• Archives of design research
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• v.17 no.2
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• pp.269-278
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• 2004

This research categorizes various icons that used in PDAs according to symbolization patterns, operating systems and support for color display. Since different icons vary in communication capacity I executed this research to verify it positively. In result, PDA loons were found to have different intuitive communication capacity according to its functions, symbolization pattern, operating system and use of color. \circled1 Icons which have similar object as ones that are used on desktop computer and icons with accurate, simple expression seems to have higher intuitive communication capacity among the icons categorized by functions. \circled2 Among the icons categorized by symbolization pattern, ones that express the action related to their functions have the highest recognition accuracy and longer delay before recognition. \circled3 Among the icons categorized by operating systems, ones that have concrete expression of object and a number of representation elements have higher recognition accuracy and longer delay before recognition. \circled4 Among the icons categorized by color and grayscale, ones with color have superior communication capacity due to additional stimulation although LCDs in most PDAs have limited color depth.

• Journal of Internet Computing and Services
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• v.17 no.1
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• pp.55-64
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• 2016

Existing Android applications for streaming video in real time are dependent on the codec, which composes the encoding function, and the version of Android operating system. Also, for streaming video in real time, most applications should be connected with a separate desktop PC. To overcome these disadvantages, we propose a new application, which records and streams video in real time. Specifically, the proposed application uses the flash video file format, which is the common media file format supported by various versions of Android operating system. Through experiments, we show that it is possible for the proposed application to record the video screens more than 20 frames per second and to stream it in real time while using the existing video encoding methods.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.752-757
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• 2009

In the last decade, many methods such as greet chamber, reservoir, or debris barrier, have been utilized to manage and prevent muddy water problem. The Vegetative Filter Strip (VFS) has been thought to be one of the most effective methods to trap sediment effectively. The VFS are usually installed at the edge of agricultural areas adjacent to stream or drainage ditches, and it has been shown that the VFS effectively removes pollutants transported with upland runoff. But, if the VFS is installed without any scientific analysis of rainfall-runoff characteristics, soil erosion, and sediment analysis, it may not reduce the sediment as much as expected. Although Soil and Water Assessment Tool (SWAT) model has been used worldwide for many hydrologic and Non-Point Source Pollution (NPSP) analysis at a watershed scale. but it has many limitations in simulating the VFS. Because it considers only 'filter strip width' when the model estimates sediment trapping efficiency, and does not consider the routing of sediment with overland flow option which is expected to maximize the sediment trapping efficiency from upper agricultural subbasin to lower spatially-explicit filter strip. Therefore, the SWAT overland flow option between landuse-subbasins with sediment routing capability was enhanced with modifications in SWAT watershed configuration and SWAT engine. The enhanced SWAT can simulate the sediment trapping efficiency of the VFS in the similar way as the desktop VFSMOD-w system does. Also it now can simulate the effects of overland flow from upper subbasin to reflect the increased runoff volume at the receiving subbasin, which is what is occurring at the field if no diversion channel is installed. In this study, the enhanced SWAT model was applied to small watershed located at Jaun-ri in South Korea to simulate diversion channel and spatially-explicit VFS. It was found that approximately sediment can be reduced by 31%, 65%, 68%, with diversion channel, the VFS, and the VFS with diversion channel, respectively.

• Journal of The Korean Association of Information Education
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• v.14 no.2
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• pp.165-174
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• 2010

The digital textbook project which embarked by the Ministry of Education, Science and Technology has focused on experiments and practices from the school designated by the government. However the previous research about digital textbook provides static interaction models and teaching-learning models analogous to web-based learning based desktop PC even the framework of the digital textbook is based of Tablet PC. This paper provides learning and teaching models for next generation digital textbook which based digital inking techinques for sketcth interface and AR(augmented reality) interactions between teacher and learner. The proposed method of this paper is applied to educational contents and we found positive effect which is supported by statistical experiments. The results of this study in the future and the future development of digital textbooks in effect will be an effective development plan.

• The KIPS Transactions:PartB
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• v.11B no.1
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• pp.35-44
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• 2004

Web contents created for desktop screens give rise to problems when they are to be displayed on the small screens of mobile terminals. While in some cases some of the objects of a page may not be displayable due to the lack of browser capability, the entire page may not be displayable due to the incompatibility with the browser in other cases. In this paper, we introduce a new mobile content adaptation approach based on web clipping, which transforms an original page into one that is optimally displayed on a mobile terminal. In this method, a source page is automatically clipped and transformed according to the clip specification made by the content provider using a clip editing tool. The clip editing tool allows the user to specify group clips, multi-level cups and dynamic clips as well as simple clips, and the presentation layout through a graphic user interface. Based on the clip specifications, each clip is transformed into an intermediate meta-language document, which in turn is transformed into a presentation page in the target markup language. Transcoding of image objects in major image file formats is also supported.

• Journal of Korea Multimedia Society
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• v.2 no.4
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• pp.459-467
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• 1999

With fully harnessing the functions provided by Windows NT, we suggest the generating method of RPL profile and the RPL protocol for remote booting on DL-NCS(Network Computing System for Diskless client PCs). This system can offer clients, without having hard disk, boot remotely Window 9x stored in server's hard disk and can share peripheral devices and application programs in the server side. For booting Window 9x from DL-NCS, twenty-five clients' PCs were set for simultaneous on and finally the PCs were booted in similar time interval compared to that from a desktop PC having local disk. This system was also experimented to the application programs. And this system can yield excellent networking environments. In sum, with using this DL-NCS, we can reduce the installing costs of peripheral device, recycle the lower grade PCs such as 486SX/DX, and save the budgets for software purchase.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.11
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• pp.581-588
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• 2007

In Digital Right Management, symmetric cipher is used for content encryption to reduce encryption cost, AES, advanced encryption standard is usually used to multimedia encryption under desktop environment because of its reasonable security level and computation cost. But mobile handheld device often uses slow speed processor and operates under battery-powered environment. Therefore it requires low computation cost and low energy consumption. This paper proposes new stream cipher scheme which combines pseudo random number generator(PRNG) and dynamically generated permutations. Proposed scheme activates PRNG and generates original key streams. Then it generates extended key streams by applying permutation to original sequence. These extended key streams are XORed with plaintext and generate ciphertext. Proposed scheme reduces the usage of PRNG. Therefore this scheme is fast and consumes less energy in comparison with normal stream cipher. Especially, this scheme shows great speed up (almost 2 times) than normal stream cipher scheme in random access.

• Journal of KIISE
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• v.41 no.10
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• pp.832-837
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• 2014

Application loading speed can be improved by timely prefetching disk blocks likely to be needed by an application. However, existing prefetchers -- if they are not specialized to a particular application -- incur high overheads and are poor at identifying the blocks that will actually be required. There are many sequences in which blocks may be needed and, even if two access sequences are identical, block tracing and access timings can be affected significantly by the state of the buffer cache. We propose a new application-independent software-based prefetching technique, in which breakpoints are inserted at appropriate places in an application to collect the information on correlations between the blocks and to prefetch the potential blocks ahead of their schedule based on it. Experiments on an HDD-based desktop PC demonstrated an average 30% reduction in application launch time and 15% in general I/O, while reducing the wasted overhead.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.1
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• pp.211-224
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• 2015

Financial companies have invested a lot in their disaster recovery system and exercised training more than once a year to comply related laws and regulations. But massive PCs(Personal Computers) became disrupted simultaneously and it took a lot of time to recover massive PCs concurrently when March 20 cyber attack occurred. So, it was impossible to meet the tartgeted business continuity level. It was because the importance of PC recovery was neglected compared to other disaster recovery areas. This study suggests the measure to recover massive branch terminal PCs of financial companies simultaneously in cost-effective way utilizing the existing technology and tests recovery time. It means that in the event of disaster financial companies could recover branch terminal PCs in 3 hours which is recommended recovery time by regulatory body. Other financial companies operating similar type and volume of branches would refer to the recovery structure and method proposed by this study.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.37-44
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• 2009

This paper describes a new tiled display framework called, iTDF (Interactive Tiled Display Framework), that is designed to support rapid construction of the interactive digital 3D contents running on top of the cluster-based tiled display. This framework allows synchronizing the rendering slaves, sharing software's state over the network, the features, such as, launching multiple applications on a cluster-based computers, moving and resizing windows, synchronization of rendering slaves, distributed shared memory, and unified input interface. This paper analyzes the requirements of the framework and describes the design and implementation of the framework. A couple desktop-based applications are ported with the new iTDF and to find out the usefulness and usability of the framework.