Towards Automatic Learning of Heuristics for Mechanical Transformations of Procedural Code

The current trend in next-generation exascale systems goes towards integrating a wide range of specialized (co-)processors into traditional supercomputers. However, the integration of different specialized devices increases the degree of heterogeneity and the complexity in programming such type of systems. Due to the efficiency of heterogeneous systems in terms of Watt and FLOPS per surface unit, opening the access of heterogeneous platforms to a wider range of users is an important problem to be tackled. In order to bridge the gap between heterogeneous systems and programmers, in this paper we propose a machine learning-based approach to learn heuristics for defining transformation strategies of a program transformation system. Our approach proposes a novel combination of reinforcement learning and classification methods to efficiently tackle the problems inherent to this type of systems. Preliminary results demonstrate the suitability of the approach for easing the programmability of heterogeneous systems.Comment: Part of the Program Transformation for Programmability in Heterogeneous Architectures (PROHA) workshop, Barcelona, Spain, 12th March 2016, 9 pages, LaTe

Card-based systems: systematic literature review of new systems and proposal of a list of soft factors for systems implementation

Although Production Control Systems are considered a mature topic in literature, up to now, the focus of literature has been on optimizing the operating parameters of each system, assigning little importance to factors related to human influence (soft factors). Implementation, however, remains a complex problem. This paper aims to reduce this gap by proposing, through a combination of research methods, a list of soft factors critical to success in implementing card-based systems, which which are the most studied and implemented and which share as a characteristic a strong human influence on their functioning. However, to achieve this goal, it was initially necessary to identify which systems are based on cards. Although for systems such as Kanban and CONWIP there is a large literature available, systems developed after POLCA proposal in 1998 were little explored. Therefore, this dissertation initially performs a systematic literature review identifying 13 systems developed between 1999 and 2018, such as COBACABANA, DDMRP, Redutex, B-CONWIP, BK-CONWIP, among others. Briefly, it presents how each system works, its characteristics, current research stage and environments in which it has been proved to be useful, aiming to increase researches about them. The systems are also compared in relation to six variables defined in the literature, identifying that many of the new systems are card-based. The soft factors proposed for the implementation of card-based systems are based on the analysis of problems cited in the literature as well as difficulties identified through a longitudinal case study. This list was validated by experts as well as a group of employees from the focus company that participated in the implementation of kanban. This dissertation also proposes a soft factor house for the implementation of card-based systems, in which the factors are classified as exclusive to this theme or classic management factors, as well as in relation to the organizational level in which it operates (organization, implementation group, or individual). This house aims to assist managers in implementing card-based systems, increasing success rates in this process. In addition, by reviewing recent production control systems, this dissertation aims to increase the repertoire of managers on existing systems, enabling the implementation of more appropriate options for the productive environment in which they are located.Não recebi financiamentoEmbora os Sistemas de Coordenação de Ordens sejam considerado um tópico maduro na literatura, o foco da literatura até o momento recaiu especialmente sobre a otimização dos parâmetros de funcionamento de cada sistema, atribuindo pouca importância aos fatores relacionados a influência humana (soft factors). A implementação, contudo, continua a ser um problema complexo. Esse trabalho visa reduzir essa lacuna, propondo, através de uma combinação de métodos de pesquisa, uma lista de fatores soft críticos para o sucesso na implementação de sistemas baseado em cartão, os quais são os mais estudados e implementados e que compartilham como característica uma forte influência humana em seu funcionamento. Contudo, para realização desse objetivo, inicialmente foi necessário identificar quais são os sistemas baseados em cartão. Embora para sistemas como o Kanban e o CONWIP exista uma grande literatura disponível, sistemas desenvolvidos após a proposta do POLCA em 1998 foram pouco explorados. Assim, essa dissertação inicialmente realiza uma revisão sistemática de literatura identificando 13 sistemas desenvolvidos entre 1999 e 2018, tais como COBACABANA, DDMRP, Redutex, B-CONWIP, BK-CONWIP, dentre outros. Brevemente, é apresentado o funcionamento, características, estágio atual de pesquisa e ambientes propícios para cada sistema, visando aumentar as pesquisas sobre eles. Os sistemas são também comparados em relação a seis variáveis, identificando-se que muitos dos novos sistemas são baseados em cartão. Os fatores soft propostos para a implementação de sistemas baseado em cartão se baseiam na análise de problemas citados na literatura bem como de dificuldades identificadas através de um estudo de caso longitudinal. Essa lista foi validada por especialistas assim como por um grupo de colaboradores da empresa foco que participou da implementação do kanban. Nessa dissertação é proposta também uma casa de fatores soft para a implementação de sistemas baseados em cartão, nas quais os fatores são classificados como exclusivos dessa temática ou fatores clássicos de administração, bem como em relação ao nível organizacional em que atua. (organização, grupo de implementação ou indivíduo). Essa casa tem como objetivo auxiliar os gerentes na implementação de sistemas baseados em cartão, aumentando as taxas de sucesso nesse processo. Além disso, através da revisão de sistemas de coordenação de ordens recentes, essa dissertação visa aumentar o repertório dos gerentes sobre os sistemas existentes, possibilitando a implementação de opções mais adequadas para o ambiente produtivo em que se encontram

Ride-hailing and (dis)Advantage: Perspectives from Users and Non-users

The introduction of ride-hailing in cities of Latin America and the Caribbean (LAC) remains a relatively new topic in regional research and a contentious issue in local policy and practice. Evidence regarding users and how do they differ from non-users is scarce, and there is little documented evidence about how user preferences and perceptions may influence the uptake of ride-hailing. This paper uses primary data from a survey collected from users and non-users of ride-hailing in Bogotá during 2019 to develop a Latent Class Analysis Model (LCA) to identify clusters of users and non-users of ride-hailing. The paper builds on results from the LCA to reflect on conditions of advantage and disadvantage that may make ride-hailing attractive and beneficial for particular social groups. The paper identifies four unique clusters: Carless middle-income ride-hailing users, Disadvantaged non-users, Young middle-class non-users, and Advantaged ride-hailing users. The research uses data on such perceptions to draw insights that may inform commercial and policy decisions. Findings suggest that issues such as the perception of legality in ride-hailing and aversion to crime play a significant role in the choice of such a mode in the context of Bogotá, particularly among socially and transport advantaged users

Introduction to Production: Philosophies, Flow, and Analysis

Production is a fundamental societal and economic activity. Production has to do with the transformation of raw materials into useful objects and includes the knowledge to complete the transformation effectively. Thus, production is a board topic ranging from philosophies about how to approach production such as lean and quick response manufacturing, how to organize production facilities, how to analyze production operations, how to control the flow of materials during production, the devices used to move materials within a facility, and strategies for coordinating multiple production facilities. An integrated introduction to production is presented in a set of learning modules. In significant part, these learning modules are based on over 20 years of interactions with the professional production community in the West Michigan region where Grand Rapids and Holland are the principal cities. This community consists almost exclusively of small and medium size companies engaged primarily in high mix, low volume manufacturing. Students in the Bachelor of Science in Engineering and Master of Science in Engineering programs at Grand Valley State University often work in production for these companies. Thus, interactions are facilitated particularly though master’s degree capstone projects, several of which are referenced in the learning modules. The learning modules are well-grounded in established production concepts. Emphasis is placed on proven procedures such as systematic layout planning, factory physics, various production flow control techniques such as kanban and POLCA, and discrete event simulation. Professional practice is a focus of the learning modules. Material from processional groups such as the Lean Enterprise Institute and the Material Handling Institute (MHI) is integrated. The opportunity to read and discuss professional publications presenting production improvement projects is provided. Students are referred to professional videos and web sites throughout the learning modules. All materials provided are referenced are open access and free of charge. When downloading the main file, it is important to also download and use the Main File Support as it contains supplemental materials.https://scholarworks.gvsu.edu/books/1022/thumbnail.jp

Deriving stencil hardware accelerators from a single higher-order function

Stencil computations are array based algorithms that apply a computation to all array elements in a fixed regular pattern and can be found in many scientific and engineering applications. Parallelization of these applications becomes more and more important in order to keep up with the demand for computing power. FPGAs offer a lot of computing power but are considered hard to program. In this paper, a design methodology based on transformations of higher-order functions is introduced to facilitate this parallelization process. Using this methodology, efficient FPGA hardware is derived achieving good performance. Two architectures for heat flow computations are synthesized for an FPGA and evaluated. To show the general applicability of the design methodology, several applications have been implemented

Solving non-linear Horn clauses using a linear Horn clause solver

In this paper we show that checking satisfiability of a set of non-linear Horn clauses (also called a non-linear Horn clause program) can be achieved using a solver for linear Horn clauses. We achieve this by interleaving a program transformation with a satisfiability checker for linear Horn clauses (also called a solver for linear Horn clauses). The program transformation is based on the notion of tree dimension, which we apply to a set of non-linear clauses, yielding a set whose derivation trees have bounded dimension. Such a set of clauses can be linearised. The main algorithm then proceeds by applying the linearisation transformation and solver for linear Horn clauses to a sequence of sets of clauses with successively increasing dimension bound. The approach is then further developed by using a solution of clauses of lower dimension to (partially) linearise clauses of higher dimension. We constructed a prototype implementation of this approach and performed some experiments on a set of verification problems, which shows some promise.Comment: In Proceedings HCVS2016, arXiv:1607.0403

Music and Identity in Paraguay: Expressing National, Racial, and Class Identity in Guitar Music Culture

This article illustrates, with particular focus on Rolando Chaparro’s rock fusion album Bohemio (2009), the way that music operates in expressing Paraguayan national, racial, and class identity. It first reviews the literature on music and identity more generally, and music and identity in Paraguay more specifically. It then explores expressions of nationalism and paraguayidad in folkloric “popular” musics (música popular), and the concept of raza Guaraní in the construction, maintenance, and expression of identity. Finally, it explores three waves of Barrios revival (1950s, 1970s, early noughties) and people’s class consciousness before arriving at the article’s conclusions

N queens on an fpga: mathematics,programming, or both?

This paper presents a design methodology for deriving an FPGA implementation directly from a mathematical specification, thus avoiding the switch in semantic perspective as is present in widely applied methods which include an imperative implementation as an intermediate step. The first step in the method presented in this paper is to transform a mathematical specification into a Haskell program. The next step is to make repetition structures explicit by higher order functions, and after that rewrite the specification in the form of a Mealy Machine. Finally, adaptations have to be made in order to comply to the fixed nature of hardware. The result is then given to CaSH, a compiler which generates synthesizable VHDL from the resulting Haskell code. An advantage of the approach presented here is that in all phases of the process the design can be directly simulated by executing the defining code in a standard Haskell environment. To illustrate the design process, the N queens problem is chosen as a running example