• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.11
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• pp.1217-1227
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• 2012

There are several antenna calibration methods, so-called 3-Antenna Method, Standard Site Method, and Standard Antenna Method which measure the antenna gains or antenna factors. These methods yield the free space or quasi free space antenna gains in only the frequency domain. In this paper, an antenna calibration method using the time domain in the open area test site is discussed. The reflected waves due to the ground are traced in the time domain. After they are removed by the time gating function of network analyzer, the free space transmission coefficient $S_{21}$ is extracted. Such a way is applied to the broad band horn antenna ranging 1 GHz to 18 GHz, and the free space gains are obtained by Friis transmission equation. The method is checked by Standard Site Method in open area test site. The results show comparatively good agreement except for 18 GHz.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.81-90
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• 2017

The purpose of this study is to analyze the strategic behaviors of the Broadcasting advocacy coalition and IT advocacy coalition in the process of establishing the Korea Communications Commission(KCC) in 2008. Broadcasting and telecommunications convergence policy has been confronted with long-term conflicts because of ideological clashes between public interest and industrialism and stakeholder relations. Under this circumstance, the two advocacy coalitions sought to bring out the favorable outcomes through strategic behavior. However, the strategic behaviors were limited, and the establishment of the Korea Communications Commission was decided by political negotiation. Since then, KCC has been buried in political issues and has produced policy failure cases. In order to reduce these adverse effects, it is necessary to establish institutional devices in the reorganization process. Above all, efforts are needed to overcome the practice of using organizational restructuring as a political tool.

• Corrosion Science and Technology
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• v.22 no.6
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• pp.447-456
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• 2023

In this work, we performed a comparative study examining two coatings on Ti Gr.1 for use in fuel cell bipolar plates. The coatings consisted of carbon black as the conductor along with acrylic polymer and Ti Sol-Gel binder as the binder. Ti Sol-Gel that had precipitated as TiO₂ in areas impregnated between carbon black gaps, thereby acting as a binder for carbon black and serving as a polymer coating. Neither of the coatings peeled off during the 90° bend test to check formability. The contact resistance of the TiO₂ coating was found to be lower than that of the polymer binder coating. Moreover, due to coating shrinkage (denser) that occurred during the heat treatment process, the TiO₂ binder coating showed almost the same level of corrosion resistance, as measured by potentiostatic and EIS tests, despite being thinner than the polymer coating. However, both the polymer binder coating and the TiO₂ binder coating had many pores and irregularities internally (around 10 ~ 100 nm) and on the surface (0.1 ~ 2 ㎛). We considered that these pores and irregularities contributed to the lower corrosion resistance.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.27 no.1
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• pp.43-52
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• 2024

Purpose: In this study, we investigated the clinical profile, survival at discharge, and proportion of children with acute liver failure (ALF) meeting the criteria for, yet surviving without, liver transplantation (LT). Methods: Medical case records of children aged >28 days to ≤15 years over a period of 7 years, identified from pediatric admission and discharge registers, were screened. Children satisfying the criteria for ALF were included in this study. Results: A total of 71 records meeting the pediatric ALF (PALF) criteria were included. The survival rate at discharge was 61% (n=44). A considerable proportion of children satisfied the King's College Criteria (KCC) (56.3%) and the European Association for the Study of the Liver (EASL) criteria (7%) for LT at admission. Nonetheless, the survival rate in the absence of LT was 42.5% in children who satisfied the KCC and 20% in those who met the EASL criteria. Infection (29.5%) and paracetamol overdose (19.7%) were the major identifiable causes of PALF. Hepatitis A was the most common infection identified. No significant predictors of poor outcomes were identified in multivariable analysis. Conclusion: Our study highlights the changing survival rates and the clinical and etiological profiles of patients with PALF. In areas with poor access to LT services, survival in these children could be improved through early referral to centers with adequate intensive care facilities. Preventing ALF and referring patients to LT services are paramount to reducing mortality.

• Macromolecular Research
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• v.9 no.1
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• pp.51-65
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• 2001

Two-stage emulsion polymerizations of hydrophobic monomers on hydrophilic seed polymer particles were carried out to make core-shell composite particles. It was found that the loci of polymerization in the second stage were the surface layer of the hydrophilic seed latex particles, and that it has resulted in the formation of either eccentric core-shell particles with the core exposed to the aqueous phase or aggregated nonspherical composite particles with the shell attached on the seed surface as many small separated particles. The driving force of these phenomena is related to the gain in free energy of the system in going from the hydrophobic polymer-water interface to hydrophilic polymer-water interface. Thermodynamic analysis of the present polymerization system, which was based on spreading coefficients, supported the likely occurrence of such nonspherical particles due to the combined effects of interfacial free energies and phase separation between the two polymer phases. A hypothetical pathway was proposed to prepare hydrophilic core-hydrophobic shell composite latex particles, which is based on the concept of opposing driving and resistance forces for the phase migration. It was found that the viscosity of the monomer-swollen polymer phase played important role in the formation of particle morphology.

• Journal of the Semiconductor & Display Technology
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• v.12 no.1
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• pp.9-14
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• 2013

In this paper, we first introduce a Koinonia technology. Then we present a wireless Digital Video Recorder (DVR) system based on the Koinonia technology. In addition we implement the wireless DVR system, which is composed of Wireless DVR-Slave (WDVR-S), Wireless DVR-Access Point (WDVR-AP), and Wireless DVR-Emergence Management System (WDVR-EMS). Also we present the acquired Korea Communication Commission (KCC) mark for the last products. The developed system will give a hint that the Koinonia technology can be adopted in wireless DVR systems to handle safety and security issues.

• Food Science of Animal Resources
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• v.21 no.2
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• pp.110-115
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• 2001

The major objective of this study is provide to basic data for developing of new chicken products. The findings from this study are as follow. Eating times of chicken is increased in comparison with National Livestock Cooperative Federation(NLCF) & Korea Chicken Council(KCC)s survey results. Consumers are frequently having fried chicken and this results are no difference in KCCs survey results. In eating place of chicken, consumers are mostly preferred to have chicken at home. In the use of chicken consumption, the ratio of replacing meal is high and this is no difference in previous study. However there are a few differences in consumption behavior by age and gender.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.719-724
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• 2013

In the case of newly developed stud which has more performance of sound transmission loss, it is expected that sound would transmit through runner than stud. so we developed construction method of runner and stud. As a result, sound transmission loss is improved about 2 dB by using this method. But this construction method could be applied to only newly developed stud. In addition, sound leak of wall joint is about 2 dB, and it could be improved by using rubber gasket at joint.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.626-628
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• 2015

빅 데이터의 시대가 도래 하면서 데이터의 양이 기하급수적으로 증가 하고 있으며, 이에 따라 데이터를 효율적으로 처리하는 기술의 중요성이 부각 되고 있다. 데이터를 효율적으로 처리하기 위한 기술 중 하나인, 데이터 중복제거 기술은 저장 시스템 공간을 효율적으로 사용 할 수 있게 할 뿐만 아니라, 네트워크 환경에서 전송되는 데이터의 양도 획기적으로 줄여 주어 통신비용을 절감하게 한다. 기존의 데이터 중복제거 기술과 데이터 동기화 기법을 분석하고, 이를 바탕으로 클라우드 환경에서 데이터 중복제거를 통한 효율적인 데이터 동기화 기법을 제안하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.973-975
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• 2015

최근 강화된 개인정보 보호법으로 인해 개인의 고객정보 이용 및 약관 동의서와 그에 따른 디지털 자필 서명을 필요로 하는 기업이 증가하고 있다. 그러나 고객에게 자필 서명을 받기 위한 플랫폼은 PC, 맥, 안드로이드, 아이폰 등 다양한 디바이스의 호환을 필요로 한다. 이에 본 논문에서는 이기종 호환 스크립트인 jQuery를 이용하여 HTML5 가 호환되지 않는 PC기반 IE6 이상의 브라우저부터 안드로이드, iOS 등 터치기반 스마트 디바이스의 최신 브라우저까지 모두 호환되는 자필 서명 시스템을 설계 및 구현한다.