Hybrid Geometric Reduction of Hybrid Systems

This paper presents a unifying framework in which to carry out the hybrid geometric reduction of hybrid systems, generalizing classical reduction to a hybrid setting

Orientation of the cores of hybrid morphology radio sources

The FRI/FRII dichotomy is a much debated issue in the astrophysics of extragalactic radio sources. Study of the properties of HYbrid MOrphology Radio Sources (HYMORS) may bring crucial information and lead to a step forward in understanding the origin of FRI/FRII dichotomy. HYMORS are a rare class of double-lobed radio sources where each of the two lobes clearly exhibits a different FR morphology. This article describes follow-up high resolution VLBA observations of the five discovered by us HYMORS. The main aim of the observations was to answer the questions of whether the unusual radio morphology is connected to the orientation of objects towards the observer. We obtained the high resolution radio maps of five hybrid radio morphology objects with the VLBA at C-band and L-band. Two of them revealed milliarcsecond core-jet structures, the next two objects showed hints of parsec-scale jets, and the last one remained point-like at both frequencies. We compared properties of observed milliarcsecond structures of hybrid sources with the larger scale ones previously detected with the VLA. We find that on both scales the fluxes of their central components are similar, which may indicate the lack of additional emission in the proximity of the nucleus. This suggests that jets present on the 1-10 kpc scale in those objects are FRII-like. When possible, the detected core-jet structures were used for estimating the core's spatial orientation. The result is that neither the FRI-like nor the FRII-like side is preferred, which may suggest that no specific spatial orientation of HYMORS is required to explain their radio morphology. Their estimated viewing angles indicate they are unbeamed objects. The 178 MHz luminosity of observed HYMORS exceed the traditional FRI/FRII break luminosity, indicating they have radio powers similar to FRIIs.Comment: 7 pages, 5 figures, accepted for publication in A&

Predicting spectral features in galaxy spectra from broad-band photometry

We explore the prospects of predicting emission line features present in galaxy spectra given broad-band photometry alone. There is a general consent that colours, and spectral features, most notably the 4000 A break, can predict many properties of galaxies, including star formation rates and hence they could infer some of the line properties. We argue that these techniques have great prospects in helping us understand line emission in extragalactic objects and might speed up future galaxy redshift surveys if they are to target emission line objects only. We use two independent methods, Artifical Neural Neworks (based on the ANNz code) and Locally Weighted Regression (LWR), to retrieve correlations present in the colour N-dimensional space and to predict the equivalent widths present in the corresponding spectra. We also investigate how well it is possible to separate galaxies with and without lines from broad band photometry only. We find, unsurprisingly, that recombination lines can be well predicted by galaxy colours. However, among collisional lines some can and some cannot be predicted well from galaxy colours alone, without any further redshift information. We also use our techniques to estimate how much information contained in spectral diagnostic diagrams can be recovered from broad-band photometry alone. We find that it is possible to classify AGN and star formation objects relatively well using colours only. We suggest that this technique could be used to considerably improve redshift surveys such as the upcoming FMOS survey and the planned WFMOS survey.Comment: 10 pages 7 figures summitted to MNRA

Origin of the `He/N' and `Fe II' Spectral Classes of Novae

The spectra of postoutburst novae display either He+N or Fe II lines as the most prominent non-Balmer lines at maximum light. Spectral diagnostics indicate physical conditions for 'He/N' spectra that are consistent with their origin in the white dwarf (WD) ejecta, whereas 'Fe II' spectra point to their formation in a large circumbinary envelope of gas whose origin is the secondary star. A determining parameter for which of the two types of spectra predominates may be the binary mass ratio Msec/MWD. The increasing fraction of novae that are observed to be 'hybrid' objects, where both classes of spectra appear sequentially, is explained by changing parameters in the two emitting regions during the postoutburst decline. We argue that most novae may be hybrids that show both types of spectra during decline. The emission line intensity ratio O I {\lambda}8446/{\lambda}7773 is suggested as a good density diagnostic for the ejecta, and a finding list of emission lines identified in recent spectroscopic surveys of novae is presented as an aid to future line identification work.Comment: 14 pages, 2 table

A Rewriting-Logic-Based Technique for Modeling Thermal Systems

This paper presents a rewriting-logic-based modeling and analysis technique for physical systems, with focus on thermal systems. The contributions of this paper can be summarized as follows: (i) providing a framework for modeling and executing physical systems, where both the physical components and their physical interactions are treated as first-class citizens; (ii) showing how heat transfer problems in thermal systems can be modeled in Real-Time Maude; (iii) giving the implementation in Real-Time Maude of a basic numerical technique for executing continuous behaviors in object-oriented hybrid systems; and (iv) illustrating these techniques with a set of incremental case studies using realistic physical parameters, with examples of simulation and model checking analyses.Comment: In Proceedings RTRTS 2010, arXiv:1009.398

Exploring the aesthetics of tangible interaction : experiments on the perception of hybrid objects

We report the results of an extended empirical two-stage study on the aesthetics of hybrid objects that combine form and behaviour. By combining two shapes (spheres and cubes); two sizes (7.5cm and 15cm); two materials (fabric and plastic); and four behaviours (emitting light, emitting sound, vibrating or displaying no behaviour) we created 32 objects that differ for a single feature. In a between-participants study, 175 participants assessed and described the 32 objects. From this, seven dimensions were identified: pleasant; interesting; comfortable; playful; relaxing; special and surprising. In a second between-participants experiment 486 participants rated each object on the seven dimensions from the first study. Overall Spheres, Fabric, and Vibration were the preferred features, but for some of the dimensions specific combinations of features were rated more positively. This paper contribution is twofold: it provides a first study on the aesthetic of tangible interaction as a combination of form and behaviour outlining a potential instrument to measure it; and it provides empirical evidence of the value of experimenting with different forms (spheres) and material (fabric) even if they are difficult to create as they generate the strongest aesthetic effects

Compiled - A Format for Hybrid Objects

The thesis is a practice oriented study describing the design process of a series of lamps, entitled Compiled. The exploratory research process is based on principles for combining universal forms into pluralistic hybrid objects. I strive to answer the following question: What kind of format can be defined for generating hybrid objects? I will illuminate five concepts on which I base my research. System to unify aesthetics; Universal forms; Object categories; Pluralistic objects; and Hybrid Objects. These five concepts will create a framework and substance and for the design procedure. I will start with describing terminology that I use; namely, what I intend with terms such as Pluralistic and Hybrid Objects. In chapter three, I refer to Gregor Paulsson’s idealistic idea for consistent systems, to Kaj Franck and his simplified and reduced tableware based on universal forms, and to the objects cocktails by Pekka Harni. After having defined the five key concepts of this study, I introduce an idea of a Format, based on the five research concepts. I strive to build a more holistic and complete Format, and create a theoretical explanation of the procedure of generating the Compiled lamps. I use the pluralistic design methodology of industrial designer Stephen Burks as a foundation for generating a format for hybrid objects. Through out the examination of the procedure, I will refer to the design process of the Compiled lamp series, as well as other designers’ work that demonstrates the concept of Hybridism or otherwise indicate a pluralistic approach. I examine criteria for a format of practice, where rational principles generate forms. Consequently, form will determine function and attributes. I will condense the process into the phrase “Function Follows Form & Form Follows Format”, a contradictory variation of the original statement by Louis Sullivan. I examine a process that could possible be used as a format for generating objects and will also attempt to generalize the practice into a methodology that may support establishing a personal design vocabulary. The prototypes of the Compiled series have been invited to a range of exhibitions, which I will demonstrate. The exhibitions have also played a crucial role for gaining feedback and objective perceptions on this experimental project. This has helped me to create a broader understanding of the potential and the deficiencies of the concept. The Compiled lamps are evaluated by producibility, merchandisability and by commercial relevance, in conjunction with Managing Director of Saas Instruments, Håkan Långstedt. Based on the evaluation, we have created a reduced collection of lamps that will represent the final collection of the Compiled series. Regarding the continuity of Compiled, I will hereafter attempt to source a suitable cooperative manufacturer and brand for the Compiled collection