The top 10 R&T Challenges for each R&T Area are listed in Table 5-1.1 The quantitative scores for the Challenges are relative scores that are valid in an ordinal sense within each R&T Area. They represent the results of linked, but separate, comparative analyses within each R&T Area and therefore should not be used to make absolute comparisons of the relative priority of various Challenges from different R&T Areas.
The QFD rankings in Table 5-1 should be taken as a guide rather than a prescription. Many of the R&T Challenges are considerably dissimilar in scope and content. In some cases, progress will require success in overcoming multiple linked Challenges. Other Challenges stand on their own. All of the R&T Challenges are considered worthy of NASA attention. In addition, many of the high-priority R&T Challenges have uses in fields other than civil aeronautics and are applicable to the missions of other federal agencies—DoD, DHS, and FAA, among others. Cooperative research between NASA and other agencies could therefore produce substantial national benefits.
The steering committee believes that the highest-priority R&T Challenges in each R&T Area should be included in the “foundation for the future” that forms the core of NASA’s aeronautics program. The steering committee made no specific budgetary recommendations, in accordance with the statement of task for this study.
Success will require stable funding and consistent research priorities and planning, with the intent to pursue identified challenges for a decade or longer, as long as satisfactory progress continues. For NASA to exert strong leadership in key cutting-edge aeronautics R&T, it should focus on state-of-the-art research. Research plans should not be openended, however. An acceptable level of feasibility needs to be demonstrated (see suggested milestones in Appendixes A-E), and it is critical to have a process to stop or redirect efforts that fail to progress.
In Chapter 4 the steering committee identified threads of commonality among the R&T Thrusts and the R&T Challenges from different R&T Areas. These threads have been captured as five Common Themes:
Physics-based analysis tools
Multidisciplinary design tools
Intelligent and adaptive systems
Complex interactive systems
Each Theme encompasses enabling approaches that will contribute to multiple R&T Challenges.
Exploiting the synergies identified in each Common Theme would enable NASA’s aeronautics program to make the most efficient use of available resources.
The steering committee identified two key barriers in Chapter 4: certification and change management. If these barriers are not addressed, the Strategic Objectives will not be accomplished, even if individual R&T Challenges are successfully overcome.
As systems become more complex, methods to ensure that new technologies can be readily applied to FAA-certified systems become more difficult to validate. NASA
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Decadal Survey of Civil Aeronautics: Foundation for the Future 5 Findings and Recommendations PRINCIPAL FINDINGS R&T Challenges The top 10 R&T Challenges for each R&T Area are listed in Table 5-1.1 The quantitative scores for the Challenges are relative scores that are valid in an ordinal sense within each R&T Area. They represent the results of linked, but separate, comparative analyses within each R&T Area and therefore should not be used to make absolute comparisons of the relative priority of various Challenges from different R&T Areas. The QFD rankings in Table 5-1 should be taken as a guide rather than a prescription. Many of the R&T Challenges are considerably dissimilar in scope and content. In some cases, progress will require success in overcoming multiple linked Challenges. Other Challenges stand on their own. All of the R&T Challenges are considered worthy of NASA attention. In addition, many of the high-priority R&T Challenges have uses in fields other than civil aeronautics and are applicable to the missions of other federal agencies—DoD, DHS, and FAA, among others. Cooperative research between NASA and other agencies could therefore produce substantial national benefits. The steering committee believes that the highest-priority R&T Challenges in each R&T Area should be included in the “foundation for the future” that forms the core of NASA’s aeronautics program. The steering committee made no specific budgetary recommendations, in accordance with the statement of task for this study. Success will require stable funding and consistent research priorities and planning, with the intent to pursue identified challenges for a decade or longer, as long as satisfactory progress continues. For NASA to exert strong leadership in key cutting-edge aeronautics R&T, it should focus on state-of-the-art research. Research plans should not be openended, however. An acceptable level of feasibility needs to be demonstrated (see suggested milestones in Appendixes A-E), and it is critical to have a process to stop or redirect efforts that fail to progress. Common Themes In Chapter 4 the steering committee identified threads of commonality among the R&T Thrusts and the R&T Challenges from different R&T Areas. These threads have been captured as five Common Themes: Physics-based analysis tools Multidisciplinary design tools Advanced configurations Intelligent and adaptive systems Complex interactive systems Each Theme encompasses enabling approaches that will contribute to multiple R&T Challenges. Exploiting the synergies identified in each Common Theme would enable NASA’s aeronautics program to make the most efficient use of available resources. Key Barriers The steering committee identified two key barriers in Chapter 4: certification and change management. If these barriers are not addressed, the Strategic Objectives will not be accomplished, even if individual R&T Challenges are successfully overcome. As systems become more complex, methods to ensure that new technologies can be readily applied to FAA-certified systems become more difficult to validate. NASA 1 The top 11 R&T Challenges are listed for Area A because the NASA priority scores for Challenges A10 and A11 are very close, and there is a large gap between the scores for Challenges A11 and A12.
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Decadal Survey of Civil Aeronautics: Foundation for the Future TABLE 5-1 Fifty-one Highest Priority Research and Technology Challenges for NASA Aeronautics, Prioritized by R&T Area A Aerodynamics and Aeroacoustics B Propulsion and Power C Materials and Structures D Dynamics, Navigation, and Control, and Avionics E Intelligent and Autonomous Systems, Operations and Decision Making, Human Integrated Systems, Networking and Communications A1 Integrated system performance through novel propulsion–airframe integration A2 Aerodynamic performance improvement through transition, boundary layer, and separation control A3 Novel aerodynamic configurations that enable high performance and/or flexible multi-mission aircraft A4a Aerodynamic designs and flow control schemes to reduce aircraft and rotor noise A4b Accuracy of prediction of aerodynamic performance of complex 3-D configurations, including improved boundary layer transition and turbulence models and associated design tools A6 Aerodynamics robust to atmospheric disturbances and adverse weather conditions, including icing A7a Aerodynamic configurations to leverage advantages of formation flying A7b Accuracy of wake vortex prediction, and vortex detection and mitigation techniques A9 Aerodynamic performance for V/STOL and ESTOL, including adequate control power A10 Techniques for reducing/mitigating sonic boom through novel aircraft shaping A11 Robust and efficient multidisciplinary design tools B1a Quiet propulsion systems B1b Ultraclean gas turbine combustors to reduce gaseous and particulate emissions in all flight segments B3 Intelligent engines and mechanical power systems capable of self-diagnosis and reconfiguration between shop visits B4 Improved propulsion system fuel economy B5 Propulsion systems for short takeoff and vertical lift B6a Variable-cycle engines to expand the operating envelope B6b Integrated power and thermal management systems B8 Propulsion systems for supersonic flight B9 High-reliability, high-performance, and high-power-density aircraft electric power systems B10 Combined-cycle hypersonic propulsion systems with mode transition C1 Integrated vehicle health management C2 Adaptive materials and morphing structures C3 Multidisciplinary analysis, design, and optimization C4 Next-generation polymers and composites C5 Noise prediction and suppression C6a Innovative high-temperature metals and environmental coatings C6b Innovative load suppression, and vibration and aeromechanical stability control C8 Structural innovations for high-speed rotorcraft C9 High-temperature ceramics and coatings C10 Multifunctional materials D1 Advanced guidance systems D2 Distributed decision making, decision making under uncertainty, and flight-path planning and prediction D3 Aerodynamics and vehicle dynamics via closed-loop flow control D4 Intelligent and adaptive flight control techniques D5 Fault-tolerant and integrated vehicle health management systems D6 Improved onboard weather systems and tools D7 Advanced communication, navigation, and surveillance technology D8 Human–machine integration D9 Synthetic and enhanced vision systems D10 Safe operation of unmanned air vehicles in the national airspace E1 Methodologies, tools, and simulation and modeling capabilities to design and evaluate complex interactive systems E2 New concepts and methods of separating, spacing, and sequencing aircraft E3 Appropriate roles of humans and automated systems for separation assurance, including the feasibility and merits of highly automated separation assurance systems E4 Affordable new sensors, system technologies, and procedures to improve the prediction and measurement of wake turbulence E5 Interfaces that ensure effective information sharing and coordination among ground-based and airborne human and machine agents E6 Vulnerability analysis as an integral element in the architecture design and simulations of the air transportation system E7 Adaptive ATMtechniques to minimize the impact of weather by taking better advantage of improved probabilistic forecasts E8a Transparent and collaborative decision support systems E8b Using operational and maintenance data to assess leading indicators of safety E8c Interfaces and procedures that support human operators in effective task and attention management
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Decadal Survey of Civil Aeronautics: Foundation for the Future should anticipate the need to certify new technology before its introduction, and it should conduct research on methods to improve the confidence in and the timeliness of certification. Methods might include new approaches (e.g., “design for certification”). If the civil aeronautics R&T program does not address this certification barrier, manufacturers and users will not be able to effectively exploit new technology in operations. As discussed in Chapter 4, changing a complex interactive system such as the air transportation system is becoming more difficult due to the growing complexity of interactions between the various elements and the growing number of internal and external constraints. To effectively exploit the benefits of R&T to meet the Strategic Objectives, new tools and techniques are required to anticipate and introduce change. Without research to better define and develop change management tools and techniques, the inability to introduce change in a timely manner will serve as a barrier to exploiting the benefits offered by meeting the R&T Challenges. OTHER FINDINGS OF IMPORTANCE Allocation of Resources and Workforce Issues NASA’s aeronautics program is likely to operate in an environment of constrained resources for the foreseeable future. Nonetheless, the committee believes that NASA must meet its commitment to the nation as the leader of cutting-edge aeronautics research. This requires NASA to carry out, at a minimum, the following missions: Perform cutting-edge, high-value aeronautics research in support of the nation’s future industrial and government aeronautics needs. Maintain in-house technical expertise to advise other parts of the U.S. government, including the FAA, the Environmental Protection Agency, and DoD, on relevant aeronautics issues. Maintain state-of-the-art research, testing, computational, and analytical capabilities in support of the U.S. civil aviation community, including industry, academia, and the general public. Facilitate the exchange of information on civil aeronautics R&T among academia, industry, U.S. government agencies, and the international regulatory community. Provide aeronautics expertise and capabilities in support of NASA’s space program. For NASA to complete these missions in a constrained fiscal environment, the committee believes that NASA must consider the criteria listed below when considering whether to perform the work in-house by NASA engineers and technical specialists or externally by industry and/or universities: Specialized technical expertise of in-house and external organizations. Specialized facilities and capabilities, such as wind tunnels, simulators, laboratories, and analytical methods, that are available in-house and at external organizations. The requirement for NASA to have the expertise and experience necessary to be an informed buyer of aero-nautics R&T. The requirement for NASA to provide independent technical advice to other federal agencies on aeronautics issues. As of January 2006, NASA seemed intent on allocating 93 percent of NASA’s aeronautics research funding for in-house use.2 While the committee has no specific recommendation on the in-house/external split, it does not believe that such a split would serve the best interests of NASA or the nation. NASA R&T would likely suffer from the absence of relevant, specialized technical expertise, facilities, and capabilities (the first two criteria, above) without procuring expertise and capabilities from academia and, to a lesser degree, industry. Also, NASA would likely be limited in its ability to provide technology that supports the nation’s future industrial aeronautics needs (Mission 1, above) without greater inclusion of industry. Furthermore, an insular approach to R&T would not leverage the creativity and multiplicative ideas that a more inclusive approach would likely produce. Technology transfer among government, universities, and industry would be more effective if all three groups have significant roles in NASA’s research programs. NASA researchers in some cases possess world-class technical expertise, and this expertise should be maintained. Furthermore, some level of technical expertise in a wide range of subjects is required for NASA to meet its obligations for conducting cutting-edge research, advising the government, and facilitating outside collaboration (Missions 1, 2, and 4, above). However, NASA should consider the capabilities of other research organizations before deciding whether to outsource R&T related to cutting-edge research, state-of-the-art capabilities, and the space program (Missions 1, 3, and 5, above). A more balanced allocation of aeronautics R&T funding would allow NASA to form stronger partnerships with academia and industry. Stable funding of academic research grants, graduate student fellowships, student internships, and 2 NASA’s Aeronautics Research Mission Directorate has established four levels of research. NASA plans to allocate 7 percent of the total aeronautics budget to university and small company research at Level 1 (foundational research) (Wlezien, 2006b). Research at Level 2 (develop discipline-specific technologies and tools) and Level 3 (develop integrated, multidisciplinary methods and technologies) will be performed in-house by NASA. Research at Level 4 (develop integrated solutions for airspace and airport systems) will include collaboration with industry and partnerships with other agencies, but participating companies will be expected to pay their own way (NASA, 2006; Wlezien, 2006a).
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Decadal Survey of Civil Aeronautics: Foundation for the Future cooperative NASA-university research centers would expand the intellectual pool contributing to NASA R&T, improve the skills of the nation’s future aeronautics workforce, recruit new talent into the NASA workforce, and foster R&T projects that could not be done by NASA working alone. NASA should strive to foster close collaborative research with university partners, continuing a tradition of supporting basic research and new research directions in the academic environment. Stronger partnerships with industry would help (1) identify technologically important problems, the answers to which can benefit the nation, (2) advance important precompetitive R&T that would not otherwise be done, (3) leverage industry research funded by other agencies or industry itself, (4) ensure that the results of NASA aeronautics research take into account relevant standards and practices, and (5) facilitate the transfer of research results to industry so that they find valuable, real-world applications. Ideally, programs that involve university, industry, and NASA researchers would lead to long-term benefits to NASA and the nation. A more inclusive approach to NASA’s research would also increase the return on the government’s investment in aeronautics R&T. Taking Advantage of Advances in Cross-Cutting Technology Funded by Others Most of the federal government’s civil aeronautics research is done by NASA, but operational products are developed by manufacturers and operated by industry or the FAA. The FAA and industry also have the lead when it comes to certification issues. Within the federal government, no agency is responsible for all of the federal government’s aeronautics research, nor is one agency focused exclusively on aeronautics research. This organizational structure mandates close cooperation and coordination between NASA’s civil aeronautics R&T program and other federal agencies that support related research. DoD conducts research on and development of many technologies important to national defense. At a fundamental technology level, much of the work sponsored by DoD is synergistic with NASA’s civil aeronautics R&T, especially in transition modeling, reacting-flow physics, multiphase flows, novel aerodynamic configurations, morphing aerodynamic surfaces, adaptive cycle engines, high-speed and high-performance propulsion systems, integrated power systems, network-centric operations, control systems, UAVs, rotorcraft, impact dynamics, high-temperature and multifunctional materials and structures, low-cost materials and manufacturing, sensors, and multidisciplinary optimization. Interactions with and coordination of research conducted by the FAA should be pursued in areas such as ATM and the measurement and modeling of aircraft wakes and weather phenomena. The large-scale weather models developed by the National Oceanic and Atmospheric Administration (NOAA) and the National Center for Atmospheric Research (NCAR) should be coordinated with the local terminal weather models important for prediction of wake vortex trajectories. Where synergistic research is being conducted, structured interactions and collaborations should be pursued. Software-intensive systems are being developed in many industries. Applications relevant to civil aviation include highly autonomous systems, advanced decision aids, morphing aircraft, and advanced guidance systems. NASA should support these applications by collaborating with other organizations that are supporting research to write and qualify complex, safety-critical software in a more timely and cost-effective manner. Significant opportunities also exist for NASA to collaborate with international research organizations, especially at the level of foundational physics. Structured processes should be developed to monitor international activities and plan appropriate collaborations. With so many organizations involved in the development of new civil aeronautics technologies, advances often occur piecemeal, in areas of particular interest to individual stakeholders. Singularity of vision is needed to ensure that R&T programs develop all of the pieces necessary for game-changing advancements across the board. Within NASA, this is complicated by the fact that NASA’s vision, resources, and energy must be shared between aeronautics and the much larger space exploration and space science programs—and the aeronautics program does not have a clear vision akin to the space program’s vision of the human exploration of the Moon and Mars. Although organizational issues are beyond the purview of this study, the steering committee noted in the course of its deliberations that the factors cited above represent a potential barrier to the pursuit and implementation of aeronautics R&T. Because the issues transcend NASA, the steering committee observes that in the national interest, organizational options should be reviewed by a senior group commissioned by or within the federal government. How Far Should NASA Advance Research? NASA’s congressionally mandated charter directs it to “preserve the role of the United States as a leader in aeronautical science and technology and the application thereof.” To achieve this goal, NASA should embrace a comprehensive roadmap of foundational research that develops discipline-specific and multidisciplinary capabilities, including system-level design. The roadmap should include (1) progressive empirical validation up to and including a limited number of flight demonstration vehicles (X-planes), (2) technology readiness metrics, such as NASA’s technology readiness levels (TRLs) (see Table 5-2), and (3) research partnerships with industry, academia, and other federal agencies. X-planes have played and will continue to play a crucial role
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Decadal Survey of Civil Aeronautics: Foundation for the Future TABLE 5-2 NASA Technology Readiness Levels 1 to 9 for Aeronautics Research Key Player Stage of System Development TRL Description Industry System test and operations (TRL 8-9) 9 Actual system flight proven on operational flight 8 Actual system completed and flight qualified through test and demonstration System/subsystem development (TRL 6-8) 7 System prototype demonstrated in flight environment Government Technology demonstration (TRL 5-6) 6 System/subsystem model or prototype demonstrated/validated in a relevant environment 5 Component and/or breadboard verification in a relevant environment Technology development (TRL 3-5) 4 Component and/or breadboard test in a laboratory environment Research to prove feasibility (TRL 2-3) 3 Analytical and experimental critical function or characteristic proof of concept 2 Technology concept and/or application formulated (candidate selected) Basic technology research (TRL 1-2) 1 Basic principles observed and reported SOURCE: NASA, 2000. in the advancement of aeronautical research by validating the practicality and robustness of specific technological advances. It is important to note that they are not limited to high TRL research. While an X-plane may represent a system prototype (TRL 7), it may also be used to observe basic phenomena, prove concepts, or validate a component or subsystem (TRL 1-6). TRLs provide a consistent and objective measure of technology maturation and progress. Research partnerships with external organizations provide an important mechanism to maintain the crucial links between NASA and the organizations that will use the results of NASA’s aeronautics R&T. These partnerships also help to ensure that the research priorities of the aeronautics community as a whole remain relevant. NASA is also charged with identifying, encouraging, and fostering cutting-edge R&T that will address important national goals but cannot be justified by individual companies in terms of return on investment. NASA should have clear criteria and metrics for entering, continuing to support, and leaving a research area (because of lack of progress or because goals have been achieved). Emerging areas are characterized by a multitude of ideas and approaches. Setting clear criteria for success and a timescale for evaluation allows research to focus on the most fruitful areas without prematurely abandoning an idea that still holds promise. As noted in Table 5-2, NASA has historically supported research through TRL 6 and then transferred research results to industry, with the expectation that industry would continue development of new technologies through TRL 9. The steering committee, however, believes that different transfer points are often appropriate, because industry’s interest in developing new technologies varies based on urgency and expected payoff. For urgent, high-payoff applications, for example, it may be sufficient for NASA to mature technologies to TRL 5. When NASA is developing technologies for transfer to operational federal agencies such as the FAA, the committee believes that research results should normally be transferred to industry first, to ensure product support, enhancement, integration with other systems, and certification. For government agencies that include an R&D mission, agency-to-agency transfer is appropriate, and such transfers may occur at reasonably low TRLs (e.g., TRL 3). Ground and Flight Test Capabilities Since the creation of the small wind tunnel used by the Wright brothers to investigate aerodynamics for the first powered aircraft, advances in aeronautics have been closely tied to ground test facilities, such as simulators, wind tunnels, combined-environment load facilities, propulsion test cells, and acoustic facilities. These facilities allow repeatable and accurate assessment of physical processes and play a vital role in validating physical and computational models. To conduct the cutting-edge research outlined above, NASA must maintain world-class facilities and diagnostic capabilities. It should invest in research associated with improved facilities and diagnostics in coordination with DoD and industry. Furthermore, NASA should establish facility access and pricing policies that enable and encourage industry and academia to use NASA facilities. If costs are too high, they drive away potential customers, causing the price for remaining customers to spiral higher still. Eventually, underutilized tunnels are mothballed, and NASA loses testing capabilities and the expertise of workers who move on to other jobs or industries. NASA should seek a business model that will generate the optimal combination of income and utilization. Flight test capabilities are required for research that cannot be adequately simulated in ground facilities. This research includes atmospheric propagation of noise and sonic booms, reacting-flow hypersonic phenomena, and large-scale propulsion–airframe integration. While this study did not include a detailed assessment of facilities, some key facilities—and their deficiencies—are noted in Appendixes A-E. Facility concerns have been addressed in detail by studies devoted solely to this topic
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Decadal Survey of Civil Aeronautics: Foundation for the Future (Anton et al., 2004; Kegelman, 2006; NRC, 1994, 2004). These reports have identified critical issues associated with the capabilities, funding, and use of national aeronautical test facilities, many of which have yet to be resolved. RECOMMENDATIONS The steering committee offers eight recommendations: NASA should use the 51 Challenges listed in Table 5-1 as the foundation for the future of NASA’s civil aeronautics research program during the next decade. The U.S. government should place a high priority on establishing a stable aeronautics R&T plan, with the expectation that the plan will receive sustained funding for a decade or more, as necessary, for activities that are demonstrating satisfactory progress. NASA should use five Common Themes to make the most efficient use of civil aeronautics R&T resources:3 Physics-based analysis tools Multidisciplinary design tools Advanced configurations Intelligent and adaptive systems Complex interactive systems NASA should support fundamental research to create the foundations for practical certification standards for new technologies. The U.S. government should align organizational responsibilities as well as develop and implement techniques to improve change management for federal agencies and to assure a safe and cost-effective transition to the air transportation system of the future. NASA should ensure that its civil aeronautics R&T plan features the substantive involvement of universities and industry, including a more balanced allocation of funding between in-house and external organizations than currently exists. NASA should consult with non-NASA researchers to identify the most effective facilities and tools applicable to key aeronautics R&T projects and should facilitate collaborative research to ensure that each project has access to the most appropriate research capabilities, including test facilities; computational models and facilities; and intellectual capital, available from NASA, the Federal Aviation Administration, the Department of Defense, and other interested research organizations in government, industry, and academia. The U.S. government should conduct a high-level review of organizational options for ensuring U.S. leadership in civil aeronautics. REFERENCES Anton, P.S., E.C. Gritton, R. Mesic, and P. Steinberg. 2004. Wind Tunnel and Propulsion Test Facilities: An Assessment of NASA’s Capabilities to Serve National Needs. Santa Monica, Calif.: RAND Corporation. Available online at <http://ntrs.nasa.gov/index.cgi?method=ordering&oaiID=oai:casi.ntrs.nasa.gov:20050199428>. Kegelman, J. 2006. Wind Tunnel Enterprise. NASA Langley Research Center. Available online at <http://windtunnels.larc.nasa.gov/enterprise.htm>. National Aeronautics and Space Administration (NASA). 2000. Ultra Efficient Engine Technology Program. Home and Home Visit Series. Glenn Research Center, April 4-5. Available online at <www.aero-space.nasa.gov/events/home&home/glenn/ueet/sld004.htm>. NASA. 2006. ARMD [Aeronautics Research Mission Directorate] Requests for Information (RFI) Questions and Answers. Available online at <www.aero-space.nasa.gov/rfi_qa.htm>. National Research Council (NRC). 1994. Aeronautical Facilities: Assessing the National Plan for Aeronautical Ground Test Facilities. Washing-ton, D.C.: National Academy Press. Available online at <http://fermat.nap.edu/catalog/9088.html>. NRC. 2004. Investments in Federal Facilities: Asset Management Strategies for the 21st Century. Washington, D.C.: The National Academies Press. Available online at <http://fermat.nap.edu/catalog/11012.html>. Wlezien, R. 2006a. NASA’s Fundamental Research Program. Presentation to 44th AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nev., January 12. Available online at <www.aero-space.nasa.gov/reno_presentations.htm>. Wlezien, R. 2006b. NASA’s Fundamental Research Program. Remarks made during presentation to 44th AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nev., January 12. Available online at <www.streammercials.com/aiaa/player.htm>. 3 The Common Themes are defined in Chapter 4.