• Title/Summary/Keyword: raster

Search Result 278, Processing Time 0.025 seconds

Development of a Grid Based Two-Dimensional Numerical Method for Flood Inundation Modeling Using Globally-Available DEM Data (범용 DEM 데이터를 이용한 2차원 홍수범람 모형의 개발)

  • Lee, Seung-Soo;Lee, Gi-Ha;Jung, Kwan-Sue
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2010.05a
    • /
    • pp.659-663
    • /
    • 2010
  • In recent, flood inundation damages by hydraulic structure failures have increased drastically and thus a variety of countermeasures were needed to minimize such damages. A real-time flood inundation prediction technique is essential to protect and mitigate flood inundation damages. In the context of real time flood inundation modeling, this study aims to develop a grid based two-dimensional numerical method for flood inundation modeling using globally-available DEM data: SRTM with $90m{\times}90m$ spatial resolution. The newly-developed model guarantees computational efficiency in terms of geometric data processing by direct application of DEM for flood inundation modeling and also have good compatibility with various types of raster data when compared to a commercial model such as FLUMEN. The model, which employed the leap-frog algorithm to solve shallow water and continuity equations, can simulate inundating flow from channel to lowland and also returning flow from lowland to channel by comparing water levels between channel and lowland in real time. We applied the model to simulate the BaekSan levee break in the Nam river during a flood period from August 10 to 13, 2002. The simulation results had good agreements with the field-surveyed data in terms of inundated area and also showed physically-acceptable velocity vector maps with respect to inundating and returning flows.

  • PDF

Revision of 1/1,000 digital Map for Application of 3Dimensional Geospatial Data (1/1,000 수치지도의 수정을 위한 3차원 공간정보의 활용 방안)

  • Lee, Hyunjik
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.32 no.2
    • /
    • pp.77-86
    • /
    • 2014
  • As raster-based high quality and resolution spatial information has appeared, 1/1,000 digital map lost either its recognition or uses because of insufficient new modified and updated information. Therefore, this study analyzed the linkage between three-dimensional spatial information and 1/1,000 digital map, and also suggested a modification plan of 1/1,000 digital map, made by three-dimensional spatial information. In fact, some area of Incheon and Busan were presented with the modification plan of 1/1,000 digital map as three-dimensional trial models. These trials reflected possibilities of modification by qualitative and quantitative analysis of 1/1,000 digital map, using three-dimensional object model.

Design of Graphic Generator for Driving HUD(Head-Up Display) and MFD(Multi-Function Display) (전방시현기 및 다기능시현기 구동을 위한 그래픽 영상생성기 설계 연구)

  • 황상현;이재억;박덕배
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.5 no.2
    • /
    • pp.72-82
    • /
    • 2002
  • This paper presents the design technology of a Graphic Generator which drives the embedded aircraft display equipments such as HUD(Head-Up Display) and MFD (Multi-Function Display) those provide pilot with the most important mission information. The main issue of this design is how we can implement the real-time embedded graphic generator using a general purpose processor as a substitute for the obsolete the production of specific graphic processor in the military market. So we proposed two kinds of method that one is a software solution so called graphic kernel system, interpreting the display file, controlling the graphic system and pre-processing graphic primitives, the other is a hardware solution so called graphic engine, interpreting passed commands through the graphic kernel system, post-processing the looping calculation taking much of time as implemented by software. We have tested and verified the functionalities and the required performance of Graphic Generator.

Character Grouping using 3-D Neighborhood Graph on Raster Map (래스터 지도상에서 3차원 인접 그래프를 이용한 문자 그룹핑)

  • Gang, Yong-Bin;Ok, Se-Yeong;Jo, Hwan-Gyu
    • Journal of KIISE:Software and Applications
    • /
    • v.26 no.2
    • /
    • pp.273-283
    • /
    • 1999
  • 래스터 지도에서 직선 또는 곡선과 중첩되어 있는 경우의 문자는 추출하기가 쉽지 않다. 따라서 본 논문에서는 고립되어 있는 문자뿐만 아니라 문자이외의 요소와 중첩되어 있는 문자도 효과적으로 추출할수 있는 분할 정복(divide and conquer) 개념에 기반한 문자 추출방법을 제시한다. 이를 위해 먼저 이미지의 연결 요소로부터 볼록다각형(convex hull)을 생성한다. 그리고 이 다각형이 충분한게 문자영역만을 포함할때가지 볼록 다각형을 이등분하면서 가장 긴 선분(투사 선분)을 기준으로 두 영역으로 분할한다. 다음으로 문자를 추출하기 위해서 이 선분을 기준으로 연결 요소상의 픽셀의 밀집도를 계산하는 알고리즘(프로파일링)을 적용한다. 또한 지도상에서 추출된 개별적인 문자들을 의미있는 단어들로 묶기(grouping)한 새로운 알고리즘을 소개한다. 특히 지도상에 나타나는 문자의 종류는 매우 다양하고 또한 이 문자들이 놓여있는 방향 역시 일정하지 않기 때문에 이러한 단어를 찾는 kd법은 쉽지 않다. 이를 위해 본 논문에서는 3차원 인접 그래프(3-D neighborhood graph)G를 소개한다. 이 그래프 G에서 각 노드는 하나의 분리된 문자를 나타내며 자신의 크기와 위치에 따라서 3차원 공간상에서 위치하게된다. 따라서, 크기가 큰 (작은)문자들은 보다 큰 (작은) z값을 가지고 되며 이 그래프 G에서 서로 인접한 노드들을 연결함으로써 지도상에 존재하는 서로 다른 종류의 문자 스트링을 추출할수 있다. 실험결과는 서로 다른 지도 이미지에 대해서 약 95% 이상의 단어 추출율을 보여준다.

A Study on Optimal Proofing Conditions for Evaluation of the Domestic Offset Prints (국내 오프셋 인쇄물 평가를 위한 최적의 Proofing 조건에 관한 연구)

  • Lee, Won-Kyu;Cho, Ga-Ram;Ko, Chul-Whoi
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.29 no.1
    • /
    • pp.1-21
    • /
    • 2011
  • Because of high demand of color quality of the prints, proof prints are more important for end-user to predict and correct the final prints directly as an intermediate. Thus, proof prints can be used as a reference to take minimum ${\Delta}E^*ab$between the originals and finals in the field. The advantage of proof prints is to predict and correct color easily through the RIP(Raster Image Processor) without printing plates and plate making steps. While, it is thought that the proof systems are almost equivalent to the press in the past, present proof systems are more simple to take proof prints more easily due to the automation and digitalization. This paper addresses a method to perform an accurate profiling according to proof paper types and find optimal proof papers which meet proofing requirement. Although proof papers are matched with ISO 12647-7, we were trying to reduce ${\Delta}E^*ab$, In addition to the above, through the Gamut Mapping and Iteration, We were trying to find optimal proofing conditions.

The Development of a Prototype of Car Navigation Information System Using GPS (GPS를 이용한 자동차용 주행안내 시스템 프로토타입 개발)

  • Lee, Jong-Hun;Kang, Tae-Ho;Kim, Jin-Seo
    • 한국지형공간정보학회:학술대회논문집
    • /
    • 1995.10b
    • /
    • pp.33-40
    • /
    • 1995
  • In this paper, we developed the prototype of Car Navigation Information System which uses GPS to determine the current location. Car Navigation Information System is the one which can determine and display the current location and direction through the display monitor, search the destination point, calculate and check out the shortest path to the destination. The system we developed can determine the current location using GPS data, search the destination point in various ways, calculate the shortest path, serve the driver all the above mentioned data, and display the raster and vector data. To testify the system, we made the vectorized data about Taejeon area. Then we testified the system performance by installing the system to the notebook computer.

  • PDF

A Statistic Correlation Analysis Algorithm Between Land Surface Temperature and Vegetation Index

  • Kim, Hyung-Moo;Kim, Beob-Kyun;You, Kang-Soo
    • Journal of Information Processing Systems
    • /
    • v.1 no.1 s.1
    • /
    • pp.102-106
    • /
    • 2005
  • As long as the effective contributions of satellite images in the continuous monitoring of the wide area and long range of time period, Landsat TM and Landsat ETM+ satellite images are surveyed. After quantization and classification of the deviations between TM and ETM+ images based on approved thresholds such as gains and biases or offsets, a correlation analysis method for the compared calibration is suggested in this paper. Four time points of raster data for 15 years of the highest group of land surface temperature and the lowest group of vegetation of the Kunsan city Chollabuk_do Korea located beneath the Yellow sea coast, are observed and analyzed their correlations for the change detection of urban land cover. This experiment based on proposed algorithm detected strong and proportional correlation relationship between the highest group of land surface temperature and the lowest group of vegetation index which exceeded R=(+)0.9478, so the proposed Correlation Analysis Model between the highest group of land surface temperature and the lowest group of vegetation index will be able to give proof an effective suitability to the land cover change detection and monitoring.

Store-Release based Distributed Hydrologic Model with GIS (GIS를 이용한 기저-유출 바탕의 수문모델)

  • Kang, Kwang-Min;Yoon, Se-Eui
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2012.05a
    • /
    • pp.35-35
    • /
    • 2012
  • Most grid-based distributed hydrologic models are complex in terms of data requirements, parameter estimation and computational demand. To address these issues, a simple grid-based hydrologic model is developed in a geographic information system (GIS) environment using storage-release concept. The model is named GIS Storage Release Model (GIS-StoRM). The storage-release concept uses the travel time within each cell to compute howmuch water is stored or released to the watershed outlet at each time step. The travel time within each cell is computed by combining the kinematic wave equation with Manning's equation. The input to GIS-StoRM includes geospatial datasets such as radar rainfall data (NEXRAD), land use and digital elevation model (DEM). The structural framework for GIS-StoRM is developed by exploiting geographic features in GIS as hydrologic modeling objects, which store and process geospatial and temporal information for hydrologic modeling. Hydrologic modeling objects developed in this study handle time series, raster and vector data within GIS to: (i) exchange input-output between modeling objects, (ii) extract parameters from GIS data; and (iii) simulate hydrologic processes. Conceptual and structural framework of GIS StoRM including its application to Pleasant Creek watershed in Indiana will be presented.

  • PDF

Landslide susceptibility mapping using Logistic Regression and Fuzzy Set model at the Boeun Area, Korea (로지스틱 회귀분석과 퍼지 기법을 이용한 산사태 취약성 지도작성: 보은군을 대상으로)

  • Al-Mamun, Al-Mamun;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
    • /
    • v.23 no.2
    • /
    • pp.109-125
    • /
    • 2016
  • This study aims to identify the landslide susceptible zones of Boeun area and provide reliable landslide susceptibility maps by applying different modeling methods. Aerial photographs and field survey on the Boeun area identified landslide inventory map that consists of 388 landslide locations. A total ofseven landslide causative factors (elevation, slope angle, slope aspect, geology, soil, forest and land-use) were extracted from the database and then converted into raster. Landslide causative factors were provided to investigate about the spatial relationship between each factor and landslide occurrence by using fuzzy set and logistic regression model. Fuzzy membership value and logistic regression coefficient were employed to determine each factor's rating for landslide susceptibility mapping. Then, the landslide susceptibility maps were compared and validated by cross validation technique. In the cross validation process, 50% of observed landslides were selected randomly by Excel and two success rate curves (SRC) were generated for each landslide susceptibility map. The result demonstrates the 84.34% and 83.29% accuracy ratio for logistic regression model and fuzzy set model respectively. It means that both models were very reliable and reasonable methods for landslide susceptibility analysis.

Developing a Method to Define Mountain Search Priority Areas Based on Behavioral Characteristics of Missing Persons

  • Yoo, Ho Jin;Lee, Jiyeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.37 no.5
    • /
    • pp.293-302
    • /
    • 2019
  • In mountain accident events, it is important for the search team commander to determine the search area in order to secure the Golden Time. Within this period, assistance and treatment to the concerned individual will most likely prevent further injuries and harm. This paper proposes a method to determine the search priority area based on missing persons behavior and missing persons incidents statistics. GIS (Geographic Information System) and MCDM (Multi Criteria Decision Making) are integrated by applying WLC (Weighted Linear Combination) techniques. Missing persons were classified into five types, and their behavioral characteristics were analyzed to extract seven geographic analysis factors. Next, index values were set up for each missing person and element according to the behavioral characteristics, and the raster data generated by multiplying the weight of each element are superimposed to define models to select search priority areas, where each weight is calculated from the AHP (Analytical Hierarchy Process) through a pairwise comparison method obtained from search operation experts. Finally, the model generated in this study was applied to a missing person case through a virtual missing scenario, the priority area was selected, and the behavioral characteristics and topographical characteristics of the missing persons were compared with the selected area. The resulting analysis results were verified by mountain rescue experts as 'appropriate' in terms of the behavior analysis, analysis factor extraction, experimental process, and results for the missing persons.