• Journal of Astronomy and Space Sciences
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• v.24 no.4
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• pp.275-284
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• 2007

For the application to the numerical weather prediction (NWP) in active service, it is necessary to ensure that the GPS precipitable water vapor (PWV) data has less than one hour latency and three millimeter accuracy. The comparison and the verification between the daily products from GPS measurement by using the IGS final ephemeris and the conventional meteorological observation has been done in domestic researches. In case of using IGS final ephemeris, GPS measurements can be only post processed in daily basis in three weeks after the observation. Thus this method cannot be applied to any near real-time data processing. In this paper, a GPS data processing method to produce the PWV output with three mm accuracy and one hour latency for the data assimilation in NWP has been planned. For our new data processing strategy, IGS ultra-rapid ephemeris and the sliding window technique are applied. And the results from the new strategy has been verified. The GPS measurements during the first 10 days of January, April, July and October were processed. The results from the observations at Sokcho, where the GPS and radiosonde were collocated, were compared. As the results, a data processing strategy with 0.8 mm of mean bias and 1.7 mm of standard deviation in three minutes forty-three seconds has been established.

• Journal of Advanced Navigation Technology
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• v.20 no.5
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• pp.425-432
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• 2016

When user estimates user's position, GPS positions can be obtained from the navigation message transmitted from the GPS. However, the broadcast ephemeris cannot be used in the applications required high-level accuracies because it can cause errors of several meters. To correct satellite positions and clocks, user can use RTS corrections provided by IGS. In this paper, the accuracy of broadcast and RTS corrections are analyzed by comparing with the IGS final for 3-months. The RTS errors are analyzed for each user's locations and satellite blocks. The correlations between errors and shadow condition, and solar and geomagnetic activities are analyzed. The latency is applied to the RTS corrections, and these are extrapolated by polynomial. Then, the extrapolated RTS are compared with true RTS. The single-day performances of the PPP by broadcast ephemeris and RTS corrected ephemeris are analyzed. As a result, RTS 3D orbit and clock errors are 1/20 and 1/3 less than broadcast ephemeris errors. 3D positioning error of the RTS is 1/5 less than that of broadcast ephemeris.

• The Magazine of the IEIE
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• v.21 no.11
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• pp.42-48
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• 1994

• Water for future
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• v.25 no.4
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• pp.31-36
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• 1992

• The Plant Pathology Journal
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• v.20 no.4
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• pp.264-270
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• 2004

Fusarium oxysporum f. sp. fragariae is a fungal pathogen causing strawberry wilt disease. The random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphisms (RFLPs) of intergenic spacer (IGS) region of rDNA were used to identify genetic variation among 22 F. oxysporum f. sp. fragariae isolates. All isolates could be distinguished from each other by RAPD analysis and RFLP of 2.6 kb amplified with primer CNS1 and CNL12 for IGS region of rDNA. Cluster analysis using UPGMA showed eight distinct clusters based on the banding patterns obtained from RAPD and rDNA RFLP. These results indicate that F. oxysporum f. sp. fragariae isolates are genetically distinct from each other, There was a high level genetic variation among F. oxysporum f. sp. fragariae.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.269-270
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• 1998

Image-guided surgery (IGS) system has become well known in the field of neurosurgery and spine surgery. A patient's anatomy is first registered to preoperatively acquired CT/ MRI data using the point matching algorithm. A magnetic field digitizer was used to measure the physical space data and the system was based on Workstation of Unix system. To evaluate the spatial accuracy of interactive IGS system, the phantom consisting of rods varied height and known location was used. The RMS error value between CT/MR images and real location was 3-4mm. For the more convenience of the surgery, we provide various image display modules.

• Proceedings of the IEEK Conference
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• 2003.11c
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• pp.223-226
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• 2003

In this paper, we propose new agent discovery and route discovery schemes to support Mobile IP (MIP) in Ad Hoc networks with wireless backbone. The wireless backbone consisting of stationary wireless routers and Internet gateways (IGs) is a kind of wireless access network of IP-based core network. The proposed scheme utilizes favorable features of wireless backbone such as stable links and no energy constraints. In the agent discovery scheme, backbone-limited periodic Agent Advertisement (AA) and proxy-AA messages are used, which reduce network-wide broadcasting overhead caused by AA and Agent Solicitation messages and decentralize MIP processing overhead in IGs. In order to reduce delay time and control message overhead during route discovery far the destination outside Ad Hoc network, we propose a cache-based scheme which can be easily added to the conventional on-demand routing protocols. The proposed schemes can reduce control overhead during agent discovery and route discovery, and efficiently support MIP in Ad Hoc network with wireless backbone.

• Korean Journal of Plant Taxonomy
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• v.49 no.4
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• pp.282-293
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• 2019

Broussonetia × kazinoki Siebold has long been utilized as a major component in the manufacturing of Korean traditional paper, hanji, and has been suggested as a hybrid species of B. papyrifera and B. monoica. By applying three molecular markers, chloroplast (cp) ndhF-rpl32 IGS, a nuclear ribosomal internal transcribed spacer, and the TOPO6 gene, the hybrid origin of B. × kazinoki is tested. As a result, B. × kazinoki in Korea is demonstrated to be a hybrid of B. monoica × B. papyrifera, most likely formed naturally in Korea. The cp haplotypes detected provided information about the origins and genetic diversity of the maternal lineage B. monoica and paternal lineage B. papyrifera. The two nuclear markers were supplemented to each other, leading to the discovery of introgression in Broussonetia.

• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.1
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• pp.104-113
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• 2012

Wind farm grid codes require wind generators to ride through voltage sags, which means that normal power production should be re-initiated once the nominal grid voltage has been recovered. Doubly Fed Induction Generator (DFIG) based wind farm is gaining popularity these days because of its inherent advantages like variable speed operation and independent controllability of active and reactive power over conventional Induction Generator (IG). This paper proposes a new control strategy using DFIGs for stabilizing a wind farm composed of DFIGs and IGs. Simulation analysis by using PSCAD/EMTDC shows that the DFIGs can effectively stabilize the IGs and hence the entire wind farm through the proposed control scheme by providing sufficient reactive power to the system.

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.37.1-37.1
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• 2010

이 연구는 국제항법서비스(IGS)에서 진행 중인 실시간 IGS 산출물 서비스 구축을 위한 실시간 파일럿 프로젝트(Real-Time Pilot Project; RTPP)의 진행 현황의 파악을 위한 것이다. 본 동향조사에서는 RTPP의 구성요소 별 진행현황과 현재 기술 수준 및 해결해야 할 이슈 등에 대해 분석하였다. 조사결과 현재 4개의 분석센터의 실시간 산출물이 예비 서비스를 하고 있으며, 이를 활용한 연구도 활발히 진행되고 있는 현황이다. 하지만, 실시간 자료 전송을 위한 자료형식과 전송방식의 표준이 정해지지 않았고, 이온층과 대류층 정보의 경우도 아직 논의가 진행 중이다. IGS가 목표로 하는 실시간 서비스는 고정밀 위치결정, 우주환경, 자연재해 감시, 기상 및 기후 연구 등의 분야에 매우 활용도가 높은 서비스로 본 동향 조사를 통해 이를 활용하기 위한 관련 연구와 기술 개발에 있어 참고자료가 될 것으로 기대된다.