• 정보보호학회지
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• 제13권6호
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• pp.92-100
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• 2003

본 논문에서는 국내 광대역 위성 액세스 망(BSAN： Broadband Satellite Access Network)에 적용 가능한 보안 기능을 위한 가이드 라인을 살펴보고, RCST(Return Channel Satellite Terminal)와 NCC(Network Control Centre)간에 인증 및 키 관리 기능을 위하여 요구되는 주요 핵심 보안 메커니즘에 대하여 기술한다. 더불어 국내 광대역 위성 액세스 망의 ETSI(European Telecommunications Standards Institute) 표준을 분석한다. 특히 위성 망에서 이용되는 세 가지 키교환 메커니즘 MKE(Main Key Exchange), QKE(Quick Key Exchange), EKE(Explicit Key Exchange)에 대해 분석하였으며, 국내 보안 알고리즘과 키교환을 위한 향상된 보안 알고리즘을 적용한 규격을 제안하였다.

• 한국위성정보통신학회논문지
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• 제4권2호
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• pp.46-51
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• 2009

본 논문에서는 저궤도 위성망(LEO satellite network)과 지상망간의 간섭 영향을 분석하기 위해 사용되는 간섭 계산 요소 및 기법들을 정리하였다. 저궤도 위성의 궤도 및 위치정보를 시간에 따라 계산하는 요소들을 도출하고 두 시스템간의 실제 간섭량 계산에 적용되는 간섭 계산 기법을 서술하였다. 도출된 간섭 계산 기법은 저궤도 위성망과 지상망이 상호 간섭 영향 없이 운용될 수 있는 공유 조건을 설정하는데 활용될 수 있다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.557-560
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• 2005

The Korea Multi-Purpose SATellite-2 (KOMPSAT -2) will be launched into a circular sun synchronous orbit in Dec. 2005. For the mission operation of the KOMPSAT-2 satellite, KARl Ground Station (KGS) consists of the Mission Control Elements (MCE), Image Reception & Processing Elements (IRPE) and the overseas stations. For the oversea stations, the Kongsberg Satellite Services (KSAT) is the prime supplier of support service. KSAT has the capability to provide Tracking Telemetry and Commanding (TT&C) nominal, contingency and anomaly support for every single orbit for most polar orbiting satellites. Also KSAT provides nodal service through the network management functionality for all oversea ground stations. This paper describes the oversea stations and the support for Launch and nominal TT&C services for KOMPSAT-2 and the operation plan for KOMPSAT-2.

• ETRI Journal
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• 제22권1호
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• pp.1-11
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• 2000

The Satellite Operation System (SOS) has been developed for a low earth orbiting remote sensing satellite, Korea Multipurpose Satellite-I, to monitor and control the spacecraft as well as to perform the mission operation. SOS was designed to operate on UNIX in the HP workstations. In the design of SOS, flexibility, reliability, expandability and interoperability were the main objectives. In order to achieve these objectives, a CASE tool, a database management system, consultative committee for space data systems recommendation, and a real-time distributed processing middle-ware have been integrated into the system. A database driven structure was adopted as the baseline architecture for a generic machine-independent, mission specific database. Also a logical address based inter-process communication scheme was introduced for a distributed allocation of the network resources. Specifically, a hotstandby redundancy scheme was highlighted in the design seeking for higher system reliability and uninterrupted service required in a real-time fashion during the satellite passes. Through various tests, SOS had been verified its functional, performance, and inter-face requirements. Design, implementation, and testing of the SOS for KOMPSAT-I is presented in this paper.

• 한국통신학회논문지
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• 제42권2호
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• pp.424-431
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• 2017

요즘 차량 네비게이션 시스템은 큰 관심 분야이다. GNSS(Global Navigation Satellite System)은 실외 측위를 위한 기술 중 핵심적인 기술이다. 그러나 GNSS는 높은 정확도와 신뢰도를 제공하지 못한다. 이러한 이유로, 우리는 차량의 GNSS 성능의 정확도를 향상시키기 위하여 Network-RTK를 적용하였다. 이 Network-RTK 모드에서 GNSS 에러는 급격히 감소하게 된다. 본 논문에서 우리는 ntrip client 프로그램을 설명하고 다양한 환경에서의 실험 결과를 보여준다.

• 한국농촌건축학회논문집
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• 제6권1호
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• pp.32-41
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• 2004

Many administrative policies for regional activation have progressed the expansion and improvement of convenience institutions. Most appraisals about rural community influenced by urban life convenience are affirmative, but chasing urban life convenience is a cause of breaking out regional identity. Recently, new rising methods of theme and characteristic to imply regional identity, are ways of regional activation through neighboring network around satellite of rural community. In this study, I research and suggest applicable possible proposal of rural communities in Korea. by survey of neighboring network methods of Asan Live Museum in Japan applied ecomuseum concept for regional activation.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.34-37
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• 2005

An efficient and robust neural network-based scheme is introduced in this paper to perform automatic cloud detection. Unlike many existing cloud detection schemes which use thresholding and statistical methods, we used the artificial neural network methods, the multi-layer perceptrons (MLP) with back-propagation algorithm and radial basis function (RBF) networks for cloud detection from Geostationary satellite images. We have used a simple scene (a mixed scene containing only cloud and clear sky). The main results show that the neural networks are able to handle complex atmospheric and meteorological phenomena. The experimental results show that two methods performed well, obtaining a classification accuracy reaching over 90 percent. Moreover, the RBF model is the most effective method for the cloud classification.

• 한국위성정보통신학회논문지
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• 제5권1호
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• pp.94-99
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• 2010

In this paper, we discuss a proposed two hop relay network with PB/MC-CDMA(partial block MC-CDMA) technique. The main advantages of PB/MC-CDMA system are the increased cell capacity and the high quality of performances. In the system, we employ relay scheme to focus on the coverage reduction and hotspot problem, hotspot is a location where a cluster of users are blocked or dropped for the reason of insufficient frequency resources. Frequency resource allocation scheme is put forward in a three cells system according to each problem. The simulation result shows the performance of the two hop transmission is better than the direct transmission and the proposed network can support much more users to relief hotspot effect compared to the conventional one.

• ETRI Journal
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• 제46권2호
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• pp.307-322
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• 2024

Most object detection methods use a horizontal bounding box that causes problems between adjacent objects with arbitrary directions, resulting in misaligned detection. Hence, the horizontal anchor should be replaced by a rotating anchor to determine oriented bounding boxes. A two-stage process of delineating a horizontal bounding box and then converting it into an oriented bounding box is inefficient. To improve detection, a box-boundary-aware vector can be estimated based on a convolutional neural network. Specifically, we propose a ResNeXt101 encoder to overcome the weaknesses of the conventional ResNet, which is less effective as the network depth and complexity increase. Owing to the cardinality of using a homogeneous design and multi-branch architecture with few hyperparameters, ResNeXt captures better information than ResNet. Experimental results demonstrate more accurate and faster oriented object detection of our proposal compared with a baseline, achieving a mean average precision of 89.41% and inference rate of 23.67 fps.

• Journal of Positioning, Navigation, and Timing
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• 제13권2호
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• pp.137-147
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• 2024

This paper presents a novel Long Short-Term Memory (LSTM) network architecture for the integration of an Inertial Measurement Unit (IMU) and Global Navigation Satellite Systems (GNSS). The proposed algorithm consists of two independent LSTM networks and the LSTM networks are trained to predict attitudes and velocities from the sequence of IMU measurements and mechanization solutions. In this paper, three GNSS receivers are used to provide Real Time Kinematic (RTK) GNSS attitude and position information of a vehicle, and the information is used as a target output while training the network. The performance of the proposed method was evaluated with both experimental and simulation data using a lowcost IMU and three RTK-GNSS receivers. The test results showed that the proposed LSTM network could improve positioning accuracy by more than 90% compared to the position solutions obtained using a conventional Kalman filter based IMU/GNSS integration for more than 30 seconds of GNSS outages.