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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Certification Validation Libraries

“The code “Certificate Validation Libraries” provides the ability to validate x509 certificates in python using a simple library. These libraries validate certificates in 3 ways: 1) validation that certificate has not expired. 2) validation that certificate has not been revoked and 3) validation of certificate's digital signature. The benefits of this code is that one can properly validate x509 certificates, thus strengthening the security of systems using these libraries.”

Maerz, StefanA↗
NASA NTRS1993

Experimental evaluation of the certification-trail method

Certification trails are a recently introduced and promising approach to fault-detection and fault-tolerance. A comprehensive attempt to assess experimentally the performance and overall value of the method is reported. The method is applied to algorithms for the following problems: huffman tree, shortest path, minimum spanning tree, sorting, and convex hull. Our results reveal many cases in which an approach using certification-trails allows for significantly faster overall program execution time than a basic time redundancy-approach. Algorithms for the answer-validation problem for abstract data types were also examined. This kind of problem provides a basis for applying the certification-trail method to wide classes of algorithms. Answer-validation solutions for two types of priority queues were implemented and analyzed. In both cases, the algorithm which performs answer-validation is substantially faster than the original algorithm for computing the answer. Next, a probabilistic model and analysis which enables comparison between the certification-trail method and the time-redundancy approach were presented. The analysis reveals some substantial and sometimes surprising advantages for ther certification-trail method. Finally, the work our group performed on the design and implementation of fault injection testbeds for experimental analysis of the certification trail technique is discussed. This work employs two distinct methodologies, software fault injection (modification of instruction, data, and stack segments of programs on a Sun Sparcstation ELC and on an IBM 386 PC) and hardware fault injection (control, address, and data lines of a Motorola MC68000-based target system pulsed at logical zero/one values). Our results indicate the viability of the certification trail technique. It is also believed that the tools developed provide a solid base for additional exploration.

Sullivan, Gregory F.↗
NASA NTRS2009

Proceedings of the Third International Workshop on Proof-Carrying Code and Software Certification

This NASA conference publication contains the proceedings of the Third International Workshop on Proof-Carrying Code and Software Certification, held as part of LICS in Los Angeles, CA, USA, on August 15, 2009. Software certification demonstrates the reliability, safety, or security of software systems in such a way that it can be checked by an independent authority with minimal trust in the techniques and tools used in the certification process itself. It can build on existing validation and verification (V&V) techniques but introduces the notion of explicit software certificates, Vvilich contain all the information necessary for an independent assessment of the demonstrated properties. One such example is proof-carrying code (PCC) which is an important and distinctive approach to enhancing trust in programs. It provides a practical framework for independent assurance of program behavior; especially where source code is not available, or the code author and user are unknown to each other. The workshop wiII address theoretical foundations of logic-based software certification as well as practical examples and work on alternative application domains. Here "certificate" is construed broadly, to include not just mathematical derivations and proofs but also safety and assurance cases, or any fonnal evidence that supports the semantic analysis of programs: that is, evidence about an intrinsic property of code and its behaviour that can be independently checked by any user, intermediary, or third party. These guarantees mean that software certificates raise trust in the code itself, distinct from and complementary to any existing trust in the creator of the code, the process used to produce it, or its distributor. In addition to the contributed talks, the workshop featured two invited talks, by Kelly Hayhurst and Andrew Appel. The PCC 2009 website can be found at http://ti.arc.nasa.gov /event/pcc 091.

Ewen, Denney, W.↗
NASA NTRSDate not supplied

Initial Regulatory and Certification Approach for the SUSAN Electrofan Concept

New aircraft concepts and associated technologies are required to meet emerging environ-mental impact goals, while still meeting established airworthiness certification standards and regulations. The SUbsonic Single Aft eNgine (SUSAN) Electrofan is one of these concepts, utilizing a single aft-mounted engine, electrified aircraft propulsion, and an emergency backup battery. This paper explores the current certification and regulatory barriers to this novel aircraft design and the potential methods for adapting certification and regulatory requirements for the SUSAN Electrofan concept. Although some certification requirements, such as the Extended Operations regulations for continued operation after the loss of an engine, can be met with only minor changes, other requirements require modifications to the regulations or the aircraft concept for compliance. Early insight to the certification approach for the SUSAN concept, while the design is still undergoing trade space exploration, allows the development of the aircraft alongside any modifications to certification standards.

SUSAN Electrofan↗
DOE OSTI2018

Training and Certification Programs on Industrial Energy Systems in the United States

The major industrial energy systems commonly found in manufacturing facilities are compressed air, ammonia refrigeration, chilled water, steam, process heating, combined heat and power, pumps, and fans. The efficiency of these systems contributes significantly to the whole-facility energy performance. On the national and even the international level, well-structured training and highly recognized certification programs help develop a highly skilled and qualified workforce to maintain and improve facilities' energy performance, particularly as technologies within these systems become more and more advanced. The purpose of this paper is to review currently available vendor-agnostic training and certification programs focusing on these systems and to identify the gap between market needs and currently available programs. Its three major conclusions are (1) most training programs focus on operations, maintenance, safety, and design although some briefly touch on energy performance aspects. (2) The Certified Refrigeration Energy Specialist certification by RETA the and Pump System Assessment Professional certification by HI were the only certifications found to be tool-agnostics and emphasize knowledge and skills for improving and maintaining systems energy performance. (3) Developing energy efficiency focused training and ANSI accredited certification programs for industrial energy systems will fill the gap between market needs and currently available programs.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
NASA NTRS1993

Certification of computational results

A conceptually novel and powerful technique to achieve fault detection and fault tolerance in hardware and software systems is described. When used for software fault detection, this new technique uses time and software redundancy and can be outlined as follows. In the initial phase, a program is run to solve a problem and store the result. In addition, this program leaves behind a trail of data called a certification trail. In the second phase, another program is run which solves the original problem again. This program, however, has access to the certification trail left by the first program. Because of the availability of the certification trail, the second phase can be performed by a less complex program and can execute more quickly. In the final phase, the two results are compared and if they agree the results are accepted as correct; otherwise an error is indicated. An essential aspect of this approach is that the second program must always generate either an error indication or a correct output even when the certification trail it receives from the first program is incorrect. The certification trail approach to fault tolerance is formalized and realizations of it are illustrated by considering algorithms for the following problems: convex hull, sorting, and shortest path. Cases in which the second phase can be run concurrently with the first and act as a monitor are discussed. The certification trail approach are compared to other approaches to fault tolerance.

Sullivan, Gregory F.↗
NASA NTRS1993

Experimental evaluation of certification trails using abstract data type validation

Certification trails are a recently introduced and promising approach to fault-detection and fault-tolerance. Recent experimental work reveals many cases in which a certification-trail approach allows for significantly faster program execution time than a basic time-redundancy approach. Algorithms for answer-validation of abstract data types allow a certification trail approach to be used for a wide variety of problems. An attempt to assess the performance of algorithms utilizing certification trails on abstract data types is reported. Specifically, this method was applied to the following problems: heapsort, Hullman tree, shortest path, and skyline. Previous results used certification trails specific to a particular problem and implementation. The approach allows certification trails to be localized to 'data structure modules,' making the use of this technique transparent to the user of such modules.

Wilson, Dwight S.↗
NASA NTRS1993

Using certification trails to achieve software fault tolerance

A conceptually novel and powerful technique to achieve fault tolerance in hardware and software systems is introduced. When used for software fault tolerance, this new technique uses time and software redundancy and can be outlined as follows. In the initial phase, a program is run to solve a problem and store the result. In addition, this program leaves behind a trail of data called a certification trail. In the second phase, another program is run which solves the original problem again. This program, however, has access to the certification trail left by the first program. Because of the availability of the certification trail, the second phase can be performed by a less complex program and can execute more quickly. In the final phase, the two results are accepted as correct; otherwise an error is indicated. An essential aspect of this approach is that the second program must always generate either an error indication or a correct output even when the certification trail it receives from the first program is incorrect. The certification trail approach to fault tolerance was formalized and it was illustrated by applying it to the fundamental problem of finding a minimum spanning tree. Cases in which the second phase can be run concorrectly with the first and act as a monitor are discussed. The certification trail approach was compared to other approaches to fault tolerance. Because of space limitations we have omitted examples of our technique applied to the Huffman tree, and convex hull problems. These can be found in the full version of this paper.

Sullivan, Gregory F.↗
NASA NTRS1993

Certification trails for data structures

Certification trails are a recently introduced and promising approach to fault detection and fault tolerance. The applicability of the certification trail technique is significantly generalized. Previously, certification trails had to be customized to each algorithm application; trails appropriate to wide classes of algorithms were developed. These certification trails are based on common data-structure operations such as those carried out using these sets of operations such as those carried out using balanced binary trees and heaps. Any algorithms using these sets of operations can therefore employ the certification trail method to achieve software fault tolerance. To exemplify the scope of the generalization of the certification trail technique provided, constructions of trails for abstract data types such as priority queues and union-find structures are given. These trails are applicable to any data-structure implementation of the abstract data type. It is also shown that these ideals lead naturally to monitors for data-structure operations.

Sullivan, Gregory F.↗
NASA NTRS1994

Human factors certification: A useful concept?

This paper considers what is involved in certification processes and their relation to human factors aspects of systems. It derives from recognition of a lack of understanding of the processes and purposes of certification. This was encountered when attempting to address the workshop topic by integrating an understanding of human factors with the observed processes of certification. The paper considers what human factors (HF) certification might be and then develops a simple model of the elements of a certification process. It then tries to relate these elements to the needs of the aviation communities and other parties with an interest in the certification of advance aviation technologies.

Jackson, Alistair↗
NASA NTRS1994

The successful management of programs for human factors certification of advanced aviation technologies

In recent years there have been immense pressures to enact changes on the air traffic control organizations of most states. In addition, many of these states are or have been subject to great political, sociological and economic changes. Consequently, any new schemes must be considered within the context of national or even international changes. Europe has its own special problems, and many of these are particularly pertinent when considering human factors certification programs. Although these problems must also be considered in the wider context of change, it is usually very difficult to identify which forces are pressing in support of human factors aspects and which forces are resisting change. There are a large number of aspects which must be taken into account if human factors certification programs are to be successfully implemented. Certification programs would be new ventures, and like many new ventures it will be essential to ensure that managers have the skills, commitment and experience to manage the programs effectively. However, they must always be aware of the content and the degree of certainty to which the human factors principles can be applied - as Debons and Horne have carefully described. It will be essential to avoid the well known pitfalls which occur in the implementation of performance appraisal schemes. While most appraisal schemes are usually extremely well thought out, they often do not produce good results because they are not implemented properly and staff therefore do not have faith in them. If the manager does not have the commitment and interest in his/her staff as human beings, then the schemes will not be effective. Thus, one aspect of considering human factors certification schemes is within the context of a managed organization. This paper outlines some of the management factors which need to be considered for the air traffic control services. Many of the points received attention during the plenary sessions while others were covered by the working groups when the question arose of how various aspects of human factors certification programs would be managed. Management and organizational issues will certainly need to be included in any frame of reference by those who may be involved in developing certification programs.

Baldwin, Rod↗
NASA NTRS1994

Advanced automated glass cockpit certification: Being wary of human factors

This paper presents some facets of the French experience with human factors in the process of certification of advanced automated cockpits. Three types of difficulties are described: first, the difficulties concerning the hotly debated concept of human error and its non-linear relationship to risk of accident; a typology of errors to be taken into account in the certification process is put forward to respond to this issue. Next, the difficulties connected to the basically gradual and evolving nature of pilot expertise on a given type of aircraft, which contrasts with the immediate and definitive style of certifying systems. The last difficulties to be considered are those related to the goals of certification itself on these new aircraft and the status of findings from human factor analyses (in particular, what should be done with disappointing results, how much can the changes induced by human factors investigation economically affect aircraft design, how many errors do we need to accumulate before we revise the system, what should be remedied when human factor problems are discovered at the certification stage: the machine? pilot training? the rules? or everything?). The growth of advanced-automated glass cockpits has forced the international aeronautical community to pay more attention to human factors during the design phase, the certification phase and pilot training. The recent creation of a human factor desk at the DGAC-SFACT (Official French services) is a direct consequence of this. The paper is divided into three parts. Part one debates human error and its relationship with system design and accident risk. Part two describes difficulties connected to the basically gradual and evolving nature of pilot expertise on a given type of aircraft, which contrasts with the immediate and definitive style of certifying systems. Part three focuses on concrete outcomes of human factors for certification purposes.

Amalberti, Rene↗
NASA NTRS2010

Tracking Data Certification for the Lunar Reconnaissance Orbiter

This paper details the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF) tracking data certification effort of the Lunar Reconnaissance Orbiter (LRO) Space Communications Network (SCN) complement of tracking stations consisting of the NASA White Sands 1 antenna (WS1), and the commercial provider Universal Space Network (USN) antennas at South Point, Hawaii; Dongara Australia; Weilheim, Germany; and Kiruna, Sweden. Certification assessment required the cooperation and coordination of parties not under the control of either the LRO project or ground stations as uplinks on cooperating spacecraft were necessary. The LRO range-tracking requirement of 10m 1 sigma could be satisfactorily demonstrated using any typical spacecraft capable of range tracking. Though typical Low Earth Orbiting (LEO) or Geosynchronous Earth Orbiting (GEO) spacecraft may be adequate for range certification, their measurement dynamics and noise would be unacceptable for proper Doppler certification of 1-3mm/sec 1 sigma. As LRO will orbit the Moon, it was imperative that a suitable target spacecraft be utilized which can closely mimic the expected lunar orbital Doppler dynamics of +/-1.6km/sec and +/-1.5m/sq sec to +/-0.15m/sq sec, is in view of the ground stations, supports coherent S-Band Doppler tracking measurements, and can be modeled by the FDF. In order to meet the LRO metric tracking data specifications, the SCN ground stations employed previously uncertified numerically controlled tracking receivers. Initial certification testing revealed certain characteristics of the units that required resolution before being granted certification.

Morinelli, Patrick J.↗
NASA NTRS2017

Managing Fire Risk During Drought: The Influence of Certification and El Nino on Fire-Driven Forest Conversion for Oil Palm in Southeast Asia

Indonesia and Malaysia have emerged as leading producers of palm oil in the past several decades, expanding production through the conversion of tropical forests to industrial plantations. Efforts to produce "sustainable" palm oil, including certification by the Roundtable on Sustainable Palm Oil (RSPO), include guidelines designed to reduce the environmental impact of palm oil production. Fire-driven deforestation is prohibited by law in both countries and a stipulation of RSPO certification, yet the degree of environmental compliance isunclear, especially during El Niño events when drought conditions increase fire risk. Here, we used time series of satellite data to estimate the spatial and temporal patterns of fire-driven deforestation on and around oil palm plantations. In Indonesia, fire-driven deforestation accounted for one-quarter of total forest losses on both certified and noncertified plantations. After the first plantations in Indonesia received RSPO certification in 2009,forest loss and fire-driven deforestation declined on certified plantations but did not stop altogether. Oil palm expansion in Malaysia rarely involved fire; only 5 % of forest loss on certified plantations had coincident activefire detections. Interannual variability in fire detections was strongly influenced by El Nino and the timing of certification. Fire activity during the 2002, 2004, and 2006 El Nino events was similar among oil palm plantations in Indonesia that would later become certified, noncertified plantations, and surrounding areas. However, total fire activity was 75% and 66% lower on certified plantations than noncertified plantations during the 2009 and 2015 El Nino events, respectively. The decline in fire activity on certified plantations, including during drought periods, highlights the potential for RSPO certification to safeguard carbon stocks in peatlands and remaining forests in accordance with legislation banning fires. However, aligning certification standards with satellite monitoring capabilities will be critical to realize sustainable palm oil production and meet industry commitments to zero forestation.

Noojipady, Praveen↗
DOE OSTI2017

Industrial Energy Training and Certification

Compressed air systems, ammonia refrigeration systems, chilled water systems, steam systems, process heating systems, combined heat and power systems, pump systems and fan systems are major industrial energy systems commonly found in manufacturing facilities. Efficiency of these systems contributes significantly to whole facilities' energy performance. On the national, even international level, well-structured training and highly recognized certification programs help develop a highly-skilled and qualified workforce to maintain and improve facilities' energy performance, particularly as technologies within these systems become more advanced. The purpose of this paper is to review currently available training and certification programs focusing on these systems and to identify the gap between market's needs and currently available programs. Three major conclusions are: first, most training programs focus on operations, maintenance, safety and design although some briefly touch the energy performance aspect; second, except CRES by RETA and PSA Certificate and PSAP Master Certification by HI, no other certifications had been found emphasizing on knowledge and skills for improving and maintaining these systems' energy performance; third, developing energy efficiency focused training and ANSI accredited certification programs on these energy systems will fill the gap between market's needs and currently available programs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2017

Industrial Energy Training and Certification

We present compressed air systems, ammonia refrigeration systems, chilled water systems, steam systems, process heating systems, combined heat and power systems, pump systems and fan systems are major industrial energy systems commonly found in manufacturing facilities. Efficiency of these systems contributes significantly to whole facilities' energy performance. On the national, even international level, well-structured training and highly recognized certification programs help develop a highly-skilled and qualified workforce to maintain and improve facilities' energy performance, particularly as technologies within these systems become more advanced. The purpose of this paper is to review currently available training and certification programs focusing on these systems and to identify the gap between market's needs and currently available programs. Three major conclusions are: first, most training programs focus on operations, maintenance, safety and design although some briefly touch the energy performance aspect; second, except CRES by RETA and PSA Certificate and PSAP Master Certification by HI, no other certifications had been found emphasizing on knowledge and skills for improving and maintaining these systems' energy performance; third, developing energy efficiency focused training and ANSI accredited certification programs on these energy systems will fill the gap between market's needs and currently available programs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

Certification systems for sustainable neighbourhoods: What do they really certify?

Certification systems for sustainable neighbourhoods started to emerge around a decade ago. This study analysed the content, structure, weighting and indicators of two established certification systems for sustainable urban development – BREEAM Communities and LEED for Neighborhood Development. Several limitations of these systems were identified: both have a bias for procedure and feature indicators over indicators that assess actual performance; performance demands are set according to a relative understanding of sustainable development; the focus is on internal sustainability, while upstream and downstream impacts of construction are disregarded; the number and distribution of mandatory issues do not cover essential sustainability aspects; and the disproportionately large number of non-mandatory issues makes benchmarking difficult and signals that sustainability aspects are exchangeable. Altogether, this means that an area can be certified without being sustainable. Moreover, the lack of continuous development of certification requirements in the systems means that they risk exerting a conservative effect on urban development, rather than pushing it forward. - Highlights: • BREEAM-C and LEED-ND were analysed in terms of content and structure. • Specific attention was given to the type of indicators used for showing compliance. • In both systems procedure and feature indicators dominate over performance indicators. • Several other limitations of these certification systems were also identified. • Altogether the limitations imply that a certificate does not warrant sustainability.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
NASA NTRSDate not supplied

Development Strategies for Uncertainty Quantification to Enable Aircraft Certification by Analysis

Aircraft Certification by Analysis (CbA) is a broad term that describes the process by which engineering analysis tools are used to supplement flight testing to demonstrate compliance with regulatory requirements. For each requirement that is to be met through this process, the analysis tools must be sufficiently accurate to ensure that an equivalent level of safety is obtained as if the aircraft to be certified had been flight tested for the requirement. In recent decades, the ability of analysis tools to accurately predict aircraft performance has improved dramatically, leading to increasing interest and limited early adoption of Certification by Analysis across the aerospace industry. However, rigorously demonstrating the credibility of analysis tools remains a challenge for many types of certification requirements, yet is necessary for widespread adoption of CbA approaches in the future. The field of uncertainty quantification is well-suited to address this problem, but will require substantial advances in order to achieve the ambitious industry goals for Certification by Analysis. The objective of this position paper is to highlight gaps in the current technical and programmatic state of uncertainty quantification. Four main categories – Mindset & Awareness, Tools & Capabilities, Data and Benchmarks for V&V, and Applied Research & Established Processes – will be introduced. Each of these categories contains several shortcomings and impediments which, if overcome, will enable more widespread possibilities for Certification by Analysis in the 2040-2050 timeframe.

Uncertainty Quantification↗