• Journal of the Korean earth science society
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• v.38 no.7
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• pp.561-569
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• 2017

Fault plane solutions of the Iksan earthquake ($M_L=3.85$) and two aftershocks were obtained using the FOCMEC (FOCal MEChanism determination) program. The main event showed the characteristic of strike slip faulting with reverse component. It has the fault planes with NE-SW or NW-SE direction. This is similar to the fault characteristics of earthquake pattern in the inland area of the Korean Peninsula. In order to detect micro-earthquake events, continuous seismic waveform data of the thirteen seismic stations within a radius of 100km from epicenter were analyzed by PQLII program (PASSCAL, 2017) for the period from December 15, 2015 to January 22, 2016. The epicenters of nineteen micro-events were newly determined by Hypoinverse-2000 program. They are not concentrated along some lineaments or fault lines. The intensity of the Iksan earthquake was obtained by estimating the telephone inquiries, the degree of ground shaking or damage all around the southern peninsula. The instrumental intensity was also obtained using PGA (Peak Ground Acceleration) records. As a result, the maximum MM intensity was estimated to be V near the epicenter.

• Journal of Astronomy and Space Sciences
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• v.24 no.4
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• pp.297-308
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• 2007

The AOPOD (Atmosphere Occultation and Precision Orbit Determination) system, the secondary payload of KOMPSAT (KOrea Multi-Purpose SATellite)-5 scheduled to be launched in 2010, shall provide GPS radio occultation data. In this paper, we simulated the GPS radio occultation characteristic of KOMPSAT-5 and retrieved electron density profiles using KROPS (KASI Radio Occultation Processing Software). The electron density retrieved from CHAMP (CHAllenging Minisatellite Payload) GPS radio occultation data on June 20, 2004 was compared with IRI (International Reference Ionosphere) - 2001, PLP (Planar Langmuir Probe), and ionosonde measurements. When the result was compared with ionosonde measurements, the discrepancies were 5 km on the $F_2$ peak height ($hmF_2$) and $3{\times}10^{10}el/m^3$ on the electron density of the $F_2$ peak height ($NmF_2$). By comparing with the Laugmuir Probe measurements of CHAMP satellite (PLP), both agrees with $1.6{\times}10^{11}el/m^3$ at the height of 365.6 km.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.372-379
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• 2017

Software reliability factor during the software development process is elementary. Case of the infinite failure NHPP for identifying software failure, the occurrence rates per fault (hazard function) have the characteristic point that is constant, increases and decreases. In this paper, we propose a reliability model using the chi - square distribution which depends on the degree of freedom that represents the application efficiency of software reliability. Algorithm to estimate the parameters used to the maximum likelihood estimator and bisection method, a model selection based on the mean square error (MSE) and coefficient of determination($R^2$), for the sake of the efficient model, were employed. For the reliability model using the proposed degree of freedom of the chi - square distribution, the failure analysis using the actual failure interval data was applied. Fault data analysis is compared with the intensity function using the degree of freedom of the chi - square distribution. For the insurance about the reliability of a data, the Laplace trend test was employed. In this study, the chi-square distribution model depends on the degree of freedom, is also efficient about reliability because have the coefficient of determination is 90% or more, in the ground of the basic model, can used as a applied model. From this paper, the software development designer must be applied life distribution by the applied basic knowledge of the software to confirm failure modes which may be applied.

• Journal of Environmental Health Sciences
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• v.38 no.4
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• pp.291-299
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• 2012

Creatinine-adjustment is an important process in the urinary monitoring of the environmental exposure of children and adolescents. The purpose of this study was to investigate the concentrations of urinary creatinine and factors associated with them among Korean children and adolescents. We recruited 1,025 persons from 128 extracted schools. They were from three to 18 years old and supplied urine samples for measuring creatinine. The concentrations of urinary creatinine were 98.18 mg/dl (SD, 67.67) in arithmetic mean and 72.05 mg/dl (GSD 2.49) in geometric mean, were significantly higher among male children/adolescents than females in all age groups, and higher values appeared following increasing ages, heights and BMIs. The rates of the number who were below the lowest limit recommended by WHO (<30 mg/dl) were 25.57% among three to four year olds, 21.77% among five to six year olds, 20.0% among seven to eight year olds and 14.69% among nine to ten year olds, respectively. The rates of those above the highest limit (>300 mg/dl) were 0.0% among three to twelve year olds. The coefficient of determination R-square of the fitted regression model for urinary creatinine was 27.4% with general characteristic variables of sex, age, BMI and height. The significant variables among these were height (standardized beta = 0.372) and age (standardized beta = 0.129). Another coefficient of determination R-square was 15.3% with dietary habit variables of smoking, drinking, dining area, number of meals and snacks, and intake of milk food, cup-noodles, canned foods, popcorn, nachos, and hamburgers. In conclusion, the concentration of urinary creatinine was significantly lower in children than in adults, and was very significantly associated with the height of children. Therefore, children need the recommended concentrations for urinary creatinine, as distinguished from adults.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.634-639
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• 2020

In general, the stability and response characteristics of the system can be improved by changing the pole position because a nonlinear system can be linearized by the product of a 1st and 2nd order system. Therefore, a controller that moves the pole can be designed in various ways. Among the other methods, LQ control ensures the stability of the system. On the other hand, it is difficult to specify the location of the pole arbitrarily because the desired response characteristic is obtained by selecting the weighting matrix by trial and error. This paper evaluated a method of selecting a weighting matrix of LQ control that moves multiple double poles with Jordan blocks to real poles. The relational equation between the double poles and weighting matrices were derived from the characteristic equation of the Hamiltonian system with a diagonal control weighting matrix and a state weighting matrix represented by two variables (ρ_d, ϕ_d). The Moving-Range was obtained under the condition that the state-weighting matrix becomes a positive semi-definite matrix. This paper proposes a method of selecting poles in this range and calculating the weighting matrices by the relational equation. Numerical examples are presented to show the usefulness of the proposed method.

• The Journal of Engineering Geology
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• v.20 no.3
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• pp.281-295
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• 2010

A new, automated apparatus is proposed for calculating the Soil-Water Characteristic Curve (SWCC), representing a simple and easily applied testing device for continuous measurements of the volumetric water content and suction of unsaturated soils. The use of this apparatus helps to avoid the errors that arise when performing experiments. Consequently, the apparatus provides greater accuracy in calculating the SWCC of unsaturated soils. The apparatus is composed of a pressure panel, flow cell, water reservoir, air bubble trap, balance, sample-preparation accessories, and measurement system, among other components. The air pressure can attain 300 kPa, and a general test can be completed in a short time. The apparatus can simply control the drying process and wetting process. The changes in volumetric water content that occur during the drying and wetting processes are shown directly in the SWRC program, in real time. As a case study, we performed an SWCC test of Joomunjin sand (75% relative density) to measure matric suction and volumetric water content during both the drying and wetting processes. The test revealed hysteresis behavior, whereby the water content on the wetting curve is always lower than that on the drying curve for a specific matric suction, during the wetting and drying processes. Based on the test results, SWCCs were estimated using the Brooks and Corey, van Genuchten, and Fredlund and Xing models. The van Genuchten model performed best for the given soil conditions, as it yielded the highest coefficient of determination.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.363-368
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• 2014

Determination of the cause of malignant pleural effusions is important for treatment and management, especially in cases of unknown primaries. There are limited biomarkers available for prediction of the cause of malignant pleural effusion in clinical practice. Hence, we evaluated pleural levels of five tumor biomarkers (CEA, AFP, CA125, CA153 and CA199) in predicting the cause of malignant pleural effusion in a retrospective study. Kruskal-Wallis or Mann-Whitney U tests were carried out to compare levels of tumor markers in pleural effusion among different forms of neoplasia - lung squamous cell carcinoma, adenocarcinoma, or small cell carcinoma, mesothelioma, breast cancer, lymphoma/leukemia and miscellaneous. Receiver operator characteristic analysis was performed to evaluate sensitivity and specificity of biomarkers. The Kruskal-Wallis test showed significant differences in levels of pleural effusion CEA (P<0.01), AFP (P<0.01), CA153 (P<0.01) and CA199 (P<0.01), but not CA125 (P>0.05), among the seven groups. Receiver operator characteristic analysis showed that, compared with other four tumor markers, CA153 was the best biomarker in diagnosing malignant pleural effusions of lung adenocarcinoma (area under curve (AUC): 0.838 (95%confidence interval: 0.787, 0.888); cut-off value: 10.2U/ml; sensitivity: 73.2% (64.4-80.8)%, specificity: 85.2% (77.8-90.8)%), lung squamous cell carcinoma (AUC: 0.716 (0.652, 0.780); cut-off value: 14.2U/ml; sensitivity: 57.6% (50.7-64.3)%, specificity: 91.2% (76.3-98.0)%), and small-cell lung cancer (AUC: 0.812 (0.740, 0.884); cut-off value: 9.7U/ml; sensitivity: 61.5% (55.0-67.8)%, specificity: 94.1% (71.2-99.0)%); CEA was the best biomarker in diagnosing MPEs of mesothelioma (AUC: 0.726 (0.593, 0.858); cut-off value: 1.43ng/ml; sensitivity: 83.7% (78.3-88.2)%, specificity: 61.1% (35.8-82.6)%) and lymphoma/leukemia (AUC: 0.923 (0.872, 0.974); cut-off value: 1.71ng/ml; sensitivity: 82.8% (77.4-87.3)%, specificity: 92.3% (63.9-98.7)%). Thus CA153 and CEA appear to be good biomarkers in diagnosing different causes of malignant pleural effusion. Our findings implied that the two tumor markers may improve the diagnosis and treatment for effusions of unknown primaries.

• Journal of Korea Water Resources Association
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• v.39 no.7 s.168
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• pp.605-615
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• 2006

In order to analyze movement of soil moisture, Time Domain Reflectometry(TDR) with multiplex system has been installed at the Bumreunsa hillslope of Sulmachun Watershed to configure spatial-temporal variation pattern considering seasonal characteristic. An intensive surveying was performed to build a refined digital elevation model(DEM) and flow determination algorithms with inverse surveying have been applied to establish an efficient soil moisture monitoring system. Soil moisture data were collected through an intensive and long term monitoring 380 hrs in November of 2003 and 1037 hrs in May and June of 2004. Soil moisture data shows corresponding variation characteristics of soil moisture on the up slope, buffer, main channel zones of the hillslope which were classified from terrain analysis. Measured soil moisture data were discussed in conjunction with flow characteristic through terrain analysis. Regardless season, immediate responses of soil moisture about rainfall looks similar but recession and recharge are primary characteristics of intermediate soil moisture variation for spring to summer and fall to winter season, respectively.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.3
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• pp.135-142
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• 2015

Floating offshore structures should be designed by considering the most extreme environmental loadings which may be encountered in their design life. The most severe loading on a wave-offshore wind hybrid power generation system is wave loads. The principal parameters of wave loads are wave length, wave height and wave direction. The wave loads have different effects on the structural behavior characteristic depending on the combination of wave parameters. Therefore, the process of investigation for critical loads based on the individual wave loading parameter is need. Namely, the equivalent design wave should be derived by finding the wave condition which generates the maximum stress in entire wave conditions. Through a series of analysis, an equivalent regular wave height can be obtained which generates the same amount of the hydrodynamic loads as calculated in the response analysis. The aim of this study is the determination of equivalent design wave regarding to characteristic global hydrodynamic responses for wave-offshore wind hybrid power generation system. It will be utilized in the global structural response analysis subjected to selected design waves and this study also includes an application of global structural analysis.

• Korean Journal of Heritage: History & Science
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• v.45 no.4
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• pp.74-91
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• 2012

This study puts its focus on Honjeon space which relatively small number of precedent studies chose as a subject of a study. The objective is to analyze Honjeon space's spatial relationship and palaces that consist Honjeon through analysis of spatial configuration and elements that affected construction of Honjeon space. The Royal Funeral, among other ceremonies of Joseon Dysnasty, carries religious characteristic along with functional and structural characteristics. By analyzing "National Five Rites", "Uigwe for the State Funeral 魂殿都監儀軌", and "Annals of Joseon Dynasty", the study organized elementary details about Honjeon space and surrounding spaces to determine the symbolism of Honjeon space's location at each palace and compared them to see if any systematical features existed between Honjeon spaces of each palace. Through this study, it was apparent the king mainly used Jaseongdang Hall of Gyeongbokgung in the early period of Joseon Dynasty and he mainly used Sunjeongjun of Changdeokgung while the queen used Munjeongjun of Changgyeonggung as the time reached the later period of Joseon Dynasty. Also in determination of Honjeon space, the study found that there were records of avoiding Pyeonjeon space in need for political space. The study also determined that places other than Pyeonjeon space was intended to be used for Honjeon space through the analysis which indicates that spaces that were initially used as Pyeonjun in the early Joseon Dynasty and simultaneously as Honjeon space were moved due to changes made in terms of theirs usages. Through the study, it could be also known that primary spaces of Honjeon was composed accordingly to "National Five Rites" and constant pattern of spaces existed among buildings near Honjeon which were arranged according to each palace's characteristic.