• Proceedings of the Korean Vacuum Society Conference
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• 2002.02a
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• pp.208-208
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• 2002

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2636-2640
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• 2003

KARI had developed an Local Area Augmentation System for aircraft precision landing as following ICAO SARPs(Standards and Recommended Practices) draft and FAA's recommended algorithm( carrier smoothing techniques). JPO in charge of managing GPS has introduced the signal structure of GPS modernization program. This paper estimates the accuracy performance of KARI-LAAS with modernized GPS signal but the same processing algorithm.

• Current Industrial and Technological Trends in Aerospace
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• v.5 no.1
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• pp.65-74
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• 2007

현재 운용중인 전 세계적인 위성항법시스템(GNSS : Global Navigation Satellite System)은 미국의 GPS(Global Positioning System)와 러시아의 GLONASS(Global Navigation Satellite System)가 있다. 전 세계적으로 주로 사용되는 시스템은 GPS이며, GLONASS는 러시아의 경제사정 악화로 인하여 지속적인 위성발사가 이루어지지 못하고 있다. 추가적으로 추진되고 있는 위성항법시스템은 유럽의 갈릴레오(Galileo), 중국의 북두(Beidou), 일본의 JRANS(Japanese Regional Advanced Navigation System) 그리고 2006년 5월에 구축 프로젝트가 승인된 인도의 IRNSS(Indian Regional Navigation Satellite System)가 있다. 보강시스템의 경우, 미국 FAA(Federal Aviation Administration)는 광역오차보정시스템(WAAS)을 Raytheon사와 개발하였으며, 현재 착륙용 근거리오차보정시스템(LAAS)을 Raytheon사 및 Honeywell사와 함께 정부/산업체 공동개발 사업(GIP; Government Industry Partnership)으로 진행 중에 있다. 유럽은 EGNOS(European Geostationary Navigation Overlay Service)를 사용하고 있으며, 일본의 MSAT(MTSAT Satellite Based Augmentation System)와 인도의 GAGAN(GPS and GEO Augmented Navigation)은 추진 중이다. 이 글에서는 위성항법시스템과 위성항법 보강시스템의 현황을 살펴본다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2574-2587
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• 2019

Blind Source Separation (BSS) is a technique used to separate supposed independent sources of signals from a given set of observations. In this paper, the High Exploration Particle Swarm Optimization (HEPSO) algorithm, which is an enhancement of the Particle Swarm Optimization (PSO) algorithm, has been used to separate a set of source signals. Compared to PSO algorithm, HEPSO algorithm depends on two additional operators. The first operator is based on the multi-crossover mechanism of the genetic algorithm while the second one relies on the bee colony mechanism. Both operators have been employed to update the velocity and the position of the particles respectively. Thus, they are used to find the optimal separating matrix. The proposed method enhances the overall efficiency of the standard PSO in terms of good exploration and performance. Based on many tests realized on speech and music signals supplied by the BSS demo, experimental results confirm the robustness and the accuracy of the introduced BSS technique.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.941-944
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• 1993

In this paper, we present an international benchmark used in the adaptive control specialist community in order to evaluated the fuzzy control performances. Before solving the corresponding problems, we introduce some improvements on a classic fuzzy controller in order to consider high order systems and time delays. At the end of this paper, the simulation results obtained with the extended Fuzzy Controller will be compared with those obtained with a Supervised Adaptive Controller.

• Journal of Cadastre & Land InformatiX
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• v.46 no.1
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• pp.133-148
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• 2016

Voices demanding a revision of the aviation law on the operating drones are continuously rising high with the increase of their applicability in various industry fields. According to the current regulations, drones are permitted to fly under very strict conditions, which include limited places and the line-of-sight visibility from pilots. Because of the strict regulations, it is almost impossible for drones to be used in many industries such as parcel delivery services. To improve the business value of drones, we have to improve the accuracy of drones' positions and provide the proper protection levels in order to detect and avoid any risks including the collisions with the other drones. SBAS(Satellite Based Augmentation System) can support the aviation requirements with the accuracy and integrity so as to reduce the position errors and to calculate the protection levels of drones. In this paper, we assign the flight heights of drones according to the decision heights as per LAAS(Local Area Augmentation System) landing categories and conduct a simulation to predict the SBAS available time of the day.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.272-280
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• 2022

An aircraft carrier is a combat ship that acts as an aircraft base at sea and performs combat through aircraft mounted as a military ship operating the aircraft. The Navy proposed a 40,000-ton light aircraft carrier operation plan that could be equipped with vertical takeoff and landing fighter jets and helicopters around 2033, and based on this, this study examined the operation of aircraft control equipment among the aviation support systems required for operating light aircraft carriers in Korea. PriFly, TWR's ILARTS, ILM for airspace control, ASR, PAR, LAAS or RNAV, PALS (JPALS) for access control are required as essential equipment, and communication network and SCATT-16 are required along with URN-25 TACAN, ICLS (El/Az), ACLS OLS, MOVAS, IFLOLS, etc. This study consists of two parts, and part 2 will describe a specific control method on an aircraft carrier.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.798-804
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• 2011

A number of navigation improvements are envisaged : Differential GPS - WAAS, LAAS, and Performance Based Navigation. The GPS receiver verifies the integrity(usability) of the signals received from the GPS constellation through a process called receiver autonomous integrity monitoring(RAIM) to determine if a satellite is providing corrupted information. This paper describe the RAIM function and Performance-Based Navigation implementation of Mission Equipment Package(MEP) for Korean Utility Helicopter.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.788-797
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• 2011

This paper analyzes the accuracy on the approach and landing of aircraft to an airport through comparison with airbase Precision Approach Radar and aircraft track data of DGPS equipped in aircraft. The proposed analysis result could be a basis for verifying the possibility that DGPS can be utilized in Airbase precision approach and landing. Position identification capability of widely used commercial DGPS is fairly accurate on latitude and longitude, while there is a slight error for being used in an airbase accurate approach and landing of Category I precision when it comes to altitude. Thus, we tested accuracy by analyzing actual flight track data of high performance aircraft to verify the accuracy of the airbase approach and landing using DGPS. Through the research, we developed instrumentation to compare PAR track data with DGPS track data, which can be used in reducing the number of PAR verification Flight utilizing it as a system measuring PAR accuracy at PAR installation phase.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.96-116
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• 2016

Sensing coverage is a fundamental issue for Wireless Sensor Networks (WSNs). Several coverage configuration protocols have been developed; most of them presume the availability of precise knowledge about each node location via GPS receivers. However, equipping each sensor node with a GPS is very expensive in terms of both energy and cost. On the other hand, several GPS-less localization algorithms that aim at obtaining nodes locations with a low cost have been proposed. Although their deep correlation, sensing coverage and localization have long been treated separately. In this paper, we analyze, design and evaluate a novel integrated framework providing both localization and coverage guarantees for WSNs. We integrate the well-known Coverage Configuration Protocol CCP with an improved version of the localization algorithm AT-Dist. We enhanced the original specification of AT-Dist in order to guarantee the necessary localization accuracy required by CCP. In our proposed framework, a few number of nodes are assumed to know their exact positions and dynamically vary their transmission ranges. The remaining sensors positions are derived, as accurately as possible, using this little initial location information. All nodes positions (exact and derived) are then used as an input for the coverage module. Extensive simulation results show that, even with a very low anchor density, our proposal reaches the same performance and efficiency as the ideal CCP based on complete and precise knowledge of sensors coordinates.