• Title/Summary/Keyword: recurrent space

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Postpneumonectomy Esophagopleural Fistula: Muscle Flap Transposition for Closure (우측폐 전절제술후 발생한 식도늑막루의 수술 치험 : 1례 보고)

  • 이형교
    • Journal of Chest Surgery
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    • v.23 no.6
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    • pp.1275-1279
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    • 1990
  • Esophagopleural fistula is a rare complication that should be suspected in all patients with recurrent empyema following pneumonectomy and in whom a bronchopleural fistula can be excluded. In late postpneumonectomy esophagopleural fistula, diagnosis is difficult due to its rarity and no specific symptom and sign, but we have experienced a man who had suffered dysphagia and odynophagia. In surgical treatment of late postpneumonectomy esophageal fistula, closure of empyema space is of prime importance. We have adopted a type of latissimus dorsi muscle and serratus anterior muscle flap transposition We present here this technique and result obtained in patient with late postpneumonectomy esophagopleural fistula.

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Robot Trajectory Control using Prefilter Type Chaotic Neural Networks Compensator (Prefilter 형태의 카오틱 신경망을 이용한 로봇 경로 제어)

  • 강원기;최운하김상희
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.263-266
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    • 1998
  • This paper propose a prefilter type inverse control algorithm using chaotic neural networks. Since the chaotic neural networks show robust characteristics in approximation and adaptive learning for nonlinear dynamic system, the chaotic neural networks are suitable for controlling robotic manipulators. The structure of the proposed prefilter type controller compensate velocity of the PD controller. To estimate the proposed controller, we implemented to the Cartesian space control of three-axis PUMA robot and compared the final result with recurrent neural network(RNN) controller.

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RECURSIVE PROPERTIES OF A MAP ON THE CIRCLE

  • Cho, Seong-Hoon;Min, Kyung-Jin;Yang, Seung-Kab
    • The Pure and Applied Mathematics
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    • v.2 no.2
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    • pp.157-162
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    • 1995
  • Let I be the interval, $S^1$ the circle and let X be a compact metric space. And let $C^{circ}(X,\;X)$ denote the set of continuous maps from X into itself. For any f$f\in\;C\circ(X,\;X),\;let\;P(f),\;R(f),\;\Gamma(f),\;\Lambda(f)\;and\;\Omega(f)$ denote the collection of the periodic points, recurrent points, ${\gamma}-limit{\;}points,{\;}{\omega}-limit$ points and nonwandering points, respectively.(omitted)

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Prediction of the Stress-Strain Curve of Materials under Uniaxial Compression by Using LSTM Recurrent Neural Network (LSTM 순환 신경망을 이용한 재료의 단축하중 하에서의 응력-변형률 곡선 예측 연구)

  • Byun, Hoon;Song, Jae-Joon
    • Tunnel and Underground Space
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    • v.28 no.3
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    • pp.277-291
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    • 2018
  • LSTM (Long Short-Term Memory) algorithm which is a kind of recurrent neural network was used to establish a model to predict the stress-strain curve of an material under uniaxial compression. The model was established from the stress-strain data from uniaxial compression tests of silica-gypsum specimens. After training the model, it can predict the behavior of the material up to the failure state by using an early stage of stress-strain curve whose stress is very low. Because the LSTM neural network predict a value by using the previous state of data and proceed forward step by step, a higher error was found at the prediction of higher stress state due to the accumulation of error. However, this model generally predict the stress-strain curve with high accuracy. The accuracy of both LSTM and tangential prediction models increased with increased length of input data, while a difference in performance between them decreased as the amount of input data increased. LSTM model showed relatively superior performance to the tangential prediction when only few input data was given, which enhanced the necessity for application of the model.

Robust DTC Control of Doubly-Fed Induction Machines Based on Input-Output Feedback Linearization Using Recurrent Neural Networks

  • Payam, Amir Farrokh;Hashemnia, Mohammad Naser;Fai, Jawad
    • Journal of Power Electronics
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    • v.11 no.5
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    • pp.719-725
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    • 2011
  • This paper describes a novel Direct Torque Control (DTC) method for adjustable speed Doubly-Fed Induction Machine (DFIM) drives which is supplied by a two-level Space Vector Modulation (SVM) voltage source inverter (DTC-SVM) in the rotor circuit. The inverter reference voltage vector is obtained by using input-output feedback linearization control and a DFIM model in the stator a-b axes reference frame with stator currents and rotor fluxes as state variables. Moreover, to make this nonlinear controller stable and robust to most varying electrical parameter uncertainties, a two layer recurrent Artificial Neural Network (ANN) is used to estimate a certain function which shows the machine lumped uncertainty. The overall system stability is proved by the Lyapunov theorem. It is shown that the torque and flux tracking errors as well as the updated weights of the ANN are uniformly ultimately bounded. Finally, effectiveness of the proposed control approach is shown by computer simulation results.

Transient postoperative inferior subluxation of the shoulder after surgical stabilization of recurrent anterior dislocation in a patient with myasthenia gravis: a case report

  • Samuel Baek;Geum-Ho Lee;Myung Ho Shin;Tae Min Kim;Kyung-Soo Oh;Seok Won Chung
    • Clinics in Shoulder and Elbow
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    • v.26 no.3
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    • pp.302-305
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    • 2023
  • The authors present a case of transient postoperative inferior subluxation of the shoulder after arthroscopic surgical stabilization for recurrent anterior dislocation. The patient was a 61-year-old woman with myasthenia gravis (MG). The first anterior shoulder dislocation occurred because of a fall to the ground. Despite a successful closed reduction, two more dislocations occurred in 3 weeks. Magnetic resonance imaging revealed an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion, an engaging Hill-Sachs lesion, and large tears of the supraspinatus and infraspinatus tendons. The patient underwent arthroscopic rotator cuff repair and ALPSA repair with a remplissage procedure. Intraoperatively, no tendency for instability was found; however, a widened glenohumeral joint space and inferior subluxation of the humeral head without functional compromise was observed on the day after surgery and disappeared spontaneously on radiographs 2 weeks later. To the authors' knowledge, this is the first report documenting the occurrence of transient postoperative inferior subluxation of the shoulder in a patient with MG.

Spinal Drop Metastasis from a Posterior Fossa Choroid Plexus Papilloma

  • Ahn, Soon-Seob;Cho, Young-Dae
    • Journal of Korean Neurosurgical Society
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    • v.42 no.6
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    • pp.475-477
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    • 2007
  • Choroid plexus papillomas (CPPs) are typically considered as benign tumors, with a favorable long-term prognosis. Drop metastasis of CPP into the spinal subarachnoid space is rare. We report a 42-year-old woman who presented with headache and back pain 6 years after removal of a posterior fossa CPP. Magnetic resonance imaging revealed mass lesions in the lumbosacral subarachnoid space and recurrent intracranial tumor. The lesions were resected and histologically diagnosed was CPP. We consider that CPP can spread via cerebrospinal fluid pathways and cause spinal drop metastasis. Therefore, it is necessary to evaluate the whole spinal axis and to perform periodic follow-up examinations in patients with CPP.

GENERIC LIGHTLIKE SUBMANIFOLDS OF AN INDEFINITE KAEHLER MANIFOLD WITH A SEMI-SYMMETRIC METRIC CONNECTION

  • Lee, Jae Won;Lee, Chul Woo
    • Honam Mathematical Journal
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    • v.42 no.3
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    • pp.621-643
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    • 2020
  • Depending on the characteristic vector filed ζ, a generic lightlike submanifold M in an indefinite Kaehler manifold ${\bar{M}}$ with a semi-symmetric metric connection has various characterizations. In this paper, when the characteristic vector filed ζ belongs to the screen distribution S(TM) of M, we provide some characterizations of (Lie-) recurrent generic lightlike submanifold M in an indefinite Kaehler manifold ${\bar{M}}$ with a semi-symmetric metric connection. Moreover, we characterize various generic lightlike submanifolds in an indefinite complex space form ${\bar{M}}$ (c) with a semi-symmetric metric connection.

Primary Subcapsular Reflux as an Etiology of Subcapsular Renal Abscess

  • Yoo, Eun Ju;Oh, Jae Hyuk;Jung, Hyun Joo;Lee, Su Jin;Park, Ji Eun;Pai, Ki Soo
    • Childhood Kidney Diseases
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    • v.25 no.2
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    • pp.133-139
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    • 2021
  • Herein, we report two rare cases of renal infection. The first case was renal subcapsular urine reflux in a 8-month-old girl with recurrent urinary tract infection and the second was subcapsular abscess in a 14-year-old girl with diabetes, who was successfully treated with percutaneous drainage. It has been suggested that renal subcapsular abscesses could be caused by the direct reflux of urine into the subcapsular space, rather than spread of infection from an existing parenchymal lesion, and that complete recovery can be achieved if percutaneous drainage is performed in a timely manner. We propose primary subcapsular reflux, in which urine directly refluxes upwards into the subcapsular space of the kidney, as one of the mechanisms for development of renal subcapsular abscesses.