Existential Second-Order Logic Over Graphs: A Complete Complexity-Theoretic Classification

Descriptive complexity theory aims at inferring a problem's computational complexity from the syntactic complexity of its description. A cornerstone of this theory is Fagin's Theorem, by which a graph property is expressible in existential second-order logic (ESO logic) if, and only if, it is in NP. A natural question, from the theory's point of view, is which syntactic fragments of ESO logic also still characterize NP. Research on this question has culminated in a dichotomy result by Gottlob, Kolatis, and Schwentick: for each possible quantifier prefix of an ESO formula, the resulting prefix class either contains an NP-complete problem or is contained in P. However, the exact complexity of the prefix classes inside P remained elusive. In the present paper, we clear up the picture by showing that for each prefix class of ESO logic, its reduction closure under first-order reductions is either FO, L, NL, or NP. For undirected, self-loop-free graphs two containment results are especially challenging to prove: containment in L for the prefix $\exists R_1 \cdots \exists R_n \forall x \exists y$ and containment in FO for the prefix $\exists M \forall x \exists y$ for monadic $M$. The complex argument by Gottlob, Kolatis, and Schwentick concerning polynomial time needs to be carefully reexamined and either combined with the logspace version of Courcelle's Theorem or directly improved to first-order computations. A different challenge is posed by formulas with the prefix $\exists M \forall x\forall y$: We show that they express special constraint satisfaction problems that lie in L.Comment: Technical report version of a STACS 2015 pape

Tactor devices : using tactile interface designs for mobile digital appliances : a practice-based research thesis for the fulfilment of a Master of Design degree, College of Design, Fine Arts, and Music, Massey University, Wellington

This Thesis focuses the potential of communication interfaces that use tactors (tactile actuators) to improve user interactions with mobile digital devices which are currently based on audio and visual technologies. It presents two product concepts, which use tactile signals to enable new ways in tele-operations, such as tactile telecommunication and tactile navigation. Tactor interfaces, although still in its infancy as elements of modern digital communication and technology, have considerable potential for the future as designers attempt to maximise the use of all human senses in people's interaction with technology. Only the military and a few entertainment companies have introduced tactile signals into Human-Computer Interactions (HCI). Human touch perception uses the hands as the main sensing organs. They perceive tactile signals while handling, typing or navigating with digital devices and receive direct confirmation of physical actions. In contrast to other senses, touch perceptions are based on interactions with the sensed objects. The study analyses, experiments and evaluates if these interactions are useful in interface designs and recommends how tactile stimulations can be introduced to interface designs besides images and sounds that dominate the control of current digital appliances. Tactile actuators and sensors enable devices to use tactile signals, such as impulses and vibrations, to communicate with the users. Users and tactor devices will be able to communicate in a physical and direct way. Touch reflective interfaces, could react like living creatures that respond to touch, for example a cat that starts purring when touched. Digital product design is always challenged to create human-computer interactions that meet people's needs. Designing digital devices is difficult because they are not necessarily three-dimensional objects. They are stimulator of the human senses and can be as small as the sensing nerve endings that detect sensations. By miniaturisation, form and function become invisible and Product Design is increasingly incorporating Process Design that explores and enables new interactions between users and products to work interactively and efficiently. The study is divided into four chapters: Chapter 1 gives an introduction to the thesis. Chapter 2 presents a survey on current literature which examines the five human senses to define the limits and possibilities in interface design. It reviews current research on materials and technologies as well as the psychology and physiology of touch as a potential sense in human-computer interactions. It evaluates the technical feasibilty of tactile signal performances and how they could be used as tele-touch codes in navigation and telecommunication. Chapter 3 is focused on primary research undertaken to extend the knowledge in tactile sensing. It includes experiments, questionnaires, and concepts that give examples how tactor interfaces can be used in tele-operations. This section focuses on specific user groups, that may primarily benefit from tactile signal transmissions, such as sight and hearing-impaired people or professionals who have to deal with limited perceptions like fire fighters, for example. These case studies are aimed at exploring and expanding a wider range of possibilities in tactile device innovations in the networked society. Chapter 4 gives a conclusion of the research

Pop stars and idolatry: an investigation of the worship of popular music icons, and the music and cult of Prince.

Prince is an artist who integrates elements from the sacred into his work. He uses popular iconography to present himself as an icon of consumer culture, as a deified ‘rock god’ worshipped by his fans, and as a preacher leading his audience like a congregation. His personality cult mixes spirituality and sexuality, and deals with issues of ecstasy and liberation, a transgressional approach that draws both controversy and public interest. This paper investigates Prince’s work and the role of the pop star as an icon within contemporary culture, an icon that contains a physicality and sexuality not present in contemporary western religious traditions. It discusses to what extent popular musical culture operates as a form of religious practice within contemporary western culture, and the implications that this has. The paper investigates the construction of Prince’s public character, his manipulation of the star system, and how he uses popular iconography to blur the distinctions between spirituality and sexuality, the idealised performer and the real world, the sacred and the profane, and the human and the divine. It explores how he possesses and is possessed by the audience, who enter into the hollow vessel he offers up to his fans

The quantification of gender: Anorexia nervosa and femininity

The ways in which Anorexia Nervosa (AN) has been described and explained has differed drastically over time although since it was first named in 1874 it has been primarily associated with women and girls it is argued in this paper that it came to be more fundamentally associated with femininity due to certain disciplinary changes in the psy sciences. The influential psychiatrist Hilde Bruch lamented the loss in clarity of the clinical picture that was the result of psychoanalytic interpretations, to remedy this she reformulated AN into a pathology that was the result of the individual being too determined by external influences. Bruch’s changes increased the emphasis that psychiatrists placed on the relationship between women and their social context and the lack of individual autonomy that many felt. Feminist writers adapted Bruch’s theory to suggest that patriarchal culture was colonizing the lives of women and that social rather than individual change needed to occur. Psychiatrists subsequently developed scales for assessing gender identity which switched the emphasis back onto individuals and rendered gender as an individualised, quantifiable, manipulable object. When reified and individualised in this fashion it became more legitimate to discuss femininity as causative of, and masculinity as a protection against, AN

Exit, Voice, and Cyclicality: A Micro-Logic of Voting Behaviour in European Parliament Elections

Unlike other classics of political economy, “Exit, Voice, and Loyalty” (EVL) has not sparked many innovations in the field of electoral studies. This paper aims to demonstrate that scholars miss out on a powerful theory of political behaviour by leaving Hirschman’s ideas to other disciplines. To change this, I resolve several theoretical complications that have hampered the application of EVL to democratic elections. On this basis, I construct a model of voting behaviour through the electoral cycle to explain typical “second-order” effects in elections to the European Parliament (EP). Building on the parameters of EVL allows to unite such diverse phenomena as anti-government swings, declining turnout, protest voting, conversion and alienation in one theoretical framework. Testing the model with survey data from the European Election Studies of 1999 and 2004 reveals novel insights into the dynamics at work in EP elections. The role of strategic voting in the form of voice appears to be limited. Instead, processes of de- and realignment in the form of exit dominate a picture of EP elections that undermines the widespread conception of second-order irrelevance

Permutation Modular Invariants from Modular Functors

For any finite group G with a finite G-set X and a modular tensor category C we construct a part of the algebraic structure of an associated G-equivariant monoidal category: For any group element g in G we exhibit the module category structure of the g-component over the trivial component. This uses the formalism of permutation equivariant modular functors that was worked out in arXiv:1004.1825. As an application we show that the corresponding modular invariant partition function is given by permutation by g.Comment: 30 pages, several figure