• 한국항행학회논문지
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• 제28권4호
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• pp.442-449
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• 2024

본 연구는 도심항공교통(UAM; urban air mobility) 혹은 미래항공교통(AAM; advanced air mobility) 인프라의 통신, 항법, 감시 및 정보 시스템 인프라에 대한 사이버 위협 분석을 위한 포괄적인 프레임워크를 제안하고자 한다. 잠재적인 취약점과 위협 벡터를 검토함으로써 UAM 인프라의 보안과 회복력을 강화하려고 한다. 또한, 다양한 유형의 사이버 위협을 식별하고 분류하며, 이들 위협이 CNSi 시스템에 미치는 영향을 평가하고, 이러한 위협으로 악용될 수 있는 시스템 내의 취약점을 평가하는 상세한 사이버 위협 분석을 수행하고자 한다. 해당 연구는 UAM 시스템의 배치 및 운영에 참여하는 이해관계자들에게 귀중한 통찰을 제공하고, 궁극적으로 도시 공중 교통의 안전하고 효율적인 통합에 기여하는 것을 목적으로 한다.

• 한국항공운항학회지
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• 제19권1호
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• pp.88-93
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• 2011

In order to ensure the safety, regularity and efficiency of air transportation, ICAO has established the international standards for air navigation systems since 1940s. In 1991, ICAO announced the concept of New CNS/ATM systems and recommended States to carry out the development of the sub systems as well as propose the standards due to many problems caused by service limitations and considerable errors from the conventional systems. As a result, international standards for 21 systems have been established. However, many problems have also been raised. In this paper the problems on new international standard establishment are analyzed and the measures to cure them are suggested.

• 한국항행학회논문지
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• 제20권3호
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• pp.203-209
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• 2016

자동종속 감시 시스템 (ADS-B; automatic dependent surveillance - broadcast) 시스템과 다변측정 항공감시 시스템(MLAT, multilateration) 시스템은 통신/항행/감시 및 교통관리 (CNS/ATM; communications, navigation, and surveillance/air traffic management)의 다양한 분야 중에서 감시분야에 속한다. ADS-B와 MLAT는 위성 및 디지털 통신 기술을 기반으로 구현되어 레이더 보다 성능이 뛰어나지만, 여전히 오차는 가지고 있다. 우는 이러한 오차를 줄이기 위해 reweighted convex combination method를 제안한다. Reweighted convex combination method는 기존의 convex combination method를 개선한 정보융합 기법으로 시스템에 주어지는 가중치를 재조정하여 항공기 추적 성능을 향상시킨다. reweighted convex combination method을 ADS-B와 MLAT에 적용 시켰을 때, 평균 51.51 %의 성능향상이 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권1호
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• pp.216-239
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• 2021

The present work addresses the challenging problem of coordinating power allocation with interference management in multi-robot networks by applying the promising expansion capabilities of multiple-input multiple-output (MIMO) and full duplex systems, which achieves it for maximizing the throughput of networks under the impacts of Doppler frequency shifts and external jamming. The proposed power allocation with interference coordination formulation accounts for three types of the interference, including cross-tier, co-tier, and mixed-tier interference signals with cluster head nodes operating in different full-duplex modes, and their signal-to-noise-ratios are respectively derived under the impacts of Doppler frequency shifts and external jamming. In addition, various optimization algorithms, including two centralized iterative optimization algorithms and three decentralized optimization algorithms, are applied for solving the complex and non-convex combinatorial optimization problem associated with the power allocation and interference coordination. Simulation results demonstrate that the overall network throughput increases gradually to some degree with increasing numbers of MIMO antennas. In addition, increasing the number of clusters to a certain extent increases the overall network throughput, although internal interference becomes a severe problem for further increases in the number of clusters. Accordingly, applications of multi-robot networks require that a balance should be preserved between robot deployment density and communication capacity.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권11호
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• pp.5377-5391
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• 2017

In this paper, we propose a new scheme to suppress the narrowband interference (NBI) in OFDM-based systems. The scheme utilizes code division multiple access (CDMA) and weighted-type fractional Fourier transform (WFRFT) domain preprocessing technologies. Through setting the WFRFT order, the scheme can switch into a single carrier (SC) or a multi-carrier (MC) frequency division multiple access block transmission system. The residual NBI can be eliminated to the maximum extent when the WFRFT order is selected properly. Final simulation results show that the proposed system can outperform MC and SC with CDMA and frequency domain preprocessing in terms of the narrowband interference suppression.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.33-37
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• 2006

Since 1993, the civil aviation community through RTCA (Radio Technical Commission for Aeronautics) and the ICAO (International Civil Air Navigation Organization) have been working on the definition of GNSS augmentation systems that will provide improved levels of accuracy and integrity. These augmentation systems have been classified into three distinct groups: Aircraft Based Augmentation Systems (ABAS), Space Based Augmentation Systems (SBAS) and Ground Based Augmentation Systems (GBAS). The last one is an implemented system to support Air Navigation in CAT-I approaching operation. It consists of three primary subsystems: the GNSS Satellite subsystem that produces the ranging signals and navigation messages; the GBAS ground subsystem, which uses two or more GNSS receivers. It collects pseudo ranges for all GNSS satellites in view and computes and broadcasts differential corrections and integrity-related information; the Aircraft subsystem. Within the area of coverage of the ground station, aircraft subsystems may use the broadcast corrections to compute their own measurements in line with the differential principle. After selection of the desired FAS for the landing runway, the differentially corrected position is used to generate navigation guidance signals. Those are lateral and vertical deviations as well as distance to the threshold crossing point of the selected FAS and integrity flags. The Department of Applied Science in Naples has create for its study a virtual GBAS Ground station. Starting from three GPS double frequency receivers, we collect data of 24h measures session and in post processing we generate the GC (GBAS Correction). For this goal we use the software Pegasus V4.1 developed from EUROCONTROL. Generating the GC we have the possibility to study and monitor GBAS performance and integrity starting from a virtual functional architecture. The latter allows us to collect data without the necessity to found us authorization for the access to restricted area in airport where there is one GBAS installation.

• 한국항공운항학회지
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• 제18권1호
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• pp.45-50
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• 2010

Air Traffic Management aims to fulfill the requirement of the aviation demander by constructing the most effective and safety aviation systems for providing safety and cost-effective service. All concerned parties of aviation present the needs of improving Air Traffic Management system for solving the issue of the current system and the air traffic capacity in the 21st century, and introduce the significant improvements from the conventional technology and method for the past 40 years. Accordingly, ICAO promotes the development of innovative procedures and technologies to solve the problems and meet the demands. It is the concept of Performance based Navigation(PBN) based on Communication, Navigation, and Surveillance/Air Traffic Management(CNS/ATM). This study defines differences between RNAV and RNP RNAV as methods of air navigation based on the CNS/ATM, and needs and requirements of PBN as an emerging global standard. It also outlines basic elements supporting and implementing the PBN concept.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.456-461
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• 1993

In this paper, a new guidance law for a short-range air-to-air missile with constant thrust is presented. It is essentially based on the concept of proportional navigation. First, the theoretical guidance law is derived. Then, we show the technique for practical implementation of the guidance law. By a computer simulation, it is shown that the new guidance law gives better performance than the conventional proportional navigation.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.273-278
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• 2007

In this paper, a performance comparison between CLOS(Command to Line-of-Sight) guidance law and PN(Proportional Navigation) guidance law is made, based on a short range surface-to-air missile simulation program called KNUCLOS. This simulation program has a full nonlinear aerodynamic missile model, a tracker model for missile and target, and target model. According to the simulation results, the PN guidance law has a better performance than CLOS guidance law under various target speed.

• 한국항행학회논문지
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• 제27권6호
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• pp.699-709
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• 2023

전 세계 항공교통량은 1977년 이래로 매 15년 간격으로 2배씩 성장하는 비약적인 증가세를 보임에 따라 국내·외 항공교통관제 서비스와 항행안전시설 운영관리 체계 및 현황 검토를 통한 관리 운영의 효율성 등을 진단하여 기능을 통합한 항공교통관제기관의 설립 타당성을 제시하고 미래 항공운송 환경에 대비하여 선진화된 항공교통관제서비스의 제공을 위한 독립 전담기관 운영체계의 수립이 필요하다. 특히, 2021년에는 국제정책·기준 등 항행환경 변화를 적극 반영하여 항공교통을 안전하고 효율적으로 처리하기 위한 운영, 시설, 제도 등에 대한 맞춤형 종합계획인 국가항행계획(NARAE; national ATM reformation and enhancement)이 수립됨에 따라 더욱 항공교통관제기관의 역할이 중요하게 되어 관제 및 항행 운영체계의 향상된 실행계획이 추진되어야 한다.