• Title/Summary/Keyword: Radio Network

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A study on the efficient early warning method using complex event processing (CEP) technique (복합 이벤트 처리기술을 적용한 효율적 재해경보 전파에 관한 연구)

  • Kim, Hyung-Woo;Kim, Goo-Soo;Chang, Sung-Bong
    • 한국정보통신설비학회:학술대회논문집
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    • 2009.08a
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    • pp.157-161
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    • 2009
  • In recent years, there is a remarkable progress in ICTs (Information and Communication Technologies), and then many attempts to apply ICTs to other industries are being made. In the field of disaster managements, ICTs such as RFID (Radio Frequency IDentification) and USN (Ubiquitous Sensor Network) are used to provide safe environments. Actually, various types of early warning systems using USN are now widely used to monitor natural disasters such as floods, landslides and earthquakes, and also to detect human-caused disasters such as fires, explosions and collapses. These early warning systems issue alarms rapidly when a disaster is detected or an event exceeds prescribed thresholds, and furthermore deliver alarm messages to disaster managers and citizens. In general, these systems consist of a number of various sensors and measure real-time stream data, which requires an efficient and rapid data processing technique. In this study, an event-driven architecture (EDA) is presented to collect event effectively and to provide an alert rapidly. A publish/subscribe event processing method to process simple event is introduced. Additionally, a complex event processing (CEP) technique is introduced to process complex data from various sensors and to provide prompt and reasonable decision supports when many disasters happen simultaneously. A basic concept of CEP technique is presented and the advantages of the technique in disaster management are also discussed. Then, how the main processing methods of CEP such as aggregation, correlation, and filtering can be applied to disaster management is considered. Finally, an example of flood forecasting and early alarm system in which CEP is incorporated is presented It is found that the CEP based on the EDA will provide an efficient early warning method when disaster happens.

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The Study of Implementation of SignBoard Receiving DARC for Vehicle 1. The Implementation of Sign Board Receiving DARC (차량용 FM 부가방송 수신 전광판의 구현에 관한 연구 1. FM 부가방송 수신 전광판의 구현)

  • 최재석;김영길
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.8
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    • pp.1169-1174
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    • 2002
  • In this paper, we implemented the sign board system that displays user's image, user's sentence, the information from DARC. The existing sign board is displaying only user's image and sentence. Or other existing sign board is displaying the information via CDMA network. However, our system is also able to display the user's message like other system and gain the information more cheap by DARC. This system includes the main processor, the program memory, the external memory, the DARC module and the LED display module. The external memory stores the user's message files and the order file that decides the displaying order of user's file and the DARC information The DARC module extracts the DARC information from FM signal. From the experiment, we could confirm that this system display the DARC information and the user's message by the order file.

Analysis of Receiving Environment Changes According to Channel Reallocation Method of Terrestrial DMB (지상파 DMB 채널 재배치 방안에 따른 송수신환경 변화 분석)

  • Kim, Joo-Seok;Kim, Kyung-Seok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.6
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    • pp.195-202
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    • 2013
  • Many communications and broadcast media have emerged by the rapid development of wireless communication and broadcasting technologies, so the radio resources are insufficient for these services. DMB can use the regional integrated channel due to the SFN broadcasting network, so DMB uses the frequency efficiently. However, the domestic DMB uses the existing analog TV frequency band and uses a plurality of channels in some areas because of the interference with the analog TV. However, the broadcasting of the analog TV was terminated, so the channel reallocation of the terrestial DMB is necessary for the efficient use of frequencies. This paper proposes the channel reallocation method of the terrestial DMB and analyzes the change of transmission and reception environments by using simulations.

Design and Implementation of Wi-Fi based Drone to Save People in Maritime (해상 인명구조를 위한 무선랜기반 드론 설계 및 구현)

  • Kim, Dong Hyun;Shin, Jae Ho;Kim, Jong Deok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.1
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    • pp.53-60
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    • 2017
  • This paper is to design and implement the drone that supports a wideband multimedia communication and a long-range to save people in maritime. The drone is an Unnamed Aerial Vehicle (UAV) that is controlled by a radio wave not by people boarding the machine. We use the drone to respond quickly to the boating accident. To develop a smart drone for the high speed seamless video streaming in a long-range maritime, a necessary techniques are hardware design techniques that design structure of a drone, controlling techniques that operate a drone and communication techniques that control a drone in a long distance. In this paper, the limitations and techniques to design and implement the structure of drone supporting wideband multimedia communication for long-range maritime are explained. By expanding this communication drone network, it is aimed at improving utility of a drone.

An Effective Frequency Sharing Method using Spectrum Etiquette and Genetic Algorithm for the Coexistence of WRAN and WLAN in TV White Space (TVWS에서 스펙트럼 에티켓 및 GA를 사용한 WRAN과 WLAN의 효율적 주파수 공유기법)

  • Jeong, Won-Sik;Jang, Sung-Jeen;Yong, Seulbaro;Kim, Jae-Moung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.2A
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    • pp.83-94
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    • 2012
  • Various wireless communication devices or network such as WRAN and WLAN will coexist in the TVWS(TV White Space). Because of this coexistence, the wireless devices which use the TVWS have to avoid interfering to not only licensed TV receiver and wireless microphone but also homogeneous or heterogeneous TVBD(TV Band Device)s. In this paper, we propose two frequency sharing methods for the coexistence of WLAN and WRAN in terms of interference reduction and throughput enhancement in both homogeneous and heterogeneous networks. One is the WRAN spectrum etiquette to provide more wide bandwidth for WLAN users and the other is the WLAN frequency selection methods to improve the throughput performance. The simulation results have confirmed the throughput improvement of the proposed methods. Moreover, the proposed methods is also applicable to improve the throughput performance and reduce interference of similar systems working in a cognitive manner.

Current Status of Ocean Satellite Remote Sensing Data and Its Distribution (해양의 인공위성 자료 현황과 배포 소개)

  • Yang, Chan-Su
    • Proceedings of KOSOMES biannual meeting
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    • 2007.11a
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    • pp.51-55
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    • 2007
  • As for satellite programs, the multipurpose satellite 1(KOMPSAT-1) was successfully launched on Dec. 21, 1999 and operated for three years. It is still properly operated even though its life cycle was ended. The development of KOMPSAT-2 (Korea Multipurpose Satellite-2) is near completion and the development of KOMPSAT-3, KOMPSAT-5 and COMS (Communication, Ocean, Meterological Satellite) are proceeding swiftly. In KORDI(Korea Ocean Research and Development Institute), the KOSC (Korea Ocean Satellite Center) construction project is being prepared for acquisition, processing and distribution of sensor data via L-band from GOCI(Geostationary Ocean Color Imager) instrument which is loaded on COMS(Communication, Ocean and Meteorological Satellite); it will be launched in 2000. Ansan(the headquarter of KORDD has been selected for the location of KOSC between 5 proposed sites, because it has the best condition to receive radio wave. The data acquisition system is classified antenna and RF. Antenna is designed to be ${\emptyset}$ 9m cassegrain antenna which has 19.35 $G/T(dB/^{\circ}K)$ at 1.67GHz, RF module, is divided into LNA(Low noise amplifier) and down converter, those are designed to send only horizontal polarization to modem The existing building is re-designed and classified for the KOSC operation concept; computing room, board of electricity, data processing room, operation room Hardware and network facilities have been designed to adapt for efficiency of each functions. The distribution system which is one of the most important systems will be constructed mainly on the internet, and it is also being considered constructing outer data distribution system as a web hosting service for to offering received data to user under an hour.

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The Identification of Japanese Black Cattle by Their Faces

  • Kim, Hyeon T.;Ikeda, Y.;Choi, Hong L.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.6
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    • pp.868-872
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    • 2005
  • Individual management of the animal is the first step towards reaching the goal of precision livestock farming that aids animal welfare. Accurate recognition of each individual animal is important for precise management. Electronic identification of cattle, usually referred to as RFID (Radio Frequency Identification), has many advantages for farm management. In practice, however, RFID implementations can cause several problems. Reading speed and distance must be optimized for specific applications. Image processing is more effective than RFID for the development of precision farming system in livestock. Therefore, the aim of this paper is to attempt the identification of cattle by using image processing. The majority of the research on the identification of cattle by using image processing has been for the black-and-white patterns of the Holstein. But, native Japanese and Korean cattle do not have a consistent pattern on the body, so that identification by pattern is impossible. This research aims to identify to Japanese black cattle, which does not have a black-white pattern on the body, by using image processing and a neural network algorithm. 12 Japanese black cattle were tested. Values of input parameter were calculated by using the face image values of 12 cows. The face was identified by the associate neural memory algorithm, and the algorithm was verified by the transformed face image, for example, of brightness, distortion, noise and angle. As a result, there was difference due to a transformation ratio of the brightness, distortion, noise, and angle. The algorithm could identify 100% in the range from -30 to +30 degrees of brightness, -20 to +40 degrees of distortion, 0 to 60% of noise and -20 to +30 degree of angle transformed images.

An Analysis of the Radio Interference in Wireless Vehicular Networks based on IEEE802.11b(WLAN) (IEEE802.11b(WLAN)기반의 차량 무선통신환경에서 전파간섭분석)

  • Lee, Myungsub;Park, Changhyeon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.6
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    • pp.117-125
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    • 2012
  • Recently, there has been a fast paradigm shift in the automotive market from the traditional machine-oriented technology into the technology for vehicle informatics and electronics. In particular, telematics market is accelerating the development of technologies for vehicle informatics through the close cooperation between the vehicle makers and mobile communication companies. However, there may be the degradation of the quality of service by the interference since the telematics uses the wireless communication infrastructure for the base station-to-vehicle communication and the vehicle-to-vehicle communication. This paper presents an analysis device to easily analyze the interference by the wireless communication in the vehicle wireless network environment. Using the analysis results by the presented device, this paper shows that the link quality can be improved through the simulation and the experiment in real environment both.

DTDMA Procedure design of Tactical Data Link

  • Kim, Jin-Woo;Lee, Woo-Sin;Kim, Hack-Joon;Jin, So-Yeon;Kim, Min-Chul
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.12
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    • pp.43-50
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    • 2019
  • In this paper, we designed a dynamic TDMA scheme for smooth tactical data distribution in TDMA tactical datalinks. Since the existing tactical datalinks use fixed time radio resources, it is impossible to change the resource status according to network conditions during operation. To overcome these limitations, we designed, implemented, and simulated the DTDMA processing and related messages such as initial timeslot allocation, intermediate time slot allocation, time slot return, and timeslot retrieval. As a result, it was shown that the method of effectively allocating and using timeslot resources according to the situation is applicable. Therefore, we will continue research to manage DTDMA communication on tactical data link in the future.

A SEARCH FOR AGN INTRA-DAY VARIABILITY WITH KVN

  • LEE, TAESEOK;TRIPPE, SASCHA;OH, JUNGHWAN;BYUN, DO-YOUNG;SOHN, BONG-WON;LEE, SANG-SUNG
    • Journal of The Korean Astronomical Society
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    • v.48 no.5
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    • pp.313-323
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    • 2015
  • Active galactic nuclei (AGN) are known for irregular variability on all time scales, down to intra-day variability with relative variations of a few percent within minutes to hours. On such short timescales, unexplored territory, such as the possible existence of a shortest characteristic time scale of activity and the shape of the high frequency end of AGN power spectra, still exists. We present the results of AGN single-dish fast photometry performed with the Korean VLBI Network (KVN). Observations were done in a “anti-correlated” mode using two antennas, with always at least one antenna pointing at the target. This results in an effective time resolution of less than three minutes. We used all four KVN frequencies, 22, 43, 86, and 129 GHz, in order to trace spectral variability, if any. We were able to derive high-quality light curves for 3C 111, 3C 454.3, and BL Lacertae at 22 and 43 GHz, and for 3C 279 at 86 GHz, between May 2012 and April 2013. We performed a detailed statistical analysis in order to assess the levels of variability and the corresponding upper limits. We found upper limits on flux variability ranging from ~1.6% to ~7.6%. The upper limits on the derived brightness temperatures exceed the inverse Compton limit by three to six orders of magnitude. From our results, plus comparison with data obtained by the University of Michigan Radio Astronomy Observatory, we conclude that we have not detected source-intrinsic variability which would have to occur at sub-per cent levels.