• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.918-921
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• 2005

According to the mechanical-electrical coupling characteristics and the electrical Impedance property of resistor-inductor-capacitor(RLC) series resonant circuit, the mechanical impedance analysis of a bimorph piezoceramic patch shunted with a series RLC resonant circuit is conducted. The displacement transfer function of a cantilever beam bonded with a piezoelectric shunt damping module is deduced in the case of single mode vibration of the beam. By the use of vibration damping theory of tuned mass damper system, the parameter optimization of piezoelectric shunt damping system is performed. The optimal resonant state of the shunting circuit can be obtained when the resister and conductor are optimally adjusted. Test results show that the vibration control effect as well improved with optimized piezoelectric shunt system.

• The Journal of Internal Korean Medicine
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• v.42 no.2
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• pp.197-206
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• 2021

Subarachnoid hemorrhage (SAH) is a disease that causes bleeding in the subarachnoid space; 70%-80% of nontraumatic subarachnoid hemorrhages are caused by saccular aneurysms. If the patient has already experienced a ruptured aneurysm that causes subarachnoid bleeding, rebleeding can result in a high mortality rate and serious sequelae. Therefore, if the patient can undergo surgical or interventional treatment, it should always be performed. This patient was diagnosed with acute aneurysmal subarachnoid hemorrhage and hydrocephalus. The patient was hospitalized for uncontrolled headache and vertigo after aneurysm coil embolization and ventriculoperitoneal shunting. The patient was treated with Yangkyuksanwha-tang and acupuncture and was observed with a symptom checklist for 25 days. Headache improved, from a visual analog scale (VAS) score of 7 to 0. Vertigo also improved, from a numeric rating scale (NRS) of 6 to 2, and the vertigo pattern changed from rotational to nonrotational. This case suggests that Korean medicine treatment is helpful in managing subarachnoid hemorrhage sequelae.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.1
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• pp.80-85
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• 2019

Purpose: Abernethy malformation is a rare condition, which was first described in 1793 as a congenital extrahepatic porto-systemic shunt (CEPS) directing splanchnic blood flow into the inferior vena cava. Eighty cases have been published so far that reported CEPS, while in Korea, very few cases have been reported. Through this study, we present 6 cases of patients diagnosed with CEPS at Samsung Medical Center and compare these with other such cases published in France and China. Methods: We reviewed clinical, laboratory, and imaging data of 6 children with CEPS in our pediatric clinic between 2004 and 2017. Results: A total of 6 children with CEPS was included in this study, namely, one with type 1a, two with type 1b, and three with type 2 CEPS. The most common presenting symptom was gastrointestinal bleeding (50.0%). Therapeutic interventions included shunting vessel ligation (16.7%) in type 2 CEPS and liver transplantation (16.7%) in type 2 CEPS patient with suddenly developed hepatic encephalopathy. Conclusion: There is no consensus guideline for the optimal management of patients with CEPS. Large-sample studies regarding CEPS are needed to evaluate the characteristics of patients with CEPS and determine the treatment guideline for CEPS.

• Journal of Korean Neurosurgical Society
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• v.65 no.6
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• pp.841-845
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• 2022

Objective : Chiari III malformations are extremely rare hindbrain malformations that are associated with a high early mortality rate, or severe neurologic deficits in the survivors. The treatment is early operative closure and cerebrospinal fluid diversion (CSF) shunting. Methods : We operated on 15 patients by repair and excision between July 2014 till June 2020 and retrospective data collection was done. Only one patient doesn't need ventriculoperitoneal (VP) shunt and the other 14 patients need a VP shunt. We described stepwise dissection and untethering of the cerebellum from the bony edge to regrowth and herniation of cerebellum again into this potential space and simple dural closure or repair with graft was done. Results : We started with VP in eight patients (53%) and the other seven patients (46.7%) started with excision and then six patients need VP shunt later on because four patients developed CSF leak and two patients developed increased high intracranial tension. Only four patients (26.7%) needed a blood transfusion. Conclusion : There are variations in the outcome and not all cases of Chiari malformation III will die and severe developmental delay is not a must. Proper management and repair carry a good prognosis.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.613-617
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• 2007

A 1-year-old castrated male Maltese dog(weighing 2.4 kg) was presented with primary complaints of occasional coughing, dyspnea and exercise intolerance. Based on diagnostic findings including paradoxical split S2, diastolic regurgitant murmur, marked dilation of pulmonary artery, right ventricular eccentric hypertrophy with thickening of ventricular septum, severe tricuspid and pulmonic regurgitation(5.4 m/sec and 3.4 m/sec, respectively) and the absence of any congenital intracardiac shunting, obstructive pulmonary diseases and systemic diseases associated with right ventricular pressure overload or pulmonary hyperperfusion, the case was tentatively diagnosed as primary pulmonary hypertension. The dog was treated with furosemide, aspirin and oxygen supplementation. This case report described a rare case of primary pulmonary hypertension in a Maltese dog.

• Journal of Chest Surgery
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• v.29 no.9
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• pp.1017-1022
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• 1996

Patients with fractured ribs necessarily suffer from severe chest ain, which prevents coughing, deep breathing and bronchial toilette, cause atelectasis and pulmonary shunting. Relief of chest pain is benecial to patients, providing consort and facilitating physiotherapy and effective expectoration. We compared the efficacy of pain relief be!ween continuous epidural analgesia and conventional intramlrscular analgesia in 20 patients with fractured ribs. Among 20 patients, epidural analgesia was done or 10 patients(experimental group) and the remainder ten received intramuscular analgesia(control group). The pain and ROM(range of motion) scores, vital sign, PaO2, forced vital capacity(FVC) and forced expiratory volume for 1 second(FEVI) were checked on immediate admission and 12, 24 hours, third, fifth, and seventh day after starting of continuous epidural block. The pain and ROM scores were decreased and the PaO2, FRC and FEVI were significantly increased in experimental group. The side effects of epidural analgesia were mild and reversible. With th se result, we can suggest that epidural analgesia is more effective for pain relief and restoration of pulmonary mechanics in patients with fractured ribs.

• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.468-472
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• 2013

A 12-year-old intact female mixed dog (weighing 6.2 kg) was referred with primary complaints of severe abdominal distension, persistent coughing and exercise intolerance. Diagnostic studies found ascites, jugular distension, loud left and right apical systolic (grade 4/6) murmur, generalized cardiomegaly with caudal vena cava distension and left atrial dilation. Echocardiographic findings were consistent with degenerative mitral and tricuspid valve endocardiosis and bi-ventricular congestive heart failure. There was also a left to right shunting patent foramen ovale. The LV systolic function is depressed relative to the degree of volume overload. Based on diagnostic findings, this case was diagnosed as PFO complicated with mitral and tricuspid valve endocardiosis with ISACHC IIIa heart failure. The dog was treated with furosemide (2 mg/kg, q12hr, PO), sildenafil (1 mg/kg, q8hr, PO), pimobendan (0.3 mg/kg, q12hr, PO), enalapril (0.5 mg/kg, q12hr, PO) and spironolactone (1 mg/kg, q12hr). The clinical signs were gradually improved after medical therapy.

• Journal of the Korean Society for Railway
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• v.15 no.6
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• pp.604-608
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• 2012

Traditionally, the track circuits have been used for the purpose of train locating. However, the recent train control systems like a CBTC(Communications Based Train Control) do not utilize the track circuits to minimize the amount of ground signal devices. Therefore, there are increasing concerns over the system that can locate the position of train exactly without using the track circuits. Then, the contactless locating methods are added to ensure safety when the shunting sensitivity of the track circuit becomes low for the existing sections equipped with the track circuits. In this paper, a prototype of train locating device has been designed and tested, which utilizes the current phase difference upon magnetic field variation. The results show improved features of this method over the conventional track circuits method.

• Investigative Magnetic Resonance Imaging
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• v.22 no.1
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• pp.26-36
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• 2018

Purpose: Children born with single ventricle physiology demonstrate poor growth rate and suffer from malnutrition, which lead to increased morbidity and mortality in this population. We assume that an anabolic steroid, oxandrolone, will promote growth in these infants by improving myocardial energy utilization. The purpose of this paper is to study the efficacy of oxandrolone on myocardial energy consumption in these infants. Materials and Methods: We modeled single ventricle physiology in a lamb by prenatally shunting the aorta to the pulmonary artery and then postnatally, we monitored cardiac energy utilization by quantitatively measuring the first order reaction rate constant, $k_f$ of the creatine-kinase reaction in the heart using magnetization transfer $^{31}P$ magnetic resonance spectroscopy, home built $^1H/^{31}P$ transmit/receive double tuned coil, and transmit/receive switch. We also performed cine MRI to study the structure and dynamic function of the myocardium and the left ventricular chamber. The spectroscopy data were processed using home-developed python software, while cine data were analyzed using Argus software. Results: We quantitatively measured both the first order reaction rate constant and ejection fraction in the control, shunted, and the oxandrolone-treated lambs. Both $k_f$ and ejection fraction were found to be more significantly reduced in the shunted lambs compared to the control lambs, and they are increased in oxandrolone-treated lambs. Conclusion: Some improvement was observed in both the first order reaction rate constant and ejection fraction for the lamb treated with oxandrolone in our preliminary study.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.427-427
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• 2016

Organic-inorganic hybrid perovskite have attracted significant attention as a new revolutionary light absorber for photovoltaic device due to its remarkable characteristics such as long charge diffusion lengths (100-1000nm), low recombination rate, and high extinction coefficient. Recently, power conversion efficiency of perovskite solar cell is above 20% that is approached to crystalline silicon solar cells. Planar heterojunction perovskite solar cells have simple device structure and can be fabricated low temperature process due to absence of mesoporous scaffold that should be annealed over 500 oC. However, in the planar structure, controlling perovskite film qualities such as crystallinity and coverage is important for high performances. Those controlling methods in one-step deposition have been reported such as adding additive, solvent-engineering, using anti-solvent, for pin-hole free perovskite layer to reduce shunting paths connecting between electron transport layer and hole transport layer. Here, we studied the effect of alkali metal halide to control the fabrication process of perovskite film. During the morphology determination step, alkali metal halides can affect film morphologies by intercalating with PbI2 layer and reducing $CH3NH3PbI3{\cdot}DMF$ intermediate phase resulting in needle shape morphology. As types of alkali metal ions, the diverse grain sizes of film were observed due to different crystallization rate depending on the size of alkali metal ions. The pin-hole free perovskite film was obtained with this method, and the resulting perovskite solar cells showed higher performance as > 10% of power conversion efficiency in large size perovskite solar cell as $5{\times}5cm$. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma optical emission spectrometry (ICP-OES) are analyzed to prove the mechanism of perovskite film formation with alkali metal halides.