13,032 research outputs found
Art and psychoanalysis register at the White Hotel
My title refers to the fact that in D. M. Thomas's remarkable
novel, both art, in the form of literary imagination, and
psychoanalysis seek to comprehend the life of a woman named Lisa
Erdman, and both register certain truths or part truths. The novel
traces Lisa's life from the time she enters analysis with Freud in
Vienna until her death at Babi Yar at the hands of the Nazis. In a
final chapter entitled "the camp" that has troubled many readers we
witness a kind of apotheosis in which Lisa and most of the characters we
have met survive their own deaths. Most readers find The White Hotel
to be a brilliant treatment of human aggression, which it certainly is;
and an equally brilliant portrait of Freud, who is presented in his
role as the man who first unlocked the secrets of hysteria. But the
landscape of hysteria, which is the terrain of the novel, is also the
landscape of imagination, and so there is a basic opposition between
art and psychoanalysis from the outset
Mutual information based clustering of market basket data for profiling users
Attraction and commercial success of web sites depend heavily on the additional values visitors may find. Here, individual, automatically obtained and maintained user profiles are the key for user satisfaction. This contribution shows for the example of a cooking information site how user profiles might be obtained using category information provided by cooking recipes. It is shown that metrical distance functions and standard clustering procedures lead to erroneous results. Instead, we propose a new mutual information based clustering approach and outline its implications for the example of user profiling
Technology Push, Demand Pull And The Shaping Of Technological Paradigms - Patterns In The Development Of Computing Technology
An assumption generally subscribed in evolutionary economics is thatnew technological paradigms arise from advances is science anddevelopments in technological knowledge. Demand only influences theselection among competing paradigms, and the course the paradigm afterits inception. In this paper we argue that this view needs to beadapted. We demonstrate that in the history of computing technology inthe 20th century a distinction can be made between periods in whicheither demand or knowledge development was the dominant enabler ofinnovation. In the demand enabled periods new technological (sub-)paradigms in computing technology have emerged as well.enablers of innovation;history of computing;technological paradigms
Trade-throughs in European cross-traded equities after transaction costs – empirical evidence for the EURO STOXX 50
This paper investigates the accuracy and heterogeneity of output growth and inflation forecasts during the current and the four preceding NBER-dated U.S. recessions. We generate forecasts from six different models of the U.S. economy and compare them to professional forecasts from the Federal Reserve’s Greenbook and the Survey of Professional Forecasters (SPF). The model parameters and model forecasts are derived from historical data vintages so as to ensure comparability to historical forecasts by professionals. The mean model forecast comes surprisingly close to the mean SPF and Greenbook forecasts in terms of accuracy even though the models only make use of a small number of data series. Model forecasts compare particularly well to professional forecasts at a horizon of three to four quarters and during recoveries. The extent of forecast heterogeneity is similar for model and professional forecasts but varies substantially over time. Thus, forecast heterogeneity constitutes a potentially important source of economic fluctuations. While the particular reasons for diversity in professional forecasts are not observable, the diversity in model forecasts can be traced to different modeling assumptions, information sets and parameter estimates. JEL Classification: G14, G15, G2
Influence of confinement by smooth and rough walls on particle dynamics in dense hard-sphere suspensions
We used video microscopy and particle tracking to study the dynamics of confined hard-sphere suspensions. Our fluids consisted of 1.1-μm-diameter silica spheres suspended at volume fractions of 0.33–0.42 in water-dimethyl sulfoxide. Suspensions were confined in a quasiparallel geometry between two glass surfaces: a millimeter-sized rough sphere and a smooth flat wall. First, as the separation distance (H) is decreased from 18 to 1 particle diameter, a transition takes place from a subdiffusive behavior (as in bulk) at large H, to completely caged particle dynamics at small H. These changes are accompanied by a strong decrease in the amplitude of the mean-square displacement (MSD) in the horizontal plane parallel to the confining surfaces. In contrast, the global volume fraction essentially remains constant when H is decreased. Second, measuring the MSD as a function of distance from the confining walls, we found that the MSD is not spatially uniform but smaller close to the walls. This effect is the strongest near the smooth wall where layering takes place. Although confinement also induces local variations in volume fraction, the spatial variations in MSD can be attributed only partially to this effect. The changes in MSD are predominantly a direct effect of the confining surfaces. Hence, both the wall roughness and the separation distance (H) influence the dynamics in confined geometries
The C-Numerical Range in Infinite Dimensions
In infinite dimensions and on the level of trace-class operators rather
than matrices, we show that the closure of the -numerical range is
always star-shaped with respect to the set , where
denotes the essential numerical range of the bounded operator .
Moreover, the closure of is convex if either is normal with
collinear eigenvalues or if is essentially self-adjoint. In the case of
compact normal operators, the -spectrum of is a subset of the
-numerical range, which itself is a subset of the convex hull of the closure
of the -spectrum. This convex hull coincides with the closure of the
-numerical range if, in addition, the eigenvalues of or are
collinear.Comment: 31 pages, no figures; to appear in Linear and Multilinear Algebr
A Structural Model of Tenure and Specific Investments
Though a lot of work has been done on the distribution of job tenures, we are still uncertain about its main determinants. In this paper, we stress random shocks to match productivity after the start of an employment relation. The specificity of investment makes hiring and separation decisions irreversible.These decisions therefore have an option value. Assumptions on riskneutrality, efficient bargaining, and the efficient resolution of hold up problems allow investment and separation decisions to be analyzed separately from wage setting. The tenure profiles in wages implied by the model fit the observed pattern quite well. The model yields a hump shaped pattern in separation rates, similar to learning models, but with a slowerdecline after the peak. Estimation results using job tenure data from the NLSY support this humped shaped pattern and favor this model above the learning model. We develop a methodology to analyze the decomposition of shocks to match productivity into idiosyncratic and macro-level shocks.When assuming a Last-In-First-Out (LIFO) separation rule, this model of individualemployment relations is embedded in a model of firm level employment, that satisfies Gibrat’s law. The LIFO rule is interpreted as an institution protecting the property rights on specific investments of incumbentworkers against hiring new workers by the firm.option value, job tenure, tenure profiles
Unitary Dilations of Discrete-Time Quantum-Dynamical Semigroups
We show that the discrete-time evolution of an open quantum system generated
by a single quantum channel can be embedded in the discrete-time evolution
of an enlarged closed quantum system, i.e. we construct a unitary dilation of
the discrete-time quantum-dynamical semigroup . In
the case of a cyclic channel , the auxiliary space may be chosen (partially)
finite-dimensional. We further investigate discrete-time quantum control
systems generated by finitely many commuting quantum channels and prove a
similar unitary dilation result as in the case of a single channel.Comment: 32 pages, no figure
Breath figures under electrowetting: electrically controlled evolution of drop condensation patterns
We show that electrowetting (EW) with structured electrodes significantly
modifies the distribution of drops condensing onto flat hydrophobic surfaces by
aligning the drops and by enhancing coalescence. Numerical calculations
demonstrate that drop alignment and coalescence are governed by the drop
size-dependent electrostatic energy landscape that is imposed by the electrode
pattern and the applied voltage. Such EW-controlled migration and coalescence
of condensate drops significantly alter the statistical characteristics of the
ensemble of droplets. The evolution of the drop size distribution displays
self-similar characteristics that significantly deviate from classical breath
figures on homogeneous surfaces once the electrically-induced coalescence
cascades set in beyond a certain critical drop size. The resulting reduced
surface coverage, coupled with earlier drop shedding under EW, enhances the net
heat transfer.Comment: 5 pages, 5 figure
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