• Journal of Korea Spatial Information System Society
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• v.12 no.1
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• pp.49-56
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• 2010

Many researches of frequent pattern mining technique for detecting unknown patterns on spatial data have studied actively. Existing data structures have classified into tree-structure and array-structure, and those structures show the weakness of performance on dense or sparse data. Since spatial data have obtained the characteristics of dense and sparse patterns, it is important for us to mine quickly dense and sparse patterns using only single algorithm. In this paper, we propose novel data structure as compressed patricia frequent pattern tree and frequent pattern mining algorithm based on proposed data structure which can detect frequent patterns quickly in terms of both dense and sparse frequent patterns mining. In our experimental result, proposed algorithm proves about 10 times faster than existing FP-Growth algorithm on both dense and sparse data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11C
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• pp.901-906
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• 2010

Low density parity check (LDPC) code, first introduced by Gallager and re-discovered by MacKay et al, has attracted researcher's interest mainly due to their performance and low decoding complexity. It was remarkable that the performance is very close to Shannon capacity limit under the assumption of having long codeword length and iterative decoder. However, comparing to turbo codes widely used in the current mobile communication, the encoding complexity of LDPC codes has been regarded as the drawback. This paper proposes a solution for DVB-S2 LDPC encoder to reduce the encoder latency. We use the fast IRA encoder that use the transformation of the parity check matrix into block-wise form and the partial parallel process to reduce the number of system clocks for the IRA code encoding. We compare the proposed encoder with the current DVB-S2 encoder to show that the performance of proposal is better than that of the current DVB-S2 encoder.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.5
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• pp.1047-1054
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• 2012

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice, and its risk increases with age. Conventionally, the way of detecting AF was the time·frequency domain analysis of RR variability. However, the detection of ECG signal is difficult because of the low amplitude of the P wave and the corruption by the noise. Also, the time·frequency domain analysis of RR variability has disadvantage to get the details of irregular RR interval rhythm. In this study, we describe an atrial fibrillation pattern analysis based on symbolization and information entropy. We transformed RR interval data into symbolic sequence through differential partition, analyzed RR interval pattern, quantified the complexity through Shannon entropy and detected atrial fibrillation. The detection algorithm was tested using the threshold between 10ms and 100ms on two databases, namely the MIT-BIH Atrial Fibrillation Database.

• KSBB Journal
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• v.8 no.3
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• pp.200-208
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• 1993

As a separation membrane for water-ethanol mixtures, alginic acid has been used which is hydrophilic polysaccharide and has excellent bonding capacity with divalent metal ions. Pervaporation characteristics of the alginic acid membrane were examined. The membrane was crosslinked with metal ions for the improvement of mechanical strength and chemical affinity. And its pervaporation characteristics were investigated. The first group(I A) metal complexed membrane cannot be used because of their brittleness and excessive swelling in low concentrations of ethanol solution. But the permeation characteristics of other metal complexed membrane were more improved than that of the alginic acid membrane because of their contraction of the membrane and hydrophilic property of metal ion.

• (The) Research of the performance art and culture
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• no.25
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• pp.211-251
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• 2012

I attempted to study the resolution of how I can show the essence of an original musical production to audience, the possibilities of how recreate impossible elements according to Korean musical environment because of cultural and linguistic differences, and verify the meaning of adjusting an original production to Korean one through directorial approaches to licensed musical production. I mainly exemplified 2009 Korean production (Charlotte Theatre, March ~ August, 2009) that I directed. The purpose that I wanted to analyze the case of Korean production mainly is able to prove a wide variety of possible challenges rather than simply licensed ones because the former was recreated in 30 years after the first original production. Recreation and coaching to acting through fine and precise analysis of an original production, Koreanizing Western culture of the licensed musical, resolving the problem of linguistic nuances are the important ways to direct licensed musical. For licensed musical director, cooperation with original creative team and Korean production company must be the most important job.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.323-337
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• 2021

This study will attempt to analyze media art and discuss its main characteristics by using the concept based on Relational Aesthetics 'Affective Turn' as a basis of the theory. In addition, this study has some theoretical and practical implications, both in terms of the research and analysis of artworks and the structure development of art theories and aesthetics. To conduct the research, I have gone through a literature review on previous studies related to media art and Relational Aesthetics. Then, I have conducted a case study on the media art of TeamLab. This study shows that from the perspective of Relational Aesthetics, media art shows unique characteristics such as borderless and shareability. Moreover, it can allow the audience to actually 'feel' the relationship and integration between various objects. I hopethat this research could be used as a solid basis for future research and helpstrengthen the interaction between modern art and the public.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.5
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• pp.516-521
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• 2022

We investigated the microstructure, crystal structure, dielectric, and elecromechanical strain properties of lead-free BaTiO₃ (BT)-modified (Bi_1/2Na_1/2)TiO₃-SrTiO₃ (BNT-ST) piezoelectric ceramics. Samples were prepared by a conventional ceramic processing route. Temperature dependent dielectric properties confirmed that a phase transition from a nonergodic relaxor to an ergodic relaxor was induced when the BT concentration reached 1.5 mol%, interestingly, where the average grain size reached a maximum value of 4.5 ㎛. At the same time, enhanced electromechanical strain (S_max/E_max = 600 pm/V) was obtained. It is suggested that the induced ferroelectric-relaxor phase transition by the BT modification is responsible for the enhancement of electromechanical strain in 1.5 mol% BT-modified BNT-ST ceramics.

• Journal of Digital Convergence
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• v.19 no.7
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• pp.359-369
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• 2021

The purpose of this study was to examine the effect of achievement motivations of university students on depression and the mediating effect of self-esteem in these relationships. For this, data were collected from 267 university students enrolled in universities in Y city, and analyzed using SPSS 22.0 and SPSS PROCESS macro 3.3. As a result of the study, first, it was found that the achievement motivation of university students had a significant positive effect on self-esteem, a parameter. Second, it was found that the achievement motivation of university students had a significant negative effect on depression. Third, in the relationship between achievement motivation and depression in university students, self-esteem, a parameter, was found to have a significant negative effect on depression, whereas achievement motivation did not have a significant effect on depression. In view of this, it was confirmed that self-esteem was completely mediated in the effect of achievement motivation of university students on depression. Based on the results of this study, the implications and limitations of this study were discussed, and support plans and follow-up studies for university students were suggested.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.12
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• pp.1863-1871
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• 2022

In the era of Fourth Industrial Revolution, secure networking technology is playing an essential role in the defense weapon systems. Encryption technology is used for information security. The safety of cryptographic technology, according to Kerchoff's principles, is based on secure key management of cryptographic technology, not on cryptographic algorithms. However, traditional centralized key management is one of the problematic issues in battlefield environments since the frequent movement of the forces and the time-varying quality of tactical networks. Alternatively, the system resources of each node used in the IoBT(Internet of Battlefield Things) environment are limited in size, capacity, and performance, so a lightweight key management system with less computation and complexity is needed than a conventional key management algorithm. This paper proposes a novel key escrow scheme in a lightweight manner for the IoBT environment. The safety and performance of the proposed technique are verified through numerical analysis and simulations.

• Journal of Ethics
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• no.84
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• pp.243-274
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• 2012

The purpose of this study is to study the community narrative ethics of China·Taiwan film. in the context of globalization and locality. I especially wish to look this part through narrative·hermenutical approach and communitarian ethics against contemporary liberalism and individualism. In particular, this article focuses on the works of Hou Hsiao-Hsien, Zhang Yimou, Lee Ang, Tsai Ming-Liang, Chang Tso-chi and Chen Kaige. China and Taiwan's main directors show family and country's community narratives through the self understanding and identification that we call narrative conception of the self. The idea of local community and identity is related with inheritances, history and tradition from the past of my family, my city, my tribe, my nation. Main directors make and have the story of those communities which I derive my identity. And community narratives from the life histories that define us form local community's solidarity should have the openness to other communities. Community narratives shouldn't be separated from the aspect of globalization and locality. After all, I examined whether the local community narratives reveals meaningfully from the standpoint of globalization and locality through China·Taiwan film.