• 한국연소학회:학술대회논문집
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• 한국연소학회 2007년도 제34회 KOSCO SYMPOSIUM 논문집
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• pp.133-138
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• 2007

Influence of changing combustor pressure on flame stabilization and emission index in the swirl-stabilized flame was investigated The combustor pressure was controlled by suction fan at combustor exit. Pressure index ($P^{\ast}=P_{abs}/P_{atm}$), where $P_{abs}$ and $P_{atm}$ indicated the absolute pressure and atmosphere pressure, respectively, was controlled in the range of $0.7{\sim}1.3$ for each equivalence ratio conditions. The flammable limits of swirl flames were largely influenced by changing combustor pressure and they showed similar tendency with laminar flames. $NO_x$ emission index decreased with decreasing pressure index for overall equivalence ratio conditions. R.m.s. of pressure fluctuations is increased with decreasing combustor pressure. This flame fluctuation caused incomplete combustion , hence CO emission index increased. These oscillating flames were measured by simultaneous $CH{\ast}$ chemiluminescence time-series visualization and pressure fluctuation measurement.

• 정보과학회 논문지
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• 제44권2호
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• pp.208-212
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• 2017

플래시 SSD는 기존 하드디스크에 비해 높은 에너지 효율성, 외부 충격에 강한 내구성, 높은 입출력 처리량 등 여러 장점을 지니고 있다. 따라서 3D-NAND 및 V-NAND 등 단위 용량 당 비용을 획기적으로 개선하는 최신 기술의 등장과 맞물려서, 플래시 SSD가 많은 영역에서 하드디스크를 급격하게 대체하고 있다. 하지만, 주로 하드디스크를 가정하고 개발된 기존 데이터베이스 엔진은 플래시 SSD의 특성 (예를 들어, 내부 병렬성)을 제대로 활용하지 못하고 있다. 본 논문에서는, 더 빠른 질의 처리를 위해 플래시 SSD에 내재한 내부 병렬성을 활용하는 방법으로, MySQL InnoDB엔진에서 보조 인덱스(Secondary Index)를 이용한 스캔을 위해 비 동기적 입출력을 활용한 Prefetch 기능을 구현하였다. Prefetching을 사용한 스캔 기법은, 기존 InnoDB엔진의 보조 인덱스 스캔과 비교해서, 데이터 페이지 크기가 16KB일 경우, 약 3배 이상, 데이터 페이지 크기가 4KB일 경우, 약 4.2배 이상 성능 향상을 보인다.

• 한방안이비인후피부과학회지
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• 제24권3호
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• pp.84-107
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• 2011

Purposes : The purpose of present study is to detect the effects of ointment contained Takrisodok-Eum on the skin barrier's recovery of the Atopic dermatitis. Methods : A total of 44 patients who visited Semyung Oriental Medical Center from April 27th, 2011 to September 20th, 2011 were included in the study. In this study, the patients were treated with Takrisodok-Eum (experimental group) and positive control group. For 8 weeks of gross examination, hematological examination and instrumental asessment were made before and after the study to examine how well the products for experimental group with those for control group in recovering the damaged skin barriers by Atopic dermatitis. Results : 1. In the primary endpoint, SCORAD Index showed a statistically significant decline in experimental group. 2. In the secondary endpoint index of skin hydration, both the experimental group and the control group showed statistical significance. 3. In the secondary endpoint index of TEWL, the experimental group showed greater statistical significance than the control group. 4. In the secondary endpoint index of skin pH, skin pH showed a statistically significant decline in both the control group and the experimental group within the normal range. 5. In the secondary endpoint index of Total IgE, Eosinophil count, IL-10, IL-13, both the experimental group and the control group showed no statistical significance. 6. To evaluate the safety of the products for the human body, hematological examination and hematological biochemical examination, vital sign check were conducted; both control group and experimental group showed no abnormal level. And There were no severe adverse events during this study. Therefore, it is suggested that the safety of the products, if used for certain period, should be safe for the human body. Conclusions : According to the above experiments, it is suggested that Takrisodok-Eum should be effective for the Atopic dermatitis.

• Geomechanics and Engineering
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• 제16권2호
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• pp.125-140
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• 2018

Tianjin, which is located on the west shore of the Bohai Sea, is part of China's Circum-Bohai-Sea Region, where very weak clay is deposited. From the 1970s to the early $21^{st}$ century, Tianjin marine clay deposits have been the subject of numerous geotechnical investigations. Because of these deposits' geological complexity, great depositional thickness, high water content, large void ratio, excessive settlement, and low shear strength, the geotechnical properties of Tianjin marine clay need to be summarized and evaluated based on various in situ and laboratory tests so that Tianjin can safely and economically sustain more infrastructure in the coming decades. In this study, the properties of Tianjin marine clay, especially its consolidation properties, are summarized, evaluated and discussed. The focus is on establishing correlations between the geotechnical property indexes and mechanical parameters of Tianjin marine clay. These correlations include the correlations between the water content and the void ratio, the depth and the undrained shear strength, the liquid limit and the compression index, the tip resistance and the constrained modulus, the plasticity index and the ratio of undrained shear strength and the preconsolidation pressure. In addition, the primary consolidation properties of Tianjin marine clay, such as the intrinsic compression line (ICL), sedimentation compression line (SCL), compression index, $C_c$, coefficient of consolidation, $C_v$, and hydraulic conductivity change index, $C_{kv}$, are evaluated and discussed. A secondary consolidation property, i.e., the secondary compression index, $C_a$, is also investigated, and the results show that the ratio of $C_a/C_c$ for Tianjin marine clay can be used to calculate $C_a$ in secondary consolidation settlement predictions.

• 상하수도학회지
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• 제27권5호
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• pp.561-570
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• 2013

There are two types of rectangular secondary clarifier at biological nutrient removal (BNR) facility to settle MLSS; conventional activated sludge secondary clarifier and Gould Type I clarifier. In this study, the performances of two types at respective biological nutrient removal facility are compared using weekly operational data. Surface Overflow Rate (SOR), Surface Loading Rate (SLR), Sludge Volume Index (SVI), secondary effluent SS concentration are studied. It has found that Gould Type I has 3.5 times less average secondary effluent SS concentration that is 2.4 mg/L than that of conventional activated sludge secondary clarifier. Both SOR and SLR have shown little effect on secondary effluent SS concentrations at Gould Type I clarifier in contrary that SOR affects the secondary effluent SS concentrations at conventional activated sludge rectangular secondary clarifier. From this study, it is recommended that Gould Type I must be considered for secondary clarifier when BNR plant is designed.

• Journal of Forest and Environmental Science
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• 제37권4호
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• pp.292-303
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• 2021

Studies that relate the structure of tropical regrowth vegetation to soil properties are generally lacking in the literature. This study proposes three indices for assessing the structural regeneration of secondary forests. They are: (1) the tree diameter class, (2) the plant life form and (3) the woody/herbaceous plants ratio indices. They were applied to assess the regeneration status of forest regrowth vegetation (aged 1-10 years), derived savanna regrowth vegetation in south western Nigeria, and to secondary forests in different stages of succession in Columbia and Venezuela, Bolivia, Mexico in South and Central America and semi-arid savanna in Ethiopia and seasonal deciduous forest successional stages in India. In all the cases, the indices increased with increasing age of regrowth vegetation and hence, with increasing structural complexity of regenerating vegetation. The tree diameter class index increased from 32.1% in a 9-year secondary forest to 69.0% in an 80-year-old secondary forest in Columbia and Venezuela and from 0.4% in a 1-year fallow to 20.9% in 10-year regrowth vegetation in southwestern Nigeria. In semi-arid savanna in northern Ethiopia, the woody/herbaceous plants ratio index increased from 18.1% in a 5-year protected grazing enclosure to 75.1% in 15-year protected enclosure, relative to the status of 20-year enclosure. The indices generally had correlations of 0.6-0.90 with species richness and Simpson's/Margalef's species diversity, implying that they are appropriate measures of ecosystem development over time. The proposed indices also had strong and positive correlations with soil organic carbon and nutrients. They are therefore, significant indicators of fertility status.

• 한국지반공학회논문집
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• 제24권8호
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• pp.99-109
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• 2008

본 연구는 군산 새만금지역의 점성토를 소성지수 15%, 30%, 45%, 60%가 되도록 벤초나이트를 첨가한 인공의 시료를 이용하여 하중재하기간을 1일, 2일, 4일, 8일 등으로 달리한 표준압밀시험을 실시하였다. 그리고 인천, 광양, 울산지역의 불교란 시료에 대한 압밀시험도 같이 수행하여 소성지수와 압밀하중재하기간이 2차 압밀에 어떤 영향이 있는지를 밝혔다. 그리고 각 소성지수에 따른 하중과 침하특성, 압밀계수특성, 압축지수 및 2차 압축지수특성, 간극수압특성을 밝히고 압축지수, 압밀계수, 2차 압축지수 등을 소성지수, 하중에 관하여 정식화하였다. 또한 정식화한 식을 이용한 1차 및 2차 압밀침하량 예측결과와 탄소성 구성모델인 수정 Cam-Clay모델과 탄 점소성 모델인 Sekiguchi모델을 이용한 예측결과를 모형시험 결과와 같이 비교하였다. 그 결과, 2차 압밀특성을 고려한 Sekiguchi모델이 매우 정도 높게 결과를 예측할 수 있음을 알 수 있었다.

• Geomechanics and Engineering
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• 제24권1호
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• pp.43-55
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• 2021

Peatland is distributed in China widely, and organic matters in soil frequently induce problems in the construction and maintenance of highway engineering due to the high permeability and compressibility. In this paper, a selected site of Dali-Lijiang expressway was surveyed in China. A numerical model was built to predict the settlement of the foundation of the selected section employing the soft soil creep (SSC) model in PLAXIS 8.2. The model was subsequently verified by the result of field observance. Consequently, the parameters of 17 types of soils from different regions in China with organic contents varying from 1.1-74.9% were assigned to the numerical model to study the settlement characteristics. The calculated results showed that the duration of primary consolidation and proportion of primary settlement in the total settlement decreased with increasing organic content. Two empirical equations, for total consolidation settlement and secondary settlement, were proposed using multiple linear regression based on the calculated results from the numerical models. The analysis results of the significances of certain soil parameters demonstrated that the natural compression index, secondary compression index, cohesion and friction angle have significant linear relevance with both the total settlement and secondary settlement, while the initial coefficient of permeability exerts significant influence on the secondary settlement only.

• 한국비블리아학회지
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• 제20권4호
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• pp.17-29
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• 2009

본 연구에서는 서지, 색인, 목록의 개념을 정의하고, 어린이청소년자료를 가공하여 생산된 국내외 이차자료를 조사하였다. 따라서 서지, 색인, 종합목록, 권장도서목록, 수상아동도서목록, 주요저널을 중심으로 생산실태와 주요 특징을 살펴보았다. 본 연구의 결과를 통해서 국내 어린이 이차자료의 현황을 파악할 수 있었으며, 권장도서목록과 문학상수상도서목록이 주를 이루었을 뿐 그 외의 서지, 색인은 전무한 실정이었다. 반면에, 외국의 경우에는 서지 및 색인 등 다양한 이차자료가 생산되고 있었다.

• 보건행정학회지
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• 제7권1호
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• pp.155-182
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• 1997

Objectives : This study was designed to compare North Korea and South Korea in measures of the quality of life (physical quality of life index and human development index) and to investigate the impact of selected medical and socioeconomic factors on PQL variables. Data and Methods : The World Bank, the United Nations Development Programme, and Population Reference Bureau were the principal sources of statistical data of 121 countries. Variables included infant mortality, life expectancy at birth, literacy rate, secondary school enrollment (male and female), GNP per capita, population per doctor, daily calorie supply per capita, and a composite PQL index. The Ordinary Least Square model was employed for cross-countries analysis. Findings : Both countries under quite different political and economic systems saw big improvememts in the quality of life, reducing mortality and prolonging life expectancy during the past three decades. In recent decad, however, North Korea has experienced abrupt exacerbation in the quality of life. Significant improvements in infant mortality of the population wer attributable mainly to GNP per capita and the secondary school enrollemt of female. The principal predictors of life expectancy at birth were population per doctor, infant mortality, and literacy rate. The secondary school enrollment of female and population per doctor were significantly associated with improvements in the physical quality of life index (PQLI). Conclusion : The results of this study confirmed a point illustrated by other studies : The association between quality of life as a measure of health status and socioeconomic factors was strong and positive. The important contribution of educational attainment in general, female education level in particular to improvements in the quality of life deserves good news for building an integrated health care system in the reunified Korea, taking into account the high level of education two koreas are enjoying. Meanwhile, when a sharp drop in the quality of life has been observed in North Korea under serious economic difficulties and food shortage in recent decade, the significant contribution of economic development to improvements in the quality of life poses bad nows for reunifying Korean health care in economic terms.