364 research outputs found
Ernst Jünger and the problem of Nihilism in the age of total war
As a singular witness and actor of the tumultuous twentieth century, Ernst Jünger remains a controversial and enigmatic figure known above all for his vivid autobiographical accounts of experience in the trenches of the First World War. This article will argue that throughout his entire oeuvre, from personal diaries to novels and essays, he never ceased to grapple with what he viewed as the central question of the age, namely that of the problem of nihilism and the means to overcome it. Inherited from Nietzsche’s diagnosis of Western civilization in the late nineteenth century to which he added an acute observation of the particular role of technology within it, Jünger would employ this lens to make sense of the seemingly absurd industrial slaughter of modern war and herald the advent of a new voluntarist and bellicist order that was to imminently sweep away timorous and decadent bourgeois societies obsessed with security and self-preservation. Jünger would ultimately see his expectations dashed, including by the forms of rule that National Socialism would take, and eventually retreated into a reclusive quietism. Yet he never abandoned his central problematique of nihilism, developing it further in exchanges with Martin Heidegger after the Second World War. And for all the ways in which he may have erred, his life-long struggle with meaning in the age of technique and its implications for war and security continue to make Jünger a valuable interlocutor of the present
Universality-class dependence of energy distributions in spin glasses
We study the probability distribution function of the ground-state energies
of the disordered one-dimensional Ising spin chain with power-law interactions
using a combination of parallel tempering Monte Carlo and branch, cut, and
price algorithms. By tuning the exponent of the power-law interactions we are
able to scan several universality classes. Our results suggest that mean-field
models have a non-Gaussian limiting distribution of the ground-state energies,
whereas non-mean-field models have a Gaussian limiting distribution. We compare
the results of the disordered one-dimensional Ising chain to results for a
disordered two-leg ladder, for which large system sizes can be studied, and
find a qualitative agreement between the disordered one-dimensional Ising chain
in the short-range universality class and the disordered two-leg ladder. We
show that the mean and the standard deviation of the ground-state energy
distributions scale with a power of the system size. In the mean-field
universality class the skewness does not follow a power-law behavior and
converges to a nonzero constant value. The data for the Sherrington-Kirkpatrick
model seem to be acceptably well fitted by a modified Gumbel distribution.
Finally, we discuss the distribution of the internal energy of the
Sherrington-Kirkpatrick model at finite temperatures and show that it behaves
similar to the ground-state energy of the system if the temperature is smaller
than the critical temperature.Comment: 15 pages, 20 figures, 1 tabl
Optimization by thermal cycling
Thermal cycling is an heuristic optimization algorithm which consists of
cyclically heating and quenching by Metropolis and local search procedures,
respectively, where the amplitude slowly decreases. In recent years, it has
been successfully applied to two combinatorial optimization tasks, the
traveling salesman problem and the search for low-energy states of the Coulomb
glass. In these cases, the algorithm is far more efficient than usual simulated
annealing. In its original form the algorithm was designed only for the case of
discrete variables. Its basic ideas are applicable also to a problem with
continuous variables, the search for low-energy states of Lennard-Jones
clusters.Comment: Submitted to Proceedings of the Workshop "Complexity, Metastability
and Nonextensivity", held in Erice 20-26 July 2004. Latex, 7 pages, 3 figure
Improved limits on nuebar emission from mu+ decay
We investigated mu+ decays at rest produced at the ISIS beam stop target.
Lepton flavor (LF) conservation has been tested by searching for \nueb via the
detection reaction p(\nueb,e+)n. No \nueb signal from LF violating mu+ decays
was identified. We extract upper limits of the branching ratio for the LF
violating decay mu+ -> e+ \nueb \nu compared to the Standard Model (SM) mu+ ->
e+ nue numub decay: BR < 0.9(1.7)x10^{-3} (90%CL) depending on the spectral
distribution of \nueb characterized by the Michel parameter rho=0.75 (0.0).
These results improve earlier limits by one order of magnitude and restrict
extensions of the SM in which \nueb emission from mu+ decay is allowed with
considerable strength. The decay \mupdeb as source for the \nueb signal
observed in the LSND experiment can be excluded.Comment: 10 pages, including 1 figure, 1 tabl
Spin glasses and algorithm benchmarks: A one-dimensional view
Spin glasses are paradigmatic models that deliver concepts relevant for a
variety of systems. However, rigorous analytical results are difficult to
obtain for spin-glass models, in particular for realistic short-range models.
Therefore large-scale numerical simulations are the tool of choice. Concepts
and algorithms derived from the study of spin glasses have been applied to
diverse fields in computer science and physics. In this work a one-dimensional
long-range spin-glass model with power-law interactions is discussed. The model
has the advantage over conventional systems in that by tuning the power-law
exponent of the interactions the effective space dimension can be changed thus
effectively allowing the study of large high-dimensional spin-glass systems to
address questions as diverse as the existence of an Almeida-Thouless line,
ultrametricity and chaos in short range spin glasses. Furthermore, because the
range of interactions can be changed, the model is a formidable test-bed for
optimization algorithms.Comment: 10 pages, 8 figures (two in crappy quality due to archive
restrictions). Proceedings of the International Workshop on
Statistical-Mechanical Informatics 2007, Kyoto (Japan) September 16-19, 200
100 Hz ROCS microscopy correlated with fluorescence reveals cellular dynamics on different spatiotemporal scales
Fluorescence techniques dominate the field of live-cell microscopy, but bleaching and motion blur from too long integration times limit dynamic investigations of small objects. High contrast, label-free life-cell imaging of thousands of acquisitions at 160 nm resolution and 100 Hz is possible by Rotating Coherent Scattering (ROCS) microscopy, where intensity speckle patterns from all azimuthal illumination directions are added up within 10 ms. In combination with fluorescence, we demonstrate the performance of improved Total Internal Reflection (TIR)-ROCS with variable illumination including timescale decomposition and activity mapping at five different examples: millisecond reorganization of macrophage actin cortex structures, fast degranulation and pore opening in mast cells, nanotube dynamics between cardiomyocytes and fibroblasts, thermal noise driven binding behavior of virus-sized particles at cells, and, bacterial lectin dynamics at the cortex of lung cells. Using analysis methods we present here, we decipher how motion blur hides cellular structures and how slow structure motions cover decisive fast motions
impulsivity and the impact of contextual cues on instrumental behavior in alcohol dependence
Alcohol-related cues acquire incentive salience through Pavlovian conditioning
and then can markedly affect instrumental behavior of alcohol-dependent
patients to promote relapse. However, it is unclear whether similar effects
occur with alcohol-unrelated cues. We tested 116 early-abstinent alcohol-
dependent patients and 91 healthy controls who completed a delay discounting
task to assess choice impulsivity, and a Pavlovian-to-instrumental transfer
(PIT) paradigm employing both alcohol-unrelated and alcohol-related stimuli.
To modify instrumental choice behavior, we tiled the background of the
computer screen either with conditioned stimuli (CS) previously generated by
pairing abstract pictures with pictures indicating monetary gains or losses,
or with pictures displaying alcohol or water beverages. CS paired to money
gains and losses affected instrumental choices differently. This PIT effect
was significantly more pronounced in patients compared to controls, and the
group difference was mainly driven by highly impulsive patients. The PIT
effect was particularly strong in trials in which the instrumental stimulus
required inhibition of instrumental response behavior and the background CS
was associated to monetary gains. Under that condition, patients performed
inappropriate approach behavior, contrary to their previously formed
behavioral intention. Surprisingly, the effect of alcohol and water pictures
as background stimuli resembled that of aversive and appetitive CS,
respectively. These findings suggest that positively valenced background CS
can provoke dysfunctional instrumental approach behavior in impulsive alcohol-
dependent patients. Consequently, in real life they might be easily seduced by
environmental cues to engage in actions thwarting their long-term goals. Such
behaviors may include, but are not limited to, approaching alcohol
Between Smart Technologies and Soviet Guns: Imaging the New Heroic Figure in Postdigital Warfare
In March 2017, I travelled to the frontline between the Ukrainian army and Pro-Russian separatist forces in the Donbass region, East Ukraine, as part of a research project into the return of 20th century weapons in digital culture across Europe. While embedded in a patrol with soldiers of the Ukraine Volunteer Corps, an organization affiliated with the nationalist Right Sector movement, I ended up in a firefight on the edge of the no man’s land. I documented how the soldiers alternatingly operated Soviet-era Kalashnikov assault rifles and contemporary consumer technologies, such as smartphones an action cameras.
I will read the simultaneous performance of the soldiers with weapon and consumer technologies from different eras from the perspective of Russell Davies’ concept of the post-digital, in relation to selfie practices and microcelebrity performance in networked culture. In this context, I will reflect on Alain Badiou’s concept of the soldier as ‘heroic figure’. In response to Badiou’s claim that the traditional soldier is no longer an effective symbolic trope in a highly technologized culture, I will reflect on the – embodied and digitally networked – soldiers I accompanied as possible heroic figures of the post-digital
Using Sifting for k-Layer Straightline Crossing Minimization
We present a new algorithm for k-layer straightline crossing minimization which is based on sifting that is a heuristic for dynamic reordering of decision diagrams used during logic synthesis and formal verification of logic circuits. The experiments prove sifting to be very efficient. In particular it outperforms the traditional layer by layer sweep based heuristics known from literature by far when applied to k-layered graphs with k \ge 3
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