• Journal of Positioning, Navigation, and Timing
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• v.11 no.3
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• pp.191-198
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• 2022

In order to increase the practical use and navigational application performance of the Korean Positioning System (KPS), it is required to provide interoperability with other Global Navigation Satellite System (GNSS). This kind of interoperability can be obtained by broadcasting the time offset between KPS and GNSS using a KPS navigation message. With the assumption that KPS Time (KPST) will be generated by the similar method and equipment of UTC(KRIS), the overall behavior of KPST will be close to that of UTC(KRIS). Therefore, the time offset between KPST and GPS Time (GPST) is estimated by using UTC(KRIS) instead of KPST because KPST can not available at the present time. In this paper, we describe the estimation results of the KPS to GPS Time Offset (KGTO) obtained by using a GNSS time transfer receiver which reference inputs are fed from UTC(KRIS). The estimated KGTO performance is compared to the time offset between UTC(KRIS) and UTC(USNO) which is used to generate GPST and considered as the real GPST. The time offset between UTC(KRIS) and UTC(USNO) is obtained by using the Bureau International des Poids et Mesures (BIPM) Circular T report. From the results, it is observed that KGTO can be estimated under 10 ns with the assumption that KPST will be generated by a similar method of UTC(KRIS) generation.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.232-233
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• 2002

Nanostructed high energy Nd-Fe-B based bulk magnet can be prepared by hot-working process (hot press and die-upset) from melt-spun amorphous or nanocrystalline powder.[1] Recently, we have investigated a modified method, current-applied pressure-assisted (CAPA) process, to produce nanocrystalline isotropic and anisotropic NdFeB magnets. The process consists of current-applied pressing the melt-spun powders to obtain isotropic precursor subsequent current-applied deforming the precursor to obtain textured magnet.[2-3] (omitted)

• Bulletin of the Society of Naval Architects of Korea
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• v.17 no.3
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• pp.29-35
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• 1980

With installation of the computerized data acquisition system on the towing carriage of KRIS towing tank, the testing techniques of resistance test, propeller open-water test, self-propulsion test and wake survey at propeller disk were remarkably improved and automated. For the self-propulsion test a new method was developed with aid of a digital desk-top computer. This method is based on extracting advantages both from British method and Continental method, that is, the accuracy from the constant speed method and the effciency from the constant load method. The KRIS method has been successfully practized with the improved accuracy, stability and efficiency. Details of the new method are described in this paper.

• Journal of the Korea Safety Management & Science
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• v.22 no.4
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• pp.1-8
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• 2020

In general, companies operate systematically in response to financial risks such as exchange rates and liquidity, while they are vulnerable to risks in the manufacturing and sales processes. In particular, logistics refers to the activities for planning, managing and implementing efficient flows from the starting point of goods and products to the point of consumption, The purpose of this study was to develop key risks and key risk management indicators (KRIs) for risks that undermine logistics efficiency so that logistics risks can be effectively prevented and managed. As a result, 40 risk management indicators (KRIs) were developed in a total of six categories in the logistics sector, and the definition, calculation method and early warning grade of each KRI were presented so that companies could prevent risks in advance in logistics activities and contribute to enhancing efficiency of their work.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.490-492
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• 2006

본 논문에서는 현재 KRISS(한국표준과학연구원)에 구축 된 JCSAT-1B 위성과 PAS-8 위성 그리고 PAS-4 위성을 이용하여 KRISS와 NICT(일본의 정보통신연구기관)간의 양방향 시각비교를 통하여 그들의 안정도를 비교분석하고 향후 JCSAT-1B 위성의 백업시스템으로써 PAS-4 위성과 PAS-8 위성의 활용성을 검토하였다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.4
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• pp.21-31
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• 1997

• Journal of Korea Fair Competition Federation
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• no.161
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• pp.56-67
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• 2012

• Proceedings of the Korean Vacuum Society Conference
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• 2002.06a
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• pp.135-135
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• 2002

• Journal of Navigation and Port Research
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• v.40 no.1
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• pp.15-20
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• 2016

In this study we measured a differential ASF to improve the accuracy of time synchronization with the signal transmitted from Pohang 9930M Loran station. We obtained the differential ASF which is calculated from a difference of the TOA measurements between KRISS and Chungnam National University(CNU), and KRISS and National Maritime PNT Office respectively. The TOA measurement at KRISS was measured by UTC(KRIS) reference clock and other sites were measured by atomic clocks respectively. The time variations of differential ASF measurements at CNU and National Maritime PNT Office were within $0.1{\mu}s$ and $0.05{\mu}s$ respectively. And we found the time variations of $0.1{\mu}s$ depending on the surrounding radio-wave environments from the differential ASF measurements of 60 minute moving averages. We can improve the accuracy of time synchronization of the local clock to within 10 ns by compensating the differential ASF through removing the common component of ASF. And we measured the absolute ASF between the Pohang transmit station and KRISS by the measurement technique of absolute time delay using a cesium atomic clock. The average ASF between two points is about $3.5{\mu}s$.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.103-103
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• 2011

고진공의 바이러스격인 탈기체의 속성과 KRISS에서 보유중인 탈기체의 측정장치들의 각 특징들을 소개한다. 또한 산업체에서 시험 의뢰한 재료 종류 분석을 통해 산업체의 동향을 간접적으로 제시한다.