• Journal of the korean society of oceanography
• /
• v.37 no.2
• /
• pp.66-75
• /
• 2002

Temporal variation of nutrients and dissolved major and trace elements have been studied in the Yeongsan River, Korea. There were significant temporal fluctuations in the concentrations of these elements depending upon the flow condition. $NH_4$, $PO_4$, Na, Mg, Ca, K, Mn, Cu, Ni, Zn, Co, As and U concentrations were inversely related to the flow; that is, they are the highest at low flow and the lowest at high flow. It indicates that these elements are derived from point sources such as rock weathering and/or human activities and then diluted by increasing flow. Meanwhile, Fe and Si concentrations varied proportionally to the flow indicating that they are derived from diffuse sources including reactions within soil. The concentration-flow relationships showed that hydrology of the river is the most important factor controlling the chemical composition of the Yeongsan riverwater, which was compatible of the results of R-mode factor analysis.

• Journal of the Korean Wood Science and Technology
• /
• v.27 no.4
• /
• pp.51-56
• /
• 1999

Finite element method was utilized to analyze crack tip stress and displacement field under drying stress case as stepwise loading. Opening mode of single-edge-notched model was employed and analyzed by linear elastic fracture mechanics of plane stress case. The drying stresses were applied as stepwise loads at the boundary elements of the model with 10 steps of time serial. The stress intensity factor($K_I$) for opening mode reached to its maximum just prior to the stress reversal. The $K_I$ from the displacement fields revealed 1.7 times higher than those from stress fields. By comparing the two sets of $K_I$ from displacement and stress fields, single parameter $K_I$ showed its validity to characterize displacement fields around the crack tip front while stress field could not be characterized due to large variations between two sets of data.

• Journal of Mechanical Science and Technology
• /
• v.15 no.1
• /
• pp.61-65
• /
• 2001

Using the theory of linear piezoelectricity, the problem of two layered strip with a piezoelectric ceramic bonded to an elastic material containing a finite interface crack is considered. The out-of-plane mechanical and in-plane electrical loadings are simultaneously applied to the strip. Fourier transforms are used to reduce the problem to a pair of dual integral equations, which is then expressed in terms of a Fredholm integral equation of the second kind. The stress intensity factor is determined, and numerical analyses for several materials are performed and discussed.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.13 no.1
• /
• pp.125-134
• /
• 1989

Pseudo-random load waves for fatigue testing were generated by personal computer simulation and preliminary study was performed on the growth behavior of surface fatigue crack under random ladings. The closure behavior and growth rates of surface fatigue crack were significantly influenced by the characteristics of random waves. It was also found that the growth rates of surface fatigue crack under random loadings could not be always described by the effective stress intensity factor based on the concept of crack closure.

• Korean Journal of Child Studies
• /
• v.26 no.1
• /
• pp.47-59
• /
• 2005

The Early Life Problems Scale consisting of 5-point rating for each item was prepared from the results of a questionnaire of 163 items with two sub scales constructed on the basis of Diagnostic Classification: 0-3. Respondents were 361 parents with newborn to 3-year-old children (197 boys and 164 girls). Hypothetical constructs of mental and developmental problems were identified by exploratory factor analysis. The resulting 22 factors explained 58.5% and 72.9% of the common variance for scales I and II, respectively. The rotation procedure yielded 134 items of which 118 had factor loadings of more than .30. Face validity was obtained on the basis of 18 items. The coefficients of correlation between and within factors suggest that there are interrelationships. The reliability of total scales by Cronbach's Alpha was relatively high.

• Korean Journal of Adult Nursing
• /
• v.26 no.4
• /
• pp.403-412
• /
• 2014

Purpose: The purpose of this study was to validate the Korean version of shortened Nursing Decision-Making Instrument developed by Lauri & $Salanter{\ddot{a}}$(2002). Methods: The subjects were 247 nurses working in eight hospitals of Korea. Data were collected by questionnaires from June to July, 2012 and were analyzed by Principal Component Analysis for construct validity and Cronbach's ${\alpha}$ coefficient for reliability. Results: Factor loadings of the four subscales ranged from .32 to .73. The explained variance from the four factors was 48.54% of the total variance. The factors were named 'implementation of plan, monitoring and evaluation', 'plans of action', 'data collection', and 'data processing and identification'. The first factor consisted of 6 items which explained 13.21% of the total variance and the second factor contained 8 items. The Cronbach's ${\alpha}$ coefficients of the four subscales were from .64 to .81. Conclusion: The Korean version of the shortened Nursing Decision-Making Instrument has satisfactory construct validity and reliability. However, that the scores of the analytic items weren't reversed unlike the analysis method of the original tools is the biggest limitation of this study. In addition, based on the fact that there were several discrepancies for item interpretation of Korean comparing to the findings of the instrument development study, repetitive researches would be suggested.

• Journal of Korean Academy of Nursing
• /
• v.45 no.4
• /
• pp.544-553
• /
• 2015

Purpose: To investigate the validity and reliability of the Korean Version of the Assault Response Questionnaire (ARQ-K) measuring the intensity of reaction to victimization of emergency nurses in Korea. Methods: An internal consistency reliability and construct validity using exploratory and confirmatory factor analysis were conducted using SPSS WIN (20.0) and AMOS (20.0). Survey data were collected from 321 nurses who worked in 3 levels - wide regional emergency centers, regional emergency centers, appointed emergency centers - of emergency care facilities in Busan, Korea. Results: The Cronbach's alpha values regarding internal consistency were .77~.93 for the subscales of ARQ-K. Factor loadings of the 26 items on the four subscales ranged from .59 to .84. The four-subscale model was validated by confirmatory factor analysis (${\chi}^2/df=3.85$, p<.001, RMR=.06, GFI=.80, NFI=.81, TLI=.83, CFI=.85, RMSEA=.09). Conclusion: This study shows that the Korean Version of the Assault Response Questionnaire is a valid and reliable instrument to assess nurses' reaction to victimization of emergency nurses in Korea.

• Proceedings of the KSME Conference
• /
• 2004.11a
• /
• pp.43-48
• /
• 2004

When structures are loaded by a combination of primary and secondary stresses, plasticity effects occur which cannot be evaluated by a simple linear addition of the effects resulting from the two independent stress systems. Thermal stress due to temperature gradient is classified as secondary stress. It is known that secondary stress is released as increase of plastic zone. In this paper, two and three dimensional elastic-plastic finite element analyses are performed for the cracked plates and pipes under combined thermal and mechanical loading. And V-factor is introduced to account for plasticity effect. The present results provide that V-factor is function of thermal factor and loading and is consistent regardless of geometry. We developed the prediction method of elastic-plastic fracture mechanics parameter under combined primary and secondary loading from the present results.

• Journal of Korean Public Health Nursing
• /
• v.17 no.1
• /
• pp.113-121
• /
• 2003

Purpose : This study was performed to develop a scale of outdoor school safety behavior in Korean elementary students. Methods : A list of 40 items were selected by priori experiences of school health teachers and a literature review. For evaluation of the appropriateness of the 32 items, questionnaires were reviewed by an expert group which was consisted of 10 professionals. Validity of the 31 items was screened in this process with 4 point Likert scale. Using the preliminary tool. data were collected from 684 subjects for item analysis and factor analysis. A total of 26 items were remained, and items with the lower than 0.2 item-total correlation coefficient were removed. Factor analysis was done with these 26 items, and 26 items with factor loadings higher or equal to 0.4 were remained. Relsult : 1. Cronbach's alpha for the 26 items was 0.70 2. Five factors were identified with eigen value 1.0 These contributed $51.617\%$ of the variance in the total score. 3. Each factor was labled 'vonobserbance of safety rule', 'good habit for safety', 'careless action', 'lack of safety knowledge', 'injurious action to friend' It is suggested that this scale could be used to measure outdoor school safety behaviors among elementary students in Korea.

• Journal of Environmental Science International
• /
• v.11 no.12
• /
• pp.1281-1289
• /
• 2002

This study was conducted to evaluate water quality in the Keum River using multivariate analysis. The analysis data in Keum river made use of surveyed data by the ministry of environment from January 1994 to December 2001. Thirteen water quality parameter were determined on each sample. The results was summarized as follow; Water quality in the Keum River could be explained up to 71.39% by four factors which were included in loading of organic matter and nutrients by the tributaries (32.88%), seasonal variation (16.09%), loading of pathogenic bacteria by domestic sewage of Gapcheon (13.39%) and internal metabolism in estuary as lakes(9.03%). For spatial variation of factor score, four group was classified by each factor characterization. Station 1 and 2 was influenced by Daechung dam, station 3 was affected by domestic sewage of Gapcheon, station 10~12 was affected by estuary dyke and the rest station. The result of cluster analysis by station was classified into four group that has different water quality characteristics. In monthly cluster analysis, three group was classified according to seasonal characteristic. Also, in yearly cluster analysis, three group was classified. It is necessary to control the pollutant loadings by Gapcheon inflow domestic sewage in Daejeon city for the sake of water quality management of Keum river.