Geometric properties of 2-dimensional minimal surfaces in a sub-Riemannian manifold which models the Visual Cortex

In this paper we study the notion of degree forsubmanifolds embedded in an equiregular sub-Riemannian manifold and we provide the definition of their associated area functional. In this setting we prove that the Hausdorff dimension of a submanifold coincides with its degree, as stated by Gromov. Using these general definitions we compute the first variation for surfaces embedded in low dimensional manifolds and we obtain the partial differential equation associated to minimal surfaces. These minimal surfaces have several applications in the neurogeometry of the visual cortex.

What happens at the gap between knowledge and practice? Spaces of encounter and misencounter between environmental scientists and local people

Researchers studying processes of global environmental change are increasingly interested in their work having impacts that go beyond academia to influence policy and management. Recent scholarship in the conservation sciences has pointed to the existence of a research-action gap and has proposed various solutions for overcoming it. However, most of these studies have been limited to the spaces of dissemination, where the science has already been done and is then to be passed over to users of the information. Much less attention has been paid to encounters that occur between scientists and nonscientists during the practice of doing scientific research, especially in situations that include everyday roles of labor and styles of communication (i.e., fieldwork). This paper builds on theories of contact that have examined encounters and relations between different groups and cultures in diverse settings. I use quantitative and qualitative evidence from Madidi National Park, Bolivia, including an analysis of past research in the protected area, as well as interviews (N = 137) and workshops and focus groups (N = 12) with local inhabitants, scientists, and park guards. The study demonstrates the significance of currently unacknowledged or undervalued components of the research-action gap, such as power, respect, and recognition, to develop a relational and reciprocal notion of impact. I explain why, within such spaces of encounter or misencounter between scientists and local people, knowledge can be exchanged or hidden away, worldviews can be expanded or further entrenched, and scientific research can be welcomed or rejected.

Geometric Hamiltonian formulation of a variational problem depending on the covariant acceleration

We consider a second-order variational problem depending on the covariant acceleration, which is related to the notion of Riemannian cubic polynomials. This problem and the corresponding optimal control problem are described in the context of higher order tangent bundles using geometric tools. The main tool, a presymplectic variant of Pontryagin’s maximum principle, allows us to study the dynamics of the control problem.

On f-vectors of polytopes and matroids

Thesis (Ph.D.)--University of Washington, 2016-08

Towards a Definition of Death Anxiety

There is currently no consensus about what the notion of death anxiety means. This commentary explores the complexity of death anxiety, asserts the distinction between anxiety and fear,and attempts a definition that encompasses the many facets associated with the term.

‘The Emergence of the Operatic’

The chapter discusses the notion of the ‘operatic’ with particular reference to movement. Through observation of singers in rehearsal and through interviews with singers over two years, the research posits that ‘operatic’ movement may be identified and explored as a discrete quality of movement in performance and recognised as an, albeit underappreciated, aspect of the artistry of the opera singer. The paper explores the effects of the demands of singing on the dramatic expressivity of the body and the strategies employed by singers to navigate, the sometimes conflicting demands of the composer and the director. ‘Operatic’ movement is regarded as that which is not generated through character or narrative (positioned as a normative approach to acting) but through the negotiation of the physical constrictions and artificiality of breath associated with operatic singing, combined with sensitivity towards opera’s non-normative performance conventions. This position is aided by an interrogation of opera through the lens of gender theory. The chapter makes two propositions, that the ‘operatic’, which does not form part of the formal pedagogy of singers, is an emergent property, especially evident at the intersection of the various creative disciplines that contribute to opera, such as when the orchestra is introduced to the rehearsal process, and that ‘operaticness’ is acquired and passed on through a process of kinaesthetic empathy.

Concepts of the Global South

Where and what is the Global South? If you ask people on the street, many would probably not have the faintest idea. In everyday parlance and mass media, Global South has hardly become a household term. In academic and (global) policy circles, though, the term is used with much more gusto. Politicians refer to it. The United Nations organize their statistical data in accordance with the term. Academics write books about it - or, as in our case, explicitly include the term in the name of a research center: Global South Studies Center (GSSC). But what does the term entail? Who uses it and why? And what are the implications of marking distinctions between the Global South and the Global North? We thought it relevant to address these questions in more detail – after all, we work for a recently established research institute featuring the term in its name. Accordingly, we asked a number of academics, journals and academic institutions to reflect on the term. In this online issue, we share their various perspectives and critical reflections on the notion of the Global South – see also a short discussion on a number of YouTube videos we have included.

Surveillance in Nineteen Eighty-Four : The Dismantling of Privacy in Oceania

The purpose of this essay is to analyze how certain elements of panopticism manage to dismantle the notion of privacy in George Orwell’s novel Nineteen Eighty-Four. By reading the text through a lens of panopticism, a theory introduced by Jeremy Bentham, I give examples on how the surveillance methods used by the Party share similarities with the system of surveillance within a Panoptic prison, but also in what ways that they differ. In the end, it is obvious that the society of Oceania cannot be considered to be a complete Panopticon, although several elements of panopticism are present within the text and that they dismantle the aspect of privacy in the novel. 

Behavioral equivalence of hidden k-logics: an abstract algebraic approach

This work advances a research agenda which has as its main aim the application of Abstract Algebraic Logic (AAL) methods and tools to the specification and verification of software systems. It uses a generalization of the notion of an abstract deductive system to handle multi-sorted deductive systems which differentiate visible and hidden sorts. Two main results of the paper are obtained by generalizing properties of the Leibniz congruence — the central notion in AAL. In this paper we discuss a question we posed in [1] about the relationship between the behavioral equivalences of equivalent hidden logics. We also present a necessary and sufficient intrinsic condition for two hidden logics to be equivalent.

Software tools for automating the parallelisation of FORTRAN computational mechanics codes

It is now clear that the concept of a HPC compiler which automatically produces highly efficient parallel implementations is a pipe-dream. Another route is to recognise from the outset that user information is required and to develop tools that embed user interaction in the transformation of code from scalar to parallel form, and then use conventional compilers with a set of communication calls. This represents the key idea underlying the development of the CAPTools software environment. The initial version of CAPTools is focused upon single block structured mesh computational mechanics codes. The capability for unstructured mesh codes is under test now and block structured meshes will be included next. The parallelisation process can be completed rapidly for modest codes and the parallel performance approaches that which is delivered by hand parallelisations.

Sharing the vision: representing the matters of concern for design-led fledgling companies in Scotland

Design is being performed on an ever-increasing spectrum of complex practices arising in response to emerging markets and technologies, co-design, digital interaction, service design and cultures of innovation. This emerging notion of design has led to an expansive array of collaborative and facilitation skills to demonstrate and share how such methods can shape innovation. The meaning of these design things in practice can't be taken for granted as matters of fact, which raises a key challenge for design to represent its role through the contradictory nature of matters of concern. This paper explores an innovative, object-oriented approach within the field of design research, visually combining an actor-network theory framework with situational analysis, to report on the role of design for fledgling companies in Scotland, established and funded through the knowledge exchange hub Design in Action (DiA). Key findings and visual maps are presented from reflective discussions with actors from a selection of the businesses within DiA's portfolio. The suggestion is that any notions of strategic value, of engendering meaningful change, of sharing the vision of design, through design things, should be grounded in the reflexive interpretations of matters of concern that emerge.

Adobe's Acrobat -- providing the missing link?

Adobe's Acrobat software, released in June 1993, is based around a new Portable Document Format (PDF) which offers the possibility of being able to view and exchange electronic documents, independent of the originating software, across a wide variety of supported hardware platforms (PC, Macintosh, Sun UNIX etc.). The fact that the imageable objects are rendered with full use of Level 2 PostScript means that the most demanding requirements can be met in terms of high-quality typography, device-independent colour and full page fidelity with respect to the printed version. PDF possesses an internal structure which supports hypertextual features, and a range of file compression options. In a sense PDF establishes a low-level multiplatform machine code for imageable objects but its notion of hypertext buttons and links is similarly low-level , in that they are anchored to physical locations on xed pages. However, many other hypertext systems think of links as potentially spanning multiple files, which may in turn be located on various machines scattered across the Internet. The immediate challenge is to bridge the "abstraction gap" between high-level notions of a link and PDF's positionally-anchored low-level view. More specifically, how can Mosaic, WWW and Acrobat/PDF be configured so that the notions of "link ", in the various systems, work together harmoniously? This paper reviews progress so far on the CAJUN project (CD-ROM Acrobat Journals Using Networks) with particular reference to experiments that have already taken place in disseminating PDF via e-mail, Gopher and FTP. The prospects for integrating Acrobat seamlessly with WWW are then discussed.

Between Bacchus and Dionysus: European Union policies on rural development: the cases of Nemea and Basto wine regions

A actividade vitivinícola possui um conjunto diverso de características presentes no solo, território e comunidade que fazem parte do património cultural de uma determinada região. Quando a tradição se traduz num conceito como terroir que é formado por características territoriais, sociais e culturais de uma região rural, o vinho apresenta uma “assinatura” que se escreve “naturalmente” no paladar regionalmente identificado. Os vinhos da Região de Nemea, na Grécia e de Basto (Região dos Vinhos Verdes) em Portugal, estão ambos sob a proteção dos regulamentos das Denominações de Origem. No entanto, apesar de ambos serem regulados por sistemas institucionais de certificação e controlo de qualidade, afigura-se a necessidade de questionar se o património cultural e a identidade territorial específica, “impressa” em ambos os terroirs, pode ser protegida num sentido mais abrangente do que apenas origem e qualidade. Em Nemea, a discussão entre os produtores diz respeito ao estabelecimento de sub-zonas, isto é incluir na regulação PDO uma diferente categorização territorial com base no terroir. Ou seja, para além de estar presente no rótulo a designação PDO, as garrafas incluirão ainda informação certificada sobre a área específica (dentro do mesmo terroir) onde o vinho foi produzido. A acontecer resultaria em diferentes status de qualidade de acordo com as diferentes aldeias de Nemea onde as vinhas estão localizadas. O que teria possíveis impactos no valor das propriedades e no uso dos solos. Para além disso, a não participação da Cooperativa de Nemea na SON (a associação local de produtores de vinho) e como tal na discussão principal sobre as mudanças e os desafios sobre o terroir de Nemea constitui um problema no sector vitivinícola de Nemea. Em primeiro lugar estabelece uma relação de não-comunicação entre os dois mais importantes agentes desse sector – as companhias vinícolas e a Cooperativa. Em segundo lugar porque constituiu uma possibilidade real, não só para os viticultores ficarem arredados dessa discussão, como também (porque não representados pela cooperativa) ficar impossibilitado um consenso sobre as mudanças discutidas. Isto poderá criar um ‘clima’ de desconfiança levando a discussão para ‘arenas’ deslocalizadas e como tal para decisões ‘desterritorializadas’ Em Basto, há vários produtores que começaram a vender a sua produção para distribuidoras localizadas externamente à sub-região de Basto, mas dentro da Região dos Vinhos Verdes, uma vez que essas companhias tem um melhor estatuto nacional e internacional e uma melhor rede de exportações. Isto está ainda relacionado com uma competição por uma melhor rede de contactos e status mais forte, tornando as discussões sobre estratégias comuns para o desenvolvimento rural e regional de Basto mais difícil de acontecer (sobre isto a palavra impossível foi constantemente usada durante as entrevistas com os produtores de vinho). A relação predominante entre produtores é caracterizada por relações individualistas. Contudo foi observado que essas posições são ainda caracterizadas por uma desconfiança no interior da rede interprofissional local: conflitos para conseguir os mesmos potenciais clientes; comprar uvas a viticultores com melhor rácio qualidade/preço; estratégias individuais para conseguir um melhor status político na relação com a Comissão dos Vinhos Verdes. Para além disso a inexistência de uma activa intermediação institucional (autoridades municipais e a Comissão de Vinho Verde), a inexistência entre os produtores de Basto de uma associação ou mesmo a inexistência de uma cooperativa local tem levado a região de Basto a uma posição de subpromoção nas estratégias de promoção do Vinho Verde em comparação com outras sub-regiões. É também evidente pelos resultados que as mudanças no sector vitivinícolas na região de Basto têm sido estimuladas de fora da região (em resposta também às necessidades dos mercados internacionais) e raramente de dentro – mais uma vez, ‘arenas’ não localizadas e como tal decisões desterritorializadas. Nesse sentido, toda essa discussão e planeamento estratégico, terão um papel vital na preservação da identidade localizada do terroir perante os riscos de descaracterização e desterritorialização. Em suma, para ambos os casos, um dos maiores desafios parece ser como preservar o terroir vitivinícola e como tal o seu carácter e identidade local, quando a rede interprofissional em ambas as regiões se caracteriza, tanto por relações não-consensuais em Nemea como pelo modus operandi de isolamento sem comunicação em Basto. Como tal há uma necessidade de envolvimento entre os diversos agentes e as autoridades locais no sentido de uma rede localizada de governança. Assim sendo, em ambas as regiões, a existência dessa rede é essencial para prevenir os efeitos negativos na identidade do produto e na sua produção. Uma estratégia de planeamento integrado para o sector será vital para preservar essa identidade, prevenindo a sua desterritorialização através de uma restruturação do conhecimento tradicional em simultâneo com a democratização do acesso ao conhecimento das técnicas modernas de produção vitivinícola.

FRAMEWORK SYNTHESIS FOR SYMBOLIC EXECUTION OF EVENT-DRIVEN FRAMEWORKS

Symbolic execution is a powerful program analysis technique, but it is very challenging to apply to programs built using event-driven frameworks, such as Android. The main reason is that the framework code itself is too complex to symbolically execute. The standard solution is to manually create a framework model that is simpler and more amenable to symbolic execution. However, developing and maintaining such a model by hand is difficult and error-prone. We claim that we can leverage program synthesis to introduce a high-degree of automation to the process of framework modeling. To support this thesis, we present three pieces of work. First, we introduced SymDroid, a symbolic executor for Android. While Android apps are written in Java, they are compiled to Dalvik bytecode format. Instead of analyzing an app’s Java source, which may not be available, or decompiling from Dalvik back to Java, which requires significant engineering effort and introduces yet another source of potential bugs in an analysis, SymDroid works directly on Dalvik bytecode. Second, we introduced Pasket, a new system that takes a first step toward automatically generating Java framework models to support symbolic execution. Pasket takes as input the framework API and tutorial programs that exercise the framework. From these artifacts and Pasket's internal knowledge of design patterns, Pasket synthesizes an executable framework model by instantiating design patterns, such that the behavior of a synthesized model on the tutorial programs matches that of the original framework. Lastly, in order to scale program synthesis to framework models, we devised adaptive concretization, a novel program synthesis algorithm that combines the best of the two major synthesis strategies: symbolic search, i.e., using SAT or SMT solvers, and explicit search, e.g., stochastic enumeration of possible solutions. Adaptive concretization parallelizes multiple sub-synthesis problems by partially concretizing highly influential unknowns in the original synthesis problem. Thanks to adaptive concretization, Pasket can generate a large-scale model, e.g., thousands lines of code. In addition, we have used an Android model synthesized by Pasket and found that the model is sufficient to allow SymDroid to execute a range of apps.

What can be learned from failed proofs of non-theorems?

This paper reports an investigation into the link between failed proofs and non-theorems. It seeks to answer the question of whether anything more can be learned from a failed proof attempt than can be discovered from a counter-example. We suggest that the branch of the proof in which failure occurs can be mapped back to the segments of code that are the culprit, helping to locate the error. This process of tracing provides finer grained isolation of the offending code fragments than is possible from the inspection of counter-examples. We also discuss ideas for how such a process could be automated.