| 1. |
- Aupke, Phil, et al.
(författare)
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Impact of Clustering Methods on Machine Learning-based Solar Power Prediction Models
- 2022
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Ingår i: 2022 IEEE International Smart Cities Conference (ISC2). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781665485616
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Konferensbidrag (refereegranskat)abstract
- Prediction of solar power generation is important in order to optimize energy exchanges in future micro-grids that integrate a large amount of photovoltaics. However, an accurate prediction is difficult due to the uncertainty of weather phenomena that impact produced power. In this paper, we evaluate the impact of different clustering methods on the forecast accuracy for predicting hourly ahead solar power when using machine learning based prediction approaches trained on weather and generated power features. In particular, we compare clustering methods using clearness index and K-means clustering, where we use both euclidian distance and dynamic time-warping. For evaluating prediction accuracy, we develop and compare different prediction models for each of the clusters using production data from a swedish SmartGrid. We demonstrate that proper tuning of thresholds for the clearness index improves prediction accuracy by 20.19% but results in worse performance than using K-means with all weather features as input to the clustering.
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| 2. |
- Björkelund, Anders, et al.
(författare)
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On the Integration of Skilled Robot Motions for Productivity in Manufacturing
- 2011
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Ingår i: IEEE International Symposium on Assembly and Manufacturing (ISAM), 2011. - 9781612843438 - 9781612843421 ; , s. 1-9
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Konferensbidrag (refereegranskat)abstract
- Robots used in manufacturing today are tailored to their tasks by system integration based on expert knowledge concerning both production and machine control. For upcoming new generations of even more flexible robot solutions, in applications such as dexterous assembly, the robot setup and programming gets even more challenging. Reuse of solutions in terms of parameters, controls, process tuning, and of software modules in general then gets increasingly important. There has been valuable progress within reuse of automation solutions when machines comply with standards and behave according to nominal models. However, more flexible robots with sensor-based manipulation skills and congnitive functions for human inteaction are far too complex to manage, and solutions are rarely reusable since knowledge is either implicit in imperative software or not captured in machine readable form. We propose techniques that build on existing knowledge by converting structured data into an RDF-based knowledge base. By enhancements of industrial control systems and available engineering tools, such knowledge can be gradually extended as part of the interaction during the definition of the robot task.
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| 3. |
- Bågesund, Josef, et al.
(författare)
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Treatment of Intrabony Defects with Emdogain : Results After 16-20 Years
- 2016
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Objectives: The aim was to evaluate retrospectively the outcome of treatment with enamel matrix derivative (EMD) as adjunct to open flap debridement in periodontal intrabony defects, on the long-term (>15 years). Methods: All journals of patients in a public dental service specialist clinic treated with EMD (Straumann Emdogain®) as adjunct to open flap debridement in periodontal intrabony defects > 15 years ago were assessed for clinical and radiographic data. On digitized/digital bite-wing radiographs from prior to treatment (baseline), 1-year, and > 15 years after treatment, measurements of radiographic defect depth (RDD) defect width (RDW), and defect angle (RDA) were performed with ImageJ® and subjected to statistical analysis with the student’s t-test. Results: Twenty-two patients (11 female; mean age of 55±12 years) were identified. Out of 28 teeth treated 16-20 years ago, only one was lost; thus data from 27 available sites (22 patients) were available. Due to inconsistencies in the clinical registrations, only radiographic data were used. At baseline, PPD, CAL, RDD and RDW averaged 8.37±2.33mm, 9.33±2.19mm, 5.26±2.34mm and 2.33±0.77mm, respectively. After an average of 17 years from reconstructive EMD treatment, RDD and RDW were reduced by 2.84±3.50mm (p=0.0003) and 0.88±1.30mm (p=0.002), respectively comparing to baseline. Compared to 1 year after EMD treatment (RDD 1.90±1.31mm RDW 1.43±0.86mm ) no significant changes in RDD (-0.52±2.98mm, p=0.38) or RDW (-0.03±1.01mm, p=0.89) were observed 16-20 years after EMD treatment. Compared to baseline RDA (26.87±12.84°), no significant changes were observed 16-20 years after EMD treatment (25.14±19.21° p=0.66). Conclusions: The radiographic improvements, (i.e. defect depth and defect width reduction) achieved 1 year after treatment with EMD as an adjunct to open flap debridement in periodontal intrabony defects can be preserved over a period of 16-20 years.
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| 4. |
- Lantz, Andreas, et al.
(författare)
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Investigation of ozone stimulated combustion in the SGT-800 burner at atmospheric conditions
- 2016
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Ingår i: Combustion, Fuels and Emissions. - 9780791849750 ; 4A-2016
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Konferensbidrag (refereegranskat)abstract
- The effect of ozone (O3) in a turbulent, swirl-stabilized natural gas/air flame was experimentally investigated at atmospheric pressure conditions using planar laser-induced fluorescence imaging of formaldehyde (CH2O PLIF) and dynamic pressure monitoring. The experiment was performed using a dry low emission (DLE) gas turbine burner used in both SGT-700 and SGT-800 industrial gas turbines from Siemens. The burner was mounted in an atmospheric combustion test rig at Siemens with optical access in the flame region. CH2O PLIF imaging was carried out for four different seeding gas compositions and seeding injection channel configurations. Two seeding injection-channels were located around the burner tip while the other two were located along the center axis of the burner at different distances upstream the burner outlet. Four different seeding gas compositions were used: nitrogen (N2), oxygen (O2) and two ozone/oxygen (O3/O2) mixtures with different O3 concentration. The results show that the O3 clearly affects the combustion chemistry. The natural gas/air mixture is preheated before combustion which is shown to kick-start the cold combustion chemistry where O3 is highly involved. The CH2O PLIF signal increases with O3 seeded into the flame which indicates that the pre-combustion activity increases and that the cold chemistry starts to develop further upstream. The small increase of the pressure drop over the burner shows that the flame moves upstream when O3 is seeded into the flame, which confirms the increase in pre-combustion activity.
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| 5. |
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| 6. |
- Toor, Salman, et al.
(författare)
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SNIC Science Cloud (SSC): A national-scale cloud infrastructure for Swedish academia
- 2017
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Ingår i: Proceedings - 13th IEEE International Conference on eScience, eScience 2017. - Los Alamitos, CA : IEEE Computer Society. ; , s. 219-227, s. 219-227
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Konferensbidrag (refereegranskat)abstract
- The cloud computing paradigm have fundamentally changed the way computational resources are being offered. Although the number of large-scale providers in academia is still relatively small, there is a rapidly increasing interest and adoption of cloud Infrastructure-as-a-Service in the scientific community. The added flexibility in how applications can be implemented compared to traditional batch computing systems is one of the key success factors for the paradigm, and scientific cloud computing promises to increase adoption of simulation and data analysis in scientific communities not traditionally users of large scale e-Infrastructure, the so called long tail of science. In 2014, the Swedish National Infrastructure for Computing (SNIC) initiated a project to investigate the cost and constraints of offering cloud infrastructure for Swedish academia. The aim was to build a platform where academics could evaluate cloud computing for their use-cases. SNIC Science Cloud (SSC) has since then evolved into a national-scale cloud infrastructure based on three geographically distributed regions. In this article we present the SSC vision, architectural details and user stories. We summarize the experiences gained from running a nationalscale cloud facility into ten simple rules for starting up a science cloud project based on OpenStack. We also highlight some key areas that require careful attention in order to offer cloud infrastructure for ubiquitous academic needs and in particular scientific workloads.
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| 7. |
- Abbasi, Maisam, et al.
(författare)
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Who controls logistics emissions? Challenges in making fragmented supply chains environmentally sustainable from a logistics service provider's perspective
- 2014
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Ingår i: Proceedings of the 26th Conference of the Nordic Logistics Research Network: NOFOMA 2014. - 9788799743308 ; , s. 201-218
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Konferensbidrag (refereegranskat)abstract
- Purpose The purpose of this article is to explore the environmental impact of Logistics Service Provider (LSP) activities in the light of increased customer attention and fragmentation of the industry. We try to answer the question, to what extent the LSPs can actually monitor the environmental impact of logistics activities in the supply chain? Design/methodology/approach The methodology of this paper is a literature review, a qualitative interview survey, and three case studies. A framework on sustainability challenges in supply chains derived from the literature is used to structure and analyze the findings. Findings Our findings reveal that despite ambitious environmental schemes communicated by several LSPs, LSPs exert very little control over the actual emissions created from their transport operations. Furthermore, it is clear from this study that any real interest in environmental solutions that impact the cost and time requirements from customers of logistics services are not yet a reality. Research limitations/implications This paper implies that LSP sustainability cannot be investigated in isolation if a company does not manage proprietary resources. Practical implications Our findings imply that environmental policies between different LSPs appear similar, but in practice differs, which stresses the importance of follow-up control by environmentally aware logistics service buyers. Originality/value This paper represents a novel approach as to how LSP environmental policies should be viewed.
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| 8. |
- Abgrall, N., et al.
(författare)
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The large enriched germanium experiment for neutrinoless double beta decay (LEGEND)
- 2017
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Ingår i: AIP Conference Proceedings. - : Author(s). - 1551-7616 .- 0094-243X. ; 1894
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Konferensbidrag (refereegranskat)abstract
- The observation of neutrinoless double-beta decay (0νββ) would show that lepton number is violated, reveal that neu-trinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of ∼0.1 count /(FWHM·t·yr) in the region of the signal. The current generation 76Ge experiments GERDA and the Majorana Demonstrator, utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0νββ signal region of all 0νββ experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale 76Ge experiment. The collaboration aims to develop a phased 0νββ experimental program with discovery potential at a half-life approaching or at 1028 years, using existing resources as appropriate to expedite physics results.
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| 9. |
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| 10. |
- Agebro, Markus, et al.
(författare)
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Driver preferences of steering gear ratio and steering wheel effort : A driving simulator study
- 2006
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Ingår i: Proceedings of the FISITA World Automotive Congress, Yokohama, Japan 2006..
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Konferensbidrag (refereegranskat)abstract
- When driving an automobile, the driver has to correct the course as a result of road curvature and external disturbances. In order to make the vehicle both controllable and comfortable to drive, it is important that the steering system is designed with different drivers in mind. In this work, driver preferences of steering system characteristics is investigated by comparing standard steering wheel settings with unconventional steering gear ratio and steering wheel effort. The investigation is made using 18 test subjects in a moving base driving simulator. The evaluation includes two scenarios. In the first scenario the driver is overtaking a bus at 110 km/h when meeting traffic in the opposite lane. In the second scenario the driver is doing a manoeuvre by following a cone track at 55 km/h. To investigate if there are differences in preference of drivers with varying experience of driving, the drivers are chosen to either be low or high mileage drivers. People that drive less than 5,000 km/year are considered to be low mileage drivers, and people that drive more than 25,000 km/year are considered to be high mileage drivers. The results show that original settings of a typical passenger car, which served as reference, prove to display favourable characteristics compared to the unconventional settings investigated. However, there might be settings within the investigated intervals that can be considered superior. A distinct trend in the results is that increasing effort will lead to increased perceived stability, independent of ratio. High mileage drivers find the setting with low ratio and reference effort to possess better qualities than the reference when evaluating the attributes steering wheel force and response and only slightly less favourable properties than the reference when evaluating the attribute stability. High mileage drivers display a more distinct opinion and a higher sensitivity when evaluating the attributes. Despite the differing setup of the scenarios, many similarities can be observed when studying the results. Even though there are similarities in the results both between the scenarios and the categories of drivers, a study of the individual test subjects´ preferences reveal that several drivers prefer other settings than the reference for the investigated scenarios. Therefore, it is clear that the driver-vehicle system would benefit from tailoring the steering characteristics to the situation and driver.
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