• 한국치위생학회지
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• 제1권1호
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• pp.125-132
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• 2001

This study was carried out to investigate the effect of multi or single application of fluoride plus 0.05% NaF solution on the remineralization of dental caries lesion. The microhardness changes of enamel surface were measured after application of fluoride and precipitation of 0.05% NaF solution on 6 groups of cow's tooth on which the artificial carious lesions were formed first. Test groups were calssified into two step application with NaF, $SnF_2$ and APF under different application time conditions plus 0.05% NaF solution(group I, II, III, IV) and single application with APF plus 0.05% NaF solution (group V) and control(0.05% NaF solution only, group IV). The obtained results were as follows. 1. Regarding microhardness change of enamel surface. microhardness increments in group I(NaF for 1 minute+APF for 3 minutes+0.05% NaF solution for 1 minute), II($SnF_2$ 1 min+APF 3 min+NaF sol.), III($SnF_2$ 2 min+APF 2 min+NaF sol.), IV(NaF 2 min+APF 2 min+NaF sol.) and V(APF 4 min+NaF sol.) were significantly greater than group VI.(P<0.05) 2. Microhardness changes of shorter application time of $SnF_2$ (group II) were significantly greater than group III. (P<0.05) 3. Microhardness changes were variable with kinds of fluoride, application sequence and application time of fluoride. but had no relation with the number of fluoride application.

• 대한환경공학회지
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• 제37권8호
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• pp.458-464
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• 2015

본 연구에서는 사산화삼철과 활성탄을 발열체로 하여 벙커C유 오염토양에 마이크로파를 조사한 후 온도변화 양상 및 TPH 제거효율을 살펴보았다. 사산화삼철 및 활성탄 함유 오염토양에 100~500 Watt로 마이크로파를 조사하였을 때 승온율은 $1.4{\sim}1.6^{\circ}C/Watt$로 나타났다. 조사시간에 따른 온도의 변화는 활성탄보다 사산화삼철 함유토양에서 민감하게 나타났으며, 사산화삼철과 활성탄의 경우 발열체 함량이 각각 10% 이상과 25%에서 열탈착을 위한 충분한 온도가 확보될 수 있음을 관찰하였다. 사산화삼철은 평균 44.1%, 활성탄은 평균 89.4%의 TPH 제거 효율을 나타났으며, 벙커C유의 제거 양상은 활성탄이 함유되었을 때 사산화삼철 보다 고분자탄화수소의 휘발이 더욱 원활하게 진행되고 있음을 확인하였다.

• 한국지역지리학회지
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• 제12권5호
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• pp.595-613
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• 2006

개발이익은 토지소유자의 노력과 투자를 동반하지 않은 토지가치의 증가를 일반적으로 지칭하며, 개발이익 환수는 이러한 유형의 토지가치 증가는 공유하여야 한다는 사고를 전제하고 있다. 이러한 개발이익의 발생메커니즘, 향유 주체 및 환수의 경제적 효과를 둘러싸고 많은 논쟁이 전개되었다. 정책대상으로서 개발이익은 토지가치세와 같은 조세형평성의 강화, 도시하부구조 건설재원조달, 토지이용 및 공간계획 관리 목적으로 활용하고 있다. 그러나 개발이익에 대한 이러한 이론적 정책적 논의의 발전을 위해서는 개발이익 발생규모와 특성을 구체적으로 규명하는 작업이 필요하다. 본 연구에서는 택지개발촉진법 도입 이후 주도적으로 택지개발사업을 수행하고 있는 한국토지공사와 대한주택공사의 1995년 이후 전체 204개 개발사업지구를 대상으로 화폐의 시간적 가치를 고려한 할인현금흐름분석법으로 개발이익을 추계하고 그 특성을 밝힌다.

• Journal of Dairy Science and Biotechnology
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• 제37권4호
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• pp.247-255
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• 2019

The objective of this study was to evaluate the sensory profiles of market milk, yogurt, and kefir, supplemented with the powder of Hibiscus sabdariffa Linnaeus (Roselle) in 1% increments, ranging from 0% (control) to 4%. In this study, there was no statistically significant difference in titratable acidity and pH between the treated groups and the control group. All samples were evaluated in five categories by thirteen appraisers. Compared to the control group, the best sensory profiles were observed in the market milk sample supplemented with 1.0% of Hibiscus sabdariffa Linnaeus (Roselle) powder, in the yogurt samples supplemented with 2.0% and 3.0% of Hibiscus sabdariffa Linnaeus (Roselle) powder, and in the Kefir sample supplemented with 3% of Hibiscus sabdariffa Linnaeus (Roselle) powder. According to statistical analysis of the sensory profiles obtained in this study, there was a statistical difference in the taste, flavor, color, and overall acceptability of market milk; in the taste, color, texture, and overall acceptability of yogurt; and in the taste, color, and overall acceptability of Kefir, between the treated groups and the control group (p<0.05). In the future, when Hibiscus sabdariffa Linnaeus (Roselle) powder is used as a food additive for dairy products, studies on improvement of biofunctionality, as well as of sensory profiles in dairy products must be carried out.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 Techno-Fair 및 합동춘계학술대회 논문집 전기물성,응용부문
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• pp.175-176
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• 2008

In this study, the sintering properties and structural properties of the $Mg_5Ta_4O_{15}$cation-deficient perovskite ceramics with $Li_2CO_3$ additions are investigated. The cation-deficient perovskite ceramics are prepared through the solid-state route. According to the XRD pattern, $Mg_4Ta_2O_9$, $MgTa_2O_6$ and $Mg_5Ta_4O_{15}$ phase existed in sintered pure $Mg_5Ta_4O_{15}$ ceramics. With $Li_2CO_3$, additions, the peak intensities of $Mg_4Ta_2O_9$ and $MgTa_2O_6$ phase were reduced. Also, diffraction intensity of the $Mg_5Ta_4O_{15}$ phase was increased with increments of $Li_2CO_3$ additions. The bulk densities were increased with increasing of $Li_2CO_3$ amount and approach the theoretical density of the $Mg_5Ta_4O_{15}$ ceramics, more and more. Microstructure of the $Mg_5Ta_4O_{15}$ ceramics were densified more and more by additions of $Li_2CO_3$. The bulk density of $Mg_5Ta_4O_{15}$+5wt% $Li_2CO_3$ ceramics sintered at $1500^{\circ}C$ for 10 hours was $5.88g/cm^3$.

• 한국산업융합학회 논문집
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• 제3권2호
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• pp.155-166
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• 2000

In order to elucidate the interrelationship between electrolytes and exercise the investigation was undertaken to determine the electrolyte levels in young males took on varied environmental temperatures ($13^{\circ}C$, $24^{\circ}C$ or $34^{\circ}C$). 10 healthy young males were used for the experiments. Our results showed the following significant changes; 1. The raising of the environmental temperature, the weight reduction were increased due to marked sweating. 2. In the electrolytes of serum, decreased the $K^+$ concentration at $13^{\circ}C$, but increased the $Na^+$ or $Cl^-$ concentration at $24^{\circ}C$, and increased the $Na^+$ or $Cl^-$, or $Mg^{+}^{+}$ concentrations at $34^{\circ}C$. 3. The raising of environmental temperature appear to be increased PRA,Ang I, Ang II and ALD levels, whereas no changed ADH level. 4. Serum levels of PRA, Ang I, Ang II and ALD were incresed after exercise, and their increments were incresed paralel ttie incresed environmental temperature. However, there no significant change in ADH, level. In conclusion, exercise induced not only changes of serum electrolytes levels such as $Na^+$, $Cl^-$, $K^+$, $Mg^{+}^{+}$, but also serum hormonal changes such as PRA, Ang I, Ang II, ALD. However, ADH level was not changed significantly, These changes were more prominent in exercise at hot temperature than in lower temperature.

• 한국항공우주학회지
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• 제32권4호
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• pp.12-17
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• 2004

고속 유동 속에 놓인 모델 표변의 압력분포를 정량적으로 측정하기 위해 PSP 기술이 사용되고 있다. 본 연구에서는 아음속 유동에 적용 가능한 PSP 기술을 개발하였다. 2가지의 백금계열 (PtOEP와 PtTFPP)의 발광분자와 2 가지의 폴리머 (Poly(TMSP)와 RTV-118)를 사 용하여 4가지의 PSP 조합을 만들어 그 성능을 확인하였다. 압력변화에 따른 PSP의 발광강 도를 측정하기 위해 $0{\sim}11kPa$까지 0.5, 1, 2kPa썩 압력을 증가시키면서 정적보정실험을 수행하였다. 4가지의 PSP 조성 중에 PtOEP 와 RTV-118의 조합이 가장 좋은 성능을 보였다. 충돌평판에 작용하는 압력장 분포를 측정하기 위하여 경사충돌분류에 본 연구에서 개발된 PSP 기술을 응용하였다.

• 농약과학회지
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• 제6권2호
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• pp.64-71
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• 2002

Pseudomonas cepacia로부터 유래한 quinolinone 대사물질인 2-(2-hepteny)-3-methyl-4-quinolinone (1), 2-heptyl-3-methyl-4-quinolinone, 2-nonyl-3-methyl-4-quinolinone 및 합성물질 ethyl 2-methyl-3-alkyl-4-quinolinone carboxylate의 식물생장촉진 효과를 보기 위해 종자발아검정 및 경엽처리 후의 생장량을 측정하였다. 또한 종자침지 및 관주 처리후의 초고, 생체중, 과실수도 조사하였다. 화합물 1은 종자발아 효과와 경엽처리 후에 일관된 생장촉진 효과를 보였다. 종자침지와 관주처리 후에, 화합물 1과 합성물질 ethyl 2-methyl-4-quinolinone-3-carboxylate (5)를 처리한 식물에서의 생체중과 과실수는 크게 증가하였다. 화합물1과 5는 대조관보다 각각 44%와 84%의 과실수 증가를 나타냈다.

• Journal of Nutrition and Health
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• 제35권1호
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• pp.69-77
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• 2002

The purpose of this study was to determine the probability of overweight throughout childhood in relation to the presence of overweight at birch or in early childhood, and presence of overweight in children's parents. Weight and height measures were collected at birth and at ages of 7, 10, 12 years from 655 6th grade primary schoolchildren. Childhood overweight was defined as a body mass index at or above the 85th percentile for age and sex, and overweight in children's parents as a body mass index at or above 27. The prevalence of overweight increased with age of the children. Overweight at birth was not associated with overweight at 12 years of ages. However, overweight at 12 years old was already related to overweight at 7 years old. In comparison to non-overweight peers, overweight children at ages 7(OR = 7.64, 95% CI = 4.32-13.51) and 10 years(OR = 19.69, 95% CI = 11.42-33.94) had a higher rick of becoming overweight at 12 years of age. Among children who was overweight at age 7years, 60.7% remained overweight 5 years later, Yearly increment in BMI of overweight children was larger than that of non-obese children (1.15-1.65kg/m$^2$vs 0.50-0.71kg/m$^2$. As compared with the lower case in mealy increment of BMI, the probability of being overweight at age of 12 years was greater in higher case. BMI values at age 7years were positively correlated with BMI values at age of 10 and 127ear,i, and with annual increments in BMI. But those relationships with birth weight were not observed. Children were at greater risk for overweight if at least ogle parent was overweight. The odds ratio for child overweight associated with maternal overweight was 2.41(95% CI = 1,13-5.IS), and those associated with paternal overweight 1.70(95% CI = 0.92-3.17). And parents' BMIs were positively correlated with children's BMI values and yearly BMI increment. In conclusion, overweight at early childhood and annual inclement in BMI can be important in predicting the prevalence of overweight and the risk that overweight will remain after 7 years of age. The risk of being overweight throughout the childhood increases by the parents'overweight.

• Earthquakes and Structures
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• 제14권5호
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• pp.411-424
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• 2018

This study explores the inelastic behavior of systems with flexible base. The use of a single degree of freedom system (ESDOF) with equivalent ductility to represent the response of flexible base systems is discussed. Two different equations to compute equivalent ductility are proposed, one which includes the contribution of rigid body components, and other based on the overstrength of the structure. In order to asses the accuracy of ESDOF approach with the proposed equations, the behavior of a 10-story regular building with reinforced concrete (RC) moment resisting frames is studied. Local and global ductility capacity and demands are used to study the modifications introduced by base flexibility. Three soil types are considered with shear wave velocities of 70, 100 and 250 m/s. Soil-foundation stiffness is included with a set of springs on the base (impedance functions). Capacity curves of the building are computed with pushover analysis. In addition, non linear time history analysis are used to asses the ductility demands. Results show that ductility capacity of the soil-structure system including rigid body components is reduced. Base flexibility does not modify neither yield and maximum base shear. Equivalent ductility estimated with the proposed equations is fits better the results of the numerical model than the one considering elastoplastic behavior. Modification of beams ductility demand due to base flexibility are not constant within the structure. Some elements experience reduced ductility demands while other elements experience increments when flexible base is considered. Soil structure interaction produces changes in the relation between yield strength reduction factor and structure ductility demand. These changes are dependent on the spectral shape and the period of the system with fixed and flexible base.