163,171 research outputs found
J. O. Fleckenstein, G. W. Leibniz, Barock und Universalismus
No full textRobinet André. J. O. Fleckenstein, G. W. Leibniz, Barock und Universalismus. In: Revue d'histoire des sciences et de leurs applications, tome 12, n°3, 1959. pp. 275-276
J. O. Fleckenstein, G. W. Leibniz, Barock und Universalismus
No full textRobinet André. J. O. Fleckenstein, G. W. Leibniz, Barock und Universalismus. In: Revue d'histoire des sciences et de leurs applications, tome 12, n°3, 1959. pp. 275-276
Peter Glassen. Ausgewählte Aufsätze unter Mit wirkung von C.-J. Glassen und J. Fried, herausgegeben von J. Fleckenstein ; Sigmaringen : J. Thorbecke, 1983 ; in-8°, 544 pages, 13 planches [Vorträge und Forschungen, herausgegeben vom Konstanzer Arbeitskreis für mittelalterliche Geschichte, 28
No full textGuyotjeannin Olivier. Peter Glassen. Ausgewählte Aufsätze unter Mit wirkung von C.-J. Glassen und J. Fried, herausgegeben von J. Fleckenstein ; Sigmaringen : J. Thorbecke, 1983 ; in-8°, 544 pages, 13 planches [Vorträge und Forschungen, herausgegeben vom Konstanzer Arbeitskreis für mittelalterliche Geschichte, 28. In: Bibliothèque de l'école des chartes. 1985, tome 143, livraison 1. pp. 231-232
Jakob Bernoulli, Die Werke von — , herausgegeben von der Naturforschenden Gesellschaft in Basel, Band I, Bearbeiter : J. 0. Fleckenstein, Basel, Birkhàuser Verlag, 1969,
No full textBos Henk J. M. Jakob Bernoulli, Die Werke von — , herausgegeben von der Naturforschenden Gesellschaft in Basel, Band I, Bearbeiter : J. 0. Fleckenstein, Basel, Birkhàuser Verlag, 1969,. In: Revue d'histoire des sciences, tome 24, n°3, 1971. pp. 267-269
Robustness of sweeping-window arc therapy treatment sequences against intrafractional tumor motion
No full textPurpose: Due to the potentially periodic collimator dynamic in volumetric modulated arc therapy (VMAT) dose deliveries with the sweeping-window arc therapy (SWAT) technique, additional manifestations of dosimetric deviations in the presence of intrafractional motion may occur. With a fast multileaf collimator (MLC), and a flattening filter free dose delivery, treatment times close to 60 s per fraction are clinical reality. For these treatment sequences, the human breathing period can be close to the collimator sweeping period. Compared to a random arrangement of the segments, this will cause a further degradation of the dose homogeneity. Methods: Fifty VMAT sequences of potentially moving target volumes were delivered on a two dimensional ionization chamber array. In order to detect interplay effects along all three coordinate axes, time resolved measurements were performed twice-with the detector aligned in vertical (V) or horizontal (H) orientation. All dose matrices were then moved within a simulation software by a time-dependent motion vector. The minimum relative equivalent uniform dose EUDr,m for all breathing starting phases was determined for each amplitude and period. Furthermore, an estimation of periods with minimum EUD was performed. Additionally, LINAC logfiles were recorded during plan delivery. The MLC, jaw, gantry angle, and monitor unit settings were continuously saved and used to calculate the correlation coefficient between the target motion and the dose weighed collimator motion component for each direction (CC, LR, AP) separately. Results: The resulting EUDr,m were EUDr,m(CCV) = (98.3 +/- 0.6)%, EUDr,m(CCH) = (98.6 +/- 0.5)%, EUDr,m(AP(V)) = (97.7 +/- 0.9)%, and EUDr,m(LRH) = (97.8 +/- 0.9)%. The overall minimum relative EUD observed for 360. arc midventilation treatments was 94.6%. The treatment plan with the shortest period and a minimum relative EUD of less than 97% was found at T = 6.1 s. For a partial 120 degrees arc, an EUDr,m = 92.0% was found. In all cases, a correlation coefficient above 0.5 corresponded to a minimum in EUD. Conclusions: With the advent of fast VMAT delivery techniques, nonrobust treatment sequences for human breathing patterns can be generated. These sequences are characterized by a large correlation coefficient between a target motion component and the corresponding collimator dynamic. By iteratively decreasing the maximum allowed dose rate, a low correlation coefficient and consequentially a robust treatment sequence are ensured. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License
Josef Fleckenstein, Rittertum und ritterliche Welt, Berlin, Siedler Verlag, 2002, pp. 256
No full textRecensione del volume di J. Fleckenstein Rittertum und ritterliche Welt, che dimostra come la storia dell'Europa medievale ruoti attorno alla cavalleria
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Development of a Geant4 based Monte Carlo Algorithm to evaluate the MONACO VMAT treatment accuracy
No full textA method to evaluate the dosimetric accuracy of volumetric modulated arc therapy (VMAT) treatment plans, generated with the MONACO (TM) (version 3.0) treatment planning system in realistic CT-data with an independent Geant4 based dose calculation algorithm is presented. Therefore a model of an Elekta Synergy linear accelerator treatment head with an MLCi2 multileaf collimator was implemented in Geant4. The time dependent linear accelerator components were modeled by importing either logfiles of an actual plan delivery or a DICOM-RT plan sequence. Absolute dose calibration, depending on a reference measurement, was applied. The MONACO as well as the Geant4 treatment head model was commissioned with lateral profiles and depth dose curves of square fields in water and with film measurements in inhomogeneous phantoms. A VMAT treatment plan for a patient with a thoracic tumor and a VMAT treatment plan of a patient, who received treatment in the thoracic spine region including metallic implants, were used for evaluation. MONACO, as well as Geant4, depth dose curves and lateral profiles of square fields had a mean local gamma (2%, 2 mm) tolerance criteria agreement of more than 95% for all fields. Film measurements in inhomogeneous phantoms with a global gamma of (3%, 3 mm) showed a pass rate above 95% in all voxels receiving more than 25% of the maximum dose. A dose-volume-histogram comparison of the VMAT patient treatment plans showed mean deviations between Geant4 and MONACO of -0.2% (first patient) and 2.0% (second patient) for the PTVs and (0.5 +/- 1.0)% and (1.4 +/- 1.1)% for the organs at risk in relation to the prescription dose. The presented method can be used to validate VMAT dose distributions generated by a large number of small segments in regions with high electron density gradients. The MONACO dose distributions showed good agreement with Geant4 and film measurements within the simulation and measurement errors
Die Ausdauerleistungsfähigkeit als Prädiktor der kognitiven Leistung: Ergebnisse der SMART-Studie.
No full textSchwarz S, Fleckenstein J, Engeroff T, et al. Die Ausdauerleistungsfähigkeit als Prädiktor der kognitiven Leistung: Ergebnisse der SMART-Studie. Deutsche Zeitschrift für Sportmedizin. 2015;66:174-219
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