• Title/Summary/Keyword: 효율 성

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Community Structure of Pinus thunbergii Stand in the Eastern Coast of Gyeongsangbuk-do (경상북도 동해안 곰솔림의 군집구조)

  • Cheon, Kwang-Il;Jung, Sung-Cheol;Youn, Ho-Joong;Byeon, Jun-Gi;Joo, Sung-Hyun
    • Journal of agriculture & life science
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    • v.46 no.4
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    • pp.57-68
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    • 2012
  • This study was conducted to provide basic data for the effective conservation and management in the black pine(Pinus thunbergii) stand which is located in the eastern coast of Gyeongsangbuk-do where the fragmentation of vegetation has been caused by the exploitation and the increase of tourists, and installed the seventy study sites($20{\times}20m$) in the dominant black pine stand. The black pine stand was classified into three groups(P. thunbergii - P. densiflora community, P. thunbergii - Robinia pseudoacacia community, P. thunbergii - P. densiflora-Celtis sinensis community) by a cluster analysis. As a result of Multi-Response Permutation Procedures test, there is significance among the communities. Pinus densiflora, Callicarpa japonica, Juniperus rigida, Rhododendron yedoense for. poukhanense etc. nineteen species were significant by indicator species analysis. The population structure of black pine stand showed that the class of diameter 12 to 26 cm was dominance, which had the inverse hump-shape pattern. Species diversity index(H') of investigated ranged from $1.033{\pm}0.234$ to $1.629{\pm}0.226$ in the woody layer group and from $2.448{\pm}0.457$ to $2.545{\pm}0.318$ $2.174{\pm}0.333$ in the herb layer group.

Radarsat-1 ScanSAR Quick-look Signal Processing and Demonstration Using SPECAN Algorithm (SPECAN 알고리즘을 이용한 Radatsat-1 ScanSAR Quick-look 신호 처리 및 검증 알고리즘 구현)

  • Song, Jung-Hwan;Lee, Woo-Kyung;Kim, Dong-Hyun
    • Korean Journal of Remote Sensing
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    • v.26 no.2
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    • pp.75-86
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    • 2010
  • As the performance of the spaceborne SAR has been dramatically enhanced and demonstrated through advanced missions such as TerraSAR and LRO(Lunar Reconnaissance Orbiter), the need for highly sophisticated and efficient SAR processor is also highlighted. In Korea, the activity of SAR researches has been mainly concerned with SAR image applications and the current SAR raw data studies are mostly limited to stripmap mode cases. The first Korean spaceborne SAR is scheduled to be operational from 2010 and expected to deliver vast amount of SAR raw data acquired from multiple operational scenarios including ScanSAR mode. Hence there will be an increasing demand to implement ground processing systems that enable to analyze the acquired ScanSAR data and generate corresponding images. In this paper, we have developed an efficient ScanSAR processor that can be directly applied to spaceborne ScanSAR mode data. The SPECAN(Spectrum Analysis) algorithm is employed for this purpose and its performance is verified through RADARSAT-1 ScanSAR raw data taken over Korean peninsular. An efficient quick-look processing is carried out to produce a wide-swath SAR image and compared with the conventional RDA processing case.

Development of Korea Ocean Satellite Center (KOSC): System Design on Reception, Processing and Distribution of Geostationary Ocean Color Imager (GOCI) Data (해양위성센터 구축: 통신해양기상위성 해색센서(GOCI) 자료의 수신, 처리, 배포 시스템 설계)

  • Yang, Chan-Su;Cho, Seong-Ick;Han, Hee-Jeong;Yoon, Sok;Kwak, Ki-Yong;Yhn, Yu-Whan
    • Korean Journal of Remote Sensing
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    • v.23 no.2
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    • pp.137-144
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    • 2007
  • 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 2008. Ansan (the headquarter of KORDI) 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 into antenna and RF. Antenna is designed to be $\phi$ 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 arranged 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 offering received data to user less than an hour.

Building a Satellite Image Rinsed Blog System Using PPGIS (People Participatory GIS) (국민참여형 위성영상 블로그 시스템 구축)

  • Lee, Ki-Hwan;Lee, Dong-Cheon;Park, Seok-Ho;Kim, Il;Shin, Sang-Hee
    • Korean Journal of Remote Sensing
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    • v.23 no.2
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    • pp.125-130
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    • 2007
  • This paper introduce a satellite image based blog system built by JeonNam local province. Main goals of this system are as follows : (1)Overcome the static aspect of traditional Web-GIS, (2)Providing a geoUCC generating platform by combining multimedia technology and GIS in a single web environment, (3)Building a two-way Web-GIS through user's participation, (4)Creating a new communicative way between government and citizen by using this system. As a result of the system building, this system enables users to create his/her own UCC(User Created Contents) on high-resolution satellite image and enables users to share his/her own UCC with other system using Web2.0 technology.

Automated Geometric Correction of Geostationary Weather Satellite Images (정지궤도 기상위성의 자동기하보정)

  • Kim, Hyun-Suk;Lee, Tae-Yoon;Hur, Dong-Seok;Rhee, Soo-Ahm;Kim, Tae-Jung
    • Korean Journal of Remote Sensing
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    • v.23 no.4
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    • pp.297-309
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    • 2007
  • The first Korean geostationary weather satellite, Communications, Oceanography and Meteorology Satellite (COMS) will be launched in 2008. The ground station for COMS needs to perform geometric correction to improve accuracy of satellite image data and to broadcast geometrically corrected images to users within 30 minutes after image acquisition. For such a requirement, we developed automated and fast geometric correction techniques. For this, we generated control points automatically by matching images against coastline data and by applying a robust estimation called RANSAC. We used GSHHS (Global Self-consistent Hierarchical High-resolution Shoreline) shoreline database to construct 211 landmark chips. We detected clouds within the images and applied matching to cloud-free sub images. When matching visible channels, we selected sub images located in day-time. We tested the algorithm with GOES-9 images. Control points were generated by matching channel 1 and channel 2 images of GOES against the 211 landmark chips. The RANSAC correctly removed outliers from being selected as control points. The accuracy of sensor models established using the automated control points were in the range of $1{\sim}2$ pixels. Geometric correction was performed and the performance was visually inspected by projecting coastline onto the geometrically corrected images. The total processing time for matching, RANSAC and geometric correction was around 4 minutes.

Estimation of Forest Biomass based upon Satellite Data and National Forest Inventory Data (위성영상자료 및 국가 산림자원조사 자료를 이용한 산림 바이오매스 추정)

  • Yim, Jong-Su;Han, Won-Sung;Hwang, Joo-Ho;Chung, Sang-Young;Cho, Hyun-Kook;Shin, Man-Yong
    • Korean Journal of Remote Sensing
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    • v.25 no.4
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    • pp.311-320
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    • 2009
  • This study was carried out to estimate forest biomass and to produce forest biomass thematic map for Muju county by combining field data from the 5$^{th}$ National Forest Inventory (2006-2007) and satellite data. For estimating forest biomass, two methods were examined using a Landsat TM-5(taken on April 28th, 2005) and field data: multi-variant regression modeling and t-Nearest Neighbor (k-NN) technique. Estimates of forest biomass by the two methods were compared by a cross-validation technique. The results showed that the two methods provide comparatively accurate estimation with similar RMSE (63.75$\sim$67.26ton/ha) and mean bias ($\pm$1ton/ha). However, it is concluded that the k-NN method for estimating forest biomass is superior in terms of estimation efficiency to the regression model. The total forest biomass of the study site is estimated 8.4 million ton, or 149 ton/ha by the k-NN technique.

Reference Station of Aerial Photogrammetry with GPS/INS by VRS (GPS/INS 항공사진측량의 지상기준국 측량의 VRS(가상기준점)적용에 관한 연구)

  • Song, Tae-Min;Kwon, Jay-Hyoun
    • Korean Journal of Remote Sensing
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    • v.24 no.4
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    • pp.381-388
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    • 2008
  • In the common practice of air-photographing measurement aerial-photogrammetric, the location of camera at the time of photographing is identified by performing aerotriangulation. However, installing ground-base station to enable aerotriangulation takes majority portion of a map making cost. Aerial-photogrammetric has shown a great improvement helped by steady upgrading in equipment and development in quantitative study. Aerotriangulation can be replaced by Direct Georeferencing, which uses GPS/INS to identify a camera location and to produce detailed information. An innovative technique replacing aerotriangulation, it has a disadvantage that base station has to be available in the area of photographing. The study intends to suggest a method applying VRS in GPS/INS aerotriangulation. Despite the fact that Direct Georeferencing is the innovated technique which substitutes existing aerotriangulation, it still need to install the ground-base station in GPS/INS aerotriangulation. GPS/INS data was analyzed with 4 different cases in order to accomplish the purpose of this study. In addition, in the thesis, it was approved that VRS can be utilized to make small-scale map as accurate as base station. This study is expected to improve the efficiency of work by showing that VRS can be used not only in base station but also enabling base station in the ground-access challenging area.

Estimation of Total Precipitable Water from MODIS Infrared Measurements over East Asia (MODIS 적외 자료를 이용한 동아시아 지역의 총가강수량 산출)

  • Park, Ho-Sun;Sohn, Byung-Ju;Chung, Eui-Seok
    • Korean Journal of Remote Sensing
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    • v.24 no.4
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    • pp.309-324
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    • 2008
  • In this study the retrieval algorithms have been developed to retrieve total precipitable water (TPW) from Terra/Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) infrared measurements using a physical iterative retrieval method and a split-window technique over East Asia. Retrieved results from these algorithms were validated against Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) over ocean and radiosonde observation over land and were analyzed for investigating the key factors affecting the accuracy of results and physical processes of retrieval methods. Atmospheric profiles from Regional Data Assimilation and Prediction System (RDAPS), which produces analysis and prediction field of atmospheric variables over East Asia, were used as first-guess profiles for the physical retrieval algorithm. We used RTTOV-7 radiative transfer model to calculate the upwelling radiance at the top of the atmosphere. For the split-window technique, regression coefficients were obtained by relating the calculated brightness temperature to the paired radiosonde-estimated TPW. Physically retrieved TPWs were validated against SSM/I and radiosonde observations for 14 cases in August and December 2004 and results showed that the physical method improves the accuracy of TPW with smaller bias in comparison to TPWs of RDAPS data, MODIS products, and TPWs from split-window technique. Although physical iterative retrieval can reduce the bias of first-guess profiles and bring in more accurate TPWs, the retrieved results show the dependency upon initial guess fields. It is thought that the dependency is due to the fact that the water vapor absorption channels used in this study may not reflect moisture features in particular near surface.

Two-Dimensional Filtering Through the Radon Transform (라돈변환을 이용한 2차원 필터링)

  • 원중선
    • Korean Journal of Remote Sensing
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    • v.14 no.1
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    • pp.17-36
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    • 1998
  • The Radon transform has been widely used in various techniques of digital image processing such as the computerized topography, lineament analysis in a remotely sensed image, slant-stack processing of seismic data, and so on. Compared to the Fourier transform, the utility of two-dimensional convolutional or correlational properties of the Radon transform, however, has been underestimated. We show that the two-dimensional convolution and correlation is respectively reduced to be one-dimensional convolution and correlation with respect to ρ in the Radon space. Therefore, one can achieve a two dimensional filtering by applying a simple one-dimensional convolution in the Radon space followed by an inverse Radon transform. Tests of the approach using FIR filters are carried out specifically for enhancing the ship wake in a RADARSAT SAR image. The test results demonstrate that the two-dimensional filtering through the Radon transform effectively enhance the ship wake features as well as reducing sea speckle in the image. Although two-dimensional convolution and correlation through the Radon transform are not so much useful as those through the courier transform in views of efficiency and effectiveness, it can be utilized to improve the quality of a digitally processed output when the process should be accompanied by the Radon transform such as topography and lineament analysis of SAR image.

A Survey of Students' Satisfaction on the 2nd Brain Korea (BK) 21 Project: a Case Study of the Humanities and Social Sciences at K University (제2단계 BK21사업에 대한 학생들의 만족도 조사 - 인문·사회계열을 중심으로 -)

  • Jung, Woojin;Kim, Gyeong-Yeon;Lee, Young-Mee;Jo, Bo-Gyeong
    • (The)Korea Educational Review
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    • v.14 no.2
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    • pp.155-179
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    • 2008
  • The objective of this study was to analyze the satisfaction of graduate students participating in the Brain Korea21 (BK21) project in five supporting areas of the project: curriculum, job searching and career development, academic development, the globalization of education, and educational environment. A further objective was to find efficient methods of providing students with stable academic and financial support for their research in order to develop them as distinguished researchers. In order to answer research questions, this study conducted a survey of the BK21 project satisfaction with students majoring in humanities or social sciences and analyzed the survey results. The tool has 7 dimensions: 'curriculum', 'job searching and career development', 'stable support for academic development', 'support for academic activities out of school', 'globalization of education', 'lectures in English', and 'educational environment'. The survey found that survey participants were in general satisfied with the BK21 project. Of these 7 dimensions, the results showed remarkably high satisfaction dimensions for 'stable support for academic development' and 'support for academic activities out of school' while indicating a comparatively low satisfaction for 'job searching and career development'. The result and analysis of this study suggests that the BK21 project needs to emphasize the following: PR for the project, provide opportunities for the training for career development and job information to students, modify the areas of academic support, remodel programs of short- and long-term studies in foreign countries, improve the educational service system for lectures in English, and secure research facilities.