• Journal of Advanced Navigation Technology
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• v.21 no.6
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• pp.549-553
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• 2017

The KASS development project, a Korean SBAS launched in 2014, is under development for the APV-1 Class SOL service in 2022. Flight tests should be conducted to analyze development requirements and performance requirements for KASS R & D. However, since the evaluation items have not yet been presented in Korea, FAA and ICAO regulations should be analyzed so that evaluation items for flight testing for KASS development should be structured and comply with international standards. In this paper, we analyze the procedure verification of SBAS for flight test using satellite navigation system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.109-112
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• 2014

Korean informationization technology development speed is growing fastly and IT technology become world-class. Especially, by grafting IT technology to war commanding system, built an network center operational environment. However, conscription administration and the barracks informationization have inadequate points, to provide the people who have a duty of military service and parents with benefits and develop conscription administration and the barracks informationization base system conformed to IT age include using online system to guarantee military personnel's studying environment, writer proposed an improvement plan.

• Journal of the Korean Data and Information Science Society
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• v.25 no.6
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• pp.1171-1180
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• 2014

We considered saddlepoint approximations to VaR (value at risk) and ES (expected shortfall) which frequently encountered in finance and insurance as the measures of risk management. In this paper we supposed univariate and multivariate skew-normal distributions, instead of traditional normal class distributions, as underlying distribution of linear portfolios. Simulation results are provided and showed the suggested saddlepoint approximations are very accurate than normal approximations.

• ETRI Journal
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• v.24 no.4
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• pp.311-322
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• 2002

Presently, optical burst switching (OBS) technology is under study as a promising solution for the backbone of the optical Internet in the near future because OBS eliminates the optical buffer problem at the switching node with the help of no optical/electro/optical conversion and guarantees class of service without any buffering. To implement the OBS network, there are a lot of challenging issues to be solved. The edge router, burst offset time management, and burst assembly mechanism are critical issues. In addition, the core router needs data burst and control header packet scheduling, a protection and restoration mechanism, and a contention resolution scheme. In this paper, we focus on the burst assembly mechanism. We present a novel data burst generation algorithm that uses hysteresis characteristics in the queueing model for the ingress edge node in optical burst switching networks. Simulation with Poisson and self-similar traffic models shows that this algorithm adaptively changes the data burst size according to the offered load and offers high average data burst utilization with a lower timer operation. It also reduces the possibility of a continuous blocking problem in the bandwidth reservation request, limits the maximum queueing delay, and minimizes the required burst size by lifting up data burst utilization for bursty input IP traffic.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.719-730
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• 2013

The English Conversation class as a required course in S university is designed as blended learning to reinforce English education. To identify the influence of this blended learning on its students' achievement, the research about what variables are related with it was conducted. Data analysis indicates that gender, major, military service, overseas stay, face-to-face attendance, quiz, and online attendance have an effect on the student achievement. However, the students' style of online learning--study place, study time, and study frequency--doesn't have any relationship with their achievement. Their satisfaction with the online study was questioned in the three areas such as instructor, contents, and system, among which only the 'system' area has an influence on their achievement.

• The Transactions of the Korea Information Processing Society
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• v.4 no.7
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• pp.1781-1787
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• 1997

Future high speed networks are expected to use the Asynchronous Transfer Mode(ATM), which provides desired quality of service for the various traffic types(e.g., voice, video and data). Proper traffic control scheme helps ensure efficient and fair operation of networks. In this paper, we analyze various related traffic-control strategies and propose a new traffic control scheme and ATM control architecture with an integrated buffer management method and multi-thresholds in order to solve the problem of each class's cell loss ratio and cell delay in ATM networks. In addition, we evaluate the performance improvement of the proposed traffic control scheme through simulation. As shown in the result, the proposed traffic control scheme improves cell loss ratio in proportion to the buffer size.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.153-154
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• 2018

군에서는 무기체계인 유형전력 뿐만 아니라 눈에 보이지 않는 무형전력 또한 중요하다. 그중에서도 정신전력도 전투력의 중요 요인으로 이에 대한 효과를 높이기 위해 다양한 연구가 이루어지고 있지만, 계급사회인 군의 특징을 고려한 연구는 미흡한 실정이다. 이에 정신전력 교관의 계급과 교육 참여자들의 수준이 교육효과에 미치는 영향이 있는지를 통해 정신전력 효과를 제고하는 방안을 모색하게 되었다. 교관의 계급이 높을수록 효과도 높을 것이라는 관념적 생각이 잘못되었음을 입증하였으며, 교육효과에 영향을 미치는 요인은 무엇보다 교육생들과 직접 접촉하는 교관의 준비상태인 것으로 나타났다. 또한 이번 연구에서는 교육에 대한 참여의지와 교육의 중요성 인식이 교육기간 동안 증가할수록 교육의 효과도 증가한다는 결론을 얻었다.

• Journal of Digital Contents Society
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• v.18 no.6
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• pp.1207-1211
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• 2017

Long-Reach PON (LR-PON) is a broadband access network using passive optical network (PON) technology which the reach is extended to 100 km or higher. A major challenge in LR-PON is that the propagation delay between OLT and ONUs is increased by a very significant amount. To effectively and fairly distribute the upstream bandwidth dynamically in LR-PON, we propose a new periodic and multi-thread polling based dynamic bandwidth allocation (DBA) algorithm. We compare the proposed algorithm with traditional DBAs and show its advantage on average packet delay. Numerical results are analyzed under varying offered loads.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.3
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• pp.47-52
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• 1999

Fatigue test is an essential procedure in the dynamic structure design. It is performed to confirm that the structure should safety the required life. In this study, fatigue life for 750㎾ class horizontal axis wind turbine composite blade was investigated. Required fatigue stress was calculated by fan Bond's empirical equation and S-N linear damage method. Fatigue load for FEM analysis was calculated using load spectrum through experiments and Spera's method. Service fatigue stress was obtained by FEM with the calculated fatigue load. From comparison of the fatigue stresses, fatigue life over 20 years was confirmed.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2000.04a
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• pp.164-164
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• 2000

지리산왕등재 습지의 바람직한 관리를 위하여 미국야생생물보호청(US Fish & Wildlife Service)에서 개발한 습지 유형 분류방법론을 적용하여 유형분류와 평가를 수행하였다. 지리산왕등재 습지는 계(System), 아계(Subsystem), 강(Class), 아강(Subclass), 수영역(Water Regime), 수문지형 단위 (Hydrogeomorphic Units), 저질/우점유형 (Substrate/Dominants Type)의 계층적 분류체계에 따라 소호소습지생태계(Palustrine wetland system), 정수습지생태계 강, 영속형 정수식물 습지생태계 아강, 영구적으로 습윤한 수영역, 범주성 수화학(pH 6.1), 산악의 영구적인 초원 수문지형, 저질은 유기체 유형(이탄토)으로 사초과와 고랭이속이 우점하는 습지로 분류되었다. 지리산 왕등재 습지와 비교하여 대암산 용늪의 분류체계는 이끼/지의류 강, 이끼 아강, 영구적으로 습윤한 수영역, 산성의 수화학, 저질은 유기체 유형(이탄토)으로 물이끼가 우점하고 관속식물이 혼재하는 유형으로 분류되어 많은 차이가 난 반면, 무제치늪은 매우 유사한 습지유형으로 우점유형(진퍼리새 우점)과 특정 종에서만 차이가 났다.