• Title/Summary/Keyword: Satellite Communications

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Integrated Ray Tracing Model for In-Orbit Optical Performance Simulation for GOCI (통합적 광추적 모델에 의한 해양탑재체 GOCI의 궤도 상 광학 성능 검증)

  • Ham, Seon-Jeong;Lee, Jae-Min;Kim, Seong-Hui;Yun, Hyeong-Sik;Gang, Geum-Sil;Myeong, Hwan-Chun;Kim, Seok-Hwan
    • Journal of Satellite, Information and Communications
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    • v.1 no.2
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    • pp.1-7
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    • 2006
  • GOCi (Geostationary Ocean Color Imager) is one of the COMS payloads that KARI is currently developing and scheduled to be in operation from around 2008. Its primary objective is to monitor the Korean coastal water environmental condition. We report the current progress in development of the integrated optical model as one of the key analysis tools for the GOCI in-orbit performance verification. The model includes the Sun as the emitting light source. The curved Earth surface section of 2500 km x 2500 km includingthe Korean peninsular os defined as a Lambertian scattering surface consisted of land and sea surface. From its geostationary orbit, the GOCI optical system observes the reflected light from the surfaces with varying reflectance representing the changes in its environmental conditions. The optical ray tracing technique was used to demonstrate the GOCI in-orbit performances such as red tide detection. The computational concept, simulation results and its implications to the on-going development of GOCI are presented.

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A study of a system for predicting damages of complex disasters considering the damage of major facilities (주요 시설물 피해를 고려한 복합재난 피해 예측 시스템 방안 연구)

  • Lee, Byung-Jin;Lee, Byung-Hoon;Oh, Seung-Hee;Lee, Yong-Tea;Kim, Kyung-Seok
    • Journal of Satellite, Information and Communications
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    • v.12 no.4
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    • pp.18-25
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    • 2017
  • Recently, disasters have become bigger and more complex, and the economic damage has increased due to the increase of urbanization and the concentration of infrastructure. These large complex disasters occur simultaneously in the second and third disasters due to the first single disaster, but the existing disaster management system in Korea is less adaptable because it is divided into natural disasters and social disasters. The cause of the complex disaster is the rapid urbanization of the residential environment caused by the change of the industrial structure, and the threat factors are various and unpredictable in the living environment. Natural disasters are becoming larger and more complex due to climate change due to global warming. Unlike the past, natural disasters are likely to develop into multiple disasters such as urban paralysis. Therefore, this paper considers natural disasters and social disasters in a comprehensive concept in order to overcome limitations of disaster management by existing single factors and manage disasters effectively and rationally. It is expected that it will play a big role in protecting the lives and property of the people through the establishment of a preemptive disaster management framework.

Japan's Missile Detection Capability using Electromagnetic Wave in free space (일본의 자유공간에서 전자파를 이용한 미사일 탐지능력)

  • Lee, Yongsik
    • Journal of Satellite, Information and Communications
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    • v.12 no.4
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    • pp.78-86
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    • 2017
  • Japan has a lot of interest about weapons systems development of surrounding national and has invested heavily in securing intelligence assets to get information about them, because of conflict issues between Japan and Russia with four northern islands, China with Senkaku Islands and entry policy into the Pacific. Japan has used a large budget to detect and intercept ballistic missile for reasons of the launch of the Taepodong missile in 1998. After took over SIGINT equipments which U.S. force had operated in 1950s~1960s, Japan made a technological analysis and advanced IT technology to produce superior equipments. Japan's SDF has installed them in 19 locations across Japan. In addition, Japan's JASDF has installed advanced early warning RADAR to detect aircraft and high speed ballistic missile entering JADIZ with S-band in 28 locations across Japan. It is possible to detect missile launch preparations, engine tests, and launch moments at any time for operation of 6 satellites high resolution reconnaissance system and 6 aegis ships. In close cooperation with the US, Japan is accessible to the SBIRS networks which detects the launch of a ballistic missile in neighboring countries. In the future, Because the United States wants Japan to act as part of the United States in East, south Asia, it is believed that the exchange of intelligence on the surrounding countries between two countries will be enhanced.

A Research of Relationship between Animation Content and Traditional Folk Culture: Centered around Michel Ocelot's <Kirikou et la Sorcière>(Kirikou and the Sorceress) and KBS Satellite Channel's <Animentary Korean Folklore>. (애니메이션 콘텐츠 창작소재와 전통 민속문화와의 만남: 미셸 오슬로의 <키리쿠와 마녀>와 KBS 위성 TV <애니멘터리 한국설화>를 중심으로)

  • Lee, Jong-Seung
    • Cartoon and Animation Studies
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    • s.19
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    • pp.65-88
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    • 2010
  • The purpose of this article is to investigate the relation the animation to culture archetype, focusing on the case of the matter for animation content creation. Furthermore, in the paper, we also study about the animation industry development using various cultural archetypes such as the tale, myth, legend, folk tale, which are usable for animation content industry. For purposes of this study, we analyzed the aspects of power of folk tale and the essential vitality of folk tale in KBS Satellite Channel's and Michel Ocelot's $\grave{e}$re>. Above all, the origin of literature, folk tales are characterized by their uniqueness of each people as well as the global universality, being reproduced over and over again in oral literature. In the existent mode, folk tales have a firm structure because of storytelling, and have characteristics of performance and tradition on the basis of this structure. These characteristics can make emotional experience deepen and insure quality of narrative experience through direct communications. In this context, comparing folk tales of diverse forms of each nation and discovering the ethnicism and universality would not only be critical in the animation content development aspects, but provide precious data for effective animation marketing to apply One Source-Multi Use.

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Improvement of Unicast Traffic Performance in High-availability Seamless Redundancy (HSR) Using Port Locking (PL) Algorithm (Port Locking (PL) 알고리즘을 이용한 HSR (High-availability Seamless Redundancy)의 유니캐스트 트래픽 성능개선)

  • Abdulsam, Ibraheem Read;Kim, Se Mog;Choi, Young Yun;Rhee, Jong Myung
    • Journal of Satellite, Information and Communications
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    • v.9 no.1
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    • pp.51-56
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    • 2014
  • High-availability seamless redundancy (HSR) is a protocol for fault-tolerant Ethernet (FTE) networks. It provides two frame copies and each copy is forwarded on a separate physical path, which provides zero fail-over time. Therefore, the HSR is becoming a potential candidate for various real-time FTE applications. However, the generation and circulation of unnecessary frames due to the duplication of every sending frame is inherent drawback of HSR. Such drawback degrades the performance of the network and may deplete its resources. In this paper, we present a new algorithm called port locking (PL) based on the media access control (MAC) address to solve the abovementioned problem in popular connected-rings network. Our approach makes the network gradually learn the locations of the source and the destination nodes without relying on network control frames. It then prunes all the rings that do not contain the destination node by locking corresponding rings' entrance ports. With the PL algorithm, the traffic can be significantly reduced and therefore the network performance will be greatly enhanced specially in a large scale connected-rings network. Analytical results are provided to validate the PL algorithm.

Design of Microstrip Patch Antenna using Inset-Fed Layered for Metallic Object in u-Port (U-항만 환경에서 금속부착을 위한 인셋 급전 마이크로패치 안테나 설계)

  • Choi, Yong-Seok;Seong, Hyeon-Kyeong
    • Journal of Satellite, Information and Communications
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    • v.10 no.2
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    • pp.80-85
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    • 2015
  • In this paper, we present, an indstrial RFID layered microstrip patch antenna is designed using an inset feed method in order to improve recognition rates in a long distance as tags are attached to metal object by improving a problem of feeding power in fabricating metal tags and reducing effects of metallic object. The inset feed shows a distinctive characteristic that has no separation between emitters and feed lines differing from a structure with the conventional inductive coupling feed. This structure makes possible to produce a type that presents a low antenna height and enables impedance coupling for tag chips. Although it shows a difficulty in the impedance coupling due to increases in the parasite capacitance between a ground plane and an emitter in an antenna according to decreases in the height of a tag antenna, it may become a merit in designing the tag antenna because the antenna impedance can be determined as an inductive manner if a shorted structure is used for feeding power. Therefore, in this paper the microstrip patch antenna is designed as a modified type and applies the inset feed in order to reduce effects of metallic objects where the antenna is be attached. Also, the antenna uses a multi-layer structure that includes a metal plate between radiator and ground instead of using a single layer.

Study On The Signal Radar Plan Position Indicator Scope Of The Data Expressed Scanning System Implemented As An Sticking Image On LCD Display (Plan Position Indicator Scope 주사방식의 Radar 영상신호를 LCD Display에 잔상영상으로 데이터 표출 구현에 관한 연구)

  • Shin, Hyun Jong;Yu, Hyeung Keun
    • Journal of Satellite, Information and Communications
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    • v.10 no.3
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    • pp.94-101
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    • 2015
  • The display device is an important video information communication system device to connect between human and device. it transfers the information as characters, shapes, images and pattern to enable recognizing by eyes. Theres absolutely needs some key functions and role to quickly display informations. It can analyse a information through a PPI Scope of a cathode-ray tube(CRT) displays information which can perform a role. this research proposed a radar device to display informations as received signal. The radar display researches can apply to fixed function graphics pipeline algorithms of the large capacity type through a vertical blanking interval and buffer swap of display unit. Also, it can be possible to apply to performed algorithms to FPGA logic without high-performance graphics processing unit GPU through synchronization which can implement a display system. In this paper, we improved the affordability and reliability through proposed research. 이So, we have studied the radar display unit which can change a flat display from radar display of CRT radar display.

LED lighting control system using the variable FOV according to movements of stage actors based on multi sensor (멀티센서기반 무대배우 이동에 따른 FOV가변형 LED조명 제어 시스템)

  • Koo, EunJa;Cha, Jaesang;Kim, Daeho;Park, Myungsook
    • Journal of Satellite, Information and Communications
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    • v.7 no.3
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    • pp.16-21
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    • 2012
  • Recently, an importance of culture industry has been emphasized through an increased income level, spare time and changed values of modern people. And demands of the performance, arts, exhibit are steadily being increased. However the stage equipment depends on foreign manufactures on account of the inactive domestic technical skills. Especially in the lighting direction part, it is essential to control the lighting source and detect the moving line of actors but it generally uses the manual control type and realization of actor's moving line regardless of existing IT-based technologies. Also the system operation of existing sensor-based tracking and detecting technologies depends on the main lighting source of the stage. Therefore, this paper proposed LED lighting control system using the variable FOV and multi sensor-based tracking algorithm, which are possible to efficiently track the stage actors and direct the stage lights. Also we demonstrated the practicality and possibility of realization through the integrated experiment of the proposed system and implementation of the salient hardware, software. Additionally, the usefulness of proposed system was demonstrated using performance simulations and actual measurements of implemented sensor output.

GPS L5 Signal Tracking Scheme Using GPS L1 Signal Tracking Results (GPS L1 신호추적 결과를 이용한 GPS L5 신호추적 기법)

  • Joo, Inone;Lee, Sanguk
    • Journal of Satellite, Information and Communications
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    • v.7 no.3
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    • pp.99-104
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    • 2012
  • The United States will proceed with the effort to modernize the GPS system, and one of its main content is to provide L5 signal. L5 will be transmitted in a radio band reserved exclusively for aviation safety services. And, L5, in combination with L1, will improve the position accuracy via ionospheric correction and robustness via signal redundancy. However, The acquisition processing time of L5 takes longer than that of L1 as the code length of L5 is 10 times longer than that of L1. To reduce this acquisition processing time, a higher number of correlators in the aquisition module should be used. However, there is a problem that this causes increase in the complexity of the correlator configuration and the computation power. So, in this paper, we propose L5 signal tracking scheme using tracking results in the GPS L1/L5 receiver. The proposed scheme could reduce the hardware complexity as the GPS L5 signal acquisition module is not needed, and provide fast and stable tracking of L5 signal by aiding L1 tracking results such as PRN, the code phase synchronization, and the Doppler frequency. The feasibility of the proposed scheme is demonstrated through simulation results.

Design of spectrum spreading technique applied to DVB-S2

  • Kim, Pan-Soo;Chang, Dae-Ig;Lee, Ho-Jin
    • Journal of Satellite, Information and Communications
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    • v.2 no.2
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    • pp.22-28
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    • 2007
  • Spectrum spreading, in its general form, can be conceived as an artificial expansion of the signal bandwidth with respect to the minimum Nyquist band required to transmit the desired information. Spreading can be functional to several objectives, including resilience to interference and jammers and reduction of power spectral density levels. In the paper, signal spreading is manly used for increasing the received energy, thus satisfying link budget constraints, for terminals with low aperture antennas, without increasing the transmitted EIRP. As a matter of fact, in many mobile scenarios, even when MODCOD configurations with very low spectral efficiency (i.e. QPSK-1/4) in DVB-S2 standard, are used, the link budget cannot be closed. Spectrum spreading has been recently proposed as a technique to improve system performance without introducing additional MODCOD configurations under the constraint of fixed power spectrum density level at the transmitter side. To this aim, the design of spectrum spreading techniques shall keep into consideration requirements such as spectrum mask, physical layer performance, link budget, hardware reuse, robustness, complexity, and backward compliance with existing commercial equipments. The proposed implementation allows to fully reuse the standard DVB-S2 circuitry and is inserted as an 'inner layer' in the standard DVB-S2 chain.

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