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A Delay-based Nonlinear Controller for Nanopositioning of Linear Ultrasonic Motors
Luis Luna,Kevin López,Rubén Garrido,Sabine Mondié,Luis Cantera 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.1
This work introduces a delay-based nonlinear controller aimed at position control of linear ultrasonic motors (LUMs), which is termed the cascade nonlinear proportional integral retarded (CNPIR) control law. This new controller incorporates a time delay in its structure, composed of two nested loops. The inner velocity loop is regulated through an integral retarded (IR) controller that contains a time delay in its structure. The outer position loop resorts to a nonlinear proportional (NP) controller endowed by a saturation function. A tuning procedure for the CNPIR controller is also proposed, and it is based on the placement of multiple dominant roots. The inner loop is tuned by assigning a dominant triple root, whereas a method based on solving a transcendental equation allows tuning the outer loop and assigns two dominant roots. Moreover, pole dominance is assessed through the argument principle. Experimental results on a linear ultrasonic motor allow assessing the real-time performance of the proposed controller to achieve high precision and fast response in spite of the effects of inner disturbances, hysteresis, and friction phenomena.
Luis Alberto Ortega-Porcayo,Eibar Ernesto Cabrera-Aldana,Nicasio Arriada-Mendicoa,Juan Luis Gómez-Amador,Martín Granados-García,Juan Barges-Coll 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.6
Anterior exposure for cervical chordomas remains challenging because of the anatomical complexities and the restoration of the dimensional balance of the atlanto-axial region. In this report, we describe and analyze the transmandibular transoral approach and multilevel spinal reconstruction for upper cervical chordomas. We report two cases of cervical chordomas (C2 and C2–C4) that were treated by marginal en bloc resection with a transmandibular approach and anterior-posterior multilevel spinal reconstruction/fixation. Both patients showed clinical improvement. Postoperative imaging was negative for any residual tumor and revealed adequate reconstruction and stabilization. Marginal resection requires more extensive exposure to allow the surgeon access to the entire pathology, as an inadequate tumor margin is the main factor that negatively affects the prognosis. Anterior and posterior reconstruction provides a rigid reconstruction that protects the medulla and decreases axial pain by properly stabilizing the cervical spine.
Analysis of Compression and Permeability Behavior of Porous Ti6Al4V by Computed Microtomography
Luis Olmos,Didier Bouvard,Jose Luis Cabezas‑Villa,Jose Lemus‑Ruiz,Omar Jiménez,Dante Arteaga 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.3
Porous materials were developed as a good alternative to replace different bones in the human body as they improve osseointegration,tissue ingrowth and simulate the mechanical properties of human bones. Such characteristics highly depend on thepore features and volume fraction. Samples with a pore volume fraction between 16 and 60% and a pore size distribution of100–500 μm were analyzed by computed microtomography. 3D images acquisition was performed at 10 μm pixel resolution,which permitted to observe the complete sample. Features like size, shape, orientation, connectivity and pore coordinationwere determined from the 3D image analysis. Compression behavior was evaluated by interrupted compression testing and,after that, new 3D images were acquired. In order to evaluate permeability, numerical simulations of flow throughout the3D images were carried out by using Avizo® software. It was found that shape and pore size distribution was similar in allsamples, showing good distribution of the pore formers inside the matrix. Full connectivity of pores was obtained with 32%volume fraction and above, and the coordination number follows the Artz model. The pores showed a radial orientation,which induces anisotropy in the flow properties. The compression showed two different behaviors, pore closing and porecoalescence. Values of permeability match with those reported for bones as well as the anisotropy in the radial and verticaldirections. It is concluded that the sample with 60 vol% of pores could be consider to be used for bone implants.
Luis Alberto Ortega-Porcayo,Andres Leal-López,Miroslava Elizabeth Soriano-López,Carlos Francisco Gutiérrez-Partida,Luis Rodolfo Ramírez-Barrios,Sergio Soriano-Solis,Manuel Rodríguez-García,Hector Anto 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.2
Study Design: Retrospective comparative clinical study. Purpose: This study aimed to assess paraspinal muscle atrophy in patients who underwent minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and unilateral pedicle screw fixation using a novel contralateral intact muscle-controlled model. Overview of Literature: The increased incidence of paravertebral lumbar muscle injuries after open techniques has raised the importance of implementing minimally invasive spine surgical techniques using tubular retractors and minimally invasive screw placement. The functional cross-sectional area (FCSA) represents the lean muscle mass; furthermore, FCSA is a useful marker of the contractile ability of a muscle following a spine surgery. However, the benefits of unilateral fixation and MI-TLIF on paraspinal muscles have not been defined. Methods: We performed a retrospective imagenological review on eleven patients who underwent unilateral MI-TLIF and unilateral transpedicular screw lumbar placement. FCSAs of the multifidus and erector spinae were measured 1 year after surgery at adjacent levels and were compared to the contralateral intact muscles. Measurement differences between the surgical and nonsurgical sites were compared. The interobserver reliability was calculated using an intraclass correlation coefficient. Results: The mean FCSA at the surgical site was 20.97±5.07 cm2 at the superior level and 8.89±2.87 cm2 at the inferior level. The mean FCSA at the contralateral nonsurgical site was 20.15±5.95 cm2 at the superior level and 9.20±2.66 cm2 at the inferior level was. The superior and inferior FCSA measurements showed no significant difference between the surgical and nonsurgical sites (p =0.5, p =0.922, respectively). Conclusions: Using a mini-open tubular approach through the sulcus between the longissimus and iliocostalis, MI-TLIF and unilateral pedicle screw instrumentation produced minimal paraspinal muscle damage at the superior and inferior adjacent levels.
( Luis Miguel Ruiz ),( Jose Luis Graupera ),( Melchor Gutierrez ),( Motohide Miyahara ) 한국스포츠정책과학원(구 한국스포츠개발원) 2003 International Journal of Applied Sports Sciences Vol.15 No.1
The Movement Assessment Battery for Children (Movement ABC; Henderson and Sudgen, 1992) is one of the most popular instruments in the assessment of children with movement coordination problems. It is generally assumed that the published norms for the test are valid for use with European children and one of the aims of this study was to compare the results of Miyaharas study with Japanese children (53 boys, 49 girls) and the American standardization (237 boys, 284 girls) with the Spanish sample (202 boys and 183 girls). The cross-cultural comparisons revealed that there are many differences in performance among children of these samples. These differences were distributed among tasks and countries in the two age bands. Gender differences in all samples shown that girls outperform boys in manual and balance tasks, and boys got better scores in ball skills. This data and its analysis so far suggest different consequences: 1) The question of cultural differences in motor skill learning and performance; 2) The problem of gender differences in motor coordination; 3) The norms of the test. As a final consequence it will be necessary to study this test in a larger and more broadly based sample of Spanish boys and girls for it to be accepted as a useful test in the assessment of motor coordination in Spain.
Bursectomy, Curettage, and Chemotherapy in Tuberculous Trochanteric Bursitis
Luis R. Ramos-Pascua,José A. Carro-Fernández,José A. Santos-Sánchez,Paula Casas Ramos,Luis J. Díez-Romero,Francisco M. Izquierdo-García 대한정형외과학회 2016 Clinics in Orthopedic Surgery Vol.8 No.1
We presented three patients with trochanteric tuberculosis and described the clinical and imaging findings of the infection. Histology revealed a necrotizing granulomatous bursitis and microbiology confirmed tuberculosis. All cases were successfully treated with bursectomy and curettage of the trochanteric lesion and antituberculous chemotherapy including isoniazid, pyrazinamide, rifampicin, and ethambutol.
Structural and optical characterization of InGaN/GaN quantum wells grown in cubic phase by MBE
Luis Faustino MEJIA-CUELLAR,Yenny Lucero CASALLAS-MORENO,Alberto PIEDRA-LORENZANA,Carlos Alberto HERNANDEZ-GUTIE,Dagoberto CARDONA,Saul ARIAS-CERON,Juan HERNANDEZ-ROSAS,Jose Luis HERRERA-PEREZ,Emmanue 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8
Luis Felipe Sallum,Luis Otavio Sarian,Liliana Lucci De Angelo Andrade,José Vassallo,Fernando Augusto Soares,Glauce Aparecida Pinto,Patrícia Andréia Ferreira,Sophie Derchain 대한부인종양학회 2013 Journal of Gynecologic Oncology Vol.24 No.2
Objective: To examine the patterns of estrogen receptor (ER) and progesterone receptor (PR) expression in borderline ovarian tumors (BOTs) and ovarian carcinomas. We also assessed the disease-free survival (DFS) and overall survival (OS) in women with ovarian carcinoma, in relation to ER and/or PR expression. Methods: We examined ER/PR expression in 38 BOTs and 172 ovarian carcinomas removed from patients treated at the State University of Campinas-UNICAMP (Brazil), from 1993 to 2008 and followed for up to 60 months using tissue microarray-based immunohistochemistry. Results: Twenty-eight (73.7%) mucinous and 10 (26.3%) serous BOTs were included. Ovarian carcinomas consisted mainly of 79 (46.0%) serous, 44 (25.5%) mucinous, 17 (9.8%) endometrioid, 10 (5.8%) clear-cell types. There was no significant difference of the ER/PR expression between BOT and ovarian carcinoma (p=0.55 for ER alone, 0.90 for PR alone, and 0.12 for combined expression). The level of ER/PR expression in BOTs was significantly higher in serous than in mucinous tumors (p<0.01). In carcinomas, ER/PR was higher in serous tumors than in mucinous (p<0.01) and clear cell tumors (p=0.02), and higher in endometrioid tumors than in mucinous tumors (p<0.01). DFS was affected neither by the clinical characteristics nor by combined steroid receptor status. OS was found to be significantly worse (p<0.01) only in women with stages II-IV tumors and those with residual disease after surgery (p<0.01). Conclusion: Overall, serous and endometrioid tumors were predominantly ER/PR positive, whereas mucinous and clear-cell tumors were preponderantly ER/PR negative. DFS and OS were not affected by ER/PR expression.
Luis A Gaytán Martínez,Luis A Sánchez-Ruiz,Laura Y Zuñiga,Manuel González-Ortiz,Esperanza Martínez-Abundis 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.1
Gymnema sylvestre, a plant typical of India, has long been known for its hypoglycemic effects. The objective of this study was to evaluate the effect of G. sylvestre administration on glycemic control, insulin secretion, and insulin sensitivity in patients with impaired glucose tolerance (IGT). A randomized, double-blind, placebo-controlled clinical trial was conducted in 30 patients with IGT. Fifteen patients randomly received G. sylvestre in doses of 300 mg b.i.d. and the other 15 received placebo in the same way. Before and after the intervention, anthropometric and metabolic measurements were taken, including 2-h oral glucose tolerance test (2-h OGTT), fasting plasma glucose, glycated hemoglobin A1c (A1C), and the lipid profile panel. Areas under the curve of glucose and insulin were calculated, as well as the insulinogenic, Stumvoll, and Matsuda indices. Wilcoxon, Mann–Whitney U, and chi-square or Fisher's exact tests were performed, and a P-value ≤.05 was considered statistically significant. There was a significant reduction in 2-h OGTT (9.1 ± 1.2 vs. 7.8 ± 1.7 mmol/L, P = .003), A1C (5.8 ± 0.3% vs. 5.4 ± 0.4%, P = .025), body weight, body mass index, and low-density lipoprotein cholesterol levels in the G. sylvestre group, with an increment in the Matsuda index (1.8 ± 0.8 vs. 2.4 ± 1.2, P = .008). At the end of the intervention, 46.7% of the patients obtained normal values in A1C. In conclusion, G. sylvestre administration in patients with IGT decreased 2-h OGTT and A1C, increasing insulin sensitivity. There were also improvements in anthropometric measures and the lipid profile.