• Title/Summary/Keyword: 인터넷 위성통신

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Design and Implementation of eRTOS Real-time Operating Systems for Wearable Computers (웨어러블 컴퓨터를 위한 저전력 실시간 운영체제 eRTOS 설계 및 구현)

  • Cho, Moon-Haeng;Choi, Chan-Woo;Lee, Cheol-Hoon
    • The Journal of the Korea Contents Association
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    • v.8 no.9
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    • pp.42-54
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    • 2008
  • In recent years, embedded systems have been expanding their application domains from traditional embedded systems such as military weapons, robots, satellites and digital convergence systems such as celluar phones, PMP(Portable Multimedia Player), PDAs(Personal Digital Assistants) to Next Generation Personal Computers(NGPCs) such as eating PCs, wearable computers. The NGPCs are network-based, human-centric digital information devices diverged from the traditional PCs used mainly for document writing, internet searching and database management. Wearable computers with battery capacity and memory size limitations have to use real-time operating systems with small footprints and low power management techniques to provide user's QoS in spite of hardware constraints. In this paper, we have designed and implemented a low-power RTOS (called eRTOS) for wearable computers. The implemented eRTOS has 18KB footprints and the dynamic power management and the device power management schemes are adapted in it. Experimental results with wearable computer applications show that the low power techniques could save energy up to 47 %.

The Method of Real-Time Location Information Service by using GPS and OpenAPI for Cost-cutting (비용 절감을 위한 GPS와 OpenAPI을 이용한 실시간 위치정보 서비스 방안)

  • Youn, Jae-Hong;Kim, Eun-Seok;Hur, Gi-Taek
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.902-905
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    • 2008
  • With development of internet, location-based service (LBS) is getting more interest in wire and wireless network, and many studies are in progress to provide various services such as GIS and GPS technique related to this. Today positioning and information providing service is accomplished by mobile communication companies' chasing the cell or building unique GIS system, but there is a lot of building-cost that must be endured to define boundary of collecting precise location information from chasing Cell and provide unique location information service. In this paper, it desires to make the database of location information with using GPS, relatively precise satellite positioning system, to cut the cost of building location information service, and to present service models such as children's positioning service that is to reduce the cost of building GIS by using Web Open API and provide location information of discrete object in real-time.

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Availability Evaluation of FKP-RTK Positioning for Construction Survey Application (FKP-RTK 측위의 시공측량 적용성 실험)

  • Kim, In Seup
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.6_1
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    • pp.463-469
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    • 2013
  • In addition to the VRS-RTK service, FKP-RTK service launched recently in Korea however unlike VRS, it is not yet applied to various surveying tasks. VRS system is operated in two way communication over the mobile Internet. When user send rover position data to network RTK server and the server provides correction data to users continuously. It causes to increase communications load and makes delaying or failure in data transmission depends on server capacity and number of concurrent users. In contrast, since FKP system is one way communication system, user only receives correction data and area correction parameters for the selected Continuous Reference Station from the server. Thus, there is no limitation to the number of concurrent users in FKP system and it would be more efficient than VRS system in terms of economic. To this end, we performed FKP-RTK test for Unified Control Points and Urban Control Points where are located at 5 regions in Korea to evaluate the accuracy. As a result, almost of FKP positioning data are in error range of ${\pm}6.2cm$ in horizontal and it would be enough for construction survey such as for earth work in limited except precise structure survey.

Development of Android Smartphone App for Corner Point Feature Extraction using Remote Sensing Image (위성영상정보 기반 코너 포인트 객체 추출 안드로이드 스마트폰 앱 개발)

  • Kang, Sang-Goo;Lee, Ki-Won
    • Korean Journal of Remote Sensing
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    • v.27 no.1
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    • pp.33-41
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    • 2011
  • In the information communication technology, it is world-widely apparent that trend movement from internet web to smartphone app by users demand and developers environment. So it needs kinds of appropriate technological responses from geo-spatial domain regarding this trend. However, most cases in the smartphone app are the map service and location recognition service, and uses of geo-spatial contents are somewhat on the limited level or on the prototype developing stage. In this study, app for extraction of corner point features using geo-spatial imagery and their linkage to database system are developed. Corner extraction is based on Harris algorithm, and all processing modules in database server, application server, and client interface composing app are designed and implemented based on open source. Extracted corner points are applied LOD(Level of Details) process to optimize on display panel. Additional useful function is provided that geo-spatial imagery can be superimposed with the digital map in the same area. It is expected that this app can be utilized to automatic establishment of POI (Point of Interests) or point-based land change detection purposes.

Six Major Shifts and Implications of the Video Distribution Ecosystem in the Era of N-screen and OTT Services: A case of US media industry (N-/멀티스크린 및 OTT 서비스시대의 미디어 생태계 변환의 여섯 가지 특징과 함의: 미국 사례)

  • Han, Gwang Jub James
    • The Journal of the Korea Contents Association
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    • v.14 no.8
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    • pp.342-364
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    • 2014
  • The purpose of this paper is to provide an answer for the following question: What are the major shifts and implications of the unprecedently competitive and rapidly changing media ecosystem in the era of N-screen and OTT services? I've attempted to understand the complex and competitive nexus among media from an historical context by focusing on the displacement vs. complement thesis. The TPC model by Han has been employed for the analysis of the current dynamics of US media industries by triangulating three areas: Technology/industry, public policy and consumer/culture. More specifically, the US media landscape is initially divided into two competitive turfs - the competitors equipped with OTT services and the legacy media industry, and then the traditional media industry was grouped again into PayTV group(telecom service providers with IPTV and mobile TV, cable/Satellite TV networks) and Free (over-the-air) TV networks. Six major shifts were identified by the analysis: power shift in telecom carriers, power shifts in TV industry, Telecom/OTT partnership, time shifts, place shifts, and finally business model shifts.

Applications of "High Definition Digital Climate Maps" in Restructuring of Korean Agriculture (한국농업의 구조조정과 전자기후도의 역할)

  • Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.9 no.1
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    • pp.1-16
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    • 2007
  • The use of information on natural resources is indispensable to most agricultural activities to avoid disasters, to improve input efficiency, and to increase lam income. Most information is prepared and managed at a spatial scale called the "Hydrologic Unit" (HU), which means watershed or small river basin, because virtually every environmental problem can be handled best within a single HU. South Korea consists of 840 such watersheds and, while other watershed-specific information is routinely managed by government organizations, there are none responsible for agricultural weather and climate. A joint research team of Kyung Hee University and the Agriculture, forestry and Fisheries Information Service has begun a 4-year project funded by the Ministry of Agriculture and forestry to establish a watershed-specific agricultural weather information service based on "high definition" digital climate maps (HD-DCMs) utilizing the state of the art geospatial climatological technology. For example, a daily minimum temperature model simulating the thermodynamic nature of cold air with the aid of raster GIS and microwave temperature profiling will quantify effects of cold air drainage on local temperature. By using these techniques and 30-year (1971-2000) synoptic observations, gridded climate data including temperature, solar irradiance, and precipitation will be prepared for each watershed at a 30m spacing. Together with the climatological normals, there will be 3-hourly near-real time meterological mapping using the Korea Meteorological Administration's digital forecasting products which are prepared at a 5 km by 5 km resolution. Resulting HD-DCM database and operational technology will be transferred to local governments, and they will be responsible for routine operations and applications in their region. This paper describes the project in detail and demonstrates some of the interim results.