• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.59-76
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• 2015

Recent wide spread of embedded devices and technology growth of broadband communication has led to rapid increase in the volume of created and managed data. As a result, data centers have to increase the storage capacity cost-effectively to store the created data. Data deduplication is one way to save the storage space by removing redundant data. This work propose IO extent based deduplication schemes called CORE-Dedup that exploits content-preserving access locality. We acquire IO traces from block device layer in virtual machine host, and compare the deduplication performance of chunking method between the fixed size and IO extent based. At multiple workload of 10 user's compile in virtual machine environment, the result shows that 4 KB fixed size chunking and IO extent based chunking use chunk index 14500 and 1700, respectively. The deduplication rate account for 60.4% and 57.6% on fixed size and IO extent chunking, respectively.

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.775-782
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• 2001

Recently the use of Linux OS is increasing to tremendous figures. But due to the fact that Linux is distributed on an open-source policy, the need of security is an upcoming question which leads to widespread development of security on a Linux based environment. Cryptography, however, can cause various problems because of difficulty of key management. A lot of researchers have been concentrating on the key recovery technique to eliminate the reverse effect of using these kinds of security and to promote positive aspects of using it. In this thesis I am suggesting an mechanism based on the key recovery technique, as a method to save time in recovery and resetting a disconnection between two end-users through IPSec (IP Security) protocols in a VPN (Virtual Private Network) environment. The main idea of the newly suggested mechanism, KRFSH (Key Recovery Field Storage Header), is to store the information of the session in advance for the case of losing the session information essential to establish a tunnel connection between a SG and a host in the VPN environment, and so if necessary to use the pre-stored information for recovery. This mechanism is loaded on the IPSec based FreeS/WAN program (Linux environment), and so the VPN problem mentioned above is resolved.

• Journal of KIISE:Computer Systems and Theory
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• v.28 no.9
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• pp.415-423
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• 2001

Recently, there are many attempts to reproduce real world fine art pieces in digital forms. The digital representations are convenient to store and/or transmit. In contrast, mobiles, or moving sculptures, such as those designed by Alexander Calder cannot to reproduced realistically by usual reproduction techniques. Since mobiles are originally designed to generate motions in response to external forces applied to it, people could not fully enjoy them through photographs or static images. We present a virtual mobile system where use can easily control the mobile and can feel the impressions that the artist originally intended to provide. A real-world mobile is reconstructed in a three-dimensional physically-based model. and then virtual wind is generated to give motions to it. The motions of the mobile are generated by constraint dynamics and impulse dynamics techniques, which are modified to fully utilize the characteristics of the mobile, and finally give interactive displays on the PC platforms. The techniques presented can easily be extended to simulate other interactive dynamics systems.

• (The)Study of the Eastern Classic
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• no.41
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• pp.37-59
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• 2010

This thesis is for clarifying a few aspects of 'Kyung(敬)' ideology and figures appearing in Yeheon(旅軒)'s poem. This ideology and figures is a kind of a imaginative thing that a poet designed. This feature is a very important subject of Yeheon(旅軒)'s poem world, so that we are going to make it clear. First, we focused his aspirations of virtual uncontaminated areas and found out his big store of life wisdom and knowledge. The second is we thought about a displaying a emphasis of proud spirit[氣像] in his own poem world, and we found that he saw things from an unworldly point of view. Finally we talked about several features of Yeheon(旅軒)'s poem world. Now we have to compare Yeheon(旅軒)'s poem and any other Dohakpa(道學派) poets for example Toegye(退溪), Hwejae(晦齋) etc. And we must clarify the whole poem world of Dohakpa(道學派). In the end, I'm so sure that we will get a prospect of their literature.

• Fashion & Textile Research Journal
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• v.17 no.5
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• pp.770-780
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• 2015

This study intended to explore fundamental causes affecting consumers' response actions from psychological factors in the situation of sellout occurring during shopping in online fashion stores. In addition, this study devised a virtual online shop in order to measure consumers' cognitive and emotional psychological responses they experienced when goods were sold out. The subjects involved women in 20s~30s, major customers of online shopping, and the subjects were randomly allocated to one of eight questionnaire forms (2(stockout size: high vs low)${\times}2$(product assortment similarity: similar vs. dissimilar)${\times}2$(restocking cue: included vs excluded)). The number of final data used for the analysis was 336 and through SPSS 21.0 program, two-way ANOVA and bootstrap were utilized. The analysis result was that consumers' psychological responses (emotions, psychological reactance) of online shops differed by means of varying stockout situations. The stockout size had positive effect on psychological reactance and negative emotions. On the other hand, there was no difference in positive emotions (arousal) according to stockout size. In stockout situation of online fashion store, the moderating effect of product assortment similarity and restocking cues were verified. According to the analysis result, interaction effects between stockout size and restocking cues, product stockout size and product assortment for psychological reactance were significant. Lastly, the mediation effect of psychological reactance and emotion between stockout size and behavioral response was tested. As a result, the moderated mediation effects of psychological reactance for substitute were significant when product assortment was dissimilar and restocking cue was exclude.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.6105-6110
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• 2012

Smart devices have made our daily life more intelligent and provided convenient life styles in which advanced interface and high speed LTE enable us to have proliferation of empirical Apps. This research has analyzed and evaluated Unstructured data from the users who experienced 'Hair Style Magic Mirror App' by focusing on emotional information. Further this study suggests some directions that the application development industry should take in the near future. The findings through Chi-Square analysis indicate that the application has not affected the overall satisfaction of the consumers; consumers received higher satisfaction in paid version of applications than free versions. Emotional Information analysis shows that users value the practicality of each application the most. Thus, the application developers should focus on practicality and sensitivity side corresponding to the demand of consumers.

• The KIPS Transactions:PartA
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• v.10A no.1
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• pp.25-34
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• 2003

Parallel file system solves I/O bottleneck to store a file distributedly and read it parallel exchanging messages among computers that is connected multiple computers with high speed networks. However, they do not consider the message characteristics and performances are decreased. Accordingly, the current study proposes the Hybrid Channel model (HCM) as a message-management method, whereby the messages of a parallel file system are classified by a message characteristic between control messages and file data blocks, and the communication channel is divided into a message channel and data channel. The message channel then transfers the control messages through TCP/IP with reliability, while the data channel that is implemented by Virtual Interface Architecture (VIA) transfers the file data blocks at high speed. In tests, the proposed parallel file system that is implemented by HCM exhibited a considerably improved performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.103-109
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• 2017

In this paper, the advancement in IT technology is not only inducing the multi-functionality of simple products but also changing even the lifestyle, that is, the pattern of consumers' daily life. The actual paradigm for the conversion from off-line to on-line is at the level of threatening the ecology of off-line. In this study, the diversified advancement method of off-line is in functional relationship with the increase in sales revenue and profits not only through the visit of consumers to the sales outlets for the simple purpose of making purchase but also through the application of augmented realities such as 3-dimensional sense in space and sense in reality, which are entertainment experience factors. Therefore, the improvement in the enhancement of sales revenues by applying augmented reality to off-line department store was researched in this study.

• Journal of KIISE:Databases
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• v.29 no.6
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• pp.441-452
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• 2002

If continuous moving objects are managed by conventional database, it is not possible for them to store all position information changed over time in the database. Therefore, a time period of regular rate is determined and position information of moving objects are discretely stored in the system for every time period. However, if continuous moving objects are managed as discrete model, we will have problems which cannot properly answer to the query about uncertain past or future position information. To solve this problem, in this paper, we propose the method and algorithm which use the history information stored in the same database, to estimate the past or future location of moving objects. The cubic spline interpolation is used to estimate the past location and the mean movement value of the history information is used to predict the future location of moving objects. Finally, from the location estimation experimentation of using virtual trajectory and location sample, we proved that the proposed cubic spline function has less error than the linear function.

• Journal of KIISE
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• v.43 no.9
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• pp.1026-1033
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• 2016

Path-finding on a grid map is a problem generally addressed in the fields of robotics, intelligent agents, and computer games. As technology advances, virtual game worlds tend to be represented more accurately and more realistically, resulting in an excessive increase in the number of grid tiles and in path-search time. In this study, we propose a path-finding algorithm that allows a prompt response to real-time queries by constructing a reduced state space and by precomputing all possible paths in an offline preprocessing stage. In the preprocessing stage, we vertically decompose free space on the grid map, construct a connectivity graph where nodes are the decomposed regions, and store paths between all pairs of nodes in matrix form. In the real-time query stage, we first find the nodes containing the query points and then retrieve the corresponding stored path. The proposed method is simulated for a set of maps that has been used as a benchmark for grid-based path finding. The simulation results show that the state space and the search time decrease significantly.