• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.273-291
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• 2020

The strength characteristics of the three orthogonal splitting planes, known as rift, grain and hardway planes in granite quarries, were examined. R, G and H specimens were obtained from the block samples of Jurassic granites in Geochang and Hapcheon areas. The directions of the long axes of these three specimens are perpendicular to each of the three planes. First, The chart, showing the scaling characteristics of three graphs related to the uniaxial compressive strengths of R, G and H specimens, were made. The graphs for the three specimens, along with the increase of strength, are arranged in the order of H < G < R. The angles of inclination of the graphs for the three specimens, suggesting the degree of uniformity of the texture within the specimen, were compared. The above angles for H specimens(θ^H, 24.0°~37.3°) are the lowest among the three specimens. Second, the scaling characteristics related to the three graphs of RG, GH and RH specimens, representing a combination of the mean compressive strengths of the two specimens, were derived. These three graphs, taking the various N-shaped forms, are arranged in the order of GH < RH < RG. Third, the correlation chart between the strength difference(Δσ_t) and the angle of inclination(θ) was made. The above two parameters show the correlation of the exponential function with an exponent(λ) of -0.003. In both granites, the angle of inclination(θ^RH) of the RH-graph is the lowest. Fourth, the six types of charts, showing the correlations among the three kinds of compressive strengths for the three specimens and the five parameters for the two sets of microcracks aligned parallel to the compressive load applied to each specimen, were made. From these charts for Geochang and Hapcheon granites, the mean value(0.877) of the correlation coefficients(R²) for total density(Lt), along with the frequency(N, 0.872) and density(ρ, 0.874), is the highest. In addition, the mean values(0.829) of correlation coefficients associated with the mean compressive strengths are more higher than the minimum(0.768) and maximum(0.804) compression strengths of three specimens. Fifth, the distributional characteristics of the Brazilian tensile strengths measured in directions parallel to the above two sets of microcracks in the three specimens from Geochang granite were derived. From the related chart, the three graphs for these tensile strengths corresponding to the R, G and H specimens show an order of H(R1+G1) < G(R2+H1) < R(R1+G1). The order of arrangement of the three graphs for the tensile strengths and that for the compressive strengths are mutually consistent. Therefore, the compressive strengths of the three specimens are proportional to the three types of tensile strengths. Sixth, the values of correlation coefficients, among the three tensile strengths corresponding to each cumulative number(N=1~10) from the above three graphs and the five parameters corresponding to each graph, were derived. The mean values of correlation coefficients for each parameter from the 10 correlation charts increase in the order of density(0.763) < total length(0.817) < frequency(0.839) < mean length(Lm, 0.901) ≤ median length(Lmed, 0.903). Seventh, the correlation charts among the compressive strengths and tensile strengths for the three specimens were made. The above correlation charts were divided into nine types based on the three kinds of compressive strengths and the five groups(A~E) of tensile strengths. From the related charts, as the tensile strength increases with the mean and maximum compressive strengths excluding the minimum compressive strength, the value of correlation coefficient increases rapidly.

• Clinical and Experimental Pediatrics
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• v.48 no.4
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• pp.411-415
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• 2005

Purpose : This study was performed to determine the developmental expression pattern of nerve growth factor(NGF) in the urine of healthy children. It was hypothesized that NGF may contribute to the development of the spinobulbospinal micturition reflex that represents the adult micturition pattern. Methods : Voided urine was collected in 60 healthy children during the first 5 years of life(0-1 month, n=10; 1 month-1 year, n=10; 2 years, n=10; 3 years, n=10; 4 years, n=10). The urinary NGF was analyzed by using an enzyme linked immunosorbent assay. Results were normalized based on creatinine or total protein in urine. Results : NGF was significantly greater among neonates compared to other age groups(P<0.05). NGF levels declined during 1 month to 1 year and increased by age 2 years. NGF levels at age 3 years were less than in neonates examined. When comparing the NGF levels according to continence in children over 1 year old, NGF levels were significantly lower in children with continence than in children with incontinence(P<0.05). Conclusion : These data suggest that NGF is involved in the achievement of continence and in mechanisms of bladder nerve growth and in the reorganization of bladder reflex pathway.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.333-338
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• 2006

The purpose of the present study was to clarify the sexual difference of the Heath-Carter somatotype related variables in boys and girls from 7 through 19 years of age. In the study design, the subjects and the methods were used by the cross-sectional investigation. The subjects participated in this study were 7 through 19 years of age who belonged to typical primary, junior, senior high school and college students, and about 250 males and 250 females in each group and both sexes. Therefore, the total subjects were 3,046 males and 2,984 females. All subjects of this study lived in Pusan metropolitan city, Korea. Somatotype was calculated by the Heath-Carter's anthropometric somatotype method, In this study, in attaiment rates of sum of 4 sites skinfold and endomorphy growth, girls were significantly higher than boys in all ages intervals except through 13 years of aged groups, respectively. In attainment rates of humerus and femur breadths growth, boys were significantly higher than girls in all ages interval except 13 through 15 years of aged groups, respectively. In attainment rate of arm circumference growth, boys were significantly higher than girls in all ages interval except 7 years of aged group. In attainment rate of calf circumference growth, boys were significantly higher than girls in all ages interal except 15years of aged group. In attainment rate of ectomorphy growth, boys were significantly higher than girls in all aged interal except 8 thorough 12 years of aged groups. This results suggests the urgent necessity of developing systematic and sperate progams to treat such sexual difference in boys and girls.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.3
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• pp.191-204
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• 2017

Concerns on the air pollution problem caused by ambient fine particles have become a big social issue in Korea. Important factors that should be addressed to develop effective and efficient air quality management policy, especially, against fine particles are discussed and research and policy directions to address these factors are suggested. It is suggested that two factors are in high priority; one is scientific understanding of the major formation mechanisms of fine particles and the other is the process of policy decision and implementation. For the scientific understanding, smog chamber measurement, intensive field study, and chemical transport model development that can simulate the characteristics of Northeast Asia are considered to be important. For the policy directions, priority setting of the proposed policies and development and implement of effective communication sytem are considered to be important.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.4
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• pp.389-397
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• 2010

Purpose: This study was to investigate the changes of refractive error and astigmatism associated with age in Korean subjects between the ages of 6 and 80 years during 10-year period. Methods: 220 normal subjects (345 eyes) who visited ophthalmic clinic was recruited and followed for 10 years between 1999 and 2009, cycloplegic manifest refraction being performed annually. Visual acuity was tested on a Han's chart. Results: The mean 10-year change in the spherical equivalent refraction (SER) of age 6 to 10 years old and 10 to 20 years was -3.649D and -2.165D respectively. There was no change of refractive error in age 21 to 40 years. The myopic shift decreased with age from 41 up to 69 years but increased slightly in patients 70 years and older; the hyperopic shift showed the opposite trend. The distribution of refractive error over the 10 years in aged 6 to 10 and 11 to 20 years was shifted myopic. The incidence of medium (> -3.01D) to high myopia at age 6 to 10 years was 4.8% and after 10 years was 62.5%. The 10-year change of astigmatism axis was in "with the rule" direction for younger age group and in a "against the rule" direction for older subjects. Conclusions: This study has documented refractive error changes in Korean subjects and confirmed reported trends of myopic shift from age 6-20 years and hyperopic shift before age 70 years and a myopic shift thereafter. The axis of astigmatism turns to "against the rule" after 40's.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.355-361
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• 2017

Pediatrics are more sensibility to radiation than adults and because they are organs that are not completely grown, they have a life expectancy that can be adversely affected by exposure. Therefore, the management of exposure dose is more important than the case of adult. The purpose of this study was to determine the suitability of the 10 year old phantom for the 5 year old pediatric's recommendation and the incident surface dose, and to measure the organ absorbed dose. This study is compared the organ absorbed dose and the entrance surface dose in the clinical conditions at 5 and 10 years old pediatric. Clinical 5 year old condition was slightly higher than recommendation condition and 10 year old condition was very high. In addition, recommendation condition ESD was found to be 43% higher than the ESD of the 5 year old group and the ESD of the 10 year old group was 126% higher than that of the 5 year old group. The recommended ESD at 5 years old and the ESD according to clinical imaging conditions were 31.6%. There was no significant difference between the 5 year old recommended exposure conditions and the organ absorbed dose due to clinical exposure conditions, but there was a large difference between the Chest and Pelvic. However, it was found that there was a remarkable difference when comparing the organ absorbed dose by 10 year clinical exposure conditions. Therefore, more detailed standard exposure dose for the recommended dose of pediatric should be studied.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.801-812
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• 2021

In order to delivery biotin to skin, ethosomes containing both biotin and ceramide were researched by using high pressure homogenizer. Biotin was utilized as a drug and ceramide NP was utilized as a supporter of bilayer. The biotin was entrapped in aqueous core, while ceramide NP was packed in the bilayer of the ethosomes. Looking at the physical properties of vesicles containing ceramide NP, the sized was 80~130 nm, the polydispersity index was 0.09~0.16, and the zeta potential was -40~-49 mV. In vesicles without ceramide NP, the size was 124.80±1.46 nm, and the zeta potential and polydispersity index were -45.48±1.27 mV and 0.088±0.018, respectively. Therefore, the ethosome with ceramide NP has improved physical properties of vesicles compared to the ethosome without ceramide NP. Skin absorption rates of ethosomes with ceramide NP were 6.13~14.98%, while skin absorption rate of ethosome without ceramide NP was 7.08% at 12 h. In conclusion, ethosomes containing ceramide NP not only improved the skin absorption efficiency, but had also a positive effect on the stability of vesicles.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.360-365
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• 1991

This experiment was conducted to determine mechanized seeding ability of barley drill seeder on the seeding time, growth and yield of sorghum-sudangrass hybrid. The time required for machine drill seeding was 42 minutes per l0a which was one-thirteenth of the time required by the manual drill seeding, and percentage of seedling establishment by machine drill seeding was better than that of manual drill seeding. Leaf area index in seeding rate with 30 x 5cm and 40 x 5cm of machine drill seeding was higher than those of manual drill seeding, the leaf distribution was better and the total nonstructural carbohydrate content of stubble after cutting was short increased than that of manual drill seeding, Content of feed composition was not significantly different between manual and machine drill seeding. At seeding rate of 40 x 5cm of machine seeding. dry matter and TDN yield were increased to 29% and 30% respectiyely, than those of manual drill seeding.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.375-378
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• 1998

본 연구의 목적은 한국에 존재하는 세 종류 파찰음/ㅈ,ㅊ, ㅉ/의 시간적.공간적 조음 특성을 전자구개도와 스펙트로그램 분석을 통하여 면밀히 검토해 보려는 것이다. 이를 위하여 두 실험이 행해 졌는데, 조음 음성학적인 실험(전자구개도를 이용한 실험)에는 한 명의 피험자가, 그리고 음향 음성학적인 실험(음향 자료의 스펙트로그램 분석)에는 세 명의 피험자가 발화한 자료가 이용되었다. 대상이 되는 세 자음들은 /ㅏ_ㅏ/, /ㅡ_ㅡ/, /ㅣ_ㅣ/ 등 세 모음 사이에서 발화되었으나, 모음이 자음의 조음에 미치는 영향, 즉 모음_자음 동시조음은 본 연구의 범위에서 제외되었다.

• Environmental and Resource Economics Review
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• v.9 no.1
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• pp.209-228
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• 1999

탄소세는 기후변화 방지를 위한 구체적 수단으로 교토의정서에서 채택된 시장원리 중심의 유연성체계 장치와의 결합선상에서 주목을 받고 있다. 국제경쟁력 감소 총탄소배출량증가 등 잠재적 부작용에도 불구하고, 탄소세는 기후변화협약에 따른 의무감축 수행을 위한 비용 효과적인 방안으로 인식되고 있다. 선진국을 중심으로 볼 때, 지금까지 탄소세는 덴마크, 핀랜드, 네덜란드, 노르웨이, 스웨덴 등 북유럽 5개국이 부분적으로 실시하고 있으나 갖가지 예외조항의 실시로 인해 본래의 의미인 환경보호는 소홀히 취급되고 경쟁력 약화 우려가 정책결정의 주요한 변수로 작용하고 있다.