• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.23 no.1
• /
• pp.1-14
• /
• 2020

In this study, we 1) identified the damaged areas along the south limit line (SLL) of the demilitarized zone (DMZ) by the military's 'DMZ barren land campaign', and 2) categorized the identified damaged areas into a few ecological types. Using high-resolution satellite images, we delineated the total damaged areas to be 1,183.2 ha, which accounted for 50.1% of the 100-m northern buffer regions from the SLL. Of the total damaged areas, 16% were severely damaged, i.e., they had been damaged until recently and so remained barren without vegetation cover. In other areas, the levels of damage were either moderate (59.9%) or slight (24.1%), due to natural succession that turned those areas to grassland or forest. Using satellite image-derived land cover maps and climatic and topographic data, we categorized the damaged areas into seven types: lowland grassland (19.8%), western lowland forest (21.4%), low-altitude forest (25.5%), mid-altitude forest (18.4%), high-altitude forest (6.8%), vicinity in east coast (7.9%), and waterbody (0.2%). These types can be used to identify proper measures to restore ecosystems in the DMZ for now and after Korean reunification.

• Journal of Korean Ophthalmic Optics Society
• /
• v.13 no.4
• /
• pp.115-119
• /
• 2008

Purpose: To compare the tentative and final addition, a combination chart of cross-grid and red green with the final addition prescribed in presbyopia were used in this study. Methods: The study subjects were 60 persons with presbyopia who were 41 to 60 years (mean: 51.7 years). Tentative addition were determined using red green chart (RG), cross-grid chart (CG) and the combination chart (red green cross-grid chart, RGCG) of the above two. And the final addition for a 40 cm working distance was determined for each subject by adjusting the tentative addition. Results: It was found that there were statistically significant differences of the final addition and the tentative addition between the each different test method. This result indicated that using the red-green cross-grid chart is the higher repeatability. Conclusions: This study shows that red green cross-grid chart (RGCG) seems to be get proper data for determining addition in presbyopes, and this method would be helpful in the diagnostic evaluation of addition in binocular vision testing.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.35 no.3
• /
• pp.203-210
• /
• 2017

Korea has established an advanced infrastructure for real-time precise positioning such as CORS, virtual reference station service and perform continuous upgrading. However, in order to utilize the national infrastructure, it is necessary to process the acquired spatial information and take many steps to derive the final product. In addition, this process is highly dependent on foreign software. In this study, GNSS field survey system was developed and evaluation of its usability was performed. Real-time GNSS field survey system was developed and the system improves user̓s convenience and usability. The system was able to conduct survey effectively and produce the results. In addition, we compare the existing software with the survey performance to show the availability of the real-time GNSS surveying system. The system developed through the research can perform all the functions from real-time survey to the production of the outputs. It can create economical added value of the foreign software as a whole and simplify the work required for post-survey performance.

• The Journal of the Korea Contents Association
• /
• v.9 no.6
• /
• pp.436-443
• /
• 2009

There have been rapid increases to the demands for modeling diverse and complex spatial phenomena and utilizing spatial data through the computer across all the aspects of society. As a result, the importance and utilization of remote sensing and GIS's(geographic information systems) have also increased. It can produce digital data of enormous accuracy and value by incorporating remote sensing images into GIS analysis technology and make various thematic maps by classifying and analyzing land cover. Once such a map is made for the target area, it can easily do modeling and constant monitoring based on the map, revise the database with ease, and thus efficiently update geo-spatial information. Under the goal of analyzing changes to land cover along the road by combining the remote sensing and GIS technology, this study classified land cover from the images of two periods, detected changes to the six classes over ten years, and obtained statistics about the study area's quantitative area changes in order to provide basic decision making data for urban planning and development. By analyzing land use along the road, one can set up plans for the area along the road and the downtown to supplement each other.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.12 no.10
• /
• pp.1751-1758
• /
• 2008

Digital holography interference pattern generated by a computer calculation (CGH) is one of the most expensive contents and its usage is being expanded. Thus, it is highly necessary to protect the ownership of digital hologram. In this paper a hologram-domain and a frequency-domain electronic watermarking schemes were proposed. The hologram-domain scheme was only to compare the results to the ones from frequency-domain scheme and the frequence-domain scheme used 2-dimensional against the attaks. Especially the MDWT-domain scheme was very high robustness such that th error ratio at the worst case was only 3%. Thus, we expect that it is used as a good watermarking scheme of digital hologram with high performance.

• Korean Journal of Remote Sensing
• /
• v.25 no.2
• /
• pp.113-126
• /
• 2009

With high temporal resolution, four times receiving during a day, MODIS images from Terra and Aqua satellites provide several advantages for monitoring spacious land. Especially, diverse MODIS products related to land, atmosphere, and ocean have been provided with radiance MODIS images. The products such as surface reflectance, NDVI, cloud mask, aerosol etc. are based on theoretical algorithms developed in academic areas. Comparing with other change detection studies mainly using the vegetation index, this study investigated temporal surface reflectance of landcovers for five years from 2004 to 2008. The near infrared (NIR) reflectance in urbanized and burned areas showed considerable difference before and after events. The specific characteristics of surface reflectance temporal profiles are possibly useful for the detection of landcover changes and classification.

• Korean Journal of Remote Sensing
• /
• v.10 no.2
• /
• pp.1-15
• /
• 1994

Since Seasat SAR mission in 1978, SAR has become one of the most important surface imaging tools in satellite remote sensing SAR achieves high resolution by signal processing synthesizing a larger aperture. Therefore, SAR signal processing along with antenna technology has been centered upon SAR technologies. Thus interpreters of SAR imagery as well as those who involved in signal processing require the knowledge of the principal SAR processing algorithm. Although the conventional range-Doppler approach has been widely adopted by many SAR processors, azimuth compression including the range migration has been problematic. The recent development of the wavenumber domain approace is able to provide high precision SAR focusing algorithm. Compared with the wavenumber domain algorithm derived by applying Born (first) approximation, the transfer function of the conventional range-Doppler algorithm accounts only for the first order approximation of the exact transfer function. The results of a simulation and an actual test using airborne C-band SAR configuration demonstrate the dxcellent performance of the wavenumber domain algorithm.

• Korean Journal of Remote Sensing
• /
• v.15 no.2
• /
• pp.107-117
• /
• 1999

A comparison of a neural network approach with the conventional statistical methods, multiple regression and band ratio analyses, for the estimation of water quality parameters in presented in this paper. The Landsat TM image of Lake Daechung acquired on March 18, 1996 and the thirty in-situ sampling data sets measured during the satellite overpass were used for the comparison. We employed a three-layered and feedforward network trained by backpropagation algorithm. A cross validation was applied because of the small number of training pairs available for this study. The neural network showed much more successful performance than the conventional statistical analyses, although the results of the conventional statistical analyses were significant. The superiority of a neural network to statistical methods in estimating water quality parameters is strictly because the neural network modeled non-linear behaviors of data sets much better.

• The Journal of the Convergence on Culture Technology
• /
• v.5 no.4
• /
• pp.209-215
• /
• 2019

The purpose of this study is to suggest the development of interactive services and technologies in the media industry. Through the analysis of domestic two-way broadcasting contents service, this study analyzed platform and services type according to service type of terrestrial broadcasting, SO operator and Telco. Also, by identifying the characteristics of interactive programs(open, interactive, personalized, stereoscopic), this study propose important convergence possibilities of the future providers and development plans through supporting technologies and services for each characteristic. In the case of terrestrial broadcasters, ARS, web sites and mobile apps were mostly provided in both directions, and SO and satellite broadcasting operators were found to provide diversity in interactive service operation using data domain. In the case of IPTV companies, most of them provide interactive services with additional video or information service through adjustment button or app, and cable TV operators had more adjustment data broadcasting than exclusive use data broadcasts. Therefore, domestic interactive broadcasting service type needs convergence type of revenue model needs and needs to be converted into new competitive interactive broadcasting program service environment.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.100-100
• /
• 2019

최근 대기 중 미세먼지의 농도가 높은 일수가 급증하면서, 미세먼지를 저감하고자 하는 연구가 활발히 이루어지고 있다. 미세먼지는 주로 자동차 혹은 공장 등 인간 활동에 의한 오염물질 배출에 의해 발생하는 것으로 알려져 있으며, 태양복사에너지, 토양수분, 강우, 풍속 등의 수문기상학적 인자에 의해 발생, 이동, 소멸의 과정을 거친다. 현재 우리나라에서는 미세먼지 농도를 관측하기 위해 지점 기반의 관측소를 운영하고 있으며, 관측소가 위치하지 않은 지역의 미세먼지 농도는 선형 보간법 등을 활용한 내삽 기법을 통해 제공하고 있다. 그러나 미세먼지 농도는 다양한 수문기상인자들의 영향에 의한 차이가 크게 나타나기 때문에 지점 기반의 자료로는 해당 지역의 미세먼지 농도를 추정하는 데 어려움이 많다. 본 연구에서는 미세먼지의 공간적인 분포를 추정하고자 MODerate resolution Imaging Spectroradiometer (MODIS) 에어로졸 자료와 Global Land Data Assimilation System (GLDAS) 수문기상인자를 활용하여 미세먼지 농도에 영향을 주는 것으로 판단되는 다양한 수문기상인자들과의 상관성을 분석하였다. 미세먼지와 각 인자간의 상관성을 분석하여 높은 상관성을 갖는 수문기상인자들을 도출하고 최적의 선형회귀분석 모델을 구축하기 위해 베이지안 모델 평균(Bayesian Model Averaging, BMA)을 사용하였으며, 지점 데이터와의 비교를 통해 활용성을 검증하였다. 전체적으로 수문기상인자를 사용한 선형회귀분석 결과에서는 미세먼지농도 변화의 경향을 반영하고 있는 것을 확인할 수 있었으나, 계절별, 지역별 등 대기 특성을 고려하지 않아 각 기간의 급격한 농도 변화를 감지하기에 어려움이 있었다. 이러한 연구를 바탕으로 수문기상인자와 미세먼지 농도의 패턴이 더욱 정확히 분석된다면, 미세먼지 농도 모니터링과 정확한 예보 시스템의 구축에 효과적으로 활용 될 것으로 기대된다.