Gilberto Herrera Ruiz

A long span bridge and a greenhouse roof truss structure optimized by means of a consistent genetic algorithm with a natural crossover

Purpose – The purpose of this paper is to introduce a novel methodology that has the capability of finding symmetrical and nonsymmetrical solutions in complex design domains without additional tuning when changing the design domain. These go from an academic design domain to a practical one.Design/methodology/approach – Various crossovers operators are applied over the same representation using a genetic algorithm for truss structural optimization cases where literature solutions have a tendency to forced symmetry in order to find an optimal design with fewer iterations. Continuous‐discrete representations were cross‐bred by a uniform‐sbx simultaneous crossover, called zygote crossover. Specialized mutations operations are proposed to generate localized changes to improve the solution according with the design domain.Findings – Design solutions found were lighter and stiffer when comparing against cases reported in current literature and in engineering practice. Also these solutions were found in fewer it...

An object-oriented architecture for sensorless cutting force feedback for CNC milling process monitoring and control

Intelligent Manufacturing Systems require fault-tolerant components capable of preventing and detecting failures, and optimizing their own performance. Although there are a number of process monitoring and control systems (PMCS) available for these tasks, most of them require special equipment that increases cost and setup time. This work proposes a standard software architecture and methodology for implementing a sensorless PMCS which separates data representation from its algorithmic processing. Two different case studies are introduced showing the feasibility and applicability of the proposed design, one for cycle time optimization and another one for online tool condition detection. A good performance was obtained in both case studies based on the proposed PMCS architecture, which can be implemented using different distributed software technologies.

Cable 3D non linear model and damping systems on stayed bridges

The dynamic analysis using computational models is an important tool to simulate the dynamic of structures that have specific uncertain behavior like the cable stayed bridges which nowadays is an alternative to solve long span bridges with a slim structure. In this work we developed a 3D non linear model of a cable in order to evaluate the wind effect on the Papaloapan cable stayed bridge located on Veracruz Mexico, under different scenarios. The health of the structure is an important factor to analyze and there are many different fail causes, one of them is the fatigue fall that is relevant in the anchorage elements of the cable stayed bridges. It is possible to modify the behavior of the structure using dampers to minimize that effect. The geometry and all the forces and stress on the structures are a challenge also for the specialists of the structures, in this work the developed methodology resulted very successful to analyze the behavior of a cable on a cable stayed bridge using damping.The dynamic analysis using computational models is an important tool to simulate the dynamic of structures that have specific uncertain behavior like the cable stayed bridges which nowadays is an alternative to solve long span bridges with a slim structure. In this work we developed a 3D non linear model of a cable in order to evaluate the wind effect on the Papaloapan cable stayed bridge located on Veracruz Mexico, under different scenarios. The health of the structure is an important factor to analyze and there are many different fail causes, one of them is the fatigue fall that is relevant in the anchorage elements of the cable stayed bridges. It is possible to modify the behavior of the structure using dampers to minimize that effect. The geometry and all the forces and stress on the structures are a challenge also for the specialists of the structures, in this work the developed methodology resulted very successful to analyze the behavior of a cable on a cable stayed bridge using damping.

FPGA Implementation of a Tool Breakage Detection Algorithm in CNC Milling Machines

In this paper, an on-line tool breakage detection algorithm in CNC milling machines is implemented into a single 32,000-gate FPGA from Actel. The tool breakage detection algorithm is based on three pipelined processing units: a two-channel modulo operator, a one dimension wavelet transform and an asymmetry correlator. The two-channel modulo operator performs two twelve-bit square operations and a 25-bit square root. The one dimension wavelet transform performs a 256x8 point matrix per a 256 point vector multiplication over the incoming data from the modulo operator. The third processor performs an asymmetry correlation over the wavelet data to give a single value which contains the estimation of the tool condition. The overall processing unit cost is kept low by using optimized numeric digital structures, suited to fit into a 32,000-gate FPGA while allowing the system to give on-line tool condition estimation. Results are presented in order to show overall system performance.

Sa1927 Significant Genetic Variability Associated With the Evolution of Gastric Cancer Precursor Lesions in a Spanish Population

Objective Preoperative chemoradiotherapy has recently become common practice in treatment of esophageal cancer with a gain in 5-year survival of 10-15%. However, a significant proportion of patients do not respond well and experiencing unnecessary severe side-effects. Accurate risk-stratification of patients using informative biomarkers before therapy may help to avoid unnecessary morbidity due to ineffective treatment. The aim of this study was to investigate the correlation between the expression of SOX2 and P53 in pre-treatment tumor biopsies and grade of pathological tumor response in resected specimen of patients with esophageal adenocarcinoma (EAC) treated with neoadjuvant chemoradiotherapy (nCRT). Methods All EAC patients who received nCRT according to the CROSS regimen followed by esophagectomy, between January 2003 and July 2011 at the Erasmus University Medical Center, were included. SOX2 and P53 protein expression was visualized by immunohistochemistry on all pre-treatment tumor biopsies and scored independently by two investigators who were blinded for clinical outcome. Aberrant expression was defined as negative expression of SOX2 and overexpression or complete loss of P53 expression. The overall Tumor Regression Grade (TRG) was evaluated using the modified Mandard scoring system. Patients with TRG 1 or TRG 2 were classified as major responders (ie, 10% of tumor cells remaining). Results In total 77 patients were included. Forty (53%) patients had a major pathological response (TRG 1-2) and 37 (47%) a minor response (TRG 3-4). In pre-treatment biopsies aberrant SOX2 and P53 expression was seen in 40% (31/77) and 83% (64/77), respectively. A major response was significantly associated with an aberrant SOX2 expression (OR 3.9, 95% CI: 1.5 10.2, p=0.005) and aberrant p53 expression (OR 4.5, 95% CI: 1.15 18.2, p=0.031). Aberrant expression of both biomarkers increased the probability of a major response in the individual patient (OR of 5.6; 95% CI: 2.1 14.9, p= 0.001), with a sensitivity of 68%, specificity of 73% and a positive predictive value of 73%. Conclusion SOX2 and P53 expression in the pre-treatment biopsies predict response to nCRT in patients with EAC. These biomarkers might help to identify patients who are likely to benefit most from this multimodality treatment.