1. Parametrično konstruiranje rotorskega navitja : diplomsko deloAjdin Šabanagić, 2024, diplomsko delo Opis: V avtomobilski industriji sta učinkovitost in zanesljivost pogonskega motorja ključni za
dolgotrajno obratovanje vozila. S tem razlogom postajajo motorji z navitimi rotorji vse
bolj razširjeni, saj zmanjšujejo tudi količino uporabljenih redkih elementov. V diplomskem
delu je opisano parametrično konstruiranje rotorskega navitja in z njim povezanih
komponent. Glavni izziv je razviti natančen parametrični geometrijski model, ki dobro
odraža realno stanje in upošteva potrebne parametre. Osnovni parametri izvirajo iz
rezultatov elektro magnetnih in strukturnih simulacij ter lastnostih proizvodnega
procesa. Parametrični modeli omogočajo enostavno in hitro spreminjanje oblik in
dimenzij, hkrati pa omogočajo znaten prihranek časa in s tem denarja. Z uporabo
parametričnih modelov je bila vzpostavljena osnova za natančno konstrukcijo in
proizvodnjo rotorskega navitja.
Ključne besede: parametrično konstruiranje, rotor, rotorsko navitje, pogonski
motor, elektromotor
Objavljeno v DKUM: 30.09.2024; Ogledov: 0; Prenosov: 31
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2. Teaching strategies for promoting motor creativity and motor skill proficiency in early childhoodMiha Marinšek, Nina Lukman, 2022, izvirni znanstveni članek Opis: Existing research provides ambiguous evidence for associations between motor competency and motor creativity. Therefore, this study examined the association between motor skill proficiency and motor creativity. The Test of Gross Motor Development (second edition) and Bertsch's motor creativity test were used to assess motor skill proficiency and motor creativity among 39 children aged five to six. Results revealed that motor proficiency and motor creativity are not interrelated traits. Therefore, it is necessary to use different teaching strategies to promote these traits. Teaching with direct instructions and reproduction of demonstrated movement is probably the most appropriate to acquaint children with motor skills. Learning through play with less explicit teaching instructions and emphasis on motivating children to find novel and original solutions to the motor tasks is probably more suitable for facilitating motor creativity.
Ključne besede: physical education, didactics, motor behaviour
Objavljeno v DKUM: 30.09.2024; Ogledov: 0; Prenosov: 3
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3. Objectively measured physical activity in patients with coronary artery disease : a cross-validation studyTim Kambič, Nejc Šarabon, Vedran Hadžić, Mitja Lainščak, 2021, izvirni znanstveni članek Opis: Physical activity (PA) and sedentary behavior (SB) levels in healthy adults are predominately based on self-reporting measures, which generally overestimate PA but underestimate SB. Patients with coronary artery disease (CAD) eligible for cardiac rehabilitation (CR) follow an individualized program; thus, objective assessment of physical performance and regular daily activity is required. This study aimed to compare self-reported and objectively measured PA and SB in patients with CAD prior to out-patient CR. We included 91 patients with CAD and assessed their PA with an accelerometer for 8 days prior to CR, along with the short form of the international physical activity questionnaire. We found that most patients were sedentary (61%, ~8 h/day), and on average performed 63 min/day of moderate-to-vigorous-intensity physical activity (MVPA). Males performed less daily light-intensity physical activity (−5%, p = 0.011) and performed more MVPA (+2%, p = 0.002) compared to females. Maximal aerobic capacity was significantly associated with MVPA (Spearman rho = 0.483, p < 0.001) and MVPA > 10 min bouts (Spearman rho = 0.391, p < 0.001). Self-reported measures overestimated MVPA (total MVPA, +108 min/day, p < 0.001; MVPA > 10 min bouts, +152 min, p < 0.001) and underestimated SB (−174 min/day, p < 0.001) compared to objective measures. There was no significant correlation between methods in MVPA (Spearman rho = 0.147, p = 0.165)), MVPA > 10 min bouts (Spearman rho = −0.059, p = 576), and SB (Spearman rho = 0.139, p = 0.187). Quantitative analysis demonstrated the huge proportional bias for MVPA, MVPA > 10 min bouts, and SB. Our findings demonstrate that self-reported physical activity provides inaccurate estimates of MVPA and SB in patients with CAD entering the ambulatory CR. This strongly supports the more objective assessments of daily PA, preferably using an accelerometer.
Ključne besede: myocardial infarction, cardiovascular disease, acute coronary syndrome, sedentary behavior, motor activity, accelerometry, moderate intensity, vigorous intensity
Objavljeno v DKUM: 20.08.2024; Ogledov: 117; Prenosov: 9
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4. Acute intermittent hypoxia increases maximal motor unit discharge rates in people with chronic incomplete spinal cord injuryGregory E. P. Pearcey, Babak Afsharipour, Aleš Holobar, Milap S. Sandhu, William Zev Rymer, 2024, izvirni znanstveni članek Opis: Acute intermittent hypoxia (AIH) is an emerging technique for enhancing neuroplasticity and motor function in respiratory and limb musculature. Thus far, AIH-induced improvements in strength have been reported for upper and lower limb muscles after chronic incomplete cervical spinal cord injury (iSCI), but the underlying mechanisms have been elusive. We used high-density surface EMG (HDsEMG) to determine if motor unit discharge behaviour is altered after 15 × 60 s exposures to 9% inspired oxygen, interspersed with 21% inspired oxygen (AIH), compared to breathing only 21% air (SHAM). We recorded HDsEMG from the biceps and triceps brachii of seven individuals with iSCI during maximal elbow flexion and extension contractions, and motor unit spike trains were identified using convolutive blind source separation. After AIH, elbow flexion and extension torque increased by 54% and 59% from baseline (P = 0.003), respectively, whereas there was no change after SHAM. Across muscles, motor unit discharge rates increased by ∼4 pulses per second (P = 0.002) during maximal efforts, from before to after AIH. These results suggest that excitability and/or activation of spinal motoneurons is augmented after AIH, providing a mechanism to explain AIH-induced increases in voluntary strength. Pending validation, AIH may be helpful in conjunction with other therapies to enhance rehabilitation outcomes after incomplete spinal cord injury, due to these enhancements in motor unit function and strength.
Ključne besede: muscle strength, motoneuron function, motor unit
Objavljeno v DKUM: 02.08.2024; Ogledov: 73; Prenosov: 0 |
5. REKONSTRUKCIJA VALJČNE PROGE 800 V ŠTORE STEEL : diplomsko deloGregor Pusar, 2024, diplomsko delo Opis: Diplomsko delo obravnava rekonstrukcijo valjčne proge 800 v podjetju Štore Steel, ki jo je izvedlo podjetje ETRA, d. o. o. V osnovi gre za krmiljenje asinhronskih motorjev, ki so ostali nespremenjeni od začetka delovanja proge. Proga 800 uporablja 16 asinhronskih motorjev, pri čemer je prvotno en pretvornik krmilil osem asinhronskih motorjev (pretvornik ASEA tip »YRYB«), tj. pretvornik ASEA tip »YRYB«, ki je bil v uporabi ob zagonu stroja. Pretvornik ASEA tip »YRYB« je bil sprva najustreznejša rešitev, nato pa se je pojavila težava z vzdrževanjem, saj je bila elektronika draga in težavna za pridobiti, predvsem zaradi pomanjkanja rezervnih delov. Prva faza prenove je vključevala postopno demontažo obstoječih pretvornikov ASEA in namestitev pretvornikov SIMOVERT MASTERDRIVES Vector Control. Ta izvedba je težavna za vzdrževanje, saj če odpove samo en segment (DC-link), so štirje motorji v napaki. Kljub temu da je ta izvedba težavna za vzdrževanje, je bila v tistem času najboljša možna rešitev. Prav zaradi tega je sledila nadaljnja zamenjava za Sinamics S120, ki krmili štiri asinhronske motorje. Ta izvedba je prav tako predstavljala izzive za vzdrževanje, saj je odpoved enega segmenta (DC-link) povzročila napako pri štirih asinhronskih motorjev, podobno kot pri SIMOVERT MASTERDRIVES Vector Control. Končna faza prenove je vključevala uporabo pretvornikov Sinamics G120C. Vsak asinhronski motor je dobil svoj pretvornik, kar je omogočilo izboljšano vzdrževanje in boljšo diagnostiko. Morebitna okvara enega pretvornika ni več vplivala na celotno proizvodnjo in proizvodni proces. Delo prav tako podrobno opisuje postopek optimizacije pretvornika Sinamics G120C z uporabo programskega orodja STARTER.
Ključne besede: asinhronski motor, optimizacija, regulacija, Siemens Sinamics G120C, Štore Steel
Objavljeno v DKUM: 01.07.2024; Ogledov: 265; Prenosov: 66
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6. Numerično določanje karakteristik sinhronskega motorja z različnimi velikostmi trajnih magnetov : magistrsko deloDavor Car, 2024, magistrsko delo Opis: Magistrsko delo obravnava osnovni pristopa k modeliranju in konstruiranju sinhronskega motorja s trajnimi magneti s pomočjo računalniškega programa Flux. Izvedena je numerična analiza konstrukcijskih parametrov trajnih magnetov na navorno karakteristiko motorja. Analiza zajema vpliv različnih dimenzij in postavitev magnetov na vrednost valovitosti navora in razmerje navora proti volumnu trajnih magnetov. Rezultati nakazujejo, da je s predstavljenim računalniško podprtim pristopom, moči že v fazi načrtovanja motorja izbrati najustreznejše dimenzije za doseganje čim boljšega izkoristka z želeno navorno karakteristiko.
Ključne besede: Elektromotor, sinhronski stroj, sinhronski motor s trajnimi magneti, STSM, modeliranje, Flux, MKE, metoda končnih elementov, navitje, trajni magneti, valovitost navora, razmerje navora na volumen
Objavljeno v DKUM: 01.07.2024; Ogledov: 136; Prenosov: 41
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7. Motor unit identification in the M waves recorded by high-density electromyMiloš Kalc, Jakob Škarabot, Matjaž Divjak, Filip Urh, Matej Kramberger, Matjaž Vogrin, Aleš Holobar, 2023, izvirni znanstveni članek Ključne besede: M wave, high-density surface EMG, firing identification, motor unit
Objavljeno v DKUM: 13.06.2024; Ogledov: 144; Prenosov: 10
Celotno besedilo (2,30 MB)
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8. Identification of motor unit firings in H-reflex of soleus muscle recorded by high-density surface electromyographyMiloš Kalc, Jakob Škarabot, Matjaž Divjak, Filip Urh, Matej Kramberger, Matjaž Vogrin, Aleš Holobar, 2023, izvirni znanstveni članek Ključne besede: motor units identification, high-density surface EMG, decomposition, H-reflex
Objavljeno v DKUM: 13.06.2024; Ogledov: 133; Prenosov: 11
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9. Materials for HybridNeuro webinar titled "Validation of results: statistical models and MU identification accuracy"Aleš Holobar, Nina Murks, 2024, zaključena znanstvena zbirka raziskovalnih podatkov Opis: This dataset contains a collection of teaching materials that were used in the HybridNeuro project webinar titled "Validation of results: statistical models and MU identification accuracy". The webinar was presented by Aleš Holobar and covered the complexities of motor unit (MU) identification accuracy, regression analysis and Bayesian models. The primary aim of the webinar was to spark a robust discussion within the scientific community, particularly focusing on the application and implications of linear mixed models and Bayesian regression in the realm of MU identification. The teaching materials include Matlab and R source code for statistical analysis of the included data, as well as three examples of MU identification results in CSV format (from both synthetic and experimental HDEMG signals). The presentation slides in PDF format are also included. The dataset is approximately 9 MB in size.
Ključne besede: HybridNeuro, webinar, teaching materials, statistical models, regression analysis, motor unit identification, matlab, rstudio, statistics, surface high density electromyogram (HDEMG), tibialis anterior, dataset
Objavljeno v DKUM: 30.05.2024; Ogledov: 221; Prenosov: 19
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10. Simulated and experimental HDEMG signals of biceps brachii muscle for analysis of motor unit mergingAleš Holobar, Jakob Škarabot, Dario Farina, 2024, zaključena znanstvena zbirka raziskovalnih podatkov Opis: This dataset contains a collection of simulated and experimental surface HDEMG recordings of the biceps brachii muscle during the isometric elbow flexion. Simulated data contains 50 recordings: 5 subjects and 5 excitation levels, each with and without added noise. Experimental data contains 16 recordings: 2 subjects with 4 excitation levels and 2 repetitions of each level. Synthetic data was simulated using the cylindrical volume conductor model [1] and the motor unit recruitment and firing modulation model proposed in [2]. Each recording is 20 seconds in length with 90 HDEMG channels sampled at 2048 Hz and is stored as a 2D matrix of raw EMG values in Matlab’s MAT format. Experimental surface EMG data was recorded on two volunteers during isometric contractions at constant force level. Each recording is 25 seconds in length with 64 HDEMG channels sampled at 2048 Hz and is also stored as a 2D matrix of raw EMG values in Matlab’s MAT format. The dataset is approximately 1.5 GB in size.
Ključne besede: surface high density electromyogram (HDEMG), motor unit, spike train, motor unit merging, simulated data, experimental data, biceps brachii, dataset
Objavljeno v DKUM: 30.05.2024; Ogledov: 172; Prenosov: 14
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