Main topic of the paper is a problem of designing the input-output decoupling controllers for nonholonomic mobile manipulators. We propose a selection of output functions in much more general form than in [1,2]. Regularity conditions guaranteeing the existence of the input-output decoupling control law are presented. Theoretical considerations are illustrated with simulations for mobile manipulator consisting of RTR robotic arm mounted atop of a unicycle which moves in 3D-space.
The article discusses the architectural expression of houses built on water, based on the design process of the floating house in the Czerniakowski Port in Warsaw, designed by Mai Bui Ngoc and Rafał Mazur. The question of the form of the floating house was the starting point of the work on this project. Usually buildings are designed in a specific location, which gives architects an inspiration for the design of the new form. In the case of the floating houses the goal was to make a universal artefact as a car or a phone. This artefact should be more connected to the owner than to the landscape. This artefact should be also neutral to the landscape and it should not be destructive for the surroundings. The answer lays between two archetypes; a typical house and a boat. Analysis of the existing floating houses gave the conclusion that authors of these houses were usually very close to one of these two archetypes. It is a need to put a lot of effort to design an object which does not remind a real house and a yacht design.
This article is an attempt to represent the aspirations of the Polish aristocracy during the First World War by imagining the dreams of Maria Lubomirska – wife of Prince Zdzisław Lubomirski, arguably the most important Polish politician in Warsaw at the time. Lubomirska and her circle attended séances led by a popular medium, and they saw what they wanted to see, just as they perceived the changing political tides in the same way. Though aristocrats were in some sense already anachronistic at this time, they still wished to maintain their superior social and political position into the future. Lubomirska in particular envisioned an independent Poland led by a king. The idea of Poland becoming a monarchy may seem absurd in hindsight, but as the article shows, if we return to this moment in history without teleological presumptions it was a likely outcome until the last days of the war. Text in italics comes directly from Lubomirska’s diary.
This work presents the results acquired during simulation studies done for a 3D free-floating satellite behaviour with input-output decoupling approach. The research object is a free-floating satellite with a 3 DoF rigid 3D manipulator where a noise disturbance was introduced. Different approaches are used to compensate the noise influence. Systems using a visual aid to determine the position of manipulator joints are not ideal and introduce some uncertainties. What is more, determining the position from joints encoders is not error-free while computing angular velocity from numerical differentiation introduces even greater disturbance to the system. A couple of scenarios were investigated where state of the manipulator, including its position and velocity, was disturbed with homogeneous noise. Also the control inputs of the manipulator were disturbed. Simulation results show that the biggest impact on the control quality has a scenario where the satellite’s state has been disturbed with additive noise.
One of the major subjects that construct the emotional right-wing script is the history of the postwar Polish independence Underground and the related present-day politics and historical policy. The analysis of the right-wing press enables the distinction of four temporal categories to which specific toposes can be assigned as well as the moulded emotional elements: 1) the period of struggle, 2) the period of imprisonment and possible death, 3) the period of the Third Republic [of Poland], and 4) the period from the victory of the Law and Justice party (PiS) in the parliamentary elections until the present.
This article analyses the transformative influence of Marcel Proust’s fiction on early works of Jarosław Iwaszkiewicz (1925–1927) in the light of the short story Nowa miłość [A New Love]. The article argues – on the basis of a reconstruction of the order in which Iwaszkiewicz read the volumes of In Search of Lost Time – that the date of its composition has be to revised and proceeds to explore the affinity between the two writers. The analyses, which draw on Harold Bloom’s infl uence theory, compare and contrast their handling of scenes and narratives, relations of analogy and visions of love. The article claims that Iwaszkiewicz was keen to enter into dialogue with the French author and adopted some of Proust’s techniques, yet without compromising his own creative autonomy. In the course of that dialogue he developed a notion of Proust’s literary art which, it is argued, provides the key to the interpretation of homoeroticism and narcissism in Nowa miłość.
We discuss the empirical importance of long term cyclical effects in the volatility of financial returns. Following Amado and Teräsvirta (2009), ČiŽek and Spokoiny (2009) and others, we consider a general conditionally heteroscedastic process with stationarity property distorted by a deterministic function that governs the possible time variability of the unconditional variance. The function proposed in this paper can be interpreted as a finite Fourier approximation of an Almost Periodic (AP) function as defined by Corduneanu (1989). The resulting model has a particular form of a GARCH process with time varying parameters, intensively discussed in the recent literature.
In the empirical analyses we apply a generalisation of the Bayesian AR(1)-GARCH model for daily returns of S&P500, covering the period of sixty years of US postwar economy, including the recently observed global financial crisis. The results of a formal Bayesian model comparison clearly indicate the existence of significant long term cyclical patterns in volatility with a strongly supported periodic component corresponding to a 14 year cycle. Our main results are invariant with respect to the changes of the conditional distribution from Normal to Student-tand to the changes of the volatility equation from regular GARCH to the Asymmetric GARCH.
Vibrating plates have been recently used for a number of active noise control applications. They are resistant to difficult environmental conditions including dust, humidity, and even precipitation. However, their properties significantly depend on temperature. The plate temperature changes, caused by ambient temperature changes or plate heating due to internal friction, result in varying response of the plate, and may make it significantly different than response of a fixed model. Such mismatch may deteriorate performance of an active noise control system or even lead to divergence of a model-based adaptation algorithm.
In this paper effects of vibrating plate temperature variation on a feedforward adaptive active noise reduction system with the multichannel Filtered-reference LMS algorithm are examined. For that purpose, a thin aluminum plate is excited with multiple Macro-Fiber Composite actuators. The plate temperature is forced by a set of Peltier cells, what allows for both cooling and heating the plate. The noise is generated at one side of the plate, and a major part of it is transmitted through the plate. The goal of the control system is to reduce sound pressure level at a specified area on the other side of the plate.
To guarantee successful operation of the control system in face of plate temperature variation, a gain-scheduling scheme is proposed to support the Filtered-reference LMS algorithm.