DESIGNING POLICIES FOR LOCAL PRODUCTION SYSTEMS: A METHODOLOGY BASED ON EVIDENCE FROM BRAZIL

Using a previously developed methodology for identifying, classifying and characterizing local production systems (LPS) in Brazil, and evidence produced by a number of case studies, the paper suggests that policies aimed at LPS (or industrial clusters) should be tailored according to a typology of clusters. This typology must take into account the cluster importance for local or regional development, its share in the respective industry, and its characteristics in terms of production structure, trading schemes, institutional infrastructure, governance structures, and social contexts. The paper starts by reviewing, from the point of view of policy-making, the theories that support industrial cluster analyses, namely those that explain clusters as: outcomes of plain agglomeration economies and increasing returns; the result of spatial dynamic processes; knowledge systems emerging from the geography of innovation and agglomeration; governance structures, and as evolving complex systems. Next, the results from an application of the methodology to Brazilian data and information and from a number of case studies are summarized. Finally, the paper suggests policy guidelines with some measures of general application, aimed at problems observed in all LPS, and some specific measures differentiated according to a typology of local production systems that resulted from the application of the methodology.

Designing Policies for Local Production Systems: A Methodology Based on Evidence from Brazil

Using a previously developed methodology for identifying, classifying and characterizing local production systems (LPS) in Brazil, and evidence produced by a number of case studies, the paper suggests that policies aimed at LPS (or industrial clusters) should be tailored according to a typology of clusters. This typology must take into account the cluster importance for local or regional development, its share in the respective industry, and its characteristics in terms of production structure, trading schemes, institutional infrastructure, governance structures, and social contexts. The paper starts by reviewing, from the point of view of policy-making, the theories that support industrial cluster analyses, namely those that explain clusters as: outcomes of plain agglomeration economies and increasing returns; the result of spatial dynamic processes; knowledge systems emerging from the geography of innovation and agglomeration; governance structures, and as evolving complex systems. Next, the results from an application of the methodology to Brazilian data and information and from a number of case studies are summarized. Finally, the paper suggests policy guidelines with some measures of general application, aimed at problems observed in all LPS, and some specific measures differentiated according to a typology of local production systems that resulted from the application of the methodology.Manufacturing Industry, Cluster, Local Production System, Industrial Policy

Joint Access Point Selection and Power Allocation for Uplink Wireless Networks

We consider the distributed uplink resource allocation problem in a multi-carrier wireless network with multiple access points (APs). Each mobile user can optimize its own transmission rate by selecting a suitable AP and by controlling its transmit power. Our objective is to devise suitable algorithms by which mobile users can jointly perform these tasks in a distributed manner. Our approach relies on a game theoretic formulation of the joint power control and AP selection problem. In the proposed game, each user is a player with an associated strategy containing a discrete variable (the AP selection decision) and a continuous vector (the power allocation among multiple channels). We provide characterizations of the Nash Equilibrium of the proposed game, and present a set of novel algorithms that allow the users to efficiently optimize their rates. Finally, we study the properties of the proposed algorithms as well as their performance via extensive simulations.Comment: Revised and Resubmitted to IEEE Transactions on Signal Processin

Local production and innovation systems in the state of São Paulo, Brazil

This paper applies a specific methodology to geographically locate and delimit local production and innovation systems in the state of São Paulo. A first task, and a bulk part of the paper, is the elaboration of a number of quantitative indicators for the geographic concentration of manufacturing industries and for the location of industries at regional and local levels in that state. The elaboration of indices and other indicators for measuring regional location and specialization of economic activities is an old practice and has been an important object of study in regional economics since the seminal contributions by the pioneers of Regional Science. However, the statistical work developed in this paper is based on two most important recent contributions by P. Krugman (in Geography and Trade, 1991) and D. B. Audretsch & M. Feldman (in R&D spillovers and the geography of innovation and production, The American Economic Review, 86 (3), 1996). These authors calculated locational Gini coefficients for branches of U. S. manufacturing industry (Krugman) and for the geographic concentration of innovative activities and the location of U. S. manufacturing industries (Audretsch & Feldman). This paper applies the same methodology to calculate locational Gini coefficients for manufacturing industries in the state of São Paulo, the most advanced state in Brazilian industrialization. The Gini coefficients were calculated from data in RAIS - Relação Anual de Informações Sociais, elaborated by the Brazilian Ministry of Labor. This database provides detailed information on employment and number of plants by branches of manufacturing industries at micro-region and municipality levels. On the basis of the locational Gini coefficients the paper assesses which manufacturing industries are mostly spatially concentrated. Once these industries are identified, the paper proceeds by adding other indicators such as locational quotients, share of the local industry in the total manufacturing employment in the state, number of jobs and number of plants in the local industry. Combined, the Gini coefficients and the other indicators allow to identify, locate, and geographically delimit local production and innovation systems. Additionally, they make it possible to assess to what extent the local system is integrated. These findings are essential for guiding field research and, afterwards, for designing policies oriented to local production and innovation systems.

Knowledge, Innovation and Agglomeration - regionalized multiple indicators and evidence from Brazil

This paper develops multiple indicators to map the geographical distribution of knowledge and scientific and technological capabilities as proxies of the geographical distribution of Science, Technology & Innovation activities, and applies such indicators to data and information from the state of São Paulo, Brazil. The overall view of the geographical distribution of S,T&I activities in the state is complemented by the analysis of the same activities in the perspective of a local production and innovation system: the case of information and communication technologies in the micro-region of Campinas. The results show a pattern for the regional distributions of S,T&I activities along the main highways of the state, around metropolitan areas such as São Paulo and Campinas, and in regions where educational, science and technology, and R&D institutions are strongly concentrated. Firms tend to agglomerate in these areas and regions, forming local production and innovation systems. The paper produces evidence on the adherence of the geographical distribution of those systems to the geographical distribution of S,T&I activities as shown by the indicators. This confirms the empirical findings of the literature about the relationship between geography and innovation.

Finite element exterior calculus for parabolic problems

In this paper, we consider the extension of the finite element exterior calculus from elliptic problems, in which the Hodge Laplacian is an appropriate model problem, to parabolic problems, for which we take the Hodge heat equation as our model problem. The numerical method we study is a Galerkin method based on a mixed variational formulation and using as subspaces the same spaces of finite element differential forms which are used for elliptic problems. We analyze both the semidiscrete and a fully-discrete numerical scheme.Comment: 17 page

Practical Hidden Voice Attacks against Speech and Speaker Recognition Systems

Voice Processing Systems (VPSes), now widely deployed, have been made significantly more accurate through the application of recent advances in machine learning. However, adversarial machine learning has similarly advanced and has been used to demonstrate that VPSes are vulnerable to the injection of hidden commands - audio obscured by noise that is correctly recognized by a VPS but not by human beings. Such attacks, though, are often highly dependent on white-box knowledge of a specific machine learning model and limited to specific microphones and speakers, making their use across different acoustic hardware platforms (and thus their practicality) limited. In this paper, we break these dependencies and make hidden command attacks more practical through model-agnostic (blackbox) attacks, which exploit knowledge of the signal processing algorithms commonly used by VPSes to generate the data fed into machine learning systems. Specifically, we exploit the fact that multiple source audio samples have similar feature vectors when transformed by acoustic feature extraction algorithms (e.g., FFTs). We develop four classes of perturbations that create unintelligible audio and test them against 12 machine learning models, including 7 proprietary models (e.g., Google Speech API, Bing Speech API, IBM Speech API, Azure Speaker API, etc), and demonstrate successful attacks against all targets. Moreover, we successfully use our maliciously generated audio samples in multiple hardware configurations, demonstrating effectiveness across both models and real systems. In so doing, we demonstrate that domain-specific knowledge of audio signal processing represents a practical means of generating successful hidden voice command attacks

Fixed-Point Actions in 1-Loop Perturbation Theory

It has been pointed out in recent papers that the example considered earlier in the O(N) sigma-model to test whether fixed-point actions are 1-loop perfect actually checked classical perfection only. To clarify the issue we constructed the renormalized trajectory explicitly in 1-loop perturbation theory. We found that the fixed-point action is not exactly 1-loop perfect. The cut-off effects are, however, strongly reduced also on the 1-loop level relative to those of the standard and tree level improved Symanzik actions. Some points on off- and on-shell improvement, Symanzik's program and fixed-point actions are also discussed.Comment: 18 pages, Latex2