• Title/Summary/Keyword: satellite association

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Coverage Prediction for Aerial Relay Systems based on the Common Data Link using ITU Models (ITU 모델을 이용한 공용데이터링크 기반의 공중중계 시스템의 커버리지 예측)

  • Park, Jae-Soo;Song, Young-Hwan;Choi, Hyo-Gi;Yoon, Chang-Bae;Hwang, Chan-Ho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.1
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    • pp.21-30
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    • 2020
  • In this paper, we predicted the propagation loss for the air-to-ground (A2G) channel between the ground control system and the unmanned aerial vehicle (UAV) using the prediction model for the aircraft recommended by the International Telecommunication Union (ITU). We analyzed the network coverage of the aerial relay system based on the medium altitude UAVs by expanding it into the air-to-air (A2A) channel. Climate and geographic factors in Korea were used to predict propagation loss due to atmospheres. We used the measured data published by the Telecommunication Technology Association (TTA) for regional rainfall-rate and effective earth radius factors to increase accuracy. In addition, the aerial relay communication system used the key parameter of the common data link (CDL) system developed in Korea recently. Prediction results show that the network coverage of the aerial relay system broadens at higher altitude.

Insight Sources and Influence of Yellow-sand Events in Spring 2003

  • Zhuanshi He;Kim, Young J.;Kim, Jeong E.;K.O. Ogunjobi;Seong Y. Ryu;Kim, Kyung W.;Lee, Kwon H.;Park, Sung C.;Lee, Chul K.;Park, han S.;Yong M. Noh;Jin S. Jung;Kim, Min J.;Hyun R. Jung
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.05b
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    • pp.281-282
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    • 2003
  • The significant spring-time phenomenon known as the "Yellow Sand" influences not only regional but also global climate. It′s believed that frequency of yellow-sand events has increased in recent years. To investigate the possible factors inducing these special strong weather phenomenon and its impacts on meteorological elements, intensive sampling will be conducted by ADEMRC/KJIST from March to May 2003. Lagrangian trajectory (forward and backward), cluster analysis, factor analysis and satellite remote sense (SRS) techniques will be employed to inspect the mechanisms of yellow-sand. (omitted)

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The Study on the improvement plan for Military combat power by the future computer (미래형컴퓨터를 이용한 군전투력 발전방안 연구)

  • Heo, Yeong Dae
    • Convergence Security Journal
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    • v.13 no.5
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    • pp.57-66
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    • 2013
  • Predicting pattern of future combat ensures a successful war. It is possible to anticipate the shape of the future combat from the fighting method of US Army in the Iraq War. The fighting method: a series of combat progress by real time information to pinpoint strike using a guided weapon by GPS, an intelligence satellite and unmanned surveillance vehicle (USV), shows that real time unification combat power is key element for decide outcome of a war. The NCW is an organically connected network centric warfare paradigm by networking a factor of operation. In this paper, studied on the improvement plan for combat power by the future computer like a portable computer, an audio-recognized computer and non-keyboard computer. In addition, this paper attempts to establish a comprehensive intelligence network of Korea Marine Corps and to apply to combat or training.

Urbanization and Population Distribution in North Korea : A Comparison to South Korea (북한의 도시화와 인구분포 : 남한과의 비교)

  • 김두섭
    • Korea journal of population studies
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    • v.18 no.2
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    • pp.70-97
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    • 1995
  • The main purpose of this paper is to analyze the trend of urbanization and population distribution in North Korea. Although North Korean data lack comparable details, attention has been given to the comparison of urban system between North and South Korea. In North Korea, the pace of urbanization was most rapid just after the Korean War, from 1954 to 1960. However, the pace slowed down markedly in the early 1970s and has remained sluggish since then. North Korea is currently much less urbanized than South Korea. As specific features of urbanization in North Korea, emergence of new cities along inland borders, prominence of intermediate-sized cities, and sudden population growth of major cities due to boundary expansion are stressed. Available demographic data also indicate an overwhelming primacy of Pyongyang Municipality in the urban system, and rapid growth of satellite cities in the west-central region. It appears that, in North Korea, urbanization process has been a product of the government's development policies rather than individual's socioeconomic motivation to migrate urbanward. Finally, migration issues after unification of the Korean Peninsula and related problems are discussed in this study.

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The Genetic Diversity of Trans-caucasian Native Sheep Breeds

  • Hirbo, Jibril;Muigai, Anne;Naqvi, A.N.;Rege, E.D.;Hanotte, Olivier
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.7
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    • pp.943-952
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    • 2006
  • The genetic variation in 10 indigenous Caucasian sheep breeds was studied with 14 micro-satellite loci in order to determine the genetic diversity among and between the breeds. Five breeds from Asia, five breeds from Europe and one breed from Africa, were included in order to study any relationships or influences they may have with the Caucasian sheep analyzed. A Karakul population from Uzbekistan was included in the study to see whether there was any Central Asian influence. All the 14 loci were found to be polymorphic in all the breeds, with the exception of ILST0056, which was monomorphic in Imeretian. A total of 231 alleles were generated from all the 688 individuals of the sheep analyzed. The mean number of alleles (MNA) at each locus was 16.5. The total number of alleles detected in all samples ranged from 13 in several loci to 23 in OarJMP029. Out of total 308 Hardy-Weinberg Equilibrium (HWE) tests, 85 gave significant results. After Bonferroni correction for multiple tests, 30 comparisons still remained significant to the experimental levels. The Gala population was the most diverse and Imeretian the least diverse with a MNA of 8.50 and 5.51, respectively. Gene diversity estimates exhibited the same trend and ranged from 0.803 in Gala and 0.623 in Imeretian, but generally there is higher diversity among the Caucasian breeds in comparison to other eference breeds. The closest breeds were Tushin and Bozakh with Da of 0.113 and most distant breeds were $Djallonk{\acute{e}}$ and North Rondalsy with Da of 0.445. Principal Component (PC) analyses were done. PC1 described 14% of the differences. PC2, which described 13% of the differences, further separated the Caucasian breeds from Asian breeds except Karakul and Awasi, and the two British breeds. PC3 described 10% of the differences, allowing better differentiation of the Caucasian breeds. A moderate degree of reliability was observed for individual-breed assignment from the 14 loci using different approaches among which the Bayesian method proved to be the most efficient. About 72% of individuals analyzed were correctly assigned to their respective breeds.

Patterns of Zooplankton Distribution as Related to Water Masses in the Korea Strait during Winter and Summer (여름철 및 겨울철 수괴에 따른 대한해협의 동물플랑크톤 분포 양상)

  • Jang, Min-Chul;Baek, Seung-Ho;Jang, Pung-Guk;Lee, Woo-Jin;Shin, Kyoung-Soon
    • Ocean and Polar Research
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    • v.34 no.1
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    • pp.37-51
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    • 2012
  • We investigated the distribution and species composition of zooplankton in relation to hydrographical characteristics in the Korea Strait during the winter (February) and summer (July) of 2009. Satellite images of sea surface temperatures and in situ CTD data showed that the southeastern water zone (St3-5) off Jeju Island was strongly influenced by the Tsushima Current during both the winter and summer, whereas the Changjiang Diluted Water, characterized as water with relatively low salinity, was evident in the coastal waters of Jeju Island during the summer. During winter, zooplankton abundance was significantly higher than in the summer, with dominance by copepods, ostracods, siphonophorans, appendicularians, and nauplii. In both seasons, copepods represented >70% of the total zooplankton population. Calanus sinicus, a large calanoid copepod, was dominant in near the coast, and that may be associated with the intrusion of low salinity water (i.e., the Changjiang Diluted Water) along the coast. The abundance of P. parvus s.l. and A. omorii, known as neritic copepods, was mainly associated with the Korea Southern Coastal Water. Foraminiferans, Ostracods, O. plumifera, and P. aculeatus were concentrated in the southeastern water off Jeju Island during both seasons; showing their association with the Tsushima Current, which is characterized warm, high salinity water. Our results suggest that the distribution, abundance, and species composition of zooplankton are highly influenced by different water masses in the Korea Strait.

Some Problems of e-Learning Market in Korea (최근 우리나라 e-Learning 시장의 주요 동향 및 향후 전망)

  • Yoon, Young-Han
    • International Commerce and Information Review
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    • v.9 no.2
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    • pp.103-120
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    • 2007
  • The knowledge based economy requires more and more people to learn new knowledge and skills in a timely and effective manner. These needs and new technology such as computer and Internet are fueling a transition in e-learning. According to specialist's opinion, imagination experience studying is generalized, and learning environment that language barrier by studying, multi-language studying Machine that experience past things that disappear through simulation, and travel area, and experience future changed state disappears is forecasting to come. This is previewing finally that it may become future education that education and IT, element of entertainment is combined. Already, became story that argument for party satellite of e-Learning existence passes one season already. e-Learning is utilized already in all educations that we touch by effectiveness by corporation's competitive power improvement and implement of lifelong education in educational institutions through present e-Learning. It is obvious that when see from our viewpoint which is defining e-Learning by one industry and rear by application to education as well as one new growth power about these, e-Learning industry becomes very important means that can solve dilemma of growth real form. Only, special quality of digital industry that e-Learning is being same with other digital industry and repeat putting out a fire rapidly, and is repeating sudden change that these evolution is not gradual growth of accumulation and improvement of technology that is appearing consider need to. In the meantime, we need to observe about evolution of Information Technology. Because there is some scholars who e-Learning's concept foresees to evolve by u-Learning.(although, a person who see that these concept is not more in marketing terminology by some scholars' opinion is). This u-Learning's concept means e-Learning that take advantage of ubiquitous technology as Ubiquitous-Learning's curtailment speech. Ubiquitous, user means Information-Communication surrounding that can connect to network freely regardless of place without feeling network or computer. There is controversy about introduction time regarding these direction, but e-Learning is judged to evolve by u-Learning necessarily. Because keep in step and age that study all contents that learner wants under environment of 3A (any time, any whrer, any device) by individual order thoroughly is foreseen to come in ubiquitous learning environment that approach more festinately.

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Suggestion on the SBAS Augmentation Message Providing System for the the Low-cost GPS Receiver of Drone Operation (드론의 저가형 GPS 수신기용 SBAS 보강 정보 전송 시스템 제안)

  • Seok, Hyo-jeong;Yoon, Dong-hwan;Lim, Cheol-soon;Park, Byung-woon
    • Journal of Advanced Navigation Technology
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    • v.21 no.3
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    • pp.272-278
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    • 2017
  • In order to meet performance requirements specified by the ICAO in drone operation, a system that provides augmentation information such as SBAS is needed. However, the operating range of the drone is limited in situation where the drone can not received the SBAS message continuously. In this paper, we propose a system to transmit SBAS augmentation message using a separate communication channel assuming the SBAS satellite signal to the drone has been shielded. We implemented the proposed system and verified its performance in the static environment. The DGPS positioning results showed that the accuracy difference is about 10cm, which means the accuracy performance was very similar. In addition, the protection level calculated by the system also shows the difference within 2m from the value calculated by the airborne receiver.

Infant nurture management guide service widget based on Smart-TV (스마트TV 기반 유아 양육 도우미 서비스 위젯)

  • Jo, Hui-Joon;Choi, Jong-Hyuk;Jung, Jai-Jin
    • Convergence Security Journal
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    • v.10 no.4
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    • pp.93-99
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    • 2010
  • Smart TV, Internet content and interactive services are available, the operating system to mount the Web, App Store, you can enjoy a variety of content. Smart TV market, TV replacement cycle is long, watching for changes in the way copyright issues such as adaptation period and, unlike the case of a smart phone TV market in the short term are expected to occupy will not find, if IPTV, satellite, cable and real-time TV platform for broadcasters to adopt a smart, smart TV market could spread more quickly than expected. Long term, Google, Apple, TV gajeonsa and broadcasters to compete with various companies through the process of expanding the TV market is smart, the media are expected to dominate the market. Smart TV with the latest technology-related research and to investigate the Smart TV, Smart TV is designed based widgets. Widgets on the desktop, mobile, IPTV, etc. can be implemented in various environments and various features and types of users already are using the widget. In particular the advantages of the widget can be implemented to meet the needs of the users, because users to more efficiently and meet their desired widget. In this paper, propose Smart-TV-based Baby management widget.

Extraction of the aquaculture farms information from the Landsat- TM imagery of the Younggwang coastal area

  • Shanmugam, P.;Ahn, Yu-Hwan;Yoo, Hong-Ryong
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2004.03a
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    • pp.493-498
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    • 2004
  • The objective of the present study is to compare various conventional and recently evolved satellite image-processing techniques and to ascertain the best possible technique that can identify and position of aquaculture farms accurately in and around the Younggwang coastal area. Several conventional techniques performed to extract such information fiom the Landsat-TM imagery do not seem to yield better information about the aquaculture farms, and lead to misclassification. The large errors between the actual and extracted aquaculture farm information are due to existence of spectral confusion and inadequate spatial resolution of the sensor. This leads to possible occurrence of mixture pixels or 'mixels' of the source of errors in the classification techniques. Understanding the confusing and mixture pixel problems requires the development of efficient methods that can enable more reliable extraction of aquaculture farm information. Thus, the more recently evolved methods such as the step-by-step partial spectral end-member extraction and linear spectral unmixing methods are introduced. The farmer one assumes that an end-member, which is often referred to as 'spectrally pure signature' of a target feature, does not appear to be a spectrally pure form, but always mix with the other features at certain proportions. The assumption of the linear spectral unmxing is that the measured reflectance of a pixel is the linear sum of the reflectance of the mixture components that make up that pixel. The classification accuracy of the step-by-step partial end-member extraction improved significantly compared to that obtained from the traditional supervised classifiers. However, this method did not distinguish the aquaculture ponds and non-aquaculture ponds within the region of the aquaculture farming areas. In contrast, the linear spectral unmixing model produced a set of fraction images for the aquaculture, water and soil. Of these, the aquaculture fraction yields good estimates about the proportion of the aquaculture farm in each pixel. The acquired proportion was compared with the values of NDVI and both are positively correlated (R$^2$ =0.91), indicating the reliability of the sub-pixel classification.ixel classification.

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