| 1. |
- Saguna, Saguna, et al.
(författare)
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Building activity definitions to recognize complex activities using an online activity toolkit
- 2012
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Ingår i: IEEE 13th International Conference on Mobile Data Management, MDM 2012. - Piscataway, NJ : IEEE Communications Society. - 9780769547138 ; , s. 344-347
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Konferensbidrag (refereegranskat)abstract
- One of the biggest challenges in the field of activity recognition is gathering training data for building activity inference models. To address this problem, we have developed an online activity toolkit for gathering activity data from online users. We use this data to build activity definitions for use in our system which is based on Context-Driven Activity Theory. We use Markov chain analysis to assign weights to activities and context attributes of a complex activity as well as to build activity signatures based on transition and path probabilities. Our demo is intended to show how complex activities and associated atomic activities and context attributes can be described using an activity toolkit. The toolkit is used to take input from users available online and the results analysis of different complex activities can be viewed online in near real-time using the graphical user interface (GUI).
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| 2. |
- Saguna, Saguna, et al.
(författare)
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Complex activity recognition using context-driven activity theory and activity signatures
- 2013
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Ingår i: ACM Transactions on Computer-Human Interaction. - : Association for Computing Machinery (ACM). - 1073-0516 .- 1557-7325. ; 20:6
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Tidskriftsartikel (refereegranskat)abstract
- In pervasive and ubiquitous computing systems, human activity recognition has immense potential in a large number of application domains. Current activity recognition techniques (i) do not handle variations in sequence, concurrency and interleaving of complex activities; (ii) do not incorporate context; and (iii) require large amounts of training data. There is a lack of a unifying theoretical framework which exploits both domain knowledge and data-driven observations to infer complex activities. In this article, we propose, develop and validate a novel Context-Driven Activity Theory (CDAT) for recognizing complex activities. We develop a mechanism using probabilistic and Markov chain analysis to discover complex activity signatures and generate complex activity definitions. We also develop a Complex Activity Recognition (CAR) algorithm. It achieves an overall accuracy of 95.73% using extensive experimentation with real-life test data. CDAT utilizes context and links complex activities to situations, which reduces inference time by 32.5% and also reduces training data by 66%.
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| 3. |
- Saguna, Saguna, et al.
(författare)
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Complex activity recognition using context driven activity theory in home environments
- 2011
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Ingår i: Smart spaces and next generation wired/wireless networking. - Heidelberg : Encyclopedia of Global Archaeology/Springer Verlag. - 9783642228742 ; , s. 38-50
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a context driven activity theory (CDAT) and reasoning approach for recognition of concurrent and interleaved complex activities of daily living (ADL) which involves no training and minimal annotation during the setup phase. We develop and validate our CDAT using the novel complex activity recognition algorithm on two users for three weeks. The algorithm accuracy reaches 88.5% for concurrent and interleaved activities. The inferencing of complex activities is performed online and mapped onto situations in near real-time mode. The developed systems performance is analyzed and its behavior evaluated.
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| 4. |
- Saguna, Saguna, et al.
(författare)
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CrysP : multi-faceted activity-infused presence in emerging social networks
- 2010
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Ingår i: Smart spaces and next generation Wired/Wireless networking. - Berlin, Heidelberg : Encyclopedia of Global Archaeology/Springer Verlag. - 9783642148903 ; , s. 50-61
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Konferensbidrag (refereegranskat)abstract
- This paper presents Crystal Presence (CrysP) approach wher- e we fuse presence and activity in the realm of social networking. CrysP functions on the basis of the activity-infused multi-faceted presence information. This information is derived from user's involvement in multiple activities at any point in time. We propose and develop the CrysP System (CrysPSys) to determine CrysP from the user and his/her environmental context information (mainly relating to user activity, moods/emotions and cognition/thoughts) and then sharing the relevant CrysP with the appropriate devices, services and social-networks (corporate, personal and interest networks) and blogs (text, micro, video, photo and voice). We also highlight the benefits and challenges faced in developing such a system. This paper proposes the architecture and its test-bed and prototype implementation.
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| 5. |
- Saguna, Saguna, et al.
(författare)
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Recognizing concurrent and interleaved activities in social interactions
- 2011
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Ingår i: Ninth International Conference on Dependable, Autonomic and Secure Computing (DASC). - Piscataway, NJ : IEEE Communications Society. - 9781467300063 ; , s. 230-237
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Konferensbidrag (refereegranskat)abstract
- Social networks constitute an important research area where users are involved in social interactions and inform each other of activities they perform. In this paper a complex activity recognition system (SEMACT) is proposed, built and validated. Different activities performed by users form an activity hierarchy. We perform semantic reasoning by using ontological constructs and rules to recognize both concurrent and interleaved complex activities at different levels of granularity of this activity hierarchy. Different application domains require activity recognition systems to define and recognize activities at different levels of granularity. Our system tackles this problem by recognizing complex activities which are then shared across application domains using a generic API. A test-bed and prototype are built to validate our SEMACT system. Extensive experimentation is performed which demonstrates that high accuracy of 94.35% was achieved for the recognition of complex activities both concurrent and interleaved within computationally feasible time
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| 6. |
- Saguna, Saguna, et al.
(författare)
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Towards a robust concurrent and interleaved activity recognition of mobile users
- 2011
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Ingår i: 12th International Conference on Mobile Data Management (MDM), 2011. - Piscataway, NJ : IEEE Communications Society. - 9781457705816 ; , s. 297-298
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a situation and context-aware complex activity recognition system where we use on-body sensor information along with other context information to infer mobile user activities which are both concurrent and interleaved. We develop and validate our complex activity recognition algorithm for detecting these multiple complex activities. Activities are mapped onto situations using spatio-temporal analysis. We further build a test-bed in the social-networking domain to test and validate our approach in different scenarios using mobile devices
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| 7. |
- Thanos, George A., et al.
(författare)
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Evaluating demand response programs by means of key performance indicators
- 2013
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Ingår i: 5th International Conference on Communication Systems and Networks, COMSNETS 2013. - Piscataway, NJ : IEEE Communications Society. - 9781467354943
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Konferensbidrag (refereegranskat)abstract
- Demand response (DR) has received significant attention in recent years and several DR programs are being deployed and evaluated worldwide. DR systems provide a wide range of economic and operational benefits to different stakeholders of the electrical power system including consumers, generators and distributors. DR can be achieved through a number of different mechanisms such as direct-load-control, incentives, pricing signals, or a combination of these schemes. Due to the remarkable variation in demand response systems, it becomes a challenge to evaluate and compare the effectiveness of different DR programs holistically. In this work, we define a number of different performance metrics that could be used to evaluate DR programs based on peak reduction, demand variation and reshaping, and economic benefits
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| 8. |
- Aad, G., et al.
(författare)
-
- 2010
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swepub:Mat__t
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