GRASP with evolutionary path-relinking for the capacitated arc routing problem

The Capacitated Arc Routing Problem (CARP) is a well-known NP-hard combinatorial optimization problem where, given an undirected graph, the objective is to find a minimum cost set of tours servicing a subset of required edges under vehicle capacity constraints. There are numerous applications for the CARP, such as street sweeping, garbage collection, mail delivery, school bus routing, and meter reading. A Greedy Randomized Adaptive Search Procedure (GRASP) with Path-Relinking (PR) is proposed and compared with other successful CARP metaheuristics. Some features of this GRASP with PR are (i) reactive parameter tuning, where the parameter value is stochastically selected biased in favor of those values which historically produced the best solutions in average; (ii) a statistical filter, which discard initial solutions if they are unlikely to improve the incumbent best solution; (iii) infeasible local search, where high-quality solutions, though infeasible, are used to explore the feasible/infeasible boundaries of the solution space; (iv) evolutionary PR, a recent trend where the pool of elite solutions is progressively improved by successive relinking of pairs of elite solutions. Computational tests were conducted using a set of 81 instances, and results reveal that the GRASP is very competitive, achieving the best overall deviation from lower bounds and the highest number of best solutions found. © 2011 Elsevier Ltd. All rights reserved.

A redistricting problem applied to meter reading in power distribution networks

The capacitated redistricting problem (CRP) has the objective to redefine, under a given criterion, an initial set of districts of an urban area represented by a geographic network. Each node in the network has different types of demands and each district has a limited capacity. Real-world applications consider more than one criteria in the design of the districts, leading to a multicriteria CRP (MCRP). Examples are found in political districting, sales design, street sweeping, garbage collection and mail delivery. This work addresses the MCRP applied to power meter reading and two criteria are considered: compactness and homogeneity of districts. The proposed solution framework is based on a greedy randomized adaptive search procedure and multicriteria scalarization techniques to approximate the Pareto frontier. The computational experiments show the effectiveness of the method for a set of randomly generated networks and for a real-world network extracted from the city of São Paulo. © 2013 Elsevier Ltd.

A questão dos resíduos sólidos urbanos: uma abordagem socioambiental com ênfase no município de Ribeirão Preto (SP)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A coleta seletiva de lixo no município de Santa Gertrudes/SP e seus benefícios socioeconômicos e ambientais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diagnóstico e avaliação do saneamento básico da zona leste da cidade de Teresina - PI

Pós-graduação em Geografia - IGCE

Epidemiologia da leishmaniose visceral canina no município do Poxoréo-MT

Pós-graduação em Medicina Veterinária - FMVZ

Realidade socioeconômica e ambiental de um agrupamento de bairros da zona norte de Teresina, Piauí

Pós-graduação em Geografia - IGCE

Uma proposta de resolução para problemas de roteirização de veículos baseada no algoritmo genético

The vehicle routing problem is to nd a better route to meet a set of customers who are geographically dispersed using vehicles that are a central repository to which they return after serving customers. These customers have a demand that must be met. Such problems have a wide practical application among them we can mention: school transport, distribution of newspapers, garbage collection, among others. Because it is a classic problem as NP-hard, these problems have aroused interest in the search for viable methods of resolution. In this paper we use the Genetic Algorithm as a resolution

A gestão dos resíduos sólidos no município de Bauru - SP

The destination of urban solid waste has became a very relevant theme because of the fast growth of cities. Bauru, a strategically located municipality, needs solutions for that problem. This research aims to show solid waste management in Bauru through a survey of the selective or regular garbage collection programs, treatment and final disposal of the waste. To do so, a questionnaire with 85 questions was used about solid waste management in the municipality and visits were made to the solid waste collection and disposal sites. Bauru has a bad selective collection program and very significant clandestine disposal of Hazardous waste. Furthermore, it doesnot treat hospital waste and has a deficient final disposal landfill.

Invisibilidade social e saúde do trabalhador: dinâmica territorial do trabalho na coleta de lixo domiciliar urbano em Presidente Prudente/SP

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Back to the future in one week - implementing a Smalltalk VM in PyPy

We report on our experiences with the Spy project, including implementation details and benchmark results. Spy is a re-implementation of the Squeak (i.e., Smalltalk-80) VM using the PyPy toolchain. The PyPy project allows code written in RPython, a subset of Python, to be translated to a multitude of different backends and architectures. During the translation, many aspects of the implementation can be independently tuned, such as the garbage collection algorithm or threading implementation. In this way, a whole host of interpreters can be derived from one abstract interpreter definition. Spy aims to bring these benefits to Squeak, allowing for greater portability and, eventually, improved performance. The current Spy codebase is able to run a small set of benchmarks that demonstrate performance superior to many similar Smalltalk VMs, but which still run slower than in Squeak itself. Spy was built from scratch over the course of a week during a joint Squeak-PyPy Sprint in Bern last autumn.

Identification of logically related heap regions

This paper introduces a novel technique for identifying logically related sections of the heap such as recursive data structures, objects that are part of the same multi-component structure, and related groups of objects stored in the same collection/array. When combined withthe lifetime properties of these structures, this information can be used to drive a range of program optimizations including pool allocation, object co-location, static deallocation, and region-based garbage collection. The technique outlined in this paper also improves the efficiency of the static analysis by providing a normal form for the abstract models (speeding the convergence of the static analysis). We focus on two techniques for grouping parts of the heap. The first is a technique for precisely identifying recursive data structures in object-oriented programs based on the types declared in the program. The second technique is a novel method for grouping objects that make up the same composite structure and that allows us to partition the objects stored in a collection/array into groups based on a similarity relation. We provide a parametric component in the similarity relation in order to support specific analysis applications (such as a numeric analysis which would need to partition the objects based on numeric properties of the fields). Using the Barnes-Hut benchmark from the JOlden suite we show how these grouping methods can be used to identify various types of logical structures allowing the application of many region-based program optimizations.

A simple approach to distributed objects in prolog

We present the design of a distributed object system for Prolog, based on adding remote execution and distribution capabilities to a previously existing object system. Remote execution brings RPC into a Prolog system, and its semantics is easy to express in terms of well-known Prolog builtins. The final distributed object design features state mobility and user-transparent network behavior. We sketch an implementation which provides distributed garbage collection and some degree of tolerance to network failures. We provide a preliminary study of the overhead of the communication mechanism for some test cases.

Valuation: Developer support for by-references to by-value type conversion.

Modern object oriented languages like C# and JAVA enable developers to build complex application in less time. These languages are based on selecting heap allocated pass-by-reference objects for user defined data structures. This simplifies programming by automatically managing memory allocation and deallocation in conjunction with automated garbage collection. This simplification of programming comes at the cost of performance. Using pass-by-reference objects instead of lighter weight pass-by value structs can have memory impact in some cases. These costs can be critical when these application runs on limited resource environments such as mobile devices and cloud computing systems. We explore the problem by using the simple and uniform memory model to improve the performance. In this work we address this problem by providing an automated and sounds static conversion analysis which identifies if a by reference type can be safely converted to a by value type where the conversion may result in performance improvements. This works focus on C# programs. Our approach is based on a combination of syntactic and semantic checks to identify classes that are safe to convert. We evaluate the effectiveness of our work in identifying convertible types and impact of this transformation. The result shows that the transformation of reference type to value type can have substantial performance impact in practice. In our case studies we optimize the performance in Barnes-Hut program which shows total memory allocation decreased by 93% and execution time also reduced by 15%.

QUALIDADE DE VIDA DE PARTICIPANTES DE PROGRAMAS DE ECONOMIA SOLIDÁRIA

Este estudo buscou estudar qualidade de vida em indivíduos que trabalhavam em cooperativas com a filosofia da Economia Solidária. Mais especificamente procurou: levantar o perfil sócio econômico cultural e demográfico de indivíduos adultos integrantes de programas de Economia Solidária; avaliar a qualidade de vida desses indivíduos integrantes de programas; descrever a compreensão desses trabalhadores sobre o conceito de qualidade de vida. Participaram desse estudo 69 pessoas, trabalhadores de três cooperativas distintas de catadores de lixo reciclável. Foi aplicado um questionário elaborado especialmente para esse estudo contendo dados de identificação dos participantes, com o propósito de fazer um levantamento relativo aos dados sócioeconômicos, culturais e demográficos e, nesse questionário foi agregado o critério de classificação de renda e classe social da Associação Brasileira dos Institutos de Pesquisa - ABIPEME e utilizou-se a Escala de Qualidade de vida Whoqol Bref . Verificou-se, que os trabalhadores apresentaram um bom nível de qualidade de vida. Em relação aos dados sócio-econômicos culturais, observou-se um predomínio da presença de mulheres, solteiras ou com parceiros, mas com filhos. Com relação aos domínios que compõem Qualidade de Vida, houve uma correlação significativa entre os domínios físico e psicológico e também uma correlação entre os domínios: psicológico e de relações sociais. Por outro lado, o domínio meio ambiente foi o que apresentou um índice menor de qualidade de vida em relação aos demais. Levanta-se a hipótese de que o fato dos cooperados estarem insatisfeitos com seus ganhos, por os considerarem insuficientes, acrescido de suas condições de moradia serem precárias, além da maioria ser oriunda de um sistema econômico competitivo e individualista e não terem ainda a devida adaptação que esse novo sistema exige, interferiram no domínio meio ambiente de forma negativa..(AU)