Towards Energy Consumption Verification via Static Analysis

In this paper we leverage an existing general framework for resource usage verification and specialize it for verifying energy consumption specifications of embedded programs. Such specifications can include both lower and upper bounds on energy usage, and they can express intervals within which energy usage is to be certified to be within such bounds. The bounds of the intervals can be given in general as functions on input data sizes. Our verification system can prove whether such energy usage specifications are met or not. It can also infer the particular conditions under which the specifications hold. To this end, these conditions are also expressed as intervals of functions of input data sizes, such that a given specification can be proved for some intervals but disproved for others. The specifications themselves can also include preconditions expressing intervals for input data sizes. We report on a prototype implementation of our approach within the CiaoPP system for the XC language and XS1-L architecture, and illustrate with an example how embedded software developers can use this tool, and in particular for determining values for program parameters that ensure meeting a given energy budget while minimizing the loss in quality of service.Comment: Presented at HIP3ES, 2015 (arXiv: 1501.03064

GfK Panel Data Analysis of meat consumption

This short report represents a summary of the analysis conducted so far on the GfK Panel Data. The focus was on the main three types of raw meat: chicken, pork, beef, as well as three categories of processed food products: liver paste, cold cuts and sausages. The aim was to look at the market indicators for each one of the six sub-categories, out of which market share and penetration were considered to be the most important. Besides these two indicators, I also included some extra calculations for each category, which can be analysed further and more in-depth if needed. One of the desired outcomes of the analyses was to identify companies and brands that were successful in each sub-category. Unfortunately, due to the generally low market shares of the organic products, the number of options was limited. Beef and pork were two categories where no brands were registered in the original product and sales Files. In the chicken category there was only one brand registered between 2006 and 2010, however, the market shares were extremely low for this category. There were only one or two households buying organic chicken products. The processed meat sub-categories both had a few companies registered. However, the diversity isn’t large. Still, it is good to notice that in the three sub-categories there were two companies that were most present: Farre Food and Hanegal. Market shares were generally low for all six sub-categories. Organic beef, pork and liver paste were the only categories to reach market shares of over 1%, while organic chicken had the lowest market shares of all. The trends were generally fluctuating over time. The highest market shares for liver paste, pork, chicken and beef were registered in 2007. All these four categories had much lower market shares in 2009, but it is interesting to notice that in the same year, organic cold cuts and sausages registered the highest market shares. Except for chicken, all market shares dropped in 2010 compared to 2009. Penetration levels had a clear descending trend for organic beef and liver paste, whereas for the other subcategories the levels fluctuated. Organic chicken and sausage generally had an ascending trend, while organic pork and cold cuts usually had descending trends in penetration levels. The highest penetration rates were registered in 2006 for liver paste, beef and cold cuts and in 2008 for sausages, chicken and pork. Out of all the six sub-categories that were analysed, organic beef has had the highest market shares and highest penetration rates, even though the figures were lower and lower every year. Regarding the average price paid/100 gr of meat products, we notice that in the organic category there is more fluctuation than in the conventional category, meaning that the price of organic products varies more between years. According to the analysis, the price difference between the organic and the conventional options in a sub-category is clearly notices in the processed meat category, but it is not as well defined for chicken, pork and beef. There are some limitations regarding the analysis of the panel data. On the one hand, these are due to the fact that there are some incompatibilities between the product file and the sales file regarding the identification of products as being organic or not. On the other hand, some of the products were registered as “unknown”, meaning that they are neither analysed as being organic, nor as being conventional, but as being a separate category. It is considered however that due to the fact that the results of the analysis are so small, the correction of these errors would not change the numbers significantly

Financial Expectations, Consumption and Saving: A Microeconomic Analysis

We explore the determinants of individuals´ financial expectations using data from the British Household Panel Survey (BHPS) 1991-2001. Our findings suggest that individuals´ financial predictions are influenced by both the life cycle and the business cycle. We also investigate the extent to which the accuracy of past financial expectations affects current financial expectations. Interestingly, only past financial optimism matters, regardless of the accuracy of the prediction. We also explore the relationship between financial realisations and expectations and we find that expectations tend to fall short of financial realisations. Finally, we investigate the relationship between financial expectations, savings and consumption. Our findings suggest that financial optimism is inversely associated with savings and that current financial expectations serve to predict future consumption

Static analysis of energy consumption for LLVM IR programs

Energy models can be constructed by characterizing the energy consumed by executing each instruction in a processor's instruction set. This can be used to determine how much energy is required to execute a sequence of assembly instructions, without the need to instrument or measure hardware. However, statically analyzing low-level program structures is hard, and the gap between the high-level program structure and the low-level energy models needs to be bridged. We have developed techniques for performing a static analysis on the intermediate compiler representations of a program. Specifically, we target LLVM IR, a representation used by modern compilers, including Clang. Using these techniques we can automatically infer an estimate of the energy consumed when running a function under different platforms, using different compilers. One of the challenges in doing so is that of determining an energy cost of executing LLVM IR program segments, for which we have developed two different approaches. When this information is used in conjunction with our analysis, we are able to infer energy formulae that characterize the energy consumption for a particular program. This approach can be applied to any languages targeting the LLVM toolchain, including C and XC or architectures such as ARM Cortex-M or XMOS xCORE, with a focus towards embedded platforms. Our techniques are validated on these platforms by comparing the static analysis results to the physical measurements taken from the hardware. Static energy consumption estimation enables energy-aware software development, without requiring hardware knowledge

Embracing ethical fields: constructing consumption in the margins

Purpose Literature examining resistant consumer behaviour from an ethical consumption stance has increased over recent years. This paper argues that the conflation between ethical consumer behaviour and ‘anti-consumption’ practices results in a nihilistic reading and fails to uncover the tensions of those who seek to position themselves as ethical whilst still participating in the general market. Design/methodology/approach The study adopts an exploratory approach through semi-structured in-depth interviews with a purposive sample of 7 ethical consumers. Findings The analysis reveals the process through which ethical consumption is constructed and defined in relation to the subject position of the ‘ethical consumer’ and their interactions with the dominant market of consumption. Research limitations/implications This research is limited to a single country and location and focused on a specific consumer group. Expansion of the research to a wider group would be valuable. Practical implications The impact of ethical consumption on the wider field of consumption can be witnessed in the ‘mainstreaming’ of many ethical ideals. This highlights the potential movements of power between various stakeholders that occupy particular spaces of social action. Originality/value Understanding the analysis through Bourdieu’s concepts of field and the margins created between spaces of consumption we focus on the theoretical cross-section of practice between ethical and market-driven forms of consumption, advancing discussion by exploring how self-identified ‘ethical consumers’ defined, legitimatised and negotiated their practices in relation to consumption acts and lifestyles. Keywords Anti-consumption, ethical consumption, consumer decision-making, Bourdieu

Water Consumption and Long-Run Urban Development: The Case of Milan

Analyses of long run consumption series are rare in literature. We study the evolution of water consumption in Milan in the twentieth century. The objective is twofold: on one side, the univariate analysis tries both to assess the impact of relevant socio-economic and environmental changes on water consumption in Milan and verify if consumers have deeply rooted consumption habits. On the other side, the multivariate analysis is used to identify the socio-economic factors that are relevant in explaining consumption evolution. Results indicate both that water users have well entrenched consumption habits and that population, climate and economic structure behave more similarly, in Euclidean terms, to water consumption than to other economic and social variables.Urban consumption, Long-run, Development, Environmental changes