Es wird gezeigt, wie Erkenntnisse eines Prototyps in den weiteren Entwicklungsprozess eines Produktes Anwendung finden können. Dazu wird ein entwickelter Rechenkern genutzt, welcher einen hybriden Ansatz aus Numerik und einem neuronalen Netz beinhaltet. Zusätzlich soll dieser Rechenkern den gesamten Produktentwicklungsprozess unterstützen und Produktvorschläge generieren, welche unter Restriktionen und einem globalen Optimierer ermittelt werden. Durch den Ansatz der Optimierung wurde Wert auf einen Kompromiss zwischen Schnelligkeit und Genauigkeit in der Rechenroutine gelegt. In diesem Artikel wird diese Vorgehensweise vorgestellt.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第24220号 / 工博第5048号 / 新制||工||1788(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 五十嵐 晃, 教授 杉浦 邦征, 教授 KIM Chul-Woo / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

With the emergence of Fifth Generation (5G) mobile networks, the employment ofhigher frequencies in the millimeter-wave (mmWave) range and the realization of agreat number of beams in 5G radio base stations (RBS) make the electromagnetic (EM)simulation of RBS products very costly in terms of hardware and time requirements.In order to compute the electromagnetic field (EMF) exposure in close proximity of theRBS, more efficient simulation methods are required.The move to mmWave frequencies enables the use of the so-called high frequencymethods for EM simulation with RBS antennas. In this thesis, conventional fullwavesimulation solvers and different implementations of hybridization of highfrequency methods with conventional methods are used with different commercial EMsimulation tools, and their performance is evaluated for the purpose of EMF exposureassessment in close proximity of 5G mmWave RBS.Among all the investigated methods, the hybrid scheme with Finite IntegrationTechnique (FIT) and Shooting and Bouncing Rays (SBR) methods, e.g., thatimplemented in CST Studio Suite 2020, outperforms in terms of hardwarerequirements and time costs, although the accuracy is compromised on the side andbehind the mmWave RBS. The Multilevel Fast Multipole Method (MLFMM), e.g.,that implemented in Altair FEKO 2019, though not a hybrid method, also has goodperformance but requires very large Random Access Memory (RAM), and it cannothandle very exquisite details of RBS. The Finite Difference Time Domain (FDTD)method implemented in EMPIRE XPU can also handle the investigated problemseffciently, but for extremely large problems, its requirements on RAM may become thebottleneck. In the thesis, many other hybrid implementations are also investigated,but it is found that they are not suitable for the EMF exposure assessment in closeproximity of the mmWave RBS with evaluation on a planar area of 0.42 m × 1 m at 28 GHz due to various reasons. / För den femte generationens (5G) mobilnät kommer användningen av millimetervågoroch det stora antalet lober som en radiobasstation (RBS) kan hantera att betydaett kraftigt ökat behov av hårdvara och större tidsåtgång för att göra beräkningarav exponeringen för elektromagnetiska fält nära utrustningen. Därför behövs mereffektiva simuleringsmetoder.Eftersom systemen opererar på millimetervåg-frekvenser kan högfrekvensmetoderanvändas i simuleringen av simuleringen av en RBS. I den här avhandlingenutvärderas konventionella metoder, samt olika hybridmetoder för beräkningenav EMF-exponeringen av millimetervågor i närheten av en RBS. De utvärderadehybridmetoderna är implementerade i olika mjukvaror och blandar användandet avhögfrekvensmetoder och konventionella metoder.Av alla utvärderade metoder fungerar hybridmetoden implementerad med finitaintegralmetoden (FIT) och ”Shooting and Bouncing Rays”-metoden (SBR) i CST bästi termer av vilken hårdvara som behövs för beräkningarna och för tidsåtgången.Dock är noggrannheten i beräkningarna på sidan av och bakom RBSen mindrebra. Multilevel Fast Multipole Method (MLFMM)”-lösaren i Feko i FEKO använderingen hybridmetod men presterar bra, men den kräver mycket RAM-minne och kaninte ta hänsyn till små detaljer i RBSen. Finita differensmetoden i tidsdomänen(FDTD) i EMPIRE kan också användas men dess RAM-krav blir en flaskhals förstora simuleringar. Ytterligare hybridmetoder är undersökta i avhandlingen men medslutsatsen att de inte är användbara (av olika anledningar) för beräkningen av EMFexponeringenfrån en RBS opererandes på frekvensen 28 GHz och över en yta som är0.42 x 1 m.

Κατά τις υβριδικές δοκιμές δύσκαμπτων κατασκευών, παρουσιάζονται σημαντικά προβλήματα όταν αυτές διεξάγονται με έλεγχο της μετακίνησης των υδραυλικών εμβόλων. Καθ’ ότι στις υβριδικές δοκιμές η δύναμη αντίδρασης σε κάθε βήμα χρησιμοποιείται για την εύρεση της μετακίνησης του επόμενου, το οιοδήποτε λάθος μέτρησής της (εγγενές στις δύσκαμπτες κατασκευές), δρα σωρευτικά οδηγώντας σε αμφιβόλου αξιοπιστίας αποτελέσματα. Επιπροσθέτως, σε πολλές περιπτώσεις δοκιμών δύσκαμπτων κατασκευών παρουσιάζονται φαινόμενα αλληλεπίδρασης μεταξύ των εμβόλων που δυσχεραίνουν τη διεξαγωγή τους. Λύση στο πρόβλημα των δοκιμών δύσκαμπτων κατασκευών μπορεί να δοθεί εφόσον η διεξαγωγή τους γίνεται σε έλεγχο δύναμης αντί της μετακίνησης. Αυτό όμως προϋποθέτει την προγενέστερη γνώση των δυνάμεων που θα επιβληθούν από τα έμβολα σε κάθε βήμα. Οι επικρατέστερες προσεγγίσεις για την εύρεση των δυνάμεων κάθε βήματος βασίζονται είτε στον προσδιορισμό του εφαπτομενικού μητρώου δυσκαμψίας, ή σε διαδοχικές προσεγγίσεις. Στην παρούσα μελέτη παρουσιάζεται μία καινοτόμος προσέγγιση η οποία αποφεύγει τον προσδιορισμό του εφαπτομενικού μητρώου δυσκαμψίας. Χρησιμοποιούνται δύο ελεγκτές PID (αντί για έναν όπως γίνεται συνήθως) για τον έλεγχο κάθε εμβόλου. Ο πρώτος μετατρέπει την στοχευόμενη μετακίνηση σε στοχευόμενη δύναμη, ενώ ο δεύτερος είναι υπεύθυνος για τον έλεγχο του εμβόλου με βάση τη δύναμη που προέρχεται από τον πρώτο. Επίσης, με την υιοθέτηση αυτής της στρατηγικής (στρατηγική διπλού τύπου ελεγκτή) σε συνδυασμό με τη συνεχή ψευδοδυναμική μέθοδο αποφεύγονται οι διαδοχικές προσεγγίσεις που μπορούν να οδηγήσουν σε παρασιτικούς κύκλους φόρτισης – αποφόρτισης. Η εγκυρότητα της στρατηγικής ελέγχθηκε με υβριδικές δοκιμές σε δύσκαμπτο δοκίμιο οπλισμένου σκυροδέματος μεγάλης κλίμακας. Το δοκίμιο χρησιμοποιήθηκε και για την αξιολόγηση της στρατηγικής για την εφαρμογή της σε απλές κυκλικές δοκιμές. Τέλος, παρουσιάζεται το σύστημα τηλεπαρακολούθησης του Εργαστηρίου Κατασκευών, το οποίο αναβαθμίζει το σύστημα ελέγχου δοκιμών και συνδράμει αφενός στη διασφάλιση της ποιότητας των δοκιμών και αφετέρου στη διάχυση των παραγόμενων αποτελεσμάτων στην επιστημονική κοινότητα. / Hybrid simulation of stiff structures encounters significant difficulties when relying on the displacement control of hydraulic actuators. The reason being that in hybrid tests the restoring force in each step is used to calculate the displacement of the next step; therefore a potential error in the calculation (intrinsic in the case of stiff structures) has a cumulative effect, leading to results of questionable validity. Furthermore, in many cases interaction between actuators hinders the execution of tests of stiff structures. A solution to this problem encountered when testing stiff structures may be given if tests are conducted in force control rather than displacement control. This, however, presupposes that the forces to be applied by actuators in each step are known beforehand. Dominant approaches in terms of calculating forces in each step are either based on the secant stiffness matrix, or on iterations. The present doctoral thesis introduces an innovative approach which bypasses the secant stiffness matrix calculation. Two PID controllers are used (instead of one, which is the standard practice) in order to control each actuator. The first controller converts the target displacement to target force, whilst the second one controls the actuator based on the force calculated by the first controller. Moreover, when combining this strategy (dual type control strategy) with the continuous pseudodynamic method, iterations that may lead to unwanted loading-unloading cycles are avoided. The validity of the proposed strategy was assessed by conducting hybrid tests on a large-scale stiff reinforced concrete specimen. The same specimen was also used to assess the application of the strategy to cyclic tests. Lastly, the telepresence system of the Structures Laboratory is presented, which upgrades the test control system and at the same time contributes to the quality of testing and to the distribution of results to the scientific community.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-25T14:57:44Z No. of bitstreams: 1 thainansantostheodoro.pdf: 6277443 bytes, checksum: 64fdae570574b42d13c86c42cedaca9e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-25T15:29:25Z (GMT) No. of bitstreams: 1 thainansantostheodoro.pdf: 6277443 bytes, checksum: 64fdae570574b42d13c86c42cedaca9e (MD5) / Made available in DSpace on 2017-04-25T15:29:25Z (GMT). No. of bitstreams: 1 thainansantostheodoro.pdf: 6277443 bytes, checksum: 64fdae570574b42d13c86c42cedaca9e (MD5) Previous issue date: 2016-09-05 / Esta dissertação apresenta uma técnica de simulação híbrida no domínio do tempo de programas de transitórios eletromecânicos e eletromagnéticos usando o MatLab/ Simulink, a qual confere eficiência computacional e precisão, tanto na análise de sistemas de potência, quanto de controle, sobretudo em situações nas quais fenômenos eletromagnéticos e eletromecânicos se sobrepõe, como é o caso da integração de grandes parques eólicos. Para que ocorra a interação entre os dois programas é necessário a adequação das grandezas de fasores para formas de onda e vice versa, assim, é apresentada uma nova abordagem de extração de fasores instantâneos a partir do DSOGI com boa eficiência computacional com perda desprezível de informações. A comunicação regular entre os programas é feita através do protocolo de comunicação baseado na plataforma TCP/IP, que possibilita a representação de modelos distribuídos e a divisão do esforço computacional. São apresentados resultados de simulação para a integração de um parque eólico, representado por um aerogerador DFIG, à uma rede de 29 barras e 7 geradores. Todo o sistema foi representado em um programa de transitórios eletromagnéticos para comparação com os resultados do programa híbrido. Os resultados se mostraram encorajadores já que houve diminuição de quase 70% do tempo de processamento. / This dissertation presents a hybrid simulation technique in the time domain of electromechanical and electromagnetic transient programs using the MatLab/Simulink, which confers computational efficiency and precision, in both power system and control analysis, mainly in situations where electromagnetic and electromechanical phenomena overlap, such as the integration of large wind farms. In order to guarantee the interaction between the two programs it is necessary to adapt the phasor magnitudes to waveforms and vice versa, thus, a new approach is presented for the extraction of instantaneous phasors using the DSOGI approach, with good computational efficiency and negligible loss of information. The regular communication between the programs is done through the communication protocol based on the TCP/IP platform, which allows the representation of distributed models and enables the division of computational effortt between computers. Simulation results are presented for the integration of a wind farm, represented by a DFIG, to a network of 29 bars and 7 generators. The entire system was represented in an electromagnetic transient program for comparison with the results of the hybrid program. The results were encouraging since there was a decrease of almost 70 % of the processing time.

Goal and incentive alignment are a means of establishing collaborative behavior in supply chains. Essay 1 examines goal and incentive alignment at the strategic level in the purchasing process. It employs survey research in conjunction with structural equation modelling to examine the source selection strategy as a means of aligning the goals of the offeror with those of the buyer. Essay 2 examines goal and incentive alignment at the tactical level. It uses discrete event simulation to explore how the pursuit of localized profit objectives affects the global profitability of a supply chain. Lastly, Essay 3 examines goal and incentive alignment at the operational level. By employing a hybrid simulation approach to model a complex product refurbishment process, this research demonstrates that evaluating subprocesses based solely on their throughput does not equate to greater cost savings for the company at the focal point of this case study. These essays contribute to the body of knowledge in several ways. To the best of the author's knowledge, Essay 1 demonstrates the first empirical linkage, in the realm of public procurement, between the fear of a bid protest and the appropriateness of the sourcing strategy. Similarly, Essay 2 represents the first adaptation of Sterman's Beer Game to a format in which the value of products increases while they travel downstream. It also stands as the first research to quantitively explore the value of supply chain cooperation as a function of relative position in a supply chain. Lastly, the methodology employed in Essay 3 answers calls for research as they pertain to the need for case studies from industry, as well as the need to preserve the ‘real-world' context in complex, industry-based problems.

L'objectif de cette thèse est de mettre en œuvre une description multi-échelle adaptée aux écoulements de fluides dans des micro-/nano-conduites. Cette approche doit permettre de décrire, aussi bien les petites échelles relatives aux interactions du fluide avec les atomes du mur, que les grandes échelles de l’écoulement engendrées par les conditions aux limites d'entrée/sortie du canal. Pour cela, nous avons développé une méthode qui couple une modélisation continue des écoulements et des transferts de chaleur dans le cœur du canal avec une modélisation discrète proche des parois, basée sur une représentation atomistique du fluide et du mur.Les équations de Navier-Stokes et de l’énergie, couplées à une équation d’état, sont approximées par une méthode de volumes finis dans le cœur de l’écoulement alors que des simulations de dynamique moléculaire sont utilisées pour représenter finement les interactions entre le fluide et la paroi. Cette approche hybride nécessite la transmission d’informations entre les modélisations : les grandeurs moyennées moléculaires sont imposées comme conditions aux limites pour le modèle continu, et la dynamique sous contrainte, couplée à un thermostat de Langevin, est utilisée pour piloter l’échelle moléculaire. Une représentation par des plots moléculaires locaux de petite taille, intelligemment répartis le long de l’interface entre le fluide et le mur, permet de traiter des écoulements et des transferts dans des canaux de très grands allongements, pour des coûts de calcul raisonnables.Après une partie de validation, des simulations hybrides multi-échelles d’écoulements dans des canaux constitués de parois en platine ont été menées pour de l’argon en phase liquide (incompressible) ou gazeuse (compressible), en tenant compte éventuellement du changement de phase au voisinage de la paroi / The main objective of this thesis is to model the multi-scale heat and fluid flows in micro-/nano channels. This method must be able of capturing at the same time the fluid/solid interaction at the small scale but also the flows induced by the inlet/outlet boundary conditions at the large scale. To this aim, we have adopted an approach coupling the continuum model in the bulks of the channel and the discrete model at the vicinity of the wall, based on an atomistic representation of the fluid and the solid.The Navier-Stokes and energy equations, coupled with an equation of state, are approximated by a finite volume method and the molecular dynamics simulations are used to finely represent the interaction between the fluid and the solid. This hybrid method requires information transmission between the former two regions: averaged quantity in molecular dynamics simulations are imposed as boundary conditions for the continuous model and constrained dynamics, coupled with a thermostat Langevin, is used to control in the molecular level. A set of small molecular dynamics blocks, smartly distributed all along the wall/fluid interface, allows to treat flow and heat transfers in a long micro/nano-channel with a reasonable computational cost.After a validation step, the hybrid multi-scale simulations of complex fluid flows in the channel composed of the platinum wall have been conducted for argon in incompressible liquid or compressible gaseous phase with and without phase change in the vicinity of the wall

Low-aspect-ratio reinforced concrete (RC) shear walls, characterized by height-to-length ratios of less than two, have been widely used as a seismic force-resisting system (SFRS) in a wide array of structures, ranging from conventional buildings to critical infrastructure systems such as nuclear facilities. Despite their extensive applications, recent research has brought to light the inadequate understanding of their seismic performance, primarily attributed to the intricate nonlinear flexure-shear interaction behaviour unique to these walls. In this respect, the current research dissertation aims to bridge this knowledge gap by conducting a comprehensive evaluation to quantify the seismic performance of low-aspect-ratio RC shear walls when used in different applications. Chapter 2 focuses on low-aspect-ratio RC shear walls that are employed in residential and industrial structures. Considering their significance, the seismic response modification factors of such walls, as defined in various standards, are thoroughly examined and evaluated utilizing the FEMA P695 methodology. The analysis revealed potential deficiencies in the current code-based recommendations for response modification factors. Consequently, a novel set of response modification factors, capable of mitigating the seismic risk of collapse under the maximum considered earthquake, is proposed. Such proposed values can be integrated into the forthcoming revisions of relevant building codes and design standards. While the FEMA P695 methodology offers a comprehensive approach to assessing building seismic performance factors, its practical implementation is associated with many challenges for practicing engineers. Specifically, the methodology heavily relies on resource-intensive and time-consuming incremental dynamic analyses, making it less feasible for routine engineering practices. To enhance its practicality, a data-driven framework is developed in Chapter 3, circumventing the need for such demanding analyses. This framework provides genetic programming-based expressions capable of producing accurate predictions of the median collapse intensities—a key metric in the acceptance criteria of the FEMA P695 methodology, for different structural systems. To demonstrate its use, the developed framework is operationalized to low-aspect-ratio RC shear walls and the predictive expression is evaluated considering several statistical and structural parameters, which showed its adequacy in predicting the median collapse intensities of such walls. Furthermore, the adaptability of this framework is showcased, highlighting its applicability across various SFRSs. Chapters 4 and 5 tackle the scarcity of experimental assessments pertaining to the seismic performance of low-aspect-ratio RC walls in nuclear facilities. The seismic hybrid simulation testing technique is employed herein to merge the simplicity of numerical simulations with the efficiency of experimental tests. Hybrid simulation can overcome obstacles related to physical specimen sizes, limited actuator capacities, and space constraints in most laboratories. In these two chapters, the experimental program delves into evaluating the seismic performance of three two-storey low-aspect-ratio nuclear RC walls under different earthquake levels, including operational, design, and beyond-design-level scenarios. Diverse design configurations, including the use of increased thickness boundary elements and different materials (i.e., normal- and high-strength reinforcement), are considered in such walls to provide a comprehensive understanding of several structural parameters and economic metrics. Key structural parameters, such as the force-displacement responses, multi-storey effects, lateral and rotational stiffnesses, ductility capacities, displacement components, rebar strains, crack patterns and damage sequences, are all investigated to provide direct comparisons between the walls in terms of their seismic performances. Additionally, economic metrics, including the total rebar weights, overall construction costs and the expected seismic repair costs, are considered in order to evaluate the seismic performance of the walls considering an economic perspective. The findings of this experimental investigation are expected to inform future nuclear design standards by enhancing the resilience and safety of their structures incorporating low-aspect-ratio RC shear walls. / Thesis / Doctor of Philosophy (PhD)

<p>Real-time hybrid simulation (RTHS) has demonstrated certain advantages over conventional large-scale testing. In an RTHS, the system that is under study is partitioned into a numerical and a physical substructure, where the numerical part is comprised of those elements that are easier to model mathematically, while the physical part consists of those that present a complex behavior difficult to capture in a numerical model. The most complex part of this study is the isolation system, a technology used to protect structures against earthquakes by modifying how they respond to ground motions. Unbonded Fiber Reinforced Elastomeric Isolators (UFREIs) are devices that can accomplish this task and have gained attention in recent years because of their modest but valuable features that make them suitable for implementation in low-rise buildings and in developing countries because of their low cost. Our end goal for this work is to enable the testing of scaled versions of these elastomeric isolators to understand their behavior under shear tests and realistic loading. </p> <p>A testing instrument was designed and constructed to apply a uniaxial compressive force up to 22kN and a shear force of 8kN simultaneously to the specimens. A testing program was conducted where four primary sources of signal distortion were identified as caused by the servo-hydraulic system. From these results, a mechanics-based model was developed to understand better the dynamics that the sliding table can introduce to the measured signals accounting for inertial and dissipative forces. Two Bouc-Wen models were implemented to simulate the behavior of the UFREIs. The first only accounts for the hysteretic behavior of the isolator, and the second accounts for the additional nonlinearities found in the isolator’s behavior. These models were assembled in a virtual RTHS which is available to users interested in learning the applications of RTHS of a base-isolated structure with a nonlinear component.</p> <p>An RTHS experiment was conducted in the IISL where the control system comprised a delay compensator and a proportional-integral controller, which exhibited a good tracking performance with minimal delay and low RMSE. However, it can increase the distortion of the oil-column resonance in the measured signals. The simulation captures the behavior of the isolated structure for small displacements. However, it underestimates the displacement of the full-scale specimen for large displacements. The RTHS showed a better approximation of the displacement of the full-scale structure than the theoretical behavior approximated by the Bouc-Wen models.</p>

Additive manufacturing (AM), commonly known as 3D printing, has been attracting attention from practitioners as well as academicians with its continuous evolution from being used primarily for prototyping to now end-product production. Despite this technology's current and future potential, few studies indicate that AM has not been extensively used across all industries. This dissertation addresses knowledge gaps by providing theoretical and empirical support for adopting AM through three essays that study the role of AM in restructuring supply chains. Essay 1 provides systematic support for AM implementation by developing a typology derived from technology-specific potentials and challenges to adopting AM. This study uses an exploratory research approach to collect and analyze data from semi-structured interviews of practitioners with deep knowledge of AM and supply chains from diverse industries. In Essay 2, our results show that AM adoption positively influences supply chain responsiveness and, in turn, reshoring decisions. Essay 3 compares different supply chain configurations based on traditional and AM. We developed a hybrid simulation model combining discrete event simulation and agent-based simulation and compared the performance in terms of wait time and costs. Our results indicate that under certain conditions, the centralized configuration delivers spare parts faster than the distributed configuration, contrary to previous literature findings. However, a hybrid configuration (a combination of centralized and decentralized) provides a better response (reduced wait time) than the traditional, centralized, and decentralized configurations. Collectively, the three essays provide academicians and practitioners with a more comprehensive understanding of how AM creates value for supply chains.