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Universal Deformation Rings of Modules over Self-injective Cluster-Tilted Algebras Are Trivial

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Algebra Colloquium 2021年第2期28卷 269-280页

作者： I.D.M.gaviria JoséA.Vélez-Marulanda Peng Shan Universidad Nacional de Colombia Bogota D.C.Colombia Department of Mathematics Valdosta State UniversityValdostaGAUSA 不详

Let k be a fixed algebraically closed field of arbitrary characteristic,let Λ be a finite dimensional self-injective k-algebra,and let ∨ be an indecomposable non-projective left Λ-module with finite dimension over *** prove that if τΛ∨ is the Auslander-Reiten translation of ∨,then the versal deformation rings R(Λ,∨)and R(Λ,τΛ∨)(in the sense of *** and the second author)are *** use this to prove that if Λ is further a cluster-tilted k-algebra,then R(Λ,∨)is universal and isomorphic to k.

关键词： self-injective cluster tilted algebras Frobenius algebras (uni)versal deformation rings

Closed loop harmonic content reduction for three phase induction machines control

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Closed loop harmonic content reduction for three phase induc...

Computational Study of the Formation Reaction of Polyacid Precursors of Glass-Ionomer Materials

2010 Chinese Control and Decision Conference

作者： Francisco Franco carlos gaviria Elena Munoz Cauca University PoapyanColombia

ISBN: (纸本)9781424451814;9781424451821

＜正＞This paper presents a closed loop control technique for harmonic content reduction in the stator current of an induction machine feeded with a three phase inverter,within a velocity control *** a digital filter for Clarke transformation,a robust sliding flux observer,and a closed loop control for the zero sequence of a SVPWM three phase inverter,this work shows how the proposed schema can effectively reduce the harmonic content in the stator currents of the induction machine despite of variations on the load torque using just two sensors:a current sensor for one of the stator phases and a velocity sensor for the closed loop control of the velocity of the machine.

关键词： SVPWM induction machine flux observer sliding-mode

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Journal of Materials Science and Chemical Engineering 2021年第8期9卷 1-9页

作者： Jair gaviria Jairo Quijano Pablo Ruiz Facultad de Ciencias Universidad Nacional de Colombia Medellín Colombia Facultad de Ciencias Exactas y Aplicadas Instituto Tecnológico Metropolitano Medellín Colombia

The formation of polyacids in a glass-ionomer cement was computationally modeled. The polyacid modelled is an oligomer made up of three molecules: acrylic acid, itaconic acid and an additional molecule that acts as a spacer group between the previous two. Acryloyl and meta-acryloyl derivatives of some amino acids and related molecules such as N-vinyl pyrrolidone and N-vinyl caprolactam were used as spacer groups. Some of these molecules have been previously used experimentally as spacer groups. In this work the spacer behaviour of 15 different molecules was investigated. To our knowledge, this is the first computational attempt to model some promising molecules to be incorporated into glass-ionomer dental cements. The results revealed the best structural arrangement for the investigated molecules.

关键词： Cements Glass Ionomer Polyacids Spacers Terpolymers

One-stage reconstruction of neck burns with single-Iayer dermal matrix

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Plastic and Aesthetic Research 2018年第9期5卷 12-18页

作者： Jorge Luis gaviria Viviana Gómez-Ortega Department of Plastic and Reconstructive Surgery Burn Unit Hospital Simón BolivarBogotá110131Colombia Department of Plastic and Reconstructive Surgery Fundación Santa Féde BogotáBogotá110111Colombia

Aim: The aim of the study was to describe the applicability of a single-layer acellular dermal matrix, in combination with split-thickness skin graft (STSG) in one-stage surgical procedure in patients with deep neck second - and third - degree burns. Methods: A descriptive longitudinal study was conducted at the Burn Unit of the Health Services Unit of Simón Bolívar North Subnetwork E.S.E. of the Secretariat of Health in Bogotá, Colombia, from January 12016 to December 312017 in which we describe the applicability of a single-layer acellular dermal matrix in combination with STSG in one-stage surgical procedure in patients with deep neck second and third degree burns. Results: A total of 9 patients were treated. Exposed areas required definitive coverage using a single-layer dermal regeneration matrix and autografts in a one-stage procedure, following excision of keloid scars and scar retractions (n= 7), and in the case of acute-phase deep burn wounds, following complete necrotic tissue removal (n = 2). No patient presented infection during postoperative follow-up. At 2 months postoperatively, stability of treated area and adequate resistance of the skin substitute and autografts could be observed. They appeared normal in color, with no degree of contractures or functional limitations. Conclusion: This is the first study demonstrating that the use of a single-layer acellular dermal matrix template for one stage reconstruction of post-burn full thickness neck defects is an effective, safe and excellent reconstructive option. The use of an artificial dermal matrix in one-step surgical approach, allows rapid healing and early mobilization of the neck, and in selective cases, it may reduce the need for local-regional or free flap coverage;moreover, it is associated with excellent skin formation, good functional and esthetic results and minimal donor site morbidity.

关键词： Neck burns matrix template reconstruction

Flood Vulnerability Assessment： A Multiscale, Multitemporal and Multidisciplinary Approach

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Journal of Earth Science and Engineering 2013年第2期3卷 102-108页

作者： Edna M. Rodriguez-gaviria Veronica Botero-Fernadez Faculty of Architecture and Engineering University Institution Colegio Mayor de Antioquia Medellin 05001 Colombia School of Geosciences and Environment National University of Colombia Medellin 05001 Colombia

Recent catastrophic events related to floods in Colombia reveal again the situation of disaster as a development issue not solved in the country. It is necessary to analyze in more detail the areas under threat and their respective vulnerability to the different mechanisms can generate flooding events and make adjustments in the assessment of disaster risks for the appropriate decision-making at local, regional and national levels. This paper presents a research project in its first phase, whose main objective is to develop a methodology for vulnerability assessment from a multiscale, multitemporal and multidisciplinary perspectives, combining the use of indicators and a spatial information system to analyze exposure and vulnerability at regional and local level in specific areas. This methodological tool will also enable local and regional authorities to identify the most appropriate strategies to reduce vulnerability and adaptation options, and make better decisions in assessing disaster risk. The information generated in this study will contribute to public policy action structured to correct short- and medium-term situations of actual or potential vulnerability, which can also be used in other activities of territorial and environmental planning, developing technology transfer activities and training associated with the research project in the service of the authorities and communities. Results obtained of the vulnerability analysis for a Colombian study area will relate to the hazards obtained in a parallel project whose goal is to identify the best risk management strategies through the development of GIS （geographic information system）-based scenarios for different risk and vulnerability reduction options.

关键词： Floods hazards developing countries GIS disaster indicators.

The Mechanism of Formation of Glass-Ionomer Cement: A Theoretical Study

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Modeling and Numerical Simulation of Material Science 2013年第4期3卷 149-154页

作者： Jair gaviria Claudia G. García Ederley Vélez Jairo Quijano Departamento de Ciencias Básicas Universidad de Medellín Medellín Colombia Universidad Nacional de Colombia Sede Medellín Colombia

A resin-modified glass-ionomer cement (RMGIC) was studied from a computational point of view. We suggest terpolymer formation by reaction of fixation through a combination of acrylic acid (AA), itaconic acid (IA) and an aminoacid derivative (AAD) in different positions. We found that AAD-AA-IA is thermodynamically more stable, but AA-IA-AAD is the combination which can react with glycidyl methacrylate (GM) to form a grafted polymer with two pendant methacrylate groups which can be used later in the process of light-curing. A RMGIC contains a glass powder of calcium-fluoroaluminosilicate acting as the source of cross linking, and for this reason, we have optimized two intramolecular Al3+ tricarboxylate complexes (salt-bridges) formed from the most stable grafted polymers. A possible reaction mechanism for the addition of (GM) to copolymer is proposed.

关键词： Dental Cements Resin-Modified Glass-Ionomer Cement Glycidyl Methacrylate Amino Acid Derivatives Density Functional Theory

人脸识别技术——设计保护隐私和防止偏见的系统

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信息安全与通信保密 2021年第2期19卷 45-53页

作者：杨·道格拉斯丽贝卡·巴拉贝卡卡洛斯·伊格纳西奥·古铁雷斯迈克尔·查科夫斯基编辑部美国兰德公司不详

人脸识别技术(FRTs)设计用来检测和识别被摄像机镜头捕捉到的人的图像。实施这种技术有许多与安全有关的实际情况。尽早识别FRTs系统中固有的隐私和偏见问题有助于缓解未来的风险。理解人脸识别技术有两个维度。第一个维度描述了受试者... 详细信息

人脸识别技术(FRTs)设计用来检测和识别被摄像机镜头捕捉到的人的图像。实施这种技术有许多与安全有关的实际情况。尽早识别FRTs系统中固有的隐私和偏见问题有助于缓解未来的风险。理解人脸识别技术有两个维度。第一个维度描述了受试者如何与FRTs系统合作:同意和不同意。在同意的情况下,受试对象知道他们的图像已被捕获并自愿参加。在不同意的情况下,受试对象没有机会拒绝捕获其图像。受试者愿意与FRTs合作的程度影响FRTs的错误率。

关键词：人脸识别启发式方法偏见政策框架