Search NASA⌕ Search

SEARCH · Search NASA

Results for “performance measures”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1998

The Aviation Performance Measuring System (APMS): An Integrated Suite of Tools for Measuring Performance and Safety

This is a report of work in progress. In it, I summarize the status of the research and development of the Aviation Performance Measuring System (APMS) for managing, processing, and analyzing digital flight-recorded data, The objectives of the NASA-FAA APMS research project are to establish a sound scientific and technological basis for flight-data analysis, to define an open and flexible architecture for flight-data analysis systems, and to articulate guidelines for a standardized database structure on which to continue to build future flight-data-analysis extensions. APMS offers to the air transport community an open, voluntary standard for flight-data-analysis software; a standard that will help to ensure suitable functionality and data interchangeability among competing software programs. APMS will develop and document the methodologies, algorithms, and procedures for data management and analyses to enable users to easily interpret the implications regarding safety and efficiency of operations. APMS does not entail the implementation of a nationwide flight-data-collection system. It is intended to provide technical tools to ease the large-scale implementation of flight-data analyses at both the air-carrier and the national-airspace levels in support of their Flight Operations and Quality Assurance (FOQA) Programs and Advanced Qualifications Programs (AQP). APMS cannot meet its objectives unless it develops tools that go substantially beyond the capabilities of the current commercially available software and supporting analytic methods that are mainly designed to count special events. These existing capabilities, while of proven value, were created primarily with the needs-of aircrews in mind. APMS tools must serve the needs of the government and air carriers, as well as aircrews, to fully support the FOQA and AQP programs. They must be able to derive knowledge not only through the analysis of single flights (special-event detection), but also through statistical evaluation of the performance of large groups of flights. This paper describes the integrated suite of tools that will assist analysts in evaluating the operational performance and safety of the national air transport system, the air carrier, and the aircrew.

Statler, Irving C.↗
NASA NTRS1984

Performance measurement of low concentration ratio solar array for space application

The measured performance of a silicon and a gallium arsenide low concentration ratio solar array (LCRSA) element is presented. The element characteristics measured in natural sunlight are off pointing performance and response to mechanical distortions. Laboratory measurements of individual silicon and gallium-arsenide solar cell assemblies are also made. The characteristics measured in the laboratory involved responses to temperature and intensity variations as well as to the application of reverse bias potentials. The element design details covered include the materials, the solar cells, and the rationale for selecting these specific characteristics. The measured performance characteristics are contrasted with the predicted values for both laboratory testing and high altitude natural sunlight testing. Excellent agreement between analytical predictions and measured performance is observed.

Mills, M. W.↗
NASA NTRS1997

APMS: An Integrated Suite of Tools for Measuring Performance and Safety

This is a report of work in progress. In it, I summarize the status of the research and development of the Aviation Performance Measuring System (APMS) for managing, processing, and analyzing digital flight-recorded data. The objectives of the NASA-FAA APMS research project are to establish a sound scientific and technological basis for flight-data analysis, to define an open and flexible architecture for flight-data-analysis systems, and to articulate guidelines for a standardized database structure on which to continue to build future flight-data-analysis extensions . APMS will offer to the air transport community an open, voluntary standard for flight-data-analysis software, a standard that will help to ensure suitable functionality, and data interchangeability, among competing software programs. APMS will develop and document the methodologies, algorithms, and procedures for data management and analyses to enable users to easily interpret the implications regarding safety and efficiency of operations. APMS does not entail the implementation of a nationwide flight-data-collection system. It is intended to provide technical tools to ease the large-scale implementation of flight-data analyses at both the air-carrier and the national-airspace levels in support of their Flight Operations and Quality Assurance (FOQA) Programs and Advanced Qualifications Programs (AQP). APMS cannot meet its objectives unless it develops tools that go substantially beyond the capabilities of the current commercially available software and supporting analytic methods that are mainly designed to count special events. These existing capabilities, while of proven value, were created primarily with the needs of air crews in mind. APMS tools must serve the needs of the government and air carriers, as well as air crews, to fully support the FOQA and AQP programs. They must be able to derive knowledge not only through the analysis of single flights (special-event detection), but through statistical evaluation of the performance of large groups of flights. This paper describes the integrated suite of tools that will assist analysts in evaluating the operational performance and safety of the national air transport system, the air carrier, and the air crew.

Statler, Irving C.↗
NASA NTRS1997

APMS: An Integrated Suite of Tools for Measuring Performance and Safety

This is a report of work in progress. In it, I summarize the status of the research and development of the Aviation Performance Measuring System (APMS) for managing, processing, and analyzing digital flight-recorded data. The objectives of the NASA-FAA APMS research project are to establish a sound scientific and technological basis for flight-data analysis, to define an open and flexible architecture for flight-data-analysis systems, and to articulate guidelines for a standardized database structure on which to continue to build future flight-data-analysis extensions. APMS will offer to the air transport community an open, voluntary standard for flight-data-analysis software, a standard that will help to ensure suitable functionality, and data interchangeability, among competing software programs. APMS will develop and document the methodologies, algorithms, and procedures for data management and analyses to enable users to easily interpret the implications regarding safety and efficiency of operations. APMS does not entail the implementation of a nationwide flight-data-collection system. It is intended to provide technical tools to ease the large-scale implementation of flight-data analyses at both the air-carrier and the national-airspace levels in support of their Flight Operations and Quality Assurance (FOQA) Programs and Advanced Qualifications Programs (AQP). APMS cannot meet its objectives unless it develops tools that go substantially beyond the capabilities of the current commercially available software and supporting analytic methods that are mainly designed to count special events. These existing capabilities, while of proven value, were created primarily with the needs of air crews in mind. APMS tools must serve the needs of the government and air carriers, as well as air crews, to fully support the FOQA and AQP programs. They must be able to derive knowledge not only through the analysis of single flights (special-event detection), but through statistical evaluation of the performance of large groups of flights. This paper describes the integrated suite of tools that will assist analysts in evaluating the operational performance and safety of the national air transport system, the air carrier, and the air crew.

Statler, Irving C.↗
NASA NTRS1987

Performance measurements of a diode laser optical communications link with Q = 4 PPM signaling

The theoretical and measured performance characteristics of a direct detection optical communication system are reported. The system consisted of a semiconductor diode laser, silicon avalanche photodiode detector, and used Q = 4 optical pulse position modulation signaling to transmit binary source data at a rate of 25 megabits/sec. Operation at a receiver bit error probability of 10 to the -6th was demonstrated at received signal energies corresponding to an average of 160 detected photons per PPM symbol, or 80 photons per source bit.

Sun, X.↗
NASA NTRS1992

Performance measurement for information systems: Industry perspectives

Performance measurement has become a focal topic for information systems (IS) organizations. Historically, IS performance measures have dealt with the efficiency of the data processing function. Today, the function of most IS organizations goes beyond simple data processing. To understand how IS organizations have developed meaningful performance measures that reflect their objectives and activities, industry perspectives on IS performance measurement was studied. The objectives of the study were to understand the state of the practice in IS performance techniques for IS performance measurement; to gather approaches and measures of actual performance measures used in industry; and to report patterns, trends, and lessons learned about performance measurement to NASA/JSC. Examples of how some of the most forward looking companies are shaping their IS processes through measurement is provided. Thoughts on the presence of a life-cycle to performance measures development and a suggested taxonomy for performance measurements are included in the appendices.

Bishop, Peter C.↗
NASA NTRS1994

Performance measurement: A tool for program control

Performance measurement is a management tool for planning, monitoring, and controlling as aspects of program and project management--cost, schedule, and technical requirements. It is a means (concept and approach) to a desired end (effective program planning and control). To reach the desired end, however, performance measurement must be applied and used appropriately, with full knowledge and recognition of its power and of its limitations--what it can and cannot do for the project manager. What is the potential of this management tool? What does performance measurement do that a traditional plan vs. actual technique cannot do? Performance measurement provides an improvement over the customary comparison of how much money was spent (actual cost) vs. how much was planned to be spent based on a schedule of activities (work planned). This commonly used plan vs. actual comparison does not allow one to know from the numerical data if the actual cost incurred was for work intended to be done.

Abell, Nancy↗
NASA NTRS1984

Performance Measures for Aircraft Landings as a Function of Aircraft Dynamics

A theory of performance measurement for operator controlled systems is presented. The theory permits synthesis of a system performance measure which scores performance on successive data samples based on the impact of the sampled performance on the overall summary of performance. The development of measures for aircraft carrier landings for the glide path and angle of attack control channels is documented. While developing the performance measures, the measures used previously were evaluated and were found to lack the necessary discrimination capability. The previously used measure, the RMS of deviations from the glide path, can, for instance, provide identical scores for both satisfactory and unsatisfactory flight paths. Two types of performance measures developed for aircraft landings are described. Also, an argument is given for the need to test performance measures prior to their use. A suggested test of the measures is offered.

Connelly, E. M.↗
NASA NTRS1982

Performance measures for multiprocessor controllers

Performance measures to characterize fault tolerant multiprocessors used in the control of critical processes are considered. Our performance indices are based on controller response time. By relating this to the needs of the application, we have been able to derive indices that faithfully reflect the performance of the multiprocessor in the context of the application, that permit the objective comparison of rival computer systems, and that can either be definitively estimated or objectively measured. An example of a controller in an idealized satellite application is provided.

Krishna, C. M.↗
NASA NTRS2004

APMS 3.0 Flight Analyst Guide: Aviation Performance Measuring System

The Aviation Performance Measuring System (APMS) is a method-embodied in software-that uses mathematical algorithms and related procedures to analyze digital flight data extracted from aircraft flight data recorders. APMS consists of an integrated set of tools used to perform two primary functions: a) Flight Data Importation b) Flight Data Analysis.

Jay, Griff↗
NASA NTRS1972

A performance measure for manual control systems

A new performance measure is introduced for multivariable closed loop experiments with a human operator. The essential feature of the phase margin performance measure (PMPM) is that the performance of each control loop can be determined independently, with prescribed disturbance and error levels. A variable filter parameter is used as the PMPM within the loop and it assures a high workload at the same time. There is a straightforward relationship between the PMPM and the inner loop feedback augmentation that can be utilized in trade-off studies. An adjustment scheme that seeks the PMPM automatically is described as employed in a single loop control task. This task applies directly to the experimental study of displays for helicopters and VTOL aircraft.

Dukes, T. A.↗
NASA NTRS2011

Using Technical Performance Measures

All programs have requirements. For these requirements to be met, there must be a means of measurement. A Technical Performance Measure (TPM) is defined to produce a measured quantity that can be compared to the requirement. In practice, the TPM is often expressed as a maximum or minimum and a goal. Example TPMs for a rocket program are: vacuum or sea level specific impulse (lsp), weight, reliability (often expressed as a failure rate), schedule, operability (turn-around time), design and development cost, production cost, and operating cost. Program status is evaluated by comparing the TPMs against specified values of the requirements. During the program many design decisions are made and most of them affect some or all of the TPMs. Often, the same design decision changes some TPMs favorably while affecting other TPMs unfavorably. The problem then becomes how to compare the effects of a design decision on different TPMs. How much failure rate is one second of specific impulse worth? How many days of schedule is one pound of weight worth? In other words, how to compare dissimilar quantities in order to trade and manage the TPMs to meet all requirements. One method that has been used successfully and has a mathematical basis is Utility Analysis. Utility Analysis enables quantitative comparison among dissimilar attributes. It uses a mathematical model that maps decision maker preferences over the tradeable range of each attribute. It is capable of modeling both independent and dependent attributes. Utility Analysis is well supported in the literature on Decision Theory. It has been used at Pratt & Whitney Rocketdyne for internal programs and for contracted work such as the J-2X rocket engine program. This paper describes the construction of TPMs and describes Utility Analysis. It then discusses the use of TPMs in design trades and to manage margin during a program using Utility Analysis.

Garrett, Christopher J.↗
NASA NTRS2010

Spaceport Performance Measures

Spaceports have traditionally been characterized by performance measures associated with their site characteristics. Measures such as "Latitude" (proximity to the equator), "Azimuth" (range of available launch azimuths) and "Weather" (days of favorable weather) are commonly used to characterize a particular spaceport. However, other spaceport performance measures may now be of greater value. These measures can provide insight into areas of operational differences between competing spaceports and identify areas for improving the performance of spaceports. This paper suggests Figures of Merit (FOMs) for spaceport "Capacity" (number of potential launch opportunities per year and / or potential mass' to low earth orbit (LEO) per year); "Throughput" (actual mass to orbit per year compared to capacity); "Productivity" (labor effort hours per unit mass to orbit); "Energy Efficiency" (joules expended at spaceport per unit mass to orbit); "Carbon Footprint" tons CO2 per unit mass to orbit). Additional FOMS are investigated with regards to those areas of special interest to commercial launch operators, such as "Assignment Schedule" (days required for a binding assignment of a launch site from the spaceport); "Approval Schedule" (days to complete a range safety assessment leading to an approval or disapproval of a launch vehicle); "Affordability" (cost for a spaceport to assess a new launch vehicle); "Launch Affordability" (fixed range costs per launch); "Reconfigure Time" (hours to reconfigure the range from one vehicle's launch ready configuration to another vehicle's configuration); "Turn,Around Time" (minimum range hours required between launches of an identical type launch vehicle). Available or notional data is analyzed for the KSC/CCAFS area and other spaceports. Observations regarding progress over the past few decades are made. Areas where improvement are needed or indicated are suggested.

Finger, G. Wayne↗
NASA NTRS1970

Human performance measuring device

Complex coordinator, consisting of operator control console, recorder, subject display panel, and limb controls, measures human performance by testing perceptual and motor skills. Device measures psychophysiological functions in drug and environmental studies, and is applicable to early detection of psychophysiological body changes.

Michael, J.↗
NASA NTRS1985

A performance measurement system for engineering services

A performance measurement system which provides both a means of monitoring performance and a resource to support management decision making is described. The process of performance indicator development is discussed and typical indicators are described. The paper concludes with a summary of some of the lessons learned in applying productivity measurements to engineering services tasks and in automating data collection, evaluation and interpretation.

West, R. L.↗
NASA NTRS2009

Gallium Electromagnetic (GEM) Thruster Performance Measurements

Discharge current, terminal voltage, and mass bit measurements are performed on a coaxial gallium electromagnetic thruster at discharge currents in the range of 7-23 kA. It is found that the mass bit varies quadratically with the discharge current which yields a constant exhaust velocity of 20 km/s. Increasing the electrode radius ratio of the thruster from to 2.6 to 3.4 increases the thruster efficiency from 21% to 30%. When operating with a central gallium anode, macroparticles are ejected at all energy levels tested. A central gallium cathode ejects macroparticles when the current density exceeds 3.7 10(exp 8) A/square m . A spatially and temporally broad spectroscopic survey in the 220-520 nm range is used to determine which species are present in the plasma. The spectra show that neutral, singly, and doubly ionized gallium species are present in the discharge, as well as annular electrode species at higher energy levels. Axial Langmuir triple probe measurements yield electron temperatures in the range of 0.8-3.8 eV and electron densities in the range of 8 x 10(exp )20 to 1.6 x 10(exp 21) m(exp -3) . Triple probe measurements suggest an exhaust plume with a divergence angle of 9 , and a completely doubly ionized plasma at the ablating thruster cathode.

Thomas, Robert E.↗