Publications by authors named "Young-Hun Park"

In this study, we present an alternative solution for detecting crack damages in rotating shafts under torque fluctuation by directly estimating the reduction in torsional shaft stiffness using the adaptive extended Kalman filter (AEKF) algorithm. A dynamic system model of a rotating shaft for designing AEKF was derived and implemented. An AEKF with a forgetting factor () update was then designed to effectively estimate the time-varying parameter (torsional shaft stiffness) owing to cracks.

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The design of amphiphilic polymer compatibilizers for solubility manipulation of CNT composites was systematically generalized in this study. Structurally tailored multiamphiphilic compatibilizer were designed and synthesized by applying simple, high-yield reactions. This multiamphiphilic compatibilizer was applied for noncovalent functionalization of CNTs as well as provided CNTs with outstanding dispersion stability, manipulation of solubility, and hybridization with Ag nanoparticles (NPs).

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Although hemophagocytic syndrome (HS) featuring secondary hemophagocytic lymphohistiocytosis (HLH) has a grave prognosis, little is known about the natural course of the disease. Patients who showed the clinical features of HLH as well as tissue-proven hemophagocytosis when seen at Asan Medical Center between 1999 and 2010 were included in this analysis. Patients with proven lymphoma were excluded.

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Hyaluronic acid (HA) was extracted in a relatively large scale from rooster comb using a method similar to that reported previously. The extraction method was modified to simplify and to reduce time and cost in order to accommodate a large-scale extraction. Five hundred grams of frozen rooster combs yielded about 500 mg of dried HA.

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Pine trees comprise over 35% of the forests in Korea, since 1989, pine wilt disease introduced via the Japanese pine sawyer has been infecting many of these trees. As a renewable resource, pine can be converted to bio-oil, gas, and char through pyrolysis. In this study, the pyrolysis characteristics of pine trees were investigated using thermogravimetric analyzer, with most of the materials decomposing between 330 and 370 degrees C at heating rates of 5-20 degrees C/min.

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Background: The aim of this study was to test the utility of our computed tomography (CT) grading system, compared with endoscopy, for association with the development of esophageal stricture in patients with caustic ingestion.

Methods: This retrospective case series involved 49 patients with caustic ingestion from 1998 to 2009. The degree of esophageal damage was graded using a scoring system based on the extent of esophageal wall edema and the damage in adjacent tissue as seen on thoracoabdominal CT scans.

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In this work, pyrolysis characteristics were investigated using thermogravimetric analysis (TGA) at heating rates of 5-20 degrees C/min. Most of the materials were decomposed between 330 degrees C and 370 degrees C at each heating rate. The average activation energy was 236.

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Carbon black is one of the most useful particulate materials in the industrial field. Among the various physical properties of carbon black, size and size distribution are the most important properties to affect the quality of a final product. However, it is difficult to measure the exact particle size of carbon black since it suffers unavoidable interference from flocculation.

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