• Title/Summary/Keyword: 위성군

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Efficient QoS Policy Implementation Using DSCP Redefinition: Towards Network Load Balancing (DSCP 재정의를 통한 효율적인 QoS 정책 구현: 네트워크 부하 분산을 위해)

  • Hanwoo Lee;Suhwan Kim;Gunwoo Park
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.3
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    • pp.715-720
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    • 2023
  • The military is driving innovative changes such as AI, cloud computing, and drone operation through the Fourth Industrial Revolution. It is expected that such changes will lead to a rapid increase in the demand for information exchange requirements, reaching all lower-ranking soldiers, as networking based on IoT occurs. The flow of such information must ensure efficient information distribution through various infrastructures such as ground networks, stationary satellites, and low-earth orbit small communication satellites, and the demand for information exchange that is distributed through them must be appropriately dispersed. In this study, we redefined the DSCP, which is closely related to QoS (Quality of Service) in information dissemination, into 11 categories and performed research to map each cluster group identified by cluster analysis to the defense "information exchange requirement list" on a one-to-one basis. The purpose of the research is to ensure efficient information dissemination within a multi-layer integrated network (ground network, stationary satellite network, low-earth orbit small communication satellite network) with limited bandwidth by re-establishing QoS policies that prioritize important information exchange requirements so that they are routed in priority. In this paper, we evaluated how well the information exchange requirement lists classified by cluster analysis were assigned to DSCP through M&S, and confirmed that reclassifying DSCP can lead to more efficient information distribution in a network environment with limited bandwidth.

Unmanned AerialVehicles Images Based Tidal Flat Surface Sedimentary Facies Mapping Using Regression Kriging (회귀 크리깅을 이용한 무인기 영상 기반의 갯벌 표층 퇴적상 분포도 작성)

  • Geun-Ho Kwak;Keunyong Kim;Jingyo Lee;Joo-Hyung Ryu
    • Korean Journal of Remote Sensing
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    • v.39 no.5_1
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    • pp.537-549
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    • 2023
  • The distribution characteristics of tidal flat sediment components are used as an essential data for coastal environment analysis and environmental impact assessment. Therefore, a reliable classification map of surface sedimentary facies is essential. This study evaluated the applicability of regression kriging to generate a classification map of the sedimentary facies of tidal flats. For this aim, various factors such as the number of field survey data and remote sensing-based auxiliary data, the effect of regression models on regression kriging, and the comparison with other prediction methods (univariate kriging and regression analysis) on surface sedimentary facies classification were investigated. To evaluate the applicability of regression kriging, a case study using unmanned aerial vehicle (UAV) data was conducted on the Hwang-do tidal flat located at Anmyeon-do, Taean-gun, Korea. As a result of the case study, it was most important to secure an appropriate amount of field survey data and to use topographic elevation and channel density as auxiliary data to produce a reliable tidal flat surface sediment facies classification map. In addition, regression kriging, which can consider detailed characteristics of the sediment distributions using ultra-high resolution UAV data, had the best prediction performance compared to other prediction methods. It is expected that this result can be used as a guideline to produce the tidal flat surface sedimentary facies classification map.

Assessment of the Utility of Remote Sensing Techniques for Monitoring Compliance with Direct Payment Programs (직불제 이행점검 모니터링을 위한 원격탐사 기법 활용성 평가)

  • Hoyong Ahn;Jae-Hyun Ryu;Kyungdo Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1467-1475
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    • 2023
  • The public-interest direct payment program involves providing direct payments to agricultural producers and rural residents through public funds, premised on performing public functions such as environmental conservation, stable food supply, and maintaining rural communities via agricultural activities. Scientific estimation of crop cultivation areas and production levels is crucial for formulating agricultural policies linked to regulating food supply, which increasingly impacts the national economy. Conducting comprehensive on-site inspections for compliance monitoring of direct payment programs has shown very low efficiency in relation to budget and time. The expansion of areas subject to compliance monitoring and various challenges in on-site inspections necessitate streamlining current monitoring methods and devising effective strategies. As a solution, the application of Remote Sensing technology and spatial information utilization, allowing swift acquisition of necessary information for policies without overall on-site visits, is being discussed as an efficient compliance monitoring method. Therefore, this study evaluated the potential use of remote sensing for improving operational efficiency in monitoring compliance with public-interest direct payment programs. Using satellite images during farming seasons in Gimje and Hapcheon, vegetation indices and spatial variations were utilized to identify cultivated areas, presence of mixed crops, validated against on-site inspection data.

원격 탐사용 레이다의 연구개발 동향

  • Kim, Young-Su;Jeon, Min
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.1
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    • pp.57-66
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    • 1997
  • 1950년대 이래로 주로 군에서 발달되어 온 원격 탐사용 레이다에는 여러 종류가 있지만 주로 SLAR(Sidelooking Airborne Radar), SAR(Synthetic Aperture Radar), Scatterometer, Alti- meter 등이 많이 사용된다. SLAR와 SAR는 주로 넓은 지역의 레이다 영상을 얻는데 사용되기 때문에 영상 레이다라고 일반적 으로 분류된다. SLAR에서는 안테나 빔폭에 의해 분해능이 결정되기 때문에 원거리(특히 인공위성) 에서는 사용하기 곤란하다. SAR는 거대한 안테나를 시간적으로 합성해서 분해능을 향상시키는 방 식이므로 기본적으로 방대한 양의 데이타를 처리해야 하는데, 분해능을 좋게 할수록 필요한 신호 처리의 양은 기하급수적으로 증가한다. SAR의 기본 구성품은 일반적인 레이다와 크게 다를 바 없 으며, 단지 아주 작은 분해능을 실시간으로 요구할 때에는 막대한 계산량으로 인한 신호처리에서 의 병목현상을 적절히 처리하는 것이 중요한 연구 테마가 되고 있다.

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A day and night large aperture monitoring system proposal (주야간 대구경 감시시스템 제안)

  • Kim, Gwang-Dong;Na, Ja-Gyeong;Han, Jeong-Yeol;O, Se-Jin;Jang, Bi-Ho;Jang, Jeong-Gyun;Han, In-U;Im, In-Seong
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.1
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    • pp.66.2-66.2
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    • 2011
  • 2010년11월 23일 14:00 북한의 연평도 포격사건 이후 주야간으로 원거리 적을 감시하거나 미확인 표적을 확인 할 수 있는 장비가 필요하다고 생각되어진다. 한국천문연구원은 그 동안 천체관측을 목적으로 시민천문대 및 연구용으로 60cm급 광학망원경과 위성용 적외선망원경과 카메라를 개발하여 왔다. 이 기술을 이용하여 군에서 활용할 수 있는 주야간 대구경 감시 시스템을 개발 할 수 있으리라 본다. 또한 개발 한다면 대적 감시능력을 강화할 것이며, 국방의 핵심기술을 확보하리라 생각되어진다.

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Diagnosis of bovine cryptosporidiosis by indirect immunofluorescence assay using monoclonal antibody (단세포군항체를 이용한 간접형광항체법에 의한 송아지 작은와포자충증의 진단)

  • Wi, Seong-Hwan;Lee, Jeong-Gil;Ju, Hu-Don
    • Parasites, Hosts and Diseases
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    • v.33 no.2
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    • pp.107-116
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    • 1995
  • Two hybridoma cell lines against Cwptosporinium possum oocysts nFRl-CN911 were produced. The isotype of these 2 monoclonal antibodies (mAbs) was IgG2b (lE7.2) and and IgM (C6). Enzyme immuno-transfer blotting analysis showed that 157.2 reacted specifically to 36 kDa protein and C6 reacted to 67 and 70 kDa proteins. C. pcnlum was bound specifically to the surface region of oocysts by these mobs. No cross-reactivity was observed with tachyzoites of ToxopLosma gonnii and oocysts of Eimeria zuernii,5. bouis and E. canadensis of bovine origin. The indirect immunofluorescence assay (IIF) using mAb C6 was successful with counterstain. With the IIF using mob C6, oocysts appeared as 3 to $5{\mu}m$ spherical objects fluorescing bright apple green against a reddish dark background. The IIF using mAb C6 was agreed in specificity and sensitivity with those of a commercial diagnostic kit. These results demonstrated that the produced mAbs were specific to C. parvum and that the mAb C6 could be used for diagnosis of cryptosporidiosis.

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Multiple Noise OFDM Waveforms for Wide Swath MIMO SAR (광역 MIMO SAR 영상 획득을 위한 다중 잡음 OFDM 파형 활용 연구)

  • Moon, Minjung;Song, Kyungmin;Lee, Wookyung;Ryu, Sang-Burm;Lee, Hyeon-Cheol;Lee, Sang-Gyu
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.6
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    • pp.464-472
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    • 2018
  • Future spaceborne satellite synthetic aperture radar(SAR) system is expected to acquire high-resolution images over wide swath areas. Conventional SAR systems suffer from ambiguity problems in both azimuth and range directions that lead to image quality degradation. Recently, multiple input multiple output(MIMO) SAR techniques having multiple orthogonal waveforms are proposed to overcome the conventional ambiguity problems in wide-swath imaging modes. In this paper, noisy orthogonal frequency division multiplex(OFDM) waveforms are developed to reduce the ambiguity problems and suppress the image quality degradation. SAR simulations are performed to evaluate the performance of the proposed technique for wide-swath SAR imaging.

A Performance of Positioning Accuracy Improvement Scheme using Wavelet Denoising Filter (Wavelet Denoising Filter를 이용한 측위 정밀도 향상 기법 성능)

  • Shin, Dong Soo;Park, Ji Ho;Park, Young Sik;Hwang, Yu Min;Kim, Jin Young
    • Journal of Satellite, Information and Communications
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    • v.9 no.3
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    • pp.9-14
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    • 2014
  • Recently, precision guided munition systems and missile defense systems based on GPS have been taking a key role in modern warfare. In warfare however, unexpected interferences cause by large/small scale fading, radio frequency interferences, etc. These interferences result in a severe GPS positioning error, which could occur late supports and friendly fires. To solve the problems, this paper proposes an interference mitigation positioning method by adopting a wavelet denoising filter algorithm. The algorithm is applied to a GPS/QZSS/Wi-Fi combined positioning system which was performed by this laboratory. Experimental results of this paper are based on a real field test data of a GPS/QZSS/Wi-Fi combined positioning system and a simulation data of a wavelet denoising filter algorithm. At the end, the simulation result demonstrates its superiority by showing a 21.6% improved result in comparison to a conventional GPS system.

Regional Alternative Navigation Using HALE UAV, Pseudolite & Transceiver (고고도 장기체공 무인기와 의사위성/트랜시버를 활용한 국지적 대체항법에 관한 연구)

  • Choi, Min-woo;Yu, Sun-Kyoung;Kim, O-Jong;Kee, Chang-Don;Park, Byung-Woon;Seo, Seung-Woo;Park, Jun-Pyo
    • Journal of Advanced Navigation Technology
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    • v.19 no.6
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    • pp.499-506
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    • 2015
  • Global navigation satellite systems (GNSS) is operating widely in civil and military area. GNSS signals, however, can be easily interfered because its signal is vulnerable to jamming. Thus, a sort of backup or alternative system is needed in order that the navigation performance is assured to a certain degree in case of GNSS jamming. In order to suggest a series of backup or alternative system of regional navigation, in this paper, we introduced a high altitude long endurance unmanned aerial vehicle (HALE UAV) with pseudolites using inverted GPS and transceiver system. We simulated the positioning error of the regional navigation system using HALE UAV with inverted GPS or transceivers concepts. We estimated the position error of HALE UAV calculate user position errors based on the position error of HALE UAV and general pseudorange error.

A Study on Frequency Spectrum Allocation for the Next-Generation Terrestrial Broadcasting Service (차세대 지상파 방송을 위한 주파수 배분 연구)

  • Oh, Jai-Pil;Kim, Min-Ki;Kim, Dong Ho
    • Journal of Satellite, Information and Communications
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    • v.9 no.1
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    • pp.79-84
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    • 2014
  • Increasing demand for realistic media and improvement of transmission and device techniques accelerate ultra-high definition(UHD) service realization. In Korea, the cable TV broadcasting companies are planning to commercialize in Apr. 2014. For the terrestrial TV broadcasting service, technical issues are considered for the specification of UHD broadcasting system. However, the frequency bands and the system bandwidth for the terrestrial UHD broadcasting system have not been decided. In this paper, we propose required spectrum bandwidth for the next-generation terrestrial broadcasting service considering source coding, error correcting codes and modulation techniques. Also, we propose frequency management plan for terrestrial UHD broadcasting system in which we divide all parts of the country into 9 frequency zones and allocate 4 frequency band to each frequency zone considering single frequency network (SFN).