ltd (SSTL) has designed a low-cost platform aimed at telecommunications and navigation applications. SSTL's Geostationary Minisatellite Platform (GMP) is a new entrant addressing the lower end of the market with payloads up to 250kg requiring less than 1.5 kW power. The British National Space Centre through the MOSAIC Small Satellite Initiative supported the development of GMP. The main design goals for GMP are low-cost for the complete mission including launch and operations and a platform allowing flexible payload accommodation. GMP is specifically designed to allow rapid development and deployment with schedules typically between 1 and 2 years from contract signature to flight readiness. GMP achieves these aims by a modular design where the level of integration between the platform and payload is low. The modular design decomposes the satellite into three major components - the propulsion bay, the avionics bay and the payload module. Both the propulsion and avionics bays are reusable, largely unchanged, and independent of the payload configuration. Such a design means that SSTL or a 3rd party manufacturer can manufacture the payload in parallel to the platform with integration taking place quite late in the schedule. In July 2003 SSTL signed a contract for ESA's first Galileo navigation satellite known as GSTBV2/A. The satellite is based on GMP and ESA plan to launch it into a MEO orbit late in 2005. The second flight of GMP is likely to be in 2006 carrying a geostationary payload

  6. Identification of Francisella tularensis by whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry: fast, reliable, robust, and cost-effective differentiation on species and subspecies levels.

    PubMed

    Seibold, E; Maier, T; Kostrzewa, M; Zeman, E; Splettstoesser, W

    2010-04-01

    Francisella tularensis, the causative agent of tularemia, is a potential agent of bioterrorism. The phenotypic discrimination of closely related, but differently virulent, Francisella tularensis subspecies with phenotyping methods is difficult and time-consuming, often producing ambiguous results. As a fast and simple alternative, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was applied to 50 different strains of the genus Francisella to assess its ability to identify and discriminate between strains according to their designated species and subspecies. Reference spectra from five representative strains of Francisella philomiragia, Francisella tularensis subsp. tularensis, Francisella tularensis subsp. holarctica, Francisella tularensis subsp. mediasiatica, and Francisella tularensis subsp. novicida were established and evaluated for their capability to correctly identify Francisella species and subspecies by matching a collection of spectra from 45 blind-coded Francisella strains against a database containing the five reference spectra and 3,287 spectra from other microorganisms. As a reference method for identification of strains from the genus Francisella, 23S rRNA gene sequencing was used. All strains were correctly identified, with both methods showing perfect agreement at the species level as well as at the subspecies level. The identification of Francisella strains by MALDI-TOF MS and subsequent database matching was reproducible using biological replicates, different culture media, different cultivation times, different serial in vitro passages of the same strain, different preparation protocols, and different mass spectrometers.

  7. Solar array flight dynamic experiment

    NASA Technical Reports Server (NTRS)

    Schock, R. W.

    1986-01-01

    The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-31D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

  8. Solar array flight dynamic experiment

    NASA Technical Reports Server (NTRS)

    Schock, Richard W.

    1987-01-01

    The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures' dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on space shuttle flight STS-41D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

  9. Solar array flight dynamic experiment

    NASA Technical Reports Server (NTRS)

    Schock, Richard W.

    1986-01-01

    The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on Space Shuttle flight STS-31D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

  10. Solar array flight dynamic experiment

    NASA Technical Reports Server (NTRS)

    Schock, Richard W.

    1986-01-01

    The purpose of the Solar Array Flight Dynamic Experiment (SAFDE) is to demonstrate the feasibility of on-orbit measurement and ground processing of large space structures dynamic characteristics. Test definition or verification provides the dynamic characteristic accuracy required for control systems use. An illumination/measurement system was developed to fly on Space Shuttle flight STS-31D. The system was designed to dynamically evaluate a large solar array called the Solar Array Flight Experiment (SAFE) that had been scheduled for this flight. The SAFDE system consisted of a set of laser diode illuminators, retroreflective targets, an intelligent star tracker receiver and the associated equipment to power, condition, and record the results. In six tests on STS-41D, data was successfully acquired from 18 retroreflector targets and ground processed, post flight, to define the solar array's dynamic characteristic. The flight experiment proved the viability of on-orbit test definition of large space structures dynamic characteristics. Future large space structures controllability should be greatly enhanced by this capability.

  11. 14 CFR 91.1062 - Duty periods and rest requirements: Flight attendants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...) Except as provided in paragraph (b) of this section, a program manager may assign a duty period to a..., no program manager may assign a flight attendant to a scheduled duty period of more than 14 hours. (2... duty period. (4) A program manager may assign a flight attendant to a scheduled duty period of more...

  12. Gain-Scheduled Controller Design: Variable Weighting Approach

    NASA Astrophysics Data System (ADS)

    Ilka, Adrian; Veselý, Vojtech

    2014-03-01

    Among the most popular approaches to non-linear control is gain-scheduled (GS) controller, which can have better performance than robust and other ones. Our approach is based on a consideration that in linear parameter varying (LPV) system, scheduling parameters and their derivatives with respect to time are supposed to lie in a priori given hyper rectangles. To access the performance quality a new quadratic cost function is used, where weighting matrices are time varying depends on scheduled parameter. The class of control structure includes decentralised fixed order output feedbacks like PID controller. Numerical examples illustrate the effectiveness of the proposed approach.

  13. A distributed scheduling algorithm for heterogeneous real-time systems

    NASA Technical Reports Server (NTRS)

    Zeineldine, Osman; El-Toweissy, Mohamed; Mukkamala, Ravi

    1991-01-01

    Much of the previous work on load balancing and scheduling in distributed environments was concerned with homogeneous systems and homogeneous loads. Several of the results indicated that random policies are as effective as other more complex load allocation policies. The effects of heterogeneity on scheduling algorithms for hard real time systems is examined. A distributed scheduler specifically to handle heterogeneities in both nodes and node traffic is proposed. The performance of the algorithm is measured in terms of the percentage of jobs discarded. While a random task allocation is very sensitive to heterogeneities, the algorithm is shown to be robust to such non-uniformities in system components and load.

  14. Affirmative Action: The Scheduled Castes and the Scheduled Tribes.

    ERIC Educational Resources Information Center

    Sivaramayya, B.

    This paper considers Indian affirmative action policies that provide reservations (quotas) in favor of two disadvantaged groups, the scheduled castes and the scheduled tribes. First, definitions and background are presented. The scheduled castes ("untouchables") are said to suffer from social segregation, and the scheduled tribes from…

  15. Real-time adaptive aircraft scheduling

    NASA Technical Reports Server (NTRS)

    Kolitz, Stephan E.; Terrab, Mostafa

    1990-01-01

    One of the most important functions of any air traffic management system is the assignment of ground-holding times to flights, i.e., the determination of whether and by how much the take-off of a particular aircraft headed for a congested part of the air traffic control (ATC) system should be postponed in order to reduce the likelihood and extent of airborne delays. An analysis is presented for the fundamental case in which flights from many destinations must be scheduled for arrival at a single congested airport; the formulation is also useful in scheduling the landing of airborne flights within the extended terminal area. A set of approaches is described for addressing a deterministic and a probabilistic version of this problem. For the deterministic case, where airport capacities are known and fixed, several models were developed with associated low-order polynomial-time algorithms. For general delay cost functions, these algorithms find an optimal solution. Under a particular natural assumption regarding the delay cost function, an extremely fast (O(n ln n)) algorithm was developed. For the probabilistic case, using an estimated probability distribution of airport capacities, a model was developed with an associated low-order polynomial-time heuristic algorithm with useful properties.

  16. Robust adaptive control of HVDC systems

    SciTech Connect

    Reeve, J.; Sultan, M. )

    1994-07-01

    The transient performance of an HVDC power system is highly dependent on the parameters of the current/voltage regulators of the converter controls. In order to better accommodate changes in system structure or dc operating conditions, this paper introduces a new adaptive control strategy. The advantages of automatic tuning for continuous fine tuning are combined with predetermined gain scheduling in order to achieve robustness for large disturbances. Examples are provided for a digitally simulated back-to-back dc system.

  17. 14 CFR 121.523 - Flight time limitations: Crew of three or more pilots and additional airmen as required.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR... operations may schedule an airman for flight deck duty as a flight engineer, or navigator in a crew of...

  18. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  19. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  20. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  1. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  2. 14 CFR Appendix B to Subpart 1214... - Occupancy Fee Schedule

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Occupancy Fee Schedule B Appendix B to Subpart 1214.2 of Part 1214 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT Reimbursement for Shuttle Services Provided to Civil U.S. Government Users and Foreign Users...

  3. X-29 flight-research program

    NASA Technical Reports Server (NTRS)

    Putnam, T. W.

    1984-01-01

    The X-29A aircraft is the first manned, experimental high-performance aircraft to be fabricated and flown in many years. The approach for expanding the X-29 flight envelope and collecting research data is described including the methods for monitoring wind divergence, flutter, and aeroservoelastic coupling of the aerodynamic forces with the structure and the flight-control system. Examples of the type of flight data to be acquired are presented along with types of aircraft maneuvers that will be flown. A brief description of the program management structure is also presented and the program schedule is discussed.

  4. The Stanford School Scheduling System.

    ERIC Educational Resources Information Center

    Stanford Univ., CA. Dept. of Industrial Engineering.

    This booklet gives a general overview of the computerized Stanford School Scheduling System (SSSS) which is designed to make scheduling less difficult for individualized programs in secondary education. Topics covered include new flexible scheduling and variable course structure designs in secondary education, the school scheduling problem,…

  5. Toward robust adaptive radiation therapy strategies.

    PubMed

    Böck, Michelle; Eriksson, Kjell; Forsgren, Anders; Hårdemark, Björn

    2017-06-01

    To set up a framework combining robust treatment planning with adaptive re-optimization in order to maintain high treatment quality, to respond to interfractional geometric variations and to identify those patients who will benefit the most from an adaptive fractionation schedule. The authors propose robust adaptive strategies based on stochastic minimax optimization for a series of simulated treatments on a one-dimensional patient phantom. The plan applied during the first fractions should be able to handle anticipated systematic and random errors. Information on the individual geometric variations is gathered at each fraction. At scheduled fractions, the impact of the measured errors on the delivered dose distribution is evaluated. For a patient having received a dose that does not satisfy specified plan quality criteria, the plan is re-optimized based on these individually measured errors. The re-optimized plan is then applied during subsequent fractions until a new scheduled adaptation becomes necessary. In this study, three different adaptive strategies are introduced and investigated. (a) In the first adaptive strategy, the measured systematic and random error scenarios and their assigned probabilities are updated to guide the robust re-optimization. (b) In the second strategy, the degree of conservativeness is adapted in response to the measured dose delivery errors. (c) In the third strategy, the uncertainty margins around the target are recalculated based on the measured errors. The simulated treatments are subjected to systematic and random errors that are either similar to the anticipated errors or unpredictably larger in order to critically evaluate the performance of these three adaptive strategies. According to the simulations, robustly optimized treatment plans provide sufficient treatment quality for those treatment error scenarios similar to the anticipated error scenarios. Moreover, combining robust planning with adaptation leads to improved organ

  6. Robust nonlinear control of vectored thrust aircraft

    NASA Technical Reports Server (NTRS)

    Doyle, John C.; Murray, Richard; Morris, John

    1993-01-01

    An interdisciplinary program in robust control for nonlinear systems with applications to a variety of engineering problems is outlined. Major emphasis will be placed on flight control, with both experimental and analytical studies. This program builds on recent new results in control theory for stability, stabilization, robust stability, robust performance, synthesis, and model reduction in a unified framework using Linear Fractional Transformations (LFT's), Linear Matrix Inequalities (LMI's), and the structured singular value micron. Most of these new advances have been accomplished by the Caltech controls group independently or in collaboration with researchers in other institutions. These recent results offer a new and remarkably unified framework for all aspects of robust control, but what is particularly important for this program is that they also have important implications for system identification and control of nonlinear systems. This combines well with Caltech's expertise in nonlinear control theory, both in geometric methods and methods for systems with constraints and saturations.

  7. Single photon ionization (SPI) via incoherent VUV-excimer light: robust and compact time-of-flight mass spectrometer for on-line, real-time process gas analysis.

    PubMed

    Mühlberger, F; Wieser, J; Ulrich, A; Zimmermann, R

    2002-08-01

    Fast on-line detection of organic compounds from complex mixtures, such as industrial process gas streams, require selective and sensitive analytical methods. One feasible approach for this purpose is the use of mass spectrometry (MS) with a selective and soft (fragment-free) ionization technique, such as chemical ionization (CI) or photo ionization (PI). Single photon ionization (SPI) with vacuum ultraviolet (VUV) light is a particularly sof tionization technique, well-suited for detection of both aromatic and aliphatic species. Problematic, however, is the generation of the VUV light. In general, the vacuum ultraviolet (VUV) light sources for SPI-MS are based either on lasers (e.g., 118-nm radiation generated by frequency-tripling of the third harmonic of a Nd:YAG laser) or on conventional VUV lamps, such as deuterium lamps. Althoughthe laser-based techniques are very sophisticated and expensive, the conventional lamps have serious drawbacks regarding their optical parameters, such as low-output power, low spectral power density, and broad emission bands. In this work, a novel excimer VUV light source, in which an electron beam is used to form rare gas excimer species, is used. The excimer VUV light sourceproduces brilliant and intense VUV light. The novel VUV light source was coupled to a compact and mobile time-of-flight mass spectrometer (TOFMS). A special interface design, including optical (VUV optics) as well as electronic measures (e.g., pulsed ion extraction) was realized. The use of the excimer VUV lamp for SPI will allow the realization of very compact, rugged, and sensitive SPI-TOFMS devices, which preferably will be adapted for process analytical application or monitoring issues (e.g., chemical warfare detection). The excimer VUV-lamp technology delivers VUV light with a good beam quality and high-output power at low costs. Furthermore, it allows changing the emitted wavelength as well as the bandwidth of the excimer VUV lamp in t he 100-200-nm region

  8. On-Line Robust Modal Stability Prediction using Wavelet Processing

    NASA Technical Reports Server (NTRS)

    Brenner, Martin J.; Lind, Rick

    1998-01-01

    Wavelet analysis for filtering and system identification has been used to improve the estimation of aeroservoelastic stability margins. The conservatism of the robust stability margins is reduced with parametric and nonparametric time- frequency analysis of flight data in the model validation process. Nonparametric wavelet processing of data is used to reduce the effects of external disturbances and unmodeled dynamics. Parametric estimates of modal stability are also extracted using the wavelet transform. Computation of robust stability margins for stability boundary prediction depends on uncertainty descriptions derived from the data for model validation. The F-18 High Alpha Research Vehicle aeroservoelastic flight test data demonstrates improved robust stability prediction by extension of the stability boundary beyond the flight regime. Guidelines and computation times are presented to show the efficiency and practical aspects of these procedures for on-line implementation. Feasibility of the method is shown for processing flight data from time- varying nonstationary test points.

  9. ACTEX flight experiment: development issues and lessons learned

    NASA Astrophysics Data System (ADS)

    Schubert, S. R.

    1993-09-01

    The ACTEX flight experiment is scheduled for launch and to begin its on orbit operations in early 1994. The objective of the ACTEX experiment is to demonstrate active vibration control in space, using the smart structure technology. This paper discusses primarily the hardware development and program management issues associated with delivering low cost flight experiments.

  10. Aviation Pilot Training I & II. Flight Syllabus. Field Review Copy.

    ERIC Educational Resources Information Center

    Upchurch, Richard

    This guide for aviation pilot training I and II begins with a course description, resource information, and a course outline. The syllabus is designed to be used concurrently with the ground school program. A minimum of 29 flights are scheduled with a minimum of 40 hours total flight time. Tasks/competencies are categorized into five concept/duty…

  11. 14 CFR 121.503 - Flight time limitations: Pilots: airplanes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Flight time limitations: Pilots: airplanes... Operations § 121.503 Flight time limitations: Pilots: airplanes. (a) A certificate holder conducting supplemental operations may schedule a pilot to fly in an airplane for eight hours or less during any...

  12. 14 CFR 121.503 - Flight time limitations: Pilots: airplanes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Pilots: airplanes... Operations § 121.503 Flight time limitations: Pilots: airplanes. (a) A certificate holder conducting supplemental operations may schedule a pilot to fly in an airplane for eight hours or less during any...

  13. Air Traffic Control: Economics of Flight

    NASA Technical Reports Server (NTRS)

    Murphy, James R.

    2004-01-01

    Contents include the following: 1. Commercial flight is a partnership. Airlines. Pilots. Air traffic control. 2. Airline schedules and weather problems can cause delays at the airport. Delays are inevitable in de-regulated industry due to simple economics. 3.Delays can be mitigated. Build more runways/technology. Increase airspace supply. 4. Cost/benefit analysis determine justification.

  14. Laser data transfer flight experiment definition

    NASA Technical Reports Server (NTRS)

    Merritt, J. R.

    1975-01-01

    A set of laser communication flight experiments to be performed between a relay satellite, ground terminals, and space shuttles were synthesized and evaluated. Results include a definition of the space terminals, NASA ground terminals, test methods, and test schedules required to perform the experiments.

  15. Automated Scheduling Via Artificial Intelligence

    NASA Technical Reports Server (NTRS)

    Biefeld, Eric W.; Cooper, Lynne P.

    1991-01-01

    Artificial-intelligence software that automates scheduling developed in Operations Mission Planner (OMP) research project. Software used in both generation of new schedules and modification of existing schedules in view of changes in tasks and/or available resources. Approach based on iterative refinement. Although project focused upon scheduling of operations of scientific instruments and other equipment aboard spacecraft, also applicable to such terrestrial problems as scheduling production in factory.

  16. Automated Scheduling Via Artificial Intelligence

    NASA Technical Reports Server (NTRS)

    Biefeld, Eric W.; Cooper, Lynne P.

    1991-01-01

    Artificial-intelligence software that automates scheduling developed in Operations Mission Planner (OMP) research project. Software used in both generation of new schedules and modification of existing schedules in view of changes in tasks and/or available resources. Approach based on iterative refinement. Although project focused upon scheduling of operations of scientific instruments and other equipment aboard spacecraft, also applicable to such terrestrial problems as scheduling production in factory.

  17. Schedule-Tracker Computer Program

    NASA Technical Reports Server (NTRS)

    Collazo, Fernando F.

    1990-01-01

    Schedule Tracker provides effective method for tracking tasks "past due" and/or "near term". Generates reports for each responsible staff member having one or more assigned tasks falling within two listed categories. Schedule Organizer (SO) (COSMIC program MSC-21525), Schedule Tracker (ST), and Schedule Report Generator (SRG) (COSMIC program MSC-21527) computer programs manipulating data-base files in ways advantageous in scheduling. Written in PL/1 and DEC Command Language (DCL).

  18. Are accidents scheduled. [safety management problems

    NASA Technical Reports Server (NTRS)

    Childs, C.

    1976-01-01

    Two major sets of safety problems associated with project scheduling are examined. The first set involves problems resulting from the improper scheduling of the safety tasks. The second involves problems which result from inadequate attention to scheduling of those project tasks which lead to tests and operations and includes condensed schedules, modified schedules, schedule workarounds, eliminated portions of the schedules and strung out schedules.

  19. Pegasus Mated to B-52 Mothership - First Flight

    NASA Image and Video Library

    1989-11-09

    The Pegasus air-launched space booster is carried aloft under the right wing of NASA's B-52 carrier aircraft on its first captive flight from the Dryden Flight Research Center, Edwards, California. The first of two scheduled captive flights was completed on November 9, 1989. Pegasus is used to launch satellites into low-earth orbits cheaply. In 1997, a Pegasus rocket booster was also modified to test a hypersonic experiment (PHYSX). An experimental "glove," installed on a section of its wing, housed hundreds of temperature and pressure sensors that sent hypersonic flight data to ground tracking facilities during the experiment’s flight.

  20. Scheduling with genetic algorithms

    NASA Technical Reports Server (NTRS)

    Fennel, Theron R.; Underbrink, A. J., Jr.; Williams, George P. W., Jr.

    1994-01-01

    In many domains, scheduling a sequence of jobs is an important function contributing to the overall efficiency of the operation. At Boeing, we develop schedules for many different domains, including assembly of military and commercial aircraft, weapons systems, and space vehicles. Boeing is under contract to develop scheduling systems for the Space Station Payload Planning System (PPS) and Payload Operations and Integration Center (POIC). These applications require that we respect certain sequencing restrictions among the jobs to be scheduled while at the same time assigning resources to the jobs. We call this general problem scheduling and resource allocation. Genetic algorithms (GA's) offer a search method that uses a population of solutions and benefits from intrinsic parallelism to search the problem space rapidly, producing near-optimal solutions. Good intermediate solutions are probabalistically recombined to produce better offspring (based upon some application specific measure of solution fitness, e.g., minimum flowtime, or schedule completeness). Also, at any point in the search, any intermediate solution can be accepted as a final solution; allowing the search to proceed longer usually produces a better solution while terminating the search at virtually any time may yield an acceptable solution. Many processes are constrained by restrictions of sequence among the individual jobs. For a specific job, other jobs must be completed beforehand. While there are obviously many other constraints on processes, it is these on which we focussed for this research: how to allocate crews to jobs while satisfying job precedence requirements and personnel, and tooling and fixture (or, more generally, resource) requirements.

  1. Synthesis of robust controllers

    NASA Technical Reports Server (NTRS)

    Marrison, Chris

    1993-01-01

    At the 1990 American Controls Conference a benchmark problem was issued as a challenge for designing robust compensators. Many compensators were presented in response to the problem. In previous work Stochastic Robustness Analysis (SRA) was used to compare these compensators. In this work SRA metrics are used as guides to synthesize robust compensators, using the benchmark problem as an example.

  2. Appliance Commitment for Household Load Scheduling

    SciTech Connect

    Du, Pengwei; Lu, Ning

    2011-06-30

    This paper presents a novel appliance commitment algorithm that schedules thermostatically-controlled household loads based on price and consumption forecasts considering users comfort settings to meet an optimization objective such as minimum payment or maximum comfort. The formulation of an appliance commitment problem was described in the paper using an electrical water heater load as an example. The thermal dynamics of heating and coasting of the water heater load was modeled by physical models; random hot water consumption was modeled with statistical methods. The models were used to predict the appliance operation over the scheduling time horizon. User comfort was transformed to a set of linear constraints. Then, a novel linear, sequential, optimization process was used to solve the appliance commitment problem. The simulation results demonstrate that the algorithm is fast, robust, and flexible. The algorithm can be used in home/building energy-management systems to help household owners or building managers to automatically create optimal load operation schedules based on different cost and comfort settings and compare cost/benefits among schedules.

  3. Intelligent retail logistics scheduling

    SciTech Connect

    Rowe, J.; Jewers, K.; Codd, A.; Alcock, A.

    1996-12-31

    The Supply Chain Integrated Ordering Network (SCION) Depot Bookings system automates the planning and scheduling of perishable and non-perishable commodities and the vehicles that carry them into J. Sainsbury depots. This is a strategic initiative, enabling the business to make the key move from weekly to daily ordering. The system is mission critical, managing the inwards flow of commodities from suppliers into J. Sainsbury`s depots. The system leverages Al techniques to provide a business solution that meets challenging functional and performance needs. The SCION Depot Bookings system is operational providing schedules for 22 depots across the UK.

  4. STS-113 Flight Day 9 Highlights

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This video shows the activities of the STS-113 (Jim Wetherbee, Commander; Paul Lockhart, Pilot; Michael Lopez-Alegria, John Herrington, Mission Specialists) crew during flight day 9. Also seen are the outgoing Expedition 5 (Valeri Korzun, Commander; Peggy Whitsun, ISS Science Officer/Flight Engineer; Sergei Treschev, Flight Engineer) and incoming Expedition 6 (Kenneth Bowersox, Commander; Donald Pettit, Nikolai Budarin, Flight Engineers) crews of the ISS (International Space Station). Flight day 9 is a relatively inactive day, with some off-time scheduled for crew bonding and enjoying views. Seven of the joint crew members, including Lopez-Alegria, Wetherbee, Herrington, and Whitsun, pose together and answer questions. Footage shows ISS Science Officers Whitsun and Pettit troubleshooting equipment. The video also contains a clear view of southern South America, a cloudy view of the South Pacific, and external footage of the ISS including the Canadarm robotic arm. The payload bay of the shuttle Endeavour is also shown.

  5. STS-113 Flight Day 9 Highlights

    NASA Astrophysics Data System (ADS)

    2002-12-01

    This video shows the activities of the STS-113 (Jim Wetherbee, Commander; Paul Lockhart, Pilot; Michael Lopez-Alegria, John Herrington, Mission Specialists) crew during flight day 9. Also seen are the outgoing Expedition 5 (Valeri Korzun, Commander; Peggy Whitsun, ISS Science Officer/Flight Engineer; Sergei Treschev, Flight Engineer) and incoming Expedition 6 (Kenneth Bowersox, Commander; Donald Pettit, Nikolai Budarin, Flight Engineers) crews of the ISS (International Space Station). Flight day 9 is a relatively inactive day, with some off-time scheduled for crew bonding and enjoying views. Seven of the joint crew members, including Lopez-Alegria, Wetherbee, Herrington, and Whitsun, pose together and answer questions. Footage shows ISS Science Officers Whitsun and Pettit troubleshooting equipment. The video also contains a clear view of southern South America, a cloudy view of the South Pacific, and external footage of the ISS including the Canadarm robotic arm. The payload bay of the shuttle Endeavour is also shown.

  6. Contribution of Schedule Delays to Cost Growth: How to Make Peace with a Marching Army

    NASA Technical Reports Server (NTRS)

    Majerowicz, Walt; Bitten, Robert; Emmons, Debra; Shinn, Stephen A.

    2016-01-01

    Numerous research papers have shown that cost and schedule growth are interrelated for NASA space science missions. Although there has shown to be a strong correlation of cost growth with schedule growth, it is unclear what percentage of cost growth is caused by schedule growth and how schedule growth can be controlled. This paper attempts to quantify this percentage by looking at historical data and show detailed examples of how schedule growth influences cost growth. The paper also addresses a methodology to show an alternate approach for assessing and setting a robust baseline schedule and use schedule performance metrics to help assess if the project is performing to plan. Finally, recommendations are presented to help control schedule growth in order to minimize cost growth for NASA space science missions.

  7. cFE/CFS (Core Flight Executive/Core Flight System)

    NASA Technical Reports Server (NTRS)

    Wildermann, Charles P.

    2008-01-01

    This viewgraph presentation describes in detail the requirements and goals of the Core Flight Executive (cFE) and the Core Flight System (CFS). The Core Flight Software System is a mission independent, platform-independent, Flight Software (FSW) environment integrating a reusable core flight executive (cFE). The CFS goals include: 1) Reduce time to deploy high quality flight software; 2) Reduce project schedule and cost uncertainty; 3) Directly facilitate formalized software reuse; 4) Enable collaboration across organizations; 5) Simplify sustaining engineering (AKA. FSW maintenance); 6) Scale from small instruments to System of Systems; 7) Platform for advanced concepts and prototyping; and 7) Common standards and tools across the branch and NASA wide.

  8. Atmospheric reentry flight test of winged space vehicle

    NASA Astrophysics Data System (ADS)

    Inatani, Yoshifumi; Akiba, Ryojiro; Hinada, Motoki; Nagatomo, Makoto

    A summary of the atmospheric reentry flight experiment of winged space vehicle is presented. The test was conducted and carried out by the Institute of Space and Astronautical Science (ISAS) in Feb. 1992 in Kagoshima Space Center. It is the first Japanese atmospheric reentry flight of the controlled lifting vehicle. A prime objective of the flight is to demonstrate a high speed atmospheric entry flight capability and high-angle-of-attack flight capability in terms of aerodynamics, flight dynamics and flight control of these kind of vehicles. The launch of the winged vehicle was made by balloon and solid propellant rocket booster which was also the first trial in Japan. The vehicle accomplishes the lfight from space-equivalent condition to the atmospheric flight condition where reaction control system (RCS) attitude stabilization and aerodynamic control was used, respectively. In the flight, the vehicle's attitude was measured by both an inertial measurement unit (IMU) and an air data sensor (ADS) which were employed into an auto-pilot flight control loop. After completion of the entry transient flight, the vehicle experienced unexpected instability during the atmospheric decelerating flight; however, it recovered the attitude orientation and completed the transonic flight after that. The latest analysis shows that it is due to the ADS measurement error and the flight control gain scheduling; what happened was all understood. Some details of the test and the brief summary of the current status of the post flight analysis are presented.

  9. CMS multicore scheduling strategy

    SciTech Connect

    Perez-Calero Yzquierdo, Antonio; Hernandez, Jose; Holzman, Burt; Majewski, Krista; McCrea, Alison

    2014-01-01

    In the next years, processor architectures based on much larger numbers of cores will be most likely the model to continue 'Moore's Law' style throughput gains. This not only results in many more jobs in parallel running the LHC Run 1 era monolithic applications, but also the memory requirements of these processes push the workernode architectures to the limit. One solution is parallelizing the application itself, through forking and memory sharing or through threaded frameworks. CMS is following all of these approaches and has a comprehensive strategy to schedule multicore jobs on the GRID based on the glideinWMS submission infrastructure. The main component of the scheduling strategy, a pilot-based model with dynamic partitioning of resources that allows the transition to multicore or whole-node scheduling without disallowing the use of single-core jobs, is described. This contribution also presents the experiences made with the proposed multicore scheduling schema and gives an outlook of further developments working towards the restart of the LHC in 2015.

  10. Schedule-Induced Stereotypy.

    ERIC Educational Resources Information Center

    Emerson, Eric; Howard, Denise

    1992-01-01

    The phenomena of the induction and entrainment of adjunctive behaviors was investigated in 8 people (ages 5-51) with severe or profound mental retardation who exhibited stereotypic behaviors. Seven of the eight demonstrated evidence of schedule-induced stereotypic behavior, whereas five also showed evidence of the entrainment of these behaviors by…

  11. Optimizing Observation Scheduling Objectives

    NASA Technical Reports Server (NTRS)

    Bresina, John L.; Morris, Robert A.; Edgington, William R.

    1997-01-01

    In this paper, we present an approach that enables the automatic generation of high quality schedules, with respect to a given objective function. The approach involves the combination of two techniques: GenH, which automatically generates a search heuristic specialized to the given problem instance, and HBSS, which employs the generated heuristic as a bias within a stochastic sampling method.

  12. "Creative" Work Schedules.

    ERIC Educational Resources Information Center

    Blai, Boris

    Many creative or flexible work scheduling options are becoming available to the many working parents, students, handicapped persons, elderly individuals, and others who are either unable or unwilling to work a customary 40-hour work week. These options may be broadly categorized as either restructured or reduced work time options. The three main…

  13. Parent Interview Schedule.

    ERIC Educational Resources Information Center

    Purdue Univ., Lafayette, IN. Educational Research Center.

    This 116-item interview schedule designed for parents who failed to respond to the Questionnaire for Parents, is individually administered to the mother of the child of elementary school age. It consists of scales measuring 14 parent variables plus a section devoted to demographic variables: (1) parent's achievement aspirations for the child, (2)…

  14. "Creative" Work Schedules.

    ERIC Educational Resources Information Center

    Blai, Boris

    Many creative or flexible work scheduling options are becoming available to the many working parents, students, handicapped persons, elderly individuals, and others who are either unable or unwilling to work a customary 40-hour work week. These options may be broadly categorized as either restructured or reduced work time options. The three main…

  15. Scheduling Advisory. Research Brief

    ERIC Educational Resources Information Center

    Muir, Mike

    2005-01-01

    More and more high schools are implementing Advisory programs for a variety of reasons: personalization, academics & study skills, life success skills, self-knowledge, addressing the concern about students feeling "lost" in the high school setting, first line of contact for the parents, and portfolios. But finding a way to schedule advisory can…

  16. Scheduling THE Computer.

    ERIC Educational Resources Information Center

    McKay, Martin D.

    1998-01-01

    Focuses on how to schedule the use of a single computer so that all students are represented and given equal access. Suggests that a computer management team be selected from within the class; discusses the teacher's role and student role definition and responsibility assignments. (AEF)

  17. Prescribing Schedule 8 drugs.

    PubMed

    Bird, Sara

    2006-01-01

    Case histories are based on actual medical negligence cases, however certain facts have been omitted or changed by the author to ensure the anonymity of the parties involved. This article examines a general practitioner's legal obligations when prescribing Schedule 8 drugs (drugs of addiction), with particular emphasis on dealing with patients who are drug dependent.

  18. Round Robin Schedules.

    ERIC Educational Resources Information Center

    Iannone, Michael A.

    1983-01-01

    Presented is a computer program written in BASIC that covers round-robin schedules for team matches in competitions. The program was originally created to help teams in a tennis league play one match against every other team. Part of the creation of the program involved use of modulo arithmetic. (MP)

  19. Scale-free Graphs for General Aviation Flight Schedules

    NASA Technical Reports Server (NTRS)

    Alexandov, Natalia M. (Technical Monitor); Kincaid, Rex K.

    2003-01-01

    In the late 1990s a number of researchers noticed that networks in biology, sociology, and telecommunications exhibited similar characteristics unlike standard random networks. In particular, they found that the cummulative degree distributions of these graphs followed a power law rather than a binomial distribution and that their clustering coefficients tended to a nonzero constant as the number of nodes, n, became large rather than O(1/n). Moreover, these networks shared an important property with traditional random graphs as n becomes large the average shortest path length scales with log n. This latter property has been coined the small-world property. When taken together these three properties small-world, power law, and constant clustering coefficient describe what are now most commonly referred to as scale-free networks. Since 1997 at least six books and over 400 articles have been written about scale-free networks. In this manuscript an overview of the salient characteristics of scale-free networks. Computational experience will be provided for two mechanisms that grow (dynamic) scale-free graphs. Additional computational experience will be given for constructing (static) scale-free graphs via a tabu search optimization approach. Finally, a discussion of potential applications to general aviation networks is given.

  20. Effectiveness of Circadian countermeasures in simulated transmeridian flight schedules

    NASA Technical Reports Server (NTRS)

    Moline, Margaret L.; Monk, Timothy H.

    1989-01-01

    The symptoms of jet-lag commonly afflict travelers who cross time zones. Insomnia during the new night, daytime fatigue, malaise, sleepiness, and gastrointestinal disturbances can occur for as long as 3 weeks after jet travel across even a few time zones. These symptoms are largely due to the slow rate of adjustment of the internal circadian timing system to the new time zone. Since business (or pleasure) can be seriously interrupted by such symptoms, it is important to determine ways to speed up the adjustment process to ameliorate the symptoms. Airline pilots have reported that they frequently nap to counter jet lag symptoms, and that they view this as a useful technique. Napping as a countermeasure would be attractive since it is practical and would take advantage of a naturally occurring phase of sleepiness after lunch. Napping also makes sense since insomnia is a common jet lag symptom. Thus, a laboratory simulation of jet lag was designed to test the ability of napping to increase the rate of adjustment following a time zone shift in a population of middle-aged men.

  1. The Incorporation of Changes in an Existing Flight Schedule

    DTIC Science & Technology

    1990-06-01

    890621, rils, s, a ) ,c(upleted( sextonb, 890618, bilOx, d, aa completed( se:. tonb , 890617, bi9, d, aa ,completed( sextonb, 890615, bi8xs, s, a ’,omnpleted...npleted sextonb, 890602, bi~s, s, a ,’.-npleted sextonb, 890601, bi4s, s, a completed( se:: tonb , 890528, bi3s, s, a -’oMpleted( sextonb, 890520, bi2s

  2. Particle swarm optimization based space debris surveillance network scheduling

    NASA Astrophysics Data System (ADS)

    Jiang, Hai; Liu, Jing; Cheng, Hao-Wen; Zhang, Yao

    2017-02-01

    The increasing number of space debris has created an orbital debris environment that poses increasing impact risks to existing space systems and human space flights. For the safety of in-orbit spacecrafts, we should optimally schedule surveillance tasks for the existing facilities to allocate resources in a manner that most significantly improves the ability to predict and detect events involving affected spacecrafts. This paper analyzes two criteria that mainly affect the performance of a scheduling scheme and introduces an artificial intelligence algorithm into the scheduling of tasks of the space debris surveillance network. A new scheduling algorithm based on the particle swarm optimization algorithm is proposed, which can be implemented in two different ways: individual optimization and joint optimization. Numerical experiments with multiple facilities and objects are conducted based on the proposed algorithm, and simulation results have demonstrated the effectiveness of the proposed algorithm.

  3. Spitzer Operations: Scheduling the Out Years

    NASA Technical Reports Server (NTRS)

    Mahoney, William A.; Effertz, Mark J.; Fisher, Mark E.; Garcia, Lisa J.; Hunt, Joseph C. Jr.; Mannings, Vincent; McElroy, Douglas B.; Scire, Elena

    2012-01-01

    Spitzer Warm Mission operations have remained robust and exceptionally efficient since the cryogenic mission ended in mid-2009. The distance to the now exceeds 1 AU, making telecommunications increasingly difficult; however, analysis has shown that two-way communication could be maintained through at least 2017 with minimal loss in observing efficiency. The science program continues to emphasize the characterization of exoplanets, time domain studies, and deep surveys, all of which can impose interesting scheduling constraints. Recent changes have significantly improved on-board data compression, which both enables certain high volume observations and reduces Spitzer's demand for competitive Deep Space Network resources.

  4. Matlab as a robust control design tool

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.

    1994-01-01

    This presentation introduces Matlab as a tool used in flight control research. The example used to illustrate some of the capabilities of this software is a robust controller designed for a single stage to orbit air breathing vehicles's ascent to orbit. The global requirements of the controller are to stabilize the vehicle and follow a trajectory in the presence of atmospheric disturbances and strong dynamic coupling between airframe and propulsion.

  5. Overview of the LaNCETS Flight Experiment and the CFD Analysis

    NASA Technical Reports Server (NTRS)

    Cliatt, Larry J., II; Haering, Edward A., Jr.; Bui, Trong

    2008-01-01

    LaCETS baseline flight study include: 29 high-quality nearfield shock structure probings at three Mach numbers; Shocks in exhaust plume measured; ! CFD study of simplified nozzle shows similar plume structures as flight data; ! Phase II flights scheduled for October 2008; and ! US Industry and Academia invited to participate in analysis, review, and assessment of LaNCETS data.

  6. 41 CFR 301-10.117 - May I keep compensation an airline gives me for voluntarily vacating my seat on my scheduled...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... an airline gives me for voluntarily vacating my seat on my scheduled airline flight when the airline... compensation an airline gives me for voluntarily vacating my seat on my scheduled airline flight when the airline asks for volunteers? Yes: (a) If voluntarily vacating your seat will not interfere with performing...

  7. STS-79 Flight Day 5

    NASA Technical Reports Server (NTRS)

    1996-01-01

    On this fifth day of the STS-79 mission, the flight crew, Cmdr. William F. Readdy, Pilot Terrence W. Wilcutt, Mission Specialists, Thomas D. Akers, Shannon Lucid, Jay Apt, and Carl E. Walz, in the first full day of joint Shuttle/Mir operations begin in with the transfer of a biotechnology investigation and logistical supplies from Atlantis to Mir. The Biotechnology System, an investigation that will study the long-term development of cartilage cells in microgravity, was transported to Mir early this morning. During his planned four-month stay on Mir, John Blaha will take weekly samples of the culture which may provide researchers with information on engineering cartilage cells for possible use in transplantation. They also took time out of their schedules to talk with Good Morning America's Elizabeth Vargas in a brief interview. Prior to beginning the day's transfer activities, all nine astronauts and cosmonauts participated in a joint planning session to outline the day's schedule.

  8. A Robust Biomarker

    NASA Technical Reports Server (NTRS)

    Westall, F.; Steele, A.; Toporski, J.; Walsh, M. M.; Allen, C. C.; Guidry, S.; McKay, D. S.; Gibson, E. K.; Chafetz, H. S.

    2000-01-01

    Polymers of bacterial origin, either through cell secretion or the degraded product of cell lysis, form isolated mucoidal strands as well as well-developed biofilms on interfaces. Biofilms are structurally and compositionally complex and are readily distinguishable from abiogenic films. These structures range in size from micrometers to decimeters, the latter occurring as the well-known, mineralised biofilms called stromatolites. Compositionally bacterial polymers are greater than 90 % water, with while the majority of the macromolecules forming the framework of the polymers consisting of polysaccharides (with and some nucteic acids and proteins). These macromolecules contain a vaste amount of functional groups, such as carboxyls, hydroxyls, and phosphoryls which are implicated in cation-binding. It is the elevated metal- binding capacity which provides the bacterial polymer with structural support and also helps to preserves it for up to 3.5 b.y. in the terrestrial rock record. The macromolecules, thus, can become rapidly mineralised and trapped in a mineral matrix. Through early and late diagenesis (bacterial degradation, burial, heat, pressure and time) they break down, losing the functional groups and, gradually, their hydrogen atoms. The degraded product is known as "kerogen". With further diagenesis and metamorphism, all the hydrogen atoms are lost and the carbonaceous matter becomes graphite. until the remnant carbonaceous material become graphitised. This last sentence reads a bit as if ALL these macromolecules break down and end up as graphite., but since we find 441 this is not true for all of the macromolecules. We have traced fossilised polymer and biofilms in rocks from throughout Earth's history, to rocks as old as the oldest being 3.5 b.y.-old. Furthermore, Time of Flight Secondary Ion Mass Spectrometry has been able to identify individual macromolecules of bacterial origin, the identities of which are still being investigated, in all the samples

  9. A Robust Biomarker

    NASA Technical Reports Server (NTRS)

    Westall, F.; Steele, A.; Toporski, J.; Walsh, M. M.; Allen, C. C.; Guidry, S.; McKay, D. S.; Gibson, E. K.; Chafetz, H. S.

    2000-01-01

    Polymers of bacterial origin, either through cell secretion or the degraded product of cell lysis, form isolated mucoidal strands as well as well-developed biofilms on interfaces. Biofilms are structurally and compositionally complex and are readily distinguishable from abiogenic films. These structures range in size from micrometers to decimeters, the latter occurring as the well-known, mineralised biofilms called stromatolites. Compositionally bacterial polymers are greater than 90 % water, with while the majority of the macromolecules forming the framework of the polymers consisting of polysaccharides (with and some nucteic acids and proteins). These macromolecules contain a vaste amount of functional groups, such as carboxyls, hydroxyls, and phosphoryls which are implicated in cation-binding. It is the elevated metal- binding capacity which provides the bacterial polymer with structural support and also helps to preserves it for up to 3.5 b.y. in the terrestrial rock record. The macromolecules, thus, can become rapidly mineralised and trapped in a mineral matrix. Through early and late diagenesis (bacterial degradation, burial, heat, pressure and time) they break down, losing the functional groups and, gradually, their hydrogen atoms. The degraded product is known as "kerogen". With further diagenesis and metamorphism, all the hydrogen atoms are lost and the carbonaceous matter becomes graphite. until the remnant carbonaceous material become graphitised. This last sentence reads a bit as if ALL these macromolecules break down and end up as graphite., but since we find 441 this is not true for all of the macromolecules. We have traced fossilised polymer and biofilms in rocks from throughout Earth's history, to rocks as old as the oldest being 3.5 b.y.-old. Furthermore, Time of Flight Secondary Ion Mass Spectrometry has been able to identify individual macromolecules of bacterial origin, the identities of which are still being investigated, in all the samples

  10. Block Schedule and Traditional Schedule Achievement: A Comparison

    ERIC Educational Resources Information Center

    Arnold, Douglas E.

    2002-01-01

    Block scheduling constitutes one of the major types of restructuring considered by school administrators seeking to improve student performance. The relationship between two school schedules--the seven-period A/B block and the seven-period traditional schedule--and achievement of students in grade 11 was examined. Comparisons showed no significant…

  11. Scheduling techniques in the Request Oriented Scheduling Engine (ROSE)

    NASA Technical Reports Server (NTRS)

    Zoch, David R.

    1991-01-01

    Scheduling techniques in the ROSE are presented in the form of the viewgraphs. The following subject areas are covered: agenda; ROSE summary and history; NCC-ROSE task goals; accomplishments; ROSE timeline manager; scheduling concerns; current and ROSE approaches; initial scheduling; BFSSE overview and example; and summary.

  12. Dynamic Flight Envelope Assessment with Flight Safety Applications

    NASA Astrophysics Data System (ADS)

    Pandita, Rohit

    FDI filter and a geometric filter design are compared using the metrics and the results validated through simulation. This research was expanded to include synthesis, real-time implementation and flight validation of robust FDI filters for a small uninhabited aerial vehicle. The influence of different closed-loop controllers on FDI filter performance is investigated. A comparison is presented between simulation of the predicted FDI filter performance and flight experiment results.

  13. Cascading Delay Risk of Airline Workforce Deployments with Crew Pairing and Schedule Optimization.

    PubMed

    Chung, Sai Ho; Ma, Hoi Lam; Chan, Hing Kai

    2017-08-01

    This article concerns the assignment of buffer time between two connected flights and the number of reserve crews in crew pairing to mitigate flight disruption due to flight arrival delay. Insufficient crew members for a flight will lead to flight disruptions such as delays or cancellations. In reality, most of these disruption cases are due to arrival delays of the previous flights. To tackle this problem, many research studies have examined the assignment method based on the historical flight arrival delay data of the concerned flights. However, flight arrival delays can be triggered by numerous factors. Accordingly, this article proposes a new forecasting approach using a cascade neural network, which considers a massive amount of historical flight arrival and departure data. The approach also incorporates learning ability so that unknown relationships behind the data can be revealed. Based on the expected flight arrival delay, the buffer time can be determined and a new dynamic reserve crew strategy can then be used to determine the required number of reserve crews. Numerical experiments are carried out based on one year of flight data obtained from 112 airports around the world. The results demonstrate that by predicting the flight departure delay as the input for the prediction of the flight arrival delay, the prediction accuracy can be increased. Moreover, by using the new dynamic reserve crew strategy, the total crew cost can be reduced. This significantly benefits airlines in flight schedule stability and cost saving in the current big data era. © 2016 Society for Risk Analysis.

  14. Explanation of Registration Review Schedule

    EPA Pesticide Factsheets

    Updated information on EPA's schedule for opening dockets to begin pesticide registration reviews during the next several years. The schedule is subdivided into conventional pesticides, antimicrobials, biochemicals, and microbials.

  15. Registration Review Docket Opening Schedule

    EPA Pesticide Factsheets

    Dockets are opened on a fiscal year schedule for reevaluation of all pesticides. They are subdivided into conventional pesticides, antimicrobials, biochemicals, and microbials. The schedules for 2014 to 2017 are attached.

  16. STS-78 Flight Day 7

    NASA Technical Reports Server (NTRS)

    1996-01-01

    On this seventh day of the STS-78 mission, the flight crew, Cmdr. Terence T. Henricks, Pilot Kevin R. Kregel, Payload Cmdr. Susan J. Helms, Mission Specialists Richard M. Linnehan, Charles E. Brady, Jr., and Payload Specialists Jean-Jacques Favier, Ph.D. and Robert B. Thirsk, M.D., continue as test subjects in a series of investigations that seek to understand the effects of microgravity on the human musculoskeletal system. As they approach the half-way mark of a possible record-setting Space Shuttle mission, the crew of Columbia continues its full schedule of life science and microgravity experiments.

  17. STS-72 Flight Day 5

    NASA Technical Reports Server (NTRS)

    1996-01-01

    On this fifth day of the STS-72 mission, the flight crew, Cmdr. Brian Duffy, Pilot Brent W. Jett, and Mission Specialists Leroy Chiao, Daniel T. Barry, Winston E. Scott, and Koichi Wakata (NASDA), awakened to music from the television show, 'Star Trek: The Next Generation'. Chiao and Barry are shown suiting up for the first of the two scheduled 6 1/2 hour spacewalks and, later, conducting tests with various tools and materials from the shuttle's cargo bay during the spacewalk. The new heating and cooling units in the spacesuits will be tested during these EVAs.

  18. STS-72 Flight Day 9

    NASA Technical Reports Server (NTRS)

    1996-01-01

    On this ninth day of the STS-72 mission, the flight crew, Cmdr. Brian Duffy, Pilot Brent W. Jett, and Mission Specialists Leroy Chiao, Daniel T. Barry, Winston E. Scott, and Koichi Wakata (NASDA), awakened to music from the movie Star Wars. The astronauts conducted a news conference via satellite and answered questions from both Japanese and U.S. reporters at the Kennedy Space Center and the Johnson Space Center. The preparation for the scheduled night landing continues from the previous day's activities.

  19. An open-source scheduler for small satellites

    NASA Astrophysics Data System (ADS)

    Torgerson, Donovan; Straub, Jeremy; Mohammad, Atif; Korvald, Christoffer; Limesand, Dayln

    2013-05-01

    The limited power generation capability of a small satellite (e.g., a CubeSat) requires robust scheduling. A scheduling approach for small satellites which considers subsystem inter-dependency (where co-operation is required, desirable or prohibited), operational requirements and ground communication windows is presented. The paper considers what the optimal way of scheduled tasks for autonomous operation (required for scheduling when not in communication with ground controllers and desirable at all times during the mission) is. It compares a genetic algorithm-based approach, an exhaustive search-based approach and a heuristic-based approach. Performance maximization is considered (in light of both decision-making time and reducing activity time).

  20. Shuttle program. STS-7 conceptual flight profile. IUS/TDRS-A

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The Space Transportation System (STS) Flight Assignment Manifest has has scheduled a Tracking and Data Relay Satellite System (TDRSS) spacecraft for a February 1981 launch on STS Flight 7. The preliminary flight profile that conceptually implements the flight requirements and constraints levied by the STS, inertial upper stage (IUS), and the TDRS spacecraft is presented. The integrated major flight design guidelines and requirements used in the development of the flight profile are included together with a flight sequence of events and time line that describe the profile and reflect implementation of the integrated set of requirements.

  1. Robust Adaptive Control

    NASA Technical Reports Server (NTRS)

    Narendra, K. S.; Annaswamy, A. M.

    1985-01-01

    Several concepts and results in robust adaptive control are are discussed and is organized in three parts. The first part surveys existing algorithms. Different formulations of the problem and theoretical solutions that have been suggested are reviewed here. The second part contains new results related to the role of persistent excitation in robust adaptive systems and the use of hybrid control to improve robustness. In the third part promising new areas for future research are suggested which combine different approaches currently known.

  2. Revisiting conjugate schedules.

    PubMed

    MacAleese, Kenneth R; Ghezzi, Patrick M; Rapp, John T

    2015-07-01

    The effects of conjugate reinforcement on the responding of 13 college students were examined in three experiments. Conjugate reinforcement was provided via key presses that changed the clarity of pictures displayed on a computer monitor in a manner proportional to the rate of responding. Experiment 1, which included seven parameters of clarity change per response, revealed that responding decreased as the percentage clarity per response increased for all five participants. These results indicate that each participant's responding was sensitive to intensity change, which is a parameter of conjugate reinforcement schedules. Experiment 2 showed that responding increased during conjugate reinforcement phases and decreased during extinction phases for all four participants. Experiment 3 also showed that responding increased during conjugate reinforcement and further showed that responding decreased during a conjugate negative punishment condition for another four participants. Directions for future research with conjugate schedules are briefly discussed.

  3. Observation Scheduling System

    NASA Technical Reports Server (NTRS)

    Chien, Steve A.; Tran, Daniel Q.; Rabideau, Gregg R.; Schaffer, Steven R.

    2011-01-01

    Software has been designed to schedule remote sensing with the Earth Observing One spacecraft. The software attempts to satisfy as many observation requests as possible considering each against spacecraft operation constraints such as data volume, thermal, pointing maneuvers, and others. More complex constraints such as temperature are approximated to enable efficient reasoning while keeping the spacecraft within safe limits. Other constraints are checked using an external software library. For example, an attitude control library is used to determine the feasibility of maneuvering between pairs of observations. This innovation can deal with a wide range of spacecraft constraints and solve large scale scheduling problems like hundreds of observations and thousands of combinations of observation sequences.

  4. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media are briefed on the upcoming Orion flight test by Jeremy Graeber, Orion Recovery Director in Ground Systems Development and Operations at Kennedy. Also participating in the news conference are Bryan Austin, Lockheed Martin mission manager, left, and Ron Fortson, United Launch Alliance director of Mission Management. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  5. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media are briefed on the upcoming Orion flight test by Mark Geyer, NASA Orion Program manager. Also participating in the news conference are Bill Hill, NASA deputy associate administrator for Exploration Systems Development, left, and Bryan Austin, Lockheed Martin mission manager. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  6. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media are briefed on the upcoming Orion flight test by Mark Geyer, NASA Orion Program manager. Also participating in the news conference are Bryan Austin, Lockheed Martin mission manager, center, and Jeremy Graeber, Orion Recovery Director in Ground Systems Development and Operations at Kennedy. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  7. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media are briefed on the upcoming Orion flight test by Bill Hill, NASA deputy associate administrator for Exploration Systems Development. Mark Geyer, NASA Orion Program manager, is on the right. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  8. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media are briefed on the upcoming Orion flight test by Jeremy Graeber, Orion Recovery Director in Ground Systems Development and Operations at Kennedy. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  9. SARDA Surface Schedulers

    NASA Technical Reports Server (NTRS)

    Malik, Waqar

    2016-01-01

    Provide an overview of algorithms used in SARDA (Spot and Runway Departure Advisor) HITL (Human-in-the-Loop) simulation for Dallas Fort-Worth International Airport and Charlotte Douglas International airport. Outline a multi-objective dynamic programming (DP) based algorithm that finds the exact solution to the single runway scheduling (SRS) problem, and discuss heuristics to restrict the search space for the DP based algorithm and provide improvements.

  10. State-based scheduling: An architecture for telescope observation scheduling

    NASA Technical Reports Server (NTRS)

    Muscettola, Nicola; Smith, Stephen F.

    1989-01-01

    The applicability of constraint-based scheduling, a methodology previously developed and validated in the domain of factory scheduling, is extended to problem domains that require attendance to a wider range of state-dependent constraints. The problem of constructing and maintaining a short-term observation schedule for the Hubble Space Telescope (HST), which typifies this type of domain is the focus of interest. The nature of the constraints encountered in the HST domain is examined, system requirements are discussed with respect to utilization of a constraint-based scheduling methodology in such domains, and a general framework for state-based scheduling is presented.

  11. Computational Simulation for Decision of Scheduling Period in Reactive Scheduling

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Tatsuhiko; Kamimura, Toshihide; Shirase, Keiichi

    Unexpected disruptions often occur in the manufacturing systems. The manufacturing systems cannot execute the manufacturing operations in accordance with the predetermined production schedule due to such disruptions. Therefore, a systematic scheduling method is required to cope with such disruptions. In this research, distribution of processing time is described with the normal distribution. The reactive scheduling method for distribution of processing time is proposed in order to modify the predetermined production schedule. And the suitable re-scheduling period is considered through the computational experiments.

  12. FlexMod Scheduling Redux

    ERIC Educational Resources Information Center

    Murray, Shannon

    2008-01-01

    Flexible modular scheduling (flex mod)--a schedule philosophy and system that has been in place at Wausau West High School in Wausau, Wisconsin, for the last 35 years and aligns nicely with current research on student learning--is getting more and more attention from high school administrators across the country. Flexible modular scheduling was…

  13. FlexMod Scheduling Redux

    ERIC Educational Resources Information Center

    Murray, Shannon

    2008-01-01

    Flexible modular scheduling (flex mod)--a schedule philosophy and system that has been in place at Wausau West High School in Wausau, Wisconsin, for the last 35 years and aligns nicely with current research on student learning--is getting more and more attention from high school administrators across the country. Flexible modular scheduling was…

  14. Conflict-Aware Scheduling Algorithm

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Borden, Chester

    2006-01-01

    conflict-aware scheduling algorithm is being developed to help automate the allocation of NASA s Deep Space Network (DSN) antennas and equipment that are used to communicate with interplanetary scientific spacecraft. The current approach for scheduling DSN ground resources seeks to provide an equitable distribution of tracking services among the multiple scientific missions and is very labor intensive. Due to the large (and increasing) number of mission requests for DSN services, combined with technical and geometric constraints, the DSN is highly oversubscribed. To help automate the process, and reduce the DSN and spaceflight project labor effort required for initiating, maintaining, and negotiating schedules, a new scheduling algorithm is being developed. The scheduling algorithm generates a "conflict-aware" schedule, where all requests are scheduled based on a dynamic priority scheme. The conflict-aware scheduling algorithm allocates all requests for DSN tracking services while identifying and maintaining the conflicts to facilitate collaboration and negotiation between spaceflight missions. These contrast with traditional "conflict-free" scheduling algorithms that assign tracks that are not in conflict and mark the remainder as unscheduled. In the case where full schedule automation is desired (based on mission/event priorities, fairness, allocation rules, geometric constraints, and ground system capabilities/ constraints), a conflict-free schedule can easily be created from the conflict-aware schedule by removing lower priority items that are in conflict.

  15. Surprise Benefits of Arena Scheduling

    ERIC Educational Resources Information Center

    Surloff, Andrew

    2008-01-01

    One of the most challenging tasks a principal must accomplish every year is the construction of the master schedule. Free from the magnetic scheduling boards and wall charts of yesteryear, principals now have technological tools--such as programs that offer schools solutions for their scheduling needs--that can save time and enable them to work…

  16. Rural Inservice Using Alternate Scheduling.

    ERIC Educational Resources Information Center

    Kimmet, James L.

    Three small rural school districts in Montana and Wyoming used alternate school day scheduling to make time for staff and curriculum development inservice programs. The schedule of one short and four long days delivered the instructional time of 175 6-hour days each year. Benefits of alternate scheduling included time for regular inservice…

  17. Flexible Scheduling: Making the Transition

    ERIC Educational Resources Information Center

    Creighton, Peggy Milam

    2008-01-01

    Citing literature that supports the benefits of flexible scheduling on student achievement, the author exhorts readers to campaign for flexible scheduling in their library media centers. She suggests tips drawn from the work of Graziano (2002), McGregor (2006) and Stripling (1997) for making a smooth transition from fixed to flexible scheduling:…

  18. Surprise Benefits of Arena Scheduling

    ERIC Educational Resources Information Center

    Surloff, Andrew

    2008-01-01

    One of the most challenging tasks a principal must accomplish every year is the construction of the master schedule. Free from the magnetic scheduling boards and wall charts of yesteryear, principals now have technological tools--such as programs that offer schools solutions for their scheduling needs--that can save time and enable them to work…

  19. Hybrid adaptive ascent flight control for a flexible launch vehicle

    NASA Astrophysics Data System (ADS)

    Lefevre, Brian D.

    hybrid adaptive flight controller, development of a Newton's method based online parameter update that is modified to include a step size which regulates the rate of change in the parameter estimates, comparison of the modified Newton's method and recursive least squares online parameter update algorithms, modification of the neural network's input structure to accommodate for the nature of the nonlinearities present in a launch vehicle's ascent flight, examination of both tracking error based and modeling error based neural network weight update laws, and integration of feedback filters for the purpose of preventing harmful interaction between the flight control system and flexible structural modes. To validate the hybrid adaptive controller, a high-fidelity Ares I ascent flight simulator and a classical gain-scheduled proportional-integral-derivative (PID) ascent flight controller were obtained from the NASA Marshall Space Flight Center. The classical PID flight controller is used as a benchmark when analyzing the performance of the hybrid adaptive flight controller. Simulations are conducted which model both nominal and off-nominal flight conditions with structural flexibility of the vehicle either enabled or disabled. First, rigid body ascent simulations are performed with the hybrid adaptive controller under nominal flight conditions for the purpose of selecting the update laws which drive the indirect and direct adaptive components. With the neural network disabled, the results revealed that the recursive least squares online parameter update caused high frequency oscillations to appear in the engine gimbal commands. This is highly undesirable for long and slender launch vehicles, such as the Ares I, because such oscillation of the rocket nozzle could excite unstable structural flex modes. In contrast, the modified Newton's method online parameter update produced smooth control signals and was thus selected for use in the hybrid adaptive launch vehicle flight

  20. Towards a Decision Support System for Space Flight Operations

    NASA Technical Reports Server (NTRS)

    Meshkat, Leila; Hogle, Charles; Ruszkowski, James

    2013-01-01

    The Mission Operations Directorate (MOD) at the Johnson Space Center (JSC) has put in place a Model Based Systems Engineering (MBSE) technological framework for the development and execution of the Flight Production Process (FPP). This framework has provided much added value and return on investment to date. This paper describes a vision for a model based Decision Support System (DSS) for the development and execution of the FPP and its design and development process. The envisioned system extends the existing MBSE methodology and technological framework which is currently in use. The MBSE technological framework currently in place enables the systematic collection and integration of data required for building an FPP model for a diverse set of missions. This framework includes the technology, people and processes required for rapid development of architectural artifacts. It is used to build a feasible FPP model for the first flight of spacecraft and for recurrent flights throughout the life of the program. This model greatly enhances our ability to effectively engage with a new customer. It provides a preliminary work breakdown structure, data flow information and a master schedule based on its existing knowledge base. These artifacts are then refined and iterated upon with the customer for the development of a robust end-to-end, high-level integrated master schedule and its associated dependencies. The vision is to enhance this framework to enable its application for uncertainty management, decision support and optimization of the design and execution of the FPP by the program. Furthermore, this enhanced framework will enable the agile response and redesign of the FPP based on observed system behavior. The discrepancy of the anticipated system behavior and the observed behavior may be due to the processing of tasks internally, or due to external factors such as changes in program requirements or conditions associated with other organizations that are outside of

  1. Space Surveillance Network Scheduling Under Uncertainty: Models and Benefits

    NASA Astrophysics Data System (ADS)

    Valicka, C.; Garcia, D.; Staid, A.; Watson, J.; Rintoul, M.; Hackebeil, G.; Ntaimo, L.

    2016-09-01

    Advances in space technologies continue to reduce the cost of placing satellites in orbit. With more entities operating space vehicles, the number of orbiting vehicles and debris has reached unprecedented levels and the number continues to grow. Sensor operators responsible for maintaining the space catalog and providing space situational awareness face an increasingly complex and demanding scheduling requirements. Despite these trends, a lack of advanced tools continues to prevent sensor planners and operators from fully utilizing space surveillance resources. One key challenge involves optimally selecting sensors from a network of varying capabilities for missions with differing requirements. Another open challenge, the primary focus of our work, is building robust schedules that effectively plan for uncertainties associated with weather, ad hoc collections, and other target uncertainties. Existing tools and techniques are not amenable to rigorous analysis of schedule optimality and do not adequately address the presented challenges. Building on prior research, we have developed stochastic mixed-integer linear optimization models to address uncertainty due to weather's effect on collection quality. By making use of the open source Pyomo optimization modeling software, we have posed and solved sensor network scheduling models addressing both forms of uncertainty. We present herein models that allow for concurrent scheduling of collections with the same sensor configuration and for proactively scheduling against uncertain ad hoc collections. The suitability of stochastic mixed-integer linear optimization for building sensor network schedules under different run-time constraints will be discussed.

  2. SOFIA: flight planning and execution

    NASA Astrophysics Data System (ADS)

    Leppik, K.

    2016-09-01

    The Stratospheric Observatory For Infrared Astronomy (SOFIA) is a 2.5-m telescope mounted inside of a Boeing 747SP. Planning and executing astronomical observations from an aircraft moving at 500 miles per hour has its own unique challenges and advantages. Scheduling and optimizing an entire year of science observations is a balancing act with target availability, instrument availability, and operational constraints. A SOFIA flight is well choreographed, and successfully executing observations on SOFIA requires many systems and people to work together- from the telescope assembly compensating for the continual vibration and movement of the plane in order to accurately point the telescope, the expertise of the telescope operators to prepare the telescope for use by the instrument operators, aircraft operations ensuring that the aircraft is ready for flight, and the mission systems control computers keeping track of all the data. In this paper we will discuss what it takes to plan a SOFIA flight, and what we do once we're in the air. We will share a typical science flight, as well as more challenging and unique observations that require SOFIA being in the right place at the right time.

  3. NICMOS flight FPA qualification program

    NASA Astrophysics Data System (ADS)

    Markum, Arvel D.; Kormos, Karen A.; Edwards, Jere B.

    1993-10-01

    A comprehensive program has been developed for the production of focal plane assemblies (FPA) for use on the University of Arizona Near Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument which is to be installed in the Hubble Space Telescope (HST). This paper describes the current schedule, tests to be performed, test conditions and unique test facilities of the flight FPA qualification test program. This test series is intended to validate design, assembly, performance and reliability of flight qualified FPAs. Also described are the design features, performance characteristics and test results obtained with prototype FPAs used as engineering evaluation units prior to committing the flight qualification units to manufacture. The qualification tests will demonstrate performance margins over and above requirements under operating environmental conditions. Included in the qualification tests are electrical, mechanical and thermal tests. Random vibration tests and mechanical shock tests will be performed at 1.5 times the load level specified for acceptance requirements. The random vibration tests simulate launch conditions and will induce stresses to uncover any potential structural deficiencies that might exist. The mechanical shock tests will simulate potential impacts incurred as a result of handling or transport. The qualification test program is intended to maximize confidence in the quality and integrity of the flight FPAs.

  4. Automation Improves Schedule Quality and Increases Scheduling Efficiency for Residents

    PubMed Central

    Perelstein, Elizabeth; Rose, Ariella; Hong, Young-Chae; Cohn, Amy; Long, Micah T.

    2016-01-01

    Background Medical resident scheduling is difficult due to multiple rules, competing educational goals, and ever-evolving graduate medical education requirements. Despite this, schedules are typically created manually, consuming hours of work, producing schedules of varying quality, and yielding negative consequences for resident morale and learning. Objective To determine whether computerized decision support can improve the construction of residency schedules, saving time and improving schedule quality. Methods The Optimized Residency Scheduling Assistant was designed by a team from the University of Michigan Department of Industrial and Operations Engineering. It was implemented in the C.S. Mott Children's Hospital Pediatric Emergency Department in the 2012–2013 academic year. The 4 metrics of schedule quality that were compared between the 2010–2011 and 2012–2013 academic years were the incidence of challenging shift transitions, the incidence of shifts following continuity clinics, the total shift inequity, and the night shift inequity. Results All scheduling rules were successfully incorporated. Average schedule creation time fell from 22 to 28 hours to 4 to 6 hours per month, and 3 of 4 metrics of schedule quality significantly improved. For the implementation year, the incidence of challenging shift transitions decreased from 83 to 14 (P < .01); the incidence of postclinic shifts decreased from 72 to 32 (P < .01); and the SD of night shifts dropped by 55.6% (P < .01). Conclusions This automated shift scheduling system improves the current manual scheduling process, reducing time spent and improving schedule quality. Embracing such automated tools can benefit residency programs with shift-based scheduling needs. PMID:26913102

  5. Wavelet Filtering to Reduce Conservatism in Aeroservoelastic Robust Stability Margins

    NASA Technical Reports Server (NTRS)

    Brenner, Marty; Lind, Rick

    1998-01-01

    Wavelet analysis for filtering and system identification was used to improve the estimation of aeroservoelastic stability margins. The conservatism of the robust stability margins was reduced with parametric and nonparametric time-frequency analysis of flight data in the model validation process. Nonparametric wavelet processing of data was used to reduce the effects of external desirableness and unmodeled dynamics. Parametric estimates of modal stability were also extracted using the wavelet transform. Computation of robust stability margins for stability boundary prediction depends on uncertainty descriptions derived from the data for model validation. F-18 high Alpha Research Vehicle aeroservoelastic flight test data demonstrated improved robust stability prediction by extension of the stability boundary beyond the flight regime.

  6. 75 FR 42831 - Proposed Collection; Comment Request for Form 1065, Schedule C, Schedule D, Schedule K-1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-22

    ... Items), Schedule L (Balance Sheets per Books), Schedule M-1 (Reconciliation of Income (Loss) per Books.... (Schedule K-1), Balance Sheets per Books (Schedule L), Reconciliation of Income (Loss) per Books With Income...

  7. The development of a Flight Test Engineer's Workstation for the Automated Flight Test Management System

    NASA Technical Reports Server (NTRS)

    Tartt, David M.; Hewett, Marle D.; Duke, Eugene L.; Cooper, James A.; Brumbaugh, Randal W.

    1989-01-01

    The Automated Flight Test Management System (ATMS) is being developed as part of the NASA Aircraft Automation Program. This program focuses on the application of interdisciplinary state-of-the-art technology in artificial intelligence, control theory, and systems methodology to problems of operating and flight testing high-performance aircraft. The development of a Flight Test Engineer's Workstation (FTEWS) is presented, with a detailed description of the system, technical details, and future planned developments. The goal of the FTEWS is to provide flight test engineers and project officers with an automated computer environment for planning, scheduling, and performing flight test programs. The FTEWS system is an outgrowth of the development of ATMS and is an implementation of a component of ATMS on SUN workstations.

  8. Robust Control Systems.

    DTIC Science & Technology

    1981-12-01

    Controller ................... 38 Sampled-Data Performance Analysis ............. 44 Doyle and Stein Technique in Discrete-Time Systems - 1...48 Doyle and Stein Technique in Discretd-Time System.s - 2 ................................. 50 Enhancing Robustness of... Technique Extended to Sampled-Data Controllers ................ 73 G715 Robustness Enhancement by Directly D"?C TAB E

  9. Robust Critical Point Detection

    SciTech Connect

    Bhatia, Harsh

    2016-07-28

    Robust Critical Point Detection is a software to compute critical points in a 2D or 3D vector field robustly. The software was developed as a part of the author's work at the lab as a Phd student under Livermore Scholar Program (now called Livermore Graduate Scholar Program).

  10. Mechanisms for Robust Cognition

    ERIC Educational Resources Information Center

    Walsh, Matthew M.; Gluck, Kevin A.

    2015-01-01

    To function well in an unpredictable environment using unreliable components, a system must have a high degree of robustness. Robustness is fundamental to biological systems and is an objective in the design of engineered systems such as airplane engines and buildings. Cognitive systems, like biological and engineered systems, exist within…

  11. Mechanisms for Robust Cognition

    ERIC Educational Resources Information Center

    Walsh, Matthew M.; Gluck, Kevin A.

    2015-01-01

    To function well in an unpredictable environment using unreliable components, a system must have a high degree of robustness. Robustness is fundamental to biological systems and is an objective in the design of engineered systems such as airplane engines and buildings. Cognitive systems, like biological and engineered systems, exist within…

  12. L(sub 1) Adaptive Flight Control System: Flight Evaluation and Technology Transition

    NASA Technical Reports Server (NTRS)

    Xargay, Enric; Hovakimyan, Naira; Dobrokhodov, Vladimir; Kaminer, Isaac; Gregory, Irene M.; Cao, Chengyu

    2010-01-01

    Certification of adaptive control technologies for both manned and unmanned aircraft represent a major challenge for current Verification and Validation techniques. A (missing) key step towards flight certification of adaptive flight control systems is the definition and development of analysis tools and methods to support Verification and Validation for nonlinear systems, similar to the procedures currently used for linear systems. In this paper, we describe and demonstrate the advantages of L(sub l) adaptive control architectures for closing some of the gaps in certification of adaptive flight control systems, which may facilitate the transition of adaptive control into military and commercial aerospace applications. As illustrative examples, we present the results of a piloted simulation evaluation on the NASA AirSTAR flight test vehicle, and results of an extensive flight test program conducted by the Naval Postgraduate School to demonstrate the advantages of L(sub l) adaptive control as a verifiable robust adaptive flight control system.

  13. Flight Software for the LADEE Mission

    NASA Technical Reports Server (NTRS)

    Cannon, Howard N.

    2015-01-01

    The Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft was launched on September 6, 2013, and completed its mission on April 17, 2014 with a directed impact to the Lunar Surface. Its primary goals were to examine the lunar atmosphere, measure lunar dust, and to demonstrate high rate laser communications. The LADEE mission was a resounding success, achieving all mission objectives, much of which can be attributed to careful planning and preparation. This paper discusses some of the highlights from the mission, and then discusses the techniques used for developing the onboard Flight Software. A large emphasis for the Flight Software was to develop it within tight schedule and cost constraints. To accomplish this, the Flight Software team leveraged heritage software, used model based development techniques, and utilized an automated test infrastructure. This resulted in the software being delivered on time and within budget. The resulting software was able to meet all system requirements, and had very problems in flight.

  14. Ceramic Fairings for A Hypersonic Flight Experiment

    NASA Technical Reports Server (NTRS)

    Churchward, Rex; Piquette, R.; Smith, D.; Arnold, M.; Rasky, Daniel J. (Technical Monitor)

    1998-01-01

    Fairings composed of Rigid Fibrous Insulations (RSI) were fabricated, instrumented, and coated using techniques that were recently developed at NASA Ames Research Center. These RSI components are part of a specific assembly of materials which were built onto a wing of a Pegasus flight vehicle. The assembly was designed to collect aerothermal data during a designated mission to deliver a satellite to earth orbit. The objective of the flight experiment is to validate the theory of boundary layer transition at flight speeds in excess of Mach 3. The actual flight experiment is scheduled to occur during the summer of 1998. Fabrication and installation methodologies will be discussed with a brief description of the wing glove assembly.

  15. An framework for robust flight control design using constrained optimization

    NASA Technical Reports Server (NTRS)

    Palazoglu, A.; Yousefpor, M.; Hess, R. A.

    1992-01-01

    An analytical framework is described for the design of feedback control systems to meet specified performance criteria in the presence of structured and unstructured uncertainty. Attention is focused upon the linear time invariant, single-input, single-output problem for the purposes of exposition. The framework provides for control of the degree of the stabilizing compensator or controller.

  16. A Prescribed Flight Performance Assessment for Undersea Vehicle Autopilot Robustness

    DTIC Science & Technology

    2016-06-16

    class of the highly utilized axisymmetric undersea vehicle design sometimes requires unplanned and unforeseen mission payload weight and mass ...occur. These changes often include vehicle mission payload weight and vehicle mass distribution. For example, one could envision a UV being tasked with...lighter mid-body. Therefore, the UV’s weight and mass distribution changes. It is important to note that changes to a UV’s weight and mass distribution

  17. Parallel job-scheduling algorithms

    SciTech Connect

    Rodger, S.H.

    1989-01-01

    In this thesis, we consider solving job scheduling problems on the CREW PRAM model. We show how to adapt Cole's pipeline merge technique to yield several efficient parallel algorithms for a number of job scheduling problems and one optimal parallel algorithm for the following job scheduling problem: Given a set of n jobs defined by release times, deadlines and processing times, find a schedule that minimizes the maximum lateness of the jobs and allows preemption when the jobs are scheduled to run on one machine. In addition, we present the first NC algorithm for the following job scheduling problem: Given a set of n jobs defined by release times, deadlines and unit processing times, determine if there is a schedule of jobs on one machine, and calculate the schedule if it exists. We identify the notion of a canonical schedule, which is the type of schedule our algorithm computes if there is a schedule. Our algorithm runs in O((log n){sup 2}) time and uses O(n{sup 2}k{sup 2}) processors, where k is the minimum number of distinct offsets of release times or deadlines.

  18. Microgravity Flight - Accommodating Non-Human Primates

    NASA Technical Reports Server (NTRS)

    Dalton, Bonnie P.; Searby, Nancy; Ostrach, Louis

    1994-01-01

    Spacelab Life Sciences-3 (SLS-3) was scheduled to be the first United States man-tended microgravity flight containing Rhesus monkeys. The goal of this flight as in the five untended Russian COSMOS Bion flights and an earlier American Biosatellite flight, was to understand the biomedical and biological effects of a microgravity environment using the non-human primate as human surrogate. The SLS-3/Rhesus Project and COSMOS Primate-BIOS flights all utilized the rhesus monkey, Macaca mulatta. The ultimate objective of all flights with an animal surrogate has been to evaluate and understand biological mechanisms at both the system and cellular level, thus enabling rational effective countermeasures for future long duration human activity under microgravity conditions and enabling technical application to correction of common human physiological problems within earth's gravity, e.g., muscle strength and reloading, osteoporosis, immune deficiency diseases. Hardware developed for the SLS-3/Rhesus Project was the result of a joint effort with the French Centre National d'Etudes Spatiales (CNES) and the United States National Aeronautics and Space Administration (NASA) extending over the last decade. The flight hardware design and development required implementation of sufficient automation to insure flight crew and animal bio-isolation and maintenance with minimal impact to crew activities. A variety of hardware of varying functional capabilities was developed to support the scientific objectives of the original 22 combined French and American experiments, along with 5 Russian co-investigations, including musculoskeletal, metabolic, and behavioral studies. Unique elements of the Rhesus Research Facility (RRF) included separation of waste for daily delivery of urine and fecal samples for metabolic studies and a psychomotor test system for behavioral studies along with monitored food measurement. As in untended flights, telemetry measurements would allow monitoring of

  19. Microgravity Flight - Accommodating Non-Human Primates

    NASA Technical Reports Server (NTRS)

    Dalton, Bonnie P.; Searby, Nancy; Ostrach, Louis

    1994-01-01

    Spacelab Life Sciences-3 (SLS-3) was scheduled to be the first United States man-tended microgravity flight containing Rhesus monkeys. The goal of this flight as in the five untended Russian COSMOS Bion flights and an earlier American Biosatellite flight, was to understand the biomedical and biological effects of a microgravity environment using the non-human primate as human surrogate. The SLS-3/Rhesus Project and COSMOS Primate-BIOS flights all utilized the rhesus monkey, Macaca mulatta. The ultimate objective of all flights with an animal surrogate has been to evaluate and understand biological mechanisms at both the system and cellular level, thus enabling rational effective countermeasures for future long duration human activity under microgravity conditions and enabling technical application to correction of common human physiological problems within earth's gravity, e.g., muscle strength and reloading, osteoporosis, immune deficiency diseases. Hardware developed for the SLS-3/Rhesus Project was the result of a joint effort with the French Centre National d'Etudes Spatiales (CNES) and the United States National Aeronautics and Space Administration (NASA) extending over the last decade. The flight hardware design and development required implementation of sufficient automation to insure flight crew and animal bio-isolation and maintenance with minimal impact to crew activities. A variety of hardware of varying functional capabilities was developed to support the scientific objectives of the original 22 combined French and American experiments, along with 5 Russian co-investigations, including musculoskeletal, metabolic, and behavioral studies. Unique elements of the Rhesus Research Facility (RRF) included separation of waste for daily delivery of urine and fecal samples for metabolic studies and a psychomotor test system for behavioral studies along with monitored food measurement. As in untended flights, telemetry measurements would allow monitoring of

  20. Source Inspection Scheduling Calendar

    NASA Technical Reports Server (NTRS)

    Hollis, Brayden

    2011-01-01

    Quality is an essential component for creating flight hardware travelling through space since the hardware is extremely expensive and cannot be reworked or repaired once launched. An important step in this process is ensuring the quality of hardware procured from Jet Propulsion Laboratory's (JPL) suppliers. An important element of determining supplier quality is source inspection. Source inspections are performed at suppliers' facilities by JPL employeesto ensure that hardware characteristics are acceptable before being covered up and/or delivered to JPL.

  1. Guidance and Control for Mars Atmospheric Entry: Adaptivity and Robustness

    NASA Technical Reports Server (NTRS)

    Lu, Wei-Min; Bayard, David S.

    1997-01-01

    In this paper, we address the atmospheric entry guidance and control problem for Mars precision landing. The guidance and control design is based on the principle of tracking a reference drag versus velocity profile in the entry flight corridor, which is determined by physical constraints of the flight. An integrated adaptive/robust control approach to atmospheric entry guidance and control is introduced to deal with different uncertainties.

  2. X-37 Flight Demonstrator Completes Structural Tests

    NASA Technical Reports Server (NTRS)

    2003-01-01

    NASA's X-37 Approach and Landing Test Vehicle is installed is a structural facility at Boeing's Huntington Beach, California plant, where technicians make adjustments to composite panels. Tests, completed in July, were conducted to verify the structural integrity of the vehicle in preparation for atmospheric flight tests. Atmospheric flight tests of the Approach and Landing Test Vehicle are scheduled for 2004 and flight tests of the Orbital Vehicle are scheduled for 2006. The X-37 experimental launch vehicle is roughly 27.5 feet (8.3 meters) long and 15 feet (4.5 meters) in wingspan. It's experiment bay is 7 feet (2.1 meters) long and 4 feet (1.2 meters) in diameter. Designed to operate in both the orbital and reentry phases of flight, the X-37 will increase both safety and reliability, while reducing launch costs from $10,000 per pound to $1,000.00 per pound. The X-37 program is managed by the Marshall Space Flight Center and built by the Boeing Company.

  3. X-37 Flight Demonstrator Completes Structural Tests

    NASA Technical Reports Server (NTRS)

    2003-01-01

    NASA's X-37 Approach and Landing Test Vehicle is installed is a structural facility at Boeing's Huntington Beach, California plant. Tests, completed in July, were conducted to verify the structural integrity of the vehicle in preparation for atmospheric flight tests. Atmospheric flight tests of the Approach and Landing Test Vehicle are scheduled for 2004 and flight tests of the Orbital Vehicle are scheduled for 2006. The X-37 experimental launch vehicle is roughly 27.5 feet (8.3 meters) long and 15 feet (4.5 meters) in wingspan. It's experiment bay is 7 feet (2.1 meters) long and 4 feet (1.2 meters) in diameter. Designed to operate in both the orbital and reentry phases of flight, the X-37 will increase both safety and reliability, while reducing launch costs from $10,000 per pound to $1,000.00 per pound. The X-37 program is managed by the Marshall Space Flight Center and built by the Boeing Company.

  4. A Novel Approach to Noise-Filtering Based on a Gain-Scheduling Neural Network Architecture

    NASA Technical Reports Server (NTRS)

    Troudet, T.; Merrill, W.

    1994-01-01

    A gain-scheduling neural network architecture is proposed to enhance the noise-filtering efficiency of feedforward neural networks, in terms of both nominal performance and robustness. The synergistic benefits of the proposed architecture are demonstrated and discussed in the context of the noise-filtering of signals that are typically encountered in aerospace control systems. The synthesis of such a gain-scheduled neurofiltering provides the robustness of linear filtering, while preserving the nominal performance advantage of conventional nonlinear neurofiltering. Quantitative performance and robustness evaluations are provided for the signal processing of pitch rate responses to typical pilot command inputs for a modern fighter aircraft model.

  5. Dimpled Ball Grid Array process development for space flight applications

    NASA Technical Reports Server (NTRS)

    Barr, S. L.; Mehta, A.

    2000-01-01

    The 472 Dimpled Ball Grid Array (D-BGA) package has not been used in past space flight environments, therefore it is necessary to determine the robustness and reliability of the solder joints. The 472 D-BGA packages passed the above environmental tests within the specifications and are now qualified for use on space flight electronics.

  6. Aeroassist flight experiment guidance, navigation and control

    NASA Technical Reports Server (NTRS)

    Brand, Timothy J.; Engel, Albert G.

    1986-01-01

    The Aeroassist Flight Experiment scheduled for the early 1990's will demonstrate the use of a low L/D lifting brake using aerodynamic drag to return a spacecraft from a high energy to a low earth orbit. The experimental vehicle will be deployed and retrieved by the Shuttle Orbiter. This paper reviews some of the challenges, problems, and solutions encountered to date during guidance system development, with emphasis on technology advances which will benefit an operational Orbit Transfer Vehicle (OTV). Key factors to be discussed include guidance alternatives, aerodynamic modeling, navigation requirements, the impact of atmospheric uncertainties, and flight profile alternatives considered during initial planning.

  7. Robustness. [in space systems

    NASA Technical Reports Server (NTRS)

    Ryan, Robert

    1993-01-01

    The concept of rubustness includes design simplicity, component and path redundancy, desensitization to the parameter and environment variations, control of parameter variations, and punctual operations. These characteristics must be traded with functional concepts, materials, and fabrication approach against the criteria of performance, cost, and reliability. The paper describes the robustness design process, which includes the following seven major coherent steps: translation of vision into requirements, definition of the robustness characteristics desired, criteria formulation of required robustness, concept selection, detail design, manufacturing and verification, operations.

  8. Robustness. [in space systems

    NASA Technical Reports Server (NTRS)

    Ryan, Robert

    1993-01-01

    The concept of rubustness includes design simplicity, component and path redundancy, desensitization to the parameter and environment variations, control of parameter variations, and punctual operations. These characteristics must be traded with functional concepts, materials, and fabrication approach against the criteria of performance, cost, and reliability. The paper describes the robustness design process, which includes the following seven major coherent steps: translation of vision into requirements, definition of the robustness characteristics desired, criteria formulation of required robustness, concept selection, detail design, manufacturing and verification, operations.

  9. Green Flight Challenge

    NASA Image and Video Library

    The CAFE Green Flight Challenge sponsored by Google will be held at the CAFE Foundation Flight Test Center at Charles M. Schulz Sonoma County Airport in Santa Rosa, Calif. The Green Flight Challeng...

  10. 2007 Wholesale Power Rate Schedules : 2007 General Rate Schedule Provisions.

    SciTech Connect

    United States. Bonneville Power Administration.

    2006-11-01

    This schedule is available for the contract purchase of Firm Power to be used within the Pacific Northwest (PNW). Priority Firm (PF) Power may be purchased by public bodies, cooperatives, and Federal agencies for resale to ultimate consumers, for direct consumption, and for Construction, Test and Start-Up, and Station Service. Rates in this schedule are in effect beginning October 1, 2006, and apply to purchases under requirements Firm Power sales contracts for a three-year period. The Slice Product is only available for public bodies and cooperatives who have signed Slice contracts for the FY 2002-2011 period. Utilities participating in the Residential Exchange Program (REP) under Section 5(c) of the Northwest Power Act may purchase Priority Firm Power pursuant to the Residential Exchange Program. Rates under contracts that contain charges that escalate based on BPA's Priority Firm Power rates shall be based on the three-year rates listed in this rate schedule in addition to applicable transmission charges. This rate schedule supersedes the PF-02 rate schedule, which went into effect October 1, 2001. Sales under the PF-07 rate schedule are subject to BPA's 2007 General Rate Schedule Provisions (2007 GRSPs). Products available under this rate schedule are defined in the 2007 GRSPs. For sales under this rate schedule, bills shall be rendered and payments due pursuant to BPA's 2007 GRSPs and billing process.

  11. Effect of Sampling Schedule on Pharmacokinetic Parameter Estimates of Promethazine in Astronauts

    NASA Technical Reports Server (NTRS)

    Boyd, Jason L.; Wang, Zuwei; Putcha, Lakshmi

    2005-01-01

    Six astronauts on the Shuttle Transport System (STS) participated in an investigation on the pharmacokinetics of promethazine (PMZ), a medication used for the treatment of space motion sickness (SMS) during flight. Each crewmember completed the protocol once during flight and repeated thirty days after returned to Earth. Saliva samples were collected at scheduled times for 72 h after PMZ administration; more frequent samples were collected on the ground than during flight owing to schedule constraints in flight. PMZ concentrations in saliva were determined by a liquid chromatographic/mass spectrometric (LC-MS) assay and pharmacokinetic parameters (PKPs) were calculated using actual flight and ground-based data sets and using time-matched sampling schedule on ground to that during flight. Volume of distribution (V(sub c)) and clearance (Cl(sub s),) decreased during flight compared to that from time-matched ground data set; however, Cl(sub s) and V(sub c) estimates were higher for all subjects when partial ground data sets were used for analysis. Area under the curve (AUC) normalized with administered dose was similar in flight and partial ground data; however AUC was significantly lower using time-matched sampling compared with the full data set on ground. Half life (t(sub 1/2)) was longest during flight, shorter with matched-sampling schedule on ground and shortest when complete data set from ground was used. Maximum concentration (C(sub max)), time for C(sub max), (t(sub max)), parameters of drug absorption, depicted a similar trend with lowest and longest respectively, during flight, lower with time-matched ground data and highest and shortest with full ground data.

  12. Effect of Sampling Schedule on Pharmacokinetic Parameter Estimates of Promethazine in Astronauts

    NASA Technical Reports Server (NTRS)

    Boyd, Jason L.; Wang, Zuwei; Putcha, Lakshmi

    2005-01-01

    Six astronauts on the Shuttle Transport System (STS) participated in an investigation on the pharmacokinetics of promethazine (PMZ), a medication used for the treatment of space motion sickness (SMS) during flight. Each crewmember completed the protocol once during flight and repeated thirty days after returned to Earth. Saliva samples were collected at scheduled times for 72 h after PMZ administration; more frequent samples were collected on the ground than during flight owing to schedule constraints in flight. PMZ concentrations in saliva were determined by a liquid chromatographic/mass spectrometric (LC-MS) assay and pharmacokinetic parameters (PKPs) were calculated using actual flight and ground-based data sets and using time-matched sampling schedule on ground to that during flight. Volume of distribution (V(sub c)) and clearance (Cl(sub s),) decreased during flight compared to that from time-matched ground data set; however, Cl(sub s) and V(sub c) estimates were higher for all subjects when partial ground data sets were used for analysis. Area under the curve (AUC) normalized with administered dose was similar in flight and partial ground data; however AUC was significantly lower using time-matched sampling compared with the full data set on ground. Half life (t(sub 1/2)) was longest during flight, shorter with matched-sampling schedule on ground and shortest when complete data set from ground was used. Maximum concentration (C(sub max)), time for C(sub max), (t(sub max)), parameters of drug absorption, depicted a similar trend with lowest and longest respectively, during flight, lower with time-matched ground data and highest and shortest with full ground data.

  13. Logistically Constrained Asset Scheduling in Maritime Security Operations

    DTIC Science & Technology

    2008-09-01

    the effects of other advancements that improve the effectiveness of a given platform in performing MIO . D. SCHEDULE EXTRACTION To attain the end...Allocation for Scenarios 9 through 16 from C-RAMS To demonstrate the improved relative expected effectiveness in performing MIO by augmenting Flight I...School. Commeagle.com (2008). Boeing Awarded Contract for Scan Eagle Services. Retrieved August 2, 2008, from www.comeagle.com/pdf.cfm? cid =111

  14. Robust Active Portfolio Management

    DTIC Science & Technology

    2006-11-27

    the Markowitz mean-variance model led to development of the Capital Asset Pricing Model ( CAPM ) for asset pricing [35, 29, 23] which remains one of the...active portfolio management. Our model uses historical returns and equilibrium expected returns predicted by the CAPM to identify assets that are...we construct robust models for active portfolio management in a market with transaction costs. The goal of these robust models is to control the impact

  15. NASA's Flight Opportunities Program

    NASA Image and Video Library

    NASA's Flight Opportunities Program is facilitating low-cost access to suborbital space, where researchers can test technologies using commercially developed vehicles. Suborbital flights can quickl...

  16. DTS: Building custom, intelligent schedulers

    NASA Technical Reports Server (NTRS)

    Hansson, Othar; Mayer, Andrew

    1994-01-01

    DTS is a decision-theoretic scheduler, built on top of a flexible toolkit -- this paper focuses on how the toolkit might be reused in future NASA mission schedulers. The toolkit includes a user-customizable scheduling interface, and a 'Just-For-You' optimization engine. The customizable interface is built on two metaphors: objects and dynamic graphs. Objects help to structure problem specifications and related data, while dynamic graphs simplify the specification of graphical schedule editors (such as Gantt charts). The interface can be used with any 'back-end' scheduler, through dynamically-loaded code, interprocess communication, or a shared database. The 'Just-For-You' optimization engine includes user-specific utility functions, automatically compiled heuristic evaluations, and a postprocessing facility for enforcing scheduling policies. The optimization engine is based on BPS, the Bayesian Problem-Solver (1,2), which introduced a similar approach to solving single-agent and adversarial graph search problems.

  17. 75 FR 20672 - Notice of Submission Deadline for Schedule Information for O'Hare International Airport, John F...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Notice of Submission Deadline for Schedule Information for O'Hare... deadline of May 13, 2010, for Winter 2010 flight schedules at Chicago's O'Hare International Airport...

  18. 76 FR 18622 - Notice of Submission Deadline for Schedule Information for O'Hare International Airport, John F...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... Federal Aviation Administration Notice of Submission Deadline for Schedule Information for O'Hare... submission deadline of May 19, 2011, for Winter 2011-2012 flight schedules at Chicago's O'Hare International... by e-mail to: 7-AWA-slotadmin@faa.gov . FOR FURTHER INFORMATION CONTACT: Robert Hawks, Office of...

  19. Structurally robust biological networks

    PubMed Central

    2011-01-01

    Background The molecular circuitry of living organisms performs remarkably robust regulatory tasks, despite the often intrinsic variability of its components. A large body of research has in fact highlighted that robustness is often a structural property of biological systems. However, there are few systematic methods to mathematically model and describe structural robustness. With a few exceptions, numerical studies are often the preferred approach to this type of investigation. Results In this paper, we propose a framework to analyze robust stability of equilibria in biological networks. We employ Lyapunov and invariant sets theory, focusing on the structure of ordinary differential equation models. Without resorting to extensive numerical simulations, often necessary to explore the behavior of a model in its parameter space, we provide rigorous proofs of robust stability of known bio-molecular networks. Our results are in line with existing literature. Conclusions The impact of our results is twofold: on the one hand, we highlight that classical and simple control theory methods are extremely useful to characterize the behavior of biological networks analytically. On the other hand, we are able to demonstrate that some biological networks are robust thanks to their structure and some qualitative properties of the interactions, regardless of the specific values of their parameters. PMID:21586168

  20. Analysis and design of gain scheduled control systems. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Shamma, Jeff S.

    1988-01-01

    Gain scheduling, as an idea, is to construct a global feedback control system for a time varying and/or nonlinear plant from a collection of local time invariant designs. However in the absence of a sound analysis, these designs come with no guarantees on the robustness, performance, or even nominal stability of the overall gain schedule design. Such an analysis is presented for three types of gain scheduling situations: (1) a linear parameter varying plant scheduling on its exogenous parameters, (2) a nonlinear plant scheduling on a prescribed reference trajectory, and (3) a nonlinear plant scheduling on the current plant output. Conditions are given which guarantee that the stability, robustness, and performance properties of the fixed operating point designs carry over to the global gain scheduled designs, such as the scheduling variable should vary slowly and capture the plants nonlinearities. Finally, an alternate design framework is proposed which removes the slowing varying restriction or gain scheduled systems. This framework addresses some fundamental feedback issues previously ignored in standard gain.

  1. Synchronizing production and air transportation scheduling using mathematical programming models

    NASA Astrophysics Data System (ADS)

    Zandieh, M.; Molla-Alizadeh-Zavardehi, S.

    2009-08-01

    Traditional scheduling problems assume that there are always infinitely many resources for delivering finished jobs to their destinations, and no time is needed for their transportation, so that finished products can be transported to customers without delay. So, for coordination of these two different activities in the implementation of a supply chain solution, we studied the problem of synchronizing production and air transportation scheduling using mathematical programming models. The overall problem is decomposed into two sub-problems, which consists of air transportation allocation problem and a single machine scheduling problem which they are considered together. We have taken into consideration different constraints and assumptions in our modeling such as special flights, delivery tardiness and no delivery tardiness. For these purposes, a variety of models have been proposed to minimize supply chain total cost which encompass transportation, makespan, delivery earliness tardiness and departure time earliness tardiness costs.

  2. Effective Scheduling Using Sacred Time.

    PubMed

    Baum, Neil

    2016-01-01

    Doctors need to become more efficient in order to become more productive. One of the best ways to enhance efficiency is effective scheduling. Every practice has several urgencies or emergencies every day that have to be worked into the schedule, and these few additional patients can wreak havoc with the schedule. This article will discuss.how to use "sacred time" in order to enhance efficiency in the practice.

  3. MS Gernhardt on Columbia's forward flight deck

    NASA Image and Video Library

    2012-09-18

    STS083-305-006 (4-8 April 1997) --- Astronaut Michael L. Gernhardt, mission specialist, talks to ground controllers while temporarily occupying the commander's station on the forward flight deck of the Earth-orbiting Space Shuttle Columbia. Crewed by Gernhardt, four other NASA astronauts and two payload specialists, the scheduled 16-day Microgravity Science Mission (MSL-1) mission was later cut short by a power shortage.

  4. Wheels-Off Time Uncertainty Impact on Benefits of Early Call for Release Scheduling

    NASA Technical Reports Server (NTRS)

    Palopo, Kee; Chatterji, Gano B.; Almog, Noam

    2017-01-01

    Arrival traffic scenarios with 808 flights from 173 airports to Houston George Bush International airport are simulated to determine if Call For Release flights can receive a benefit in terms of less delay over other flights by scheduling prior to gate pushback (look-ahead in time) as opposed to at gate pushback. Call for Release flights are departures that require approval from Air Route Traffic Control Center prior to release. Realism is brought to the study by including gate departure delay and taxi-out delay uncertainties for the 77 major U. S. airports. Gate departure delay uncertainty is assumed to increase as a function of look-ahead time. Results show that Call For Release flights from an airport within the freeze horizon (a region surrounding the arrival airport) can get an advantage over other flights to a capacity constrained airport by scheduling prior to gate pushback, provided the wheels-off time uncertainty with respect to schedule is controlled to a small value, such as within a three-minute window. Another finding of the study is that system delay, measured as the sum of arrival delays, is smaller when flights are scheduled in the order of arrival compared to in the order of departure. Because flights from airports within the freeze horizon are scheduled in the order of departure, an increase in the number of internal airports with a larger freeze horizon increases system delay. Delay in the given scenario was found to increase by 126% (from 13.8 hours to 31.2 hours) as freeze horizon was increased from 30-minutes to 2-hours in the baseline scenario.

  5. Constellations Solar Array Design, Industrialization And In-Flight Results

    NASA Astrophysics Data System (ADS)

    Combet, Yannick; Clapper, Paul

    2011-10-01

    Constellations has become a recurring opportunities in Thales Alenia Space since 3 majors programs had been awarded: Globalstar was the pathfinder with 48 flight sets followed by O3b with 8 an the latest is Iridium Next with 81 models. For these 3 programs, the Solar Array is fully developed, validated and produced by Thales Alenia Space with major subcontractors. This new segment of the activity leads to new development, design and industrialization approaches. This paper describes the Solar Array design and the alternative to current approach build and applied with the following drivers: - the low recurring cost and mass of the flight hardware, with particular attention on the Solar Array, - high robustness for system integration and in-orbit operations, - a long mission duration (typically 15 years in LEO) leading to take into account high number of thermal cycles (60 to 72.000 cycles), - new production concept with strict schedule management, - design segmented in subassemblies to reduce the integration time as well as a improved trouble shooting management, - delivery rate up to 1 wing per week and after learning curve effect, a integration duration divided by 3 compared to current production, - a delivery of a qualified PFM solar array in 22 months including the design to producibility constrains, This demanding requirement for delivery scheme and cost target did not jeopardize the requirements and standards for space application. After a brief description of the way the main drivers have been considered, the paper presents the main features and performances of the subsystem and shows the main validation test results. The first launch was successful in October 2010 and the first in-orbit results are presented.

  6. COMPASS: An Ada based scheduler

    NASA Technical Reports Server (NTRS)

    Mcmahon, Mary Beth; Culbert, Chris

    1992-01-01

    COMPASS is a generic scheduling system developed by McDonnell Douglas and funded by the Software Technology Branch of NASA Johnson Space Center. The motivation behind COMPASS is to illustrate scheduling technology and provide a basis from which custom scheduling systems can be built. COMPASS was written in Ada to promote readability and to conform to DOD standards. COMPASS has some unique characteristics that distinguishes it from commercial products. This paper discusses these characteristics and uses them to illustrate some differences between scheduling tools.

  7. 1993 Wholesale Power and Transmission Rate Schedules.

    SciTech Connect

    US Bonneville Power Administration

    1993-10-01

    Bonneville Power Administration 1993 Wholesale Power Rate Schedules and General Rate Schedule Provisions and 1993 Transmission Rate Schedules and General Transmission Rate Schedule Provisions, contained herein, were approved on an interim basis effective October 1, 1993. These rate schedules and provisions were approved by the Federal Energy Commission, United States Department of Energy, in September, 1993. These rate schedules and provisions supersede the Administration`s Wholesale Power Rate Schedules and General Rate Schedule Provisions and Transmission Rate Schedules and General Transmission Rate Schedule Provisions effective October 1, 1991.

  8. Dynamics in scheduled networks

    NASA Astrophysics Data System (ADS)

    Zanin, Massimiliano; Lacasa, Lucas; Cea, Miguel

    2009-06-01

    When studying real or virtual systems through complex networks theories, usually time restrictions are neglected, and a static structure is defined to characterize which node is connected to which other. However, this approach is oversimplified, as real networks are indeed dynamically modified by external mechanisms. In order to bridge the gap, in this work we present a scheduled network formalism, which takes into account such dynamical modifications by including generic time restrictions in the structure of an extended adjacency matrix. We present some of its properties and apply this formalism to the specific case of the air transportation network in order to analyze its efficiency. Real data are used at this point. We finally discuss on the applicability of this formalism to other complex systems.

  9. Optimum connection management scheduling

    NASA Astrophysics Data System (ADS)

    Kadar, Ivan

    2000-08-01

    Connection Management plays a key role in both distributed 'local' network-centric and 'globally' connected info- centric systems. The role of Connection Management is to provide seamless demand-based sharing of the information products. For optimum distributed information fusion performance, these systems must minimize communications delays and maximize message throughput, and at the same time take into account relative-sensors-targets geometrical constraints and data pedigree. In order to achieve overall distributed 'network' effectiveness, these systems must be adaptive, and be able to distribute data s needed in real- time. A system concept will be described which provides optimum capacity-based information scheduling. A specific example, based on a satellite channel, is used to illustrate simulated performance results and their effects on fusion systems performance.

  10. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis approaches the Vehicle Assembly Building (VAB) high bay 4. It is being towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis approaches the Vehicle Assembly Building (VAB) high bay 4. It is being towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  11. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is turned into position outside the Orbiter Processing Facility (OPF) for its tow to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is turned into position outside the Orbiter Processing Facility (OPF) for its tow to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  12. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis backs out of the Orbiter Processing Facility (OPF) for its move to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis backs out of the Orbiter Processing Facility (OPF) for its move to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  13. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is moments away from a tow from the Orbiter Processing Facility (OPF) to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is moments away from a tow from the Orbiter Processing Facility (OPF) to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  14. KENNEDY SPACE CENTER, FLA. - Workers back the Space Shuttle orbiter Atlantis out of the Orbiter Processing Facility (OPF) for its move to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - Workers back the Space Shuttle orbiter Atlantis out of the Orbiter Processing Facility (OPF) for its move to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  15. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is moved into high bay 4 of the Vehicle Assembly Building (VAB). It was towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is moved into high bay 4 of the Vehicle Assembly Building (VAB). It was towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  16. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis approaches the Vehicle Assembly Building (VAB). It is being towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis approaches the Vehicle Assembly Building (VAB). It is being towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  17. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis arrives in high bay 4 of the Vehicle Assembly Building (VAB). It was towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis arrives in high bay 4 of the Vehicle Assembly Building (VAB). It was towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  18. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis nears the Vehicle Assembly Building (VAB). It is being towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis nears the Vehicle Assembly Building (VAB). It is being towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  19. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis awaits a tow from the Orbiter Processing Facility (OPF) to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis awaits a tow from the Orbiter Processing Facility (OPF) to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  20. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis moves into high bay 4 of the Vehicle Assembly Building (VAB). It was towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis moves into high bay 4 of the Vehicle Assembly Building (VAB). It was towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  1. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is towed from the Orbiter Processing Facility (OPF) to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is towed from the Orbiter Processing Facility (OPF) to the Vehicle Assembly Building (VAB). The move will allow work to be performed in the OPF that can only be accomplished while the bay is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  2. KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is almost in position in high bay 4 of the Vehicle Assembly Building (VAB). It was towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

    NASA Image and Video Library

    2003-12-05

    KENNEDY SPACE CENTER, FLA. - The Space Shuttle orbiter Atlantis is almost in position in high bay 4 of the Vehicle Assembly Building (VAB). It was towed from the Orbiter Processing Facility (OPF) to allow work to be performed in the bay that can only be accomplished while it is empty. Work scheduled in the processing facility includes annual validation of the bay's cranes, work platforms, lifting mechanisms, and jack stands. Atlantis will remain in the VAB for about 10 days, then return to the OPF as work resumes to prepare it for launch in September 2004 on the first return-to-flight mission, STS-114.

  3. KENNEDY SPACE CENTER, FLA. - STS-82 Pilot Scott J. "Doc" Horowitz flashes a wide grin for photographers after landing his T-38 jet at KSC's Shuttle Landing Facility. Horowitz and the other six members of the STS-82 crew came from their home base at Johnson Space Center in Houston, Texas, to spend the last few days before launch at KSC. STS-82 is scheduled for liftoff on Feb. 11 during a 65-minute launch window that opens at 3:56 a.m. EST. The 10-day flight aboard the Space Shuttle Discovery will be the second Hubble Space Telescope (HST) servicing mission.

    NASA Image and Video Library

    1997-02-07

    KENNEDY SPACE CENTER, FLA. - STS-82 Pilot Scott J. "Doc" Horowitz flashes a wide grin for photographers after landing his T-38 jet at KSC's Shuttle Landing Facility. Horowitz and the other six members of the STS-82 crew came from their home base at Johnson Space Center in Houston, Texas, to spend the last few days before launch at KSC. STS-82 is scheduled for liftoff on Feb. 11 during a 65-minute launch window that opens at 3:56 a.m. EST. The 10-day flight aboard the Space Shuttle Discovery will be the second Hubble Space Telescope (HST) servicing mission.

  4. Modern digital flight control system design for VTOL aircraft

    NASA Technical Reports Server (NTRS)

    Broussard, J. R.; Berry, P. W.; Stengel, R. F.

    1979-01-01

    Methods for and results from the design and evaluation of a digital flight control system (DFCS) for a CH-47B helicopter are presented. The DFCS employed proportional-integral control logic to provide rapid, precise response to automatic or manual guidance commands while following conventional or spiral-descent approach paths. It contained altitude- and velocity-command modes, and it adapted to varying flight conditions through gain scheduling. Extensive use was made of linear systems analysis techniques. The DFCS was designed, using linear-optimal estimation and control theory, and the effects of gain scheduling are assessed by examination of closed-loop eigenvalues and time responses.

  5. A Presentation on Robust Flutter Margin Analysis and a Flutterometer

    NASA Technical Reports Server (NTRS)

    Lind, Rick C.

    1997-01-01

    This paper documents an invited presentation given to The Boeing Company, Seattle, Washington, on September 9, 1997. The audience consisted of structural dynamic and flight test engineers from the Boeing Commercial Airplane Group who were interested in discussing research which may be applied to future flight flutter test programs. A method to compute robust flutter margins is described which is a significant departure from traditional methods. This method uses the structured singular value, mu, to compute a flutter margin which directly accounts for modeling errors such that a worst-case flutter margin is computed with respect to those errors. This method may be applied in several ways. A post-flight application uses data sets from multiple test points to compute worst-case flutter margins and a worst-case flight envelope. An on-line implementation computes flutter margins at each test point to track the flutter margins during a flight test. This on-line implementation is the basis for a flutterometer flight test tool that displays the distance to flutter at a given test point. Such a tool was not previously possible using traditional flutter flight test analysis methods. The F/A-18 System Research Aircraft was used to demonstrate these applications using flight data recorded from test points throughout the flight envelope.

  6. STS-5 Fifth Space shuttle mission, first operational flight: Press Kit

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Schedules for the fifth Space Shuttle flight are provided. Launching procedure, extravehicular activity, contingency plans, satellite deployment, and onboard experiments are discussed. Landing procedures, tracking facilities, and crew data are provided.

  7. 14 CFR 121.505 - Flight time limitations: Two pilot crews: airplanes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... conducting supplemental operations schedules a pilot to fly more than eight hours during any 24 consecutive... flight duty. This rest period must be at least twice the number of hours flown since the preceding...

  8. Schedules of Controlled Substances: Temporary Placement of 4-Fluoroisobutyryl Fentanyl into Schedule I. Temporary scheduling order.

    PubMed

    2017-05-03

    The Administrator of the Drug Enforcement Administration is issuing this temporary scheduling order to schedule the synthetic opioid, N-(4-fluorophenyl)-N-(1-phenethylpiperidin-4-yl)isobutyramide (4-fluoroisobutyryl fentanyl or para-fluoroisobutyryl fentanyl), and its isomers, esters, ethers, salts and salts of isomers, esters, and ethers, into schedule I pursuant to the temporary scheduling provisions of the Controlled Substances Act. This action is based on a finding by the Administrator that the placement of 4-fluoroisobutyryl fentanyl into schedule I of the Controlled Substances Act is necessary to avoid an imminent hazard to the public safety. As a result of this order, the regulatory controls and administrative, civil, and criminal sanctions applicable to schedule I controlled substances will be imposed on persons who handle (manufacture, distribute, reverse distribute, import, export, engage in research, conduct instructional activities or chemical analysis, or possess), or propose to handle, 4-fluoroisobutyryl fentanyl.

  9. Orion Flight Test Preview Briefing

    NASA Image and Video Library

    2014-11-06

    In the Kennedy Space Center’s Press Site auditorium, members of the news media are briefed on the upcoming Orion flight test. From left are: Rachel Kraft, NASA Public Affairs, Bill Hill, NASA deputy associate administrator for Exploration Systems Development, Mark Geyer, NASA Orion Program manager, Bryan Austin, Lockheed Martin mission manager, Jeremy Graeber, Operations Integration Branch of Ground Systems Development and Operations at Kennedy, and Ron Fortson, United Launch Alliance director of Mission Management. Mike Sarafin, NASA's lead flight director, participated by video from the Johnson Space Center. Orion is the exploration spacecraft designed to carry astronauts to destinations not yet explored by humans, including an asteroid and Mars. It will have emergency abort capability, sustain the crew during space travel and provide safe re-entry from deep space return velocities. The first unpiloted flight test of Orion is scheduled to launch Dec. 4, 2014 atop a United Launch Alliance Delta IV Heavy rocket, and in 2018 on NASA’s Space Launch System rocket.

  10. Adaptive nonlinear flight control

    NASA Astrophysics Data System (ADS)

    Rysdyk, Rolf Theoduor

    1998-08-01

    Research under supervision of Dr. Calise and Dr. Prasad at the Georgia Institute of Technology, School of Aerospace Engineering. has demonstrated the applicability of an adaptive controller architecture. The architecture successfully combines model inversion control with adaptive neural network (NN) compensation to cancel the inversion error. The tiltrotor aircraft provides a specifically interesting control design challenge. The tiltrotor aircraft is capable of converting from stable responsive fixed wing flight to unstable sluggish hover in helicopter configuration. It is desirable to provide the pilot with consistency in handling qualities through a conversion from fixed wing flight to hover. The linear model inversion architecture was adapted by providing frequency separation in the command filter and the error-dynamics, while not exiting the actuator modes. This design of the architecture provides for a model following setup with guaranteed performance. This in turn allowed for convenient implementation of guaranteed handling qualities. A rigorous proof of boundedness is presented making use of compact sets and the LaSalle-Yoshizawa theorem. The analysis allows for the addition of the e-modification which guarantees boundedness of the NN weights in the absence of persistent excitation. The controller is demonstrated on the Generic Tiltrotor Simulator of Bell-Textron and NASA Ames R.C. The model inversion implementation is robustified with respect to unmodeled input dynamics, by adding dynamic nonlinear damping. A proof of boundedness of signals in the system is included. The effectiveness of the robustification is also demonstrated on the XV-15 tiltrotor. The SHL Perceptron NN provides a more powerful application, based on the universal approximation property of this type of NN. The SHL NN based architecture is also robustified with the dynamic nonlinear damping. A proof of boundedness extends the SHL NN augmentation with robustness to unmodeled actuator

  11. Flight Test Series 3: Flight Test Report

    NASA Technical Reports Server (NTRS)

    Marston, Mike; Sternberg, Daniel; Valkov, Steffi

    2015-01-01

    This document is a flight test report from the Operational perspective for Flight Test Series 3, a subpart of the Unmanned Aircraft System (UAS) Integration in the National Airspace System (NAS) project. Flight Test Series 3 testing began on June 15, 2015, and concluded on August 12, 2015. Participants included NASA Ames Research Center, NASA Armstrong Flight Research Center, NASA Glenn Research Center, NASA Langley Research center, General Atomics Aeronautical Systems, Inc., and Honeywell. Key stakeholders analyzed their System Under Test (SUT) in two distinct configurations. Configuration 1, known as Pairwise Encounters, was subdivided into two parts: 1a, involving a low-speed UAS ownship and intruder(s), and 1b, involving a high-speed surrogate ownship and intruder. Configuration 2, known as Full Mission, involved a surrogate ownship, live intruder(s), and integrated virtual traffic. Table 1 is a summary of flights for each configuration, with data collection flights highlighted in green. Section 2 and 3 of this report give an in-depth description of the flight test period, aircraft involved, flight crew, and mission team. Overall, Flight Test 3 gathered excellent data for each SUT. We attribute this successful outcome in large part from the experience that was acquired from the ACAS Xu SS flight test flown in December 2014. Configuration 1 was a tremendous success, thanks to the training, member participation, integration/testing, and in-depth analysis of the flight points. Although Configuration 2 flights were cancelled after 3 data collection flights due to various problems, the lessons learned from this will help the UAS in the NAS project move forward successfully in future flight phases.

  12. Requirements and feasibility study of flight demonstration of Active Controls Technology (ACT) on the NASA 515 airplane

    NASA Technical Reports Server (NTRS)

    Gordon, C. K.

    1975-01-01

    A preliminary design study was conducted to evaluate the suitability of the NASA 515 airplane as a flight demonstration vehicle, and to develop plans, schedules, and budget costs for fly-by-wire/active controls technology flight validation in the NASA 515 airplane. The preliminary design and planning were accomplished for two phases of flight validation.

  13. Multi-objective approach for energy-aware workflow scheduling in cloud computing environments.

    PubMed

    Yassa, Sonia; Chelouah, Rachid; Kadima, Hubert; Granado, Bertrand

    2013-01-01

    We address the problem of scheduling workflow applications on heterogeneous computing systems like cloud computing infrastructures. In general, the cloud workflow scheduling is a complex optimization problem which requires considering different criteria so as to meet a large number of QoS (Quality of Service) requirements. Traditional research in workflow scheduling mainly focuses on the optimization constrained by time or cost without paying attention to energy consumption. The main contribution of this study is to propose a new approach for multi-objective workflow scheduling in clouds, and present the hybrid PSO algorithm to optimize the scheduling performance. Our method is based on the Dynamic Voltage and Frequency Scaling (DVFS) technique to minimize energy consumption. This technique allows processors to operate in different voltage supply levels by sacrificing clock frequencies. This multiple voltage involves a compromise between the quality of schedules and energy. Simulation results on synthetic and real-world scientific applications highlight the robust performance of the proposed approach.

  14. Job scheduling on a hypercube

    SciTech Connect

    Zhu, Yahui.

    1990-01-01

    The author studies the scheduling of independent jobs on hypercube multiprocessors. He assumes that the hypercube system supports space-sharing for multiprogramming, i.e., a hypercube is partitioned into subcubes and each job is assigned to a dedicated subcube and many jobs can be running simultaneously without interfering with each other. Then the problem of how to schedule a set of jobs so that they can be finished as early as possible becomes important. He investigates two kinds of scheduling algorithms for the problem. The first one is nonpreemptive scheduling, i.e., no job is allowed to be interrupted during its execution. In this case, the problem is NP-Complete. He proposes an approximation algorithm called LDF, which generates a schedule with a finish time less than twice that of an optimal schedule. Compared with the earlier proposed algorithm, his algorithm is simpler and has almost the same performance. More importantly, his LDF algorithm can achieve this performance without knowing the job processing times, which may be hard to obtain in practice. Also he proves a lower bound result which implies that it is unlikely to find simple heuristic algorithms that can perform much better than the existing algorithms including LDF. The second kind is preemptive scheduling, i.e., a job can be preempted during its execution and rescheduled later. He develops a feasibility algorithm that runs in O (n log n) time and generates a schedule with at most min{l brace}n-2, 2{sup m}-1{r brace} preemptions. It can generate a feasible schedule for the given job set if there exists one. This improvement is important because many scheduling algorithms depend on a feasibility algorithm as a building block. Furthermore, based on an advanced search technique, he presents an algorithm that can find the optimal schedule in O(n{sup 2} log {sup 2}n) time.

  15. Differences in Characteristics of Aviation Accidents during 1993-2012 Based on Flight Purpose

    NASA Technical Reports Server (NTRS)

    Evans, Joni K.

    2016-01-01

    Usually aviation accidents are categorized and analyzed within flight conduct rules (Part 121, Part 135, Part 91) because differences in accident rates within flight rules have been demonstrated. Even within a particular flight rule the flights have different purposes. For many, Part 121 flights are synonymous with scheduled passenger transport, and indeed this is the largest group of Part 121 accidents. But there are also non-scheduled (charter) passenger transport and cargo flights. The primary purpose of the analysis reported here is to examine the differences in aviation accidents based on the purpose of the flight. Some of the factors examined are the accident severity, aircraft characteristics and accident occurrence categories. Twenty consecutive years of data were available and utilized to complete this analysis.

  16. Test flights of the NASA ultra long duration balloon

    NASA Astrophysics Data System (ADS)

    Cathey, H.

    The NASA Ultra Long Duration Balloon development project is attempting to extend the potential flight durations for large scientific balloon payloads. The culmination of each of the development steps has been the fabrication and test flight of progressively larger balloons. This new super-pressure balloon is a pumpkin balloon design. This paper concentrates on the super-pressure balloon development test flights that have been, and are currently being planned by the National Aeronautics and Space Administration (NASA) Balloon Program Office at Goddard Space Flight Center's Wallops Flight Facility. Two Ultra Long Duration balloon test flights took place from Australia in early 2001. The results from these flights, as well as the challenges presented, will be discussed. With these lessons learned and incorporating both material and design improvements, a test flight of a full-scale 610,500m3 balloon with a 2,800 kg suspended load will be completed in Spring of 2002 from Ft. Sumner, New Mexico. This balloon, the largest single celled super- pressure balloon ever flown, has been sized to satisfy the requirements for the planned ULDB CREAM mission in late 2003. A description of the balloon design, including the modifications made as a result of the lessons learned from the two Australia flights, will be presented. The results, highlighting balloon performance, from the Spring 2002 test flight will be presented. This will include information related to the balloon preparation, flight operations, and flight performance. A review of the radiative environmental influences on the balloon related to this flight will be presented. A second test flight of a full-scale Ultra Long Duration Balloon is scheduled for December of 2002. This flight is expected to be one orbit or approximately 15 days. The plans for this Southern Hemisphere, Australia launched, global flight will also be presented.

  17. Engineering robust intelligent robots

    NASA Astrophysics Data System (ADS)

    Hall, E. L.; Ali, S. M. Alhaj; Ghaffari, M.; Liao, X.; Cao, M.

    2010-01-01

    The purpose of this paper is to discuss the challenge of engineering robust intelligent robots. Robust intelligent robots may be considered as ones that not only work in one environment but rather in all types of situations and conditions. Our past work has described sensors for intelligent robots that permit adaptation to changes in the environment. We have also described the combination of these sensors with a "creative controller" that permits adaptive critic, neural network learning, and a dynamic database that permits task selection and criteria adjustment. However, the emphasis of this paper is on engineering solutions which are designed for robust operations and worst case situations such as day night cameras or rain and snow solutions. This ideal model may be compared to various approaches that have been implemented on "production vehicles and equipment" using Ethernet, CAN Bus and JAUS architectures and to modern, embedded, mobile computing architectures. Many prototype intelligent robots have been developed and demonstrated in terms of scientific feasibility but few have reached the stage of a robust engineering solution. Continual innovation and improvement are still required. The significance of this comparison is that it provides some insights that may be useful in designing future robots for various manufacturing, medical, and defense applications where robust and reliable performance is essential.

  18. Robust computational vision

    NASA Astrophysics Data System (ADS)

    Schunck, Brian G.

    1993-08-01

    This paper presents a paradigm for formulating reliable machine vision algorithms using methods from robust statistics. Machine vision is the process of estimating features from images by fitting a model to visual data. Vision research has produced an understanding of the physics and mathematics of visual processes. The fact that computer graphics programs can produce realistic renderings of artificial scenes indicates that our understanding of vision processes must be quite good. The premise of this paper is that the problem in applying computer vision in realistic scenes is not the fault of the theory of vision. We have good models for visual phenomena, but can do a better job of applying the models to images. Our understanding of vision must be used in computations that are robust to the kinds of errors that occur in visual signals. This paper argues that vision algorithms should be formulated using methods from robust regression. The nature of errors in visual signals is discussed, and a prescription for formulating robust algorithms is described. To illustrate the concepts, robust methods have been applied to several problems: surface reconstruction, dynamic stereo, image flow estimation, and edge detection.

  19. Collaborative Scheduling Using JMS in a Mixed Java and .NET Environment

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Wax, Allan; Lam, Ray; Baldwin, John; Borden, Chet

    2006-01-01

    A collaborative framework/environment was proto-typed to prove the feasibility of scheduling space flight missions on NASA's Deep Space Network (DSN) in a distributed fashion. In this environment, effective collaboration relies on efficient communications among all flight mission and DSN scheduling users. There-fore, messaging becomes critical to timely event notification and data synchronization. In the prototype, a rapid messaging system using Java Message Service (JMS) in a mixed Java and .NET environment is established. This scheme allows both Java and .NET applications to communicate with each other for data synchronization and schedule negotiation. The JMS approach we used is based on a centralized messaging scheme. With proper use of a high speed messaging system, all users in this collaborative framework can communicate with each other to generate a schedule collaboratively to meet DSN and projects tracking needs.

  20. Collaborative Scheduling Using JMS in a Mixed Java and .NET Environment

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Wax, Allan; Lam, Ray; Baldwin, John; Borden, Chet

    2006-01-01

    A collaborative framework/environment was proto-typed to prove the feasibility of scheduling space flight missions on NASA's Deep Space Network (DSN) in a distributed fashion. In this environment, effective collaboration relies on efficient communications among all flight mission and DSN scheduling users. There-fore, messaging becomes critical to timely event notification and data synchronization. In the prototype, a rapid messaging system using Java Message Service (JMS) in a mixed Java and .NET environment is established. This scheme allows both Java and .NET applications to communicate with each other for data synchronization and schedule negotiation. The JMS approach we used is based on a centralized messaging scheme. With proper use of a high speed messaging system, all users in this collaborative framework can communicate with each other to generate a schedule collaboratively to meet DSN and projects tracking needs.

  1. KENNEDY SPACE CENTER, FLA. - The turbulent weather common to a Florida afternoon in the summer subsides into a serene canopy of cornflower blue, and a manmade "bird" takes flight. The Space Shuttle Discovery soars skyward from Launch Pad 39B on Mission STS-64 at 6:22:35 p.m. EDT, Sept. 9. On board are a crew of six: Commander Richard N. Richards; Pilot L. Blaine Hammond Jr.; and Mission Specialists Mark C. Lee, Carl J. Meade, Susan J. Helms and Dr. J.M. Linenger. Payloads for the flight include the Lidar In-Space Technology Experiment (LITE), the Shuttle Pointed Autonomous Research Tool for Astronomy-201 (SPARTAN-201) and the Robot Operated Material Processing System (ROMPS). Mission Specialists Lee and Meade also are scheduled to perform an extravehicular activity during the 64th Shuttle mission.

    NASA Image and Video Library

    1994-09-09

    KENNEDY SPACE CENTER, FLA. - The turbulent weather common to a Florida afternoon in the summer subsides into a serene canopy of cornflower blue, and a manmade "bird" takes flight. The Space Shuttle Discovery soars skyward from Launch Pad 39B on Mission STS-64 at 6:22:35 p.m. EDT, Sept. 9. On board are a crew of six: Commander Richard N. Richards; Pilot L. Blaine Hammond Jr.; and Mission Specialists Mark C. Lee, Carl J. Meade, Susan J. Helms and Dr. J.M. Linenger. Payloads for the flight include the Lidar In-Space Technology Experiment (LITE), the Shuttle Pointed Autonomous Research Tool for Astronomy-201 (SPARTAN-201) and the Robot Operated Material Processing System (ROMPS). Mission Specialists Lee and Meade also are scheduled to perform an extravehicular activity during the 64th Shuttle mission.

  2. Optimisation of assembly scheduling in VCIM systems using genetic algorithm

    NASA Astrophysics Data System (ADS)

    Dao, Son Duy; Abhary, Kazem; Marian, Romeo

    2017-01-01

    Assembly plays an important role in any production system as it constitutes a significant portion of the lead time and cost of a product. Virtual computer-integrated manufacturing (VCIM) system is a modern production system being conceptually developed to extend the application of traditional computer-integrated manufacturing (CIM) system to global level. Assembly scheduling in VCIM systems is quite different from one in traditional production systems because of the difference in the working principles of the two systems. In this article, the assembly scheduling problem in VCIM systems is modeled and then an integrated approach based on genetic algorithm (GA) is proposed to search for a global optimised solution to the problem. Because of dynamic nature of the scheduling problem, a novel GA with unique chromosome representation and modified genetic operations is developed herein. Robustness of the proposed approach is verified by a numerical example.

  3. Optimisation of assembly scheduling in VCIM systems using genetic algorithm

    NASA Astrophysics Data System (ADS)

    Dao, Son Duy; Abhary, Kazem; Marian, Romeo

    2017-01-01

    Assembly plays an important role in any production system as it constitutes a significant portion of the lead time and cost of a product. Virtual computer-integrated manufacturing (VCIM) system is a modern production system being conceptually developed to extend the application of traditional computer-integrated manufacturing (CIM) system to global level. Assembly scheduling in VCIM systems is quite different from one in traditional production systems because of the difference in the working principles of the two systems. In this article, the assembly scheduling problem in VCIM systems is modeled and then an integrated approach based on genetic algorithm (GA) is proposed to search for a global optimised solution to the problem. Because of dynamic nature of the scheduling problem, a novel GA with unique chromosome representation and modified genetic operations is developed herein. Robustness of the proposed approach is verified by a numerical example.

  4. Return to Flight activities at The Mall at Cortana

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Christian Gonzales, 11 (right), watches as his little brother Walter, 2, adds his own brand of good wishes to a banner encouraging the crew of Space Shuttle Discovery on NASA's Return to Flight mission, scheduled to launch in summer 2005. The brothers, of Baton Rouge, were participating in a Camp Kids event at The Mall at Cortana, where Return to Flight activities were presented by NASA's Stennis Space Center (SSC).

  5. Return to Flight activities at The Mall at Cortana

    NASA Image and Video Library

    2005-06-28

    Christian Gonzales, 11 (right), watches as his little brother Walter, 2, adds his own brand of good wishes to a banner encouraging the crew of Space Shuttle Discovery on NASA's Return to Flight mission, scheduled to launch in summer 2005. The brothers, of Baton Rouge, were participating in a Camp Kids event at The Mall at Cortana, where Return to Flight activities were presented by NASA's Stennis Space Center (SSC).

  6. Pilot Searfoss in experiment measuring effects space flight & pilot ability

    NASA Image and Video Library

    1993-10-18

    STS058-14-006 (18 Oct- 1 Nov 1993) --- Astronaut Richard A. Searfoss, pilot, participates in an experiment that measures the effects of space flight on pilot proficiency. Astronauts Searfoss (seen here at the pilot's station) and John E. Blaha, mission commander, are conducting the first tests of the Portable Inflight Landing Operations Trainer (PILOT). STS-58 is the first of six scheduled test flights of PILOT designed to determine its effectiveness as a training tool.

  7. On-board emergent scheduling of autonomous spacecraft payload operations

    NASA Technical Reports Server (NTRS)

    Lindley, Craig A.

    1994-01-01

    This paper describes a behavioral competency level concerned with emergent scheduling of spacecraft payload operations. The level is part of a multi-level subsumption architecture model for autonomous spacecraft, and it functions as an action selection system for processing a spacecraft commands that can be considered as 'plans-as-communication'. Several versions of the selection mechanism are described, and their robustness is qualitatively compared.

  8. Constraint-Based Scheduling System

    NASA Technical Reports Server (NTRS)

    Zweben, Monte; Eskey, Megan; Stock, Todd; Taylor, Will; Kanefsky, Bob; Drascher, Ellen; Deale, Michael; Daun, Brian; Davis, Gene

    1995-01-01

    Report describes continuing development of software for constraint-based scheduling system implemented eventually on massively parallel computer. Based on machine learning as means of improving scheduling. Designed to learn when to change search strategy by analyzing search progress and learning general conditions under which resource bottleneck occurs.

  9. Block Schedule: Breaking the Barriers.

    ERIC Educational Resources Information Center

    West, Mike

    As of 1996, Chaparral High School in Las Vegas, Nevada, was in the fourth year of a radical restructuring effort. The school changed from a 6-period day, composed of 51-minute periods, to an alternating day schedule, composed of 3 102-minute periods per day. This report describes how the school developed and implemented the new schedule. Faculty…

  10. Modeling the Cray memory scheduler

    SciTech Connect

    Wickham, K.L.; Litteer, G.L.

    1992-04-01

    This report documents the results of a project to evaluate low cost modeling and simulation tools when applied to modeling the Cray memory scheduler. The specific tool used is described and the basics of the memory scheduler are covered. Results of simulations using the model are discussed and a favorable recommendation is made to make more use of this inexpensive technology.

  11. Modeling the Cray memory scheduler

    SciTech Connect

    Wickham, K.L.; Litteer, G.L.

    1992-04-01

    This report documents the results of a project to evaluate low cost modeling and simulation tools when applied to modeling the Cray memory scheduler. The specific tool used is described and the basics of the memory scheduler are covered. Results of simulations using the model are discussed and a favorable recommendation is made to make more use of this inexpensive technology.

  12. Scheduling Guide for Program Managers

    DTIC Science & Technology

    2001-10-01

    and val- leys are evened out without scheduling more work than nine people can do. In this ex- ample, this rearrangement can be accom- plished quickly...full advantage of event- driven scheduling. Additional information on the development of IMSs can be found in various sections of the Defense

  13. Interactive computer aided shift scheduling.

    PubMed

    Gaertner, J

    2001-12-01

    This paper starts with a discussion of computer aided shift scheduling. After a brief review of earlier approaches, two conceptualizations of this field are introduced: First, shift scheduling as a field that ranges from extremely stable rosters at one pole to rather market-like approaches on the other pole. Unfortunately, already small alterations of a scheduling problem (e.g., the number of groups, the number of shifts) may call for rather different approaches and tools. Second, their environment shapes scheduling problems and scheduling has to be done within idiosyncratic organizational settings. This calls for the amalgamation of scheduling with other tasks (e.g., accounting) and for reflections whether better solutions might become possible by changes in the problem definition (e.g., other service levels, organizational changes). Therefore shift scheduling should be understood as a highly connected problem. Building upon these two conceptualizations, a few examples of software that ease scheduling in some areas of this field are given and future research questions are outlined.

  14. Nontraditional work schedules for pharmacists.

    PubMed

    Mahaney, Lynnae; Sanborn, Michael; Alexander, Emily

    2008-11-15

    Nontraditional work schedules for pharmacists at three institutions are described. The demand for pharmacists and health care in general continues to increase, yet significant material changes are occurring in the pharmacy work force. These changing demographics, coupled with historical vacancy rates and turnover trends for pharmacy staff, require an increased emphasis on workplace changes that can improve staff recruitment and retention. At William S. Middleton Memorial Veterans Affairs Hospital in Madison, Wisconsin, creative pharmacist work schedules and roles are now mainstays to the recruitment and retention of staff. The major challenge that such scheduling presents is the 8 hours needed to prepare a six-week schedule. Baylor Medical Center at Grapevine in Dallas, Texas, has a total of 45 pharmacy employees, and slightly less than half of the 24.5 full-time-equivalent staff work full-time, with most preferring to work one, two, or three days per week. As long as the coverage needs of the facility are met, Envision Telepharmacy in Alpine, Texas, allows almost any scheduling arrangement preferred by individual pharmacists or the pharmacist group covering the facility. Staffing involves a great variety of shift lengths and intervals, with shifts ranging from 2 to 10 hours. Pharmacy leaders must be increasingly aware of opportunities to provide staff with unique scheduling and operational enhancements that can provide for a better work-life balance. Compressed workweeks, job-sharing, and team scheduling were the most common types of alternative work schedules implemented at three different institutions.

  15. The Effectiveness of Block Scheduling.

    ERIC Educational Resources Information Center

    Creamean, Sharon Lightle; Horvath, Robert Jeffery

    This report describes a program for the exploration of block scheduling. The targeted population consists of high school students in a growing, middle-class community, located in a suburban setting of a large mid-western city. The historical background of block scheduling is documented through data gathered using attendance reports, student…

  16. HIFIRE Flight 2 Overview and Status Update 2011

    NASA Technical Reports Server (NTRS)

    Jackson, Kevin R.; Gruber, Mark R.; Buccellato, Salvatore

    2011-01-01

    A collaborative international effort, the Hypersonic International Flight Research Experimentation (HIFiRE) Program aims to study basic hypersonic phenomena through flight experimentation. HIFiRE Flight 2 teams the United States Air Force Research Lab (AFRL), NASA, and the Australian Defence Science and Technology Organisation (DSTO). Flight 2 will develop an alternative test technique for acquiring high enthalpy scramjet flight test data, allowing exploration of accelerating hydrocarbon-fueled scramjet performance and dual-to-scram mode transition up to and beyond Mach 8 flight. The generic scramjet flowpath is research quality and the test fuel is a simple surrogate for an endothermically cracked liquid hydrocarbon fuel. HIFiRE Flight 2 will be a first of its kind in contribution to scramjets. The HIFiRE program builds upon the HyShot and HYCAUSE programs and aims to leverage the low-cost flight test technique developed in those programs. It will explore suppressed trajectories of a sounding rocket propelled test article and their utility in studying ramjet-scramjet mode transition and flame extinction limits research. This paper describes the overall scramjet flight test experiment mission goals and objectives, flight test approach and strategy, ground test and analysis summary, development status and project schedule. A successful launch and operation will present to the scramjet community valuable flight test data in addition to a new tool, and vehicle, with which to explore high enthalpy scramjet technologies.

  17. Robust distribution network reconfiguration

    SciTech Connect

    Lee, Changhyeok; Liu, Cong; Mehrotra, Sanjay; Bie, Zhaohong

    2015-03-01

    We propose a two-stage robust optimization model for the distribution network reconfiguration problem with load uncertainty. The first-stage decision is to configure the radial distribution network and the second-stage decision is to find the optimal a/c power flow of the reconfigured network for given demand realization. We solve the two-stage robust model by using a column-and-constraint generation algorithm, where the master problem and subproblem are formulated as mixed-integer second-order cone programs. Computational results for 16, 33, 70, and 94-bus test cases are reported. We find that the configuration from the robust model does not compromise much the power loss under the nominal load scenario compared to the configuration from the deterministic model, yet it provides the reliability of the distribution system for all scenarios in the uncertainty set.

  18. Flight projects overview

    NASA Technical Reports Server (NTRS)

    Levine, Jack

    1988-01-01

    Information is given in viewgraph form on the activities of the Flight Projects Division of NASA's Office of Aeronautics and Space Technology. Information is given on space research and technology strategy, current space flight experiments, the Long Duration Exposure Facility, the Orbiter Experiment Program, the Lidar In-Space Technology Experiment, the Ion Auxiliary Propulsion System, the Arcjet Flight Experiment, the Telerobotic Intelligent Interface Flight Experiment, the Cryogenic Fluid Management Flight Experiment, the Industry/University In-Space Flight Experiments, and the Aeroassist Flight Experiment.

  19. Scheduling Software for Complex Scenarios

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Preparing a vehicle and its payload for a single launch is a complex process that involves thousands of operations. Because the equipment and facilities required to carry out these operations are extremely expensive and limited in number, optimal assignment and efficient use are critically important. Overlapping missions that compete for the same resources, ground rules, safety requirements, and the unique needs of processing vehicles and payloads destined for space impose numerous constraints that, when combined, require advanced scheduling. Traditional scheduling systems use simple algorithms and criteria when selecting activities and assigning resources and times to each activity. Schedules generated by these simple decision rules are, however, frequently far from optimal. To resolve mission-critical scheduling issues and predict possible problem areas, NASA historically relied upon expert human schedulers who used their judgment and experience to determine where things should happen, whether they will happen on time, and whether the requested resources are truly necessary.

  20. Astronaut Office Scheduling System Software

    NASA Technical Reports Server (NTRS)

    Brown, Estevancio

    2010-01-01

    AOSS is a highly efficient scheduling application that uses various tools to schedule astronauts weekly appointment information. This program represents an integration of many technologies into a single application to facilitate schedule sharing and management. It is a Windows-based application developed in Visual Basic. Because the NASA standard office automation load environment is Microsoft-based, Visual Basic provides AO SS developers with the ability to interact with Windows collaboration components by accessing objects models from applications like Outlook and Excel. This also gives developers the ability to create newly customizable components that perform specialized tasks pertaining to scheduling reporting inside the application. With this capability, AOSS can perform various asynchronous tasks, such as gathering/ sending/ managing astronauts schedule information directly to their Outlook calendars at any time.

  1. An Enabling Technology for New Planning and Scheduling Paradigms

    NASA Technical Reports Server (NTRS)

    Jaap, John; Davis, Elizabeth

    2004-01-01

    The Night Projects Directorate at NASA's Marshall Space Flight Center is developing a new planning and scheduling environment and a new scheduling algorithm to enable a paradigm shift in planning and scheduling concepts. Over the past 33 years Marshall has developed and evolved a paradigm for generating payload timelines for Skylab, Spacelab, various other Shuttle payloads, and the International Space Station. The current paradigm starts by collecting the requirements, called ?ask models," from the scientists and technologists for the tasks that are to be scheduled. Because of shortcomings in the current modeling schema, some requirements are entered as notes. Next, a cadre with knowledge of vehicle and hardware modifies these models to encompass and be compatible with the hardware model; again, notes are added when the modeling schema does not provide a better way to represent the requirements. Finally, the models are modified to be compatible with the scheduling engine. Then the models are submitted to the scheduling engine for automatic scheduling or, when requirements are expressed in notes, the timeline is built manually. A future paradigm would provide a scheduling engine that accepts separate science models and hardware models. The modeling schema would have the capability to represent all the requirements without resorting to notes. Furthermore, the scheduling engine would not require that the models be modified to account for the capabilities (limitations) of the scheduling engine. The enabling technology under development at Marshall has three major components: (1) A new modeling schema allows expressing all the requirements of the tasks without resorting to notes or awkward contrivances. The chosen modeling schema is both maximally expressive and easy to use. It utilizes graphical methods to show hierarchies of task constraints and networks of temporal relationships. (2) A new scheduling algorithm automatically schedules the models without the

  2. An Enabling Technology for New Planning and Scheduling Paradigms

    NASA Technical Reports Server (NTRS)

    Jaap, John; Davis, Elizabeth

    2004-01-01

    The Night Projects Directorate at NASA's Marshall Space Flight Center is developing a new planning and scheduling environment and a new scheduling algorithm to enable a paradigm shift in planning and scheduling concepts. Over the past 33 years Marshall has developed and evolved a paradigm for generating payload timelines for Skylab, Spacelab, various other Shuttle payloads, and the International Space Station. The current paradigm starts by collecting the requirements, called ?ask models," from the scientists and technologists for the tasks that are to be scheduled. Because of shortcomings in the current modeling schema, some requirements are entered as notes. Next, a cadre with knowledge of vehicle and hardware modifies these models to encompass and be compatible with the hardware model; again, notes are added when the modeling schema does not provide a better way to represent the requirements. Finally, the models are modified to be compatible with the scheduling engine. Then the models are submitted to the scheduling engine for automatic scheduling or, when requirements are expressed in notes, the timeline is built manually. A future paradigm would provide a scheduling engine that accepts separate science models and hardware models. The modeling schema would have the capability to represent all the requirements without resorting to notes. Furthermore, the scheduling engine would not require that the models be modified to account for the capabilities (limitations) of the scheduling engine. The enabling technology under development at Marshall has three major components: (1) A new modeling schema allows expressing all the requirements of the tasks without resorting to notes or awkward contrivances. The chosen modeling schema is both maximally expressive and easy to use. It utilizes graphical methods to show hierarchies of task constraints and networks of temporal relationships. (2) A new scheduling algorithm automatically schedules the models without the

  3. Space Launch System Ascent Flight Control Design

    NASA Technical Reports Server (NTRS)

    VanZwieten, Tannen S.; Orr, Jeb S.; Wall, John H.; Hall, Charles E.

    2014-01-01

    A robust and flexible autopilot architecture for NASA's Space Launch System (SLS) family of launch vehicles is presented. As the SLS configurations represent a potentially significant increase in complexity and performance capability of the integrated flight vehicle, it was recognized early in the program that a new, generalized autopilot design should be formulated to fulfill the needs of this new space launch architecture. The present design concept is intended to leverage existing NASA and industry launch vehicle design experience and maintain the extensibility and modularity necessary to accommodate multiple vehicle configurations while relying on proven and flight-tested control design principles for large boost vehicles. The SLS flight control architecture combines a digital three-axis autopilot with traditional bending filters to support robust active or passive stabilization of the vehicle's bending and sloshing dynamics using optimally blended measurements from multiple rate gyros on the vehicle structure. The algorithm also relies on a pseudo-optimal control allocation scheme to maximize the performance capability of multiple vectored engines while accommodating throttling and engine failure contingencies in real time with negligible impact to stability characteristics. The architecture supports active in-flight load relief through the use of a nonlinear observer driven by acceleration measurements, and envelope expansion and robustness enhancement is obtained through the use of a multiplicative forward gain modulation law based upon a simple model reference adaptive control scheme.

  4. Flight control electronics reliability/maintenance study

    NASA Technical Reports Server (NTRS)

    Dade, W. W.; Edwards, R. H.; Katt, G. T.; Mcclellan, K. L.; Shomber, H. A.

    1977-01-01

    Collection and analysis of data are reported that concern the reliability and maintenance experience of flight control system electronics currently in use on passenger carrying jet aircraft. Two airlines B-747 airplane fleets were analyzed to assess the component reliability, system functional reliability, and achieved availability of the CAT II configuration flight control system. Also assessed were the costs generated by this system in the categories of spare equipment, schedule irregularity, and line and shop maintenance. The results indicate that although there is a marked difference in the geographic location and route pattern between the airlines studied, there is a close similarity in the reliability and the maintenance costs associated with the flight control electronics.

  5. A plume spectroscopy system for flight applications

    NASA Astrophysics Data System (ADS)

    Makel, D. B.; Petersen, T. V.; Duncan, D. B.; Madzsar, G. C.

    1993-06-01

    An operational plume spectroscopy system will be an important element of any rocket engine health management system (HMS). The flight capable FPI spectrometer will enable prognosis and response to incipient rocket engine failures as well as diagnosis of wear and degradation for on-condition maintenance. Spectrometer application to development programs, such as the Space Lifter, NASP, and SSTO, will reduce program risks, allow better adherence to schedules and save money by reducing or eliminating redesign and test costs. The diagnostic capability of a proven, calibrated spectrometer will enhance post-burn certification of high value, reusable engines, such as the Space Shuttle Main Engine (SSME), where life and reliability are key cost drivers. This paper describes a prototype FPI spectrometer for demonstration and validation testing on NASA's Technology Test Bed Engine (TTBE) at Marshall Space Flight Center. The TTBE test unit is designed with flight prototype optics and a commercial off-the-shelf data processing system.

  6. A plume spectroscopy system for flight applications

    NASA Technical Reports Server (NTRS)

    Makel, D. B.; Petersen, T. V.; Duncan, D. B.; Madzsar, G. C.

    1993-01-01

    An operational plume spectroscopy system will be an important element of any rocket engine health management system (HMS). The flight capable FPI spectrometer will enable prognosis and response to incipient rocket engine failures as well as diagnosis of wear and degradation for on-condition maintenance. Spectrometer application to development programs, such as the Space Lifter, NASP, and SSTO, will reduce program risks, allow better adherence to schedules and save money by reducing or eliminating redesign and test costs. The diagnostic capability of a proven, calibrated spectrometer will enhance post-burn certification of high value, reusable engines, such as the Space Shuttle Main Engine (SSME), where life and reliability are key cost drivers. This paper describes a prototype FPI spectrometer for demonstration and validation testing on NASA's Technology Test Bed Engine (TTBE) at Marshall Space Flight Center. The TTBE test unit is designed with flight prototype optics and a commercial off-the-shelf data processing system.

  7. Orbiter Auxiliary Power Unit Flight Support Plan

    NASA Technical Reports Server (NTRS)

    Guirl, Robert; Munroe, James; Scott, Walter

    1990-01-01

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

  8. 14 CFR 121.481 - Flight time limitations: One or two pilot crews.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... operations may schedule a pilot to fly in an airplane that has a crew of one or two pilots for eight hours or... certificate holder conducting flag operations schedules a pilot to fly more than eight hours during any 24... of flight duty. This rest period must be at least twice the number of hours flown since the...

  9. Upper-Stage Flight Experiment

    NASA Technical Reports Server (NTRS)

    Anderson, W. E.; Boxwell, R.; Crockett, D. V.; Ross, R.; Lewis, T.; McNeal, C.; Verdarame, K.

    1999-01-01

    For propulsion applications that require that the propellants are storable for long periods, have a high density impulse, and are environmentally clean and non-toxic, the best choice is a combination of high-concentration hydrogen peroxide (High Test Peroxide, or HTP) and a liquid hydrocarbon (LHC) fuel. The HTP/LHC combination is suitable for low-cost launch vehicles, space taxi and space maneuvering vehicles, and kick stages. Orbital Sciences Corporation is under contract with the NASA Marshall Space Flight Center in cooperation with the Air Force Research Lab to design, develop and demonstrate a new low-cost liquid upper stage based on HTP and JP-8. The Upper Stage Flight Experiment (USFE) focuses on key technologies necessary to demonstrate the operation of an inherently simple propulsion system with an innovative, state-of-the-art structure. Two key low-cost vehicle elements will be demonstrated - a 10,000 lbf thrust engine and an integrated composite tank structure. The suborbital flight test of the USFE is scheduled for 2001. Preceding the flight tests are two major series of ground tests at NASA Stennis Space Center and a subscale tank development program to identify compatible composite materials and to verify their compatibility over long periods of time. The ground tests include a thrust chamber development test series and an integrated stage test. This paper summarizes the results from the first phase of the thrust chamber development tests and the results to date from the tank material compatibility tests. Engine and tank configurations that meet the goals of the program are described.

  10. Robust Fault Detection Using Robust Z1 Estimation and Fuzzy Logic

    NASA Technical Reports Server (NTRS)

    Curry, Tramone; Collins, Emmanuel G., Jr.; Selekwa, Majura; Guo, Ten-Huei (Technical Monitor)

    2001-01-01

    This research considers the application of robust Z(sub 1), estimation in conjunction with fuzzy logic to robust fault detection for an aircraft fight control system. It begins with the development of robust Z(sub 1) estimators based on multiplier theory and then develops a fixed threshold approach to fault detection (FD). It then considers the use of fuzzy logic for robust residual evaluation and FD. Due to modeling errors and unmeasurable disturbances, it is difficult to distinguish between the effects of an actual fault and those caused by uncertainty and disturbance. Hence, it is the aim of a robust FD system to be sensitive to faults while remaining insensitive to uncertainty and disturbances. While fixed thresholds only allow a decision on whether a fault has or has not occurred, it is more valuable to have the residual evaluation lead to a conclusion related to the degree of, or probability of, a fault. Fuzzy logic is a viable means of determining the degree of a fault and allows the introduction of human observations that may not be incorporated in the rigorous threshold theory. Hence, fuzzy logic can provide a more reliable and informative fault detection process. Using an aircraft flight control system, the results of FD using robust Z(sub 1) estimation with a fixed threshold are demonstrated. FD that combines robust Z(sub 1) estimation and fuzzy logic is also demonstrated. It is seen that combining the robust estimator with fuzzy logic proves to be advantageous in increasing the sensitivity to smaller faults while remaining insensitive to uncertainty and disturbances.

  11. Robust Fault Detection Using Robust Z1 Estimation and Fuzzy Logic

    NASA Technical Reports Server (NTRS)

    Curry, Tramone; Collins, Emmanuel G., Jr.; Selekwa, Majura; Guo, Ten-Huei (Technical Monitor)

    2001-01-01

    This research considers the application of robust Z(sub 1), estimation in conjunction with fuzzy logic to robust fault detection for an aircraft fight control system. It begins with the development of robust Z(sub 1) estimators based on multiplier theory and then develops a fixed threshold approach to fault detection (FD). It then considers the use of fuzzy logic for robust residual evaluation and FD. Due to modeling errors and unmeasurable disturbances, it is difficult to distinguish between the effects of an actual fault and those caused by uncertainty and disturbance. Hence, it is the aim of a robust FD system to be sensitive to faults while remaining insensitive to uncertainty and disturbances. While fixed thresholds only allow a decision on whether a fault has or has not occurred, it is more valuable to have the residual evaluation lead to a conclusion related to the degree of, or probability of, a fault. Fuzzy logic is a viable means of determining the degree of a fault and allows the introduction of human observations that may not be incorporated in the rigorous threshold theory. Hence, fuzzy logic can provide a more reliable and informative fault detection process. Using an aircraft flight control system, the results of FD using robust Z(sub 1) estimation with a fixed threshold are demonstrated. FD that combines robust Z(sub 1) estimation and fuzzy logic is also demonstrated. It is seen that combining the robust estimator with fuzzy logic proves to be advantageous in increasing the sensitivity to smaller faults while remaining insensitive to uncertainty and disturbances.

  12. Robustness of spatial micronetworks.

    PubMed

    McAndrew, Thomas C; Danforth, Christopher M; Bagrow, James P

    2015-04-01

    Power lines, roadways, pipelines, and other physical infrastructure are critical to modern society. These structures may be viewed as spatial networks where geographic distances play a role in the functionality and construction cost of links. Traditionally, studies of network robustness have primarily considered the connectedness of large, random networks. Yet for spatial infrastructure, physical distances must also play a role in network robustness. Understanding the robustness of small spatial networks is particularly important with the increasing interest in microgrids, i.e., small-area distributed power grids that are well suited to using renewable energy resources. We study the random failures of links in small networks where functionality depends on both spatial distance and topological connectedness. By introducing a percolation model where the failure of each link is proportional to its spatial length, we find that when failures depend on spatial distances, networks are more fragile than expected. Accounting for spatial effects in both construction and robustness is important for designing efficient microgrids and other network infrastructure.

  13. Wetting: Intrinsically robust hydrophobicity

    NASA Astrophysics Data System (ADS)

    Tian, Ye; Jiang, Lei

    2013-04-01

    Ceramic surfaces can be rendered hydrophobic by using polymeric modifiers, but these are not robust to harsh environments. A known family of rare-earth oxide ceramics is now found to exhibit intrinsic hydrophobicity, even after exposure to high temperatures and abrasive wear.

  14. Robustness of Embryonic Patterning

    NASA Astrophysics Data System (ADS)

    Barkai, Naama

    2002-03-01

    Developmental patterning proceeds reliably despite natural fluctuations in the expression levels of genes and changes in gene dosage. Patterning mechanisms that rely on morphogen gradients generally involve a network of feedback loops, which buffer against such perturbations. Although most components of the patterning networks have been identified and characterized, quantitative and mechanistic understanding of how their functions are integrated to achieve robustness is still missing. Here, we report a quantitative study of a morphogen gradient, determining cell fates in the fruit-fly embryo. We find that differential protein cleavage, coupled with selective diffusion, defines a robust system which can adjust to large variations in levels of the different protein components. The mechanism underlying robustness relies on the convergence of the signaling profile to a finite distribution, which in most regions is independent of physical boundary conditions such as production rates. An excess of signaling molecules is stored in a restricted spatial domain. This limiting profile property is exhibited by a class of reaction-diffusion equations, and may represent a general mechanism for achieving robustness in morphogen gradient systems. Experimental verification of model's predictions will be described.

  15. Robustness of spatial micronetworks

    NASA Astrophysics Data System (ADS)

    McAndrew, Thomas C.; Danforth, Christopher M.; Bagrow, James P.

    2015-04-01

    Power lines, roadways, pipelines, and other physical infrastructure are critical to modern society. These structures may be viewed as spatial networks where geographic distances play a role in the functionality and construction cost of links. Traditionally, studies of network robustness have primarily considered the connectedness of large, random networks. Yet for spatial infrastructure, physical distances must also play a role in network robustness. Understanding the robustness of small spatial networks is particularly important with the increasing interest in microgrids, i.e., small-area distributed power grids that are well suited to using renewable energy resources. We study the random failures of links in small networks where functionality depends on both spatial distance and topological connectedness. By introducing a percolation model where the failure of each link is proportional to its spatial length, we find that when failures depend on spatial distances, networks are more fragile than expected. Accounting for spatial effects in both construction and robustness is important for designing efficient microgrids and other network infrastructure.

  16. Application of Artificial Intelligence Techniques in Uninhabited Aerial Vehicle Flight

    NASA Technical Reports Server (NTRS)

    Dufrene, Warren R., Jr.

    2004-01-01

    This paper describes the development of an application of Artificial Intelligence (AI) for Unmanned Aerial Vehicle (UAV) control. The project was done as part of the requirements for a class in AI at NOVA Southeastearn University and a beginning project at NASA Wallops Flight Facility for a resilient, robust, and intelligent UAV flight control system. A method is outlined which allows a base level application for applying an Artificial Intelligence method, Fuzzy Logic, to aspects of Control Logic for UAV flight. One element of UAV flight, automated altitude hold, has been implemented and preliminary results displayed.

  17. Application of Artificial Intelligence Techniques in Uninhabitated Aerial Vehicle Flight

    NASA Technical Reports Server (NTRS)

    Dufrene, Warren R., Jr.

    2003-01-01

    This paper describes the development of an application of Artificial Intelligence (AI) for Unmanned Aerial Vehicle (UAV) control. The project was done as part of the requirements for a class in AI at NOVA southeastern University and a beginning project at NASA Wallops Flight Facility for a resilient, robust, and intelligent UAV flight control system. A method is outlined which allows a base level application for applying an Artificial Intelligence method, Fuzzy Logic, to aspects of Control Logic for UAV flight. One element of UAV flight, automated altitude hold, has been implemented and preliminary results displayed.

  18. Application of Artificial Intelligence Techniques in Uninhabitated Aerial Vehicle Flight

    NASA Technical Reports Server (NTRS)

    Dufrene, Warren R., Jr.

    2003-01-01

    This paper describes the development of an application of Artificial Intelligence (AI) for Unmanned Aerial Vehicle (UAV) control. The project was done as part of the requirements for a class in AI at NOVA southeastern University and a beginning project at NASA Wallops Flight Facility for a resilient, robust, and intelligent UAV flight control system. A method is outlined which allows a base level application for applying an Artificial Intelligence method, Fuzzy Logic, to aspects of Control Logic for UAV flight. One element of UAV flight, automated altitude hold, has been implemented and preliminary results displayed.

  19. Rehabilitation After International Space Station Flights

    NASA Technical Reports Server (NTRS)

    Chauvin, S. J.; Shepherd, B. A. S.; Guilliams, M. E.; Taddeo, T.

    2003-01-01

    Rehabilitating U.S. crew members to preflight status following flights on the Russian Mir Space Station required longer than six months for full functional recovery of some of the seven crew members. Additional exercise hardware has been added on the International Space Station as well as a rehabilitative emphasis on functional fitness/agility and proprioception. The authors will describe and present the results of the rehabilitation program for ISS and evaluate rehabilitative needs for longer missions. Pre- and in-flight programs emphasize strength and aerobic conditioning. One year before launch, crew members are assigned an Astronaut Strength and Conditioning specialist. Crew members are scheduled for 2 hours, 3 days a week, for pre-flight training and 2.5 hours, six days a week, for in-flight training. Crewmembers are tested on functional fitness, agility, isokinetic strength, and submaximal cycle ergometer evaluation before and after flight. The information from these tests is used for exercise prescriptions, comparison, and evaluation of the astronaut and training programs. The rehabilitation program lasts for 45 days and is scheduled for 2 hours during each crew workday. Phase 1 of the rehabilitation program starts on landing day and places emphasis on ambulation, flexibility, and muscle strengthening. Phase 2 adds proprioceptive exercise and cardiovascular conditioning. Phase 3 (the longest phase) focuses on functional development. All programs are tailored specifically for each individual according to their test results, preferred recreational activities, and mission roles and duties. Most crew members reached or exceeded their preflight test values 45 days after flight. Some crew members subjectively indicated the need for a longer rehabilitation period. The current rehabilitation program for returning ISS crew members seems adequate in content but may need to be extended for longer expeditions.

  20. X-33 Flight Visualization

    NASA Technical Reports Server (NTRS)

    Laue, Jay H.

    1998-01-01

    The X-33 flight visualization effort has resulted in the integration of high-resolution terrain data with vehicle position and attitude data for planned flights of the X-33 vehicle from its launch site at Edwards AFB, California, to landings at Michael Army Air Field, Utah, and Maelstrom AFB, Montana. Video and Web Site representations of these flight visualizations were produced. In addition, a totally new module was developed to control viewpoints in real-time using a joystick input. Efforts have been initiated, and are presently being continued, for real-time flight coverage visualizations using the data streams from the X-33 vehicle flights. The flight visualizations that have resulted thus far give convincing support to the expectation that the flights of the X-33 will be exciting and significant space flight milestones... flights of this nation's one-half scale predecessor to its first single-stage-to-orbit, fully-reusable launch vehicle system.