• Journal of information and communication convergence engineering
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• v.6 no.1
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• pp.80-85
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• 2008

Images are often corrupted by noises during signal acquisition and transmission. Among those noises, additive white Gaussian noise (AWGN) and impulse noise are most representative. For different types of noise have different characters, how to remove them separately from degraded image is one of the most fundamental problems. Thus, a modified image restoration algorithm is proposed in this paper, which can not only remove impulse noise of random values, but also remove the AWGN selectively. The noise detection step is by calculating the intensity difference and the spatial distance between pixels in a mask. To divide two different noises, the method is based on three weighted parameters. And the weighted parameters in the filtering mask depend on spatial distances, positions of impulse noise and standard deviation of AWGN. We also use the peak signal-to-noise ratio (PSNR) to evaluate restoration performance, and simulation results demonstrate that the proposed method performs better than conventional median-type filters, in preserving edge details.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.6
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• pp.657-662
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• 2014

Usually, spatial information can be incorporated into histograms by taking histograms of a multiresolution image. For these reasons, many researchers are interested in multiresolution histogram processing. If the relation and sensitivity of the multiresolution images are well combined without loss of information, we can obtain satisfactory results in several fields of image processing including histogram equalization, specification and pattern matching. In this paper, we propose a multiresolution histogram specification method that improves the accuracy of histogram specification. The multiresolution decomposition technique is used in order to overcome the unique feature of a histogram specification affected by a quantization error of a digitalized image. The histogram specification is processed after the reduction of image resolution in order to enhance the accuracy of the results by histogram specification methods. The experimental results show that the proposed method enhances the accuracy of specification compared to conventional methods.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.135-142
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• 2013

This study aims to seek adequate and optimized method of applying high quality three-dimensional spatial data created via high-resolution digital aerial photograph image and aerial LiDAR data onto three-dimensional planning of environmentally friendly, ecological restoration of rivers in accordance with irrigation and flood control objectives of urban rivers. Through three-dimensional modeling of before and after the restoration, the research also offers basic information regarding restorations of rivers. Also the transition from the conventional two-dimensional planning into three-dimensional planning environment using smart spatial information acquire accuracy of river analysis, analyze possible civil complaints and suggest solutions to potential problems.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.178-180
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• 2002

모바일 클라이언트(Mobile Client, MC) - 서버 환경에서 캐쉬된 공간 데이타는 용량과 가용성이 크고 긴단절을 가지는 특징이 있다. 이러한 긴 단절을 거친 MC의 일관성 제어시 캐쉬된 데이타 전체가 무효화되어 재전송 하는 것은 비효율적이므로 서버는 변경된 객체 정보를 로그로 기록하여, 캐쉬된 영역에 속하는 최근 변경 정보만을 전송하는 것이 필요하다. 또한 일반적으로 로그의 순차 검색과 불필요한 로그의 누적으로 인해 일관성 제어시 통신 비용이 증가하게 되므로, 서버의 로그 검색 시간과 전송량을 최소화 하기위한 기법이 필요하다. 이를 위해 본 논문에서는 로그를 이용안 공간 로그 인덱스(Spatial Log Index, SLI) 기법과 공간 로그 관리(Spatial Log Management, SLM) 기법을 제시하고 있다.

• 한국지형공간정보학회:학술대회논문집
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• 2002.11a
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• pp.159-163
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• 2002

• Journal of Korea Spatial Information System Society
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• v.11 no.3
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• pp.79-84
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• 2009

As a surveying standard of a nation, the Korean geodetic control points such as triangulation points and benchmarks require continuous and effective management toward a spatially enabled society. As the developments of information technologies, use of mobile devices like PDA (personal digital assistant) has been increasing and the Web 2.0 environment became an important part of GIS. In this context, the management systems for national geodetic control points should be upgraded in accordance with the current trend, particularly for more interactive user-interface on the Web 2.0. This paper describes the framework design and prototype implementation of a Web 2.0 GIS application for the management of Korean geodetic control points. Our system enables a real-time update of the control point information and provides aerial photos on vector maps using Ajax(Asynchronous JavaScript and XML) techniques.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.259-268
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• 2004

For supporting Interoperability among heterogeneous data sources in different geographic information systems, it is required to use open API like OGIS OLE DB Proposed in OGC. The OLE/COM Implementation Specification of OGIS only provides interfaces to discover and access spatial data, but does not support interfaces for updating distributed spatial data. To solve this problem, we propose and add interfaces for updating spatial objects distributed over heterogeneous data sources and examining the consistency of spatial relationships between updated objects. We also devise a 2-phase commit protocol based on spatial relationships in order to guarantee the consistency of updated objects. To justify the update scheme using the proposed Interfaces and 2-phase commit prototype we design and implement a prototype system for updating distributed spatial objects.

• Spatial Information Research
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• v.19 no.6
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• pp.67-74
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• 2011

This study attempts to establish sewerage underground facility map using aerial photograph with high readability and accessibility as an alternative of digital map and compilation cadastral map. A study on utility and consistency of established sewerage underground facility map in line with the current continuous cadastral map of underground facility was carried out. If underground facility map is established and utilized by converging digital image and compilation cadastral map, various spatial information analysis and systematic and integrated information utilization is available. The drawing of underground facility map using aerial photograph in this highly information-oriented society shall play a role in basic map for integrated control as an alternative of problems in the current drawing and designs created and managed by controlling institutions. In addition, the information of sewerage underground facility map using aerial photograph shall be used for establishing systematized urban planning and control.

• Korean Journal of Remote Sensing
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• v.30 no.3
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• pp.383-397
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• 2014

Information technology advances are allowing conventional surveillance systems to be combined with mobile communication technologies, creating ubiquitous monitoring systems. This paper proposes monitoring system that uses smart camera technology. We discuss the dependence of interior orientation parameters on calibration target sheets and compare the accuracy of a three-dimensional monitoring system with camera location calculated by space resectioning using a Digital Surface Model (DSM) generated from stereo images. A monitoring housing is designed to protect a camera from various weather conditions and to provide the camera for power generated from solar panel. A smart camera is installed in the monitoring housing. The smart camera is operated and controlled through an Android application. At last the accuracy of a three-dimensional monitoring system is evaluated using a DSM. The proposed system was then tested against a DSM created from ground control points determined by Global Positioning Systems (GPSs) and light detection and ranging data. The standard deviation of the differences between DSMs are less than 0.12 m. Therefore the monitoring system is appropriate for extracting the information of objects' position and deformation as well as monitoring them. Through incorporation of components, such as camera housing, a solar power supply, the smart camera the system can be used as a ubiquitous monitoring system.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.1
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• pp.1-6
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• 2016

Keeping a system in stable state is one of the important issues of control theory. The main goal of our basic research is stability of unmanned aerial vehicle (quadrotor). This type of system uses a variety of sensors to stabilize. In control theory and automatic control system to stabilize any system it is need to apply feedback control based on information from sensors. Our aim is to provide balance based on the 3D spatial information in real time. We used PID control method for stabilization of a seesaw balancing system and the article presents our experimental results. This paper presents the possibility of balancing of seesaw system based on feedback information from stereo vision system only.