• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.6
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• pp.699-710
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• 2009

If a country has her geoid model, it could be determine accurate orthometric height because the geoid model could provide continuous equi-gravity potential surface. And it is possible to improve the coordinates accuracy of national control points through geodetic network adjustment considering geoidal heights. This study aims to find the best way to develop geoid model in Philippines which have similar topographic conditions as like Malaysia and Indonesia in Eastsouth asia. So, in this study, it is surveyed the general theories of geoid determination and development cases of geoid model in Asia and it is computed that the geoidal heights and gravity anomalies by spherical harmonic analysis using EGM2008, the latest earth geopotential model. The results show that first, the development of gravimetric geoid model based on airborne gravimetry is needed and second, about 200 GPS surveying data at national benchmark is needed. It is concluded that it is the most reasonable way to develop the hybrid geoid model through fitting geometric geoid by GPS/leveling data to gravimetric geoid. Also, it is proposed that four band spherical Fast fourier transformation(FFT) method for evaluation of Stokes integration and remove and restore technique using EGM2008 and SRTM for calculation of gravimetric geoid model and least square collocation algorithm for calculation of hybrid geoid model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.346-357
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• 2019

The purpose of this study was to examine the effects of flipped learning and explore the learners' experiences. Data were collected from 64 students who participated in flipped learning for 7 weeks at N university. The results were as follows. First, after applying flipped learning, learners feel more comfortable learning together and prefer collaborative learning. Second, flipped learning had no significant effects on learner's overall metacognition, but it had positive effects on the awareness and cognitive strategies. Third, flipped learning had no significant effects on academic self-efficacy, but it positively affected the task difficulty preference and confidence of learners who had a lower level of collaborative tendencies. Fourth, flipped learning had no significant effects on SDL ability, but it positively affected the learning plan of learners who had a higher level of collaborative tendencies. Fifth, learners' class satisfaction of flipped learning was generally very high. We suggested a policy, instructional design and strategies for effective implementation of flipped learning.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.801-812
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• 2021

In order to delivery biotin to skin, ethosomes containing both biotin and ceramide were researched by using high pressure homogenizer. Biotin was utilized as a drug and ceramide NP was utilized as a supporter of bilayer. The biotin was entrapped in aqueous core, while ceramide NP was packed in the bilayer of the ethosomes. Looking at the physical properties of vesicles containing ceramide NP, the sized was 80~130 nm, the polydispersity index was 0.09~0.16, and the zeta potential was -40~-49 mV. In vesicles without ceramide NP, the size was 124.80±1.46 nm, and the zeta potential and polydispersity index were -45.48±1.27 mV and 0.088±0.018, respectively. Therefore, the ethosome with ceramide NP has improved physical properties of vesicles compared to the ethosome without ceramide NP. Skin absorption rates of ethosomes with ceramide NP were 6.13~14.98%, while skin absorption rate of ethosome without ceramide NP was 7.08% at 12 h. In conclusion, ethosomes containing ceramide NP not only improved the skin absorption efficiency, but had also a positive effect on the stability of vesicles.

• The Journal of Korean Association of Computer Education
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• v.14 no.2
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• pp.47-59
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• 2011

Linked Data is about using the web to link related data that wasn't linked previously. To publish linked data, people should be able to represent, share, and link pieces of data, information, and knowledge by using URIs and RDF. However, building linked data is not easy for the common users who do not know the knowledge or skill about using URIs and RDF. In this paper, we present a system that the common users can create linked data by connecting data originated from different RDFs. They build linked data by adding new links to connect between RDF data saved in their computers or searched from Swoogle. We can apply the proposed system to creating educational contents. For example, teachers can develop various learning contents by building linked data that connects different data suited to the learning level of their students.

• Journal of Korean Library and Information Science Society
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• v.43 no.2
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• pp.247-271
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• 2012

The institutional repository and linked data share a purpose, co-creation and joint usage of information resources. Therefore, a new approach linking these two concepts can be utilized for co-production and utilization of resources. This study hoped to configure the Korean dCollection repository as linked data. For this purpose, first, we analyzed the current data structure of dColleciton. Second, we investigated the resource types which dCollection is targeting. Third, we focused and analyzed a case study of resource types targeted by dCollection constructed as linked data. Fourth, this study examined in detail how to build the linked dCollection data and how to connect this linked data to the linked cloud. Finally, we discussed the problems that might oc cur in the process of building the linked data.

• Membrane Journal
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• v.15 no.4
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• pp.281-288
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• 2005

The hyaluronic acid (HA) with excellent biocompatibility can be combined with lactide, the ester dimer of polylactide, with good biodegradability to produce biocompatible materials applicable to drug delivery system. By freeze drying method, HA and lactide were crosslinked with crosslinking agent, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide. Degree of lactide and EDC reaction was determined by the analysis of nuclear magnetic resonance (NMR) spectroscopy. The degree of lactide and EDC reaction increased and swelling ratio decreased as the mole ratio of lactide to HA or crosslinking agent concentration increased or reaction temperature decreased. The drug release experiment result from membranes having different degree of lactide reaction showed that drug release rate reduced in proportion to the degree of lactide reaction. The drug release experiment result from drugs having different hyrodphobicity showed that the more hydrophobic drug was released more slowly.

• Resources Recycling
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• v.5 no.1
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• pp.14-20
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• 1996

For recycl~ng alumhx~rn dross, the cbaraclcrislics of dross and ils reutll~zalin~af~te r plocsssing should he considered. Nurn~llumd ross was classified according to iB sire in this shldy. Tbe dross larger Illan 3001~1w as directly re-meltcd to recover aluminum, and the s~nallerd ~ossw as leachcd and riln~tedl o scparalc 111s eri~lerls alt and to oxidize the rnelals contained in the dross. As a rcwlt, amount of the dross uscd lo be dircarded ahcr processing could hc reduced Also, lhc chem~cal culnposit~ons of a domzstic alumlnum dross and the changes in con~posilii~ndsu ring processings were investigated. and Cound that most mctaU'ic aluminum in the dross was changed inlu alu~n~numox ide lhruugli the roasting. Tile processed dross would he ulillzed for malerials such as alumina, alumma cemenl or tilcs.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.59-67
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• 2019

This study was conducted to examine the effect of the characteristics of branded contents on consumers. To attain the purpose of the study, we carried out a survey with 286 male and female undergraduates and collected data for analysis. The findings demonstrated the followings: First, the satisfaction of using branded contents is positively affected by entertaining, empathy, creativity, and indirectness. Second, the intention to share branded contents and the intention for continuous use of them are positively affected by entertaining only. In conclusion, this study confirmed that only informativeness, which is one of 5 characteristics of branded contents, does not have any effect on the consumer. This result provides useful empirical data for developing high-quality contents that meet user's needs and convenience, helping understand user's behavior toward branded contents and also serves as the basic data on which related researches can expand.

• Composites Research
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• v.31 no.6
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• pp.293-298
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• 2018

In this paper, we have studied the physical properties of braided composites for use as aircraft stringers. Process variables such as drum winder speed, braid velocity, and mandrel diameter for $30^{\circ}$, $45^{\circ}$ and $60^{\circ}$ braid preforms were quantified and different epoxy resin types were applied to the braided preform using TGDDM, YD-128. Physical properties such as tensile strength and flexural strength of braided composites were investigated. Thermal properties and decomposition temperature of epoxy resin were investigated by TGA analysis. As a result, the lower the angle of the braid composites, the higher the tensile strength and the Flexural strength. The physical properties of braided composites fabricated using TGDDM epoxy resin were superior to the physical properties of braided composites fabricated using YD-128 epoxy resin. This is because the molecular weight of TGDDM epoxy resin was higher than that of YD-128 epoxy resin.

• Journal of Creative Information Culture
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• v.5 no.2
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• pp.183-191
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• 2019

The purpose of this paper is to develop an unplugged education program that develops the 4C (Creativity, Critical thinking, Communication ability, Collaboration) and CT (Computational Thinking) competencies required in modern society. This study discovered "Fine Dust Robot" as a theme suitable for the unplugged education program, and designed the Unplugged 4-hour education program which can develop 4C and CT competencies. The first stage motivates learning, and the second and third stages develop unplugged activity to develop CT. In the fourth stage, the algorithms created through unplugged activities were programmed through the natural language instruction card and produced the output. We developed educational materials that can be utilized in the unplugged education program. Finally, education programs were conducted for elementary school students, and pre- and post-tests of computational thinking were conducted for general students and gifted students. Educational effective was found in both groups.