VR from a Learning Perspective

Det finns många exempel på att använda teknologi i skolan för att förbättra elevers lärande. En relativt oanvänd teknologi i utbildning är Virtual Reality. De flesta VR applikationer som används i utbildning idag är passiva virtuella studiebesök, där användaren interagerar med applikationen genom att observera den virtuella världen. Detta examensarbete undersöker om interaktiva Virtual Reality applikationer kan ha en positiv effekt på elevers lärande och engagemang, när det kommer till att lära sig grunderna i naturvetenskap. Detta utfördes genom att utveckla en applikation och testa den på högstadieelever. Detta exjobb studerar också hur en Virtual Reality applikation bör utvecklas för att fungera som ett lärandeverktyg. Applikationen lär ut grunderna i elektriska kretsar och designades med en användarcentrerad designprocess och baseras på variationsteori. Ämnet elektriska kretsar valdes baserat på enkäter och en intervju med lärare. En komparativ studie utfördes med två grupper av elever; en grupp som hade en traditionell lektion, och en grupp som använde Virtual Reality applikationen. Båda grupperna testades på vad de hade lärt sig och den andra gruppen svarade på en enkät om deras upplevelse med applikationen. Resultatet från testet visar att eleverna uppskattade användandet av Virtual Reality som lärandeverktyg och att de hade lärt sig av att använda applikationen. På grund av det låga antalet medverkande och att eleverna hade mycket kort tid med applikationen kunde inga konkreta svar ges på huruvida elever lär sig bättre med Virtual Reality. Dock visades det att Virtual Reality har god potential som ett lärandeverktyg på grund av Virtual Realitys uppslukande och interaktiva karaktär.There are many examples of using technology in schools for enhancing student’s learning experience. A relatively unexplored technology in education is Virtual Reality. Most of the existing VR applications aimed at learning are passive virtual field trips, where the user only interacts with the application by observing the virtual world. This thesis explores if interactive Virtual Reality applications can have a positive effect on high school students’ learning and engagement when it comes to learning the basics of natural science. This was done by developing a Virtual Reality application and testing it on high school students. The thesis also studies how a Virtual Reality application should be developed to function as a learning tool. The application teaches the basics of electric circuits and was designed using a user-centered design process and by utilizing variation theory. Electric circuits was chosen as a subject, based on questionnaires and an interview with teachers. A comparative study was performed with two groups of students; one group had a traditional lecture and the other used the Virtual Reality application. Both groups were then tested on what they had learned and the second group answered a questionnaire about their experience with the application. The results of the test show that the students enjoyed using Virtual Reality as a learning tool and that they were able to learn. Due to the small sample size and the short time each student had with the application, there was no conclusive answer to whether or not the students could learn better from a Virtual Reality application. However, it was concluded that Virtual Reality has great potential as a learning tool due to the immersive and interactive nature of Virtual Reality technology

Refined SRP Stack Memory Analysis by Exploiting Critical Sections for Shared Resources

International audienceIn this paper we refine previous results on stack memory analysis for SRP based systems. For a task J we associate the section of code in between a resource request and release of R to a sub-task J R . If J R is implemented as a function, the stack usage of J R can be accounted for locally (and not part of the initial allocation for J as done in previously published work.

Mosasaurerne - Kridthavenes kæmpeøgler

Med sine langstrakte, næsten ormelignende kroppe, kraftfulde kæber og store, koniske tænder var mosasaurerne virkelighedens svar på myternes søslanger. Deres aggressive adfærd kombineret med en ofte gigantisk størrelse må have gjort dem til et voldsomt og frygtet indslag i det hav, som dækkede Danmark under sen Kridttid

Järnvägsprojektering – analys av tekniska gränssnitt och samordning

Railway detail planning is divided in seven major technical branches; ground works, track, power supply, catenary, signalling, telecommunication and cable-trenching. Technical consultants perform detail planning at the request of a client, usually the Swedish Rail Administration (Banverket). The work results in design and other technical documents. According to common public opinion the quality in these documents has decreased and co-ordination of technical interfaces has great impact on this matter. Because of that the purpose of this study is to identify important technical interfaces and to analyse co-ordination. The author proposes a list of actions aimed to improve the quality in detail planning documents. Data input are interviews with more than twenty persons, mostly representing a consultant but also the Swedish Rail Administration. Their opinions then were analysed in the light of facts based on the regulations of the Swedish Rail Administration. Some of the identified important technical interfaces are: Ground works: Placement of concrete foundations for catenary Track: Placement of isolation joints for signalling Power supply: Placement of catenary objects Catenary: Earthing together with objects for ground works, power supply, signalling and telecommunication. Signalling: Placement of catenary masts Telecommunication: Communication requirements for signalling Cable-trenching: Major cable-trenching for power supply, catenary, signalling and telecommunication. Different things have effects on the co-ordination of technical interfaces. Yet, a main cause seems to exist – technical modifications during detail planning. To reduce the amount of modifications and also to improve the handling of these following actions are proposed: 1. Accomplish railway investment projects with “enlarged co-operation” 2. Use the CAD-handling program BVADM and the model SESAM. Keywords: Railway detail planning, technical interfaces, co-ordination, co operation, SESAM, BVADM

In situ tempering of martensite during laser powder bed fusion of Fe-0.45C steel

During laser powder bed fusion (L-PBF), materials experience cyclic re-heating as new layers are deposited, inducing an in situ tempering effect. In this study, the effect of this phenomenon on the tempering of martensite during L-PBF was examined for Fe-0.45C steel. Detailed scanning electron microscopy, transmission electron microscopy, atom probe tomography, and hardness measurements indicated that martensite was initially in a quenched-like state after layer solidification, with carbon atoms segregating to dislocations and to martensite lath boundaries. Subsequent tempering of this quenched-like martensite was the result of two in situ phenomena: (i) micro-tempering within the heat affected zone and (ii) macro-tempering due to heat conduction and subsequent heat accumulation. Hardness measurements showed that although both influenced martensite tempering, micro-tempering had the most significant effect, as it reduced martensite hardness by up to ∼380 HV. This reduction was due to the precipitation of nano-sized Fe3C carbides at the previously carbon-enriched boundaries. Lastly, the magnitude of in situ tempering was found to be related to the energy input, where increasing the volumetric energy density from 60 to 190 J/mm3 reduced martensite hardness by ∼100 HV. These findings outline the stages of martensite tempering during L-PBF and indicate that the level of tempering can be adjusted by tailoring the processing parameters

Characterization of monoclonal antibodies against human protein C specific for the calcium ion-induced conformation or for the activation peptide region

AbstractThree monoclonal antibodies have been produced that are specific for the activation peptide region m human protein C. These antibodies inhibited the activation of protein C by thrombin and by the thrombin-thrombomodulin complex. A fourth monoclonal antibody specifically recognized the Ca2+-stabilized conformation in protein C. This antibody bound both intact protein C and protein C from which the γ-carboxy-glutamic acid-containing region had been removed by limited proteolysis. These results indicate that this antibody recognizes the conformation in protein C stabilized by Ca2+ bound to the single binding site that is independent of γ-carboxyglutamic acid

HgCl2 addition to pore water samples from cold seeps can affect the geochemistry of dissolved inorganic carbon ([DIC], δ13CDIC)

The conventional use of mercuric chloride (HgCl2) as an antimicrobial agent in water samples for dissolved inorganic carbon (DIC) analysis poses health and environmental risks related to its handling and disposal. Even though there is an increasing interest in quantifying pore water DIC contribution to the ocean carbon cycle and deep-sea acidification, the paucity of comparative studies on marine pore waters prevents the modification of sampling protocols and HgCl2 still remains widely used. Here, we compared DIC concentrations and δ13CDIC composition in pore water samples from methane seepage areas in the Barents Sea and offshore N. Svalbard. Samples were extracted using 0.15 μm rhizon filters and split into two aliquots with 2–3 replicates each. Only one aliquot was treated with 10 μL saturated HgCl2(aq) and all samples were stored in the dark at 4 ◦C, prior to measurements ~30 days later. The samples yielded extremely wide ranges of DIC concentrations, from 1.8 mM to 20.1 mM, and δ13CDIC values, from − 36.0‰ to − 1.6‰ (VPDB), due to variable contributions of methane-derived DIC to the pore water system. Overall, we obtained lower [DIC] (77% samples; N = 26) and heavier δ13C values (79% samples; N = 42) in Hg-treated samples. Isotopic and concentration differences larger than the uncertainties on the mean of replicated measurements (±0.2–0.5‰; ± 0.5 mM) and analytical precision (0.15‰; 0.71 mM) represent the 38% and 19% of the samples, with offsets of up to 7.4‰ and 1.9 mM, respectively. The largest offsets are in agreement with our CO2-degassing model, suggesting an interaction between mercuric chloride and dissolved hydrogen sulfide released by sulfate-driven methane oxidation. We therefore caution against further use of HgCl2 for DIC studies of marine pore waters from cold seeps