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INVESTIGATION OF BAIKDU-SAN VOLCANO WITH SPACE-BORNE SAR SYSTEM

  • Kim, Duk-Jin;Feng, Lanying;Moon, Wooil-M.
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.148-153
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    • 1999
  • Baikdu-san was a very active volcano during the Cenozoic era and is believed to be formed in late Cenozoic era. Recently it was also reported that there was a major eruption in or around 1002 A.D. and there are evidences which indicate that it is still an active volcano and a potential volcanic hazard. Remote sensing techniques have been widely used to monitor various natural hazards, including volcanic hazards. However, during an active volcanic eruption, volcanic ash can basically cover the sky and often blocks the solar radiation preventing any use of optical sensors. Synthetic aperture radar(SAR) is an ideal tool to monitor the volcanic activities and lava flows, because the wavelength of the microwave signal is considerably longer that the average volcanic ash particle size. In this study we have utilized several sets of SAR data to evaluate the utility of the space-borne SAR system. The data sets include JERS-1(L-band) SAR, and RADARSAT(C-band) data which included both standard mode and the ScanSAR mode data sets. We also utilized several sets of auxiliary data such as local geological maps and JERS-1 OPS data. The routine preprocessing and image processing steps were applied to these data sets before any attempts of classifying and mapping surface geological features. Although we computed sigma nought ($\sigma$$^{0}$) values far the standard mode RADARSAT data, the utility of sigma nought image was minimal in this study. Application of various types of classification algorithms to identify and map several stages of volcanic flows was not very successful. Although this research is still in progress, the following preliminary conclusions could be made: (1) sigma nought (RADARSAT standard mode data) and DN (JERS-1 SAR and RADARSAT ScanSAR data) have limited usefulness for distinguishing early basalt lava flows from late trachyte flows or later trachyte flows from the old basement granitic rocks around Baikdu-san volcano, (2) surface geological structure features such as several faults and volcanic lava flow channels can easily be identified and mapped, and (3) routine application of unsupervised classification methods cannot be used for mapping any types of surface lava flow patterns.

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Identifying the Comic Festival's values on the Urban Revitalization: in the case of BICOF (만화축제의 도시 활성화 가치 인식에 관한 연구 : BICOF 사례를 중심으로)

  • Yim, Hak-Soon
    • Cartoon and Animation Studies
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    • s.24
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    • pp.1-24
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    • 2011
  • This article is concerned with the values of the BICOF in terms of the urban revitalization. The values of the BICOF cover the economic value, social value, cultural value and city image value. The 13 indicators for measuring the values of the BICOF are developed. The article examined how the related stakeholders identified the BICOF's values on the Bucheon City by using AHP method. In addition, the objectives and programmes of the BICOF are analyzed in the perspective of the urban revitalization. As a result, the recognition of the BICOF's values varied according to the stakeholders. In addition, the result of AHP analysis indicates that the cultural values and image values should have priorities in comparison with the social values and economic values. This recognitions is different from the recent formal statements that BICOF's economic values should be emphasized as a priority. The article concludes that the identity of the BICOF should be established in the base of building the value consensus among the related stakeholders.

A Study on DEM Generation from Kompsat-3 Stereo Images (아리랑 3호 스테레오 위성영상의 DEM 제작 성능 분석)

  • Oh, Jae Hong;Seo, Doo Chun;Lee, Chang No
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.1
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    • pp.19-27
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    • 2014
  • Kompsat-3 is an optical high-resolution earth observation satellite launched in May 2012. In addition to its 0.7m spatial resolution, Kompsat-3 is capable of in-track stereo acquisition enabling quality Digital Elevation Model(DEM) generation. Typical DEM generation procedure requires accurate control points well-distributed over the entire image region. But we often face difficult situations especially when the area of interests is oversea or inaccessible area. One solution to this is to use existing geospatial data even though they only cover a part of the image. This paper aimed to assess accuracy of DEM from Kompsat-3 with different scenarios including no control point, Rational Polynomial Coefficients(RPC) relative adjustment, and RPC adjustment with control points. Experiments were carried out for Kompsat-3 stereo data in USA. We used Digital Orthophoto Quadrangle(DOQ) and Shuttle Radar Topography Mission(SRTM) as control points sources. The generated DEMs are compared to a LiDAR DEM for accuracy assessment. The test results showed that the relative RPC adjustment significantly improved DEM accuracy without any control point. And comparable DEM could be derived from single control point from DOQ and SRTM, showing 7 meters of mean elevation error.

Changes in the Socialistic Planned Economy System and Propaganda of Animation - Focusing on China - (사회와 시장의 체제전환이 애니메이션 프로파간다 표현방식에 미치는 영향- 중국사례를 중심으로-)

  • Kim, Jin-Young
    • Cartoon and Animation Studies
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    • s.40
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    • pp.83-107
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    • 2015
  • Propaganda is often accepted as the political promotion that had used mostly by the socialist states during the First and the Second World Wars and the Cold War and by Hitler who governed Germany. Therefore, cases of the study on the image and picture propaganda were mostly posters or films of the socialism period when the propaganda was active. However, today it is not easy any more to find propaganda of the clear promotion characteristic as the past. In these modern times, it has changed into metaphorical propaganda based on 'persuasion', rather than publicity like past. Therefore, it has been changing from the direct promotion of the past into the indirect persuasion; and from the raw, direct and powerful publicity and claim into the soft and metaphorical persuasion and appeal. Thus, investigating again the contemporary propaganda will be an important element in analyzing contemporary images. The animation, selected as a target of the analysis of propaganda, exists in various ways in various images of the modern times, which is not too much to say that today's society is the television society. Besides, the animation is the image that can cover all ages as men and women of all ages can watch, so it is proper for analysis of the contemporary propaganda of metaphorical, indirect and various forms.

A New Algorithm for the Interpretation of Joint Orientation Using Multistage Convergent Photographing Technique (수렴다중촬영기법을 이용한 새로운 절리방향 해석방법)

  • 김재동;김종훈
    • Tunnel and Underground Space
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    • v.13 no.6
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    • pp.486-494
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    • 2003
  • When the orientations of joints are measured on a rock exposure, there are frequent cases that are difficult to approach by the surveyor to the target joints or to set up scanlines on the slope. In this study, to complement such limit and weak points, a new algorithm was developed to interpret joint orientation from analyzing the images of rock slope. As a method of arranging the multiple images of a rock slope, the multistage convergent photographing system was introduced to overcome the limitation of photographing direction which existing method such as parallel stereophotogrammetric system has and to cover the range of image measurement, which is the overlapping area between the image pair, to a maximum extent. To determine camera parameters in the perspective projection equation that are the main elements of the analysis method, a new method was developed introducing three ground control points and single ground guide point. This method could be considered to be very simple compared with other existing methods using a number of ground control points and complicated analysis process. So the global coordinates of a specific point on a rock slope could be analyzed with this new method. The orientation of a joint could be calculated using the normal vector of the joint surface which can be derived from the global coordinates of several points on the joint surface analyzed from the images.

The Memory of War : from War Damages to Natural Disaster -The Evacuation Image Portrayed in Korean War Painting (전쟁의 기억: 전재에서 자연재해로 - 6.25전쟁기 회화 작품에 나타난 피난 이미지)

  • Cho, Eun-jung
    • The Journal of Art Theory & Practice
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    • no.13
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    • pp.7-33
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    • 2012
  • The memory of the Korean War is about the time period when people lived toughly during evacuation, due to being exposed to the natural climate such as intense cold or heat without any protection, leaving their comfortable home and living in temporary built shelters which were barely enough to avoid the wind. 'Death is concealed and only the figures of evacuation for survival were expressed, just as how the government ordered. Since the experience of the battlefield is personal and fragmentary, that is broken into pieces, it does not have compatibility. As war is a distorted experience that cannot be placed in a big picture, it is not possible to take a view of the war's big picture. Having this individualized experience as a common collective memory is an issue and it is the will that people tries to pursue. The reason why the evacuees from north to south, and as well as from the south to further south were all able to be adopted as the theme of artworks due to the military action that emptied the occupied territories of the North Korean Army under the forced removal command. In such situations, the natural state of the 'snow' was like a symbol of the 1.4 Recession. The group of people who were thrown into the intense cold displaced the war damage of loosing their base livelihood, and symbolized the obedient citizens who faithfully follow their government's command. The figure of advocating anti-communism is projected as a figure of a refugee during cold winter-time and it contains ones past which he or she obeyed its own country's commands. Evacuation, especially the evacuation during the winter is a visual device that can confirm these kinds of country's command. The consequences were same for the artists as well. Therefore, the situation being communal could be found due to the individual experiences during war are ideological. The image of the refuge shown in the picture played the role of strengthening the consciousness of defecting to South Korea into the meaning of the 'Finding Freedom.' I would like to express that the reason of them leave their home during the harsh winter is in order to avoid the oppression of the Communist Party. The evacuation that people went through was not to 'Finding Freedom', but 'To Survive'. Later, this evacuation has been imprinted as a behavior of choosing free Republic of Korea, which was an ideological issue. Anti-communism was the rule of survival in South Korea society, and people have the tendency to remember what they want to remember. As it is not the people who possesses an incident, but the memory that possesses ones, people cover their memory with disguised plots in order to forget the violence and to live a different prologue. They share the incident of violence as a hurtful memory. The tragedy of the Korean War was the result of Ideology and being in between the powerful nations' rights, but the violence during the war has been depicted as a natural disaster, which was the evacuation in heavy snow.

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A Study on the Environmental Changes of Coastal Area in Oncheon Gun of Pyeongnam Province by Neural Network Classification Using Satellite Images, West Coast of North Korea (위성영상의 신경망 분류에 의한 평안남도 온천군 해안지역의 환경 변화 연구)

  • Lee, Min-Boo;Kim, Nam-Shin;Lee, Gwang-Ryul;Han, Uk
    • Journal of the Korean association of regional geographers
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    • v.11 no.2
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    • pp.278-290
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    • 2005
  • This study deals with the geomorphic, environmental and land use changes by comparative analysis using Landsat TM images of 1988 year and ETM ones of 2002 year, partly together with the new Quick Bird images having 60cm resolution for more detail analysis, focusing on the Oncheon gun(county) in Pyeongnam Province, west coast zone of North Korea. The main analysis methodology is neural network classification, which is more advanced techniques for the classification of land cover and land use, with higher accuracy rate and lower errors. The TM images of 1988 year show, mainly, the on-construction tide embank for the reclamation at Gwangryangman bay and salt farm on the reclaimed tidal flat. But, ETM images of 2002 year present stabilized reclaimed land, salt farm and rice field, recently transformed from salt farm. Especially, new tidal land has been naturally developed on the coastal shallow out of tide embank and salt farm. The results of the study may help to database coastal environmental changes and to support for reasonable and productive land use of North Korea, and to manage and plan unified national land in the near future.

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Technique for the Measurement of Crack Widths at Notched / Unnotched Regions and Local Strains (콘크리트의 노치 및 비노치 구역에서의 균열폭 및 국부 변형률 정밀 측정기법)

  • Choi, Sok-Hwan;Lim, Bub-Mook;Oh, Chang-Kook;Joh, Chang-Bin
    • Journal of the Korea Concrete Institute
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    • v.24 no.2
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    • pp.205-214
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    • 2012
  • Crack widths play an important role in the serviceability limit state. When crack widths are controlled sufficiently, the reinforcement corrosion can be reduced using only existing concrete cover thickness due to low permeability in the region of finely distributed hair-cracks. Thus, the knowledge about the tensile crack opening is essential in designing more durable concrete structures. Therefore, numerous researches related to the topic have been performed. Nevertheless accurate measurement of a crack width is not a simple task due to several reasons such as unknown potential crack formation location and crack opening damaging strain gages. In order to overcome these difficulties and measure precise crack widths, a displacement measurement system was developed using digital image correlation. Accuracy calibration tests gave an average measurement error of 0.069 pixels and a standard deviation of 0.050 pixels. Direct tensile test was performed using ultra high performance concrete specimens. Crack widths at both notched and unnotched locations were measured and compared with clip-in gages at various loading steps to obtain crack opening profile. Tensile deformation characteristics of concrete were well visualized using displacement vectors and full-field displacement contour maps. The proposed technique made it possible to measure crack widths at arbitrary locations, which is difficult with conventional gages such as clip-in gages or displacement transducers.

Generation of Land Surface Temperature Orthophoto and Temperature Accuracy Analysis by Land Covers Based on Thermal Infrared Sensor Mounted on Unmanned Aerial Vehicle (무인항공기에 탑재된 열적외선 센서 기반의 지표면 온도 정사영상 제작 및 피복별 온도 정확도 분석)

  • Park, Jin Hwan;Lee, Ki Rim;Lee, Won Hee;Han, You Kyung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.4
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    • pp.263-270
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    • 2018
  • Land surface temperature is known to be an important factor in understanding the interactions of the ground-atmosphere. However, because of the large spatio-temporal variability, regular observation is rarely made. The existing land surface temperature is observed using satellite images, but due to the nature of satellite, it has the limit of long revisit period and low accuracy. In this study, in order to confirm the possibility of replacing land surface temperature observation using satellite imagery, images acquired by TIR (Thermal Infrared) sensor mounted on UAV (Unmanned Aerial Vehicle) are used. The acquired images were transformed from JPEG (Joint Photographic Experts Group) to TIFF (Tagged Image File Format) format and orthophoto was then generated. The DN (Digital Number) value of orthophoto was used to calculate the actual land surface temperature. In order to evaluate the accuracy of the calculated land surface temperature, the land surface temperature was compared with the land surface temperature directly observed with an infrared thermometer at the same time. When comparing the observed land surface temperatures in two ways, the accuracy of all the land covers was below the measure accuracy of the TIR sensor. Therefore, the possibility of replacing the satellite image, which is a conventional land surface temperature observation method, is confirmed by using the TIR sensor mounted on UAV.

A Study on the Distribution and Changes of Sand Dune at the Lower Reach of Duman River, North Korea (두만강 하류 사구의 분포와 변화에 관한 연구)

  • Lee Min-Boo;Kim Nam-Shin;Lee Gwang-Ryul;Han Uk;Jin, Shizhu
    • Journal of the Korean Geographical Society
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    • v.41 no.3 s.114
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    • pp.331-345
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    • 2006
  • This study deals with geomorphological process of the sand dune landform including the distribution and surface environments, characteristics of sediments, origins and moving processes in lower reach and mouth delta of Duman River, Northeast Korea and China. The methodology of the study includes image analysis of Landsat TM(1992.10) and ETM(2000.9) and Spot(2005.4) for analysis of land cover, 2 times field survey for recognition of landform and acquisition of sediments raw data materials, and grain analysis and exoscopy about raw data materials. The geomorphic elements from satellite image analysis are composed of the delta, sand spit, active and stable dune, sand bar and riparian vegetated zone. Results of the grain analysis indicate the sediments originated from marine coastal zone than riverine one. This means that present sand dune not so much reflect present climatic and geomorphic environments. Result of the exoscopy analysis show that ratio of quartz, which is comparatively resistant to environment, is highest as $65{\sim}83%$ out of sediments. But the surface of the $30{\sim}40%$ of mineral grains was coated by yellow-colored stained materials, due to chemical weathering. Some grains show rough skin, looking as acicular, network structure and etching pits, affected by physical and chemical weathering.