• Journal of Korean Society for Geospatial Information Science
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• v.19 no.4
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• pp.3-12
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• 2011

Understanding of water sediment trends is an important part of water quality monitoring. Water quality variables change over time and space, and cannot be modeled or explained clearly by either temporal or spatial analysis alone. This research analysed the trends of temperature, pH levels and dissolved oxygen levels based on the sediment records and spatial data obtained in Lower Mekong Basin (LMB) during 1985-2005. Our aim is to evaluate spatio-temporal trends and graphical analyses using an Inverse Distance Weighting (IDW) interpolation method. The main results from this research can be summarized as follows. The maximum temperature and pH have been stable during the study period and the maximum dissolved oxygen has been increasing gradually until 2002. The minimum pH and dissolved oxygen have been changing in an unsteady trend during the period. A spatial analysis shows that the water temperature in this region has been increasing over time. The pH trend shows that it is decreasing during 1993-2005. Dissolved oxygen concentration has been increasing from 1989 onwards and stays in that track.

• Korean Journal of Social Welfare
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• v.37
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• pp.381-405
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• 1999

The primary purpose of this study is to design and perform juvenile group program and. to evaluate the effectiveness of that program The group was consisted of 10 fourth-grade elementary school boys who have had such factors that might force themselves to be delinquent, for example, broken family, having delinquent siblings or friends, family violence, and etc. The group had been held once a week and continued for 5 months. The effectiveness of that program is evaluated quantitatively and qualitatively through goal-attainment model. The ultimate goal of this program is reduction of delinquency stimulating factors which are operationalized with overall self-esteem - family related self-esteem, friend related self-esteem, and school related self-esteem. Quantitative evaluation is performed by pre- and post-test with Hare Self-Esteem Scale. Case records, family records, group activities records, and reports from schools are analyzed for the qualitative evaluation. According to paired samples t-test scores, average overall self-esteem scores of experimental group members were escalated from 67.57 to 74.86, and this difference between pre-test and post-test was statistically significant. Difference of experimental group was bigger and more striking than that of control group. These results suggest that designed and performed group program in this study would be effective in preventing juvenile from being delinquent.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.41-49
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• 2005

We have developed a random heterogeneous velocity model with bimodal distribution in methane hydrate-bearing Bones. The P-wave well-log data have a von Karman type autocorrelation function and non-Gaussian distribution. The velocity histogram has two peaks separated by several hundred metres per second. A random heterogeneous medium with bimodal distribution is generated by mapping of a medium with a Gaussian probability distribution, yielded by the normal spectral-based generation method. By using an ellipsoidal autocorrelation function, the random medium also incorporates anisotropy of autocorrelation lengths. A simulated P-wave velocity log reproduces well the features of the field data. This model is applied to two simulations of elastic wane propagation. Synthetic reflection sections with source signals in two different frequency bands imply that the velocity fluctuation of the random model with bimodal distribution causes the frequency dependence of the Bottom Simulating Reflector (BSR) by affecting wave field scattering. A synthetic cross-well section suggests that the strong attenuation observed in field data might be caused by the extrinsic attenuation in scattering. We conclude that random heterogeneity with bimodal distribution is a key issue in modelling hydrate-bearing Bones, and that it can explain the frequency dependence and scattering observed in seismic sections in such areas.