• Smart Structures and Systems
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• v.13 no.3
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• pp.453-471
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• 2014

The fault diagnosis of rolling element bearings has drawn considerable research attention in recent years because these fundamental elements frequently suffer failures that could result in unexpected machine breakdowns. Artificial intelligence algorithms such as artificial neural networks (ANNs) and support vector machines (SVMs) have been widely investigated to identify various faults. However, as the useful life of a bearing deteriorates, identifying early bearing faults and evaluating their sizes of development are necessary for timely maintenance actions to prevent accidents. This study proposes a new two-layer structure consisting of support vector regression machines (SVRMs) to recognize bearing fault patterns and track the fault sizes. The statistical parameters used to track the fault evolutions are first extracted to condense original vibration signals into a few compact features. The extracted features are then used to train the proposed two-layer SVRMs structure. Once these parameters of the proposed two-layer SVRMs structure are determined, the features extracted from other vibration signals can be used to predict the unknown bearing health conditions. The effectiveness of the proposed method is validated by experimental datasets collected from a test rig. The results demonstrate that the proposed method is highly accurate in differentiating between fault patterns and determining their fault severities. Further, comparisons are performed to show that the proposed method is better than some existing methods.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.1024-1028
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• 2003

Influenza-associated encephalopathy is regarded as one of the major neurologic disease entities along with those of Reye syndrome, acute necrotizing encephalopathy, and myelitis which are known to be related to influenza virus, mostly type A. And it is being actively researched in Japan as it has caused a tremendous increase in the number of deaths from 1997 to 2002, but it has not been yet reported in the Korean pediatric medical community. It attacks those previously healthy children, who have not been vaccinated. Patients start with such symptoms as fever and common respiratory problems, but within 24 to 48 hours they suffer from seizures with acute mental deterioration, become worse, and suffer multiple organ failures including marked elevated transaminase levels as well as coagulopathy. It induces deaths in a couple of days after the symptoms appear or remains a serious neurologic sequelae. Confirmative diagnosis is used to demonstrate influenza viral infection. We report here a 37 month aged boy who was admitted to our hospital during the last influenza season under the diagnosis of influenza associated encephalopathy on the basis of serologic testing by hemagglutinin inhibition(HI). This is the first report confirmed by increased antibody titer of the influenza A virus in Korea.

• Journal of Veterinary Clinics
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• v.23 no.2
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• pp.197-201
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• 2006

A 2-year-old female mongrel dog was referred to the Veterinary Medical Center of Chungbuk National University due to anorexia, depression and weight loss after the administration of exogenous estrogen for contraception in the local hospital. Although the dog was medicated with antibiotics and fluid for two weeks in the local hospital, there was a deterioration in the patient's general condition. Therefore the dog was referred to our Veterinary Medical Center. Hematological and biochemical analysis showed non-regenerative anemia, thrombocytopenia, severely immature leukocytosis, hyperbilirubinemia, hyperglycemia and elevated serum alkaline phosphatase, gamma-glutamyltransferase, and lactate dehydrogenase. Abdominal ultrasonography showed double line of gallbladder and irregular hypertrophic wall of uterus. On the basis of these examination's results and history taking, final diagnosis was exogenous estrogen-induced myelotoxicosis with cholecystitis and endometritis. The symptomatic therapy for estrogen toxicosis was performed for 26 days after the final diagnosis. However, the symptom had no response to therapy except endometritis and anemia. On day 135 after administration of estrogen, platelet and neutrophil count were normalized, but monocytic leukocytosis was occurred.

• Journal of Chest Surgery
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• v.27 no.12
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• pp.989-994
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• 1994

Between January 1986 and August 1993, 11 patients underwent surgical repair of ventricular septal defect [VSD] complicated with myocardial infarction. The ages of patients were ranged from 22 years to 83 years with a mean of 64 years. There were 8 male and 3 female patients. The preoperative cineangiograms of all patients were reviewed to measure both ventricular function and to evaluate coronary artery disease. The mean time interval between occurance of VSD and operation was 13 days. The operations were performed as soon as possible if there were hemodynamic derangement. Postmyocardial infarction VSD were repaired simultaneuously with coronary artery bypass graft in 3 patients, repaired with left ventricular aneurysmectomy in 6 patients, with left ventricular thrombectomy in 1 patient and with mitral valve chordae repair in 1 patient. There was no early death [within 30 days]. There were 6 postoperative complications; one with perioperative myocardial infarction, two with recurred VSD on postoperative 1 and 6 days respectively, two with lower leg embolism associated with intraaortic balloon pump insertion, one with wound infection. Of the complicated patients, 1 patient with lower leg embolism performed left above ankle amputation. Among two patients with recurred ventricular septal defect, one patient is doing well without problem. On follow up echocardiogram, the residual VSD was occluded completely. However another patient was with recurred VSD died 3 months after the operation because of congestive heart failure. Of the long term survivors, all patients are in NEW YORK Heart Association functional Class I or II. Although number of patients were small, our results of surgical closure of postmyocardial infarction VSD were favored to the others. Moreover, seven patients with preoperative cardiogenic shock among 11 were performed early operation after diagnosis of ventricular septal rupture. All of the patients were survived and doing well during the follow up period. Therefore early diagnosis with aggressive preoperative care with intraaortic balloon pumping and early operation seems to be very important for prevention of deterioration of vital organ.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.3
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• pp.109-116
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• 2020

PURPOSE: The objective of this study was to provide a basis for the need to apply psychological factors-based rehabilitation programs to osteoarthritis patients by understanding how the limitations on the activities of osteoarthritis patients relate to the health-related quality of life and depression. METHODS: This study assessed 1,994 osteoarthritis patients from the 7th Korea National Health and Nutrition Examination Survey (KNHANES, 2016-2018). The subjects were divided into two categories: with activity limitation and without activity limitation. A Chi-square test and logistic regression analysis were conducted. RESULTS: The EQ-5D index of subjects with activity limitation was .84 ± .16, it was .94 ± .12 in those with no activity limitation (p < .05). The diagnosis of depression was 16.8% and; 8.3% in those with and without activity limitation, respectively (p < .05). There was a significant difference in the odds ratio for each item in the EQ-5D. Moreover, the odds ratio for depression with an activity limitation was 2.171 (1.512 - 3.118) compared with no activity limitation. CONCLUSION: The activity limitation of osteoarthritis patients reduces the health-related quality of life significantly and increases the probability of depression. Therefore, the treatment of osteoarthritis patients should be approached considering the psychological conditions. Moreover, early diagnosis of depressive symptoms is needed to prevent symptom deterioration and increase the compliance with rehabilitation therapy.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.210-222
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• 2017

Railway turnout systems play a key role in railway systems that change train directions. The turnout systems are one of the weakest systems in railway systems, and consecutive maintenance is required. A turnout diagnostic system can automatically measure the turnout status and its deterioration. To diagnose the turnout systems, we follow conventional maintenance procedures and need to identify their physical characteristics to coincide the procedures and the characteristics. According to the physical characteristics, we should choose and install adequate sensors on the turnout systems to measure their physical characteristics. We studied the phenomenon of the turnout system responses for point moving and train running on the turnout systems. We installed sensors on the turnout system in a revenue line to measure the identified physical quantities and to reveal the robustness of the sensors under the turnout system environment.

• Journal of the Korean Institute of Rural Architecture
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• v.22 no.2
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• pp.9-17
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• 2020

The ratio of the deterioration housing in rural area was 29.6%, but it was 18.3% in urban area based on a 2018 survey. In consideration of the point, this study aims to analyze the actual condition of indoor air quality in rural houses to provide basic data for improving the indoor air environment. It was investigated 15housings of Hongseong-gun, Chungchengnam-do. To investigate the correlation between indoor air quality and housing type, both the field survey of housing type and precision diagnosis of concentration of indoor air pollutants such as HCHO, TVOC, Fine dust(PM-10, PM-2.5), CO₂, Radon. The results of this study are as follows. First, according to the average value of each element of rural old housing, the construction year was distributed in 1939~2004, and 12households(80%) living in houses older than 30years have passed for about 46years. As for the housing area, more than 12houses(80%) of 60㎡ or more and 3 houses (20%) of less than 60㎡ were often living in relatively small-scale housing. Second, as a result of measuring indoor air pollutants in rural houses, substances exceeding the standard values were found in HCHO, TVOC, CO₂. Third, in the case of Fine dust and Radon, none of such factors were exceeded the standard. Fourth, there was no significant difference in indoor air quality depending on housing type in rural houses. This paper is expected to contribute to the regional development projects and effective implementation of rural policies.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.6
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• pp.104-108
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• 2009

The insulation aging characteristics and structural analysis test were performed to analyze the correlations among the insulation deterioration, diagnostic results and the breakdown strength for the underground power cables. From the results of the degree of crosslinking test, hot-oil test etc., it could be confirmed that there were no manufacturing defects in the power cables under test. From the results of the water tree test and chemical structural analysis, it could be confirmed that the aging status of cable under test were very poor, especially for B-Phase and the degree of aging was increased in the orders of A, C and B-phase. From the above results, it could be concluded that the insulation aging characteristic analysis results were well consistent with the diagnostic and breakdown test results, and also confirmed that the diagnostic system under consideration was successful to discriminate the bad cables which is likely to cause cable system failure.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.160-173
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• 2013

This research aims to understand the precise character of relics based on literature search and material analysis of the jade excavated from the first buried place of King Jung-jo, and to assess the level of damage through non-destructive diagnosis. Furthermore, scientific conservation treatment was used to restore the original shape of the excavated jade. According to literature search, the excavated jade is known to be jasper, but material analysis showed that it was as a serpentine with the mineral composition of antigorite. Infrared thermography analysis to assess deterioration showed that the internal damage is the result of the interstices developed along the boundary surface of the obtained jade. For conservation treatment of the damaged area on the surface, the jade was filled with a mixture of plaster and glue, and covered with a mixture of acrylic paint and gloss medium for protection, and color was adjusted.

• Journal of Genetic Medicine
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• v.19 no.1
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• pp.22-26
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• 2022

Cerebrotendinous xanthomatosis (CTX) is a rare genetic disease caused by a deficiency of enzymes for the synthesis of bile acid, resulting in the accumulation of cholestanol with reduced chenodeoxycholic acid (CDCA) production and causing various symptoms such as chronic diarrhea in infancy, juvenile cataracts in childhood, tendon xanthomas in adolescence and young adulthood, and progressive neurologic dysfunction in adulthood. Because oral CDCA replacement therapy can effectively prevent disease progression, early diagnosis and treatment are critical in CTX. This study reports the case of CTX in a 10-year-old male who presented with Achilles tendon xanthoma and mild intellectual disability. Biochemical testing showed normal cholesterol and sitosterol levels but elevated cholestanol levels. Genetic testing showed compound heterozygous variants of CYP27A1, c.379C>T (p.Arg127Trp), and c.1214G>A (p.Arg405Gln), which confirmed the diagnosis of CTX. The patient had neither cataracts nor other focal neurologic deficits and showed no abnormalities on brain imaging. The patient received oral CDCA replacement therapy without any adverse effects; thereafter, the cholestanol level decreased and no disease progression was noted. The diagnostic possibility of CTX should be considered in patients with tendon xanthoma and normolipidemic conditions to prevent neurological deterioration.