• Journal of KIISE:Databases
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• v.28 no.3
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• pp.512-527
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• 2001

In a client-server spatial database, it is desirable to maintain the cached data in a client side to minimize the communication overhead across a network. This paper deals with the issues of concurrency and consistency of map updates in this environment. A client transaction to update map data is an interactive work and takes a long time to complete it. The map update in a client site may affect the other sites'updates because of dependencies between spatial data stored at different sites. The concurrent updates should be propagated to the other clients as well as the server to keep the consistency of map replicated in a client cache, and also the communication overhead of the update propagation should be minimized not to lose the benefit of caching. The newly proposed cache region locking with CR lock and CX lock controls the update dependency due to spatial relationships. CS lock and COD lock are suggested to use optimistic detection-based approaches for guaranteeing the consistency of cached client data. The cooperative update protocol uses these extended locking primitives and Spatial Relationship-based 2PC (SR-based 2PC). This paper argues that the concurrent updates of cached client spatial data can be achieved by deciding on collaborative updates or independent updates based on spatial relationships.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.1
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• pp.51-60
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• 2014

In this study, ICT medical service provider's level of knowledge fire fighting safety and methods on coping with fires in the regions of Gwangju and Jeonam Province of Korea were investigated to determine the elements affecting such levels and provide basic information on the manuals for educating how to cope with the fire fighting safety in medical facilities. The data were analyzed using SPSS Win 14.0. The scores of level of knowledge fire fighting safety of ICT medical service provider's were 7.06(10 point scale), and the scores of level of recognizing how to cope with fire fighting safety were 6.61(11 point scale). level of recognizing how to cope with fire fighting safety were significantly different according to gender(t=4.12, p<.001), age(${\chi}^2$=17.24, p<.001), length of career(${\chi}^2$=22.76, p<.001), experience with fire fighting safety education(t=6.10, p<.001), level of subjective knowledge on fire fighting safety(${\chi}^2$=53.83, p<.001). In order to enhance the level of understanding of fire fighting safety and methods of coping by the ICT medical service providers it is found that: self-directed learning through avoiding the education just conveying knowledge by lecture tailored learning for individuals fire fighting education focused on experiencing actual work by developing various contents emphasizing cooperative learning deploying patients by classification systems using simulations and a study on the implementation of digital anti-fire monitoring system with multipoint communication protocol, a design and development of the smoke detection system using infra-red laser for fire detection in the wide space, video based fire detection algorithm using gaussian mixture mode developing an education manual for coping with fire fighting safety through multi learning approach at the medical facilities are required.