Exact limiting solutions for certain deterministic traffic rules

We analyze the steady-state flow as a function of the initial density for a class of deterministic cellular automata rules (``traffic rules'') with periodic boundary conditions [H. Fuks and N. Boccara, Int. J. Mod. Phys. C 9, 1 (1998)]. We are able to predict from simple considerations the observed, unexpected cutoff of the average flow at unity. We also present an efficient algorithm for determining the exact final flow from a given finite initial state. We analyze the behavior of this algorithm in the infinite limit to obtain for R_m,k an exact polynomial equation maximally of 2(m+k)th degree in the flow and density.Comment: 25 pages, 8 figure

Akzeptanz von Armprothesen im Kindes -und Jugendalter

Aufgabe dieser Arbeit ist es, objektivierbare Kriterien über die Compliance des kindlichen Prothesentrageverhaltens bei fehlenden Gliedmaßen zu finden. Dazu wurde eine retrospektive Analyse von Daten aus Krankenblättern und Fragebögen armprothetisch versorgter Patienten vorgenommen, die im Zeitraum von 1984 bis 2004 in der Klinik für Technische Orthopädie und Rehabilitation der WWU Münster behandelt worden sind. Die Daten enthalten Angaben über das Geschlecht, das Alter, das Alter bei Erstvorstellung und Erstversorgung, das Prothesentrageverhalten, die Tragedauer, Ablehnungsgründe, die Stigmatisierung der Eltern und der Kinder und das Umfeld der Kinder. Die Ergebnisse zeigen, dass das Geschlecht der Patienten, die jeweilige Diagnose, das Alter bei der Erstversorgung, die Verordnung, die Stigmatisierung der Eltern und der Kinder Einfluss auf deren Compliance und die daraus resultierende Akzeptanz der Prothese haben. Die Ergebnisse decken sich mit der Literatur der letzten Jahre

Controlled manipulation of light by cooperative response of atoms in an optical lattice

We show that a cooperative atom response in an optical lattice to resonant incident light can be employed for precise control and manipulation of light on a subwavelength scale. Specific collective excitation modes of the system that result from strong light-mediated dipole-dipole interactions can be addressed by tailoring the spatial phase-profile of the incident light. We demonstrate how the collective response can be used to produce optical excitations at well-isolated sites on the lattice.Comment: 8 pages, 1 figur

Deep convolutional neural networks for estimating porous material parameters with ultrasound tomography

We study the feasibility of data based machine learning applied to ultrasound tomography to estimate water-saturated porous material parameters. In this work, the data to train the neural networks is simulated by solving wave propagation in coupled poroviscoelastic-viscoelastic-acoustic media. As the forward model, we consider a high-order discontinuous Galerkin method while deep convolutional neural networks are used to solve the parameter estimation problem. In the numerical experiment, we estimate the material porosity and tortuosity while the remaining parameters which are of less interest are successfully marginalized in the neural networks-based inversion. Computational examples confirms the feasibility and accuracy of this approach

Impactful contributions of usability practitioners to open source software projects:a multiple case study

Abstract. Open source software (OSS) has been described as being designed by and for technically advanced users. As OSS has been gaining popularity among non-technical users, concern about its usability has been raised, as it is difficult for technically-minded developers to design for average users. Hiring usability experts to represent the needs of average users has been used in commercial software development as an effective solution for improving usability. It has been also suggested as a way of addressing the usability issues of OSS, but it has been observed that it is often difficult for usability experts to contribute to OSS so that their work has a major impact on the usability of the software. In this thesis, a multiple case study of four usability interventions was conducted. The cases were a part of a larger research program called UKKOSS, which aims to test ways how usability experts can meaningfully contribute to OSS by conducting usability interventions, where student teams act as usability practitioners who enter OSS projects and carry out usability work on them. This study examined how OSS developers reacted to four of those usability interventions by examining the data gathered during those interventions. The analysed data included documents, such as summary reports, communication logs, project plans, and reports on the conducted usability activities. The larger goal of studying these cases was to gather information on how usability practitioners can conduct impactful usability work on OSS projects. The outcomes of the cases were examined through the lens of prior research, and the factors that may have contributed to the success of the cases were examined through cross-case analysis. The developers welcomed the usability work of the usability teams in generally all of the four cases, but the actual impacts the interventions had varied from none of the suggested usability changes being implemented to most of them being implemented to the software. The outcomes of the most successful cases suggest that an approach where usability practitioners implement their suggested changes themselves after discussing about them with the core developers, establishing trust with the developers by contacting them via voice call or video conferencing instead of using only asynchronous communication, and making usability reports as persuasive as possible by including user testing metrics which strengthen the validity of the issues, should be studied further to evaluate if they can have a positive effect on the impact of the work of usability practitioners. The main contributions of this research were supporting the prior research on the obstacles faced by usability experts entering OSS projects by supporting it with empirical evidence and proposing new areas of research on the subject based on the outcomes of the cases

Designing a cooling system for a Formula Student race car

Abstract. The aim of this bachelor’s thesis is to document the primary design of the liquid cooled cooling system for a Formula Student race car and to get acquainted with the basics of a modern liquid-cooled cooling system. The physics in the cooling is presented with the working principle of the cooling system itself. Finally, the primary design of a liquid-cooled cooling system for a Formula Student race car is presented with a brief summary of the results. Another aim of this thesis is also to provide a comprehensive but brief package of information regarding the cooling system and its design especially for the new members of Formula Student Oulu (FSO) to help in the continuity of development and to ease the familiarization of the subject. The applied theory has been gathered mainly on the subject-related literature. The emphasis in the theory is in the heat exchanger and water pump sizing due to dominant role in the cooling system. Due to lack of component properties few assumptions had to be made during the design process but as the successful result shows, assumptions have been adequately good. However, this leads in the difficulty of design improvements due to number of possible parameter changes. Though, the design method is very applicable in the automotive use and thoughts about the development and next steps are presented also at the end of the thesis.Jäähdytysjärjestelmän suunnittelu Formula Student -kilpa-autoon. Tiivistelmä. Tämän kandidaatintyön tarkoituksena on dokumentoida nestejäähdytteisen jäähdytysjärjestelmän suunnitteluprosessi sekä tutustua modernin nestejäähdytteisen jäähdytysjärjestelmän perusteisiin. Jäähtymisen teoria on esitetty jäähdytysjärjestelmän toimintaperiaatteen lisäksi. Viimeisenä esitellään Formula Student -kilpa-autoon suunniteltu jäähdytysjärjestelmä lyhyen tuloskatsauksen kera. Työn toisena tavoitteena on toimia kattavana mutta tiiviinä informaatiopakettina erityisesti uusille Formula Student Oulun jäsenille helpottaakseen suunnittelutyön kehitystä ja aiheeseen tutustumista. Teorialähteinä on käytetty pääasiassa alan kirjallisuutta. Painotus teoriassa kohdistuu jäähdyttimen ja vesipumpun mitoitukseen johtuen niiden suuresta roolista jäähdytysjärjestelmän toiminnassa. Suunnitteluprosessin edetessä muutamia arvioita jouduttiin tekemään puutteellisten komponenttien ominaisuustietojen takia, mutta kuten tulokset osoittavat, arviot olivat riittävän hyviä. Tästä syystä tulevaisuuden kehitystyö on kuitenkin hieman vaikeampaa johtuen muuttujien suuresta määrästä. Suunnittelumetodi on kuitenkin erinomaisesti sovellettavissa autoteollisuuden kohteisiin ja parannusehdotuksia on listattukin työn loppupuolella