• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.4
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• pp.659-664
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• 2020

In this paper, we propose a silicon-based electro-optic (EO) modulator which can modulate a sign of a topological charge number l of |l|=1 orbital angular momentum (OAM) mode. The proposed EO modulator consists of position-dependent doped Si waveguide core and undoped SiO2, cladding, which enables control of the effective index and propagation loss of two OAM constitutive eigenmodes. The modulator functions as OAM mode maintaining waveguide at -0.33V and as topological charge sign inverter at 10V. The output OAM mode purity is calculated through electric field distribution, showing high purity of |l|>0.92 in both cases.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.33-37
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• 2006

Since 1993, the civil aviation community through RTCA (Radio Technical Commission for Aeronautics) and the ICAO (International Civil Air Navigation Organization) have been working on the definition of GNSS augmentation systems that will provide improved levels of accuracy and integrity. These augmentation systems have been classified into three distinct groups: Aircraft Based Augmentation Systems (ABAS), Space Based Augmentation Systems (SBAS) and Ground Based Augmentation Systems (GBAS). The last one is an implemented system to support Air Navigation in CAT-I approaching operation. It consists of three primary subsystems: the GNSS Satellite subsystem that produces the ranging signals and navigation messages; the GBAS ground subsystem, which uses two or more GNSS receivers. It collects pseudo ranges for all GNSS satellites in view and computes and broadcasts differential corrections and integrity-related information; the Aircraft subsystem. Within the area of coverage of the ground station, aircraft subsystems may use the broadcast corrections to compute their own measurements in line with the differential principle. After selection of the desired FAS for the landing runway, the differentially corrected position is used to generate navigation guidance signals. Those are lateral and vertical deviations as well as distance to the threshold crossing point of the selected FAS and integrity flags. The Department of Applied Science in Naples has create for its study a virtual GBAS Ground station. Starting from three GPS double frequency receivers, we collect data of 24h measures session and in post processing we generate the GC (GBAS Correction). For this goal we use the software Pegasus V4.1 developed from EUROCONTROL. Generating the GC we have the possibility to study and monitor GBAS performance and integrity starting from a virtual functional architecture. The latter allows us to collect data without the necessity to found us authorization for the access to restricted area in airport where there is one GBAS installation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.559-562
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• 2011

It is very essential issue in industrial advancement and company survival for international standard body to adopt standards including ICT that domestic company or our country owns. Also, advanced countries fiercely contest in order to include domestic technology in international standard and make every effort to secure essential patent relating to core and basic technology in international standard. In this circumstances, it is necessary to develop standardization strategies and take systematic approaches in an attempt to upgrade our country to strongly knowledge-based country in 21th century and achieve a leading position in ICT market. Therefore, this paper will suggest systematic and comprehensive approaches from planning of technology development to securing essential patent of international standard and have the purpose of making standardization base as well as promoting international standardization of domestic technology.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.1
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• pp.61-73
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• 2002

This paper addresses the conceptual design results of the HAUSAT-1 (Hankuk Aviation University SATellite-1), developed by Space System Research Lab. of Hankuk Aviation Univ., which is a new generation picosatellite. This project has been funded by Korean Government for the purpose of developing the space core technology. This is the first attempt at the level of university in Korea to develop the satellite weighing less than 1kg and accelerates opportunities with low construction, low launch cost space experiment platforms. The purpose of the HAUSAT-1 project is to offer graduate and undergraduate students great opportunities to be able to understand the design process of satellite development as a team member. Its mission objectives are to track its position by the GPS receiver system, to deploy the thin film solar cell panel to generate extra power, and to measure plasma density and temperature with the plasma sensor. The HAUSAT-1 will orbit at the altitude of 650 km with 65 degree inclination angle with 12 months of design mission life. It is planned to be launched on November 2003 by Russian launch vehicle "Dnepr".

• Korean Journal of Materials Research
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• v.27 no.6
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• pp.345-349
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• 2017

The effects of electron beam(EB) irradiation on the electrical and optical properties of InGaZnO(IGZO) thin films fabricated using a sol-gel process were investigated. As the EB dose increased, the electrical characteristic of the IGZO TFTs changed from semiconductor to conductor, and the threshold voltage values shifted to the negative direction. X-ray photoelectron spectroscopy analysis of the O 1s core level showed that the relative area of oxygen vacancies increased from 14.68 to 19.08 % as the EB dose increased from 0 to $1.5{\times}10^{16}electrons/cm^2$. In addition, spectroscopic ellipsometer analysis showed that the optical band gap varied from 3.39 to 3.46 eV with increasing EB dose. From the result of band alignment, it was confirmed that the Fermi level($E_F$) of the sample irradiated with $1.5{\times}10^{16}electrons/cm^2$ was located at the closest position to the conduction band minimum(CBM) due to the increase of electron carrier concentration.

• Tunnel and Underground Space
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• v.16 no.3 s.62
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• pp.241-250
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• 2006

Ice ring formation, one of the core techniques in LNG storage in a lined rock cavern, is investigated through hydro-thermal coupled analysis. An ice ring acts as a secondary barrier in case of leakage of cryogenic liquid and as a primary barrier for groundwater intrusion into an LNG cavern. Therefore, the thickness and location of the ice ring are crucial factors for the safe operation of an LNG storage cavern, especially for maintaining the integrity of a primary barrier composed of concrete, PU foam, and steel membrane. Through numerical analyses, the position and thickness of the ice ring are estimated, and the temperature and groundwater level are compared with measured values. The temperature md groundwater level by numerical analyses show good agreement with the field measurements when temperature-dependent properties and phase change are taken into account. The schemes used in this paper can be applied for estimation of ice ring formation in designing a full-scale LNG cavern.

• Journal of Information Management
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• v.39 no.1
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• pp.27-52
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• 2008

Electronic information, especially e-journals took their position as core resources in current scholarly communication. However, the publishing and pricing structure of e-journal licensing process have not yet succeeded to be reorganized in accord with newly changed electronic scholarly communication environment. That resulted in a lot of challenges scholarly communication now faced. This study aimed to analyze key issues regarding big deal, pricing, licensing, archiving, copyright and public access by conducting comprehensive literature review and examining movements of world wide scholarly institutes and alliances. And then this study eventually purposed to draw some strategies which domestic libraries and consortia should take in order to lead current changes in scholarly communication.

• Journal of Korea Port Economic Association
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• v.22 no.3
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• pp.141-160
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• 2006

In order to obtain and maintain competitive advantage, under rapidly changing maritime environment, liners should make efforts to reinforce their logistics service capabilities. Most of all, for this, shipping lines should accurately recognize and evaluate their logistics service attributes. In the present research, various logistics service attributes for ocean carriers were selected from previous studies and the observed data for 6 main service attributes were collected through a questionnaire survey to 31 maritime experts. Moreover, shipping lines' relative logistics service capabilities were measured by an additional survey process. The comparative gravity between core evaluation factors were measured by AHP technique and the relative capability levels of 2 Korean liners and 5 foreign shipping companies were assessed by utilizing a fuzzy model. The empirical result presents that Korean liners are superior at customer service capability but inferior at freight rate competitiveness. This research shows that Korean liners are ranked at high position for overall logistics service capabilities and focusing on the differentiation strategy but not on the cost related strategy.

• Korean Journal of Optics and Photonics
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• v.14 no.6
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• pp.594-599
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• 2003

By using the spectroscopic ellipsometry, we have measured and analyzed the optical characteristics of P $r^3$$^{+}$-doped selenide glasses of Ge-Sb-Se system, a strong candidate material for U band fiber amplifiers. The ellipsometric spectra measured in the transparent wavelengths range of the material were all fitted to a model consisting of ambient/roughness/thin fil $m_strate structures to obtain simultaneously the optical properties such as refractive index, in terms of Sellmeier parameters and film structure of P $r^3$$^{+}$-doped selenide glasses. Repeated measurements on different positions in both polished faces rendered to verify positional dependence of measured spectre-ellipsometric data. Hence, the model made possible the analysis of the optical characteristics of the glasses. Even though surface roughness was mainly responsible for the position dependencies, the averaged refractive indexes were as precise as to reflect the minute compositional change tantamount to 1 mol%. The measured refractive indexes are useful for design of core and clad compositions of single-mode selenide optical fibers.

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.8-15
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• 2021

This study was conducted with the purpose of exploring the dilemma and improvement strategies for the integrated management of extracurricular education programs at Duksung Women's University. The research method was finally composed of a procedure with a meeting of experts based on the procedure of collecting and analyzing the previous research literature. As for the contents of the study, the dilemma of the integrated management of the extracurricular education program at Duksung Women's University was presented first. Examples of dilemmas include difficulties in organizing and operating programs from the perspective of a roadmap customized for each grade level, difficulties in establishing a foundation for balanced mapping of core competencies and cultivating programs, difficulties in managing the performance of regular program monitoring and feedback improvement, and activating the linkage system between subjects and extracurricular education programs difficulties and difficulties in establishing a support system for the operation of the extracurricular education integrated management system were reflected. In addition, a strategy to complement and improve this dilemma was presented in a linkage. As a result of the study, the integrated management dilemma of Duksung Women's University's extracurricular education programs needs to be resolved in the long term through formal infrastructure such as external expert advice and expert exchange, and the development and use of related manuals should be considered aspects were analyzed. In addition, the content of this study was analyzed not only in the educational case of Duksung Women's University, but also in that it deals with cases that can be usefully referenced in most universities that develop and operate extracurricular education programs. Finally, this study presents an evidence-based practices that can be referenced in promoting the integrated management of extracurricular education programs in university sites, and the position and identity of extracurricular education throughout the university curriculum. It is judged that the significance and expected effect of the study can be obtained in that it provides an opportunity to improve from the management point of view.