Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
480
result(s) for
"data- och systemvetenskap"
Sort by:
A comprehensive workflow for general-purpose neural modeling with highly configurable neuromorphic hardware systems
by
Schemmel, Johannes
,
Petkov, Venelin
,
Mayr, Christian
in
Bioinformatics
,
Biomedical and Life Sciences
,
Biomedicine
2011
In this article, we present a methodological framework that meets novel requirements emerging from upcoming types of accelerated and highly configurable neuromorphic hardware systems. We describe in detail a device with 45 million programmable and dynamic synapses that is currently under development, and we sketch the conceptual challenges that arise from taking this platform into operation. More specifically, we aim at the establishment of this neuromorphic system as a flexible and neuroscientifically valuable modeling tool that can be used by non-hardware experts. We consider various functional aspects to be crucial for this purpose, and we introduce a consistent workflow with detailed descriptions of all involved modules that implement the suggested steps: The integration of the hardware interface into the simulator-independent model description language PyNN; a fully automated translation between the PyNN domain and appropriate hardware configurations; an executable specification of the future neuromorphic system that can be seamlessly integrated into this biology-to-hardware mapping process as a test bench for all software layers and possible hardware design modifications; an evaluation scheme that deploys models from a dedicated benchmark library, compares the results generated by virtual or prototype hardware devices with reference software simulations and analyzes the differences. The integration of these components into one hardware–software workflow provides an ecosystem for ongoing preparative studies that support the hardware design process and represents the basis for the maturity of the model-to-hardware mapping software. The functionality and flexibility of the latter is proven with a variety of experimental results.
Journal Article
The effect of critical success factors on IT governance performance
by
Nfuka, Edephonce N
,
Rusu, Lazar
in
Computer and systems science
,
Computer and Systems Sciences
,
Correlated effect
2011
Purpose - The purpose of this paper is to analyse the effect of critical success factors (CSFs) on information technology (IT) governance performance in public sector organizations in a developing country such as Tanzania.Design methodology approach - Based on a previous study and a further literature review, a research model was developed for analysing the relationship between the CSFs found for effective IT governance in this environment and their effect on IT governance performance. A survey research method was applied for data collection and sample data from Tanzanian public sector organizations (this environment) obtained. Subsequently, a second-generation structural equation modelling technique, namely partial least squares, was applied to test statistically the correlated effect.Findings - The results indicate significant small to strong positive correlated effects on IT governance performance. The CSF with the most significant correlated effect was \"involve and get support of senior management\" and the one with the least \"consolidate, standardize and manage IT infrastructure and application to optimize costs and information flow across the organization\". Finally, a CSF model for effective IT governance in this environment was proposed.Research limitations implications - The findings imply that decision makers can optimize IT-related plans and use of scarce resources by concentrating on the CSFs that have a significant effect on IT governance performance that could lead to an improvement of public service delivery. This study is limited to a single developing country but future studies can involve more such countries to broaden the insights into the effect of CSFs on IT governance performance in such environments.Originality value - By establishing the correlated effects between these CSFs and the IT governance performance, this study has revealed a significant impact of CSFs on IT governance performance. It also suggests a CSFs model for effective IT governance in this less-resourced environment in which such studies have not been conducted before, yet which are vital for analysing and improving IT governance.
Journal Article
Virtual patient simulation: what do students make of it? A focus group study
by
Hult, Håkan
,
Botezatu, Mihaela
,
Fors, Uno G
in
Attitude of Health Personnel
,
Coding
,
Communication
2010
Background
The learners' perspectives on Virtual Patient Simulation systems (VPS) are quintessential to their successful development and implementation. Focus group interviews were conducted in order to explore the opinions of medical students on the educational use of a VPS, the Web-based Simulation of Patients application (Web-SP).
Methods
Two focus group interviews-each with 8 undergraduate students who had used Web-SP cases for learning and/or assessment as part of their Internal Medicine curriculum in 2007-were performed at the Faculty of Medicine of Universidad el Bosque (Bogota), in January 2008. The interviews were conducted in Spanish, transcribed by the main researcher and translated into English. The resulting transcripts were independently coded by two authors, who also performed the content analysis. Each coder analyzed the data separately, arriving to categories and themes, whose final form was reached after a consensus discussion.
Results
Eighteen categories were identified and clustered into five main themes: learning, teaching, assessment, authenticity and implementation. In agreement with the literature, clinical reasoning development is envisaged by students to be the main scope of VPS use; transferable skills, retention enhancement and the importance of making mistakes are other categories circumscribed to this theme. VPS should enjoy a broad use across clinical specialties and support learning of topics not seen during clinical rotations; they are thought to have a regulatory effect at individual level, helping the students to plan their learning. The participants believe that assessment with VPS should be relevant for their future clinical practice; it is deemed to be qualitatively different from regular exams and to increase student motivation. The VPS design and content, the localization of the socio-cultural context, the realism of the cases, as well as the presence and quality of feedback are intrinsic features contributing to VPS authenticity.
Conclusions
Five main themes were found to be associated with successful VPS use in medical curriculum: Learning, Teaching, Assessment, Authenticity and Implementation. Medical students perceive Virtual Patients as important learning and assessment tools, fostering clinical reasoning, in preparation for the future clinical practice as young doctors. However, a number of issues regarding VPS design, authenticity and implementation need to be fulfilled, in order to reach the potential educational goals of such applications.
Journal Article
Reporting Patterns Indicative of Adverse Drug Interactions
by
Norén, Niklas
,
Caster, Ola
,
Strandell, Johanna
in
Adverse and side effects
,
Biological and medical sciences
,
Computer and systems science
2011
Background:
Adverse drug interaction surveillance in collections of Individual Case Safety Reports (ICSRs) remains underdeveloped. Most efforts to date have focused on disproportionality analysis, but the empirical support for its value is based on isolated examples. Additionally, too little attention has been given to the potential value of the detailed content of ICSRs for improved adverse drug interaction surveillance.
Objective:
The aim of the study was to identify reporting patterns indicative of suspected adverse drug interactions before the drug interactions are generally established.
Methods:
A reference set of known adverse drug interactions and drug pairs not known to interact was constructed from information added to Stockley’s Drug Interactions Alerts between the first quarter of 2007 and the third quarter of 2009. The reference set was used to systematically study differences in reporting patterns between adverse drug interactions before they are generally established and adverse drug reactions (ADRs) to drug pairs that are not known to interact, in the WHO Global ICSR Database, VigiBase. The scope of the study included pharmacological properties such as common cytochrome P450 metabolism, explicit suspicions of drug interactions as noted by the reporter, clinical details such as dose and treatment overlap, and the lower limit of the 95% credibility interval of a three-way measure of disproportionality, Omega
025
(Ω
025
), based on the total number of reports on two drugs and one ADR together. Analyses were carried out including and excluding concomitant medicines.
Results:
Five reporting patterns were highlighted as particularly strong indicators of adverse drug interactions before they are known: suspicion of interactions as noted by the reporter in a case narrative, the assignment of the two drugs as interacting or through an ADR term; co-reporting of effect increased with the drug pair; and, finally, an excess total number of reports on the ADR together with the two drugs, as measured by Ω
025
. Overall, the inclusion of concomitant medicines led to a larger number of true adverse drug interactions being highlighted, but at a substantial decrease in the strength of most indicators. Notably, the inclusion of concomitant medicines completely eliminated the value of Ω
025
as an indicator of adverse drug interactions, in this systematic evaluation.
Conclusions:
Reported suspicion of interactions as noted by the reporter in a case narrative, the assignment of the two drugs as interacting or through an ADR term; co-reporting of effect increased with the drug pair and by the Ω
025
each provide unique information to highlight adverse drug interactions before they become known in the literature. To our knowledge, this is the first systematic analysis demonstrating the value of disproportionality analysis for adverse drug interactions using a comprehensive reference set, and the first study to consider a broader basis including clinical information for systematic drug interaction surveillance.
Journal Article
Exploring agile values in method configuration
by
Karlsson, Fredrik
,
Ågerfalk, Pär
in
agile method
,
Business and Management
,
Business Information Systems
2009
The Method for Method Configuration (MMC) has been proposed as a method engineering approach to tailoring information systems development methods. This meta-method has been used on a variety of methods, but none of these studies have focused on the ability to manage method tailoring with the intention to promote specific values and goals, such as agile ones. This paper explores how MMC has been used during three software development projects to manage method tailoring with the intention to promote agile goals and values. Through content examples of method configurations we have shown that it is possible to use MMC and its conceptual framework on eXtreme Programming and we report on lessons learned with regard to maintaining coherency with the overall goals of the original method.
Journal Article
Information dynamics shape the sexual networks of Internet-mediated prostitution
2010
Like many other social phenomena, prostitution is increasingly coordinated over the Internet. The online behavior affects the offline activity; the reverse is also true. We investigated the reported sexual contacts between 6,624 anonymous escorts and 10,106 sex buyers extracted from an online community from its beginning and six years on. These sexual encounters were also graded and categorized (in terms of the type of sexual activities performed) by the buyers. From the temporal, bipartite network of posts, we found a full feedback loop in which high grades on previous posts affect the future commercial success of the sex worker, and vice versa. We also found a peculiar growth pattern in which the turnover of community members and sex workers causes a sublinear preferential attachment. There is, moreover, a strong geographic influence on network structure--the network is geographically clustered but still close to connected, the contacts consistent with the inverse-square law observed in trading patterns. We also found that the number of sellers scales sublinearly with city size, so this type of prostitution does not, comparatively speaking, benefit much from an increasing concentration of people.
Journal Article
De-identifying Swedish clinical text - refinement of a gold standard and experiments with Conditional random fields
2010
Background
In order to perform research on the information contained in Electronic Patient Records (EPRs), access to the data itself is needed. This is often very difficult due to confidentiality regulations. The data sets need to be fully de-identified before they can be distributed to researchers. De-identification is a difficult task where the definitions of annotation classes are not self-evident.
Results
We present work on the creation of two refined variants of a manually annotated Gold standard for de-identification, one created automatically, and one created through discussions among the annotators. The data is a subset from the Stockholm EPR Corpus, a data set available within our research group. These are used for the training and evaluation of an automatic system based on the Conditional Random Fields algorithm. Evaluating with four-fold cross-validation on sets of around 4-6 000 annotation instances, we obtained very promising results for both Gold Standards: F-score around 0.80 for a number of experiments, with higher results for certain annotation classes. Moreover, 49 false positives that were verified true positives were found by the system but missed by the annotators.
Conclusions
Our intention is to make this Gold standard, The Stockholm EPR PHI Corpus, available to other research groups in the future. Despite being slightly more time-consuming we believe the manual consensus gold standard is the most valuable for further research. We also propose a set of annotation classes to be used for similar de-identification tasks.
Journal Article
Negation detection in Swedish clinical text: An adaption of NegEx to Swedish
2011
Background
Most methods for negation detection in clinical text have been developed for English text, and there is a need for evaluating the feasibility of adapting these methods to other languages. A Swedish adaption of the English rule-based negation detection system NegEx, which detects negations through the use of trigger phrases, was therefore evaluated.
Results
The Swedish adaption of NegEx showed a precision of 75.2% and a recall of 81.9%, when evaluated on 558 manually classified sentences containing negation triggers, and a negative predictive value of 96.5% when evaluated on 342 sentences not containing negation triggers.
Conclusions
The precision was significantly lower for the Swedish adaptation than published results for the English version, but since many negated propositions were identified through a limited set of trigger phrases, it could nevertheless be concluded that the same trigger phrase approach is possible in a Swedish context, even though it needs to be further developed.
Availability
The triggers used for the evaluation of the Swedish adaption of NegEx are available at
http://people.dsv.su.se/~mariask/resources/triggers.txt
and can be used together with the original NegEx program for negation detection in Swedish clinical text.
Journal Article