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Displaying 1-50 out of 118 total
A Heuristics-Based Approach to Query Optimization in Structured Document Databases
Found in: Database Engineering and Applications Symposium, International
By Dunren Che, Karl Aberer
Issue Date:August 1999
pp. 24
The number of documents published via WWW in form of SGML/HTML has been rapidly growing for years. Efficient, declarative access mechanisms for this type of documents - structured documents in general - are becoming of great importance. This paper reports ...
 
Keynote: OpenSense: Open sensor networks for air quality monitoring
Found in: Pervasive Computing and Communications Workshops, IEEE International Conference on
By Karl Aberer
Issue Date:March 2012
pp. 1
Wireless sensor networks and publishing of sensor data on the Internet bear the potential to substantially increase public awareness and involvement in environmental sustainability. Air pollution monitoring in urban areas is a prime example of such an appl...
   
Efficient, Self-Contained Handling of Identity in Peer-to-Peer Systems
Found in: IEEE Transactions on Knowledge and Data Engineering
By Karl Aberer, Anwitaman Datta, Manfred Hauswirth
Issue Date:July 2004
pp. 858-869
<p><b>Abstract</b>—Identification is an essential building block for many services in distributed information systems. The quality and purpose of identification may differ, but the basic underlying problem is always to bind a set of attri...
 
Improving Data Access in P2P Systems
Found in: IEEE Internet Computing
By Karl Aberer, Magdalena Punceva, Manfred Hauswirth, Roman Schmidt
Issue Date:January 2002
pp. 58-67
<p>Gridella, a P2P system based on the P-Grid approach, improves on Gnutella's search performance while reducing bandwidth requirements.</p>
 
An Evaluation of Model-Based Approaches to Sensor Data Compression
Found in: IEEE Transactions on Knowledge and Data Engineering
By Nguyen Quoc Viet Hung,Hoyoung Jeung,Karl Aberer
Issue Date:November 2013
pp. 2434-2447
As the volumes of sensor data being accumulated are likely to soar, data compression has become essential in a wide range of sensor-data applications. This has led to a plethora of data compression techniques for sensor data, in particular model-based appr...
 
Energy-Efficient Opportunistic Collaborative Sensing
Found in: 2013 IEEE 10th International Conference on Mobile Ad-Hoc and Sensor Systems (MASS)
By Julien Eberle, Zhixian Yan,Karl Aberer
Issue Date:October 2013
pp. 374-378
This paper studies mobile sensing in a complete distributed and opportunistic scheme. We present a novel sensing strategy for sensing nodes without movement constraints. This strategy offers information sharing and sensor scheduling that maximizes the bene...
 
Impact of Instance Seeking Strategies on Resource Allocation in Cloud Data Centers
Found in: 2013 IEEE 6th International Conference on Cloud Computing (CLOUD)
By Hao Zhuang, Xin Liu, Zhonghong Ou,Karl Aberer
Issue Date:June 2013
pp. 27-34
With the prosperity of cloud computing, an increasing number of Small and Medium-sized Enterprises (SMEs) move their business to public clouds such as Amazon EC2. To help tenants deploy services in the cloud, researchers either conduct performance evaluati...
 
AFFINITY: Efficiently querying statistical measures on time-series data
Found in: 2013 IEEE International Conference on Data Engineering (ICDE 2013)
By Saket Sathe,Karl Aberer
Issue Date:April 2013
pp. 841-852
Computing statistical measures for large databases of time series is a fundamental primitive for querying and mining time-series data [1]–[6]. This primitive is gaining importance with the increasing number and rapid growth of time series databases. In thi...
 
Topick: Accurate Topic Distillation for User Streams
Found in: 2012 IEEE 12th International Conference on Data Mining Workshops
By Anton Dimitrov,Alexandra Olteanu,Luke Mcdowell,Karl Aberer
Issue Date:December 2012
pp. 882-885
Users of today's information networks need to digest large amounts of data. Therefore, tools that ease the task of filtering the relevant content are becoming necessary. One way to achieve this is to identify the users who generate content in a certain top...
 
Scalia: An adaptive scheme for efficient multi-cloud storage
Found in: 2012 SC - International Conference for High Performance Computing, Networking, Storage and Analysis
By Thanasis G. Papaioannou,Nicolas Bonvin,Karl Aberer
Issue Date:November 2012
pp. 1-10
A growing amount of data is produced daily resulting in a growing demand for storage solutions. While cloud storage providers offer a virtually infinite storage capacity, data owners seek geographical and provider diversity in data placement, in order to a...
 
Global Sensor Modeling and Constrained Application Methods Enabling Cloud-Based Open Space Smart Services
Found in: 2012 IEEE 9th Int'l Conference on Ubiquitous Intelligence & Computing / 9th Int'l Conference on Autonomic & Trusted Computing (UIC/ATC)
By Anh Le Tu'n,Hoan N. Mau Quoc,Martin Serrano,Manfred Hauswirth,John Soldatos,Thanasis Papaioannou,Karl Aberer
Issue Date:September 2012
pp. 196-203
The deployment and provisioning of intelligent systems and utility-based services will greatly benefit from a cloud-based intelligent middleware framework, which could be deployed over multiple infrastructure providers (such as smart cities, hospitals, cam...
 
OptiMoS: Optimal Sensing for Mobile Sensors
Found in: 2012 13th IEEE International Conference on Mobile Data Management (MDM)
By Zhixian Yan,Julien Eberle,Karl Aberer
Issue Date:July 2012
pp. 105-114
Both sensor coverage maximization and energy cost minimization are the fundamental requirements in the design of real-life mobile sensing applications, e.g., (1) deploying environmental sensors (like CO2, fine particle measurement) on public transports to ...
 
Social and Sensor Data Fusion in the Cloud
Found in: 2012 13th IEEE International Conference on Mobile Data Management (MDM)
By Surender Reddy Yerva,Jonnahtan Saltarin,Hoyoung Jeung,Karl Aberer
Issue Date:July 2012
pp. 276-277
This paper explores the potential of fusing social and sensor data in the cloud, presenting a practice -- a travel recommendation system that offers the predicted mood information of people on where and when users wish to travel. The system is built upon a...
 
Energy-Efficient Continuous Activity Recognition on Mobile Phones: An Activity-Adaptive Approach
Found in: 2012 16th Annual International Symposium on Wearable Computers (ISWC)
By Zhixian Yan,Vigneshwaran Subbaraju,Dipanjan Chakraborty,Archan Misra,Karl Aberer
Issue Date:June 2012
pp. 17-24
Power consumption on mobile phones is a painful obstacle towards adoption of continuous sensing driven applications, e.g., continuously inferring individual's locomotive activities (such as 'sit', 'stand' or 'walk') using the embedded accelerometer sensor....
 
SAMMPLE: Detecting Semantic Indoor Activities in Practical Settings Using Locomotive Signatures
Found in: 2012 16th Annual International Symposium on Wearable Computers (ISWC)
By Zhixian Yan,Dipanjan Chakraborty,Archan Misra,Hoyoung Jeung,Karl Aberer
Issue Date:June 2012
pp. 37-40
We analyze the ability of mobile phone-generated accelerometer data to detect high-level (i.e., at the semantic level) indoor lifestyle activities, such as cooking at home and working at the workplace, in practical settings. We design a 2-Tier activity ext...
 
Towards the Realization of Decentralized Online Social Networks: An Empirical Study
Found in: 2012 32nd International Conference on Distributed Computing Systems Workshops (ICDCS Workshops)
By Rammohan Narendula,Thanasis G. Papaioannou,Karl Aberer
Issue Date:June 2012
pp. 155-162
As the Online Social Networks (OSNs) amass un-precedented amounts of personal information, the privacy concerns gain considerable attention from the community. Apart from privacy-enabling approaches for existing OSNs, a number of initiatives towards buildi...
 
Analyzing the Emergence of Semantic Agreement among Rational Agents
Found in: E-Commerce Technology, IEEE International Conference on
By Golnaz Vakili,Thanasis G. Papaioannou,Zolt´n Miklós,Karl Aberer,Siavash Khorsandi
Issue Date:September 2011
pp. 161-166
To days complex online applications often require the interaction of multiple services that potentially belong to different business entities. Interoperability is a core element of such an environment, yet not a straightforward one. In this paper, we argue...
 
Towards Online Multi-model Approximation of Time Series
Found in: Mobile Data Management, IEEE International Conference on
By Thanasis G. Papaioannou,Mehdi Riahi,Karl Aberer
Issue Date:June 2011
pp. 33-38
The increasing use of sensor technology for various monitoring applications (e.g. air-pollution, traffic, climate-change, etc.) has led to an unprecedented volume of streaming data that has to be efficiently aggregated, stored and retrieved. Real-time mode...
 
Autonomic SLA-Driven Provisioning for Cloud Applications
Found in: Cluster Computing and the Grid, IEEE International Symposium on
By Nicolas Bonvin, Thanasis G. Papaioannou, Karl Aberer
Issue Date:May 2011
pp. 434-443
Significant achievements have been made for automated allocation of cloud resources. However, the performance of applications may be poor in peak load periods, unless their cloud resources are dynamically adjusted. Moreover, although cloud resources dedica...
 
Advanced search, visualization and tagging of sensor metadata
Found in: Data Engineering, International Conference on
By Ioannis Paparrizos,Hoyoung Jeung,Karl Aberer
Issue Date:April 2011
pp. 1356-1359
As sensors continue to proliferate, the capabilities of effectively querying not only sensor data but also its metadata becomes important in a wide range of applications. This paper demonstrates a search system that utilizes various techniques and tools fo...
 
Creating probabilistic databases from imprecise time-series data
Found in: Data Engineering, International Conference on
By Saket Sathe,Hoyoung Jeung,Karl Aberer
Issue Date:April 2011
pp. 327-338
Although efficient processing of probabilistic databases is a well-established field, a wide range of applications are still unable to benefit from these techniques due to the lack of means for creating probabilistic databases. In fact, it is a challenging...
 
An Economic Approach for Scalable and Highly-Available Distributed Applications
Found in: Cloud Computing, IEEE International Conference on
By Nicolas Bonvin, Thanasis G. Papaioannou, Karl Aberer
Issue Date:July 2010
pp. 498-505
Service-oriented architecture (SOA) paradigm for orchestrating large-scale distributed applications offers significant cost savings by reusing existing services. However, the high irregularity of client requests and the distributed nature of the approach m...
 
Privacy-Aware and Highly-Available OSN Profiles
Found in: Enabling Technologies, IEEE International Workshops on
By Rammohan Narendula, Thanasis G. Papaioannou, Karl Aberer
Issue Date:June 2010
pp. 211-216
The explosive growth of online social networks (OSNs) and their wide popularity suggest the impact of OSNs on today's Internet. At the same time, concentration of vast amount of personal information within a single administrative domain causes critical pri...
 
Effective Metadata Management in Federated Sensor Networks
Found in: Sensor Networks, Ubiquitous, and Trustworthy Computing, International Conference on
By Hoyoung Jeung, Sofiane Sarni, Ioannis Paparrizos, Saket Sathe, Karl Aberer, Nicholas Dawes, Thanasis G. Papaioannou, Michael Lehning
Issue Date:June 2010
pp. 107-114
As sensor networks become increasingly popular, heterogeneous sensor networks are being interconnected into federated sensor networks and provide huge volumes of sensor data to large user communities for a variety of applications. Effective metadata manage...
 
Continuous query evaluation over distributed sensor networks
Found in: Data Engineering, International Conference on
By Oana Jurca, Sebastian Michel, Alexandre Herrmann, Karl Aberer
Issue Date:March 2010
pp. 912-923
In this paper<sup>1</sup> we address the problem of processing continuous multi-join queries, over distributed data streams. Our approach makes use of existing work in the field of publish/subscribe systems. We show how these principles can be ...
 
Cost-efficient and differentiated data availability guarantees in data clouds
Found in: Data Engineering, International Conference on
By Nicolas Bonvin, Thanasis G. Papaioannou, Karl Aberer
Issue Date:March 2010
pp. 980-983
Failures of any type are common in current datacenters. As data scales up, its availability becomes more complex, while different availability levels per application or per data item may be required. In this paper, we propose a self-managed key-value store...
 
Towards better entity resolution techniques for Web document collections
Found in: Data Engineering Workshops, 22nd International Conference on
By Surender Reddy Yerva, Zoltan Miklos, Karl Aberer
Issue Date:March 2010
pp. 209-214
As person names are non-unique, the same name on different Web pages might or might not refer to the same real-world person. This entity identification problem is one of the most challenging issues in realizing the Semantic Web or entity-oriented search. W...
 
Enabling Secure Secret Sharing in Distributed Online Social Networks
Found in: Computer Security Applications Conference, Annual
By Le-Hung Vu, Karl Aberer, Sonja Buchegger, Anwitaman Datta
Issue Date:December 2009
pp. 419-428
We study a new application of threshold-based secret sharing in a distributed online social network (DOSN), where users need a means to back up and recover their private keys in a network of untrusted servers. Using a simple threshold-based secret sharing ...
 
Self-organized Fault-tolerant Routing in Peer-to-Peer Overlays
Found in: Self-Adaptive and Self-Organizing Systems, IEEE International Conference on
By Wojciech Galuba, Karl Aberer, Zoran Despotovic, Wolfgang Kellerer
Issue Date:September 2009
pp. 30-39
In sufficiently large heterogeneous overlays message loss and delays are likely to occur. This has a significant impact on overlay routing, especially on longer paths. The existing solutions to this problem rely on message redundancy to mask the loss and d...
 
Synergies of Different Reputation Systems: Challenges and Opportunities
Found in: Privacy, Security, Trust and the Management of e-Business, World Congress on
By Le-Hung Vu, Thanasis G. Papaioannou, Karl Aberer
Issue Date:August 2009
pp. 218-226
Reputation is a well established means to determine trustworthiness in online systems in various contexts, e.g. online transactions, product recommendation, e-mail spam fighting, etc. However, typically these reputation systems are ``closed'' outside of th...
 
Towards Probabilistic Estimation of Quality of Online Services
Found in: Web Services, IEEE International Conference on
By Le-Hung Vu, Karl Aberer
Issue Date:July 2009
pp. 99-106
Accurate estimation of quality of online services is both an important and difficult problem, since a service has many interdependent quality attributes influenced by several contextual factors. It is even more challenging as quality ratings come from sour...
 
Knowing When to Slide - Efficient Scheduling for Sliding Window Processing
Found in: Mobile Data Management, IEEE International Conference on
By Ali Salehi, Mehdi Riahi, Sebastian Michel, Karl Aberer
Issue Date:May 2009
pp. 202-211
We consider sliding window query execution scheduling in stream processing engines. Sliding windows are an essential building block to limit the query focus at a particular part of the stream, based either on value count or time ranges. These so called sli...
 
Environmental Monitoring 2.0
Found in: Data Engineering, International Conference on
By Sebastian Michel, Ali Salehi, Liqian Luo, Nicholas Dawes, Karl Aberer, Guillermo Barrenetxea, Mathias Bavay, Aman Kansal, K. Ashwin Kumar, Suman Nath, Marc Parlange, Stewart Tansley, Catharine van Ingen, Feng Zhao, Yongluan Zhou
Issue Date:April 2009
pp. 1507-1510
A sensor network data gathering and visualization infrastructure is demonstrated, comprising of Global Sensor Networks (GSN) middleware and Microsoft SensorMap. Users are invited to actively participate in the process of monitoring real-world deployments a...
 
Sensor Metadata Management and Its Application in Collaborative Environmental Research
Found in: eScience, IEEE International Conference on
By Nicholas Dawes, K. Ashwin Kumar, Sebastian Michel, Karl Aberer, Michael Lehning
Issue Date:December 2008
pp. 143-150
This paper considers metadata generation and tracking in a collaborative environment where users publish raw sensor data in the form of virtual sensors and post-process data by means of filtering, modeling, or query processing techniques. In the metadata s...
 
Effective Usage of Computational Trust Models in Rational Environments
Found in: Web Intelligence and Intelligent Agent Technology, IEEE/WIC/ACM International Conference on
By Le-Hung Vu, Karl Aberer
Issue Date:December 2008
pp. 583-586
Reputation-based trust models using statistical learning have been intensively studied for distributed systems where peers behave maliciously. However practical applications of such models in environments with both malicious and rational behaviors are stil...
 
ProtoPeer: From Simulation to Live Deployment in One Step
Found in: Peer-to-Peer Computing, IEEE International Conference on
By Wojciech Galuba, Karl Aberer, Zoran Despotovic, Wolfgang Kellerer
Issue Date:September 2008
pp. 191-192
We present ProtoPeer 1, a peer-to-peer systems prototyping toolkit that allows for switching between the event driven simulation and live network deployment without changing any of the application code. ProtoPeer exports a set of APIs for message passing, ...
 
Efficient and Robust Secure Aggregation for Sensor Networks
Found in: IEEE Workshop on Secure Network Protocols
By Parisa Haghani, Panos Papadimitratos, Marcin Poturalski, Karl Aberer, Jean-Pierre Hubaux
Issue Date:October 2007
pp. 1-6
Wireless Sensor Networks (WSNs) rely on in-network aggregation for efficiency, however, this comes at a price: A single adversary can severely influence the outcome by contributing an arbitrary partial aggregate value. Secure in-network aggregation can det...
 
On Routing in Distributed Hash Tables
Found in: Peer-to-Peer Computing, IEEE International Conference on
By Fabius Klemm, Sarunas Girdzijauskas, Jean-Yves Le Boudec, Karl Aberer
Issue Date:September 2007
pp. 113-122
<p>There have been many proposals for constructing routing tables for Distributed Hash Tables (DHT). They can be classified into two groups: A) those that assume that the peers are uniformly randomly distributed in the identifier space, and B) those ...
 
An Extensible and Personalized Approach to QoS-enabled Service Discovery
Found in: Database Engineering and Applications Symposium, International
By Le-Hung Vu, Fabio Porto, Karl Aberer, Manfred Hauswirth
Issue Date:September 2007
pp. 37-45
We present an extensible and customizable framework for the autonomous discovery of Semantic Web services based on their QoS properties. Using semantic technologies, users can specify the QoS matching model and customize the ranking of services flexibly ac...
 
GridVine: An Infrastructure for Peer Information Management
Found in: IEEE Internet Computing
By Philippe Cudré-Mauroux, Suchit Agarwal, Karl Aberer
Issue Date:September 2007
pp. 36-44
GridVine is a semantic overlay infrastructure based on a peer-to-peer (P2P) access structure. Built following the principle of data independence, it separates a logical layer&#8212;in which data, schemas, and schema mappings are managed&#8212;from ...
 
Infrastructure for Data Processing in Large-Scale Interconnected Sensor Networks
Found in: Mobile Data Management, IEEE International Conference on
By Karl Aberer, Manfred Hauswirth, Ali Salehi
Issue Date:May 2007
pp. 198-205
No summary available.
 
Smart Earth: From Pervasive Observation to Trusted Information
Found in: Mobile Data Management, IEEE International Conference on
By Karl Aberer
Issue Date:May 2007
pp. 3-7
No summary available.
 
Query-load balancing in structured overlays
Found in: Cluster Computing and the Grid, IEEE International Symposium on
By Anwitaman Datta, Roman Schmidt, Karl Aberer
Issue Date:May 2007
pp. 453-460
Query-load (forwarding and answering) balancing in structured overlays is one of the most critical and least studied problems. It has been assumed that caching heuristics can take care of it. We expose that caching, while necessary, is not in itself suffic...
 
Oscar: A Data-Oriented Overlay For Heterogeneous Environments
Found in: Data Engineering, International Conference on
By Sarunas Girdzijauskas, Anwitaman Datta, Karl Aberer
Issue Date:April 2007
pp. 1365-1367
Quite a few data-oriented overlay networks have been designed in recent years. These designs often (implicitly) assume various homogeneity which seriously limit their usability in real world. In this paper we present some performance results of the Oscar o...
 
Scalable Peer-to-Peer Web Retrieval with Highly Discriminative Keys
Found in: Data Engineering, International Conference on
By Ivana Podnar, Martin Rajman, Toan Luu, Fabius Klemm, Karl Aberer
Issue Date:April 2007
pp. 1096-1105
The suitability of Peer-to-Peer (P2P) approaches for fulltext web retrieval has recently been questioned because of the claimed unacceptable bandwidth consumption induced by retrieval from very large document collections. In this contribution we formalize ...
 
Invited Talk: Zero-Programming Sensor Network Deployment
Found in: Applications and the Internet Workshops, IEEE/IPSJ International Symposium on
By Karl Aberer, Manfred Hauswirth, Ali Salehi
Issue Date:January 2007
pp. 1
The availability of cheap and smart wireless sensing devices provides unprecedented possibilities to monitor the physical world. On the technical side these devices introduce several original research problems, many of them related to the integration of th...
 
Structure and Dynamics of Emergent Semantics Systems
Found in: Semantics, Knowledge and Grid, International Conference on
By Karl Aberer
Issue Date:November 2006
pp. 1
Until recently, most data interoperability techniques involved central components, e.g., global schemas or ontologies, to overcome semantic heterogeneity for enabling transparent access to heterogeneous data sources. Today, however, with the democratizatio...
   
Internet-Scale Storage Systems under Churn -- A Study of the Steady-State using Markov Models
Found in: Peer-to-Peer Computing, IEEE International Conference on
By Anwitaman Datta, Karl Aberer
Issue Date:June 2006
pp. 133-144
Content storage in a distributed collaborative environment uses redundancy for better resilience and thus provides good availability and durability. In a peer-to-peer environment, where peers continuously leave and rejoin the network, various lazy strategi...
 
Congestion Control for Distributed Hash Tables
Found in: Network Computing and Applications, IEEE International Symposium on
By Fabius Klemm, Jean-Yves Le Boudec, Karl Aberer
Issue Date:July 2006
pp. 189-195
Distributed Hash Tables (DHTs) provide a scalable mechanism for mapping identifiers to socket addresses. As each peer in the network can initiate lookup requests, a DHT has to process concurrently a potentially very large number of requests. In this paper,...
 
Probabilistic Message Passing in Peer Data Management Systems
Found in: Data Engineering, International Conference on
By Philippe Cudre-Mauroux, Karl Aberer, Andras Feher
Issue Date:April 2006
pp. 41
Until recently, most data integration techniques involved central components, e.g., global schemas, to enable transparent access to heterogeneous databases. Today, however, with the democratization of tools facilitating knowledge elicitation in machine-pro...
 
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