• Proceedings of the KIEE Conference
• /
• 2002.06a
• /
• pp.102-105
• /
• 2002

In this paper, the electron transport characteristics in $CF_4$ has been analysed over the E/N range 1${\sim}$300 [Td] by a two-term approximation Boltzmann equation method and by a Monte Carlo simulation. The motion has been calculated to give swarm parameters for the electron drift velocity, longitudinal diffusion coefficient, the ratio of the diffusion coefficient to the mobility, electron ionization and attachment coefficients, effective ionization coefficient, mean energy, collision frequency and the electron energy distribution function. The swarm parameter from the swarm study are expected to serve as a critical test of current theories of low energy electron scattering by atoms and molecules, in particular, as well as crucial information for quantitative simulations of weakly ionized plasmas.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11a
• /
• pp.613-616
• /
• 2001

This $SF_{6}$ gas is widely used in industrial of insulation field. In this paper, $N_2$ is mixed to improve pure $SF_{6}$ gas characteristics. Electron transport coefficients in $SF_{6}$-$N_2$ mixture gases are simulated in range of E/N values from 70 to 400 [Td] at 300K and 1 Torr by using Boltzmann equation method. The results of this method, which are like electron drift velocity, ionization coefficient, attachment coefficient, effective ionization coefficient, and critical E/N, can be important data to present characteristic of gas for insulation. Specially critical E/N is a data to evaluate insulation strength of a gas and is presented in this paper for various mixture ratios of $SF_{6}$-$N_2$ mixture gases.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.468-469
• /
• 2007

In this paper, the electron transport characteristics in $CF_4$ has been analysed over the E/N range 1~300[Td] by a two-tenn approximation Boltzmann equation method and by a Monte Carlo simulation. The motion has been calculated to give swarm parameters for the electron drift velocity, longitudinal diffusion coefficient, the ratio of the diffusion coefficient to the mobility, electron ionization and attachment coefficients, effective ionization coefficient, mean energy, collision frequency and the electron energy distribution function. The swarm parameter from the swarm study are expected to serve as a critical test of current theories of low energy electron scattering by atoms and molecules, in particular, as well as crucial information for quantitative simulations of weakly ionized plasmas.

• Journal of Korean Society of Water and Wastewater
• /
• v.10 no.1
• /
• pp.112-120
• /
• 1996

In this study, the porous glass media was utilized as biomass carrier, and the optimum characteristics of this new media in fixed bed biofilm process were investigated. The characteristics of media considered here are a void volume fraction, a specific surface area, and surface characteristics of media. The effect of surface roughness and material could be clearly demonstrated by the fact that the porous glass media showed a good potential for biofilm development. This might results from the fact that biofilm is initially formed in the surface cavities of the media is protect from the shear effect. Therefore, the microcolonies are not readily detached by the fluid shear. In the steady state, biofilm formation along the packing bed depth was different from media to media. The specific area was also an important factor for the attachment of microorganism on the media surface. The specific area was also an important factor for the attachment of microorganism on the media surface. In the case of porous glass media, about $100m^2/m^3$ was enough to obtain a good organic removal efficiency The organic removal efficiency could be improved by increasing the void volume fraction in the reactor, at least 80% was required to obtain a high removal efficiency and prevent clogging. From the analysis of kinetics study, the yield coefficient, Y, was 0.42 mgMLSS/mgSBOD, endogenous respiration coefficient, ke, was $0.12day^{-1}$ and substrate removel coefficient of Mckinney. km, was $16.8hr^{-1}$ for the porous glass media G-2

• Research in Community and Public Health Nursing
• /
• v.8 no.2
• /
• pp.277-288
• /
• 1997

The purpose of this study is to identify the behavioral subsystems of the obese adult and contribute to the utility of Johnson's Behavioral System Model. The subjects were 167 obese adults in out-patients clinics of 2 hospitals and health clinics for 4 companies. These data were collected by a structured questionnaire with 52 items from July 1 to Sep. 30, 1995. The instrument used for this study was modified from the DBSM -self reporting instrument (1983) and Grubbs(1980)'s. The reliability of this method was cronbach's ${\alpha}$=.8476 and the construct validity of it was accepted by using a factor analysis. These data were analyzed by frequency, percentage, mean, standard deviation, factor analysis, pearson's correlation coefficient, Kruskal-Wallis with an SPSS PC+ Program. The results of this study were as follows: 1. The 9 behavioral subsystems of the obese were indentified : sex-related, attachment-affiliative I(social), dependency, ingestive, eliminative, restorative, aggressive-protective, attachment-affiliative and II (familial), an achievement behavioral subsystem. 2. Out of 9 subsystems, the highest significant positive correlation between dependency and acheivement subsystem was found(r=.5357, p<.01), The next, attachment-affiliative I and attachment-affiliative II subsystem was correlated significantly (r=.4526, p<.01). Significant positive correlations among sex-related, achivement, attachment-affiliative I, II, dependency, restorative, and aggressive-protective subsystems were found. But, ingestive and eliminative subsystems were not correlated with the above seven subsystems significantly, only the positive correlation between the ingestive and eliminative subsystems was found. 3. The explained variance of the 9 subsystems was explained as 56.1% out of a total of one. The sex-related subsystem was the first factor explaining 16.3% of the total variance and then the next 8 factors which resulted in 39.8%. According to the results of this study, the suggestions were as follows: 1. In the nursing practice, nursing assessmentand intervention of the obese should be in cluded not only in ingestive and eliminative subsystems but also in sex-related, attachment-affiliative I, dependency, restorative, aggressive-protective, attachment -affiliative II, and achievement behavioral subsystem. 2. Concerning instruments, some items to measure the eliminative, dependency, and aggressive-protective behavioral subsystems with relatively reliability are needed. 3. Johnson's concept of a dependency subsystem should be clarified. 4. Correlation among the 7 subsystems, and the ingestive and eliminative subsystems should be clarified.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.3 no.4
• /
• pp.271-275
• /
• 1998

Controversial observations on the effect of pre-attached bacteria on the attachment of diatoms to artificial surfaces immersed in seawater have been made. Furthermore, it is not known whether or not pre-attached bacteria on artificial surfaces influence attachment of diatoms in natural seawater. In this study, we used various surfaces to which marine bacteria were pre-attached for different incubation periods. In the first experiment, glass slides were initially attached by marine natural bacteria with different exposure time (0-133 hr) and then immersed into seawater for a certain time period. The attachment of diatoms was not affected by the abundance of pre-attached bacteria (p > 0.05). The maximum abundance of attached diatoms was found on control surfaces, and the minimum abundance on surfaces where attached bacterial abundance was highest. In the second experiment, glass slides and acryl slides, either attached by marine natural bacteria for 6 days or coated by agar, were immersed in seawater. Untreated slides were also employed. On the surfaces of acryl slides with the most abundant attached bacteria ($5.4{\pm}0.02{\times}10^5\;cells\;cm^{-2}$), abundances of attached diatoms were less than those on untreated slides. On the surfaces of glass slides with bacterial abundance of $2.5{\pm}1.0{\times}10^5\;cells\;cm^{-2}$, however, abundances of attached diatoms were not different from those of untreated slides. On the agar-coated slides, the immigration rate and immigration coefficient were on average > 2 folds compared to other surfaces, indicating high rates of diatom attachment on mucilage simulated surfaces. Therefore, it seems that pre-attachment of bacteria is not prerequisite for the attachment of diatoms on artificial surfaces.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.3
• /
• pp.47-52
• /
• 2024

The purpose of this study was to examine the relationship between children's self-esteem, peer attachment, parenting attitudes, and children's grit, and to specifically identify the influence of children's self-esteem, peer attachment, and parenting attitudes on children's grit. The characteristics of the survey subjects were identified through frequency analysis and descriptive statistics analysis of the 11th year of the Korea Children's Panel (2018) data, and Pearson's moment correlation coefficient was calculated for correlation analysis between major variables. Multiple regression analysis was conducted to examine the influence of children's self-esteem, peer attachment, and parenting attitudes on children's grit. The research results are as follows. First, children's self-esteem, peer attachment, and parenting attitudes were found to be positively correlated. Second, the child's self-esteem was found to have a positive influence on the child's grit, and among the peer attachment sub-variables, peer trust was found to have an influence, and among the sub-factors of parenting attitude, 'mother' affection/involvement, 'father' Democratic relationships were found to have an effect. In other words, it can be seen that children's self-esteem at the personal level, peer trust at the school level, and maternal affection and paternal relationship at the family level are useful variables that strengthen children's grit. Accordingly, in order to improve children's grit level, we must consider promotion measures through intervention and support at a multifaceted level.

• Human Ecology Research
• /
• v.54 no.6
• /
• pp.611-620
• /
• 2016

This study examined how parent-child attachment, parental involvement in child rearing and instruction for children's effective use of a smart device reflect on young children's smart device overuse behavior. We collected questionnaires from 196 parents with children attending early childhood education institutions for the survey. Frequency analysis as well as Person correlation coefficient and regression analysis were conducted using IBM SPSS 21.0 statistics. The results showed that 91% of targeted young children were using a smart device and 78% first used them before age 5. As for time of use hours, 43.9% used their smart device from 30 minutes to 1 hour on average. In addition, parent-child attachment and father's involvement in child rearing were found to be inversely correlated to young children's smart device overuse. The result of hierarchical regression analysis on parent factors influencing young children's smart device overuse behavior indicated that mothers' contact-seeking behavior to young children, mother's involvement in learning and instruction for children's effective use of a smart device at home had beneficial effects. This study analyzed parent factors that influenced young children's smart device overindulgence. In addition, the baseline data of this study will be utilized to develop programs for the prevention and therapy to solve the smart device overindulgence as well as to establish young children's guidelines for using a smart device.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1544-1545
• /
• 2011

For quantitative understanding of gas discharge phenomena, we should know electron collision cross section. Processing plasma etching of semiconductor, and research are being used in the etching source $C_4F_6$ gas may be used by itself and mixed with other gases are also used. However, the molecular gas $C_4F_6$ study on the characteristics of the electron transport and the cross-sectional area of the decision is still lacking. Therefore, we understand the electron transport characteristics and analysed the electron transport coefficients. And to understand and interpret physical properties of the ionization coefficient ${\alpha}$/N, and the attachment coefficient ${\eta}$/N in $C_4F_6$ gas.

• Journal of Periodontal and Implant Science
• /
• v.42 no.6
• /
• pp.212-216
• /
• 2012

Purpose: The aim of this study was to evaluate the relationship between maternal periodontal disease and the health status of newborns using Apgar scores. Methods: One hundred pregnant women with periodontal disease were included in the case series and 100 pregnant women without periodontal disease were placed in the control group, respectively. The periodontal parameters of bleeding on probing (BOP), clinical attachment loss (CAL), probing depth (PD), birth weight, and Apgar scores were recorded in both groups. T-tests and Pearson's correlation coefficient were used to determine the birth weight odds ratio to analyze the relationship between the periodontal parameters of BOP, CAL, and PD on the one hand and an Apgar score of less than 7. An unpaired Student's t-test was used to analyze differences in means between the case and control groups using SPSS ver. 13. Results: The means of the ages, periodontal pocket depths, attachment loss, areas with BOP, Apgar score in the first 5 minutes and infant birth weight exhibited statistically significant differences between the case and control groups. The ratio of an Apgar score of <7 to periodontal disease was 3.14; the ratio of low birth weight risk in mothers with periodontal disease to that in mothers without periodontal disease was 2.74. Pearson's correlation coefficient revealed a significant correlation between the infant birth weight and BOP, CAL, and PD of the mother. In addition, there was a significant correlation between the Apgar score and BOP, CAL, and PD and also between the Apgar score and infant birth weight. Conclusions: The results of this study showed a significant relationship between periodontal disease and infant birth weight; in addition, there was a significant relationship between the periodontal indexes of BOP, CAL, and PD on the one hand and the Apgar score on the other.