1,986 research outputs found
Data-assisted modeling of complex chemical and biological systems
Complex systems are abundant in chemistry and biology; they can be multiscale, possibly high-dimensional or stochastic, with nonlinear dynamics and interacting components. It is often nontrivial (and sometimes impossible), to determine and study the macroscopic quantities of interest and the equations they obey. One can only (judiciously or randomly) probe the system, gather observations and study trends. In this thesis, Machine Learning is used as a complement to traditional modeling and numerical methods to enable data-assisted (or data-driven) dynamical systems. As case studies, three complex systems are sourced from diverse fields: The first one is a high-dimensional computational neuroscience model of the Suprachiasmatic Nucleus of the human brain, where bifurcation analysis is performed by simply probing the system. Then, manifold learning is employed to discover a latent space of neuronal heterogeneity. Second, Machine Learning surrogate models are used to optimize dynamically operated catalytic reactors. An algorithmic pipeline is presented through which it is possible to program catalysts with active learning. Third, Machine Learning is employed to extract laws of Partial Differential Equations describing bacterial Chemotaxis. It is demonstrated how Machine Learning manages to capture the rules of bacterial motility in the macroscopic level, starting from diverse data sources (including real-world experimental data). More importantly, a framework is constructed though which already existing, partial knowledge of the system can be exploited. These applications showcase how Machine Learning can be used synergistically with traditional simulations in different scenarios: (i) Equations are available but the overall system is so high-dimensional that efficiency and explainability suffer, (ii) Equations are available but lead to highly nonlinear black-box responses, (iii) Only data are available (of varying source and quality) and equations need to be discovered. For such data-assisted dynamical systems, we can perform fundamental tasks, such as integration, steady-state location, continuation and optimization. This work aims to unify traditional scientific computing and Machine Learning, in an efficient, data-economical, generalizable way, where both the physical system and the algorithm matter
Anpassen verteilter eingebetteter Anwendungen im laufenden Betrieb
The availability of third-party apps is among the key success factors for software ecosystems: The users benefit from more features and innovation speed, while third-party solution vendors can leverage the platform to create successful offerings.
However, this requires a certain decoupling of engineering activities of the different parties not achieved for distributed control systems, yet.
While late and dynamic integration of third-party components would be required, resulting control systems must provide high reliability regarding real-time requirements, which leads to integration complexity.
Closing this gap would particularly contribute to the vision of software-defined manufacturing, where an ecosystem of modern IT-based control system components could lead to faster innovations due to their higher abstraction and availability of various frameworks.
Therefore, this thesis addresses the research question:
How we can use modern IT technologies and enable independent evolution and easy third-party integration of software components in distributed control systems, where deterministic end-to-end reactivity is required, and especially, how can we apply distributed changes to such systems consistently and reactively during operation?
This thesis describes the challenges and related approaches in detail and points out that existing approaches do not fully address our research question.
To tackle this gap, a formal specification of a runtime platform concept is presented in conjunction with a model-based engineering approach.
The engineering approach decouples the engineering steps of component definition, integration, and deployment.
The runtime platform supports this approach by isolating the components, while still offering predictable end-to-end real-time behavior.
Independent evolution of software components is supported through a concept for synchronous reconfiguration during full operation, i.e., dynamic orchestration of components.
Time-critical state transfer is supported, too, and can lead to bounded quality degradation, at most.
The reconfiguration planning is supported by analysis concepts, including simulation of a formally specified system and reconfiguration, and analyzing potential quality degradation with the evolving dataflow graph (EDFG) method.
A platform-specific realization of the concepts, the real-time container architecture, is described as a reference implementation.
The model and the prototype are evaluated regarding their feasibility and applicability of the concepts by two case studies.
The first case study is a minimalistic distributed control system used in different setups with different component variants and reconfiguration plans to compare the model and the prototype and to gather runtime statistics.
The second case study is a smart factory showcase system with more challenging application components and interface technologies.
The conclusion is that the concepts are feasible and applicable, even though the concepts and the prototype still need to be worked on in future -- for example, to reach shorter cycle times.Eine große Auswahl von Drittanbieter-Lösungen ist einer der Schlüsselfaktoren für Software Ecosystems:
Nutzer profitieren vom breiten Angebot und schnellen Innovationen, während Drittanbieter über die Plattform erfolgreiche Lösungen anbieten können.
Das jedoch setzt eine gewisse Entkopplung von Entwicklungsschritten der Beteiligten voraus, welche für verteilte Steuerungssysteme noch nicht erreicht wurde.
Während Drittanbieter-Komponenten möglichst spät -- sogar Laufzeit -- integriert werden müssten, müssen Steuerungssysteme jedoch eine hohe Zuverlässigkeit gegenüber Echtzeitanforderungen aufweisen, was zu Integrationskomplexität führt.
Dies zu lösen würde insbesondere zur Vision von Software-definierter Produktion beitragen, da ein Ecosystem für moderne IT-basierte Steuerungskomponenten wegen deren höherem Abstraktionsgrad und der Vielzahl verfügbarer Frameworks zu schnellerer Innovation führen würde.
Daher behandelt diese Dissertation folgende Forschungsfrage:
Wie können wir moderne IT-Technologien verwenden und unabhängige Entwicklung und einfache Integration von Software-Komponenten in verteilten Steuerungssystemen ermöglichen, wo Ende-zu-Ende-Echtzeitverhalten gefordert ist, und wie können wir insbesondere verteilte Änderungen an solchen Systemen konsistent und im Vollbetrieb vornehmen?
Diese Dissertation beschreibt Herausforderungen und verwandte Ansätze im Detail und zeigt auf, dass existierende Ansätze diese Frage nicht vollständig behandeln.
Um diese Lücke zu schließen, beschreiben wir eine formale Spezifikation einer Laufzeit-Plattform und einen zugehörigen Modell-basierten Engineering-Ansatz.
Dieser Ansatz entkoppelt die Design-Schritte der Entwicklung, Integration und des Deployments von Komponenten.
Die Laufzeit-Plattform unterstützt den Ansatz durch Isolation von Komponenten und zugleich Zeit-deterministischem Ende-zu-Ende-Verhalten.
Unabhängige Entwicklung und Integration werden durch Konzepte für synchrone Rekonfiguration im Vollbetrieb unterstützt, also durch dynamische Orchestrierung.
Dies beinhaltet auch Zeit-kritische Zustands-Transfers mit höchstens begrenzter Qualitätsminderung, wenn überhaupt.
Rekonfigurationsplanung wird durch Analysekonzepte unterstützt, einschließlich der Simulation formal spezifizierter Systeme und Rekonfigurationen und der Analyse der etwaigen Qualitätsminderung mit dem Evolving Dataflow Graph (EDFG).
Die Real-Time Container Architecture wird als Referenzimplementierung und Evaluationsplattform beschrieben.
Zwei Fallstudien untersuchen Machbarkeit und Nützlichkeit der Konzepte.
Die erste verwendet verschiedene Varianten und Rekonfigurationen eines minimalistischen verteilten Steuerungssystems, um Modell und Prototyp zu vergleichen sowie Laufzeitstatistiken zu erheben.
Die zweite Fallstudie ist ein Smart-Factory-Demonstrator, welcher herausforderndere Applikationskomponenten und Schnittstellentechnologien verwendet.
Die Konzepte sind den Studien nach machbar und nützlich, auch wenn sowohl die Konzepte als auch der Prototyp noch weitere Arbeit benötigen -- zum Beispiel, um kürzere Zyklen zu erreichen
RegDspLib: Development of a C++ DSP common control library for Cancun, HL-LHC18kA and RF3kA power converters at CERN
English: The European Organization for Nuclear Research (CERN, Conseil Européen pour la Recherche Nucléaire in French), located in Geneva, Switzerland, hosts the largest particle accelerator complex in the world, which aims to push the boundaries of human knowledge on particle physics. The main acceleration technologies at CERN rely on radio-frequency (RF) cavities and superconducting electromagnets. Usually, these systems need to be fed from the grid using high-efficiency and high-precision switch-mode power electronic converters. This Master’s Thesis has been conducted to complete the Master's studies in Advanced Electronic Systems at the Univesity of the Basque Country (EHU/UPV, Universidad del País Vasco in Spanish). It has been carried out during a short-term internship at CERN’s System Department-Electric Power Converters-Low Power Converters (SY-EPC-LPC) group. This group is in charge of designing and developing low-voltage and high-current modular and compact converters, ranging from some Watts up to several kW. The SY-EPC-LPC manages a variety of power converters within the particle accelerator complex. Most digitally controlled ones share the same control hardware architecture consisting of a proprietary crate, named RegFGC3, which includes several cards. Among these, a Digital Signal Processor (DSP) regulation board and a State Control card containing a Field Programmable Gate Array (FPGA) can be highlighted. This RegFGC3 crate is part of a larger control platform, named FGC3. Although the hardware is highly standardized, nowadays each power supply uses converter-specific software for control purposes, coded in C programming language. This makes all code redundant, difficult to test, debug and maintain. Considering the aforementioned drawbacks, this Master's Thesis aims to design, develop and test a common control library which supports the regulation software of several power converters, providing standardization, flexibility and time-saving. To do so, as a first step, three of the accelerators' power converters have been selected: CANCUN (Cern Acdc Narrow CoNverter), HL-LHC18kA (High Luminosity Large Hadron Collider 18 kA) and RF3kA (Radio-Frequency 3 kA). This selection is based on that these converters incorporate a variety of operating and control requirements, i.e., 1-quadrant, 2-quadrant and 4-quadrant architectures, module parallelization, various current and voltage regulation loops, and different Pulse Width Modulation (PWM) modes including, in some cases, interleaving. After analysing the three power converters and their control (hardware and software), synergies have been identified, which are still missing at the software level. To provide a unified control software library that takes into account such synergies, the refactorization of the code from C to C++ has been justified as the best option. This approach allows using a fast and efficient Object Oriented Programming (OOP) language, whose nature facilitates the expression of the existing relationship between converter-specific codes. The main idea behind the proposed and implemented library, named RegDspLib, is based on constructing a parent class that supports all the converters. It contains all the shared similarities between converters, which eases the development of additional and specialized code. This base class allows the inheritance of the configured common features with the possibility of using, modifying, or adding what is needed by each converter in their corresponding derived classes. C++ language mechanisms have been used to correlate different classes, modules, methods and attributes of the code, easing the development of the common library. This, would have been more laborious in the C language. A variety of modules have been configured to provide logic to the classes, in which a generic module for the configuration of a generic Finite State Machine (FSM) template, and a regulation module with configurable PWM inputs are included, among others. Besides this and to make this library design possible, multiple modifications have been proposed. These consist of the design of a standard FSM for all the converters, the modification of the FPGA which is controlling and monitoring the power converter’s status, the interrupt handling on the DSP, and the building of new generic functions that work with multiple converters. The latter includes the slew rate method that controls the increasing/decreasing rate of the control algorithm’s reference value and an automatic parameter calculation script for interleaving control mechanisms. Verification of the RegDspLib library has been carried out using the CANCUN power converter. First, the same regulation response has been proved when comparing the original and the proposed library-based codes. Regarding digital resources, experimental results show an increase of only 2.48 % in the execution time of the program for the worst-case scenario, and up to a 24.63 % time-saving for the best-case. This demonstrates that it has been possible to standardize, refactor the code to C++ and add more features to the software without generating overruns. All things considered, the C++ programming language is proven valid for real-time control in the DSP target of CERN’s power converters. Besides, building a control library that groups all the common features has also provided a better-structured program, making it easier to understand and to work with. This work could lead to further improvements in the library and it can be completed in order to generalize it to control other power converters besides the presented ones. Moreover, although the RegDspLib library was originally aimed at the FGC3 control platform, this work provides the first steps for developing libraries taking into mind the future control hardware upgrade FGC4 (already in development). In such novel architecture, dedicated cards in the FGC3 (control, monitoring, regulation, measurement, etc.) will be replaced by one single main Central Processing Unit (CPU).Euskeraz: Ikerketa Nuklearrerako Europako Kontseilua (CERN, Conseil Européen pour la Recherche Nucléaire, frantsesez) Genevan (Suitza) dago kokatua. Partikula-fisikaren ezagutzaren mugak handitzea du helburu erakundeak. Horretarako, gaur egun munduko partikula azeleratzaile handiena dago bertan. CERNen erabiltzen diren azelerazio-teknologia nagusiak irrati-maiztasun (RF) kabitateak eta elektroiman supereroaleetan oinarritzen dira. Normalean, sistema horiek saretik hornitzen direnez, potentzia-bihurgailuak erabili behar dira. Oro har, bihurgailu horiek kommutatuak dira, eta eraginkortasun eta zehaztasun handiarekin operatzen dute. Euskal Herriko Unibertsitatearen (EHU/UPV) Sistema Elektroniko Aurreratuen masterra osatzeko helburuarekin burutu da master amaierako lan hau. CERNek unibertsitate-ikasleentzat duen praktika-programa baten testuinguruan garatu da lana, hain zuzen ere, Sistema Departamendua-Potentzia Bihurgailu Elektrikoak- Potentzia Baxuko Bihurgailu (SY-EPC-LPC) taldean. Bere izenak adierazten duen bezala, tentsio baxuko eta korronte altuko bihurgailu modularrak eta konpaktuak diseinatzeko eta garatzeko ardura du talde horrek. Bereziki, partikula-azeleradore konplexuaren parte diren bihurgailu ugari kudeatzen ditu SY-EPC-LPCek, Watt batzuetatik hasi eta zenbait kW-etaraino iristen direnak. Horien artean, hardware arkitektura berdina partekatzen dute digitalki kontrolaturiko bihurgailu gehienek, CERNen diseinatutako RegFGC3 modulua erabiltzen dutenak. Zenbait txartel elektronikok osatzen dute RegFGC3 modulua. Horien artean Seinale Digitalen Prozesadorea (DSP, Digital Signal Processor, ingelesez) duen erregulazio-txartela eta Ate-Matrize Programagarria (FPGA, Field Programmable Gate Array, ingelesez) daukan egoera-kontrol txartela nabarmentzen dira. Aldi berean, FGC3 izeneko bihurgailuen kontrolerako plataforma handiago baten parte da RegFGC3 moduloa. Hardwarea nahikoa estandarizatua dagoen arren, gaur egun bihurgailuetako bakoitzak bere kontrol-software espezifikoa erabiltzen du, C programazio-lengoaian idatzita. Horrek, erredundantzia eragiteaz gain, kodea frogatzeko, arazteko eta mantentzeko zailtasunak sortzen ditu. Aipatutako arazoak aztertu ondoren, master amaierako lanak bihurgailuen erregulazio-softwarea bateratzen duen kontrol-liburutegi amankomuna diseinatu, garatu eta frogatzea du helburu. Horrekin, estandarizazioa, malgutasuna eta denbora aurreztea bilatu da. Lehenengo urrats bezala, partikula-azeleradoreen parte diren hiru bihurgailu aukeratu dira: CANCUN (Cern Acdc Narrow CoNverter), HL-LHC18kA (High Luminosity Large Hadron Collider 18 kA) eta RF3kA (Radio-Frequency 3 kA). Bihurgailu ezberdinek duten aniztasuna hartzen da kontuan aukeraketa horretan. Hori da, 1, 2 eta 4-koadranteko arkitekturak aurki daitezke; horrez gain, korrontearen eta tentsioaren kontrolerako begizta eta Pultsu Zabalera bidezko Modulazio (PWM, Pulse Width Modulation ingelesez) algoritmo ezberdinak, zenbait kasutan, tartekatutako (interleaved, ingelesez) modulazio-eskemak barne. Behin hiru bihurgailuak eta horien kontrola aztertuta (hardware eta software mailan), sinergiak antzeman dira horien artean. Sinergiak kontuan hartzen dituen kontrol software-liburutegi amankomuna sortzeko, kodea C-tik C++-ra berreraikitzea justifikatu da aukerarik onena bezala. Horrek, Objektuetara Bideratutako Programazio-hizkuntza (OOP, Object Oriented Programming, ingelesez) azkar eta eraginkorra erabiltzea ahalbideratu du, programaren izaerak bihurgailuaren kode espezifikoen arteko erlazioen adierazpena sinplifikatuz. Proposatu eta inplementatutako RegDspLib izeneko liburutegian dagoen ideia nagusia da bihurgailu guztiei euskarria ematen dien funtsezko klase bat eraikitzean oinarritzen dela. Bihurgailuek partekatutako antzekotasun guztiak biltzen ditu klase horrek, eta kode gehigarria eta espezializatua garatzeko erraztasunak ematen ditu, konfiguratutako ezaugarri komunak heredatzea baimenduz. Liburutegi horrekin, bihurgailu bakoitzak behar duena erabiltzeko, aldatzeko edo gehitzeko aukera ematen da, klase deribatuen bidez. RegDspLib liburutegian C++ hizkuntzaren mekanismoak erabili dira klase, modulu, metodo eta atributu ezberdinak elkarrekin lotzeko. Garrantzitsua da aipatzea, nahiz eta helburu horiek lortzeko C programazio-hizkuntza erabiltzea posible izan, lana zailagoa izango litzatekeela. Elementu batzuk konfiguratzen dira klaseetan horiei logika emateko. Besteak beste, Egoera Finituko Makinak (FSM, Finite State Machine, ingelesez) konfiguratzeko modulu generiko bat eta PWM irteera konfiguragarriak dituen erregulazio-moduluak diseinatu dira. Horrez gain, aldaketa ugari burutu behar izan dira liburutegiaren diseinu egokia ahalbidetzeko. Horien artean hauexek nabarmen daitezke: FSM estandarra diseinatzea, potentzia-bihurgailuaren egoera kontrolatzen eta gainbegiratzen duen FPGAren programa-aldaketa, DSParen etenak kudeatzen eta, azkenik, bihurgailu anitzetan funtzionatzen duten funtzio generiko berriak sortzea. Funtzio berri horien artean kontrol algoritmoaren erreferentzia balioaren hazkunde/murrizketa abiadura kontrolatzen duen metodoa eta tartekatutako modulazio-mekanismoaren parametroak automatikoki kalkulatzen dituen funtzioa nabarmentzen dira, besteak beste. CANCUN potentzia-bihurgailuan gauzatu da RegDspLib liburutegiaren egiaztapena. Lehenik eta behin, korrontearen erreferentziari sistemak egindako jarraipenak frogatu du erregulazio-emaitza berdinak lortzen direla, bai proposatutako liburutegiarekin eta baita jatorrizko softwarearekin ere. Baliabide digitalei dagokienez, % 2,48ko exekuzio-denboraren gehikuntza erakutsi dute emaitza esperimentalek, kasurik okerrean, eta % 24,63ko murrizketa, kasurik onenean. Horrek guztiak frogatzen du posible dela, denbora-mugak gainditu gabe, kodea estandarizatzea, C++ lengoaiara berreraikiz, softwareari ezaugarriak gehituz. Laburbilduz, C++ programazio-lengoaia CERNen potentzia-bihurgailuak denbora errealean kontrolatzeko baliozkoa dela frogatu da. Gainera, ezaugarri amankomun guztiak biltzen dituen kontrol-liburutegi bat eraikitzeak, hobeto egituratutako programa bat sortu du, eta kodea hobeto ulertu eta honekin lan egitea erraztu du. Lan honetatik abiatuta, inplementatutako liburutegiaren hobekuntza gehigarriak garatu daitezke etorkizunean. Gainera, liburutegia beste bihurgailu batzuetan (aurkeztutakoez gain) erabiltzeko osatu daiteke. Azkenik, garrantzitsua da aipatzea, RegDspLib liburutegia FGC3 kontrol-plataformara bideratzeko asmoarekin sortu bada ere, proiektu honek FGC4 bertsiorako baliagarriak izango diren liburutegien garatze-ibilbidea hasi duela. Nabarmentzekoa da puntu hori, FGC3ko txartel espezifikoak (kontrola, ikuskapena, erregulazioa, neurketa, etab.) Prozesatzeko Unitate Zentral (CPU, Central Processing Unit, ingelesez) bakar batek ordezkatuko baititu FGC4n.Español: La Organización Europea para la Investigación Nuclear (CERN, Conseil Européen pour la Recherche Nucléaire, en francés) esta situada en Ginebra, Suiza. Tiene como objetivo superar los límites del conocimiento humano en física de partículas. Para poder cumplirlo, el CERN alberga actualmente el complejo de aceleradores de partículas más grande del mundo. Dentro de este, las principales tecnologías de aceleración se basan en cavidades de radiofrecuencia (RF) y electroimanes superconductores. En general, estos sistemas necesitan alimentarse de la red utilizando convertidores electrónicos de potencia, conmutados de alta eficiencia y precisión.
Este Trabajo de Fin de Máster se ha llevado a cabo con el objetivo de completar los estudios del Máster en Sistemas Electrónicos Avanzados en la Universidad del País Vasco (EHU/UPV). Se ha realizado durante una estancia a través de un programa de prácticas del CERN, en el Departamento de Sistemas-Convertidores de Potencia Eléctricos-Baja Potencia (SY-EPC-LPC). Como su nombre indica, este grupo se encarga del diseño y desarrollo de convertidores modulares y compactos de baja tensión y alta corriente, que operan desde unos pocos Watt hasta varios kW. Este grupo gestiona una gran variedad de convertidores de potencia dentro del complejo de aceleradores de partículas. Entre estos, la mayoría de los controlados digitalmente comparten la misma arquitectura de hardware de control, que consiste en un módulo propietario, llamado RegFGC3. Este módulo incluye varias tarjetas, entre las que destacan una placa de regulación con un Procesador de Señal Digital (DSP, Digital Signal Processor, en inglés) y una tarjeta de control de estado que contiene una Matriz de Puertas Programable (FPGA, Field Programmable Gate Array, en inglés). A su vez, este módulo RegFGC3 forma parte de una plataforma de control mayor, llamada FGC3.
Aunque el hardware esté estandarizado, actualmente cada uno de los convertidores utiliza un software de control específico, escrito en el lenguaje de programación C. Esto hace que el código resulte redundante y difícil de testear, depurar y mantener. Teniendo en cuenta las desventajas mencionadas, el objetivo del Trabajo de Fin de Máster ha sido diseñar, desarrollar y probar una librería de control común que englobe el software de regulación de varios convertidores de potencia, proporcionando estandarización, flexibilidad y ahorro de tiempo en el desarrollo de este. Para ello, como primer paso, se han seleccionado tres de los convertidores de potencia que forman parte de los aceleradores, CANCUN (Cern Acdc Narrow CoNverter), HL-LHC18kA (High Luminosity Large Hadron Collider 18 kA) y RF3kA (Radio-Frequency 3 kA). Esta selección se basa en que los convertidores incorporan arquitecturas de 1-cuadrante, 2-cuadrantes y 4-cuadrantes, distintos lazos de regulación de corriente y tensión, y varios modos de Modulación por Anchura de Pulso (PWM, Pulse Width Modulation, en inglés), incluyendo, en algunos casos, técnicas de entrelazamiento.
Después de analizar los tres convertidores de potencia y su control (a nivel de hardware y software), se ha identificado una sinergia entre ellos, la cual falta a nivel de software. Para proporcionar una librería de software de control unificada que tenga en cuenta estas sinergias, se justifica la reescritura del código de C a C++ como la mejor opción. Esto permite utilizar un lenguaje de Programación Orientada a Objetos (OOP, Object Oriented Programming, en inglés) rápido y eficiente, cuya naturaleza facilita la expresión de la relación existente entre los códigos específicos del convertidor. La idea principal de la librería propuesta e implementada, llamada RegDspLib, se basa en la construcción de una clase padre que de soporte a todos los convertidores. Esta clase contiene todas las similitudes compartidas entre los convertidores, lo que facilita el desarrollo de código adicional y especializado al permitir la herencia de las características comunes configuradas. La librería posibilita utilizar, modificar o agregar lo que sea necesario para cada convertidor, a través de clases derivadas. Se han utilizado mecanismos del lenguaje C++ para correlacionar distintas clases, módulos, métodos y atributos del código, facilitando el desarrollo de una librería común. Esto hubiera sido más laborioso mediante el lenguaje de programación C.
Con el objetivo de dotar de lógica a estas clases, se configuran una variedad de módulos. Se incluyen, entre otros, un módulo genérico para la configuración de Máquinas de Estados Finitas (FSM, Finite State Machine, en inglés) y un módulo de regulación con entradas PWM configurables. Además de esto, para posibilitar el diseño de la librería se han tenido que realizar múltiples modificaciones. Estas incluyen el diseño de una FSM estándar, la modificación de la FPGA que controla y supervisa el estado del convertidor de potencia, el manejo de interrupciones en la DSP y la creación de nuevas funciones genéricas que sirvan para múltiples convertidores. Entre estas últimas destacan el método de tasa de variación que controla el ratio de aumento/disminución del valor de referencia del algoritmo de control y el cálculo automático de los parámetros del mecanismo de control de entrelazamiento.
La verificación de la librería RegDspLib se ha llevado a cabo en el convertidor de potencia CANCUN. Por un lado, se ha obtenido la misma respuesta al escalón de entrada de corriente, tanto con la librería propuesta como con el software original. Por otro, los resultados experimentales muestran un aumento del 2,48 %, en el tiempo de ejecución, para el peor de los casos, y una reducción de hasta el 24,63 %, en el mejor. Esto demuestra que ha sido posible estandarizar, reescribir el código a C++ y agregar características adicionales al software sin exceder los límites de tiempo. En resumen, el lenguaje de programación C++ se ha demostrado como válido para el control en tiempo real de los convertidores de potencia del CERN a través de la regulación en la DSP. Además, la construcción de una librería de control que engloba todas las características comunes ha proporcionado un programa mejor estructurado, lo que facilita su comprensión y trabajar con el mismo.
En un futuro, este proyecto podría llevar a mejoras adicionales de la librería y ser completado para su utilización con otros convertidores de potencia, además de con los tres presentados. Por último, aunque la librería RegDspLib estaba originalmente destinada a la plataforma de control FGC3, este proyecto marca los primeros pasos hacia el desarrollo de librerías para la futura actualización del FGC4, donde las tarjetas dedicadas del FGC3 (control, supervisión, regulación, medición, etc.) serán reemplazadas por una sola Unidad Central de Procesamiento (CPU, Central Processing Unit, en inglés) principal.Français: Le Conseil Européen Pour la Recherche Nucléaire (CERN), situé à Genève, Suisse, abrite le plus grand complexe d'accélérateurs de particules au monde, qui vise à repousser les limites de la connaissance humaine en matière de physique des particules. Les principales technologies d'accélération du CERN reposent sur des cavités radiofréquences (RF) et les électro-aimants supraconducteurs. Ces systèmes doivent être alimentés par le réseau à l'aide de convertisseurs électroniques de puissance à découpage, à haut rendement et haute précision. Ce mémoire de maîtrise a été réalisé afin de compléter les études de maîtrise en systèmes électroniques avancés à L'Université du Pays Basque (EHU/UPV, Universidad del Pais Vasco en espagnol). Le projet a été réalisé à la suite d’un stage de courte durée dans le groupe System Department-Electric Power Converters-Low Power Converters (SY-EPC-LPC). Au sein du CERN, comme son nom l'indique, SY-EPC-LPC est chargé de concevoir et de développer des convertisseurs modulaires et compacts à basse tension et à courant élevé, d'une puissance allant de quelques Watts à plusieurs kW. Ce groupe gère une variété de convertisseurs de puissance au sein du complexe d'accélérateurs de particules. Ces convertisseurs partagent la même architecture matérielle de contrôle, qui consiste en un boîtier propriétaire, appelé RegFGC3, comprenant plusieurs cartes, dont une carte de régulation à processeur de signal numérique (DSP, Digital Signal Processor en anglais) et une carte de contrôle d'état contenant une réseau de portes programmables sur site (FPGA, Field Programmable Gate Array en anglais). Ce boîtier RegFGC3 fait partie d'une plateforme de contrôle plus large appelée FGC3, qui contrôle le convertisseur de puissance. Bien que le matériel soit fortement standardisé, aujourd’hui, chacun convertisseur utilise un logiciel spécifique au convertisseur à des fins de contrôle, écrite à l'origine dans le langage de programmation C. Cela rend tout le code redondant et difficile à tester, à déboguer et à entretenir. En tenant compte des inconvénients
Engineering Blockchain Based Software Systems: Foundations, Survey, and Future Directions
Many scientific and practical areas have shown increasing interest in reaping
the benefits of blockchain technology to empower software systems. However, the
unique characteristics and requirements associated with Blockchain Based
Software (BBS) systems raise new challenges across the development lifecycle
that entail an extensive improvement of conventional software engineering. This
article presents a systematic literature review of the state-of-the-art in BBS
engineering research from a software engineering perspective. We characterize
BBS engineering from the theoretical foundations, processes, models, and roles
and discuss a rich repertoire of key development activities, principles,
challenges, and techniques. The focus and depth of this survey not only gives
software engineering practitioners and researchers a consolidated body of
knowledge about current BBS development but also underpins a starting point for
further research in this field
OpenLB User Guide: Associated with Release 1.6 of the Code
OpenLB is an object-oriented implementation of LBM. It is the first
implementation of a generic platform for LBM programming, which is shared with
the open source community (GPLv2). Since the first release in 2007, the code
has been continuously improved and extended which is documented by thirteen
releases as well as the corresponding release notes which are available on the
OpenLB website (https://www.openlb.net). The OpenLB code is written in C++ and
is used by application programmers as well as developers, with the ability to
implement custom models OpenLB supports complex data structures that allow
simulations in complex geometries and parallel execution using MPI, OpenMP and
CUDA on high-performance computers. The source code uses the concepts of
interfaces and templates, so that efficient, direct and intuitive
implementations of the LBM become possible. The efficiency and scalability has
been checked and proved by code reviews. This user manual and a source code
documentation by DoxyGen are available on the OpenLB project website
Pre-Trained Driving in Localized Surroundings with Semantic Radar Information and Machine Learning
Entlang der Signalverarbeitungskette von Radar Detektionen bis zur Fahrzeugansteuerung, diskutiert diese Arbeit eine semantischen Radar Segmentierung, einen darauf aufbauenden Radar SLAM, sowie eine im Verbund realisierte autonome Parkfunktion. Die Radarsegmentierung der (statischen) Umgebung wird durch ein Radar-spezifisches neuronales Netzwerk RadarNet erreicht. Diese Segmentierung ermöglicht die Entwicklung des semantischen Radar Graph-SLAM SERALOC. Auf der Grundlage der semantischen Radar SLAM Karte wird eine beispielhafte autonome Parkfunktionalität in einem realen Versuchsträger umgesetzt.
Entlang eines aufgezeichneten Referenzfades parkt die Funktion ausschließlich auf Basis der Radar Wahrnehmung mit bisher unerreichter Positioniergenauigkeit.
Im ersten Schritt wird ein Datensatz von 8.2 · 10^6 punktweise semantisch gelabelten Radarpunktwolken über eine Strecke von 2507.35m generiert. Es sind keine vergleichbaren Datensätze dieser Annotationsebene und Radarspezifikation öffentlich verfügbar. Das überwachte
Training der semantischen Segmentierung RadarNet erreicht 28.97% mIoU auf sechs Klassen.
Außerdem wird ein automatisiertes Radar-Labeling-Framework SeRaLF vorgestellt, welches das Radarlabeling multimodal mittels Referenzkameras und LiDAR unterstützt.
Für die kohärente Kartierung wird ein Radarsignal-Vorfilter auf der Grundlage einer Aktivierungskarte entworfen, welcher Rauschen und andere dynamische Mehrwegreflektionen unterdrückt. Ein speziell für Radar angepasstes Graph-SLAM-Frontend mit Radar-Odometrie
Kanten zwischen Teil-Karten und semantisch separater NDT Registrierung setzt die vorgefilterten semantischen Radarscans zu einer konsistenten metrischen Karte zusammen. Die Kartierungsgenauigkeit und die Datenassoziation werden somit erhöht und der erste semantische Radar Graph-SLAM für beliebige statische Umgebungen realisiert.
Integriert in ein reales Testfahrzeug, wird das Zusammenspiel der live RadarNet Segmentierung und des semantischen Radar Graph-SLAM anhand einer rein Radar-basierten autonomen Parkfunktionalität evaluiert. Im Durchschnitt über 42 autonome Parkmanöver
(∅3.73 km/h) bei durchschnittlicher Manöverlänge von ∅172.75m wird ein Median absoluter Posenfehler von 0.235m und End-Posenfehler von 0.2443m erreicht, der vergleichbare
Radar-Lokalisierungsergebnisse um ≈ 50% übertrifft. Die Kartengenauigkeit von veränderlichen, neukartierten Orten über eine Kartierungsdistanz von ∅165m ergibt eine ≈ 56%-ige Kartenkonsistenz bei einer Abweichung von ∅0.163m. Für das autonome Parken wurde ein gegebener Trajektorienplaner und Regleransatz verwendet
HLG: A framework for computing graphs in Residue Number System and its application in Fully Homomorphic Encryption
Implementation of Fully Homomorphic Encryption (FHE) is challenging. Especially when considering hardware acceleration, the major performance bottleneck is data transfer. Here we propose an algebraic framework called Heterogenous Lattice Graph (HLG) to build and process computing graphs in Residue Number System (RNS), which is the basis of high performance implementation of mainstream FHE algorithms.
There are three main design goals for HLG framework:
• Design a dedicated IR (HLG IR) for RNS system, here splitting and combination of data placeholders has practical implications in an algebraic sense. Existing IRs cannot efficiently support these operations.
• Lower the technical barriers for both crypto researchers and hardware engineers by decoupling front-end cryptographic algorithms from the back-end hardware platforms. The algorithms and solutions built on HLG framework can be written once and run everywhere. Researchers and engineers don’t need to understand each other.
• Try to reduce the cost of data transfer between CPU and GPU/FPGA/dedicated hardware, by providing the intermediate representation (IR) of the computing graph for hardware compute engine, which allows task scheduling without help from CPU.
We have implemented CKKS algorithm based on HLG framework, together with a compute engine for multiple CPU cores. Experiment shows that we can outperform SEAL v3 Library in several use cases in multi-threading scenarios
Multitenant Containers as a Service (CaaS) for Clouds and Edge Clouds
Cloud computing, offering on-demand access to computing resources through the
Internet and the pay-as-you-go model, has marked the last decade with its three
main service models; Infrastructure as a Service (IaaS), Platform as a Service
(PaaS), and Software as a Service (SaaS). The lightweight nature of containers
compared to virtual machines has led to the rapid uptake of another in recent
years, called Containers as a Service (CaaS), which falls between IaaS and PaaS
regarding control abstraction. However, when CaaS is offered to multiple
independent users, or tenants, a multi-instance approach is used, in which each
tenant receives its own separate cluster, which reimposes significant overhead
due to employing virtual machines for isolation. If CaaS is to be offered not
just at the cloud, but also at the edge cloud, where resources are limited,
another solution is required. We introduce a native CaaS multitenancy
framework, meaning that tenants share a cluster, which is more efficient than
the one tenant per cluster model. Whenever there are shared resources,
isolation of multitenant workloads is an issue. Such workloads can be isolated
by Kata Containers today. Besides, our framework esteems the application
requirements that compel complete isolation and a fully customized environment.
Node-level slicing empowers tenants to programmatically reserve isolated
subclusters where they can choose the container runtime that suits application
needs. The framework is publicly available as liberally-licensed, free,
open-source software that extends Kubernetes, the de facto standard container
orchestration system. It is in production use within the EdgeNet testbed for
researchers
2023-2024 Boise State University Undergraduate Catalog
This catalog is primarily for and directed at students. However, it serves many audiences, such as high school counselors, academic advisors, and the public. In this catalog you will find an overview of Boise State University and information on admission, registration, grades, tuition and fees, financial aid, housing, student services, and other important policies and procedures. However, most of this catalog is devoted to describing the various programs and courses offered at Boise State
- …