• Nuclear Engineering and Technology
• /
• 제35권2호
• /
• pp.108-120
• /
• 2003

In assessing the long term post closure radiological safety assessment of a potential HLW repository in Korea, three categories of uncertainties exist. The first one is the scenario uncertainty where series of different natural events are translated into written statements. The second one is the modeling uncertatinty where different mathematical models are applied for an identical scenario. The last one is the data uncertainty which can be expressed in terms of probabilistic density functions. In this analysis, three different scenarios are seleceted; a small well scenario, a radiolysis scenario, and a naturally discharged scenario. The MASCOT-K and the AMBER, probabilistic safety assessment codes based on connection of sub-modules and a compartment theory respectively, are applied to assess annual individual doses for a generic biosphere. Results illustrate that for a given scenario, predictions from two different codes fairly match well each other But the discrepancies for the different scenarios are significant. However, total doses are still well below the guideline of 2 mRem/yr. Detailed analyses with model and data uncertainties are underway to further assure the safety of a Korean reference dispsoal concept.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
• /
• pp.123-128
• /
• 1999

Recently, as a performance based design concept is introduced, assurance of expected performances on serviceability and safety in the whole span of life is exactly requested. So, quantitative assessments about durability related properties of concrete in early-age long term are come to necessary, Especially in early age, deterioration which affects long-term durability performance can be occurred by hydration heat and shrinkage, so development of reasonable hydration heat model which can simulate early age behavior is necessary. The micor-pore structure formation property also affects shrinkage behavior in early age and carbonations and chloride ion penetration characteristic in long term, So, for the quantitative assessment on durability performance of concrete, modelings of early age concrete based on hydration process and micor-pore structure formation characteristics are important. In this paper, a micromechanics based hydration heat evolution model is adopted and a quantitative model which can simulate micro-pore structure development is also verified with experimental results. The models can be used effectively to simulate the early-age behavior of concrete composed of different mix proportions.

• Annals of Clinical Neurophysiology
• /
• 제9권2호
• /
• pp.51-58
• /
• 2007

Autoimmune myasthenia gravis (MG) is the neuromuscular junction disorder mostly caused by antibody against the acetylcholine receptor (AChR antibody) at the muscle endplate. The goal of treatment is to induce and maintain remission, i.e., absence of symptoms, with the least cost-to-benefit ratio. Although corticosteroids are effective in inducing remission in most patients, they have numerous potentially serious adverse effects with their long-term use. In addition, some patients do not respond or are intolerant to the conventional treatment. In this article, we discuss the difficulties encountered in long-term immunosuppressive treatment of MG, and review useful tips for the use of corticosteroids. Long-term immunosuppressive agents that can be used in steroid-refractory or -dependent patients will be reviewed with their safety profiles and efficacy in MG.

• 한국항공운항학회지
• /
• 제28권4호
• /
• pp.154-163
• /
• 2020

The pilot's aeronautical decision-making during the flying greatly affects flight safety, and the importance of situational awareness has been greatly emphasized as a prerequisite for making the right decision. This is the reason why more research and interests are needed to help students entering the pilot training program develop excellent situational awareness from the initial stage of training. Situational awareness is closely related to long-term memory activities in human information processing, and pedagogy and cognitive psychology have emphasized the encoding techniques as an effective long-term memory method. This study was conducted to confirm whether pilot students' using the encoding techniques to learn flight education materials in the early stage of their training at domestic universities has a positive effect on improving their situational awareness.

• Clinical and Experimental Pediatrics
• /
• 제53권7호
• /
• pp.741-744
• /
• 2010

Purpose: To evaluate the long-term safety of polyethylene glycol (PEG) 4000 in children with constipation, particularly the biochemical aspects of safety. Methods: Medical records were evaluated, and 100 children, who had been taking PEG 4000 for more than 6 months, and who had been under clinical and biochemical monitoring, were enrolled. Ages; $6.11{\pm}3.12$ years, Duration of therapy; $16.93{\pm}7.02$ months, dose of PEG 4000; $0.72{\pm}0.21g/kg/d$. Results: None of the children complained of clinical adverse effect. The first biochemical test was performed at 8.05 months after beginning of PEG 4000. Serum phosphate (SP) value was high in 10 children, and leucopenia was noted in one child. The second test was performed in 44 children at 7.57 months after the first test. The SP value was high in four children, including the three children whose initial SP value was high and one new child. Six out of 10 children with high initial SP value became normal and one was lost. Hypernatremia was noted in one child. The third test was done in 15 children at 7.5 months after the second test. The SP value of the new child from the second test was high, but became normal after finishing treatment. Two out of 3 children with high SP value at the second test became normal and one was lost. The fourth test was done in 2 children few months after the third test. All of the results were normal. There were no relation between duration of therapy and hyperphosphatemia, or between dose of PEG 4000 and hyperphosphatemia. Conclusions: PEG 4000 is safe for long-term therapy in children with constipation with respect to biochemical parameters.

• 디지털콘텐츠학회 논문지
• /
• 제16권1호
• /
• pp.43-51
• /
• 2015

국가재난안전통신망 구축사업 기술방식으로 공공안전 롱텀에볼루션(PS-LTE) 방식이 선정됐다. 이를 통해 2017년부터 경찰, 소방, 군 등 모든 재난안전 책임기관이 음성뿐 아니라 동영상 등 멀티미디어 정보를 활용해 구조활동을 벌일 수 있게 됐다. PS-LTE는 기존 LTE 기술에 그룹통화, 단말기 간 직접통신, 단독 기지국 기능 등이 추가된 방식이다. 지금까지 각 재난안전기관이 사용하던 통신기술은 음성만 전달할 수 있었다. PS-LTE 기술을 이용하면 멀티미디어 전송이 가능해진다. 본 논문에서는 해외 주요국에서 추진 중에 있는 광대역 공공안전통신정책 기술동향을 분석하고, 이를 통해 국내 광대역 공공안전통신 도입 시 고려해야 할 사항을 알아보았다.

• 보건행정학회지
• /
• 제19권4호
• /
• pp.78-97
• /
• 2009

This study examined the factors related to family caregiver satisfaction with institutional care services for beneficiaries under the Public Long-Term Care Insurance(PLTCI) system. Determining what contributes to family caregiver satisfaction is a critical step toward implementing effective quality improvement strategies. A national cross-sectional descriptive survey was conducted from November to December 2008, using proportionate quota sampling based on the location and level of Long-Term Care of the beneficiaries. Total 1,745 family caregivers wrote informed consents and 733 (response rate 42%) completed questionnaires, which included caregiver characteristics, organizational resources, primary objective and subjective stressors, perceived quality of services, and family caregiver satisfaction. Family caregivers were satisfied overall with institutional care. In multiple regression analysis, there was a statistically significant difference in degree of family caregiver satisfaction according to caregiver characteristics(relationship to beneficiary), primary objective stressors (insurance type of beneficiary), perceived quality of services(respect to family caregivers' idea, ADL support, expertness of staff, careful concern of staff, fulfillment of client's requests, and safety of institution's environment). In public long-term care, satisfaction efforts are in an early stage of development. This study is meaningful as the first attempt to measure family caregiver satisfaction with institutional care for beneficiaries under the PLTCI system, and to identify factors affecting the satisfaction. Among the identified factors, the policy makers, the insurer, and the providers need to pay attention to perceived quality of services, in particular, to improve customer satisfaction. Our findings can provide quality care improvement initiatives in the public long-term care setting.

• 한국지반환경공학회 논문집
• /
• 제24권11호
• /
• pp.19-24
• /
• 2023

그라운드 앵커 공법은 최근 깎기 비탈면과 교대 등의 보강을 목적으로 사용이 증가하고 있다. 그라운드 앵커는 구조물의 사용연한 이상의 내구성을 확보하여야 하지만 국내 고속도로에 시공된 대부분의 앵커에서 장기적인 긴장력 손실이 발생하여 안정성이 문제가 있는 것으로 나타났다. 본 연구에서는 실규모 모형실험을 통하여 긴장력 감소원인에 대한 분석을 수행하였다. 실험결과 물-결합재 비가 55%가 되는 시점부터 부착력의 감소현상이 나타났으며, 인장쐐기의 영향으로 강연선 파단강도의 14%의 감소현상이 나타났다. 지반강도, 앵커형식, 지하수의 유무에 따라 극한인발력이 차이를 보였으며, 특히 지하수의 유무는 그라우트의 강도 및 품질에 관여하여 앵커의 거동특성에 미치는 영향이 가장 높은 것으로 나타났다. 장기거동에서는 초기 정착이 안정되는 시점까지 급격하게 하중이 감소하다가 이후에는 일정하게 긴장력이 감소하는 것으로 나타났다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.1405-1405
• /
• 2011

Sudden earthquake is changing national energy stratagem for future energy resource. In case Germany, current nuke power station will be shut down with several decades. Newly constructed build in Japan must have photovoltaic system as a obligations.. As a long-term sustainable energy one, PV should give confidence to customers up to more than 20 years. Today, IEC 61215 and IEC 61646 standards are representative one for ensuring performance and safety of PV module. But it is still needed to develop more realistic test method. For example, if we think about extreme condition like desert and North Pole, the temperature condition describe in test standards can have little effect on life time expectation of PV module. Installation speed of PV system is very high, but establishing test standards are very complex and not easy. So in this paper, I tried to open the long-term test method for PV module to ensure 25 year's old life time. It is just starting point of PV related long-term test methods. The specific and technical explanation will be shown in the following paper in detail.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 춘계 학술발표회 논문집
• /
• pp.561-568
• /
• 2005

The factors affecting the long-term design strength of geogrid can be classified into factors on creep deformation, installation damage, temperature, chemical degradation and biological degradation. Especially, creep deformation and installation damage are considered as main factors to determine the long-term design strength of geogrid. Current practice in the design of reinforced soil is to calculate the long-term design strength of a reinforcement damaged during installation by multiplying the two partial safety factors, $RF_{ID} and RF_{CR}$. This method assumes that there is no synergy effect between installation damage and creep deformation of geogrids. Therefore, this paper describes the results of a series of experimental study, which are carried out to assess the combined effect of installation damage and creep deformation for the long-term design strength of geogrid reinforcement. The results of this study show that the tensile strength reduction factors, RF, considering combined effect between installation damage and creep deformation is less than that calculated by the current design method.