| 1. |
- Broman, David, et al.
(författare)
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Precision Timed Infrastructure : Design Challenges
- 2013
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Ingår i: Proceedings of the Electronic System Level Synthesis Conference (ESLsyn). - : IEEE conference proceedings. - 9781467364140
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Konferensbidrag (refereegranskat)abstract
- In general-purpose software applications, computation time is just a quality factor: faster is better. In cyber-physical systems (CPS), however, computation time is a correctness factor: missed deadlines for hard real-time applications, such as avionics and automobiles, can result in devastating, life-threatening consequences. Although many modern modeling languages for CPS include the notion of time, implementation languages such as C lack any temporal semantics. Consequently, models and programs for CPS are neither portable nor guaranteed to execute correctly on the real system; timing is merely a side effect of the realization of a software system on a specific hardware platform. In this position paper, we present the research initiative for a precision timed (PRET) infrastructure, consisting of languages, compilers, and microarchitectures, where timing is a correctness factor. In particular, the timing semantics in models and programs must be preserved during compilation to ensure that the behavior of real systems complies with models. We also outline new research and design challenges present in such an infrastructure.
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| 2. |
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| 3. |
- Bothelius, Kristoffer, et al.
(författare)
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Manual-guided cognitive-behavioural therapy for insomnia delivered by ordinary primary care personnel in general medical practice : a randomized controlled effectiveness trial
- 2013
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Ingår i: Journal of Sleep Research. - : Wiley. - 0962-1105 .- 1365-2869. ; 22:6, s. 688-696
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Tidskriftsartikel (refereegranskat)abstract
- Chronic insomnia is a prevalent problem in primary health care and tends to be more serious than insomnia in the general population. These patients often obtain little benefit from hypnotics, and are frequently open to exploring various options for medical treatment. However, most general practitioners (GPs) are unable to provide such options. Several meta-analyses have shown that cognitive-behavioural therapy (CBT) for insomnia results in solid improvements on sleep parameters, and a few studies have demonstrated promising results for nurse-administered CBT in primary care. The aim of this randomized controlled study was to investigate the clinical effectiveness of manual-guided CBT for insomnia delivered by ordinary primary care personnel in general medical practice with unselected patients. Sixty-six primary care patients with insomnia were randomized to CBT or a waiting-list control group. The CBT group improved significantly more than the control group using the Insomnia Severity Index as the outcome. The effect size was high. Sleep diaries showed a significant, medium-sized treatment effect for sleep onset latency and wake time after sleep onset. However, for all measures there is a marked deterioration at follow-up assessments. Almost half of the treated subjects (47%) reported a clinically relevant treatment effect directly after treatment. It is concluded that this way of delivering treatment may be cost-effective.
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| 4. |
- Broman, David, et al.
(författare)
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Determinate Composition of FMUs for Co-Simulation
- 2013
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Ingår i: Proceedings of the International Conference on Embedded Software (EMSOFT 2013). - : IEEE conference proceedings. ; , s. 1-12
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Konferensbidrag (refereegranskat)abstract
- In this paper, we explain how to achieve deterministic execution of FMUs (Functional Mockup Units) under the FMI (Functional Mockup Interface) standard. In particular, we focus on co-simulation, where an FMU either contains its own internal simulation algorithm or serves as a gateway to a simulation tool. We give conditions on the design of FMUs and master algorithms (which orchestrate the execution of FMUs) to achieve deterministic co-simulation. We show that with the current version of the standard, these conditions demand capabilities from FMUs that are optional in the standard and rarely provided by an FMU in practice. When FMUs lacking these required capabilities are used to compose a model, many basic modeling capabilities become unachievable, including simple discrete-event simulation and variable-step-size numerical integration algorithms. We propose a small extension to the standard and a policy for designing FMUs that enables deterministic execution for a much broader class of models. The extension enables a master algorithm to query an FMU for the time of events that are expected in the future. We show that a model can be executed deterministically if all FMUs in the model are either memoryless or implement one of rollback or step-size prediction. We show further that such a model can contain at most one “legacy” FMU that is not memoryless and provides neither rollback nor step-size prediction.
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| 5. |
- Broman, David, et al.
(författare)
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Endlessly Circulating Messages in IEEE 1588-2008 Systems
- 2014
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Ingår i: Proceedings of the International IEEE Symposium on Precision Clock Synchronization for Measurement, Control and Communication (ISPCS 2014). - : IEEE conference proceedings. - 9781479926985 ; , s. 7-12
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Konferensbidrag (refereegranskat)abstract
- This paper studies conditions where messages endlessly circulate in a system of IEEE 1588-2008clocks. The study is based on two independent analysis techniques. One uses a discrete event simulation environment for describing the operation of the best master clock (BMC) algorithm inIEEE 1588-2008. The second uses a model checking tool. We discuss several cases illustrating conditions under which circulating messages occur and the effectiveness of measures to squelch these messages. This paper demonstrates that one or more of the squelching mechanisms must be implemented.
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| 6. |
- Broman, David, et al.
(författare)
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Viewpoints, Formalisms, Languages, and Tools for Cyber-Physical Systems
- 2012
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Ingår i: Proceedings of the 6th International Workshop on Multi-Paradigm Modeling (MPM). - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450318051 ; , s. 49-54
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Konferensbidrag (refereegranskat)abstract
- Cyber-physical systems (CPS) are becoming indispensable in our modern way of life. As an application domain CPS is not new. As an intellectual discipline, however, it is. This paper focuses on CPS modeling, which is an essential activity in CPS design, with multiple challenges. In particular, stakeholders lack a systematic framework and guidelines to help them choose among the many available modeling languages and tools. We propose such a framework in this paper. Our framework consists of three elements: viewpoints, which capture the stakeholders’ interests and concerns; concrete languages and tools, among which the stakeholders must make a selection when defining their CPS design environments; and abstract, mathematical formalisms, which are the “semantic glue” linking the two worlds. As part of the framework, we survey various formalisms, languages, and tools and explain how they are related. We also provide examples of viewpoints and discuss how they are related to formalisms.
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| 7. |
- Broman, M, et al.
(författare)
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Phosphate-containing dialysis solution prevents hypophosphatemia during continuous renal replacement therapy.
- 2011
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; Dec, s. 39-45
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hypophosphatemia occurs in up to 80% of the patients during continuous renal replacement therapy (CRRT). Phosphate supplementation is time-consuming and the phosphate level might be dangerously low before normophosphatemia is re-established. This study evaluated the possibility to prevent hypophosphatemia during CRRT treatment by using a new commercially available phosphate-containing dialysis fluid. Methods: Forty-two heterogeneous intensive care unit patients, admitted between January 2007 and July 2008, undergoing hemodiafiltration, were treated with a new Gambro dialysis solution with 1.2 mM phosphate (Phoxilium) or with standard medical treatment (Hemosol B0). The patients were divided into three groups: group 1 (n=14) receiving standard medical treatment and intravenous phosphate supplementation as required, group 2 (n=14) receiving the phosphate solution as dialysate solution and Hemosol B0 as replacement solution and group 3 (n=14) receiving the phosphate-containing solution as both dialysate and replacement solutions. Results: Standard medical treatment resulted in hypophosphatemia in 11 of 14 of the patients (group 1) compared with five of 14 in the patients receiving phosphate solution as the dialysate solution and Hemosol B0 as the replacement solution (group 2). Patients treated with the phosphate-containing dialysis solution (group 3) experienced stable serum phosphate levels throughout the study. Potassium, ionized calcium, magnesium, pH, pCO(2) and bicarbonate remained unchanged throughout the study. Conclusion: The new phosphate-containing replacement and dialysis solution reduces the variability of serum phosphate levels during CRRT and eliminates the incidence of hypophosphatemia.
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| 8. |
- Broman, S. L., et al.
(författare)
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Dihydroazulene Photoswitch Operating in Sequential Tunneling Regime: Synthesis and Single-Molecule Junction Studies
- 2012
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 22:20, s. 4249-4258
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Tidskriftsartikel (refereegranskat)abstract
- Molecular switches play a central role for the development of molecular electronics. In this work it is demonstrated that the reproducibility and robustness of a single-molecule dihydroazulene (DHA)/vinylheptafulvene (VHF) switch can be remarkably enhanced if the switching kernel is weakly coupled to electrodes so that the electron transport goes by sequential tunneling. To assure weak coupling, the DHA switching kernel is modified by incorporating p-MeSC6H4 end-groups. Molecules are prepared by Suzuki cross-couplings on suitable halogenated derivatives of DHA. The synthesis presents an expansion of our previously reported brominationeliminationcross-coupling protocol for functionalization of the DHA core. For all new derivatives the kinetics of DHA/VHF transition has been thoroughly studied in solution. The kinetics reveals the effect of sulfur end-groups on the thermal ring-closure of VHF. One derivative, incorporating a p-MeSC6H4 anchoring group in one end, has been placed in a silver nanogap. Conductance measurements justify that transport through both DHA (high resistivity) and VHF (low resistivity) forms goes by sequential tunneling. The switching is fairly reversible and reenterable; after more than 20 ON-OFF switchings, both DHA and VHF forms are still recognizable, albeit noticeably different from the original states.
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| 9. |
- Broman, T, et al.
(författare)
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Molecular Detection of Persistent Francisella tularensis Subspecies holarctica in Natural Waters
- 2011
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Ingår i: International Journal of Microbiology. - : Hindawi Publishing Corporation. - 1687-918X .- 1687-9198. ; 2011, s. Article ID 851946-
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Tidskriftsartikel (refereegranskat)abstract
- Tularemia, caused by the bacterium Francisella tularensis, where F. tularensis subspecies holarctica has long been the cause of endemic disease in parts of northern Sweden. Despite this, our understanding of the natural life-cycle of the organism is still limited. During three years, we collected surface water samples (n = 341) and sediment samples (n = 245) in two areas in Sweden with endemic tularemia. Real-time PCR screening demonstrated the presence of F. tularenis lpnA sequences in 108 (32%) and 48 (20%) of the samples, respectively. The 16S rRNA sequences from those samples all grouped to the species F. tularensis. Analysis of the FtM19InDel region of lpnA-positive samples from selected sampling points confirmed the presence of F. tularensis subspecies holarctica-specific sequences. These sequences were detected in water sampled during both outbreak and nonoutbreak years. Our results indicate that diverse F. tularensis-like organisms, including F. tularensis subsp. holarctica, persist in natural waters and sediments in the investigated areas with endemic tularemia.
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| 10. |
- Schalk, Oliver, et al.
(författare)
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On the Condensed Phase Ring-Closure of Vinylheptafulvalene and Ring-Opening of Gaseous Dihydroazulene
- 2013
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 117:16, s. 3340-3347
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Tidskriftsartikel (refereegranskat)abstract
- Dihydroazulenes are interesting because of their photoswitching behavior. While the ring-opening to vinylheptafulvalene (VHF) is light induced, the back reaction is known to proceed thermally. In the present paper, we show the first gas phase study of the ring-opening reaction of 2-phenyl-1,8a-dihydroazulene-1,1-dicarbonitrile (Ph-DHA) by means of time-resolved photoelectron spectroscopy which permits us to follow the ring-opening process. Moreover, we investigated s-trans-Ph-VHF in a series of transient absorption experiments, supported by ab initio computations, to understand the origin of the absence of light-induced ring-closure. The transient absorption results show a biexponential decay governed by a hitherto unknown state. This state is accessed within 1-2 ps and return to the ground state is probably driven through a cis-trans isomerization about the exocyclic C-1=C-2 double bond. The rapid decrease in potential energy disfavors internal rotation to s-cis-Ph-VHF, the structure that would precede the ring-closure reaction.
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