Astigmatism and Pseudoaccommodation in Pseudophakic Eyes

noAdvanced IOLs with circumferential zones of different power provide pseudoaccommodation. We investigated the potential for power variation with meridian, namely astigmatism, to provide pseudo-accommodation. With appropriate power and axis orientations, acceptable pseudo-accommodation can be achieved

EU banks rating assignments: Is there heterogeneity between new and old member countries?

We model EU countries’ bank ratings using financial variables and allowing for intercept and slope heterogeneity. We find that country-specific factors (in the form of heterogeneous intercepts) are a crucial determinant of ratings. Whilst “new” EU countries typically have lower ratings than “old” EU countries, after ontrolling for financial variables, all countries are found to have significantly different intercepts, which confirms our hypothesis. This intercept heterogeneity may reflect differences in country risk and the legal and regulatory framework that banks face (such as foreclosure laws). In addition, ratings may respond differently to the liquidity and operating expenses to operating income variables across countries: typically ratings are more responsive to the former and less sensitive to the latter for “new” EU countries compared with “old” EU countries

The village and the city: a diagnostic study of the spatial embedding patterns in villages absorbed by cities in Bahrain

During the growth of cities villages are frequently absorbed into the fabric of that conurbation. But what are the consequences of this? To what extent and how well do these villages become part of the overall fabric of the city? What is the effect on the village and the wider city? How do these villages interact with the configuration of the city to create a rich spatial urban structure? This study focuses on the spatial distribution of the internal and edge commercial activity within the villages absorbed by Manama and Muharraq, cities of Bahrain, and their correspondence with the syntactic factors as a key factor for the subject. Fully understanding these interactions entails answering three critical questions: Does the commercial activity on the streets in the ten villages of Manama and Muharraq differ in configuration and scale? If yes, what is the level of the differences? How does the commercial activity in these villages relate to the structure of the city? Are the commercial activities related to the local or global structure of the city? Are the commercial activities in absorbed villages part of the context or are they distinguished? What are the spatial dimensions of the commercial activity of the village and how do they determine the means of creating a superior spatial structure in the city? Theses questions are addressed in this paper against the background of a coherent body of literature which uses the space syntax theory and methods, and offers a certain rigour in the analysis of spatial layout. Its syntactic concepts also provide a rigorous spatial framework for the analysis, enabling us to study the key attributes of the absorbed villages in a city context. It is the intention of this paper to develop deep syntactic studies of villages absorbed in a city's fabric by identifying different spatial factors, and looking at their performance over different scales from local to global radii. It focuses on explicitly exploring the properties of contextual structure in the formation of absorbed villages rather than simply the properties of the internal structure. It seeks to contribute to a better understanding of the spatial city structure. The framework is built through a comparison case study of ten villages absorbed by the cities of Manama and Muharraq. The paper explores the relationships between different components such as, on the one hand, spatial factors, and on the other hand, social and economic factors of the villages. It shows that the main dimension of spatial layout of commercial activity derives from a set of basic principles. Depending on the way a village's commercial streets become part of the context or are kept separate from the context, it is possible to distinguish different spatial relationships between the village and the city's fabric

Cluster and Feature Modeling from Combinatorial Stochastic Processes

One of the focal points of the modern literature on Bayesian nonparametrics has been the problem of clustering, or partitioning, where each data point is modeled as being associated with one and only one of some collection of groups called clusters or partition blocks. Underlying these Bayesian nonparametric models are a set of interrelated stochastic processes, most notably the Dirichlet process and the Chinese restaurant process. In this paper we provide a formal development of an analogous problem, called feature modeling, for associating data points with arbitrary nonnegative integer numbers of groups, now called features or topics. We review the existing combinatorial stochastic process representations for the clustering problem and develop analogous representations for the feature modeling problem. These representations include the beta process and the Indian buffet process as well as new representations that provide insight into the connections between these processes. We thereby bring the same level of completeness to the treatment of Bayesian nonparametric feature modeling that has previously been achieved for Bayesian nonparametric clustering.Comment: Published in at http://dx.doi.org/10.1214/13-STS434 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Spatiality and transpatiality in workplace environments

It is widely considered that the physical layout of workplace environments has an influence on social interaction and therefore the social structure of an organisation. However, there is little accordance among scholars from different disciplines on exactly how the relationship between space and organisation is constituted. Empirical studies often come to different conclusions: for example, on the influence of an open-plan office on communication patterns among staff, as many studies report increases as report decreases or unchanged communication behaviours. This evidence-base is further confused since few studies make a link between a profound spatial and an organisational analysis. We suggest that the inconsistency of results is for two main reasons: first, methodologies for operationalising variables differ significantly with each study tending to analyse a distinct notion of a phenomenon. This makes further comparative conclusions and predictive modelling problematic. Second, even where the same methods are used, contradictory evidence emerges, where one organisation reacts differently to another to similar spatial conditions. This suggests that, at the core of the problem, lies an apparent lack of understanding of the nature of the space-organisation relationship. This paper explores these phenomena by drawing on the results of various case studies conducted over the last few years in diverse organisational settings (a university, a research institute, and in corporate media companies). Two main lines of argument will be developed: first we will show that some influences of space on organisational behaviour seem to be generic. Understanding of these generic influences may be used to design spaces enhancing interaction and knowledge flow for any type of organisation. Second, we outline how organisations depend on context, culture and character, and may react to similar spatial configurations in a unique way. We will suggest why this may be the case, referring to Hillier and Hanson's notion of spatial and transpatial modes of social cohesion. The two underlying theoretical concepts, i.e. space as 'generic function' and spatial versus transpatial operations will be discussed concerning their application to, and meaningfulness for, workplace environments. Finally, inferences are drawn for the practice of evidence-based design

Tree Buffers

In runtime verification, the central problem is to decide if a given program execution violates a given property. In online runtime verification, a monitor observes a program’s execution as it happens. If the program being observed has hard real-time constraints, then the monitor inherits them. In the presence of hard real-time constraints it becomes a challenge to maintain enough information to produce error traces, should a property violation be observed. In this paper we introduce a data structure, called tree buffer, that solves this problem in the context of automata-based monitors: If the monitor itself respects hard real-time constraints, then enriching it by tree buffers makes it possible to provide error traces, which are essential for diagnosing defects. We show that tree buffers are also useful in other application domains. For example, they can be used to implement functionality of capturing groups in regular expressions. We prove optimal asymptotic bounds for our data structure, and validate them using empirical data from two sources: regular expression searching through Wikipedia, and runtime verification of execution traces obtained from the DaCapo test suite

Context-aware adaptation in DySCAS

DySCAS is a dynamically self-configuring middleware for automotive control systems. The addition of autonomic, context-aware dynamic configuration to automotive control systems brings a potential for a wide range of benefits in terms of robustness, flexibility, upgrading etc. However, the automotive systems represent a particularly challenging domain for the deployment of autonomics concepts, having a combination of real-time performance constraints, severe resource limitations, safety-critical aspects and cost pressures. For these reasons current systems are statically configured. This paper describes the dynamic run-time configuration aspects of DySCAS and focuses on the extent to which context-aware adaptation has been achieved in DySCAS, and the ways in which the various design and implementation challenges are met

Spatial sustainability in cities: organic patterns and sustainable forms

Because the complexity of cities seems to defy description, planners and urban designers have always been forced to work with simplified concepts of the city. Drawn from natural language, these concepts emphasize clear hierarchies, regular geometries and the separation of parts from wholes, all seemingly at variance with the less orderly complexity of most real cities. Such concepts are now dominating the debate about sustainability in cities. Here it is argued that space syntax has now brought to light key underlying structures in the city, which have a direct bearing on sustainability in that they seem to show that the spatial form of the self-organised city, as a foreground network of linked centres at all scales set into a background network of mainly residential space, is already a reflection of the relations between environmental, economic and socio-cultural forces, that is between the three domains of sustainability. Evidence that this is so in all three domains is drawn from recent and new research, and a concept of spatial sustainability is proposed focused on the structure of the primary spatial structure of the city, the street network