| 1. |
- Jakobsson, Henrik, et al.
(författare)
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CrySSMEx, a novel rule extractor for recurrent neural networks : Overview and case study
- 2005
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Ingår i: Artificial Neural Networks: Formal Models and Their Applications. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 3540287558 - 9783540287551 - 9783540287568 ; , s. 503-508
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Konferensbidrag (refereegranskat)abstract
- In this paper, it will be shown that it is feasible to extract finite state machines in a domain of, for rule extraction, previously unencountered complexity. The algorithm used is called the Crystallizing Substochastic Sequential Machine Extractor, or CrySSMEx. It extracts the machine from sequence data generated from the RNN in interaction with its domain. CrySSMEx is parameter free, deterministic and generates a sequence of increasingly deterministic extracted stochastic models until a fully deterministic machine is found.
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| 2. |
- Ahmad, Tausif, et al.
(författare)
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Controllable phytosynthesis of gold nanoparticles and investigation of their size and morphology-dependent photocatalytic activity under visible light
- 2020
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Ingår i: Journal of Photochemistry and Photobiology A. - : Elsevier. - 1010-6030 .- 1873-2666. ; 392, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Plants mediated synthesis of gold nanoparticles (AuNPs) containing desired characteristics for their suitable potential applications has been a challenging task, which is causing a major hindrance towards its commercialization. Therefore, herein phytosynthesis of AuNPs with required size and morphology has been achieved through manipulating the reaction conditions including reaction temperature and volume of Elaeis guineensis leaves (EGL) extract. Furthermore, photocatalytic potential of EGL mediated AuNPs having different size and shape has also been explored for the removal of methylene blue (MB) under visible light irradiation. The reaction temperature and volume of EGL strongly influenced the size and morphology of AuNPs, which are directly associated with the photocatalytic activities. The experimental results revealed that predominantly spherical and ultra-smaller size AuNPs with particle size of 16.26 ± 5.84 nm, formed at 70 °C showed the highest removal efficiency up to 92.55 % in 60 min. This highest photocatalytic activity of AuNPs could be attributed to the availability of higher number of low-coordinated gold (Au) atoms in the MB aqueous solution, which might have boosted the adsorption of the MB on the surface of particles and accelerated the degradation phenomenon. The proposed photocatalytic degradation mechanism of AuNPs for MB was also explained. The highly photoactive EGL mediated AuNPs with controllable morphology and size could be an advance step in future in chemical and biomedical applications.
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| 3. |
- Ahmad, T, et al.
(författare)
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Diabetic osteopathy and the IGF system in the Goto-Kakizaki rat
- 2008
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Ingår i: Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society. - : Elsevier BV. - 1096-6374. ; 18:5, s. 404-411
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Ahmad, Tariq, et al.
(författare)
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Machine Learning Methods Improve Prognostication, Identify Clinically Distinct Phenotypes, and Detect Heterogeneity in Response to Therapy in a Large Cohort of Heart Failure Patients
- 2018
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Ingår i: Journal of the American Heart Association. - : WILEY. - 2047-9980 .- 2047-9980. ; 7:8
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Tidskriftsartikel (refereegranskat)abstract
- Background-Whereas heart failure (HF) is a complex clinical syndrome, conventional approaches to its management have treated it as a singular disease, leading to inadequate patient care and inefficient clinical trials. We hypothesized that applying advanced analytics to a large cohort of HF patients would improve prognostication of outcomes, identify distinct patient phenotypes, and detect heterogeneity in treatment response. Methods and Results-The Swedish Heart Failure Registry is a nationwide registry collecting detailed demographic, clinical, laboratory, and medication data and linked to databases with outcome information. We applied random forest modeling to identify predictors of 1-year survival. Cluster analysis was performed and validated using serial bootstrapping. Association between clusters and survival was assessed with Cox proportional hazards modeling and interaction testing was performed to assess for heterogeneity in response to HF pharmacotherapy across propensity-matched clusters. Our study included 44 886 HF patients enrolled in the Swedish Heart Failure Registry between 2000 and 2012. Random forest modeling demonstrated excellent calibration and discrimination for survival (C-statistic=0.83) whereas left ventricular ejection fraction did not (C-statistic=0.52): there were no meaningful differences per strata of left ventricular ejection fraction (1-year survival: 80%, 81%, 83%, and 84%). Cluster analysis using the 8 highest predictive variables identified 4 clinically relevant subgroups of HF with marked differences in 1-year survival. There were significant interactions between propensity-matched clusters (across age, sex, and left ventricular ejection fraction and the following medications: diuretics, angiotensin-converting enzyme inhibitors, )i-blockers, and nitrates, Pamp;lt;0.001, all). Conclusions-Machine learning algorithms accurately predicted outcomes in a large data set of HF patients. Cluster analysis identified 4 distinct phenotypes that differed significantly in outcomes and in response to therapeutics. Use of these novel analytic approaches has the potential to enhance effectiveness of current therapies and transform future HF clinical trials.
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| 5. |
- Chemin, J. Eduardo, et al.
(författare)
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Integration Policies, Practices and Experiences – Germany Country Report
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report is about Germany's integration system. Germany is a “reluctant” immigration country. Despite its post-World-War-II history of immigration, Germany has never adopted a coherent strategy or policy of integration. Immigration was considered a transitory phenomenon as the notorious term “guest workers” suggests. Considering the expected return of immigrants to their countries of origin, integration policy making has long remained implicit. Recent processes of refugee immigration have opened a policy window for a more proactive approach to immigration and integration. However, the formulation and implementation of integration policies are situated in a setting of double complexity. First, integration is a crosscutting policy issue which connects to the responsibilities of various federal ministries. Second, it is a multi-level system in which policy making and monitoring largely take place on the federal level. However, the actual implementation is mainly realized on the level of regional states and municipalities.At least since 2016, integration measures (as those stipulated on Asylum Package II for example), point to the competing and paternalistic logic of retaining control over refugees. This is accomplished by the imposition of restrictions on movement and the expansion of value education as part of the integration courses. It is also supported by a logic of human capital, which privileges refugees as to their economic value whilst restricting basic rights, such as the freedom of movement. Individuals applying for asylum in Germany live highly restricted lives subject to accountability, compliance and punitive measures.While the “Asylum Packages” and the “Integration Act” have mainly focused on structural integration through labour market inclusion, the “Migration Masterplan” has emphasized sociocultural aspects, such as identification and acculturation. It’s obvious that most initiatives respond to an alleged public expectation of refugees smoothly fitting in the society rather than to the actual demands of support and participation which they may have.
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| 6. |
- Olwa, Joseph
(författare)
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Investigation of thermal biomass gasification for sustainable small scale rural electricity generation in Uganda
- 2011
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- With the increasing need for renewable energy technologies in the world, biomass fuel transformation technology is growing towards meeting that need, among others. Challenges remain certain and new innovations are being tested in bid to overcome them with the application of biomass as energy source. This report presents some studies carried out into understanding the potential and challenges associated with utilization of biomass fuel, especially for technologies that are appropriate for rural applications. Utilization of biomass gasification technologies is in the focus of this study. The great potential biomass fuel provide to Uganda for possible energy production in small scale application is presented. This study was carried out to understand the possibility of using biomass as fuel in electricity power generation in Uganda. It takes into consideration the use of biomass gasification technology in energy production. Challenges related to the application of biomass fuels are discussed, mostly with tar and alkali metal compounds in the gas stream. Suggested methods to combat some of the challenges with biomass fuels are pointed out in this study. Application of externally fired gas turbine (EFGT) system is a particular approach discussed and its technical performance analyzed. The analysis revealed that efficiency of the EFGT system is greatly dependent on the heat exchanger effectiveness and on turbine inlet temperature. Optimum performance can be realized with air compression ratio of 3.4. It is also noted that fouling and deposition in the heat exchanger can affect its performance. A related study carried out was on the retention of alkali metals in an updraft gasifier. The gasifier was chosen for possible integration with the EFGT system. Finding was that about 99% of the alkali metals are retained in the gasifier. It is anticipated that this would reduce on the deposition in the heat exchanger, reducing on maintenance time. A need is identified to determine the level of deposition mentioned. A simple thermodynamic modeling of the alkali metals condensation reaction on a high temperature heat exchanger surface was conducted. The results showed that with appropriate quantity of S in the raw fuel, alkali metals bounding with Cl are greatly reduced. Cl is passed out as gaseous HCl, leaving deposition of none corrosive sulphates. Recommendation is made to study this phenomenon in an experimental setting. Biomass gasification technology integration with an internal combustion (IC) engine is also studied. Here requirements for the producer gas quality have been discussed. Some tests carried out with wood pellets and wood cylinders compared the yield of tar from the two physically different fuels. Wood pellets were found to yield more tar than wood cylinders. Economic analysis of biomass gasifier integrated with an IC engine running a generator of 100 kWe was carried out. Comparison with a diesel electricity generator of similar capacity was made for a scenario in Uganda over a project life of 20 years. Different Plant Capacity Factors (PCF) and fuel costs including subsidies were considered. The analysis showed that over long period of time biomass power plant was more beneficial than the diesel power plant at PCF over 40%. This is more pronounced with unsubsidized diesel fuel.
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| 7. |
- Wretborn, Jens, et al.
(författare)
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Emergency department crowding and mortality : an observational multicenter study in Sweden
- 2023
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Ingår i: Frontiers in Public Health. - : FRONTIERS MEDIA SA. - 2296-2565. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Emergency department (ED) crowding is a serious problem worldwide causing decreased quality of care. It is reasonable to assume that the negative effects of crowding are at least partially due to high staff workload, but previous crowding metrics based on high workload have not been generalisable to Swedish EDs and have not been associated with increased mortality, in contrast to, e.g., occupancy rate. We recently derived and validated the modified Skåne Emergency Department Assessment of Patient Load model (mSEAL) that measures crowding based on staff workload in Swedish EDs, but its ability to identify situations with increased mortality is unclear. In this study, we aimed to investigate the association between ED crowding measured by mSEAL model, or occupancy rate, and mortality. Methods: All ED patients from 2017-01-01 to 2017-06-30 from two regional healthcare systems (Skåne and Östergötland Counties with a combined population of approximately 1.8 million) in Sweden were included. Exposure was ED- and hour-adjusted mSEAL or occupancy rate. Primary outcome was mortality within 7 days of ED arrival, with one-day and 30-day mortality as secondary outcomes. We used Cox regression hazard ratio (HR) adjusted for age, sex, arrival by ambulance, hospital admission and chief complaint. Results: We included a total of 122,893 patients with 168,900 visits to the six participating EDs. Arriving at an hour with a mSEAL score above the 95th percentile for that ED and hour of day was associated with an non-significant HR for death at 7 days of 1.04 (95% CI 0.96–1.13). For one- and 30-day mortality the HR was non-significant at 1.03 (95% CI 0.9–1.18) and 1.03 (95% CI 0.97–1.09). Similarly, occupancy rate above the 95th percentile with a HR of 1.04 (95% CI 0.9–1.19), 1.03 (95%CI 0.95–1.13) and 1.04 (95% CI 0.98–1.11) for one-, 7- and 30-day mortality, respectively. Conclusion: In this multicenter study in Sweden, ED crowding measured by mSEAL or occupancy rate was not associated with a significant increase in short-term mortality.
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| 8. |
- Zhu, Weizhen, 1985, et al.
(författare)
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Precipitation of lignin from softwood black liquor: An investigation of the equilibrium and molecular properties of lignin
- 2015
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Ingår i: BioResources. - : BioResources. - 1930-2126 .- 1930-2126. ; 10:1, s. 1696-1714
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Tidskriftsartikel (refereegranskat)abstract
- Extracting lignin from black liquor is an attractive option in modern pulp mills as a unit process for a combined biorefinery. The lignin obtained can be utilized as solid fuel or other high-value added products. The precipitation equilibrium of kraft lignin from softwood black liquor was studied in this work. It was found that with decreasing pH and temperature, or increasing ion strength, the solid yield increases. Moreover, precipitated softwood kraft lignin has a higher molecular weight and contains lower amounts of carbohydrates and phenolic groups than lignin precipitated from mixed hardwood/softwood black liquor. The content of methoxyl groups in softwood kraft lignin was found to decrease with increasing precipitation yield. An empirical model for estimating the precipitation yield of lignin was proposed and evaluated.
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| 9. |
- Dán, György, et al.
(författare)
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Cloud Computing for the Power Grid : From Service Composition to Assured Clouds
- 2013
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Ingår i: Proceedings of the 5th USENIX Workshop on Hot Topics in Cloud Computing (HotCloud), June 2013<em></em><em></em>. - : USENIX Association.
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Konferensbidrag (refereegranskat)abstract
- The electric power industry is one of the few industries where cloud computing has not yet found much adoption, even though electric power utilities rely heavily on communications and computation to plan, operate and analyze power systems. In this paper we explore the reasons for this phenomenon. We identify a variety of power system applications that could benefit from cloud computing. We then discuss the security requirements of these applications, and explore the design space for providing the security properties through application layer composition and via assured cloud computing. We argue that a combination of these two approaches will be needed to meet diverse application requirements at a cost that can justify the use of cloud computing.
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| 10. |
- Dán, György, et al.
(författare)
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Delay Asymptotics and Scalability for Peer-to-Peer Live Streaming
- 2009
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Ingår i: IEEE Transactions on Parallel and Distributed Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1045-9219 .- 1558-2183. ; 20:10, s. 1499-1511
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Tidskriftsartikel (refereegranskat)abstract
- A large number of peer-to-peer streaming systems have been proposed and deployed in recent years. Yet, there is no clear understanding of how these systems scale and how multipath and multihop transmission, properties of all recent systems, affect the quality experienced by the peers. In this paper, we present an analytical study that considers the relationship between delay and loss for general overlays: we study the trade-off between the playback delay and the probability of missing a packet and we derive bounds on the scalability of the systems. We present an exact model of push-based overlays and show that the bounds hold under diverse conditions: in the presence of errors, under node churn, and when using forward error correction and various retransmission schemes.
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