• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.15-20
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• 2010

In this study, AZO (Al: 3 wt%) thin films have been prepared on PES Plastic substrates at various working pressure (5~20 mTorr), $O_2$ gas flow rate(0~3%) and the fixed substrate temperature of 200 f by using the RF magnetron sputtering and their optical and electrical properties have been studied. The XRD measurement shows that AZO thin films exhibit c-axis preferred orientation. From the results of AFM measurements, it is known that the lowest surface roughness (3.49 nm) is obtained for the AZO thin film fabricated at 5 mTorr of working pressure and 3% of $O_2$ gas flow rate. The optical transmittance of AZO thin films is measured as 80% in the visible region. We observe that the energy band gap of AZO thin films increases with decreasing the working pressure and the $O_2$ gas flow rate. This phenomenon is due to the Burstein-Moss effect. Hall measurement shows that the maximum carrier concentration ($2.63\;{\times}\;10^{20}\;cm^{-3}$) and the minimum resistivity ($4.35\;{\times}\;10^{-3}\;{\Omega}cm$) are obtained for the AZO thin film fabricated at 5mTorr of working pressure and 0% of $O_2$ gas flow rate.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.1
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• pp.95-105
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• 2022

Recently, as the scale of a construction project has become larger and more complicated, there are many cases where construction projects with complex structures are carried out in a fast track method to save construction duration. In the fast track method, the proper division of construction phases is an important issue in determining the overall project period. This study presents a rational phase division method that can be applied when a construction project with complex structures is carried out as a fast track. For this study, a subdivided work breakdown structure (WBS) is developed using the construction of 4 soccer stadiums as application examples, and the schedule is analyzed by dividing the construction process of major phases. To this end, five proposals are applied to analyze the adequacy of the fast track phase division. For the draft with the minimum construction period, the fast track phase division and the schedule model of by each phase were presented. This methodology can have an application in the appropriate phase division and schedule model by construction phase when fast track is applied in large construction project of a similar size.

• Journal of the Korea Convergence Society
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• v.7 no.4
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• pp.191-198
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• 2016

As the electricity produced from the electricity industry, a national key industry in Korea, are supplied to other industries as an intermediate goods, the supply shortage of electricity industry has a large impact on the national economy. This paper attempts to analyze the supply shortage effects which are defined as the negative impact of one won of supply failure in the electricity on the production of other industries. To this end, an input-output analysis using an input-output (I-O) table describing inter-industry flow of intermediate goods is applied. More concretely, the supply-driven model is applied subject to the OECD countries. The value of the supply effects interfere with Denmark's best large 1.682 was followed by South Korea, Japan, Australia, the UK.

• Spatial Information Research
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• v.17 no.2
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• pp.231-241
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• 2009

Recently, The importance of a quality control for implementing 3D geospatial database has being emphasized to build a 21st century knowledge society and an ubiquitous land. The improvement of 3D geospatial database quality control through establishing an integrated quality control makes data suppliers update data efficiently and users get high quality data. The purpose of this study was to derive the improvement plan of 3D geospatial database quality control through the analyses of the existing 3D geospatial database quality control and case studies. The results of this study are as follows. Firstly, we defined the concept of 3D geospatial database quality control. Secondly, we set the boundary, factors and process of 3D geospatial database quality control through classifying it in detail. Lastly, we drew improvement contents such as the quality control checklist by implementation process according to the improvement plan of 3D geospatial database implementation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1097-1103
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• 2010

Injection pressure, an important factor in the filling procedure, should be minimized to enhance injection molding quality. In addition, warping deformation and weld lines, which are representative failures, should be avoided to enhance injection molding quality. To improve injection molding quality, the design procedure for an automotive fog blank cover is divided into two stages. In the first stage, we optimally obtain injection molding process variables that minimize injection pressure and warping deformation by using design of experiments, approximation and optimization techniques equipped in PIAnO (Process Integration, Automation and Optimization), a commercial PIDO (Process Integration and Design Optimization) tool. Then, we determine the thickness of the automotive fog blank cover that enables us to avoid generating weld lines. The design results we obtain in this study are found far better than those of the initial design, which demonstrates the effectiveness of our design method.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.381-395
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• 1989

The main purpose of this research is to provide scientific informations about standard wage and performance tariffs in forest management with special reference to working time for thinning. To identify relationships between net working time and tree characteristics, three geographically different sample plots were established at Yangsan, Bongpyung and Jinan and 460 oaks, 372 Japanese larches, 232 red pine and 240 pitch pine mere selected at each sample plots. The results of statistical analysis using multiple regression are as follows ; 1. Five independent variables of breast height diameter(DBH), mid-diameter(MD) large end diameter(LD), log-length(L), No. of branches(NOB) were stable independent of worker and tree species. 2. Comparing correlation coefficient of five independent variables, the best predictive variables, breast height diameter and No. of branches, were selected. Breast height diameter and No. of branches were identified as the most important independent variables in terms of effect on the dependent variable of the working time. 3. Comparing coefficient of determination (Rp) and residual mean square (MSEp), the best Linear regression equation for each tree species was selected as follower : $WT=a+b1{\times}NOB+b2{\times}DBF$ 4. Proportion of hang-up time to total working time in thinning were 66% in oak stand, 74%, in Japanese larch stand, 55%, in red pine stand and 52% in pitch pine stand, respectively. 5. Based on the best regression equation, a table of working time was made by strata of number of branches and breast height diameter. 6. Total working time using the best regression equation in Table 5 can be predicted in terms of felling time, limbing time, hang-up time, i.e., total working time increases by 11 to 13 seconds with every 1 centimeter increase in breast height diameter from 7 to 16 centimeter.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.4
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• pp.303-311
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• 2013

This study was performed to investigate the anti-inflammatory activities of fermented Scutellaria baicalensis extracts using Lactobacillus rhamnosus. The extracts were WE (water extract at $100^{\circ}C$ for 24 h), EE (70% ethanol extract at $60^{\circ}C$ for 24 h), FWE (fermented and water extract at $60^{\circ}C$ for 24 h), FEE (fermented and 70% ethanol extract at $60^{\circ}C$ for 24 h). The cytotoxicity of the extracts was in the range of 11.2 ~ 15.6 % at 1.0 mg/mL concentratioin. The FEE showed the lowest activity at 1.0 mg/mL concentratioin. Compared to the WE, hyaluronidase inhibitory activity contents in the FEE increased to 9.2% at 1.0 mg/mL concentratioin. Nitric oxide production of WE, EE, FWE and FEE at 1.0 mg/mL concentration was mesured as 7.6, 7.9, 6.9, 6.4 ${\mu}M$, respectively. $PGE_2$ secretion of the human fibroblast of the FEE were lower than 810 pg/mL. Our results suggested that the extracts from fermentation process after 70% ethanol extraction had relatively high anti-inflammatory activities and that the Scutellaria baicalensis could be more extracted in FEE than others.

• Resources Recycling
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• v.28 no.4
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• pp.30-36
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• 2019

In this study, Li powder was recovered from the by-product of LNO ($Li_2NiO_2$) process, which is the positive electrode active material of waste lithium ion battery, through the $CO_2$ thermal reaction process. In the process of recovering Li powder, the $CO_2$ injection amount is 300 cc/min. The $Li_2NiO_2$ award was phase-separated into the $Li_2CO_3$ phase and the NiO phase by holding at $600^{\circ}C$ for 1 min. After this, the collected sample:distilled water = 1:50 weight ratio, and after leaching, the solution was subjected to vacuum filtration to recover $Li_2CO_3$ from the solution, and the NiO powder was recovered. In order to increase the purity of Ni, it was maintained in $H_2$ atmosphere for 3 hours to reduce NiO to Ni. Through the above-mentioned steps, the purity of Li was 2290 ppm and the recovery was 92.74% from the solution, and Ni was finally produced 90.1% purity, 92.6% recovery.

• Korean Journal of Construction Engineering and Management
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• v.21 no.2
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• pp.88-97
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• 2020

Practical and efficient application of lean construction, which has been proposed as an alternative to the limitations of traditional construction management methods, was developed to facilitate application on site and improve productivity through the fusion of traditional construction management methods. The concepts of Lean Time and Lean Cycle Time, which are the principles of lean construction, were introduced to eliminate waste and smooth flow production and pursuit of perfection, and the goal of establishing and improving the criteria for measurement and improvement was established and the information collection template was configured and applied to ensure reliability of measurement and analysis. Based on this, the project feasibility, reliability, and continuous improvement process were applied to the Field case to verify its effectiveness.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.3
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• pp.491-511
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• 2016

This paper attempts to understand the nature and dynamics of global value chains in the auto industry using the OECD TiVA 2015 edition on the bilateral foreign value added in exports over the period 1995-2011 and employing the techniques of social network analysis such as the computation of network measures and visualization of value added trade flows. It is shown that there has been a tendency towards increasing production fragmentation both within and across regions. The automotive value-added network is found to have small-world properties with a hierarchical, clustered and dense structure. The differences among the US, Germany and China as major suppliers of foreign value added in global automotive value chains are remarkably revealed. Although the fragmentation of production has been developed on a global scale, a dichotomous tension between center and periphery and domestic and foreign capital lies behind it.