http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Fractional Sliding Mode Control of Underwater ROVs subject to Non-differentiable Disturbances
Aldo-Jonathan Muñoz-Vázquez,Heriberto Ramírez-Rodríguez,Vicente Parra-Vega,Anand Sánchez-Orta 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.3
Some hydrodynamic phenomena of an underwater Remotely Operated Vehicle (ROV), such as turbulence,cavitation, and multi-phase fluidic regimes, are associated to continuous but nowhere differentiable functions. These disturbances stand as complex forces potentially influencing the ROVs during typical navigation tasks. In thispaper, the tracking control of a ROV subject to nonsmooth Hölder disturbances is proposed based on a fractionalorderrobust controller that ensures exponential tracking. Notably, the controller gives rise to a closed-loop systemwith the following characteristics: a) continuous control signal that alleviates chattering effects; b) the fractionalsliding motion is substantiated on a proposed resetting memory principle; c) the control is robust to model uncertainties;and d) exact rejection of Hölder disturbances in finite-time. A representative simulation study reveals thefeasibility of the proposed scheme.
Maytté Marcano-Caldera,Jose Luis Mejia-Cardona,María del Pilar Blanco-Uribe,Elena Carolina Chaverra-Mesa,Didier Rodríguez-Lezama,Jose Hernán Parra-Sánchez 대한치과보존학회 2019 Restorative Dentistry & Endodontics Vol.44 No.2
Objectives: The upper molars generally have three roots; therefore, different combinations of fusion can occur, increasing the possibility of finding more complex root canal systems. The purpose of this study was to evaluate the prevalence and characterization of fused roots in first and second maxillary molars using cone-beam computed tomography (CBCT) in a Colombian population. Materials and Methods: A total of 1274 teeth were evaluated, of which 534 were maxillary first molars and 740 were maxillary second molars. Axial sections were made at the cervical, middle, and apical levels to determine the prevalence of root fusion and the types of fusion. Results: Overall, 43% of the molars (n = 551) presented some type of fused root. Root fusion was present in 23.4% of the maxillary first molars. The most frequent type of fused root was type 3 (distobuccal-palatal; DB-P) (58.9%). Root fusion was observed in 57.6% of the maxillary second molars, and the most prevalent type of fused root was type 6 (cone-shaped) (45.2%). Of the maxillary molars, 12.5% were classified as C-shaped. Conclusion: Within the limitations of this study, there was a high prevalence of fused roots in maxillary molars in the Colombian population, mainly in the maxillary second molars. In first molars, the most common type of fused root was type 3 (DB-P) and in second molars, the most common type was type 6 (cone-shaped). Additionally, molars with root fusion presented variation at different levels of the radicular portion, with implications for treatment quality.
Choi, M.,Kadara, H.,Zhang, J.,Parra, E.R.,Rodriguez-Canales, J.,Gaffney, S.G.,Zhao, Z.,Behrens, C.,Fujimoto, J.,Chow, C.,Kim, K.,Kalhor, N.,Moran, C.,Rimm, D.,Swisher, S.,Gibbons, D.L.,Heymach, J.,Kaf Elsevier 2017 Annals of oncology Vol.28 No.1
<P>Conclusion(s): Our findings pinpoint mutated genes that may impact clinical outcome as well as personalized strategies for targeted immunotherapies in early-stage LUSC.</P>
Lower Body Motion Analysis to Detect Falls and Near Falls on Stairs
Gemma S. Parra-Dominguez,Jasper Snoek,Babak Taati,Alex Mihailidis 대한의용생체공학회 2015 Biomedical Engineering Letters (BMEL) Vol.5 No.2
Purpose We present a methodology to automatically detect falls on stairs, an application of computer vision and machine learning techniques with major real-world importance. Falls on the stairs, in particular, are a common cause of injury among older adults. Comprehending the conditions under which accidents take place could significantly aid in the prevention of falls, support independent living, and improve quality of life. Methods We extract a set of features, composed of Fourier coefficients and entropy metrics of instantaneous velocities from 3D motion sensor data, to encode lower body motion during stair navigation. A supervised learning algorithm is then trained on manually annotated data simulated in a home laboratory. Results In our empirical analysis, the algorithm obtains high fall detection accuracy (> 92%) and a low false positive rate (5-7%). In contrast with previous research, we identify that motion of the hips, rather than that of the feet, is the best indicator of dangerous activity given the 3D trajectory of various lower body joints. It is also shown that entropy measures alone provide sufficient information to detect abnormal events on stairs. Conclusions The study of falls is difficult due to their exceedingly sparse nature; but an automatic non-contact fall detection system can assist in data collection by sieving through large quantities of data, e.g., from public stairways.
Kadara, H,Choi, M,Zhang, J.,Parra, E.R.,Rodriguez-Canales, J.,Gaffney, S.G.,Zhao, Z.,Behrens, C.,Fujimoto, J.,Chow, C.,Yoo, Y.,Kalhor, N.,Moran, C.,Rimm, D.,Swisher, S.,Gibbons, D.L.,Heymach, J.,Kafta Elsevier 2017 ANNALS OF ONCOLOGY Vol.28 No.1
<P>Conclusion(s): Our study highlights molecular and immune phenotypes that warrant further analysis for their roles in clinical outcomes and personalized immune-based therapy of LUAD.</P>
Dynamic Response of Low-Aspect-Ratio Cantilever NACA0012 Airfoil at Low-To-Moderate Reynolds Numbers
S. Martínez-Aranda,A. García-González,L. Parras,J. F. Velazquez-Navarro,C. del Pino 한국항공우주학회 2018 International Journal of Aeronautical and Space Sc Vol.19 No.3
The influence of the angle of attack (AoA) and the chord based Reynolds number (Rec) on the lift and drag coefficients has been analyzed experimentally in a low-aspect-ratio NACA0012 airfoil, AR = 2. Results are shown for chord based Reynolds numbers in the range 3.33 × 104 ≤ Rec ≤ 1.33 × 105 and AoA between 0º and +35º, the stall angle being close to 12º. The aerodynamic characteristics show an increase and decrease of lift and drag force fluctuations for AoA greater than the stall angle. The explanation of how these aerodynamic variations appear has been reported numerically and it is based on two-dimensional effects which are mainly the unstable laminar separation bubble (LSB) and the subsequent downstream propagation of leading edge vortex (LEV) as AoA increases. In addition, the dynamic response of the wing has been studied using frequency analysis. We compute the power spectral density (PSD) from the temporal evolution of the net force exerted over the wing, showing that the main response of the wing is the presence of two natural frequencies of the wing-base system. The mean PSD suddenly increases for Rec ≈ 1 × 105, particularly at AoA exceeding the critical point that corresponds to the stall angle. Finally, and despite from the fact that our model is rigid, we find PSD peaks at very low and high frequencies in agreement with other authors’ results which correspond to energetic modes in the wingtip vortex and the formation and emission of coherent turbulent structures behind the airfoil, respectively.
Carlos S. Ortiz,Casey Richards,Ashlee Terry,Joselyn Parra,심원보 한국식물병리학회 2015 Plant Pathology Journal Vol.31 No.3
Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field.
Ortiz, Carlos S.,Richards, Casey,Terry, Ashlee,Parra, Joselyn,Shim, Won-Bo The Korean Society of Plant Pathology 2015 Plant Pathology Journal Vol.31 No.3
Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field.
Asynchronies during invasive mechanical ventilation: narrative review and update
Saavedra Santiago Nicolás,Barisich Patrick Valentino Sepúlveda,Maldonado José Benito Parra,Lumini Romina Belén,Gómez-González Alberto,Gallardo Adrián 대한중환자의학회 2022 Acute and Critical Care Vol.37 No.4
Invasive mechanical ventilation is a frequent therapy in critically ill patients in critical care units. To achieve favorable outcomes, patient and ventilator interaction must be adequate. However, many clinical situations could attempt against this principle and generate a mismatch between these two actors. These asynchronies can lead the patient to worst outcomes; because of that is vital to recognize and treat these entities as soon as possible. Early detection and recognition of the different asynchronies could favor the reduction of the days of mechanical ventilation, the days of hospital stay, and in intensive care and improve clinical results.
A ´ngel L. A ´ lvarez,Santiago Melo´n,Kevin P. Dalton,Ine´s Nicieza,Annele Roque,Bele´n Sua´rez,Francisco Parra 한국식품영양과학회 2012 Journal of medicinal food Vol.15 No.6
The anti–herpes simplex virus type 1 and anti–herpes simplex virus type 2 effects of apple pomace, a byproduct from the cider-processing industry, were investigated. The mechanisms of antiviral action were assessed using a battery of experiments targeting sequential steps in the viral replication cycle. The anti-herpetic mechanisms of apple pomaces included the inhibition of virus attachment to the cell surface and the arrest of virus entry and uncoating. Quercitrin and procyanidin B2 were found to play a crucial role in the antiviral activity.