Stereoselective Synthesis of 3‐Hydroxy‐4‐arylcyclopentanones and 4‐Arylcyclopentenones through a Heck–Matsuda Desymmetrization of meso cis‐4‐Cyclopentene‐1,3‐diol

A new palladium‐catalyzed route to 3‐hydroxy‐4‐arylcyclopentanones and 4‐arylcyclopentenones in a diastereo‐ and enantioselective manner by a Heck–Matsuda desymmetrization was achieved from the commercially available meso cis‐4‐cyclopentene‐1,3‐diol. This method is highly practical, mild, high yielding and is carried out under “open vessel” conditions. Protected and unprotected substrates provide distinct products bearing considerable value as synthetic scaffolds for the synthesis of natural and unnatural bioactive compounds containing a five‐membered ring.

     

Systematic review: an analysis model for measuring the coopetitive performance in horizontal cooperation networks mapping the critical success factors and their variables

Several strategies have been developed for micro-enterprises and small enterprises in relation to their competitiveness enhancement. In recent years, one of the most widespread strategies has been the formation of horizontal cooperation networks (HCNs), based on the evolutionary development of coopetition. This study aimed to support and validates an analysis model developed by Petter (Modelo para análise da competitividade de redes de cooperação horizontais de empresas, Universidade Tecnológica Federal do Paraná, UTFPR, Ponta Grossa, 2012), in order to point out which are critical success factors (CSF), and their variables which influence the coopetition performance of a HCN under aspects of cooperation and competitiveness. A systematic review supported by Sampaio and Mancini (Revista Brasileira de Fisioterapia 11(1):83–89, 2007) was used to measure the status quo of published journals related to the subject, among several databases. A large informational gap was found concerning the development of methods and tools, as well as subsidies. Regarding the raise of publications found inside the scope, 18 CSF, 52 variables were mapped correlating them with 144 indicators, therefore, supporting and validating the proposed model of analysis.     

Joint routing and dimensioning of optical burst switching networks

Existing methods for handling routing and dimensioning in dynamic WDM networks solve the two problems separately. The main drawback of this approach is that a global minimum cost solution cannot be guaranteed. Given that wavelengths are costly resources, determining the minimum network cost is of fundamental importance. We propose an approach which jointly solves the routing and dimensioning problems in optical burst switching (OBS) networks, guaranteeing a target blocking per connection. The method finds the set of routes and the number of wavelengths per network link that minimise the total network cost. To accomplish this, an integer linear programming problem is solved. The proposed method was applied to ring networks, where the optimal solution achieves a reduction in the network cost of 10–40% (for traffic loads <0.4, compared to solving both problems separately). In the case of mesh topologies, to reduce the computational complexity of the method, we applied a variation of it which achieves a local minimum. Even so, a reduction of 5–20% (for traffic loads <0.4) in the network cost was obtained. This ability to lower network cost could make the proposed method the best choice to date for dynamic network operators.     

Optimizing the cutting of stock plates in a furniture company

In this study we analysed practical aspects of the application of a cutting stock model to a Brazilian company that manufactures furniture on a large scale with a high degree of standardization. The model is based on the classical approach of Gilmore and Gomory (1965, Operations Research, 14, 94-120), which combines a linear program and a column generation procedure. Besides the two-stage and three-stage guillotine cutting patterns, we also considered one-group guillotine patterns that improve the productivity of the cutting equipment. Examples derived from the furniture company are used to illustrate some of the trade-offs involved, in particular the trade-off between cutting simpler patterns and patterns that yield less waste material, but reduce the productivity of the cutting machine.     

Modeling of Three-Phase Fibrous Composite Using the Asymptotic Homogenization Method

A three-phase concentric fiber-reinforced periodic composite is considered wherein the constituents exhibit piezoelectric properties. The cross-section of the periodic cell is a regular hexagon with two concentric circles and the periodicity is the same in two directions at an angle ~ /3. Simple closed-form expressions are obtained for the effective properties of this composite by means of the asymptotic homogenization method. Numerical computations have been done. The analytical solution of the required resulting plane- and antiplane-strain local problems, which turns out to be only two, makes use of potential methods of a complex variable and properties of Weierstrass elliptic and related functions of periods (1,0) and (cos ~ /3, sin ~ /3). Benveniste's universal type of relations for this composite are satisfied. Comparison with other models is shown.     

Relax and fix heuristics to solve one-stage one-machine lot-scheduling models for small-scale soft drink plants

The production planning of regional small-scale soft drink plants can be modeled by mixed integer models that integrate lot sizing and scheduling decisions and consider sequence-dependent setup times and costs. These plants produce soft drinks in different flavors and sizes and they have typically only one production line. The production process is carried out basically in two main stages: liquid preparation (stage I) and bottling (stage II). However, since the production bottleneck of these plants is often in stage II, in this study we represent the problem as a one-stage one-machine lot-scheduling model that considers stage II as the bottleneck but also takes into account a capacity constraint of stage I. To solve the problem, we propose relax and fix heuristics exploring the model structure and we evaluate their computational performances solving different problem instances based on real data of a Brazilian small-scale soft drink company. The solutions obtained are compared to the company solutions and the solutions of a general-purpose optimization software.