Victor Edgar Delgado Mendez - Academia.edu (original) (raw)
Papers by Victor Edgar Delgado Mendez
Theoría. Revista del Colegio de Filosofía, 2015
Tópicos, Revista de Filosofía, 2013
Mauricio BEUCHOT y Javier SALDAÑA: Derechos humanos y naturaleza humana, México: UNAM 2000 (Cuade... more Mauricio BEUCHOT y Javier SALDAÑA: Derechos humanos y naturaleza humana, México: UNAM 2000 (Cuadernos del Instituto de Investigaciones Filológicas, 22), 195 pp.
Acta Medica Peruana, Jul 1, 2010
Reporte de caso Ceguera bilateral y manifestaciones hemato-neurológicas producidas durante un acc... more Reporte de caso Ceguera bilateral y manifestaciones hemato-neurológicas producidas durante un accidente botrópico Bilateral blindness and hematoneurological signs after bothropic bite
Acta Medica Colombiana, Dec 1, 2006
Revista Colombiana De Gastroenterologia, Sep 1, 2007
Revista Colombiana De Gastroenterologia, Mar 1, 2010
2013 World Haptics Conference (WHC), 2013
Trilateral haptic systems can be modeled as three-port networks. Analysis of coupled stability of... more Trilateral haptic systems can be modeled as three-port networks. Analysis of coupled stability of a three-port network can be accomplished in either the passivity or the absolute stability frameworks assuming all three ports are connected to passive but otherwise unknown terminations. This paper first reviews our recent results in terms of passivity and absolute stability criteria for general threeport networks-both criteria are founded on the properties of a positive-real Hermitian matrix. Next, we show that the absolute stability criterion is less conservative than the passivity criterion and that the two criteria become the same when the trilateral system is represented by a reciprocal immitance matrix. Then, to show how the two criteria may be utilized at the system design stage, we apply them to the problem of designing controllers for a dual-user haptic teleoperation system. Using the two criteria, controllers are then designed and compared in terms of conservatism and performance in simulations.
Cuadernos de Economía y Dirección de la Empresa, 2009
The International journal of periodontics & restorative dentistry, 2012
Because of the peri-implant bone resorption that occurs when a non-platform switched implant is e... more Because of the peri-implant bone resorption that occurs when a non-platform switched implant is exposed to the oral environment, it has been recommended to maintain 1.5 mm between the tooth and implant to preserve the bone adjacent to the teeth. Several studies have documented that platform-switched implants have less peri-implant bone resorption than matched implants. This retrospective radiographic analysis studied 70 platform-switched implants placed less than 1.5 mm from an adjacent tooth and with prostheses loaded for a minimum of 6 months. The mean distance between the implant and tooth was 0.99 mm (range, 0.20 to 1.49 mm); the mean horizontal and vertical bone resorption was 0.36 and 0.43 mm, respectively. The mean bone peak reduction was 0.37 mm. The results confirm that the use of platform-switched implants reduces bone resorption after two-piece implants have been uncovered and that it is possible to place this type of implant 1 mm from teeth while maintaining the bone lev...
The European journal of esthetic dentistry : official journal of the European Academy of Esthetic Dentistry, 2012
It is currently accepted that success in implant-supported restorations is based not only on osse... more It is currently accepted that success in implant-supported restorations is based not only on osseointegration, but also on achieving the esthetic outcome of natural teeth and healthy soft tissues. The socalled "pink esthetic" has become the main challenge with implant-supported rehabilitations in the anterior area. This is especially difficult in the cases with two adjacent implants. Two components affect the final periimplant gingiva: a correct bone support, and a sufficient quantity and quality of soft tissues. Several papers have emphasized the need to regenerate and preserve the bone after extractions, or after the exposure of the implants to the oral environment. The classical implantation protocol entails entering the working area several times and always involves the surgical manipulation of peri-implant tissues. Careful surgical handling of the soft tissues when exposing the implants and placing the healing abutments (second surgery) helps the clinician to obtain t...
The International journal of oral & maxillofacial implants
To review a series of 454 pterygoid implants placed more vertically than the previous standard an... more To review a series of 454 pterygoid implants placed more vertically than the previous standard angle (45 degrees) over a functional loading period ranging from 2 months to 14 years with a mean follow-up period of 6 years. A retrospective study was made. The sample was composed of patients rehabilitated with pterygoid implants between January 1997 and December 2010. Patient selection criteria included: edentulism on the posterior area of an atrophic maxilla, with less than 8 mm remaining from the sinus floor to the alveolar crest, and the presence of an anterior implant or tooth to ensure mesial support for a partial denture. After a healing period between 2 and 7 months, panoramic x-rays were taken at the time of loading. The implant length, implant diameter, implant success, and the angulation of the pterygoid implants were measured. Three hundred ninety-two patients (206 women and 186 men) ranging in age from 34 to 75 years were fitted with 454 pterygoid implants and followed up. ...
The International journal of oral & maxillofacial implants
The aim of this study was to describe the average angulation and dimensions of the pterygomaxilla... more The aim of this study was to describe the average angulation and dimensions of the pterygomaxillary area in the atrophic maxilla to facilitate the orientation of pterygoid implants during their placement. A retrospective radiologic study was made. A virtual pterygoid implant, 13, 15, or 18 mm long, was placed in the pterygomaxillary area following the axis of the bone, with a distance of at least 2 mm maintained between the artery and palatine nerve and the implant. The long axis of the implant was inclined slightly toward the palatal to follow the cortical palatal bone. The angles between the long axis of the virtual implant and Frankfort horizontal were measured in both sagittal and frontal views. To calculate the average length of the pterygomaxillary area, the virtual long axis of the implant was measured from the alveolar crest to the pterygomaxillary suture. The average anteroposterior axis inclination of the pterygomaxillary area was 72.5 ± 4.9 degrees relative to Frankfort h...
The Semantic Web – ISWC 2011, 2011
Observational studies in the literature have highlighted low levels of user satisfaction in relat... more Observational studies in the literature have highlighted low levels of user satisfaction in relation to the support for ontology visualization and exploration provided by current ontology engineering tools. These issues are particularly problematic for non-expert users, who rely on effective tool support to abstract from representational details and to be able to make sense of the contents and the structure of ontologies. To address these issues, we have developed a novel solution for visualizing and navigating ontologies, KC-Viz, which exploits an empirically-validated ontology summarization method, both to provide concise views of large ontologies, and also to support a 'middle-out' ontology navigation approach, starting from the most information-rich nodes (key concepts). In this paper we present the main features of KC-Viz and also discuss the encouraging results derived from a preliminary empirical evaluation, which suggest that the use of KC-Viz provides performance advantages to users tackling realistic browsing and visualization tasks. Supplementary data gathered through questionnaires also convey additional interesting findings, including evidence that prior experience in ontology engineering affects not just objective performance in ontology engineering tasks but also subjective views on the usability of ontology engineering tools.
Advanced Robotics, 2014
This paper presents a novel criterion to study the stability of multilateral teleoperation system... more This paper presents a novel criterion to study the stability of multilateral teleoperation systems based on passivity. Such systems (modelled as-port networks) have recently found interesting applications in cooperative haptic teleoperation and haptic-assisted training. The criterion provides researchers with an analytical, closed-form, necessary and sufficient condition useful for both analysis and design of multilateral haptic teleoperation systems. The paper shows that when = 2 the proposed conditions reduce to the wellknown Raisbeck's passivity criterion for 2-port networks. The proposed conditions are used to study the passivity (and consequently the stability) of a dual-user haptic system for control of a single teleoperated robot. Simulations and experiments are performed to further test the validity of the proposed criterion.
49th IEEE Conference on Decision and Control (CDC), 2010
1. This paper presents a criterion for passivity of nport networks, which can be used to model mu... more 1. This paper presents a criterion for passivity of nport networks, which can be used to model multilateral systems involving haptic information sharing between a number of users. Such systems have recently found interesting applications in both cooperative haptic teleoperation and haptics-assisted training. The criterion presented in Theorem 1, which is necessary and sufficient for passivity of the n-port network, imposes 2n conditions on the immitance parameters of the network and on the residues of the immitance parameters at their imaginary-axis poles. It is shown that when n = 2, the proposed conditions reduce to the well-known Raisbeck's passivity criterion for two-port networks. Another special case for which the proposed criterion has been simplified corresponds to three-port networks. Finally, the passivity of a dual-user haptic system for control of a single teleoperated robot is investigated.
Journal of Intelligent & Robotic Systems, 2014
Trilateral haptic systems can be modeled as threeport networks. Analysis of coupled stability of ... more Trilateral haptic systems can be modeled as threeport networks. Analysis of coupled stability of a three-port network can be accomplished in either the passivity or the absolute stability frameworks assuming all three ports are connected to passive but otherwise unknown terminations. This paper first introduces our recent results in terms of extending Raisbecks passivity criterion and Llewellyns absolute stability criterion to general three-port networks-both criteria are founded on the properties of a positive-real Hermitian matrix. Next, we show that the absolute stability criterion is less conservative than the passivity criterion. Then, to show how the two criteria may be utilized at the system design stage, we apply them to the problem of designing controllers for a dual-user haptic teleoperation system and a triple-user collaborative haptic virtual environment. Using the two criteria, controllers are then designed and compared in terms of conservatism in simulations and experiments.
IEEE Internet Computing, 2011
Clinical Oral Implants Research, 2011
Objectives: The purpose of this animal study was to radiologically measure the influence of abutm... more Objectives: The purpose of this animal study was to radiologically measure the influence of abutment disconnection on bone resorption and to compare this influence on platform-switched vs. non-platform-switched implants. Methods: The study design included extraction of all mandibular premolars in five canines. After 2 months, six implants were placed in each dog. Four of them were platform-switched (PS) implants and two were non-platform-switched (NPS) implants. Some or all of the abutments connected to the implants were disconnected at pre-ordained post-surgical intervals. Radiographs were taken at the time of implant placement and at every handling. The values for mesial (horizontal and vertical) and distal (horizontal and vertical) bone resorption were taken and compared for each implant at every abutment dis/reconnection. Results: The average vertical bone resorption around NPS implants after four dis/reconnections was 1.09 mm (SD 0.25 mm), and the average horizontal bone resorption was 0.98 mm (SD 0.27 mm). The average vertical bone resorption around PS implants after four dis/reconnections was 0.24 mm, (SD 0.08 mm) and the average horizontal bone resorption was 0.24 mm (SD 0.13 mm). The difference of the average horizontal and vertical bone resorption around NPS (site D) and PS (site A) implants was statically significant (P < 0.05). The average mesial and distal bone resorption values around PS (site A) implant adjacent to a tooth were compared, and statically significant differences were found (P < 0.05). Conclusions: Implants with a PS design show less peri-implant bone resorption during the healing process and as their abutments are disconnected, than do comparably dis/reconnected NPS implants. The location of the PS implant next to a tooth may decrease radiographically visible periimplant bone resorption significantly.
Rev. colomb. …, 2006
Base de dados : LILACS. Pesquisa : 463754 [Identificador único]. Referências encontradas : 1 [ref... more Base de dados : LILACS. Pesquisa : 463754 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. Texto completo. experimental, Documentos relacionados. Id: 463754 ...
Theoría. Revista del Colegio de Filosofía, 2015
Tópicos, Revista de Filosofía, 2013
Mauricio BEUCHOT y Javier SALDAÑA: Derechos humanos y naturaleza humana, México: UNAM 2000 (Cuade... more Mauricio BEUCHOT y Javier SALDAÑA: Derechos humanos y naturaleza humana, México: UNAM 2000 (Cuadernos del Instituto de Investigaciones Filológicas, 22), 195 pp.
Acta Medica Peruana, Jul 1, 2010
Reporte de caso Ceguera bilateral y manifestaciones hemato-neurológicas producidas durante un acc... more Reporte de caso Ceguera bilateral y manifestaciones hemato-neurológicas producidas durante un accidente botrópico Bilateral blindness and hematoneurological signs after bothropic bite
Acta Medica Colombiana, Dec 1, 2006
Revista Colombiana De Gastroenterologia, Sep 1, 2007
Revista Colombiana De Gastroenterologia, Mar 1, 2010
2013 World Haptics Conference (WHC), 2013
Trilateral haptic systems can be modeled as three-port networks. Analysis of coupled stability of... more Trilateral haptic systems can be modeled as three-port networks. Analysis of coupled stability of a three-port network can be accomplished in either the passivity or the absolute stability frameworks assuming all three ports are connected to passive but otherwise unknown terminations. This paper first reviews our recent results in terms of passivity and absolute stability criteria for general threeport networks-both criteria are founded on the properties of a positive-real Hermitian matrix. Next, we show that the absolute stability criterion is less conservative than the passivity criterion and that the two criteria become the same when the trilateral system is represented by a reciprocal immitance matrix. Then, to show how the two criteria may be utilized at the system design stage, we apply them to the problem of designing controllers for a dual-user haptic teleoperation system. Using the two criteria, controllers are then designed and compared in terms of conservatism and performance in simulations.
Cuadernos de Economía y Dirección de la Empresa, 2009
The International journal of periodontics & restorative dentistry, 2012
Because of the peri-implant bone resorption that occurs when a non-platform switched implant is e... more Because of the peri-implant bone resorption that occurs when a non-platform switched implant is exposed to the oral environment, it has been recommended to maintain 1.5 mm between the tooth and implant to preserve the bone adjacent to the teeth. Several studies have documented that platform-switched implants have less peri-implant bone resorption than matched implants. This retrospective radiographic analysis studied 70 platform-switched implants placed less than 1.5 mm from an adjacent tooth and with prostheses loaded for a minimum of 6 months. The mean distance between the implant and tooth was 0.99 mm (range, 0.20 to 1.49 mm); the mean horizontal and vertical bone resorption was 0.36 and 0.43 mm, respectively. The mean bone peak reduction was 0.37 mm. The results confirm that the use of platform-switched implants reduces bone resorption after two-piece implants have been uncovered and that it is possible to place this type of implant 1 mm from teeth while maintaining the bone lev...
The European journal of esthetic dentistry : official journal of the European Academy of Esthetic Dentistry, 2012
It is currently accepted that success in implant-supported restorations is based not only on osse... more It is currently accepted that success in implant-supported restorations is based not only on osseointegration, but also on achieving the esthetic outcome of natural teeth and healthy soft tissues. The socalled "pink esthetic" has become the main challenge with implant-supported rehabilitations in the anterior area. This is especially difficult in the cases with two adjacent implants. Two components affect the final periimplant gingiva: a correct bone support, and a sufficient quantity and quality of soft tissues. Several papers have emphasized the need to regenerate and preserve the bone after extractions, or after the exposure of the implants to the oral environment. The classical implantation protocol entails entering the working area several times and always involves the surgical manipulation of peri-implant tissues. Careful surgical handling of the soft tissues when exposing the implants and placing the healing abutments (second surgery) helps the clinician to obtain t...
The International journal of oral & maxillofacial implants
To review a series of 454 pterygoid implants placed more vertically than the previous standard an... more To review a series of 454 pterygoid implants placed more vertically than the previous standard angle (45 degrees) over a functional loading period ranging from 2 months to 14 years with a mean follow-up period of 6 years. A retrospective study was made. The sample was composed of patients rehabilitated with pterygoid implants between January 1997 and December 2010. Patient selection criteria included: edentulism on the posterior area of an atrophic maxilla, with less than 8 mm remaining from the sinus floor to the alveolar crest, and the presence of an anterior implant or tooth to ensure mesial support for a partial denture. After a healing period between 2 and 7 months, panoramic x-rays were taken at the time of loading. The implant length, implant diameter, implant success, and the angulation of the pterygoid implants were measured. Three hundred ninety-two patients (206 women and 186 men) ranging in age from 34 to 75 years were fitted with 454 pterygoid implants and followed up. ...
The International journal of oral & maxillofacial implants
The aim of this study was to describe the average angulation and dimensions of the pterygomaxilla... more The aim of this study was to describe the average angulation and dimensions of the pterygomaxillary area in the atrophic maxilla to facilitate the orientation of pterygoid implants during their placement. A retrospective radiologic study was made. A virtual pterygoid implant, 13, 15, or 18 mm long, was placed in the pterygomaxillary area following the axis of the bone, with a distance of at least 2 mm maintained between the artery and palatine nerve and the implant. The long axis of the implant was inclined slightly toward the palatal to follow the cortical palatal bone. The angles between the long axis of the virtual implant and Frankfort horizontal were measured in both sagittal and frontal views. To calculate the average length of the pterygomaxillary area, the virtual long axis of the implant was measured from the alveolar crest to the pterygomaxillary suture. The average anteroposterior axis inclination of the pterygomaxillary area was 72.5 ± 4.9 degrees relative to Frankfort h...
The Semantic Web – ISWC 2011, 2011
Observational studies in the literature have highlighted low levels of user satisfaction in relat... more Observational studies in the literature have highlighted low levels of user satisfaction in relation to the support for ontology visualization and exploration provided by current ontology engineering tools. These issues are particularly problematic for non-expert users, who rely on effective tool support to abstract from representational details and to be able to make sense of the contents and the structure of ontologies. To address these issues, we have developed a novel solution for visualizing and navigating ontologies, KC-Viz, which exploits an empirically-validated ontology summarization method, both to provide concise views of large ontologies, and also to support a 'middle-out' ontology navigation approach, starting from the most information-rich nodes (key concepts). In this paper we present the main features of KC-Viz and also discuss the encouraging results derived from a preliminary empirical evaluation, which suggest that the use of KC-Viz provides performance advantages to users tackling realistic browsing and visualization tasks. Supplementary data gathered through questionnaires also convey additional interesting findings, including evidence that prior experience in ontology engineering affects not just objective performance in ontology engineering tasks but also subjective views on the usability of ontology engineering tools.
Advanced Robotics, 2014
This paper presents a novel criterion to study the stability of multilateral teleoperation system... more This paper presents a novel criterion to study the stability of multilateral teleoperation systems based on passivity. Such systems (modelled as-port networks) have recently found interesting applications in cooperative haptic teleoperation and haptic-assisted training. The criterion provides researchers with an analytical, closed-form, necessary and sufficient condition useful for both analysis and design of multilateral haptic teleoperation systems. The paper shows that when = 2 the proposed conditions reduce to the wellknown Raisbeck's passivity criterion for 2-port networks. The proposed conditions are used to study the passivity (and consequently the stability) of a dual-user haptic system for control of a single teleoperated robot. Simulations and experiments are performed to further test the validity of the proposed criterion.
49th IEEE Conference on Decision and Control (CDC), 2010
1. This paper presents a criterion for passivity of nport networks, which can be used to model mu... more 1. This paper presents a criterion for passivity of nport networks, which can be used to model multilateral systems involving haptic information sharing between a number of users. Such systems have recently found interesting applications in both cooperative haptic teleoperation and haptics-assisted training. The criterion presented in Theorem 1, which is necessary and sufficient for passivity of the n-port network, imposes 2n conditions on the immitance parameters of the network and on the residues of the immitance parameters at their imaginary-axis poles. It is shown that when n = 2, the proposed conditions reduce to the well-known Raisbeck's passivity criterion for two-port networks. Another special case for which the proposed criterion has been simplified corresponds to three-port networks. Finally, the passivity of a dual-user haptic system for control of a single teleoperated robot is investigated.
Journal of Intelligent & Robotic Systems, 2014
Trilateral haptic systems can be modeled as threeport networks. Analysis of coupled stability of ... more Trilateral haptic systems can be modeled as threeport networks. Analysis of coupled stability of a three-port network can be accomplished in either the passivity or the absolute stability frameworks assuming all three ports are connected to passive but otherwise unknown terminations. This paper first introduces our recent results in terms of extending Raisbecks passivity criterion and Llewellyns absolute stability criterion to general three-port networks-both criteria are founded on the properties of a positive-real Hermitian matrix. Next, we show that the absolute stability criterion is less conservative than the passivity criterion. Then, to show how the two criteria may be utilized at the system design stage, we apply them to the problem of designing controllers for a dual-user haptic teleoperation system and a triple-user collaborative haptic virtual environment. Using the two criteria, controllers are then designed and compared in terms of conservatism in simulations and experiments.
IEEE Internet Computing, 2011
Clinical Oral Implants Research, 2011
Objectives: The purpose of this animal study was to radiologically measure the influence of abutm... more Objectives: The purpose of this animal study was to radiologically measure the influence of abutment disconnection on bone resorption and to compare this influence on platform-switched vs. non-platform-switched implants. Methods: The study design included extraction of all mandibular premolars in five canines. After 2 months, six implants were placed in each dog. Four of them were platform-switched (PS) implants and two were non-platform-switched (NPS) implants. Some or all of the abutments connected to the implants were disconnected at pre-ordained post-surgical intervals. Radiographs were taken at the time of implant placement and at every handling. The values for mesial (horizontal and vertical) and distal (horizontal and vertical) bone resorption were taken and compared for each implant at every abutment dis/reconnection. Results: The average vertical bone resorption around NPS implants after four dis/reconnections was 1.09 mm (SD 0.25 mm), and the average horizontal bone resorption was 0.98 mm (SD 0.27 mm). The average vertical bone resorption around PS implants after four dis/reconnections was 0.24 mm, (SD 0.08 mm) and the average horizontal bone resorption was 0.24 mm (SD 0.13 mm). The difference of the average horizontal and vertical bone resorption around NPS (site D) and PS (site A) implants was statically significant (P < 0.05). The average mesial and distal bone resorption values around PS (site A) implant adjacent to a tooth were compared, and statically significant differences were found (P < 0.05). Conclusions: Implants with a PS design show less peri-implant bone resorption during the healing process and as their abutments are disconnected, than do comparably dis/reconnected NPS implants. The location of the PS implant next to a tooth may decrease radiographically visible periimplant bone resorption significantly.
Rev. colomb. …, 2006
Base de dados : LILACS. Pesquisa : 463754 [Identificador único]. Referências encontradas : 1 [ref... more Base de dados : LILACS. Pesquisa : 463754 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. Texto completo. experimental, Documentos relacionados. Id: 463754 ...