| 1. |
- Kristoffersson, Annica, 1980-, et al.
(författare)
-
User-centered evaluation of robotic telepresence for an elderly population
- 2010
-
Konferensbidrag (refereegranskat)abstract
- The goal of our studies is to iteratively refine prototypes of the robot by involving end users in development cycles of the prototype throughout the project. The evaluations will be conducted with the aim of maximizing usability across geographic, demographic and cultural boundaries, as well as diverse home environments and user preferences and attitudes. The project ExCITE focuses on end users’ perspectives when using a robotic telepresence platform, the Giraff. The Giraff system consists of a tiltable screen and web camera mounted on a moveable robotic base that can be teleoperated. Our application area is elder care. We motivate the use of telepresence in elder care as a way to ensure safety, facilitate independent living and enhance social interaction.
|
|
| 2. |
- Nemati, Farhang, Senior Lecturer, 1975-
(författare)
-
Partitioned Scheduling of Real-Time Tasks on Multi-core Platforms
- 2010
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In recent years multiprocessor architectures have become mainstream, and multi-core processors are found in products ranging from small portable cell phones to large computer servers. In parallel, research on real-time systems has mainly focused on traditional single-core processors. Hence, in order for real-time systems to fully leverage on the extra capacity offered by new multi-core processors, new design techniques, scheduling approaches, and real-time analysis methods have to be developed.In the multi-core and multiprocessor domain there are mainly two scheduling approaches, global and partitioned scheduling. Under global scheduling each task can execute on any processor at any time while under partitioned scheduling tasks are statically allocated to processors and migration of tasks among processors is not allowed. Besides simplicity and efficiency of partitioned scheduling protocols, existing scheduling and synchronization methods developed for single-core processor platforms can more easily be extended to partitioned scheduling. This also simplifies migration of existing systems to multi-cores. An important issue related to partitioned scheduling is distribution of tasks among processors which is a bin-packing problem.In this thesis we propose a partitioning framework for distributing tasks on the processors of multi-core platforms. Depending on the type of performance we desire to achieve, the framework may distribute a task set differently, e.g., in an application in which tasks process huge amounts of data the goal of the framework may be to decrease cache misses.Furthermore, we propose a blocking-aware partitioning heuristic algorithm to distribute tasks onto the processors of a multi-core architecture. The objective of the proposed algorithm is to decrease blocking overhead of tasks which reduces the total utilization and has the potential to reduce the number of required processors.Finally, we have implemented a tool to facilitate evaluation and comparison of different multiprocessor scheduling and synchronization approaches, as well as different partitioning heuristics. We have applied the tool in the evaluation of several partitioning heuristic algorithms, and the tool is flexible to which any new scheduling or synchronization protocol as well as any new partitioning heuristic can easily be added.
|
|
| 3. |
- Smedberg, Åsa, et al.
(författare)
-
Stress Management 2.0 : A Holistic Approach to Self-management Online
- 2010
-
Ingår i: International Multi-Conference on Complexity, Informatics and Cybernetics (IMCIC 2010). - Orlando, Florida USA : International Institute of Informatics and Systemics (IIIS). ; , s. 312-317
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The last years have put stress management on the agenda of healthcare. Intense lifestyles with job and domestic demands let people experience high levels of stress and to react strongly to different stressors. Long-term sickness and absence from work can be a consequence of too high stress exposure during a long period of time. This negative trend can be counteracted if we allow a combination of actions to support people who experience stressful lives. Different online programs are available for people with stress symptoms. However, there is a lack of conceptual understanding and a holistic approach to learning online for this group of people. In this article, we present a holistic and integrated approach to ‘stress management 2.0’ that considers several areas: stress management, self-management, informatics and continuous learning through communication and feedback. The approach is based on findings from previous research studies of web based solutions for learning new lifestyles, stress management and results from clinical trials. At the end of the article, we present some design principles to be used for developing systems in accordance with ‘stress management 2.0’ from a holistic view.
|
|
| 4. |
- Åkerberg, Johan, et al.
(författare)
-
Deterministic Downlink Transmission in WirelessHART Networks enabling Wireless Control Applications
- 2010
-
Ingår i: IECON 2010 - 36th Annual Conference on IEEE Industrial Electronics Society. - New York : Institute of Electrical and Electronics Engineers (IEEE). - 9781424452255 - 9781424452262 ; , s. 2120-2125
-
Konferensbidrag (refereegranskat)abstract
- Wireless sensor and actuator networks bring many benefits to industrial automation systems. However, unreliable wireless and multihop communications among sensors and actuators cause challenges in designing such systems. Wireless HART is the first standard for wireless real-time industrial applications. However, current Wireless HART standard does not provide services for efficient usage of actuators, which are an essential part of automation. In this paper we focus on Wireless HART and propose a periodic and deterministic downlink transmission functionality which enables efficient usage of actuators and control applications. Furthermore, we define new HART commands extending the interface, without affecting available services, to support the integration of actuators. This can be achieved with minor changes in the current standard.
|
|
| 5. |
- Åkerberg, Johan, et al.
(författare)
-
Integration of WirelessHART Networks in Distributed Control Systems using PROFINET IO
- 2010
-
Ingår i: 8th IEEE International Conference on Industrial Informatics (INDIN). - Osaka, Japan : Institute of Electrical and Electronics Engineers (IEEE). - 9781424472987 - 9781424473007 ; , s. 154-159
-
Konferensbidrag (refereegranskat)abstract
- In this paper we describe a method to integrate WirelessHART networks in Distributed Control Systems (DCS)using PROFINET IO. By modeling the WirelessHART network in the Generic Station Description file, that describes a PROFINET IO device, the WirelessHART related configuration can be distributed from the central engineering stations. In this way, both process controller configuration and WirelessHART network configuration is engineered and maintained from a central location. Thus the end-user do not need any additional tool-specific training, as the existing tools are used to engineer the WirelessHART networks. We base the method of integration on the keywords simple deployment and maintenance, and flexible topology. A proof-of-concept implementation of the proposed method shows that it is possible to download WirelessHART configuration both to the WirelessHART network managers, as well as the WirelessHART sensors. By integrating WirelessHART in this way, maintenance is greatly simplified as the actual configuration will be downloaded automatically by the DCS when faulty field devices are replaced.
|
|
| 6. |
- Nemati, Farhang, et al.
(författare)
-
Partitioning Real-Time Systems on Multiprocessors with Shared Resources
- 2010
-
Ingår i: Lecture Notes in Computer Science, vol. 6490. - Berlin, Heidelberg : Springer. - 9783642176524 - 9783642176531 ; , s. 253-269
-
Bokkapitel (refereegranskat)abstract
- There are two main approaches to task scheduling on multiprocessor/multi-core platforms; 1) global scheduling, under which migration of tasks among processors is allowed, and 2) partitioned scheduling under which tasks are allocated onto processors and task migration is not allowed. Under global scheduling a higher utilization bound can be achieved, but in practice the overheads of migrating tasks is high. On the other hand under partitioned scheduling, besides simplicity and efficiency, existing scheduling and synchronization methods developed for uniprocessor platforms can more easily be extended to partitioned scheduling. However the partitioned scheduling protocols suffer from the problem of partitioning tasks among processors/cores which is a bin-packing problem. Therefore, several heuristic algorithms have been developed for partitioning a task set on multiprocessor platforms. However, these algorithms typically assume independent tasks while in practice real-time systems often contain tasks that share resources and hence may block each other.In this paper we propose a blocking-aware partitioning algorithm which allocates a task~set onto processors in a way that the overall amount of blocking times of tasks are decreased. The algorithm reduces the total utilization which, in turn, has the potential to decrease the total number of required processors (cores). In this paper we evaluate our algorithm and compare it with an existing similar algorithm. The comparison criteria includes both number of schedulable systems as well as processor reduction performance.
|
|
| 7. |
- Nilsson, Per, 1967-, et al.
(författare)
-
Focal event, contextualization, and effective communication in the mathematics classroom
- 2010
-
Ingår i: Educational Studies in Mathematics. - : Springer Science and Business Media LLC. - 0013-1954 .- 1573-0816. ; 74:3, s. 241-258
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this article is to develop analytical tools for studying mathematical communication in collaborative activities. The theoretical construct of contextualization is elaborated methodologically in order to study diversity in individual thinking in relation to effective communication. The construct of contextualization highlights issues of diversity in collaborative activities as it emphasizes how students may struggle differently with a learning activity. The interaction of students (12 to 13 years old), playing a specifically designed dice game, is used as an example for illustration. The article shows how accounting for the focal events of the interlocutors, and the contexts in which they contextualize these events, help in organizing our thinking about mathematically effective communication in collaborative activities.
|
|
