• The Journal of Engineering Geology
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• 제17권1호
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• pp.57-64
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• 2007

This study was conducted to characterize on the relationships among rainfall intensity, slope angle and pore water pressure in the gneissic weathered soil by landslide laboratory flume tests. Under the several test conditions dependent on rainfall intensity and slope angle, the authors measured pore water pressure, failure and displacement of slope on a regular time interval. According to the test results, the increasing times of pore water pressures have direct proportional trends to the rainfall intensity. The pore water pressure was increased earlier at the head part of slope than the toe part. Compared with the test results of Chae et al(2006), the results of this study explain that the seepage velocity in the gneissic weathered soil is slower than that in the standard sands. It results in faster and ear-lier increase of pore water pressure at the head part of slope due to slow flow of water in the gneissic weathered soil. In case of the relationship between slope angle and pore water pressure, gentle slope angle has faster increase of pore water pressure than steeper slope angle. It is also thought to be due to slow seepage velocity and flow velocity in the gneissic weathered soil.

• Korean Journal of Head & Neck Oncology
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• 제17권2호
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• pp.179-184
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• 2001

Objective: The role of chemotherapy in locally advanced head and neck cancer has been established in nasopharynx and larynx as definitive therapy and organ preserving therapy, respectively. Oral cavity cancers are relatively uncommon and local recurrence is the main cause of treatment failure. We planned this retrospective study to evaluate the role of neoadjuvant chemotherapy in locally advanced oral cavity cancer patients. Materials and Methods: From 1988 March to 2001 February, locally advanced, previously untreated oral cavity cancer patients who received neoadjuvant chemotherapy were examined. Chemotherapy had been done in the following patients: Histologically proven squamous cell or poorly differentiated carcinoma, stage 3 or 4, and performance state 0-2 patients. Chemotherapy regimen consisted of cisplatin and infusional 5-fluorouracil. Response was evaluated after 2 cycles and in case of no response, definitive local therapy was done; otherwise 3 cycles was done before local treatment. Results: 48 patients were treated and 47 patients were evaluable for responses. Complete response rate was 6.4%(3/47) and partial response 80.0%(38/47), scoring overall response rate of 87.2%. Median time to progression was 27.0 months (95% CI : 0-58months) and overall 5 year survival was 54.8%. 5-year disease-free survival in the patients in remission after local treatment was 51.9%. In multivariate analysis, contributing factor to the survival were response to neoadjuvant chemotherapy and local treatment modalities. Extensive surgery was done in 10 patients and 25 patents (52.1%) was followed up with preserved function. With median follow-up of 57.0 months, 19 recurrences were detected, most of which were local or regional type. Conclusion: Neoadjuvant chemotherapy followed by local treatment in oral cavity cancer showed high response rate and was thought to be effective therapeutic approach especially in view of organ preservation.

• Journal of Distribution Science
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• 제17권2호
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• pp.53-69
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• 2019

Purpose - National scientific technology R&D investment is exceeding 60 trillion won per year, and the results of patent applications and technology transfers are visually improving. However, despite the improving research results of national R&D, the practical results of technology startups are mediocre. It is now time to expand the construction of the technology commercialization ecosystem, where the expansion of national R&D leads to the results of technology startups. Therefore, this study discussed the measures to increase the competitiveness of technology startups through the factual survey of the companies that benefitted from R&D support programs. Research design, data, and methodology - This study targeted 996 companies that benefitted from the R&D projects of the Technology Transfer Center for National R&D Programs, and deducted itemized issues through the survey replies. Survey questions were prepared to estimate the national R&D results, and the technology recognition path, the purpose of detailed introduction of the technology, investment of the commercialization fund, economic results, and the factors of success and failure were analyzed. Results - As for the recognition rate of technology during the process of corporate technology commercialization through the technology transfer, recognition through project participation showed a high response rate, and diverse implications of technology commercialization were deducted through the analysis of economic results. As for the resolution alternatives, the proliferation of technology commercialization platform that can create excellent technology for the companies in early stages and the measure of expanding the distribution of technology infrastructure were suggested. In this study, public technology commercialization strategy is established, and the innovative marketing strategy is presented. Conclusions - This study reveal that the result of creating scientific technology jobs should be deducted, in order to produce the revolutionary results of job creation by suggesting the success models of technology commercialization based on domestic scientific technology. In particular, even though the support systems for public research results are being diversely suggested, accurate studies on their actual conditions are currently lacking. Therefore, this study suggest realistic political alternatives to assure results in the process of public technology commercialization, by examining the current state of public research results of R&D support institutions and diagnosing the issues.

• Journal of Biomedical Engineering Research
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• 제19권5호
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• pp.503-511
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• 1998

In this study, the stress distribution for different tibial components was observed In order to Investigate the load transfer and potential failure mechanism of the tibial components subjected to dynamic impact loading and also to evacuate the effect of bone-implant bonding conditions on the implant system. The 3-dimensional finite element models included an intact tibia, cemented metal-backed tibial component, uncemented metal-blocked tibial component, cemented all-polyethylene tibial component, and metal-backed component with a debonded bone/stem interface. The results showed that the cemented metal-hocked component Induced slightly higher peak stress at stem tip than the uncemented component. The peak stress of the all-polyethylene tibia1 component at stem trip showed about half thats of metal-backed tibial components. The all-polyethylene component showed a similar dynamic response to intact tibia. In case of debonded bone/stem interface, the peak stress below the metal tray was three times Higher than that of the fully bonded interface and unstable stress distribution at the stem tip was observed with time, which causes another adverse bone apposition and implant loosening. Thus, the all-polyethylene tibial component bonded fully to the surrounding bone might be most desirable system under an impact loading.

• Journal of Chest Surgery
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• 제29권3호
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• pp.278-284
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• 1996

Nine infants with transposition of great arteries have undergone arterial switch operation from May 1989 to May 1994 in the Department of Thoracic and Cardiovascular Surgery, Yeungnam University Hospital. Patients' age ranged from 3 days to 90 days, averaging 30$\pm$21 days. Diagnosis was made by two-dimensional echocardiography in all patients. Eight patients were diagnosed as transposition of great arteries with ventricular septal defect and one patient was a simple transposition of great arteries. Associated anomalies were patent ductus arteriosus (8), atrial septal defect (7) and coarctation of aorta(1). The anatomy of the coronary arteries were 7 (77 %) type A and 2 (23 %) type D according to the Yacoub classification. Pulmonary artery reconstruction was done according to Lecompte maneuver with tautologous pericardial patch in 8 patients. Overall operative mortality rate was 55% Left heart failure and pulmonary hypertensive crisis were the cause of death on postoperative 1~2 days in three patients, and two succumbed to death due to sepsis on postoperative 2~ 3 weeks. The mean follow-up period was mean 17 months. No patient had clinically significant postoperative aortic regurgitation and supravalvular pulmonary stenosis. The excessive use of inotropic support postoperatively was identified as a stastically significant risk factor following the arterial switch operation. But other variables such as low body weight, long cardiopulmonary bypass time, excessive hemodilution during cardiopulmonary bypass, hypothermia and volume loading were not significant risk factors.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8281-8285
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• 2016

Background: Helicobacter pylori is a cause of chronic gastritis, peptic ulcer disease, and gastric malignancy, infection being a serious health problem in Thailand. Recently, clarithromycin resistant H. pylori strains represent the main cause of treatment failure. Therefore this study aimed to determine the prevalence and pattern of H. pylori resistance to clarithromycin in Suranaree University of Technology Hospital, Suranree University of Technology, Nakhon Ratchasima, Northeastern Thailand, Nakhon Ratchasima province, northeast of Thailand. Materials and Methods: This hospital-based cross-sectional study was carried out between June 2014 and February 2015 with 300 infected patients interviewed and from whom gastric mucosa specimens were collected and proven positive by histology. The gastric mucosa specimens were tested for H. pylori and clarithromycin resistance by 23S ribosomal RNA point mutations analysis using real-time polymerase chain reactions. Correlation of eradication rates with patterns of mutation were analyzed by chi-square test. Results: Of 300 infected patients, the majority were aged between 47-61 years (31.6%), female (52.3%), with monthly income between 10,000-15,000 Baht (57%), and had a history of alcohol drinking (59.3%). Patient symptoms were abdominal pain (48.6%), followed by iron deficiency anemia (35.3%). Papaya salad consumption (40.3%) was a possible risk factor for H. pylori infection. The prevalence of H. pylori strains resistant to clarithromycin was 76.2%. Among clarithromycin-resistant strains tested, all were due to the A2144G point mutation in the 23S rRNA gene. Among mutations group, wild type genotype, mutant strain mixed wild type and mutant genotype were 23.8%, 35.7% and 40.5% respectively. With the clarithromycin-based triple therapy regimen, the efficacy decreased by 70% for H. pylori eradication (P<0.01). Conclusions: Recent results indicate a high rate of H. pylori resistance to clarithromycin. Mixed of wild type and mutant genotype is the most common mutant genotype in Nakhon Ratchasima province, therefore the use of clarithromycin-based triple therapy an not advisable as an empiric first-line regimen for H. pylori eradication in northeast region of Thailand.

• Journal of the Korean Data and Information Science Society
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• 제26권3호
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• pp.707-714
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• 2015

The SF-36 is the most common instrument to check the quality of life for dialysis patients with chronic renal failure. However, there were too much burden for them to answer 36 items of it. So we purposed to develop the RFQoL-K reduced type of the SF-36. Participants who had newly registered for dialysis were enrolled in 29 medical centers during 45months from 2009. We developed the RFQoL-K through 355 people who applied the SF-36 at 3 and 12 months after registration and then checked it's internal validity. External validity about it was checked via 411 people who answered only one time survey after registration. In conclusion, the RFQoL-K had total 14 items which was consisted of 8 items on physical factors and 6 items on mental factors from the SF-36. The RFQoL-K summary scores explained 91-93% of the SF-36 summary scores. The RFQoL-K was well reflected SF-36 because the correlation and the internal consistency between two tools were very high 0.96 to 0.98 and 0.96 to 0.98 respectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제15권4호
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• pp.81-90
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• 2016

As an autonomous driving vehicle (AV) need to cope with external road conditions by itself, its perception performance for road environment should be better than that of a human driver. A vision sensor, one of AV sensors, performs lane detection function to percept road environment for performing safe vehicle steering, which relates to define vehicle heading and lane departure prevention. Performance standards for a vision sensor in an ADAS(Advanced Driver Assistance System) focus on the function of 'driver assistance', not on the perception of 'independent situation'. So the performance requirements for a vision sensor in AV may different from those in an ADAS. In assuming that an AV keep previous steering due to lane detection failure, this study calculated lane departure distances between the AV location following curved road alignment and the other one driving to the straight in a curved section. We analysed lane departure distance and time with respect to the allowance of lane detection malfunction of an AV vision sensor. With the results, we found that an AV would encounter a critical lane departure situation if a vision sensor loses lane detection over 1 second. Therefore, it is concluded that the performance standards for an AV should contain more severe lane departure situations than those of an ADAS.

• Journal of the Korean Society of Safety
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• 제32권2호
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• pp.34-37
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• 2017

In recent emerging industry, Display field becomes bigger and bigger, and also semiconductor technology becomes high density integration. In Flat Panel Display, there is an issue that electrostatic phenomenon results in fine dust adsorption as electrostatic capacity increases due to bigger size. Destruction of high integrated circuit and pattern deterioration occur in semiconductor and this causes the problem of weakening of thermal resistance. In order to solve this sort of electrostatic failure in this process, Soft X-ray ionizer is mainly used. Soft X-ray Ionizer does not only generate electrical noise and minute particle but also is efficient to remove electrostatic as it has a wide range of ionization. X-ray Generating efficiency has an effect on soft X-ray Ionizer affects neutralizing performance. There exist variable factors such as type of anode, thickness, tube voltage etc., and it takes a lot of time and financial resource to find optimal performance by manufacturing with actual X-ray tube source. MCNPX (Monte Carlo N-Particle Extended) is used for simulation to solve this kind of problem, and optimum efficiency of X-ray generation is anticipated. In this study, X-ray generation efficiency was measured according to target material thickness using MCNPX under the conditions that tube voltage is 5 keV, 10 keV, 15 keV and the target Material is Tungsten(W), Gold(Au), Silver(Ag). At the result, Gold(Au) shows optimum efficiency. In Tube voltage 5 keV, optimal target thickness is $0.05{\mu}m$ and Largest energy of Light flux appears $2.22{\times}10^8$ x-ray flux. In Tube voltage 10 keV, optimal target Thickness is $0.18{\mu}m$ and Largest energy of Light flux appears $1.97{\times}10^9$ x-ray flux. In Tube voltage 15 keV, optimal target Thickness is $0.29{\mu}m$ and Largest energy of Light flux appears $4.59{\times}10^9$ x-ray flux.

• Journal of Korean Tunnelling and Underground Space Association
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• 제22권5호
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• pp.529-541
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• 2020

Although TBM's cutterhead requires design review for fatigue failure due to wear-induced section loss as well as heavy load during excavation, it is difficult to find a case of fatigue analysis for TBM cutterhead at present. In this study, a stress-life design review was conducted on cutter heads with a diameter of 8.2 m using S-N curves as a safety life design concept. Also, we introduced the fatigue design method of construction equipment and the method of assessing fatigue damage and explained the results of the fatigue analysis on the TBM cutter head with a diameter of 8.2 m. The S-N curve has been shown to play a key role in fatigue design and can also be used to assess how much fatigue damage a structure is suffering from at this point in time. In the future, it is necessary to find out when fatigue problems occur during using the equipment and when it is good to conduct safety inspections of the equipment.