• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.5
• /
• pp.537-546
• /
• 2008

The digital map has been updated in every five years in the past. However, it has been changed to make corrections and updated in every two years for metropolitan region and every four years for other regions since year 2008. Although, the correctness and reliability were decreased and updating work is being delayed due to the updating work in a lump. The period update spends a lot of money because this method uses aerial photogrammetry, and the digital map has the time gap between periods. Therefore, this study provides information necessary for digital map produced by the government and develops digital map production system based on objects which can be updated frequently in order to save state and local government budgets that double investment are generated to update digital map. In order to analyze usefulness of the developed system, subject area was selected and errors of updated data were analyzed. As the result of analysis, checked 66 errors were corrected and saved in the database.

• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.1
• /
• pp.89-100
• /
• 2000

Recently, studies on the mobile computing environments that enable mobile hosts to move while retaining its network connection are in progress. In these mobile computing environments, one of the necessary components is the distributed file system supporting mobile hosts, and there are several issues for the design and implementation of the shared file system. Among these issues, there are problems caused by network traffic on limited bandwidth of wireless media. Also, there are consistency maintenance issues that are caused by update-conflicts on the shared files in the distributed file system. In this paper, we propose TWB(Trickle Write-Back) scheme that utilizes weak connectivity for cache management of mobile clients. This scheme focuses on saving bandwidth, reducing waste of disk space, and reducing risks caused by disconnection. For such goals, this scheme lets mobile clients write back intermediate states periodically or on demand while delaying unnecessary write-backs. Meanwhile, this scheme is based on the existing distributed file system architecture and provides transparency.

• Journal of KIISE:Information Networking
• /
• v.31 no.2
• /
• pp.123-130
• /
• 2004

Routing and wavelength assignment(RWA) problem is an important issue in optical transport networks based on wavelength division multiplexing(WDM) technique. It is typically solved using a combination of linear programming and graph coloring, or path selection based graph algorithms. Such methods are either complex or make extensive use of heuristics. In this paper we propose a novel and efficient approach which basically obtains the maximum edge disjoint paths (EDPs) for each source-destination demand pair. And those EDPs obtained are stored in Lookup Table and used for the update of weight matrix. Routes are determined in order by the weight matrix for the demand set. The comprehensive computer simulation shows that the Proposed algorithm uses similar or fewer wavelengths with significantly less execution time than bounded greedy approach (BGA) for EDP which is currently known to be effective in practice.

• Journal of Cadastre & Land InformatiX
• /
• v.45 no.1
• /
• pp.17-30
• /
• 2015

Local governments' spatial information policies are very important in that it can increase the relatedness to upper policy regarding the share, openness and converged utilization of spatial information and contribute to voluntary participation and creative uses linked to big data. However, local governments' spatial information policies require enhancement since it need to update framework spatial data, to derive spatial information service and to share the data. In this research, we compared the spatial information policies and related systems of central and local governments, and analyzed the local governments' spatial information policy enforcement plans and the Seoul metropolitan government's utilization survey on 32 spatial information systems. In the result, for the improvement of local governments' spatial policies, on-demand updating of base map using the as built drawings linked to field work departments, securing up-to-date public domain spatial information through the NSDI system, sharing of spatial information based on the spatial information platform and benchmarking of best practices related to the spatial information based policy participation are suggested.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.27 no.6
• /
• pp.741-747
• /
• 2009

For construction of 3D virtual city models, airborne digital cameras, laser scanners, multi-oblique photograph systems and other devices are currently being used. With such advanced techniques, precise 3D spatial information can be collected and high quality 3D city models can be built in a considerably large area. The 3D spatial information to be built has to provide the latest information that quickly reflects the causes of any change due to urban development. In this study, a UAV photogrammetric method using low cost UAV and digital camera was proposed to acquire and update 3D spatial information effectively on small areas where information continuously change. In the proposed UAV photogrammetric method, the elements of interior orientation were acquired through camera calibration and the vertical and oblique photographs were taken at 9 points and the 3D drawing of ground control points and buildings was performed using 20 images among the pictured images. This study also analyzed the accuracy of the proposed method comparing with ground survey data and digital map in order to examine whether the method can be used in on-demand 3D spatial information update on relatively small areas.

• Journal of the Korean Society for information Management
• /
• v.36 no.1
• /
• pp.269-294
• /
• 2019

To effectively cope with new and different types of disasters, it is very important to communicate and update disaster information to the public quickly and efficiently. SNS enables rapid spread of information and continuous exposure. SNS enables two-way communication by directly communicating with users. SNS complements the shortcomings of mass media, and increases the effectiveness of disaster management work. This study analyzed user awareness and requirements to derive effective methods of SNS operation of disaster management institutions. For this purpose, a user survey was conducted to identify the types of information that are highly user-interested and to select information items suitable for SNS services. Through this, we suggest ways to improve the SNS disaster record information service of the disaster management institution.

• Journal of Internet of Things and Convergence
• /
• v.2 no.2
• /
• pp.21-26
• /
• 2016

In this paper, it is possible to update the tourist information in real time, on/off-line tour proposes a solution(BBTS) based on a bluetooth beacon can provide tourist information without the need for wireless data network. BBTS consists of a bluetooth based data of the low-power supply system and the beacons and interoperable smart applications. Data supply system consists of the BLE & Beacon Pairing-based / non-pairing data transmission module with integral hardware. Smart application modules that provide indoor location of users information, internal server module and tourist information collection and information guide around comprised of applications. The proposed BBTS is possible that indoor service tourism tourist demand due to utilizing the beacon technology. Outdoor tourist information is designed to be downloaded to the smartphone receives the information received from the beacon APK file to provide services. BBTS system is expected to make a big impact on the smart tourism services industry.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.10 no.4
• /
• pp.35-45
• /
• 2007

Currently, the necessity of inter-system integration and sharing system increases to additionally construct and efficiently utilize the geographical information data in accordance with the increase in demand for geographical information. The provision of the data within the domestic sharing system is led by the tasks within national geographical information distribution network or intra-local governmental combined system. However, any voluntary geographical information sharing cooperation body is increasingly required with the increase in necessity of administrative cooperation among neighboring metropolitan areas, including space planning and development. Accordingly, this study is aimed at looking into the constitutions and roles of cooperation bodies within metropolitan areas by the composition, distribution, update and management of data with special regard to overseas advanced cases whose sharing systems and their effects are highly evaluated, and at presenting any model of the domestic future voluntary sharing cooperation organization within metropolitan area.

• Proceedings of the Korea Contents Association Conference
• /
• 2008.05a
• /
• pp.575-578
• /
• 2008

Currently the automobile parts manufacturing industry of most, it is difficult in the automobile part development and purchase and production management. And when new regulation it will develop this automobile parts and changing design, it is difficult in new registration and history management. Automatic history management and DB construction about automobile parts is in great demand. The purpose of paper is a design of data retrieval and real-time production integration management for automobile parts. Automatic data update is accomplished as input material changing process for design data change and integration management of history information about parts is possible when input the name of an part and the number of an part.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.16 no.11
• /
• pp.3738-3760
• /
• 2022

Due to increasing spectrum demand for new wireless devices applications, cooperative spectrum sensing (CSS) paradigm is the most promising solution to alleviate the spectrum shortage problem. However, in the interweave cognitive radio (CR) system, the inherent nature of CSS opens a hole to Byzantine attack, thereby resulting in a significant drop of the CSS security and efficiency. In view of this, a weighted differential sequential single symbol (WD3S) algorithm based on MATLAB platform is developed to accurately identify malicious users (MUs) and benefit useful sensing information from their malicious reports in this paper. In order to achieve this, a dynamic Byzantine attack model is proposed to describe malicious behaviors for MUs in an interweave CR system. On the basis of this, a method of data transmission consistency verification is formulated to evaluate the global decision's correctness and update the trust value (TrV) of secondary users (SUs), thereby accurately identifying MUs. Then, we innovatively reuse malicious sensing information from MUs by the weight allocation scheme. In addition, considering a high spectrum usage of primary network, a sequential and differential reporting way based on a single symbol is also proposed in the process of the sensing information submission. Finally, under various Byzantine attack types, we provide in-depth simulations to demonstrate the efficiency and security of the proposed WD3S.