SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Johansson Christopher 1977 ) "

Sökning: WFRF:(Johansson Christopher 1977 )

  • Resultat 1-10 av 16
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Furukawa, Toshi A., et al. (författare)
  • Dismantling, optimising, and personalising internet cognitive behavioural therapy for depression : a systematic review and component network meta-analysis using individual data
  • 2021
  • Ingår i: Lancet psychiatry. - London, United Kingdom : Elsevier. - 2215-0374 .- 2215-0366. ; 8:6, s. 500-511
  • Forskningsöversikt (refereegranskat)abstract
    • Findings We identified 76 RCTs, including 48 trials contributing individual participant data (11 704 participants) and 28 trials with aggregate data (6474 participants). The participants' weighted mean age was 42.0 years and 12 406 (71%) of 17 521 reported were women. There was suggestive evidence that behavioural activation might be beneficial (iMD -1.83 [95% credible interval (CrI) -2.90 to -0.80]) and that relaxation might be harmful (1.20 [95% CrI 0.17 to 2.27]). Baseline severity emerged as the strongest prognostic factor for endpoint depression. Combining human and automated encouragement reduced dropouts from treatment (incremental odds ratio, 0.32 [95% CrI 0.13 to 0.93]). The risk of bias was low for the randomisation process, missing outcome data, or selection of reported results in most of the included studies, uncertain for deviation from intended interventions, and high for measurement of outcomes. There was moderate to high heterogeneity among the studies and their components. 511
  •  
2.
  • Staudt, Matthias, 1977, et al. (författare)
  • Coupling of an erbium spin ensemble to a superconducting resonator
  • 2012
  • Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 1361-6455 .- 0953-4075. ; 45:12, s. Art. no. 124019-
  • Tidskriftsartikel (refereegranskat)abstract
    • A quantum coherent interface between optical and microwave photons can be used as a basic building block within a future quantum information network. The interface is envisioned as an ensemble of rare-earth ions coupled to a superconducting resonator, allowing for coherent transfer between optical and microwave photons. Towards this end, we have realized a hybrid device coupling a Er3+-doped Y2SiO5 crystal in a superconducting coplanar waveguide cavity. We observe a collective spin coupling of 4 MHz and a spin linewidth of down to 75 MHz.
  •  
3.
  • Afzelius, M., et al. (författare)
  • Proposal for a coherent quantum memory for propagating microwave photons
  • 2013
  • Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 15, s. Art. no. 065008-
  • Tidskriftsartikel (refereegranskat)abstract
    • We describe a multi-mode quantum memory for propagating microwave photons that combines a solid-state spin ensemble resonantly coupled to a frequency tunable single-mode microwave cavity. We first show that high efficiency mapping of the quantum state transported by a free photon to the spin ensemble is possible both for strong and weak coupling between the cavity mode and the spin ensemble. We also show that even in the weak coupling limit unit efficiency and faithful retrieval can be obtained through time reversal inhomogeneous dephasing based on spin echo techniques. This is possible provided that the cavity containing the spin ensemble and the transmission line are impedance matched. We finally discuss the prospects for an experimental implementation using a rare-earth doped crystal coupled to a superconducting resonator.
  •  
4.
  • Bott, Lukas Thomas, et al. (författare)
  • Coulomb dissociation of O-16 into He-4 and C-12
  • 2023
  • Ingår i: NUCLEAR PHYSICS IN ASTROPHYSICS - X, NPA-X 2022. - : EDP Sciences. - 2100-014X. ; 279
  • Konferensbidrag (refereegranskat)abstract
    • We measured the Coulomb dissociation of O-16 into He-4 and C-12 within the FAIR Phase-0 program at GSI Helmholtzzentrum fur Schwerionenforschung Darmstadt, Germany. From this we will extract the photon dissociation cross section O-16(alpha,gamma)C-12, which is the time reversed reaction to C-12(alpha,gamma)O-16. With this indirect method, we aim to improve on the accuracy of the experimental data at lower energies than measured so far. The expected low cross section for the Coulomb dissociation reaction and close magnetic rigidity of beam and fragments demand a high precision measurement. Hence, new detector systems were built and radical changes to the (RB)-B-3 setup were necessary to cope with the high-intensity O-16 beam. All tracking detectors were designed to let the unreacted O-16 ions pass, while detecting the C-12 and He-4.
  •  
5.
  • Galván, Ignacio Fdez., et al. (författare)
  • OpenMolcas : From Source Code to Insight
  • 2019
  • Ingår i: Journal of Chemical Theory and Computation. - : American Chemical Society (ACS). - 1549-9618 .- 1549-9626. ; 15:11, s. 5925-5964
  • Tidskriftsartikel (refereegranskat)abstract
    • In this Article we describe the OpenMolcas environment and invite the computational chemistry community to collaborate. The open-source project already includes a large number of new developments realized during the transition from the commercial MOLCAS product to the open-source platform. The paper initially describes the technical details of the new software development platform. This is followed by brief presentations of many new methods, implementations, and features of the OpenMolcas program suite. These developments include novel wave function methods such as stochastic complete active space self-consistent field, density matrix renormalization group (DMRG) methods, and hybrid multiconfigurational wave function and density functional theory models. Some of these implementations include an array of additional options and functionalities. The paper proceeds and describes developments related to explorations of potential energy surfaces. Here we present methods for the optimization of conical intersections, the simulation of adiabatic and nonadiabatic molecular dynamics, and interfaces to tools for semiclassical and quantum mechanical nuclear dynamics. Furthermore, the Article describes features unique to simulations of spectroscopic and magnetic phenomena such as the exact semiclassical description of the interaction between light and matter, various X-ray processes, magnetic circular dichroism, and properties. Finally, the paper describes a number of built-in and add-on features to support the OpenMolcas platform with postcalculation analysis and visualization, a multiscale simulation option using frozen-density embedding theory, and new electronic and muonic basis sets.
  •  
6.
  • Hartmann, Martin, 1977, et al. (författare)
  • V-RevComp: automated high-throughput detection of reverse complementary 16S ribosomal RNA gene sequences in large environmental and taxonomic datasets
  • 2011
  • Ingår i: FEMS Microbiology Letters. - : Oxford University Press (OUP). - 0378-1097. ; 319:2, s. 140-145
  • Tidskriftsartikel (refereegranskat)abstract
    • Reverse complementary DNA sequences – sequences that are inadvertently given backwards with all purines and pyrimidines transposed – can affect sequence analysis detrimentally unless taken into account. We present an open-source, high-throughput software tool – V-RevComp (http://www.cmde.science.ubc.ca/mohn/software.html) – to detect and reorient reverse complementary entries of the small-subunit rRNA (16S) gene from sequencing datasets, particularly from environmental sources. The software supports sequence lengths ranging from full-length down to the short reads that are characteristic of next generation sequencing technologies. We evaluated the reliability of V-RevComp by screening all 406 781 16S sequences deposited in release 102 of the curated SILVA database and demonstrated that the tool has a detection accuracy of virtually 100%. We subsequently used V-RevComp to analyze 1 171 646 16S sequences deposited in the International Nucleotide Sequence Databases and found that about 1% of these user-submitted sequences were reverse complementary. In addition, a non-trivial proportion of entries were otherwise anomalous, including reverse complementary chimeras, sequences associated with wrong taxa, non-ribosomal genes, sequences of poor quality or otherwise erroneous sequences without reasonable match to any other entry in the database. Thus, V-RevComp is highly efficient in detecting and reorienting reverse complementary 16S sequences of almost any length and can be used to detect various sequence anomalies.
  •  
7.
  • Johansson, Christopher, 1977- (författare)
  • An Attractor Memory Model of Neocortex
  • 2006
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • This thesis presents an abstract model of the mammalian neocortex. The model was constructed by taking a top-down view on the cortex, where it is assumed that cortex to a first approximation works as a system with attractor dynamics. The model deals with the processing of static inputs from the perspectives of biological mapping, algorithmic, and physical implementation, but it does not consider the temporal aspects of these inputs. The purpose of the model is twofold: Firstly, it is an abstract model of the cortex and as such it can be used to evaluate hypotheses about cortical function and structure. Secondly, it forms the basis of a general information processing system that may be implemented in computers. The characteristics of this model are studied both analytically and by simulation experiments, and we also discuss its parallel implementation on cluster computers as well as in digital hardware. The basic design of the model is based on a thorough literature study of the mammalian cortex’s anatomy and physiology. We review both the layered and columnar structure of cortex and also the long- and short-range connectivity between neurons. Characteristics of cortex that defines its computational complexity such as the time-scales of cellular processes that transport ions in and out of neurons and give rise to electric signals are also investigated. In particular we study the size of cortex in terms of neuron and synapse numbers in five mammals; mouse, rat, cat, macaque, and human. The cortical model is implemented with a connectionist type of network where the functional units correspond to cortical minicolumns and these are in turn grouped into hypercolumn modules. The learning-rules used in the model are local in space and time, which make them biologically plausible and also allows for efficient parallel implementation. We study the implemented model both as a single- and multi-layered network. Instances of the model with sizes up to that of a rat-cortex equivalent are implemented and run on cluster computers in 23% of real time. We demonstrate on tasks involving image-data that the cortical model can be used for meaningful computations such as noise reduction, pattern completion, prototype extraction, hierarchical clustering, classification, and content addressable memory, and we show that also the largest cortex equivalent instances of the model can perform these types of computations. Important characteristics of the model are that it is insensitive to limited errors in the computational hardware and noise in the input data. Furthermore, it can learn from examples and is self-organizing to some extent. The proposed model contributes to the quest of understanding the cortex and it is also a first step towards a brain-inspired computing system that can be implemented in the molecular scale computers of tomorrow. The main contributions of this thesis are: (i) A review of the size, modularization, and computational structure of the mammalian neocortex. (ii) An abstract generic connectionist network model of the mammalian cortex. (iii) A framework for a brain-inspired self-organizing information processing system. (iv) Theoretical work on the properties of the model when used as an autoassociative memory. (v) Theoretical insights on the anatomy and physiology of the cortex. (vi) Efficient implementation techniques and simulations of cortical sized instances. (vii) A fixed-point arithmetic implementation of the model that can be used in digital hardware.
  •  
8.
  • Johansson, Christopher, 1977-, et al. (författare)
  • Attractor neural networks with patchy connectivity
  • 2007
  • Ingår i: ESANN 2005 Proceedings - 13th European Symposium on Artificial Neural Networks. - 2930307056 - 9782930307053 ; , s. 429-434
  • Konferensbidrag (refereegranskat)abstract
    • We investigate the effects of patchy (clustered) connectivity in sparsely connected attractor neural networks (NNs). This study is motivated by the fact that the connectivity of pyramidal neurons in layer II/III of the mammalian visual cortex is patchy and sparse. The storage capacity of hypercolumnar attractor NNs that use the Hopfield and Willshaw learning rules with this kind of connectivity is investigated analytically as well as by simulation experiments. We find that patchy connectivity gives a higher storage capacity, given an overall sparse connectivity and regardless of learning rule.
  •  
9.
  • Johansson, Christopher, 1977-, et al. (författare)
  • Reinforcement Learning Based on a Bayesian Confidence Propagating Neural Network
  • 2003
  • Konferensbidrag (refereegranskat)abstract
    • We present a system capable of reinforcement learning (RL) based on the Bayesian confidence propagating neural network (BCPNN). The system is called BCPNNRL and its architecture is somewhat motivated by parallels to biology. We analyze the systems properties and we benchmark it against a simple Monte Carlo (MC) based RL algorithm, pursuit RL methods, and the Associative Reward Penalty (AR-P) algorithm. The system is used to solve the n-armed bandit problem, pattern association, and path finding in a maze.
  •  
10.
  • Kraepelien, Martin, et al. (författare)
  • Digital psychological self-care for problematic alcohol use : feasibility of a new clinical concept
  • 2023
  • Ingår i: BJPsych Open. - : Cambridge University Press. - 2056-4724. ; 9:3
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Digital interventions based on cognitive–behavioural therapy and relapse prevention can increase treatment access for people with problematic alcohol use, but for these interventions to be cost-effective, clinician workload needs to remain low while ensuring patient adherence and effects. Digital psychological self-care is the provision of a self-guided digital intervention within a structured care process.Aims: To investigate the feasibility and preliminary effects of digital psychological self-care for reducing alcohol consumption.Method: Thirty-six adults with problematic alcohol use received digital psychological self-care during 8 weeks, including telephone assessments as well as filling out self-rated questionnaires, before, directly after and 3 months after the intervention. Intervention adherence, usefulness, credibility and use of clinician time were assessed, along with preliminary effects on alcohol consumption. The study was prospectively registered as a clinical trial (NCT05037630).Results: Most participants used the intervention daily or several times a week. The digital intervention was regarded as credible and useful, and there were no reported adverse effects. Around 1 h of clinician time per participant was spent on telephone assessments. At the 3-month follow-up, preliminary within-group effects on alcohol consumption were moderate (standardised drinks per week, Hedge's g = 0.70, 95% CI = 0.19–1.21; heavy drinking days, Hedge's g = 0.60, 95% CI = 0.09–1.11), reflecting a decrease from 23 to 13 drinks per week on average.Conclusions: Digital psychological self-care for reducing alcohol consumption appears both feasible and preliminarily effective and should be further optimised and studied in larger trials.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-10 av 16
Typ av publikation
tidskriftsartikel (10)
konferensbidrag (4)
doktorsavhandling (1)
forskningsöversikt (1)
Typ av innehåll
refereegranskat (15)
övrigt vetenskapligt/konstnärligt (1)
Författare/redaktör
Johansson, Göran, 19 ... (7)
Wilson, Christopher, ... (7)
Delsing, Per, 1959 (6)
Shumeiko, Vitaly, 19 ... (3)
Afzelius, M. (2)
Sangouard, N. (2)
visa fler...
Staudt, Matthias, 19 ... (2)
Bauch, Thilo, 1972 (2)
Abarenkov, Kessy (1)
Nilsson, R. Henrik, ... (1)
Veldre, Vilmar (1)
Johansson, Robert (1)
Carlbring, Per (1)
Johansson, Håkan T, ... (1)
Nilsson, Thomas, 196 ... (1)
Heinz, Andreas Marti ... (1)
Guo, Meiyuan (1)
Lundberg, Marcus, 19 ... (1)
Johansson, Kristina (1)
Veryazov, Valera (1)
Kovačević, Goran (1)
Krantz, Philip, 1984 (1)
Berger, Thomas (1)
Danilov, Andrey, 196 ... (1)
Johansson, Magnus (1)
Angeli, Celestino (1)
Knecht, Stefan (1)
Malmqvist, Per-Åke (1)
Jonson, Björn, 1941 (1)
Tengblad, Olof, 1957 (1)
Alavi, Ali (1)
Johansson, Peter, 19 ... (1)
Andersson, Gerhard, ... (1)
Kaldo, Viktor, Profe ... (1)
Johansson, Marcus (1)
Cuijpers, Pim (1)
Johansson, Per (1)
Forsell, Erik (1)
Riper, Heleen (1)
Hadjistavropoulos, H ... (1)
Vernmark, Kristofer, ... (1)
Kivi, Marie (1)
Aquilante, Francesco (1)
Gagliardi, Laura (1)
Fernández Galván, Ig ... (1)
Autschbach, Jochen (1)
Chibotaru, Liviu F. (1)
Freitag, Leon (1)
Lindh, Roland, Profe ... (1)
Norell, Jesper (1)
visa färre...
Lärosäte
Chalmers tekniska högskola (8)
Kungliga Tekniska Högskolan (4)
Stockholms universitet (3)
Uppsala universitet (2)
Karolinska Institutet (2)
Göteborgs universitet (1)
visa fler...
Mälardalens universitet (1)
Linköpings universitet (1)
Lunds universitet (1)
Linnéuniversitetet (1)
Sveriges Lantbruksuniversitet (1)
visa färre...
Språk
Engelska (16)
Forskningsämne (UKÄ/SCB)
Naturvetenskap (13)
Medicin och hälsovetenskap (3)
Teknik (2)
Samhällsvetenskap (2)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy