GRA Incorporated

Jenkintown, PA, United States

GRA Incorporated

Jenkintown, PA, United States

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Gawdiak Y.,NASA | Stouffer V.,Logistics Management Institute LMI | Creedon J.,Old Dominion University | Holmes B.,NextGen | And 3 more authors.
AIAA AVIATION 2014 -14th AIAA Aviation Technology, Integration, and Operations Conference | Year: 2014

This paper describes the analysis trajectory of the NextGen8 portfolio tradespace explorations from 2009 to 2013. We document how the discoveries in that process has driven the needs for new analytical requirements based on evolving social, environmental, and economic dynamics and how those challenges now require a wider solution scope to the traditional aviation tradespace. We document how the core principles of NASA's aeronautics goals are affected given these emergent requirements and why we believe new modeling approaches and simulations will help illuminate new possible policy and technology investment strategies.


Ota T.,Japan National Food Research Institute | Iwasaki Y.,Japan National Food Research Institute | Yamane H.,GRA Inc. | Sugeno W.,GRA Inc. | And 3 more authors.
Engineering in Agriculture, Environment and Food | Year: 2015

We developed a prototypic automatic spacing-controlled movable bench system for high-density planting of tomato third-truss pinching cultivation. The bench spacing can be changed to 600, 1000, or 1400 mm according to the growth stage. Cultivation experiments using a manufactured experimental model of the movable bench system gave yields of 9.7-12.4 kg/m2 over 4 months' cultivation without the need for a secondary nursery system. The yield of the experimental model was higher than that of conventional cultivation systems or other cultivation systems developed for tomato low-node cultivation. Bench spacing was controlled automatically by motors and a programmable logic controller. Multiple benches could be moved together automatically to clear a work path or change use modes; manual operation took much more time. During movement on the system's rails, acceleration in the vertical direction, the direction of travel, and the longitudinal direction was less than 1.0 m/s2. © 2015 Asian Agricultural and Biological Engineering Association.


Golaszewski R.,GRA Incorporated | Sheth K.,NASA | Helledy G.,GRA Incorporated | Gutierrez-Nolasco S.,University of California at Santa Cruz
12th AIAA Aviation Technology, Integration and Operations (ATIO) Conference and 14th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference | Year: 2012

Prior research has suggested that the allocation of scarce National Airspace System capacity could be improved if aircraft operators were able to exchange the priority in which their flights will be handled by the air traffic control system to reflect how much they value timeliness for specific aircraft flights. The current priority allocation system is based on a first-come first-served mechanism. FAA and users have made some modifications to first-come first-served to give operators more control over the priority in which their own flights get served through Collaborative Decision-Making. There are also programs which allow a carrier to give up a flight time slot that it will not use without having to go to the "end of the line," which is called slot credit substitution. Significant research has been done into ways to further improve demand-capacity balance in the National Airspace System while taking users' flight priorities into account. Many researchers have proposed market-based allocation systems, which are used when airport slots are bought and sold. Other researchers propose quasi-market systems that could be developed using a points system. This paper illustrates how the initial allocation of priority points among carriers influences how they use these points in establishing the priority for their flights to reduce their delays. The paper then reports the results from the human-in-the-loop simulation of aircraft operators' decisions that show how the delay reduction differences for each operator vary among the different methods used to allocate the points. In general, the paper finds that a system which uses the number of flights in the allocation tends to benefit operators of smaller aircraft, while systems that use passengers and distance in the allocation favor operators of larger aircraft. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.


Golaszewski R.,GRA Incorporated | David Ballard B.,GRA Incorporated
11th AIAA Aviation Technology, Integration,and Operations (ATIO) Conference, including the AIAA Balloon Systems Conference and 19th AIAA Lighter-Than-Air Technology Conference | Year: 2011

The JPDO, FAA and others use metrics to track the progress of NextGen and to evaluate implementation alternatives. However, to track NextGen deployment it is also necessary to understand the financial flows among the many parties that have to make NextGen investments. In some cases, a stakeholder's business case is related to a specific metric. In other cases, a top-level metric will show that overall stakeholder benefits exceed stakeholder costs, the underlying business case decisions are driven by how funds flow among parties. When individual stakeholders cannot capture investment impacts as increased revenues or decreased costs, the stakeholder business case is not made and there is no reason to expect that party to invest on its own. This paper highlights how flows of funds among stakeholders occur and how these flows affect incentives to invest. It also suggests that if overall benefits to society exceed overall costs but are distributed in ways such that individual stakeholders lack the incentives to invest, other policies such as subsidies or regulatory standards may be needed. © 2011 by the American Institute of Aeronautics and Astronautics, Inc.


Gunnam A.K.,GRA Incorporated | Trani A.A.,Virginia Polytechnic Institute and State University | Li T.,Virginia Polytechnic Institute and State University | Graham T.C.,U.S. Federal Aviation Administration | Campos N.V.,U.S. Federal Aviation Administration
AIAA AVIATION 2014 -14th AIAA Aviation Technology, Integration, and Operations Conference | Year: 2014

This paper gives a description of a computer simulation model called North Atlantic Simulation and Modelling developed by Virginia Tech's Air Transportation Systems Laboratory. The model is capable of investigating the effects of implementing different operational policies and strategies in oceanic airspace such as Reduced Lateral Separation Minima, North Atlantic Region Data link mandate, Reduced Longitudinal Separation Minima, cruise-climb profiles, variable Mach number profiles, step-climbs and other operational concepts. This paper describes the methodology, various components of the model and validation results. The effects on aircraft fuel consumption due of ICAO's North Atlantic data link mandate and reduced lateral separation minima, which are being implemented in the North Atlantic airspace are also discussed.


Ballard D.,GRA Inc | Gawdiak Y.,Mission Research
2013 Aviation Technology, Integration, and Operations Conference | Year: 2013

The demand for transportation is primarily an expression of a desire to interact directly with some other person or with some other aspect of the world. That is, any demand for transportation - which is costly in both resources and time - derives from an underlying demand for some direct experience or communication that the travel facilitates. Because of this, any technology that can also enable some fashion of interaction or communication for an individual can serve as a substitute for actual travel and the physical proximity that travel makes possible. Humans (and other species) have devised means of communication at a distance that permit information to be sent and received from others, although these means may be more coarse and less nuanced tools for communications than is direct interaction at a common location. In the past century, rapid developments in electronic and digital communications tools have allowed transmission of increasingly complex messages that verge closer and closer to actual physical presence. We term the (as yet unattained) culmination of these developments telepresence, noting that this term is already in use by some business firms for proprietary forms of high fidelity video-conferencing services. In this paper we examine these recent and imminent developments in digital and virtual interactions and communications. They are enabling levels of verisimilitude, complexity and capability that rival and substitute for actual personal interaction. We examine the trends and possibilities that characterize the future development of telepresence, and outline how telepresence can interact with modes of physical travel. We then consider some potential economic and societal impacts of telepresence by examining demographic, economic and environmental consequences of increased use of telecommuting and at home work that replaces some of the physical costs of the nation's workplaces. We discuss the integration of these telepresence capabilities into two broad economic and demographic models currently being used to examine socio-economic scenarios and assess their consequences for transportation investment requirements. We conclude with a consideration of next steps for better understanding the ways in which telepresence capabilities can contribute to national goals and federal investment requirements.


Chow A.,GRA Incorporated | Gulding J.,U.S. Federal Aviation Administration
2013 Aviation Technology, Integration, and Operations Conference | Year: 2013

Performance as measured by the standard Key Performance Indicators (KPIs) of delay, flight efficiency, on-time punctuality and predictability are directly influenced by the capacity available in the system. Capacity is increased with new technology and airport infrastructure. However, capacity also varies due to other short-term events such as weather or airport maintenance. These interdependencies complicate performance analysis by masking other effects such as changes in demand or longer term investment that improves the operation of the National Airspace System (NAS). An automated means of determining causal reasons for capacity variation is difficult and labor intensive as the causes may be site specific, due to weather events difficult to extract from traditional sources, or not recorded in a database that lends itself to automation. Simulation modeling and performance analysis that rely on ceiling and visibility will often under predict the effects of weather on capacity variation. Therefore, understanding other causal factors is a key step in determining inefficiencies that are actionable by Air Navigation Service Providers (ANSP) and aviation investment programs. This paper examines performance at airports determined to be most sensitive to capacity variation and determines which causal factors can be best automated by weather, demand and performance databases in use today. A set of weather rules are provided that show an improved correlation between METAR provided weather condition and Air Traffic Control (ATC) called rates than what is obtained using the more basic rules of ceiling and visibility. The paper concludes by estimating the improvements to NAS-wide simulation and performance modeling that could be realized by utilizing more detailed causal relationships of weather and capacity.


Hotle S.,GRA Incorporated | Baszczewski B.,U.S. Federal Aviation Administration | Gulding J.,U.S. Federal Aviation Administration
16th AIAA Aviation Technology, Integration, and Operations Conference | Year: 2016

Surface performance indicators for taxi-out delay depend on reference ideal unimpeded (nominal) times to identify areas in need of improvement. Current FAA practice derives unimpeded taxi-out times through a statistical analysis of ASPM-provided Out-Off-On-In (OOOI) sensor timestamps. This statistical technique uses a regression of taxi-times against the number of aircraft active on the surface to determine times of low congestion and presumably under conditions when times would be “unimpeded.” These OOOI timestamps are rounded to the nearest minute and reported by a subset of carriers, leading to data concerns. Furthermore, the current unimpeded taxi-out method is only based on departure airport, operating carrier, season, and calendar year, which fails to include both start taxi-out location (gate/terminal) and wheels-off location (runway). Given these shortcomings, opportunities exist to estimate surface performance indicators through the use of surveillance data. Surveillance systems, such as the Airport Surface Detection Equipment-Model X (ASDE-X) system, provide aircraft temporal and spatial information by the second, enabling terminal area and runway information to be incorporated. The purpose of this paper is to utilize these new capabilities when identifying taxi-out routings that contribute the most to delay and inefficiency. The paper first assesses the current statistically derived unimpeded time against alternatives based on upper percentile benchmark methods. It then evaluates alternatives to current methodology by developing both an ASDE-X and hybrid ASDE-X/ASPM Key Surface Event Database. Techniques using the ASPM, ASDE-X, and hybrid surface databases are compared for five top U.S. airports during Fiscal Year 2014. Results show that ASDE-X provides better and more consistent data coverage when compared to the current ASPM process. An ASDE-X source also allows the taxi-start location to be identified, unlike ASPM. However, given existing data limitations, it is recommended that ASDE-X be supplemented with ASPM messages in order for an analysis to capture a more complete understanding of surface performance, specifically in the masked, non-movement area. © 2016 American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.


Litvinas B.,GRA Incorporated | Dickerson N.,Booz Allen Hamilton
2013 Aviation Technology, Integration, and Operations Conference | Year: 2013

The Interagency Portfolio and Systems Analysis (IPSA) Division of the Joint Planning and Development Office (JPDO) supported by the National Aeronautics & Space Agency Aeronautics Research Mission Directorate is responsible for supporting the partnerships necessary to implement the Next Generation Air Traffic System (NextGen). Consequently, the IPSA examines potential new technologies that will exist in the National Airspace System (NAS), and evaluates their economic and technological efficiency and practicality in the context of NextGen. As mandated by Congress, the eventual introduction of unmanned aircraft systems (UAS) into the NAS presents a unique opportunity for the civilian aviation industry. Leveraging emerging technologies and new policies set by the Federal Aviation Administration (FAA), future civilian UAS operators will have the opportunity to create significant value through new business models and operating methods. It is important for policymakers to understand the potential scale and source of value creation so that they can create appropriate rules to accommodate UAS while still meeting the needs of other, existing aviation stakeholders. Using a simple discounted cash flow model, this paper attempts to estimate the level of value creation for three different UAS applications.


Li T.,GRA Incorporated | Trani A.A.,Virginia Polytechnic Institute and State University
ICNS 2016: Securing an Integrated CNS System to Meet Future Challenges | Year: 2016

This study is to develop a procedure to estimate the market share of itinerant GA operations (MSIGO) by aircraft type at an airport. The procedure can be used, for example, by the Federal Aviation Administration (FAA) and airport planners to make projections of itinerant operations by aircraft type for airport planning and improvements. Our procedure consists of two sub-procedures. The first one is a national level logistic model which separates the MSIGO by three fixed-wing aircraft types (i.e., piston, turboprop, and turbofan) from the other aircraft types. The second sub-procedure includes an airport-level logistic model and a national level estimation model. The airport-level logistic model is to estimate the MSIGO by each of the three fixed-wing aircraft types under IFR flight plan. The national level estimation model is designed to estimate the MSIGO by aircraft type under all flight rules. We validated our procedure using the statistics reported in the Air Traffic Activity System. In addition, we applied our procedure to the projections of itinerant GA operations made by the FAA in the Terminal Area Forecasting. Based on our results for the towered airports, between 2013 and 2018, the number of itinerant operations by piston and turboprop would decline at about 0.2% per year, and the number of itinerant operations by turbofan and the other aircraft types would increase at 0.75% and 1.33% per year, respectively. © 2016 IEEE.

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