México: partida de ajedrez. Mario Pani

Se ensaya aquí cómo construye su mirada el arquitecto Mario Pani Darqui (México, D.F., 1911-1993), cuya visión es la del jugador de ajedrez: estratégica, cenital y transversal, profunda y extrañada, inci- siva y extensa, mimética y contrapuesta. Todo al mismo tiempo. Con base en esta reconstrucción de su forma de ver ―crucial para el entendimiento de la arquitectura y el urbanismo de México en el si- glo XX― se plantea una acción conceptual en el entorno del río Manzanares en Madrid. Un paisaje espiritual, silente, que a través de tres situaciones radicales obliga a quien lo contempla a un ejercicio instantáneo de meditación. Se ejecuta y se cartografía, dando como resultado una aproximación sen- sible sobre cómo intervenir en el paisaje y su registro.

Hybrid incremental modeling based on least squares and fuzzy K-NN for monitoring tool wear in turning processes

There is now an emerging need for an efficient modeling strategy to develop a new generation of monitoring systems. One method of approaching the modeling of complex processes is to obtain a global model. It should be able to capture the basic or general behavior of the system, by means of a linear or quadratic regression, and then superimpose a local model on it that can capture the localized nonlinearities of the system. In this paper, a novel method based on a hybrid incremental modeling approach is designed and applied for tool wear detection in turning processes. It involves a two-step iterative process that combines a global model with a local model to take advantage of their underlying, complementary capacities. Thus, the first step constructs a global model using a least squares regression. A local model using the fuzzy k-nearest-neighbors smoothing algorithm is obtained in the second step. A comparative study then demonstrates that the hybrid incremental model provides better error-based performance indices for detecting tool wear than a transductive neurofuzzy model and an inductive neurofuzzy model.

Tool wear monitoring using neuro-fuzzy techniques: a comparative study in a turning process

Tool wear detection is a key issue for tool condition monitoring. The maximization of useful tool life is frequently related with the optimization of machining processes. This paper presents two model-based approaches for tool wear monitoring on the basis of neuro-fuzzy techniques. The use of a neuro-fuzzy hybridization to design a tool wear monitoring system is aiming at exploiting the synergy of neural networks and fuzzy logic, by combining human reasoning with learning and connectionist structure. The turning process that is a well-known machining process is selected for this case study. A four-input (i.e., time, cutting forces, vibrations and acoustic emissions signals) single-output (tool wear rate) model is designed and implemented on the basis of three neuro-fuzzy approaches (inductive, transductive and evolving neuro-fuzzy systems). The tool wear model is then used for monitoring the turning process. The comparative study demonstrates that the transductive neuro-fuzzy model provides better error-based performance indices for detecting tool wear than the inductive neuro-fuzzy model and than the evolving neuro-fuzzy model.

México: partida de ajedrez. Mario Pani.

Se ensaya aquí cómo construye su mirada el arquitecto Mario Pani Darqui (México, D.F., 1911 - 1993), cuya visión es la del jugador de ajedrez: estratégica, cenital y transversal, profunda y extrañada, inc i- siva y extensa, mimética y contrapuesta. Todo al mismo tiempo. Con base en esta reconstrucción de su forma de ver ―crucial para el entendimiento de la arquitectura y el urbanismo de México en el s i- glo XX― se plantea una acción conceptual en el entorno del río Manzanares en Madrid. U n paisaje espiritual, silente, que a través de tres situaciones radicales obliga a quien lo contempla a un ejercicio instantáneo de meditación. Se ejecuta y se cartografía, dando como resultado una aproximación se n- sible sobre cómo intervenir en el paisaje y su registro