• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2101-2108
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• 2008

Most of train fires which occur in usual cases do not grow up significantly on a large scale enough to bring about casualties and harmful damages. However, the consequence of some train fire accidents can be devastating disaster so that it would be even recorded in history in unusual cases. Accordingly, such a probability of fire disaster cannot be ignored in aspect of the railway safety assesment. A scale of injury and damage is very difficult to predict and analyze. Because it is depend on various factors, i.e. fire load, burning period, facilities, environment condition, and so on. Thus, a prediction of fire load could be understood as a one methodology to estimate railway safety assesment. The summation method which is one of them is used to evaluate the overall fire load by assuming that sum of heat release rate per unit area or mass of each composite material equals the total. However, since the train fire is classified into a compartment fire in under-ventilation condition. The summation method do not estimate a fire load completely. In this journal, Various methods to predict fire load are introduced and evaluated. Especially the fire simulation tool FDS(Fire Dynamics Simulator)which is based on the CFD(Computational Fluid Dynamics) is introduced, too. Through the FDS simulation, numerical analyses for the fire load and flame spread are performed. Then, these results of the simulation are validated through the comparison study with the experimental data. Then, limitations and approximations including in simulation process are discussed. The future direction of research is proposed.

• 동아시아식생활학회지
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• 제15권4호
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• pp.483-492
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• 2005

The propose of this study was to investigate the status of current nutrition labeling on the packaging of processed foods. The 2432 processed foods purchased at various retail markets in Jeonju and Daegu during June, 2004, were classified by food category according to the 2004 Food Codes and evaluated for the type of nutrition composition labeling and nutritional content claims. The results are summarized as follows: The percentage of processed food products with nutrition labeling was $27.5\%$ and $71.6\%$ of noodles had nutrition composition labeling, which was the largest number among the food category. Various unit of measurements were used in the nutrition labeling of the processed foods, per 100g or 100ml being the most common($51.8\%$) under the currently practiced nutrition labeling. Nutrition claims were made for $9.5\%$ (231 items) of the products. Drinks bad the largest number of nutrition claims of $27.3\%$ The most frequently used technology was 'contained' among the claims ($36.0\%$) and 'added' was the next ($30.7\%$). 'High in calcium' or the equivalent was the most popular nutritional claim Other nutrients for which content claims were made included: lipid, vitamin C, DHA, camitine, taurine etc.

• 청정기술
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• 제8권2호
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• pp.61-66
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• 2002

알루미늄 제조 공정에서 부산물로 발생되는 적니와 제지슬러지를 이용하여 휘발성 유기화합물을 제거하기 위한 흡착제 개발 연구를 수행하였다. 흡착제의 제조를 용이하게 하기 위해 고밀도폴리에틸렌과 저밀도폴리에틸렌을 이용하였다. 흡착제에 고밀도폴리에틸렌을 사용한 것이 저밀도폴리에틸렌을 사용한 것 보다 비표면적 값이 높아서 흡착량이 증대되었다. 제조된 흡착제의 비표면적 값이 활성탄과 비교하여 상대적으로 매우 낮은 값 ($10^{-2}$에서 $10^{-3}$ 정도)을 가졌는데 이는 흡착제 제조시 제지슬러지를 완전히 분해하는데 충분한 시간을 주지 못하였기 때문으로 생각된다. 그러나 제조된 흡착제의 흡착용량(단위 표면적당 흡착량)은 활성탄에 비하여 약 10배에서 100배 정도의 높은 값을 가졌다. 그러므로 제조된 흡착제가 활성탄과 같은 성능을 갖기 위해서는 비표면적을 증대시키는 것이 중요하다.

• Fisheries and Aquatic Sciences
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• 제21권1호
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• pp.1.1-1.12
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• 2018

Pacific bluefin tuna (Thunnus orientalis) is one of the commercially important species in Korea as well as other countries of the North Pacific. Korean offshore large purse seine fisheries targeting small pelagic fishes such as chub mackerel have caught T. orientalis temporarily in the east of Jeju Island. The catch of T. orientalis in March through June occupied approximately 60% of the total. The monthly catch around Jeju Island from 2004 to 2013 showed a negative correlation (r = - 0.755, p < 0.01) with the seawater temperature at 50 m and had a significant positive correlation (r = 0.856, p < 0.01) with the Pacific Decadal Oscillation Index (PDOI). The highest catch and catch per unit effort (CPUE) of T. orientalis around Jeju Island occurred either when the seawater temperature ranged between 15 and $16^{\circ}C$ at 50 m or when the catch was taken near the frontal area where two water masses from offshore and coastal areas collide. The length of T. orientalis caught around Jeju Island from 2004 to 2013 ranged from 19 to 193 cm in fork length (FL). The time series of the monthly mean FL of T. orientalis had a negative correlation (r = - 0.592, p < 0.01) with the seawater temperature at 50 m and had a significant positive correlation (r = 0.668, p < 0.05) with PDOI.

• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.41-59
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• 1991

This study was performed to elucidate the distribution and correlation of immunoglobulin G subclasses with the degree of inflammation in the experimentally induced rat pulp and periapical pathoses. The pulp exposures were made in 108 mandibular 1st molars of 54 rats and the teeth were left open to the oral environment The animals were sacrified at 3, 7, 15, 30, 60 and 90 days after pulp exposure, and examined microscopically and radiographically Seventy one specimens were routinely sectioned at the thickness of 4 - $6{\mu}$ and stained with Hematoxylin - eosin for histologic examination, with toluidine blue for mast cells, and with the primary antibodies against rat IgG subclasses by using the Avidin - Biotin complex method. The following results were obtained: 1. As the degree of inflammation of rat pulp and periapeces intensified, the number of IgG subclass containing cells per unit area, especially IgG2a and IgG2c, decresased. 2. The IgG2c cells were most predominantly found in the lesions with slight inflammation, IgG1 cells in mild or severe inflammation, and IgG2a cells in moderate inflammation. 3. IgG subclass containg cells were more predominantly observed in the periapical granuloma than periapical abscess or cyst(p<0.01). 4. IgG2a containing cells were predominant in pulp inflammation, IgG1 containing cells in periapical granuloma, IgG2a cells and IgG1 cells in periapical abscess, and IgG2a cells were significantly predominant in periapical cyst. 5. The number of IgG subclass containing cells and mast cells in periapical tissue decreased with time lapse after pulp exposure. And correlation index between mast cells and IgG1, IgG2a, IgG2b was stastically high.

• 대한화학회지
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• 제37권10호
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• pp.855-860
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• 1993

SDS(sodium dodecyl sulfate) 존재하에서 NP-40EO[nonylphenol-(ethylene oxide)40]와 요오드와의 상호작용에 따른 $Ca^{2+}$의 영향을 UV-visible spectrophotometer를 이용하여 수용액 중에서 조사하였다. SDS 부재시보다 상호작용 피크의 흡광도는 줄어들었으며, CMC 이상에서 $Ca^{2+}$ 첨가에 따른 상호작용 피크의 강도는 크게 증가하였다. 상호작용 피크의 감소는 SDS 삽입에 따른 혼합미셀 단위 표면적당 요오드와 상호작용할 수 있는 EO 수의 감소에 기인하며, 상호작용 피크 강도의 증가는 $Ca^{2+}$ 존재하에서 미셀 구조가 더욱 조밀해진데 따른 전자주게-받게 겹침 증가로 불 수 있다. 이러한 현상들은 수용액 중에서 상대적으로 자유로운 배향을 갖는 선형 EO 사슬이 유사 크라운 에테르 구조를 형성하여 $Ca^{2+}$ 이온과 착물을 형성할 수 있는 가능성을 보여준다.

• Journal of Ecology and Environment
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• 제43권4호
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• pp.400-420
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• 2019

The aims of the study were to analyze (1) the effects of Prosopis juliflora (Prosopis) on the spatial distribution and soil seed banks (SSB) diversity and density, (2) the effects of environmental factors on SSB diversity and density (number of seeds in the soil per unit area), and (3) the effects of animal fecal droppings on SSB diversity, density, and dispersal. Aboveground vegetation data were collected from different Prosopis-infested habitats from quadrats (20 × 20 m) in Prosopis thickets, Prosopis + native species stand, non-invaded woodlands, and open grazing lands. In each Prosopis-infested habitats, soil samples were collected from the litter layer and three successive soil layer, i.e., 0-3 cm, 3-6 cm, and 6-9 cm. Seeds from soil samples and animal fecal matter were separated in the green house using the seedling emergence technique. Invasion of Prosopis had significant effects on the soil seed bank diversity. Results revealed that the mean value of the Shannon diversity of non-invaded woodlands was being higher by 19.2%, 18.5%, and 11.0% than Prosopis thickets; Prosopis + native species stand and open grazing lands, respectively. The seed diversity and richness, recovered from 6-9-cm-deep layer were the highest. On the other hand, the density of Prosopis seeds was the highest in the litter layer. About 156 of seeds/kg (92.9%) of seeds were germinated from cattle fecal matter. However, in a small proportion of seedlings, 12 of seeds/kg (7.1%) were germinated from shot fecal matter. Thus, as the seeds in the soil were low in the study areas, in situ and ex situ conservation of original plants and reseeding of persistent grass species such as Cynodon dactylon, Cenchrus ciliaris, Chrysopogon plumulosus, and Brachiaria ramosa are recommended.

• 대한치과교정학회지
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• 제46권3호
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• pp.155-162
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• 2016

Objective: The aim of this study was to investigate whether labial tooth inclination and alveolar bone loss affect the moment per unit of force ($M_t/F$) in controlled tipping and consequent stresses on the periodontal ligament (PDL). Methods: Three-dimensional models (n = 20) of maxillary central incisors were created with different labial inclinations ($5^{\circ}$, $10^{\circ}$, $15^{\circ}$, and $20^{\circ}$) and different amounts of alveolar bone loss (0, 2, 4, and 6 mm). The $M_t/F$ necessary for controlled tipping ($M_t/F_{cont}$) and the principal stresses on the PDL were calculated for each model separately in a finite element analysis. Results: As labial inclination increased, $M_t/F_{cont}$ and the length of the moment arm decreased. In contrast, increased alveolar bone loss caused increases in $M_t/F_{cont}$ and the length of the moment arm. When $M_t/F$ was near $M_t/F_{cont}$, increases in Mt/F caused compressive stresses to move from a predominantly labial apical region to a palatal apical position, and tensile stresses in the labial area moved from a cervical position to a mid-root position. Although controlled tipping was applied to the incisors, increases in alveolar bone loss and labial tooth inclination caused increases in maximum compressive and tensile stresses at the root apices. Conclusions: Increases in alveolar bone loss and labial tooth inclination caused increases in stresses that might cause root resorption at the root apex, despite the application of controlled tipping to the incisors.

• 한국산림과학회지
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• 제77권3호
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• pp.283-293
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• 1988

산공재(散孔材)인 왕버들(Salix glandulosa Seemenn)과 환공재(環孔材)인 굴참나무(Quercus variabilis BI.)의 뿌리, 줄기 및 가지에 있어서 2기(二期) 목부조직(木部組織)을 해부학적(解剖學的)으로 비교관찰(比較觀察)하였다. 굴참나무의 뿌리의 도관분포(導管分布)는 줄기와 달리 산공형(散孔型)이다. 뿌리의 연륜(年輪) 경계(境界)는 양(兩) 수종(樹種)에서 대체(大體)로 불분명(不分明)하다. 도관요소(導管要素) 및 대섬유(大纖維)는 뿌리에서 제일 길고, 가지에서 가장 짧다. 또한 도관(導管)의 직경(直徑)은 뿌리, 줄기, 가지의 순(順)으로 좁아진다. 횡단면상(橫斷面上)에서 도관(導管)의 단위면적당(單位面積當) 분포수(分布數)는 가지에서 제일 많고 뿌리에서 가장 적다. 도관요소(導管要素)의 천공(穿孔)은 두 수종(樹種) 모두 단천공(單穿孔)이고, 천공판(穿孔板)의 경사각(傾斜角)은 뿌리, 줄기, 가지의 순(順)으로 작아진다. 접선단면상(接線斷面上)에서 방사조직(放射組織)은 뿌리가 줄기나 가지에 비(比)해 높은 반면(反面), 단위면적당(單位面積當) 분포수(分布數)는 뿌리에서 줄기나 가지에 비(比)해 적다.

• 한국안전학회지
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• 제33권4호
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• pp.90-97
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• 2018

As the result(also after it's been carried out the damping force test with 800ea lateral dampers of 50ea trainset from entering heavy maintenance workshop to implement heavy maintenance inspection cycle, there were 86.25%(650ea) which were out of $350kg{\pm}15%$ of the standard value of damping force compared to the reference value. After the implementation of heavy maintenance inspection cycle, it's been examined damping force test with total samples 32ea(samples 8ea per a trainset) from actual running EMU 4ea trainset. As the result, percent defective was 84.4%(27ea), which was a very high level. System. The lateral damper's the failure cause of damping force defective was oil leakage caused by tearing crack of oil seal and foreign material in oil iron 473 ~ 1932 times higher than that of new oil, copper 36 ~ 98 times higher than that of new oil reduced oil amount cycling damping valve. It resulted from the change cause of damping force. In the static analysis on the shape of lateral damper oil seal's the existing and improved product, the stress of the improved product was smaller than that of the existing product. In the fatigue analysis, the existing product showed a low life in the upper area. However, in case of the improved product, it could be confirmed that the destruction did not occur up to the specified 1.0e + 006 cycles and the lifetime was further improved in most areas.