TY  - JOUR
A1  - Sepp, T.
A1  - Tempel, E.
A1  - Gramann, M.
A1  - Nurmi, P.
A1  - Haupt, Michael
T1  - Studying the patterns of the universe
JF  - Baltic astronomy
N2  - The SDSS galaxy catalog is one of the best databases for galaxy distribution studies. The SDSS DR8 data is used to construct the galaxy cluster catalog. We construct the clusters from the calculated luminosity density field and identify denser regions. Around these peak regions we construct galaxy clusters. Another interesting question in cosmology is how observable galaxy structures are connected to underlying dark matter distribution. To study this we compare the SDSS DR7 galaxy group catalog with galaxy groups obtained from the semi-analytical Millennium N-Body simulation. Specifically, we compare the group richness, virial radius, maximum separation and velocity dispersion distributions and find a relatively good agreement between the mock catalog and observations. This strongly supports the idea, that the dark matter distribution and galaxies in the semi-analytical models and observations are very closely linked.
KW  - galaxies: groups, clusters
KW  - cosmology: dark matter, large-scale structure of the Universe
Y1  - 2011
SN  - 1392-0049
VL  - 20
IS  - 2
SP  - 309
EP  - 312
PB  - Institute of Theoretical Physics and Astronomy
CY  - Moletai
ER  - 
TY  - JOUR
A1  - Hirschfeld, Robert
A1  - Perscheid, Michael
A1  - Haupt, Michael
T1  - Explicit use-case representation in object-oriented programming languages
JF  - ACM SIGPLAN notices
N2  - Use-cases are considered an integral part of most contemporary development processes since they describe a software system's expected behavior from the perspective of its prospective users. However, the presence of and traceability to use-cases is increasingly lost in later more code-centric development activities. Use-cases, being well-encapsulated at the level of requirements descriptions, eventually lead to crosscutting concerns in system design and source code. Tracing which parts of the system contribute to which use-cases is therefore hard and so limits understandability.
 In this paper, we propose an approach to making use-cases first-class entities in both the programming language and the runtime environment. Having use-cases present in the code and the running system will allow developers, maintainers, and operators to easily associate their units of work with what matters to the users. We suggest the combination of use-cases, acceptance tests, and dynamic analysis to automatically associate source code with use-cases. We present UseCasePy, an implementation of our approach to use-case-centered development in Python, and its application to the Django Web framework.
KW  - design
KW  - languages
KW  - use-cases
KW  - separation of concerns
KW  - traceability
Y1  - 2012
U6  - https://doi.org/10.1145/2168696.2047856
SN  - 0362-1340
VL  - 47
IS  - 2
SP  - 51
EP  - 60
PB  - Association for Computing Machinery
CY  - New York
ER  - 
TY  - JOUR
A1  - Haupt, Michael
A1  - Adams, Bram
A1  - Timbermont, Stijn
A1  - Gibbs, Celina
A1  - Coady, Yvonne
A1  - Hirschfeld, Robert
T1  - Disentangling virtual machine architecture
N2  - Virtual machine (VM) implementations are made of intricately intertwined subsystems, interacting largely through implicit dependencies. As the degree of crosscutting present in VMs is very high, VM implementations exhibit significant internal complexity. This study proposes an architecture approach for VMs that regards a VM as a composite of service modules coordinated through explicit bidirectional interfaces. Aspect-oriented programming techniques are used to establish these interfaces, to coordinate module interaction, and to declaratively express concrete VM architectures. A VM architecture description language is presented in a case study, illustrating the application of the proposed architectural principles.
Y1  - 2009
UR  - http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=4124007
U6  - https://doi.org/10.1049/iet-sen.2007.0121
SN  - 1751-8806
ER  -