• Korean Journal of Materials Research
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• v.26 no.8
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• pp.430-437
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• 2016

Aluminum oxide ($Al_2O_3$) thin films were grown by atomic layer deposition (ALD) using a new Al metalorganic precursor, dimethyl aluminum sec-butoxide ($C_{12}H_{30}Al_2O_2$), and water vapor ($H_2O$) as the reactant at deposition temperatures ranging from 150 to $300^{\circ}C$. The ALD process showed typical self-limited film growth with precursor and reactant pulsing time at $250^{\circ}C$; the growth rate was 0.095 nm/cycle, with no incubation cycle. This is relatively lower and more controllable than the growth rate in the typical $ALD-Al_2O_3$ process, which uses trimethyl aluminum (TMA) and shows a growth rate of 0.11 nm/cycle. The as-deposited $ALD-Al_2O_3$ film was amorphous; X-ray diffraction and transmission electron microscopy confirmed that its amorphous state was maintained even after annealing at $1000^{\circ}C$. The refractive index of the $ALD-Al_2O_3$ films ranged from 1.45 to 1.67; these values were dependent on the deposition temperature. X-ray photoelectron spectroscopy showed that the $ALD-Al_2O_3$ films deposited at $250^{\circ}C$ were stoichiometric, with no carbon impurity. The step coverage of the $ALD-Al_2O_3$ film was perfect, at approximately 100%, at the dual trench structure, with an aspect ratio of approximately 6.3 (top opening size of 40 nm). With capacitance-voltage measurements of the $Al/ALD-Al_2O_3/p-Si$ structure, the dielectric constant of the $ALD-Al_2O_3$ films deposited at $250^{\circ}C$ was determined to be ~8.1, with a leakage current density on the order of $10^{-8}A/cm^2$ at 1 V.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.2
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• pp.79-93
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• 1990

The purpose of this study is to establish better residential environment in APT. complex. In this study, the actual conditions of exterior space, user behavior and degree of satisfaction are investigated and analyzed on the 5 high-rise story APT complex in Taegu city. The results of this study were as follow ; The size and arrangement of organizational elemnnt to exterior space in APT. complex have been regulated by law and regulations as the buildings coverage and floor space index, but housinghold and accessibility to the racility will be simultaneously considered to raise Quality of the residential environoment. The main user behavior to exterior space in APT. complex was practical activity and the user behavior pattern by week and among APT. complex were found similiarly. In the ratio of use to exterior space in APT. Complex, that of high-rise residents were lower than that of lowrise residents. In the degree of satisfaction by property of variables to exterior environment In APT. comples, physical of buildings, social - psychologic, managerial economical, physical property of exterior space were estimated positively, but properly of facility were estimated negatively. The degee of satisfaction to exterior environment in APT. complex was highly Influenced by green space, site size. As a result of ractor analysis, the four factors were drawn out from exterior environment in APT. complex. and the factors that have an effect on the degree of residents' satisfaction by factorscore were found in the order of importance as fallow ; managemental, physical, environmental, organizalional factor. Therefore, devilopment of APT. complex should be considered in a view of environmental psychology according to physical organization for used in the future. It is recommended that this problems should be necessitated to be more deeply studies in the future.

• Atmosphere
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• v.22 no.1
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• pp.13-28
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• 2012

The $PM_{10}$ concentration data is useful for indentifying intensity and a transport way of Asian dust. However, it is difficult to identify them properly due to the limited spatial resolution and coverage. Therefore, a methodology to estimate $PM_{10}$ concentration using visibility data obtained from synoptic observation was developed. To derive the converting function, correlation between visibility and $PM_{10}$ concentration is investigated using visibility and $PM_{10}$ concentration data observed at 20 stations in Korea from 2005 to 2009. To minimize bias due to atmospheric moisture, data with higher relative humidity over a critical value were eliminated while deriving $PM_{10}$-visibility relationship. As a result, an exponentially decreasing function of visibility is obtained under the condition that relative humidity is less than 82%. Verification of the visibility converting function to $PM_{10}$ concentration was carried out for the dust cases in 2010. It was found that spatial distributions of $PM_{10}$ calculated by visibility are in good agreement with the observed $PM_{10}$ distribution, especially for the strong dust cases in 2010. And correlation between the derived and observed $PM_{10}$ concentration was 0.63. We applied the function to obtain distributions of $PM_{10}$ concentration over North Korea, in which concentration data are not available, and compared them with satellite derived dust index, IODI distributions for dust cases in 2010. It is shown that the visibility function estimates quite similar patterns of dust concentration with IODI image, which suggests that it can contribute for prediction by indentifying transport route of Asian dust.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.449-458
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• 2010

The e-Learning quality assurance is a part of responsibility for education in latest information age, and should be understood as a basic direction for qualitative enhancement rather than quantifiable expansion. In such a context, this study sought to survey latest trends of e-Learning quality assurance activities deployed around overseas countries, so that it could give possible implications on how to plan and perform e-Learning quality assurance in Korea. So, this study focused on surveying actual conditions, coverage, target and useful indices of e-Learning quality assurance activities deployed by 9 institutions across 5 countries, and characterizing those activities across 5 countries. As a result, this study could find out its implications such as acquisition of various resources available for e-Learning, nationwide consolidation of e-Learning quality assurance activities, development of specialists in e-Learning quality assurance, and choice and focus for e-Learning quality assurance system. In other words, it was found that e-Learning quality assurance should be approached from nationwide standpoint in the interest of better educational quality, rather than from viewpoint of task.

• Ocean and Polar Research
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• v.33 no.1
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• pp.85-97
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• 2011

The tidal flats of Korea today have reduced by 40% in size compared to 1964. To manage this important habitat properly, development of well-organized and nationwide-applicable grading systems is required. There have been several assessment systems proposed previously in Korea, but they are critically flawed in that selected biological indicators are not adequate and grading criteria are obscure and arbitrary. We reviewed the indicators used in these previous evaluation systems (e.g., diversity indices, quantity and quality of benthic macrofauna, halophytes, water birds, etc.) and subsequently proposed new indicators and an improved grading scheme. For the quantitative assessment of macrobenthic community, biomass reflecting production and ecosystem function is recommended over density, which is much less discriminatory among habitats. Of biodiversity indices used, within-, between-habitat and regional biodiversity indices that accurately reflect sampling efforts are suggested. In addition, we proposed to include species rarity, ecosystem engineers, and the ecological quality index ISEP (Inverse function of Shannon-Wiener Evenness Proportion). As for halophytes, their low spatial coverage on benthic habitat suggests that their presence can be used as an ecological indicator of benthic habitat, regardless of their protective status. We stress the need to introduce 1) quantile approach for quantitative indicators (e.g., diversity, biomass, etc.) in relation to grading, 2) presence-absence approach for spatial or aggregate indicators (e.g., boundaries of halophytes and feeding ground of water birds) and 3) benthic habitat mapping that combines all of these indicators.

• Korean Journal of Remote Sensing
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• v.30 no.4
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• pp.505-510
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• 2014

Normalized Difference Vegetation Index (NDVI) is a major indicator for monitoring climate change and detecting vegetation coverage. In order to retrieve NDVI, it is preprocessed using cloud masking and atmospheric correction. However, the preprocessed NDVI still has abnormally low values known as noise which appears in the long-term time series due to rainfall, snow and incomplete cloud masking. An existing method of using polynomial regression has some problems such as overestimation and noise detectability. Thereby, this study suggests a simple method using amoving average approach for correcting NDVI noises using SPOT/VEGETATION S10 Product. The results of the moving average method were compared with those of the polynomial regression. The results showed that the moving average method is better than the former approach in correcting NDVI noise.

• The Korean Journal of Pain
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• v.29 no.4
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• pp.255-261
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• 2016

Background: Thoracic epidural anesthesia is frequently used to maintain intraoperative and postoperative analgesia. Frequently, 3 ml of local anesthetic is used as a test dose, or for intermittent epidural injection. We assessed the extent of the spread of 3 ml of contrast medium in the thoracic epidural space and attempted to identify any correlating factors affecting the epidurography. Methods: A total of 70 patients were enrolled in the study, and thoracic epidural catheterizations were performed under fluoroscopic guidance. Using 3 ml of contrast medium, epidurography was evaluated to confirm the number of spinal segments covered by the contrast medium. Correlation analysis was performed between patient characteristics (sex, age, body mass index, weight, height, and location of catheter tip) and the extent of the contrast spread. Results: The mean number of vertebral segments evaluated by contrast medium was $7.9{\pm}2.2$ using 3 ml of contrast medium. The contrast spread in the cranial direction showed more extensive distribution than that in the caudal direction, with statistical significance (P < 0.01). Patient height demonstrated a negative correlation with the extent of distribution of contrast medium (r = -0.311, P < 0.05). Conclusions: Thoracic epidurography using 3 ml of contrast medium results in coverage of a mean of $7.9{\pm}2.2$ spinal segments, with more extensive cranial spread, and patient height showed a weak negative correlation with the distribution of contrast medium.

• Journal of radiological science and technology
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• v.43 no.1
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• pp.23-27
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• 2020

In South Korea, female individuals in their forties show a high rate of incidence, with approximately 13% of the patients being <40 years. This statistic is more than twice as high as that in Western countries. It is therefore necessary to identify the risk factors for breast cancer incidence by age and economic activity participation status. Women aged 30 to 59-whether breast cancer patients or those in the control group and having no breast cancer-were appraised from the sample cohort database. The data were analyzed using the statistical software R36.2. To identify the factors affecting breast cancer incidence, the degree of association was determined with HR and 95% CI by means of cox regression analysis. As for the socio-demographic variables, the older the individual, the higher the risk of breast cancer incidence becomes. As for the economic activity variables, those who were dependents (unemployed) and who had higher income (medium and high) were at higher risk of breast cancer incidence, which was statistically significant. The income-adjusted HR (model 1) for breast cancer development associated with the economic activity was 1.452 (95% CI, 1.19-1.77). The body mass index and alcohol intake-adjusted HR (model 2) was 1.431 (95% CI, 1.18-1.74). One needs to pay attention to policy plans regarding women's quality of life, as well as to the risk of breast cancer incidence by their economic activity. In other words, policies need to give post care, instead of focus on early detection and cancer treatment.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.276-285
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• 2015

The aim of this study was to identify the impact of community factors on the community-level Health-Related Quality of Life (HRQOL) in Korea. This was a cross-sectional study conducted in 2012 using secondary data(n=209) of the Korean Statistical Information Service. The framework was based on community factors provided by the International Council of Science (ICSU) and community factors were categorized based on six aspects. Multiple regression was applied to community factors depending on the community EQ-5D index. Smoking rate, "Good" self-rated health rate, water and wastewater coverage rate, and financial independency rate were significantly and positively associated with the EQ-5D score. Net migration rate(more move out than move in), obesity rate, unmet needed health care rate, and community type(rural than urban) were significantly and negatively associated with the EQ-5D score. This study identifies association for the impact of community factors on the community-level HRQOL and can provide useful evidence for development of community health promotion policies.

• Korean journal of communication and information
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• v.32
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• pp.75-111
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• 2006

The purpose of this study is to investigate the dependency level of news attributes on the government source and to measure up the impact of news negativity, press ideology, and the conflict level on the forementioned relationship in the context of the prime definer role of the government. The prime definer means that the official source such as the government may dominate media access and create media dependency on the issue and issue attributes. To test the research questions, the content analyses of both the government briefing materials and newspapers were conducted. Textual arguments regarding the new administrative capital were chosen for the analysis. The results showed that the government source played a prime definer role in framing issue attributes of news reporting. This prime definer role was not diminished even among the negative coverage about the chosen topic. However, press ideology and the conflict level influenced the relationship between news attributes and the government-released information in some extent.