793 research outputs found
Instanton dynamics in finite temperature QCD via holography
We investigate instantons in finite temperature QCD via Witten's holographic
QCD. To study the deconfinement phase, we use the setup proposed in [1]
(arXiv:1107.4048). We find that the sizes of the instantons are stabilized at
certain values both in the confinement and deconfinement phases. This agrees
with the numerical result in the lattice gauge theory. Besides we find that the
gravity duals of the large and small instantons in the deconfinement phase have
different topologies. We also argue that the fluctuation of the topological
charges is large in confinement phase while it is exponentially suppressed in
deconfinement phase, and a continuous transition occurs at the
Gross-Witten-Wadia (GWW) point. It would be difficult to observe the
counterpart of this transition in lattice QCD, since the GWW point in QCD may
stay at an unstable branch.Comment: 25 pages, 4 figures; v2: references added, minor correction
Geometrical Formulation of 3-D Space-Time Finite Integration Method
A geometrical formulation of a space-time finite-integration (FI) method is studied for application in electromagnetic-wave propagation calculations. Based on the Hodge duality and Lorentzian metric, a modified relation is derived between the incidence matrices of space-time primal and dual grids. A systematic method to construct the Maxwell grid equations on the space-time primal and dual grids is developed. The geometrical formulation is implemented on a simple space-time grid, which is proven equivalent to an explicit time-marching scheme of the space-time FI method
Frequency-Domain Model Order Reduction of Electromagnetic Field in Induction Motor
A model order reduction (MOR) method for an induction motor using a Cauer ladder network (CLN) is developed in the frequency domain. A multiport frequency transformation between the stator and mover domains is derived by neglecting the spatial harmonic interactions. Even after neglecting the harmonic interactions, the reduced model provides a reasonably accurate frequency response, which is more accurate than that of the conventional approximated equivalent circuit
An Autopsy Case of Branchiogenic Carcinoma
Branchiogenic cysts arise from the remnant of the branchial apparatus. It is no doubt that primary carcinoma arising in a branchiogenic cyst does exist as a pathological and clinical entity. A 45-year-old man complained a painless mass in the left lateral neck. There were no other symptoms. Postmortem examination revealed a huge 11 by 10 by 10 cm ulcerated, partly necrotic and hemorrhagic tumor. Microscopic picture exhibited epidermoid carcinoma composed in part of a travecular pattern of large, polyhedral cells with faintly granular and acidophilic cytoplasm. Intercellular bridges were observed but not prominently. Occasionally giant cells, with giant nuclei or multiple nuclei, were seen. Individual cell keratinization was frequent, but keratin pearls were not found. Mitotic figures were numerous. Special stains failed to reveal any cytoplasmic inclusions. There have been only a few cases reported that showed histological evidence of carcinoma arising in a branchiogenic cleft cyst. In this case the author could not demonstrate cancer arising in the wall of a branchiogenic cyst, and no remnant of the branchial apparatus were found. Exhaustive studies failed to demonstrate a primary site for the cancer in other areas. Clinically the tumor was soft and fluctuant, and serous bloody fluid was removed by puncture. These findings suggest the possibility of branchial cyst origin
Unnatural Error Correction: GPT-4 Can Almost Perfectly Handle Unnatural Scrambled Text
While Large Language Models (LLMs) have achieved remarkable performance in
many tasks, much about their inner workings remains unclear. In this study, we
present novel experimental insights into the resilience of LLMs, particularly
GPT-4, when subjected to extensive character-level permutations. To investigate
this, we first propose the Scrambled Bench, a suite designed to measure the
capacity of LLMs to handle scrambled input, in terms of both recovering
scrambled sentences and answering questions given scrambled context. The
experimental results indicate that most powerful LLMs demonstrate the
capability akin to typoglycemia, a phenomenon where humans can understand the
meaning of words even when the letters within those words are scrambled, as
long as the first and last letters remain in place. More surprisingly, we found
that only GPT-4 nearly flawlessly processes inputs with unnatural errors, even
under the extreme condition, a task that poses significant challenges for other
LLMs and often even for humans. Specifically, GPT-4 can almost perfectly
reconstruct the original sentences from scrambled ones, decreasing the edit
distance by 95%, even when all letters within each word are entirely scrambled.
It is counter-intuitive that LLMs can exhibit such resilience despite severe
disruption to input tokenization caused by scrambled text.Comment: EMNLP 2023 (with an additional analysis section in appendix
Numerical Stability Analysis of Space-Time Finite Integration Method Based on the Dependent Domain Concept
A method for estimating the stability criterion in the space-time finite integration (FI) method using the subgrid technique was developed. Numerical- and analytical-dependent domains were compared to estimate the stability limit. Space-time subgrids locally refined with two, three, and four divisions were examined. The stability limit based on the proposed method almost agrees with that of the numerical experiment
Bilateral Optic Neuritis and Hypophysitis With Diabetes Insipidus 1 Month After COVID-19 mRNA Vaccine: Case Report and Literature Review
Either optic neuritis (neuropathy) or hypopituitarism has been known to occur separately after COVID-19 vaccination. In this report, we describe the rare combination of hypophysitis and optic neuritis which occurred after COVID-19 vaccination. A 74-year-old woman began to have thirst, polydipsia, and polyuria, and was diagnosed as central diabetes insipidus 1 month after the fourth COVID-19 mRNA vaccine. Head magnetic resonance imaging (MRI) disclosed the thickened pituitary stalk and enlarged pituitary gland with high contrast enhancement as well as the absence of high-intensity signals in the posterior pituitary lobe on the T1-weighted image, leading to the diagnosis of lymphocytic hypophysitis. She was well with desmopressin nasal spray until further 2 months later, when she developed bilateral optic neuritis, together with gait disturbance, intention tremor of the upper extremities, urinary retention, constipation, abnormal sensation in the distal part of the lower extremities, and moderate hemiplegia on the left side. Autoantibodies, including anti-aquaporin 4 (AQP4) and anti-myelin oligodendrocyte glycoprotein (MOG), were all negative. She showed multifocal spinal cord lesions on MRI and oligoclonal bands in the cerebrospinal fluid obtained by spinal tap, and so underwent steroid pulse therapy with methylprednisolone in the tentative diagnosis of multiple sclerosis, resulting in visual acuity recovery and alleviation of neurological symptoms. In the literature review, the combination of optic neuritis and hypophysitis, mostly with diabetes insipidus, was reported in 15 patients as case reports before the years of COVID-19 pandemic. The COVID-19 vaccination would trigger the onset of hypophysitis and optic neuritis in this patient
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