3,569 research outputs found
Decoherence of flux qubits due to 1/f flux noise
We have investigated decoherence in Josephson-junction flux qubits. Based on
the measurements of decoherence at various bias conditions, we discriminate
contributions of different noise sources. In particular, we present a Gaussian
decay function of the echo signal as evidence of dephasing due to flux
noise whose spectral density is evaluated to be about /Hz
at 1 Hz. We also demonstrate that at an optimal bias condition where the noise
sources are well decoupled the coherence observed in the echo measurement is
mainly limited by energy relaxation of the qubit.Comment: 4 pages, error in Fig.4 corrected, to appear in PR
Fundamental Cycle of a Periodic Box-Ball System
We investigate a soliton cellular automaton (Box-Ball system) with periodic
boundary conditions. Since the cellular automaton is a deterministic dynamical
system that takes only a finite number of states, it will exhibit periodic
motion. We determine its fundamental cycle for a given initial state.Comment: 28 pages, 6 figure
The Dynamics of Exploitation and Class in Accumulation Economies
This paper analyses the equilibrium dynamics of exploitation and class in general accumulation economies with population growth, technical change, and bargaining by adopting a novel computational approach. First, the determinants of the emergence and persistence of exploitation and class are investigated, and the role of labour-saving technical change and, even more importantly, power is highlighted. Second, it is shown that the concept of exploitation provides the foundations for a logically coherent and empirically relevant analysis of inequalities and class relations in advanced capitalist economies. An index that identifies the exploitation level, or intensity of each individual can be defined and its empirical distribution studied using the standard tools developed in the theory of inequality measurement
On the initial value problem of a periodic box-ball system
We show that the initial value problem of a periodic box-ball system can be
solved in an elementary way using simple combinatorial methods.Comment: 9 pages, 2 figure
Correlation function for a periodic box-ball system
We investigate correlation functions in a periodic box-ball system. For the
two point functions of short distance, we give explicit formulae obtained by
combinatorial methods. We give expressions for general N-point functions in
terms of ultradiscrete theta functions.Comment: 13 pages, 2 figures, submitted to J. Phys. A: Math. Theo
Fatal outcome after brain stem infarction related to bilateral vertebral artery occlusion - case report of a detrimental complication of cervical spine trauma
<p>Abstract</p> <p>Background</p> <p>Vertebral artery injury (VAI) after blunt cervical trauma occurs more frequently than historically believed. The symptoms due to vertebral artery (VA) occlusion usually manifest within the first 24 hours after trauma. Misdiagnosed VAI or delay in diagnosis has been reported to cause acute deterioration of previously conscious and neurologically intact patients.</p> <p>Case presentation</p> <p>A 67 year-old male was involved in a motor vehicle crash (MVC) sustaining multiple injuries. Initial evaluation by the emergency medical response team revealed that he was alert, oriented, and neurologically intact. He was transferred to the local hospital where cervical spine computed tomography (CT) revealed several abnormalities. Distraction and subluxation was present at C5-C6 and a comminuted fracture of the left lateral mass of C6 with violation of the transverse foramen was noted. Unavailability of a spine specialist prompted the patient's transfer to an area medical center equipped with spine care capabilities. After arrival, the patient became unresponsive and neurological deficits were noted. His continued deterioration prompted yet another transfer to our Level 1 regional trauma center. A repeat cervical spine CT at our institution revealed significantly worsened subluxation at C5-C6. CT angiogram also revealed complete occlusion of bilateral VA. The following day, a repeat CT of the head revealed brain stem infarction due to bilateral VA occlusion. Shortly following, the patient was diagnosed with brain death and care was withdrawn.</p> <p>Conclusion</p> <p>Brain stem infarction secondary to bilateral VA occlusion following cervical spine trauma resulted in fatal outcome. Prompt imaging evaluation is necessary to assess for VAI in cervical trauma cases with facet joint subluxation/dislocation or transverse foramen fracture so that treatment is not delayed. Additionally, multiple transportation events are risk factors for worsening when unstable cervical injuries are present. Close attention to proper immobilization and neck position depending on the mechanism of injury is mandatory.</p
A crystal theoretic method for finding rigged configurations from paths
The Kerov--Kirillov--Reshetikhin (KKR) bijection gives one to one
correspondences between the set of highest paths and the set of rigged
configurations. In this paper, we give a crystal theoretic reformulation of the
KKR map from the paths to rigged configurations, using the combinatorial R and
energy functions. This formalism provides tool for analysis of the periodic
box-ball systems.Comment: 24 pages, version for publicatio
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