The Experts below are selected from a list of 48606 Experts worldwide ranked by ideXlab platform
John Romanelli - One of the best experts on this subject based on the ideXlab platform.
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developing minimally invasive procedure quality Metrics one step at a time
Surgical Endoscopy and Other Interventional Techniques, 2019Co-Authors: Thomas A Aloia, Jonathan Dort, Erin Schwarz, Amir A Ghaferi, Tim Jackson, John RomanelliAbstract:Background Despite extensive first-hand surgical experience, rank and file members of surgical societies are generally not trained in and have not therefore been included in surgical quality measure development. The purpose of this exercise was to determine if a structured quality Metric Design tool could bridge this gap, facilitating rapid development of focused quality Metrics by minimally invasive surgeon attendees of the April 2018 SAGES Annual Meeting.
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developing minimally invasive procedure quality Metrics one step at a time
Surgical Endoscopy and Other Interventional Techniques, 2019Co-Authors: Thomas A Aloia, Jonathan Dort, Erin Schwarz, Amir A Ghaferi, Tim Jackson, John RomanelliAbstract:Despite extensive first-hand surgical experience, rank and file members of surgical societies are generally not trained in and have not therefore been included in surgical quality measure development. The purpose of this exercise was to determine if a structured quality Metric Design tool could bridge this gap, facilitating rapid development of focused quality Metrics by minimally invasive surgeon attendees of the April 2018 SAGES Annual Meeting. Expert minimally invasive surgeons attended a 90-min workshop with didactic and interactive quality Metric Design sessions during the Annual Meeting. The interactive portion was formed around a novel structured quality measure development tool that graded presenting symptoms, short-term complications, and long-term disutility of care. For first-time symptomatic inguinal hernia repair, first-time small to moderate size ventral hernia repair, and elective laparoscopic cholecystectomy, each workgroup was able to develop one quality, one short-term complication, and one long-term disutility Metric. A structured quality Metric Design tool facilitates application of knowledge through rapid development of multifaceted, patient-centric outcomes measures by expert minimally invasive surgeons, otherwise not formally trained in Metric development. The exercise also highlighted the need to rigorously define denominator populations and to guard against Metric-driven undertreatment.
Paolo Robuffo Giordano - One of the best experts on this subject based on the ideXlab platform.
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online leader selection for improved collective tracking and formation maintenance
IEEE Transactions on Control of Network Systems, 2018Co-Authors: Antonio Franchi, Paolo Robuffo GiordanoAbstract:The goal of this paper is to propose an extension of the popular leader-follower framework for multiagent collective tracking and formation maintenance in the presence of a time-varying leader. In particular, the leader is persistently selected online in order to optimize the tracking performance of an exogenous collective velocity command while also maintaining a desired formation via a (possibly time-varying) communication-graph topology. The effects of a change in the leader identity are theoretically analyzed and exploited for defining a suitable error Metric that is able to capture the tracking performance of the multiagent group. Both the group performance and the Metric Design are found to depend upon the spectral properties of a special directed graph induced by the identity of the chosen leader. By exploiting these results, as well as distributed estimation techniques, we are then able to detail a fully decentralized adaptive strategy that is able to periodically select online the best leader among the neighbors of the current leader. Numerical simulations show that the application of the proposed technique results in an improvement of the overall performance of the group behavior with regard to other possible strategies.
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online leader selection for improved collective tracking and formation maintenance
arXiv: Systems and Control, 2013Co-Authors: Antonio Franchi, Paolo Robuffo GiordanoAbstract:The goal of this work is to propose an extension of the popular leader-follower framework for multi-agent collective tracking and formation maintenance in presence of a time- varying leader. In particular, the leader is persistently selected online so as to optimize the tracking performance of an exogenous collective velocity command while also maintaining a desired formation via a (possibly time-varying) communication-graph topology. The effects of a change in the leader identity are theoretically analyzed and exploited for defining a suitable error Metric able to capture the tracking performance of the multi- agent group. Both the group performance and the Metric Design are found to depend upon the spectral properties of a special directed graph induced by the identity of the chosen leader. By exploiting these results, as well as distributed estimation techniques, we are then able to detail a fully-decentralized adaptive strategy able to periodically select online the best leader among the neighbors of the current leader. Numerical simulations show that the application of the proposed technique results in an improvement of the overall performance of the group behavior w.r.t. other possible strategies.
Ulrich Engelke - One of the best experts on this subject based on the ideXlab platform.
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reduced reference Metric Design for objective perceptual quality assessment in wireless imaging
Signal Processing-image Communication, 2009Co-Authors: Ulrich Engelke, Maulana Kusuma, Hansjurgen Zepernick, M CalderaAbstract:The rapid growth of third and development of future generation mobile systems has led to an increase in the demand for image and video services. However, the hostile nature of the wireless channel makes the deployment of such services much more challenging, as in the case of a wireline system. In this context, the importance of taking care of user satisfaction with service provisioning as a whole has been recognized. The related user-oriented quality concepts cover end-to-end quality of service and subjective factors such as experiences with the service. To monitor quality and adapt system resources, performance indicators that represent service integrity have to be selected and related to objective measures that correlate well with the quality as perceived by humans. Such objective perceptual quality Metrics can then be utilized to optimize quality perception associated with applications in technical systems. In this paper, we focus on the Design of reduced-reference objective perceptual image quality Metrics for use in wireless imaging. Specifically, the normalized hybrid image quality Metric (NHIQM) and a perceptual relevance weighted L"p-norm are Designed. The main idea behind both feature-based Metrics relates to the fact that the human visual system (HVS) is trained to extract structural information from the viewing area. Accordingly, NHIQM and L"p-norm are Designed to account for different structural artifacts that have been observed in our distortion model of a wireless link. The extent by which individual artifacts are present in a given image is obtained by measuring related image features. The overall quality measure is then computed as a weighting sum of the features with the respective perceptual relevance weight obtained from subjective experiments. The proposed Metrics differ mainly in the pooling of the features and amount of reduced-reference produced. While NHIQM performs the pooling at the transmitter of the system to produce a single value as reduced-reference, the L"p-norm requires all involved feature values from the transmitted and received image to perform the pooling on the feature differences at the receiver. In addition, non-linear mapping functions are developed that relate the Metric values to predicted mean opinion scores (MOS) and account for saturations in the HVS. The evaluation of prediction performance of NHIQM and the L"p-norm reveals their excellent correlation with human perception in terms of accuracy, monotonicity, and consistency. This holds not only for the prediction performance on images taken for the training of the Metrics but also for the generalization to unknown images. In addition, it is shown that the NHIQM approach and the perceptual relevance weighted L"p-norm outperform other prominent objective quality Metrics in prediction performance.
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Regional attention to structural degradations for perceptual image quality Metric Design
2008 IEEE International Conference on Acoustics Speech and Signal Processing, 2008Co-Authors: Ulrich Engelke, Vuong Xuan Nguyen, Hansjurgen ZepernickAbstract:In this paper, regional attention to structural degradations in images is analyzed to improve perceptual quality prediction performance of objective image quality Metrics. Subjective experiments were conducted to identify regions-of-interest for a set of natural images. A region-selective Metric Design is then applied to four objective image quality Metrics which were trained and validated with respect to quality prediction accuracy and generalization to unknown images. For this purpose, data is used from subjective quality experiments conducted at two independent laboratories. It is shown that the region-selective Design is highly beneficial for the considered objective image quality Metrics, in particular, prediction accuracy can be significantly increased.
Thomas A Aloia - One of the best experts on this subject based on the ideXlab platform.
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developing minimally invasive procedure quality Metrics one step at a time
Surgical Endoscopy and Other Interventional Techniques, 2019Co-Authors: Thomas A Aloia, Jonathan Dort, Erin Schwarz, Amir A Ghaferi, Tim Jackson, John RomanelliAbstract:Background Despite extensive first-hand surgical experience, rank and file members of surgical societies are generally not trained in and have not therefore been included in surgical quality measure development. The purpose of this exercise was to determine if a structured quality Metric Design tool could bridge this gap, facilitating rapid development of focused quality Metrics by minimally invasive surgeon attendees of the April 2018 SAGES Annual Meeting.
-
developing minimally invasive procedure quality Metrics one step at a time
Surgical Endoscopy and Other Interventional Techniques, 2019Co-Authors: Thomas A Aloia, Jonathan Dort, Erin Schwarz, Amir A Ghaferi, Tim Jackson, John RomanelliAbstract:Despite extensive first-hand surgical experience, rank and file members of surgical societies are generally not trained in and have not therefore been included in surgical quality measure development. The purpose of this exercise was to determine if a structured quality Metric Design tool could bridge this gap, facilitating rapid development of focused quality Metrics by minimally invasive surgeon attendees of the April 2018 SAGES Annual Meeting. Expert minimally invasive surgeons attended a 90-min workshop with didactic and interactive quality Metric Design sessions during the Annual Meeting. The interactive portion was formed around a novel structured quality measure development tool that graded presenting symptoms, short-term complications, and long-term disutility of care. For first-time symptomatic inguinal hernia repair, first-time small to moderate size ventral hernia repair, and elective laparoscopic cholecystectomy, each workgroup was able to develop one quality, one short-term complication, and one long-term disutility Metric. A structured quality Metric Design tool facilitates application of knowledge through rapid development of multifaceted, patient-centric outcomes measures by expert minimally invasive surgeons, otherwise not formally trained in Metric development. The exercise also highlighted the need to rigorously define denominator populations and to guard against Metric-driven undertreatment.
Hansjurgen Zepernick - One of the best experts on this subject based on the ideXlab platform.
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reduced reference Metric Design for objective perceptual quality assessment in wireless imaging
Signal Processing-image Communication, 2009Co-Authors: Ulrich Engelke, Maulana Kusuma, Hansjurgen Zepernick, M CalderaAbstract:The rapid growth of third and development of future generation mobile systems has led to an increase in the demand for image and video services. However, the hostile nature of the wireless channel makes the deployment of such services much more challenging, as in the case of a wireline system. In this context, the importance of taking care of user satisfaction with service provisioning as a whole has been recognized. The related user-oriented quality concepts cover end-to-end quality of service and subjective factors such as experiences with the service. To monitor quality and adapt system resources, performance indicators that represent service integrity have to be selected and related to objective measures that correlate well with the quality as perceived by humans. Such objective perceptual quality Metrics can then be utilized to optimize quality perception associated with applications in technical systems. In this paper, we focus on the Design of reduced-reference objective perceptual image quality Metrics for use in wireless imaging. Specifically, the normalized hybrid image quality Metric (NHIQM) and a perceptual relevance weighted L"p-norm are Designed. The main idea behind both feature-based Metrics relates to the fact that the human visual system (HVS) is trained to extract structural information from the viewing area. Accordingly, NHIQM and L"p-norm are Designed to account for different structural artifacts that have been observed in our distortion model of a wireless link. The extent by which individual artifacts are present in a given image is obtained by measuring related image features. The overall quality measure is then computed as a weighting sum of the features with the respective perceptual relevance weight obtained from subjective experiments. The proposed Metrics differ mainly in the pooling of the features and amount of reduced-reference produced. While NHIQM performs the pooling at the transmitter of the system to produce a single value as reduced-reference, the L"p-norm requires all involved feature values from the transmitted and received image to perform the pooling on the feature differences at the receiver. In addition, non-linear mapping functions are developed that relate the Metric values to predicted mean opinion scores (MOS) and account for saturations in the HVS. The evaluation of prediction performance of NHIQM and the L"p-norm reveals their excellent correlation with human perception in terms of accuracy, monotonicity, and consistency. This holds not only for the prediction performance on images taken for the training of the Metrics but also for the generalization to unknown images. In addition, it is shown that the NHIQM approach and the perceptual relevance weighted L"p-norm outperform other prominent objective quality Metrics in prediction performance.
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Regional attention to structural degradations for perceptual image quality Metric Design
2008 IEEE International Conference on Acoustics Speech and Signal Processing, 2008Co-Authors: Ulrich Engelke, Vuong Xuan Nguyen, Hansjurgen ZepernickAbstract:In this paper, regional attention to structural degradations in images is analyzed to improve perceptual quality prediction performance of objective image quality Metrics. Subjective experiments were conducted to identify regions-of-interest for a set of natural images. A region-selective Metric Design is then applied to four objective image quality Metrics which were trained and validated with respect to quality prediction accuracy and generalization to unknown images. For this purpose, data is used from subjective quality experiments conducted at two independent laboratories. It is shown that the region-selective Design is highly beneficial for the considered objective image quality Metrics, in particular, prediction accuracy can be significantly increased.