• Journal of the Korean Geotechnical Society
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• v.27 no.5
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• pp.45-59
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• 2011

This study introduces the diagrammatic Upper and Lower Bound (UB and LB) methods theoretically in order to derive the bearing capacity factor, $N_c$ in undrained clay and to compare with Prandtl's exact solution (1921). As a result of the theoretical study, an exact solution comes out when the UB and LB solutions are the same. In addition, the finite element analyses show that the failure loads approach to the bearing capacity factor of 5.14. Results of the FEA significantly depend on the finite element type, a number of elements, and a number of increments. From this study the exact solution defines that solutions from UB and LB are the same. However, this situation is very difficult to process, so we can confirm the exact solution as a range between UB and LB solutions.

• Journal of the Korean Geotechnical Society
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• v.22 no.9
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• pp.23-36
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• 2006

This study presents the development of a new closed-form analytical solution for the ultimate bearing capacity of an embedded wall in a granular mass. The closed-form analytical solution consists of upper and lower bound solutions (UB and LB). The calculated values from these bound solutions were compared with the author's two-dimensional laboratory wall model loading test and finite element analysis in the plastic region. The comparison showed that ultimate bearing loads from both the model test and finite element analysis are located between UB and LB. In particular, the ultimate bearing load from LB showed good agreement with the ultimate bearing load values from both the model test and finite element analysis. However, the calculated value from the conventional empirical form subjected to plane-strain conditions was shown to be much smaller than the LB.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.228-231
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• 1995

Phthalocyanine have a good sensitivity to the toxic gases like NO$_2$. Also its properties of good chemical and thermal suability give a potential to superiors gas sensing system. Depositioni of Octa(2-ethyhexyloxy) Copper Phthalocyanine is confirmed by transfers ratio, UB/visible spectra and current-voltage (I-V) characteristics.

• Journal of the Earthquake Engineering Society of Korea
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• v.19 no.2
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• pp.63-74
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• 2015

This study investigated the influence of probabilistic variability in stiffness and nonlinearity of soil on response of nuclear power plant (NPP) structure subjected to seismic loads considering the soil-structure interaction (SSI). Both deterministic and probabilistic methods have been employed to evaluate the dynamic responses of the structure. For the deterministic method, $SRP_{min}$ method given in USNRC SRP 3.7.2(2013) (envelope of responses using three shear modulus profiles of lower bound($G_{LB}$), best estimate($G_{BE}$) and upper bound($G_{UB}$)) and $SRP_{max}$ method (envelope of responses by more than three ground profiles within range of $G_{LB}{\leq}G{\leq}G_{UB}$) have been considered. The probabilistic method uses the Latin Hypercube Sampling (LHS) that can capture probabilistic feature of soil stiffness defined by the median and the standard deviation. These analysis results indicated that 1) number of samples shall be larger than 60 to apply the probabilistic approach in SSI analysis and 2) in-structure response spectra using equivalent linear soil profiles considering the nonlinear behavior of soil medium can be larger than those based on low-strain soil profiles.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.302-306
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• 2013

We report the dietary exposure to rotenone in the Korean population and children (1-18) through consumption of lettuce and cucumber. To obtain the residue data, we analyzed using the GC-NPD and HPLC-DAD method. Rotenone residues in samples were as follows; lettuce 0.16-1.15, cucumber < 0.001-0.006. The average dietary intake was determined using result from the 2009 Korea National Health and Nutrition Examination Survey Data. The risk index (RI) was calculated using rotenone residues and dietary intakes. The lettuce and cucumber showed the highest at 18.41%, 0.00, respectively. RI fell below 100 of %RfD showing no risks in these vegetables. Therefore, the risk assessment on the detected rotenone was evaluated as safe level.

• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.151-156
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• 2003

To provide some guideline for microscrew implants, 73 patients that received a total of 180 mini- or microscrew implants were scrutinized. The overall success rate was $93.3\%$ (168 among 180 mini- or microscrew implants) and the mean period of utilization was 15.8 months. Microscrew implants in the UB group (maxillary buccal area) succeeded at a rate of $94.6\%$ (87 among 92), mini- or microscrew implants in the LB group (mandibular buccal area) succeeded $96.6\%$ of the time (56 out of 58), while microscrew implants in the UP group (maxillary palatal area) had a $100\%$ success rate (11 out of 11), and mini- or microscrew implants in the LR group (retromolar area) succeeded in $73.7\%$ of cases (14 among 19). This study might indicate that microscrew implants can be used successfully as orthodontic anchorage in daily orthodontic practice.