• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.1-4
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• 2008

Fuel cells have the potential of providing several times higher energy storage densities than those possible using current state-of-the-art lithium-ion batteries, but current energy density of fuel cell system is not better than that of lithium-ion batteries. To achieve the high energy density, volume and weight of fuel cell system need to be reduced by miniaturizing system components such as stack, fuel tank, and balance-of-plant. In this paper, the thin flexible PCB (Printed circuit board) is used as a current collector to reduce the stack volume. Two end plates are made from light weight aluminum alloy plate. The plate surface is wholly oxidized through the anodizing treatment for electrical insulation. The opening rate of cathode plate hole is optimized through unit cell performance measurement of various opening rates. The performances are measured at room temperature and ambient pressure condition without any repulsive air supply. The active area of MEA is 10.08 $cm^2$ and active area per a unit cell is 1.68 $cm^2$. The peak power density is about 210 mW/$cm^2$ and the air-breathing planar stack of 2 Wis achieved as a small volume of 18 cc.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.433-436
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• 2008

Deterioration in the concrete structure are due to carbonation, chloride ion attack and frost attack. Therefore, concrete structure is needed to surface protection for increase durability using silicate impregnants. Thus, this study is concerned with self-cleaning and durability of silicate hydrophilic impregnants of concrete structure using lithium and potassium silicates. From the experimental test results, lithium and potassium silicates have a good properties as a carbonation resistance. Lithium and potassium silicates make good use of hydrophilic impregnants of concrete structures.

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.486-489
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• 2006

A 16 year-old boy was admitted to our department because of mild chest discomfort and mild dyspnea. A mass involving posterior wall of the left ventricle near posterior mitral annulus was found on echocardiography and cardiac MRI. Total excision of the mass was performed via posterior ventriculotomy under the cardiopulmonary bypass. The pathologic diagnosis revealed mature cardiac myocyte hamartoma. There was no evidence of arrhythmia and tumor recurrence during the 1 year of follow up after the surgery.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.173-175
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• 2004

Primary pulmonary arterial sarcomas, especially those originating from the pulmonary valve are extremely rare. A 35 year-old male patient was admitted for exertional dyspnea and fatigue. Large intraluminal mass in the main pulmonary artery and both pulmonary arteries was detected by chest computed tomogram, chest magnetic resonance imaging, echocardiogram, and pulmonary angiogram. We regarded the mass as a primary pulmonary arterial malignant tumor, and resected under cardiopulmonary bypass. The mass was appeared to originate from the posterior cusp of pulmonary valve, and extended from below pulmonary valve to main pulmonary artery and both pulmonary arteries. We resected the mass by pulmonary endarterectomy and replaced the pulmonary valve. The mass was diagnosed as a pulmonary arterial sarcoma in histopathologic examination.

• Journal of Chest Surgery
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• v.34 no.8
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• pp.644-647
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• 2001

Lamierre's syndrome is characterized by a rare fulminant condition resulting from primary oropharyngeal infection followed by secondary septic thrombophlebitis of the internal jugular vein and metastatic infection. A forty-year-old man who had been on ventilator due to servere chest trauma, showed severe reddish inflammatory swelling of the right cervical soft tissue and newly developed pneumonia. He went into in septic condition shortly thereafter. Thrombophlebitis with central abscess in the right internal jugular vein was identified by neck CT and MRA(magnetic resonance angiography). Right cervical swelling worsened in spite of clindamycin and heparin therapy. We performed immediate surgery for removal of septic thrombus and resection of internal jugular vein. Patient's septic condition, pneumonia, and local inflammatory reaction were improved within several days after surgery.

• Journal of Chest Surgery
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• v.30 no.6
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• pp.617-620
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• 1997

Traumatic aneurysm of both the thoracic aorta and the left ventricle are extremely rare in children because it is characterized by high mortality. We report a case which we experienced recently with sucessful outcome. A Five-year-old boy had a blunt trauma by bongo bus. He had pulmonary hemorrage and pericardial effusion complicated by multiorgan failure threatening his life. Aneurysm of LV and Descending aorta were showed by 2-D echocardiogram and MRI. The atient underwent successful corrective surgery 2 and half momths after trauma, the Postoperative status of this patient was uneventful, now he is being followed up the OPD.

• Journal of Korean Academy of Nursing
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• v.53 no.2
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• pp.191-207
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• 2023

Purpose: This study aimed to develop a motivational interviewing pulmonary rehabilitation program based on self-determination theory to maintain pulmonary rehabilitation-related health behaviors in patients with chronic obstructive pulmonary disease. The program was developed by reviewing the literature on pulmonary rehabilitation guidelines, drawing on the self-determinism theory to establish its contents, recruiting experts to test its validity, and conducting a preliminary survey. Methods: A quasi-experimental design was used to confirm the effect of the program. The participants were outpatients diagnosed with chronic obstructive pulmonary disease at three general hospitals in Busan. There were 33 subjects: 15 in the experimental group and 18 in the control group. The experimental group performed a motivational interviewing pulmonary rehabilitation program which comprised 11 sessions delivered over 10 weeks. The outcomes were measured using basic psychological needs, dyspnea, 6-minute walking distance, and functional status. Intervention effects were analyzed using repeated-measures ANOVA. Results: The analysis revealed significant differences between the experimental and control groups in competence among the subdomains of basic psychological needs, dyspnea during exercise, and functional status. Conclusion: The developed program affects physical conditions and can be applied as an effective clinical nursing intervention to continuously improve the pulmonary rehabilitation behavior of patients with chronic obstructive pulmonary disease.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1309-1323
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• 2023

Purpose To assess the quality of four images obtained using single-breath-hold (SBH), single-shot fast spin-echo (SSFSE) and multiple-breath-hold (MBH) SSFSE with and without deep-learning based reconstruction (DLR) in patients with Crohn's disease. Materials and Methods This study included 61 patients who underwent MR enterography (MRE) for Crohn's disease. The following images were compared: SBH-SSFSE with (SBH-DLR) and without (SBH-conventional reconstruction [CR]) DLR and MBH-SSFSE with (MBH-DLR) and without (MBH-CR) DLR. Two radiologists independently reviewed the overall image quality, artifacts, sharpness, and motion-related signal loss using a 5-point scale. Three inflammatory parameters were evaluated in the ileum, the terminal ileum, and the colon. Moreover, the presence of a spatial misalignment was evaluated. Signal-to-noise ratio (SNR) was calculated at two locations for each sequence. Results DLR significantly improved the image quality, artifacts, and sharpness of the SBH images. No significant differences in scores between MBH-CR and SBH-DLR were detected. SBH-DLR had the highest SNR (p < 0.001). The inter-reader agreement for inflammatory parameters was good to excellent (κ = 0.76-0.95) and the inter-sequence agreement was nearly perfect (κ = 0.92-0.94). Misalignment artifacts were observed more frequently in the MBH images than in the SBH images (p < 0.001). Conclusion SBH-DLR demonstrated equivalent quality and performance compared to MBH-CR. Furthermore, it can be acquired in less than half the time, without multiple BHs and reduce slice misalignments.

• Journal of the Korean Society of Radiology
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• v.5 no.3
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• pp.143-148
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• 2011

The purpose of this study was to examine the usefulness of SPIO contrast agent in Magnetic Resonance Cholangiopancreatography (MRCP) by performing a quantitative comparative analysis in patients undergoing MRCP for gallbladder stones with and without oral injection of SPIO (Superparamagnetic iron oxide) contrast agent. The subjects were 36 patients undergoing MRCP for suspected gallbladder stones between January 2009 and February 2010 and they were divided into halves to compare the two groups of with and without SPIO agent. For each subject in both the injected and non-injected group, T2-weighted images on a 1.5T MR scanner were obtained, using both the breath-holding and respiratory-triggered methods, respectively. The following regions were measured; for breath-hold T2-weighted images, the measurement regions were located at the central part of the gallbladder, and the areas 15 mm away from its center, toward the front and back, respectively, which were chosen to include surrounding tissues, while for respiratory-triggered T2-weighted images, at the central part of the gallbladder, and segment 5 and 6 of liver. In a quantitative analysis, average signal to noise ratio (SNR) in each of regions of interest (ROI) for each group were calculated and then average contrast to noise ratio (CNR) in each of ROI were obtained by using the SNR in the gallbladder as the basis to compare and analyze the values between the two groups. The CNR were higher for the injected group in those regions.

• Investigative Magnetic Resonance Imaging
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• v.11 no.1
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• pp.39-48
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• 2007

Purpose : To determine the diagnostic accuracy of four different sequences : moderately T2 weighted, two heavily T2-weighted single shot turbo spin-echo sequence and breath-hold axial-2D balanced turbo field-echo sequence(bFFE) for characterization of focal lesions. Materials and Methods : During the 3-month period between June and August 2005, seventy-six patients were proved to have ninety-three focal hepatic lesions on MR imaging. The patients consisted of 49 men and 27 women (age range, 15-75 years; mean age, 56.23 years). All MR images were acquired on a 1.5-T MR using the following sequences: 1. A breath-hold axial T2-weighted single shot turbo spin-echo sequence, 2. a breath-hold axial-2D balanced turbo field-echo sequence. Two radiologists performed quantitative analysis. Another radiologist measured the lesion-to-liver contrast-to-noise ratio at the region-of-interest in the four sequences. Results : There was no significant difference in inter-observer variability between the four sequences. The accuracy for both cyst and malignancy of moderate T2 weighted MRI (echo time: 80 msec) was also highest. There was significant difference for lesion characterization between moderate T2 weighted MRI and balanced steady state procession (p-value: 0.004) in the second reader. For longer echo time, the CNR of cystic lesions were markedly increased in comparison to lesions of other component. Conclusion : The accuracy and inter-observer variability of single shot turbo spin echo T2 weighted sequence was higher than bFFE. Although there was no statically significant difference, moderate T2 weighted MRI (echo time: 80 msec) was more accurate than heavily T2 weighted sequence (echo time: 300 msec). If the results for lesion characterization is equivocal in TE 80, the addition of heavily T2 weighted MRI (echo time: 180 msec) can be helpful.