• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.487-494
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• 2019

Recently, interest in and use of drones is increasing. In this study, to provide accurate wind prediction at ultra low altitudes of 150 meters or below, the sensitivity of the physical process parameterization and initial conditions was assessed to select the optimal physical process and initial conditions. For this purpose, GFS and LDAPS data were used as initial and boundary conditions, and 7 experiments were constructed using a combination of PBL schemes such as YSU, RUC, ACM2, and LSM such as Noah, RUC, and Pleim. The experiment conducted for 1 month in April 2018. As a result, the RUC-YSU physical process combination using the GFS initial data showed the best performance. This study is meaningful in establishing an optimal modeling method for ultra low altitude wind prediction through experiments using different initial conditions and combination of physical processes.

• Journal of the Korean Society for information Management
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• v.16 no.2
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• pp.149-164
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• 1999

The purpose of this paper is to introduce and discuss a newly-constructed metadata database system that facilitates the retrieval of faculty syllabi available on the Internet. This gateway system aims to provide users with one-stop access to syllabi posted by the faculty of the institutes of post-secondary education from all around the world. Several elements of the Dublin Core (DC) and other supplementary elements were used for cataloging the syllabi. The conceptual schema of all the selected elements of the syllabi was developed following the entity-relationship model. The metadata of the syllabi was then stored in a relational database system. Various searching and browsing interfaces were implemented to facilitate effective retrieval. The prototype, named as Gateway to Faculty Syllabi (GFS), is available at http:/Ais.skku.ac.kr/gfs/.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.1
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• pp.231-237
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• 2004

Most of the masonry buildings have many structural defects under an earthquake load due to the small tensile force and ductility. In the foreign countries there are many the reinforcing methods of masonry buildings, but the glass fiber sheet reinforcements must be used due to various conditions in Korea. The purpose of this paper is to estimate the seismic capacity of masonry buildings damaged by earthquake and reinforced by Glass Fiber Sheet. On the basis of test results, the maximum base shear force and deformation of the masonry building with GFS were remarkably increased. From the comparison by existing strength equations and test data, the new strength equation of reinforced masonry buildings with GFS was developed.

• Composites Research
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• v.31 no.2
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• pp.57-62
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• 2018

Interfacial and mechanical properties of neat and two sizing agents coated glass fiber (GF)/polydicyclopentadiene (p-DCPD) composites were evaluated at room and low temperatures, $25^{\circ}C$ and $-20^{\circ}C$. Sizing agents of GFs were extracted using acetone and compared via FT-IR. Surface energy and work of adhesion between GFs and p-DCPD were calculated by dynamic contact angle measurement. Mechanical properties of different GFs were determined using single fiber tensile test and interfacial properties of single GF reinforced DCPD strip were determined using cyclic loading tensile test. Mechanical properties of GFs/p-DCPD composites at room and low temperatures were determined using tensile, compressive, and Izod impact tests. Interfacial and mechanical properties were different with sizing agents of GFs and the optimized condition of sizing agent was found.

• Journal of the Institute of Convergence Signal Processing
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• v.15 no.4
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• pp.176-182
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• 2014

This paper introduces the development of global fringe search (GFS) software for preprocessing of Daejeon Correlator. In case of the VLBI observation, a observer conducts the observation for the reference sources with strong and point-like radio stars on schedule in order to confirm the well-observedness of the radio source by the radio telescope. The correlator performs the correlation for the reference sources to detect the fringe completely. We developed the GFS software by calculating the precise delay time between each observatory based on specific observatory. Then, this software calculates the precise delay time by using the delay model (correlator model) of reference source and information of time offset between the Hydrogen Maser frequency standard and GPS (Global Positioning System) clock located in each observatory through the correlation preprocessing. In order to confirm the performance of the developed software, experiments were carried out for the reference sources and target sources observed by the KaVA (KVN and VERA Array). Experimental results show that the GFS software has effectively good performance by finding the precise delay time offset according to the comparison between the compensated delay time offset and one without compensation.

• Journal of radiological science and technology
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• v.27 no.1
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• pp.43-46
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• 2004

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.565-570
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• 1997

This study is on the strength capacity and the strengthening effects of crarbon fiber sheets(CFS) and glass fiber sheets (GFS) on steel reinforced concrete(SRC) beams. SRC beams are often used on high-rise building construction to save story height and construction cost. However, there are no strengthening design code in Korea and most engineers design it as steel beams ignored the composite effect if reinforced concrete. Test results on steel reinforced concrete beams reveal thar the strength capacity of SRC beam is more than simple addition of steel and reinforced concrete beams. In case of steel reinforced concrete beams, ultimate moment capacity of strengthening beam of carbon fiber sheets is 120% of non-strengthening one.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.62-62
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• 2019

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.64-64
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• 2019

• The korean journal of orthodontics
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• v.42 no.6
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• pp.307-317
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• 2012

Objective: The purpose of this study was to investigate the isolation and characterization of multipotent human periodontal ligament (PDL) stem cells and to assess their ability to differentiate into bone, cartilage, and adipose tissue. Methods: PDL stem cells were isolated from 7 extracted human premolar teeth. Human PDL cells were expanded in culture, stained using anti-CD29, -CD34, -CD44, and -STRO-1 antibodies, and sorted by fluorescent activated cell sorting (FACS). Gingival fibroblasts (GFs) served as a positive control. PDL stem cells and GFs were cultured using standard conditions conducive for osteogenic, chondrogenic, or adipogenic differentiation. Results: An average of $152.8{\pm}27.6$ colony-forming units was present at day 7 in cultures of PDL stem cells. At day 4, PDL stem cells exhibited a significant increase in proliferation (p < 0.05), reaching nearly double the proliferation rate of GFs. About $5.6{\pm}4.5%$ of cells in human PDL tissues were strongly STRO-1-positive. In osteogenic cultures, calcium nodules were observed by day 21 in PDL stem cells, which showed more intense calcium staining than GF cultures. In adipogenic cultures, both cell populations showed positive Oil Red O staining by day 21. Additionally, in chondrogenic cultures, PDL stem cells expressed collagen type II by day 21. Conclusions: The PDL contains multipotent stem cells that have the potential to differentiate into osteoblasts, chondrocytes, and adipocytes. This adult PDL stem cell population can be utilized as potential sources of PDL in tissue engineering applications.