• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.8
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• pp.711-717
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• 2012

During the conceptual design phase of a light sport aircraft, the wind tunnel tests were conducted to investigate the static stability of newly-designed configuration. The 1/5 scale-down wind tunnel model consisted of fuselage, main wing, vertical tail and horizontal tail. The main wing and tails were able to be attached or detached from the fuselage. The aerodynamic forces and moments acting on the 6 different configurations compounding each component were measured by using the internal balance system and their static stability derivatives were derived. With these experimental data, the baseline lift and drag characteristics as well as the effects of each component to the longitudinal, directional and lateral static stability were quantitatively analyzed.

• Journal of Energy Engineering
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• v.17 no.4
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• pp.218-226
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• 2008

A component-scale two-phase analysis code has been developed for a realistic simulation of two-phase flow transients in a light water nuclear reactor component. In the code, a two-fluid three-field model is adopted and the governing equations are solved on an unstructured mesh. For the numerical solution scheme, the semi-implicit method used in the RELAP5 code was selected, which has been proved to be very stable and accurate for most of practical applications. However, some modifications were needed for its application to an unstructured non-staggered grid. This paper presents the modified semi-implicit numerical method for unstructured grid and the preliminary results of the calculations.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.5
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• pp.355-361
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• 2000

A recycling reactor system operated under sequential anoxic and oxic conditions for the treatment of swine wastewater has been developed, in which piggery slurry is fermentatively and aerobically treated and then part of the effluent is recycled to the pigsty. This system significantly removes offensive smells (at both the pigsty and the treatment plant), BOD and others, and may be cost effective for small-scale farms. The most dominant heterotrophic were, in order, Alcaligenes faecalis, Brevundimonas diminuta and Streptococcus sp., while lactic acid bacteria were dominantly observed in the anoxic tank. We propose a novel monitoring system for a recycling piggery slurry treatment system through the use of neural networks. In this study, we tried to model the treatment process for each tank in the system (influent, fermentation, aeration, first sedimentation and fourth sedimentation tanks) based upon the population densities of the heterotrophic and lactic acid bacteria. Principal component analysis(PCA) was first applied to identify a relationship between input and output. The input would be microbial densities and the treatment parameters, such as population densities of heterotrophic and lactic acid bacteria, suspended solids(SS), COD, NH$_4$(sup)+-N, ortho-phosphorus (o-P), and total-phosphorus (T-P). then multi-layer neural networks were employed to model the treatment process for each tank. PCA filtration of the input data as microbial densities was found to facilitate the modeling procedure for the system monitoring even with a relatively lower number of imput. Neural network independently trained for each treatment tank and their subsequent combined data analysis allowed a successful prediction of the treatment system for at least two days.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.89-97
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• 2008

In this paper, we present a method for the enhancement of marker detection correctness and marker recognition speed by using artificial neural network. Contours of objects are extracted from the input image. They are approximated to a list of line segments. Quadrangles are found with the geometrical features of the approximated line segments. They are normalized into exact squares by using the warping technique and scale transformation. Feature vectors are extracted from the square image by using principal component analysis. Artincial neural network is used to checks if the square image is a marker image or a non-marker image. After that, the type of marker is recognized by using an artificial neural network. Experimental results show that the proposed method enhances the correctness of the marker detection and recognition.

• Journal of Korea Water Resources Association
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• v.38 no.10 s.159
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• pp.895-906
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• 2005

The diversity of observed hydrologic data and the development of geographic information system leads significant progress for developing distributed runoff models in the world. One of the typical examples is TOPMODEL, but the spatial coverage of its application Is limited on small headwater basins. The purpose of this study attempts to overcome its limitation and consequently develops a semi-distributed TOPMODEL. The developed model is composed of two components: a watershed runoff component for a lumped representation of hydrologic runoff process on the catchment scale and a kinematic wave type hydraulic channel routing component lot routing the catchment outflows. The application basin is the $2,703km^2$ upper Soyang dam site and several daily and hourly events are selected for model calibrations and verifications. The model parameters are estimated on 1990 daily event. The model performance on correlation coefficient between observed and computed flows are above 0.90 for the verification events. It is concluded that the developed model in this study can be used for flood analysis in large drainage basins.

• Korean Journal of Medicinal Crop Science
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• v.20 no.2
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• pp.108-116
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• 2012

In this study, to develop hair growth agents using natural products which has excellent ability to promote hair growth effect and fewer side effect, animal experiment and clinical trials was performed to evaluate hair growth promotion effect of herbal product containing $Rosa$ $mutiflora$ roots extracts as a main component (RMHP). 4-week-old male C57BL/6 mice were removed the dorsal hair using thioglycolate, and applied 15% EtOH solution as a negative control, 5% minoxidil as a positive control and RMHP to dorsal skin. In the results of macroscopy and photo-interpretation, RMHP group recorded 100% (+++++) of hair growth was proved to significantly stimulate hair growth against 80% (++++) negative control group. 37 patients were treated with RMHP and evaluated the therapeutic effect at 16 weeks. Hair density was significantly increased at 16 weeks after applying RMHP ($125.0{\pm}4.9\;FU/cm^2$) compared to before treatment ($104.3{\pm}4.7\;FU/cm^2$, p < 0.05), and hair thickness were also significantly increased ($0.066{\pm}0.003$ mm) than before treatment ($0.055{\pm}0.002$ mm, p < 0.05). The result of clinical photo-interpretation using 7-point rating scale assessment, after 16 weeks clinical symptoms were evaluated to significantly improve with $1.23{\pm}0.05$ (p < 0.05). Therefore, the results of this study were observed that RMHP have hair loss prevention effect and hair growth promotion effect to hair loss patients.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.66.1-66.1
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• 2016

We present our observational results of BL Lacertae(2200+420) obtained at 22, 43, 86, and 129 GHz simultaneously during 27 months(2013.Jan ~ 2015.Mar) which includes their two gamma-ray outbursts(2013.Oct & 2015.Mar) to study a connection between the gamma-ray outbursts and the radio activity. We mainly use a Korean VLBI monitoring program, IMOGABA(Interferometric Monitoring Of Gamma-ray Bright AGNs) which is a monthly monitoring program with the KVN(Korean VLBI Network). Overall, our KVN image shows two components in the map, a stationary core at the center and one moving jet component to the south, but almost core only at 86, 129 GHz. The location of the moving jet component in the maps depend on the frequencies that 22, 43, 86, and 129 GHz. We have checked light curves, spectral index, kinematics, and radio structure to find differences before and after the gamma-ray outbursts, but there was no significant correlation. We also have derived a decay time scale of ~9 months for the major radio outburst by applying an exponential decay fitting.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.1
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• pp.163-173
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• 1999

The CORBA provides a object-oriented middleware that lets applications extend their range across networks, languages, component boundaries, and operating systems. Java can provide a potable object that works in any operating system. Mapping Java into CORBA helps large scale information system operate through the Web by using the mobile code property of Java and object component technique of CORBA. This development environment is called the Object Web. This paper proposes an architecture of OSI network management with a CORBA manager using Object Web and an CORBA/CMIS gateway which apply a CMIS-level gateway model to gateway. In this architecture, CORBA manager is based on Object Web and can manage MOs in the OSI domain. The gateway has a role to translate CORBA IDLs into CMIS services and vice versa. In addition, an OSI agent is abstracted into a CORBA agent.

• Education of Primary School Mathematics
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• v.23 no.2
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• pp.63-72
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• 2020

The purpose of this study is to develop a mathematics self-efficacy test tool for elementary school students based on the sub-factors of mathematical self-efficacy derived from current studies. In this study, I verified the validity and reliability of the test tool by statistically evaluating the results of applying the test tool to the 3rd-6th grade students. In this study, Principal Component Analysis was performed on the tool for measuring the self efficacy of mathematics for elementary school students. For the validity test, the mathematics anxiety status of the participants was measured. The mathematics anxiety who were known to have a negative correlation with the mathematical self efficacy. The mathematics self efficacy tool developed in this study consists of 16 items with three subcategories: master experience, social persuasions, and emotional and physiological state. The mathematical self efficacy test tool developed in this study is expected to provide grounds for diagnosing the mathematics self-efficacy status of elementary school students and looking for ways to improve it.

• Perspectives in Nursing Science
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• v.8 no.1
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• pp.62-72
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• 2011

Purpose: The purpose of this study was to investigate QOL and the factors related to family caregivers who care for Amyotrophic Lateral Sclerosis (ALS) patients. Methods: The subjects were 83 family caregivers caring for ALS patients who visited the neurology outpatient section of a tertiary hospital located in Seoul between January and July of 2008. Their demographic characteristics were assessed and data were collected using the amyotrophic lateral sclerosis functional rating scale (ALSFRS), the caregiver burden inventory (CBI), HADS, and SF-36. Results: The mean score of the physical health component (PHC) of the family caregiver's QOL was $62.6{\pm}24.4$, and the mean score of the mental health component (MHC) of their QOL was $57.7{\pm}22.4$. The mean score of caregiver burden was $76.5{\pm}30.7$. Anxious family caregivers amounted to 55.4% and depressed family caregivers accounted for 63.9% overall. In a multivariate analysis, the PHC of QOL was explained by caregiver burden (41.1%), depression (9.4%), caregiver gender (3.8%), and caregiver age (3.1%). Anxiety (39.8%), caregiver burden (10.9%), patient gender (5.4%) and depression (1.7%) were predictive factors of the MHC of QOL. Conclusion: Caregiver burden and depression affected both the PHC and the MHC. Caregiver burden affected the PHC more than it did the MHC of QOL, but anxiety affected the MHC more than it did the PHC of QOL.