385 research outputs found
Adaptive Management of Multimodel Data and Heterogeneous Workloads
Data management systems are facing a growing demand for a tighter integration of heterogeneous data from different applications and sources for both operational and analytical purposes in real-time. However, the vast diversification of the data management landscape has led to a situation where there is a trade-off between high operational performance and a tight integration of data. The difference between the growth of data volume and the growth of computational power demands a new approach for managing multimodel data and handling heterogeneous workloads.
With PolyDBMS we present a novel class of database management systems, bridging the gap between multimodel database and polystore systems. This new kind of database system combines the operational capabilities of traditional database systems with the flexibility of polystore systems. This includes support for data modifications, transactions, and schema changes at runtime. With native support for multiple data models and query languages, a PolyDBMS presents a holistic solution for the management of heterogeneous data. This does not only enable a tight integration of data across different applications, it also allows a more efficient usage of resources. By leveraging and combining highly optimized database systems as storage and execution engines, this novel class of database system takes advantage of decades of database systems research and development.
In this thesis, we present the conceptual foundations and models for building a PolyDBMS. This includes a holistic model for maintaining and querying multiple data models in one logical schema that enables cross-model queries. With the PolyAlgebra, we present a solution for representing queries based on one or multiple data models while preserving their semantics. Furthermore, we introduce a concept for the adaptive planning and decomposition of queries across heterogeneous database systems with different capabilities and features.
The conceptual contributions presented in this thesis materialize in Polypheny-DB, the first implementation of a PolyDBMS. Supporting the relational, document, and labeled property graph data model, Polypheny-DB is a suitable solution for structured, semi-structured, and unstructured data. This is complemented by an extensive type system that includes support for binary large objects. With support for multiple query languages, industry standard query interfaces, and a rich set of domain-specific data stores and data sources, Polypheny-DB offers a flexibility unmatched by existing data management solutions
Rhodium-catalysed hydroformylation of N-(2-propenyl)-β-lactams as a key step in the synthesis of functionalised N-[4-(2-oxoazetidin-1-yl)but-1-enyl]acetamides
Biologically relevant functionalised N-[4-(2-oxoazetidin-1-yl)but-1-enyl]acetamides have been prepared in a two-step approach starting from N-(2-propenyl)-beta-lactams, involving initial rhodium-catalysed hydroformylation followed by subjection of the obtained aldehydes to Staudinger reaction conditions after initial imination
Adapting IT Governance Frameworks using Domain Specific Requirements Methods: Examples from Small & Medium Enterprises and Emergency Management
IT Governance methods and frameworks have been applied in most large for-profit organizations since these enterprisesrealize the benefits of IT Governance for their business. However, former research and our own surveys show thatframeworks such as ITIL and COBIT are not very well established in Small and Medium Enterprises (SME) as well as inEmergency Management (EM) organizations. Thus, we investigated what kind of barriers can be the cause for the lowadoption rate. These results built the basis for our Domain Specific Engineering (DSE) approach. The research is based onthe data of two research projects. The first project investigated the utilization of ITSM methods in European SMEs, and thesecond has researched different emergency management organizations. This paper defines similarities and differences of thetwo domain specific solutions, describes the engineering approach, and gives guidelines for further research in otherdomains
Rh-catalyzed linear hydroformylation of styrene
Usually the Rh-catalyzed hydroformylation of styrene predominantly yields the
branched, chiral aldehyde. An inversion of regioselectivity can be achieved
using strong π-acceptor ligands. Binaphthol-based diphosphite and bis
(dipyrrolyl-phosphorodiamidite) ligands were applied in the Rh-catalyzed
hydroformylation of styrene. High selectivities up to 83% of 3-phenylpropanal
were obtained with 1,1-bi-2-naphthol-based bis(dipyrrolyl-phosphorodiamidite)
with virtually no hydrogenation to ethyl benzene. The coordination chemistry
of those ligands towards Rh(I) was investigated spectroscopically and
structurally
1167-223 Should patients with complete heart block and severe heart failure be upgraded to a resynchronization system?
Predictive value of tissue doppler echocardiographic findings on positive left ventricular remodeling induced by cardiac resynchronization therapy
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