Horacio Hideki Yanasse

A note on linear models for two-group and three-group two-dimensional guillotine cutting problems

Due to the particular characteristics of certain cutting machines, special classes of cutting patterns, such as 1-group, 2-group and 3-group, requiring shorter processing times appear in the furniture, hardboard and stone industries. In this study we present integer linear models to generate 2-group and 3-group constrained and unconstrained two-dimensional guillotine cutting patterns. The models are derived from the linear models for 1-group guillotine cutting patterns proposed in Yanasse, H.H. and Morabito, R., Linear models for one-group two-dimensional guillotine cutting problems. International Journal of Production Research, in press. The performances of the models were evaluated by solving a number of examples randomly generated and an actual example derived from a furniture company. These results were produced using GAMS modelling language and the CPLEX solver, and they show that the models are effective to solve problems of small and moderate size.

The one-dimensional cutting stock problem with usable leftovers - A survey

In this article, we review published studies that consider the solution of the one-dimensional cutting stock problem (1DCSP) with the possibility of using leftovers to meet future demands, if long enough. The one-dimensional cutting stock problem with usable leftovers (1DCSPUL) is a problem frequently encountered in practical settings but often, it is not dealt with in an explicit manner. For each work reviewed, we present the application, the mathematical model if one is proposed and comments on the computational results obtained. The approaches are organized into three classes: heuristics, item-oriented, or cutting pattern-oriented.

Production scheduling of assembly fixtures in the aeronautical industry

In this work, we study the production scheduling of a real world assembly problem present in the aeronautical industry. Parts of aircrafts should be produced on fixtures, which are commonly used in aircraft manufacturing and consist of several workstations. Due to a lack of physical space in the fixture, when a workstation is in use, other workers cannot use adjacent workstations in this fixture. These constraints are called here adjacency constraints. This assembly fixture scheduling problem is studied in the context of a workforce learning process including four main qualification stages (or epochs). Mathematical models are developed and implemented for each stage using a modeling language and an optimization solver. Computational experiments with this approach were performed in a case study of a Brazilian aeronautical company and they resulted in better solutions than those currently practiced in the company.

Um algoritmo exato com ordenamento parcial para solução de um problema de programação da produção: experimentos computacionais

In this paper, we present the computational test results of an implementation made of an exact algorithm proposed in the literature to solve a sequencing problem that arises in some productive environments where open orders of clients should be minimized. From the computational tests, it can be observed that the dominance criteria incorporated in the enumeration process of this algorithm reduces the search space, making the algorithm more efficient in terms of execution time.

A heuristic approach to minimize the number of saw cycles in small-scale furniture factories

This paper addresses a two-dimensional cutting stock problem arising in furniture factories. The problem involves the simultaneous optimization of two, usually conflicting, objectives: minimizing the total number of objects and maximizing the cutting machine productivity in terms of the number of objects that are simultaneously cut. A heuristic algorithm to solve the problem is proposed based on variables and constraints generation. The main idea is to add, in a dynamic way, bounds to the frequency of some chosen cutting patterns. At each iteration a solution is generated and at the end we have a set of non-dominated solutions. A computational study was conducted using real data from a small-scale furniture factory. The results show that the proposed algorithm finds solutions that are as good as or better than the ones used in practice in the furniture factory.

An analysis of bibliometric indicators to JCR according to Benford's law

Journal Citation Reports (JCR) is the main source of bibliometric indicators known by the scientific community. This paper presents the results of a study of the distributions of the first and second significant digits according to Benford’s law (BL) of the number of articles, citations, impact factors, half-life and immediacy index bibliometric indicators in journals indexed in the JCR Sciences and Social Sciences Editions from 2007 to 2014. We also performed the data analysis to country’s origin and by journal’s category, and we verified that the second digit has a better adherence to BL. The use of the second digit is important since it provides a more sound, complete and consistent analysis of the bibliometric indicators.

Perfil dos bolsistas PQ da área de Química baseado na Plataforma Lattes

PROFILE OF CNPq PRODUCTIVITY RESEARCH FELLOWS IN THE CHEMISTRY AREA BASED ON THE LATTES PLATFORM. The Lattes Platform, an information system maintained by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), is the main source of information on Brazilian researchers. This paper presents a scientific output profile of the CNPq Productivity Research Fellows in the Chemistry area based on the information extracted automatically from Lattes curricula in the 2002-2011 period using the language “LattesMiner”. This paper also provides a comparison with the results of Santos et al. (2010). The findings confirmed that the majority of the researchers are male (67.9%), classified as category 2 (63.2%) and working in the Southeast region (60.7%).

XVI Latin-Ibero-American Conference on Operations Research/XLIV Brazilian Symposium on Operations Research (CLAIO/SBPO - 2012)

This special issue of Pesquisa Operacional includes some papers presented at the XVI LatinIbero-American Conference on Operations Research (CLAIO), the biannual conference organized by the Latin-Ibero-American Association of Operations Research Societies (ALIO), and the XLIV Brazilian Symposium on Operations Research (SBPO), the annual conference organized by the Brazilian Operations Research Society (SOBRAPO), held during September, 24-28, 2012, in Rio de Janeiro, Brazil. These events have been a great opportunity for researchers and practitioners in the region to further exchange their experiences, to contribute, establish, and deepen their ties and to help young undergraduate and graduate students in their professional development.

Technological competencies mapping: A Petrobras' information system for aiding the decision process based on the Lattes Platform

Competencies Mapping is a major challenge for organizations seeking for technological solutions. This article describes a Petrobras information system for aiding the decision process based on the Lattes Platform to map technological competencies.