1,166 research outputs found
Cooling of suspended nanostructures with tunnel junctions
We have investigated electronic cooling of suspended nanowires with SINIS
tunnel junction coolers. The suspended samples consist of a free standing
nanowire suspended by four narrow ( 200 nm) bridges. We have compared two
different cooler designs for cooling the suspended nanowire. We demonstrate
that cooling of the nanowire is possible with a proper SINIS cooler design
Ohjelmoitu opetus
Alkusanoissa todetaan, ettÀ "Nykyisen yhteiskunnan valtavasti lisÀÀntynyt koulutustarve on pakottanut tutkimuksiin uusien ja tehokkaampien opetusmenetelmien kehittÀmiseen. teknillistyvÀt taisteluvÀlineet, uudet taistelumenetelmÀt ja nopeasti alkavan sodan mahdollisuus asettavat myös sotilaskoulutukselle uusia vaatimuksia." Artikkelin tarkoituksena on selvittÀÀ eri maissa esitettyjen teorioiden ja muun aineiston perusteella, mitÀ on ohjelmoitu opetus. EnsimmÀisessÀ luvussa kÀsitellÀÀn ohjelmoidun opetuksen teoreettista perustaa ja erÀitÀ ohjelmoituun opetukseen liittyviÀ oppimispsykologisia kÀsitteitÀ. Toisessa luvussa tarkastellaan ohjelmatyyppejÀ ja ohjelmoidun opintomateriaalin laatimisen yleisiÀ periaatteita. Kolmannessa luvussa kÀsitellÀÀn ohjelmoidun opetusaineiston esittÀmisvÀlineitÀ ja niiden soveltuvuutta sotilaskoulutukseen. SiinÀ esitellÀÀn opetuskoneet ja kÀsitellÀÀn tietokoneohjattua opetusta, ohjelmoitua oppikirjaa, television hyödyntÀmistÀ, kielistudiota sekÀ simulaattoreita. NeljÀnnessÀ luvussa, "Ohjelmoidun opetuksen sopivuus sotilaskoulutukseen", esitellÀÀn aluksi ohjelmoidun opetuksen asemaa erÀiden maiden sotilaskoulutuksessa sekÀ tarkastellaan tutkimuksista ja kokeiluista saatuja tuloksia. YhdistelmÀssÀ todetaan, ettÀ "Sotilaskoulutuksessa ei kuitenkaan liene syytÀ odottaa siviilipiireissÀ tapahtuvaa kehitystÀ, vaan on pyrittÀvÀ mahdollisimman nopeasti kÀyttÀmÀÀn muissa maissa saatuja tutkimusten tuloksia."There is summary in English at the end of the article
Reversible control of the electronic density of states at the Fermi level of Ca3Co4O9+ÎŽ misfit-layered oxide single crystals through O+/H+ plasma exposure
Misfit-layered Ca3Co4O9 crystals were grown and characterized via XRD, SEM, and photo-emission spectroscopy (PES). The evolution of the intensity at the Fermi level (E F) with varying oxygen content was studied by PES. Oxygen species were successfully introduced and removed through O+ and H+ microwave-plasma (2.45GHz, 2-5mbar) treatments, respectively. A 5min O+ plasma exposure was observed to result into a drastic enhancement in the E F intensity, demonstrating the influence of oxygen content to the charge carrier population in layered cobalt-oxide material
Suomalaisten opettajien asenteita ja valmiuksia ohjelmoinnin opetukseen
TiivistelmÀ. TÀssÀ pro gradu -tutkielmassa tarkastellaan suomalaisten perusopetuksen opettajien valmiuksia opettaa ohjelmointia sekÀ asenteita ohjelmoinnin opettamista kohtaan. LÀhtökohtana tutkielmalle on uusi Perusopetuksen opetussuunnitelman perusteet ja sen mukanaan tuoma ohjelmoinnin opetuksen sisÀllyttÀminen opetukseen. Pro gradun teoreettinen osa ja sen pohjalta laadittu mittaristo perustuu kahteen pÀÀteoriaan. Tutkielmassa kerÀtty aineisto on avointa ja se on kaikkien kÀytettÀvissÀ Aalto-yliopiston kautta. Aineistonkeruun instrumentissa opettajien teknologia-asenteen taustalla ovat Davisin (1989) teknologian hyvÀksymismalli (Technology Acceptance Model, TAM) sekÀ Venkatesh et al. (2003) Yhdistetty teoria teknologian hyvÀksymisestÀ ja kÀytöstÀ (Unified Theory of Acceptance and Use of Technology, UTAUT). Tutkielmassa on tarkoituksena tarkastella suomalaisen perusopetuksen opettajan valmiuksia opettaa ohjelmointia sekÀ asenteita niin ohjelmoinnin asemasta perusopetuksessa, kuin ohjelmoinnin opetuksesta yleisesti. Työn tuloksien avulla pyritÀÀn kehittÀmÀÀn suomalaisten peruskoulun opettajien koulutusta ohjelmoinnin opetuksessa. Pro gradu tutkielman aineisto on kerÀtty yhteistyössÀ koodiaapinen.fi-sivuston ohjelmointikurssin kanssa. Tutkimuskysely jÀrjestettiin kurssin osallistujille. Tutkielma perustuu 317 suomalaisen opettajan web-kyselylomakkeeseen.
Tutkielman pÀÀtulokset: Noin yksi kymmenestÀ vastaajasta ilmoitti pystyvÀnsÀ opettamaan joitakin seuraavista kielistÀ: Scratch, Scratch Jr., Code.org, ja HTML/CSS. Muiden ohjelmointikielten ja -ympÀristöjen osaajia oli merkittÀvÀsti vÀhemmÀn. Uskoa ohjelmoinnin opettamisen osaamiseen vastaajien keskuudessa kuitenkin on, sillÀ lÀhes puolet vastaajista ilmoitti pystyvÀnsÀ ratkaisemaan ohjelmoinnin opetuksen ongelmia, vaikka paikalla ei olisi ketÀÀn ohjeistamassa ja yli 70 % vastaajasta ilmoitti pystyvÀnsÀ ratkaisemaan ohjelmoinnin opetuksen ongelmia, jos kÀytettÀvissÀ on runsaasti (riittÀvÀsti) aikaa.
Ohjelmoinnin opettaminen peruskoulussa nĂ€hdÀÀn tarpeellisena vastaajien keskuudessa. 74,1 % on osittain samaa mieltĂ€ tai tĂ€ysin samaa mieltĂ€ vĂ€ittĂ€mĂ€n âOhjelmoinnin opettamista tarvitaan peruskoulussaâ. Suomalaisten opettajien suhtautuminen ohjelmoinnin opettamiseen on hieman neutraalia positiivisempi tai opettajat eivĂ€t tiedĂ€ miten he asennoituvat ohjelmointia kohtaan. Yleinen suhtautuminen ja ahdistuksen vĂ€hyys kertovat kuitenkin opettajien ottavan ohjelmoinnin opettamisen ennakkoluulotomasti kĂ€yttöönsĂ€.Abstract. The main objective of this Masterâs thesis is to explore Finnish primary school teachersâ readiness to teach programming and their attitudes towards teaching of programming. The new National Curriculum of Finland requires teachers to be able to teach programming commencing from autumn 2016. Koodiaapinen.fi has designed a massive open online course to educate Finnish teachers on teaching of programming to tackle this requirement. The research questionnaire was offered to the teachers who participated in the course. The results of this thesis are intended to be used on developing of the Finnish primary school teacher training on the area of teaching of programming.
Research method of this thesis was web-based questionnaire (n=317). Instrument of the research is based on TAM (Technology Acceptance Model) (Davis, 1989.) and UTAUT (Unified Theory of Acceptance and Use of Technology) (Venkatesh et al., 2003.). Those models were translated and modified to match the research problem and the language of this thesis. One great contributor to the instrument was the questionnaire developed by the researchers of âThe programming studio: investigating teachersâ readiness for teaching programming in the Island of Irelandâ. The questionnaire used in this thesis is partially similar to the one used in Ireland to allow direct comparison of the results between these studies.
Main results of the thesis: About one in ten of the respondents declared to be able to teach some of the following programming languages: Scratch, Scratch Jr., Code.org and HTML/CSS. The respondents were significantly less familiar with other programming languages. However, almost half of the respondents indicated ability to solve problems of the teaching of programming even if there were no help available and over 70 % of the respondents declared they would solve those problems if they had enough time to work on the problem. Teaching of programming was seen necessary among the respondents as 74,1 % partially agreed or strongly agreed with the statement âthe teaching of programming is needed in primary schoolâ. The attitude towards teaching of programming is somewhat more positive than neutral among the respondents or the respondents were not yet able to state their attitudes. The general attitude and lack of anxiety among the respondents denotes that Finnish teachers are openmindedly welcoming programming into primary schoolâs curriculum
Production of a C-15 radioactive ion beam based on O-18(n, alpha)
.In the context of the SPIRAL2 radioactive beam facility the production rate of the neutron-rich C-15 nucleus by O-18(n,) has been investigated. In a water target of 20 cm(3), enriched in O-18 and placed behind the neutron converter, a rate of a few 10(10) nuclei per second can be reached with 1mA of 40MeV deuterons. A O-18(n,) cross-section based on the activation method is proposed. It is intermediate between the highest and lowest evaluations available to date.Peer reviewe
What influences the speed of prototyping? An empirical investigation of twenty software startups
It is essential for startups to quickly experiment business ideas by building
tangible prototypes and collecting user feedback on them. As prototyping is an
inevitable part of learning for early stage software startups, how fast
startups can learn depends on how fast they can prototype. Despite of the
importance, there is a lack of research about prototyping in software startups.
In this study, we aimed at understanding what are factors influencing different
types of prototyping activities. We conducted a multiple case study on twenty
European software startups. The results are two folds, firstly we propose a
prototype-centric learning model in early stage software startups. Secondly, we
identify factors occur as barriers but also facilitators for prototyping in
early stage software startups. The factors are grouped into (1) artifacts, (2)
team competence, (3) collaboration, (4) customer and (5) process dimensions. To
speed up a startups progress at the early stage, it is important to incorporate
the learning objective into a well-defined collaborative approach of
prototypingComment: This is the author's version of the work. Copyright owner's version
can be accessed at doi.org/10.1007/978-3-319-57633-6_2, XP2017, Cologne,
German
A sextupole ion beam guide to improve the efficiency and beam quality at IGISOL
The laser ion source project at the IGISOL facility, Jyvaskyla, has motivated
the development and construction of an rf sextupole ion beam guide (SPIG) to
replace the original skimmer electrode. The SPIG has been tested both off-line
and on-line in proton-induced fission, light-ion and heavy-ion induced
fusion-evaporation reactions and, in each case, has been directly compared to
the skimmer system. For both fission and light-ion induced fusion, the SPIG has
improved the mass-separated ion yields by a factor of typically 4 to 8.
Correspondingly, the transmission efficiency of both systems has been studied
in simulations with and without space charge effects. The transport capacity of
the SPIG has been experimentally determined to be 10^12 ions/s before space
charge effects start to take effect. A direct comparison with the simulation
has been made using data obtained via light-ion fusion evaporation. Both
experiment and simulation show an encouraging agreement as a function of
current extracted from the ion guide.Comment: Latex formatted, submitted to NIM B, 17 pages with 22 .eps figure
The Laser Ion Source Trap (LIST) coupled to a gas cell catcher
The proof of principle of the Laser Ion Source Trap (LIST) coupled to a gas
cell catcher system has been demonstrated at the Leuven Isotope Separator
On-Line (LISOL). The experiments were carried out by using the modified gas
cell-based laser ion source and the SextuPole Ion Guide (SPIG). Element
selective resonance laser ionization of neutral atoms was taking place inside
the cold jet expanding out of the gas cell catcher. The laser path was oriented
in longitudinal as well as transverse geometries with respect to the atoms
flow. The enhancement of beam purity and the feasibility for in-source laser
spectroscopy were investigated in off-line and on-line conditions.Comment: 11 pages, 13 figure
Postexercise Heart Rate Recovery in Adults Born Preterm
Objective To evaluate postexercise heart rate recovery (HRR) in adults born preterm. Study design We studied the association between preterm birth and postexercise HRR in 545 adults (267 women) at 23.3 years of age (range 19.9-26.3 years). One hundred three participants were born early preterm ( Results Mean peak HR was 159.5 bpm in the early preterm (P = .16 with controls), 157.8 bpm in the late preterm (P = .56), and 157.0 bpm in the control group. Mean HRR 30 seconds after exercise was 3.2 bpm (95% CI 1.1-5.2) lower in the early preterm group and 2.1 bpm (0.3-3.8) lower in the late preterm group than the full term controls. Mean 60s HRR was 2.5 (-0.1 to 5.1) lower in the early preterm group and 2.8 bpm (0.6-4.9) lower in the late preterm group. Mean maximum slope after exercise was 0.10 beats/s (0.02-0.17) lower in the early preterm group and 0.06 beats/s (0.00-0.12) lower in the late preterm group. Conclusions Our results suggest reduced HRR after exercise in adults born preterm, including those born late preterm. This suggests altered reactivation of the parasympathetic nervous system, which may contribute to cardiovascular risk among adults born preterm.Peer reviewe
Early age exposure to moisture damage and systemic inflammation at the age of 6 years
Cross-sectional studies have shown that exposure to indoor
moisture damage and mold may be associated with subclinical
inflammation. Our aim was to determine whether early age
exposure to moisture damage or mold is prospectively associated
with subclinical systemic inflammation or with immune
responsiveness in later childhood. Home inspections were
performed in children's homes in the first year of life. At age
6 years, subclinical systemic inflammation was measured by serum
C-reactive protein(CRP) and blood leucocytes and immune
responsiveness by ex vivo production of interleukin
1-beta(IL-1beta), IL-6 and tumor necrosis
factor-alpha(TNF-alpha) in whole blood cultures without
stimulation or after 24h stimulation with phorbol 12-myristate
13-acetate and ionomycin(PI), lipopolysaccharide(LPS) or
peptidoglycan(PPG) in 251 to 270 children. Moisture damage in
child's main living areas in infancy was not significantly
associated with elevated levels of CRP or leucocytes at 6 years.
In contrast, there was some suggestion for an effect on immune
responsiveness, as moisture damage with visible mold was
positively associated with LPS-stimulated production of
TNF-alpha and minor moisture damage was inversely associated
with PI-stimulated IL-1beta. While early life exposure to mold
damage may have some influence on later immune responsiveness,
it does not seem to increase subclinical systemic inflammation
in later life. This article is protected by copyright. All
rights reserved
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