SLO | ENG

Večja pisava | Manjša pisava

Iskanje po katalogu digitalne knjižnice Pomoč

Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju

Opcije:
  Ponastavi


21 - 30 / 714
Na začetekNa prejšnjo stran12345678910Na naslednjo stranNa konec
21.
Izzivi oddaljenega spremljanja stanja hidravličnih olj
Vito Tič, Darko Lovrec, objavljeni znanstveni prispevek na konferenci

Opis: Zagotavljanje ustrezne kakovosti hidravličnega olja ter ustrezno predvidevanje menjave polnitve je ključnega pomena za stabilno in nemoteno obratovanje mnogih industrijskih naprav. Pri tem nam največjo mero zanesljivosti vsekakor ponuja stalno spremljanje stanja hidravličnih olj, ki se običajno vrši oddaljeno s pomočjo sodobnih senzorjev. Kljub temu pa razvoj in implementacija takšnega sistema predstavlja svojevrstni izziv, saj je merjenje stanja olja veliko bolj zapleteno, kot merjenje običajnih obratovalnih parametrov, kot sta na primer tlak ali temperatura.
Ključne besede: hidravlično olje, kakovost, oddaljeno spremljanje, menjava olja, sodobni senzorji
Objavljeno: 10.10.2017; Ogledov: 43; Prenosov: 2
.pdf Celotno besedilo (415,93 KB)

22.
Pomen poznavanja dejanskega stanja hidravličnega olja kot osnova za strateška odločanja
Darko Lovrec, Vito Tič, objavljeni znanstveni prispevek na konferenci

Opis: Običajna hidravlična olja na mineralni osnovi in turbinska olja, katera se uporabljajo na strojih in napravah imajo različno dolgo uporabno dobo. Ta je odvisna od vrste različnih faktorjev: od pravilnega vzdrževanja in uporabljen vrste nadzora in aktivnosti in od skrbne izbire vrste olja. Mehanizmi staranja hidravličnih olj in pa vzroki, zakaj jih je potrebno zamenjati so sicer zelo dobro znani uporabnikom, manj poznano pa je dejstvo, da so med posameznimi vrstami olj velike razlike glede njihove vzdržljivosti, ko so le ta izpostavljena delovnim pogojem stroja. Vsako podaljšanje uporabne dobe hidravličnega ali turbinskega olja ponuja tako finančne kot okoljske prednosti, a predpostavlja poznavanje dejanskega stanja olja. Za namene ocene preostale uporabne dobe olja, je v prispevku predstavljena nova metoda za primerna za on-line nadzor stanja in za testiranje vzdržljivosti oz. oksidacijske odpornosti različnih hidravličnih olj. Rezultati takšnega testiranja uporabniku nudijo možnost strateškega odločanja pri postopku nabave najprimernejšega olja z dolgo uporabno dobo.
Ključne besede: hydraulic oil, aging, on-line monitoring, testing, strategical decision-making
Objavljeno: 10.10.2017; Ogledov: 37; Prenosov: 2
.pdf Celotno besedilo (732,34 KB)

23.
Ovrednotenje modelov verjetnostne porazdelitve napake napovedi proizvodnje vetrnih elektrarn
Boštjan Polajžer, Dunja Srpak, objavljeni znanstveni prispevek na konferenci

Opis: V članku so obravnavani različni modeli verjetnostne porazdelitve napake proizvodnje vetrnih elektrarn. Poleg modelov, znanih iz literature (beta, Weibull, gamma), so obravnavani modeli z razširjeno nesimetrično posplošeno normalno porazdelitvijo. Obravnavan je tudi model s t.i. verzatilno verjetnostno porazdelitvijo, ki je občutljiv na valovitost empirične porazdelitve, vendar omogoča analitičen izračun percentilne funkcije. Dobljeni rezultati kažejo, da modeli z beta, Weibull in gamma verjetnostno porazdelitvijo ne dajejo dobrih rezultatov, bistveno bolj ustrezni so modeli z nesimetrično posplošeno normalno verjetnostno porazdelitvijo.
Ključne besede: model verjetnostne porazdelitve, verjetnostna analiza, porazdelitev napake, proizvodnja električne energije, vetrne elektrarne
Objavljeno: 10.10.2017; Ogledov: 63; Prenosov: 8
.pdf Celotno besedilo (907,97 KB)

24.
Analysis of the spanish electricity market and proposals for future development
Ester Getino, Emilio García, Klemen Deželak, objavljeni znanstveni prispevek na konferenci

Opis: Nowadays the electricity is found in any daily activity, while a state can not develop its economic and social potential without a consolidated electricity system. In sense of the liberalized electrical systems, the figure of an electric market becomes fundamental. This paper shows an overview of the Spanish electricity market, involving its problems and future objectives. Spain as a member of the European Union faces the demands proposed by the European Commission. The European challenge is not an individual challenge for individual member but requires the cooperation of all member states, moving towards an energetically integrated European Union.
Ključne besede: electricity market, liberalization, Spain, generation, transportation, distribution
Objavljeno: 10.10.2017; Ogledov: 36; Prenosov: 2
.pdf Celotno besedilo (380,59 KB)

25.
Koncept prostorske analize rabe in proizvodnje toplote v Mestni občini Maribor
Jure Čižman, Damir Staničić, Matjaž Česen, Miran Rožman, Ljubo Germič, Filip Kokalj, objavljeni znanstveni prispevek na konferenci

Opis: Trajnostne rešitve za ogrevanje in hlajenje temeljijo na sodobnih tehnologijah in vedno večjem povezovanju različnih sektorjev rabe in proizvodnje energije – stavb, industrije, proizvodnje električne energije ter prometa. Sistemi daljinskega ogrevanja in hlajenja omogočajo povezovanje različnih sektorjev in s tem zagotavljajo učinkovito upravljanje z vsemi razpoložljivimi viri in ponori energije. Takšen pristop zahteva sistemsko črtovanje ravnanja z energijo v lokalni skupnosti, ki temelji na podrobni prostorski analizi obstoječega stanja in prihodnjega razvoja. V prispevku je predstavljen koncept prostorske analize rabe in oskrbe s toploto z uporabo orodij geografskega informacijskega sistema v Mestni občini Maribor(MOM).
Ključne besede: trajnostne rešitve, ogrevanje, hlajenje, prostorska analiza, geografski informacijski sistem
Objavljeno: 10.10.2017; Ogledov: 51; Prenosov: 8
.pdf Celotno besedilo (927,05 KB)

26.
Trend analysis of journal metrics: a new academic library service?
Peter Kokol, 2017, izvirni znanstveni članek

Opis: Objective: Temporal trends in source normalized impact per paper (SNIP) values for the three top-ranking nursing journals were analyzed and compared to explore whether predicting future SNIP values based on trend analysis could be an innovative service provided by librarians. Methods: The International Journal of Nursing Studies, Journal of Nursing Scholarship, and Journal of Advanced Nursing were the three top-ranked nursing journals according to 2015 SNIP values. SNIP values for the selected journals were retrieved from the Scopus database, and extracted data were exported to Joinpoint trend analysis software to perform trend analysis. Results: The trend in SNIP values for the International Journal of Nursing Studies was the most stable and positive, whereas the trend in SNIP values for the Journal of Advanced Nursing was the most negative. The annual percentage change of the most recent trend line, which is the best indicator for predicting future SNIP values, was the largest for the International Journal of Nursing Studies. Conclusions: Predictions of journal metrics based on statistical joinpoint regression may not be completely accurate. Using this technique, however, a librarian can reasonably claim which journal will retain or even improve its prestige in the future and thus safely advise prospective authors on where to publish their research.
Ključne besede: publish or perish, medical library, trend analysis, journal impact factor, joinpoint regression
Objavljeno: 09.10.2017; Ogledov: 76; Prenosov: 6
.pdf Celotno besedilo (227,10 KB)

27.
Simulating various terrestrial and UAV LiDAR scanning configurations for understory forest structure modelling
Marina Hämmerle, Niko Lukač, K.-C. Chen, Zsófia Koma, C.-K. Wang, K. Anders, B. Höfle, 2017, objavljeni znanstveni prispevek na konferenci

Opis: Information about the 3D structure of understory vegetation is of high relevance in forestry research and management (e.g., for complete biomass estimations). However, it has been hardly investigated systematically with state-of-the-art methods such as static terrestrial laser scanning (TLS) or laser scanning from unmanned aerial vehicle platforms (ULS). A prominent challenge for scanning forests is posed by occlusion, calling for proper TLS scan position or ULS flight line configurations in order to achieve an accurate representation of understory vegetation. The aim of our study is to examine the effect of TLS or ULS scanning strategies on (1) the height of individual understory trees and (2) understory canopy height raster models. We simulate full-waveform TLS and ULS point clouds of a virtual forest plot captured from various combinations of max. 12 TLS scan positions or 3 ULS flight lines. The accuracy of the respective datasets is evaluated with reference values given by the virtually scanned 3D triangle mesh tree models. TLS tree height underestimations range up to 1.84 m (15.30 % of tree height) for single TLS scan positions, but combining three scan positions reduces the underestimation to maximum 0.31 m (2.41 %). Combining ULS flight lines also results in improved tree height representation, with a maximum underestimation of 0.24 m (2.15 %). The presented simulation approach offers a complementary source of information for efficient planning of field campaigns aiming at understory vegetation modelling.
Ključne besede: forest structure, understory, laser scanning simulation, full waveform, 3D point cloud analysis, field campaign planning
Objavljeno: 09.10.2017; Ogledov: 118; Prenosov: 4
.pdf Celotno besedilo (3,71 MB)

28.
29.
Inference attacks and control on database structures
Muhamed Turkanović, Tatjana Welzer Družovec, Marko Hölbl, 2015, izvirni znanstveni članek

Opis: Today’s databases store information with sensitivity levels that range from public to highly sensitive, hence ensuring confidentiality can be highly important, but also requires costly control. This paper focuses on the inference problem on different database structures. It presents possible treats on privacy with relation to the inference, and control methods for mitigating these treats. The paper shows that using only access control, without any inference control is inadequate, since these models are unable to protect against indirect data access. Furthermore, it covers new inference problems which rise from the dimensions of new technologies like XML, semantics, etc.
Ključne besede: inference, attacks, database, security, semantics
Objavljeno: 09.08.2017; Ogledov: 65; Prenosov: 8
.pdf Celotno besedilo (322,91 KB)

30.
Sleeping beauties in pediatrics
Jernej Završnik, Peter Kokol, 2016, kratki znanstveni prispevek

Opis: Sleeping beauties (SBs) in science have been known for few decades; however, it seems that only recently have they become popular. An SB is a publication that ‘‘sleeps’’ for a long time and then almost suddenly awakes and becomes highly cited. SBs present interesting findings in science. Pediatrics research literature has not yet been analyzed for their presence, and 5 pediatrics SBs were discovered in this research. Their prevalence was approximately 0.011%. Some environments or periods are more ‘‘SB fertile’’ than others: 3 of 5 SBs were published in the journal Pediatrics, 4 originated from the United States, and 4 were published in the period from 1992 to 1993. No institutions or authors published more than 1 SB.
Ključne besede: pediatrics, paediatrics, scientific literature, citation, sleeping beauties, bilbliometrics, citation analysis, publications, research
Objavljeno: 07.08.2017; Ogledov: 103; Prenosov: 5
.pdf Celotno besedilo (72,12 KB)

Iskanje izvedeno v 0.51 sek.
Na vrh
Logotipi partnerjev Univerza v Mariboru Univerza v Ljubljani Univerza na Primorskem Univerza v Novi Gorici