Sensorless control of induction machine at low speed

Regulirani asinhronski pogoni brez mehanskega senzorja hitrosti so zanimivi zaradi nizke cene in visoke zanesljivosti. Meritev hitrosti nadomestimo z meritvami statorskih tokov in napetosti. Vendar meritev napetosti vnaša dodaten strošek in se ji poskušamo izogniti. Predstavljena regulacijska shema z opazovalnikom rotorskega fluksa temelji samo na meritvah tokov in omogoča delovanje tudi v območju nizkih hitrosti, kot je to razvidno iz eksperimentalnih rezultatov.Speed sensorless drives have been receiving a lot of attention in last years. Their main advantages are their low cost and increased reliability. The rotor speed measurement is replaced by the measurement of the stator currents and voltages. However, the measurement of voltages in the pulse width modulated drives is quite complicated and presents an additional cost. In this paper, a new rotor flux observer (Fig. 3), based on an estimation of the electromotive force (EMF) ^er, is presented. By using a stator current observer (11), we can calculate the estimation error (12), which is then fed into the PI controller. The output from this regulator is ^er, which has the meaning of EMF. The estimated rotor flux is then calculated from (14) and the estimated rotor speed is calculated from the cross product of ^er and estimated rotor flux. The low-speed performance as well as the reference tracking performance of speed at no load and rapidly changing load are demonstrated in series of transient characteristics by experimental results in Figures 6 - 9

A COMPARISON OF THE INFLUENCE OF DNA POLYMORPHISMS IN THE GENES INVOLVED IN LIPID METABOLISM ON THE FATTY ACID PROFILES AMONG THE PATIENTS WITH DIFFERENT COMPLEX DISEASES

V diplomskem delu smo proučevali povezavo med polimorfizmi genov, ki sodelujejo pri presnovi maščobnih kislin, in profilom maščobnih kislin bolnikov s pogostimi kompleksnimi boleznimi. Namen dela je bilo ugotoviti povezavo med genotipom posameznega polimorfizma in masnimi deleži maščobnih kislin v eritrocitih, torej da prisotnost bolezenskega alela spremeni maščobno sestavo. Po preučevanju dosedanje literature smo izbrali primerne polimorfizme na genih, ki bi lahko vplivali na maščobni profil. Nato smo vzorce DNK genotipizirali z metodo RFLP ali s HRM. Genotipizirali smo slovenske bolnike z astmo (51), kronično vnetno črevesno boleznijo (103), polipi debelega črevesa (17), miomi maternice (52) in kontrolni skupini zdravih posameznikov (82) za SNP-ja v genih LTA4H, ki kodira encim levkotrien A4 hidrolazo, in PTGS2, ki kodira encim prostaglandin-endoperoksid sintazo 2. Funkcija encima LTA4H je hidrolizirati levkotrien A4 v levkotrien B4encim PTGS2 pa metabolizira arahindonsko kislino v PGH2. Podatke pridobljene z genotipizacijo smo statistično obdelali. Asociacijska študija je pokazala statistično signifikantno povezavo med bolezenskim alelom za SNP rs2540487 na genu LTA4H in patogenezo miomov maternice (p = 0,031). Rezultati kažejo več statistično signifikantnih povezav med profilom maščobnih kislin in genotipom polimorfizma rs2540487 v genu LTA4Hpri bolezenskih alelih zmanjšan delež adrenske in Osbondove kisline in povišan delež oleinske kisline. Adrenska in Osbondova kislina sta produkta arahidonske kisline pri podaljševanju omega-6 maščobnih kislin, kar bi lahko pomenilo, da se arahidonska kislina hitreje presnavlja po drugih metabolnih poteh. Razlog takšni spremembi v metabolizmu je povečano delovanje encima LTA4H, ki je povezano s SNP-jem rs2540487.We investigated the relationship between polymorphisms of genes involved in the metabolism of fatty acids and the fatty acid profile of patients with frequent complex diseases. The purpose of the work was to establish a statistically significant link between the genotype of the chosen polymorphism and weight percentages of fatty acids in erythrocytes, in other words, that the presence of the mutated allele alters the fatty composition. After examining existing literature, we selected suitable polymorphisms in genes that could affect the lipid profile. Then, the samples of DNA were tested with RFLP or by the HRM method. Slovenian patients with asthma (51), inflammatory bowel disease (103), colorectal polyps (17), uterine myomas (52) and a control group of healthy individuals (82) were genotyped for the SNP in genes LTA4H encoding the enzyme leukotriene A4 hydrolase and PTGS2 encoding the enzyme prostaglandin endoperoxide synthase 2. The LTA4H enzyme is hydrolyzed leukotriene A4 to leukotriene B4PTGS2 enzyme metabolizes arahidonic acid to PGH2. The data obtained by genotyping were statistically analyzed. The association study showed a statistically significant link between the disease allele of SNP rs2540487 in the LTA4H gene and the pathogenesis of uterine myomas (p = 0.031). The results show a number of statistically significant relationships between the fatty acid profile of patients and polymorphism rs2540487 genotype in the gene LTA4Hin disease alels the level of adrenic and Osbond acid is reduced while the level of oleic acid is increased. Adrenic and Osbond acid are products of arachidonic acid in the omega-6 fatty acid elongation process, which could mean that arachidonic acid is metabolized though other pathways. The reason for such a change is an increase in LTA4H enzyme activity, which is linked to the SNP rs2540487

INFLUENCE OF GENOME WIDE POLYMORPHISMS ON FATTY ACID PROFILES IN PATIENTS WITH INFLAMMATORY BOWEL DISEASE

V magistrskem delu smo s intenzivno bioinformacijsko analizo preučevali povezave med profili maščobnih kislin in polimorfizmi posameznega nukleotida (SNP-ji), ki so bili genotipizirani na SNP mikromreži, ki obsega več kot 200.000 SNP-jev celotnega genoma. Namen tega dela je bil najti genetske regije, ki vplivajo na deleže maščobnih kislin v membranah rdečih krvnih celic bolnikov s kronično vnetno črevesno boleznijo (KVČB) in razložiti, kako s tem prispevajo k patogenezi bolezni ali njenemu poteku. Pri bioinformacijski analizi smo uporabili več programskih orodij, med njimi PLINK, R in Haploview. Bioinformacijska analiza je pokazala močan statistično značilen signal v FADS regiji, ki vpliva na delež dihomo-γ-linolenske kisline (p = 6.84 × 10-7). Signal je del večjega haplotipskega bloka, katerega vpliv na kinetiko metabolizma maščobnih kislin in eikozanoidov je že dobro opisan. Haplotip D namreč poveča sintezo daljših maščobnih kislin. V prisotnosti moderne zahodnjaške diete bogate s krajšimi ω-6 maščobnimi kislinami vodi do proizvodnje velikih količin arahidonske kisline, katere derivati delujejo vnetno. Ta mehanizem je lahko patogen za kronično vnetno črevesno bolezen. Haplotip D v KVČB deluje negativno tudi s porabo esencialnih maščobnih kislin v času hudega vnetja in s tem vpliva na potek bolezni. Rezultati te asociacijske študije kažejo na vlogo maščobnih kislin v poteku KVČB. Nadaljnje raziskave na tem področju bi prispevale k napovedovanju poteka bolezni in uspešnosti terapij ter odkrivanju novih terapevtskih tarč.In this thesis we performed a comprehensive bioinformatical analysis between the fatty acids profiles and single nucleotide polymophisms (SNP), which were genotyped on a genome-wide human SNP microarray consisting of more than 200.000 SNP. The aim of this work was to find genetic regions that affect the fatty acids profile in red blood cell membranes of patients with inflammatory bowel disease and explain how they contribute to the pathogenesis of the disease or its progression. We used several software tools in the bioinformatical analysis, including Plink, R and Haploview. The bioinformatics analysis showed a strong statistically significant signal in the FADS gene region (p = 6.84 x 10-7), which affects the proportion of dihomo-γ-linolenic acid. The signal is part of a larger haplotype block whose effect on the kinetics of fatty acids metabolism and eicosanoids has been well described. Haplotype D increases the synthesis of long chain fatty acids. In the presence of the modern western diet rich in shorter ω-6 fatty acids, it leads to the production of large amounts of arachidonic acid, which produces inflammatory derivatives. This mechanism can be pathogenic for inflammatory bowel disease. Haplotype D in IBD also acts negatively by consuming essential fatty acids during severe colon inflammation and thus influences the course of the disease. The results of the association studies highlight the role of fatty acids in the disease course of IBD. Further research in this field could contribute to better prediction of disease course and therapy success and potential discovery of new therapeutic targets

Development of a model for evaluating investments in to the purchase of the milk machine

Namen diplomske naloge je bilo ugotoviti ekonomsko upravičenost investicije v nakup mlekomata za prodajo svežega mleka in razviti računalniški model, ki bo omogočal izračunavanje ekonomske upravičenosti investicije po predpostavljenih parametrih. Za izračunavanje upravičenosti investicije smo uporabili metodo NSV (neto sedanje vrednosti) in ISD (interno stopnjo donosnosti). Izdelali smo model v elektronski preglednici s pomočjo programa Microsoft Office EXCEL 2003, ki omogoča preračunavanje upravičenosti investicije po različnih scenarijih. Predvideli smo štiri različne scenarije. Ugotovili smo, da bi bila po prvem scenariju investicija upravičena že četrto leto. V drugem scenariju smo ugotovili, da bi bila investicija upravičena pri povprečni dnevni prodaji 40 litrov mleka in več. V tretjem scenariju smo ugotovili, da bi bila investicija upravičena pri prodajni ceni 0,8 € za liter mleka. V četrtem scenariju pa smo ugotovili, da je po vseh predpostavljenih parametrih investicija upravičena.The aim of our graduation thesis was to evaluate the economic viability of investments in the purchase of milking machine for selling raw milk and develop a computer model to calculate the economic viability of investments under the assumed parameters. We used the methods of NPV (net present value) and IRR (internal rate of return ). We developed a model of the electronic spreadsheet using Microsoft Office Excel 2003 that enables conversion of eligible investments in various scenarios. We assumed four different scenarios. We found out that in the first scenario the investment was justified in its fourth year. In the second scenario, we found that the investment was justified in case of average daily sales of 40 liters and more. In the third scenario, we found that the investment was justified at a selling price of € 0.8 per liter of milk. The results of the fourth scenario showed, that under all the assumed parameters the investment was justified

Gene Ontology Analysis Highlights Biological Processes Influencing Non-Response to Anti-TNF Therapy in Rheumatoid Arthritis

Anti-TNF therapy has significantly improved disease control in rheumatoid arthritis, but a fraction of rheumatoid arthritis patients do not respond to anti-TNF therapy or lose response over time. Moreover, the mechanisms underlying non-response to anti-TNF therapy remain largely unknown. To date, many single biomarkers of response to anti-TNF therapy have been published but they have not yet been analyzed as a system of interacting nodes. The aim of our study is to systematically elucidate the biological processes underlying non-response to anti-TNF therapy in rheumatoid arthritis using the gene ontologies of previously published predictive biomarkers. Gene networks were constructed based on published biomarkers and then enriched gene ontology terms were elucidated in subgroups using gene ontology software tools. Our results highlight the novel role of proteasome-mediated protein catabolic processes (p = 2.91 × 10−15) and plasma lipoproteins (p = 4.55 × 10−11) in anti-TNF therapy response. The results of our gene ontology analysis help elucidate the biological processes underlying non-response to anti-TNF therapy in rheumatoid arthritis and encourage further study of the highlighted processes

Biological processes and predicting non-response to tumor necrosis factor inhibitors in Crohn\u27s disease by integrating genomic data

Razvoj bioloških zdravil je pomembno prispeval k možnostim zdravljenja raka in imunsko pogojenih bolezni. Med najpogosteje uporabljenimi biološkimi zdravili so zaviralci dejavnika tumorske nekroze (TNF). Crohnova bolezen je pogosta imunsko pogojena bolezen prebavil, ki se zdravi z zaviralci TNF. Kljub tarčnemu delovanju zaviralcev TNF del bolnikov s Crohnovo boleznijo žal ne doseže dobrega odziva na zaviralce TNF že ob uvedbi terapije ali pa sprva dober odziv na zaviralce TNF s časom izzveni. Neodzivnost na zaviralce TNF predstavlja pomeni izgubo nadzora nad pogosto hudim bolezenskim stanjem bolnika s Crohnovo boleznijo, ki je po nepotrebnem izpostavljen potencialno hudim neželenim stranskim učinkom bioloških zdravil, in tudi precejšnje finančno breme za zdravstveno blagajno. Ti razlogi utemeljujejo potrebo po napovedovanju odziva na biološka zdravila, po možnosti še pred uvedbo zdravljenja. V doktorski disertaciji smo celostno raziskali biološke označevalce odziva na zaviralce dejavnika tumorske nekroze na ravni DNA in RNA ter maščobnih kislin v vzorcih periferne venske krvi skupine slovenskih bolnikov s Crohnovo boleznijo, ki se je zdravila z adalimumabom. Rezultate teh analiz smo uporabili za oblikovanje novih napovednih modelov s pristopi strojnega učenja, t.i. metode podpornih vektorjev. Za namene iskanja vzročnih bioloških procesov, ki pogojujejo neodzivnost na zaviralce dejavnika tumorske nekroze, smo sistematsko preučili gensko ontologijo že objavljenih bioloških označevalcev odziva na zaviralce dejavnika tumorske nekroze v kronični vnetni črevesni bolezni. Za primerjalno analizo genske ontologije smo zbrali tudi biološke označevalce odziva v revmatoidnem artritisu. Ker je neodzivnost pogostejša med pediatričnimi bolniki, smo analizo genske ontologije razširili še na vzročne gene pediatričnih dednih oblik kronične vnetne črevesne bolezni in sindrome s klinično sliko, skladno s kronično vnetno črevesno boleznijo. Dodatno smo tudi poskusili ponoviti že objavljen napovedni model odziva na infliksimab, ki temelji na izražanju petih genov v črevesni sluznici. Rezultati genske ontologije že objavljenih označevalcev kažejo na povezavo med krvnimi lipoproteini in odzivom na zaviralce dejavnika tumorske nekroze pri kronični vnetni črevesni bolezni, kot tudi pri revmatoidnem artritisu. Na osnovi rezultatov genske ontologije pediatričnih dednih oblik kronične vnetne črevesne bolezni lahko sklepamo, da so zelo zgodnje pediatrične oblike z nastopom bolezni pred šestim letom starosti ločena genetska entiteta in je neodzivnost pogojena z drugimi procesi, npr. s primarno imunsko pomanjkljivostjo. Analiza bioloških podatkov na ravni DNA in RNA ter maščobnih kislin ni pokazala biološkega označevalca, ki bi dosegel statistično značilnost, kar odraža tudi analiza napovedne moči s pristopi strojnega učenja. Profili maščobnih kislin nimajo napovedne moči za določevanje odziva na zaviralce dejavnika tumorske nekroze, genomski in transkripromski podatki pa imajo le nizko napovedno moč. Napovedni model na osnovi že objavljenega modela izražanja genov v črevesni sluznici smo uspešno ponovili in prenesli na drugo učinkovino (adalimumab). Na osnovi izražanja štirih genov v vneti in nevneti črevesni sluznici je možno napovedati odziv na zaviralce dejavnika tumorske nekroze s natančnostjo do 100 %. Nato smo še analizirali diagnostično napovedno moč bioloških podatkov s vključitvijo bioloških podatkov zdravih prostovoljcev, ki so že bili na voljo. Napovedni model na osnovi dednega zapisa in profilov maščobnih kislin je z natančnostjo do 100 % ločil med zdravimi prostovoljci in bolniki s Crohnovo boleznijo.The development of biological drugs has significantly contributed to therapeutic options in cancer and immune-mediated chronic diseases. Tumor necrosis factor (TNF) inhibitors are one of the most commonly used biological drugs. Crohn\u27s disease is a common gastrointestinal immune disease that is treated with TNF inhibitors. Despite the targeted action of TNF inhibitors, some patients with Crohn\u27s disease unfortunately do not respond to TNF inhibitors or lose response to TNF inhibitors over time. Non-response to TNF inhibitors usually represents a loss of control over severe symptoms, unnecessarily exposes Crohn\u27s disease patients to potentially severe side effects of biological medicines and represents a significant burden on the health fund. These reasons justify the need to predict the response to biological drugs, preferably before initiating treatment. In this doctoral dissertation we thoroughly investigated the biological markers of response to tumor necrosis factor inhibitors on the level of DNA, RNA and fatty acids in samples of peripheral venous blood of a group of Slovenian patients with Crohn\u27s disease treated with adalimumab. The results were used to design new predictive models with machine learning approaches, i.e. support vector machines. To investigate biological processes causal for non-response to tumor necrosis factor inhibitors, we systematically examined the genetic ontology of previously published biological markers of response to tumor necrosis factor inhibitors in inflammatory bowel disease. We expanded the search to biological response markers in rheumatoid arthritis for comparative gene ontology analysis. Since non-response is more common among pediatric patients, we also extended the gene ontology analysis to causal genes for pediatric hereditary forms of chronic inflammatory bowel disease and syndromes with clinical characteristics consistent with inflammatory bowel disease. In addition, we attempted to replicate a published predictive model of response to infliximab based on the expression of five genes in the intestinal mucosa. The results of the gene ontology analysis of previously reported response markers suggest an association between blood lipoproteins and the response to tumor necrosis factor inhibitors in inflammatory bowel disease as well as in rheumatoid arthritis. Based on the results of gene ontology analysis of pediatric inherited forms of inflammatory bowel disease, we conclude that very early pediatric forms with an onset before the age of six are a separate genetic entity and are their non-response is likely caused by other processes, e.g. primary immune deficiency. Analysis of biological data on the level of DNA, RNA and fatty acids did not reveal biological markers with statistical significance, which is also reflected by the analysis of predictive power through machine learning approaches. Fatty acid profiles have no predictive power to determine response to tumor necrosis factor inhibitors while genomic and transcriptomic data has low predictive power. The predictive model based on the previously published intestinal mucosa gene expression model was successfully replicated and applied to another biological drug (adalimumab). Based on the expression of four genes in the inflamed and non-inflamed intestinal mucosa, it is possible to predict the response to tumor necrosis factor inhibitors with an accuracy of up to 100 %. We then further analyzed the diagnostic predictive power of biological data by incorporating already available biological data of healthy volunteers. A predictive model based on genetic data and fatty acid profiles distinguished between healthy volunteers and patients with Crohn\u27s disease with an accuracy of up to 100 %

Low Speed Sensorless Variable Structure Control of Induction Motor

Torque and speed sensorless induction motor control is presented in this paper. The idea is realized using a sliding mode closed loop rotor flux observer for estimation of electromotive force of machine. This signal is then used in nonlinear stator flux and torque control of induction motor and in rotor flux observer for speed and flux estimation. The analysis of the proposed method is included. Proposed control scheme was implemented on DSP system extended with FPGA where PWM procedure with dead time compensation was realized. Experimental results demonstrated high efficiency of the proposed estimation and control method