| 1. |
- Andersson, Niklas, et al.
(författare)
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Models and Implementation of a Dynamic Element Matching DAC
- 2003
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Ingår i: Analog Integrated Circuits and Signal Processing. - Netherlands : Springer. - 0925-1030 .- 1573-1979. ; 34:1, s. 7-16
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Tidskriftsartikel (refereegranskat)abstract
- The dynamic element matching (DEM) techniques for digital-to-analog converters (DACs) has been suggested as a promising method to improve matching between the DAC''s reference levels. However, no work has so far taken the dynamic effects that limit the performance for higher frequenciesinto account. In this paper we present a model describing the dynamic properties of a DEM DAC and compare the simulated results with measurements of a 14-bit current-steering DEM DAC implemented in a 0.35-μm CMOS process. The measured data agrees well with the results predicted by the used model. It is also shown that the DEM technique does not necessarily increase the performance of a DAC when dynamic errors are dominating the achievable performance.
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| 2. |
- Andersson, Ola, et al.
(författare)
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A 14-Bit dual current-steering DAC
- 2003
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Ingår i: Proc. Swedish System-on-Chip Conf., SSoCC'03.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A 14-bit dual current-steering digital-to-analog converter implemented in a 0.25 µm CMOS process is presented in this work. Both implementation issues and measurement results are presented. The measured spurious-free dynamic range is higher than 73 dB for signal frequencies up to 3 MHz, and a measured multi-tone power ratio of approximately 71 dB is reported for an ADSL-like input.
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| 3. |
- Andersson, Ola, et al.
(författare)
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A differential DAC architecture with variable common-mode level
- 2002
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Ingår i: Proc. 2002 IEEE Int. Symp. on Circuits and Systems, ISCAS'02. - 0780374487 ; , s. I-113-I-116
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Konferensbidrag (refereegranskat)abstract
- A differential current-steering digital-to-analog converter (DAC) architecture allowing the common-mode level of the input signal to be varied is presented. Simulation results with models of different DAC nonlinearities indicate that the proposed architecture has a potential of improving the linearity of the converters.
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| 4. |
- Andersson, Ola, et al.
(författare)
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A method of segmenting digital-to-analog converters
- 2003
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Ingår i: Proc. IEEE Southwest Symposium on Mixed-Signal Design, SSMSD'03. - 0780377788 ; , s. 32-37
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Konferensbidrag (refereegranskat)abstract
- Segmented architectures are often used in digital-to-analog converters (DACs). Here we propose a DAC structure based on recursive decomposition of an N-bit binary DAC into two (N-1) bit DACs and one 1 bit DAC. A DAC model that includes matching errors has been simulated. The simulation results indicate that by using four layers of decomposition it is possible to achieve similar performance as when using seven bits of traditional segmentation.
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| 5. |
- Andersson, Ola, et al.
(författare)
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Combining DACs for improved performance
- 2002
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Ingår i: Proc. 4th IEE Int. Conf. on Advanced A/D and D/A Conversion Techniques and their Applications, ADDA'02.
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Konferensbidrag (refereegranskat)abstract
- This work is an overview of recently proposed methods on combining DACs in order to improve performance. Some further development of these techniques are also presented. The techniques aim at reducing glitches and sensitivity towards limited output impedance in current sources.
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| 6. |
- Andersson, Ola, 1976-, et al.
(författare)
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Spectral shaping of DAC nonlinearity errors through modulation of expected errors
- 2001
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Ingår i: Circuits and Systems, 2001. ISCAS 2001. The 2001 IEEE International Symposium on. - : IEEE. - 0780366859 ; , s. 417-420
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Konferensbidrag (refereegranskat)abstract
- Traditionally, delta-sigma modulation has been used for shaping of quantization noise. We present a modified version of delta-sigma modulation which also takes into account unwanted nonlinearities by feeding back not only the quantization error, but also the expected physical error. Behavioral-level simulations of a 5th-order structure showing an improvement of up to 4 effective bits are included
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| 7. |
- Ansari, Daniel, et al.
(författare)
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Single-institution experience with solid pseudopapillary neoplasm of the pancreas.
- 2011
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 46:12, s. 1492-1497
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Objective. Solid pseudopapillary neoplasm (SPN) of the pancreas is a rare clinical entity. The objective of this study was to review a single institution's experience with this uncommon tumor, as well as review the literature. Material and Methods. Consecutive patients, who underwent surgery for a pathologically confirmed SPN between 1991 and 2010, were retrospectively reviewed. A PubMed search (January 1980-June 2011) was conducted to identify risk factors for death among SPN patients. Results. The institutional review identified 16 patients with SPN. Thirteen patients were female and three patients were male (median age 34 years). All patients underwent radical resection. Two patients had metastatic disease at the time of operation as evident by the presence of lymph node metastasis and gallbladder metastasis. One developed liver metastasis 4 months postoperatively and subsequently died. The other patient received adjuvant chemotherapy (gemcitabine and capecitabine), and 23 months after the initial operation, no tumor recurrence was detected and the patient is still alive. All other patients remain disease-free. Analysis of 29 fatalities reported in the English literature (including the present case) revealed several atypical features including male gender, old age, tumor size >5 cm, diffuse growth pattern, cellular or nuclear atypia, high mitotic rate, extensive necrosis, extrapancreatic invasion, metastasis and incomplete resection. Conclusions. SPN is not always indolent. Male patients and those with old age, atypical histopathology (large tumors, diffuse growth, cellular/nuclear atypia, mitotic activity, necrosis, invasion/metastasis) and incomplete resection may have a higher risk of recurrence and death, deserving particular attention.
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| 8. |
- Bombarda, F., et al.
(författare)
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Runaway electron beam control
- 2019
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Tidskriftsartikel (refereegranskat)
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| 9. |
- Kjellström, Sofia, 1970-, et al.
(författare)
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Exploring, measuring and enhancing the coproduction of health and well-being at the national, regional and local levels through comparative case studies in Sweden and England : the 'Samskapa' research programme protocol
- 2019
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Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION:Cocreation, coproduction and codesign are advocated as effective ways of involving citizens in the design, management, provision and evaluation of health and social care services. Although numerous case studies describe the nature and level of coproduction in individual projects, there remain three significant gaps in the evidence base: (1) measures of coproduction processes and their outcomes, (2) mechanisms that enable inclusivity and reciprocity and (3) management systems and styles. By focusing on these issues, we aim to explore, enhance and measure the value of coproduction for improving the health and well-being of citizens.METHODS AND ANALYSIS:Nine ongoing coproduction projects form the core of an interactive research programme ('Samskapa') during a 6-year period (2019-2024). Six of these will take place in Sweden and three will be undertaken in England to enable knowledge exchange and cross-cultural comparison. The programme has a longitudinal case study design using both qualitative and quantitative methods. Cross-case analysis and a sensemaking process will generate relevant lessons both for those participating in the projects and researchers. Based on the findings, we will develop explanatory models and other outputs to increase the sustained value (and values) of future coproduction initiatives in these sectors.ETHICS AND DISSEMINATION:All necessary ethical approvals will be obtained from the regional Ethical Board in Sweden and from relevant authorities in England. All data and personal data will be handled in accordance with General Data Protection Regulations. Given the interactive nature of the research programme, knowledge dissemination to participants and stakeholders in the nine projects will be ongoing throughout the 6 years. External workshops-facilitated in collaboration with participating case studies and citizens-both during and at the end of the programme will provide an additional dissemination mechanism and involve health and social care practitioners, policymakers and third-sector organisations.
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| 10. |
- Markljung, Ellen, et al.
(författare)
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ZBED6, a novel transcription factor derived from a domesticated DNA transposon regulates IGF2 expression and muscle growth
- 2009
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Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 7:12, s. e1000256-
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Tidskriftsartikel (refereegranskat)abstract
- A single nucleotide substitution in intron 3 of IGF2 in pigs abrogates a binding site for a repressor and leads to a 3-fold up-regulation of IGF2 in skeletal muscle. The mutation has major effects on muscle growth, size of the heart, and fat deposition. Here, we have identified the repressor and find that the protein, named ZBED6, is previously unknown, specific for placental mammals, and derived from an exapted DNA transposon. Silencing of Zbed6 in mouse C2C12 myoblasts affected Igf2 expression, cell proliferation, wound healing, and myotube formation. Chromatin immunoprecipitation (ChIP) sequencing using C2C12 cells identified about 2,500 ZBED6 binding sites in the genome, and the deduced consensus motif gave a perfect match with the established binding site in Igf2. Genes associated with ZBED6 binding sites showed a highly significant enrichment for certain Gene Ontology classifications, including development and transcriptional regulation. The phenotypic effects in mutant pigs and ZBED6-silenced C2C12 myoblasts, the extreme sequence conservation, its nucleolar localization, the broad tissue distribution, and the many target genes with essential biological functions suggest that ZBED6 is an important transcription factor in placental mammals, affecting development, cell proliferation, and growth.
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