• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2550-2563
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• 2022

This study performed a precise dynamic finite element time history elastic-plastic seismic analysis considering the welds, which have been not considered in design stage, on the nuclear components subjected to severe seismic loadings such as beyond-design basis earthquakes for sustainable nuclear power plants. First, the dynamic finite element elastic-plastic seismic analysis was performed for a general design practice that does not take into account the welds of the pressurizer surge line system, one of safety class I components in nuclear power plants, and then the reference values for the accumulated equivalent plastic strain, equivalent plastic strain, and von Mises effective stress were set. Second, the dynamic finite element elastic-plastic seismic analyses were performed for the case of considering only the mechanical strength over-mismatch of the welds as well as for the case of considering both the strength over-mismatch and welding residual strain. Third, the effects of the strength over-mismatch and welding residual strain were analyzed by comparing the finite element analysis results with the reference values. As a result of the comparison, it was found that not considering the strength over-mismatch may lead to conservative assessment results, whereas not considering the welding residual strain may be non-conservative.

• 대한토목학회논문집
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• 제37권3호
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• pp.603-610
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• 2017

최근 집중호우, 잦은 강설, 급격한 기온차이 등 환경변화의 가속화에 따라 균열, 단차, 포트홀 등 다양한 형태의 도로 파손이 급증하고 있다. 이중 포트홀 관련 사고는 파손 특징상 대형사고를 유발하며 08년 기준 5년간 약 5배 이상 증가하였다. 매년 포트홀로 인한 인명피해, 차량파손 등 직 간접적인 피해가 증가함에 따라 보다 신속하고 효율적인 관리 대책이 필요하다. 따라서 본 연구에서는 포트홀 규모, 면적과의 상관관계를 통해 체적 보정계수와 보수재료 물량산출 알고리즘을 제시하였다. 제시된 물량산출 알고리즘의 검증을 위해 수도권 지역 15개소의 포트홀을 측정한 결과 통상적으로 개소당 약 5~7 kg까지 발생하던 재료 잔량이 1~2 kg까지 감소하는 것으로 나타났다. 작업자의 주관적인 판단에 의존하여 시공하고 있는 실정에서 포트홀 체적 감지 자동화 통합시스템은 재료/자원 절감뿐 아니라 적정한 보수물량 산정을 통해 다짐상태 등 포장 품질향상에 기여할 수 있을 것이다.

• 한국치위생학회지
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• 제18권2호
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• pp.217-226
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• 2018

Objectives: The purpose of this study is to find out differences in oral health status, defined as their oral health and oral health quality of life among the elderly depending on their income and education levels. Methods: This study used 922 senior citizens over 65 from the data (2015) of the 6th National Health and Nutrition Survey (NHNS). The regression analysis was adopted to identify factors affecting their oral health status which has effect on their oral health quality of life. The statistical package SPSS 21.0 was employed. Frequency analysis, chi-squared analysis and regression analysis were used, and the significance level or Cronbach's alpha value was 0.05. Results: Depending on income levels, there were differences in their oral health status as to whether they use oral hygiene products, take dental examinations, join private health-insurances, and delay dental treatments or not. And educational levels also made significant differences in their oral health status as to whether they smoke, drink alcohol, how many times they brush teeth a day, whether they use oral hygiene products, take dental treatments, and join private health-insurances. Regression analysis on the relationship between their oral health status and the oral health quality of life showed that there were significant differences depending on whether they take dental treatments, delay dental medical treatments, smoke, take oral examinations, how many times they brush teeth a day, and whether they use oral hygiene products, or join private health-insurances. Conclusions: The study shows that a comprehensive plan is needed to raise attention on proper oral health-care and ultimately to improve the quality of life by considering the daily number of tooth brushing, oral hygiene product use, regular dental treatments, and other medical uses.

• Archives of Plastic Surgery
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• 제38권4호
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• pp.552-554
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• 2011

Purpose: Though its general usage, traditional tie-over dressing using suture has a few drawbacks such as difficulty in re-fixation after its opening especially when hematoma or seroma has occurred. It is rather difficult to maintain a stable dressing on curvy parts of body like flank, buttocks and that leads to unsatisfactory results of the surgery. Authors recommend a quick and repeatedly doable method, tie-over dressing that incorporates the usage of hooks and rubber bands. Methods: Debridement was done at a recipient site to be able to do skin graft. A right size of skin graft was prepared and placed upon the defect site with suture. Enough number of hooks were attached using Blue nylon at the normal skin of the edge of grafted area. We Applied dressing with ointment and fluffy gauze then fixed the dressing by attaching a rubber band at the hook to give a certain amount of tension. One or two days after the surgery, we opened the tie-over dressing and repeated the tie-over dressing by reusing the hooks and rubber band. Results: The skin grafts were all successfully taken and by repeating tie-over dressing using hooks and rubber, we could take the advantage of shortened the dressing time and eliminate the inconvenience of the patient and the surgeon by using bandages and fixing tapes. Conclusion: The advantage of tie over dressing using hooks and rubber bsnds are its easy re-doability early detection of probable complications, preventability of reoccurence of hematoma and seroma. Therefore, authors report this as considering the tie-over dressing using hooks and rubber bands is recommendable.

• 한국식생활문화학회지
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• 제27권3호
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• pp.324-330
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• 2012

This study investigated the perception, consumer pattern and satisfaction of the ginseng products of 600 people in the Seoul area surveyed from Feb. 1 to 28, 2011. The perception and satisfaction tests were performed using a 5-point scale (1=disagree (dissatisfy) very much, 5=agree (satisfy) very much. People perceived ginseng to have refreshment (3.86), immuno-modulation (3.78), anticancer (3.51), and antiaging (3.41) properties. People in their 20s (4.02) scored high on refreshment compared to people in their 60s and over (3.73). Most people (79.8%) consume ginseng products and prefer red ginseng (74.3%). More people in their 40s (54.1%) and 50s (48.2%) consume ginseng products for refreshment than people in their 20s (38.7%), 30s (41.5%) or 60s and over (40.0%). However, more people in their 50s (36.1%) and 60s and over (43.6%) consume ginseng products for disease prevention than people in their 20s (8.6%). Most people (66.4%) take ginseng all year round. People in their 20s (2.70) showed a smaller satisfaction score of the taste of ginseng products than those in their 30s (3.21), 40s (3.23), 50s (3.26) and 60s and over (3.38).

• 한국정보통신학회논문지
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• 제2권1호
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• pp.133-140
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• 1998

본 논문에서는 페이딩이 존재하는 이동통신 채널에서 DTMF 변조의 신뢰성을 보장하기 위해 RS 부호의 적용을 고려하고, (15, 9) RS 인코더와 디코더 회로를 제안 및 합성하였으며, 페이딩 채널에서 부호의 성능을 구하였다. 소요된 게이트는 2-Input NAND 게이트를 기준으로 약 14,000 게이트가 소요되었다. 이와 같이 구현된 (15,9) RS 부호를 DTMF 신호방식에 적용하였을 경우 IMT-2000 등 이동통신에서 데이터 전송의 기준인 10-6의 비트오율을 기준으로 페이딩 채널의 경우 20 dB 이상의 부호이득을 보인다. 따라서 페이딩이 존재하는 이동 통신에서 데이터 전송을 위한 DTMF 신호방식에 본 부호기를 적용하는 것은 매우 효과적이라 할 수 있다.

• Strategy21
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• 통권30호
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• pp.177-199
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• 2012

As is generally known, the sovereignty dispute over the Senkaku Islands between China/Taiwan and Japan was triggered by a report commissioned by the UN in 1968, which reported the possibility of a substantial amount of petroleum and natural gas buried in the South China Sea. When the administrative authority over the Ryukyu Islands was transferred from the US to Japan in 1972, jurisdiction over the Senkaku Islands was also transferred. A dispute ensued between China (Taiwan) and Japan over the Senkaku Islands except during the period in which formal relations were established between the two states. This paper will take a look particularly at the events that occurred in the 2000's and discuss their recent trends and aspects of the dispute. Though China and Japan agreed to joint resource development in 2008, the agreed zone was a very small area adjacent to the Korea-Japan Joint Continental Shelf Development Zone, and the points of agreement have not been implemented. China has been developing four oil fields including Chunxiao in its waters adjacent to the median line asserted by Japan. However, China also has been excluding the participation of Japan, while Japan has been strongly objecting to the unilateral development of oil fields by China. If indeed the oil fields on China's side are connected past the median line asserted by Japan, then China's unilateral development will infringe upon the potential sovereign rights of Japan, thereby violating international law.

• 대한방사선치료학회지
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• 제13권1호
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• pp.75-90
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• 2001

Although it is presumed that cancer patients take various alternative therapies, the present status is not well recognized. The purpose of this study is to survey alternative therapies used by cancer patients receiving radiation therapy and then, find associated factors of taking alternative therapies. The study subjects were composed of those who receiving radiation therapy in the department of radiation oncology in 5 hospitals located at Extended Busan city and who were on follow-up after medical cure. They were 394 male and female patients over 20 years old. The mean age of the subjects was 53.2 years old and the age ranged from 23 to 83 years old. 188 patients($47.7\%$) used alternative therapies. Total 68 different kinds of alterative therapies were used, average 7.3 kinds per patient were experienced, and average total cost expenditure was 2,830,000 won. Among the alternative therapies, black bean($38.8\%$) was the most commonly used and brown rice($38.3\%$), ganoderm lucidum($37.8\%$), elm tree($33.5\%$), and phellinus linteus($30.8\%$) were followed in order of frequency. However in considering the time, cost and effort spent, phellinus linteus was the first. In terms of cost, phellinus linteus was the highest with average expenditure of 2,740,000 won. Among the motivation of using alternative therapies, expecting auxiliary help for the hospital therapy was the highest ($31.4\%$). About half of users($56.9\%$) of alternative therapies were recommended by their relatives to use alternative therapies. In comparing the characteristics of experienced and unexperienced groups, alternative therapy was experienced significantly more in patients of younger age(p=0.001), in patient of higher educational level(p=0.001), and in patients of higher income(p=0.030) The proportion of using alternative therapies was significantly higher in the group treated with chemotherapy(p=0.005), and in the patients who did not satisfy with radiation therapy(p=0.001). The frequency of drinking was significantly higher tendency in the inexperienced group(p=0.046), There was no significant difference in marital status, job, religion, other disease, surgical operation of the cancer and smoking staus between the two groups. Among the unexperienced group, $34.0\%$ of the patients did not take the alternative therapies because they did not have know]edge for the alternatives, and $22.3\%$ worried about negative effects on hospital-based therapy $58.7\%$ of them were willing to take the alternative therapies if the effects and safety were proven by the government or research institutes. $21.9\%$ of the patients wanted to take the alternatives if they were affordable. $72.3\%$ of the patients was willing to take them if their families recommend, but $27.2\%$ responded they would not take them in any situation. Conclusively, various kinds of alternative therapies which were not proved medically were exposed to patients, In these circumstances, it is required to investigate, study and evaluate the medical effects and safety of the alternative therapies.

• International Journal of Contents
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• 제8권2호
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• pp.19-22
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• 2012

New and handoff calls control mechanisms are the key point to wireless cellular networks. In this paper, we present an adaptive algorithm for dynamic channel allocation scheme with guard channels and also with handoff calls waiting queue ensuring that handoff calls take priority over new calls. Our goal is to find better tradeoff between handoffs and new calls blocking probabilities in order to achieve more efficient channel utilization. Simpy is a Python based discrete event simulation system. We use Simpy to build our simulation models to get analytical data.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.25-28
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• 2000

In this paper, we assume various number of multipaths in one chip duration according to spreading bandwidth. And we take into account of the effects of autocorrelation and relative phases among multipath components within one chip duration, and analyze fading effects. We derive the average error probability for different number of users. Then, we compare the performance of W-CDMA systems with different bandwidths. From the simulation results for different band-widths, wideband CDMA systems show better performance than narrowband CDMA systems in vehicular and pedestrian environments.