Obstructive Sleep Apnea (OSA) is a common, but severely under- diagnosed sleep disorder characterized by recurring periods of shallow or paused breathing during sleep. It is our long-term goal to allow people to perform the first step towards a sleep apnea de- tection at home by utilizing smartphones, low-cost consumer-grade sensors, and data mining techniques. In this work, we evaluate the signal quality of four respiratory effort sensors (BITalino, FLOW, RespiBAN, and Shimmer), using a RIP sensor from NOX Medical as the gold standard. We design a sixteen-minute signal capture procedure to simulate epochs of disrupted breathing, and capture data from twelve (BITalino and Shimmer) and eleven (RespiBAN and FLOW) subjects during wakefulness. Our signal quality eval- uation approach is based on the breath detection accuracy met- rics sensitivity and positive predictive value (PPV), along with the breath amplitude accuracy metric weighted absolute percentage er- ror (WAPE). These metrics are closely related to how apneic and hypopneic episodes are scored by medical personnel, making it straightforward to reason about their interpretation. Our results show that false breaths are the primary concern affecting the breath detection accuracy of BITalino, Shimmer, and RespiBAN. Respec- tively, the sensitivity of BITalino, Shimmer, RespiBAN, and FLOW is 99.61%, 98.53%, 98.41%, and 98.91%. Their PPV is 96.28%, 96.58%, 90.81%, and 98.81%. Finally, their WAPE is 13.82%, 16.89%, 13.60%, and 8.75%. The supine (back) position is consistently showing the overall best signal quality compared to the side position.
Kristiansen, Stein; Plagemann, Thomas Peter & Goebel, Vera Hermine (2018). An Activity Rule Based Approach to Simulate ADL Sequences. IEEE Access. ISSN 2169-3536. 6, s 12551- 12572 . doi: 10.1109/ACCESS.2018.2807761 Fulltekst i vitenarkiv.
One important class of applications for the Internet of Things is related to the need to gain timely and continuous situational awareness, like smart cities, automated traffic control or emergency and rescue operations. Events happening in the real-world need to be detected in real-time based on sensor data and other data sources. Complex Event Processing (CEP) is a technology to detect complex (or composite) events in data streams and has been successfully applied in high volume and high velocity applications like stock market analysis. However, these applica- tion domains faced only the challenge of high performance, while the Internet of Things and Mobile Big Data introduce a new set of challenges caused by mobility. This chapter aims to explain these challenges and give an overview how they are solved respectively how far state-of-the-art research has advanced to be useful to solve mobile big data problems. At the infrastructure level the main challenge is to trade performance against resource consumption and energy efficiency and op- erator placement is the most dominant mechanisms to address these problems. At the application and consumer level mobile queries pose a new set of challenges for CEP related to continuously changing positions of consumers and producers and the need to adapt the query processing to these changes. Finally, methods and tools for systematical testing and reproducible performance evaluation for mobile distributed CEP is an open problem.
Network simulation is commonly used to evaluate the performance of distributed systems, but these approaches do not account for the performance impact that protocol execution on nodes has on performance, which can be significant. We provide a methodology to extract from real devices models of communication software execution that can be used to extend network simulators to improve their accuracy. The models are obtained by instrumenting the target devices to obtain the events necessary to describe software execution. We specify which events must be captured, how to capture them, and how to transform the event traces into models that can be used to extend network simulators. The obtained models are based on high-level abstractions that can be used to describe the execution of a wide range of communication software, and the design principles to extend network simulators are not restricted to any specific network simulator. The same model of communication software execution can be used without modification in all discrete event-based network simulators that are extended according to our principles. The models are represented in a human-readable format that is suitable for modification and can therefore be used to predict how software modifications impact performance. We evaluate our models with two proof-of-concept extensions of Ns-3 that execute the models of two modern smartphones: the Google Nexus One (GN1) and the Nokia N900. We measure the accuracy of our models by comparing results from real experiments with those from simulations with our models and analyze the simulation overhead of our approach.
Hansen, Hans Vatne; Velazquez, Francisco Javier; Goebel, Vera Hermine & Plagemann, Thomas Peter (2012). Efficient Data Sharing for Multi-device Multimedia Applications, In Christian Fuhrhop; Stephan Steglich & Ajit Jaokar (ed.), Proceedings of the Workshop on Multi-device App Middleware, Multi-Device '12. Association for Computing Machinery (ACM). ISBN 978-1-4503-1617-0. 2.
Hansen, Hans Vatne; Velazquez-Garcia, Francisco Javier; Goebel, Vera Hermine; Munthe-Kaas, Ellen & Plagemann, Thomas Peter (2012). Migration of Fine-grained Multimedia Applications, In Eric Wohlstadter (ed.), Proceedings of the Posters and Demo Track, Middleware '12. Association for Computing Machinery (ACM). ISBN 978-1-4503-1612-5. 12.
Automated home care uses sensors to report about the well-being of monitored persons. Our complex event processing (CEP) system CommonSens simplifies the work of the application programmers, i.e., those who write the complex queries, by facilitating reuse of queries, sensor instances and environments. We have observed that many automated home care systems focus on detecting alarming behaviour, e.g., falls and heart attacks. However, it is impossible to predict and describe everything that can go wrong. In this paper we define deviation detection in CommonSens, which means that the application programmer only needs to state queries that define correct behaviour. If something happens that does not correspond to the query, this is interpreted as a deviation and a notification or alarm is sent. We believe that this approach further simplifies the work of the application programmer. Deviation detection is implemented in our CommonSens prototype, and we show that our prototype detects deviations as expected by running a set of functionality tests and an experiment based on real-world trace files.
May, Martin; Siekkinen, Matti Mikael; Goebel, Vera Hermine; Plagemann, Thomas Peter; Chaparadza, Ranganai & Peluso, Lorenzo (2007). Monitoring as First Class Citizen in an Autonomic Network Universe, In Kenji Leibnitz (ed.), 2nd International Conference on Bio-Inspired Models of Network, Information, and Computing Systems, 2007. IEEE conference proceedings. ISBN 978-963-9799-05-9. Workshop on Technologies for Situated and Autonomic Communications (SAC).
Plagemann, Thomas Peter; Munthe-Kaas, Ellen; Skjelsvik, Katrine S; Puzar, Matija; Goebel, Vera Hermine; Johansen, Ulrik Albert; Gorman, Joe & Marín, Santiago Pérez (2007). A Data Sharing Facility for Mobile Ad-Hoc Emergency and Rescue Applications, In Ling Liu (ed.), 27th International Conference on Distributed Computing Systems - Workshops (ICDCS Workshops 2007). IEEE. ISBN 978-0-7695-2838-0. Kap.
Sanderson, Norun Christine; Goebel, Vera Hermine & Munthe-Kaas, Ellen (2006). Ontology Based Dynamic Updates in Sparse Mobile Ad-hoc Networks for Rescue Scenarios, In Kien Hua & Masaru Kitsuregawa (ed.), Proceedings of the 7th International Conference on Mobile Data Management (MDM'06). IEEE. ISBN 0769525261. artikkel.
Skevik, Karl Andre; Goebel, Vera Hermine & Plagemann, Thomas Peter (2005). Performance comparison of request models for a P2P based streaming Content Distribution Network. Proceedings of the IEICE General Conference. ISSN 1349-1377.
Goebel, Vera Hermine; Griwodz, Carsten; Hafsøe, Trude; Halvorsen, Pål; Johnsen, Frank Trethan; Plagemann, Thomas Peter; Skevik, Karl Andre & Tetlie, Ole Jørgen (2003). A Testbed for Advanced Content Distribution Experiments. Proceedings / IEEE International Conference on Telecommunications (ConTEL).
Ecklund, Denise Joy; Goebel, Vera Hermine; Plagemann, Thomas Peter & Ecklund, Earl Frank (2002). Dynamic End-to-End QoS Management Middleware for Distributed Multimedia Systems. Multimedia Systems. ISSN 0942-4962.
Kristiansen, Stein; Goebel, Vera Hermine; Øyri, Karl & Plagemann, Thomas Peter (2017). Event Modeling and Processing to Simplify Real-Time Analysis of Physiological Signals. Fulltekst i vitenarkiv.
Starks, Fabrice; Goebel, Vera Hermine; Kristiansen, Stein & Plagemann, Thomas Peter (2017). Mobile Distributed Complex Event Processing - Ubi Sumus? Quo Vadimus?. Fulltekst i vitenarkiv.
Fabrice, Bigirimana; Goebel, Vera Hermine & Plagemann, Thomas Peter (2014). Investigation of contradicting optimization goals for event processing overlays in MANETs.
Goebel, Vera Hermine (2014). Personalisation of Complex Event Processing.
In emergency intervention and rescue operations, the coordination and collaboration of the rescue personnel is highly important for the success of the mission. Data networks formed between the devices carried by the rescue personnel can provide the means for collaboration and coordination on the operation scene. Unfortunately, the unforeseeable conditions and characteristics (e.g., size of the scene, availabilities of access ways for the rescue personnel, availability and status of the infrastructure) of the rescue operations can hinder (e.g., intermittently unavailable network infrastructure) and disrupt (e.g., network partitions) communication of data networks. Even in these adverse conditions coordination and collaboration need to be enabled between the participants of the rescue operation. In this technical report we analyse the usage of streaming services (data, audio and video) to improve coordination and collaboration tasks in rescue and emergency operations. We present a detailed requirement analysis for middleware services that support streaming of data, imposed by this application domain from a research and an industrial perspective. For this purpose, we present two rescue scenarios, which helped us perform the requirements analysis for supporting streaming in intermittently connected networks. Additionally, we also present an example from a middleware for streaming voice traffic within large organizations with multiple working sites. Although these examples might seem different, they have similar requirements considering the availability and awareness of network resources.
Kamisinski, Piotr; Mondet, Sebastien; Plagemann, Thomas Peter & Goebel, Vera Hermine (2010). Resource-Aware Complex Event Processing for Mobile Ubiquitous Environments.
Drugan, Ovidiu Valentin; Plagemann, Thomas Peter; Goebel, Vera Hermine; Munthe-Kaas, Ellen; Omang, Knut; Kamwendo, Kennedy Samuel; Lindeberg, Morten Gunnar Bjørner; Kristiansen, Stein & Rodriguez-Fernandez, Daniel (2009). Delay Tolerant Streaming in Rescue Scenarios: Requirements Analysis and Resulting Industrial Issues.
Rodriguez-Fernandez, Daniel; Goebel, Vera Hermine & Plagemann, Thomas Peter (2009). Using Autonomic Networking for Delay Tolerant Streaming.
Sanderson, Norun Christine; Goebel, Vera Hermine & Munthe-Kaas, Ellen (2008). Network Wide Information Sharing in Rescue and Emergency Situations. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 720.
Skjelsvik, Katrine S; Goebel, Vera Hermine & Plagemann, Thomas Peter (2008). A Distributed Event Notification Service for Sparse Mobile Ad-hoc networks. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 1501-7710.
Skjelsvik, Katrine S; Søberg, Jarle; Goebel, Vera Hermine & Plagemann, Thomas Peter (2007). Using continuous queries for event filtering and routing in sparse manets.
Søberg, Jarle; Hernes, Kjetil; Siekkinen, Matti Mikael; Goebel, Vera Hermine & Plagemann, Thomas Peter (2007). A practical evaluation of load shedding in data stream management systems for network monitoring.
Sanderson, Norun Christine; Goebel, Vera Hermine & Munthe-Kaas, Ellen (2006). Ontology Based Dynamic Updates in Sparse Mobile Ad-hoc Networks for Rescue Scenarios in MDM '06: Proceedings of the 7th International Conference on Mobile Data Management (MDM'06), IEEE Computer Society, ISBN 0-7695-2526-1.
Siekkinen, Matti; Goebel, Vera Hermine & Biersack, Ernst (2006). Object-Relational DBMS for Packet-Level Traffic Analysis: Case Study on Performance Optimization.
Skjelsvik, Katrine S; Goebel, Vera Hermine & Plagemann, Thomas Peter (2006). A Configurable Event Notification Service for MANETs.
Sanderson, Norun Christine; Goebel, Vera Hermine & Munthe-Kaas, Ellen (2005). Metadata Management for Ad-Hoc InfoWare - A Rescue and Emergency Use Case for Mobile Ad-Hoc Scenarios. In: On the Move to Meaningful Internet Systems 2005: CoopIS, DOA, and ODBASE. Lecture Notes in Computer Science 2005(3761):1365-1380. ISBN 3-540-29738-3.
Siekkinen, Matti; Biersack, Ernst; Goebel, Vera Hermine; Plagemann, Thomas Peter & Urvoy-Keller, Guillaume (2005). IntraBase: Integrated Traffic Analysis Based on a Database Management System.
Siekkinen, Matti; Biersack, Ernst; Urvoy-Keller, Guillaume; Goebel, Vera Hermine & Plagemann, Thomas Peter (2005). InTraBase: integrated traffic analysis based on a database management system.
Skevik, Karl Andre; Goebel, Vera Hermine & Plagemann, Thomas Peter (2005). Performance comparison of request models for a P2P based streaming Content Distribution Network.
Plagemann, Thomas Peter; Andersson, Jon; Drugan, Ovidiu Valentin; Goebel, Vera Hermine; Griwodz, Carsten; Halvorsen, Pål; Munthe-Kaas, Ellen; Puzar, Matija; Sanderson, Norun Christine & Skjelsvik, Katrine S (2004). Middleware Services for Information Sharing in Mobile Ad-hoc Networks - Challenges and Approach.
Plagemann, Thomas Peter & Goebel, Vera Hermine (2004). Data Stream Management Systems.
Plagemann, Thomas Peter & Goebel, Vera Hermine (2004). Data Stream Management Systems - Concepts, Prototypes, and Applications.
Plagemann, Thomas Peter; Goebel, Vera Hermine; Bergamini, Andrea; Tolu, Giacomo; Urvoy-Keller, Guillaume & Biersack, Ernst (2004). Using Data Stream Management Systems for Traffic Analysis - A Case Study -.
Sanderson, Norun Christine; Goebel, Vera Hermine & Munthe-Kaas, Ellen (2004). Knowledge Management in Mobile Ad-hoc Networks for Rescue Scenarios.
Skevik, Karl Andre; Goebel, Vera Hermine & Plagemann, Thomas Peter (2004). Design of a Hybrid CDN.
Halvorsen, Pål; Griwodz, Carsten; Goebel, Vera Hermine & Plagemann, Thomas Peter (2003). Storage System Support for Multimedia Applications", Research Report No. 307,.
Goebel, Vera Hermine & Plagemann, Thomas Peter (2002). Towards Better Integrated Distributed Multimedia Systems - Results from the OMODIS Project.
Internet services like the world-wide web and multimedia applications like News- and Video-on-Demand have become very popular over the last years. Due to the large number of users that retrieve multimedia data with high data rates concurrently, the data servers represent a severe bottleneck in this context. Traditional time and resource consuming operations like memory copy operations limit the number of streams that can concurrently be transmitted from the server. To avoid this bottleneck and make memory and CPU resources available for other tasks, i.e., more concurrent clients, we have implemented a specialized zero-copy data path from the storage system through the communication system out to the network. In order to perform better than existing related approaches, we remove overhead of memory related operations by statically allocating the necessary buffers. In this paper, we describe the design, implementation, and evaluation of the zero-copy data path. Our results show the potential for substantial performance improvement when moving data through the communication system without any copy operations and using statically allocated buffers.