자녀 교육의 기회비용과 저출산

김대일 서울대학교 경제연구소 2022 經濟論集 Vol.61 No.2

스마트도시 산업 활성화를 위한 스마트도시 정책 및 기술현황 분석에 관한 연구

김대일,박성찬,염춘호 한국IT서비스학회 2022 한국IT서비스학회지 Vol.21 No.1

Recently, Korea is promoting cooperation with various countries, centering on ASEAN countries, with the aim of exporting Korean smart cities for the globalization of smart cities. The purpose of this study is to select excellent smart city technologies through analysis of smart city technologies owned by domestic companies and company status, and to prepare a plan for revitalization of companies with smart city technologies. Through prior research, the implications were derived through research on the existing smart city. Next, established a smart city policy analysis and smart city technology classification criteria through Korea and Overseas smart city policy and Korea smart city technology status DB. And the big data of smart city technology possessed by Korea companies and a plan for selecting a smart city export technology was prepared through analysis by region and company. As a result, to activate the technology possessed by Korea companies and to export overseas, it seems to need financial support and tax incentives that secure a pathway to export specialized smart technologies of SMEs, along with citizen participation and institutional supplementation. The smart city technology fields with the highest utilization in Korea were traffic, green energy, e-government, crime prevention, and construction, and the service types were platform, IoT, AI, big data, and GIS/GPS. These technologies are expected to contribute to building a platform for overseas smart city technology exports.

Effect of the Cu Bottom Layer on the Optical and Electrical Properties of In_2O_3/Cu Thin Films

김대일 한국진공학회 2011 Applied Science and Convergence Technology Vol.20 No.5

Indium oxide (IIn_2O_3) single layer and In_2O_3/copper (Cu) bi-layer films were prepared on glass substrates by RF and DC magnetron sputtering without intentional substrate heating. In order to determine the effect of the Cu bottom layer on the optical, electrical and structural properties of In_2O_3 films, 3-nm-thick Cu film was deposited on the glass substrate prior to deposition of the In_2O_3 films. As-deposited In_2O_3 films had an optical transmittance of 79% in the visible wavelength region and a sheet resistance of 2,300 Ω/□, while the In_2O_3/Cu film had optical and electrical properties that were influenced by the Cu bottom layer. In_2O_3/Cu films had a lower sheet resistance of 110 Ω/□ and an optical transmittance of 71%. Based on the figure of merit, it can be concluded that the Cu bottom layer effectively increases the performance of In_2O_3 films for use as transparent conducting oxides in flexible display applications.

철도 및 대중교통 연계형 도시재생의 사회경제적 효과 검토

김대일,염춘호,장기욱,이상근 한국철도학회 2024 한국철도학회 학술발표대회논문집 Vol.2024 No.5

규소 결정 표면의 구조 결함의 형성에 미치는 기계적 손상의 영향

김대일,김종범,김영관,Kim, Dae-Il,Kim, Jong-Bum,Kim, Young-Kwan 한국결정성장학회 2005 한국결정성장학회지 Vol.15 No.2

During oxidation process, several type of defects are formed on the surface of the silicon crystal which was damaged mechanically before oxidation. As the size of abrasive particle increases multiple dislocation loops are produced favorably over oxidation-induced stacking faults, which are dominantly produced when ground with finer abrasive particle. These defects are not related with the crystal growth process like Czochralski or directional solidification. During directional solidification process, twins and stacking faults are the two major defects observed in the bulk of the silicon crystal. On the other hand, slip dislocations produced by the thermal stress are not observed. Thus, not only in single crystalline silicon crystal but also in multi-crystalline silicon, extrinsic gettering process with programmed production of surface defects might be highly applicable to silicon wafers for purification.

Genetic Relationships in Genus Prunus by Multivariate Analysis Based on Morphological Characteristics

김대일 한국원예학회 2007 Horticulture, Environment, and Biotechnology Vol.48 No.5

Genetic relationships were clarified by multivariate analysis using 96 morphological characteristics in the 43 taxa of genus Prunus including thirteen peach cultivars, six plums, seven apricot or mume, three sweet cherries, four ornamental cherries, and seven wild Prunus. Among 35 inflorescence characteristics, flower type, sepal hair, pedicel hair, and inflorescence organ shapes, such as petal shape and receptacle shape, were useful to characterize the Prunus. Fruit and putamen shapes were also helpful characteristics in clarifying. Leaf size, shape, and hair were useful to distinguish genetic relationships in stone fruit trees. As the result of cluster analysis, the 43 Prunus taxa were divided into nine groups at Manhattan distance of 1389.7. The classified groups could be divided into three bigger subfamilies which were the Amygdalus including the group Ⅰ and Ⅱ, the Prunophora including the group Ⅲ to Ⅴ, and the Cerasus including group Ⅳ to Ⅸ. The biggest cluster was characterized by 13 peach cultivars as the group Ⅰ. The group Ⅱ was divided into three wild peaches, P. davidiana, P. triloba, and red leafed peach. Mumes, apricots, and plums were classified into the group Ⅲ, Ⅳ, and Ⅴ, respectively. Three Korean native cherries had very distinctive tomentose characteristics in fruit and leaf. Those ‘Baesil’, ‘Yonin’, and ‘Nanking’ were belonged to the group Ⅵ. The group Ⅶ were classified with three sweet cherry cultivars. Two cherry rootstocks and four ornamental cherries were divided into the group Ⅷ and Ⅸ in each. Although multivariate analysis derived morphological characteristics was useful to distinguish genetic relationships in genus Prunus, much more data were needed for precise analysis of sub-species and cultivars.

태양전지용 규소 기판에 존재하는 기계적 손상의 gettering 공정에의 활용

김대일,김영관,Kim, Dae-Il,Kim, Young-Kwan 한국결정성장학회 2006 한국결정성장학회지 Vol.16 No.2

Various kind of structural defects are observed to be present on the oxidized surface of the silicon crystal which was previously damaged mechanically. The formation of such defects was found to depend on the amount of damage induced and the temperature of thermal oxidation. It was confirmed by the measurement of minority carrier life time that gettering capability decreases as the size of the defects increase. The strained layer which is formed due to smaller amount of damage or lower oxidation temperature believed to has higher capability of gettering over defects like dislocation loops or stacking faults.

선종과 문인화에 대하여

김대일 한국종교교육학회 1999 종교교육학연구 Vol.8 No.-

Therapeutic monitoring of vancomycin according to initial dosing regimen in pediatric patients

김대일,임미선,최진형,이지나,이환종,최은화 대한소아청소년과학회 2010 Clinical and Experimental Pediatrics (CEP) Vol.53 No.12

Purpose: This study aimed to determine the optimal initial vancomycin dose to achieve appropriate trough levels in pediatric patients. Methods: We analyzed clinical data for 309 children treated with intravenous vancomycin between 2004 and 2009 at 2 different hospitals in South Korea. The patients were 1-16 years old and exhibited normal renal function. Patient data, including reason for treatment and initial dosing regimen, were reviewed. Two subgroups were identified and compared according to initial vancomycin dose:40 (35-45) mg/kg/day and 60 (55-65) mg/kg/day. Trough levels were obtained at steady state after at least 4 doses of vancomycin. Results: Patients who received vancomycin had post-operation or wound-related infections (37.2%), localized infection (12.9%), catheterrelated infections (9.4%), meningitis (8.7%), or endocarditis (6.8%). Pathogens were confirmed in 79 cases: 28 cases of methicillinresistant Staphylococcus epidermidis (35.4%) and 25 of methicillinresistant Staphylococcus aureus (31.6%). Out of the 309 patients, 201(65%) received vancomycin at 40 mg/kg/day and 108 (35%) at 60mg/kg/day. Average trough concentrations were significantly different between the groups (P<0.001). Trough levels over 10 mg/L were less likely to be achieved in the 40 mg/kg/day group (14%) than in the 60mg/kg/day group (49%) (P<0.001). There were no differences in renal function deterioration between the groups. Conclusion: A common vancomycin dosing regimen, 40 mg/kg/day, was not high enough to achieve trough levels of over 10 mg/L in pediatric patients. Careful drug monitoring must be performed, and increasing initial dose of vancomycin should be considered in pediatric patients.

Clinical Significance of Free-to-Total Prostate-Specific Antigen (PSA) Ratio in Advanced Prostate Cancer Patients with PSA Less than 0.1 ng/ml after Hormone Treatment

김대일,송재만,정현철 대한비뇨의학회 2012 Investigative and Clinical Urology Vol.53 No.3

Purpose: We analyzed the pattern of change in the free-to-total prostate-specific antigen (f/t PSA) ratio and the progression to castration-resistant prostate cancer (CRPC) in patients with advanced prostate cancer who received hormone treatment and whose PSA nadir was below 0.1 ng/ml. Materials and Methods: We retrospectively analyzed the medical records of 52 patients with advanced prostate cancer. All patients were treated with maximum androgen blockade (gonadotrophin-releasing hormone agonist and anti-androgen agents). The patients were divided into two groups: those with a nadir f/t PSA ratio above 60% and those with a nadir f/t PSA ratio of 60% or below. Age, initial PSA, clinical stage, lymph node metastasis, bone metastasis, and follow-up data, including PSA, free PSA, and f/t PSA ratio, were collected. The Mann-Whitney U-test, Fisher exact test, chi-square test, Kaplan-Meier survival analysis, and log rank test were used. Results: There were 24 patients in the group with a nadir f/t PSA ratio above 60% and 28 patients in the group with a nadir f/t PSA ratio of 60% or below. After hormone therapy, the median f/t PSA ratio in each group increased from 37% and 34% at 3 months to 75% and 60% at 6 months, respectively. At 9 months, however, the f/t PSA ratio increased to 80% in the group with a nadir f/t PSA ratio above 60%, whereas it decreased to 31% in the group with a nadir f/t PSA ratio of 60% or below. From 9 to 15 months, the f/t PSA ratio showed a tendency to decrease (75 to 37% and 27 to 20%, respectively). The progression to CRPC was significantly different between the two groups (10 vs. 24). Conclusions: Progression to CRPC was significantly higher in the group with a lower f/t PSA ratio. Additionally, the pattern of change in the f/t PSA ratio was significantly different after 9 months. Collectively, the f/t PSA ratio can be used as an additional marker for prognosis of hormone treatment. Purpose: We analyzed the pattern of change in the free-to-total prostate-specific antigen (f/t PSA) ratio and the progression to castration-resistant prostate cancer (CRPC) in patients with advanced prostate cancer who received hormone treatment and whose PSA nadir was below 0.1 ng/ml. Materials and Methods: We retrospectively analyzed the medical records of 52 patients with advanced prostate cancer. All patients were treated with maximum androgen blockade (gonadotrophin-releasing hormone agonist and anti-androgen agents). The patients were divided into two groups: those with a nadir f/t PSA ratio above 60% and those with a nadir f/t PSA ratio of 60% or below. Age, initial PSA, clinical stage, lymph node metastasis, bone metastasis, and follow-up data, including PSA, free PSA, and f/t PSA ratio, were collected. The Mann-Whitney U-test, Fisher exact test, chi-square test, Kaplan-Meier survival analysis, and log rank test were used. Results: There were 24 patients in the group with a nadir f/t PSA ratio above 60% and 28 patients in the group with a nadir f/t PSA ratio of 60% or below. After hormone therapy, the median f/t PSA ratio in each group increased from 37% and 34% at 3 months to 75% and 60% at 6 months, respectively. At 9 months, however, the f/t PSA ratio increased to 80% in the group with a nadir f/t PSA ratio above 60%, whereas it decreased to 31% in the group with a nadir f/t PSA ratio of 60% or below. From 9 to 15 months, the f/t PSA ratio showed a tendency to decrease (75 to 37% and 27 to 20%, respectively). The progression to CRPC was significantly different between the two groups (10 vs. 24). Conclusions: Progression to CRPC was significantly higher in the group with a lower f/t PSA ratio. Additionally, the pattern of change in the f/t PSA ratio was significantly different after 9 months. Collectively, the f/t PSA ratio can be used as an additional marker for prognosis of hormone treatment.