TY - JOUR A1 - Weigand, Christoph T1 - A new Approach for Optimal Control of a Production process JF - Economic Quality Control. 7 (1992) Y1 - 1992 SN - 0940-5151 SP - 225 EP - 251 ER - TY - JOUR A1 - Weigand, Christoph T1 - Defining Precisions for Reliable Measurement and Estimation Procedures JF - Economic Quality Control. 24 (2009), H. 1 Y1 - 2009 SN - 0940-5151 SP - 5 EP - 33 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Weigand, Christoph T1 - Statistical Tests Based on Reliability and Precision JF - Economic Quality Control : EQC ; international journal for quality and reliability N2 - The construction of a statistical test is investigated which is based only on “reliability” and “precision” as quality criteria. The reliability of a statistical test is quantifiedin a straightforward way by the probability that the decision of the test is correct. However, the quantification of the precision of a statistical test is not at all evident. Thereforethe paper presents and discusses several approaches. Moreover the distinction of “nullhypothesis” and “alternative hypothesis” is not necessary any longer. Y1 - 2012 U6 - http://dx.doi.org/10.1515/eqc-2012-0002 SN - 1869-6147 VL - 27 IS - 1 SP - 43 EP - 64 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Wegner, Lena A1 - von Arx, Georg A1 - Sass-Klaassen, Ute G. W. A1 - Eilmann, Britta T1 - ROXAS – an efficient and accurate tool to detect vessels in diffuse-porous species JF - IAWA Journal / International Association of Wood Anatomists Y1 - 2013 U6 - http://dx.doi.org/10.1163/22941932-00000034 SN - 0928-1541 (Print) SN - 2294-1932 (Online) VL - 34 IS - 4 SP - 425 EP - 432 PB - Brill CY - Leiden ER - TY - JOUR A1 - Wegmann, Kilian A1 - Hackl, Michael A1 - Staat, Manfred A1 - Mayer, Katharina A1 - Müller, Lars-Peter T1 - Double plate osteosynthesis of proximal ulna fractures: biomechanical and clinical results JF - Knee surgery, sports traumatology, arthroscopy N2 - While plate fixation of proximal ulna fractures might lead to superior clinical results compared to tension band wiring, regular plates represent an established risk factor for wound complications. The olecranon double plates (Medartis, Basel, CH) might decrease complications related to the osteosynthesis because of their low profile and better anatomical fit. This study aimed to evaluate the biomechanical performance and clinical results of the olecranon double plates. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00167-016-4079-0 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 58 EP - 59 PB - Springer CY - Berlin ER - TY - JOUR A1 - Weemstra, Monique A1 - Eilmann, Britta A1 - Sass-Klaassen, Ute G. W. A1 - Sterck, Frank J. T1 - Summer droughts limit tree growth across 10 temperate species on a productive forest site JF - Forest Ecology and Management Y1 - 2013 U6 - http://dx.doi.org/doi:10.1016/j.foreco.2013.06.007 SN - 0378-1127 (Print) SN - 1872-7042 (Online) VL - 2013 IS - 306 SP - 142 EP - 149 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Wedrowski, M. A1 - Bruyndonckx, P. A1 - Tavernier, S. A1 - Zhi, L. A1 - Dang, J. A1 - Mendes, P. R. A1 - Perez, J. M. A1 - Ziemons, Karl T1 - Robustness of neural networks algorithm for gamma detection in monolithic block detector, positron emission tomography JF - 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC) N2 - The monolithic scintillator block approach for gamma detection in the Positron Emission Tomography (PET) avoids estimating Depth of Interaction (DOI), reduces dead zones in detector and diminishes costs of detector production. Neural Networks (NN) are very efficient to determine the entrance point of a gamma incident on a scintillator block. This paper presents results on the robustness of the spatial resolution as a function of the random fraction in the data, temperature and HV fluctuations. This is important when implementing the method in a real scanner. Measurements were done with two Hamamatsu S8550 APD arrays, glued on a 20 × 20 × 10 mm3 monolithic LSO crystal block. Y1 - 2009 SN - 1082-3654 SP - 2625 EP - 2628 ER - TY - JOUR A1 - Weckesser, Matthias A1 - Hufnagel, Andreas A1 - Ziemons, Karl A1 - Grießmeier, Martin A1 - Sonnenberg, Frank A1 - Hackländer, Thomas A1 - Langen, Karl-J. A1 - Holschbach, Markus A1 - Elger, Christian E. A1 - Müller-Gärtner, Hans-W. T1 - Effect of partial volume correction on muscarinic cholinergic receptor imaging with single-photon emission tomography in patients with temporal lobe epilepsy JF - European Journal of Nuclear Medicine N2 - Animal experiments and preliminary results in humans have indicated alterations of hippocampal muscarinic acetylcholine receptors (mAChR) in temporal lobe epilepsy. Patients with temporal lobe epilepsy often present with a reduction in hippocampal volume. The aim of this study was to investigate the influence of hippocampal atrophy on the quantification of mAChR with single photon emission tomography (SPET) in patients with temporal lobe epilepsy. Cerebral uptake of the muscarinic cholinergic antagonist [123I]4-iododexetimide (IDex) was investigated by SPET in patients suffering from temporal lobe epilepsy of unilateral (n=6) or predominantly unilateral (n=1) onset. Regions of interest were drawn on co-registered magnetic resonance images. Hippocampal volume was determined in these regions and was used to correct the SPET results for partial volume effects. A ratio of hippocampal IDex binding on the affected side to that on the unaffected side was used to detect changes in muscarinic cholinergic receptor density. Before partial volume correction a decrease in hippocampal IDex binding on the focus side was found in each patient. After partial volume no convincing differences remained. Our results indicate that the reduction in hippocampal IDex binding in patients with epilepsy is due to a decrease in hippocampal volume rather than to a decrease in receptor concentration. Y1 - 1997 SN - 1619-7089 VL - 24 IS - 9 SP - 1156 EP - 1161 ER - TY - JOUR A1 - Weckesser, Martin A1 - Grießmeier, Martin A1 - Schmidt, Daniela A1 - Sonnenberg, Frank A1 - Ziemons, Karl A1 - Kemna, Lars A1 - Holschbach, Marcus A1 - Langen, Karl-J. A1 - Müller-Gärtner, Hans-W. T1 - Iodine-123 α-methyl tyrosine single-photon emission tomography of cerebral gliomas: standardised evaluation of tumour uptake and extent JF - European Journal of Nuclear Medicine N2 - Single-photon emission tomography (SPET) with the amino acid analogue l-3-[123I]iodo-α-methyl tyrosine (IMT) is helpful in the diagnosis and monitoring of cerebral gliomas. Radiolabelled amino acids seem to reflect tumour infiltration more specifically than conventional methods like magnetic resonance imaging and computed tomography. Automatic tumour delineation based on maximal tumour uptake may cause an overestimation of mean tumour uptake and an underestimation of tumour extension in tumours with circumscribed peaks. The aim of this study was to develop a program for tumour delineation and calculation of mean tumour uptake which takes into account the mean background activity and is thus optimised to the problem of tumour definition in IMT SPET. Using the frequency distribution of pixel intensities of the tomograms a program was developed which automatically detects a reference brain region and draws an isocontour region around the tumour taking into account mean brain radioactivity. Tumour area and tumour/brain ratios were calculated. A three-compartment phantom was simulated to test the program. The program was applied to IMT SPET studies of 20 patients with cerebral gliomas and was compared to the results of manual analysis by three different investigators. Activity ratios and chamber extension of the phantom were correctly calculated by the automatic analysis. A method based on image maxima alone failed to determine chamber extension correctly. Manual region of interest analysis in patient studies resulted in a mean inter-observer standard deviation of 8.7%±6.1% (range 2.7%–25.0%). The mean value of the results of the manual analysis showed a significant correlation to the results of the automatic analysis (r = 0.91, P<0.0001 for the uptake ratio; r = 0.87, P<0.0001 for the tumour area). We conclude that the algorithm proposed simplifies the calculation of uptake ratios and may be used for observer-independent evaluation of IMT SPET studies. Three-dimensional tumour recognition and transfer to co-registered morphological images based on this program may be useful for the planning of surgical and radiation treatment. Y1 - 1998 SN - 1619-7089 VL - 25 IS - 2 SP - 150 EP - 156 ER - TY - JOUR A1 - Weber, Tobias A1 - Ruff-Stahl, Hans-Joachim K. T1 - Advances in Composite Manufacturing of Helicopter Parts JF - International Journal of Aviation, Aeronautics, and Aerospace Y1 - 2017 U6 - http://dx.doi.org/10.15394/ijaaa.2017.1153 SN - 2374-6793 VL - 4 IS - 1 ER -