• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.139-146
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• 2015

The amount of by-product from sulphur increases in domestic industrial facilities. However, the amount of its consumption is limited so that the amount of unused sulphur continues to increase. Therefore, in this study, the use sulfur polymer as the concrete surface protecting material was conducted. The compressive strength showed that as the substitution ratio of filler increased up to 40%, the compressive strength also increased. A high compressive strength was shown at the curing temperature of $40^{\circ}C$ (SS, FA) and $60^{\circ}C$ (OPC) according to the type of filler. The difference of compressive strength between air dry curing and water curing was insignificant so that there was no significant influence of moisture during curing process. The evaluation result of bond strength showed that the highest bond strength was shown at the air-dry condition of $40^{\circ}C$ regardless of type of filler. Bonding didn't occur properly during water curing in comparison to air dry curing. Also, in case of the specimen cured at $60^{\circ}C$, discoloration and hair cracks appeared due to the influence of temperature, and the highest bond strength was shown at the substitution ratio of 20% (SS, FA) and 30% (OPC) according to the type of filler. The releasing test result of harmful substance showed that no harmful substance was released, so there is no harmfulness in the surface protecting material using sulfur polymer. As a conclusion drawn in this study, it is most appropriate to substitute silica by approximately 20%, mix and cure at the air-dry condition of $40^{\circ}C$ in order to use sulfur polymer as the surface protecting material.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.2
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• pp.19-30
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• 2012

Due to the fact that the social environment is improved and the urban development is stabilized, the demand of new construction of apartment becomes slowdown. Accordingly, there are many researches to lengthen the service life of the existing apartment through the remodeling and its importance is continuously rising. However, reliable design specifications and guidelines for the design of remodeling with partial demolition are not provided yet in Korea. Specially, in the apartment remodeling, slab collapse accidents take major portion in all accidents that reported by Korean Government. It is very important to prevent intial crack of slab because intial crack could cause severe accident like collapse of all structure in a short period of time. The purpose of this study is to develop structural guidelines that could guarantee the structural safety and serviceability of slab structure and could be adopted in Korean remodeling with partial demolition. There are mainly two components to determine structural behavior of slab structure. One is the shape of slab structure and the other is load which is resisted by the slab structure. In this study, the weight per unit volume of concrete debris and concrete strength are estimated through the analysis of previous researches to recognize the relationship between the shape of slab and load that loaded on the slab. Accordingly, approximately 300 pieces of floor plan are collected and analyzed. The finite element analysis is conducted using these analyzed and estimated results. From the finite element analysis results, the limited stacking height of debris is suggested and the stacking method is also discussed. In addition, to find the relationship between movement of demolition equipment and structural behavior of slab, the static and dynamic loading tests are conducted. From the results of loading tests, the impact factor which will be considered in the remodeling design could be estimated.

• Radiation Oncology Journal
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• v.23 no.3
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• pp.186-193
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• 2005

Purpose: To improve the management of a medical linear accelerator, the records of operational failures of a Varian CL2l00C over a ten year period were retrospectively analyzed. Materials and Methods: The failures were classified according to the involved functional subunits, with each class rated Into one of three levels depending on the operational conditions. The relationships between the failure rate and working ratio and between the failure rate and outside temperature were investigated. In addition, the average life time of the main part and the operating efficiency over the last 4 years were analyzed. Results: Among the recorded failures (total 587 failures), the most frequent failure was observed in the parts related with the collimation system, including the monitor chamber, which accounted for $20\%$ of all failures. With regard to the operational conditions, 2nd level of failures, which temporally interrupted treatments, were the most frequent. Third level of failures, which interrupted treatment for more than several hours, were mostly caused by the accelerating subunit. The number of failures was increased with number of treatments and operating time. The average life-times of the Klystron and Thyratron became shorter as the working ratio increased, and were 42 and $83\%$ of the expected values, respectively. The operating efficiency was maintained at $95\%$ or higher, but this value slightly decreased. There was no significant correlation between the number of failures and the outside temperature. Conclusion: The maintenance of detailed equipment problems and failures records over a long period of time can provide good knowledge of equipment function as well as the capability of predicting future failure. Wore rigorous equipment maintenance Is required for old medical linear accelerators for the advanced avoidance of serious failure and to improve the qualify of patient treatment.

• Journal of Chest Surgery
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• v.36 no.6
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• pp.384-390
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• 2003

Background: Since Ross and Sormeville first reported the use of aortic homograft valve for correction of pulmonary atresia in 1966, homograft valves are widely used in the repair of congenital anomalies as conduits between the pulmonary ventricle and pulmonary arteries. On the basis of these results, we have used it actively. In this report, we describe our experience with the use of cryopreserved valved homograft conduits for infants and children requiring right ventricle to pulmonary artery connection in various congenital cardiac anomalies. Material and Method: Between January, 1996 and December 2001, 27 infants or children with a median age of 16 months(range 9days to 18years) underwent repair of RVOTO using homograft valved conduit by two surgeons. We studied 22 patients who have been followed up at least more than one year. The diagnosis at operation included pulmonary atresia with ventricular septal defect (n=13), truncus arteriosus (n=3), TGA or corrected TGA with RVOTO (n=6). Homograft valved conduits varied in size from 15 to 26 mm (mean, 183.82 mm). The follow-up period ranged from 12 to 80.4 months (median, 48.4 months). Result: There was no re-operation due to graft failure itself. However, early progressive pulmonary homograft valve insufficiency developed in one patient, that was caused by dilatation secondary to the presence of residual distal pulmonary artery stenosis and hypoplasia after repair of pulmonary atresia with ventricular septal defect. This patient was required reoperation (conduit replacement). During follow-up period, there were significant pulmonary stenosis in one, and pulmonary regurgitation more than moderate degree in 3. And there were mild calcifications at distal anastomotic site in 2 patients. All the calcified homografts were aortic in origin. Conclusion: We observed that cryopreserved homograft conduits used in infant and children functioned satisfactorily in the pulmonic position at mid-term follow-up. To enhance the homograft function, ongoing investigation is required to re-establish the optimal strategy for the harvest, preservation and the use of it.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.3
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• pp.359-371
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• 2010

Facial asymmetry has been found with a higher frequency (70~84%) in skeletal class III malocclusion patients. Anticipating the poor prognosis of prosthesis due to malocclusion, occlusal stability must be obtained by orthodontic treatment. Moreover, orthodontic surgery would be needed in some severe cases for better functional and esthetic results. The orthognathic surgery is performed on one jaw or two jaw depending on the results of facial diagnosis. Genioplasty may change the vertical, horizontal, sagittal position of chin by osteotomy or augmentation using implants, also. This case is about a 24 year-old male patient who visited our clinic to solve the facial asymmetry and mandibular prognathism. Skeletal class III malocclusion, maxillary canting and menton deviation to left by 13 mm were detected. Multiple ill-fitting prostheses, unesthetic maxillary anterior prostheses, and several dental caries were found. After pre-operative orthodontic treatment, Le-Fort I osteotomy, sagittal split ramus osteotomy, genioplasty, right mandibular angle augmentation were done for the correction of jaw relation and asymmetry. By diagnostic wax-up after post-operative orthodontic treatment, maxillary full mouth rehabilitation and mandibular posterior restorations were planned out. For better result, clinical crown lengthening procedure was done on #11, 12 and implant was placed on left mandibular first molar area. The patient was satisfied with the final prostheses. Because of his high caries risk, long-term prognosis will depend on the consistent maintenance of oral hygiene and periodic follow-up.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.533-547
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• 1997

In periodontics, much progress was made in the understanding of periodontal disease from 1960s to 1980s and in prevention and management of periodontal disease since the end of 1980s. This presentation will discuss about the prevalence of periodontal disease, treatment need, and provision of periodontal treatment in Korea, and how we could manage the periodontal disease efficiently in the future. According to an epidemiological study in Korea, periodontal disease(including gingivitis) was present in 82% of general population and periodontitis in 30-40% in adult population over 30y and juvenile periodontitis in 0.1% of adolescents. If we consider that at least 17% of these patients may have recurrent or refractory forms, there is obviously an abundance of disease that needs treatment, As a result of increase in life expectancy, senile population over 65 y will be increased from 6% in 1996 to 6.9% in 2000, and tooth retention rate and periodontal treatment need are expected to increase. Periodontists need all the help they can get from the general dentists to control periodontal disease. As for provision, postgraduate course in periodontics started in 1957 in Korea and produced over 700 specialized dentists in periodontics. One report indicated that the periodontists as well as general practitioners did periodontal therapy on only a few periodontal patients, because of specific control by current medical insurance system in Korea. Comprehensive periodontal examination is rarely done in local dental clinic. Therefore, enhancement of periodontal care in medical insurance system and education of simplified periodontal examination such as Periodontal Screening & Recording will make dentists diagnose and manage the management of adult patients is based on the recognition that there are multiple diseases, including gingivitis, chronic adlt periodontitis, and other more aggressive forms of periodontitis, and requires the earliest possible recognition of these three disease categories. In this presentation, we discuss practical approach using PSR to diagnose, manage and refer the patients, to facilitate the separation of the simple from the complex and the predictable from the unpredictable form of periodontal diseases and to integrate diagnostic and therapeutic techniques into private practice today.

• The Journal of Korean Philosophical History
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• no.42
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• pp.197-232
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• 2014

Taoism is very political orientation from the start have. Internal alchemy has several factions, but southern school and northern school of taoism is typical of this. southern school begun from Zhang Bo-duan in north Song dynasty. Northern school is under Jin dynasty rule by Wang Chung-yang been established. Southern school did not create the platform, but northern school is developed mainly by the denomination from the first. Taoism is basically seek eternal life. Internal alchemy was created a unique discipline to reach the such stage with only Internal alchemy. Southern school's training methods were an elaborate series of logical structure with a counterpart, but northern school's methods is somewhat lacking logically. Southern school claim a training methods from the physical to mental through how to achieve it's ultimate goals, northern school took from mental to spiritual retreat methods that the way to achieve objectives. But northern school's theory of ascetic Practice is difficult to see that the contents are pure. Also, the labours of penance during his training process is the other way with Southern school. These differences are they closely associated with Confucianism and Buddhism, to understand the point of view. Southern school put a primary objective in the personal Practice, while northern school is fundamental to the relief of the people. This can see that has how long life times in southern school and northern school's main members. Because the members of southern school enjoyed great longevity, but northern school's main members was not enjoyed longevity. As a result, the southern school's flow is cut off and northern school became the center form a major organization in the history of china taoism. The southern school assimilated to the northern school. In a pure sense, host and guest's changed.

• The Korean Journal of Nuclear Medicine
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• v.4 no.1
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• pp.19-26
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• 1970

1. Sixteen normal healthy subjects free from occult blood in the stool were selected and administered with their $^{51}Cr$ labeled own blood via duodenal tube and the recovery rate of radioactivity in feces and urine was measured. The average fecal recovery rate was 90.7 per cent ($85.7{\sim}97.7%$) of the administered radioactivity, and the average urinary excretion rate was 0.8 per cent ($0.5{\sim}1.5%$) 2. There was a close correlation between the amount of blood administered and the recovery rate from the feces; the more the blood administered, the higher the recovery rate was. It was also found that the administration of the tagged blood in the amount exceeding 15ml was suitable for measuring the radioactivity in the stools. 3. In five normal healthy subjects whose circulating erythrocytes had been tagged with $^{51}Cr$, there was little fecal excretion of radioactivity (average 0.9 ml of blood per day). This excretion is not related to hemorrhage and the main route of excretion of such an negligible radioactivity was postulated as gastric juice and bile. 4. A comparison of the radioactivity in the blood and feces of the patients with $^{51}Cr$ labeled erythrocytes seems to be a valid way of estimating intestinal blood loss.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.7
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• pp.858-868
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• 2008

This study was carried out to investigate the effects of Gastrodiae Rhizoma powder on plasma lipid profiles in elderly volunteers with hyperlipidemia, hypertension, diabetes or heart disease. 32 elderly people, 11 males and 21 females aged $60{\sim}77$ years, were given Gastrodiae Rhizoma powder 15 g twice daily for 6 months. We investigated the antheropometric data, general characteristics and dietary habit by using questionnaires. Fasting blood samples were collected from the subjects before and after this 6 months intervention study. Blood pressure, glucose, hemoglobin and lipid levels of plasma, atherogenic index (AI) and cardiac risk factors (CRF, LHR, HTR) were determined before and after consumption of Gastrodiae Rhizoma powder. The mean body mass index (BMI) of the male and female subjects were 22.4 and 23.6, respectively. The percent of ideal body weight (PIBW) of males and females were 105.6% and 122.3%, respectively. The subjects had decreased intake frequency of fish and meat in their dietary habit. After consumption of Gastrodiae Rhizoma powder, there were no significant differences in blood pressure; however, the blood glucose significantly decreased with Gastrodiae Rhizoma intake in the males. In the subjects, the levels of plasma total cholesterol, triglyceride, and LDL-cholesterol were decreased by the consumption of Gastrodiae Rhizoma powder; while the levels of plasma LDL-cholesterol was significantly decreased in female. Blood pressure and biochemical assessment (blood glucose, hemoglobin, triglyceride, total cholesterol, LDL and HDL-cholesterol) of the subjects were within the normal range. It was found that AI, CRF and LHR were significantly decreased by Gastrodiae Rhizoma intake. The present results indicate that dietary supplementation of Gastrodiae Rhizoma improved lipid metabolism and cardiac risk factor in cardiovascular disease.