| 31. |
- Segolsson, Mikael, 1968-
(författare)
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Programmeringens intentionala objekt : Nio elevers uppfattningar av programmering
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- I dagens postmoderna samhälle är väsentliga delar i vårt arbete relaterade till datorer i någon form. Robotiseringen inom industrin utgör ett exempel på hur det mänskliga arbetet förskjutits från det konkret fysiska till att bestå av programmering och övervakning av produktionsprocesser. Denna utveckling ställer nya krav på både utbildning och rekrytering av arbetskraft, något som visat sig vara svårt eftersom intresset för tekniska utbildningar är svagt i Sverige, trots stora satsningar på ökad rekrytering inom de tekniska utbildningarna.I föreliggande studie presenteras forskningsfrågan: Vad riktar eleverna sin uppmärksamhet mot i sina beskrivningar av programmeringshandlingen? Studien är en del av en kartläggning av hur elever begreppsbildar då de arbetar med programmerbart konstruktionsmaterial i teknikundervisningen. Arbetet med programmerbara robotar i skolan är ett exempel på hur tekniska komponenter integreras med datorstött lärande för att ge eleverna en bild av teknik som fenomen i samhället och som introduktion till datorarbete inom skola.Studiens vetenskapsteoretiska utgångspunkt ligger inom livsvärldsfenomenologi med metodisk ansats i fenomenografi. Ett grundläggande begrepp inom fenomenologi och även för denna studie är intentionalitet. Centralt är också uppfattningsbegreppet så som det används inom fenomenografi. Syftet med uppsatsen är att beskriva vad elever i skolår 8 och 9 riktar sin uppmärksamhet mot när de programmerar – hur elevernas intentionala objekt visar sig när de beskriver sina program.Analysen har resulterat i fyra beskrivningskategorier av elevernas intentionala objekt. Programmeringshandlingen beskrivs med uppmärksamheten riktad mot: Systematisk indelning av programmet, att komma ihåg tidigare programlösningar, robotens rörelser och att lösa uppgiften.
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| 32. |
- Sternad, Mikael, et al.
(författare)
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Towards systems beyond 3G based on adaptive OFDMA transmission
- 2007
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Ingår i: Proceedings of the IEEE. - 0018-9219 .- 1558-2256. ; 95:12, s. 2432-2455
-
Forskningsöversikt (refereegranskat)abstract
- High data rates, high spectral efficiency, flexibility, and low delays over the air interface will be important features in next-generation wireless systems. The overall challenge will be packet scheduling and adaptive radio transmission for multiple users, via multiple antennas and over frequency-selective wideband channels. This problem needs to be structured to obtain feasible solutions. The basic simplifying assumptions used here are clustering of antennas into cells, orthogonal transmission by use of cyclic-prefix orthogonal frequency-division multiplexing (OFDM) and a time-scale separation view of the total link adaptation, scheduling and intercell coordination problem. Based on these assumptions, we survey techniques that adapt the transmission to the temporal, frequency, and spatial channel properties. We provide a systematic overview of the design problems, such as the dimensioning of the allocated time-frequency resources, the influence of duplexing schemes, adaptation control issues for downlinks and uplinks, timing issues, and their relation to the required performance of channel predictors. Specific design choices are illustrated by recent research within the Swedish Wireless IP program and the EU IST-WINNER project. The presented results indicate that high-performance adaptive OFDM transmission systems are indeed feasible, also for challenging scenarios that involve vehicular velocities, high carrier frequencies, and high bandwidths
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| 33. |
- Sundqvist, Jonas, et al.
(författare)
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Growth of SnO2 thin films by atomic layer deposition and chemical vapour deposition: A comparative study
- 2006
-
Ingår i: Thin Solids Films. - : Elsevier BV. - 0040-6090. ; 514:1-2, s. 63-68
-
Tidskriftsartikel (refereegranskat)abstract
- Thin films of the tetragonal rutile-type SnO2 phase have been deposited by both atomic layer deposition (ALD) and chemical vapour deposition (CVD) using the SnI4–O2 precursor combination. Depositions were carried out in the temperature region of 350–750 °C on α-Al2O3(0 1 2) substrates. In both cases the films were found to grow epitaxially with the in-plane orientation relationships [0 1 0]SnO2 || [1 0 0]α-Al2O3 and [1 0 1¯]SnO2 || [1¯ 2¯ 1]α-Al2O3. Films grown by ALD were found to be close to perfectly single crystalline, contained a low density of defects and were almost atomically smooth. The CVD films were found to have a much rougher film morphology, and exhibited both grain boundaries and twin formation.
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| 34. |
- Svensson, Inger-Lise, 1979-, et al.
(författare)
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Socio-Techincal Aspects of Potential Future Use of Excess Heat from Kraft Pulp Mills
- 2009
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Ingår i: 22nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. ; :Paper 0612, s. 995-1004
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The pulp and paper industry is one of the largest energy users in Sweden and in 2007 2.2 TWh of heat was delivered from pulp mills, mainly to district heating systems. In this study, two market kraft pulp mills and two energycompanies (ECOs) have been interviewed about their views on excess heat, energy efficiency and energy strategies.The interviews have been brought together with results from previous optimization studies concerning kraft pulp millexcess heat by the authors and results from other related work in a socio-technical synthesis that aims to provide amore comprehensive view on the factors that influence the utilization of kraft pulp mill excess heat than achieved inprevious studies. The results show that the kraft pulp mills are more positive towards sales of excess heat than theECOs, which can be related to the fact that the ECOs take a greater risk when entering a heat cooperation. Anotherbarrier to co-operations is the already existing utilities in the ECOs that compete with excess heat for the position asbase load in the district heating systems. Both internal and external use of excess heat can benefit from policymeasures. Other important factors are the view on energy-related investments in the mill, the level of communicationbetween the parties, and the goodwill qualities obtained through energy-efficient solutions.
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| 35. |
- Sörensen, Thomas
(författare)
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Den nordamerikanska milisrörelsen
- 2008
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Ingår i: Borgerlighet i vapen. - Malmö : Malmö University Press.
-
Bokkapitel (populärvet., debatt m.m.)
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| 36. |
- Thollander, Patrik, 1976-, et al.
(författare)
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An energy-efficient Swedish pulp and paper industry : exploring barriers to and driving forces for cost-effective energy efficiency investments
- 2008
-
Ingår i: Energy Efficiency. - : Springer Science and Business Media LLC. - 1570-646X .- 1570-6478. ; 1:1, s. 21-34
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Tidskriftsartikel (refereegranskat)abstract
- Despite the need for increased industrial energy efficiency, studies indicate that cost-effective energy efficiency measures are not always implemented, which is explained by the existence of barriers to energy efficiency. This paper investigates whether this holds for the Swedish pulp and paper industry, and if so, investigates the barriers inhibiting and the driving forces stressing cost-effective energy efficiency investments. By so, this case study covers about 2% of the EU-25 industrial end-use of energy. The overall results from a questionnaire show that there is an energy efficiency gap in the sector and that the largest barriers were technical risks such as risk of production disruptions, cost of production disruption/hassle/inconvenience, technology inappropriate at the mill, lack of time and other priorities, lack of access to capital, and slim organization. As regards the driving forces for energy efficiency, the highest ranked driving forces were cost reductions resulting from lower energy use, people with real ambition, long-term energy strategy, the threat of rising energy prices, the electricity certificate system, the PFE. The results show that many of the barriers and driving forces were not solely market-related, e.g., lack of time or other priorities, slim organization, other priorities for capital investments, lack of staff awareness, and long decision chains indicate that firm-specific barriers plays an important role. These barriers may not be overcome by market-related public policy instruments but is rather a consequence of how the energy issue is organized within the firms. The second and the third largest driving forces, people with real ambition and a long-term energy strategy further support this.
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| 37. |
- Thollander, Patrik, 1976-, et al.
(författare)
-
Exploring energy management in the Swedish pulp and paper industry : Volume 3
- 2009
-
Ingår i: Act! Innovate! Deliver! Reducing energy demand sustainably. - : eceee. - 9789163344541 ; , s. 1051-1058
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Konferensbidrag (refereegranskat)abstract
- The Swedish pulp- and paper industry is a considerable user of energy, accounting for about 50 percent of the Swedish industrial energy use and 2 percent of the EU-25 industrial energy use. Its high energy use makes this industry particularly important in terms of energy efficiency. Previous research has emphasised the need for companies’ to have well functioning energy management practices in order to increase energy efficiency. This paper describes and analyses energy management practices in the Swedish pulp and paper industry. A questionnaire was sent out to the person in charge of the energy issue at all Swedish mills and 40 replies were received, a response frequency of 68 percent. The results show that the energy issue has been given increasingly higher priority over the past 10 years. However, in spite of this, overall results from the questionnaire show that there is still potential for improving energy management in the studied industry. More than 20 percent of the studied mills lack a long-term energy strategy, and less than half of the studied mills have an energy strategy covering at least five years. These results indicate that the implementation of a long-term energy strategy in this energy intensive industry, in combination with other means, could be of utmost importance for increasing energy efficiency. In conclusion, based on the research results presented in this paper, a different energy policy design for the industry seems to be needed, which could be very fruitful if it focuses on establishing more efficient energy management practices and includes all energy carriers. Moreove, the fact that more than 20 percent of the studied mills lack a long-term energy strategy and the fact that the Swedish EMS standard does not require such a strategy to be formulated indicates the need for further studies regarding a plausible inclusion of a long-term energy strategy in the EMS standard.
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| 38. |
- Törndahl, Tobias, et al.
(författare)
-
Epitaxy of copper on α-Al2O3(0 0 1) by atomic layer deposition
- 2005
-
Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 276, s. 102-110
-
Tidskriftsartikel (refereegranskat)abstract
- A combined X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) study have been carried out on copper films grown by atomic layer deposition at 400 °C. The copper films have been grown on single crystalline (0 0 1) oriented α-Al2O3 up to a thickness of 500 nm. The films were relaxed and the diffraction peak broadening in 2θ was mainly dependent on the copper grain size. Broadening of the diffraction peaks in ω was found to be related to defects (mosaicity and intrinsic microstrain). The deposited films were epitaxial and grew with the (1 1 1) plane in parallel to the substrate surface. Extensive twinning in the copper grains in different Cu1 1 1 directions occurred according to the TEM study, both in directions perpendicular to the substrate surface ([1 1 1] and ) and along other 1 1 1 directions as well. As an effect of a twin, an extra Cu(5 1 1) orientation was present in the XRD data.
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| 39. |
- Törndahl, Tobias, 1974-, et al.
(författare)
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Growth of Copper(I) Nitride by ALD Using Copper(II) Hexafluoroacetylacetonate, Water and Ammonia as Precursors
- 2006
-
Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 153:3, s. C146-C151
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Films of copper(I) nitride were deposited by atomic layer deposition (ALD) using copper(II) hexafluoroacetylacetonate, water, and ammonia as precursors. Introduction of a water pulse in the ALD cycle was found to be crucial for initiating film growth on both amorphous SiO2 and single-crystalline α-Al2O3(001) substrates. The water pulses generated an oxidic copper monolayer, which in a subsequent ammonia pulse was converted to the nitride. The films have been grown in the temperature range from 210to302°C . Phase pure films of Cu3N were obtained up to 265°C . At higher deposition temperatures such as 283°C , phase mixtures of Cu3N and Cu were obtained. For temperatures above 302°C films of only Cu were grown. Film growth rate was the same on the two different substrates. The films were randomly oriented on SiO2 . Completely intact films were obtained at a thickness of 20nm . The optical bandgap of the films was measured to be 1.6eV .
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| 40. |
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