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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Control and balancing of a small vehicle with two wheels for autonomous driving

Batmanian, Saro, Naga, Pasam January 2019 (has links)
Control and balancing of an inverted pendulum has gained a lot of attention over the past few decades due to its unstable properties. This has become a great challenge for control engineers to verify and test the control theory. To control and balance an inverted pendulum, proportional integrated derivative (PID) method or linear quadratic regulator (LQR) method can be used through which a lot of simulations can be done using the represented theories.Since urban population is increasing at a very alarming rate, there is a need to discover new ways of transportation to meet the future challenges and demands. Scania has come up with a new conceptual bus called NXT which aims to develop a modular vehicle that should configure and re-configure themselves between different transportation tasks. NXT vehicle has front and rear drive modules which can be represented as single axle, two-wheeled vehicles which in-turn can be viewed as an inverted pendulum with a huge Center of Gravity. Controlling and balancing of the pod or drive module precisely and accurately is an interesting challenge since it is an unstable inverted pendulum with huge center of gravity (COG). This behaviour of the system has created a research question whether the module is controllable or not.Therefore this thesis focuses on the possibility of controlling the pod which is a two-wheeled inverted pendulum vehicle with a COG offset. Also, the thesis focuses on the construction, mod-elling, testing and validation of a down-scaled model, what sensors are needed to balance the pod precisely, how the sensors must be integrated with the system and how the pod can be controlled remotely from a certain distance by a human. The developed pod houses the technologies like sensors, BLDC motor controllers, hoverboard, Arduino board and Bluetooth transmitters.The Master Thesis starts by presenting an introduction to the inverted pendulum theories, Scania NXT project, information about the research methods, thesis outline and structure . It continues by describing related literature about the inverted pendulums, segways, hoverboards, motor controllers and Arduino boards. Afterwards, the process of deriving a mathematical model, together with simulation in Matlab, Simulink and Simscape is described. Later, construction of the pod is made and lot of effort is put to run the pod. Since the pod needs to be controlled remotely by a human, a remote controlled systemis implemented via mobile phone using an app and finally the thesis is finished with a conclusion and ideas for future work. / Reglering och balancering av en inverterad pendel har väckt stor uppmärksamhet över de senaste decennierna på grund av dess instabila egenskaper. Det har skapat stora utmaningar för regleringenjörer eftersom området tillåter test och verifikation av diverese lösningar. För reglering och balansering av en inverterad pendel, så kan en regulator med proportionell, integral och derivat (PID) konstanter eller en linjär kvadratisk regulator (LQR) användas tillsammans med simuleringar för att bekräfta teorin.I och med att stadsbefolkningen ökar i mycket hög takt, så uppstår behovet av att uppfinna nya transportmedel för att lösa framtida utmaningar och krav. Scania har tagit fram en ny konceptbuss som heter NXT, med målet att utveckla ett modulfordon som kommer att konfigurera och rekonfigurera sig själva mellan olika transportuppgifter. NXT-fordonet har fram- och bakdriv-moduler som kan representeras som enaxlade tvåhjuliga fordon, vilka i sin tur kan betraktas som en inverterad pendel med en stor massa. Att reglera och balansera drivmodulen på ett noggrant sätt är en utmaning eftersom det är ett mycket instabilt system med enorm massa och en okänd tyngdpunkt. Systemets beteende har skapat en forskningsfråga om modulen är reglerbar eller inte.Denna uppsats fokuserar därmed på möjligheterna att kunna reglera drivmodulen samt vilka begränsningar det finns. Uppsatsen fokuserar också på konstruktion, modellering, testning och validering av en nedskalad modell, vilka sensorer som krävs för att balansera drivmodulem, samt hur sensorerna måste integreras med systemet för att kunna fjärstyra fordonet från ett visst avstånd. Utveckingen av en sådan nedskalad modell berör olika områden såsom sensorer, BLDC-motorstyrenheter, hoverboard balanserings scootrar, Arduino kretskort och Bluetooth-sändare/mottagare.Uppsasten börjar med en introduction om olika inverterade pendel teorier, Scania NXT project, forskningsmetoder, en översikt och övergripande struktur. Vidare fortsätter beskrivining av relaterade litteratur om inverterade pendel, Segway, hoverboard, borstlösa motor styrenheter och Arduino kretskort. Senare fortsätter processen för att härleda matematiska modeller som beskirver systemet, tillsammans med simuleringar i Matlab, Simulink och Simscape. Därefter beskrivs konstruktionen av en nedskalad modell av drivmodulen och beskrivning av nödvändiga processer för att få hårdvara och mjkukvara att fungera ihop. Då fordonen ska ha möjlighet att fjärrstyras, så implementerades en bluetooth enhet tillsammans med en programmerbar mobil applikation. Slutligen avlutas uppsatsen med resultat, slutsats och diskussioner och förslag till framtida arbeten.
192

Extended Kalman Filter as Observer for a Hydrofoiling Watercraft : Modelling of a new hydrofoiling concept, based on the Spherical Inverted Pendulum Model

Thålin, Adam January 2022 (has links)
Hydrofoiling in general has the potential to revolutionize watercraft in the future since it allows smoother and faster transport on water with less energy consumption than traditional planning hulls. Even if the concept of hydrofoiling has been around since the last century, development in control theory and material science together with increased computing power has led to a growing interest for the technology. Especially in water sports such as speed sailing and surfing due to its superiority in speed and comfort. Researchers and students at the Engineering Mechanics Department at KTH, Royal Institute of Technology, Stockholm are working on a new type of watercraft, utilizing only one single hydrofoil with the intention to minimize drag for faster and smoother rides in various wave and weather conditions. The difficulties lie in understanding the relationship between actuators and the mechanics. This thesis is a continuation work from a previous thesis which designed a control strategy based on a model with 4 degrees of freedom (DOF). Due to simplifications and linearizations, the 4 DOF model was not rich enough to meet the performance requirements. This thesis presents a 6 DOF model by deriving the mechanical equations for the spherical inverted pendulum and actuation from the hydrofoiling module. The inverted pendulum model is a well-known control problem that can be solved with different strategies. By showing that the hydrofoiling concept can be modelled as an inverted pendulum, it is also shown that it can be controlled as an inverted pendulum. The derived model is used together with an Extended Kalman Filter to create an observer. The observer is validated with a spherical inverted pendulum model in Matlab and the block diagram environment, Simulink. Simulation results show that the 6 DOF model is able to produce accurate state estimation of the watercraft even in the presence of stochastic measurement noise. It is also concluded that viscous forces, that arise from the watercraft being partly surrounded by water and partly by air, need further investigation. / Principen för bärplan är att generera lyftkraft från vattnet på samma sätt som flygplansvingar genererar lyftkraft från luften för att lyfta farkostens skrov ur vattnet. Detta minskar motståndet från friktionen mellan skrov och vatten vilket möjliggör snabbare och jämnare transport på vatten med en lägre energiförbrukning än traditionella planande skrov. På senare år har tekniken fått ett uppsving i och med framsteg inom strömningsmekanik, reglerteknik och materiallära. Detta i takt med datorers ökande beräkningskraft har lett till att bärplanskonstruktioner har kunnat uppvisa en överlägsenhet i vattensporter som kappsegling och surfing när det kommer till fart och komfort. Forskare och studenter på avdelningen för farkostteknik och solidmekanik vid Kungliga Tekniska Högskolan, Stockholm arbetar med att ta fram en ny typ av farkost med en minimal bärplansdesign, FoilCart. Dess utformning gör att det mekaniska beteendet kan liknas vid en inverterad pendel, vilket är ett välkänt, olinjärt reglerproblem som kan lösas på flera sätt. Denna avhandling är ett vidarearbete som bygger på en modell med fyra frihetsgrader från en tidigare avhandling kring FoilCart-projektet. Modellen med fyra frihetsgrader var, på grund av förenklingar och linjärisering av systemdynamiken, bristfällig och kunde inte garantera en robust balansering av farkosten förutom i linjäriseringspunkten. Modellen som presenteras i denna avhandling har sex frihetsgrader. Mekaniken och systemdynamiken härleds från den sfäriska inverterade pendeln tillsammans med styrningen från bärplansmodulen, utan förenklingar och linjärisering. Modellen används i ett Kalmanfilter för att konstruera en observatör för tillståndsrekonstruktion. Den framtagna modellen valideras med en FoilCart-modell i Simulink. Resultaten visar att observatören kan ge en noggrann tillståndsrekonstruktion även vid simulerat mätbrus i mätsignalen. Avhandlingen syftar till att visa hur den inverterade pendelmodellen kan användas vid framtida implementation av rekonstruerad tillståndsåterkoppling. I och med avgränsningar i avhandlingen finns det också en del strömningsmekaniska aspekter som inte tagits med vid framtagningen av denna modell. Eftersom farkosten delvis är omgiven av vatten och delvis av luft skulle det vara intressant att undersöka om noggrannheten i tillståndsrekonstruktionen kan förbättras genom att använda avancerad strömningsmekanik.
193

Toward Adaptation of Data Enabled Predictive Control for Nonlinear Systems / Mot Anpassning av Dataaktiverad Prediktiv Kontroll för Icke-linjära System

Ghasemi, Hashem January 2022 (has links)
With the development of technology and availability of data, it is sometimes easier to learn the control policies directly from the data, rather than modeling a plant and designing a controller. Modeling a plant is not always possible due to the complexity of the plant. Data-enabled predictive control (DeePC) is a recently proposed approach that combines system identification, estimation, and control in a single optimization problem. DeePC is primarily designed for LTI systems. The purpose of this thesis is to extend the application of DeePC to nonlinear systems with a particular focus on a non-holonomic ground robot. To reach this goal, we decompose the system states into different working modes where each mode can be linearly approximated. Furthermore, the data collection policies were also evaluated to conclude how they affect the performance of the DeePC. We identified several key challenges in this direction, namely: data-demanding structure, high computational complexity, and performance deterioration with increased non-linearity. While these challenges prohibited the application of DeePC to the ground robot system; we successfully applied the method to a benchmark non-linear system, the inverted pendulum on cart problem, and studied the effect of various design choices on control performance. Our observations indicate potential areas of improvement toward enabling DeePC for highly nonlinear systems. / Med utvecklingen av teknik och tillgänglighet av data är det ibland enklare att lära sig styrpolicyerna direkt från data, snarare än att modellera ett system och designa en styrenhet. Att modellera ett system är inte alltid möjligt på grund av systemets komplexitet. Data aktiverad prediktiv kontroll (DeePC) är en nyligen föreslagen metod som kombinerar systemidentifiering, uppskattning och kontroll i ett enda optimeringsproblem. DeePC är främst designad för LTI-system. Syftet med denna avhandling är att utöka tillämpningen av DeePC till icke-linjära system med särskilt fokus på en icke-holonomisk markrobot. För att nå detta mål delar vi upp systemtillstånden i olika arbetslägen där varje läge kan approximeras linjärt. Dessutom utvärderades datainsamlingspolicyerna för att dra slutsatser om hur de påverkar DeePCs prestation. Vi identifierade ett antal nyckelutmaningar i denna riktning, nämligen: datakrävande struktur, hög beräkningskomplexitet och prestandaförsämring med ökad icke-linjäritet. Även om de utmaningerna hindrade tillämpningen av DeePC på markrobot systemet; har vi framgångsrikt tillämpat metoden på ett benchmark icke-linjärt system, problemet med inverterad pendel på vagn, och studerade effekten av olika designval på kontrollprestanda. Våra observationer indikerar potentiella förbättringsområden för att möjliggöra DeePC för mycket olinjära system.
194

Seismic isolation of nuclear reactor vessels considering soil-structure interaction

Samyog Shrestha (13149003) 26 July 2022 (has links)
<p>The research presented in this dissertation investigates the influence of soil-structure<br> interaction on seismic isolation of nuclear reactor vessels using numerical simulations. This<br> research is motivated by the nuclear industry searching for viable solutions to standardize<br> the design of reactor vessels. Seismic isolation of reactor vessels is a potential solution as it<br> enables deployment of standardized reactor vessels irrespective of site seismic hazard<br> thereby saving time and cost by allowing large-scale factory fabrication of standard<br> modules and by eliminating the need for repeated approval of reactor vessel design. Seismic<br> isolation is also a technology that has matured from successful implementation in buildings<br> and bridges allowing easier transition to nuclear applications. Currently, the<br> implementation of component-level seismic isolation in nuclear industry is challenging due<br> to gaps in research and lack of specific guidelines.</p> <p><br></p> <p><br> In this research, the effectiveness and potential limitations of using conventional friction<br> pendulum bearings for component-level isolation are investigated based on conceptual<br> numerical models of seismically isolated reactor vessels at different nuclear power plant<br> sites subject to a variety of ground motions. The numerical modeling and analysis<br> approach presented in this research are checked using experimental data and results from<br> multiple numerical codes to ensure reliability of the obtained analysis results.</p> <p><br></p> <p><br> Within the scope of this study, it is found that slender vessels are particularly vulnerable<br> to rotational acceleration at the isolation interface. Rotational acceleration at the isolation<br> interface is caused by rotation at the foundation level of the containment building housing<br> the isolated reactor vessel and by excitation of higher horizontal translational modes of the<br> seismically isolated system. Rotation of the building foundation increases with decrease in<br> shear wave velocity of the soil surrounding the building foundation. When the containment<br> building is embedded below the soil surface, the effect of embedment on peak horizontal<br> acceleration of the isolated vessel depends on the amount of increase in shear wave velocity<br> at the foundation level of the building. When embedment does not result in any change in<br> shear wave velocity, it is found to have negligible impact on the acceleration response of the<br> isolated vessel.</p> <p><br></p> <p>  The optimum location to support a vessel for seismic isolation is found to be on a plane<br> passing through its center of mass. It minimizes horizontal acceleration in the isolated<br> vessel as well as the tendency of isolator to uplift. Isolator uplift and exceedence of<br> displacement capacity of the isolator during extreme events are possible drawbacks in using<br> seismic isolation technology since they produce impact forces due to uplift and<br> re-engagement of the isolator or due to collision between the isolated system and the moat<br> wall. If such cases are avoided, seismic isolation of reactor vessel could provide more than<br> 50% reduction in peak acceleration of vessel except for low-intensity motions that do not<br> engage the isolator.<br>  <br>  </p>
195

Sensorgeführte Bewegungen stationärer Roboter / Sensor Guided Motions of Stationary Robots

Winkler, Alexander 22 March 2016 (has links) (PDF)
Den Kern der vorliegenden Arbeit bilden sog. sensorgeführte Roboterbewegungen, d. h. die Nutzung von Informationen externer Sensoren zur Regelung des Roboters. Da gängige Industrierobotersysteme üblicherweise positionsgeregelt sind und seitens der Robotersteuerung lediglich der Zugriff zu den Sollwerten der Lageregelkreise erlaubt wird, kann auch der Regelkreis der sensorgeführten Roboterbewegung nur über den Lageregelkreis geschlossen werden. Aus diesem Grunde werden hier nur positionsbasierte Regelungsansätze verfolgt. Die Kraft-/ Momentregelung gilt als eine der wichtigsten Varianten sensorgeführter Roboterbewegungen. Dementsprechend widmet sich auch ein großer Teil dieser Arbeit dem Thema, mit dem Ziel durch innovative und übersichtliche Regelalgorithmen die Akzeptanz der Kraft-/ Momentregelung in industriellen Produktionsprozessen zu erhöhen. Beginnend mit der eindimensionalen Kraftregelung führt der Weg dabei über Konzepte zur Konturenverfolgung und kraft-/ momentgeregelten Montageaufgaben hin zur Kooperation von Robotern. In einem weiteren Teil wird ein Konzept zur Kollisionsvermeidung zwischen Robotern und Hindernissen präsentiert. Es basiert auf dem Ansatz der virtuellen Potential- bzw. Kraftfelder. Dabei ruft das künstliche Feld eine Bewegung des Roboters hervor, die vom Hindernis weg führt. Um das Feld zu erzeugen, wird die Methode der künstlichen Punktladungen entwickelt. Diese werden auf der Oberfläche eines Hindernisses platziert und generieren dann das virtuelle Kraftfeld. Die Platzierung kann z. B. mithilfe der CAD-Daten des Hindernisses erfolgen. Bei bewegten Objekten müssen alle Ladungspositionen ständig aktualisiert werden. Für Lehr- und Präsentationszwecke ist das sog. inverse Pendel eine oft genutzte Regelstrecke. Sein Aufrichten und Stabilisieren ist auch mit Hilfe eines Industrieroboters möglich. Dazu beschäftigt sich ein Kapitel dieser Arbeit mit Fragen zur Modellbildung der Kombination inverses Pendel und Industrieroboter und mit Regelungskonzepten für das Aufschwingen und Balancieren. Letztendlichen wird in diesem Zusammenhang noch ein Visual-Servoing System präsentiert, dass den Neigungswinkel des Pendels mit einer Kamera bestimmt. Alle hier vorgestellten Konzepte und Algorithmen werden Anhand von praktischen Experimenten verifiziert. / This work deals with so-called sensor guided robot motions, which means using the data of external sensors to control the robot. The control loop of the sensor guided robot motion can be only closed around the position control loop, because industrial robot systems usually work position controlled and only access to the desired positions is enabled. For this reason here only position based control approaches are regarded. Force/torque control is a very important type of sensor guided robot motions. According to this, a good portion of this work deals with the subject of force/torque control. Thus, the acceptance of force/torque control in industrial production processes should be increased, by using innovative and clear control algorithms. For this purpose force control in one degree of freedom, contour-following, force/torque controlled assembling tasks and the cooperation between robots are discussed here in different chapters. Thereafter, a concept to collision avoidance between robots and obstacles is presented. It uses the approach of virtual potential/force fields. In this case the artificial field induces a robot motion away from the obstacle. The method of artificial charges is developed to generate this field. For this purpose virtual charges are placed on the surface of the obstacles. Placing of the charges can be performed using e.g. CAD data of the obstacles. Having moving obstacles charge positions must be updated continuously. The inverted pendulum is commonly used teaching students in control theory. The swinging up and the stabilization of the pendulum also can be performed by an industrial robot. One chapter of this work deals with modelling of the robot mounted inverted pendulum and control algorithms for its swinging up and its stabilization. Finally, in combination with the inverted pendulum a visual-servoing system is presented, which measures the pendulum inclination angle by camera. All concepts introduced in this work are verified by practical experiments.
196

Trajectory planning and control of collaborative systems : Application to trirotor UAVS. / Planification de trajectoire et contrôle d'un système collaboratif : Application à un drone trirotor

Servais, Etienne 18 September 2015 (has links)
L'objet de cette thèse est de proposer un cadre complet, du haut niveau au bas niveau, de génération de trajectoires pour un groupe de systèmes dynamiques indépendants. Ce cadre, basé sur la résolution de l'équation de Burgers pour la génération de trajectoires, est appliqué à un modèle original de drone trirotor et utilise la platitude des deux systèmes différentiels considérés. La première partie du manuscrit est consacrée à la génération de trajectoires. Celle-ci est effectuée en créant formellement, par le biais de la platitude du système considéré, des solutions à l'équation de la chaleur. Ces solutions sont transformées en solution de l'équation de Burgers par la transformation de Hopf-Cole pour correspondre aux formations voulues. Elles sont optimisées pour répondre à des contraintes spécifiques. Plusieurs exemples de trajectoires sont donnés.La deuxième partie est consacrée au suivi autonome de trajectoire par un drone trirotor. Ce drone est totalement actionné et un contrôleur en boucle fermée non-linéaire est proposé. Celui-ci est testé en suivant, en roulant, des trajectoires au sol et en vol. Un modèle est présenté et une démarche pour le contrôle est proposée pour transporter une charge pendulaire. / This thesis is dedicated to the creation of a complete framework, from high-level to low-level, of trajectory generation for a group of independent dynamical systems. This framework, based for the trajectory generation, on the resolution of Burgers equation, is applied to a novel model of trirotor UAV and uses the flatness of the two levels of dynamical systems.The first part of this thesis is dedicated to the generation of trajectories. Formal solutions to the heat equation are created using the differential flatness of this equation. These solutions are transformed into solutions to Burgers' equation through Hopf-Cole transformation to match the desired formations. They are optimized to match specific requirements. Several examples of trajectories are given.The second part is dedicated to the autonomous trajectory tracking by a trirotor UAV. This UAV is totally actuated and a nonlinear closed-loop controller is suggested. This controller is tested on the ground and in flight by tracking, rolling or flying, a trajectory. A model is presented and a control approach is suggested to transport a pendulum load.
197

民主治理下政務官與事務官互動關係:以「是的,部長(Yes, Minister)」影集之文本分析為例 / The interaction between political appointees and civil servants in democratic governance: A text analysis of the TV series “Yes, Minister.”

林俐君, Lin, Li Chun Unknown Date (has links)
隨著民主治理的發展,有效調和民主憲政與文官專業價值,才能夠確保民主政治運作的效能。背景因素使得政務官與事務官間的互動,愈具舉足輕重的角色。從相關研究可以理解,欲直接觀察政務官與事務官細部的互動並不容易,兩者間細部的互動對外界而言始終是一個黑盒子。因此,本研究使用鮮少作為該議題研究主體的影視產品進行分析。選擇英國經典影集「Yes, Minister」,乃因該劇主要以描繪政務官與事務官互動為主,描寫程度相當細膩。藉此旁觀的角度一窺政務官與事務官的互動,確實是個能夠協助深入理解該議題的良好個案。 研究設計的基礎為文本分析法,透過建構分析路徑,分別從兩者本質、選擇偏好、表現作為,以及互動後對政策產出的討論。先將14集研究樣本進行相同路徑的文本化,再將文本化的樣本進行論述與類型化。研究發現事務官的互動技巧,包括行政權力的作為與不作為、可行性評估、影響政務體系與政務官以及納入外部勢力等,目的為提升參與決策的條件,細部列出24項互動技巧;另一方面,政務官則可透過經驗複製、行政學習、媒體與聲望經營與納入外部力量等,目的為提升統治便利性與正當性,細部列出13項互動技巧。兩者的互動呈現出互相制衡的本質,若各自無法有效負責與調和時,易形成雙重價值選擇的壓力。 本研究提出以「鐘擺效果」解釋政務官與事務官的互動,兩者在制衡關係的基礎上,隨著時序性的影響而改變互動模式。基本上的互動如鐘擺式擺盪,進而系統性因素將會因時序性遞減,激發出最適的政策結果。最終提出兩大項建議:首先,從制衡到動態平衡的關係,正視制衡現象的存在、立基於分權制衡上的信任關係、減少彼此錯誤解讀的機會,以及培養持續監督與自省能力;其二,設定政策決策的妥協底線,認知非任務型指標的超然價值,以及試著創造沒有共識的共識。 / In any democratic state’s development, how to effectively reconcile the two values of constitutional democracy and bureaucratic expertise is fundamental to ensure the proper functioning and efficacy of democratic politics. As Taiwan further consolidates its democracy, the interaction between the political appointees and senior civil servants becomes ever more important in achieving a balance of pluralistic values on the one hand, and government’s administrative efficiency, on the other. Yet past research has found that it is not easy to observe directly the details of the interaction between political appointees and civil servants; to the external world, the actual interaction between the two has always been a black box. Therefore, to shed light on that black box, this study analyzes the interaction between appointees and civil servants as depicted in film and television programs. The classic British series, “Yes Minister,” was chosen as the study’s research subject because it portrays the minister-bureaucrat interactive behavior skillfully and poignantly, which allows a deeper understanding of the issue. The study employs textual analysis as the principal research method. Each of the series’ 14 episodes had been textually reinterpreted by using the same analytical paths, which were constructed by first categorizing the nature, choice preferences, display behaviors, and post-interaction reaction to policy outputs for both political appointees and senior civil servants. The research has found that civil servants, in their pursuit for greater participation in decision-making, exhibit as many as 24 distinct interactive behaviors with their political superiors. Some of these behaviors include administrative action and inaction, call for feasibility assessment, manipulation of the political system, and incorporation of external forces. On the other hand, political appointees, in their effort to achieve political expediency and legitimacy, have 13 behaviors of their own through experience replication, administrative learning, media and reputation management, and inclusion of external forces. Both sets of interactive behaviors are essentially parts of a checks-and-balances system. When responsibilities are unclear and actions cannot be coordinated effectively, the agency then becomes vulnerable to role ambiguity and double value selection problems. This research proposes a “pendulum effect” to explain the interaction between political appointees and civil servants. Because the appointees and civil servants have a mutual checks and balances relationship, both parties will alter their interactive behavior depending on the timing of events. Essentially, the interaction between the two sides will initially swing freely like a pendulum; subsequently, system factors will cause the pendulum to progressively decrease its swing, ultimately arriving at the most optimal policy result. In conclusion, this study makes two major recommendations. First, both political appointees and civil servants need to understand that they are in a dynamic equilibrium, in which they check and balance each other’s actions. By acknowledging the check and balance nature of their relationship, both minimize the chance of misinterpreting each other, and may develop the healthy capacity of ongoing oversight and self-introspection. Second, both political appointees and civil servants must establish a baseline in any policy negotiation and compromise, recognize the (sometimes) extraordinary value of non-mission-based indicators, and attempt to create a consensus when no consensus exists.
198

Porovnání H-nekonečno a LQG regulace / Comparison of H-infinity and LQG controller

Friml, Dominik January 2020 (has links)
This thesis deals with the MIMO system analysis, with a comparison of a different frequency charactersitics, and including singular values characteristic. The H2 and H norms are defined for signals and a MIMO systems. A MIMO optimal control using an LQG, an H2 and an H control is defined and described. Their general advantages, disadvantages and similarities are summed up. An H2 and an H state controller and state observer synthesis is implemented in a MATLAB using linear matrix inequalities. Control of an inverted pendulum is designed using the H optimal cascade control, the H2 state control and the H state control. The results are compared with each other. The theoretical possibility of same H2 and H optimal state controller design is presented.
199

Nové směry v oblasti asfaltových koberců mastixových / New trends in the field of stone mastic asphalts

Pfeiferová, Magdaléna January 2012 (has links)
The work consists of two parts. The first part is focused on the determination of an anti-skid properties of the test section on Vídenská street. The anti-skid properties will be measured using a pendulum tester and macrotexture will be set at the same time. Microtexture will be measured using a volumetric patch technique. In the second part we will try to gain an initial experience with design and testing of a low noise stone mastic asphalt. We will set basic characteristics and at the same time compare with a standard stone mastic asphalt. For the comparison two various bituminous binders are used. The water sensitivity, resistance against rutting and stiffness moduli are compared.
200

Zur Dynamik geometrisch nichtlinearer Balken

Weiß, Holger 01 December 1999 (has links)
Ziel der Arbeit ist es, die instationären zeitlichen und räumlichen Bewegungsabläufe stark deformierbarer eindimensionaler Kontinua durch ein allgemeines mechanisch-mathematisches Modell unter Berücksichtigung ihrer Biege- und Torsionssteifigkeit zu beschreiben und zu dessen Lösung geeignete numerische Verfahren zu testen und auszuwählen. Die entwickelten Algorithmen werden auf Aufgabenstellungen aus der Raumfahrt-, Meeres- und Textiltechnik angewendet. / It is the aim of this thesis to describe the instationary motion of flexible one-dimensional continua by a general mechanical-mathematical model, when bending and torsional stiffness is not negligible, and to test and select appropriate numerical solution methods. The developed algorithms are used to solve problems from space, marine and textil engineering.

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