Verifying Architectural Design Rules of the Flight Software Product Line

This paper presents experiences of verifying architectural design rules of the NASA Core Flight Software (CFS) product line implementation. The goal of the verification is to check whether the implementation is consistent with the CFS architectural rules derived from the developer's guide. The results indicate that consistency checking helps a) identifying architecturally significant deviations that were eluded during code reviews, b) clarifying the design rules to the team, and c) assessing the overall implementation quality. Furthermore, it helps connecting business goals to architectural principles, and to the implementation. This paper is the first step in the definition of a method for analyzing and evaluating product line implementations from an architecture-centric perspective

Analyzing the Core Flight Software (CFS) with SAVE

This viewgraph presentation describes the SAVE tool and it's application to Core Flight Software (CFS). The contents include: 1) Fraunhofer-a short intro; 2) Context of this Collaboration; 3) CFS-Core Flight Software?; 4) The SAVE Tool; 5) Applying SAVE to CFS -A few example analyses; and 6) Goals

Architecture-Based Unit Testing of the Flight Software Product Line

This paper presents an analysis of the unit testing approach developed and used by the Core Flight Software (CFS) product line team at the NASA GSFC. The goal of the analysis is to understand, review, and reconunend strategies for improving the existing unit testing infrastructure as well as to capture lessons learned and best practices that can be used by other product line teams for their unit testing. The CFS unit testing framework is designed and implemented as a set of variation points, and thus testing support is built into the product line architecture. The analysis found that the CFS unit testing approach has many practical and good solutions that are worth considering when deciding how to design the testing architecture for a product line, which are documented in this paper along with some suggested innprovennents

Microbial Production of Amylase from Cassava Waste

Bacterium mura was isolated from cassava waste, (Tamil Nadu, India) for the production of extracellular amylase. On screening for amylase producing bacteria, 5 isolates showed positive results, of which Bacterium mura showed best amylase activity. The optimal conditions for the amylase activity were found at pH 6.0 (39 U/ml) and at temperature 37°C. Amylase activity was found to be higher when lactose (31 U/ml), casein, barley (42 U/ml) and SDS (32 U/ml) were used as the carbon source, nitrogen source, agro waste source and as additives respectively. The enzyme was partially purified by dialysis and the molecular mass was found to be 65kDa by SDS-PAGE. The partially purified and crude amylase was confirmed by zymogram. The partially purified amylase was used in bread making, which improved the softening of the bread and was used as a de-sizing agent

Connecting Research and Practice: An Experience Report on Research Infusion with SAVE

NASA systems need to be highly dependable to avoid catastrophic mission failures. This calls for rigorous engineering processes including meticulous validation and verification. However, NASA systems are often highly distributed and overwhelmingly complex, making the software portion of these systems challenging to understand, maintain, change, reuse, and test. NASA's systems are long-lived and the software maintenance process typically constitutes 60-80% of the total cost of the entire lifecycle. Thus, in addition to the technical challenges of ensuring high life-time quality of NASA's systems, the post-development phase also presents a significant financial burden. Some of NASA's software-related challenges could potentially be addressed by some of the many powerful technologies that are being developed in software research laboratories. Many of these research technologies seek to facilitate maintenance and evolution by for example architecting, designing and modeling for quality, flexibility, and reuse. Other technologies attempt to detect and remove defects and other quality issues by various forms of automated defect detection, architecture analysis, and various forms of sophisticated simulation and testing. However promising, most such research technologies nevertheless do not make the transition from the research lab to the software lab. One reason the transition from research to practice seldom occurs is that research infusion and technology transfer is difficult. For example, factors related to the technology are sometimes overshadowed by other types of factors such as reluctance to change and therefore prohibits the technology from sticking. Successful infusion might also take very long time. One famous study showed that the discrepancy between the conception of the idea and its practical use was 18 years plus or minus three. Nevertheless, infusing new technology is possible. We have found that it takes special circumstances for such research infusion to succeed: 1) there must be evidence that the technology works in the practitioner's particular domain, 2) there must be a potential for great improvements and enhanced competitive edge for the practitioner, 3) the practitioner has to have strong individual curiosity and continuous interest in trying out new technologies, 4) the practitioner has to have support on multiple levels (i.e. from the researchers, from management, from sponsors etc), and 5) to remain infused, the new technology has to be integrated into the practitioner's processes so that it becomes a natural part of the daily work. NASA IV&V's Research Infusion initiative sponsored by NASA's Office of Safety & Mission Assurance (OSMA) through the Software Assurance Research Program (SARP), strives to overcome some of the problems related to research infusion

Architecture compliance checking at runtime: An industry experience report

In this paper, we report on our experiences we made with architecture compliance checking at run-time. To that end, we constructed hierarchical colored Petri nets (CP-nets), using existing general purpose functional programming languages, for bridging the abstraction gap between architectural views and run-time traces. In an industry example, we were able to extract views that helped us to identify a number of architecturally relevant issues (e.g., style constraint violations) that would not have been detected otherwise. Finally, we demonstrate how to systematically design reusable hierarchical CP-nets, and package valuable experiences and lessons learned from the example application

Optimization of milling speed and time in mechanical alloying of ferritic ODS steel through taguchi technique

The oxide dispersion strengthened (ODS) ferritic steels are one of the most important in fuel cladding materials for 4th Generation nuclear reactors because of their excellent mechanical properties such as irradiation resistance, swelling resistance, and elevated temperature tensile/compressive strength. Mechanical alloying (MA) is one of the most promising routes for developing nanocrystalline ferritic ODS steel materials. For the production of nanocrystalline ferritic ODS steel powders, the most influencing factor is the milling speed and milling time during the mechanical alloying process. With the improper selection of milling time and speed, the final milled powders become an amorphous structure consisting of high impurity inclusions in the microstructure, and strength was also affected. In order to overcome these drawbacks, the present investigation was taken into account for the selection of appropriate mechanical milling speed and time, which was optimized through Taguchi analysis followed by the MA process. The optimized mechanical milling speed and time of milled powders were characterized through X-Ray Diffraction Analysis (XRD) and Scanning Electron Microscope (SEM)

Synthesis, characterization and thermal decomposition of ethyl-2’-amino-5’-cyano-6’-(1H-indole-3yl)-2-oxospiro[indoline-3,4’-pyran]-3’-carboxylate under non‐isothermal condition in nitrogen atmosphere

A new compound, spiro-oxindole derivative compound namely ethyl-2ʹ-amino-5ʹ-cyano-6ʹ-(1H-indole-3yl)-2-oxospiro[indoline-3,4ʹ-pyran]-3ʹ-carboxylate (EACIOIPC) has been synthesized and characterized by microanalysis, FT-IR, mass spectrum and NMR (1H and 13C) techniques. The thermal decomposition of the compound was studied by thermogravimetric analysis under dynamic nitrogen atmosphere at different heating rates of 10, 15, 20 and 30 K/min. The kinetic parameters were calculated using model-free (Friedman’s, Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods) and model-fitting (Coats and Redfern (CR)) methods. The decomposition process of EACIOIPC followed a single step mechanism as evidenced from the data. Existence of compensation effect is noticed for the decomposition of EACIOIPC. Invariant kinetic parameters are consistent with the average values obtained by Friedman and KAS in conversional methods

Correlation between the Structure and Catalytic Activity of [Cp*Rh(Substituted Bipyridine)] Complexes for NADH Regeneration

A series of water-soluble half-sandwich [Cp*Rh^III(N^N)­Cl]⁺ (Cp* = pentamethylcyclopentadiene, N^N-substituted 2,2′-bipyridine) complexes containing electron-donating substituents around the 2,2′-bipyridyl ligand were synthesized and fully characterized for the regioselective reduction of nicotinamide coenzyme (NAD⁺). The influence of the positional effect of the substituents on the structural, electrochemical, and catalytic properties of the catalyst was systematically studied in detail. The catalytic efficiency of the substituted bipyridine Cp*Rh^III complexes are inversely correlated with their redox potentials. The 5,5′-substituted bipyridine Cp*Rh^III complex, which had the lowest reduction potential, most effectively regenerated NADH with a turnover frequency of 1100 h^–1. Detailed kinetic studies on the generation of intermediate(s) provide valuable mechanistic insight into this catalytic cycle and help to direct the future design strategy of corresponding catalysts