• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.808-811
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• 2008

HMIPv6는 핸드오버시 시그널링 오버헤드와 패킷 손실을 감소시키는데 목적이 있다. 그러나 HMIPv6는 성능 평가면에서 기존의 MIPv6보다 우수하지 못하다. HMIPv6 환경하에서 새로운 도메인에 진입한 MN이 MAP 선택시 최상위 MAP을 선택하여 CN과 통신할 경우 최상위 MAP에 부하가 집중되고 MN이 빈번하게 이동하거나 대용량서비스를 이용하게 되면 성능이 저하되고, 반대로 MN이 최하위 MAP을 선택하여 CN과 통신할 경우에는 HA나 CN에 대한 Binding Update 시그널 증가로 성능이 저하된다. 이에 본 논문에서는 MN이 MAP 선택시 Distance, 노드사용율 및 대역폭 사용율을 바탕으로 MAP을 선택하는 적응적 MAP을 선택하는 방안에 대해서 논하고자 한다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.120-127
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• 2008

HMIPv6 draws lots of attentions in recent years for providing an efficient handover and reducing the signaling overhead. HMIPv6 employs MAP(Mobility Anchor Point) in order to minimize a signaling overhead and a local mobility management. MAP completes an efficient mobility management in HMIPv6 network environment with frequent handover. However, HMIPv6 causes load concentration at a paricular MAP and may have unnecessary latency between HN(Mobile Node) and CN(Correspondent Node) within the same network. A MAP may also disturb the route optimization in HMIPv6 network because all packets must be transmitted through a MAP. In this paper, we propose a scheme to optimize the route in HMIPv6 networks according to MAP load. We configure a threshold in order to support the better service into MAP domain. The packets do not pass through MAP and are directly transmitted to AR(Access Router) if the number of current MNs attached to the MAP exceed the desired threshold. We simulate the performance of the proposed scheme and compare with HMIPv6. Resultly, the proposed scheme reduces signaling costs and mitigates concentration of a paticular MAP as well.

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.127-134
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• 2020

In this paper, we propose a map alignment method for maps generated by point-line monocular SLAM. In the proposed method, the information of feature lines as well as feature points extracted from multiple maps are fused into a single map. To this end, the proposed method first searches for similar areas between maps via Bag-of-Words-based image matching. Thereafter, it calculates the similarity transformation between the maps in the corresponding areas to align the maps. Finally, we merge the overlapped information of multiple maps into a single map by removing duplicate information from similar areas. Experimental results show that maps created by different users are combined into a single map, and the accuracy of the fused map is similar with the one generated by a single user. We expect that the proposed method can be utilized for fast imagery map generation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.167-170
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• 2005

In the mobile environments for the vector map services, a map simplification work through the map generalization steps helps improve the readability of the map on a large scale. The generalization operations are various such as selection, aggregation, simplification, displacement, and so on, the formal operation algorithms have not been built yet. Because the algorithms require deep special knowledge and heuristic, which make it hard to automate the processes. This thesis proposes some map generalization algorithms specialized in mobile vector map services, based on previous works. We will show the detail to adapt the approaches on the mobile environment, to display complex spatial objects efficiently on the mobile devices which have restriction on the resources

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.167-174
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• 2009

A Tile Map Service is a regular map service that has been enhanced to serve maps very quickly using a cache of static images. The map cache is a directory that contains image tiles of a map extent at specific scale levels. Returning a tile from the cache takes the server much less time than drawing the map image on demand. Use of a Tile Map Service can dramatically improve the time that clients take to display complex base-maps. Using Tile Map Services thus eliminate the need to trade quality for performance. This study provides a way to construct Tile Map Service System using Open Source GIS. We used GDAL(Geospatial Data Abstraction Library) which is one of the Open Source GIS Softwares to make Tile Map Image and OpenLayers to publish Web Page. Moreover, We conducted a performance test on Tile Map System and Dynamic Map System and evaluated the results of it. As a result, the proposed method makes it easier to construct high performance Tile Map Service using Open Source GIS without commercial products.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.4
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• pp.143-148
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• 1999

This paper presents a method which enables raster maps to be used like vector maps in the wed environment and develops a raster map viewer which can be executed in the wed browser. Through the preprocessing process the coordinates attached to each object in the raster map can be used as vector information. The raster map viewer makes the spatial analysis possible using the attribute database connected to the coordinates of each object, This map viewer makes the Web GIS can be constructed at the lower cost because the viewer uses the characteristics of raster map. And the map viewer has merit point of easily developing a component for spatial analysis.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.272-275
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• 2005

The digital map expresses natural topographies and artificial things with 3D position coordinates in the computer such as the road, railway, building, river, mountain, paddy and dryland. Therefore, the digital map is regarded as an important factor in the information-oriented society. However, it is difficult to maintain the most recent topographic information all the times because of restricted budget and time. For that, the efficient method corresponded with the digital map should be presented. This study aims to suggest the way to make an estimate of updating cost for 1:5,000 scale digital map by using remotely sensed data. To predict updating area of the digital map, the screen digitizing method was applied to the overlapped images and digital maps.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.377-379
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• 2001

Contamination flashover is responsible for insulator electrical failures. Particularly, in Korea, with its perennially dry spring, the first spring rain often cause serious line outages by forming a conductive liquid film on the insulator surface. Rainwater and fog are not normally conductive but unfortunately atmospheric dust deposited on the insulator surface contains soluble salts which may lead to bad condition of insulation by combining watery and salts. Transmission design engineers have used a contamination map drawn on the traditional paper map. But it is not convenient because it does not include the information of Geographic Information accurately. This paper explains the newly developed salt contamination map program using Geographic Information System, which provide accurate geographic information. The program is designed to use four parts of datum, salt contamination levels, 345kV & 154 kV transmission lines, power plants & substations and background map. The digital background map is composed of raster files, the others are done by vector map.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.260-266
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• 1997

The Navigation Streets Map that directly supplies information for a driver plays an important role in Car Navigation System(CNS). Therefore, cause the compatibility, preference, visibility, and readability of the navigation streets map will be hold sway over driver's information acquisition, safety, and performance in CNS, it is important that designer's requirements should be analyuzed for ergonomic design of navigation streets map. Especially, there are differences between the topographical objects marking method and that of the general map in a navigation streets map. Because much information is marked in a narrow space, it is important that the text information should be done in navigation streets map. Also, because it is a important factor to mark the text format for the marking method of the topographical objects, the design requirements will be drawn out through the factor analysis for the text marking method. And when ergonomic designers are doing, this result will be basic research for developing driving simulator of CNS and it will be a ergonomic guideline of navigation streets map.

• Journal of Information Processing Systems
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• v.13 no.1
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• pp.68-82
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• 2017

Nowadays, geographic information system (GIS) is developed and implemented in many areas. A huge volume of vector map data has been accessed unlawfully by hackers, pirates, or unauthorized users. For this reason, we need the methods that help to protect GIS data for storage, multimedia applications, and transmission. In our paper, a selective encryption method is presented based on vertex randomization and hybrid transform in the GIS vector map. In the proposed algorithm, polylines and polygons are focused as the targets for encryption. Objects are classified in each layer, and all coordinates of the significant objects are encrypted by the key sets generated by using chaotic map before changing them in DWT, DFT domain. Experimental results verify the high efficiency visualization by low complexity, high security performance by random processes.