1,721,304 research outputs found
Bracher (K.D.), Funke (M.), Jacobsen (H.-A.) (Hrsg.). Nationalsozialistische Diktatur 1933-1945.
No full textMartin Dirk. Bracher (K.D.), Funke (M.), Jacobsen (H.-A.) (Hrsg.). Nationalsozialistische Diktatur 1933-1945.. In: Revue belge de philologie et d'histoire, tome 64, fasc. 4, 1986. Histoire - Geschiedenis. pp. 903-905
Physical aspects of digital mammography technology
No full textThe establishment of digital mammography systems constitutes a slow process,the reason for this being the general need of particular image quality in mammography. This article provides an overview of the physical basis of digital mammography with high image quality and dose as low as reasonably achievable. The trade-off of high contrast resolution and effective quantum efficiency of the imaging system on the one hand, and the demand of high spatial resolution or very small pixel size on the other hand is discussed. The actual status of the available digital detector technology for mammography is described. The digital systems presently available are superior to conventional screen-film mammographic systems with respect to contrast resolution. An outlook on possible further developments in the field of digital mammography is presented
Flat panel detector-based volumetric CT - Prototype evaluation with volumetry of small artificial nodules in a pulmonary phantom
No full textPurpose: To evaluate amorphous silicone-based flat panel detector volumetric CT (VCT) in volumetric assessment of small nodules in a pulmonary phantom, and to perform comparative experiments with 4-row multislice CT (MSCT). Materials and Methods: Seventy synthetic nodules (volume range (VR): 0.99-185.77 mm(3); estimated diameter range (ED): 1.4-7.8 mm) were scanned in spherical shape and after iso-volumetric deformation with VCT and MSCT using 0.63 mm (MSCT I) and 1.25 mm (MSCT II) collimations. Measured volumes and percent measurement errors (PME) were compared between the 3 CT modes before and after nodule deformation. For each measurement pair before and after deformation, the post-deformation relative volumetric inaccuracy (RIA) was determined. Volume, PME, and RIA differences were tested using Wilcoxon and Friedman methods. Results: The volumes of the smallest nodules (VR = 0.99-2.83 mm(3), ED = 1.4-1.9 mm) were computable only from VCT scans. In VCT, measured volumes and PMEs before and after deformation differed significantly less compared with MSCT (VCT: P = 0.06 and 0.56, respectively; MSCT I: P = 0.0012 and 0.006, respectively; and MSCT II: P < 0.0001 for measured volumes and PMEs). In VCT PMEs of 5.51-32.21 mm(3) nodules (ED = 2.4-4.1 mm) before and after deformation were significantly below MSCT (VCT averages = 1.43-1.91% and 1.98-3.48%, for spherical and deformed nodules, respectively; MSCT I averages = 9.97-26.1% and 12.16-38.10%, respectively; MSCT II averages = 17.79-46.18 and 18.14-54.66%, respectively, P < 0.0001) and RIAs in VCT were significantly below MSCT (VCT: 0.50-2.62%, MSCT I: 3.35-15.97%, and MSCT II: 4.29-18.46%; P = 0.0001-0.0039). Conclusion: VCT volumetry is highly accurate in volumetry of smallest nodules with estimated diameters of 1.4-4.1 mm
Skills, Wages and Employment in East and West Germany
No full textFITZROY F. and FUNKE M. (1998) Skills, wages and employment in east and west Germany, Reg. Studies 32 , 459-467. Disaggregated data from 28 two-digit manufacturing industries in the east and west parts of unified Germany are used to estimate employment for three skill categories of blue collar workers. Employment elasticities are uniformly higher for unskilled labour. The results contradict union claims that wages had little relevance for east German job losses, and confirm the capitalskill complementarity hypothesis. FITZROY F. et FUNKE M. (1998) Competences, salaires et emploi dans l'est et l'ouest de l'Allemagne, Reg. Studies 32 , 459-467. A partir des donnees decomposees provenant de vingt-huit industries a deux chiffres situees dans l'est et l'ouest de l'Allemagne unifiee, on fait une estimation de l'emploi pour trois categories de competences des ouvriers. Les elasticites de l'emploi s'averent uniformement plus elevees pour les ouvriers non-qualifies. Les resultats contredisent les declarations des syndicats selon lesquelles les salaires ont peu d'interet avec les suppressions d'emplois dans l'est de l'Allemagne, et viennent a l'appui de l'hypothese qui prone la complementarite du capital et des competences. FITZROY F. und FUNKE M. (1998) Qualifikation, Lohne und Erwerbstatigkeit in Ost- und Westdeutschland, , Reg. Studies 32 , 459-467. Es werden getrennte Daten von 28 zweistelligen herstellenden Industrien in den ostlichen und westlichen Teilen des vereinigten Deutschland dazu benutzt, Erwerbstatigkeit fur drei Qualifikationsstufen zu schatzen. Die Beschaftigungselastizitat ist durchweg hoher bei ungelernten Arbeitern. Die Ergebnisse widerlegen die Behauptungen der Gewerkschaften, dass zwischen Lohnen und Stellenverlusten in Ostdeutschland wenig Beziehung besteht und bestatigen die Hypothese deskomplimentaren Verhaltens von Kapital und Fahigkeiten.Labour Demand, Wage Differentials, Panel Data,
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Magnification mammography: a comparison of full-field digital mammography and screen-film mammography for the detection of simulated small masses and microcalcifications
No full textThe objective of this study was a comparison of a full-field digital mammography (FFDM) system and a conventional screen-film mammography (SFM) system with respect to the detectability of simulated small masses and microcalcifications in the magnification mode. All images were obtained using 1.8 times magnification. The FFDM images were obtained at radiation dose levels of 1.39, 1.0, 0.7, 0.49 and 0.24 times that of the SFM images. A contrast-detail phantom was used to compare the detection of simulated lesions using a four alternative forced-choice reader study with three readers. The correct observation ratio (COR) was calculated as the fraction of correctly identified lesions to the total number of simulated lesions. Soft-copy reading was performed for all digital images. Direct magnification images acquired with the digital system showed a lower object contrast threshold than those acquired with the conventional system. For equal radiation dose, the digital system provided a significantly increased COR (0.95) compared with the screen-film system (0.82). For simulated microcalcifications, the corresponding difference was 0.90 to 0.72. The digital system allowed equal detection to screen-film at 40% of the radiation dose used for screen film. Digital magnification images are superior to screen-film magnification images for the detection of simulated small masses and microcalcifications even at a lower radiation dose
The contribution of different postprocessing methods for multislice spiral CT in acute pulmonary embolism
No full textPurpose: To investigate the value of different postprocessing algorithms for multislice spiral CT (MSCT) in diagnosing acute pulmonary embolism. Materials and Methods: Forty-eight patients with suspected pulmonary embolism prospectively underwent MSCT using an 8-slice spiral CT. Using a confidence level on a three-point scale, three radiologists reviewed 2-mm and 5-mm axial slices, 5-mm and 10-mm axial maximum intensity projections (MIP) and 2-mm coronal slices as well as interactively generated multiplanar reformatted images. A subsequent consensus reading of the primary 1.25-mm axial slices served as gold standard. ROC analysis was applied to the various vascular sections. Results: The ROC analysis revealed a higher diagnostic accuracy of the 2-mm axial sections as compared to the 5-mm axial slices (Az = [0.988;0.976] vs. Az = [0.988-,0.802]). Coronal and multiplanar reformations also showed excellent diagnostic accuracy (Az = [0.972;0.949] and Az = [0.997;0.951], respectively) and were significantly superior to the 5-mm axial slices through the segmental and subsegmental arteries (p=0.05). MIP showed the weakest diagnostic accuracy (Az = [0.967;0.802] for 5-mm MIP; Az = [0.879;0.781] for 10-mm MIP). Conclusion: Thin axial slices as well as coronal and multiplanar reformations are superior to thick axial slices in the diagnosis of acute pulmonary embolism. MIP is not suited for accurate diagnosis of pulmonary embolic disease
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