| 71. |
- Bergenhem, Carl, et al.
(författare)
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Heterogeneous real-time services in high-performance system area networks - application demands and case study definitions
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- To be able to verify the feasibility of high-performance networks, it is essential to evaluate them according to specific application requirements. At the same time, specifications of quite general, or understandable, application requirements are needed for the ability to make repeated analyses on different networks. Especially, heterogeneous real-time requirements must be defined to be able to analyze networks to be used in future applications. In this report, we introduce two application fields where system area networks (SANs) supporting heterogeneous real-time services are highly desirable if not required: radar signal processing and large IP routers. For each application field, a case study with heterogeneous real-time communication requirements is defined. No case studies are presented in this report. Instead, they are defined for later evaluations to determine how suitable networks are for applications with heterogeneous real-time communication requirements.
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| 72. |
- Bergenhem, Carl
(författare)
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Protocols with Heterogeneous Real-Time Services for High-Performance Embedded Networks
- 2002
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Network protocols for applications that demand high performance and heterogeneous real-time services are presented. These protocols control the medium access to the network and offer additional features to the user, both different user services for traffic and services for parallel and distributed real-time processing. The network architecture assumed is a unidirectional pipelined optical ring.Radar Signal Processing (RSP) is a typical application area. Such a system contains many computation nodes that are interconnected in order to co-operate and thereby achieve higher performance. The computing performance of the whole system is greatly affected by the choice of network. Computing nodes in a parallel computer for RSP should be tightly coupled, i.e., communications cost (e.g. latency) between nodes should be small, so that the whole system can be perceived as a single unit. This is possible if a suitable network with an efficient protocol is used.There is an industrial need for new high-performance networks with support for the, often heterogeneous, real-time requirements found in (often embedded) applications such as RSP and other areas such as multimedia. The traffic this kind of network can be classified according to its requirements. The proposed protocols partition the traffic into three classes with distinctly different qualities. These classes are traffic with hard real-time demands, such as mission critical commands, traffic with soft real-time demands, such as process data (a deadline miss here only leads to decreased performance) and, finally, traffic with no real-time constraints at all. The contributions of the present thesis are protocols that integrate heterogeneous real-time services for the three traffic classes.The performance of the proposed protocols is evaluated through simulations and analysis. It is shown that the protocol is an efficient choice for RSP systems. A brief survey of related technologies is included in the thesis. These are studied from the perspectives of application, architecture and user service.
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| 73. |
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| 74. |
- Bergman, Linda, et al.
(författare)
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Intelligent Monitoring of the Offset Printing Process
- 2004
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Ingår i: Neural Networks and Computational Intelligence - Proceedings. - : ACTA Press. ; , s. 173-178, s. 173-178
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Konferensbidrag (refereegranskat)abstract
- In this paper, we present a neural networks and image analysis based approach to assessing colour deviations in an offset printing process from direct measurements on halftone multicoloured pictures--there are no measuring areas printed solely to assess the deviations. A committee of neural networks is trained to assess the ink proportions in a small image area. From only one measurement the trained committee is capable of estimating the actual amount of printing inks dispersed on paper in the measuring area. To match the measured image area of the printed picture with the corresponding area of the original image, when comparing the actual ink proportions with the targeted ones, properties of the 2-D Fourier transform are exploited.
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| 75. |
- Bergman, Lars, et al.
(författare)
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Modelling and Control of the Web-Fed Offset Newspaper Printing Press
- 2003
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Ingår i: Proceedings of the Technical Association of the Graphic Arts, TAGA. - : Technical Association of the Graphic (TAGA). ; , s. 27-29
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Konferensbidrag (refereegranskat)abstract
- We present an approach to modelling and controlling the web-fed offset printing process. An image processing and artificial neural networks based device is used to measure the printing process output - the observable variables. The observable variables are measured on halftone areas and integrate information about both ink densities and dot sizes. From only one measurement the device is capable of estimating the actual relative amount of each cyan, magenta, yellow, and black ink dispersed on paper in the measuring area. We build and test linear and non-linear printing press models using the measured variables andother parameters characterising the press. The observable variables measured and the press model developed are then further used by a control unit for generating control signals - signals for controlling the ink keys - to compensate for colour deviation. The experimental investigations performed have shown that the non-linear model developed is accurate enough to be used in a control loop for controlling the printing process. The control accuracy - the tracking accuracy of the desired ink level - obtained from the controller was higher than that observed when controlling the press by the operator.
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| 76. |
- Bergman, Stefan, 1959-, et al.
(författare)
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Chronic widespread pain: A three year followup of pain distribution and risk factors
- 2002
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Ingår i: Journal of Rheumatology. - Toronto : Journal of Rheumatology Publishing Co. Ltd.. - 0315-162X .- 1499-2752. ; 29:4, s. 818-825
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To describe the change of pain reports over time in 3 cohorts derived from the general population: (1) no chronic pain (NCP, n = 1156); (2) chronic regional pain (CRP n = 502) and (3) chronic widespread pain (CWP; n = 242). To identify risk factors that predict the development or persistence of chronic widespread pain. Methods. A 3-year followup from 1995 to 1998 with postal questionnaire to 2425 subjects of both sexes aged 20-74 years on the west coast of Sweden. Results. At followup, a larger proportion of subjects with initial CRP compared to initial NCP reported CWP (16.4 and 2.2%, respectively; p < 0.001). The majority of subjects (56.9%) who primarily reported CWP remained in that group at followup, but 26.8% had changed status to CRP and 16.3% to NCP. The number of painful regions (7-12 vs 0 regions) reported at baseline was the strongest predictor for the development of CWP with an odds ratio (OR) of 12,13 (95% CI 4.47-32.88). The development of CWP was also predicted by higher age (OR = 3.13, 95% CI 1.47-6.69, age-group 59-74 years vs age-group 20-34 years), and a family history of chronic pain (OR = 1.87, 95% CI 1.14-3.07). A habit of drinking alcohol weekly (OR = 0.42, 95% Cl 0.21-0.85) compared to the habit of never or seldom drinking alcohol was protective, as well as having personal social support (OR = 0.49, 95% CI 0.28-0.85). The persistence of CWP was predicted by the number of painful regions (13-18 vs 1-6 regions) at baseline (OR = 7.56, 95% CI 2.17-26.30), and being an immigrant (OR 3.22, 95% CI 1.33-7.77). Conclusion. Although the overall prevalence of CWP was stable over a 3-year period there was a considerable variation on an individual basis. This variability in expressing CWP was moderately predicted by a combination of risk factors. the most important being the number of painful regions at baseline. Future research will need to show how useful the identified factors are in clinical practice and whether intervention aimed at changing these factors will improve pain outcome.
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| 77. |
- Bergman, Stefan, 1959-, et al.
(författare)
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Chronic musculoskeletal pain, prevalence rates, and sociodemographic associations in a Swedish population study
- 2001
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Ingår i: Journal of Rheumatology. - Toronto : Journal of Rheumatology Publishing Co. Ltd.. - 0315-162X .- 1499-2752. ; 28:6, s. 1369-1377
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To estimate the prevalence of chronic regional and widespread musculoskeletal pain in a sample of the general adult population and study the association to age, sex, socioeconomic class, immigration, and housing area.METHODS: A cross sectional survey with a postal questionnaire to 3928 inhabitants on the west coast of Sweden.RESULTS: The age and sex adjusted prevalence of chronic regional pain (CRP) was 23.9% and chronic widespread pain (CWP) 11.4% among 2425 subjects who responded to the complete questionnaire. Odds ratio (OR) for CWP showed a systematic increasing gradient with age and was highest in the age group 59-74 yrs (OR 6.36, 95% CI 3.85-10.50) vs age group 20-34 yrs. CWP was also associated with female sex (OR 1.91, 95% CI 1.41-2.61), being an immigrant (OR 1.83, 95% CI 1.22-2.77), living in a socially compromised housing area (OR 3.05, 95% CI 1.48-6.27), and being an assistant nonmanual lower level employee (OR 1.92, 95% CI 1.09-3.38) or manual worker (OR 2.72, 95% CI 1.65-4.49) vs being an intermediate/higher nonmanual employee. OR for CRP showed a systematic increasing gradient with age and was highest in the age group 59-74 yrs (OR 2.22, 95% CI 1.62-3.05) vs age group 20-34 yrs. CRP was also associated with being a manual worker (OR 1.63, 95% CI 1.19-2.23) vs being an intermediate/higher nonmanual employee.CONCLUSION: Chronic musculoskeletal pain is common in the general population. Sociodemographic variables were overall more frequently and strongly associated with CWP than with CRP, which indicates different pathophysiology in the development or preservation of pain in the 2 groups.
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| 78. |
- Bergman, Stefan, 1959-, et al.
(författare)
-
Health status as measured by SF-36 reflects changes and predicts outcome in chronic musculoskeletal pain: a 3-year follow up study in the general population
- 2004
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Ingår i: Pain. - Philadelphia : Ovid Technologies (Wolters Kluwer Health). - 1872-6623 .- 0304-3959. ; 108:1-2, s. 115-123
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Tidskriftsartikel (refereegranskat)abstract
- The SF-36 is a well-validated health status instrument measuring eight different health concepts. One aim of this study was to compare health status as measured by SF-36 in subjects from the general population with no chronic pain (NCP), chronic regional pain (CRP), and chronic widespread pain (CWP). A second aim was to assess if SF-36 could reflect changes in pain status over time. A third aim was to study if health status at baseline, measured by SF-36, could predict pain status 3 years later. The study was designed as a 3-year follow up with a postal questionnaire, including the SF-36 health survey, to 2357 subjects from the general population aged 20-74 years. The results were controlled for age, sex, co-morbidity, and socio-economic status. At baseline, all eight health concepts of SF-36 discriminated between subgroups with NCP, CRP and CWP. Changes in SF-36 over the 3-year follow up time coincided with improvement or deterioration of pain status. Baseline SF-36 scores predicted pain outcome 3 years later. These results support that both physical and mental aspects of health status as measured by SF-36 are affected by the burden of musculoskeletal pain, are sensitive to changes in pain status, and also predict the further development of pain. (C) 2003 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
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| 79. |
- Bergquist, Magnus, 1960, et al.
(författare)
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Practising Peer Review in Organizations: a Qualifier for Knowledge Dissemination and Legitimization
- 2001
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Ingår i: Journal of Information Technology. - London : SAGE Publications. ; 16:2, s. 99-112
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Tidskriftsartikel (refereegranskat)abstract
- A key issue in many organizations is how to disseminate information in an effective way and, more importantly, how to make use of this information in order to create new knowledge. One way of addressing this problem is to focus on how information is socially transformed into knowledge. This includes how knowledge is handled in practice and how the knowledge produced is qualiŽ ed as being something worth knowing and acting upon. Two well-established practices for doing this are the refereeing system and the peer review process. These are used in scientiŽ c communities as a means of validating and legitimating knowledge, for example by reviewing journal papers before publishing or project proposals before granting funds, etc. This paper argues that peer review is a useful concept when looking at knowledge creation and legitimization in organizations. The social meaning of peer review is to legitimize new knowledge by organizationally sanctioning it and thereby creating a platform for collective sense making. This paper uses an example from a Ž eld study in a pharmaceutical company in order to illustrate this argument. The study took place in a quality support department where the quality of health care products and processes was assessed. The organization had a need for fast and reliable updating of information that could in uence how the production process of pharmaceuticals should be carried out. In order to cope with these problems the department established an ‘evaluation loop’, which shared several characteristics with the peer review process.
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| 80. |
- Bergquist, Magnus, 1960, et al.
(författare)
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The Power of Gifts: Organizing Social Relationships in Open Source Communities
- 2001
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Ingår i: Information Systems Journal. - Chichester : Wiley. ; 11:4, s. 305-320
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Tidskriftsartikel (refereegranskat)abstract
- In writings on the open source software development model, it is often argued that it is successful as a result of the gift economy that embraces activities in online communities. However, the theoretical foundations for this argument are seldom discussed and empirically tested. Starting with the ‘classic’ theories of gift giving, we discuss how they need to be developed in order to explain giftgiving practices in digital domains. In this paper, we argue that the gift economy is important, not only because it creates openness, but also because it organizes relationships between people in a certain way. Open source software development relies on gift giving as a way of getting new ideas and prototypes out into circulation. This also implies that the giver gets power from giving away. This power is used as a way of guaranteeing the quality of the code. We relate this practice to how gifts, in the form of new scientific knowledge, are given to the research community, and how this is done through peer review processes.
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