• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.927-932
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• 2009

Toxic and recalcitrant organic pollutants in wastewaters can be effectively treated when advanced oxidation and biodegradation are combined, ideally with intimate coupling, in which both processes occur simultaneously in the same system. One means to achieve intimate coupling is to coat nanoscale $TiO_2$ on the outside of macroporous biofilm carriers. This study investigated the kinetics of photocatalysis with $TiO_2$-coated porous carriers. The carriers were made of polyvinyl alcohol (PVA) and coated with $TiO_2$ using a low-temperature sol-gel process. The $TiO_2$-coated carriers catalyzed the oxidation of methylene blue (MB) effectively under irradiation of UV light. The overall reaction rate with adsorption and photolysis saturated at high MB concentration, and approached the adsorption rate, which was first order for all MB concent rations. This result indicates that adsorbed MB may have slowed photocatalysis by blocking active sites for photocatalysis. The overall kinetics could be described by a quasi-Langmuir model. The estimated maximum specific (per unit mass of $TiO_2$) transformation rate of MB by the $TiO_2$-coated carriers was four times larger than that obtained from slurry-$TiO_2$ reactors. This observation demonstrated that the $TiO_2$ present as a coating on the carriers maintained high efficiency for transforming recalcitrant organic matter via photocatalysis. These findings serve as a foundation for advancement of an intimate coupling of photocatalysis to biodegradation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.521-531
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• 2020

QZSS (Quasi-Zenith Satellite System) provides the CLAS (Centimeter Level Augmentation Service) through the satellite's L6 band. CLAS provides correction messages called C-SSR (Compact - State Space Representation) for GPS (Global Positioning System), Galileo and QZSS. In this study, CLAS messages were received by using the AsteRx4 of Septentrio which is a GPS receiver capable of receiving L6 bands, and the messages were decoded to acquire C-SSR. In addition, Multi-GNSS (Global Navigation Satellite System) Code-PPP (Precise Point Positioning) was developed to compensate for GNSS errors by using C-SSR to pseudo-range measurements of GPS, Galileo and QZSS. And non-linear least squares estimation was used to estimate the three-dimensional position of the receiver and the receiver time errors of the GNSS constellations. To evaluate the accuracy of the algorithms developed, static positioning was performed on TSK2 (Tsukuba), one of the IGS (International GNSS Service) sites, and kinematic positioning was performed while driving around the Ina River in Kawanishi. As a result, for the static positioning, the mean RMSE (Root Mean Square Error) for all data sets was 0.35 m in the horizontal direction ad 0.57 m in the vertical direction. And for the kinematic positioning, the accuracy was approximately 0.82 m in horizontal direction and 3.56 m in vertical direction compared o the RTK-FIX values of VRS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.709-718
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• 2020

Even after Fukuyama declared "The End of History" in 1989, the challenge to liberal democracy continues. Controversy about totalitarianism is constantly being raised both internally and externally in democratic countries and leaders, as well as the US-China war of supremacy. In this paper, I explored a hypothesis about the totalitarian process, and to explain this hypothesis, I analyzed the case of Venezuela, which was once referred to as a welfare model state. This paper presupposes Fukuyama's insistence on the universality of liberal democracy but considers the last man Nietzsche argues for the last man he assumes. Accordingly, the process of totalitarianism was viewed as a process in which totalitarianism was institutionalized and spread internationally through the linkage and interaction of the last fallen humans, the masses, and totalitarians in the international and domestic environments. According to this hypothesis, the Bol?var Revolution and Chavez show the process of transformation into a typical quasi-totalism. Although the Venezuelan people preferred democracy, they remained the last man who had become a man of "rich consciousness." While investigating this hypothesis, it was confirmed that extensive and interdisciplinary studies such as digital t otalitarianism and the development of science and technology should be followed.

• The Korean Journal of Applied Statistics
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• v.30 no.4
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• pp.539-553
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• 2017

We propose a multi-state model to analyze semi-competing risks data with interval-censored or missing intermediate events. This model is an extension of the three states of the illness-death model: healthy, disease, and dead. The 'diseased' state can be considered as the intermediate event. Two more states are added into the illness-death model to incorporate the missing events, which are caused by a loss of follow-up before the end of a study. One of them is a state of the lost-to-follow-up (LTF), and the other is an unobservable state that represents an intermediate event experienced after the occurrence of LTF. Given covariates, we employ the Lin and Ying additive hazards model with log-normal frailty and construct a conditional likelihood to estimate transition intensities between states in the multi-state model. A marginalization of the full likelihood is completed using adaptive importance sampling, and the optimal solution of the regression parameters is achieved through an iterative quasi-Newton algorithm. Simulation studies are performed to investigate the finite-sample performance of the proposed estimation method in terms of empirical coverage probability of true regression parameters. Our proposed method is also illustrated with a dataset adapted from Helmer et al. (2001).

• Journal of Korean Academy of Nursing
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• v.30 no.5
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• pp.1111-1120
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• 2000

The purpose of this study is to examine the effect of social support intervention on mood and maternal confidence of premature's mothers. The social support intervention is known to induce improved mood state and provide information on caretaking so as to increase the maternal confidence in the mother of a premature. To systematically investigate its effect, this study employed a nonequivalent randomized post-repeated quasi-experimental design. The intervention was given individually to mothers of prematures five times spanning five weeks. The sample consisted of the 50 mothers (experimental 27, control 23) of a premature. The data were collected using the structured questionaires twice as post tests. Various instruments were used in this study. The POMS developed by Lee(1990) was used to measure the mothers' mood state, Mother and Baby Scales by Wolke et al (1987). The results are as follows: 1. For the hypothesis test to see the effect of the social support intervention, the mean of the experimental group and the control group was compared by means of t-test and the following results are obtained. Hypothesis I. "The mood state of mothers with social support intervention is more positive than that of the mothers without such intervention." was not statistically supported and thus discarded (t=.799, p=.429). However the mean scores were 49.68 and 51.38 for the experimantal and control group, respectively, indicating more positive mood for the experimental group. Hypothesis II. "The maternal confidence of mothers with social support intervention is higher than that of the mothers without the tervention." was statistically supported (t=3.667, p=.001). 2. The mean score of the mood state was highest before discharge (52.29), meaning most negative, declined to 49.68 shortly after the discharge, again increased a bit to 50.07 at four weeks after the discharge, and stabilized to 49.22 around six weeks after the discharge. On the other hand the mean score of the maternal confidence was continuously increased with time. In view of the above results, it is concluded that the social support intervention with a preprogrammed protocol has the definite positive effect on increasing the maternal confidence and positive effect on improving mother's mood state.

• Korean Journal of Hospice Care
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• v.1 no.1
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• pp.1-17
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• 2001

The purpose of this study was to elucidate the effects of spiritual nursing intervention on pain and anxiety of the hospice patients. This study was devised with a quasi-experimental design using non-equivalent contrast group non-synchronized design. The data were collected during the period from July 10 to September 25 in 2000 at the general hospital in CheonJu city. The subjects were sixty-seven patients who referred the hospice service. They were assigned to two groups, 36 members of the experimental group and 30 members of the contrast group. They also did not any complication, were alert enough tobe interviewed and agree willingly to participate in this study. The tools used were Yoon's Korean Version of Brief Pain Inventory and Spielberger's State Anxiety Scale. The spiritual care intervention was carried out through Hymn, Scripture, Prayer, the therapeutic use of self over a period of three weeks. Data were analyzed by mean, standard deviation, $x^2$-test, t-test, paired t-test and Pearson's Correlation Coefficients. The results of this study were as follows: 1.The examination of the same quality showed that there were not significant differences in the general characters, disease and therapeutic characters, religional characters between the experimental group and the contrast group. 2.After the spiritual nursing intervention pain scores of the experimental group were remarkably lower than those of the contrast group(right now pain: t=-2.634, p=0.012). 3.Decreasing rate in the pain scores of the experimental group were remarkably lower than those of the contrast group(right now pain: t=5.017, p=0.000). 4. After the spiritual nursing intervention state anxiety of the experimental group were remarkably lower than those of the contrast group(t=-5.987, p=0.000). 5. A positive correlation was found between reported pain and depression following the spiritual nursing intervention. In conclusion, the hospice patients who were offered spiritual care became lower than those who were not offered spiritual care and confirmed to decrease pain. According to these results, spiritual nursing intervention can be regarded as an effective nursing intervention that relieved pain and anxiety of the hospice patients.

• Steel and Composite Structures
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• v.37 no.3
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• pp.273-289
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• 2020

Due to the unique construction method of modular steel buildings (MSBs) with units prefabricated fully off the site and assembled quickly on the site, the inter-module connection for easy operation and overall performance of the system were key issues. However, it was a lack of relevant research on the system-level performance of MSBs. This study investigated the seismic performance of two-storey modular steel structure with a proposed vertical rotary inter-module connection. Three full-scale quasi-static tests, with and without corrugated steel plate and its combination, were carried out to evaluate and compare their seismic behaviour. The hysteretic performance, skeleton curves, ductile performance, stiffness degradation, energy dissipation capacity, and deformation pattern were clarified. The results showed that good ductility and plastic deformation ability of such modular steel structures. Two lateral-force resistance mechanisms with different layout combinations were also discussed in detail. The corrugated steel plate could significantly improve the lateral stiffness and bearing capacity of the modular steel structure. The cooperative working mechanism of modules and inter-module connections was further analyzed. When the lateral stiffness of upper and lower modular structures was close, limited bending moment transfer may be considered for the inter-module connection. While a large lateral stiffness difference existed initially between the upper and lower structures, an obvious gap occurred at the inter-module connection, and this gap may significantly influence the bending moments transferred by the inter-module connections. Meanwhile, several design recommendations of inter-module connections were also given for the application of MSBs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.2
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• pp.156-162
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• 2008

The static aeroelastic analysis of composite hingeless rotor blades in hover was performed using free-wake method. Large deflection beam theory was applied to analyze blade motions as a one-dimension beam. Anisotropic beam theory was applied to perform a cross-sectional analysis for composite rotor blades. Aerodynamic loads were calculated through a three-dimensional aerodynamic model which is based on the unsteady vortex lattice method. The wake geometry in hover was described using a time-marching free-wake method. Numerical results of the steady-state deflections for the composite hingeless rotor blades were presented and compared with those results based on two-dimensional quasi-steady strip theory and prescribed wake method. It was shown that wakes affect the steady-state deflections.

• Atmosphere
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• v.12 no.4
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• pp.69-90
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• 2002

The infrared and microwave satellite observations have been used to derive the information of hydrometeors (i.e., cloud and precipitation) and atmospheric temperature. The observations were made by the Nimbus-4 Infrared Interferometer Spectrometer (IRIS) in 1970, and by the Microwave Sounding Unit (MSU) during the period 1980-99, which had channel 1~4 (Chl~4). The IRIS, which has a field of view of ~100 km, has been utilized to examine the cirrus and marine stratus clouds. The cirrus and stratus distributions were obtained, respectively, based on the spectral difference in the infrared window region, and the absorption of water vapor and $CO_2$ in the spectral region $870-980cm^{-1}$. The MSU Ch1 data has been used for low tropospheric temperature and hydrometeors, while the Ch2, Ch3 and Ch4, respectively, for the thermal state of midtroposphere, tropopause, and lower stratosphere. The climatic aspects of El Ni$\tilde{n}$o, Quasi-Biennial Oscillation (QBO) and temperature trends over the globe are discussed with the MSU data. This study suggests that the IRIS and MSU data are useful for monitoring the hydrometeors and atmospheric thermal state in climate system.

• Journal of Environmental Science International
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• v.5 no.5
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• pp.593-603
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• 1996

A dual-porosity filmed agglomerate model for the porous cathode of the molten carbonate fuel has been investigated to predict the cell performance. A phenomenological treatment of molecular, kinetic and electrode parameters has been given. The major physical and chemical phenomena being modeled include mass transfer, ohmic losses and reaction kinetics at the electrode- electrolyte interface. The model predicts steady-state cell performance, given the above conditions that characterize the state of the electrode. Quasi-linearization and finite difference techniques are used to solve the coupled nonlinear differential equations. Also, the effective surface area of electrode pore was obtained by mercury porosimeter. The results of the investigation are presented in the form of plots of overpotential vs. current density with varied the electrode material, gas composition and mechanism. The predicted polarization curves are compared with the empirical data from 1 c$m^2$ cell. A fair correspondence is observed.