• Korean Journal of Soil Science and Fertilizer
• /
• v.17 no.1
• /
• pp.24-29
• /
• 1984

Seedling yield of panax ginseng depended on soil water in a modified Yang-jig seedbed with rice hull mulch and peat application which increased soil water content. Water dependency tended to increase with the increase of potassium in soil. Effect of potassium on water dependency seemed to be constant in certain range of soil water which might be the optimum water for seedling growth. Partial correlation coefficient between seedling yield and water was significant in relation to organic matter (OM), Mg and Ca. The best multiple regression of seedling yield was with $H_2O$, K and Ca. Available phosphorus (P) in soil increased with low level of peat but decreased with high level or with mulching. There was interaction between mulching and peat for P. There was significant linear relation between two of pH, $H_2O$, Ca, Mg, K, OM except between K and $H_2O$ or pH. Ammonium nitrogen negatively correlated with Mg Quadratic relation held between $NO_3-N$ and K or $NH_4-N$ and between P and K+Ca+Mg. Quadratic relation was more significant than linearity between soil factors. Mulching increased stem length. Leaf area index ranged from 1.06 to 1.67. Leaf area per plant ranged $16.0-18.8cm^2$.

• International Journal of Highway Engineering
• /
• v.10 no.2
• /
• pp.183-191
• /
• 2008

This study evaluated influence of the loading head dimension on characteristics of deformation strength ($S_D$) of asphalt mixtures. Kim test and Wheel tracking (WT) test were conducted to evaluate $S_D$ characteristics with relation to WT results for various mixtures. The $S_D$ values and coefficient of variation of $S_D$ values of r=10mm were smaller than those of r=10.5mm. It was also found that $S_D$ values obtained using r=10mm loading head showed high correlations with rut parameters of WT test. It was indicated that the aggregate size and radius (r) of round cut were statistically significant variables on $S_D$ at = 0.05 level in the analysis of variance. However, in interaction of r and aggregate size showed no significance within $10{\sim}19mm$ aggregate size at the same level. Therefore, it was concluded that the diameter (D) of 40mm and the bottom edge radius (r) of 10mm was suitable dimension of loading head for deformation strength test.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.24 no.5
• /
• pp.508-517
• /
• 2004

We described a near-field scanning microwave microscope which uses a high-quality dielectric resonator with a tunable screw. The operating frequency is f=4.5 5GHz. The probe tip is mounted in a cylindrical resonant cavity coupled to a dielectric resonator We developed a hybrid tip combining a reduced length of the tapered part with a small apex. In order to understand the function of the probe, we fabricated three different tips using a conventional chemical etching technique and observed three different NSMM images for patterened Cr films on glass substrates. We measured the reflection coefficient of different metal thin film samples with the same thickness of 300m and compared with theoretical impedance respectly. By tuning the tunable screw coming through the top cover, we could improve sensitivity, signal-to-noise ratio, and spatial resolution to better than $1{\mu}m$. To demonstrate the ability of local microwave characterization, the surface resistance of metallic thin films has been mapped.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.1
• /
• pp.19-26
• /
• 2010

The batch experiments and response surface methodology (RSM) have been applied to the investigation of the cadmium (Cd) adsorption by coal fly ash (CFA). CFA having maximum Cd removal mass of 8.51 mg/g were calculated from Langmuir model. Cd removal reaction with different initial pH ranged from 4 to 9. When the initial pH was higher, Cd was removed more by adsorption and precipitation. These results suggest that the lower pH cause an increase of $H^+$ ion concentration which competed with Cd ions for exchange sites in CFA. Also, The Cd adsorption was mathematically described as a function of parameters initial Cd concentration ($X_1$), initial pH ($X_2$), and initial CFA mass ($X_3$) being modeled by use of the Box-Behnken methods. Empirical models were developed to describe relationship between the experimental variables and response. Statistical analysis indicates that tree factors ($X_1$, $X_2$, and $X_3$) on the linear term (main effects), and tree factors ($X_1X_2$, $X_1X_3$, and $X_2X_3$) on the non-linear term (Interaction effect; cross-product) had significant effects, respectively. In this case, the value of the adjusted determination coefficient (adjusted $R^2=0.9280$) was closed to 1, showing a high significance of the model. Statistical results showed the order of Cd removal at experimental factors to be initial initial pH > initial Cd concentration > initial CFA mass.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.12 no.3
• /
• pp.139-148
• /
• 2000

In this paper, the interaction of oblique incident waves with a bottom-mounted and fluid-filled flexible membrane structure is investigated in the frame of linear hydro-elastic theory. The static shape of a membrane structure containing the fluid of a specific density is initially unknown and must be calculated before the hydrodynamic analysis. To solve hydrodynamic problem, the fluid domain is divided into the inner and outer region. The inner solution based on discrete membrane dynamic model and simple-source distribution over the entire fluid boundaries is matched to the outer solution ba~ed on an eigenfunction expansion method. The numerical results were compared to a series of Ohyama's experimental results. The measured reflection and tran¬smission coefficients reasonably follow the trend of predicted values. Using the computer program developed, the performance of a bottom-mounted and fluid-filled flexible membrane strocture is tested with various system parameters (membrane shape, internal pressure, density ratio) and wave characteristics (wave frequencies, incident wave angle). It is found that a bottom-mounted and fluid-filled flexible membrane structure can be an effel;tive wave barrier if properly designed.

• Journal of Preventive Medicine and Public Health
• /
• v.28 no.3 s.51
• /
• pp.715-725
• /
• 1995

This study was done for identifying the factors which affect psychologic symptoms of low back(LBP) patients. The study subjects were 43 work-related low back pain patients, 28 work-related non-low back pain patients and 47 general low back injury patients. The study materialis SCL 90-R for checking psychologic symptoms and questionnaire for obtaining general information about the subjects. The data were analyzed by model of analysis of covariance adjusted by several variables such as gender, age, education and marital status and then compared the least square means of symptom score between groups. To identify the factors that affect psychologic symptom, duration of suspension, return to work and interaction factor of these two variables were analyzed by multivariate model and we calcuated partial correlation coefficient of these variables. As a result, work-related LBP patients showed higher score of symptoms in somatization, depression and psychosis than work-related non-LBP and non-work-related LBP. Duration of suspension and return to work were significant explanatory variables for psychologic symptom score of work-related LBP. Then, we may conclude that the treatment and rehabilitation programe for work-related LBP should cover the strategy of early return to work.

• Journal of Astronomy and Space Sciences
• /
• v.28 no.2
• /
• pp.123-132
• /
• 2011

It is generally believed that the occurrence of a magnetic storm depends upon the solar wind conditions, particularly the southward interplanetary magnetic field (IMF) component. To understand the relationship between solar wind parameters and magnetic storms, variations in magnetic field polarity and solar wind parameters during magnetic storms are examined. A total of 156 storms during the period of 1997~2003 are used. According to the interplanetary driver, magnetic storms are divided into three types, which are coronal mass ejection (CME)-driven storms, co-rotating interaction region (CIR)-driven storms, and complicated type storms. Complicated types were not included in this study. For this purpose, the manner in which the direction change of IMF $B_y$ and $B_z$ components (in geocentric solar magnetospheric coordinate system coordinate) during the main phase is related with the development of the storm is examined. The time-integrated solar wind parameters are compared with the time-integrated disturbance storm time (Dst) index during the main phase of each magnetic storm. The time lag with the storm size is also investigated. Some results are worth noting: CME-driven storms, under steady conditions of $B_z$ < 0, represent more than half of the storms in number. That is, it is found that the average number of storms for negative sign of IMF $B_z$ (T1~T4) is high, at 56.4%, 53.0%, and 63.7% in each storm category, respectively. However, for the CIR-driven storms, the percentage of moderate storms is only 29.2%, while the number of intense storms is more than half (60.0%) under the $B_z$ < 0 condition. It is found that the correlation is highest between the time-integrated IMF $B_z$ and the time-integrated Dst index for the CME-driven storms. On the other hand, for the CIR-driven storms, a high correlation is found, with the correlation coefficient being 0.93, between time-integrated Dst index and time-integrated solar wind speed, while a low correlation, 0.51, is found between timeintegrated $B_z$ and time-integrated Dst index. The relationship between storm size and time lag in terms of hours from $B_z$ minimum to Dst minimum values is investigated. For the CME-driven storms, time lag of 26% of moderate storms is one hour, whereas time lag of 33% of moderate storms is two hours for the CIR-driven storms. The average values of solar wind parameters for the CME and CIR-driven storms are also examined. The average values of ${\mid}Dst_{min}{\mid}$ and ${\mid}B_{zmin}{\mid}$ for the CME-driven storms are higher than those of CIR-driven storms, while the average value of temperature is lower.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.5
• /
• pp.418-425
• /
• 2018

The purpose of this study was to investigate the effects of young children's empathic ability and interpersonal competence on caring behavior in forming relationships. Subjects included 152 4- and 5-year-old children attending a kindergarten located in a micropolitan city. Questionnaires required self-reporting by teachers, and were used to investigate young children's caring behavior, empathic ability and interpersonal competence in forming relationships. Data was analyzed using t-test, Pearson's correlation coefficient analysis and Stepwise-Regression analysis. Results were as follows: First, young children's caring behavior was negatively correlated with empathic ability and positively associated with interpersonal competence in forming relationships. Second, young children's emotional behavior as each domain of caring behavior were predictable variables for explaining the relative effect of the social reactivity and explaining the relative effect of relationship formation. Active behaviors were predictable variables for explaining the relative effect of follow-up instructions, but negatively affected mental burden. Normative behaviors were predictable variables for explaining the relative effect of social reactivity, but negatively predictable variables for explaining the relative effect of the relationship formation and mental burden. Value-contributing behavior in each domain of caring behavior were predictable variables for explaining the relative effect of the positive interaction.

• Korean Journal of Human Ecology
• /
• v.6 no.2
• /
• pp.133-144
• /
• 1997

Clothing is considered as a means of self-projection in the childhood and children show clear preference on their own favorite clothing on which their latent identity is reflected. Changing sex-role identity, in particular, in the modern complex society specially affects the clothing behavior of children. The purpose of this study is to investigate the clothing behavior of children in conjunction with sen-role identity and home environment variables. This study will provide fundamental information on the clothing behavior in the childhood and be of help in selecting appropriate clothing in accordance with the variation of sex-role identity. Necessary information for this study was obtained through a questionaire. 'Bem sex-role identity inventory' was used to investigate the effect of sex-role identity and the clothing behavior was studied in conjunction with the factors of conformity, dependence, aesthetics and interest. The subjects of investigation are composed of three hundred male and female elementary school students in the 5th and 6th grades. For the statistical analysis of the collected data, percentage(%), mean value(M), standard deviation(SD) and Pearson's correlation coefficient were calculated and t-test, $x^2$-test, and Duncan's multiple range test were performed. The results form this study are as follows : 1. Sex-role identity shows a little difference according to gender, order of a birth and standard of living. This small difference is shown to be statistically insignificant. 2. In clothing behavior in connection with the sex-role identity, statistically significant trend was not found in typical sex-role identity group. However, clothing behavior in modernistic sex-role identity group exhibits statistically significant results in the factors of dependence, aesthetics and interest at the level of P<.001. 3. As concerns the clothing behavior in connection with gender, boy students show statistically more significant tendency in aesthetics and interest than girls do. However, boy students show statistically more significant tendency in aesthetics than girls do in connection with the standard of living. Although the clothing behavior associated with the level of parents education, mother's age and existence of mother's job shows a little difference in mean values, statistically significant trend was not detected. 4. Clothing behavior of the children shows a meaningful correlation between the factors. 5. Through 3-dimensional variables analysis, it is found that there is no mutual interaction between gender, sex-role identity and standard of living on the clothing behavior. The results from MCA supplementary analysis reveal that there is difference according to the gender, sex-role identity and standard of living.

• Journal of the Korean Chemical Society
• /
• v.41 no.6
• /
• pp.277-283
• /
• 1997

Platinum(II) complexes(where, $[Pt(L)_2X_2]$; L=isoxazole(isox), 3,5-dimethylisoxazole(3,5-diMeisox), 3-methyl,5-phenylisoxazole(3-Me,5-Phisox), and 4-amino-3,5-dimethylisoxazole(4-ADI); X=Cl, Br) with planar ligands are investigated on antitumor activity by MM2 and EHMO calculations. It was found that, the net atomic charges of the halogen atoms in all of cis-, trans-isomers are greater than that of the nitrogen with planar form, indicating that ionic character of Pt-X bond is greater than that of Pt-N. Also, the ${\sigma}MO$ energy level($E{\sigma}_{(Pt-X)}$) of the interaction between $d_{x2-y2}$ orbital of Pt atom and $p_x$ orbital of X found to be higher than that of between $d_{x2-y2}$ orbital of Pt atom and $p_x$ orbital of N about all the complexes. It is found that bond strength of between Pt and X atom is weaker than that of between Pt and N atom. The ${\sigma}MO$ energy level($E{\sigma}_{(Pt-X)}$) of trans- complexes found to be higher than that of cis- complexes, as a result of bond strength of Pt-X in cis- and trans-complexes, for all the complexes. The degree of dissociation of X atom in Pt-X bond for trans-complexes are related to antitumor activity and the logIA value of inhibitory activity coefficient(IA).