• Title/Summary/Keyword: satellite broadcasting

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Road Extraction by the Orientation Perception of the Isolated Connected-Components (고립 연결-성분의 방향성 인지에 의한 도로 영역 추출)

  • Lee, Woo-Beom
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.1
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    • pp.75-81
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    • 2012
  • Road identification is the important task for extracting a road region from the high-resolution satellite images, when the road candidates is extracted by the pre-processing tasks using a binarization, noise removal, and color processing. Therefore, we propose a noble approach for identifying a road using the orientation-selective spatial filters, which is motivated by a computational model of neuron cells found in the primary visual cortex. In our approach, after the neuron cell typed spatial filters is applied to the isolated connected-labeling road candidate regions, proposed method identifies the region of perceiving the strong orientation feature with the real road region. To evaluate the effectiveness of the proposed method, the accuracy&error ratio in the confusion matrix was measured from road candidates including road and non-road class. As a result, the proposed method shows the more than 92% accuracy.

Audience Activity for Digital Media: In the Study of PPV(Pay Per View) Use (디지털 미디어 수용자의 능동성에 관한 연구: PPV(Pay Per View) 이용행태를 중심으로)

  • Lee, Soo-Young;Eun, Hye-Chung
    • Korean journal of communication and information
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    • v.36
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    • pp.348-373
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    • 2006
  • In the era of digital media, one of the most distinctive characteristics is the activity what audience play. This characteristic can be particularly demonstrated in the case of PPV(Pay-Per-View) use. Since this service is related with payment by audience according to each behaviour of their own media use. In doing so, this paper explores the characteristics and behavioral pattern in PPV use. In particular, the study tries to predict from the result that which trait of characteristic can explain the adoption of PPV. The analytical result shows that PPV users are much more active in gathering information as well as achieving the diversity in terms of program choice compared to non PPV users. At the same time, PPV users are prone to be unsatisfied against the other media and naturally willing to adopt the new media. PPV users are much more keen to use toward age related programme classification system in order to protect their children from inappropriate programmes. The variable of participational behaviour is the most relevant variable to predict the degree of PPV use, however, it fails to predict to distinguish the PPV users group from non PPV users group. It maybe given as a conclusion that PPV users are much more active in not only choosing their own program they like to watch but also planning ahead for maximising their pleasure from viewing.

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A Study on Conditional Access Message Multiplexing Method in T-DMB Conditional Access System (T-DMB 제한수신시스템에서 제한 수신 메시지 다중화 기법 연구)

  • Kim, Dong-Hyun;Seo, Hyung-Yoon;Bae, Byung-Jun;Kim, Jong-Deok
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.05a
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    • pp.722-724
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    • 2010
  • CAS(Conditional Access System) was developed for paid-for service in cable and fixed satellite broadcast system and technology and market maturity are high. However, these assessment is limited by CAS in fixed broadcasting system. In case of digital mobile broadcast such as T-DMB is difficult to apply CAS technology of fixed broadcasting system because of a use method and technology characteristic. Expecially, in case T-DMB using limited resources, a CAS message which must transmit in each service channel can cause problems. It is desirable that system transmits the CAS message which transmitted by each service channel through logical CAS message-only channel. In order to make a logical CAS message channel, we need a multiplexing techniques for CAS message using in each channel. In this paper, we design the CAS message multiplexing techniques for composition of CAS message-only channel.

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Development of proton test logic of RFSoC and Evaluation of SEU measurement (RFSoC의 양성자 시험 로직 개발 및 SEU 측정 평가)

  • Seung-Chan Yun;Juyoung Lee;Hyunchul Kim;Kyungdeok Yu
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.1
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    • pp.97-101
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    • 2024
  • In this paper, we present the implementation of proton beam irradiation test logic and test results for Xilinx's RFSoC FPGA. In addition to the FPGA function, RFSoC is a chip that integrates CPU, ADC, and DAC and is attracting attention in the defense and space industries aimed at reducing the size of the chip. In order to use these chips in a space environment, an analysis of radiation effects was required and radiation mitigation measures were required. Through the proton irradiation test, the logic to measure the radiation effect of RFSoC was designed. Logic for comparing values stored in memory with normal values was implemented, and protons were irradiated to RFSoC to measure SEU generated in the block memory area. To alleviate the occurrence of SEU in other areas, TMR and SEM were applied and designed. Through the test results, we intend to verify this test configuration and establish an environment in which logic design for satellites can be verified in the future.

Empirical Study on the Prediction of Rain Attenuation in EHF(44 GHz) Band (EHF(44 GHz) 대역 강우 감쇠 특성 예측 연구)

  • Park Yong-Ho;Lee Joo-Hwan;Pack Jeong-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.8 s.99
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    • pp.848-854
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    • 2005
  • The attenuation due to rain has been recognized as one of the major causes of unavailability of radio communication systems operating above about 10 GHz. To design radio links for telecommunications and to evaluate attenuation due to rainfall, it is important to have a good prediction model for rain attenuation such as a model for drop-size distribution of rainfall(DSD), a theoretical model for specific rain attenuation, and an empirical model fur effective path length through rain. In this paper, the extended generalized gamma distribution for drop-size distribution, based on the measurements in Chnugnam National University, is proposed as a new DSD model, and predicted specific attenuation characteristics using proposed DSD model and rain attenuation values in the 44 GHz satellite path using ITU-R effective path length model, are analysed. The predicted attenuation levels are also compared. It is found that an accurate prediction method for DSD is very important to reduce the prediction error in the local satellite path.

A analysis on the satellite tracking performance of Az mount on shipboard (선박탑재 Az mount의 위성추적 성능에 대한 분석)

  • 최조천;주양로
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.05a
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    • pp.132-137
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    • 2003
  • This performance is motivated to develop a tracking antenna system for receive the satellite broadcasting signal in the coast sailing ship. Therefore, this system is made to small size, light weight and simple operation which is must to low cost system for popularization of small size ship and adaptive possibilities with useful on a ship in the coast using 1 axis Az-mount. The antenna mount structure is a compact size and easy operation to the Az-axis type which is operated by step motor. The antenna unit is a domestic made plate type of patch array and ship's moving detection is using the gyro sensor for ship's moving control. We are designed to algorithm, which walking is abreast for step track and ship's moving compensation. Ship's moving compensation is adapted to the closed loop control method by detection from gyro sensor. This system is consisted of micro processor, ADC, comparative amplifier, step motor driver, mount mechanism and algorithm. We have analysised the tracking performance of prototype on sailing ship board.

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Analysis of the GPS Meaconing Signal Generator for the Live GPS L1 Signal (Live GPS L1 재방송 기만신호 생성 분석)

  • Kim, Taehee;Sin, Cheonsig
    • Journal of Satellite, Information and Communications
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    • v.11 no.4
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    • pp.15-20
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    • 2016
  • In this paper, we developed the hardware GPS signal generator for generating a GPS L1 meaconing signal with Live GPS signal signals and analyzed the performance of meaconing signal generator thorough the experiment. Deception of the signal, such as a re-broadcast, it is an object of the user to provide false information so as not to receive location information and accurate time. The signal just rebroadcast has the features that can be easily deceive the receiver via a delay of no received signal to the signal processing through an antenna. In this paper, the hardware for generating a signal only these rebroadcast designed and manufactured, by re-sending the received Live GPS signals, to confirm the effect of the receiver. The maximum delay time is possible up to about 2.6msec, also, has been successfully tested to be moved to the position of re-broadcasting based on maturity antenna the position of the receiver through a spaced antenna.

A analysis on the satellite tracking performance of Az mount on shipboard (선박탑재 Az mount의 위성추적 성능에 대한 분석)

  • 최조천
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.6
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    • pp.1130-1137
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    • 2003
  • This performance is motivated to develop a tracking antenna system for receive the satellite broadcasting signal in the coast sailing ship. Therefore, this system is made to small size, light weight and simple operation which is must to low cost system for popularization of small size ship and adaptive possibilities with useful on a ship in the coast using 1 axis Az-mount. The antenna mount structure is a compact size and easy operation to the Az-axis type which is operated by step motor. The antenna unit is a domestic made plate type of patch array and ship's moving detection is using the gyro sensor for ship's moving control. We are designed to algorithm, which walking is abreast for step track and ship's moving compensation. Ship's moving compensation is adapted to the closed loop control method by detection from gyro sensor. This system is consisted of micro processor, ADC, comparative amplifier, step motor driver, mount mechanism and algorithm. We have analysised the tracking performance of prototype on sailing ship board.

Annular ring slot antenna with a variable circular polarized mode characteristic (가변 원형편파 모드 특성을 갖는 원형 링 슬롯 안테나)

  • Kim, Yong-Jin;Kim, Jung-Han;Lee, Hong-Min
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.1
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    • pp.78-84
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    • 2008
  • In this paper, the reconfigurable annular ring slot antenna with circular polarization diversity is proposed for SDMB(Satellite Digital Multimedia Broadcasting) system. The proposed antenna consists of a ring slot with four tuning stubs. Four PIN diodes are attached to switch circular polarization diversity. By switching the diodes ON or OFF, the proposed antenna can be operated either RHCP mode or LHCP mode. The experimental result shows that the proposed antenna has an impedance bandwidth(VSWR${\leq}$2) of 570MHz(2.47-3.04GHz) at LHCP mode, an impedance bandwidth (VSWR${\leq}$2) of 560MHz(2.45-3.01GHz) at RHCP mode, a maximum gai of 3.1dBi at RHCP mode, 4.76dBi at LHCP mode. The 3dB CP bandwidth of about 100MHz at both RHCP and LHCP mode is achieved at the center frequency 2.63GHz. The proposed antenna is suitable for application such as mobile satellite communications, WLAN(Wireless Local Area Networks), and broadband wireless communication systems.

Hardware Design of SNR Estimator for Adaptive Satellite Transmission System (적응형 위성 전송 시스템을 위한 신호 대 잡음비 추정 회로 구현)

  • Lee, Jae-Ung;Kim, Soo-Seong;Park, Eun-Woo;Im, Chae-Yong;Yeo, Sung-Moon;Kim, Soo-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.2A
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    • pp.148-158
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    • 2008
  • This paper proposes an efficient signal to noise ratio (SNR) estimation algorithm and its hardware implementation for adaptive transmission system using M-ary modulation scheme. In this paper, we present the implementation results of the proposed algorithm for the second generation digital video broadcasting via satellite (DVB-S2) system, and the proposed algorithm can be tailored to the other communication systems using adaptive transmissions. We built a look-up table (LUT) using the theoretical background of the received signal distribution, and by using this LUT we need just two comparators and a counter for the hardware implementation. For this reason, the hardware of the proposed scheme produces accurate estimation results even with extremely low complexity. The simulation results investigated in this paper reveal that the proposed method can produce estimation results within the specified SNR range in the DVB-S2 system, and it requires a few hundreds of samples for average estimation error of about 1 dB.