• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.872-880
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• 2022

This paper present a design and implementation of a Contents Management System (CMS) to be integrated into a game that uses a Digital Game-based Learning (DGBL) approach for helping tourists learn about tourism spots as a part of the Package Tour Application. In terms of design, this paper shows a system architecture that consists of a database to store the game's content such as tourism spot information, score and question configuration, score history, et cetera, a web application to manage the content and a Rest API to delivers the content to the mobile game. Meanwhile, in terms of implementation, MySQL database and PHP programming language are used. Moreover, a time response performance evaluation is conducted which resulted in between 0.77 s to 1.4 s from CMS to the database. Once successfully integrated with the game, the CMS will allow the game to be played on multiple tours simultaneously, without having to rebuild the game for every package tour group.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.536-540
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• 2006

The interest in the service of 3D mobile contents becomes larger due to the technological advance of production and services of mobile contents and the appearance of the exclusive mobile phone for 3D game. Therefore, the researches about the efficient mobile services of large 3D contents are wanted in the circumstances of the narrow bandwidth and the burden of the connection charge of wireless mobile communications. In this paper, we suggest a strategy of caching for looking up and downloading the 3D marine characters efficiently and a system model for mobile service of 3D marine characters. The suggested system is designed for serving efficiently the high-quality 3D characters through the wireless mobile communications using the database on the 3D marine objects of cyber aquarium constructed for the services through the wired internet.

• The KIPS Transactions:PartB
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• v.18B no.5
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• pp.295-304
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• 2011

To effectively manage research information in the field of national defense, metadata about the information should be managed systematically, and an integrated system to help convergence and management of the information should be implemented based on the metadata. In addition, the system should provide the users with effective integrated search services in a mobile environment, because searching via the use of mobile devices is increasing. The objective of this paper is to suggest a MSISS (Mobile Semantic Integrated Search System), which satisfies the requirements for effective management of the national defense research information. Specifically, we defined national defense research ontologies and national defense research rules after analyzing the Dublin Core metadata and database information of the major military research institutions. We implemented a prototype system for MSISS to demonstrate the use of the ontologies and rules for semantic integrated searching of the military research information. We also presented a triple-based search service to support semantic integrated search in a mobile environment and suggested future mobile semantic integrated search services.

• Journal of Internet Computing and Services
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• v.7 no.4
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• pp.79-90
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• 2006

Data broadcasting is an efficient method for disseminating data, and is widely accepted in the database applications of mobile computing environments because of its asymmetric communication bandwidth between a server and mobile clients. This requires new types of concurrency control mechanism to support mobile transactions executed in the mobile clients, which have low-bandwidths toward the server. In this paper, we propose an OCC/DTA (Optimistic Concurrency Control with Dynamic Time-stamp Adjustment) protocol that can be efficiently adapted to mobile computing environments. The protocol reduces communication overhead by using client-side validation procedure and enhances transaction throughput by adjusting serialization order without violating transaction semantics. We show that the proposed protocol satisfies data consistency requirements, and simulate that this protocol can improve the performance of mobile transactions in data broadcasting environments.

• Journal of Internet Computing and Services
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• v.5 no.1
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• pp.51-57
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• 2004

Mobile Internet allows users to request critical information and receive swift responses at any places, but mobile users could suffer from unreliable and ill-timed services due to the characteristics of wireless media, One way that reduces possibility of the unsatisfactory services is data replication. Data Replica1ion, however, inevitably induces the overhead of maintaining replica consistency which requires more expensive synchronization mechanism. We propose a new replicated data management scheme in distributed mobile environment, In order to alleviate negative impact of synchronization message overhead in fault-prone mobile Internet environment, we devise a new replication control scheme called proxy quorum consensus (PQC), PQC minimizes the message overhead by coordinating quorum access activities by means of proxy mediated voting (PMV) which exploits reliable proxy hosts instead of unreliable mobile hosts in voting process, We also propose a simulation model to show the performance of PQC. Based on the results of the performance evaluation, we conclude that PQC scheme outperforms the traditional schemes.

• The KIPS Transactions:PartD
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• v.15D no.5
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• pp.609-620
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• 2008

The service handling the map data in the mobile device including navigation, LBS, Telematics, and etc., becomes various. The size of map data which is stored and managed in the mobile device is growing and reaches in several GB. The conventional navigation system has used the read-only PSF (physical storage format) in order to enhance the performance of system by maximum in the mobile device which has limited resources. So though a little part of the map data is changed the whole data must be updated. In general, it takes several ten minutes to write the 2 GB map data to a flash memory of mobile device. Therefore, we have developed the mobile spatial DBMS (database management system) to solve the problem which is that the partial map data couldn't be updated in the conventional navigation system. And we suggest the policy to guarantee the performance of the navigation system which is implemented using the spatial mobile DBMS and verify this by experiment.

• The Journal of Engineering Geology
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• v.24 no.3
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• pp.343-351
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• 2014

Tunnel face mapping plays an important role in risk analysis and infrastructure support decisions during tunnel construction. In this study, a digital mapping system using a mobile device is employed instead of existing face-mapping methods that rely upon face mapping sheets. The mobile device is then connected to the main server in the field, where a tunnel-specific database is compiled automatically. This information provides real-time feedback on the tunnel face to construction personnel and engineers, thus allowing for rapid assessment of tunnel face stability and infrastructure needs. The Douglas-Peucker algorithm, among others, is employed to resolve problems arising from the detailed mapping and speed problem by data accumulation. This system is expected to raise program optimization through field verification and additional functional improvements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.345-349
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• 2004

In order to index exactly moving objects(vehicle, mobile phone, PDA, etc.) in the mobile database, continuous updates of their locations are inevitable as well as time-consuming. The studies of pure spatial indices have focused on the efficient retrievals. However, the acquisition and management of the terminal Location of moving objects are more important than the efficiency of the query processing in the moving object databases. Therefore, it will be need to adopt parallel processing system for the moving object databases which should maintain the object's current location as precise as possible. This paper proposes a architecture of spatial indexing mobile objects using multiple processors. More precisely, we newly propose a method of splitting buckets using the properties of moving objects in order to minimize the number of database updates. We also propose a acquisition method for gathering the location information of moving objects and passing the information of the bucket extents in order to reduce the amount of passed messages between processors.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1424-1432
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• 2016

A person often needs to visit a facility that have not been visited before. In this case, it is necessary to easily identify the building in which the facility is located. Indoor navigation is also important, as the person may get lost due to the complex structure of buildings. To solve these problems, this paper presents a mobile application which provides a user with indoor place information and indoor navigation. A user is requested to take a photograph of a building of interest or of the current location. Then, the proposed application identifies the building of interest or the current location of the user by utilizing an image matching technique. For fast matching, database filtering by using GPS/magnetometer data and pre-extraction of features for images in the database are utilized. In case of indoor navigation, the application provides the actual images of check points as well as the moving direction. Simulation results show that the proposed system successfully identifies the location of users and provides place information and indoor navigation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.2
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• pp.149-155
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• 2007

Mobile facility management system is a on-site management tool to collect and update various facility data. But there is a chance to make a data inconsistency between lot of concurrent workers. And facility management system requires to keep records about work log within a certain period of time. This paper describes the design and implementation of mobile facility management system, which provide efficient data synchronization mechanism using version managent technique on large facility data in concurrent work environment. And proposed system is able to keep workers update log persistently.