• Journal of Positioning, Navigation, and Timing
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• v.8 no.3
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• pp.119-127
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• 2019

COsmicheskaya Sisteyama Poiska Avariynich Sudov Search and Rescue Satellite-Aided Tracking (COSPAS-SARSAT) is an international communication support program to perform search and rescue (SAR) operations in emergency situations by using satellite signals relayed from a beacon. The legacy COSPAS-SARSAT was originally composed of low altitude and geostationary Earth orbit satellites; thus, a limited number of directional dish antennas was sufficient to cover the limited number of visible satellites at the local user terminal. However, the second generation COSPAS-SARSAT newly added the medium Earth orbit satellites, e.g., Global Navigation Satellite Systems (GNSS) to the existing system, so that the number of visible satellites increase dramatically, and the system upgrade to cover all the visible satellites is foreseen. The additional use of planned Korea Positioning System (KPS) to existing GNSS is envisaged to provide a better performance of their SAR service. This paper presents the benefits of the additional use of KPS together with the phased array antennas at the local user terminal of the COSPAS-SARSAT. This is to effectively response to the increase of the number of visible satellites. Numerical simulation is included to evaluate the performance improvement of COSPAS-SARSAT in terms of the number of visible satellites, geometry between satellites and user, and position estimation accuracy.

• Journal of Positioning, Navigation, and Timing
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• v.9 no.4
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• pp.347-356
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• 2020

In this study, Inclined Geosynchronous Orbit (IGSO) and Geostationary Orbit (GEO) of BeiDou System (BDS) and Quasi Zenith Satellite System (QZSS) satellites positions and clock errors calculated by broadcast ephemeris and compared with Multi-GNSS Experiment (MGEX) products provided by five Analysis Centers (ACs). Root Mean Square Errors (RMSE) calculated for satellite position error. The IGSO results showed that 1.82 m, 0.91 m, 1.28 m in BDS and 1.34 m 0.36 m 0.49 m in QZSS and the GEO results showed that 2.85 m, 6.34 m, 6.42 m in BDS and 0.47 m, 4.79 m, 5.82 m in QZSS in the direction of radial, along-track and cross-track respectively. RMS calculated for satellite clock error. The IGSO result showed that 2.08 ns and 1.24 ns and the GEO result showed that 1.28 ns and 1.12 ns in BDS and QZSS respectively.

• The Journal of the Convergence on Culture Technology
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• v.8 no.3
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• pp.259-263
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• 2022

As urbanization progresses in Korea, megacities are being formed around the metropolitan area, the central area, and the southeast area. In addition, it is accelerating the development of urban air mobility (UAM) that can be operated by Mega City as a new growth engine industry in the future. At the same time, in order to become a space powerhouse, Korea plans to establish its own Korean positioning system (KPS) by 2035. Therefore, if urban air mobility and location information services provided by the Korean positioning system are used in combination, urban air mobility can be stably operated in future megacities.

• The Safety technology
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• no.156
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• pp.18-19
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• 2010

한전KPS(주)는 국내외 수화력 발전소 및 원자력발전소 등의 발전설비와 송변전설비에 대한 정비업무를 수행하여 발전된 전력이 안정적으로 공급되도록 하는 업체이며, 그 기술력을 인정받아 호주, 필리핀, 인도, 레바논 등 해외로도 시장을 확대하고 있다. 또한 작년 UAE원전 수주에 따른 해외 원전설비 시운전 및 정비업무에 참여 등 이곳은 발전설비정비에 관한 세계 최고의 정비기술을 자랑하는 내실있는 기업이다. 이곳 보령사업처는 충남 보령시 오천면에 위치한 국내 최대용량의 화력발전소인 보령화력본부의 발전설비를 정비하고 있으며 고소작업, 중량물취급 작업, 고온부 작업 등 수 많은 위험요소가 있음에도 불구하고 지금까지 무재해 3배를 달성한 안전사업장이다. 위험요소가 많음에도 무재해를 달성할 수 있었던 데에는 모든 직원들이 협심하여 안전수칙을 철저히 지킨 것의 결과이겠지만 그 이면에는 전재진 과장의 보이지 않는 꾸준한 노력이 있었기에 가능했다. 안전을 나름대로의 철학으로 실천하고 있는 한전KPS(주) 보령사업처의 전재진 과장을 만나 어떠한 노하우가 있는지 이야기를 나눠보았다.

• Korean Journal of Child Studies
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• v.22 no.4
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• pp.33-50
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• 2001

This research analyzed differences between parents and teachers in assessment of young children's potential abilities based on multiple intelligences theory. Subjects were 10 boys and 10 girls, 4 and 5 years of age and their parents and teachers. Children's potential abilities were measured by the Korean Project Spectrum(KPS) and by the assessments of parents and teachers. Data were analyzed by SPSS. Statistical methods were Cronbach's ${\alpha}$, t-test, and Pearson's and Spearman's correlations. Results revealed differences between the assessments of parents and of teachers. While teacher assessments were very similar to the results of the KPS on logical mathematical and linguistic intelligence, the results of parents' assessments were different from the results of the KPS on musical, interpersonal-intrapersonal, and naturalistic intelligence.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.329-330
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• 2008

제주-해남간 HVDC 변환설비는 제주 전력수요의 약 40%를 담당하는 주요 설비로, 국내에서는 처음으로 도입되어 상용 운전중인 직류송전 설비이다. 10년간의 변환설비 운전중에 크고 작은 고장이 많이 발생하였으며 PCB Card에 의한 고장은 전체 고장의 약 30%를 차지하고 있다. 본 논문에서는 해남변환소에서 사용중인 VBE (Valve Base Electronics : Thyristor 점호 제어반) Cubicle에 설치된 Databack PCB Card 점검장비 개발내용을 설명하였다. 이 장비 사용시 설비사고 및 고장의 원인을 줄일 수 있고, 카드의 연도별 이력관리를 할 수 있다. 또한 Card의 경년열화 특성을 파악하여 교체시기를 판단할 수 있고 Card 시험시간의 단축이 가능하다. 상기 이외에 점검기술에 대하여 기존 방식과 비교하고 시험기 개발 및 운영사항에 대하여 기술하고자 한다.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.1
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• pp.21-28
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• 2021

In order to develop a Korea Positioning System (KPS) as part of key national infrastructure, independent navigation signal design is essential. The designed signal candidates must coexist with existing or planned GNSS signals within the limited frequency band. This requires a RF compatibility assessment, which can be performed using the Spectral Separation Coefficient (SSC) and Effective Carrier to Noise Density Ratio (Effective C/N0), for navigation signals. Thus, in this paper, the analysis of RF compatibility between the designed signal candidates and the existing GNSS signals is carried out based on analytical and numerical techniques.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.4
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• pp.371-377
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• 2021

This research proposes the best combination of tropospheric delay models for Korean Positioning System (KPS). The overall results are based on real observation data of Japanese Quasi-Zenith satellite system (QZSS), whose constellation is similar to the proposed constellation of KPS. The tropospheric delay models are constructed as the combinations of three types of zenith path delay (ZPD) models and four types of mapping functions (MFs). Two sets of International GNSS Service (IGS) stations with the same receiver are considered. Comparison of observation residuals reveals that the ZPD models are more influential to the measurement model rather than MFs, and that the best tropospheric delay model is the combination of GPT3 with 5 degrees grid and Vienna Mapping Function 1 (VMF1). While the bias of observation residual depends on the receivers, it still remains to be further analyzed.

• Progress in Medical Physics
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• v.26 no.3
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• pp.137-142
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• 2015

We retrospectively analyzed the outcomes in patients who underwent reirradiation for brain metastasis. Twenty-three patients with brain metastases who were initially treated with palliative brain radiotherapy and were retreated with a second course of brain RT between June 2008 and December 2012. WBRT, 3DCRT and SRS were used for brain metastasis. The median dose of the first course of WBRT was 30 Gy (range, 23.4~30 Gy). The dose of the first course 3DCRT for lesion was 30 Gy in 3 Gy per fraction. The median dose of the first course of SRS was 16 Gy in 1 fraction (range, 12~24 Gy). The median dose of the second course of WBRT was 27.5 (range, 12~30 Gy). The median dose of the second course of 3DCRT for lesion was 30 Gy (range, 25~30 Gy). The dose of the second course of SRS was 16 Gy in 1 fraction. The second course of WBRT was administered on radiographic disease progression with symptom in all patients. With median follow-up of 25 months, overall symptom resolution rates were 47.8%. Rate of palliative efficacy was 82.6% including stable disease. The median survival time after initiation of reirradiation was 3.2 months. Median value of KPS prior to reirradiation was 30. Median value of KPS after reirradiation was 60. Reirradiation of brain metastasis maybe feasible and effective in select patients with a good performance status $KPS{\geq}60$ (: ECOG 0~2) prior to reirradiation.

• Communications of the Korean Mathematical Society
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• v.17 no.2
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• pp.237-243
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• 2002

In this paper we generalize the Lie algebras of KPS's in [4], which have no toral elements. However our generalized Lie algebras have toral elements. Moreover our Lie algebras are not isomorphic to the Witt algebra W(n) with a toral element.