The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Axel Schulte - One of the best experts on this subject based on the ideXlab platform.
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task delegation in an agent supervisory Control Relationship capability awareness in a cognitive agent
Systems Man and Cybernetics, 2014Co-Authors: Sebastian Clauss, Axel SchulteAbstract:An artificial cognitive agent, guiding a UAV based on operator-given tasks, is introduced onboard a conventionally automated aircraft in order to support the human operator. The agent acts in two roles - as subordinate to the human and at the same time as supervisor to the conventional onboard automation. The hierarchical Relationship is described by the term Agent Supervisory Control. The ACU performs Supervisory Functions, with which the tasks of the operator are aggregated into single actions. The agent considers automation functions of the UAV as capabilities that are managed and incorporated into its planning and execution process in accordance to their availability and requirements. Task delegation is highly adaptable and aims at situation adequate supervision for the operator. The agent uses its capability awareness in its subordinate role to correct possible mismatches in the mental model of the human.
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Implications for operator interactions in an agent supervisory Control Relationship
2014 International Conference on Unmanned Aircraft Systems (ICUAS), 2014Co-Authors: Sebastian Clauss, Axel SchulteAbstract:In order to support a human UAV operator during his mission management task, an artificial cognitive agent (ACU), operated on the basis of high-level tasks, is introduced onboard an unmanned automated aircraft. In analogy to human UAV guidance, the ACU does not interact directly with the aircraft, but rather formulates discrete commands for the automation and continually supervises their execution. In accordance with Sheridan's Human Supervisory Control, we describe this Relationship between the agent and the underlying automation by the term of Agent Supervisory Control. In this role, the ACU performs Supervisory Functions, with which the tasks of the operator are supplemented, reviewed and finally decomposed into single actions. These actions are then performed using the onboard conventional automation. The agent considers the automation functions of the UAV as capabilities that are managed and incorporated into its planning and execution process in accordance to their availability and requirements. During task execution, the ACU supplies the operator with information, as to keep him in charge of the aircraft at all times. The extent, form and frequency of the information depend on the necessities of the specific situation and the current task. The information requirements of the operator and a possible operator information-overload due to its detail must be weighed against each other.
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SMC - Task delegation in an agent supervisory Control Relationship capability awareness in a cognitive agent
2014 IEEE International Conference on Systems Man and Cybernetics (SMC), 2014Co-Authors: Sebastian Clauss, Axel SchulteAbstract:An artificial cognitive agent, guiding a UAV based on operator-given tasks, is introduced onboard a conventionally automated aircraft in order to support the human operator. The agent acts in two roles - as subordinate to the human and at the same time as supervisor to the conventional onboard automation. The hierarchical Relationship is described by the term Agent Supervisory Control. The ACU performs Supervisory Functions, with which the tasks of the operator are aggregated into single actions. The agent considers automation functions of the UAV as capabilities that are managed and incorporated into its planning and execution process in accordance to their availability and requirements. Task delegation is highly adaptable and aims at situation adequate supervision for the operator. The agent uses its capability awareness in its subordinate role to correct possible mismatches in the mental model of the human.
Brian D Kavanagh - One of the best experts on this subject based on the ideXlab platform.
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stereotactic body radiation therapy for melanoma and renal cell carcinoma impact of single fraction equivalent dose on local Control
Radiation Oncology, 2011Co-Authors: Michelle A Stinauer, Tracey E Schefter, Brian D Kavanagh, Rene Gonzalez, Thomas W Flaig, Karl D Lewis, William A Robinson, Mark Chidel, Michael Glode, David RabenAbstract:Melanoma and renal cell carcinoma (RCC) are traditionally considered less radioresponsive than other histologies. Whereas stereotactic body radiation therapy (SBRT) involves radiation dose intensification via escalation, we hypothesize SBRT might result in similar high local Control rates as previously published on metastases of varying histologies. The records of patients with metastatic melanoma (n = 17 patients, 28 lesions) or RCC (n = 13 patients, 25 lesions) treated with SBRT were reviewed. Local Control (LC) was defined pathologically by negative biopsy or radiographically by lack of tumor enlargement on CT or stable/declining standardized uptake value (SUV) on PET scan. The SBRT dose regimen was converted to the single fraction equivalent dose (SFED) to characterize the dose-Control Relationship using a logistic tumor Control probability (TCP) model. Additionally, the kinetics of decline in maximum SUV (SUVmax) were analyzed. The SBRT regimen was 40-50 Gy/5 fractions (n = 23) or 42-60 Gy/3 fractions (n = 30) delivered to lung (n = 39), liver (n = 11) and bone (n = 3) metastases. Median follow-up for patients alive at the time of analysis was 28.0 months (range, 4-68). The actuarial LC was 88% at 18 months. On univariate analysis, higher dose per fraction (p < 0.01) and higher SFED (p = 0.06) were correlated with better LC, as was the biologic effective dose (BED, p < 0.05). The actuarial rate of LC at 24 months was 100% for SFED ≥45 Gy v 54% for SFED <45 Gy. TCP modeling indicated that to achieve ≥90% 2 yr LC in a 3 fraction regimen, a prescription dose of at least 48 Gy is required. In 9 patients followed with PET scans, the mean pre-SBRT SUVmax was 7.9 and declined with an estimated half-life of 3.8 months to a post-treatment plateau of approximately 3. An aggressive SBRT regimen with SFED ≥ 45 Gy is effective for Controlling metastatic melanoma and RCC. The SFED metric appeared to be as robust as the BED in characterizing dose-response, though additional studies are needed. The LC rates achieved are comparable to those obtained with SBRT for other histologies, suggesting a dominant mechanism of in vivo tumor ablation that overrides intrinsic differences in cellular radiosensitivity between histologic subtypes.
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observation of a dose Control Relationship for lung and liver tumors after stereotactic body radiation therapy
International Journal of Radiation Oncology Biology Physics, 2009Co-Authors: Robert Mccammon, Tracey E Schefter, Laurie E Gaspar, Rebekah Zaemisch, Daniel J Gravdahl, Brian D KavanaghAbstract:Purpose To determine prognostic factors for local Control of primary or metastatic tumors within the lung or liver treated with stereotactic body radiation therapy (SBRT) within a single institution. Methods and Materials The records of 141 consecutive patients with 246 lesions treated with three-fraction SBRT from Oct 1999 through Aug 2005 were reviewed. Local Control was assessed radiographically. Univariate and multivariate analyses were performed to evaluate the influence of the following factors on local Control: total dose, expressed as either nominal prescription dose or equivalent uniform dose (EUD); gross tumor volume; primary site; treatment site (lung vs. other); histologic characteristics (adenocarcinoma vs. other); gender; age; and primary vs. metastatic tumor. Results On univariate analysis, increased dose (either nominal or EUD) and smaller gross tumor volume were significant predictors of higher local Control. Lesions treated to a nominal dose of 54 Gy or greater had a 3-year actuarial local Control rate of 89.3% compared with 59.0% and 8.1% for those treated to 36–53.9 Gy and less than 36 Gy. On multivariate analysis, only increased nominal dose and EUD retained statistical significance. Treatment was well tolerated; 5.7% of patients experienced Grade 3 or higher toxicity. Conclusions This large single-institution series suggests a dose–Control Relationship within the range of SBRT doses applied. Excellent local Control rates are achieved with a nominal dose of 54 Gy or greater, corresponding to an EUD greater than 65.3 Gy. These results support the use of aggressive SBRT regimens when durable tumor Control is the primary objective.
Sebastian Clauss - One of the best experts on this subject based on the ideXlab platform.
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task delegation in an agent supervisory Control Relationship capability awareness in a cognitive agent
Systems Man and Cybernetics, 2014Co-Authors: Sebastian Clauss, Axel SchulteAbstract:An artificial cognitive agent, guiding a UAV based on operator-given tasks, is introduced onboard a conventionally automated aircraft in order to support the human operator. The agent acts in two roles - as subordinate to the human and at the same time as supervisor to the conventional onboard automation. The hierarchical Relationship is described by the term Agent Supervisory Control. The ACU performs Supervisory Functions, with which the tasks of the operator are aggregated into single actions. The agent considers automation functions of the UAV as capabilities that are managed and incorporated into its planning and execution process in accordance to their availability and requirements. Task delegation is highly adaptable and aims at situation adequate supervision for the operator. The agent uses its capability awareness in its subordinate role to correct possible mismatches in the mental model of the human.
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Implications for operator interactions in an agent supervisory Control Relationship
2014 International Conference on Unmanned Aircraft Systems (ICUAS), 2014Co-Authors: Sebastian Clauss, Axel SchulteAbstract:In order to support a human UAV operator during his mission management task, an artificial cognitive agent (ACU), operated on the basis of high-level tasks, is introduced onboard an unmanned automated aircraft. In analogy to human UAV guidance, the ACU does not interact directly with the aircraft, but rather formulates discrete commands for the automation and continually supervises their execution. In accordance with Sheridan's Human Supervisory Control, we describe this Relationship between the agent and the underlying automation by the term of Agent Supervisory Control. In this role, the ACU performs Supervisory Functions, with which the tasks of the operator are supplemented, reviewed and finally decomposed into single actions. These actions are then performed using the onboard conventional automation. The agent considers the automation functions of the UAV as capabilities that are managed and incorporated into its planning and execution process in accordance to their availability and requirements. During task execution, the ACU supplies the operator with information, as to keep him in charge of the aircraft at all times. The extent, form and frequency of the information depend on the necessities of the specific situation and the current task. The information requirements of the operator and a possible operator information-overload due to its detail must be weighed against each other.
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SMC - Task delegation in an agent supervisory Control Relationship capability awareness in a cognitive agent
2014 IEEE International Conference on Systems Man and Cybernetics (SMC), 2014Co-Authors: Sebastian Clauss, Axel SchulteAbstract:An artificial cognitive agent, guiding a UAV based on operator-given tasks, is introduced onboard a conventionally automated aircraft in order to support the human operator. The agent acts in two roles - as subordinate to the human and at the same time as supervisor to the conventional onboard automation. The hierarchical Relationship is described by the term Agent Supervisory Control. The ACU performs Supervisory Functions, with which the tasks of the operator are aggregated into single actions. The agent considers automation functions of the UAV as capabilities that are managed and incorporated into its planning and execution process in accordance to their availability and requirements. Task delegation is highly adaptable and aims at situation adequate supervision for the operator. The agent uses its capability awareness in its subordinate role to correct possible mismatches in the mental model of the human.
Julien Nicolas - One of the best experts on this subject based on the ideXlab platform.
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On the structure–Control Relationship of amide-functionalized SG1-based alkoxyamines for nitroxide-mediated polymerization and conjugation
Polymer Chemistry, 2015Co-Authors: Elise Guégain, Vianney Delplace, Thomas Trimaille, Didier Gigmes, Didier Siri, Sylvain R. A. Marque, Yohann Guillaneuf, Julien NicolasAbstract:The functionalization of alkoxyamines prior to nitroxide-mediated polymerization (NMP) induces important structural variations when compared to the parent molecules. This may have important consequences on the design of functionalized materials by pre-functionalization. In this context, a wide range of amide-functionalized alkoxyamines (a functionality often obtained after conjugation from COOH– and N-succinimidyl-containing alkoxyamines) based on the nitroxide SG1 (N-tert-butyl-N-(1-diethyl phosphono-2,2-dimethylpropyl) nitroxide) have been synthesized and their dissociation rate constants (kd) have been determined. To rationalize their reactivity, a multi-parameter procedure was applied and enabled to discriminate disubstituted amide-functionalized alkoxyamines from monosubstituted ones. Monosubstituted alkoxyamines exhibited lower kd than their disubstituted counterparts (Ea increase of ∼7–10 kJ mol−1) because of the occurrence of intramolecular hydrogen bonding (IHB) between the alkyl and the nitroxide fragments. NMP of styrene, n-butyl acrylate and methyl methacrylate with a small amount of acrylonitrile was then successfully performed from two representative secondary SG1-based alkoxyamines employed for conjugation: namely AMA (COOH-containing) and AMA-NHS (N-succinimidyl derivative), and compared to polymerizations initiated with AMA-Gem, an AMA-based alkoxyamine pre-functionalized with the anticancer drug Gemcitabine (Gem) and subjected to IHB. Although AMA-NHS showed the best results due to its lower Ea, the strong polarity of the Gem moiety that counter-balanced the detrimental effect of IHB over its kd still allowed for a reasonable Control.
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SG1 Nitroxide-Mediated Polymerization of Isoprene: Alkoxyamine Structure/Control Relationship and α,ω–Chain-End Functionalization
Macromolecules, 2011Co-Authors: Simon Harrisson, Patrick Couvreur, Julien NicolasAbstract:Nitroxide-mediated polymerization of isoprene was carried out at 115 °C using a small library of SG1-based alkoxyamine initiators. Well-defined polymers were obtained, with no need to add free SG1. Efficient postfunctionalization reactions in α- (reaction of ethylene diamine with a succinimidyl-ester-functional initiator) and ω-positions (replacement of SG1 by benzyl trithiocarbonate) were demonstrated. Polymerizations mediated by alkoxyamines with tertiary initiating groups were observed to follow first order kinetics with respect to monomer, with number-average molecular weights (Mn) approximately 77% of theoretical Mn (Mn,theo). Use of alkoxyamines with primary and secondary initiating groups gave 2/3 order kinetics with respect to monomer and slightly lower molecular weights (Mn,exp ∼ 0.61 × Mn,theo). At higher conversions, the polydispersity of all polyisoprenes approached 1.1. At low conversions, however, significant differences in polydispersity were observed, indicating differences in the rate of ...
Tracey E Schefter - One of the best experts on this subject based on the ideXlab platform.
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stereotactic body radiation therapy for melanoma and renal cell carcinoma impact of single fraction equivalent dose on local Control
Radiation Oncology, 2011Co-Authors: Michelle A Stinauer, Tracey E Schefter, Brian D Kavanagh, Rene Gonzalez, Thomas W Flaig, Karl D Lewis, William A Robinson, Mark Chidel, Michael Glode, David RabenAbstract:Melanoma and renal cell carcinoma (RCC) are traditionally considered less radioresponsive than other histologies. Whereas stereotactic body radiation therapy (SBRT) involves radiation dose intensification via escalation, we hypothesize SBRT might result in similar high local Control rates as previously published on metastases of varying histologies. The records of patients with metastatic melanoma (n = 17 patients, 28 lesions) or RCC (n = 13 patients, 25 lesions) treated with SBRT were reviewed. Local Control (LC) was defined pathologically by negative biopsy or radiographically by lack of tumor enlargement on CT or stable/declining standardized uptake value (SUV) on PET scan. The SBRT dose regimen was converted to the single fraction equivalent dose (SFED) to characterize the dose-Control Relationship using a logistic tumor Control probability (TCP) model. Additionally, the kinetics of decline in maximum SUV (SUVmax) were analyzed. The SBRT regimen was 40-50 Gy/5 fractions (n = 23) or 42-60 Gy/3 fractions (n = 30) delivered to lung (n = 39), liver (n = 11) and bone (n = 3) metastases. Median follow-up for patients alive at the time of analysis was 28.0 months (range, 4-68). The actuarial LC was 88% at 18 months. On univariate analysis, higher dose per fraction (p < 0.01) and higher SFED (p = 0.06) were correlated with better LC, as was the biologic effective dose (BED, p < 0.05). The actuarial rate of LC at 24 months was 100% for SFED ≥45 Gy v 54% for SFED <45 Gy. TCP modeling indicated that to achieve ≥90% 2 yr LC in a 3 fraction regimen, a prescription dose of at least 48 Gy is required. In 9 patients followed with PET scans, the mean pre-SBRT SUVmax was 7.9 and declined with an estimated half-life of 3.8 months to a post-treatment plateau of approximately 3. An aggressive SBRT regimen with SFED ≥ 45 Gy is effective for Controlling metastatic melanoma and RCC. The SFED metric appeared to be as robust as the BED in characterizing dose-response, though additional studies are needed. The LC rates achieved are comparable to those obtained with SBRT for other histologies, suggesting a dominant mechanism of in vivo tumor ablation that overrides intrinsic differences in cellular radiosensitivity between histologic subtypes.
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observation of a dose Control Relationship for lung and liver tumors after stereotactic body radiation therapy
International Journal of Radiation Oncology Biology Physics, 2009Co-Authors: Robert Mccammon, Tracey E Schefter, Laurie E Gaspar, Rebekah Zaemisch, Daniel J Gravdahl, Brian D KavanaghAbstract:Purpose To determine prognostic factors for local Control of primary or metastatic tumors within the lung or liver treated with stereotactic body radiation therapy (SBRT) within a single institution. Methods and Materials The records of 141 consecutive patients with 246 lesions treated with three-fraction SBRT from Oct 1999 through Aug 2005 were reviewed. Local Control was assessed radiographically. Univariate and multivariate analyses were performed to evaluate the influence of the following factors on local Control: total dose, expressed as either nominal prescription dose or equivalent uniform dose (EUD); gross tumor volume; primary site; treatment site (lung vs. other); histologic characteristics (adenocarcinoma vs. other); gender; age; and primary vs. metastatic tumor. Results On univariate analysis, increased dose (either nominal or EUD) and smaller gross tumor volume were significant predictors of higher local Control. Lesions treated to a nominal dose of 54 Gy or greater had a 3-year actuarial local Control rate of 89.3% compared with 59.0% and 8.1% for those treated to 36–53.9 Gy and less than 36 Gy. On multivariate analysis, only increased nominal dose and EUD retained statistical significance. Treatment was well tolerated; 5.7% of patients experienced Grade 3 or higher toxicity. Conclusions This large single-institution series suggests a dose–Control Relationship within the range of SBRT doses applied. Excellent local Control rates are achieved with a nominal dose of 54 Gy or greater, corresponding to an EUD greater than 65.3 Gy. These results support the use of aggressive SBRT regimens when durable tumor Control is the primary objective.