• 공업화학
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• 제16권3호
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• pp.372-378
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• 2005

탄산칼슘 포화지수(LI: Langelier Index)는 탄산칼슘의 포화정도로서 수돗물의 부식성을 나타내며 수도관 부식방지를 위해 미국, 유럽, 일본 등은 수도법에 의해 관리되고 있지만 국내는 아직 도입되지 않았다. 본 연구는 LI의 국내 도입 타당성을 검토하기 위해 LI인자(5개항목: 수온, pH, 총알칼리도, 칼슘이온, 전기전도도)들을 측정하고 LI값을 산출하였다. 수온은 연간 $2.0{\sim}26^{\circ}C$, 연평균 $23.9^{\circ}C$로 나타났다. 총알칼리도는 30 mg/L (as $CaCO_3$)로 나타났으며, 총알칼리도를 $HCO_3{^-}$ 농도 값으로 대체가능성을 검토한 결과 농도 차가 거의 없는 것으로 나타났다. LI값은 2.0~-0.5로 나타나 부식성을 가지고 있는 것으로 나타났으며, 수돗물 부식성을 감소시키기 위해 정수장에서 $Ca(OH)_2$, $CaCO_3$, NaOH, $NaHCO_3$ 등을 투입할 필요가 있는 것으로 나타났다.

• Geomechanics and Engineering
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• 제8권1호
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• pp.81-95
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• 2015

The permeability behavior of Ariake clays has been investigated by constant rate of strain (CRS) consolidation tests with vertical or radial drainage. Three types of Ariake clays, namely undisturbed Ariake clay samples from the Saga plain, Japan (aged Ariake clay), clay deposit in shallow seabed of the Ariake Sea (young Ariake clay) and reconstituted Ariake clay samples using the soil sampled from the Saga plain, were tested. The test results indicate that the deduced permeability in the horizontal direction ($k_h$) is generally larger than that in the vertical direction ($k_v$). Under odometer condition, the permeability ratio ($k_h/k_v$) increases with the vertical strain. It is also found that the development of the permeability anisotropy is influenced by the inter-particle bonds and clay content of the sample. The aged Ariake clay has stronger initial inter-particle bonds than the young and reconstituted Ariake clays, resulting in slower increase of $k_h/k_v$ with the vertical strain. The young Ariake clay has higher clay content than the reconstituted Ariake clay, resulting in higher values of $k_h/k_v$. The microstructure of the samples before and after the consolidation test has been examined qualitatively by scanning electron microscopy (SEM) image and semi-quantitatively by mercury intrusion porosimetry (MIP) tests. The SEM images indicate that there are more cut edges of platy clay particles on a vertical plane (with respect to the deposition direction) and there are more faces of platy clay particles on a horizontal plane. This tendency increases with the increase of one-dimensional (1D) deformation. MIP test results show that using a sample with a larger vertical surface area has a larger cumulative intruded pore volume, i.e., mercury can be intruded into the sample more easily from the horizontal direction (vertical plane) under the same pressure. Therefore, the permeability anisotropy of Ariake clays is the result of the anisotropic microstructure of the clay samples.

• 한국산학기술학회논문지
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• 제21권8호
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• pp.572-578
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• 2020

주식 시장은 기업 실적 및 경기 상황뿐만 아니라 정치, 사회, 자연재해 등 예기치 못한 요소들에 영향을 받는다. 이런 요소들을 고려한 정확한 예측을 위해서 다양한 기법들이 사용된다. 최근 인공지능 기술이 화두가 되면서 이를 활용한 주가 예측 시도 또한 이루어지고 있다. 본 논문은 단순히 주식 관련 데이터뿐만 아닌, 거시 경제적 지표 등을 활용한 여러 종류의 데이터를 이용하여 주가에 영향을 미치는 요소에 관한 연구를 제안한다. KOSDAQ을 대상으로 1년 치 종가, 외국인 비율, 금리, 환율 데이터를 다양하게 조합한 후에 딥러닝의 Nonlinear AutoRegressive with eXternal input (NARX) 모델을 활용한다. 이 모델을 통해 1달 치 데이터를 생성하고 각 데이터 조합을 통해 만들어진 예측값을 RMSE를 통해 실제값과 비교, 분석한다. 또한, 은닉층에서 뉴런의 수, 지연 시간을 다양하게 설정하여 RMSE를 비교한다. 분석 결과 뉴런은 10개, 지연 시간은 2로 설정하고, 데이터는 미국, 중국, 유럽, 일본 환율의 조합을 사용할 때 RMSE 0.08을 보이며 가장 낮은 오차를 기록하였다. 본 연구는 환율이 주식에 가장 영향을 많이 미친다는 점과 종가 데이터만 사용했을 때의 RMSE 값인 0.589에서 오차를 낮췄다는 점에 의의가 있다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권5호
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• pp.407-416
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• 2008

Purpose: The aim of the present study is to evaluate the effect of repetitive distraction and compression on new bone formation during distraction period. Materials and methods: Sixteen healthy rabbits, weighing about 2.5kg, were used in this experiment. A unilateral mandibular osteotomy was performed in the left mandible and the distractor(Track 1 $plus^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany) was fixed with four screws (Cross driver screw $TI^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany). After 4 days, the mandibles were distracted at a rate of 0.6mm/day for 10 days to obtain the amount of 6mm distraction in the control group(n=4). In the experimental group A(n=6), they were distracted at a rate of 1.2mm/day for 5 days and then compression of 0.6mm length and distraction of 0.6mm per 12 hours were carried out as counter direction for 5 days, relatively. In the experimental group B(n=6), distraction of 1.2mm length and compression of 0.6mm length per 12 hours were repeated for 10 days to obtain the amount of 6mm distraction finally. The experimental animals were sacrificed at 2 and 4 weeks after surgery and block specimens were obtained. With histologic and histomorphometric analysis, we observed the histologic changes of the cells and bone formation after H-E and Masson- Trichrome staining and then, measured Bone Deposition Rate with TOMORO $ScopeEye^{TM}$ ver. 3.5(Olympus, Japan), Results: Histologically, new bone formation was examined in all experimental groups and the control. But, the ability of bone formation of the experimental group A was somewhat better than any other groups. On the histomorphometric analysis, Bone Deposition Rate was higher in the experimental group A$(50.67{\pm}4.36%)$ than in the control group$(45.94{\pm}3.97%)$ and in the experimental group B$(42.68{\pm}5.70%)$. These data showed significant differences statistically(p<0.05). Conclusion: These results show that the distraction osteogenesis using repetitive compression and distraction force in the early consolidation period may be effective for new bone formation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권6호
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• pp.557-564
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• 2000

The bone graft materials can be grossly divided into autogenous bone, allogenic bone, xenogenic bone, and alloplastic material. Much care was given to other bone graft materials away from autogenous bone due to its additional operation for harvesting, delayed resorption and limitation of quantity. Demineralized freeze-dried bone(DFDB) and hydroxyapatite are the representatives of bone graft materials. As resorbable hydroxyapatite is developed in these days, the disadvantage of nonresorbability can be overcome. So we planned to study on the strength and the bone formation at the rats calvarial defects of DFDB graft and those of the composite graft with DFDB and resorbable hydroxyapatite. We used the 16 male rats weighting range from 250 to 300 gram bred under the same environment during same period. After we made the 6mm diameter calvarial defect, we filled the DFDB in 8 rats and DFDB and resorbable hydroxyapatite in another 8 rats. We sacrificed them at the postoperative 1 month and 2 months with the periostium observed. As soon as the specimens were delivered, we measured the compressive forces to break the normal calvarial area and the newly formed bone in calvarial defect area using Instron(Model Autograph $S-2000^{(R)}$, Shimadzu, Japan). The rest of the specimens were stained with H&E(Hematoxylin & Eosin) and evaluated with the light microscope. So we got the following results. 1. In every rats, there was no significant difference between the measured forces of normal bone area and those of the bone graft area. 2. In 1 month, the measured forces at DFDB graft group were higher than those of the DFDB and resorbable hydroxyapatite composite graft group(P<0.05). 3. In 2 months, there was no significant differences between the measured forces of DFDB graft group and those of the DFDB and resorbable hydroxyapatite composite graft group. 4. In lightmicroscopic examination, most of the grafted DFDB were transformed into bone in 1 month and a large numbers of hydroxyapatite crystal were observed in DFDB and resorbable hydroxyapatite composite graft group in 1 month. 5. Both group showed no inflammatory reaction in 1 month. And hydroxyapatite crystals had a tight junction without soft tissue invagination when consolidated with newly formed bone. 6. In both groups, newly formed bone showed the partial bone remodeling and the lamellar bone structures and some of reversal lines were observed in 2 months. From the above results, it is suggested that DFDB and resorbable hydroxyapatite composite graft group had a better resistance to compressive force in early stage than DFDB graft group, but there would be no significant difference between two groups after some period. And it is suggested that the early stage of bone formation procedure of DFDB and resorbable hydroxyapatite composite graft group was slight slower than that of DFDB graft group, but there would be no significant difference between two groups after some period.

• 농촌의학ㆍ지역보건
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• 제5권1호
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• pp.16-27
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• 1980

Five hundred seventeen farmers(214 males and 303 females), over age 30 and living in Suh San County, Unsan township, were examined to determine the prevalence of peasants syndrome. Using the health interview questionnaire, the farmers were asked whether they had any of eight subjective symptoms during the past one month before the survey, October 1979. Those symptoms reported were scored based on a pre-determined point system. The farmers with high symptom scores(7 points or more) were further examined by the liver function test. In addition, all the sample(517 cases) were subjected to the examination of urinalysis and blood pressure. The liver function test is also undertaken for those farmers with high symptome scores(7 points or more) and those with abnormal findings in urinalysis and blood pressure. The results are summarized below: 1) 156 out of 517 farmers(30.2%) have had seven points or more of the symptom scores. Among the eight major symptoms, 72% of the farmers complained of lumbago. 2) The prevalence of peasant's syndrome were higher among females and the older age group. The symptom scores of this syndrome were slightly higher among women who have had many children (e. g. 4 or more). 3) The prevalence of peasant's syndrome was also related to the level of one's education-the lower education groups were found to have higher symptom scores of this syndrome. This may be due to the fact that the lower education groups are more exposed to manual labor. 4) The points of the peasants syndrome were higher in hypertensive farmers and those with abnormal findings of urinaly sis. 5) It was reported, in Japan, that those with high scores of the syndrome are more likely to have an abnormal findings in the liver function test. However, in this study it was observed that there was no significant difference between those with high scores of the syndrome (7 points or more) and those with low score of the syndrome(6 points or less) in the prevalence of abnormal liver function. As this study indicates that the point system given for the peasant's syndrome is closely related to the high bleod pressure and abnormal urinalysis(and to some extent to the abnormal liver function), there is a need to study peasant's syndrome more extensively. Such an effort will serve to detect varonic disease conditions among farmer's towards better management of farmer's health, which is vitally important for rural development in Korea.

• 한국항만경제학회지
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• 제26권3호
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• pp.143-164
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• 2010

동아시아 경제의 빠른 성장에도 불구하고 일본의 대형 국제항만에서는 화물증가가 둔화되었고, 국제경쟁력 약화로 인하여 기간항로에서 제외되며 일본 국내 화주의 물류불안을 야기해왔다. 이 문제를 극복하기 위해 2004년 이후 '슈퍼중추항만정책'이 실시되었다. 이 정책은 국제항만의 고규격 터미널을 민간기업에 의탁하여 효율적으로 관리, 운영되도록 다양한 정책적 지원을 제공하며, 국제항만의 코스트 절감과 서비스 향상을 달성하겠다는 취지를 가지고 있다. 다양한 법적, 제도적 지원 시책에도 불구하고 슈퍼중추항만정책은 기대했던 정책성과를 달성했다고 보기는 어려운 상황이다. 코스트 경쟁력을 달성하지 못하였뿐 아니라, 화물량 증가 및 환적화물 유치, 기간항로 서비스 유지 측면에서 정책기간 중 소기의 성과를 달성하지 못하였다. 그것은 고규격 터미널의 지정 민간기업의 운영능력, 슈퍼중추항만내의 복수항만의 연계적 효율성, 항만의 집하능력 구축에서 한계점을 가지고 있었기 때문이다. 이에 따라 2010년에는 슈퍼중추항만정책의 후속 정책인 '국제컨테이너 전략항만정책'이 등장하였고, 일본은 국제 거점항만 육성을 위한 마지막 기회를 준비하고 있다. 특히 새로운 정책에서는 부산항 경유 환적화물의 탈환을 명시적으로 내세우고 있어 향후 부산항과 일본의 국제컨테이너 전략항만 간의 화물유치 경쟁이 예상된다.

• 한국지진공학회논문집
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• 제3권1호
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• pp.113-122
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• 1999

일본 고베지진후 구조물 수직방향 내진거동의 중요성은 잘 인식되었으나 대부분의 내진설계규준에서는 지반조건을 규정하지 않아 수직방향 구조물 내진해석시 대개 토질과 기초조건을 무시하고 수행하였다 이 논문에서는 연약지반이 Taft 지진과 El Centro 지진의 수직방향 지진하중을 받는 구조물의 수직방향 반응에 미치는 영향을 알아보기 위해 기초크기, 기초 및 지반깊이 , 기초근입깊이 및 말뚝기초가 수직방향 내진반응스펙트럼에 미치는 영향에 대해 연구하였는데 지반은 UBC-97에서 분류한 Sa. Sc. SE를 기초크기는 중 대형 기초를. 기초 및 지반깊이는 30m 와 60m를 기초근입깊이를 0m와 15m를 고려하였으며 연약지반에 설치한 말뚝은 기성제 콘크리트 선단지지말뚝을 고려하였다 연구결과에 의하면 기초크기는 구조물의 수직방향 내진반응에 별 영향이 없지만 지반깊이는 수평방향 내진해석에서처럼 기초 및 60m까지 고려해야 하며 연약지반위에 설치된 묻힌기초와 얕은 말뚝기초는 구조물의 수직방향 내진거동을 크기 증폭시켰다.

• 생명과학회지
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• 제19권9호
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• pp.1245-1250
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• 2009

패모는 한국, 일본, 중국 지역에 분포하는 백합과 인경식물로 오래전부터 진해, 거담제 및 편도염, 기관지염에 이용되어 왔다. 그러나, 오랫동안 진행되어 온 기내배양, 휴면타파, 성분분석에 대한 연구와 달리 생리활성에 대한 연구는 거의 없는 실정이다. 본 연구에서는 패모로부터 메탄올 추출물을 조제하고, 이로부터 다양한 유기용매 분획물을 조제하여 이들의 항균, 항혈전 및 항산화 활성을 평가하였다. 패모의 메탄을 추출물은 다량의 수용성 당을 포함하고 있으며(물 잔류물 58.98%), 지용성 오일도 상당량 포함하였다(헥산 분획물 14.85%). 항균활성의 경우, 에틸아세테이트 및 부탄올 분획물 $500{\mu}g$/disc에서 E. coli를 제외한 실험세균 모두에서 우수한 항세균 활성이 나타났으며, 항진균 활성은 모든 시료에서 나타나지 않았다. 항혈전 활성은 메탄올 추출물에서 우수하였으며, 헥산, 에틸아세테 이트 및 부탄올 분획물은 2.4 mg/ml 농도에서 모두 300초 이상의 연장된 트름빈 타임을 나타내었고, 특히 에틸아세테이트 분획은 1.2 mg/ml 농도에서 95.4초를 나타내어 항혈전제인 아스피린 활성과 유사하였다. 메탄올 추출물 및 분획물의 항산화 활성 평가 결과, 에틸아세테이트 분획 및 부탄올 분획이 368.2 및 $344.0{\mu}g$/ml의 $IC_{50}$를 나타내어 우수한 DPPH 소거능을 나타내었으며, SOD 유사활성은 $55{\sim}63%$로, vitamin C의 20-25%, 환원력의 경우 BHT의 51-54%를 나타내어 우수한 항산화 활성을 가짐을 확인하였다.

• 한국환경복원기술학회지
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• 제16권1호
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• pp.55-69
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• 2013

The phytosocialogical study on the coastal sand dune vegetation of the East Coast was carried out. 180 phytosociological relev$\acute{e}$s of 62 sites in the East Coast were used in this study. In addition, already published syntaxa and the phytosociological hierarchy in Korea and Japan were used and comparative analyses of syntaxonomy, synecology, syngeography, and syndynamics were performed in the study. In this study, the flora was investigated 30 families, 66 genera, 77 taxa and 3 vegetation types were identified : the coastal drift-line annual communities (Calystegio soldanellae-Salsoletum komarovii), the dune glasslands communities (Elymo-Caricetum kobomugi, Carex kobomugi typical community, Elymus mollis community, Calystegia soldanella community, Zoysia macrostachya community, Cynodon dactylon community, Carex pumila community), and the dune shrubs communities (Linario-Viticetum rotundifoliae, Vitex rotundifolia community, Rosa rugosa community). The aspect of transition in the coastal sand dune vegetation of the East Coast were identified as follows : (1) reduced constancy degree and cover degree of Glehnia littoralis in each community; (2) lack of Ischaemum anthephoroides in Linario-Viticetum rotundifoliae (3) simplified species composition in Vitex rotundifolia community. Unstable habitat condition by external interference seemed to has caused the reduction of 2 taxa, Glehnia littoralis and Ischaemum anthephoroides, that usually grow in the second dune. In addition, we found changes in the distribution of the dune shrub communities influenced by rising temperature of the East Coast as results of the global warming. The results on the distribution of the dune shrub communities in this study demonstrated that the limit of the Rosa rugosa community made $0^{\circ}$ 44'N to the North and the vegetative limit of the Vitex rotundifolia community made $0^{\circ}$ 28'N to the North, respectively compared with the previously phytosociological studies. This study investigated the coastal sand dune vegetation, syntaxonomy, habitat condition and human disturbunce of the East Coast, and this will provide important information as basic data for the coastal ecosystem.