• Journal of Korea Multimedia Society
• /
• v.19 no.8
• /
• pp.1395-1403
• /
• 2016

In recent years, researches of security threats reported that various types of social engineering attack were frequently observed. In this paper, we propose secure keypad scheme for mobile devices. In our scheme, every edge of keypad is linked each other, and it looks like a sphere. With this keypad, users input their password using pre-selected grid pointer. Because of circulation of the keypad layout, even though the attacker snatch the user password typing motion through the human eyes or motion capture devices, attacker do not estimate the original password. Moreover, without the information of grid pointer position, the attacker do not acquire original password. Therefore, our scheme is resistant to password guessing attack.

• Proceedings of the IEEK Conference
• /
• 2002.06a
• /
• pp.351-354
• /
• 2002

NAPTR(Naming Authority Pointer) is a type of resource record specified IETF RFC 2915. NAPTR enables to register various services in tile domain name systems and thus Provides a way to discover services available on specific hosts. This paper describes the design and implementation of a proxy DNS system aimed at supporting NAPTRS. The goal of this work is to study on the feasibility of the service discovery registered in DNS via NAPTR records. This research result can be applied to service discovery in the resource information management for high performance GRID environments as well as to implement generic ENUM services

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.17 no.2
• /
• pp.189-196
• /
• 1999

Until now, Many approach to use the layer or attribute items in GIS the classification results of remotely sensed images is going on, but It was rarely ever tried to use the results of fuzzy classification in GIS. The fuzzy classification can be accurate than any other classification methods of remotely sensed images and can separately extract the result for each classification items. In this study, We applied to GIS database implementation with fuzzy classification result. In the process of this study, We convert the fuzzy classification image into the grid of GIS database, and Membership Grade Value files transformed to table database into the GIS. And then Membership Grade Values related to each grid-cell of database be able to verify with pointer layer. Finally, we can use the fuzzy classification images in GIS database.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.3
• /
• pp.55-62
• /
• 2009

Location based Services in the ubiquitous computing environment, namely u-LBS, use very large and skewed spatial objects that are closely related to locational information. It is especially essential to achieve fast search, which is looking for POI(Point of Interest) related to the location of users. This paper examines how to search large and skewed POI efficiently in the u-LBS environment. We propose the Dynamic-level Grid based R-Tree(DGR-Tree), which is an index for point data that can reduce the cost of stationary POI search. DGR-Tree uses both R-Tree as a primary index and Dynamic-level Grid as a secondary index. DGR-Tree is optimized to be suitable for point data and solves the overlapping problem among leaf nodes. Dynamic-level Grid of DGR-Tree is created dynamically according to the density of POI. Each cell in Dynamic-level Grid has a leaf node pointer for direct access with the leaf node of the primary index. Therefore, the index access performance is improved greatly by accessing the leaf node directly through Dynamic-level Grid. We also propose a K-Nearest Neighbor(KNN) algorithm for DGR-Tree, which utilizes Dynamic-level Grid for fast access to candidate cells. The KNN algorithm for DGR-Tree provides the mechanism, which can access directly to cells enclosing given query point and adjacent cells without tree traversal. The KNN algorithm minimizes sorting cost about candidate lists with minimum distance and provides NEB(Non Extensible Boundary), which need not consider the extension of candidate nodes for KNN search.

• Korean Institute of Interior Design Journal
• /
• v.15 no.3 s.56
• /
• pp.155-162
• /
• 2006

Space is integrated or segment with organic formation by circulation path. It estimates important problem to grasp as factor that promote movement of visitor and space organization without grasping circulation as connection relation about simple space function from these viewpoint, is a thing which this study does not cause confusion to visitor's circulation path through data that analyze form of space connection and visitor's circulation path as quantitative in museum space and layout form that access by easy each unit exhibition grasps what it is. This study does factor grasping for guideline and inspection circulation path of layout by purpose in exhibition space on the basis of analytical result that grasps connection form between exhibition area that grasp laying stress on visitor's movement and appears in space through follow-up survey for circulation path of museum exhibition area. Space connection form that is expose by sequence of investigation and analysis(II) estimates on constituent affecting to visitor's circulation, and these do not speak for all space connection forms at the museum, but may systematize typology about connection form of unit spaces to utilize by indicator pointer of space planning if continue study to various spatial sphere more than hereafter. Unit exhibition area, divide connection form of space by grid and tree and laying stress on this quantitative data by spectator follow-up survey comparison and Estimate that space connection form provides partial basis of judgement for supposition that can promote direction and circulation path about visitor's movement if summarize result of investigation and analysis (III).