From chamber to transformer: epistemological challenges in the methodology of theorised architectural history

While many architectural historians are conscious of their methodological procedures, this aspect of architectural history is rarely singled out for any prolonged consideration. In addition, while many architectural historians have, in recent years, made increasing reference to various forms of theory in order to inform their interpretations, this aspect of their work has been similarly devoid of any concentrated analysis. In order partly to redress this situation, this article does not offer any worked examples of historical analysis but, rather, focuses on the epistemological challenges facing the architectural historian. In particular, the article argues for the necessity of engaging with different kinds of critical theory in order to understand architecture. As a result, nine challenges can be identified for the discipline of architectural history: to theory as the object of study, to new architectures, to the framing of interpretative questions, to the critical nature of history, to interdisciplinary debates, to the opening of methodological procedures, to selfcritical development of the discipline, to re-engagement with critical theory, and to praxis. Only when these challenges are met, the authors contend, will a proper methodology of architectural history be constructed.     

Problems associated with the off-line programming of robots

The introduction of robots into any organization forms part of a considerable investment in new technology over a range of applications in the search for efficiency and increased productivity. The greater consistency and quality associated with robot operations, compared with that of the human operator, is regarded as an advantage both in relation to the manufacturing process and to the product. However, in order to make the most efficient use of robots, the ability to generate good robot programs must be developed. Traditional robot programming techniques are extremely slow and laborious. Off-line programming by textual input alone is an equally tedious process. In this paper, existing and potential problems associated with off-line programming are examined. Various commercial and experimental robot languages and their relative important features are described. Opinions of manufacturers of CNC (Computer Numerically Controlled) machines and robots concerning both user interfaces and potential candidate users are discussed. Both the training and the abilities of the candidate robot programmers are important aspects of any robot programming system, although obviously much will depend on the sophistication of the particular application. Recommendations are made concerning issues that should be taken into account when developing future off-line programming systems.     

A Prediction on the Strength of Glass Following the Formation of Subsurface Flaws by Scribing

An analysis is presented to predict the strength of glass after subsurface cracking is produced by drawing a lightly loaded angular particle across the surface. It is shown that the presence of subsurface cracks combined with the residual stresses introduced by such scratches under very small loads greatly lowers the strength of glass. The predicted ranges of tensile strength for soda–lime glass in dry and moist environments are in agreement with typical values in the literature.     

Discrete p-robust $$\varvec{H}({{\mathrm{div}}})$$-liftings and a posteriori estimates for elli ptic problems with $$H^{-1}$$H-1 source terms

We establish the existence of liftings into discrete subspaces of \(\varvec{H}({{\mathrm{div}}})\) of piecewise polynomial data on locally refined simplicial partitions of polygonal/polyhedral domains. Our liftings are robust with respect to the polynomial degree. This result has important applications in the a posteriori error analysis of parabolic problems, where it permits the removal of so-called transition conditions that link two consecutive meshes. It can also be used in the a posteriori error analysis of elliptic problems, where it allows the treatment of meshes with arbitrary numbers of hanging nodes between elements. We present a constructive proof based on the a posteriori error analysis of an auxiliary elliptic problem with \(H^{-1}\) source terms, thereby yielding results of independent interest. In particular, for such problems, we obtain guaranteed upper bounds on the error along with polynomial-degree robust local efficiency of the estimators.     

From Faces to Outdoor Light Probes

Image‐based lighting has allowed the creation of photo‐realistic computer‐generated content. However, it requires the accurate capture of the illumination conditions, a task neither easy nor intuitive, especially to the average digital photography enthusiast. This paper presents an approach to directly estimate an HDR light probe from a single LDR photograph, shot outdoors with a consumer camera, without specialized calibration targets or equipment. Our insight is to use a person's face as an outdoor light probe. To estimate HDR light probes from LDR faces we use an inverse rendering approach which employs data‐driven priors to guide the estimation of realistic, HDR lighting. We build compact, realistic representations of outdoor lighting both parametrically and in a data‐driven way, by training a deep convolutional autoencoder on a large dataset of HDR sky environment maps. Our approach can recover high‐frequency, extremely high dynamic range lighting environments. For quantitative evaluation of lighting estimation accuracy and relighting accuracy, we also contribute a new database of face photographs with corresponding HDR light probes. We show that relighting objects with HDR light probes estimated by our method yields realistic results in a wide variety of settings.     

Influence of soil physical properties, fertiliser type and moisture tension on N2O and NO emissions from nearly saturated Japanese upland soils

In Japan, upland soils are an important source of nitrous oxide (N₂O) and nitric oxide (NO) gas emissions. This paper reports on an investigation of the effect of soil moisture near saturation on N₂O and NO emission rates from four upland soils in Japan of contrasting texture. The aim was to relate these effects to soil physical properties. Intact cores of each soil type were incubated in the laboratory at different moisture tensions after fertilisation with NH₄-N, NO₃-N or zero N. Emissions of N₂O and NO were measured regularly over a 16–20 day period. At the end of the incubation, soil cores were analysed for physical properties. Moisture and N fertiliser significantly affected rates of emissions of both N₂O and NO with large differences between the soil types. Nitrous oxide emissions were greatest in the finer-textured soils, whereas NO emissions were greater in the coarser-textured soils. Emissions of N₂O increased at higher moisture contents in all soils, but the magnitude of increase was much greater in finer-textured soils. Nitric oxide emissions were only significant in soils fertilised with NH₄-N and were negatively correlated with soil moisture. Analysis of soil properties showed that there was a strong relationship between the magnitude of emissions and soil physical properties. The importance of soil wetness to gas emissions was mainly through its influence on soil air-filled porosity, which itself was related to gas diffusivity. From the results of this research, we can now estimate likely effects of soil texture on emissions through the influence of soil type on soil aeration and soil drainage. This is of particular value in modelling N₂O and NO emissions from soil moisture status and land use inputs.     

A review and analysis of current computer-aided fixture design approaches

A key characteristic of the modern market place is the consumer demand for variety. To respond effectively to this demand, manufacturers need to ensure that their manufacturing practices are sufficiently flexible to allow them to achieve rapid product development. Fixturing, which involves using fixtures to secure workpieces during machining so that they can be transformed into parts that meet required design specifications, is a significant contributing factor towards achieving manufacturing flexibility. To enable flexible fixturing, considerable levels of research effort have been devoted to supporting the process of fixture design through the development of computer-aided fixture design (CAFD) tools and approaches. This paper contains a review of these research efforts. Over seventy-five CAFD tools and approaches are reviewed in terms of the fixture design phases they support and the underlying technology upon which they are based. The primary conclusion of the review is that while significant advances have been made in supporting fixture design, there are primarily two research issues that require further effort. The first of these is that current CAFD research is segmented in nature and there remains a need to provide more cohesive fixture design support. Secondly, a greater focus is required on supporting the detailed design of a fixture's physical structure.