2,020 research outputs found
The Trisection Genus of Standard Simply Connected PL 4-Manifolds
No full textGay and Kirby recently introduced the concept of a trisection for arbitrary smooth, oriented closed 4-manifolds, and with it a new topological invariant, called the trisection genus. In this note we show that the K3 surface has trisection genus 22. This implies that the trisection genus of all standard simply connected PL 4-manifolds is known. We show that the trisection genus of each of these manifolds is realised by a trisection that is supported by a singular triangulation. Moreover, we explicitly give the building blocks to construct these triangulations
Ask questions, get sales : close the deak and create long-term relationships / Stephan Schiffman.
No full textIncludes index.v, 168 pages ;In Ask Questions, Get Sales, the author and sales guru Stephan Schiffman helps readers boost their careers to the gold-medal level by teaching them how to strengthen their questioning skills during the sales process. The premise is simple yet effective: In order to be successful, salespeople need to change their mindset from "need-orientated" to "do-orientated". The message of the book centers around six core "do" questions: What do you do? How do you do it? When and where do you do it? Why do you do it that way? Who do you do it with? How can we help you do it better? With this indispensable guide in their briefcase, salespeople will have information at the ready to score big sales over the short term and the long term
REVIEW OF: "Jaco William - Rubinstein J.Hyam - Tillmann Stephan, Z2-Thurston norm and complexity of 3-manifolds, Math. Ann. 356, No. 1, 1-22 (2013)". [DE061684636]
No full textGiven a closed, irreducible 3-manifold M (different from S3, RP2 and L(3, 1)), the complexity of M is known
to be the minimum number of tetrahedra in a (pseudo-simplicial) triangulation of M: see [Acta Appl. Math.
19, No.2, 101-130 (1990; Zbl 0724.57012)] and [Algorithms and Computation in Mathematics 9, Springer
(2007; Zbl 1128.57001)].
In [Algebr. Geom. Topol. 11(3), 1257-1265 (2011; Zbl 1229.57010)] the authors found a lower bound for the
complexity of M, in case M having a connected double cover (or, equivalently, a non-trivial Z2-cohomology
class).
The present paper makes use of the notion of Z2-Thurston norm (an analogue of Thurston’s norm, defined
in [Mem. Am. Math. Soc. 339, 99-130 (1986; Zbl 0585.57006)]) in order to obtain a new lower bound on
the complexity of M, if M admits multiple Z2-cohomology classes. Moreover, the minimal triangulations
realizing this bound are characterized, in terms of normal surfaces consisting entirely of quadrilateral discs.
It is worthwhile to note that the combinatorial structure of a minimal triangulation turns out to be governed
by 0-efficiency ([J. Differ. Geom. 65(1), 61-168 (2003; Zbl 1068.57023)]) and low degree edges ([J. Topol. 2(1),
157-180 (2009; Zbl 1227.57026)]), and that the unique minimal triangulation of the generalized quaternionic
space S3/Q8k (8k 2 Z+) - already obtained by the authors via the first lower bound - actually realizes this
new bound, too
Unemployment Benefits and Unemployment Rates of Low-Skilled and Elder Workers in West Germany: A Search Equilibrium Approach
No full textApproach Author & abstract Download 16 References 1 Citations Related works & more Corrections Author Listed: Launov, Andrey ([email protected]) (University of Kent) Wolff, Joachim ([email protected]) (Institute for Employment Research (IAB), Nuremberg) Klasen, Stephan ([email protected]) (University of Göttingen) Registered: Stephan Klasen Abstract In this paper we investigate whether the extension of the entitlement to unemployment benefits in the mid 80s can explain the increase in the unemployment rates of unskilled and elder workers in western Germany. To answer this question we estimate a version of the Burdett-Mortensen search equilibrium model and analyze how workers’ search behaviour responded to these reforms. We try both nonparametric and fully-parametric estimation methods and identify the cases in which the nonparametric approach cannot be applied. We find that the entitlement reforms are largely responsible for the increase of unemployment among unskilled workers
Unemployment Benefits and Unemployment Rates of Low-Skilled and Elder Workers in West Germany: A Search Equilibrium Approach
No full textApproach Author & abstract Download 16 References 1 Citations Related works & more Corrections Author Listed: Launov, Andrey ([email protected]) (University of Kent) Wolff, Joachim ([email protected]) (Institute for Employment Research (IAB), Nuremberg) Klasen, Stephan ([email protected]) (University of Göttingen) Registered: Stephan Klasen Abstract In this paper we investigate whether the extension of the entitlement to unemployment benefits in the mid 80s can explain the increase in the unemployment rates of unskilled and elder workers in western Germany. To answer this question we estimate a version of the Burdett-Mortensen search equilibrium model and analyze how workers’ search behaviour responded to these reforms. We try both nonparametric and fully-parametric estimation methods and identify the cases in which the nonparametric approach cannot be applied. We find that the entitlement reforms are largely responsible for the increase of unemployment among unskilled workers
Cell counts of Azadinium spinosum, Azadinium poporum and Amphidoma languida during POLARSTERN cruise PS92, UTHÖRN cruise UTH16 and various HEINCKE cruises to the eastern North Atlantic between 2015 and 2019
No full textThe data represent species counts (cells L-1) of the three AZA-producing dinoflagellate species Azadinium spinosum, Az. poporum and Amphidoma languida (all members of the taxonomic family Amphidomataceae) of water samples taken during in total six different field expeditions on several research vessels (RV Heincke, RV Uthörn, RV Polarstern) and on in total five stationary sampling stations (Scapa Flow/Scotland, Cuxhaven/Germany, Helgoland/Germany, Wilhelmshaven/Germany, Sylt/Germany) between 2015 and 2019. The water samples have been taken using Niskin bottles (on research vessels attached to a CTD). After DNA extraction, the species cell numbers have been calculated by quantitative PCR (qPCR) analysis using respective standard curves. These samples gained from different geographical areas in the eastern North Atlantic have been analyzed as part of the RIPAZA Project (funded by the German BMBF; in cooperation with the Third Institute of Oceanography, Xiamen/China) and the results are presented and discussed in the doctoral thesis of Stephan Wietkamp (Suppl.Tab.S6, Suppl.Tab.S7). Aim of the project and especially of this data set was to provide first reference data on the biogeography (geographical distribution and seasonality) of toxigenic Amphidomataceae in the eastern North Atlantic
Measuring Vulnerability to Poverty Using Long-Term Panel Data
No full textMeasuring Vulnerability to Poverty Using Long-Term Panel Data Author & abstract Download & other version 16 References 4 Citations Related works & more Corrections Author Listed: Katja Landau (Georg-August-University Göttingen) Stephan Klasen (Georg-August-University Göttingen) Walter Zucchini (Georg-August-University Göttingen) Registered: Stephan Klasen Abstract We investigate the accuracy of ex ante assessments of vulnerability to income poverty using cross-sectional data and panel data. We use long-term panel data from Germany and apply di fferent regression models, based on household covariates and previous-year equivalence income, to classify a household as vulnerable or not. Predictive performance is assessed using the Receiver Operating Characteristics (ROC), which takes account of false positive as well as true positive rates. Estimates based on cross-sectional data are much less accurate than those based on panel data, but for Germany, the accuracy of vulnerability predictions is limited even when panel data are used. In part this low accuracy is due to low poverty incidence and high mobility in and out of poverty
Measuring Vulnerability to Poverty Using Long-Term Panel Data
No full textMeasuring Vulnerability to Poverty Using Long-Term Panel Data Author & abstract Download & other version 16 References 4 Citations Related works & more Corrections Author Listed: Katja Landau (Georg-August-University Göttingen) Stephan Klasen (Georg-August-University Göttingen) Walter Zucchini (Georg-August-University Göttingen) Registered: Stephan Klasen Abstract We investigate the accuracy of ex ante assessments of vulnerability to income poverty using cross-sectional data and panel data. We use long-term panel data from Germany and apply di fferent regression models, based on household covariates and previous-year equivalence income, to classify a household as vulnerable or not. Predictive performance is assessed using the Receiver Operating Characteristics (ROC), which takes account of false positive as well as true positive rates. Estimates based on cross-sectional data are much less accurate than those based on panel data, but for Germany, the accuracy of vulnerability predictions is limited even when panel data are used. In part this low accuracy is due to low poverty incidence and high mobility in and out of poverty
Cell count time series of Azadinium spinosum, Azadinium poporum and Amphidoma languida at Cuxhaven, Helgoland, Sylt, Wilhelmshaven and Scapa Flow between 2015 and 2019
No full textThe data represent species counts (cells L-1) of the three AZA-producing dinoflagellate species Azadinium spinosum, Az. poporum and Amphidoma languida (all members of the taxonomic family Amphidomataceae) of water samples taken during in total six different field expeditions on several research vessels (RV Heincke, RV Uthörn, RV Polarstern) and on in total five stationary sampling stations (Scapa Flow/Scotland, Cuxhaven/Germany, Helgoland/Germany, Wilhelmshaven/Germany, Sylt/Germany) between 2015 and 2019. The water samples have been taken using Niskin bottles (on research vessels attached to a CTD). After DNA extraction, the species cell numbers have been calculated by quantitative PCR (qPCR) analysis using respective standard curves. These samples gained from different geographical areas in the eastern North Atlantic have been analyzed as part of the RIPAZA Project (funded by the German BMBF; in cooperation with the Third Institute of Oceanography, Xiamen/China) and the results are presented and discussed in the doctoral thesis of Stephan Wietkamp (Suppl.Tab.S6, Suppl.Tab.S7). Aim of the project and especially of this data set was to provide first reference data on the biogeography (geographical distribution and seasonality) of toxigenic Amphidomataceae in the eastern North Atlantic
Evaluation of in-store processes related to returnable packaging services offered in grocery stores - the store management perspective
No full textAuthor Stephan LehnerMasterarbeit Universität Linz 202
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