On the efficiency of reductions in µ-SIMD media extensions

Many important multimedia applications contain a significant fraction of reduction operations. Although, in general, multimedia applications are characterized for having high amounts of Data Level Parallelism, reductions and accumulations are difficult to parallelize and show a poor tolerance to increases in the latency of the instructions. This is specially significant for µ-SIMD extensions such as MMX or AltiVec. To overcome the problem of reductions in µ-SIMD ISAs, designers tend to include more and more complex instructions able to deal with the most common forms of reductions in multimedia. As long as the number of processor pipeline stages grows, the number of cycles needed to execute these multimedia instructions increases with every processor generation, severely compromising performance. The paper presents an in-depth discussion of how reductions/accumulations are performed in current µ-SIMD architectures and evaluates the performance trade-offs for near-future highly aggressive superscalar processors with three different styles of µ-SIMD extensions. We compare a MMX-like alternative to a MDMX-like extension that has packed accumulators to attack the reduction problem, and we also compare it to MOM, a matrix register ISA. We show that while packed accumulators present several advantages, they introduce artificial recurrences that severely degrade performance for processors with high number of registers and long latency operations. On the other hand, the paper demonstrates that longer SIMD media extensions such as MOM can take great advantage of accumulators by exploiting the associative parallelism implicit in reductions.Peer ReviewedPostprint (published version

Exploiting a new level of DLP in multimedia applications

This paper proposes and evaluates MOM: a novel ISA paradigm targeted at multimedia applications. By fusing conventional vector ISA approaches together with more recent SIMD-like (Single Instruction Multiple Data) ISAs (such as MMX), we have developed a new matrix oriented ISA which efficiently deals with the small matrix structures typically found in multimedia applications. MOM exploits a level of DLP not reachable by neither conventional vector ISAs nor SIMD-like media ISA extensions. Our results show that MOM provides a factor of 1.3x to 4x performance improvement when compared with two different multimedia extensions (MMX and MDMX) on several kernels, which translates into up to a 50% of performance gain when measuring full applications (20% in average). Furthermore, the streaming nature of MOM provides additional advantages for executing multimedia applications, such as a very low fetch pressure or a high tolerance to memory latency, making MOM an ideal candidate for the embedded domain.Peer ReviewedPostprint (published version

The impact of trade promotion services on Canadian exporter performance

We evaluate the impact of the programs delivered by the Canadian Trade Commissioner Service (TCS) on export performance by Canadian firms. We draw on a unique set of microdata created by linking three separate firm-level databases: Statistics Canada’s Exporter Register and its Business Register, which provide information on export activity and firm characteristics, and the TCS client management database maintained by Foreign Affairs and International Trade Canada, which contains details on trade promotion services provided to Canadian firms. We apply the treatment effects analytical framework to isolate the effects of public sector trade promotion. We find that TCS programs have a consistent and positive impact on Canadian exporter performance. Exporters that access TCS services export, on average, 17.9 percent more than comparable exporters that do not. Furthermore, we also find that TCS assistance benefits exporters in terms of product and market diversification.Export Promotion, Heterogeneous Firms, Canada

The impact of trade promotion services on Canadian exporter performance.

We evaluate the impact of the programs delivered by the Canadian Trade Commissioner Service (TCS) on export performance by Canadian firms. We draw on a unique set of microdata created by linking three separate firm-level databases: Statistics Canada’s Exporter Register and its Business Register, which provide information on export activity and firm characteristics, and the TCS client management database maintained by Foreign Affairs and International Trade Canada, which contains details on trade promotion services provided to Canadian firms. We apply the treatment effects analytical framework to isolate the effects of public sector trade promotion. We find that TCS programs have a consistent and positive impact on Canadian exporter performance. Exporters that access TCS services export, on average, 17.9 percent more than comparable exporters that do not. Furthermore, we also find that TCS assistance benefits exporters in terms of product and market diversification.

Smoking cessation and tobacco prevention in Indigenous populations

This article systematically reviews 91 smoking cessation and tobacco prevention studies tailored for Indigenous populations around the world, with a particular focus on Aboriginal and Torres Strait Islander populations in Australia. We identified several components of effective interventions, including the use of multifaceted programs that simultaneously address the behavioural, psychological and biochemical aspects of addiction, using resources culturally tailored for the needs of individual Indigenous populations. Pharmacotherapy for smoking cessation was effective when combined with culturally tailored behavioural interventions and health professional support, though it is generally underused in clinical practice. From a policy perspective, interventions of greater intensity, with more components, were more likely to be effective than those of lower intensity and shorter duration. For any new policy it is important to consider community capacity building, development of knowledge, and sustainability of the policy beyond guided implementation. Future research should address how the intervention can be supported into standard practice, policy, or translation into the front-line of clinical care. Investigations are also required to determine the efficacy of emerging therapies (such as e-cigarettes and the use of social media to tackle youth smoking), and under-researched interventions that hold promise based on non-Indigenous studies, such as the use of Champix. We conclude that more methodologically rigorous investigations are required to determine components of the less-successful interventions to aid future policy, practice and research initiatives. Evidence Base, issue 3, 201

CITRUS EXPORT MARKET DEVELOPMENT AND MAINTENANCE

The marketing of agricultural commodities and food products has assumed an international dimension over the past two decades. Increased funding of export development programs by the federal government and commodity organizations suggest the need for improved understanding of U.S. export development programs and of the issues associated with export market development and maintenance. The lesson to be learned from the citrus industry experience is that unless the commodity or food product being promoted can be differentiated from other competitive products, or unless the product is priced lower than competitive products, or unless the product is priced lower than competitive products, the long-run effectiveness of export promotion programs will be limited.International Relations/Trade,