• Title/Summary/Keyword: geospatial technology

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Dynamic Behavior Character of Vessel Using DGPS and Motion Sensor (DGPS와 Motion Sensor를 이용한 선박 동적 거동특성)

  • Choi, Chul-Eung;Kim, Youn-Soo
    • Journal of Korean Society for Geospatial Information Science
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    • v.12 no.4 s.31
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    • pp.35-43
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    • 2004
  • Multibeam Echosounder system is the latest technology of a hydrographic survey utilized in producing an electronic nautical chart, obtaining a DEM with high precision, making a moving image by Swath surveying a wide area. As a fundamental study for improving the precision of MBES, we compared and analyzed measurements of DGPS and Motion sensor, and studied for the dynamic characteristics of vessel's movements. DGPS was installed in front and in the rear and on both side or the vessel and surveyed. The receiving precision of surveyed GPS results was obtained to the satisfactory extent that was possible to valuate the accuracy of Motion sensor as 0.0016$^{\circ}$ of the roll value and 0.0009$^{\circ}$ of the pitch value. The relationship between the values of heading, pitch, and roll in Motion sensor and the data of DGPS was proportional correlation. In addition, it is considered that deviations by elements like rapid turning and vibration of the vessel will be occurred, although the correlation of each deviation according to each amount or change is proportional. It is suitable that GPS installs in the central line of the vessel that is less affected than other places by waving because the amount of change in the tide level obtained from GPS survey and the value of heave are similar with the values taken by Motion sensor, and the velocity of GPS is different from installed places. The accuracy of the final result from MBES could be affected by the values of gyro and Motion sensor inputted to MBES processor because there were intervals of 15s and 13s of receiving time in gyro and Motion sensor respectively compared with the real-time measurements of DGPS.

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Crime Mapping using GIS and Crime Prevention Through Environmental Design (GIS와 범죄예방환경설계 기반의 범죄취약지도 작성)

  • Park, Dong Hyun;Kang, In Joon;Choi, Hyun;Kim, Sang Seok
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.1
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    • pp.31-37
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    • 2015
  • The recent long-term economic recession and business depression are constantly increasing the occurence of the five major crimes(murder, robbery, rape, theft, violence). When looking into the previously-analyzed characteristics of how the five major crimes are committed, this study understands that the crimes mostly occur in these crime-ridden areas of poor public order and security and, in order to decrease the crime rates of the crime-prone areas, any relevant fields have been emphasizing the application of CPTED. In the light of that, referring to CPTED surveillance factors and the current crime rate data, the study presented ways to help the relevant fields draw up a crime-prone area grade map. In particular, the security center among monitoring elements was visualized by dividing it into point patrol and directed patrol and by dividing it into 3 steps monitoring levels with CCTV and street lights. In addition, we checked the crime rate by zoning through crime statistics occurred in the research areas and established a crime status map. We estimated the weight through AHP analysis on the built monitoring elements and the zoning of the occurred areas, as a result of making a map vulnerable to crime by monitoring steps by overlapping each element, we were able to confirm that 60% of theft, 52% of violence and 33% of rape in the 1st grade area were reduced compared to the 1st step in monitoring Step 3.

Analysis of Urban Heat Island Effect Using Time Series of Landsat Images and Annual Temperature Cycle Model (시계열 Landsat TM 영상과 연간 지표온도순환 모델을 이용한 열섬효과 분석)

  • Hong, Seung Hwan;Cho, Han Jin;Kim, Mi Kyeong;Sohn, Hong Gyoo
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.1
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    • pp.113-121
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    • 2015
  • Remote sensing technology using a multi-spectral satellite imagery can be utilized for the analysis of urban heat island effect in large area. However, weather condition of Korea mostly has a lot of clouds and it makes periodical observation using time-series of satellite images difficult. For this reason, we proposed the analysis of urban heat island effect using time-series of Landsat TM images and ATC model. To analyze vegetation condition and urbanization, NDVI and NDBI were calculated from Landsat images. In addition, land surface temperature was calculated from thermal infrared images to estimate the parameters of ATC model. Furthermore, the parameters of ATC model were compared based on the land cover map created by Korean Ministry of Environment to analyze urban heat island effect relating to the pattern of land use and land cover. As a result of a correlation analysis between calculated spectral indices and parameters of ATC model, MAST had high correlation with NDVI and NDBI (-0.76 and 0.69, respectively) and YAST also had correlation with NDVI and NDBI (-0.53 and 0.42, respectively). By comparing the parameters of ATC model based on land cover map, urban area had higher MAST and YAST than agricultural land and grassland. In particular, residential areas, industrial areas, commercial areas and transportation facilities showed higher MAST than cultural facilities and public facilities. Moreover, residential areas, industrial areas and commercial areas had higher YAST than the other urban areas.

A Study of 3D Modeling of Compressed Urban LiDAR Data Using VRML (VRML을 이용한 도심지역 LiDAR 압축자료의 3차원 표현)

  • Jang, Young-Woon;Choi, Yun-Woong;Cho, Gi-Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.2
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    • pp.3-8
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    • 2011
  • Recently, the demand for enterprise for service map providing and portal site services of a 3D virtual city model for public users has been expanding. Also, accuracy of the data, transfer rate and the update for the update for the lapse of time emerge are considered as more impertant factors, by providing 3D information with the web or mobile devices. With the latest technology, we have seen various 3D data through the web. With the VRML progressing actively, because it can provide a virtual display of the world and all aspects of interaction with web. It offers installation of simple plug-in without extra cost on the web. LiDAR system can obtain spatial data easily and accurately, as supprted by numerous researches and applications. However, in general, LiDAR data is obtained in the form of an irregular point cloud. So, in case of using data without converting, high processor is needed for presenting 2D forms from point data composed of 3D data and the data increase. This study expresses urban LiDAR data in 3D, 2D raster data that was applied by compressing algorithm that was used for solving the problems of large storage space and processing. For expressing 3D, algorithm that converts compressed LiDAR data into code Suited to VRML was made. Finally, urban area was expressed in 3D with expressing ground and feature separately.

The Systematization of Waste Landfill Site Selection Process utilizing GIS (GIS를 활용한 쓰레기 매립지 입지 선정과정의 체계화 연구)

  • Han, Ji Youn
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.3
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    • pp.21-30
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    • 2014
  • Waste landfill site which is the facility usually rejected by communities is generally perceived as one of the serious social problems. It causes serious conflicts between interested parties from the beginning of the site selection process and produces various difficulties throughout the installation process. This study suggests the systematization and standardization of the landfill site selection process to reduce those problems and to objectify the process. The study process and results are as follows. First, the landfill site selection process was divided into 4 general phases rather than more specific fragmented phases and the requirements for each phase were suggested accordingly. This can make the process clearly organized and bring the standardization of the process by increasing the applicability of each phase for various situations. Second, the utilization of GIS(Geographic Information System) and PAPRIKA (Potentially All Pairwise RanKings of all possible Alternatives) among the various MCDA(Multi-Criteria Decision Analysis) methods was suggested as the objective and scientific method. Third, the hypothetical case study on the landfill site selection process of Cheongju city was conducted based on the information above and the results show the practicability and objectivity of the newly defined landfill site selection process in this study.

Study on the Integration of MMS and Airborn Survey Data for the Implementation of Precise Road Spatial Database (정밀도로공간정보 구축을 위한 지상 MMS 측정자료와 항공측량자료의 결합방법 연구)

  • Hwang, Jin Sang;Kim, Jae Koo;Yun, Hong Sik;Jung, Woon Chul
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.2
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    • pp.97-104
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    • 2015
  • Due to the introduction of various IT devices, including the recently smartphones and the widespread use of the car navigation system to the location-based information service space has been increased. Spatial information users have been requiring higher levels of quality. In this paper, we study how to build accurate three-dimensional space information by integrating MMS(Moblie Mapping System) survey and airborne survey data. Thus, to analyze the tendency of deviation between the MMS survey and airborne survey data observed in the experimental region, the deviation tendency of the data, it was confirmed that was not consistent. Deviation correction model to select how to change the georeferencing information directly contained in the GPS/INS processing results for the determination, classifies the standard is a method for acquiring the correction reference point coordinates using the calibration model, and analyzed their advantages and disadvantages. With the information of the reference point obtained by airborne photograph of a project, using the method of correcting the MMS survey data. Not only clear the deviation existing between the MMS survey data, it was possible to confirm that the deviation exists between the airborne survey data and MMS survey data was also almost erased.

A Study on Development Directions of System for the Level Diagnosis of U-City for U-City Activation (U-City 고도화를 위한 수준진단체계 개발방향에 관한 연구)

  • Jang, Hwan Young;Lim, Yong Min;Lee, Jae Yong
    • Journal of Korean Society for Geospatial Information Science
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    • v.23 no.2
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    • pp.49-58
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    • 2015
  • Up to the present point in time, the level diagnosis system for urban reactivation have utilized various methods for establishment and management in Korea and overseas, such as city competitiveness evaluation, urban decay diagnosis, etc. However, contrary to performing diagnosis and evaluations on general cities in existing studies, it is found to be a very complex and difficult task to perform a diagnosis on the level of U-City due to its unique characteristics. It is difficult to determine the level of a U-City using a level diagnosis system used for general cities because a U-City is comprised of a connection/fusion of various structural elements. Therefore, in order to perform a systematic diagnosis of a U-City, it is necessary to primarily observe the structural characteristics of a U-city to derive a diagnosis system based on the relativity between each structural element. This study aims to propose a directivity of a U-City level diagnosis system in comprehensive consideration of various elements, such as the objective of a U-City, as well as the structural elements that compose a U-City based on the definitions prescribed in U-City legislations, including ubiquitous city planning, ubiquitous city infrastructure, ubiquitous city technology, services, etc. The results of this study are expected to provide a resolution for the regional quality differences of U-Cities, and also establish a stepping-stone for the realization of U-Cities with high degree of completion.

Review and Comparative Analysis of Forest Biomass Estimation Using Remotely Sensed Data: from Five Different Perspectives (원격탐사자료를 이용한 국외 산림 바이오매스 추정 현황 및 비교분석: 다섯 가지 관점에서의 고찰)

  • Cho, Kyung-Hun;Heo, Joon;Jung, Jae-Hoon;Kim, Chang-Jae;Kim, Kyung-Min
    • Journal of Korean Society for Geospatial Information Science
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    • v.19 no.1
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    • pp.87-96
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    • 2011
  • Carbon emissions and storages that are strongly related to global warming has have emerged as one of the important issues while many governments and researchers have been interested in climate change and pollution. In this regards, forest biomass estimation is quite importance since forest biomass works as an important medium of the global carbon cycle between the atmosphere and soil. Forest biomass estimation through field survey needs lots of time and labors, and has accessibility issues. Hence, many researchers have focused on the forest biomass approaches based on remotely sensed data. This research comprehensively reviewed forty one international studies using remote sensing data according to five different categories (i.e., location of study area, size of study area, biome, used remote sensing data, and estimation technology). It would be expected that the results of this study can be used for suggesting domestic research directions; domestic research in this field is at the beginning stage in terms of level of technologies and useful materials. As results, 39% out of the reviewed studies used the areas located in North America. 59% out of the researches dealt with small size of the study areas (less than 3,600km2). In case of biome, around 30% of the studies focused on the boreal/taiga areas. Moreover, 35% and 16% of the studies were carried out using Landsat series and Lidar data, respectively. Finally, regression analysis method was most frequently used for forest biomass estimation by 71% out of 41 studies.

A Discussion of the Two Alternative Methods for Quantifying Changes : by Pixel Values Versus by Thematic Categories (변화의 정량화 방법에 관한 고찰 : 픽셀값 대 분류항목별)

  • Choung, Song-Hak
    • Journal of Korean Society for Geospatial Information Science
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    • v.1 no.1 s.1
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    • pp.193-201
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    • 1993
  • In a number of areas, there are important benefits to be gained when we bring both the detection and monitoring abilities of remote sensing as well as the philosophical approach and analytic capabilities of a geographic information system to bear on a problem. A key area in the joint applications of remote sensing technology and GIS is to identify change. Whether this change is of interest for its own sake, or because the change causes us to act (for example, to update a map), remote sensing provides an excellent suite of tools for detecting change. At the same time, a GIS is perhaps the best analytic toot for quantifying the process of change. There are two alternative methods for quantifying changes. The conceptually simple approach is to un the pixel values in each of the images. This method is practical but may be too simple to identify the variety of changes in a complex scene. The common alternative is called symbolic change detection. The analyst first decides on a set of thematic categories that are important to distinguish for the application. This approach is useful only if accurate landuse/cover classifications can be obtained. Persons conducting digital change detection must be intimately familiar with the environment under study, the quality of the data set and the characteristics of change detection algorithms. Also, much work remains to identify optimum change detection algorithms for specific geographic areas and problems.

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A Study for Implementing of National GIS Training Program : Analysis of the Results for the First Year (국가 GIS 전문인력양성 활성화 연구 : 1차년도 결과를 중심으로 고찰)

  • Lee, Ho-Geun;Lee, Ki-Won;Lee, Jong-Hun;Yang, Young-Kyu
    • Journal of Korean Society for Geospatial Information Science
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    • v.5 no.1 s.9
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    • pp.147-157
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    • 1997
  • A national program for GIS Training had been established by a feasibility study which was performed during the period of from July, 1995 through April, 1996 initiated by Ministry of Science and Technology (MOST). Systems Engineering Research Institute (SERI), one of government-supported institutes in the fields of software development, have taken in charge of Korean GIS training program with emphases on short courses since July, 1996. To distinguish these national programs from those of major commercial GIS software vendor, GIS training programs by executing staffs within SERE have been established with the basis of its own educational paradigm; therefore, they was composed of several specific training curricular developed by executing staffs. In this paper, the practical aspects during execution and progress of these programs are described, and all courses named after decision maker course, GIS manager course, and user course in the first year of GIS training program are evaluated with questionnaire result riven to the trainees. As results, the satisfaction-rate after the decision maker, the GIS manager, and the user course is 84.8%, 81.2%, and 66.7% respectively These whole results are shown as more affirmative ones than expected, and each result, as a kind of feedback of this executing program, plays an important role to flourish Korean GIS training project in future.

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