| 1. |
- Bengtsson, Lars, et al.
(författare)
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The REMAP Reconfigurable Architecture : a Retrospective
- 2006
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Ingår i: FPGA Implementations of Neural Networks. - New York : Springer-Verlag New York. - 0387284850 ; , s. 325-360
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Bokkapitel (refereegranskat)abstract
- The goal of the REMAP project was to gain new knowledge about the design and use of massively parallel computer architectures in embedded real-time systems. In order to support adaptive and learning behavior in such systems, the efficient execution of Artificial Neural Network (ANN) algorithms on regular processor arrays was in focus. The REMAP-β parallel computer built in the project was designed with ANN computations as the main target application area. This chapter gives an overview of the computational requirements found in ANN algorithms in general and motivates the use of regular processor arrays for the efficient execution of such algorithms. REMAP-β was implemented using the FPGA circuits that were available around 1990. The architecture, following the SIMD principle (Single Instruction stream, Multiple Data streams), is described, as well as the mapping of some important and representative ANN algorithms. Implemented in FPGA, the system served as an architecture laboratory. Variations of the architecture are discussed, as well as scalability of fully synchronous SIMD architectures. The design principles of a VLSI-implemented successor of REMAP-β are described, and the paper is concluded with a discussion of how the more powerful FPGA circuits of today could be used in a similar architecture. © 2006 Springer.
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| 5. |
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| 6. |
- Fjalldal, S., et al.
(författare)
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Detailed assessment of hypothalamic damage in craniopharyngioma patients with obesity
- 2019
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Ingår i: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 43:3, s. 533-544
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Tidskriftsartikel (refereegranskat)abstract
- Background/objectives: Hypothalamic obesity (HO) occurs in 50% of patients with the pituitary tumor craniopharyngioma (CP). Attempts have been made to predict the risk of HO based on hypothalamic (HT) damage on magnetic resonance imaging (MRI), but none have included volumetry. We performed qualitative and quantitative volumetric analyses of HT damage. The results were explored in relation to feeding related peptides and body fat. Subjects/methods: A cross-sectional study of childhood onset CPs involving 3 Tesla MRI, was performed at median 22 years after first operation; 41 CPs, median age 35 (range: 17–56), of whom 23 had HT damage, were compared to 32 controls. After exclusions, 35 patients and 31 controls remained in the MRI study. Main outcome measures were the relation of metabolic parameters to HT volume and qualitative analyses of HT damage. Results: Metabolic parameters scored persistently very high in vascular risk particularly among HT damaged patients. Patients had smaller HT volumes compared to controls 769 (35–1168) mm3 vs. 879 (775–1086) mm3; P < 0.001. HT volume correlated negatively with fat mass and leptin among CP patients (rs = −0.67; P <.001; rs = −0.53; P = 0.001), and explained 39% of the variation in fat mass. For every 100 mm3 increase in HT volume fat mass decreased by 2.7 kg (95% CI: 1.5–3.9; P < 0.001). Qualitative assessments revealed HT damage in three out of six patients with normal volumetry, but HT damage according to operation records. Conclusions: A decrease in HT volume was associated with an increase in fat mass and leptin. We present a method with a high inter-rater reliability (0.94) that can be applied by nonradiologists for the assessment of HT damage. The method may be valuable in the risk assessment of diseases involving the HT.
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| 8. |
- Gustafsson, Mats, et al.
(författare)
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Effekter av vinterdäck : en kunskapsöversikt
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Choice of winter tyres has, from mainly being a matter of safety and economic costs for wearing of road pavements, during later years also become a matter of inhalable particles formed during pavement wear from studded tyres and their negative effects on public health. Further, the tyres' effects on environment and noise have been illustrated in several studies. The issue is also complicated by the fact that tyre choice effects on traffic safety have several components, including such diverging parameters as friction and behaviour. Finally all aspects have to be evaluated from a socioeconomic point of view for society to be able to decide which kind of distribution of tyre types that is the most profitable. This report is a summary of current knowledge in this complex research field.
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| 9. |
- Holmer, Helene, et al.
(författare)
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Hypothalamic involvement predicts cardiovascular risk in adults with childhood onset craniopharyngioma on long-term GH therapy.
- 2009
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Ingår i: European Journal of Endocrinology. - 0804-4643 .- 1479-683X. ; 16, s. 671-679
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Tidskriftsartikel (refereegranskat)abstract
- Context: Craniopharyngioma patients without GH therapy are at an increased cardiovascular disease (CVD) risk and particularly concerning women. No previous study on long-term GH therapy in adults with childhood onset (CO) craniopharyngioma was identified. Objective: To investigate CVD risk in adults with CO craniopharyngioma on complete hormone replacement, including long-term GH therapy, and to investigate the impact of disease-related factors on CVD risk. Design and participants: In a cross-sectional study of operated CO craniopharyngiomas (1958–2000) from a defined area of Sweden (2.5 million), we enrolled 42 patients (20 women) with a median age of 28 years (range 17–57) and assessed CVD risk of 20 (4–40) years after first operation. Comparisons were made with matched controls and between patients with tumor growth into the third ventricle (TGTV) versus non-TGTV. GH therapy was 10–12 years in women and men. Results: In comparison with controls, both male and female patients had increased body mass index, fat mass, insulin, and leptin levels. Overall, while not significantly increased in male patients, 55–60% of female patients had a medium–high CVD risk, compared with 10–20% in controls. An increased CVD risk (all P<0.05) and higher levels of fat mass and insulin were recorded in the TGTV group versus the non-TGTV group. Late puberty induction and lack of androgens were shown in female patients. Conclusions: Adult patients with CO craniopharyngioma, especially those with TGTV, have persistently increased CVD risk. Conventional hormone substitution, including GH, is insufficient to normalize CVD risk, suggesting an important role for irreversible hypothalamic dysfunction.
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| 11. |
- Holmlund, Bertil, et al.
(författare)
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Mind the Gap? Estimating the Effects of Postponing Higher Education
- 2008
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Ingår i: Oxford Economic Papers. - : Oxford University Press (OUP). - 0030-7653 .- 1464-3812. ; 60:4, s. 683-710
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Tidskriftsartikel (refereegranskat)abstract
- This paper estimates the effects on earnings of “gap years” between high school and university enrollment. The effect is estimated by means of standard earnings functions augmented to account for gap years and a rich set of control variables using administrative Swedish data. We find that postponement of higher education is associated with a persistent and non-trivial earnings penalty. The main source of the persistent penalty appears to be the loss of work experience after studies. The reduction of lifetime earnings associated with two years postponement of higher education amounts to 40-50 percent of annual earnings at age 40.
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| 12. |
- Jönsson, Eva, et al.
(författare)
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Psychosocial risk factors in families with infants: a municipality survey
- 2006
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Ingår i: Vård i Norden. - 0107-4083. ; 26:3, s. 9-9
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Tidskriftsartikel (refereegranskat)abstract
- Difficulties in a family's psychosocial situation during the period of infancy are associated with mental problems and behavioural disorders in children. The aim of the study was to identify the extent and type of psychosocial factors in families with infants, including social aspects, mental problems and substance abuse as well as circumstances surrounding the birth. All infants born between March 1st 2000 and August 31st 2001 whose parents had adequate knowledge of the Swedish language (N=576) were included. Data were collected by means of a questionnaire. Psychosocial risk factors were found in the families of 24% of infants whose mothers were of Swedish origin and in the families of 58% of infants whose mothers were of foreign origin. The most common risk factors were: unemployment, premature birth, and one or both parents exhibiting signs of great worry and anxiety in relation to their child and parenthood. The study also shows that mental problems and substance abuse were only present in a very small number of parents. Furthermore, the study indicates the need to review the strategies used within child health care to identify families at risk of developing mental problems and behavioural disorders as a result of dysfunctionality in their psychosocial situation during their child's infancy. It is important to study the professional network surrounding families in more detail, both in order to detect psychosocial risk factors and to develop and evaluate interventions.
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| 13. |
- Liu, Qian
(författare)
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Essays on Labor Economics: Education, Employment, and Gender
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Essay I, co-authored with Bertil Holmlund and Oskar Nordström Skans, offers evidence on how delayed transitions to higher education (“gap years”) affect subsequent earnings and lifetime earnings. We exploit rich Swedish register data and find that postponement of higher education is associated with a persistent and non-trivial earnings penalty. The main source of the earnings penalty associated with gap years is that the returns to post-university work experience are higher than the returns to gap years. Postponement of university education reduces time for post-university investment in skills and therefore entails lower earnings subsequent to university graduation. Essay II uses Swedish data to compute rates of returns to education that incorporate mechanisms operating through the marriage market. I define marriage income as the transfers one obtains from the spouse and the overall income as the sum of work income and marriage income. I find that the marriage market can work as a cushion to reduce the overall earnings gap among people in different education categories. Although women with graduate degrees earn on average more than twice as much in annual work income than women with less than two years of university, their marriage incomes are less than half of marriage incomes in the latter group. Essay III uses micro data to document and analyze patterns and trends in labor force participation and employment in urban China during the past couple of decades. Estimations of logit models show that age, education, communist-party membership and marital status are significantly associated with participation in the labor force and employment opportunities. Being a communist party member in 2002 is associated with 3.5 percentage points higher employment rate for men and 6 points higher employment rates for women. An extension of the Blinder-Oaxaca decomposition is used to analyze gender differences in participation and employment. Essay IV, co-authored with Oskar Nordström Skans, examines how parental leave policies influence children’s human capital accumulation. Using a three-month parental leave extension that covered all Swedish children born from August 1988, we evaluate children’s test scores and grades at the age of 16. We find that the duration of paid parental leave benefits have no impact on average scholastic performance, although heterogeneity analysis discovers positive effects for children to well-educated mothers. We find no effects on child health, mothers’ health and subsequent earnings or parents’ fertility and divorce rates.
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| 18. |
- Nordström Skans, Oskar, et al.
(författare)
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Wage Dispersion Between and Within Plants : Sweden 1985-2000
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The paper describes the Swedish wage distribution and how it correlates with worker mobility and plant-specific factors. It is well known that wage inequality has increased in Sweden since the mid-1980s. However, little evidence has so far been available as to whether this development reflects increased dispersion between plants, between individuals in the same plant, or both. We use a new linked employer-employee data set and discover that a trend rise in between- plant wage inequality account for the entire increase in wage dispersion. This pattern, which remains when we control for observable individual human capital characteristics, may reflect increased sorting of workers by skill levels and/or increased scope for rent sharing in local wage negotiations. Our discussion suggests that both factors may have become more important.
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| 19. |
- Nordström, Tomas, 1963-, et al.
(författare)
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Using and designing massively parallel computers for artificial neural networks
- 1992
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Ingår i: Journal of Parallel and Distributed Computing. - Orlando : Academic Press. - 0743-7315 .- 1096-0848. ; 14:3, s. 260-285
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Tidskriftsartikel (refereegranskat)abstract
- During the past 10 years the fields of artificial neural networks (ANNs) and massively parallel computing have been evolving rapidly. The authors study the attempts to make ANN algorithms run on massively parallel computers as well as designs of new parallel systems tuned for ANN computing. Following a brief survey of the most commonly used models, the different dimensions of parallelism in ANN computing are identified, and the possibilities for mapping onto the structures of different parallel architectures are analyzed. Different classes of parallel architectures used or designed for ANN are identified. Reported implementations are reviewed and discussed. It is concluded that the regularity of ANN computations suits SIMD architectures perfectly and that broadcast or ring communication can be very efficiently utilized. Bit-serial processing is very interesting for ANN, but hardware support for multiplication should be included. Future artificial neural systems for real-time applications will require flexible processing modules that can be put together to form MIMSIMD systems
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| 20. |
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| 21. |
- Sturm, Amanda, et al.
(författare)
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Lungemboli under graviditet – en jämförelse av rutiner i två regioner : Kan val av röntgenmetod förklara den stora skillnaden i incidens mellan Region Dalarna och Region Värmland?
- 2023
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Ingår i: Läkartidningen. - : Läkartidningen Förlag AB. - 0023-7205 .- 1652-7518. ; 120
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Tidskriftsartikel (refereegranskat)abstract
- Pulmonary embolism during pregnancy is a potentially life-threatening condition and the second leading cause of maternal mortality in Sweden. Diagnosis during pregnancy is challenging, and radiologic diagnostic modality is important. The incidence of pulmonary embolism among pregnant women in the Swedish region of Dalarna was 47.8/100 000 women aged 15-49 years in 2016, compared with 5.4/100 000 women in the region of Värmland, which is a region comparable in size and population. This study aimed to investigate differences in clinical practice and choice of imaging modality among pregnant women with suspected pulmonary embolism in the two regions during 2013-2017. There was no difference in background maternal characteristics, but the primary modality of diagnostic imaging was lung scintigraphy in Dalarna (79 percent), whereas computed tomography pulmonary angiography was performed in 75 percent of the cases in Värmland (P < 0.01). There were more women with a confirmed diagnosis of pulmonary embolism after diagnostic imaging in Dalarna (25 percent, n = 65) compared to Värmland (5 percent, n = 8) (P < 0,.01). Pulmonary embolism was diagnosed in more than one quarter of women investigated with scintigraphy, compared to 6 percent when computed tomography was performed.
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| 22. |
- Svensson, Bertil, 1948-, et al.
(författare)
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A running leap for embedded signal processing to future parallel platforms
- 2014
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Ingår i: WISE 2014 - Proceedings of the 2014 ACM International Workshop on Long-Term Industrial Collaboration on Software Engineering, Co-located with ASE 2014. - New York, NY, USA : Association for Computing Machinery, Inc. - 9781450330459 ; , s. 35-42
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Konferensbidrag (refereegranskat)abstract
- This paper highlights the collaboration between industry and academia in research. It describes more than two decades of intensive development and research of new hardware and software platforms to support innovative, high-performance sensor systems with extremely high demands on embedded signal processing capability. The joint research can be seen as the run before a necessary jump to a new kind of computational platform based on parallelism. The collaboration has had several phases, starting with a focus on hardware, then on efficiency, later on software development, and finally on taking the jump and understanding the expected future. In the first part of the paper, these phases and their respective challenges and results are described. Then, in the second part, we reflect upon the motivation for collaboration between company and university, the roles of the partners, the experiences gained and the long-term effects on both sides.
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| 23. |
- Svensson, Bertil, et al.
(författare)
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Execution of neural network algorithms on an array of bit-serial processors
- 1990
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Ingår i: Proceedings, 10th International Conference on Pattern Recognition. - Piscataway, NJ : IEEE Communications Society. - 0818620625 ; , s. 501-505
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Konferensbidrag (refereegranskat)abstract
- Large processor arrays are candidates for performing computations of neural network models at speeds required for real time applications, e.g. in pattern recognition. The paper gives a general model of an array of bit-serial processors and demonstrates the mapping of neural net models on such an array. The approach maps a neuron on each processing element and makes communication all-to-all available by connection weight matrices. The required communication structure is very simple. The bit-serial approach allows trade-offs between speed and precision, even dynamically. Performance figures are given. A bitserial multiplier is an important part of the design. Implementation aspects are discussed and it is shown that a one-board realization of a 1024 processor system is feasible with current, commonly available, technology.
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