Partner Organizations:

Other collaborators:

We have established a collaboration with Microsoft Research 
(Dr. Christopher Meek) and Unisys (Dr. Doug Tolbert) and with 
IBM Research (Dr. Themis Palpanas). Through these collaborations 
we expect to have impact on real-life applications of the techniques
we propose.

Activities and findings:

Research and Education Activities: 

The purpose of this research is to develop a robust, adaptive and  
scalable infrastructure for a self-organizing and highly dynamic  
sensor network.        
The distinguishing characteristic of our project is that we take a  
holistic approach that addresses multiple levels of the sensor  
network (namely the network communication, the operating system and  
the analysis of the data) in an integrated way. The network  
communication and the operating system should be managed in an  
integrated manner so as to provide a robust and adaptive 
infrastructure for the development of computing applications. The 
inferences made by the higher layer applications and data analysis 
functions will determine future trajectories of the mobile agents, 
and may invoke the tuning of certain parameters that determine the 
extent to which data is being collected and fused. These events 
would require the network to re-organize itself. On the other hand, 
the network itself may impose constraints on where the mobile agents 
can move, where data may be fused, and how different entities 
co-ordinate in order to make operations efficient.        
The broader impact of this work will be solutions with wide 
applicability, from civil applications (such as disaster recovery 
management) to military applications (situation awareness in 
battlefield management).        
The educational component of the project aims to develop a strong 
curriculum and activities that will increase educational awareness 
in sensor networks. 

Findings:

We presented new techniques for efficient keywork searching in large 
scale P2P networks (CISE2004, ISJ2004), and for managing large scale 
P2P systems (Network2004, DSO2004). 
These techniques can facilitate the deployment of large scale 
distributed systems for many applications, including finance, 
security, and surveillance. 
We are also working on techniques for managing sensor networks, and 
for analyzing data collected by sensor networks (SIGMOD2004, 
SIGMODR2003, ISCC2004, ICDE 2004).

Our research has made contributions in multiple levels of the sensor
network architecture. We have developed new techniques for data
compression (DCC 2005, TIME 2005), for robust coverage restoration
of a sensor network (DCOSS 2005), data acquisition and analysis
(NetDB 2005, DMSN 2005, SenMetrics 2005) and congestion-control
techniques for supporting multiple types of traffic (EmNets 2005) 
in sensor networks. We have also developed techniques for real-time
data dissemination (MDM 2005, ISORC 2005), for fair resource
allocation (GlobalInternet 2005), multimedia scheduling (Globecom
2004) and for managing large-scale overlay networks (SelfStar 2005,
WORDS 2005, IPDPS 2005, WPDRTS 2005). Our techniques are focused on
the deployment of an efficient and scalable sensor network
infrastructure for a wide range of monitoring and surveillance 
applications.

We have presented new techniques for managing sensor networks 
(MDM 2006, SECON 2005), for tracking objects in sensor networks
(IJWMC), for efficiently computing spatial queries in sensor
networks (GIS 2005), rate control techniques for real-time data
dissemination in sensor networks (RTSS 2005) and compression
techniques of historical information in sensor networks (ICC 2006).
We have also developed techniques for approximating aggregations 
in peer-to-peer databases (ICDE 2006) and load balancing in
distributed stream processing applications (ISORC 2006).
We are also working on techniques for data storage and for 
analyzing data collected by sensor networks (VLDB 2005, FAST 2005).
Our research will enable the development of robust, adaptable 
and scalable in-network data collection, storage and analysis 
in sensor networks in realistic environments including 
environmental monitoring, object tracking and surveillance.

We have provided new techniques to see how to describe change 
in data that have hierarchical structure (ICDE 2007, KDD 2007) 
and techniques for supporting top-k queries on data streams 
(VLDB 2007a, VLDB 2007b).
We have presented a multi-level feedback system for managing
large-scale distributed systems (JSS 2007) and migration 
algorithms that identify and alleviate hotspots in distributed 
stream processing systems (DBISP2P 2007).
We have also proposed a general framework for computing efficiently 
an approximation of multi-dimensional distributions of streaming 
data that enables the development of a wide variety of complex
streaming applications (SEBD 2007).

Training and Development:

The project has supported 4 graduate students. Fang Chen received
his PhD dgree in June 2005 and is currently working at Oracle.
Kyriakos Karenos earned his MS degree in August 2005 and 
is expected to earn his PhD degree in the 2007-2008 academic year.
Thomas Repantis earned his MS degree in June 2005 and is expected 
to earn his PhD degree in the 2007-2008 academic year. 
Song Lin earned his PhD degree in 2007 and is currently working
at Yahoo.
The PI was also advising one undergraduate student, Jessica Browdus
(through the UC Leads program) who is starting as a PhD student 
at UCR in Fall 2006.

Outreach Activities:

The PI reported parts of the findings in a tutorial presented in  
Middleware 2003.
The PI was invited as a keynote speaker at the Workshop on Mobile
Location-Aware Sensor Networks in May 2006.
The PI was invited as a keynote speaker at the Fourth International
Workshop on Databases, Information Systems and Peer-to-Peer Computing
in September 2006.

Journal Publications:

Yuan W., Krishnamurthy S.V., and Tripathi S.K.,, "Improving the Reliability of Event Reports in Wireless Sensor Networks", IEEE ISCC 2004, vol. , (2004), p. 1., " " Published

V. Kalogeraki and F. Chen, "Managing Distributed Objects in Peer-to-Peer Network", IEEE Networks Magazine, vol. 18, (2004), p. 1., " " Published

T. Palpanas, D. Papadopoulos, V. Kalogeraki and D. Gunopulos, "Distributed Deviation Detection in Sensor Networks", SIGMOD Record, special issue on Sensor Network Technology Infrastructure, Security, Data processing and Deployment, vol. 32, (2004), p. 77., " " Published

F. Chen and V. Kalogeraki, "Self-organizing Unstructured Peer-to-Peer Systems: Opportunities and Challenges", IEEE Distributed Systems Online Magazine, special issue on Peer-to-Peer, vol. , (2003), p. 1., " " Published

D. Zeinalipour-Yazti, V. Kalogeraki, D. Gunopulos, "Exploiting Locality for Scalable Information Retrieval in Peer-to-Peer Networks", Information Systems Journal, vol. 30, (2005), p. 277., " " Published

D. Zeinalipour-Yazti, V. Kalogeraki, D. Gunopulos, "Information Retrieval in Peer-to-Peer Networks", IEEE Computing in Science and Engineering (IEEE CISE) Journal, special issue on Web Engineering, vol. 6, (2004), p. 20., " " Published

T. Repantis, C. Antonopoulos, V. Kalogeraki and T. Papatheodorou, "Dynamic Page Migration in Software DSM Systems", International Conference on Cluster Computing, vol. , (2004), p. 1., " " Published

Michail Vlachos, Christopher Meek, Zografoula Vagena, Dimitrios Gunopulos, "Identifying Similarities, Periodicities and Bursts for Online Search Queries", Proc. ACM SIGMOD Conference, vol. , (2004), p. 131., " " Published

Themistoklis Palpanas, Michail Vlachos, Eamonn J. Keogh, Dimitrios Gunopulos, Wagner Truppel, "Online Amnesic Approximation of Streaming Time Series", Proceedings IEEE ICDE Conference, vol. , (2004), p. 338., " " Published

D. Zeinalipour-Yazti, Z. Vagena, D. Gunopulos, V. Kalogeraki, V. Tsotras, M. Vlachos, N. Koudas, D. Srivastava, "The Threshold Join Algorithm for Top-k Queries in Distributed Sensor Networks", Intl. Workshop on Data Management for Sensor Networks (DMSN) at VLDB'2005, vol. , (2005), p. 61., " " Published

Nitin Kumar, Dimitrios Gunopulos and Vana Kalogeraki, "Sensor Network Coverage Restoration", International Conference on Distributed Computing in Sensor Systems (DCOSS 2005), vol. , (2005), p. 409., " " Published

Kyriakos Karenos, Vana Kalogeraki and Srikanth Krisnamurthy, "Cluster-based Congestion Control for Supporting Multiple Classes of Traffic in Sensor Networks", The Second IEEE Workshop on Embedded Networked Sensors (EmNetS-II), vol. , (2005), p. 107., " " Published

S. Lin, D. Gunopulos, V. Kalogeraki, S. Lonardi, "A Data Compression Technique for Sensor Networks with Dynamic Bandwidth Allocation", 12th Int. Symp. On Temporal Representation and Reasoning (TIME 2005), vol. , (2005), p. 186., " " Published

Thomas Repantis and Vana Kalogeraki, "Data Dissemination in Mobile Peer-to-Peer Networks", International Conference on Mobile Data Management (MDM), vol. , (2005), p. 211., " " Published

Fang Chen and Vana Kalogeraki, "Adaptive Real-Time Update Dissemination in Distributed Virtual Simulation Environments", IEEE International Symposium on Object-oriented Real-time Distributed Computing (ISORC 2005), vol. , (2005), p. 233., " " Published

D. Zeinalipour-Yazti, S. Neema, D. Gunopulos, V. Kalogeraki and W. Najjar, "Data Acquision in Sensor Networks with Large Memories", IEEE International Workshop on Networking Meets Databases (NetDB'05) at ICDE 2005, vol. , (2005), p. 1188., " " Published

Fang Chen, Thomas Repantis and Vana Kalogeraki, "Coordinated Media Streaming and Transcoding in Peer-to-Peer Systems", International Parallel and Distributed Processing Synposium (IPDPS), vol. , (2005), p. 56., " " Published

Thomas Repantis, Yannis Drougas, Vana Kalogeraki, "Adaptive Resource Management in Peer-to-Peer Middleware", 13th Workshop on Parallel and Distributed Real-Time Systems (WPDRTS05) at IPDPS 2005, vol. 03, (2005), p. 132.2., " " Published

S. Neema, A. Mitra, A. Banerjee, W. Najjar, D. Zeinalipour-Yazti, D. Gunopulos, V. Kalogeraki, "NODES: A Novel System Design for Embedded Sensor Networks", IEEE Intl. Conference on Information Processing in Sensor Networks (IPSN 2005), vol. , (2005), p. 1., " " Published

Yannis Drougas, Vana Kalogeraki, "A Fair Resource Allocation Algorithm for Peer-to-Peer Overlay Networks", 8th IEEE Global Internet Symposium, vol. 4, (2005), p. 2853., " " Published

Song Lin, Dimitrios Gunopulos, Stefano Lonardi and Vana Kalogeraki, "Applying LVQ Techniques to Compress Historical Information in Sensor Networks", IEEE Data Compression Conference, vol. , (2005), p. 468., " " Published

V. Kalogeraki, F. Chen, T. Repantis, D. Zeinalipour-Yazti, "Towards Self-Managing QoS-Enabled Peer-to-Peer Systems", Self-Star Properties in Complex Information Systems, Lecture Notes in Computer Science, Springer-Verlag, vol. 3460, (2005), p. 1., " " Published

Vana Kalogeraki and Fang Chen, "On Constructing Overlay Networks to Support Distributed Real-Time Virtual Environment Applications", IEEE WORDS, vol. , (2005), p. 355., " " Published

Fang Chen and Vana Kalogeraki, "RUBEN: A Technique for Scheduling Multimedia Applications in Overlay Networks", IEEE Globecom, vol. 2, (2004), p. 1254., " " Published

Petko Bakalov, Marios Hadjieleftheriou, Eamonn J. Keogh, Vassilis J. Tsotras, "Efficient trajectory joins using symbolic representations", Mobile Data Management, vol. , (2005), p. 86., " " Published

Petko Bakalov, Marios Hadjieleftheriou, Vassilis J. Tsotras, "Time relaxed spatiotemporal trajectory joins", GIS, vol. , (2005), p. 182., " " Published

Donghui Zhang, Vassilis J. Tsotras, "Optimizing spatial Min/Max aggregations", VLDB J., vol. 14, (2005), p. 170., " " Published

D. Zeinalipour-Yazti, V. Kalogeraki, "Structuring Topologically-Aware Overlay Networks using Domain Names", Computer Networks Journal, vol. 50, (2006), p. 3064., " " Published

V. Kalogeraki, D. Zeinalipour-Yazti, D. Gunopulos and A. Delis, "Distributed Middleware Architectures for Scalable Media Services", Journal of Network and Computer Applications, vol. 30, (2006), p. 209., " " Published

M. Halkidi, D. Papadopoulos, V. Kalogeraki and D. Gunopulos, "Resilient and Efficient Tracking in Sensor Networks", International Journal on Wireless and Mobile Computing, vol. 1, (2006), p. 87., " " Published

S. Subramaniam, T. Palpanas, D. Papadopoulos, V. Kalogeraki and D. Gunopulos, "Online Outlier Detection in Sensor Data Using Non-Parametric Models", VLDB, vol. , (2006), p. 187., " " Published

Thomas Repantis, Xiaohui Gu, Vana Kalogeraki, "Synergy: Sharing-Aware Component Composition for Distributed Stream Processing Systems", ACM/IFIP/USENIX 7th International Middleware Conference, vol. , (2006), p. 322., " " Published

Song Lin, Vana Kalogeraki, Dimitrios Gunopulos and Stefano Lonardi, "Online Information Compression in Sensor Networks", International Conference on Communications (ICC 2006), vol. , (2006), p. 1., " " Published

Maria Halkidi, Vana Kalogeraki, Dimitrios Gunopulos, Dimitris Papadopoulos, Demetris Zeinalipour-Yazti and Michalis Vlachos, "Efficient Online State Tracking Using Sensor Networks", 7th International Conference on Mobile Data Management (MDM'06), vol. , (2006), p. 24., " " Published

Benjamin Arai, Gautam Das, Dimitrios Gunopulos, Vana Kalogeraki, "Approximating Aggregations in Peer-to-Peer Databases", 22nd International Conference on Data Engineering (ICDE'06), vol. , (2006), p. 42., " " Published

Yannis Drougas, Thomas Repantis, Vana Kalogeraki, "Load Balancing Techniques for Distributed Stream Processing Applications in Overlay Environments", 9th IEEE International Symposium on Object- and Component-Oriented Real-Time Distributed Computing (ISORC 2006), vol. , (2006), p. 8., " " Published

D. Zeinalipour-Yazti, S. Lin, V. Kalogeraki, D. Gunopulos and W. Najjar, "MicroHash: An Efficient Index Structure for Flash-Based Sensor Devices", 4th USENIX Conference on File and Storage Technologies (FAST '05), vol. , (2005), p. 1., " " Published

Kyriakos Karenos, Vana Kalogeraki and Srikanth Krishnamurthy, "A Rate Control Framework for Supporting Multiple Classes of Traffic in Sensor Networks", The 26th IEEE Real-Time Systems Symposium (RTSS 2005), vol. , (2005), p. 287., " " Published

Amir Soheili, Vana Kalogeraki and Dimitrios Gunopulos, "Spatial Queries in Sensor Networks", 13th International Symposium on Advances in Geographic Information Systems (GIS 2005), vol. , (2005), p. 61., " " Published

A. Banerjee, A. Mitra, W. Najjar, D. Zeinalipour-Yazti, V. Kalogeraki, D. Gunopulos, "RISE-Co-S: High Performance Sensor Storage and Co-Processing Architecture", In Proc. Second Annual IEEE Communications Society Conference on Sensor and Ad Hoc Communications and Networks (SECON 2005), vol. , (2005), p. 1., " " Published

Thomas Repantis, Christos D. Antonopoulos, Vana Kalogeraki, Theodore S. Papatheodorou, "A Case for Dynamic Page Migration in Multiple-Writer Software DSM Systems", 7th IEEE International Conference on Cluster Computing (CLUSTER 2005), vol. , (2005), p. 1., " " Published

D. Zeinalipour-Yazti, V. Kalogeraki, D. Gunopulos, A. Mitra, A. Banerjee and W. Najjar, "Towards In-Situ Data Storage in Sensor Databases", 10th Panhellenic Conference on Informatics (PCI'2005), vol. , (2005), p. 36., " " Published

Marios Hadjieleftheriou, Erik G. Hoel, Vassilis J. Tsotras, "SaIL: A Spatial Index Library for Efficient Application Integration", GeoInformatica, vol. 9, (2005), p. 367., " " Published

Marios Hadjieleftheriou, George Kollios, Petko Bakalov, Vassilis J. Tsotras, "Complex Spatio-Temporal Pattern Queries", VLDB, vol. , (2005), p. 877., " " Published

Marios Hadjieleftheriou, George Kollios, Vassilis J. Tsotras, Dimitrios Gunopulos, "Indexing spatiotemporal archives", VLDB J., vol. 15, (2006), p. 143., " " Published

V. Kalogeraki, P. M. Melliar-Smith, L. E. Moser, Y. Drougas, "Resource Management Using Multiple Feedback Loops in Soft Real-Time Distributed Object Systems", Journal of Systems and Software, vol. , (2007), p. ., " " Accepted

T. Repantis, V. Kalogeraki, "Alleviating Hot-Spots in Peer-to-Peer Stream Processing Environments", Fifth International Workshop on Databases, Information Systems and Peer-to-Peer Computing (DBISP2P 2007), vol. , (2007), p. ., " " Published

D. Barman, F. Korn, D. Srivastava, D. Gunopulos, N. E. Young, D. Agarwal, "Parsimonious Explanations of Change in Hierarchical Data", ICDE 2007, vol. , (2007), p. ., " " Published

D. Agarwal, D. Barman, D. Gunopulos, N. E. Young, F. Korn, D. Srivastava, "Efficient and effective explanation of change in hierarchical summaries", KDD 2007, San Jose, CA, August 2007, vol. , (2007), p. ., " " Published

T. Palpanas, V. Kalogeraki, D. Gunopulos, "Online Distribution Estimation for Streaming Data: Framework and Applications", SEBD 2007, Torre Canne (Fasano, BR), Italy, vol. , (2007), p. ., " " Published

G. Das, D. Gunopulos, N. Koudas, N. Sarkas, "Ad-hoc Top-k Query Answering for Data Streams", VLDB 2007, Vienna, Austria, September 2007, vol. , (2007), p. ., " " Published

B. Arai, G. Das, D. Gunopulos, N. Koudas, "Anytime Measures for Top-k Algorithms", VLDB 2007, Vienna, Austria, September 2007, vol. , (2007), p. ., " " Published

Marios Hadjieleftheriou, Erik G. Hoel, Vassilis J. Tsotras, "SaIL: A Library for Efficient Application Integration of Spatial Indices", SSDBM 2004, vol. , (2004), p. 135., " " Published

Marios Hadjieleftheriou, Vassil Kriakov, Yangui Tao, George Kollios, Alex Delis, Vassilis J. Tsotras, "Spatio-Temporal Data Services in a Shared-Nothing Environment", SSDBM 2004, vol. , (2004), p. 131., " " Published

Song Lin, Benjamin Arai, Dimitrios Gunopulos, "Reliable Hierarchical Data Storage in Sensor Networks", SSDBM 2007, vol. , (2007), p. 26., " " Published

Song Lin, Demetrios Zeinalipour-Yazti, Dimitrios Gunopulos, "Top-k Retrieval Techniques in Distributed Sensor Systems", Encyclopedia of Geographical Information science, Springer, 2007, vol. , (2007), p. ., " " Accepted

Themis Palpanas, Vana Kalogeraki, Dimitrios Gunopulos, "Online Distribution Estimation for Streaming Data: Framework and Applications", SEBD 2007, vol. , (2007), p. 430., " " Published

Song Lin, Benjamin Arai, Dimitrios Gunopulos, Gautam Das, "Region Sampling: Continuous Adaptive Sampling on Sensor Networks", 4th IEEE International Conference on Data Engineering (ICDE), Cancun, Mexico, April 2008, vol. , (2008), p. ., " " Accepted

Jakllari G., Eidenbenz S., Hengartner N., Krishnamurthy S.V. and Faloutsos M., "Link Positions Matter: A Noncommutative routing Metric for Wireless Mesh Networks", INFOCOM 2008, Phoenix, AZ, vol. , (2008), p. ., " " Accepted

He, Y., Faloutsos M., Krishnamurthy S.V. and Chrobak M., "Policy-Aware Topologies for Efficient Inter-Domain Routing Evaluations", INFOCOM Mini Conference 2008, Phoenix, AZ, vol. , (2008), p. ., " " Accepted

Book(s) of other one-time publications(s):

Other Specific Products:


Internet Dissemination:

www.cs.ucr.edu/~vana/sensors.html

Publications and other information about the project will be posted 
at the project's web page as they become available.

Contributions:

Contributions within Discipline:

 The objective of this proposal is to develop new techniques in each 
of the areas of networking, distributed systems and 
data-mining/database and in the synergy of experts from the above 
areas. We will develop a three-layer architecture that tightly 
couples:  
(a) network layer protocols that facilitate the organization of the 
sensor network in order to achieve the desired trade-offs between 
sensor power efficiency and real-time availability,  
(b) the functionalities at the operating systems layer that provide 
real-time scheduling of fusion/aggregation tasks and robustness to 
node failures through replication, and,  
(c) the application layer functions that perform data analysis which 
would in turn provide feedback to the lower layers on how to 
dynamically react to observed phenomena. 
In addition, we will tackle the important problem of integrating 
these techniques in a prototype system and deploy it in a realistic 
environment using our industry contacts. 

Contributions of each PI: 

Prof. Krishnamurthy contributed to the problems of improving the reliability
of event reports in wireless sensor networks to deal with cases of faulty
sensors or malicious intruders that generate and report misleading information
(ISCC 2004). Prof. Krishnamurthy also contributed to the problems of
cluster-based congestion control for real-time data dissemination in sensor
networks (EmNets 2005) and developed a rate control framework for supporting
multiple classes of traffic in sensor networks (RTSS 2005).
In addition, Prof. Krishnamurthy studied the problems of computing
the path with the minimum cost in terms of the expected number
of link layer transmissions when routing in wireless mesh networks (INFOCOM 2008a)
and policy-aware topologies for efficient inter-domain routing evaluations
(INFOCOM 2008b).

Prof. Gunopulos contributed to the problems of analyzing data collected
by sensor networks to identify outliers, similarities, periodicities
and bursts (SIGMODR2003, SIGMOD2004, ISCC2004, ICDE 2004).
He also contributed to the problem of efficient top-k query processing
for  distributed sensor networks (DMSN 2005), initiated a study on the
deployment and use of sensor networks characterized by large memories,
and presented data acquisition and analysis techniques (NetDB 2005,
SenMetrics 2005, PCI 2005). He developed new techniques for efficient
keywork searching in large scale P2P networks (CISE2004, ISJ2004).
He developed new techniques for data compression (DCC 2005, TIME 2005,
ICC 2006) and presented novel distributed techniques for robust coverage
restoration of a sensor network where the goal is to maximize the coverage
of the sensing field while maximizing the lifespan of the sensor network
(DCOSS 2005). He also studied a number of middleware architectures for
timely and reliable delivery of media services in p2p networks (JNCA 2006).
Prof. Gunopulos contributed in the development of techniques for tracking
objects in sensor networks (IJWMC 2006), for efficiently computing spatial
queries in sensor networks (GIS 2005), for data storage (FAST 2005) and
for efficient online outlier detection in sensor data using non-parametric
models (VLDB 2006, SEBD 2007). He also presented online techniques for
computing the state of a sensor network (MDM 2006) and developed 
techniques for approximating aggregations in peer-to-peer databases 
(ICDE 2006). Prof. Gunopulos also presented new techniques for managing
sensor networks (SECON 2005) and for indexing spatiotemporal archives
(VLDB J. 2006). Prof. Gunopulos also contributed to the problems of
reliable hierarchical data storage in sensor networks (SSDBM 2007),
top-k retrieval techniques in distributed sensor systems (Encycl.
of Inf. Science, 2007) and continuous adaptive sampling on 
sensor networks (ICDE 2008).

Prof. Tsotras contributed to the problems of efficient top-k query processing
for  distributed sensor networks where the objective is to find the k
highest ranked answers to a user defined similarity function (DMSN 2005).
He also contributed to the problem of efficient evaluation of trajectory
joins between two datasets (MDM 2005), proposed a new Time Relaxed 
Spatiotemporal Trajectory Join (TRSTJ) technique which effectively finds
groups of moving objects that have followed similar movements in different
times (GIS 2005) and proposed novel techniques to improve the performance
of MIN/MAX queries when an index structure (traditional or specialized)
is present (VLDB 2005). Prof. Tsotras also presented SalL (SpAtial Index
Library), a robust and extensible library that enables simple integration
of spatial index structures in existing applications (SSDBM 2004a,
GeoInformatic 2005). Prof. Tsotras also developed specialized query 
evaluation algorithms for spatio-temporal pattern queries with time 
(VLDB 2005, VLDB J., 2006). Prof. Tsotras proposed a system      that
exploits the inherent parallelism of a shared-nothing computing environment
for storing and indexing the spatio-temporal data (SSDBM 2004b). They
present the proposed system architecture, data organization, and outline
techniques for ensuring robustness and scalability under excessive query
loads and high update rates.


Prof. Kalogeraki contributed to the problems of managing and analyzing
data collected by sensor networks (SIGMODR2003, VLDB 2006, SEBD 2007).
She contributed to the problems of efficient top-k query processing
for  distributed sensor networks (DMSN 2005), robust coverage restoration
of a sensor network where the goal is to maximize the coverage of the
sensor network while maximizing its lifespan (DCOSS 2005). 
She developed rate control techniques for real-time data dissemination
in sensor networks (MDM 2005, ISORC 2005) and congestion-control
techniques for supporting multiple types of traffic (RTSS 2005,
EmNets 2005) in sensor networks.
She also developed novel techniques for managing large scale P2P systems
(Network2004, DSO2004), for efficient keywork searching in large scale
P2P networks (CISE2004, ISJ2004) and dynamic migration schemes to deal
with application hospots (Cluster 2004, Cluster 2005). 
Prof. Kalogeraki has developed new techniques for data compression 
(ICC 2006, DCC 2005, TIME 2005) and data acquisition and analysis techniques
(NetDB 2005, SenMetrics 2005, PCI 2005) for sensor networks. 
She has also contributed to the problems of managing large-scale 
overlays (COMNET 2006, SelfStar 2005, WORDS 2005, IPDPS 2005, WPDRTS 2005),
fair resource allocation (GlobalInternet 2005), load balancing (ISORC2006),
multimedia scheduling (Globecom 2004), timely and reliable delivery 
of media services (JNCA 2006) and sharing-aware component composition
for distributed stream processing systems (Middleware 2006). She also
contributed in the development of techniques for tracking objects 
in sensor networks (IJWMC 2006), for computing the state of a sensor 
network (MDM 2006) and for approximating aggregations in peer-to-peer
databases (ICDE 2006). She also developed efficient indexing techniques
for flash-based sensor devices (FAST 2005, SECON 2005) and techniques
for answering spatial queries in sensor networks (GIS 2005).