Cogeneration design problem Computational complexity analysis and solution through an expert system

Purpose - The purpose of this paper is twofold: to analyze the computational complexity of the cogeneration design problem; to present an expert system to solve the proposed problem, comparing such an approach with the traditional searching methods available.Design/methodology/approach - The complexity of the cogeneration problem is analyzed through the transformation of the well-known knapsack problem. Both problems are formulated as decision problems and it is proven that the cogeneration problem is np-complete. Thus, several searching approaches, such as population heuristics and dynamic programming, could be used to solve the problem. Alternatively, a knowledge-based approach is proposed by presenting an expert system and its knowledge representation scheme.Findings - The expert system is executed considering two case-studies. First, a cogeneration plant should meet power, steam, chilled water and hot water demands. The expert system presented two different solutions based on high complexity thermodynamic cycles. In the second case-study the plant should meet just power and steam demands. The system presents three different solutions, and one of them was never considered before by our consultant expert.Originality/value - The expert system approach is not a "blind" method, i.e. it generates solutions based on actual engineering knowledge instead of the searching strategies from traditional methods. It means that the system is able to explain its choices, making available the design rationale for each solution. This is the main advantage of the expert system approach over the traditional search methods. On the other hand, the expert system quite likely does not provide an actual optimal solution. All it can provide is one or more acceptable solutions.

Open design no cenário contemporâneo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Design e gênero: diretrizes metodológicas para validação do uso da linguagem visual na roupa infantil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diretrizes projetuais e o emprego das tendências: o design de móveis residenciais no polo de Arapongas/PR

Constant social, cultural and political changes influence directly people’s life and define their needs and tastes. Trends have the role of signaling through these facts people’s preferences regarding to objects and can, therefore be connected with great design, as it works with project that is a planning activity for future. In this context, this study aimed to characterize trend jobs in Brazilians home designing methodology. For both: theoretical aspects were studied that led to reasoning, a field research in five Furniture industries Pole of Arapongas/PR was done, and a research for possible developmental reference of furniture in Brazil. Results indicated: misused and mistaken concepts of trend and ignorance on how they operate lack of knowledge about industries sector consumer profile, the concern about sales and not with consumer as “furniture user” and finally, the existence of Brazilian referential sources, but the lack of skilled professionals that could decode these sources.

Trace elements as tumor biomarkers and prognostic factors in breast cancer: a study through energy dispersive x-ray fluorescence

Background The application and better understanding of traditional and new breast tumor biomarkers and prognostic factors are increasing due to the fact that they are able to identify individuals at high risk of breast cancer, who may benefit from preventive interventions. Also, biomarkers can make possible for physicians to design an individualized treatment for each patient. Previous studies showed that trace elements (TEs) determined by X-Ray Fluorescence (XRF) techniques are found in significantly higher concentrations in neoplastic breast tissues (malignant and benign) when compared with normal tissues. The aim of this work was to evaluate the potential of TEs, determined by the use of the Energy Dispersive X-Ray Fluorescence (EDXRF) technique, as biomarkers and prognostic factors in breast cancer. Methods By using EDXRF, we determined Ca, Fe, Cu, and Zn trace elements concentrations in 106 samples of normal and breast cancer tissues. Cut-off values for each TE were determined through Receiver Operating Characteristic (ROC) analysis from the TEs distributions. These values were used to set the positive or negative expression. This expression was subsequently correlated with clinical prognostic factors through Fisher’s exact test and chi-square test. Kaplan Meier survival curves were also evaluated to assess the effect of the expression of TEs in the overall patient survival. Results Concentrations of TEs are higher in neoplastic tissues (malignant and benign) when compared with normal tissues. Results from ROC analysis showed that TEs can be considered a tumor biomarker because, after establishing a cut-off value, it was possible to classify different tissues as normal or neoplastic, as well as different types of cancer. The expression of TEs was found statistically correlated with age and menstrual status. The survival curves estimated by the Kaplan-Meier method showed that patients with positive expression for Cu presented a poor overall survival (p < 0.001). Conclusions This study suggests that TEs expression has a great potential of application as a tumor biomarker, once it was revealed to be an effective tool to distinguish different types of breast tissues and to identify the difference between malignant and benign tumors. The expressions of all TEs were found statistically correlated with well-known prognostic factors for breast cancer. The element copper also showed statistical correlation with overall survival.

Design Participativo para a Sustentabilidade: desenvolvimento de painéis modulares para fechamentos, utilizando bambu associado com terra e resíduos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do design de instrumentos de escrita manual na percepção e no desempenho da atividade por pessoas com sem rizartrose

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspectos ergonômicos do design de calçados com salto para mulheres com hiperidrose plantar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)