京都大学 / 新制・課程博士 / 博士(工学) / 甲第23207号 / 工博第4851号 / 新制||工||1757(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 篠原 真毅, 教授 守倉 正博, 准教授 久門 尚史 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Relays and fuses are used in a multitude of applications to deliver and control current to its consumers. To improve the controllability of both the fuse and relay function, they can be moved to software. This will not only increase the number of available features but can also give live feedback of the systems current state. For an electronic fuse to work the software needs to be able to measure the amount of current flowing through the circuit. For this a voltage drop can be measured across a series resistor. This can be implemented in several ways and will because of this utilize the resources of the controlling microcontroller differently. This thesis focuses on the software implementation of two current measuring circuits and will characterize the behavior of these in terms of making it simple to compare their advantages and disadvantages. Any hardware related aspect found to have an impact on the result will be taken into account as well. Two implementations, using two different integrated circuits, are tested against each other. MAX4172 is fully analog while the INA226 is half digital. A shorter study of current sensing in general is made but the foundation of the study is the datasheets and characteristics of the components chosen. In this thesis, both the hardware and the software is designed and built which end with gathering data in two different electronic fuse scenarios. The thesis concludes that the two implementations as electronic fuse is at least a factor of 10 faster than the traditional breaking fuse. It also concludes that both implementations have their advantages and either may be the right solution depending on the intended end application. The fully analog solution is generally faster but is more susceptible to external noise and bad hardware design whereas the half digital is slower but more forgiving and thus shows of more precise measurements out of the box. / Relä och säkringar används i flera olika applikationer för att leverera och kontrollera strömmen till förbrukaren. Genom att förflytta denna uppgift till mjukvara kan detta förbättras genom att ge utökad funktionalitet samt realtidsövervakning av systemet. För att en mjukvara ska kunna kontrollera strömmen i en krets måste denna kunna mätas. Detta kan göras genom att mäta spänningsfallet över ett motstånd kopplat i serie med förbrukaren. Hur man väljer att implementera denna metod avgör vilka kravs som ställs på den kontrollerande mikrokontrollern. Denna studie kommer fokusera på mjukvaruimplementationen av två olika kretsar för strömmätning och har för avsikt att karakterisera dessa för att skapa en tydlig jämförelse av dess för- och nackdelar. De aspekter av hårdvaruimplementationen som påverkar detta resultat kommer också diskuteras. Två implementationer, bestående av två olika integrerade kretsar, ställs mot varandra. MAX4172 är en helt analog lösning medans INA226 är delvis digital. En kortare studie av strömmätning kommer utföras men grunden av denna studie består i huvudsak av datablad och karakteristik av de utvalda komponenterna. Både mjukvara och hårdvara är utvecklad och tillverkad för att kunna utföra test och inhämta den data som krävs för analysen. Studien visar att båda lösningar är åtminstone en faktor 10 snabbare än en traditionell säkring. Den visar också att en lösning inte är bättre än den andra i alla aspekter. Båda implementationerna kan vara den rätta lösningen beroende på de krav den tilltänkta produkten har. Den helt analoga lösningen är generellt snabbare men lider av en större känslighet mot störningar vilket ställer högre krav på hårdvarudesignen. Den delvis digitala lösningen är långsammare men betydligt mer förlåtande i dess implementation och har också större noggrannhet som resultat.

Made available in DSpace on 2016-01-26T12:51:45Z (GMT). No. of bitstreams: 1 fernandaribeirofunes_dissert.pdf: 809143 bytes, checksum: b26631e59407a8a29bb4194e0fc73690 (MD5) Previous issue date: 2011-12-15 / Introduction: The transjugular intrahepatic portosystemic shunt (TIPS) is a non-surgical treatment option with low morbidity and mortality, can be realized in patients with severe hepatic dysfunction, minimally invasive surgery that aims to decompress the portal system treating or reducing the complications portal hypertension. Objective: To analyze survival, and overall early mortality related to the etiology of the disease, characterization of the procedure in the emergency or elective and Child-Pugh and MELD classification and analyze the complications presented by patients. Methods: A retrospective study in the database of medical records of patients with cirrhosis who underwent TIPS for treatment of gastrointestinal bleeding due to portal hypertension who have not responded to medical treatment and endoscopic treatment from 1998 to 2010 in the Department of Liver Transplantation, Hospital de Base and Faculty Medicine of Sao Jose do Rio Preto. To check the rate of mortality, survival and complications were excluded patients who have failed the technical procedure and the others were followed until the closure of the study, performing a liver transplant or death occurred. The study was approved by the Ethics and Research Committee. Results: The sample consisted of 72 (84.7%) patients who were successful in the procedure of which 57 (79.2%) were male, mean age 47.4 years (between 16 and 85 years, SD=13), 21(29.2%) patients had a cause excessive consumption of alcohol, 21(29.2%) to contamination by hepatitis virus, 16(22.2%) excessive alcohol consumption associated with virus and 14(19.4%) patients had other causes. Procedure was performed on an emergency basis in 37(51.4%) and electively in 35(48.6%). The initial classification, 14 (20%) had Child-Pugh A, 33 (47.1%) Child-Pugh B and 23 (32.9%) Child-Pugh C. MELD was initially obtained in 68 patients, 37 (54.4%) with more than 15 points, while 31 (45.6%) up to 15 points. Early death occurred in 19 (26.4%). Overall mortality occurred in 41(60.3%). Conclusion: There was no difference regarding the etiology of early mortality, mortality and survival and overall mortality rate of patients undergoing emergency TIPS in characterization compared with elective TIPS. Difference was observed between the groups of patients undergoing emergency TIPS in characterizing compared to elective TIPS in early mortality rate, death is higher in emergency TIPS. Regarding the classification of Child-Pugh and MELD higher overall mortality was observed in patients early and Child-Pugh class C and MELD> 15, and shorter survival in this group of patients. Complications were similar to those described in the literature, but the percentage of occurrence of stent dysfunction (26,4%) was lower than in most studies the incidence of encephalopathy (58,3%) was higher. / Introdução: A derivação portossistêmica transjugular intra-hepática (TIPS) é uma opção de tratamento não cirúrgica com baixo índice de morbimortalidade e com possibilidade de realização em pacientes com disfunção hepática grave, por ser minimamente invasiva e que visa descomprimir o sistema porta tratando ou reduzindo as complicações da hipertensão portal. Objetivo: Analisar a sobrevida, mortalidade precoce e global relacionada à etiologia da doença, caracterização do procedimento em urgência ou eletiva e classificações de Child-Pugh e MELD e analisar as complicações apresentadas pelos pacientes. Casuística e Métodos: Estudo retrospectivo baseado no banco de dados dos prontuários dos pacientes cirróticos submetidos a TIPS para tratamento da hemorragia digestiva por hipertensão portal que não responderam ao tratamento clínico endoscópico e atendidos no período de 1998 a 2010 no Serviço de Transplante de Fígado do Hospital de Base e Faculdade de Medicina São José do Rio Preto. Para verificação da taxa de mortalidade, sobrevida e complicações os pacientes seguidos até o fechamento do estudo, realização de transplante de fígado ou ocorrência de óbito. O estudo foi aprovado pelo Comitê de Ética e Pesquisa. Resultados: A amostra foi composta de 72(84,7%) pacientes que obtiveram êxito no procedimento sendo 57(79,2%) do sexo masculino, idade média de 47,4 anos (entre 16 e 85 anos e DP=13), 21(29,2%) pacientes apresentaram como causa o consumo excessivo de álcool; 21(29,2%) a contaminação por vírus da hepatite, 16 (22,2%) o consumo excessivo de álcool associado a vírus e 14 (19,4%) pacientes apresentaram outras causas. Procedimento foi realizado em caráter de urgência em 37(51,4%) e de forma eletiva em 35 (48,6%). Quanto à classificação inicial, 14(20%) tinham Child-Pugh A, 33(47,1%) Child-Pugh B e 23(32,9%) Child-Pugh C. MELD inicial foi obtido em 68 pacientes sendo 37 (54,4%) com mais de 15 pontos, enquanto 31(45,6%) tiveram até 15 pontos. Óbito precoce ocorreu em 19(26,4%). Mortalidade global ocorreu em 41 (60,3%). Conclusão: Não houve diferença da etiologia com relação à mortalidade precoce, mortalidade global e sobrevida e na taxa de mortalidade global dos pacientes submetidos a TIPS de urgência comparados a TIPS eletivo. Observou-se diferença entre os grupos de pacientes submetidos a TIPS de urgência comparados a TIPS eletivo na taxa de mortalidade precoce, sendo o óbito maior no TIPS de urgência. Com relação as classificações de Child-Pugh e MELD foi observado maior mortalidade global e precoce nos pacientes Child-Pugh classe C e MELD >15, e menor sobrevida nesse grupo de pacientes. As complicações encontradas foram semelhantes às descritas na literatura, porém a porcentagem da ocorrência de disfunção do stent (26,4%) foi menor que na maioria dos estudos e a incidência de encefalopatia (58,3%) foi superior.

Since the early 1900's demand for fuel efficient vehicles has motivated the development of electric and hybrid electric vehicles. Unfortunately, some components used in these vehicles are expensive and complex. AC motors, complex electronic controllers and complex battery management systems are currently used in electric (EV) and hybrid vehicles. This research examines various motors and speed control methods in an attempt to help designers identify which motors would be best suited for an EV powertrain application. The feasibility of using DC motors coupled with an Infinitely Variable Transmission (IVT), to obtain an innovative new electric or hybrid electric powertrain is also presented. The results of this research include an extensive review of the many motor types including a comparison chart and motor hierarchy. An experiment was designed and built to test motorspeed control methods. Testing with two DC separately-excited motors and a differential as an IVT was also conducted. These tests revealed that field weakening appears to be a viable low-costspeed-control method. Testing of these motors, coupled with an IVT revealed that the output of a differential or planetary gear set can be controlled by varying the speed of the inputs. Combining this information in a product development mentality led to the concept of using one DC motor as a power or traction motor while another motor acts as a speed controller, with the method of speedcontrol on the speed control motor being field weakening. This concept allows most of the power to be delivered at an efficient rate with a simple form of speed control. This concept may also eliminate the need for expensive, complex electronic motor controllers. This approach could be used to improve the safety and reduce battery management requirements by lowering the operating voltage of the entire system.

In this research work detailed parallel and series equivalent circuits of a gapped iron-core shunt reactor with discretely distributed gaps are derived. The validity of the recommended equivalent circuits is verified by Finite Element Analysis and laboratory tests. Effects of fringing flux and discretely distributed gaps on inductance parameters and reactor losses are also investigated. Moving Strip Method for discretely distributed gapped shunt reactors is recommended. Two design procedures for shunt reactor with discretely distributed gaps are developed within the scope of this thesis. A simple and practical design approach is also developed which does not need any Finite Element Analysis software. This practical method is very useful for design engineers and researchers. The results of practical design approach are shown to be in good agreement with Finite Element Analysis and experimental work.

The endocrine heart synthesises and secretes two polypeptide hormones: the natriuretic peptides (NP) atrial natriuretic factor (ANF) and B-type natriuretic peptide (BNP). The biological actions of these hormones serve both acutely and chronically to reduce systemic blood pressure and hemodynamic load to the heart, thus contributing to the maintenance of cardiorenal homeostasis. Considerable effort has been focused on the elucidation of the mechanistic underlying ANF and BNP gene expression and secretion but much remains to be determined regarding specific molecular events involved in the cardiocyte secretory function. These hormones are produced by the atrial muscle cells (cardiocytes), which display a dual secretory/muscle phenotype. In contrast, ventricular cardiocytes display mainly a muscle phenotype. Comparatively little information is available regarding the genetic background for this important phenotypic difference with particular reference to the endocrine function of the heart. We postulated that comparison of gene expression profiles between atrial and ventricular muscles would help identify transcripts that underlie the phenotypic differences associated with the endocrine function of the heart as well as identify signaling pathways involved in its regulation. The cardiac atrial and ventricular transcriptomes were analyzed using oligonucleotide microarrays under normal or chronically induced aortocaval shunt volume-overload conditions. Transcriptional differences were validated by RT-PCR and transcripts of interest were knocked-down by RNAi. Comparison of gene expression profiles in the rat heart revealed a total of 1415 differentially expressed genes between normal atrial and ventricular tissues. Functional classification and pathway analysis identified numerous transcripts involved in mechanosensing, vesicle trafficking, hormone secretion, and G protein signaling. Volume-overloaded animals exhibited a progressive increase in cardiac mass over the four-week time course, an increase in expression of known hypertrophic genes, as well as the differential expression of 700 genes within the atria. Volume-overload specifically downregulated the accessory protein for heterotrimeric G protein signaling RASD1 in the atria. In vitro, knockdown of RASD1 in the atrial-derived HL-1 cells, significantly increased ANF secretion, demonstrating a previously unknown negative modulator role for RASD1. The data developed in this investigation provides insight into the expression profiles of genes particularly centered on the secretory function of the heart under normal and chronic hemodynamic overload conditions. Genome-wide expression profile analysis identified RASD1 as being differentially expressed between cardiac tissues as well as being modulated by chronic volume overload. RASD1 emerges as a tonic inhibitor of ANF secretion. The novel function identified herein for RASD1 in the atria is of considerable interest given the fact that secretory impairment of the cardiac natriuretic hormones can negatively impact cardiovascular homeostasis.

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The endocrine heart synthesises and secretes two polypeptide hormones: the natriuretic peptides (NP) atrial natriuretic factor (ANF) and B-type natriuretic peptide (BNP). The biological actions of these hormones serve both acutely and chronically to reduce systemic blood pressure and hemodynamic load to the heart, thus contributing to the maintenance of cardiorenal homeostasis. Considerable effort has been focused on the elucidation of the mechanistic underlying ANF and BNP gene expression and secretion but much remains to be determined regarding specific molecular events involved in the cardiocyte secretory function. These hormones are produced by the atrial muscle cells (cardiocytes), which display a dual secretory/muscle phenotype. In contrast, ventricular cardiocytes display mainly a muscle phenotype. Comparatively little information is available regarding the genetic background for this important phenotypic difference with particular reference to the endocrine function of the heart. We postulated that comparison of gene expression profiles between atrial and ventricular muscles would help identify transcripts that underlie the phenotypic differences associated with the endocrine function of the heart as well as identify signaling pathways involved in its regulation. The cardiac atrial and ventricular transcriptomes were analyzed using oligonucleotide microarrays under normal or chronically induced aortocaval shunt volume-overload conditions. Transcriptional differences were validated by RT-PCR and transcripts of interest were knocked-down by RNAi. Comparison of gene expression profiles in the rat heart revealed a total of 1415 differentially expressed genes between normal atrial and ventricular tissues. Functional classification and pathway analysis identified numerous transcripts involved in mechanosensing, vesicle trafficking, hormone secretion, and G protein signaling. Volume-overloaded animals exhibited a progressive increase in cardiac mass over the four-week time course, an increase in expression of known hypertrophic genes, as well as the differential expression of 700 genes within the atria. Volume-overload specifically downregulated the accessory protein for heterotrimeric G protein signaling RASD1 in the atria. In vitro, knockdown of RASD1 in the atrial-derived HL-1 cells, significantly increased ANF secretion, demonstrating a previously unknown negative modulator role for RASD1. The data developed in this investigation provides insight into the expression profiles of genes particularly centered on the secretory function of the heart under normal and chronic hemodynamic overload conditions. Genome-wide expression profile analysis identified RASD1 as being differentially expressed between cardiac tissues as well as being modulated by chronic volume overload. RASD1 emerges as a tonic inhibitor of ANF secretion. The novel function identified herein for RASD1 in the atria is of considerable interest given the fact that secretory impairment of the cardiac natriuretic hormones can negatively impact cardiovascular homeostasis.

Σποραδικές μελέτες περιγράφουν την προσωρινή εξωτερική οσφυϊκή παροχέτευση του ΕΝΥ, ως μία δοκιμασία υψηλής ακριβείας όσον αφορά στην πρόβλεψη του κλινικού αποτελέσματος μετά από κοιλιοπεριτοναϊκή παροχέτευση στους ασθενείς με ΥΦΠ. Παρόλα αυτά, σε μία πιο πρόσφατη μελέτη από τους Walchenbach και συνεργάτες, εκτιμήθηκε ότι η θετική προγνωστική αξία της ΕΟΠ ήταν υψηλή, ενώ η αρνητική χαμηλή. Δια ταύτα, πραγματοποιήσαμε μία προοπτική μελέτη με σκοπό να εκτιμήσουμε την προγνωστική αξία μιάς προσωρινής εξωτερικής οσφυικής παροχέτευσης (ΕΟΠ), η οποία ρυθμίζει την εκροή ΕΝΥ μέσω μιάς βαλβίδας μέσης πίεσης μονόδρομης ροής, σε ασθενείς με υδροκέφαλο φυσιολογικής πίεσης (ΥΦΠ). Είκοσι επτά 27 ασθενείς με ΥΦΠ εισήχθησαν στη Νευροχειρουργική Κλινική του ΠΓΝΠ και υπεβλήθησαν σε τοποθέτηση προσωρινής εξωτερικής οσφυικής παροχέτευσης (ΕΟΠ), η οποία ρυθμίζει την εκροή ΕΝΥ μέσω μιάς βαλβίδας μέσης πίεσης, για 5 ημέρες. 22 ασθενείς υπεβλήθησαν τελικά σε κοιλιοπεριτοναϊκή παροχέτευση με βαλβίδα μέσης πίεσης, βασιζόμενοι σε κλινικά και ακτινολογικά κριτήρια, ανεξαρτήτως του αποτελέσματος της ΕΟΠ. Κλινική εκτίμηση των διαταραχών της βάδισης, της ούρησης και της νόησης, όπως επίσης και ακτινολογική εκτίμηση, πραγματοποιήθηκε προ και μετά την δοκιμασία της ΕΟΠ καθώς και 3 μήνες μετά την ΚΠΠ. Είκοσι δύο 22 ασθενείς υπεβλήθησαν τελικά σε κοιλιοπεριτοναϊκή παροχέτευση και πληρούσαν τα κριτήρια για να συμπεριληφθούν τελικά στη μελέτη. Χρησιμοποιώντας ένα εγκεκριμένο σύστημα βαθμολόγησης, η συνολική βελτίωση μετά τη δοκιμασία ΕΟΠ συσχετιζόταν καλά με τη βελτίωση 3 μήνες μετά την μόνιμη ΚΠΠ. (Spearman’ s rho = 0,462, p=0,03). Όταν θεωρήσαμε κάθε βαθμό βελτίωσης ως θετική ανταπόκριση, η δοκιμασία ΕΟΠ-βαλβίδας μέσης πίεσης είχε υψηλή θετική προγνωστική αξία για κάθε μία ανεξάρτητη κλινική παράμετρο (διαταραχές της βάδισης 94%, 95% CI 71%-100%, ακράτεια στην ούρηση 100%, 95% CI 66%-100%, διαταραχές της νόησης 100%, 95% CI 66-100%), ενώ η αρνητική προγνωστική αξία ήταν χαμηλή (<50%) εκτός από τις διαταραχές της νόησης (85%, 95% CI 55%-98%). Η ανωτέρω μελέτη συμπεραίνει ότι η δοκιμασία της ΕΟΠ-βαλβίδας μέσης πίεσης, θα πρέπει να θεωρείται ένα αξιόπιστο κριτήριο για την προεγχειρητική επιλογή υδροκεφαλικών ασθενών φυσιολογικής πίεσης που βελτιώνονται κλινικά μετά την τοποθέτηση ΚΠΠ. Σε περίπτωση αρνητικής δοκιμασίας ΕΟΠ-βαλβίδας μέσης πίεσης, θα πρέπει να διενεργείται περαιτέρω διερεύνηση με επιπρόσθετες διαγνωστικές δοκιμασίες. / Although sporadic studies have described temporary external cerebrospinal fluid (CSF) lumbar drainage as a highly accurate test in predicting the outcome after ventricular shunting in normal pressure hydrocephalus (NPH) patients, a more recent study reports that the positive predictive value of external lumbar drainage (ELD) is high but the negative predictive value is deceptively low. Therefore, we conducted a prospective study in order to evaluate the predictive value of a continuous ELD, with CSF outflow controlled by medium pressure valve, in NPH patients. Twenty-seven patients with presumed NPH were admitted to our department and CSF drainage was carried out by a temporary (ELD), with CSF outflow controlled by medium pressure valve for five days. Twenty-two patients received a ventriculo¬peritoneal shunt with medium pressure valve based upon preoperative clinical and radiographic criteria of NPH, regardless of ELD outcome. Clinical evaluation of gait disturbances, urinary incontinence and mental status, and radiological evaluation with brain CT was performed prior to and after ELD test, as well as three months after shunting. Twenty-two patients were finally shunted and included in this study. In a three-month follow-up, using a previously validated score system, overall improvement after permanent shunting correlated well with improvement after ELD test (Spearman’s rho=0.462, p=0.03). When considering any degree of improvement as a positive response, ELD test yielded high positive predictive values for all individual parameters (gait disturbances 94%, 95% CI 71%-100%, urinary incontinence 100%, 95% CI 66%-100%, and mental status 100%, 95% CI 66%-100%) but negative predictive values were low (<50%) except for cognitive impairment (85%, 95% CI 55%-98%). This study suggests that a positive ELD-valve system test should be considered a reliable criterion for preoperative selection of shunt-responsive NPH patients. In case of a negative ELD-valve system test, further investigation of the presumed NPH patients with additional tests should be performed.

The management of parallel and series resonance conditions is important for ensuring that harmonic levels are managed on utility networks, and that shunt compensators are able to operate without constraints for various network conditions (states). For these and similar problems, harmonic impedance assessment of the ac network is required for the design of ac filter or shunt capacitor bank installations. This is particularly important for large installations connected to HV or EHV systems, because resonances at these voltage levels tend to be highly un-damped resulting in potentially damaging voltage and current amplification. The objective of this dissertation was to develop and demonstrate a design methodology which makes use of network impedance assessment methods to provide robust harmonic integration of large shunt compensators into a transmission and HVDC systems. The design methodology has two aspects. The first part considers network modeling, evaluation of different models and simulation of harmonic impedance. In the second part, methods of analyzing and assessing the simulated harmonic impedance are developed. A detailed step-by-step approach was taken in the development of the design methodology. The methodology was documented as a guideline and accompanied by the development of an Excel tool that can be used to assess the simulated harmonic impedance. The Excel tool permits a systematic assessment of the simulated network impedance where shunt compensators are integrated into transmission systems. The tool also ensures that the design of transmission and HVDC ac shunt compensation is optimally robust in terms of harmonic resonances. The theoretical and computational review has been tested and demonstrated on the existing Eskom Transmission system through several case studies. The results have shown the merits of the design methodology. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2013.