• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.79-91
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• 2006

The intelligent disk can improve the overall performance of the I/O subsystem by processing the I/O operations in the disk side. At present time, however, realizing the intelligent disk seems to be impossible because of the limitation of the I/O subsystem and the lack of the backward compatibility with the traditional I/O interface scheme. In this paper, we proposed new model for the intelligent disk that dynamically optimizes the I/O subsystem using the information that is only related to the physical sector. In this way, the proposed model does not break the compatibility with the traditional I/O interface scheme. For these works, the boosting algorithm that upgrades a weak learner by repeating teaming is used. If the last learner classifies a recent I/O workload as the multimedia workload, the disk reads more sectors. Also, by embedding this functionality as a firmware or a embedded OS within the disk, the overall I/O subsystem can be operated more efficiently without the additional workload.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.315-320
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• 2014

Recently, although the requirement of quality of VOD content has been transferred upto the class of HD, conventional management systems characterized by OS dependency are truly limited in quality of video image, stability, and compatibility of network environments. In addition most of the content management systems realize very limited capabilities for the real affairs of content management and distribution services in such an OS dependent environment. In this paper, we propose a new scheme of HD-Class VOD Content Management System to solve these problems. We design and implement the proposed system based on open sources by using H.264 video compression method. The proposed system offers high quality content management method based on opened systems and independent on-line distribution method so that it can be realized as an integrated management scheme for VOD contents. Moreover, our system solves the problems of occasional cutting-down video, small screen, and poor image quality that exist in the conventional wmv-type CMS. According to the result of performance evaluation, our system maintains sufficient performance and tolerence for the case of large scale HD content operations or fabrications. We expect that the proposed integrated DB scheme will especially be effective when the content management applications are changed from Internet Web environments to mobile terminal environments.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.3
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• pp.195-201
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• 2015

In this study, IT education contents have been developed based on the u-Learning approach for people with hearing impairment, focusing on allowing the user to learn from anywhere and anytime. Specifically, this study applies HTML5 to implementing IT education contents(JSP, Oracle) for the deaf because HTML5 enables the learner to access the contents through both web and mobile device on various platforms including android, Mac OS, and PC etc. The results of this study are as follows: First, the online computer courses are mostly supposed to be compatible with diverse types of mobile devices. However, some of the contents could not be run on applications residing in web and mobile devices because the contents tend to be developed using FLASH. HTML5 is the effective way to overcome the compatibility problem. Second, FLASH and HTML5 contents authoring tools have been compared in terms of their strong and weak points by applying the developed contents to those tools. The study also suggests that the future work would be needed in order to implement wide variety of event functions with HTML5. Lastly, design strategies enabling access through web and mobile devices have been analyzed in accordance with u-Learning design guidelines for the deaf and mobile application accessibility guidelines. However, in the latter case, the future work regarding design guidelines needs to be conducted to improve the educational accessibility depending on the level of impairment.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.18-30
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• 2009

Recently, although the requirement of quality of VOD content has been transferred upto the class of HD, conventional management systems characterized by OS dependency are truly limited in quality of video image, stability, and compatibility of network environments. In addition most of the content management systems realize very limited capabilities for the real affairs of content management and distribution services in such an OS dependent environment. In this paper, we propose a new scheme of HD-Class VOD Content Management System to solve these problems. We design and implement the proposed system based on open sources by using H.264 video compression method. The proposed system offers high quality content management method based on opened systems and independent on-line distribution method so that it can be realized as an integrated management scheme for VOD contents. Moreover, our system solves the problems of occasional cutting-down video, small screen, and poor image quality that exist in the conventional wmv-type CMS. According to the result of performance evaluation, our system maintains sufficient performance and tolerence for the case of large scale HD content operations or fabrications. We expect that the proposed integrated DB scheme will especially be effective when the content management applications are changed from Internet Web environments to mobile terminal environments.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.1-9
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• 2012

The purpose of this study is to present a methodology to effectively produce the e-learning contents in two platform types of PC based and mobile based platforms. Currently, the compatibility problem of flash technology widely used in the e-learning content production of existing PC based platform not supporting flash in some mobile platforms is being created while the condition of accompanying inconvenience in learning due to small screen and difference of input interface is being created in case of using the contents for PC even in case of the mobile platforms in which flash is supported. Considering this situation, this study is presenting a content development methodology that can provide services in both platform types based on standard technologies such as HTML 5. In conclusion, the methodology proposed in this study separates the content and the view of learning contents while supporting to enable content implementation using various forms of views based on the content database that has been constructed to show very efficiently characteristics in the content reuse and the multi platform support categories.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.769-779
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• 2017

Nutrient (i.e., nitrogen and phosphorus) budgets are required under a 'Livestock Excreta Survey'. A nutrient budget is one of the agri-environmental indicators that calculates the difference between the inputs and outputs of the amount of nutrients within a certain boundary and for a certain time period (e.g., 1 year). In this study, a nutrients budget model was developed to effectively determine the surplus of nutrients within a region in Korea. The C# program language was used in order to facilitate the deployment of a graphical user interface (GUI) and to enhance compatibility. Also, the model was developed on Windows OS, which is the commonly used operating system in Korea. The model was based on the OECD/Eurostat nutrient budget method, and it was modified to consider manure composting procedures as well. There are key features of the nutrient budget model, including directly use of the original data sets from various input and output sources, and a collectively exchange of the address in different formats. The model can quickly show the results of various spatial and temporal resolutions with the same data, as well as perform a sensitivity analysis with coefficients and easily compareresults using tables and graphs. Further, it would be necessary to study the extension of the scope of utilization, such as the application of various nutrient budget methods. It would also be helpful to investigate both pre and postprocessing information such as linking input data through online systems.

• The KIPS Transactions:PartA
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• v.14A no.4
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• pp.235-244
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• 2007

Caching and prefetching policies have been used in most of computer systems to compensate speed differences between primary memory and secondary storage devices. In this paper, we design and implement a Flash Cache Core Module(FCCM) on the YAFFS which operates on a file system layer for NAND flash memory. The FCCM is independent of the underlying kernel in order to support its stability and compatibility. Also, we implement the Dirty-Last memory replacement technique considering the characteristics of flash memory, and the waiting queue for pages to be prefetched according to page hit. The FCCM reduced the number of I/Os and the amount of prefetched pages by maximum 55%(20% on average) and maximum 55%(24% on average), respectively, comparing with caching and prefetching policies of Linux.