Algorithmic species : a classification of affine loop nests for parallel programming

Code generation and programming have become ever more challenging over the last decade due to the shift towards parallel processing. Emerging processor architectures such as multi-cores and GPUs exploit increasingly parallelism, requiring programmers and compilers to deal with aspects such as threading, concurrency, synchronization, and complex memory partitioning. We advocate that programmers and compilers can greatly benefit from a structured classification of program code. Such a classification can help programmers to find opportunities for parallelization, reason about their code, and interact with other programmers. Similarly, parallelising compilers and source-to-source compilers can take threading and optimization decisions based on the same classification. In this work, we introduce algorithmic species, a classification of affine loop nests based on the polyhedral model and targeted for both automatic and manual use. Individual classes capture information such as the structure of parallelism and the data reuse. To make the classification applicable for manual use, a basic vocabulary forms the base for the creation of a set of intuitive classes. To demonstrate the use of algorithmic species, we identify 115 classes in a benchmark set. Additionally, we demonstrate the suitability of algorithmic species for automated uses by showing a tool to automatically extract species from program code, a species-based source-to-source compiler, and a species-based performance prediction model

Lighting in retail environments : atmosphere perception in the real world

Although ambient lighting and atmosphere are intuitively related, there is a paucity of empirical, naturalistic data supporting such a relation. The objective of this study was to investigate the contribution of lighting in evoking an atmosphere in the real world, amongst the extensive set of other cues available there. In a field study involving 57 clothing stores, lighting attributes (e.g. brightness, contrast, glare and sparkle) and context (i.e. the shop’s interior) were assessed and quantified independently. These data were then used to predict four dimensions of perceived atmosphere in hierarchical regression analyses. Lighting attributes and interior qualities were both related to perceived atmosphere. This indicated that, even given the substantial contribution of design elements in retail environments, lighting plays a role in evoking atmosphere

Lighting in retail environments : atmosphere perception in the real world

Although ambient lighting and atmosphere are intuitively related, there is a paucity of empirical, naturalistic data supporting such a relation. The objective of this study was to investigate the contribution of lighting in evoking an atmosphere in the real world, amongst the extensive set of other cues available there. In a field study involving 57 clothing stores, lighting attributes (e.g. brightness, contrast, glare and sparkle) and context (i.e. the shop’s interior) were assessed and quantified independently. These data were then used to predict four dimensions of perceived atmosphere in hierarchical regression analyses. Lighting attributes and interior qualities were both related to perceived atmosphere. This indicated that, even given the substantial contribution of design elements in retail environments, lighting plays a role in evoking atmosphere

The effects of retail lighting on atmosphere perception

The present study's objective was to investigate the contribution of lighting in evoking an atmosphere in naturalistic environments, among the extensive set of other environmental cues. In a field study involving 57 clothing stores, lighting attributes (e.g., brightness, contrast, glare and sparkle) and context (i.e. the shop interior) were assessed and quantified independently. These data were then used to predict four dimensions of perceived atmosphere of these stores in multiple regression analyses. A hierarchical procedure was chosen, with context variables entered in the first block and lighting attributes in the second block. We were thus able to determine the effects of lighting on perceived atmosphere, while controlling for context effects. Both lighting attributes and interior qualities were successfully related to perceived atmosphere. Our most important finding was that, even given the substantial contribution of design elements in retail environments, lighting does play a significant role in evoking atmospheres

The effects of retail lighting on atmosphere perception

The present study's objective was to investigate the contribution of lighting in evoking an atmosphere in naturalistic environments, among the extensive set of other environmental cues. In a field study involving 57 clothing stores, lighting attributes (e.g., brightness, contrast, glare and sparkle) and context (i.e. the shop interior) were assessed and quantified independently. These data were then used to predict four dimensions of perceived atmosphere of these stores in multiple regression analyses. A hierarchical procedure was chosen, with context variables entered in the first block and lighting attributes in the second block. We were thus able to determine the effects of lighting on perceived atmosphere, while controlling for context effects. Both lighting attributes and interior qualities were successfully related to perceived atmosphere. Our most important finding was that, even given the substantial contribution of design elements in retail environments, lighting does play a significant role in evoking atmospheres