• Title/Summary/Keyword: Satellite Core Technology

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Efficient Transmit Antenna Selection Method for Massive MIMO system (Massive MIMO 시스템을 위한 효율적인 송신 안테나 선택 기법)

  • Ju, Sang-Lim;Lee, Byung-Jin;Kim, Young-Jae;Kim, Jin-Up;Bang, Young-Jo;Kim, Kyungseok
    • Journal of Satellite, Information and Communications
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    • v.11 no.3
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    • pp.58-64
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    • 2016
  • This paper proposes the efficient transmit antenna selection (TAS) scheme considering trade-off between the performance and the complexity in massive MIMO system. The massive MIMO system is a core technology to achieve performance objectives for 5 generation wireless communication. It achieve high spectral efficiency, a reliability, and a diversity gain. However many RF chains required by massive transmit antennas equipped in a base station create the problem such as high hardware cost and complexity. Therefor we investigates the transmit antenna selection scheme, in which the number of RF chains of BS is reduced, and the trade-off between the performance and the complexity is considered for proposed scheme. And, the spectral efficiency and complexity are analysed by transmit antenna selection schemes.

The Analysis of Crypto Communication Relay Effect in the Security Framework Technique of Network Centric Warfare Environment (NCW환경의 보안 프레임워크 기술에서 암호통신 중계영향 분석)

  • Hong, Jin-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.4
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    • pp.788-794
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    • 2007
  • The policy of US DoD is moving towards implementation of Network Centric Warfare(NCW) concepts. NCW is commonly described as the integration and synchronization of four key interdependent elements such as command and control, sensor system, engagement systems and the network. Therefore the military policy of Korea military is needed to access and examine the policy of NCW communication environment and crypto communication, which is able to apply it. In this case study, We are reviewed the security framework of the concept of network centric warfare in the centering around the US. It is introduced the core technology in the network centric warfare, and it is reviewed the security framework such as, the requirements of security, the characteristics security of global information grid, joint tactical radion system, net centric enterprise services, transformational communication satellite, in the basis of core technology, and analysis the effect of crypto communication relay between command node and surbornate node in NCW environment. This report support the assistance, which is considered the elements of surrounding effects in the varied crypto communication research area of NCW.

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Nanoplasmonics: Enabling Platform for Integrated Photonics and Sensing

  • Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.75-75
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    • 2015
  • Strong interactions between electromagnetic radiation and electrons at metallic interfaces or in metallic nanostructures lead to resonant oscillations called surface plasmon resonance with fascinating properties: light confinement in subwavelength dimensions and enhancement of optical near fields, just to name a few [1,2]. By utilizing the properties enabled by geometry dependent localization of surface plasmons, metal photonics or plasmonics offers a promise of enabling novel photonic components and systems for integrated photonics or sensing applications [3-5]. The versatility of the nanoplasmonic platform is described in this talk on three folds: our findings on an enhanced ultracompact photodetector based on nanoridge plasmonics for photonic integrated circuit applications [3], a colorimetric sensing of miRNA based on a nanoplasmonic core-satellite assembly for label-free and on-chip sensing applications [4], and a controlled fabrication of plasmonic nanostructures on a flexible substrate based on a transfer printing process for ultra-sensitive and noise free flexible bio-sensing applications [5]. For integrated photonics, nanoplasmonics offers interesting opportunities providing the material and dimensional compatibility with ultra-small silicon electronics and the integrative functionality using hybrid photonic and electronic nanostructures. For sensing applications, remarkable changes in scattering colors stemming from a plasmonic coupling effect of gold nanoplasmonic particles have been utilized to demonstrate a detection of microRNAs at the femtomolar level with selectivity. As top-down or bottom-up fabrication of such nanoscale structures is limited to more conventional substrates, we have approached the controlled fabrication of highly ordered nanostructures using a transfer printing of pre-functionalized nanodisks on flexible substrates for more enabling applications of nanoplasmonics.

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AN ASSESSMENT OF LAND COVER CHANGES AND ASSOCIATED URBANIZATION IMPACTS ON AIR QUALITY IN NAWABSHAH, PAKISTAN: A REMOTE SENSING PERSPECTIVE

  • Shaikh, Asif Ahmed;Gotoh, Keinosuke
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.555-558
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    • 2006
  • In recent years, urban development has expanded rapidly in Nawabshah City of Pakistan. A major effect associated with this population trend is transformation of the landscape from natural cover types to increasingly impervious urban land. The core objective of this study are to provide time-series information to define and measure the urban land cover changes of Nawabshah, Pakistan between the years 1992 and 2002, and to examine related urbanization impacts on air quality of the study area. Two multi-temporal Landsat images acquired in 1992 and 2002 together with standard topographical maps to measure land cover changes were used in this study. The image processing and data manipulation were conducted using algorithms supplied with the ERDAS Imagine software. An unsupervised classification approach, which uses a minimum spectral distance to assign pixels to clusters, was used with the overall accuracy ranging from 84 percent to 92 percent. Land cover statistics demonstrate that during the study period (1992-2002) extensive transformation of barren and vegetated lands into urban land have taken place in Nawabshah City. Results revealed that land cover changes due to urbanization has not only contaminated the air quality of the study area but also raised the health concerns for the local residents.

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Analysis and Design of the Generic Mission Operations System (통합지향형 임무운용시스템 분석 및 설계)

  • Jung, Ok-Chul;Kim, Hae-Dong;Choi, Su-Jin;Chung, Dae-Won
    • Aerospace Engineering and Technology
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    • v.8 no.2
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    • pp.127-132
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    • 2009
  • This paper represents the analysis and design of the generic mission operations system for next generation satellite mission. In the past, mission operations systems were developed by their own mission requirements respectively. However, these systems have the similar architecture and common functions. Mission operations systems, in general, consist of mission independent module and mission specific module. In this paper, the generic framework for the mission scheduling and automation are introduced and analyzed. Using these generic frameworks, the risk and cost for operations system development can be reduced significantly. And, these frameworks might be used for the core technology in the development of mission operations system in the future.

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Design of Encryption/Decryption Core for Block Cipher HIGHT (블록 암호 HIGHT를 위한 암·복호화기 코어 설계)

  • Sonh, Seung-Il
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.4
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    • pp.778-784
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    • 2012
  • A symmetric block cryptosystem uses an identical cryptographic key at encryption and decryption processes. HIGHT cipher algorithm is 64-bit block cryptographic technology for mobile device that was authorized as international standard by ISO/IEC on 2010. In this paper, block cipher HIGHT algorithm is designed using Verilog-HDL. Four modes of operation for block cipher such as ECB, CBC, OFB and CTR are supported. When continuous message blocks of fixed size are encrypted or decrypted, the desigend HIGHT core can process a 64-bit message block in every 34-clock cycle. The cryptographic processor designed in this paper operates at 144MHz on vertex chip of Xilinx, Inc. and the maximum throughput is 271Mbps. The designed cryptographic processor is applicable to security module of the areas such as PDA, smart card, internet banking and satellite broadcasting.

An Assessment of Technological Competitiveness in Core Products of Foreign Design & Construction markets (해외 유망 건설상품의 기술 경쟁력 평가)

  • Choi, Seok-In;Kim, Sang-Bum;Lee, Young-Whan;Kim, Woo-Young;Jang, Hyoun-Seung
    • Korean Journal of Construction Engineering and Management
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    • v.9 no.1
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    • pp.107-117
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    • 2008
  • In this study, surveys and interviews are used to evaluate technological competitiveness of each product with respect to that of foreign leading firms, for seven leading domestic construction products which have been determined to have competitive edge in offshore markets, Such evaluation provides a more in depth study than previously conducted research, and is meaningful in that corporate level, rather than industry level, perspective is projected. Major findings of such evaluations are the following. First, as expected, it has been evaluated that domestic technological competitiveness in desalination plant and power plant has reached the point where it can compete with foreign leading firms. Moreover, a noteworthy result of the evaluation is that development program sector, including urban development of satellite cities, has reached considerable level of competitiveness in offshore market. In the case of the development market, domestic firms have accumulated sufficient experience in domestic market and engineering technology is not a decisive factor as in plant sector, and these factors lead to such an evaluation. Second, in the cases of gas, oil refinery and petro-chemical plants, domestic products' technological competitiveness that can contest in offshore market is still centered around production and construction. On the other hand, there are still weaknesses in license technology and basic design capabilities, which constitute the "value added" area. Third, skyscrapers, a promising product in offshore construction market and a product group which domestic firms have much performance record and projects in progress both in domestic and offshore markets, are considered. While direct comparison between skyscrapers and plant sector is not feasible, with the exception of production and construction, overall domestic capability in this sector has been assessed to be the lowest amongst those products that were surveyed. Fourth, it has been indicated that competitiveness is relatively higher in common technology than in key technology. In project management capability, it has been assessed that there are weaknesses in procedure document area. Also, a characteristic is the point that low overall assessments have been given across all product groups for corporate and management areas, not technological areas. Especially, financing, contracting/claim, risk management and investment on research and development received low evaluations. Fifth, it has been assessed that overall corporate and governmental supports are weak. This result is especially evident for corporate management and support areas across all product groups surveyed.

Multiresolution 4- 8 Tile Hierarchy Construction for Realtime Visualization of Planetary Scale Geological Information (행성 규모 지리 정보의 실시간 시각화를 위한 다계층 4-8 타일 구조의 구축)

  • Jin, Jong-Wook;Wohn, Kwang-Yun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.4
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    • pp.12-21
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    • 2006
  • Recently, Very large and high resolution geological data from aerial or satellite imagery are available. Many researches and applications require to do realtime visualization of interest geological area or entire planet. Important operation of wide-spreaded terrain realtime visualization technique is the appropriate model resolution selection from pre-processed multi-resolution model hierarchy depend upon participant's view. For embodying such realtime rendering system with large geometric data, Preprocessing multi-resolution hierarchy from large scale geological information of interest area is required. In this research, recent Cubic multiresolution 4-8 tile hierarchy is selected for global planetary applications. Based upon the tile hierarchy, It constructs the selective terminal level tile mesh for original geological information area and starts to sample individual generated tiles for terminal level tiles. It completes the hierarchy by constructing intermediate tiles with low pass filtering in bottom-up direction. This research embodies series of efficient cubic 4-8 tile hierarchy construction mechanism with out-of-core storage. The planetary scale Mars' geographical altitude data and image data were selected for the experiment.

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Relationship between Abundances of Kaloula borealis and Meteorological Factors based on Habitat Features (서식지 특성에 따른 맹꽁이 개체수와 기상요인과의 관계 분석)

  • Rho, Paikho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.3
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    • pp.103-119
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    • 2016
  • This study aims to assess habitat feature on the large-scale spawning ground of the Boreal Digging Frog Kaloula borealis in Daemyung retarding basin of Daegu, and to analyze the relationships between species abundance and meteorological factors for each habitat. Fifty-seven(57) pitfalls were installed to collect species abundance of 4 survey regions, and high-resolution satellite image, soil sampling equipment, digital topographic map, and GPS were used to develop habitat features such as terrain, soil, vegetation, human disturbance. The analysis shows that the frog is most abundant in sloped region with densely herbaceous cover in southern part of the retarding basin. In the breeding season, lowland regions, where Phragmites communis and P. japonica dominant wetlands and temporary ponds distributed, are heavily concentrated by the species for spawning and foraging. Located in between legally protected Dalsung wetands and lowland regions of the retarding basin, riverine natural levee is ecologically important area as core habitat for Kaloula borealis, and high number of individuals were detected both breeding and non-breeding seasons. Temperate- and pressure-related meteorological elements are selected as statistically significant variables in species abundance of non-breeding season in lowland and highland regions. However, in sloped regions, only a few variables are statistically significant during non-breeding season. Moreover, breeding activities in sloped regions are statistically significant with minimum temperature, grass minimum temperature, dew point temperature, and vapor pressure. Significant meteorological factors with habitat features are effectively applied to establish species conservation strategy of the retarding basin and to construct for avoiding massive road-kills on neighboring roads of the study sites, particularly post-breeding movements from spawning to burrowing areas.

Design and Implementation of OBCP Engine based on Lua VM for AT697F/VxWorks Platform (AT697F/VxWorks 플랫폼에서 Lua 가상머신 기반의 OBCP 엔진 설계 및 구현)

  • Choi, Jong-Wook;Park, Su-Hyun
    • Journal of Satellite, Information and Communications
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    • v.12 no.3
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    • pp.108-113
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    • 2017
  • The OBCP called 'operator on board' is that of a procedure to be executed on-board, which can be easily be loaded, executed, and also replaced, without modifying the remainder of the FSW. The use of OBCP enhances the on-board autonomy capabilities and increases the robustness to ground stations outages. The OBCP engine which is the core module of OBCP component in the FSW interprets and executes of the procedures based on script language written using a high-level language, possibly compiled, and it is relying on a virtual machine of the OBCP engine. FSW team in KARI has studied OBCP since 2010 as FSW team's internal projects, and made some OBCP engines such as Java KVM, RTCS/C and KKOMA on ERC32 processor target only for study. Recently we have been studying ESA's OBCP standard and implementing Lua and MicroPython on LEON2-FT/AT697F processor target as the OBCP engine. This paper presents the design and implementation of Lua for the OBCP engine on AT697F processor with VxWorks RTOS, and describes the evaluation result and performance of the OBCP engine.