Dipl.-Math. Liz Ribe-Baumann

Technische Universität Ilmenau
Fakultät für Informatik und Automatisierung
FG Datenbanken und Informationssysteme
Postfach 100 565
D-98684 Ilmenau

Phone: +49 (0) 3677 69 4580
FAX: +49 (0) 3677 69 4541
E-Mail: liz.ribe-baumann[at]tu-ilmenau.de
Room: Zusebau 3097

Short CV

Liz Ribe-Baumann was born in 1982 in Oak Park/ USA. She received her Diploma (M.Sc.) in Mathematics from the Ilmenau University of Technology, Germany in 2009 at which time she joined the Database & Information Systems group of the Department of Computer Science and Automation as a Ph.D. student. She is a member of the Internation Graduate School on Mobile Communications.

Research

In disaster scenarios, the quantity of existing data increases quickly as the recovery organization progresses, as does the number of computers one could expect to be offering computational support. A quick, self-organizing, scalable, and well balanced solution to data management is the distribution of data among these computers. However, the wireless links, power restrictions, high failure rates, and network partitioning expected in disaster scenarios present additional challenges, and further developments are necessary to maximize robustness while conserving network resources.

Current approaches to conserving network resources are limited to reducing message latency – at the cost of scalability and load balancing – and largely fail to prepare the system for possible partitioning and conserve network resources. My work, in accord with the goals of the International Graduate School of Mobile Communication, aims to overcome these weaknesses by designing network overlays for highly dynamic systems with consideration to additional parameters such as location, node reliability, and power availability and developing corresponding replication protocols which place and maintain data in strategic positions throughout the network.

Publications

2011

D. Klan, M. Karnstedt, K. Hose, L. Ribe-Baumann, K. Sattler
Stream Engines Meet Wireless Sensor Networks: Cost-Based Planning and Processing of Complex Queries in AnduIN, Distributed and Parallel Databases
Distributed and Parallel Databases, January, Number 1, Pages 151-183, Volume 29, 2011
[Bibtex]
```
@Article{DBIS:KlaKarHos+11,
	Author 	= {Klan, D. and Karnstedt, M. and Hose, K. and Ribe-Baumann, L. and Sattler, K.},
	Journal	= {Distributed and Parallel Databases},
	Month	= {January},
	Number	= {1},
	Pages	= {151-183},
	Title	= {Stream Engines Meet Wireless Sensor Networks: Cost-Based Planning and Processing of Complex Queries in AnduIN, Distributed and Parallel Databases},
	Url	= {http://www.dbis.prakinf.tu-ilmenau.de/publications/files/DBIS:KlaKarHos+11.pdf},
	Volume	= {29},
	Year	= {2011}
}
```
[Abstract]

Wireless sensor networks are powerful, distributed, self-organizing systems used for event and environmental monitoring. In-network query processors like TinyDB afford a user friendly SQL-like application development. Due to sensor nodes' resource limitations, monolithic approaches often support only a restricted number of operators. For this reason, complex processing is typically outsourced to the base station as a part of processing tasks. Nevertheless, previous work has shown that complete or partial in-network processing can be more efficient than the base station approach. In this paper, we introduce AnduIN, a system for developing, deploying, and running complex in-network processing tasks. Particularly, we present the query planning and execution strategies used in AnduIN, which combines sensor-local in-network processing and a data stream engine. Query planning employs a multi-dimensional cost model taking energy consumption into account and decides autonomously which query parts will be processed within the sensor network and which parts will be processed at the central instance.
[Download]
Liz Ribe-Baumann
Combining Resource and Location Awareness in DHTs
OTM 2011, Part I, LNCS 7044, Pages 385-402, 2011, Publisher Springer-Verlag, Berlin Heidelberg
[Bibtex]
```
@Inproceedings{DBIS:Rib11,
	Author 	= {Ribe-Baumann, Liz},
	Booktitle	= {OTM 2011, Part I, LNCS 7044},
	Editor	= {R. Meersman, T. Dillon, and P. Herrero},
	Pages	= {385-402},
	Title	= {Combining Resource and Location Awareness in DHTs},
	Url	= {http://www.dbis.prakinf.tu-ilmenau.de/publications/files/DBIS:Rib11.pdf},
	Year	= {2011},
	Publisher	= {Springer-Verlag},
	Location	= {Berlin Heidelberg}
}
```
[Abstract]

Distributed hash tables are designed to provide reliable distributed data management, but present challenges for networks in which nodes have varying characteristics such as battery or computing power. Assuming that nodes are aware of their resource availability and relative network positions, this paper presents a novel distributed hash table protocol which uses nodes� resource levels to remove load from weak nodes, whose overuse may cause delays or failure, while using nodes� positions to reduce cross-network traffic, which may cause unwanted network load and delays. This protocol provides nodes with links that are physically near with high resource availability, and simultaneously provides scalability and an O(log(N )) routing complexity with N network nodes. Theoretical analysis and simulated evaluation show significant decreases in the routing and maintenance overhead for weak nodes, the physical distances that lookups traverse, and unwanted node failures, as well as an increase node lifetime
[Download]

2010

Markus Brueckner, Liz Ribe-Baumann
Decentralized, Resource-Aware Information Management and Delay Tolerant Networks in Command-and-Control
GI Jahrestagung (2), Pages 175-180, 2010
[Bibtex]
```
@Inproceedings{DBIS:BruRib10,
	Author 	= {Brueckner, Markus and Ribe-Baumann, Liz},
	Booktitle	= {GI Jahrestagung (2)},
	Pages	= {175-180},
	Title	= {Decentralized, Resource-Aware Information Management and
 Delay Tolerant Networks in Command-and-Control},
	Url	= {http://www.dbis.prakinf.tu-ilmenau.de/publications/files/DBIS:BruRib10.pdf},
	Year	= {2010}
}
```
[Abstract]

A robust, decentralized information management system and reliable transport of information between disconnected agents is essential to the success of command and control activities in disaster relief scenarios. We present work-in-progress aimed at developing a distributed hash table (DHT) protocol and a delay-tolerant network that meet the specific requirements of disaster relief scenarios through, among other things, the integration of location and resource awareness.
[Download]
Liz Ribe-Baumann, Kai-Uwe Sattler
A small-world DHT built on generalized network coordinates
Proceedings of the 2010 EDBT/ICDT Workshops, Pages 42:1--42:6, EDBT '10, 2010, Publisher ACM
[Bibtex]
```
@Inproceedings{DBIS:RibSat10,
	Author 	= {Ribe-Baumann,  Liz and Sattler,  Kai-Uwe},
	Booktitle	= {Proceedings of the 2010 EDBT/ICDT Workshops},
	ISBN	= {978-1-60558-990-9},
	Pages	= {42:1--42:6},
	Series	= {EDBT '10},
	Title	= {A small-world DHT built on generalized network coordinates},
	Url	= {http://www.dbis.prakinf.tu-ilmenau.de/publications/files/DBIS:RibSat10.pdf},
	Year	= {2010},
	Publisher	= {ACM},
	DOI	= {http://doi.acm.org/10.1145/1754239.1754286}
}
```
[Abstract]

Large-scale distributed hash tables (DHT) are typically implemented without respect to node location or characteristics, thus producing physically long routes and squandering network resources. Some systems have integrated round trip times through proximity-aware identifier selection (PIS), \proximity-aware route selection (PRS), and proximity-aware neighbor selection (PNS). While PRS and PNS tend to optimize existing systems, PIS deterministically selects node identifiers based on physical node location, leading to a loss of scalability and robustness. The trade off between the scalability and robustness gained from a DHT's randomness and the better allocation of network resources that comes with a location-aware, deterministically structured DHT make it difficult to design a system that is both robust and scalable extitand resource conserving. We present initial ideas for the construction of a small-world DHT which mitigates this trade off by retaining scalability and robustness while effectively integrating round trip times and additional node quality with the help of Vivaldi network coordinates.
[Download]

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