Enabling Product Design Reuse by Long-term Preservation of Engineering Knowledge

In the highly competitive engineering industry, product innovations are created with the help of a product lifecycle management (PLM) tool chain. In order to support fast-paced product development, a major company goal is the reuse of product designs and product descriptions. Due to the product’s complexity, the design of a product not only consists of geometry data but also of valuable engineering knowledge that is created during the various PLM phases. The need to preserve such intellectual capital leads engineering companies to introduce knowledge management and archiving their machine-readable formal representation. However, archived knowledge is in danger of becoming unusable since it is very likely that knowledge semantics and knowledge representation will evolve over long time periods, for example during the 50 operational years of some products. Knowledge evolution and knowledge representation technology changes are crucial issues since a reuse of the archived product information can only be ensured if its rationale and additional knowledge are interpretable with future software and technologies. Therefore, in order to reuse design data fully, knowledge about the design must also be migrated to be interoperable with future design systems and knowledge representation methods. This paper identifies problems, issues, requirements, challenges and solutions that arise while tackling the long-term preservation of engineering knowledge

Towards Support for Long-Term Digital Preservation in Product Life Cycle Management

Important legal and economic motivations exist for the design and engineering industry to address and integrate digital long-term preservation into product life cycle management (PLM). Investigations revealed that it is not sufficient to archive only the product design data which is created in early PLM phases, but preservation is needed for data that is produced during the entire product lifecycle including early and late phases. Data that is relevant for preservation consists of requirements analysis documents, design rationale, data that reflects experiences during product operation and also metadata like social collaboration context. In addition, also the engineering environment itself that contains specific versions of all tools and services is a candidate for preservation. This paper takes a closer look at engineering preservation use case scenarios as well as PLM characteristics and workflows that are relevant for long-term preservation. Resulting requirements for a long-term preservation system lead to an OAIS (Open Archival Information System) based system architecture and a proposed preservation service interface that respects the needs of the engineering industry

The Chandra Multi-Wavelength Project: Optical Spectroscopy and the Broadband Spectral Energy Distributions of X-ray Selected AGN

From optical spectroscopy of X-ray sources observed as part of ChaMP, we present redshifts and classifications for a total of 1569 Chandra sources from our targeted spectroscopic follow up using the FLWO, SAAO, WIYN, CTIO, KPNO, Magellan, MMT and Gemini telescopes, and from archival SDSS spectroscopy. We classify the optical counterparts as 50% BLAGN, 16% NELG, 14% ALG, and 20% stars. We detect QSOs out to z~5.5 and galaxies out to z~3. We have compiled extensive photometry from X-ray to radio bands. Together with our spectroscopic information, this enables us to derive detailed SEDs for our extragalactic sources. We fit a variety of templates to determine bolometric luminosities, and to constrain AGN and starburst components where both are present. While ~58% of X-ray Seyferts require a starburst event to fit observed photometry only 26% of the X-ray QSO population appear to have some kind of star formation contribution. This is significantly lower than for the Seyferts, especially if we take into account torus contamination at z>1 where the majority of our X-ray QSOs lie. In addition, we observe a rapid drop of the percentage of starburst contribution as X-ray luminosity increases. This is consistent with the quenching of star formation by powerful QSOs, as predicted by the merger model, or with a time lag between the peak of star formation and QSO activity. We have tested the hypothesis that there should be a strong connection between X-ray obscuration and star-formation but we do not find any association between X-ray column density and star formation rate both in the general population or the star-forming X-ray Seyferts. Our large compilation also allows us to report here the identification of 81 XBONG, 78 z>3 X-ray sources and 8 Type-2 QSO candidates. Also we have identified the highest redshift (z=5.4135) X-ray selected QSO with optical spectroscopy.Comment: 17 pages, 16 figures, accepted for publication in ApJS. Full data table and README file can be found online at http://hea-www.harvard.edu/~pgreen/Papers.htm

Anaerobic Microbial Degradation of Hydrocarbons: From Enzymatic Reactions to the Environment

Hydrocarbons are abundant in anoxic environments and pose biochemical challenges to their anaerobic degradation by microorganisms. Within the framework of the Priority Program 1319, investigations funded by the Deutsche Forschungsgemeinschaft on the anaerobic microbial degradation of hydrocarbons ranged from isolation and enrichment of hitherto unknown hydrocarbon-degrading anaerobic microorganisms, discovery of novel reactions, detailed studies of enzyme mechanisms and structures to process-oriented in situ studies. Selected highlights from this program are collected in this synopsis, with more detailed information provided by theme-focused reviews of the special topic issue on 'Anaerobic biodegradation of hydrocarbons' [this issue, pp. 1-244]. The interdisciplinary character of the program, involving microbiologists, biochemists, organic chemists and environmental scientists, is best exemplified by the studies on alkyl-/arylalkylsuccinate synthases. Here, research topics ranged from in-depth mechanistic studies of archetypical toluene-activating benzylsuccinate synthase, substrate-specific phylogenetic clustering of alkyl-/arylalkylsuccinate synthases (toluene plus xylenes, p-cymene, p-cresol, 2-methylnaphthalene, n-alkanes), stereochemical and co-metabolic insights into n-alkane-activating (methylalkyl) succinate synthases to the discovery of bacterial groups previously unknown to possess alkyl-/arylalkylsuccinate synthases by means of functional gene markers and in situ field studies enabled by state-of-the-art stable isotope probing and fractionation approaches. Other topics are Mo-cofactor-dependent dehydrogenases performing O-2-independent hydroxylation of hydrocarbons and alkyl side chains (ethylbenzene, p-cymene, cholesterol, n-hexadecane), degradation of p-alkylated benzoates and toluenes, glycyl radical-bearing 4-hydroxyphenylacetate decarboxylase, novel types of carboxylation reactions (for acetophenone, acetone, and potentially also benzene and naphthalene), W-cofactor-containing enzymes for reductive dearomatization of benzoyl-CoA (class II benzoyl-CoA reductase) in obligate anaerobes and addition of water to acetylene, fermentative formation of cyclohexanecarboxylate from benzoate, and methanogenic degradation of hydrocarbons

The Chandra Multi-wavelength Project: Optical Spectroscopy and the Broadband Spectral Energy Distributions of X-Ray-selected AGNs.

From optical spectroscopy of X-ray sources observed as part of ChaMP, we present redshifts and classifications for a total of 1569 Chandra sources from our targeted spectroscopic follow up using the FLWO, SAAO, WIYN, CTIO, KPNO, Magellan, MMT and Gemini telescopes, and from archival SDSS spectroscopy. We classify the optical counterparts as 50% BLAGN, 16% NELG, 14% ALG, and 20% stars. We detect QSOs out to z~5.5 and galaxies out to z~3. We have compiled extensive photometry from X-ray to radio bands. Together with our spectroscopic information, this enables us to derive detailed SEDs for our extragalactic sources. We fit a variety of templates to determine bolometric luminosities, and to constrain AGN and starburst components where both are present. While ~58% of X-ray Seyferts require a starburst event to fit observed photometry only 26% of the X-ray QSO population appear to have some kind of star formation contribution. This is significantly lower than for the Seyferts, especially if we take into account torus contamination at z>1 where the majority of our X-ray QSOs lie. In addition, we observe a rapid drop of the percentage of starburst contribution as X-ray luminosity increases. This is consistent with the quenching of star formation by powerful QSOs, as predicted by the merger model, or with a time lag between the peak of star formation and QSO activity. We have tested the hypothesis that there should be a strong connection between X-ray obscuration and star-formation but we do not find any association between X-ray column density and star formation rate both in the general population or the star-forming X-ray Seyferts. Our large compilation also allows us to report here the identification of 81 XBONG, 78 z>3 X-ray sources and 8 Type-2 QSO candidates. Also we have identified the highest redshift (z=5.4135) X-ray selected QSO with optical spectroscopy.Astronom

Darstellung von Design-Objekten in relationalen Datenbanken

Design-Objekte werden durch eine beliebig komplexe interne Struktur und durch eine explizite Zusammensetzbarkeit aus anderen Objekten beschrieben. Es werden Mechanismen dargestellt, komplexe Objekte in einer rationalen Datenbank abzulegen und konsistenz-erhaltend zu manipulieren. Durch Beispiel Schemata u.a. fuer EDIF wird gezeigt, dass sich VLSI-spezifische Datenstrukturen auf das Modell abbilden lassen. (AGD

Towards Support for Long-Term Digital Preservation in Product Life Cycle Management

Important legal and economic motivations exist for the design and engineering industry to address and integrate digital long-term preservation into product life cycle management (PLM). Investigations revealed that it is not sufficient to archive only the product design data which is created in early PLM phases, but preservation is needed for data that is produced during the entire product lifecycle including early and late phases. Data that is relevant for preservation consists of requirements analysis documents, design rationale, data that reflects experiences during product operation and also metadata like social collaboration context. In addition, also the engineering environment itself that contains specific versions of all tools and services is a candidate for preservation. This paper takes a closer look at engineering preservation use case scenarios as well as PLM characteristics and workflows that are relevant for long-term preservation. Resulting requirements for a long-term preservation system lead to an OAIS (Open Archival Information System) based system architecture and a proposed preservation service interface that respects the needs of the engineering industry

Towards Support for Long-Term Digital Preservation in Product Life Cycle Management: Paper - iPRES 2009 - San Francisco

Important legal and economic motivations exist for the design and engineering industry to address and integrate digital long-term preservation into product life cycle management (PLM). Investigations revealed that it is not sufficient to archive only the product design data which is created in early PLM phases, but preservation is needed for data that is produced during the entire product lifecycle including early and late phases. Data that is relevant for preservation consists of requirements analysis documents, design rationale, data that reflects experiences during product operation and also metadata like social collaboration context. In addition, also the engineering environment itself that contains specific versions of all tools and services is a candidate for preservation. This paper takes a closer look at engineering preservation use case scenarios as well as PLM characteristics and workflows that are relevant for long-term preservation. Resulting requirements for a long-term preservation system lead to an OAIS (Open Archival Information System) based system architecture and a proposed preservation service interface that respects the needs of the engineering industry