• Environmental Engineering Research
• /
• v.18 no.1
• /
• pp.3-8
• /
• 2013

Collision cell technology-inductively coupled plasma-mass spectrometry (CCT-ICP-MS) was used to measure the concentrations of approximately 19 elements associated with airborne PM2.5 samples that were collected from a roadside sampling station in Daejeon, Korea. Standard reference material (SRM 2783, air particulate on filter media) of the National Institute of Standards and Technology was used for the quality assurance of CCT-ICP-MS. The elemental concentrations were compared statistically with the certified (or recommended) values. The patterns of distribution were clearly distinguished between elements with their concentrations ranging over four orders of magnitude. If compared in terms of enrichment factors, it was found that toxic trace elements (e.g., Sb, Se, Cd, As, Zn, Pb, and Cu) of anthropogenic origin are much more enriched in PM2.5 samples of the study site. To the contrary, the results of the correlation analysis showed that PM2.5 concentrations can exhibit more enhanced correlations with the elements (e.g., Fe, K, Si, and Ti) arising from earth's crust. The findings of strong correlations between PM2.5 and the elements of crustal origin may be directly comparable with the dominant role of those species by constituting a major fraction of even PM2.5 as well as PM10 at the roadside area.

• Advances in environmental research
• /
• v.9 no.2
• /
• pp.123-133
• /
• 2020

A time series dataset was conducted to ascertain the effect of water table on the variability in and emission of CH₄ and CO₂ concentrations at a closed landfill site. An in-situ data of methane/carbon dioxide concentrations and environmental parameters were collected by means of an in-borehole gas monitor, the Gasclam (Ion Science, UK). Linear regression analysis was used to determine the strength of the correlation between ground-gas concentration and water table. The result shows CH₄ and CO₂ concentrations to be variable with strong negative correlations of approximately 0.5 each with water table over the entire monitoring period. The R² was slightly improved by considering their concentration over single periods of increasing and decreasing water table, single periods of increasing water table, and single periods of decreasing water table; their correlations increased significantly at 95% confidence level. The result revealed that fluctuations in groundwater level is the key driving force on the emission of and variability in groundgas concentration and neither barometric pressure nor temperature. This finding further validates the earlier finding that atmospheric pressure - the acclaimed major control on the variability/migration of CH₄ and CO₂ concentrations on contaminated sites, is not always so.

• Journal of the Korean Solar Energy Society
• /
• v.33 no.4
• /
• pp.70-79
• /
• 2013

These day cities experience serious climatic changes due to environmental load caused by disturbance in the circulation systems of water resources and energy. As technological improvement to respond to various climatic changes and disasters are also requested in the field of construction, inter-disciplinary studies linked to the establishment of sustainable environmental control and energy systems is required in a consilient perspective. This study aims to infer correlations in the impact of environmental changes caused by rooftop greening system on the photovoltaic power generation efficiency through computer simulation in an integrated perspective. By doing so, it seeks to provide basic study for developing a photovoltaic system integrated with building revegetation that is sustainable in environmental and resource aspects. A simulation showed that, in the case of sunshine hours in June, the green surface indicated temperature lowering effects of $9.19^{\circ}C$ on average compared to the non-green surface and temperature was $9.81^{\circ}C$ lower. Due to such greening effects, at the highest sunlight timepoint in June, Pmpp improved 119W and heat loss rate dropped 7.8%.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.2
• /
• pp.45.3-46
• /
• 2018

Oscillations in a sunspot are easily detected through the Doppler velocity observation. Although the sunspot oscillations look erratic, the wavelet analysis show that they consist of successive wave packets which have strong power near three or five minutes. Previous studies found that 3-min oscillation at the chromosphere is a visual pattern of upward propagating acoustic waves along the magnetic field lines. Resent multi-height observations help this like vertical study, however, we also focus on horizontal facet to extend three dimensional understand of sunspot waves. So, we investigate a fragmented sunspot expected to have complex wave profiles according to the positions in the sunspot observed by the Fast Imaging Solar Spectrograph. We choose 4 points at different umbral cores as sampling positions to determine coherence of oscillations. The sets of cross-correlation with three and five minutes bandpass filters during a single wave packet reveal interesting results. Na I line show weak correlations with some lags, but Fe I and Ni I have strong correlations with no phase difference over the sunspots. It is more remarkable at Ni I line with 3-min bandpass that all sets of cross-correlation look like the autocorrelation. We can interpret this as sunspot oscillations occur spontaneously over a sunspot at photosphere but not at chromosphere. It implies a larger or deeper origin of 3-min sunspot oscillation.

• Korean Journal of Family Welfare
• /
• v.23 no.4
• /
• pp.549-573
• /
• 2018

The purpose of this study is to examine main variables of dysfunctional communication, which worsen marital conflicts in terms of marital interaction and to clarify the relative effects of such variables. The subjects were 295 married males and females, and collected data were analyzed using SPSS WIN 23.0 program. The main findings are as follows : First, the tendencies of related variables showed that the levels of spouses' perspective taking and routine marital responsiveness were higher for both males and females, while the levels of irrational belief for marital relations and dysfunctional communication were low. Second, an analysis of spouses' perspective taking, routine marital responsiveness, irrational belief in marital relations and correlations of dysfunctional communication showed that spouses' perspective taking and routine marital responsiveness for both males and females have negative correlations with dysfunctional communication. The higher spouses' perspective taking and routine marital responsiveness, the lower the level of irrational belief related to marital relations and the lower the level of dysfunctional communication. This study clarifies that spouses' perspective taking, routine marital responsiveness and irrational faith for marital relations influence marital dysfuctional communication and has an implication, in that the findings can be used as basic data for seeking methods to solve problems of couples who experience conflicts derived from dysfunctional communication.

• Journal of Korean Society on Water Environment
• /
• v.27 no.6
• /
• pp.760-768
• /
• 2011

Jinwi Stream is considerably polluted. The urban development in a Jinwi Stream basin can make state of aquatic ecosystem worse. However, researches for aquatic ecosystems in Jinwi Stream are insufficient. In this study, biotic indices of periphytic diatoms (DAIpo and TDI), benthic macroinvertebrates (EPT, KSI and ESB) and fish (IBI) were compared with the annual water quality data. Benthic macroinvertebrates indices showed highly significant correlations with concentrations of organic materials and nutrients, while DAIpo, TDI and IBI showed low correlations with them. In particular, ESB can be considered as an useful indicator that reflects the degree of diversity and abundance of biotic community as well as water quality. In polluted and disturbed streams as Jinwi Stream, DAIpo, TDI and IBI appeared to be not available for evaluating and discriminating the water quality, although they have been known as good indices in general streams.

• International Journal of Computer Science & Network Security
• /
• v.22 no.4
• /
• pp.159-168
• /
• 2022

The recent outbreak of COVID-19 pandemic cases around the globe has affected Saudi Arabia with around 15, 00,000 confirmed cases within the initial 4 months of transmission. The present investigation analyzed the relationship between daily COVID-19 confirmed cases and meteorological parameters in seventeen cities of KSA. We used secondary published data from the Ministry of Health, KSA daily dataset of COVID-19 confirmed case counts. The meteorological parameters used in the present investigation are temperature, humidity, dew point, and wind speed. Pearson correlation and Spearman rank correlation tests were utilized for data analysis. The incubation period of COVID-19 varies from 1 day to 14 days as per available information. Therefore, an attempt has been made to analyze the effects of meteorological factors with bins of 1, 3, 7, and 14 days. The results suggested that the highest number of correlations (15 cities) was observed for temperature (maximum, minimum, and average) and humidity (12 cities) (minimum and average). The dew point showed relationships for 7 cities and wind showed moderate correlations only for 2 cities. The study results might be useful for authorities and stakeholders in taking specific measures to combat the Covid-19 pandemic.

• Journal of Technologic Dentistry
• /
• v.45 no.1
• /
• pp.8-13
• /
• 2023

Purpose: This study aims to induce interest in the future society that could change with the advance of the 4th Industrial Revolution. It also intends to identify the direction of university education by investigating the perception of university students majoring in dental laboratory technology about the latest technology used in this era. Methods: The study recruited 240 college students majoring in dental laboratory technology at K and D universities in Gangwon-do and Daejeon, respectively. Online and face-to-face surveys were conducted from March 20, 2022 to April 10, 2022. Results: Although their interest in the use of emerging technologies during the 4th Industrial Revolution was above average 3.85, the dental laboratory technology students exhibited relatively high levels of anxiety 3.19 and reluctance 2.96. Second, their interest in emerging technologies demonstrated positive correlations with major satisfaction and understanding of concepts and readiness, whereas reluctance and anxiety pointed to negative correlations with understanding of the concepts of the 4th Industrial Revolution. Conclusion: Formulating guidelines is necessary to help students increase their understanding of the 4th Industrial Revolution and prepare them appropriately by setting an educational direction that can flexibly respond to the rapidly changing industrial environment.

• The Bulletin of The Korean Astronomical Society
• /
• v.45 no.1
• /
• pp.41.1-41.1
• /
• 2020

Different molecular lines trace different physical environments (with various densities and temperatures) within molecular clouds (MCs). Therefore, multimolecular line observations are crucial to study the physical and chemical structures of MCs. We observed the Orion A and Ophiuchus clouds in six different molecular lines as a Taeduk Radio Astronomy Observatory Key Science Program (TRAO-KSP), "mapping Turbulent properties In star-forming MolEcular clouds down to the Sonic scale" (TIMES; PI: Jeong-Eun Lee). Here, we investigate the characteristic relations between the observed lines by performing the Principal Component Analysis (PCA). We also investigate the correlation between the line intensity distributions and the physical parameters, such as the gas column density and dust temperature. Finally, we will discuss how the correlations among different chemical tracers vary with the star formation environments.

• Korean Journal of Childcare and Education
• /
• v.19 no.6
• /
• pp.39-54
• /
• 2023

Objective: This study aimed to develop a parent play interaction observation scale (PPIOS-Toddler) and analyze it in terms of item discrimination, reliability, and validity. Methods: The subjects of the study were 97 toddlers and mothers. This scale consisted of three categories, six domains and 22 items on a 5-point scale. For the item discrimination of the observation scale, an independent standard t-test was conducted to analyze the significant difference in average between the upper and lower groups for each item. The reliability of the observation scale was calculated by Cronbach's α, the intra-item agreement, and the validity was examined through content validity, the correlation between subdomains and total scores, and official validity using PICCOLO. Results: In item discrimination analysis, all items exhibited differences between upper and lower groups. The overall internal agreement for the observation scale was 0.95, with factor-specific internal agreement ranging from 0.83 to 0.95. The observation scale demonstrated notable correlations between total scores and sub-factors (0.45 to 0.93) and significant correlations with PICCOLO total scores (0.66 to 0.86). Conclusion/Implications: The study successfully verified the item discrimination, reliability, and validity of the Parent Play Interaction Observation Scale (PPIOS-Toddler).